Document 4vvnJpgNQY4qXBRaxeJ0MMDzx

SC-ASHVE-016 American Society of Heating and Ventilating Engineers Heating ventilating air conditioning guide. VOL 17 19 St 628.8 AMERICAN 21718 77202 r ST.IOUIS PUBLIC LIBRARY V T W' -V Heating Ventilating Air Conditioning Guide 1939 Heating Ventilating Air Conditioning GUIDE 1939 An Instrument of Service prepared for the Profession---Containing a Technical Data Section of reference material on the desicn and specification of heating, VENTILATING AND AIR CONDITIONING SYSTEMS----BaSED ON THE TRANS ACTIONS--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 ij i! The Roll of Membership of the Society I WITH -i ii Complete Indexes M foe Technic al and Catalog Data Sections. ; Voi. 17 X736017 . Published Annually by American Society of Heating and Ventilating Engineers .. .. 51 Madison Avenue New York, N". Y. Copyright 1939 BY THE American Society of Heatinc and Ventilating Engineers and by it Dedicated To the Advancement of The Profession AND Its Allied Industries TEXT AND ILLUSTRATIONS ARE FULLY PRO TECTED BY COPYRIGHT AND NOTHISG THAT APPEARS MAY BE REPRINTED EITHER WHOLLY OR IN PART WITHOUT SPECIAL PERMISSION. Printed and Bound by The Horn-Shafer Company BALTIMORE MARYLAND c' 6 Tfct. PREFACE TO THE 17th EDITION THE 1939 edition of the Heating, Ventilating, Air Conditioning Guide contains the largest Technical Data Section of any of the annual reference volumes published by the American Society of Heating and Ventilating Engineers to serve the profession and industry. With 856 pages of text material this 17th edition of The Guide reflects the outstanding research and engineering advancements which have taken place in this field of engineering since the first Guide made its appearance in 1922. The Research Laboratory of the Society and cooperating universities have contributed much toward the advancement of the science of heating, ventilating and air conditioning in 1938. All of these developments have been summarized and added to this volume in order to maintain the original conception of The Guide, whereby only scientific and current investigative results are presented which may be of practical value to design engineers. Basic and fundamental data have been retained from previous editions but in this volume a concentrated effort has been made by the Committee to condense and combine material throughout the text. Those chapters dealing with central systems for heating, humidifying, cooling and dehumidifying have been carefully reviewed and a completely new chapter has been prepared which incorporates all of the essential material from other chapters. The title of this chapter is, Central Systems for Comfort Air Conditioning, and the material is presented in such a manner as to apply directly to the requirements set forth in the application Code of Minimum Requirements for Comfort Air Conditioning which was adopted by the Society in January, 1938. References are given in this material to other chapters which deal more specifically with the design of particular equipment and consequently this new chapter may serve as a basic guide for the design of all comfort air conditioning installations. A subject which has not heretofore received special attention in previous editions of The Guide is information dealing with heat transfer surface coils for summer and winter applications. The Committee presents in this edition a chapter which is intended to give the latest information which is available on this type of equipment. Details are given describing the conventional construction and arrangement of heating and cooling coils with suggestions for typical flow arrangements of the circulating media. Due to the wide variety of methods now in use for the selection of heat transfer coils it is impossible to give specific recommendations for the proper choice of coils until such time as ad ditional research findings are reported and uniform standardization is adopted by the industry. Charts are given which indicate the per formance of coils operating under varying design load and equipment conditions. . The problem of fuels and their combustion was recognized by the Committee this year as an important factor to the heating engineer and as a consequence a completely revised chapter on Combustion and Fuels V is presented in the 1939 edition.,. Fundamental principles of combustion together with related factwrs dealfe^ .wiitB jHJme temperature and proper air requirements are given special consideration. The latest current information on classification of all types of fuels is given along with suggested methods of firing to obtain optimum results. Another chapter closely related to this subject has been rewritten this year on Heat and Fuel Utilization. Methods are outlined for estimating fuel consumption based on calculated heat losses and degree-day factors. Charts are included for coal, oil and gas whereby fuel burning rates may be estimated for various design loads and operating efficiencies. Other chapters which have been rewritten for the 17th edition deal with Air, Water and Steam, Cooling Load, Radiators and Gravity Convectors, Steam Heating Systems, Piping for Steam Heating Systems, Mechanical Warm Air Furnace Systems, Unit Heaters, Ventilators, Air Conditioning and Cooling Units, Natural Ventilation and District Heating. Minor changes were made in the chapters on Heat Transmission Coefficients and Tables, Air Leakage, Automatic Fuel Burning Equip ment, Air Distribution and Automatic. Control. The Bulkeley Psychrometric Chart will again be found in a convenient envelope attached to the inside back cover thus making it easily accessible for performing psychrometric calculations. The Problems in Practice have been continued with new and practical solutions to expand the text material given in each of the 45 chapters. A revised table giving the weights of saturated and partially saturated air for various psychrometric pressures has been added this year to bring the data in conformity with government standards. The degree-day table appearing in the chapter on Heat and Fuel Utilization has been corrected and brought up-to-date based on more recent Weather Bureau data. The increase in usage of The Guide as a text book in many universities, engineering and technical schools for student instruction indicates its wide acceptance as a standard authority in the field of heating, venti lating and air conditioning. The manufacturers have cooperated fully to make their information useful in the Catalog Data Section so that the reader can apply it ef fectively to the selection of materials or equipment to be used in general design. The Committee appreciates the aid of those progressive manu facturers who have assisted in this cooperative enterprise to advance the art of heating, ventilating and air conditioning which so vitally affects the comfort and health of everyone.'. In 1939 it will be possible to distribute 13,000 copies of The Guide to various types of readers and it is extremely gratifying that a large number of manufacturers recognize the effective service which The Guide accomplishes as an advertising medium. For the user who desires to obtain reliable data in convenient form it is felt that a careful perusal of both the text and catalog data pages of this volume, will emphasize its brevity and simplicity of presentation. The Committee releases this 17th edition of 13,000 copies with the sincere hope that it will receive the same enthusiastic reception that was accorded to its predecessors. Chairman GUIDE PUBLICATION COMMITTEE vi EDITORIAL ACKNOWLEDGMENT EXTENDING over 17 years the Heating, Ventilating, Air Con ditioning Guide, published by the American Society of Heating and Ventilating Engineers, has maintained an enviable record as the authoritative engineering reference volume of the profession. This recognition of world-wide acceptance has been possible because of the willingness of hundreds of technically trained engineers to contribute freely from their knowledge and practical experience for the benefit of the entire profession and allied industries. It is with deep feeling of appreciation that the Guide Publication Committee acknowledges the work of the following individuals who have assisted in the preparation of the 1939 edition and it also commends those contributors who have previously prepared a firm foundation for the addition of new information. H. E. Adams T. N. Adlam J. C. Albright H. L. Alt O. W. Armspach C. L. Arnold C. M. Ashley L. T. Avery 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. Bulkeley W. H. Carlton P. D. Close Sabin Crocker R. C. Cross D. N. Crostbwait, Jr. Philip. Drinker ' C. E. Ernst John Everetts, Jr. Prof. M. K. Fahnestock F. H. Faust . W. J. Fitzsimmons, Jr. 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 Prof. P. E. Mohn L. L. Munier H. C. Murphy Prof. D- W. Nelson P. Nicholls S. F. Nicoll 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 R. W. Shields A. L. Simison D. C. Simpson . T. H. Smoot A. E. Stacey, Jr. D. J. Stewart , Clifford Strock C. A. Thinn W. W. Timmis Prof. G. L. Tuve F. O. Urban J. H. Van Alsburg A. R. Walker J. H. Walker Prof. L. Washington Prof. G. B. Wilkes G. D. Winans Prof. B. M. Woods M. S. Wunderlich Prof. C. P. Yaglou _____ _ ,,aic duupieu me cjUide as their standard reference volume and members of the Society are deeply indebted to those engineers who have assisted in the preparation of this 17th edition and the Guide Publication Committee wishes to pay tribute for this loyal cooperation and devotion to public service in advancing the art of heating, venti lating and air conditioning engineering. Albert Buenger, Chairman S. H. Downs C. H. B. Hotchkiss E. N. McDonnell, Advisory S. S. Sanford G. L. Tuve John James, Technical Secretary 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. J--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. J--He will inform a client or employer of any business connections, in terests or affiliations 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' or 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 arid 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. CONTENTS Heating V__e__n__t__i_l_a___t_in__g - rAuirn Conditioning conditioning GGuuiiddee 11993399 Title Page.............................................................................................................................`..... --...........Paghei Preface!-..:....................................-......................................................................................-...................... v Editorial Acknowledgment.............:................ ............................................................................. vii Code of Ethics for Engineers--.................................................................................................... viii Index to Technical Data......................................................... ....................................................... x Chapter 1. Air, Water and Steam................................................................................................ Chapter 2. Refrigerants and Air Drying Agents--..........!................................................... Chapter 3; Physical and Physiological Principles of Air Conditioning-...................... 1 35 49 Chapter 4. Air Pollution................................................................................................................... 77 Chapter 5. Heart Transmission Coefficients and Tables--.................................................. 87 Chapter 6. Air Leakage ................................................................................................................ 119 Chapter 7. Heating Load..............................................................................................................131 Chapter 8. Cooling Load...................... ........................................................................................... 145 Chapter 9. Combustion and Fuels......................................................................... ..................... 163 Chapter 10. Chimneys and Draft Calculations............................................................... ...... 185 Chapter 11. Automatic Fuel Burning Equipment.................................................i................ 207 Chapter 12. Heat and Fuel Utilization....... ................................................................................. 233 Chapter 13. Heating Boilers--................................................................................................. ..... 249 Chapter 14. Radiators and Gravity Convectors.................................. ......................... 269 Chapter 15. Steam Heating Systems................................................... .................. ............. . . 281 Chapter 16. Piping for Steam Heating Systems........................................................ -........... 307 Chapter 17. Hot Water Heating Systems and Piping........................................................... 337 Chapter 18. Pipe, Fittings, Welding............................................. ................................ -.............. 361 Chapter 19. Gravity Warm Air Furnace Systems......................................... -- ................... 383 Chapter 20. Mechanical Warm Air Furnace Systems........................................................... 399 Chapter 21. Central Systems for Comfort Air Conditioning...................... .*..................... 415 Chapter 22. Unit Heaters, Ventilators, Air Conditioning, Cooling Units--........... . .431 Chapter 23. Cooling and Dehumidification Methods--.................................... :................. 463 Chapter 24. Heat Transfer Surface Coils......-................... ...................................................... 493 Chapter 25. Spray Equipment for Humidification and Dehumidification......... ......... 517 Chapter 26. Air Cleaning Devices-.............................................................................................. :J537 Chapter 27. Fans..................................................................... :......................... I............... ................... 549 Chapter 28. Air Distribution.....................................................................................!................. -- 565 Chapter 29. Air Duct Design--........................................... --............................. ........................... 581 Chapter 30. Sound Control--........................................................................................................... 60i Chapter 31. Air Conditioning in the Treatment of Disease............................ .................. 615 Chapter 32. Railway Air Conditioning.................................................. ............................... -- 627 Chapter 33. Industrial Air Conditioning.............................................................'...............J....... 639 Chapter 34. Industrial Exhaust Systems................................................................................... 651 Chapter 35. Drying Systems............................................................................................................. 665 Chapter 36. Natural Ventilation..................................................................................................... 687 Chapter 37. Automatic Control...................................................................... 699 Chapter 38. Motors and Controls................................................................................................... 719 Chapter 39. Piping and Duct Insulation..... ................... 735 Chapter 40. Electrical Heating............................................... :....................................................... 757 Chapter 41. Radiant Heating........... ............................................................................................... 769 Chapter 42. District Heating........................................................................................................... 781 Chapter'43. Water Supply Piping and Water Heating.....................................'.................. 799 Chapter 44. Test Methods and Instruments..................................... 1..................... .........,..... 823 Chapter 45. Terminology...................................... ............ .................................. ......................... 835 Catalog Data Section............................................... 857 Index to Advertisers............................................................................................................. 859 Index to Modern Equipment.............................................................................................--.......1137 Roll of Membership...................................................................................................................... 1-88^ ix "JU4K-; Heating Ventilating Air Conditioning Guide 1939 INDEX HEATING VENTILATING AIR CONDITIONING GUIDE 1939 Technical Data Section Chapters1-45 and Pages 1-856 A Abbreviations* 846 . Absolute humidity* 8* 835 "' ... Absolute pressure, 823, 835 ,Absolute temperature, 835 - Absolute zero. 835 Absorption, (see also Regain) .. . agents, 43 .. ' as means of dehumidiiication, 486 by building materials, 153 of solar radiation by glass, 150 of sound, 609 ' '. system, 486, 487 Acceleration, 835 due to gravity, 835 Acclimatization, 54 Acoustics, acoustical, 601 . treatment, 609 . Activated alumina, 40 Adiabatic saturation, 11, 521, 835 - driers, 667 Adjustable speed motor, 720, 724, 725, 726 Adsorption .. - agents, 40 as means of dehumidification, 484 systems ' alumina, 485 silica gel, 485 . *v Air adiabatic saturation of, 11 amount per person, 68 atmospheric, 1 changes of, indoors, 49, 127 . cleaning devices, 537, 835 AJ3.H.V.B. code for, 537 requirements of, 537 types of, 638 composition of, 1, 49 .' density of, 6 distribution of, 70, 397, 565 balancing system, 578 for comfort,' 67 effect of turning blades, 672 factors in room cooling, 570 factors in room heating, 572 grille locations, 566 natural ventilation, 687 railway air conditioning, 578, 628 residence, 402 . . .. with unit air conditioners,. 452 with unit heaters, 437 ' with unit ventilators, 441 - dry, 1, 4, 8, 59, 838 drying agents, 85, 40 . . ducts, 581, (see also Duels, Air) - excess,' 168 . , exfiltration, 119 . . . filtration, 233, 419 - Air (continued) . flow. 70, 75 formulae, 581 into a hood, 656 - . loudness chart, 574 - natural, measurement of, 694 through openings, 689 friction of, in pipes, 585, 586 . impurities in, 77 . size of, 78 . ionization of, 73 leakage, 119, 225 minimum outdoor, requirements, 70 . mixtures with water vapor, 12 . moist, 66 ' motion, 70, 72 . movement, measurement of, 827 . odors in, 49 optimum conditions, 60 . - > -. indoors in summer, 66 outlet noises, 572 . outside, introduced, through cracks, 124, 127 * . through doors, 125 unit air conditioners, 451 - pollution, 77 . abatement of, 82 . effect on health, 81 . - .. ., ' .. . properties of, 3, 4 quality, 68 . . ' quantity necessary, ' for ventilation, 70, 627 .. recirculation of, 76 . saturated, 1, 5, 10, 843 * secondary, 168 ' ' ' . space conductances, 91. speeds to convey material, 660 standard, 843 . . still, 55 summer, conditions, 66 . velocity, (see Velocity, Air) . , , vitiation, 49 ' .. volume, 12 washer' 617, 835 (see also Washer, Air).. operation of, 706 . saturation efficiency, 520 weight of, 6 1; . ~- ' . Air conditioning, 49,'521, .835, (see also Air) air change per occupant,,69 - chemical factors, 58, 79 ... comfort .chart, 61, 62 '_ .' . - in disease treatment, 615- ' ' . fundamentals of, 1 . hospital, 615 .. ' . ^ - with ice, 490 , - ' industrial, 639 ' ** ,, apparatus for, 521 automatic control, 699' exhaust systems, 651 ' " . . process conditions, 689 j ; unit coolers, 445 1/ X Alphabetical Index to Technical Data Section Air conditioning (continued) objective of, 1 physical factors, 49 recirculation, 75 units, 448 - Algae formations, 532 Allergic disorders, 622 classification of, 622 treatment of, apparatus for, 622 limitations in, 62E Alternating current motor, 721 Altitude, 189 .. ' Alumina system of adsorption, 40, 486 Aluminum foil. 92 - Aluminum oxide, 40 Ammonia/ 35, 36, 629 - - Anemometer, 828, 835 Anesthesia, 615 . apparatus, 615 . ' effect of, 616 -' . inflammability, 616 - Anthracite. 172, 174, (see also Coal)' stokers, 211 Apartment houses, hot water supply to, 816 steam consumption, 246 stokers suitable for, 212 Appendicitis, 617 Arthritis, 625 . ' * ' : . A.S.H.V.E. Codes and Standards, 254, 552, 696, 854 -'- , A.S.hf.E. boiler construction code; 264 ' Artificial fever, 620 `. conditions for, 621 ' : . ' - ' diseases treated, 621 " limits for, 621 production of, 621 - . -- Asbestos, 741 Ash. -- " cared for by stokers, 207 . fly, 77 " . s Asphyxia, 623 - . Asthma, 622> 623 ^ . Atelectasis, 623 . Atmosphere, standard, 823 ' -, .. Atmospheric steam heating system, (see also Steam Heating Systems) , . Atmospheric water coolings apparatus, 525 \ design of, 528, 529 - efficiency of, 530, 534: Atomization, . .. : - for humidifying, 622 . of oil, 219 . >. : Attic fans, 460 ........... . -. - . Automatic control, 404, 699, (see also. Controls) Automatic fuel burning equipment, 207 . Awnings, 154, 412 '. Axial velocity formula, for, hoods, 655 . . B Babcock's formula for steam flow, '309, 782. Baby care, (see Nurseries)' - Baffles, 836 ' Balancing air distribution system, 578 ` Bananas, 646 . ; 1' Bam ventilation, 695 Barometer, - . aneroid, 824 . mercurial, 825 Barometric pressure, 189, 823 Bends, expansion, .368 .: - BET, .British equivalent temperature, 772 . Biochemical reactions, control, of, 646 Bituminous coal, 173, 176 . . Blast, 836 '' .' . Blower, blowers. 549, (see also. Fans) . standard test code for, 652 ' Body, ' r ' human, -surface area, 69 odors, 69 Boiler, boilers, 249, 836 -. . allowances, 258, 818 . `:V~ Boiler (continued) " A.S.H.V.E. test codes, 254, 855 A.S.M.E. construction code, 264 baffles, 401, 836 ' capacity, 249, 437 care during summer, 267 cast-iron, 249- cleaning, 266 codes, 264 .. combustion rate, 250 ' " connections, 321 ` controls, 714 . conversion, 262 .. .. ; design of, 252 draft loss through, 195 . efficiency of, 253, 257 ' for electric steam heating, 761 erection of, 265 - ' fittings, 264 gas-fired, 226, 251], 262 . grate area, 261 ' heat transfer rates, 258 heating surface, 253, 836 - horsepower, 257, 836 ' - installation, 262, 265 insulation, 267 '' limitations, 263 -- low pressure, construction code, 264 maintenance, 265 -' ' operation, 265 ............... output, 256 ; performance curves, 260 ~ pick up, 258 pipe tax, 259 . - . . ratings of, 254, 255 scale in, 266 . .. . selection of, 257, 260, 261 ' settings, 222, 252 , .. ' special, 251 ' .' , steel, 249 . troubles with, 266 types of, 246 ' ' : warming-up allowance, 258, 260 water line, 264 ' Boiling point of water, 28 - Booster, . ' fans, 396, 417 ' Booths, spray, 658 - -. ' ' Bourdon tube, 824 '' - Boyle's law, 7 Brake horsepower, heat equivalentof, 139 - Breeching, draft loss through, 199 . Brine, 450 . - . -- - British equivalent temperature, 772 British thermal unit, 836 . . Building, buildings, ' - -. absorption coefficients, 153 .. air velocities in, 687 - construction, heat transmission of,. 88, 95 fuel requirements of, 289 . hot water supply to, 810, 818 , intermittently heated, 139 ...... load factors, 246 .. . materials, heat transmission of, 95 ' . noise in, 605 ' .............................. - steam consumption, 246 . ; `. ' tall, infiltration in, 126 \ . . water supply to, 799 .. Burner, burners,' " ' . " ` . automatic equipment, 207 coal, 207 .. '' ... . conversion, 228 gas, 226 * oil, 218 .. By-pass method, 416, 836 C Cabinets, (see Enclosures) Calorie, 836 . Calorific values, coal, 173 gas, 182 oil, 180, 181 Heating Ventilating Air Conditioning Guide 1939 Capacitor motor, 722 . Capillary moisture, 669 Carbon dioxide, 86 concentration in air, 70 as corrosion agent, 880 ' as an index of, combustion, 168, 217, 226, 239 draft loss, 198 odors, 60 measurement of, 831 ' as a refrigerant, 39 Carbon monoxide, in air, 82 in garages, 696 - poisoning, 82 - produced by gas, 289 produced by oil burners, 226 produced by stokers, 218 Carnot cycle, 469 Cattle, heat and moisture, produced by, 696 Ceilings, heat transmission, 109 Central comfort air conditioning systems, 415 air distribution, 420 classification of, 416 - cooling cycle control for, 707 design of, 418 heat load ratios, 425 location of apparatus, 428 ratings of, 423 selection of equipment, 423 zoning, 427 Characteristics-of motors, 724 Charles' law, 7 Chemical reactions, control of, 646 Chimney, chimneys, 185 areas of, 193, 197 characteristics, 188 construction of, 201 effect. 688, 836 for gas beating, 202 gas temperature, 190 performance, 192 sizes. 193, 194, 197, 204 Venturi, 186 . . Chorea, 621 ' Cleaners, air, (see Air, Cleaning Devices) Clearance, window sash, 122 Climatic conditions, 136 '- Coal, (see also Anthracite, Coke, Lignite) air speed for conveying, 660 analysis of, 172 ' bituminous, 170 burning rate chart,' 234 calorific value, 173 classification of, 172 dust, disposal of; 77 dustless, 179 ' pulverized, 178 semi-bituminous, 178 - size of, 174 ' Coal burning systems. . automatic control of, 715 automatic firing equipment, 207 boilers, 249 ,. combustion rate, 400 draft required for, 198 furnace requirements, 401, 406 . stokers, 207 . . . ' Codes A.S.H.V.E. codes and standards, 864 for grinding, polishing, and buffing wheels, 654 for proportioning warm air heating plants, 227 for rating air conditioning equipment, 432 Coefficients of heat transmission, (see Heat Transmission, Coefficients) Coils, applications, 601 cooling, 412, 511 dehumidifying, 506 direct expansion, 498 evaporator, 412 . Coils (continued) . - flow arrangements, 500 heat transfer, 503 heating, 510 hot water, 410 performance, 509 pipe, 328 preheater, 416 radiator, 269 reheater, 416 Steam, 497 water, 497 Coke, 173. 215 combustion of, 178 Cold, effects on human body,.53 Collectors, dust, 661 Column radiator, 836 -- ** Combined system, air conditioning equipment, 416 Combustion, 163 air required for, 163, 166, 167 - constants, 677 of different coals, 169, 171, 174, 215 in driers, 673 of gas, 181, 225 of oil, 179 - rates for heating boilers, 260 . - smokeless, 253 . . - with various stokers, 215 . . Comfort, 55 ' chart, 62 conditions of, 145 effective temperature, 58, 69, 60 heating for, 769 line, 61, 63. 64, 66, 836 for men working, 64 optimum air conditions for, 60 school children, 63 ' zone. 60. 837, (see also Zone, Comfort) Compensated cooling control, 709 Composition of water, 27 Compound wound motor, 719 Compressed air, 622 . Compressors, 464 - control of, 717 . reversed refrigeration, 489, 766 types of, 465 * Condensation, , on building surfaces, 139 '' meters, 791 prevention of, 139, 760 rate in radiators, 273 return pumps, 299 - - in steam heating systems, 281, 807 ' Condenser, 475 design data, 475, 529 performance of, 475 types of, 476 water temperatures, 529 , Conditioning and' drying, 645, (see also Avr Conditioning) Conductance, 88, 90, 837 of-air spaces,`88, 91 . of building materials, -95 of insulation, 95, -789 surface, 90 .- Conduction, 837. drying by, 665 ' - heater, 768 Conductivity, -88, 90, 837 Conductor, 8?7 - Conduit, 783 Constant relative humidity, 837 Constant speed motor, 720/ 724, 725, 726 . Constant temperature drier, 668 ' ' Construction code for low pressure boilers, 264 Contours, velocity, 655 . Control, controls, 699, 837 of air conditioning equipment, 479, 699, 704, 716 combined system, 704 split system, 705 apparatus, 700 XU Alphabetical Index to Technical Data Section . Control (continued) automatic, 404, 699, 713; 714 gas burner, 714 oil burner, 714 stoker, 715 compensated cooling, 709 of cooling units, 711 domestic hot water, 716 of draft, 187 of electric motors, 726 electric systems, 702 of electrical heating, 766 of fans, 559 modulating, 703 - moisture content, 643 of natural ventilation, 691 of noise, 602 of oil burning equipment, 714 pneumatic system, 702 positive acting, 702 pressure, 701 railway systems, 630, 631 rate of biochemical reactions, 646 rate of chemical reactions, 646 rate of crystallization, 647 of refrigeration equipment, 714 compressor, 714 ice. 717 vacuum, 717 well water, 718 . of regain, 642 of relative humidity, 701 residential, systems, 715 room, 703 self-contained, system,- 702 of sound, 601 of steam heating systems, 291 of temperature, 699, 766 types of, 702 . unit, 220, 699, 766 of vacuum pumps, 302 zone. 298, 704 Convection, 837 Convectors, 269, 275, 837 A.S.H.V.E. code for, 277 connections for, 328 correction rating factors, 277 design of, 275 drying by, 666 Cooling coils, 493, 511 D Dalton, law of partial pressures, 1 Damper, dampers, < apparatus which operates, 699 control. 691 in duct systems, 404 motors, 701 - types of, 404 Decibel, 601, 837 Defrosting coils, 447 Degree-day, 837 . base temperature for, 240 methods of estimating fuel consumption, 240 records for cities, 240 ' Degrees, perspiration, 71, 73 Dehumidification, 11, 416, 463 by absorption, 486 by adsorption, 484 effective temperatures for, 64 methods of, 423, 449 by refrigeration, 463 relative humidities for, 64 - Dehumidifier, dehumidifiers, 415 alumina, 485 in central air conditioning systems, 416 in industrial air conditioning, 521 silica gel, 485 types of, 449, 625 . Density, 3, 837 . of air, 6 -' of saturated vapor, 12 Density (continued) specific, 3 . of water, 27 Dermatitus, 622 . . , Design conditions in industrial conditioning, 639 Design temperature, dry-bulb, 146 wet-bulb, 146 Dew-point, 838 relation to relative humidity, 9 temperature, 2 . . Diameter, circular equivalents oi rectangular ducts, 600 Diarrhea, 618, 619 Dichlorodifluoromethane, 35, 37, 467 - Diptheria, 50 ` Direct current motor, 719 Direct-indirect heating unit, 838 Direct radiator, 838 Direct return system, 338, 838 Dirt pockets, 334 Disease treatment, . air conditions for, 617, 618, 621 allergic disorders, 622 anesthesia, 615 . artificial fever, 620 - classification of' diseases, 620, 623 - diseases treated, 60, 6iy, 618, 621, 622, 628, 625 explosion hazard, 615 fever therapy, 620 filtering in, 618 hospital air conditioning, 625 nurseries, 618 operating rooms, 615, 616 oxygen therapy, 623 . premature infants, 618 satisfactory air conditions, 618, 621 ventilation rates, 616, 620 Distribution of air. 565, (see also Air, - Distribution) District heating, 781 conduits, 783 meters, 790 pipe, (see also Piping) distribution, 781 returns, 783 sizing, 782 rates, 793 steam consumption, 792 tunnels, 786 Diverter, back draft, 203 - Domestic oil burners, 220 Domestic stokers, 210 Domestic supply, hot water, 763, 816 control, 716 load. 259 water, 799 Doors, air leakage through, 125 coefficients of transmission of, 115 . Down-feed piping systems, (see Steam Heating Systems) Draft, 185 - available, 188, 192 back, diverter, 202 . dimensions, 202 calculations, 185 capacity, 187 control, 187 - equation, 193 gage, 824 head, 838 - intensity required, 174, 197 losses, 197 in chimneys, 198 through fuel bed, 196 mechanical, 186 natural, 185 requirements. 171 theoretical, 188 ' . ' - Drain connections, 266 Drawing, symbols fof, 851 - Heating Ventilating Air Conditioning Guide 1939 Driers, 666, 667 adiabatic, 667 agitated, 666 batch. 666 '. compartment, 666 . ' continuous, 666 cylinder, 666 design, 676 drum, 666 . festoon, 666 high temperature, 681 .. induction, 666 -. intermittent, 666 . rotary, 666 spray, 666 tower, 666 tunnel, 666 vacuum, 666 . . Drip, 838 .' Dripping of steam pipes* 333 - . . . . Drum driers, 666 Dry air, 838 Dry-bulb temperature, (see 'Temperature, Dry- Bulb) ' Dry return, 838 Drying, 645, 665, (see also Regain) 1 adiabatic temperature, 667 air circulation in, 671 combustion, 673 by conduction, 667 ' constant temperature, 668 by convection, 667 . design, 676 direct contact, 667 equipment for, 671 estimating method, 683' ' . factors influencing, 669 gas combustion constants for, 677 - high temperature, 670, 681 humidity chart, 672, 673 . humidity in, 670 - industrial, 645, 665 low temperature, 670 mechanism of, 668 . methods of, 665 .moisture in, 669 -- omissions in the cycle, 668 - by radiation, 665 . rules for, 670 . ' stages of moisture diffusion, 668 constant rate period, 668 falling rate period, 668 sun, 665 temperature in, 670 time of, 671 materials, 674 ventilation phase, 679 . . ' . . , Duct, ducts, air, 404, 581 design of, 581 . equal friction method, 587, 593 velocity method, 587 . for air distribution, 565 ' air velocities in, 407, 660 circular equivalents, 589 . . construction details, 598, 659 design of duct systems, 404, 687/ 596, 652, 658, 659 . heat loss from, 746 humidity measurement in, 830 ' insulation of, 735, 748 lining factor for sound, 609 noise transmission through, 609 pressure loss in, 682 . . . elbows, 582, 660 . for recirculated air, 387 resistance, 661 . sheet metal for. 698, 659 ' sizes of, 585,, 589, 653 temperature loss in, 421 , - - temperature measurement s, 825 - velocity measurement in, 827 - Dust, 77, 838 air speeds to convey, 653, 660 Dust (continued) ^ catching devices, 86 - . .. collectors, 661 . concentration in air, 80, 831 . counter, 831 disposal of, 84 . industrial exhaust systems, 651 measurement of, 831 . Dynamic equilibrium. Carrier's equation for,.2 Dynamic head, 838 , / Dysenteria, 60 .' Eczema, 622 EDR, equivalent direct radiation, 843 Effective temperature, (see Temperature, Effective) Elbow, elbows. design of, 373, 404 . equivalents, 406 loss of pressure in, 582 ' . resistance in, 661 sheet metal used in, 659 welding of, 374 .. Electric, electrical, - automatic, control system, 702 -. central fan heating systems,. 760 . control, motor, 719 . current, as corrosion agent,-374, 380 heat equivalent, 139, 158, 766 heaters, 758 conduction. 768 . . . gravity convection, 759 radiant, 759 . heating, 767 . auxiliary, 765 cost of, 766 of hot water, 763 `. . .. . . industrial, 764 heating elements, 758, 759 with unit heaters, 759 . ' lamp bulbs, heat from, 158 , motors, 719 resistors, 758 Eliminator plates and baffles, 518 . Enthalpy, 22, 838 Entropy, 467, 472, 839 . Equations, conversion, 848 Equilibrium, ' _ ' dynamic, 2 '' hygroscopic, 644 .. . . .......... . .... Equipment noise, 604 ' . * Equipment room, design of,- 609 ' ' Equivalent, equivalents, circular, 590 " direct radiation,'311, 843 . '' elbow. 346 ... . evaporation, 257, 839 heat, . of air infiltration, 138 ' ' of brake horsepower, 139 mechanical, 841 length of run, 312 square feet, 264 ' Estimated design load, 839 ,' Estimated maximum load, 839 ' Estimating driers, 683 _ ' Estimating fuel consumption, 233 Ether, 616 . Ethylene, 616 Eupatheoscope, 833 . ' Evaporation, 534 equivalent, 257 . , from human body, 62, 72 from water pans, 268 ' ' Evaporative condensers, 477 Evaporative cooling, 477, '489, 519' . Evaporators, 477 ExfUtration, 119 Exhaust systeihs, 651 . ' classification of, 651 collectors, 661 XIV Alphabetical Index to Technical Data Section Exhaust Systems (continued) corrosion, protection against, 663 design procedure for, 652 ducts for, construction of, 659 design of, 658 resistance in, 661, 662 efficiency of, 663 . fans for, 663 filters for, 662 .' flexible, 658 . hoods for, 655 air flow in, 656 - axial velocity formula for, 665' chemical laboratory, 658 large open, 657 velocity contours in, 665 industrial, 651 . lateral, 655 motors for, 663. spray booth, 658 . suction requirements, 653 velocity requirements, 653. 660 Expansion, of joints, 783 of pipe, 361, 783 ' in steam piping, 783 tanks, 355 Explosion hazard, inflammability of gases, 79 in operating rooms, 615 Exposure factors, 138 Extended beating surface, 839 . Extended surface heating unit, 839 F Fan, fans, 549 A.S.H.V.E. test code for, 652 attic, 460 booster, equipment, 396 control of, 559 designation of, 561 drives, arrangement of, 662 for drying, 558 for dust collecting, 559 dynamic efficiency of, 651 - efficiency of, 551 in electrical heaters, 760 furnaces, 399 . for gas-fired furnaces, 226 induced draft, 186 for industrial exhaust systems, 663 mechanical draft, 186 mechanical efficiency of, 551 motive power of, 561, 722 control of, 719 operating characteristics, 186, 551 operating velocities, 539, 658 performance of, 549, 557 ratings of, 656 selection of, 402, 556, 559, 561 static efficiency of, 651 ' system characteristics, 555 systems of heating, 416 tip speeds, 556 * total efficiency of, 551 - types of, 399, 549, 553, 657 in unit conditioners, 451 in warm air systems, 396, 402 Fatigue, human, 54 Fever therapy, (see Artificial Fever)- Filter, filters, 539 automatic, 541 cloth, 662 - design, 639 dry air, 642 . . hay fever air, 622 < installation of, 643 '' for sound, 402 unit type, 639 . ` viscous type, 539 Firing rate, 170, 176 # Fittings, 361, (see also Connections, Pipe) areas of, 364 boiler, 264 copper, 371 . flanged, 372, 739 lift, 294 screwed, 370 . welding, 372, 376 Flame, with oil burners,. 219, 223 Flanges, welding neck, 377, 378 Flexible exhaust systems, 658 Flexible materials, 607 . Floors, heat transmission through, 109 Flue-gas analysis, 832 Fluid, fluids, cooling of, 529 formula for flow of, 581 .- . meters, 790 ' Foodstuffs, regain of moisture of, 644 temperatures and humidities for processing, 640, 674 Force, 839 Forced-air heating system, design, 399 Formulae, ` conversion, 848 ' heat transmission, 89 Freezing, of cooling water, 535 - ' insulation against, 749 Friction, ' of air, in pipes, 584, 585 in chimneys, 191 coefficients, 585 . - heads in pipes, 342 losses in ducts, 583, 585, 589 . . in water pipes, 807 . . Fuel, fuels, 163, (see also. Anthracite, Coal, Coke, Gas, Lignite, OH) . bed, draft loss through, 195 burning equipment, automatic, 207 burning rate charts, 234, 235 . consumption, 233, 241 - oil gages, 226 . oil, heating value, 180, 678 . oil specifications, 180 requirements, . . ' -' . of buildings, 235 degree-day method, 239 utilization of, 233 . Fumes, 77, 839 industrial exhaust systems, 651 toxicity of, 81 . Fundamentals of heating and air conditioning, 1 Furnace, furnaces, 889 capacity, 389 ' design of, 216, 262, 383, 400, 405 'gas-fired, 226" . .` performance curves of, 391 types of, 226, 399, 409 volume, 839 . for warm air systems, 399 Fumacestat, 404 G Gage, gages, . draft, 824 ' '- fuel oil, 225 . pressure, 839 . .- steam, 264 . vacuum, 824 Galvanometer, 825 Garage, garages, air flow necessary in, 692 ' heaters, for, 228 ; Gas, gases, - - burner control, 714 . . . burning rate chart, 237 - calorific value, 139, 182 * combustion constants, 677 constant for dry air, 8 XV ' ^ Heating Ventilating Air Conditioning Guide 1939 Gas (continued) flue, analysis, 832 fuel, manufactured, 182 natural, 182 properties of, 182 inflammability, 79 . scrubbers, 84 toxicity of, 81 ' Ga^fired appliances, 226 automatic control of, 218 ' boilers, 226, 714 carbon monoxide produced by, 228 chimneys for, 202 classification, 226 combustion in, 228 control of, 229, 714 conversion burners, 228 furnace requirements for, 400, 839 heat from, 158 rate of gaa consumption, 401 ratings of, 230 sizing, 230 types of space heaters, 227 used with unit heaters. 440 warm air furnaces, 226 '. Gaskets, 372 . Glass, heat transmitted through, 115, 150 Globe thermometer, 778 Glossary of terms, 835 Goitre, 617 Gonorrhea, 621 Grates, 840 areas of. 255. 389, 408, 421, 840 - of furnaces, 255, 389, 408, 421 of stokers, 207 Gravity, circulation, 851 convectors, 269, 759 heat emission of, 269 gravity-indirect heating systems, 279 pressure heads, 850 specific. 3 steam heating systems, 281, (see also Steam Heating Systems) . warm-air heating systems, design of, 383 Grille, grilles, (see also Registers) anemometer readings through, 828 for concealed heaters, 276 recirculating, 387 of roof ventilators, 689 velocity through, 407 for warm air systems, 403 H Hartford return connection, 264, 322 Hay fever, 622 Hazard of explosion, in operating rooms, 616 Health. 81, 617, (see also Disease Treatment) Heart trouble, 623 Heat, 840 ' * absorbed by building structure, 139 of adsorption, 42 air infiltration equivalent of, 128 capacity, 163 of leader pipes, 884 of condensation, 46 conduction, 837 content, of air and water vapor, 2 of coal, 166 of dry air, 22 . of gases, 679 of saturated water vapor, 28 ' convection, 837 conversion equations, 848 demand, factors governing, 131, 247 . effects on human body, 62 electrical equivalents of, 766, 849 emission, of convectors, 269, 276 -Heat (continued) emission - by radiation, 772 of radiators, 269, 276 equivalent, equivalents, 849 * of air infiltration, 128 of brake horsepower, 138 electrical, 849 exchanger, 525, 526 shell and tube, 476 flow meter, 833 gain, . from fixtures and machinery, 158 for insulated pipe, 751 from outside air, 156 infiltration equivalent of, 128 latent, 31, 841 loss, 71, 74 of the liquid, 28, 840 loss, from bare pipe, 735, 737 computation of, 87, 140, 766, 774 cost of, 786 determination of, 128, 138, 233, 769 from ducts, 746 effect of insulation on, 753 from human body, 71, 769, 770 by infiltration, 128, 233 latent, 128 from piping of gas-fired furnaces, 230 by radiation, 58, 769 sensible, 128 to unheated rooms, 116 maximum probable demand, 131, 247 of mixing, 45 . mechanical equivalent of, 841 produced by cattle, 695 produced by human body, 51 pump, 466, 765 radiant, 769 calculation of, 774 measurement of, 777 types of, 772 radiation, 759, 769 regulation in man, 51, 55 requirements, 233 sensible, 145, 843 of air. 12 loss, 71, 772 of water, 31 solar, 149 other than heating plants 138, 147 specific, 31 total, 22, 844 of saturated steam, 28 transfer, 87 coefficients, 88 coils, 493 rate, 253 transmission, 87, 771 through air spaces, 89 through building materials, 89 calculations, 87 coefficients, 87, 94 of ceilings, 109 combined, 116 of copper pipe, 737 of doors, 115 of floors, 109 of glass walls, 115 of insulation, 95 of partition walls, 108 of roofs, 112 of skylights, 1X5 of surface conductance, 90 ' of walls, 102 . of windows, 116, 149 convection equation, 771 . definition of terms used. 88 effects of solar radiation on, 149 formulae, 89 through glass, 115, 149 measurement of, 838 - by surfaces not exposed to the sun, 147 XVI Alphabetical Index to Technical Data Section Heat (continued) transmission symbols used in formulae, 88 tables. 87, 95 through ducts, 746 time lag, 153 . utilization, 233 Heaters, direct-fired, 440 for domestic hot water, 815 electric, 757 capacity of, 756 ' conduction, 758 : convection, 769 ; radiant, 759 space, 227 unit, 759 Heating, (see also Heat) auxiliary, 765 - coils, 493, 610 construction, 494 district. 781 effect of radiators, 272 electrical, 757 elements, electric, 758 fundamentals of, 1 ' load. 131 medium, 840 ' radiant, 759, 769 *- railway air conditioning, 629 by reversed refrigeration, 489, 765 surface, 247, 840 square foot of, 843 ' symbols, 851 systems, _ district, 781 electrical, 767 fan, 416 gravity warm air furnace, 383 hot water, 337, 840 mechanical warm air furnace, 399 radiant, 759, 769 steam, 307, 761 value, fuel oil, 678 water, 799 Henry and Dalton, law of, 381 Hoods. axial velocity formula, 665 canopy, 657 for chemical laboratories, 658 design of, 662 for exhaust systems, 655 open, 657 suction pressures at, 653 Velocity pressures at, 655 Horsepower, 840 boiler, 267 brake, heat equivalent of, 138 Hospital air conditioning, merit) (see Disease Treat- Hot box, 833 Hot plate, 833 Hot water, domestic * control of, 716 load, 256 supply, 813 Hot water heaters, 261, 815 Hot water heating systems, 337, 840 forced circulation, 337, 343 * gravity circulation, 837 installation of, 857 . mechanical circulation, 339 Hot water piping, 337 Hotels, steam consumption, 246 temperatures of, in winter, 132 water supply, 799 Humidification, 10, 617, 840 apparatus for, 521 atomization for, 622 . effective temperatures for, 63 relative humidities lor, 66 for residences, 409 systems of, 621 with washer, 519 Humidifier, humidifiers, 461 atomizing, 522 with fan systems, 416 high-duty, 522 ' self-contained, 523 spray, 523 types of, 461, 521 Humidistat, 405, 840 Humidity, 8, 840 absolute, 8, 835 . control, 701 . railway air conditioning, 630 ' in drying, 670 in hospitals, 615 for industrial processing, 623, 640, 64! measurement of, 830 ` optimum, 66 ^. relative, 9, 842, (see also Relative Humidity) < in comfort zone, 61 effect on moisture regain, 643 relation to dew-point, 9 specific, 8, 84Q Hygroscopic materials, 644 moisture content, 648 processing of, 645 regain, 644 Hygrostat, 841 Hypertension. 625 , Hyperthyroidism. 625 I lee, in air conditioning, 412, 460, 490 control of, 717 Inch of water, 841 ` Induction motor, 722, 726, (see also Motors) Industrial, . air conditioning, 639 . apparatus for, 445, 521 calculations. 647 air pollution, 77 control. . biochemical reactions, 646'' chemical reactions, 646 - crystallization, 647 moisture content, 643 of regain, 642 cooling systems, 493 design conditions, 639 drying, 645 . electrical heating systems, 765 exhaust systems, 651, (see also Exhaust Systems) general requirements, 642 heat sources, 139 temperatures and humidities for processing. 640. 641 . unit heaters, 440 .- Infants, premature, 61, 63, 618 Infiltration, 219 average, 124 fuel utilization, 203 heat equivalent, 128 through shingles, 121 through walls, 120 through windows, 122, 124 Inflammability of gases, 79 Institutions, water supply to, 821 Instruments, 823 ' Insulation, 841 asbestos type, corrugated, 741, 742 laminated, 743, 744 of boilers, 247 bright metal foil, 92, 93 characteristics of, 95 of conduits, 754 . " of ducts, 748 economical thickness, 763 heat transmission through, 95, 739 for low temperatures, 749 magnesia type, 740 of piping, 735 xvn: Heating Ventilating Air Conditioning Guide. 1939 Insulation (continued) to prevent condensation, 189, 760 to prevent freezing, 749 . reflective type, 92, 93 rock wool type, 746 of sound, 605 tables, 95, 740 thickness needed, 762 underground, 753 ' of vibration, 605 . Ionization of air, 73 Isobaric, 841 Isothermal, 7, 841 J-K-L Joints, expansion, 365 ., Kata thermometer, 829 Lag in heat transmission, 153 Latent heat, 81, 841 loss, 70 of water vapor, 12 Lateral exhaust system, 655 Leader pipes, 384 heat carrying capacity of, 385 ' , ' size of, 385, 395' Leakage of air, 199, (see also Infiltration) Lignite, 173 . - . .. Liquid, heat of the, 28, 840 Lithium chloride system of adsorption, 45, 486 Load, building factors, 246 cooling, 145 '' design, 257, 839 heating, 131 . , maximum, 889 '' radiation, 839 . Low temperature insulation, 749 ' . . . M Mixture, air and water vapor, 12 Modulating control, 703 Moisture, content, of air, 70, 145, 521, 643 capillary or free, 669 of hygroscopic materials, 644, 669 loss by human body, 74 from outside air, 156 '* produced by cattle; 695 regain, 643 Mol, 841 : Monofluorotrichloromethane, 35, .40 Motive power, 719 Motors, electric, 719 adjustable speed, 720 . '- adjustable varying speed, 720 alternating current, 721 . application of, 724 - capacitor type, 722 characteristics of, 720 classification of, 724, 725, 726 compound wound, 719 . constant speed, 720 . . . control equipment for, 727 . automatic, 728 manual, 727 . multispced. 730 pilot, 728 single phase. 732 . .. - . slip ring, 731 . . . damper, 701 . direct current, 719 ' . control of, 729 speed characteristics, 724, 726 as heat source, 157 ' induction, ` automatic start, 726 . capacitor start, 722 '. repulsion, 722 -. repulsion start, 723 slip-ring wound rotor, 726 squirrel cage, 723 polyphase, 723 selection of, 663 - Machinery, as heat source, 138, 157 mountings vibration,-587, 605 ' sound insulation of, 605 Magnesia insulation, 740 Manometer, 827, 841 Manual control, (see Controls) .. Masonry materials, heat transmission through, series wound, 719 ' shunt wound, 719 single phase, 732 .. - special applications, 727 split phase, 723 synchronous, 721 varying speed, 721 MRT, mean radiant temperature, 770, 774 95 Mass, 841 . `N Mb, 337, 841 Mbh, 337, 841 . Mean radiant temperature, 770, 774 Mechanical, . draft towers, 633 equivalent of heat, 841 fuel burning equipment, 207 refrigeration, 35 ventilation, 75 ; warm air furnace systems, 399 air distribution, 402 design of, 405 register and grille locations, 403 Medical treatment, (see Diseases) Mental trouble, 623 Mercurial thermometer, 825 Metabolism, 61, 71 Meters, choice of, 790 . condensation, 791 fluid. 790 Nicholls heat flow, 833 steam flow, 791 types of, 790 water, disc, 805 . Methyl chloride, 35, 88, 529 Metric units, . 850 Micromanometers, 824 Micron, 79, 841 .' . . * . . Natural draft towers, 533 Natural ventilation, 70, 687 Nervous instability, 625 Neurosyphilis, 621 Nicholls heat flow meter, 833 Noise, (see also Sound) ' air outlet, 572 in buildings, 602, 605 . control of, 602 . . through ducts, 609 1 through room wall surface, 609 . with warm air' systems, 402 equipment, 604 kinds of, 604 level, . acceptable, 603 of fans, 557 measurement of, 602 through building construction, 605 Nozzle, 617 air spray, 517 . oil atomizer, 218 .- water spray, 517 . Nurseries, 618 equipment for, 620 requirements for, 619 ventilation rate, 620 XVlll Alphabetical Index to Technical Data Section o Odors, 67 of human origin, 49 concentration, .68 ' removed by outside air, 69 Off peak heating, 764 Oii oils, ' atomization of, 219 burner, burners, air for combustion, 218 air supply for, 218, 224 boilers, 221, 222 burning rate, chart, 235 classification, 179 combustion, 233 . . for commercial use, 221 control of, 225, 714 . design considerations, 223 ' for domestic use, classification, 218 efficiency of combustion, 225 flame with, 219 '. furnace requirements, 252, 400 ignition, 219 oil consumption, 233, 235 operation, 218 ' Orsat test, 225 '. specifications, 179 .. types of, 219 calorific value of, 181 classifications, 179 . ... ' as corrosion inhibitor, 381 . gages, 225 :. . ignition of, 180, 218' preheating, 220 specifications, 180 . One-pipe steam heating systems, 281, 841, (see also Steam Heating Systems) Openings, 689 . air inlet, 691 for natural ventilation, location of, 691 . size of, 688 types of, 689 . Operating rooms, anesthesia, 615 .. explosion hazard, 615 humidification, 616 ' . static electricity, 616 ventilation, 616 Orifice, orifices, friction heads, 349 .' steam heating systems, (see Steam Heating Systems) , . . Orsat test apparatus, 218, 225, 229, 832 Outlets, (see also Registers, Grilles) design and location of, 677 Oxygen, 381 . Oxygen therapy, . diseases treated, 623 oxygen chambers, 624 oxygen tents, 623 Ozone, 75 . .. . P Paint, effect on radiators, 271 spray booths, 658 ' temperatures and humidities for processing, 640 . Panel radiator, 842 Panel warming, 842 Partial pressures, Dalton's law of, 1 Perspiration, 49, 51, 71, 73 . Petterson-Palmquist apparatus, 831 Pipe* piping, 361 bare, heat loss from, 735 . bends, 368 . capacities, (see Pipe, Sizes) coil radiators, 269 Pipe (continued) conduit, 754, 783 connections, 320. 786. (see also Connections) copper, 362 corrosion of, 380 <. - dimensions of, 362, (see also Pipe Sizes) district steam, 781 ' expansion of, 365 . fittings, 361, (see also Connections, Fittings) for water supply, 804 welding fittings, 372 flanges, 376, 739 - flexibility of, 865 freezing, prevention of, 749 - friction, 807 . of air in, 584, 585 -' heads in, 342 . gaskets, 366 hangers, 370 beat loss from, 739 . cost of, 736 . - for hot water heating systems, 337 -. insulation of, 735 - joints, 365 leaders, 384 radiating'surface, 738 radiators, 269 - "refrigerant, 478 scale in, 380 . sizes, 341 for black iron, 343, 344 for boiler runouts, 322, 782 for central fan systems. 831 . for convector connections, 328, 329 for copper tube, 343, 845 . forced circulation systems, 343 gravity circulation systems, 351 dimensions, 362, 365 for district heating, 782 . for domestic hot water, 810 elbow equivalents, 346 - equivalent length of run, 312 friction head, 342, 843 of orifices in unions, 349 . for Hartford return connection, 322 for hot water heating systems, 341 for indirect heating units, 331 . mains, 806 ' for pipe coil connections, 328. for radiator connections, 326 refrigerant, 3, 307, 478, 480 return, capacity of, 316, 783 ' steam, 308, 315, 316 , underground, 783 tables, 314 ' .' ' tees. 870 for underground steam, 783 for water supply, 808 ' weights, 367 ' .' steam, capacity of, 311 for steam heating systems, 281, ' also Steam Heating Systems) . supports, 370 sweating, 750 tax, 259 . 307, (see . tees, dimensions of, 373 . threads, 369, 371 ` tunnels, 786 types of, 361 underground, . insulation of, 753 steam, 783 . , for unit heaters, 438 valves, 376 ` -- water supply, 799 weights of, 362 '" welding, 372 Pitot tube, 827 ' Plastering materials, heat transmission through, 99 Plenum, chamber, 842 systems, automatic control of, 704 XIX Heating Venturing Air Conditioning Guide 1939 Plumbing fixtures, 801 Pneumatic control system, 702 Pneumonia-, 50, 617, 623, 625 Pollen. 623 Pollution of air, 81 Polyphase motors, 723 Ponds, cooling, 581 Positive-acting control, 702 Post-operative pneumonia, 617 Potassium permanganate, 532 Potentiometer, 842 Power, 842 conversion equations, 849 electric, 766 supply for controls, 702 railway air conditioning, 631 Precipitators, dust, 545 Premature infants, 618 humidity of, 619 mortality of, 620 requirements of,. 619 . Pressure, pressures, . absolute, 835 air, measurement of, 827 atmospheric, 823, 836 for atomisation, 522 automatic control, 701 . barometric, 189, 835 basic. 3 controllers, 701 conversion equations, 849 drop, 584. 807 drop through refrigerant pipe, 480 dynamic, 838 gage, 824 loss in copper pipe, 345, 480 loss through ducts, 581, 661 measurement of, 823 partial, Dalton's law of, 1 of saturated vapor, 12 static, 843 . steam, in direct heating, 781 drop, 284, 310, 315 initial, 310 in orifice systems, 297 saturated, 28 . in sub-atmospheric systems, 295 total, 844 vapor, 31, 845 velocity, 845 water, 27, 805 Prime surface, 842 . Processing, 639 cooling systems, 463, 639 industrial temperatures and humidities for, 640 of textiles, 644 unit heaters, 441 Propeller fans, test code for, 552 Psychrometer, 842 sling, 830 Psychrometric, chart, 25, 58. 59, 60, (back cover) for drier, 672 explanation, 25 tests, 57 Pulmonary disturbances, 623 Pump, pumps, centrifugal, 340 characteristics, 187 circulating, 339 condensation return, 299 ' heat, 466, 765 vacuum, 298 Pyrometer, 826, 842 . mercurial, 826 optical, 826 radiation, 826 thermo-electric, 826 Q-R Quality, of air, 67, 68, 69 impaired by recirculation, 81 - Quantity, of air, ' measurement of, 82? necessary for ventilation, 68, 69,: 72, 166, 627 . * of cooling water, 529 - Radiant heaters, 759 - Radiant heating, 769 physical and physiological factors, 769 Radiation, 842 by black body, 775 drying with, 665 equivalent direct, 311 heat loss by, 74, 770 by human body, 74, 770 load, 258 of pipe, 738 by radiators, 269 solar, 149, (see also Solar Heat) occlusion of, 82 through walls, 150 ultra-violet, 78, 80 Radiator, radiators, 269, 842 A.S.H.V.E. code for, 277 column, 836 concealed, 837 condensation rate in, 273 connections, 326, 854 control of, 703 correction rating factors, 277 effect of superheated steam, 271 enclosed, 274 gas-fired, 228 heat emission of, 269 heating capacity of, 270 heating effect of, 272 . for hot water systems, 846 output of. 270 paint, effect of, 271 panel, 827 pipe coil, 269 ' ratings of, 264 recessed, 842 selection, 276 ' . tube, 829 types of, 269 wall, output, 270 warm air, 228 Railway air conditioning, 627 air distribution, 578, 628 cleaning, 629 cooling equipment, 629 calculation of, load, 637 capacity, 630 " costs, 635 heating, 629 ' humidity control. 630 - power requirements, 631, 632. tractive resistance, 633 temperature control, 631 ventilation, 627 " Raoults law, 487 Refrigerants, 85, 842 . ammonia, 86 carbon dioxide, 39 dichlorodifluoromethane,' 37 , lithium chloride, 44, 45 methyl chloride, '88 monofluorotrichloromethane, 40 water, 41 Refrigerating, capacity, 469 Refrigerating plant, 463 centrifugal, 473 compressor, 464, 530 operating methods, 479 . ' size of, 469, 479` ` steam jet system, 471, 530 types of, 465 . XX Alphabetical Index to Technical.Data Section Refrigeration, characteristics, 475 curves, 474, 475 coefficient of performance, 469 Carnot cycle, 469 . compression ratio, 471 control of, equipment, 717 dehumidification by, 464 efficiency. ' cycle, 469 ejector, 471 . mechanical, 471 ' losses, 470 , mechanical, 466 pipe sizing, 478 discharge, 480 liquid, 431 _ suction, 482 ' .. practical cycle, 469 reverse cycle, 766 . limiting factors, 765 systems, absorption, closed, 487 centrifugal, 473 mechanical, 490 steam ejector, 471 various types, 463 theoretical mechanical cycle, 467 theoretical work per pound, 468 ton of, 469, 844 ton days of, 844 unit of, 470 ' Regain, control of, 642 ' of hygroscopic materials, '644 Registers, (eee also Grilles) , with gas-fired furnaces, 228 ' . with gravity furnace systems, 387 with mechanical warm air furnace systems, 403 - selection of, 887 sizes, 387, 895 temperature, 409 velocity through, 409 Relative humidity, 9, 842 apparatus sensitive to, 700 in comfort zone, 62, 66 relation of dew-point to, 9 control of, 700 in industrial plants, 640, 642 for processing, 640 in public buildings, 65 in residences, 409 from water pans, 409 . . Relays, 701 Relief valves, 356 Repulsion motors, 722, 723 Research residence, 894, 411 Residences, . air distribution in, 402 automatic fuel burning equipment, 207 conditioning units, 292, 467 control systems, 405, 714 . gas heat, 226 humidification of, 409 . oil burners for, 218 requirements in, 411 steam consumption, 246 -stokers for, 210 . '. Resistance, ' of bright metallic surfaces, 92 of building materials, 95 in ducts, 683, 661 . of exhaust systems, 661 of filters, 402 of insulators, 95 ' thermal, 844 . thermometer, 826 Resistor, 758 . Respiratory diseases, 625 .. Restaurants, tobacco smoke, in, 68 water supply to, 821 - Return, dry, 838 mains, 842 pipe, capacity, 316 reversed, 842 wet, 845 Reverse cycle of refrigeration, 489, 765 Reversed return system, 842 Reynolds number, 190 Ringelmann chart, 832 Rock wool insulation, 98, 745 Roof, roofs, . coefficients of transmission of, 112 conductivities of, 99 solar radiation on, 150, 161, 152 ventilator, 843 Room absorption correction charts, 575 Room control, 703 . '' S Salts in cooling water, 627 ' Saturated air, 843 Saturation, fiber .point, 669 Scale, in boilers, 266 Centigrade, 825 on equipment, 527 Fahrenheit, 825 in pipe, 380 , Reaumur, 826 School, schools, - air flow necessary in, 68 optimum air conditions. 63 temperature of, in winter, 132 ventilation in, 68 Scrubbers, 517, 546 Self-contained control system, 702 Sensible heat, 146, 843 of air, 12 loss. 71 of water, 31 Series wound motor, 719 Sheet metal, for ducts, 698, 659 Shingles air leakage through, 121 Shunt wound motor, 719 Silica gel, with oxygen chambers,-624 regain of moisture of, 644 silicon dioxide, 41 equilibrium conditions, 42 system of adsorption, 41, 42, 43, 485 Single phase motor,' 722 Sizes of pipe, (see Pipe Sizes) Skin diseases, 625 Sling psychrometer, 830 Slip-ring wound motors, 726 Smoke, 77, 843 abatement of, 82 measurement of, 832 recorders, 832 tobacco, 68 . Smokeless arch, 843 Solar heat, 149 absorption coefficients, 168 effect of, awnings, 164 latitude, 150 intensity chart, 148 occlusion of, 82 radiation, factors, 162 through walls, 150 time lag, 153 - Solenoid valves, 701 Sound, 601, (see also Noise) absorption coefficients, 607 control, 426, 601 duct lining factor, 611 effect on duct design, 585 insulation of, 607 . measurement of, 602 unit of, 601 XXI Heating Ventilating Air Conditioning Guide 1939 Specific density, 3 Specific gravity, 2, 843 of fuel gas, 182 Specific heat, 3, 843 of air, 5 mean, of water vapor, 3 ` of water, 31 Specific humidity, 8 Specific volume, 3, 843 of saturated steam, 31 Split phase motor, 723 Split system, 843 air conditioning equipment, 416 . automatic control of, 705 central fan, 416 unit ventilators, 442 Spray, booths for painting, 658 . cooling, . ponds, 531 efficiency of, 530 towere, 532 - distribution of, 522 - . ', - - - generation of, 522 humidifiers, 523 ' type of central station system, 415 water coolers, 476 Square foot of heating surface, 843 Squirrel cage motors, 723 Stack, stacks, 384 effect, 688 height, 843 size of, 386, 395, 692 _ wall, 386 Stairways, 127 Standards, . air, 843 - air conditioning, 49 A.S.H.V.E. codes and standards, 254, 277, 854 for fuel oil, 1?9 for pipe, 362 * for radiators, 277 for welding, 374 . Static pressure, 426, 843 ' . ' Steam, 843 - coils, 493 condensing rates, 273 . , consumption for buildings, 246_ flow, Babcock's formula, 308' . ` heat content of, 23 ------ - - heating systems, 281, 843 . air-vent, 282, 285, 315, 818 atmospheric, 291, 295,. 328 . " . classification, 281 condensation return`pumps, 299 , connections, (see Connections, Fittings) corrosion of, 380 -. design of, 281, 307 -' dirt pockets, 334 ' district heating, 781 . dripping of, 333 . , ' electric, 761 equivalent length of run, 312 ' gravity systems, 275 : one-pipe, 275, 285, 315, 328-' '. . two-pipe, 285,' 318, 328. : with high-pressure steam, 323 mechanical, 281 .................. orifice, 297, 310, 319, 328 pipe, 307, (see also Pipe) , capacity, 314, 315 ' sizes, 310, 315 - sub-atmospheric, 295, 302, 319, 328 types of, 281 - -' vacuum, 293, 300, 302, 319, 846 . vapor, 328, 845 ` one-pipe, 287, 841 two-pipe, 287, 289, 819, 844 . water hammer in, 310 zone control, 298 . high pressure, 323 _ jet apparatus, 471 '' meters for, 790 .. pressure, 323 . ' Steam (continued) properties of, 28 requirements of buildings, 240, 792 saturated, properties of, 31 superheated, 271, 844 supply mains, 844 tables, 8, 28 trap, 843 tunnels, 786 underground, 783 in unit heaters, 436 - ' Sterilization of air, 618 Stokers, - apartment house, 212 automatic control of, 404, 715 . - classes of, 204 combustion process, 215 adjustments, 217 efficiency, 218 commercial, 212, 213, 214 controls, 218 design of, 207 economy, 207 household, 210 mechanical, 207 operating requirements, 211 . overfeed flat grate, 207 ' ' overfeed inclined grate, 208 types of, 207 ' . underfeed, 207, 844 ' . .. underfeed rear cleaning, .209 '. underfeed side cleaning, 208 . ' \' ' - Storage, .- . of hot water, 814, 818 . .' . temperatures and humidities for, 640 Storm sash, 123 ;. . Streptococcus, 49 . . Stroke, heat, 617. Sub-atmospheric systems, (see also Steam. Heat ing Systems) ' . Suction, static in exhaust systems, 653 .. '. -. Summer, care of heating boilers, 267 . . ` . comfort zone, 62, 64 . ... ' conditioning, apparatus for, 415,' 448, 517 desirable indoor conditions in, 64 .. / temperatures, 146 . . wind velocities and directions, 146 Sun, `. effect on heating requirements, 298 . factor of cooling load, 149 , . Supply outlets, selection of, 387 types of, 395 . .. . . '. ' . . .. Surface, .. ' conductance, 844- - - - . cooling, 493 ' equipment, 493 ' '' air conditioning, 415- . - ratings, 493 extended, gravity-indirect heating systems, 279 heating, 844 . Square foot of, 843 ` ^ radiant heating, 775 " " ' Sweating of pipe, 750 Swimming pool, 820 Symbols, .. . .. for drawings, 851 . for heat transmission formulae, 87 `' Synchronous motor, 727- -. Systems of control, 702 T Tank, tanks, ' for domestic water supply, 814, 818 expansion, 355 : flush, 806 xxu Alphabetical Index .to Technical Data Section Tees, dimensions of, 373 Temperature, ' absolute, 835 - of air leaving outlets, 42 lr 422, 56.7 apparatus sensitive to, 700 atmospheric, 190 ' base, for degree-day, 239, 240 basic, 3 body, 51, 52, 770 changes, effect on human beings, 53 of chimney gases, 190 in cities, 136, 146, 242 of city water main, maximum, 526 control of, 218, 225, 229, 700, 766 railway air conditioning, 631 - of cooling water, 476 dew-point, 3, 838 ' difference, between floor and ceiling, 134, 435 . in stacks and leaders, 384, 691 dry-bnlb, 2. 66, 838 maximum design, 146 '- specified in winter, 132 - ' for drying, 670 . effect on moisture regain, 640 '- effective, 56, 66, 133, 145, 838 chart, 56, 58, 69, 60, 62 - for maximum-comfort, 62 ' * optimum, 60 scale, 57 of gas flame, 182 . in industrial processing, 740, 741- inside, 61, 62, 132 `' - low, insulation for, 741 - mean radiant, 770j 774 - ' ' : ' _. measurement of, 825 - '' in occupied space, 66 . outside, 134, 146 range of cooling equipment, 529 " records of cities, 136, 146 - - : at registers, 667 room, 10, 132 ,, sensations, 55 ' surface, - '. of man, 771 - mean interior, 774 - ` systems for control of, 218, 225, 229, 699, 766 thermo-equivalent conditions, 57 ' ' water main, maximum, 626 - ,. of well Water, 524 - '' wet-bulb, 2, 11, 830, 845 average, 529 '. design, 145, 529 as index of air distribution, 70. - ' - maximum, 529 - Terminology, 836 .' " Test codes, 254 'v* Test instruments, 823' -- Test methods, 823 - .. - ' .Textile, textiles, . fibers, regain of.moisture, 639 ' - temperatures and humidities for processing, . 641 .. Theaters, temperatures of, 66, 132 : Therm, 844 " Thermal resistance, 844 -.................. Thermal resistivity, 844 - .' Thermocouples, 826 .. . Thermodynamics, 844 . of air conditioning, 1 . laws of, 841 ' .. Thermo-equivalent conditions, 57 Thermocouple, 825 . :. Thermometer, 825, 826, 827 Thermopile, 826 Thermostat, thermostats, 699, 844 differential, 10, 699 - ` with gas-fired furnaces, 229 ' immersion, 700 . insertion, 700 - location of, 405 with oil burners; 225 pilot, 706 '. . , - . Thermostat (continued) with radiant heaters, 766 room, 700 surface, 700 . types of, 700 Time lag, 153 ' Tobacco smoke, 68 - - Ton of refrigeration, 469, 844 Ton-day of refrigeration, 844 Total heat, 844 Total pressure, 844 Towers, cooling, 476, 513, 532, 533 Traps, . with steam heating systems, 803 types of, 303 Tube, Bourdon, 824 Pitot, 827 shell and tube heat exchanger, 477 Tuberculosis, 81, 625 Tubing, copper or brass, 371 Tunnels, for steam pipe, 786 Turbines, with unit heaters, 440 Two-pipe steam heating systems, Steam Heating Systems) Two position controls, 702 . Typhosus, 50 ' . - , ' .* (see ' also . - U Ultra-violet light, 73, 82 : Underfeed distribution system, 844 - Underfeed stoker, 844 . - Underground piping, 783 . Underwriters' loop, 322 Unit air conditioners, 431; 448, 844 - Unit coolers, 431, 445 ' .. ' Unit equipment, 431 . - Unit heaters, 433, 759, 844 ' Unit ventilators, 431, 441, 844 . . Unwin pressure drop formula, 782 Up-feed piping systems, 845, (see also Steam Heating Systems) ' - V Vacuum gage, 824 " ' ' ; ., Vacuum pumps, 293 . ' . ",; Vacuum refrigeration, 471. : . ' control of, 717 ' . Vacuum system of steam heating, (see also . Steam Heating .Systerns) , ...................... Valve, valves, 376 . r- apparatus which operates, 699 on boilers, 264, -321 - - -- ............. connections for, 786 .. . control, 326 , with steam heating systems,- 326, 876 with high pressure steam, 323 . . pressure-reducing, 324, 786 . .. ratings of, 323 ' -for radiators, 384 . . . relief, 356 '- roughing-in dimensions, 379 ' - - solenoid, 701 '. . . . ` sub-atmospheric system, 295. types of, 376 . .- ' for water supply, 804 . . . Velocity, 845 '. air, : . - - . , in ducts of buildings,'407, 687, 597 .' in exhaust systems, 653, '660 chimney gas, 193 ' ' draft loss, 198 ; . : contours, 655 . - in ducts, 407, 653, 660, 827 of fans, 557 :" head, of fluids, 581 ' -. . XXlll Heating Ventilating Air Conditioning Guide 1939 Velocity (continued) ' through heating units, 610 measurement of, 827 through openings, 714 through towers,. 632 sound effect of, 697 meter, 829 steam, through an orifice, 823 in underground pipes, 781 water, in pipes, 342, 344, 346 wind, - choosing, 124 measurement of, 694 . on natural draft equipment, 533 in natural ventilation, 687 Vent, vents, on traps, 303 in unit ventilators, 443 . Ventilation, 49, 687, 845, (see also Air Dis tribution) of barns, 695 in drying, 679 of garages, 696 in hospitals, 616, 620 mechanical, 75 with roof ventilators, 689 ' natural, 75 air changes per .hour, 125 -- control of, 691 general rules for, 693 . heat to be removed by, 692 openings location of, 691 skylights, 689 types of, 689 windows, 689 for public buildings, 68 quantity of air necessary for, 68 railway air conditioning, 627 . by registers, 691 for schools, 69 ` by stacks. 688, 691 symbols, 851 Ventilator, ventilators, - .roof, 689, 843 .. t unit, 241, (see also Unit Ventilators) Venturi chimney, 186 < Vibration of..machine.mountings, 605 . Vitiation of air, 49 Volume, of air and saturated vapor, 12 - conversion equations, 848 furnace, 839 specific; 3 of saturated steam, 28 of water, 27 W-Z Wall, walls. absorption of heat, 153 '' air leakage through, 120 of chimneys, 201 condensation on, .139 ' fire, 658 heat transmission coefficients for, 87, 88, 95, 102, 104, 106 radiators, output, 270 solar radiation on, 150, 151 time lag through, 153 ' Warm air heating systems, 846. . gas-fired furnaces for, 226 gravity, 383 mechanical, 399 Washers, air, 409, 517, 642, .835 Water, . boiling point of, 27 from city mains, 476, 526 . cooling, equipment, 625. ' quantity, 527 . . temperature, 624, 526 Water (continued) hot, domestic supply, 799, 813 boilers. 815 demand for, 819 electric heating of, 763 pipe sizes for, 814 - storage of, 814, 818 . heating systems, 337, (see also Hot Water Heating Systems) inches of, 841 line, in boilers, 264, 265, 281 in water supply systems, 806 - make-up, 534 meters, disc, 805 pans; for humidification, 409 pipe, 803 press' *res, 27 . probable usage, 801, 820 . properties of, 27 .. as a refrigerant, 39, 41 - replacement of, 634 supply piping, 799 down-feed systems, 802 mains, 806 . up-feed systems, 804 temperature, maximum-main, 526 from wells, 524 ' . thermal properties of, 27 vapor, 5, 10, 12 . given off in combustion of gas, 181 heat content, 12, 23 mean specific heat-of, 3 weight of saturated, 12 ' Weatherstripping, 124 Weight, of air, 6 . conversion equations, 848 of steam, 28 of vapor, 12 of water, 27 Welding, 361, 372 .. neck flanges, 377, 878 Well water refrigeration control of,*:718 . Well water temperature, 524 . Wet-bulb temperature, (see Temperature, Wet- bulb) . Wet return, 846 . Wind, in cities, 136, 146 - effect on heating requirements, 135 forces in natural ventilation, 119, 687 - prevailing, direction-of,. 125, 146 records of velocity and direction, 136, 148 velocity on natural draft equipment, 533 average, 125, 135, 146, 687 . . equivalent, in tall buildings, 126 used in calculations, 125 . , . Window, windows,' " air leakage through, 122, 124 : . ' clearance of sash,. 123 coefficients of transmission of, 115 comparison of various shades for, .154 '. crack. 122 measurement of, 122 - solar radiation through, 153 ' storm sash, 123 Winter, comfort zone, 61, 62 '. conditioning, apparatus for, 399, 415 . cooling in, 145 humidification in, 61, 66, 409 inside temperature, 132 . relative humidity in, 66 temperatures, 136 wind velocities and directions, 136 Zero, absolute, 835 -- Zone, zoning, for air conditioning systems, 415 automatic control, 704 .' comfort, 61, 62, 64, 837 control of steam heating systems, 298 water supply systems, 799 < ' XXIV Chapter 1 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 Enthalpy, Psychrometric Chart, Properties of Water, Properties of Steam 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, O2 20.75, water vapor 1.2, A 0.93, CO2 0.03 and H2 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 and pi, pi, pi, etc. = the pressure of the gases or vapors corresponding to the observed temperature, then p - Pi + Pt + P*. 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 xInternational Critical Tables. Heating Ventilating Air Conditioning Guide 1939 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 drybulb 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 clean water and whirled through the air until the thermometer assumes a steady temperature. According to the theory of W. H. Carrier8, 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 evaporating moisture from the bulb. The rate at which heat is transferred from the air to the water is substantially proportional to the wet-bulb depression (t -- l'), while the rate of heat utilization in evaporation is proportional 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 (' -- e). Carrier's equation for this dynamic equilibrium is: e'~e = B~ t - t< 2800 - 1.31' (2a) y> In the form commonly used, ,_ _ (B - ') (t - t<) 2800 - 1.31' where e -- 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. (2b) The derivation of Equation 2a was based upon the theory, supported by extensive experiments with atmospheric air, that the wet-bulb tem perature and the temperature of adiabatic saturation (see page 11) are1 identical. Subsequent study and experiment3.4.6 have shown that these temperatures are very nearly the same for air and water-vapor mixtures in the proportions and temperature range of normal atmospheric air, but that they differ widely for mixtures of dry air and vapors other than water, and for air-water mixtures at high temperature or vapor content. It is now recognized that the wet-bulb temperature is influenced, not Rational Psychrometric Formulae, by W. H. Carrier (A.S.W.E. Transactions, Vol. 33, 1911, p. 1005). The Evaporation of a Liquid into a Gas--a Correction, by W. K. Lewis (Mechanical Engineering, . September, 1933). . 4The Theory of the Psychrometer, by J. H. Arnold {Physics, July. September, 1933). . *The'Deviation of the Actual Wet-Bulb Temperature from the Temperature of Adiabatic Saturation., by David Dropkin (Cornell University Engineering Experiment Station Bulletin, No. 23, July. 1936)'. ' v 2 Chapter 1. Air. Water and Steam only by the rate of heat transfer by convection from air to wet-bulb, but also by the rate of heat conduction through the thin film of stagnant air that clings to the wet-bulb, and by the rates of outward diffusion of vapor through the air film and of convection of vapor away from the film. Thus, there is no theoretical foundation for the equality of wet-bulb and adia batic-saturation temperatures; rather, it is by mere chance that in atmos pheric air the ratio of the heat transfer and vapor transfer coefficients is such as to make these temperatures substantially equal. In accordance with current air conditioning practice, they are assumed to be equal in the psychrometric equations and chart presented in the 1939 Guide. Formula 2b may be used to determine the actual partial pressure of the water vapor 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 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. 3 / Heating Ventilating Air Conditioning Guide 1939 Temperature Dbq F Table 1. Properties of Dry AiRa Barometric Pressure 29.921 In. of Hg. Weight Pounds per Cu Ft Ratio or Volume to Volume at 70 F Btu Absorbed bt One Cu Ft Dbt Am peb Deg F Cu Ft Det Aib Warmed One Deg peb 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 0.08449 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 1 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. ' . 4 B t r ^ g r t T r -1 Chapter 1. Air, Water and Steam Table 2. Properties of Saturated Air . Weights of Air, Vapor and Saturated Mixture of Air and Vapor at 29.921 In. ol He. Temp Deg F Weiqht in a Cubic Foot op Mixture Wright of Dry Air Pounds Weight of Vapor Pounds Tota) Weight of Mixture Pounds Btu Absorbed bt One Cubic Foot Sat. Am peb Dbg F Cubic Feet Sat. Air Warmed One Deq per Btu Specific Heat Btu per Pound or Mixture 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 212 0.08622 0.08431 0.08244 0.08060 0.07876 0.07692 0.07503 0.07307 0.07099 0.06877 0.06634 0.06361 0.06057 O.OS712 0.05317 0.04863 0.04339 0.03733 0.03033 0.02228 0.01298 0.00230 0.00000 0.000068 0.000111 0.000177 0.000278 0.000409 0.000587 0.000828 0.001151 0.001578 0.002134 0.002851 0.003762 0.004912 0.006344 0.008116 0.010284 0.012919 0.016092 0.019888 0.024384 0.029700 0.035932 0.037286 0.08629 0.08442 0.08262 0.08088 0.07917 0.07751 0.07586 0.07422 0.07257 0.07090 0.06919 0.06737 0.06548 0.06346 0.06129 0.05891 0.05631 0.05342 0.05022 0.04666 0.04268 0.03616 0.03729 0.02078 0.02031 0.01987 0.01946 0.01908 0.01872 0.01838 0.01805 0.01775 0.01747 0.01721 0.01696 0.01675 0.01657 0.01642 0.01630 0.01624 0.01621 0.01624 0.01633 0.01649 0.01672 0.01818 48.12 49.24 50.33 51.39 52.41 53.42 54.41 55.40 56.34 57.24 58.11 58.96 59.70 60.35 60.91 61.35 61.58 61.69 61.58 61.24 60.64 59.81 55.01 `Compiled by W. H. Severns. based on the instantaneous specific heats of air. 0.2408 0.2406 0.2405 0.2406 0.2410 0.2415 0.2423 0.2432 0.2446 0.2464 0.2487 0.2517 0.2558 0.2611 0.2679 0.2767 0.2884 0.3034 0.3234 0.3500 0.3864 0.4624 0.4875 Table 3. Specific Heats of Dry Air* Constant Barometric Pressure of 29.921 In. of Hg. Temperature Deo F -301.0. -108.4 32.0 212.0 392.0 752.0 1112.0 Instantaneous or True Specific Heat 0.2520 0.2430 0.2399 0.2403 0.2413 0.2430 0.2470 Temperature Range Deo F 32 to 212 32 to 392 32 to 752 32 to 1112 .... ....... Mean Specific Heat 0.2401 0.2411 0.2420 0.2430 Compiled by W. H. Severns, based on data given in the International Critical Tables' 5 Heating Ventilating Air Conditioning Guide 1939 Table 4. Weight of Saturated and Partly Saturated Air* Dbt-Bulb Temp Deo F Weight op Saturated Aib fob Visions BiBOTrmic and Htgbomztbic Conditiono--Pounds peb Cubic Foot Barometric Pressure laches of Mercury 29.5 Increase In Weight Per 0.1 in. Rise in Barometer Approx. Average Increase) IN WEIGHT Per Deo Wet-Bulb Depression 30 32 34 36 0.07703 0.07839 0.07671 0.07806 0.07638 0.07772 0.07605 0.07739 0.07974 0.07940 0.07907 0.07873 0.08110 0.08075 0.08041 0.08007 0.08245 0.08210 0.08175 0.08141 0.08381 0.08345 0.08310 0.08274 0.00027 0.00027 0.00027 0.00027 0.000017 0.000017 0.000018 0.000018 38 40 42 44 0.07573 0.07706 0.07541 0.07674 0.07509 0.07641 0.07477 0.07609 0.07840 0.07806 0.07773 0.07740 0.07973 0.07939 0.07905 0.07872 0.08106 0.08072 0.08038 0.08004 0.08239 0.08205 0.08170 0.08135 0.00027 0.00027 0.00026 0.00026 0.000019 000019 1.000020 .000020 46 48 SO 52 0.07445 0.07576 0.07413 0.07544 0.07381 0.07512 0.07350 0.07479 0.07707 0.07674 0.07642 0.07609 0.07838 0.07805 0.07772 0.07739 0.07970 0.07936 0.07902 0.07868 0.08101 0.08066 0.08032 0.07998 0.00026 0.00026 0.00026 0.00026 0.000021 0.000021 0.000022 0.000023 54 56 58 60 0.07318 0.07447 0.07287 0.07415 0.07255 0.07383 0.07224 0.07352 0.07576 0.07544 0.07512 0.07479 0.07706 0.07673 0.07640 0.07607 0.07835 0.07801 0.07768 0.07734 0.07964 0.07930 0.07896 0.07862 0.00026 0.00026 0.00026 0.00026 0.000023 0.000024 0.000025 0.000026 . 62 64 66 68 0.07193 0.07320 0.07161 0.07288 0.07130 0.07256 0.07098 0.07224 0.07447 0.07414 0.07382 0.07350 0.07574 0.07541 0.07508 0.07475 0.Q7701 0.07668 0.07634 0.07601 0.07828 0.07794 0.07760 0.07727 0.00026 0.00026 0.00026 0.00026 0.000027 0.000028 0.000029 0.000030 70 72 74 76 0.07067 0.07192 0.07035 0.07160 0.07004 0.07128 0.06972 0.07096 0.07317 0.07285 0.07252 0.07220 0.07442 0.07410 0.07377 0.07343 0.07568 0.07534 0.07501 0.07467 0.07693 0.07659 0.07625 0.07591 0.00026 0.00025 0.00025 0.00025 0.000031 0.000032 0.000033 0.000034 78 80 82 84 0.06940 0.07064 0.06909 0.07032 0.06877 0.07000 0.06845 0.06967 0.07187 0.07155 0.07122 0.07089 0.07310 0.07277 0.07244 0.07211 0.07434 0.07400 03)7366 0.07333 0.07557 0.07523 0.07489 0.07454 0.00025 0.00025 0.00024 0.00024 0.000036 0.000037. 0.000039 0.000040 86 88 90 92 0.06812 0.06934 0.06780 0.06901 0.06748 03)6868 0.06715 0.06835 0.07056 0.07022 0.06989 0.06955 0.07177 0.07143 0.07109 0.07075 0.07299 0.07264 0.07230 0.07195 0.07420 0.07385 0.07351 0.07316 0.00024 0.00024 0.00024 0.00024 0.000042 0.000043 0.000045 0.000047 94 96 98 100 0.06682 0.06801 0.06648 0.06768 0.06615 0.06734 0.06581 0.06700 0.06921 0.06887 0.06853 0.06818 0.07041 0.07006 0.06972 0.06937 0.07161 0.07126 0.07091 0.07055 0.07280 0.07245 0.07209 0.07174 0.00024 0.00024 0.00024 0.00024 0.000049 0.000051' 0.000053 0.000055 " 1 1 I!! . . Approximate average decrease in weight per 0.1 F rise in dry-bulb temperature equals 0.00001? r cubic foot. 6 Chapter 1. Air, Water and Steam 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, C0, 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. 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 82 F and 29.00 in. barometer is found to be 0.07000 lb per cubic foot. There is a decrease of 0.00017 lb per degree drybulb temperature above 82 F. There is an increase of 0.00024 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 0.000039 lb per degree wet-bulb depression when the dry-bulb is 83 F. Tabu-, lating the items: 0.07000 - weight of saturated air at 82 F and 29.00 bar. -- 0.00017 = decrement for 1 deg dry-bulb, 1 X 0.00017. + 0.00096 = increment for 0.4 in. bar., 4 X 0.00024. + 0.00059 = increment for 15 deg wet-bulb depression, 15 X 0.000039. 0.07138 = Weight in pounds per cubic foot of air at 83 F dry-bulb, 68 F wet-bulb, 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 F, 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 Pt represent the initial and final absolute pressures, and Vi and Fj represent corresponding volumes of the same mass, say one pound of gas, then y = --2, or Pi Vi -- Pi Vt, but since Pi Vi for any given case is a definite constant quantity, it follows that the product of the absolute pressure and volume of a gas is a constant, or PV = 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 Heating Ventilating Air Conditioning Guide 1939 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, Vc, the resulting equation is PT or, for the same temperature range at constant pres "1 1 \ sure, Pc, the relation is V* Vi = h 7Y In general, for any weight of gas, W, since volume is proportional to weight, the relation among P, V,'and T is PV = WRT (3) where P = the absolute pressure of the gas, pounds per square foot. V = the volume of the weight W, cubic feet. ' W = the weight of the gas, pounds. R = a constant depending on the nature of the gas. The average value of R for air is 53.34. T = the absolute temperature, degrees Fahrenheit. 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 per 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 the Properties of Saturated Steam in Table 8 indicates that water vapor, either saturated or superheated, at partial pressures lower than 4 in. of mercury may be treated as a gas with a gas constant R of 1.21 (with partial pressure of vapor expressed in inches of Hg.) in the characteristic equation of the gas p V = wR (l -f- 460). Within such limits, the density (d) of water vapor is d = ~ = 1 21 (/+ 460) (Pounds per cubic foot) (4a) = (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 8 Chapter 1. Air, Water and Steam be made unity, we have an expression of 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 W, is ' i \y - = ------------ 1------- --- -i. _______ --- 1.21 (f -f 460) 0.753 (1 + 460) = 0.622 (gb) (pounds) (5a) = 4354 (jfe) (grains) (5b) where . . e = actual partial pressure of vapor,, inches of mercury. B = total pressure of mixture (barometric pressure), inches of mercury. Relative Humidity Relative humidity (<b) 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 ~ = 0.622 -) -H 0.622 (-^~) = S-v- Wt \B -- et) \B-etf B -- 4> et (7) The specific humidity of an unsaturated air-vapor mixture cannot, therefore, be accurately found by multiplying the specific humidity of saturated air 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 9 Heating Ventilating Air Conditioning Guide 1939 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 eor 50 Per Cent Relative Humidity Dry-bulb temperature.---------------------------- 65.0 70.0 75.0 80.0 85.0 90.0 Dew-point temperature. .......................... 45.8 50.5 55.25 59.75 64.25 68.75 Difference between dew-point and drybulb temperature... ....... ......... ............... 19.2 19.5 19.75 20.25 20.75 21.25 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 <i = 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, d%, 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 pet cent (4> = 0.4) when the outside air is at 0 F and 70 per cent 10 Chapter 1. Am. Water and Steam relative humidity (<I> = 0.7) and a barometric pressure, B, of 29.92 in. of mercury. Find othfethweehiguhmt oidfiwfieadtearivr.apor added to each pound of dry air and the dew-point temperature Solution. From Equation 5a and Table 6, W, = 0.622 ( ^ 0 oliii~) " 0.000548 lb per pound of dry air. Wt = 0.622 " 0.00618 lb per pound of dry air. insTpehcetiwonatoefr Tvaapboler 6a,ddWedt p~er0.p0o0u6n1d8 oaftd4r4y.5aFir,msoustht ibseis{IFth,e--deWw-i)pooirn0t.t0e0m56p3e2ralbtu:reBoyf the humidified air. An approximation of the same result from Table 6 is W\ = 0.7 X 0.0007852 = 0.00054964 lb per pound of dry air. Wt = 0.4 X 0.01574 -- 0.006296 lb per pound of dry air. 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 3 dry-bulb temperature of 84 F, a wet-bulb of 70 F, or a relative humidity of 50 per cent (<J> = 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, Wt = 0.622 ~ 0.01248 lb per pound of dry air. : . m = -623 () = a0Q887 lb per pound of dry air- Since Wt = Wt when l = 63.4 F, this is the dew-point temperature of the entering air. The weight of vapor condensed is (Wt -- Wi) or 0,00361 lb per pound of dry air. An approximate result is , Wi = 0.5 X 0.02543 = 0.012715 lb per pound of dry air. 1 Wt -- 1 X 0.008856 = 0.008856 lb per pound of dry air, since the exit air is saturated. Since Wi =* 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. . Since Table 6 was prepared, the new steam tables, Thermodynamic Properties of Steam, by J. H. Keenan and F. G. Keyes, have been pub lished. For the last two years an A.S.H.V.E. Research Technical Advisory Committee on Psychrometry has been formulating standard psychrometric data, on a tentative basis. Included in this Committee's work is a revision of Table 6 to bring it into conformity with the Keenan and Keyes tables. Pending acceptance by the Society of the Committee's report, the tabular data and psychrometric chart published in earlier editions of The Guide have been retained. ADIABATIC SATURATION OF AIR . The process of adiabatic saturation, or evaporative, cooling, is.of con siderable importance in air conditioning. Suppose that unsaturated air be made to pass at a steady rate through a tunnel which is perfectly insulated Heating Ventilating Air Conditioning Guide 1939 12 13 7 Te m p e r a t u r e s * (P a r t I ) Compiled by W. M . Sawdon. vapor pressures converted from International Critical Tables. T a b l e 6. Pr o p e r tie s of Sa t u r a t e d W a t e r V apo r w it h A ir a t L ow T e m p e r a t u r e s * (P a r t I, C o n t in u e d ) 'Compiled by W. M . Sawdon, vapor pressures converted from Jnlernatianal Critical Tables. Chapter I. Air, Water and Steam t\ ] i! Heating Ventilating Air Conditioning Guide 1939 I LT a b l e 6. P r o p e r t ie s o f Sa t u r a t e d W a t e r V a p o r w it h A ir a t ow T e m p e r a t u r e s * ( P a r t I . C o n t in u e d ) Complied by W . M . Sawdon. vapor pressures converted from International Critical Tobies. 14 15 Chapter 1. Air. Water and Steam Heating Ventilating Air Conditioning Guide 1939 16 17 " I I )T a b l e 6. P r o p e r t ie s of Sa t u r a t e d W a t e r V a p o r w it h A ir , 0 F to 200 F (P a r t converted from International Critical Tables. Ion, vapor pressures converted from International Critical Tables. Chapter 1. Air, Water and Steam Heating Ventilating Air Conditioning Guide 1939 18 19 T a b l e 6. P r o p e r t ie s o f Sa t u r a t e d W a t e r V a p o r w it h A ir , 0 F to 200 F (P a r t II, C o n t in u e d ) Compiled by W . M . Sawdon, vapor pressures converted from International Critical Tables. T a b l e 6. P r o p e r t ie s o f Sa t u r a t e d W a t e r V apo r w it h A ir , 0 F to 200 Fa (P a r t II, C o n t in u e d ) " Compiled by W. M . Sawdon, vapor pressures converted from International Critical Tables. Chapter I. Air. Water and Steam Heating Ventilating Air Conditioning Guide 1939 20 21 P r o p e r t ie s of Sa t u r a t e d W a t e r V a p o r w it h A ir , 0 F to 200 F (P a r t I I , " Compiled by W . M . Sawdon, vapor pressures converted from International Critical Tables. Chapter 1. Air. Water and Steam Heating Ventilating Air Conditioning Guide 1939 against heat transfer to or from its surroundings, and which contains an exposed water surface. Alternatively, let the air pass through an insulated air washer whose spray water is recirculated continuously without being heated or cooled externally. In either case, when the apparatus has reached equilibrium temperatures throughout, the water will have at tained a temperature (the temperature of adiabatic saturation) closely approximating the initial wet-bulb temperature of the air, and the air will have become saturated at the temperature of the water (or will have approached saturation at that temperature as a limit, the degree of saturation depending on the time and efficiency of contact of air and water). Example U. 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. The energy for evaporating moisture into the air comes only from the air and its initially superheated vapor, which led Carrier to formulate the following energy equation for adiabatic saturation: h'fs {Wt< -- HO = (1 -- (') + cPaW (t - t<) (9) and using Cpg = 0.24 and cPs - 0.45 ft'fg (Wt. - HO = (0.24 + 0.45H0 (t - 1') (9) where . A'fg = latent heat of vaporization at 1', Btu per pound. (Wt> ~ 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, t', or W, the third may be found from this equation for any process of adiabatic saturation. TOTAL HEAT AND ENTHALPY The total heat of a mixture of dry air and water vapor was originallydefined by W. H. Carrier as: S = Cpa (t -- 0) + W [A'tg + cPg (t - t')l (10) where 2 = total heat of the mixture, Btu per pound of dry air. Cpa = mean specific heat at constant pressure of dry air. cPs = 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. A'fg = latent heat of vaporization at t\ Btu per pound. .-. Since this definition holds for any mixture of dry air and water vapor, 22 Chapter 1. Air. Water and Steam 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: S' = Cpa (<* ~ 0) + Wf 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 approximately constant wet-bulb tempera ture is also approximately 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. Enthalpy - This total heal of an air-vapor mixture is not equal to the enthalpy of the mixture, since the enthalpy of the liquid is not included in Equation 10. With the meaning of enthalpy in agreement with present practice in other branches of thermodynamics, the true enthalpy 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: where A = cPn (` ~ ) + W b* = 24 (I - 0) + W As A = the enthalpy 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. As = the enthalpy of the vapor in the mixture, Btu per pound. (12) The enthalpy 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 enthalpy of steam at low partial pressures, whether superheated or saturated, depends only upon tempera ture, the following empirical equation may be used: As = 1059.2 + 0.45 t (13) Substituting this value of K in Equation 12, the enthalpy of the mixture is: A = 0.24 -- 0) + W (1059.2 + 0.451) (14) , Find theenthalpy of an air-vapor mixture having a dry-bulb temperature oi tso f and a wet-bulb^temperature of 70 F and a barometric pressure of 29.0 in. Hg. Solution. From Equation 2b and Table 6,' 0.7387 - (29.0 - 0,7387) (85 - 70) 2800 - (1.3 X 70) = 0.05822. From Equation 5a, W = 0.622 - 0.5822 '29.0 - 0.5822 = 0.01274. From Equation 14, A = (0.24 X 85) + [0.01274 (1059.2 + 0.45 X 85)1 = 34.38 Btu per pound dry air. Heating Ventilating Air Conditioning Guide 1939 Since the enthalpy is nearly constant along a wet-bulb temperature line in any air-water vapor mixture, it may be found, approximately, when the wet-bulb temperature is known by using the temperature in Table 6 as wet-bulb temperatures and reading the corresponding enthalpy from the last column, provided the barometric pressure is 29.92 in Hg. ENERGY EQUATION 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: W3 lb. Water Vapor 1 lb. Dry Air Fig. 1. Diagram Illustrating Energy Equation 15 The rectangle may represent any apparatus, e.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, h. 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, hi -f- -[-, (PF* -- Wi) h% =* ha 4- Rc or Eh - Rc = h, - hi - (PF, - Wi) h, (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. . W> = the weight of water vapor leaving, per pound of dry air. hi = the enthalpy of the water supplied at h, Btu per pound. . .... Jt, -- hi = the increase in the enthalpy of the air-water vapor mixture in passing through the apparatus, Btu per pound of dry air = 0.24 (f, - <0 + PF, (1059.2 + 0.45 h) - W, (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. .' 24 Chapter I. Air. Water and Steam For example, in Fig. I, an approximate result is: Eh - Rc = 2. -- 2, (16) From the definitions of total heat and enthalpy, it may be demon strated that Equation 16 is exactly equivalent to Equation 15, when, and only when, t's -- t\ = 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. Healing (data from Example 2). Assuming the water to be supplied at 50 F, the net quantity of heat supplied is, from Equation 15, From Equation 15, Eh - -Rc = hi - hi - (PF, - Wi) (50 - 32) h, = (0.24 X 70) + [0.00618 (1059.2 + 0.45 X 70)] = 23.54 Btu per pound leaving dry air hi = (0.24 X 0) 4- [0.000548 (1059.2 + 0.45 X 0)] = 0.58 Btu per pound entering dry air h - Rc = 23.54 - 0.58 - [0.005632 (50 - 32)J = 22.86 Btu per pound dry air, net heat supplied 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, From Equation 15, Eh + Rc = hi - h, - (PF, - Wi) (54 - 32) h = (0.24 X 84) + [0.01248 (1059.2 + 0.45 X 84)] = 33.85 Btu per pound entering dry air h3 = (0.24 X 54) + [0.00887 (1059.2 + 0.45 X 54)] = 22.57 Btu per pound leaving dry air Eh + Rc = 33.85 - 22.57 - [(0.00361 (54 - 32)] = 11.20 Btu per pound dry air, net heat removed Using Table 6, the initial enthalpy of the air-vapor mixture, since the wet-bulb temperature is 70 F, is 33.96 Btu per pound of dry air. The final enthalpy 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. PSYCHROMETRIC CHART Many types of charts which give graphical solutions of the psychrometric equations and other useful data have been devised. One of these, the revised Bulkeley Psychrometric Chart6, will be found attached to the inside back cover. It shows graphically the relationship 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: " a1t9fc0s^%A2S5H V E' 25 s Heating Ventilating Air Conditioning Guide 1939 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. Enthalpy of the liquid is not included. B is the grains of moisture or water vapor accompanying each pound of dry air and is to be referred to the figures at the left side of the chart. C is the grains of moisture or 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. 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. Fig. 2. Diagrams Showing Procedure to Follow in Using Buleelev Chart 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 4E6xapmerpclee9n.t. 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 l9.4 millimeters of mercury. (Divide by 25.E4xtaomr pinlech1e1s.). Total Heat 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 26 Chapter 1. Air, Water and Steam 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 taking the difference in total heat before and after treatment of the mixture. Example 12. 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 18. Grains of Moisture per Cubic Foot of Mixture, Partially Saturated: From 70.9 F dew-point temperature on the saturation fine 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* Fequals 555, absolute temperature. Therefore, 5-g30gj9r X 8.33 = 7.97 grains per cubic foot of partially saturated mixture. Example 14. 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 as 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 Fool 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, = 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. 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 8 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). Water Pressures. Pressures are often stated in feet or inches of water column. At 62 F, with h equal to the head in feet, the pressure of a column of water is 62.383/t lb per square foot, or 0.433k 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. 27 'I Heating Ventilating Air Conditioning Guide 1939 Boiling Point of Water. The boiling point of water varies with the pressure; it is lower at higher altitudes. A change in pressure will always be accompanied by a change in the boiling point, and there will be a cor 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 Table 7. Thermal Properties of Water Temperature Deo F 32 40 50 60 70 80 90 100 110 120 130 140. ISO 160 170 180 190 200 210 212 220 240 260 280 300 350 400 450 500 550 600 700 Sat. Press. Lb feb Sq In. 0.0887 0.1217 0.1780 0.2561 0.3628 0.5067 0.6980 0.9487 1.274 1.692 2.221 2.887 3.716 4.739 5.990 7.510 9.336 11.525 14.123 14.696 17.188 24.97 35.43 49.20 67.01 134.62 247.25 422.61 681.09 1045.4 1544.6 3096.4 Volume Co Ft feb 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 per Co 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 0.9982 0.9975 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 - 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 of the.liquid or sensible hedti When more heat is added, the water begins to evaporate and expand at constant temperature until the water, is entirely changed into steam. The heat thus added is known as the latent heat of evapotation. :. 28 Chapter 1. Air, Water and Steam I Table 8. Properties of Saturated Steam: Pressure Table* Abs. Press In. He P 0.25 0.50 0.75 1.00 1.5 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Tem p F t 40.2,3 58.8() 70.4:3 79.0C3 91.7S 101.14 125.43 140.78 152.24 161.49 169.28 176.05 152.05 187.45 192.37 196.90 201.09 205.00 208.67 212.13 Specific Volume ----------------------------------- Sat. Liquid Vf Sat. Vapor V* 0.01602 0.01604 0.01606 0.01608 0.01611 2423.7 1256.4 856.1 652.3 444.9 0.01614 0.01622 0.01630 0.01635 0.01640 339.2 176.7 120.72 92.16 74.76 0.01644 0.01648 0.01652 0:01655 0.01658 63.03 54.55 48.14 43.11 39.07 0.01661 0.01664 0.01667 0.01669 0.01672 35.73 32.94 30.56 28.52 26.74 Enthalpy Entropy Sat. Liquid hf Ey*p hfg ' Sat. Vapo r kg Sat. Liqui Sf r S 8.2J3 26.8<B 38.4 7 47.0 5 69.7 1 1071. 1060. 1054. 1049.: 1042.( 1079.l 1087. 5 1092. > I096.C uoi.- 0.0161B 0.053 2 0.0751 0.091 i 0.114 7 2.142 3 2.045 3 1.988 I 1.947,1 1.889'I 2.158 7 2.09&5 2.063,> 2.038'7 2.004 69.1() 1036.(3 93.34 1022.7 108.6" 1013.C 120.1C 1006.S 129.3f 1001.4 1105.7 1116.0 1122.3 1127.0 1130.S 0.131(> 0.173J 0.1996 0.2186 0.2335 1.848 1.7476 1.6881 1.6454 1.6121 1.979' 1.9214 1.8877 1.8640 1.8456 137.18 143.96 149.98 155.39 160,33 996.7 992.6 988.9 985.7 982.7 1133.9 1136.6 1138.9 1141.1 1143.0 0.2460 0.2568 0.2662 0.2746 0.2822 1.5847 1.5613 1.5410 1.5231 1.5069 1.8307 1.8181 1.8072 1.7977 1.7891 164.87 169.09 173.02 176.72 180.19 979.8 977.2 974.8 972.5 970.3 1144.7 1146.3 1147.8 1149.2 1150.5 0.2891 0.2955 0.3014 0.3069 0.3122 1.4923 1.4789 1-4665 1.4550 1.4442 1.7814 1.7744 1.7079 1.7619 1.7564 Press. In. He. P 0.25 0.50 0.75 1.00 1.5 2.0 4.0 6 8 10 12 14 16 18 20 22 24 26 28 30 . Sq In. _Lb 14.696 16 18 20 22 24 26 28 212.00 216.32 222.41 227.96 233.07 237.82 242.25 246.41 0.01672 0.01674 0.01679 0.01683 0.01687 0.01691 0.01694 0.01698 30 250.33 0.01701 32 254.05 0.01704 34 257.58 0.01707 36 260.95 0.02709 38 264.16 0.01712 40 267.25 0.01715 42 270.21 0.01717 44 46 48 273.05 275.80 278.45 0.01720 0.01722 0.01725 50 281.01 0.01727 52 54 56 58 283.49 285.90 288.23 290.50 0.01729 0.01731 0.01733 0.01736 60 62 64 66 292.71 294.85 296.94 298.99 0.01738 0.01740 0.01742 0.01744 . 68 300.98 0.01746 70 72 74 76 78 302.92 304.83 306.68 . 308.50 310.29 0.01748 0.01750 0.01752 0.01754 0.01755 80 82 84 86 88 312.03 313.74 315.42 , 317.07 ; 28.68 0.01757 0.01759 0.01761 0.01762 0.01764 90 j 20.27 '2 3 21.83 94 96 ' 3 3 23.36 24.87 98 3 26.35 0.01766 0.01768 0.01769 0.01771 0.01772 26.80 ~ 24.75 22.17 20.089 18.375 16.938 15.715 14.663 180.07 184.42 190.56 196.16 201,33 206.14 210.62 214.83 970.3 967.6 963.6 960.1 956.8 953.7 950.7 947.9 1150.4 1152.0 1154.2 1150.3 1158.1 1159.8 1161.3 1162.7 0.3120 0.3184 0.3275 0.3356 0.3431 0.3500 0.3564 0.3Q23 1.4446 1.4313 1.4128 1.3962 1.3811 1.3672 1.3544 1.3425 1.7566 1.7497 1.7403 1.7319 1.7242 1.7172 1.7108 2.7048 13.746 12.940 12.228 11.588 11-015 218.82 222.59 226.18 229.60 232.89 945.3 942.8 940.3 938.0 935.8 1164.1 1165.4 1106.5 1167.6 1168.7 0.3680 0.3733 0.3783 0.3831 0.3876 1.3313 1.6993 1.3209 1.6941 1.3110 1.6893 1.3017 1.6848 1.2929 .1.6805 10.498 10.029 9.601 9.209 8.848 236.03 239.04 241.95 244.75 247.47 933.7 931.6 929.6 927.7 925.8 1169.7 1170.7 1171.6 1172.4 1173.3 0.3919 0.3960 0.4000 0.4038 0.4075 1.2844 1.2764 1.2687 1.2613 1.2542 1.6763 1.6724 1.6687 1.6652 1.6617 8.515 8.208 7.922 7.656 7.407 250.09 252.63 255.09 257.50 259.82 924.0 922.2 920.5 918.8 917.1 1174.1 .1174.8 1175.6 1176.3 1176.9 0.4110 0.4144 0.4177 0.4209 0.4240 1.2474 1.2409 1.2346 1.2285 1.2226 1.6585 1.6553 1.6523 1.6494 1.6466 7.175 6.957 6.752 6.560 6.378 262.09 264.30 266.45 268.55 270.60 915.5 913.9 912.3 910.8 909.4 1177.0 1178.2 1178.8 1179.4 1180.0 0.4270 0.4300 0.4328 0.4356 0.4383 1.2168 1.2112 1.2059 1.2006 1.1955 1.6438 1.6412 1.6387 1.6362 1.6338 6.206 6.044 5.890 5.743 5.604 272.61 274.57 276.49 278.37 .280.21 907.9 906.5 905.1 903.7 ' 902.4 1180.6 0.4409 1181.1 0.4435 1181.6 0.4460 1182.1 ( 7.4484 1182.6 ( J.4508 1.1906 1.1857 1.1810 1.1764 1.1720 1.6315 1.6292 1.6270 1.6248 1.6228 5.472 5.346 5.226 5.111 5.001 5 82.02 83.79' 5.53 27.24 28.91 901.1 I183ll 899.7 . 183.5 898.5 184.0 897.2 184.4 895.9 .] 184.8 (>.4531 C .4554 C .4576 C .4598 C .4620 .1676 .1633 .1592 1 .1551 1 .1510 1.6207 .6187 .6168 .6149 1 .6130 4.896 4.796 4.699 4.606 4.517 290.56 292.18 293.78 296.34 296.89 894.7 893.5 892.3 891.1 889.9 I 185.3 1 185.7 186.1 186.4 186.8 0 .4641 0 .4661 0 .4682 0 .4702 0.4721 1 .1471 1 .1433 .1394 1 .1358 1 .1322 1 .6112 1 .6094 1 .6076 1 .6060 1 .6043 Sq In. 14.696 16 18 20 22 24 26 28 30 32 34 36 38 40 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 , ' published by fohn^yTndfSn3,7n"mrfy"'`m'C P,0P'rti" <* Steam. by J. H. Keeaan and F. G . Keyes, ' 29 Heating Ventilating Air Conditioning Guide 1939 Table 8. Properties of Saturated Steam: Pressure Table3 (Continued) Abs. Press. Lb Sq In. P 100 102 104 106 108 110 112 114 116 ,118 120 122 124 126 128 130 132 134 136 138 140 142 144 146 148 150 152 154 156 158 160 . 162 164 166 168 170 172 174 176 178 180 182 184 186 188 190 192 194 196 198 200 205 210 215 220 225 230 235 240 245 Temp F t 327.81 329.25 330.66 332.05 333.42 334.77 336.11 337.42 338.72 339.99 341.25 342.50 343.72 344.94 346.13 347.32 348.48 349.64 350.78 351.91 353.02 354.12 355.21 356.29 357.36 358.42 359.46 360.49 361.52 362.52 363.53 364.53 365.51 366.48 367.45 368.41 369.35 370.29 371.22 372.14 373.06 373.96 374.86 375.75 376.64 377.51 378.38 379.24 380.10 380.95 381.79 383.86 385.90 387.89 389.86 391.79 393.68 395.54 397.37 399.18 Specific Volume Sat. Liquid Vf 0.01774 0.01775 0.01777 0.01778 0.01780 0.01782 0.01783 0.01784 0.01786 0.01787 0.01789 0.01791 0.01792 0.01793 0.01794 0.01796 0.01797 0.01799 0.01800 0.01801 0.01802 0.01804 0.01805 0.01806 0.01808 0.01809 0.01810 0.01812 0.01813 0.01814 0.01815 0.01817 0.01818 0.01819 0.01820 0.01822 0.01823 0.01824 0.01825 0.01826 0.01827 0.01829 0.01830 0.01831 0.01832 0.01833 0.01834 0.01835 0.01836 0.01838 0.01839 0.01842 0.01844 0.01847 0.01850 0.01852 0.01854 0.01857 0.01860 0.01863 Sat. Vapor V, 4.432 4.350 4.271 4.194 4.120 4.049 3.981 3.914 3.850 3.788 3.728 3.670 3.614 3.560 3.507 3.455 3.405 3.357 3.310 3.264 3.220 3.177 3.134 3.094 3.054 3.015 2.977 2.940 2.904 2.869 2.834 2.801 2.768 2.736 2.705 2.675 2.645 2.616 2.587 2.559 2.532 2.505 2.479 2.454 2.429 2.404 2.380 2.356 2.333 2.310 2.288 2.234 2.183 2.134 2.087 2.0422 1.9992 1.9579 1.9183 1.8803 Enthalpy Entropy Sat. Liquid hf Evap. hfg SaL Vapor hg Sat. Liquid St Evap. Sfg SatVapor Abs. Press. Lb Sq In. P 298.40 299.90 301.37 302.82 304.26 888.8 887.6 886.5 885.4 884.3 1187.2 1187.5 1187.9 1188.2 1188.6 0.4740 0.4759 0.4778 0.4796 0.4814 1.1286 1.1251 1.1216 1.1182 1.1149 1.6026 1.6010 1.5994 1.5978 1.5963 100 102 104 106 108 305.66 307.06 308.43 309.79 311.12 883.2 882.1 . 881.1 880.0 879.0 1188.9 1189.2 1189.5 1189.8 1190.1 0.4832 0.4849 0.4866 0.4883 0.4900 1.1117 1.1085 1.1053 1.1022 1.0992 1.5948 1.5934 1.5919 1.5905 1.5891 110 112 114 116 118 312.44 313.75 315.04 316.31 317.57 877.9 876.9 875.9 874.9 873.9 1190.4 1190.7 1190.9 1191.2 1191.5 0.4916 0.4932 0.4948 0.4964 0.4980 1.0962 1.0933 1.0903 1.0874 1.0845 1.5878 1.5865 1.5851 1.5838 1.5825 120 122 124 126 128 318.81 320.04 321.25 322.45 323.64 872.9 872.0 871.0 870.1 869.1 1191.7 1192.0 1192.2 1192.5 1192.7 0.4995 0.5010 0.5025 0.5040 0.5054 1.0817 1.0790 1.0762 1.0735 1.0709 1.5812 1.5800 1.5787 1.5775 1.5763 130 132 134 136 138 324.82 325.98 327.13 328.27 329.39 868.2 867.2 866.3 865.3 864.5 1193.0 1193.2 1193.4 1193.6 1193.9 0.5069 0.5083 0.5097 0.5111 0.5124 1.0682 1.0657 1.0631 1.0605 1.0580 1.5751 1.5740 1.5728 1.5716 1.5705 140 142 144 146 148 330.51 331.61 332.70 333.79 334.86 863.6 862.7 861.8 860.9 860.0 1194.1 1194.3 1194.5 1194.7 1194.9 0.5138 0.5151 0.5165 0.5178 0.5191 0.0556 1.0532 1.0507 1.0483 1.0459 1.5694 1.5683 1.5672 1.5661 1.5650 150 152 154 156 158 335.93 336.98 338.02 339.05 340.07 859.2 858.3 857.5 856.6 855.7 1195.1 1195.3 1195.5 1195.7 1195.8 0.5204 0.5216 0.5229 0.5241 0,5254 1.0436 1.0414 1.0391 1.0369 1.0346 1.5640 1.5630 1.5620 1.5610 1.5600 160 162 164 166 168 341.09 342.10 343.10 344.09 345.06 854.9 854.1 853.3 852.4 851.6 1196.0 1196.2 1196.4 1196.5 1196.7 0.5266 0.5278 0.5290 0.5302 0.5313 1.0324 1.0302 1.0280 1.0259 1.0238 1.5590 1.5580 1.5570 1.5561 1.5551 170 172 174 176 178 ; 346.03 347.00 347.96 348.92 349.86 850.8 850.0 849.2 .848.4 847.6 1196.9 1197.0 1197.2 1197.3 1197.5 0.5325 0.5336 0.5348 0.5359 0.5370 1.0217 1.0196 1.0175 1.0155 .1.0136 1.5542 1.5532 1.5523 1.5514 1.5506 180 182 184 186 188 350.79 351.72 352.64 353.55 354.46 846.8 846.1 845.3 844.5 843.7 1197.6 1197.8 1197.9 1198.1 119812 0.5381 0.5392 0.5403 0.5414 0.5425 1.0116 1.0096 1.0076 1.0056 1.0037 1.5497 1.5488 1.5479 1.5470 1.5462 190 192 194 196 198 355.36 357.58 359.77 361.91 364.02 843.0 841.1 839.2 837.4 835.6 366.09 368.13 370.14 372.12 374.08 833.8 832.0 830.3 828.5 826.8 1198.4 1198.7 1199.0 1199.3 1199.6 0.5435 0.5461 0.5487 0.5512 0.5537 1.0018 0.9971 0.9925 0.9880 0.9835 1.5453 1.5432 1.5412 1.5392 1.5372 , 200 205 210 215 220 1199.9 1200.1 1200.4 1200;6 1200.9 0.5561 0.5585 0.5608 0.5631 0.5653 0.9792 0.9750 0.9708 0.9667 0.9627 1.5353 1.5334 1.5316 1.5298 1.5280 225 230 235 240 245 . *' Reprinted by permission from Thermodynamic Properties of Steam, by J. H. Keenan and F. G. Keyes, . published by John Wiley and Sons, Inc. . ' .' 30 Chapter 1. Air. Water and Steam Tables. __ Abs. Press Lb Sq In P I Tem F t Properties^ Saturated Steam: Pressure Tar, pa (Concluded) juaea; CSpoeucriirf.!i,c- Vol_u__m__e i Enthalpy ;--------------------------------------------------------Entropy Sat. Liquid Vf Sat. Vapor Vg Sat. Liqui hf J*11 Sat Vapor Liquid Evaf Sf Sfg Sat Vapc r Sg Press. Lb Sq In. 250 260 270 280 290 400.9 5 404.4 2 407.7 5 411.0 5 414.2 3 0.01865 0.01870 0.01875 0.01880 0.01885 1.8438 1.7748 1.7107 1.6511 1.5954 376.00 379.7 5 383.4 386.9 S 390.44 825.1 821.8 818.5 815.3 812.1 1201. 1 2201. 5 1201. 9 1202. 5 1202. 0.587 5 0.571 9 0.5760 0.580 0.584 0.9588 0.951 9 0.943 S 0.936. 0.929 1.5263 1.522 9 1.519 6 1.5161 1.513 3 250 260 270 280 290 300 320 340 360 380 417.3,i 423.2<) 428.9' 434.4() 439.6C 0.01890 0.01899 0.01908 0.01917 0.01925 400 420 440 460 480 444.55 449.35 454.02 458.50 462.82 0.0193 0.0194 0.0195 0.0196 0.0197 500 520 540 560 580 467.01 471.07 475.01 478.85 482.58 0.0197 0.0198 0.0199 0.0200 0.0201 600 620 640 660 680 486.21 489.75 493.21 496.58 499.88 0.0201 0.0202 0.0203 U0204 0.0204 700 720 740 760 780 503.10 506.25 509.34 512.36 515.33 0.0205 0.0206 0.0207 0.0207 0.0208 800 820 840 860 880 518.23 521.08 523.88 526.63 529.33 0.0209 0.0209 0.0210 0.0211 0.0212 900 920 940 960 980 531.98 534.59 537.16 539.68 542.17 0.0212 0.0213 0.0214 0.0214 0.0215 1000 1050 1100 1150 1200 544.61 550.57 556.31 561.86 567*22 0.0216 0.0218 0.0220 0.0221 0.0223 1250 1300 1350 1400 1450 572.42 577.46 582.35 587.10 591.73 0.0225 0.0227 0.0229 0.0231 O.0233 . 1500 1600 1700 1800 1900 596.23 304.90 313.15 >21.03 f 28.58 0.0235 0.0239 0.0243 0.0247 0.0252 2200 2400 2600 2800 35.82 6149.46 . e 62.12 6 73.94 6 84.99 0.0257 0.0268 0.0280 0.0295 0.0315 3200 95.36 7 05.11 320(.j 705.40 0.0346 0.0444 0.0503 1.5433 1.4485 1.3645. 1.2895 1.2222 393.8:L 400.3<) 406.6<3 412.6'T 418.45 809.0 803.0 797.1 791.4 785.8 1202.1i 1203. *4 1203/r 1204J 1204.3 0.587 0.595. 0.602. 0.609< 0.6153 0,922. 0.9094 0.8971 0.8851 0.8733 1.5161 1.50411 1.499.i 1.4941 1.4891 300 320 340 360 380 1.1613 1.1061 1.0556 10094 0.9670 424.0 429.4 434.6 439.7 444.6 780.5 775.2 770.0 764.9 759.9 1204.5 1204.6 1204.6 1204.6 1204.5 0.6214 0.6272 .0.6329 0.6383 0.6436 0.8630 0.8527 0.8426 0.8330 0.8237 1.4844 1.479S 1.4755 1.4713 1.4673 400 420 440 460 480 0.9278 0.8915 0.8578 0.8265 0.7973 449.4 454.1 458.6 463.0 467.4 755.0 750.1 745.4 740.8 736.1 1204.4 1204.2 1204.0 1203.8 1203.5 0.6487 0.6536 0.6584 0.6631 0.6676 0.8147 0.8060 0.7976 0.7893 0.7813 1.4634 1.4596 1.4560 1.4524 1.4489 500 520 540 560 580 0.7698 0.7440 0.7198 0.6971 0.6757 471.6 475.7 479.8 483.8 487.7 731.6 727.2 722.7 718.3 714.0 1203.2 1202.9 1202.5 1202.1 1201.7 0.6720 0.6763 0.6805 0.6846 0.6886 0.7734 0.7658 0.7584 0.7512 0.7441 1.4454 1.4421 1.4389 1.4358 1.4327 600 620 640 660 680 0.6554 0.6362 0.6180 0.6007 0.5843 491.5 495.3 499.0 502.6 506.2 709.7 705.4 701.2 697.1 692.9 1201.2 1200.7 1200.2 1199.7 1199.1 0.6925 0.6963 0.7001 0.7037 0.7073 0.7371 0.7303 0.7237 0.7172 0.7108 1.4296 1.4266 1.4237 1.4209 1.4181 700 720 740 760 780 0.5687 0.5538 0.5396 0.5260 0.5130 509.7 513.2 516.6 520.0 523.3 688.9 684.8 680.8 676.8 672.8 1198-6 1198.0 1197.4 J196.8 1196.1 0.7108 0.7143 0.7177 0.7210 0.7243 0.7045 0.6983 0.6922 0.6862 0.6803 1.4153 1.4126 1.4099 1.4072 1.4046 800 820 840 860 880 .0.5006 0.4886 0.4772 0.4663 0.4557 526.6 529.8 533.0 536.2 539.3 668.8 664.9 661.0 657.1 653.3 1195.4 1194.7 1194.0 1193.3 1192.6 0.7275 0.7307 0.7339 0.7370 0.7400 0.6744 0.6687 0.6631 0.6576 0.6521 1.4020 1 3995 1.3970 1.3945 1.3921 900 920 940 960 980 0.4456 0.4218 0.4001 0.3802 0.3619 542.4 550.0 557.4 564.6 571.7 649.4 639.9 630.4 621.0 611.7 1191.8 1189.9 1187.8 1185.6 1183.4 0.7430 0.7504 0.7575 0.7644 0.7711 0.6467 1-3897 0.6334 1.3838 0.6205 1.3780 0.6079 1-3723 0.5956 j 1.3667 1000 1050 1100 1150 1200 0.3450 0.3293 0.3148 0.3012 0.2884 578.6 585.4 592.1 598.7 505.2 602.4 593.2 584.0 574.7 565.5 3181.0 1178.6 1176.1 1173.4 1170.7 0.7776 0.7840 0.7902 0.7963 0.8023 0.5836 0.5719 0.5604 0.5491 0.5379 1.3612 13559 1.3506 1.3454 1.3402 1250 1300 1350 1400 0.2765 0.2548 0.2354 0.2179 0.2021 311.6 324.1 336.3 >48.3 t 60.1 556.3 538.0 519.6 501.1 482.4 1167.9 162.1 155.9 1 149.4 1 142.4 (0.8082 (0.8196 C0.8306 C .8412 C .8516 3.5269 3.5053 (3.4843 C1.4637 (1.4433 1.3351 3249 .3149 .3049 .2949 1500 1600 1700 1800 0.1878 0.1625 0.1407 0.1213 0.1035 e 71.7 6 94.8 7 18.4 7 43.0 7 70.1 463.4 424.4 382.7 337.2 J 84.7 1 135.1 1 119.2 1 101.1 1 080.2 1 054.8 C -8619 0 .8820 0 .9023 0 .9232 0 .9459 C .4230 C .3826 C .3411 0 .2973 0 .2487 1 .2849 1 .2646 1 .2434 1 .2205 1 .1946 2000' 2200 2400 2600 2800 0.0858 0.0580 8 02.5 S 72.4 17.8 62.0 1 020.3 0.9731 0 .1885 T .1615 934.4 1 0320 0 0532 1 0852 3000 00.0503 902.7 902.7 1 0580 0 1 0580 3206.2 publish^ by rota W:yknndf&"arfn"W5'n!,'"`C Proper,ic* f Steam. by J. H. Ceenan a nd F. G Keyes, . 31 y . . Heating Ventilating Air Conditioning Guide 1939 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 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 superheated, 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, Vo1. 24, 1918, p. 25). The Evaporation of a Liquid into a Gas, by W. K. Lewis (A.S.M.E. Transactions, Vol. 44, 1922). 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 (A.S.H.V.E. Trans actions, Vol. 32, 1926, p. 163). A Review of Psychrometric Charts, by C. 0. 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)... Mbctures of Air and Water Vapor, by C. A. Bulkeley (Refrigerating Engineering, January, 1933). .. Basic Theory of Air Conditioning, by Lawrence Washington (Western Conference on Air Conditioning, San Francisco, Calif., February 9-10, 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 ( U. 5. Bureau of Standards Miscellaneous Publication No. 143). PROBLEMS IN PRACTICE 1 A 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, . ^/ 0.5 X 6.7387 \ w - U.ozz ^29 oo _ (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. 32 Chapter 1. Air, Water and Steam 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 (t + 460) (R = 0.753 when partial pressure of air U expressed in in. He.). 28.282 X 1 = da X 0.753 X (80 + 460) 28 282 da = o 753 X 540 = 0-06955 lb = weight of dry air in 1 cu ft of the mixture. Likewise from Equation 4a, dy -- i 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 mbeture = 0.06955 + 0.000868 = 0.070418 lb. 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. 28 275 dz = o 753 x ~535 = `^18 lb = weight of dry air in 1 cu It of the mixture. From Equation 4a, , 0 525 dv = ^ 2} x 535 = 0-000811 lb = weight of vapor per cubic foot at 55 per cent relative humidity. - Weight of 1 cu ft qf the mixture = 0.07018 + 0.000811 = 0.070991 lb. Volume of 1 lb of the mixture = q 070991 = cu 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 6000 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 / 0.5158 \ V 29.92 - 0.5158 / 0.01091 lb. Pressure of saturated vapor at 70 F = 0.7387 in. Hg. With the same specific humidity 0.01091 = 0.622 0.7387 X d> (29.92 - (0.7387 X <t>)J 0 - 69.8 per cent relative humidity at 70 F. Heating Ventilating Air Conditioning Guide 1939 A = 0.24 X 80 + 0.01091 [1059.2 + (0.45 X 80)] = 31.15 Btu per pound, the enthalpy of the mixture at 80 F and 50 per cent relative humidity. A = 0.24 X 70 + 0.01091 [1059.2 + (0.45 X 70)] = 28.70 Btu per pound, the enthalpy 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. 60g0-j0jr = 2449 lb of air required per hour. 51 A building requires 50,000 cu ft of air per hour measured at standard barometric pressure of 29.92 in. Hg. 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 baro metric 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 ( 28^B^ (HH66 ) = lb- From Table 6, Pressure of vapor in the mixture, inside air = 0.30 X 0.7906 = 0.2372 in. Hg. Specific humidity, inside air = 0.622 ^28 75^--^0^3718^ = 0.005174 lb. Water to be added = 3750 (0.005174 - 0.0003589 ) = 18.06 lb per hour. Enthalpy, inside air = 0.24 X 72 + 0.005174 [1059.2 4- (0.45 X 72)] = 22.925 Btu per pound. . Enthalpy, outside air = 0.24 X (-10) -}- 0.0003589 [1059.2 + (0.45 X -10)] = --2.021 Btu per pound. 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. 6 f 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 (2875^-^0 995) = lb. Specific humidity, inside air = 0.007626 lb. Weight of water to be extracted per hour = (0.0223 -- 0.007626) X 3750 = 55.03 lb. Enthalpy, outside air = 0.24 X 95 + 0.0223 [1059.2 (0.45 X 95)] = 47.37 Btu per pound. Enthalpy, inside air = 0.24 X 50 + 0.00764 [1059.2 +- (0.45 X 50)J = 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 23. 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 (Fa), methyl 35 X Heating Ventilating Air Conditioning Guide 1939 Table 1. Properties of Ammonia Sat. Temp. F 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 so 52 54 56 58 60 62 . 64 66 68 70 72 74 76 78 80 82 84 86 88 90 92 94 96 98 100 102 104 106 108 110 112 . 114 116 118 120 122 124 126 128 Aes. Press. Sq In. 30.42 31.92 33.47 34.27 35.09 36.77 38.51 40.31 42.18 44.12 46.13 48.21 50.36 52.59 54.90 57.28 59.74 62.29 64.91 67.63 70.43 71.87 73.32 74.80 76.31 79.38 82.55 85.82 89.19 92.66 96.23 99.91 103.7 107.6 111.6 115.7 120.0 124.3 128.8 133.4 138.1 143.0 147.9 1S3.0 158.3 163.7 169.2 174.8 180.6 186.6 192.7 198.9 205.3 211.9 218.6 225.4 232.5 239.7 247.0 254.5 262.2 270.1 278.2 286.4 294.8 303.4 312.2 321.2 Volume Heat Content and Entbopt Taken From --40 F -- Heat Content ropy 100 F Superheat 200 F Superheat Liquid 0.02419 0.02424 0.02430 0.02432 0.02435 0.02440 0.02446 0.02451 0.02457 0.02462 0.02468 0.02474 0.02479 0.02485 0.02491 0.02497 0.02503 0.025* 0.025l4 0.02521 0.02527 0.02530 0.02533 0.02536 0.02539 0.0254S 0.02551 0.02558 0.02564 0.02571 0.02577 0.02584 0.02590 0.02597 0.02604 0.02611 0.02618 0.02625 0.02632 0.02639 0.02646 0.02653 0.02661 0.02668 0.02675 0.02684 0.02691 0.02699 0.02707 0.02715 0.02723 0.02731 0.02739 0.02747 0.02756 0.02764 0.02773 0.02782 0.02790 0.02799 0.02808 0.02817 0.02827 0.02836 0.02846 0.02855 0.02865 0.02875 Vapor Liquid Vapor liquid Vapor Ht Ct Entropy Ht Ct Entropy 9.116 8.714 8.333 8.150 7.971 7.629 7.304 6.996 6.703 6.425 6.161 5.910 5.671 5.443 S.227 5.021 4.825 4.637 4.459 4.289 4.126 4.048 3.971 3.897 3.823 3.682 3.547 3.418 3.294 3.176 3.063 2.954 2.851 2.751 , 2.656 2.565 2.477 2.393 2.312 2.235 2.161 2.089 2.021 1.955 1.892 1.831 1.772 1.716 1.661 1.609 1.559 1.510 1,464 1.419 1.375 1.334 1.293 1.254 1.217 1.180 1.145 1.112 1.079 1.047 1.017 0.987 0.958 0.931 42.9 611.8 45. t 612.4 47.2 613.0 48.3 613.3 49.4 613.6 51.6 614.3 53.8 614.9 56.0 615.5 58.2 616.1 60.3 616.6 62.5 617.2 64.7 617.8 66.9 618.3 69.1 618.9 71.3 619.4 73.5 619.9 75.7 620.5 77.9 621.0 80.1 621.5 82.3 622.0 84.6 622.5 85.7 622.7 86.8 623.0 87.9 623.2 89.0 623.4 91.2 93.5 95.7 97.9 100.2 623.9 624.4 624.8 625.2 625.7 102.4 104.7 106.9 109.2 111.5 626.1 626.5 626.9 627.3 627.7 113.7 116.0 118.3 120.5 122.8 628.0 628.4 628.8 629.1 629.4 125.1 127.4 129.7 132.0 134.3' 629.8 630.1 630.4 630.7 631.0 136.6 138.9 141.2 143.5 145.8 63U 631.5 631.8 632.0 632.2 148.2 150.5 152.9 155.2 157.6 632.5 632.6 632.9 633.0 633.2 159.9 162.3 164.6 167.0 169.4 . 633.4 633.5 633.6 633.7 633.8 171.8 174.2 176.6 179.0 633.9 634.0 634.0 634.0 181.4 183.9 186.3 188.8' 634.0 634.0 633.9 633.9 0.0975 0.1022 0.1069 0.1092 0.1115 0.1162 0.1208 0.1254 0.1300 0.1346 0.1392 0.1437 0.1483 0.1528 0.1573 0.1618 0.1663 0.1708 0.1753 0.1797 0.1841 0.1863 0.1885 0.1908 0.1930 0.1974 0.2018 0.2062 0.2105 0.2149 0.2192 0.2236 0.2279 0.2322 0.2365 0.2408 0.2451 0.2494 0.2537 0.2579 0.2622 0.2664 0.2706 ' 0.2749 0.2791 0.2833 0.2875 0.2917 039S8 0.3000 0.3041 0.3083 0.3125 0.3166 0.3207 0.3248 0.3289 0.3330 0.3372 0.3413 0.3453 1.3352 1.3312 1.3273 1.3253 13234 666.8 667.6 668.4 668.8 669.3 1.3195 1.3157 1.3118 1.3081 1.3043 670.1 670.9 671.7 672.5 673.4 1.3006 1.2969 1.2933 1.2897 1.2861 674.2 675.0 675.8 676.6 677.3 1.2825 1.2790 1.27S5 1.2721 1.2686 678.1 678.9 679.7 680.4 681.2 1.2652 1.2635 1.2618 1.2602 1.2585 681.9 682.3 682.7 683.1 683.4 1.2552 1.2519 1.2486 1.2453 1.2421 684.2 684.9 685.6 686.4 687.1 1.2389 1.2357 1.2325 1.2294 1.2262 687.8 6S8.5 689.2 689.9 690.6 1.2231 1.2201 1.2170 1.2140 1.2110 691.3 691.9 692.6 693.3 694.0 1.20S0 1.2050 1.2020* 1.1991 1.1962 694.6 695.3 695.9 696.6 697.2 1.1933 1.1904 1.1875 1.1846 1.1818 697.8 698.5 699.1 699.7 700.3 1.1789 1.1761 1.1733 1.1705 1.1677 700.9 701.5 702.1 702.7 703.3 1.1649 1.1621 1.1593 1.1566 1.1538 703.8 704.3 705.0 705.5 706.1 1.1510 1.1483 1.1455 1.1427 706.6 707.2 707.7 708.2 1.1400 1.1372 1.1344 1.1316 708.6 709.1 709.6 710.0 1.4439 1.4400 1.4360 1.4340 1.4321 720.3 721.2 722.2 722.6 723.1 1.4281 1.4242 1.4205 1.4168 1.4130 724.1 725.0 725.9 726.8 727.8 1.4093 1.4056 1.4021 1.3985 1.3950 728.7 729.6 730.5 731.4 732.4 1.3914 1.3879 1.3846 1.3812 1.3779 733.3 734.2 735.1 736.0 736.8 1.3745 1.3729 1.3712 1.3696 1.3680 737.7 738.2 738.6 739.0 739.5 1.3648" 1.3616 1.3584 1.3552 1.3521 740.4 741.3 742.2 743.1 744.0 1.3491 1.3460 1.3430 1.3399 1.3370 744.8 745.7 746 5 747.4 748.2 1.3341 1.3312 1.3283 1.3254 1.3226 749.1 749.9 750.8 751.6 752.4 1.3199 1.3171 1.3144 1.3U6 1.3089 753.3 754.1 755.0 755.8 756.6 1.3063 1.3040 1.3010 1.2983 1.2957 757.4 758.3 759.1 759.9 760.7 1.2932 1.2906 1.2881 1.28S5 1.2830 761.5 762.2 763.0 763.8 764.6 1.2805 1.2780 1.2755 1.2731 1.2708 765.3 766.1 766.9 767.6 768.3 1.2684 1.2661 1.2636 1.2612 769.1 769.8 770.5 771.3 1.2587 772.0 1.2563 772.8 1.2538 I 773.5 1.2513 774.2 1-5317 1-5277 1.5236 1-5216 1.5196 1.5155 1.5115 1.5077 1.5039 1.5001 1.4963 1.4925 1.4889 1.4853 1.4816 1.4780 1.4744 1.4710 1.4676 1.4643 1.4609 1.4592 1.4575 1.4559 1.4542 1.4510 1.4477 1.4445 1.4412 1.4382 1.4351 1.4321 1.4290 1.4260 1.4231 1.4202 1.4172 . 1.4143 . 1.4114 1.4086 1.4059 1.4031 1.4004 1.3976 1.3949' 1.3923 1.3896 1.3870 1.3843 1.3818 1.3793 1.3768 1.3743 1.3718 1.3693 1.3668 1.3643 1.3619-- 1.3596 1.3573 1.3550 1.3527 1.3503 1.3479 1.3455 1.3431 1 1.3407 1.3383 36 Chapter 2. Refrigerants and Air Drying Agents Table 2. Properties of Dichlorodifluoromethane(Fh) Sat. Temp. F Ass. Press. Lb per Sq In. Volume Liquid Vapor 0 23.87 2 24.89 4 25.96 5 26.51 6 27.05 8 28.18 10 29.35 12 30.56 14 31.80 16 33.08 18 34.40 20 35.75 22 37.15 24 38.58 26 40.07 28 41.59 30 43.16 32 44.77 34 46.42 36 48.13 38 49.88 39 50.78 40 51.68 41 52.70 42 53.51 44 55.40 46 57JS 48 59.35 50 61.39 52 63.49 54 65.63 56 67M 58 70.10 60 72.41 62 74.77 64 77.20 66 79.67 68 82.24 70 84.82 72 87.50 74 90.20 75 93.00 95.85 98.76 82 101.70 84 104.8 85 107.9 111.1 114.3 117.7 94 121.0 128.0 1UU lil.6 135.3 104 139.0 i^2Ji 146.8 150./ 154.a 158.9 167.4 180.8 lio 134 204.8 0.0110 0.0110 0.0111 0.0111 o.om 0.0111 0.0112 0.0112 0.0112 0.0112 0.0113 0.0113 0.0113 0.0113 0.0114 0.0114 0.0115 0.0115 0.0115 0.0116 0.0116 0.0116 0.0116 0.0116 0.0116 0.0117 0.0117 0.0117 0.0118 0.0118 0.0118 0.0119 0.0119 0.0119 0.0120 0.0120 0.0120 0.0121 0.0121 0.0121 0.0122 0.0122 0.0123 0.0123 0.0123 0.0124 0.0124 0.0124 0.0125 0.0125 0.0126 0.0126 0.0127 0.0127 0.0128 0.0128 0.0130 0.0133 U.U153 U.U154, 0.0135 U.U156 1.637 1.574 1.514 1.485 1.457 1.403 2.351 U01 1.253 1.207 1.163 1.121 1.082 1.043 1.007 0.973 0.939 0.908 0.877 0.848 0.819 0.806 0.792 0.779 0.767 0.742 0.718 0.695 0.673 0.652 0.632 0.612 0.593 0.575 0.557 0.540 0.524 0.508 0.493 0.479 0.464 0.451 0.438 0.425 0.413 0.401 0.389 0.378 0.368 0.357 0.347 0.338 0.328 0.319 0.310 0.302 0.293 0.285 0.277 0.269 0.262 0.254 0.247 0.240 0.233 0.227 0.220 0.214 0.208 0.202 0.196 0.191 0.185 0.280 . Heat Content and Entbopt Taken From -40 F Heat Content Entropy 25 F Superheat 50 F Superheat liquid Vapor liquid Vapor Ht. Ct Entropjr Ht Ct Entropy 8.25 8.67 9.10 9.32 9.53 9.96 10.39 10.82 11.26 11.70 12.12 12.55 13.00 13.44 13.88 14.32 14.76 15.21 15.65 16.10 16.55 16.77 17.00 17.23 17.46 17.91 18.36 18.82 19.27 19.72 20.18 20.64 21.11 21.57 22.03 22.49 22.95 23.42 23.90 24.37 24.84 25.32 25.80 26.28 26.76 27.24 27.72 28.21 28.70 29.19 29.68 30.18 30.67 31.16 31.65 32.15 32.65 33.15 33.65 34.15 34.65 35. IS 35.65 36.16 36.66 37.16 37.67 38.18 38.69 39.19 39.70 40.21 40.72 41.24 78.21 78.44 78.67 78.79 78.90 0.01869 0.01961 0.02052 0.02097 0.02143 0.17091 0.17075 0.17060 0.17052 0.17045 81.71 81.94 82.17 8129 82.41 0.17829 85.26 0.17812 85.51 0.17795 . 85.76 0.17786 85.89 0.17778 86.01 0.18547 0.18529 0.18511 0.18502 0.18494 79.13 79.36 79.59 79.82 80.05 0.02235 0.02328 0.02419 0.0251C 0.02601 6.17030 82.66 0.17015 82.90 0.17001 83.14 0.16987 83-38 0.16974 83.61 0.17763 86.26 0.17747 86.51 0.17733 86.76 0.17720 ; 87.01 0.17706 87.26 0.18477 0.18460 0.18444 0.18429 0.18413 80.27 80.49 80.72 80.95 81.17 0.02692 0.02783 0.02873 0.02963 0.03053 0.16961 0.16949 0.16938 0.16926 0.16913 83.85 84.09 84-32 84.5S 84.79 0.17693 0.17679 0.17666 0.17652 0.17639 87.51 87.76 88.00 88.24 88.49 0.18397 0.18382 0.18369 0.18355 0.18342 81.39 81.61 81.83 82.05 82.27 0.03143 0.03233 0.03323 0.03413 0.03502 0.16900 0.16887 0.16876 0.16865 0.16854 85.02 85.25 85.48 85.71 85.95 0.17625 0.17612 0.17600 0.17589 0.17577 88.73 88.97 89.21 89.45 89.68 0.18328 0.18315 0.18303 0.18291 0.18280 82.49 82.60 82.71 82.82 82.93 0.03591 0.0363S 0.03680 0.03725 0.03770 0.16843 0.16838 0.16833 0.16828 0.16823 86.18 86.29 86.41 86.52 86.64 0.17566 0.17560 0.17554 0.17549 0.17544 89.92 90.04 90.16 90.28 90.40 0.18268 0.18262 0.18256 0.18251 0.J8245 83.15 83.36 83.57 83.78 83.99 0.03859 0.03948 0.04037 0.04126 0.04215 0.16813 0.16803 0.16794 0.16785 0.16776 86.86 87.09 8731 87.54 87.76 0.17534 0.17525 0.17515 0.17505 0.17496 90.65 90.89 91.14 91.38 91.61 0.18235 0.18224 0.18214 0.18193 84.20 84.41 84.62 84.82 85.02 0.04304 0.04392 0.04480 0.04568 0.04657 0.16767 0.16758 0.16749 0.16741 0.16733 87.98 88.20 88.42 88.64 8836 0.17486 0.17477 0.17467 0.17458 0.17450 91.83 92.06 92.28 92.51 92.74 0.18184 0.18174 0.18165 0.18147 85.22 85.42 85.62 85.82 86.02 O.04745 0.04833 0.04921 0.05009 0.05097 0.16725 0.16717 0.16709 0.16701 0.16693 89.07 89.29 89.50 89.72 89.93 0.17442 0.17433 0.17425 0.17417 0.17409 92.97 93.20 93.43 93.66 93.99 0.18139 0.18130 0.18122 0.18114 0.18106 86.22 86.42 86.61 86.80 86.99 0.05185 0.05272 0.05359 0.05446 0.05534 0.16685 0.16677 0.16669 0.16662 0.16655 90.14 90.36 90.57 90.78 90.98 0.17402 0.17394 0.17387 0.17379 0.17372 94.12 94.34 94.57 94.80 95.01 0.18098 0.18091 0.18083 0.18075 0.18068 87.18 87-37 87-56 87.74 87.92 0.05621 0.05708 0.05795 0.05882 0.05969 0.16648 0.16640 0.16632 0.16624 0.16616 91.18 91.37 91.57 91.77 91.97 0.17365 0.17358 0.17351 0.17344 0.17337 95.22 95.44 95.65 95.86 96.07 0.18061 0.18054 0.18047 0.18040 0.18033 88.10 88.28 88.45 88,62 88.79 0.06056 0.06143 0.06230 0.06316 0.06403 0.16608 0.16600 0.16592 0.16584 0.16576 92.16 9236 92.55 92.75 92.93 0.17330 0.17322 0.17315 0.17308 0.17301 96.28 96.50 96.71 96.92 97.12 0.18026 0.18018 0.18004 0.17998 88.95 89.11 89.27 89.43 89.58 0.06490 0.06577 0.06663 0.06749 0.06836 0.16563 0.16560 0.16551 0.16542 0.16533 93.11 93.30 93.48 93.66 93.82 0.17294 0.17288 0.17281 0.17274 0.17266 97.32 97.53 97.73 97.93 98.11 0.17993 0.17987 0.17982 0.17976 0.17969 89.73 8937 90.01 90.15 90.28 0.06922 0.07008 0.07094 0.07180 0.07266 0.16524 0.16515 0.16505 0.16495 0.16484 93.98 94.15 9431 94.47 94.63 0.17258 0.17249 0.17241 0.17233 0.17224 98.29 98.48 98.66 98.84 99.01 0.17961 0.17946 0.17939 0.17931 90.40 90.52 90.64 90.76 90.86 0.07352 0.07437 0.07522 0.07607 0.07691 0.16473 0.16462 0.16450 0.16438 0.16425 94.78 94.94 95.09 95.25 95.41 0.17215 0.17206 0.17196 0.17186 0.17176 99.18* 99.35 99.53 99.70 99.87 0.17922 0.17914 0.17906 0.17897 0.17889 90.96 91.06 91.15 91.24 0.0777S 0.16411 0.07858 0.16396 0.07941 0.16380 0.08024 0.16363 95.56 95.72 95.87 96.03 0.17166 0.17156 0.17145 0.17134 100.04 100.22 100.39 100.56 0.17881 0.17873 0.17864 0.17856 37 Heating Ventilating Air Conditioning Guide 1939 Table 3. Properties of Methyl Chloride Heat Content and Entrqpt Taken From --40 F 0I Sat. Temp. F 6 16 26 36 42 52 62 72 . 82 92 Abs. Press. Sq In. 21.39 26.55 32.53 39.51 44.18 53.00 63.13 74.66 87.74 102.49 >1 Liquid 0.0163 0.0163 0.0164 0.0164 0.0164 0.0165 0.0165 0.0166 0.0166 0.0167 0.0167 0.0168 0.0169 0.0169 0.0170 0.0171 0.0171 0.0171 0.0172 0.0172 0.0173 0.0173 0 0173 0.0174 0.0174 0 0174 0.0175 0.0175 0.0176 0.0177 0.0177 0.0178 0.0178 0.0178 0.0179 0.0179 0.0180 0.0180 0.0180 Vapor 5.052 4.856 4.661 4.563 4.476 4.303 4.129 3.984 3.839 3.693 3.548 ;-3.403 3.288 3.172 3.057 2.941 2.826 2.734 2.642 2.549 2.457 2.411 2.365 2.328 2.290 2.216 2.141 2.067 1.992 1.931 . 1.870 1.810 1.749 1.688 1.638 1.588 1.539 1.489 1.439 1.398 1.357 1.315 1.274 1.233 1.199 1.165 1.130 1.096 1.062 1.033 Heat Content liquid Vapor 14.4 192.4 15.1 193.1 15.8 193.8 16.2 194.1 16.6 194.4 17.3 18.1 18.8 19.6 20.3 195.1 195.8 196.3 196.7 197.2 21.1 21.8 22.5 23.3 24.0 197.6 198.1 198.5 198.9 199.3 24.8 25.5 26.2 27.0 27.7 199.7 200.1 200.5 200.9 201.4 28.5 28.8 29.2 29.6 29.9 201.8 202.0 202.2 202.4 202.6 30.7 31.4 32.2 32.9 33.7 203.0 203.3 203.7 204.1 204.4 34.4 35.2 35.9 36.7 37.4 204.7 205.1 205.4 205.7 206.0 38.2 38.9 39.7 40.4 '41.1 206.3 206.6 206.9 207.2 207.5 41.9 42.6 43.4 44.1 44.8 207.7 208.0 208.2 208.5 208.7 45.6 46.3 ' 47.1 47.8 48.6 209.0 209.2 209.5 209.7 209.9 Entropy 100 F Superheat 200 FSu jerheat Liquid Vapor Ht. Ct. Entropy Ht. Ct. Entropy 0.0328 0.0344 0.0360 0.0368 0.0376 0.4197 0.4196 0.4195 0.4195 0.4194 215.6 216.2 216.7 217.0 217.3 0.467 0.466 0.465 0.464 0.464 237.2 237.7 238.2 238.5 238.8 0.507 0.505 0.504 0.503 0.502 0.0391 0.0407 0.0423 0.0439 0.0454 0.4193 0.4192 0.4184 0.4176 0.4168 217.9 218.5 219.0 219.5 220.0 0.463 0.463 0.462 0.462 0.461 239.4 240.0 240.5 241.0 241.5 0.501 0.500 0.499 0.0472 0.0486 0.0501 0.0516 0.0532 0.4160 0.4152 0.4148 0.4143 0.4139 220.5 221.0 221.5 222.0 222.4 0.461 0.460 0.459 0459 0.458 242.0 242.5 243.0 243.6 0.497 0.496 0.495 0.0547 0.0562 0.0577 0.0592 0.0607 0.4134 0.4130 0.4124 0.4118 0.4111 222.9 223.4 223.9 224.3 224.8 0.458 0.457 0.456 0.455 0.455 244.7 245.2 245.7 246.2 246.7 0.494 0.493 0.492 0.0622 0.0629 0.0637 0.0644 0.0651 0.4105 0.4102 0.4099 0.4096 0.4093 225.2 225.5 225.7 225.9 226.1 0.454 0.453 0.453 0.453 0.452 247.2 247.4 247 J 248.0 248.3 0.491 0.490 0.0666 0.0680 0.069S 0.0709 0.0724 0.4087 0.4081 0.4075 0.4069 0.4063 226.6 227.0 227.5 227.9 228.2 ' 0.451 0.451 0.450 0.449 0.448 248.8 249.4 249.9 250.5 251.0 . 0.489 0.486 0.0739 0.0754 0.0769 0.0784 0.0798 0.4056 0.4050 0.4043 0.4037 0.4030 228.6 228.9 229.3 229.6 229.9 0.448 0.447 0.447 0.446 0.445 251.5 252.0 252.5 253.0 255.5 0.486 0-485 U.4S5 0.0812 0.0827 0.0841 0.0855 0.0869 0.4024 0.4017 0.4011 0.4004 0.3998 230-3 230.6 231.0 231.3 231.6 0.444 0.443 0.442 0.441 0.440 254.0 254.5 255.0 255.5 256.0 0.483 0.0883 0.0898 0.0912 0.0926 0.0940 0.3992 0.3985 0.3979 0.3973 0.3967 232.0 232.3 232.7 233.0 233.3 0.439 0.439 0.438 0.437 0.436 256.5 256.9 257.4 257.9 258.4 0.480 ; 0.479 0.479 ` 0.0953 0.0967 0.0980 0.0994 0.1008 0.3960 0.3954 0.3947 0.3941 0.3935 2336 233.9 234.2 234.5 234.8 0.435 0.435 0.434 0 433 0.433 258.9 259.4 259.9 260.8 0.477 0.477 0.476 0.476 0.476 f. i; Sat. Temp. F Sq In. Liquid Vapor 0 305.5 0.01570 0.29040 2 315.9 0.01579 0.28030 4 326.5 0.01588 0.27070 5 332.0 0 01592 0.26610 6 337.4 0.01596 0.26140 8 348.7 0.01605 0.25260 10 360.2 0.01614 0.24370 12 371.9 0.01623 0.23540 14 383.9 0.01632 0.22740 16 396-2 0.01642 0.21970 IS 408.9 0.01652 0.21210 20 421-8 0.01663 0.20490 22 434.0 0.01673 0.19790 24 448.4 0.01684 0.19120 26 462.2 0.01695 0.18460 28 476.3 0.01707 0.17830 30 490.8 001719 0.17220 32 505.5 0.01731 0.16630 34 522.6 0.01744 0.16030 36 536.0 0.01759 0.15500 38 551.7 0.01773 0.14960 39 559.7 0.01780 0.14700 40 567.8 0.01787 0.14440 41 576.0 0.01794 0.14185 42 584.3 0.01801 0.13930 44 601.1 0.01817 0.13440 46 618.2 0.01834 0.12970 48 635.7 0.01851 0.12500 50 653.6 0.01868 0.12050 52 671.9 0.01887 0.11610 54 690.6 0.01906 0.11170 56 709.5 0.01927 0.10750 58 728.8 0.01948 0.10340 60 748.6 0.01970 0.09940 62 769.0 0.01995 0.09545 64 789.4 66 810.3 68 831.6 70 853.4 72 875.8 74 898.2 76 921.3 944.8 968.7 993.0 84 1017.7 86 { 1043.0 87.8 1 1069.9 0.02020 0.02048 0.02079 0.02112 0.02152 0.02192 0.02242 0.02300 0.02370 0.02456 0.02553 0.02686 0.03454 0.09180 0.08800 0.08422 0.08040 0.07654 0.07269 0.06875 0.06473 0.06064 0.05648 0.05223 0.04789 0.03454 CLEAT CONTENT AND KNTROPT* TAKEN FROM --40 F Heat Content Entropy 50 F Superheat 100 F Superheat Liquid Vapor liquid Vapor Ht. Ct Entropy Ht. Ct. Entropy 18.8 19.8 20.8 21.3 21.8 22.9 24.0 25.0 26.1 27.2 138.9 138.8 138.8 138.8 138.7. 138.7 138.7 138.6 138.6 138.5 0.0418 0.0440 0.0461 0.0472 0.0483 0.0504 0.0526 0.0548 0.0571 0.0593 0.3024 0.3014 0.3005 0.3000 0.2994 0.2982 0.2970 0.2958 0.2946 0.2933 153.7 153.7 153.7 153.7 153.7 153.7 153.7 153.7 153.7 153.7 0.3342 0.3330 0.3318 0.3312 0.3306 0.3293 0.3281 0.3270 0.3259 0.3249 167.5 167.6 167.7 167.7 167.8 167.9 168.0 168.1 168.2 168.3 0.3612 0.3600 0.3588 0.3582 0.3576. 0.3563 0.3550 0.3538 0.3526 0.3513 28.3 29.4 30.5 31.7 32.9 34.1 35.4 36.7 37.9 39.1 40.4 41.0 41.7 42.3 42.9 44.3 45.6 47.0 48.4 49.8 51.2 52.6 . 54.0 55.5 57.0 58.6 60.2 61.9 63.7 65.5 67JS 69.4 71.6 73.9 76.4 79.4 83.3 97.0 138.4 138.3 138.2 138.1 138.0 0.0616 0.0638 0.0662 0.0686 0.0710 0.2921 0.2909 0.2897 0.288S 0.2873 153.7 153.7 153.7 153.7 153.7 0.3238 0.3227 0.3214 0.3202 0.3189 137.9 137.8 137.7 137.4 137.2 0.0734 0.0758 0.0781 0.0804 0.0828. 0.2861 I 153.7 0.2849 153.7 0.2834 153.7 0.2820 153.7 0.2805 153.7 0.3177 0.3164 0.3158 0.3151 0.3145 136.9 136.8 136.7 136.5 136.3 0.0851 0.0862 0.0874 0.0887 0.0899 0.2791 0.2783 0.2776 0.2768 0.2761 153.7 153.7 153.7 153.7 153.7 0.3138 0.3135 0.3132 0.3127 0.3122 136.1 135.7 135.4 135.0 134.5 0.0924 0.0950 0.0975 0.1000 0.1027 0.2745 0.2730 0.2714 0.2699 0.2681 153.7 153.7 153.7 153.7 153.7 0.3112 0.3101 0.3091 0.3081 0.3069 133.9 133.4 132.7 132.1 131.3 0.1054 0.1081 0.1108 0.1135 0.1164 0.2663 0.2644 0.2626 0.2608 0.2584 153.7 153.7 153.7 153.7 153.7 0.3057 0.3046 0.3034 0.3022 0.3012 130.6 129.7 128.7 127.5 126.0 0.1194 0.1223 0.1253 0.1282 0.1321 0.2560 0.2535 0.2511 0.2487 0.2450 153.7 153.7 153.7 153.7 153.7 0.3002 0.2991 0.2981 0.2971 0.2962 124.5 122.8 120.9 118.7 116.6 0.1437 0.1578 0.2414 0.2377 0.2341 0.2304 0.2195 153.7 153.7 153.7 153.7 153.7 0.2953 0.2945 0.2936 0.2927 0.2920 113.9 110.4 97.0 0.1679 0.1880 0.2087 0.1978 0.1880 153.7 153.7 153.7 0.2914 0.2907 0.2901 168.5 168.6 168.7 168.8 168.9 169.0 169.1 169.2 169.3 169.4 169.5 169.5 169.6 169.6 169.7 169.8 169.9 170.0 170.1 170.2 170.3 170.5 170.6 170.7 170.8 170.9 171.0 171.1 171.2 171.3 171.4 171.5 171.6 171.7 173.8 176.0 178.2 180.1 0.3501 0.3489 0.3479 0.3470 0.3460 0.3451 0.3441 0.3431 0.3421 0.3411 0.3401 0.3396 0.3391 0.3386 0.3381 0.3371 0.3362 0.3352 0.3342 0.3333 0.3324 0.3315 0.3306 0.3297 0.3289 0.3281 0.3273 0.3265 0.3257 0.3250 0.3242 0.3235 0.3227 0.3220 0.3215 0.3209 0.3204 0.3199 0.0181 0.0181 0.0182 0.0182 102 119.00 0.0183 1.005 0 9764 0.9478 0.9193 0.8952 49.3 50.1 S0.8 51.6 52.3 210.2 210.4 210.7 210.9 211.1 0.1022 0.1035 0.1049 0.1063 0.1076 0-3929 0.3922 0.3916 0.3910 0.3903 235.1 235.4 235.7 236.0 236.4 0.432 0.432 0.431 0.431 0.430 261.2 261.6 262.0 262.4 262.8 0.475 0.4750.474 0.474 .. u ' VYO-IA.1 . ~ munuuuuiuuluiiororaeuiane w which a table is presented. Each table gives the principal physical 0.0183 0.0184 0.0184 133.40 0.0185 112 137.42 0.0185 0.8712 0.8471 0.8231 0.7990 0.7786 141.44 0.0185 0.7583 G.G186-- . 0.7379 0.0186 07176 120 1S3.50 0.0187 0.6972 53.1 53.8 54.6 55.3 56.1 56.8 57.658.3 S9.1 211.3 211.4 211.6 211.8 212.0 212.2 212.4 212.6 21243 0.1090 0.1103 0.1117 0.1130 0.1144 0.1157 0.1171 0.1184 0.1198 0.3897 0.3890 0.3884 0.3877 0.3871 0.3864 0.3858 0.3851 0.3845 236.8 237.1 237.5 237.9 238.1 238.3 238.6 238.8 239.0 0.430 0.429 0.429 0.428 0.427 0.427 0.426 0.426 0.425 263.2 263.5 263.9 264.5 264.6 0.473 0.473 264.8 0.470 ao5.L 0.470 265.3 0.469. 265.6 j 0.468 fTMvertleST saturated substance, and all are arranged in uniform "fi1'ln e^c , case columns are included which give the heat content and entropy of the superheated vapor at two selected points. Tables 1, ' ; and 4 yhl?h }ndude the refrigerants much used in. reciprocating and comPression systems have a 2 F temperature interval. temrerft,^ in?1 are> U^1. in "ntrifugal compression systems the temperature interval in Tables 5 and 6 is 5 F. . 38 39 1 II Heating Ventilating Air Conditioning Guide 1939 Table 5. Properties of Monofluorotrichloromethanb (Flt) Sat. Tehp. F AB8. Press. La FEB So In. VoLI liquid Vapor Heat Contest and Enteopt Takes Faou --40 F Heat Content Entropy 25 F Superheat SO F Superbeat liquid 1 Vapor liquid Vapor HLCt. Entropy Ht Ct Entropy 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 2.59 0.01020 13.700 2.96 0.01024 12.100 3.38 0.01028 10.700 3.85 0.01032 9.530 4.36 0.01036 8.490 4.94 0.01040 7.580 5.57 0.01045 6.770 6.27 0.01049 6.080 7.03 0.01053 5.460 7.88 0.01057 4.920 8.79 0.01062 4.440 9.80 0.01066 4.020 10.90 0.01071 3.640 12.10 0.01076 3.300 13.40 0.01081 3.000 14.80 0.01086 2.740 16.30 0.01091 2.500 17.90 0.01096 2.280 19.70 0.01101 2.090 21.60 0.01106 1.918 23.60 0.01111 1.761 25.90 0.01116 1.620 7.81 8.81 9.82 10.80 11.90 12.90 13.90 14.90 16.00 17.00 18.10 19.10 20.20 21.30 22.40 23.50 24.50 25.60 26.70 27.80 28.90 30.10 90.4 0.017810. 1975! 93.9 0.2049 97.4 0.2120 91.2 10 0200| 1974] 94.7 0.2047 98.2 0.2117 92.0 0222 1973] 95.5 0.2045] 99.0 0.2114 92.8 0243 1971 96.3 0.2043| 99.8 0.2111 93.7 0264 1970 97.2 0.2041 100.7 0.2109 94.5 0286 1969 98.0 0.2039 101.5 0.2107 95.3 0307 1969 98.8 0.2038 102.3 0.2105 96.1 0328' 1968 99.6 0.2037 103.1 0.2103 96.8 0349] 1968 100.3 0.2036 103.8 0.2101 97.6 0370| 1967 101.1 0.2035 104.6 0.2099 98.4 0391 1967 101.9 0.2034 105.4 0.2098 99.2 .0412 1967 102.7 .0.2033 106.2 0.2097 100.0 0432 1967 103.5 0.2033 107.0 0.2096 100.8 0453 1967 104.3 0.2032 107.8 0.2094 101.5 .0473 1967 105.0 0.2032] 108.5 0.2093 102.2 .0493 .1967 105.7 0.2031 109.2 0.2092 102.9 .0513 .1966 106.4 0.2030] 109.9 0.2090 103.6 .0533 .1966 107.1 0.2029 110.6 0.2089 104.4 .0553 .1966 107.9 0.2028] 111.4 0.2088 105.1 .0573 .1966 108.6 0.2028] 112.1 0.2087 105.7 .0593] .1965 109.2 0.2027 112.7 0.2085 106.4 0613 1965 109.9 0.20261 113.4 0.2084 A1H 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 s 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. 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 . 40 Chapter 2. Refrigerants and Air Drying Agents alumina will show 92 per cent of AUP*, 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 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 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 ' Table 6. Properties of Water Sat. Temp. F Aas. Press. Lb per Sq In. Volume Liquid Vapor Heat Content and Entbopt Taken From +32 F Heat Content Liquid Vapor Entropy Liquid Vapor 50 F Superheat 100 F Superheat Ht. Ct. Entropy Hl Ct. Entropy 32 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 0.0887 0.01602 3296.0 0.1000 0.01602 2941.0 0.1217 0.01602 2441.0 0.1475 0.01602 2034.0 0.1780 0.01602 1702.0 0.2140 0.01603 1430.0 0.2561 0.01603 1206.0 0.3054 0.01604 1021.0 0.3628 0.01605 868.0 0.4295 0.01606 740.0 0.507 0.01607 632.9 0.596 0.01609 543.3 0.698 0.01610 467.9 0.815 0.01612 404.2 0.949 0.01613 350.3 1.101 0.01615 304.4 0.00 3.02 1073.0 0.0000 2.1826 1096.9 2.2277 1120.8 2.2688 1074.4 0.0062 2.1724 1098.3 2.2172 1122.2 2.2531 8.05 13.07 1076.8 0.0163 2.1555 1100.6 2.2000 1124.5 2.2406 1079.2 0.0262 2.1390 1102.9 2.1832 1126.7 2.2234 18.08 1081.5 0.0361 2.1230 1105.2 2.1667 1129.0 2.2066 23.08 1083.9 0.0459 2.1073 1107.5 2.1506 1131.3 2.1902 28.08 1086.2 0.0556 2.0920 1109.8 2.1349 1133.5 2.1742 33.08 1088.6 0.0652 2.0771 1112.2 2.1196 1135.8 2.1585 38.07 1090.9 0.0746 2.0625 1114.5 2.1046 1138.1 2.1432 43.06 1093.2 0.0840 2.0483 1116.7 2.0900 1140.3 2.1283 48.05 1095.5 0.0933 2.0344 1119.0 2.0758 1142.5 2.1138 53.04 1097.8 0.1025 2.0208 1121.2 2.0619 1144.7 2.0996 58.03 1100.0 0.1116 2.0075 1123.4 2.0483 1146.8 2.0857 63.01 1102.3 0.1206 1.9946 1125.6 2.0350 1148.9 2.0721 68.00 1104.6 0.1296 1.9819 1127.9 2.0220 1151.1 2.0588 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 29. 41 Heating Ventilating Air Conditioning Guide 1939 solid adsorbents include lamisilate and charcoal but details of their physical properties are not available. ti Nature of Adsorption Process p 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 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 | water condensing inside the pores and the partial pressure of the water | vapor in the air-vapor mixture. The adsorbing process in the bed can | continue until the vapor pressures come into equilibrium. The amount f; of vapor adsorbed will depend on the adsorbent substances being used but for any single substance the amount depends on the temperature of j*; the bed as well as on the partial pressure of the air-vapor mixture being [: passed over it. As the process of adsorption goes on heat is liberated in the bed. The | heat so liberated is the latent heat of the water vapor condensed together | 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. HI The heat of wetting for silica gel, for example, is about 200 Btu, making a g total heat of adsorption of approximately 1257 Btu per pound of water | 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 while the latent heat of condensation depends only on the temperature and pressure of the water vapor. . Temperature-Pressure-Concentration Relations 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 M I at which pressure equilibrium is reached. Evidently the equilibrium conditions represent the limits beyond which adsorption of vapor cannot continue. The relationship can be 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 constant temperature while the water vapor adsorption is allowed to continue until pressure equilibrium is reached. Each curve on the chart shows a certain dew-point temperature, and therefore a certain pressure, of the saturated water vapor. . 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. Chapter 2. Refrigerants and Air Drying Agents 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 Fig. 1. Temperature--Vapor Pressure--Concentration Relation for a Silica Gel Bed at Constant Temperature 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 43 Heating Ventilating Air Conditioning Guide 1939 Chapter 2. Refrigerants and Air Drying Agents Table 9. Viscosity op Lithium Chloride Solutions (millipoise) Concentration in Molal Deg F 0 24 68 10 12 . 14 16 18 20 22 24 Q 56.75 72.44 97.05 136.8 199.5 20 28.91 37.07 47.42 63.09 84.94 123.3 178.6 40 60 15.45 19.91 25.53 32.58 43.05 11.02 14.26 18.37 23.55 30.90 58.48 41.40 81.10 116.1 165.6 56.62 79.80 111.2 156.3 0 8.61 11.19 14.42 18.62 24.32 32.28 43.45 60.26 82.04 113.8 ion 6.82 8.89 11.48 14.94 19.36 25.59 33.96 46.13 61.52 84.72 118.3 120 5-60 7.31 9.51 12.30 15.92 20.99 27.67 .36.64 48.31 65.77 89.95 140 4.70 6.15 8.07 10.42 13.43 17.66 22.96 30.06 38.99 52.48 71.12 95.94 160 180 200 4.01 3.48 5.25 4.56 6.92 6.01 8.93 11.51 7.78 10.00 3.05 4.01 5.28 6.86 8.79 15.00 12.91 11.22 19.36 16.56 14.32 25.06 21.28 18.28 32.14 27.10 23.12 42.76 35.48 29.92 56.89 75.86 106.2 46.45 60.67 84.33 38.55 50.70 67.92 220 2.72 3.58 4.72 6.14 7.83 240 2.43 3.21 4.25 5.50 7.02 9.93 12.59 16.00 20.14 25.64 32.96 43.05 56.49 8.83 11.12 14.09 17.62 22.18 28.31 36-98 47.42 260 280 300 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 5.32 320 1.74 2.32 3.08 3.89 4.94 7.91 7.19 6.67 6.19 9.91 8.97 8.28 7.73 12.47 11.27 10.38 9.64 15.50 14.00 12.82 11.86 19.36 17.22 15.70 14.45 24.60 31.92 21.78 28.05 19.68 25.12 18.03 22.80 40.55 35.56 31.92 29.11 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 pressure causes some Table 10. Properties op Lithium Chloride Solutions * Cosr.Concentration orMow (42.4 GRAMS IACI Ourper 1000 " I Grains Water) Partial Hhat op Mixing at 0 F BTU per lb Tempmature Partial Heat op Mixing BTU per lb per F Specific Heat at 70 F Booing Point F (at 760 MM Ho) Freezing Point Substance that First Separates on Freezing 0 0.0' 0.0 0.998 212.0 32 Ice 2 2.04 -0.014 0.901 215.8 16.3 Ice 4 7.24 -0.036 0.831 221.5 -5.8 Ice 6 16.7 -0.069 0.778 228.9 -34.2 Ice 8 31.9 -0.109 0.739 238.1 -69 Ice 10 51.1 -0.143 0.710 248.4 -90 Ice 12 75.7 -0.160 0.687 258.8 -40 LiO-3H,0 14 90.8 -0.167 0.666 268.9 1 LiCLZIW 16 124.8 -0.176 0.647 277.9 36.5 LiCl-2H,0 18 145 -0.186 0.631 285.8 58.1 LiCi-TEW 20 162 -0.194 0.617 293.2 86.4 LiCl-HiO 22 171 -0.20 0.604 300.2 133 LiCl-IW 24 177 -0.20 0.59 307 156 LiCl-HiO 26 182 -0.21 0.58 313 180 LiCUUtO 28 191 -0.21 0.575 318 190 LiCl-fhO 30 194 -0.21 0.57 323 195 LiCl-HiO 32 198 -0.22 0.56 ' 328 280 LiCl 45 44 Heating Ventilating Air Conditioning Guide 1939 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. CONCENTRATION, PER CENT o31 cr Q_ aor Fig. 2. Temperature--Pressure--Concentrations for Lithium 'Chloride 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 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. 46 Chapter 2. Refrigerants and Air Drying Agents 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 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. 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 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] ^ [1000 + (M X 42.37)]. . ' PROBLEMS IN PRACTICE 1 9 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 Fj2 vapor when compressed to 99.6 lb gage? The absolute pressure is 99.6 plus 14.7 or 114.3 lb. In Table 2 find that one pound of Fn 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 t 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 lb 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 3 note that the saturation temperature at this pressure is 75 F (nearly) and that the heat 47 Heating Ventilating Air Conditioning Guide 1939 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-2HsO. 6 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 One thousand pounds of air per minute at 100 F dry-bulb with a dew-point of70 F and a relative humidity of39 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 to maintain these conditions, and (b) the temperature rise of the solution in passing through the absorber. . The heat content of the entering air: From Table 6, Chapter 1, weight of vapdr 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 lOO^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. j 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. . . 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 -s- 1340 = 13.31 F. Chapter 3 PHYSICAL AND PHYSIOLOGICAL PRINCIPLES OF AIR CONDITIONING Vitiation o 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 `A.S.H.V.E. Research Report No. 921--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.H. Transactions. Vol. 38. 1932. p. 191). Heating Ventilating Air Conditioning Guide 1939 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.''6. . 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 `A.S.H.V.E. Research Report No. 959--Indices of Air Change and Air Distribution, by F. C. Hough- ten and J. L. Blaclcshaw (A.S.H.V.E. Transactions, Vol. 39, 1933, p. 261). . `A.S.H.V.E. Research Report No. 1031--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. Weils, (Journal Industrial Hygiene, November. 1935). . `Preventive Medicine and Hygiene, by Milton J. Rosenau (6tb 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 (Science. 1935. 82 p. 280). * , 50 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 skint 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. Iri 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 t6 conserve body heat. The sweat glands become inactive. 'A.S.H.V.E. Research Report No. 830--Heat and Moisture Dosses from the Human" Body and Their Relation to.Air-Conditioning Problems; by F. C. Houghten, W. W. Teague, W. B. MillSrand W. P.-'Yant (A.S.H.V.E. Transactions, Vol. 35, 1929, p. 245). . ' - * - - ' - 51 Heating VentiiiAting Air Conditioning Guide 1939 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 Works Emcnvs Temp Actual Cbsek Temp (Deg Fjhs) 60 70 80 96.1 85 96.6 90 97.0 95 97.6 100 99.6 105 104.7 no Men at Rest Men at Wonx 90,000 ft-lb or Work per Hour Rise io Rectal Temp (Deg Fahr per Hour) Increase in Pube Rate (Beats per Mio 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 Mio per Hr) Approximate Loss io Body Wt by Per spiration (Lb per Hr) 0.0 0.0 0.1 0.3 0.9 2.2 4.0 5.9>> 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 I-aboratory. ^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 A.S.H-V.E. Research Report No. 719--Basal Metabolism Before and After Exposure to High Tem peratures 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). 52 &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, Moss10 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 biood 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 ol the spinal cord is markedly affected. The organism may finally pass into an unconscious state which ends in death. Brody (Proceedings Society VofId. "Loc. Cit. Note 5. Bio/. Afed/i Vol. 24,1927. p.832}. ^^lntesunal lract' UPOn the Mlner'. by K- N- MoSS 53 0/ Heating Ventilating Air Conditioning Guide 1939 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 notexposed 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- 1S. 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 - . .. ' x ' 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 secpnd 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. Supemaw, 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).-. ... . . . f. .. - `Iron Foundry Workers Show Highest: Percentage of Deaths fromrPneumonia {Statistical .Bulletin. Metropolitan Life Insurance Company, 1928). ...x . _ `The Pneumonia Problem in the Steel Industry, by D. K. Brundage and J. J. Bloomfield, {Journal of Industrial Hygiene, 14, December, 1932). . ... . 54 Chapter 3. Physical & Physiological Principles of 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 view's 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 (dry- kUjk) ^or air an<^ ahout 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. 40. it3 RelaUon to Human Welfare, by C. A. Mills (A.S.U.V.E. Transactions, Vol. Heating Ventilating Air Conditioning Guide 1939 Fig 1. Effective Temperature Chart Showing Normal Scale'of Effective Temperature. Applicable to Inhabitants of the United States Under. . Following Conditions: .. , Custom.-,rv indoor clothing. B: Activity: Sedentary or light muscular, work. C. Heating Methods: Convection type. i.c. warm air, direct steam or hot water radiators, plenum systems.. 56 Chapter 3. Physical & Physiological Principles of Air Conditioning ditions. A series of tests19- **51-92 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 an 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 .`'AS.H.V.E. Research Report No. 673--Determining Lines of Equal Comfort, by F. C. Houghten and C. P. Yaglou (A.S.H.V.E. Transactions. VoL 29, 1923, p. 361). c.. nA^ IV.E. Research Report No. 691--Cooling Effect on Human Beings by Various Air Velocities, oy K Houghten and C. P. Yaglou (A.S.H.V.E. Transactions, Vol. 30, 1924, p. 193). W J????S.c5i_RBPOT No- 717--Effective Temperature with Clothing, by C. P. Yaglou and w. ts. Miller (A.S.H.V.E. Transactions, Vol. 31. 1925, p. S9). Worldne P,:i>9KT No. 755--Effective Temperature for Persons Lightly Clothed and VoL 32,B1926 p1 315) by F' C' Houghten- w- w- Teague and W. E. Miller (A.S.H.V.E. Transactions. 57 -X Heating Ventilating Air Conditioning Guide 1939 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. - Chapter 3. Physical & Physiological Principles of Air Conditioning 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 (warm wall room), the cooling effect of three cold walls at 55 F ofgthe experimental room was 4 F. Therefore, for the same feeling of warmth, ' 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 oc 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 -A.S.H.V.E. Research Report No. 946-Cold Walls and Their Relation to the Filing of Warmth, - by F. C. Houghten and Paul McDermott (A.S.H.V.E. Transactions, VoL 39, 1933, p. 83). . 58 a- . 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. 59 Heating Ventilating Air Conditioning Guide 1939 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 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 60 Fig. 5.- 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 <lGg.-;ET conducive to comfort in 50 per cent or more of the experimental subjects. - The most popular effective temperature was found to b.e 66 deg, and was adopted by the Society26 as the winter comfort line foc indiyiduajs at rest wearing custom ary winter clothing. ... . The comfort line separates the cool;,a.tr conditions to its left from the warmair conditions to its right. Under the air conditions existing along or denned by the comfort line, the body is able to maintain thermal and<KBOD<:aB^tf^if/PSnuiS0Sinito Premature Nurseries in Hospitals, by C. P. Yaslou. Philip Drinker U' B ckfan (A.S.H.V.E. Transactions, Vol. 36. 1930, p. 383). Vol. 38^932 p^iO)' EfIeCtive T'u'Perature index and Comfort Charts (A.S.H.V.E. Transactions, 61 Heating Ventilating Air Conditioning Guide 1939 Fig. 6. A.S.H.V.E. Comfort Chart for Air Velocities of 15 to 25 fpm......... (Still Aie)" 27 Note.--Both summer and winter comfort zones apply to inhabitants of the United States only. Appliestion of winter comfort line is,further limited .to rooms heated by cental station systems of the convection type. The line does not apply to roojns; heated by radiant methods. Application of summer comfort line is limited'to homes, offices ana tWlikei where the occupants becouie fully adapted to the artificial air con ditions. The line does not apply to cheaters, department stores, and the like Where the exposure is less than 3 hours. . . - ...... i . .- ' equilibrium with its environment withrthe 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. wall surfaces. The comfort zone tests were **A.S.H.V.E. Research. Report No. 673--Determination of the Comfort Zone With Further Verifi cation of Effective Teinperatuies Within This Zone, by F. C. Houghten and C. P- Yagleu (A.S.H.V.E. Transactions, Vol. 29. 1923. p. 361). . . **The Sunimer Comfort Zone; Climate and Clothing, by C. P. Yaglou and Philip Drinker (A.S.H.V.E. Transactions. Vol. 35, 1929, p. 269). - 62 &Chapter 3. Physical Physiological Principles of Air Conditioning 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 riot in all, these conditions will be well within the extreme comfort zone as determined experimentally. 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 born 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 cent25. 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.** **Loc. Cit. Note 27. flLoc. Cit. Note 24. .: , - "Ventilation (Report N. Y.'State Commission on Ventilation. E. P. Dutton and Co.. N. Y., 1923). 63 Heating Ventilating Air Conditioning Guide 1939 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 worn81. 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 persons 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 given due 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,* ** MLoc. Cit. Note 22. **Loc. Cit. Note 27. ^A.S.H.V.E. Research Report No. 1012--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. Trans actions, Vol. 41, 1935, p. 207). 64 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 York34, 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 cooling 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 used with 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 now going on at the A.S.H.V.E. Laboratory and other interested institutions may throw considerable light on this complex problem. For cooled banks and stores where the customers come and go spending w Aif 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). u A.S.H.V.E. Research Report No. 1035--Comfort Standards for Summer Air Conditioning, by F. C. Gutberlet (A.S.H.V.E. Transactions. Vol. 42. 1936. p. 215). A.S.H.V.E. Research Tou Requirements for Summer Air Conditioning, by F. C. Houghten, F. E. Giesecke. Cyril llSepMl)Gutberlet (A.S.H.V.E. Journal Section, Healing, Piping and Air Conditioning, December, Heating Ventilating Air Conditioning Guide 1939 Table 2. Desirable Inside Conditions in Summer Corresponding io Outside Temperatures3 Occupancy Over Jfl Min - Outbids Dbt-Bulb Deo F 100 95 90 85 80 Temperature 75 75 75 75 74 74 74 74 74 73 73 73 73 72 72 72 72 71 71 71 71 Inside Am Conditions Dry-Bulb Deg F 83 82 81 80 82 81 80 79 78 81 80 79 78 80 79 78 77 78 77 76 75 Wet-Bulb Deg F 66 67 68 70 64 66 67 68 70 63 64 66 67 61 63 64 66 61 63 64 66 Dew-Point Deg F Relative Humidity Per Cent 56 40 59 45 61 51 65 60 53 36 57 44 60 51 62 57 66 68 _________ a_____ 52 36 54 41 59 50 61 56 48 . 53 56 60 32 41 46 56 49 36 54 45 57 52 61 61 Applicable to individuals engaged in sedentary or light muscular activity. 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 "How Cool? Inside Temperature Should Depend Upon Type of Occupancy, by J. H. Walked (Bealint and Ventilating, October, 1932). - 66 Chapter 3. Physical & Physiological Principles of Air Conditioning 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 371 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 growth" 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, 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. In mild weather comparatively high relative humidities 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 mois ture 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 elsewhere43. 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). M af^cJ.ions of th* asal Cavity and Post-Nasal Space to Chilling of the Body Surfaces, by A. Goldman, ep.ta1i.5a1)n.d Concurrent Study of Bacteriology of Nose and Throat (Journal Infectious Diseases. 1921. Vol. 29 OtoLT^ihioL^Sd0^^^!^?^110113 f the NoSC' Pharynx Tonsils, by Mudd, Stuart, et al (Am. ^Loc. Cit. Note 24. "Humidity and Comfort, by W. H. Howell (The Science Press, April, 1931). WS Temperature and Sense of Comfort, by U. Miura Bulletin jA' P' Kratz* University of Illinois (Engineering Experiment Station Heating Ventilating Air Conditioning Guide 1939 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 MLoc. Cit. Note 3. Chapter 3. Physical & Physiological Principles op 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) Type op Occupants Air Space per Person Cu Ft Outdoor Air Supply CFM per Person Heating season with or without recirculation. Air not conditioned. Sedentary 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.__ Grade school children of average class.......................... Grade school children of average class............................ Grade school children of average class............................ Grade school children of average class............................ Grade school children of poor class.................................. Grade school children of better class.- .......................... Grade school children of best class_______ ___________ 100 200 300 500 200 100 200 300 500 200 200 100 25 16 12 7 23 29 21 17 11 38 18 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 hown 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. 69 X Heating Ventilating Air Conditioning Guide 1939 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 Laboratory46 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 summer time when the air Fig. 7. Relation Among Rate of Air Change per Occupant, Moisture Content 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 4`A.S.H.V.E. Research Report No. 1016--Classroom 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). , 70 &Chapter 3- Physical Physiological Principles of Air Conditioning Table 4. Relation Between Metabolic Rate and Activity3 Hourly Meta bolic Rate por Avo. Person or Total Heat Dissipated, Btu per Hour Hourly Sensible Heat Dissipated, Btu pee Hour Hourly Latent Heat Dissipated. Btu per Hour Average Person Seated at Rest1 Average Person Standing at Rest 384 431 482 Office Worker Moderately Active 490 Clerk, Moderately Active, Standing at Counter.----- Book Binder1.-- Shoe Maker*; Clerk, Very Active Standing at Counter -- Pool Player. .......------- 600 626 661 680 Walking 2 mph. 4; Light Dancing.. Metal Worker*............................... Painter of Furniture*---------------Restautent Serving, Very Busy. 761 862 ' 876 1000 Walking 3 mph*..`................. -...... 1050 Walking 4 mph*. 4; Active Dancing, Roller Skating......... 1390 Stone Mason*...............-................ Bowling.....:........... ...................... -- Man Sawing Wood*--------------- Slow Run4-- Walking 5 mph*.......................... Very Severe Exercise*........ -..... ' 1490 1500 1800 2290 2330 2560 Maximum Exertion Different People4...... ............................... 3000 to 4800 225 159 225 206 225 257 225 265 225 375 225 401 225 436 230 450 . 250 277 . 280 325 . 346 511 585 596 675 704 452 938 490 1000 490 1010 590 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; `Becker and Hamalainen; 'Douglas, Haldane. Henderson and Schneider; Henderson and Haggard; and `Benedict and Carpenter. Metabolic rate9 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 or Perspirations Atmospheric Condition 95 Per Cent Relative Humidity 20 Per Cent Relative Humidity Forehead clammy___ Body clammy_______ Body damp................. Beads on forehead__ Body wet.. Perspiration on forehead runs and drips___ Perspiration runs down body_____ ! E. T. 73.0 73.0 79.0 80.0 84.5 88.0 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 E.T. 75.0 75.0 81.0 8710 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. 71 *1 Heating Ventilating Air Conditioning Guide 1939 M cm X aCd . S3 wi2Mn m ,, g 20^ WW Q -J3 &5P H < C/2 0 {*, 2 03 22 H< f5Miss . 0S13 CJ H .a oo il5e3eae*aac*<oaht>J o * 8 go osl^l 3 I *jCO_ -?=1 &c'3-O-i0-^3 g5|cSq T rt V > ,, W M 91 3 g =*o>2S^UJe Ssl'ssS Sa?tsi is?*-1o3 "'=O q| cEtk. rt u3 553. sofSo - IsSIg-f boJC| SVeS|jeS*a Su --`-.*O0. 3Kvoefj 72 orChapter 3. Physical & Physiological Principles Air Conditioning Table 6. Degrees of Perspiration for Persons at Work Under Various ' Atmospheric Conditions Work Rato 33,000 Ft Lb per Hour Dxqhkx or Perspiration* Atmospheric Condition 95 Per Ceat Relative Humidity 20 Per Cent Relative Humidity E.T. D.B. W. B. RT. D. B. W. B. Forehead clammy--------------------------------------Body clammy---------------------------------------------------------Body damp............... ................ ------------------------------Beads on forehead-------------------------------------------------- Perspiration on forehead runs and drips.------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. E,f,cl^nges bef^"n the Bodie3 of Men Working and the Atmospheric Environment, by F. C. 4l?Si) ' E- MiU'r a"d W- R Yant (American Journal of HygUn'. Vol. XIII. No. 2. FRSRARCh Report No. 921--Changes in Ionic Content in Occupied Rooms, Ventilated by acticws Vol o^1Cal, o,e,th:lsi ^ C P Yagiou. L. C. Benjamin and S. P. Choate (A.S.H.V.E. Trans- Dosure to J-?1!' A.S.H.V.E. Research Report No. 965--Physiologic Changes During Ex- 3^1933 ! w?1 Alc' i^?bPYaglou* AA D Brandt a"d L. C. Benjamin (A.S.H.V.E, Transactions. Vol. Content* of /wRksearch Report No. 985--Diurnal and Seasonal Variations in the Small Ion Vol 40 1^d?7^iJnl?r Air*fbyy C..P. Yaglou and L. C. Benjamin (A.S.H.V.E. Transactions, ?a h v p t?* rll)` The Nature of Ions m Air and Their Possible Physiological Effects, by L. B. Loeb L V Hf-rri^^^AN?^CTIONS>'yo^ J35. p. 101). ,The Influence of Ionized Air upon Normal Subjects, by of UehtN.^V? {Journal Clinical Investigation. 14. January. 1935). The Effect of High Concentrations andKarlIffilAtmosphenc Ions on the Growth and Activity of the Albino Rat. by L. P. Herrington to Certain 'rw^w, {J^rnal ln&: Hygiene, 17. November. 1935). Subjective Reactions of Human Beings Tr^Sct.ons vT 42!"936 pnCl Cnd,tlons- by C.-E. A. Winslow and L. P. Herrington (A.S.H.V.E. Heating Ventilating Air Conditioning Guide 1939 40 5<r e& 70J ' ' eo1 90s" DRY BULB TEMPERATURE 'FAHR. |j Fig. 10. Latent Heat and Moisture Loss from the Human Body by Evaporation, in Relation to Dry-Bulb Temperature for Still Air Conditions Curve A--Men working 66,150 ft-lb per hour. Curve B--Men working 33,075 ft-lb per hour. Curve C--Men working 16,538 ft-lb per hour. Curve D--Men seated at rest. Curves A and C drawn from data at a dry-bulb temperature of 81.3 F only and extrapolating the relation between Curves B and D which were drawn from data at many temperatures. - 50 55". DR* BULB Fig. 11. Heat Loss from the Human Body by Evaporation, Radiation and Con vection in Relation to Dry-Bulb Temperature for Still Air Conditions Curve A--Men working 66,150 ft-lb per hour. Curve B--Men working 33.075 ft-lb per hour. Curve C--Men working 16.533 ft-lb per hour. Curve D--Men seated at rest. Curves A and C drawn from data at a dry-bulb temperature of 81.3 F only and extrapolating the relation between Curves B and D which were drawn from data at many temperatures. 74 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 practicaj 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. "77* British Medical Journal. Editorial. June 25, 1932, p. 1182. See also Loc. Cit. Note 5. 75 Heating Ventilating Air Conditioning Guide 1939 PROBLEMS IN PRACTICE I 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. 2-9 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 AS 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 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 an 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 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 heat 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 -5- 2.4 = 110,400 lb ol air or 110,400 X 13.4 = 1,479,000 cfh of air will be required. This is equivalent to 1,479,000 -s- (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 -J- 11.0 = 82,300 t 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 1,103,000 -5- (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- r perature from rising above the 75 F specified. The wet-bulb temperature will therefore : not rise to the maximum of 65 F. , Chapter 4 AIR POLLUTION Classification of Air Impurities, Dust Concentrations, Air Pollution and Health, Occlusion of 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 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 I micron are unlikely to remain suspended in air currents of moderate strength. Only 77 Heating Ventilating Air Conditioning Guide 1939 violent air motion will sustain them in air long enough for them to be breathed. This means that, in hygienic problems, the engineer is con cerned mostly with suspensions of particles comparable to the common Fig. 1. , Compiled by W. G. Frank and Copyrighted. Sizes and Characteristics of 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 78 ; Chapter 4. Air Pollution Table 1 Approximate Limits of Inflammability of Single Gases and Vapors ' in Air at Ordinary Temperatures and Pressures3 ................... Gas or Vapor 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.................... i................. Gasoline...................................... 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.. *"nammaoiUty ot Mints, BuUtttn No. 279, 1931). Lower Lncrr Volume in Per Cent Higher Limit Volume in Per Cent 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 J. Coward and.G. W. Jones, (7. 5. Bureau of 79 / Heating Ventilating Air Conditioning Guide 1939 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 for 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 100ft 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 Grains Per-1000 Cu Ft Mgs Pbb Cu M 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 M 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 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. *Nattonal 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. ' 80 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 Rapiolt Fatal Maximum Concentration for PROM H to 1 Hour Maximum Concentration fob 1 Hour Maximum Allowable roa Prolonged Exposure Carbon monoxide.............. Carbon dioxide............... .. Hydrocyanic acid.............. Ammonia......... .................... Hydrochloric acid gas.----- Chlorine......... ..--.......... -- Hydrofluoric add gas....... Sulphur dioxide---------...... Hydrogen sulphide______ Carbon bisulphide. Phosphene........................... Arsine------- ------------:........... Phosgene.............................. Nitrous fumes..................... Benzene........................... .... Toluene and xylene........... Aniline.................................. Nitrobenzene. Carbon tetrachloride........ Chloroform.......................... Tetrachlorethane....... ........ Trichlorethylene......... ,,..... Methyl chloride............ .. Methyl bromide................. Lead dust--.......................... Quartz dust......................... 40 800-1000 30 50-100 10-20 10 2 4-5 10-30 20 2H Over vA-m 190 190 480 250 73 370 1500-3000 200-400 15-20 1A 25 A A Ho H-l 5-7 11 4-6 A M i-l A 240 140 200-400 20-40 10 H 3 2-3 5 1-2 A 31-47 31-47 1-1A Hoo 40 50 70 10 1 H 1 Ho Hoo H3 Ho 1 A Hoo A 1H-3 Ho Hoo 1 2 Ho 5-10 2 0.15 mg/cu m 1 mg/cu m .Adapted from Y. Henderson and H. Haggard. (See Noxious Coses, 19S7, and Lessons Learned from industrial Cases 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, an" 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.2" aanndd Sayers /(Ii/T. 5t. Pdurbh*c ,,H'elal,ltuh,eRei-peonrttso,n4e9a:8i 0t,is1s9u3e4)t.o 81 ~y;rSK;- Heating Ventilating Air Conditioning Guide 1939 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. . Occlusion of Solar Radiation - 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 Baltimore* 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. SMOKE AND AIR POLLUTION ABATEMENT , Successful abatement of atmospheric pollution requires the combined I efforts of the combustion engineer, the public health officer, and the I public itself. The complete electrification of industry and railroads, and the separation of industrial and residential communities would aid materially in the effective solution of the problem. In the large cities where the nuisance from smoke, 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 dust catching devices. The gases of combustion are usually discharged at Effects of Atmospheric Pollution Upon Incidence of Solar Ultra-Violet Light, by J. H. Shrader, M. H. $ Coblcntz and F. A. Korff {American Journal of Public Health, p. 7, Vol. 19. 1929). ; Studies in Illumination, by J. E. Ives {U. S. Public Health Service Bulletin No. 197, 1930). # iv ^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). ] 82 Chapter 4. Air Pollution 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 with the air required for combustion. These jets are especially helpful for the first few minutes after each firing. : Frequent firings of small charges shorten the smoking period and reduce the density. Thinner 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 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 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. ' Legislative measures at the present time are largely concerned with the smoke discharged from the chimneys of boiler plants. Practically all of the ordinances limit the number of minutes in any one hour that smoke of a specified density, as measured by comparison with a Ringelmann Chart (Chapter 44), may be discharged. ., These ordinances do not cover the smoke discharged at low levels by automobiles, and, although they, have been instrumental in reducing the smoke emitted by boiler plants, they have, in many instances, increased e output of chimney dust and cinders due to the use of more excess air and to greater turbulence in the furnaces. .. ............ Legislative measures in general'have not as yet covered' the nqxious 83 Heating Ventilating Air Conditioning Guide 1939 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 hasbeen 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 coals when they are burned on a grate. Modern 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 studies^ 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. Ives et al {U. S. Public Health Bulletin No. 224, March, 1936). ' .. . . 84 Chapter 4. Air Pollution REFERENCES Bulletin, Air Hygiene Foundation, Inc., Pittsburgh, Pa. . rwermination and Control of Industrial Dust, by J. J. Bloomfield and J. M. Dalla Valle (y. 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; (6) 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 1.0 micron to 150 microns are called dusts (micron = H5,000 `n-)-. Particles resulting from sundry chemical reactions and ranging from 0.1 to 1.0 micron in si'ze 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. C Why is atmospheric pollution an important engineering problem? a. Certain impurities, when present in too great concentrations, cause ill health or even death. b. High concentrations of solids occlude solar radiations. c. Some materials cause permanent injury to parts of buildings, as sulphur fumes corrode exposed metal. d. Extra cleaning expense is incurred in dusty localities. ' e. Internal combustion engines are damaged by abrasive dusts. ' . cintailed *iazar<^ dust-producing industrial operations best be S?~^r0Vwn mechanical exhaust ventilation sufficient to keep dust concentration at a side ** ^See Ta" e 3) and then removing foreign bodies to reduce the pollution of out- 85 Heating Ventilating Air Conditioning Guide 1939 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 H 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 O Why has not'smoke abatement been more effective? ^ Because communities have not been made sufficiently aware of the possibilities of burning 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 fiy-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 # 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 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 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'shadesof gray, ranging from white toj black. The observer, by patching the cards;agains the shades of smoke coming from a Stack, is able to estimate the blackness of the smoke as compared with the chart. 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 samerate 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 arid 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. 87 Heating Ventilating Air Conditioning Guide 1939 HEAT TRANSFER COEFFICIENTS The symbols representing the various coefficients of heat transmission and their definitions are as follows: U = 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 conductivity 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. 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 de F between the surface and the surrounding air. To differentiate between inside and outside wall (or floor, roof or ceiling) surfaces, /i is used to designate the inside film or surface conductance and /0 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.: -i- = over-all or air-to-air resistance. -i- = internal resistivity. . -i- = internal resistance. . . -j- = 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 : H = AU(t-to) . (1) H = Btu per hour transmitted through the material-of the wall, glass, roof or floor. 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). ' t -- to -- 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. . ..... , 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 h = 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, If the coefficients/i,/o 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, k2 and k3 and thicknesses X\, xt and x3 respectively, and - laid together without air spaces, the total resistance, U (4) For a wall with air space construction consisting of two homogeneous materials of thicknesses X\ and x% and conductivities ki and k2, respectively, separated to form an air space of conductance a, the over-all resistance, _1_ 4r + -f- + -- + 1T+ ~T u fi *i a k* Jo (S) 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 Heating Ventilating Air Conditioning Guide 1939 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 fi and f0 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 lA.S.H.V.E. Research Report No. 869--Surface Conductances as Affected by Air Velocity. Tempera ture and Character of Surface, by.F. B. Rowley, A. B. Algren and J. L. Blackshaw (A.S.H.V.E. Transac tions, Vol. 36. 1930. p. 429). . ^ 90 Chapter 5. Heat Transmission Coefficients and Tables aluminum foil with low emissivity coefficients were substituted, a large part 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 giass.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 pf Tables 3 to 12, 1.65 has been selected as an average inside coefficient and 6.0 as an average outside coefficient or 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 ls conducted across an air space by a combination of radiation, i?n convec.tin.. The amount of heat by.radiation is governed betwppn k na,ture -t*le surface and the temperature difference between ffie boundary surfaces pf the air space. , Conduction and con- 91 Heating Ventilating Air Conditioning Guide 1939 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 at Various Mean Temperatures Mean Temp Deo Fahb 0.128 Conductances op Air Spaces fob 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 1.242 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 ISO 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 M 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. 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 lining 'Aluminum Foil insulation (National Bureau of Standards Letter Circular No. LC465. June? 1936). 92 5.Chapter Heat Transmission Coefficients and Tables d there is but a small amount left to be stopped by the second surface ^n- The 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 x low temperature side of the air space. For materials such as aluminum oaint 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 7 materials as applied, although they are frequently used for that purpose, f 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 j` a thickness of H in.. Certain types of blanket installations are designed i 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 1 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 93 Heating Ventilating Air Conditioning Guide 1939 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 (U) of an 8-in. brick wall and in. of plaster 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 (XT) of an 8-in. brick wall with H 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 -- 4.0 in.; k (common low density brick) = 5.0; x = 4.0 in.; k (plaster) = 3.3; x = in.;/; = 1.65;/0 = 6.0, Therefore, _L i 4,0 +0 05 1 6.0 + 9.20 + 5.0 + 3.3 + 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),/;,/<, 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 (/;) 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: . : ; i -\ . ' V ~ ----------------------------------- = 0.48 Btu per hour per square foot per degree difference . 1 0.781 M_ . 1.65 + 0.80 + 12.0 .' ( 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 i nominal thicknesses. The computations for. wood shingle roofs applied' i 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 l Spanish and French clay roofing tile, of which there are many varieties, * the figures forsuch types of roofs were taken the same, as for slate roofs, as | Chapter 5. Heat Transmission Coefficients and Tables Table 2. Conductivities (k) and Conductances (C) of Building ' Materials and Insulators3 sufficients are expressed in Btu per hour per squarefoot Per degree Fahrenheit per 1 in. thickness coej/ . ~ unless otherwise indicated. . ; | A u t h o r it t Description Material Fine Coarse Cement Aggre gate Aggre gate Slump 0-No. 4 No. 4-H Per Cent Voids Concrete----------------------- ------ 1 1 1 1 1 1 1 1l 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 S 14.6 5 . 14.7 5 14.7 oD gg dW6S. 144.7 145.7 144.5 142,5 142.5 141.1 141.1 139.2 139.2 s s -i -io Tg a iege< B 1 ssSj Pg Po OO s 11 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 12.85 12.50 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 (4) (4) 4) (4) (4) (4) (4) (4) (4) Avg. Value for Sand and Gravel Concrete___ 142.3 Limestone Concrete------------ 1 1 1 1 1 1 2.00 2.75 3.50 2.00 2.75 3.50 2.75 4.50 5.50 2.75 4.50 5.50 0 16.6 13S.3 0 15.4 137.8 0 16.3 136.4 3 20.9 130.1 3 23.4 126.0 3 23.4 127.3 -- 74.87 75.18 74.75 74.85 74.45 75.26 12.62 11.20 12.00 11.50 10.50 10.00 9.79 -- 0.09 0.08 0.09 0.10 0.10 0.10 - (4) (4) (4) (4) (4) (4) Avg. Value for limestone Concrete. ------------: 132.15 -- . 10.83 - Cinder Concrete_______ ____ 1 1 1 1 1 1 2.00 2.75 3.50 2.00 2.75 3.50 2.75 4.50 5.50 2.75 4.50 5.50 0 18.2 103.6 75.26 4.63 0.22 (4) 0 0 19.9 21.4 98.7 75.71 4.30 92.0 75.72 3.73 0.23' (4) 0.27 (4) 3. 22.8 101.4 74.95 4.89 0.20 (4) 3 26.0 94.0 75.20 4.38 0.23 (4) 3 24:4 94.4 75.55 4.24 0.24 (4) Avg. Value for Cinder Concrete __ . 97.35 4.86 ___ ; ' _ Hatditr <..- 1 2.00 2.75 0 18.0 80.7 74.82 4.15 0.25 (4) 1 1 2.75 3.50 4.50 5.50 0 19.8 75.0 75.75 3.78 0.26 (4) 0 21.8 71.7 74.82 3.67 0.27 (4) 1 1 2.00 2.75 2.75 4.50 4 21.2 4 `22.2 78.8 74.76 4.38 72.4 75.39 3.89 0.23 0.26 (4) (4) 41 2.75 4.50 4 22.2 72.4 75.49 3.86 0.26 (4) 1 3.50 5.50 23.9 71.0 75.46 4.00 0.25 (4) Avg. Value for Haydite____ ........-.... 74.57 .73.96 - __ Authorities: . .` lU. 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 and C. M. F. Peterson, tests conducted at the Massachusetts Institute of Technology 'Recommended conductivities and conductances for computing heat transmission coefficients tror thickness stated or used on construction, not per I-in. thickness. "For additional conductivity data see Chapters 3 and 15, 1937 A.S.R.E. 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, editicm 932Cnded va ue' ^ Heatin8- Ventilating and Air Conditioning, by Harding and Willard, revised Rei>ort No- 915--Conductivity of Concrete, by F. C. Houghten and Carl Gutberlet (A.S.H.V.E. Transactions. Vol. 38, 1932, p. 47). 9 &*in., 8-in. and 10-in. hollow tile figures are based on two cells in the direction of heat flow. The \fi " 4e.ls ^sed or? lhre? cella in the direction of heat flow. The 16-in. hollow tile consists of one lw*,/Kra?" one ",n* tile, each having two cells in the direction of heat flow. 'Not compressed. assumed^O 25 ^in' th'Ck ^'34 Ib per stJ ft)- covered with gravel (0.83 lb per sq ft), combined thickness Cnee'S}115Fr SPa"S or surfaces having an effective emissivity of c = 0.83 and for a temperature differ- enee'S'l"/01"air space3 or surfaces having an effective emissivity of i - 0.05 and for a temperature differ- ; 95 Heating Ventilating Air Conditioning Guide 1939 Table 2. Conductivities (k) and Conductances (C) of Building Materials and Insulators8--Continued The coefficients are expressed in Bln per hour per square foot per degree Fahrenheit per 1 in. thickness unless otherwise indicated. Material Description Fine Coarse Cement Aggre gate gate Slump 0-No. 4 No. 4-M Per Cent Voids oP |i <S5 Expanded Burned Clat_____ S .Steam Treated Limestone laq Pumice Mined in Calif 1 1 1 8.00 7.00 8.00 18.4 27.1 26.5 57.9 74.6 65.0 Bt-Pboduct of Manufacture of Phosphates____ 1 1 8.00 8.00 Modulus 3.75 25.5 21.1 86.6 91.1 Haydite__ 1 8.50 1 8.50 21.8 21.8 67.1 67.1 ri}0 Ofl -*r- Sand and gravel aggregate.. Sand and gravel aggregate used for calcu lations. Cores filled with 5.14 lb density oork_. Crashed limestone aggregate----------- Cinder aggregate. Cinder. ___,_te__used for calculations. Cores flW with 69.7 lb density cinders.. Cores filled with 5.12 lb density cort_ Cores filled with 14.2 lb density rock wool__ Haydite wpfrragnte - ............ Cores filledwith 5.06 lb density oork_____ 134.3 86.2 J? g oo SB Ogo Oo 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 0.900f l.OOOf 0.560f 0.856f 0.577f 0.600t' 0.390f 0.250f ` 0.266f 0.49Sf 0.2061 I-** -|0 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 4) W (4) tti ' /~\ fll >1 Sand and gravel aggregate.. Sand and gravel aggregate used for calcu lations. ` Cinder aggregate....... ... .........;_______ Cores filled with 5.24 lb density cork-- Ha. _yd_ite aggregate.. Cores fillea with 5.6 lb density cork.. 86.2 ITT -.sf- 0.777f o.soot 0.531f` 0.237f 0.468f 0.168f 1.88 4.22 2.13 5.94 H Cinder aggregate-------LI------------------------ 100.0 Double wall with 1 in. air space between--. 100.0 1 in. space filled with 9.97 lb density rock wool 100.0 l.OO^t 0 358t 0.204f 1.00 2.70 4.90 5 x 8 x 12 block sand and gravel aggregate-- 0.380f (4) Hiffl 5x8x12 block sand and gravel aggregate*. For notes see Page 95. 96 0.947t 1.06 (4) Chapter S. Heat Transmission Coefficients and Tables Table 2. Conductivities (fc) and Conductances (Q of Building Materials and Insulators3--Continued -- tire expressed in Btu per hour per square foot per degree Fahrenheit per l in. thickness The coefficients are exprc* unless otherwise indicated. . Material Description Density (Lb per Cu Ft) Ssi'Sta* l5a s rKrp 1 t3 D0 S So OO T t 5 o a1 aoB & < masonry materials Brice-------------------------- Baicxwoai-----....... Cucsirr Mobtab------- -------Concrete----------------- Cellular____ 40.0 Cellular____ ------- .. 50.0 Cellular 60.0 Cellular____ ... . 70.0 Typical fiber gypsum, 87.5% gypsum and 12.5% wood chips-------- . 51.2 Special concrete made with an aggregate of hardened clay--1-2-3 mix__ . 101.0 Typical hollow clay (4 in.)........... ..... ....... Typical hollow clay (6 in.)* ................. Hollow clay (2 in.)H-in. plaster both sides___ 120.0 Hollow clay (4 in.) H-iq. plaster both sides___ 127.0 - Hollow clay (6 in.) H-in. plaster both sides.__ 124.3 Solid gypsum_______ Solid gypsum_____ Tile ob Terraszo_____ ___..... Typical flooring - 51.8 ._ 75.6 IN8ULATION--BLANKET OR FLEXIBLE TYPES Chemically treated wood fibers held between layers of strong paper/ 3.62 Eel grass between stroang paper/___ 4.60 3.40 Flax fibers between strong papa1/ . 4.90 Chemically treated bog hair between kraft paper/____ . ..... ........... . .. 5.76 Chemically treated hog hair between kraft paper and asbestos paper/ 7.70 Hair felt between layers of paper/ 11.00 Kapok between burkp or paper/ 1.00 Jute fiber/._________ .. . 6.70 Ground paper between two layers, each Hrin. thick mode up of two layers of kraft paper (sample in. thick)- 12.1 INSULATION--SEMIRIGID TYPE IN80LATI0N--LOOSE FILL OR BAT TYPE friars For notes see page 95. Flat/ Flax and rye/_____ ____ Felted hair and asbestos/. 75% hair and 25% jute/ 50% hair and 50% jnttJ Jute/ Felted jute and asbestos/____ Compressed peat mrwn a 11.00 12.10 13.60 7.80 6.30 6.10 6.70 .... 10.00 11.00 1.60 75 75 75 75 74 70 110 100 105 70 76 -- 70 90 90 90 71 71 75 90 75 75 90 70 90 90 90 90 75 90 70 j- 75 5.00' 9.20* 5.00* 12.00* 12.00* 16.36 1.06 1.44 1.80 2.18 1.66* 3.98 12.50* 12.00* l.OOf* 0.64f* 0.60f* 0.40f* 0.31f* l.OOf 0.60| 0.47f 0.46f* 1.66 2.96 12.00* 0.20 0.11 0.20 0.08 0.08 0.94 0.69 0.56 0.46 0.60 0.25 0.08 0.08 1.00 1.57 1.67 2.50 3.23 1.00 1.67 2.13 2.18 0.60 0.34 0.08 0.27* . 3.70 0.25 0.26 0.25 0.28 4.00 3.85 4.00 3.57 0.26 3.85 0.28 0.25 0.24 0.25 3.57 4.00 4.17 4.00 0.40f 2.50 0.26 0.30 0.32 0.28 . 0.27 0.26 0.25 0.37 0.26 3.84 3.84 3.33 3.12 3.57 3.70 3.85 4.00 2.70 3.84 0.24 4n 4.17 (2) (5) ) (3) (3) (3) (O (3) __ (2) (2) (2) (4) (4) (3) (U (!) (1) (3) (3) 3) (1) (i) (4) 0) (1) (3) (I) (t) m (1) (3) 1) (3) (3) (3) Heating. Ventilating Air Conditioning Guide 1939 Table 2. Conductivities (k) and Conductances (C) of Building Materials and Insulators*--Continued The coefficients are expressed in Blu per hour per square foot per degree Fahrenheit Per 1 in. thickness unless otherwise indicated. Material Description fK P o eUs od. ha 3g la iT ig i ii fc as E < INSULATION--LOOSE FILL OR BAT TYPE --Continued Oranth-ar _ __ INSULATION-RIGID BUILDING BOARDS For notes see Page 95. meter, made from virgin bottle glass_____ Made from combined silicate of lime and Made from expanded aluminum-magnesium .. 1.50 9.40 103 1.50- 75 6.32 86 90 90 a aa a aa a a aa a 24.00 18.00 75 a a a a a-- Rock wool with a binding agent______ r....... Rock wool with flax, straw pulp, and binder 21.00 18,00 14.00 14.50 14.50 11.50 From maple. Seech and birch (coarse)______ 13.20 5.00 90 90 90 77 75 72 90 90 75 0.27 0.27 3.70 3.70 (3) (1) 0.27 3.70 (3) 4.17 (3) 0.29 1.00 0.77 0.59 0.44 0.60 0.52 0.48* 0.35 0.27* 0.31 0.30 0.28 0.27* 0.33 0.38 0.41 0.41 0.36 0.31 0.26 3.45 1.00 1.30 1.69 2.27 1.67 1.92 2.08 2.86 2.94 3.70 3.22 3.33 3.45 3.57 3.70 3.03 2.63 2.44 2.44 2.78 3.22 . 3.84 (3) (D (1) (1) (1) (1) (1) (3) (1) (3) (1) (1) > U) (i) (3) (3) (1) (1) (1) (1) (3) aa 'a a a a Chemically treated hog hair covered with " * exploded wood fibere_____ ______ Insulating plaster 9/10-in. thick applied to " " 85% magnesia and 15% asbestos " " shredded wood and cement Sugar cane fiber insolation blocks encased in aa aa ' aa a 10.60 7.00 14.50 90 90 0.30* 0.34 0.27 0.25 P.32 0.33* 10.00 17:90 75 71 78 70 0.28 0.33 0.32 0.32 54.00 16.10 19.30 24.20 75 81 . 86 72. 70 1.07f 0.34 0.51 . 0.46 0.33 13.80 17.00 15.90 15.00 8.50 16.90 70 68 72 70 52 72 90 0.30 0.33 0.33 0.33 0.33 0.29 0.33 0.34 3.33 2.94 3.33 3.70 4.00 3.12 3.03 3.57 3.03 3.12 3.12 0.93 2.94 1.96 2.17 3.03 3.33 3.03 3.03 3.03 3.03 3.45 3.03 2.94 (1) (1) (1) (1) (1) (3) (3) (4) (3) (3) (3) U) (3) (3) . (3) (3) (3) ((63)) (3) (i3n) Compressed cement and asbestos sheets_____ 123.00 86 Corrugated asbestos board_________________ 20.40 110 2.70 0.48 0.37 2.08 (1) (2) CONDUCTIVITT (A) OB Conductance (C) J A u t b o r it t Chapter 5. Heat Transmission Coefficients and Tables Table 2. Conductivities (k) and Conductances (C) of Building 1 Materials and Insulators*--Continued ,, A~v.fi are expressed in Blu per hour per square fool per decree Fahrenheit per 1 in. thickness The coefficten unless otherwise indicated. Material Description <5 bE0ZM3 aAMW, _5 ad S a S S9 pp ogo ogo > SB aa 33 PS PS BUILDING BOARDS --Continued _ ' Pressed asbestos mill board------------------------ 60.50 Gypsum between layers of heavy paper..___ 62.80 Rigid, gypsum between layers of heavy Gypeum mixed with sawdust between layers of heavy paper (0.39-in. thick)___________ io.) 60.70 ROOFING construction 70.00 Built up, bitumen and felt, gravel or slag Plaster board, gypsum fiber concrete and 3-ply roof covering 2^i in. thick------------- WrtnH 52.40 65.00 70.00 201.00 plastering materials Gypsum and expanded ahiminuro-magne- ' Metal Lath and Plaster...Wood Lath and Plaster . %-in. plaster, total thickness in._________ BUILDING CONSTRUCTIONS 1-in. fir sheathing, building paper, and 1-in. fir sheathing, building paper and stucco Pine lap siding and building paper--siding 39.9 -- -- 40.00 AIR 8PACE AND SURFACE COEFFICIENTS Over % in. faced ordinary building materials 3% in. faced ordinary building materials . Horizontal, heat flow upward, e -- 0.834_ Horizontal, heat flow downward, e -- 0.83* 3% in. faced reflective building materials Horizontal heat flow upward, e = 0.05*__ Surfaces, Orrtnart Horizontal, heat flow downward, e = 0.05` Horizontal heat flow upward, e -- 0.83(/i)k Horizontal heat flow downward, e = n 83(7:1* Surfaces, Rough Stucco Surface, Ruvi.RrmvTs Horizon tal, heat flow upward, e -- 0.05(/|)` For notes see Page 95. Horizontal heat flow downward, e = 0.05(/i)<_- -- -- -- -- -- 86 0.84 70 1.41 2.60f 90 3.60f 3.73f* 2.82t* 75 6.50t* 3.531* 1.33 76 0.58f 75 6.00t* 75 6.50f* 10.37* !> 1.28f* 8.00 75 0.85 73 8.80f 4.40f* 70 2.501* 30 0.86t* 20 0.50f* 20 0.82 16 0.8Sf* 1.281* 75 1.20 1.361* l.lOt* 1.32 1.17 -- 0.94 0.56 0.41 0.17 l-65f - 1.951 1.521 1.211 6.001* 9. OOf 0.80f - 1.161 Q.741 0.44f 1.19 0.71 0.28 0.27 0.35 0.15 0.75 1.72 0.17 0.15 0.10 0.78 0.13 1.18 0.11 0.23 0.40 1.16 1.22 0.78 0.83 0.74 0.76 0.86 1.06 1.79 2.44 5.88 0.51 0.66 0.83 0.17 0.11 0.86 1.35 2.27 (1) (2) (3) (1) (I) (3) (2) (4) (3) (3) (7) (2) (3) (4) (4) (4) (4) (4) (4) (3) (4) (8) (8) (8). (8) (8) (8) (4) (8) (8) (8) (4) (4) (8) 8) (8) (8) Heating Ventilating Air Conditioning Guide 1939 Table 2. Conductivities (k) and Conductances (C) of Building Materials and Insulators3--Continued The coefficients are expressed in Btn per hour per square foot per degree Fahrenheit per 1 in. thickness unless otherwise indicated. Material Description s !I -I3* -|o isD o ii 11 DD t8 | s g. o Is e g la si < AIR SPACES FACED WITH Air space, faced one side with bright alumi BRIGHT ALUMINUM num foil, over 5^-iu. wide ___ 50 0.46f* 2.17 FOIL Air space, faced one side with bright alumi num foil, H-in- wide_________ -- 50 0.62f 1.61 Air space, faced both sides with bright aluminum foil, over wide -- 50 0.41f 2.44 Air sps^e, faced both sides with bright aluminum foil. H-in. wide--------------------- -- " 50 ' 0^571 1775 Airspace divided in two with single curtain of bright aluminum foil (both sides bright) each space over Ji-io. wide SO 0.23t* 4.35 each space H*tn. wide------------------------- 50 0.31f 3.23 Air space with multiple' curtains of bright aluminum foil, bright on both sides, \ curtains mare than &-in. apart, air circu lation between spaces prevented: 2 curtains, forming 3 spaces,_: 3 curtains, forming 4 spaces 50 0.I5P 6.78 , , , 50 o.iit* 9.22 4 curtains, forming 5 spaces____ ________ -- 50 0.09P 11.C6 (4) (4) (4) (4) (4) (4) (41 4) ( SPACES FACED WITH NON- Fabric with non-metallic reflective surface METALLIC REFLECTIVE () in. thick) placed in center of a 13$ in. SURFACE air apa>__ ......................... Core of fiber board coated two sides with -- 70 0.33f 3.03 (3) non-metallic reflective surface (H in thick) placed in space having approxi mately in. air space on each side__ __ 23.4 70 0.27t 3.70 (3) Fiber board coated one side with non- metallic reflective surface (% in. thick) placed in space having approximately in. air space on each side----r--.___ -- 75 0.49f 2.04 (3) Air space divided in two with fabric faced both sides with non-metallic reflective surface, each space over W-in. wide---------- ___ 40 0.33f 3.03 (4) Air space over 9^-in. wide faced one side with noD-mctaUic reflective surface -- 40 0.67t 1.49* (4) WOODS (Acrora Grain) Balsa California Redwood___ 0% mois Douglas Fm_. Eastern Hemlock.. Hard Maple.. 0% moisture.. 0% " 16% 16% 00%% mois 16% 16% 00%%j imoisture. 8% 8% 16% 16% 20.0 90 0.58 1.72 (1) 8.8 90 0.38 2.63/ U) 7.3 90 0.33 3.03 " 22.0 75 0.66 1.53 (4) 28.0 75 0.70 .1.43 (4) 22.0 75 0.70 . 1.43 (4) 28.0 75 0.75 1.33 (4) 22.0 75 0.74 1.35 (4) 28.0 75 0.80 1.25 (4) 28.7 86 0.67 26.0 75 0.61. 1.49 1.64 ((41)) 34.0 7S 0.67 1.49 (4) 26.0 75 0.66 1.52 (4) 34.0 75 0.75 1.33 (41 26.0 75 0.76 1.32 (4) 34.0 75 0.82 1.22 (4) 22.0 75 0.60 30.0 75 0.76 1.67 1.32 !4> 4) 22.0 75 0.63 1.59 (4) 30.0 75 0.81 1.23 (4) 22.0 75 0.67 1.49 (4) 30.0 75 0.85 1.18 (4) 40.0 75 1.01 0.99 (4) 46.0 75 1.05 0.95 (4) 40.0 75 1.08 0.93 (4) 46.0 75 1.13 0.89 (4) 40.0 75 1.15 0.87 (4) 46.0 75 1.21 0.83 (4) For notes see Page 95. Chapter 5. Heat Transmission Coefficients and Tables Table 2. Conductivities (it) and Conductances (C) of Building Materials and Insulators3--Concluded The - ...fe coefficients are are expressed exy in Btu puenr/hMo5uroPtheerrwsqisueareinfdoiocat tPeedr. degree Fahrenheit per l in. thickness D ensitt (Lb per Co Ft) | Authority j Material Description WOODS--Continued Longleap Yellow Pink- Mabooant-------Maple--------------Maple or OakNobwat Pinsl. Red Ctpress- Red Oak-- 0% 8% 8% 16% 16% 0% Q% 8% 16% 0% 8% 8% 16% 0% 0% 8% 8% . gfSaoBTLEAt Yellow Pine... Soft Elm 8% 8% 16% 16% 8f 8% Virginia Pine_ West Coast Hemlock, White PineYellow Pinx_ Yellow Pine or Fm.. 164> 16% 0% 0% 8% 8% 1166%g 0% 0% 8% 8% 16% 16% 0% 0% 8% 8% 16% 16% a a a a a a a a a a * a a a a a a o a a a a' a - a a a For notes see Page 95. , S -h* s ej le g "jT la s 1P D 3g Ozo Pzo oo iSS 30.0 75 0.76 40.0 75 0.86 1.32 1.16 4> (> 30.0 75 0.83 40.0 75 0.95 1.21 1.05 ((44)) 30.0 75 0.89 1.12 (4) 40.0 75 1.03 0.97 4) 34.3 86 0.90 1.11 U 44.3 86 1.10 0.91 (1) 1.15* 0.87 22.0 75 0.62 1.61 (4) 32.0 75 0.74 1.35 (4) 22.0 75 0.68 1.47 (4) 32.0 75 0.83 1.21 (4) 22.0 75 0.74 1.35 4) 32.0 75 0.91 1.10 (4) 22.0 75 0.67 1.49 to 32.0 75 0.79 1.27 (4) 22.0 75 0.71 1.41 4) 32.0 75 0.84 1.19 (4) 22.0 75 0.74 1.35 (4) 32.0 75 0.90 1.11 4) 38.0 75 0.98 1.02 (4) 48.0 7S 1.18 0.85 <41 38.0 75 1.03 0.97 (4) 48.0 75 1.24 0.81 (4) 38.0 48.0 75 75 1.07 1.29 0.94 0.78 4 U) 26.0 75 0.74 36.0 75 0.91 1.35 1.10 54) 4> 26.0 75 0.79 1.27 (4) 36.0 75 0.97 1.03 (4) 26.0 75 0.84 36.0 75 1.04 1.19 0.96 <41 to `28.0 75 0.73 1.37 (4) 34.0 75 0.88 1.14 (4) 28.0 75 0.77 1.30 (4) 34.0 75 0.93 1.08 (4) 28.0 75 0.81 1.24 (4) 34.0 75 0.97 1.03 (4) 36.0 75 0.89 . 1.12 (4) 42.0 75 0.95 1.05 (4) 36.0 75 0.96 1.04 (4) 42.0 75 1.02 0.98 (4) 36.0 75 1.01 0.99 to 42.0 75 1.09 22.0 75 0.54 0.92 1.85 St4o> 28.0 75 0.64 1.56 (4) 22.0 75 0.59 1.70 (4) 28.0 75 0.71 1.41 4) 22.0 75 0.65 1.54 4) 28.0 75 0.78 1.28 4) 34.3 86 0.96 22.0 75 0.68 1.04 1.47 (4) 30.0 75 0.79 1.27 (4) 22.0 75 0.73 1.37 (4) 30.0 75 0.85 1.18 (4) 22.0 75 0.78 1.28 4) 30.0 75 0.91 1.10 (4) 31.2 8_6 0.78 1.00 1.28 1.00 (3) -- -- 0.80* 1.25 101 Heating Ventilating Air Conditioning Guide 1939 Table 3. Coefficients of Transmission (U) of Masonry Walls Coefficients ore expressed in Btu per hour per square foot per degree Fahrenkeii difference in temperature between the air on the two sides, and are based on a wind velocity of 15 mph. TYPICAL CONSTRUCTION TYPE OF WALL Thickness or Masonbt (Inches) _ * Wau No. Solid Brick Based on 4-in. hard brick and the remainder common brick. 8 12 16 2 3 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 10-in. tile consists of one 10-in. tile and one 6-in. tile each having two cells in the direction of heat flow. 8 10 12 16 4 5 6. 7 Limestone or Sandstone 88 12 9 16 10 24 . 11 Concrete (Monolithic) These figures may be used with sufficient accuracy for concrete walls with stucco exterior finish. Cinder (Monolithic) Conductivity k = 4.36 Haydite (Monolithic) Conductivity k = 3.96 \' Cinder Blocks 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. `Based on the actual thickness of 2-in. furring strips. 102 6 10 16 20 6 10. 16 20 6 10 16 20 8 8 8 8 12 12 8 "' 8 12 8 s. 12 12 12 13 14 15 10 17 18 19 ; 20 \ 21 22 s 23 ' 24 25 ; 26 27 , 28 ` 29 ; 30 ; 31 32 i 33 ; l 34 i 35 36 1 Chapter 5. Heat Transmission Coefficients and Tables interior finish 103 Heating Ventilating Air Conditioning Guide 1939 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 Wl Na 4 in. Brick Veneer* 6 in. 8 in. 10 in. Hollow Tile* 12 in. 37 38 3499 ' 4 in. Brick Veneer* 6 in. 10 in. Concrete 16 in. 41 43 43. j 4 in. BrickTVeneer* 8 in. Cinder Blocks 8 in. Cinder Blocks -- Corea 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--Core9 filled with granulated cork, 5.6 lb per cu ft. 44 43 46 47 .48 49 50 51 52- : 53 54. ` 4 in. Cut-Stone Veneer* O IQ. 12 in. Common Brick 16 in. 55 . 56 ; 57 4 in. Cut-Stone Veneer* 6 in. 8 10 in. in. Hollow Tile* 12 in. 4 in. Cut-Stone Veneer* 6 in. 10 in. Concrete 16 in. Computed from factors marked by * in 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 beat flow. The 12-ira 104 Chapter 5. Heat Transmission Coefficients and Tables interior finish 105 No plaster--decorated rigid or build ing ward interior finish (V$ in.) Plaster ( K in-) on metal lath--stud space faced one side with bright aluminum foil Plaster {% in.) on metal lath6 on studding--flexible insuiati&n (H in.) between studding and in contact with sheathing Plaster {% in.) on metal lath6 on studding--flexible insulation ()$ in.) between studding--2 air spaces Plaster (% in.) on metal lath6 on studding--flexible insulation (1 in.) between studding--2 air spaces Plaster (% in.) on metal, lath6 on studding--rock wool fill {3% in.*) between studding*6 Heating Ventilating Air Conditioning Guide 1939 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 IS mph. TYPICAL CONSTRUCTION EXTERIOR FINISH TYPE OF SHEATHING /T Vt>f ^ \ J*mM6LE/. 1 in. Wood*1 Wood Siding or Clapboard Rigid Insulation H in. Plaster Board Wood Shingles 1 in. Wood* 3%2 in. Rigid Insulation* in. Plaster Board* Chapter 5. Heat Transmission Coefficients and Tables INTERIOR FINISH No Insulation Between Studding Inbulation Between Studding in.) on rigid insulation i Plaster (% in.) on metal lath on studding t cc g --353 3 ja 5 j9 % o ,Srl'O2a -S ao o 3.2 Is3 Ch A B . C 0.25 0.26 0.25 a 53 .1 -T3 *3) o g> 2*3 xl --' Is D Plaster E 0.19 0.15 (1 in.) on studding d 5 -a jd o ao ^ ef 3 Is d. o F 0.11 G 0.19 a f! *"O"*oo 9? IiSta 3.3 Og--x' .2 3 --3. H 0.17 I 0.19 J 0.17 KL 0.15 0.12 M 0.072 0.19 0.20 0.19 0.16 0.13 0.10 0.16 0.14 0.16 0.15 0.13 0.10 0.068 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 0.17 0.17 0.17 0.14 0.11 0.092 0.14 0.14 0.14 0.13 0.11 0.094 0.064 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 1 in. Wood* 3%2 in. Rigid Insulation /nEAtHlNG-'. /'IppA &UCK.\ ^ in. Plaster Board 1 in: Wood* Brick/ Veneer 3%a in- Rigid Insulation in. Plaster Board 70 Computed from factors marked by * in Table 2. .. These coefficients may also be used with sufficient accuracy for plaster on wood lath Of piaster a plaster board. Based on the actual width of 2 by 4-in. studding, namely, Z% in. ' 0.30 0.32 0.30 0.22 0.16 0.12 0.22 0.19 0.23 0.20 0.17 0.13 0.076 0.22 0.23 . 0.22 0.17 0.14 0.11 0.19 0.15 0.18 0.16 0.14 0.11 0.071 0.40 0.43 0.40 0.26 0.19 0.14 0.28 0.22 0.29 0.24 0.20 0.14 0.081 0.27 0.28 0.27 0.20 0.15 0.12 0.21 0.17 0.21 0.18 0.16 0.12 0.074 0.21 0.21 0.21 0.16 0.14 0.10 0.17 0.15 0.17 0.15 0.13 0.11 0.068 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 _,' ---- * -"-'-"VOW, OMVUb /l{ 4*1. furring stnp3 between wood shingles and sheathing. /Small air space and mortar between building paper and brick veneer neglected. - . "f.mbrane should be provided between the outer material and the insulation fill to *IS,rt^ble ^ettm? SK absorPtion and a subsequent lowering of efficiency, atud and rock wool fill areas combined. Heating Ventilating Air Conditioning Guide 1939 Table 6 Coefficients of Transmission (U) of Frame Interior Walls ' and Partitions^ extents nr* arc stressed in Btu Per hour per cx^css^m^u^^p^ sbqausaedreifnooXt MPeradireg(rneoe Fahrenheit difference in temperature wind) conditions on both suits. between the air on l TYPICAL CONSTRUCTION DOUBLE PARTITION (Finished on Both Sides or Studding) SlFGLB Pabtition Wall No. (Finish on One Mr 8n>B or Space Studding) Between Studding Flaked Gpwum Between Studding Rock Wool Fill* Between Studding Flexible Insulation Between Studding (One Air Stud Space Faced !)ne 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 . M in. Rigid Insulation and Plaster4 On Studding 1 in. Rigid Insulation and Plaster4 On Studding IK in. Corkboard and Plaster4 On Studding 2 In. Corkboard and Plaster4 On Studding 77 78 79 80 81 82 83 a 0.62 0.69 0.61 0.35 0.23 0.16 0.12 B 0.34 C 0.11 0.39 0.11 0.34 0.10 0.18 0.083 0.12 0.066 0.081 0.052 0.063 0.045 D 0.076 0.0780.075 0.063 0.054 0.044 0.038 E 0.21 0.23 0.21 0.14 0.097 0.070 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 assumed Z% in. Plaster on metal lath assumed &-in. thick. ^Plaster assumed H-in. thick. Table 7. Coefficients of Transmission ((/) of Masonry Partitions Coefficients are expressed in Btu per hour between the air on the two stdes, and Per square foot per degree Fahrenheit difference in temperature are based on still air {noxeind) conditions on both stdes. T a b l e 8. C o e f f ic ie n t s o f r a n s m is s io n (CO o f F r a m e C o n s t r u c t io n F lo o r s a n d C e il in g s *T Coefficients are expressed in B tu per hour per square foot per degree Fahrenheit difference in temperature between the a ir on the two sides, and ore based on s till a ir (no wind) conditions on both sides. TYPICAL CONSTRUCTION . Chapter 5. Heat Transmission Coefficients and Tables 0.34 0.25 0.24 0.23 0.18 0.14 . 0.19 0.12 0.081 0.094 K-io. Battleship Linoleum on Yellow Pine Flooring1 no 990'0 0.25 0.24 0.24 0.18 0.14 i 0.12 0.066 j o - 11 0.094 0.27 0.21 0.20 0.13 0.17 011 . 0.063 | 0.087 a | |SJ|'a UiSs a $ o O Z %b>-3 Yellow Pine Flooring on Rigid Insulation (H in.) on Joists o s 0, o o<N C* O o a a* >E- a ao Co S3 9*-* 0.30 <T0f c<No 0<N0 <N d ooo o .ia 0.22 0.13 0.086 61*0 j 910 1 890 0 oO r- O O IN o i1 1 1 | j | ' 69 0 I 0.69 S' og < i <CND e o o Z 0.61 0.35 No od 1 | | - to w IA NO ts 00 O' 010 0.12 0.23 * 17 0.16 12 |1 j ]1 j | 10 ]1 ' | J | None j' B rig h tA lu m ln u m F o lt* j F le x ib le 4 In s u la tio n (1 in.) | F le x ib le 4 In s u la tio n (2 in.) j R ock W ool F ill (3% In.) None INSULATION BETWEEN JOISTS No. None R ig id In s u la tio n (K in.) and P laster (K in.) j None P la s te r B o a rd in .) a n d P la s te r (> in.) | N o n e | None None None | ] M e ta l L a th and Plaster {% in.) Wood L a th and Plaster o fc 3 u V tOo w ce c *3 U o Z 109 e i u I ft, O AG J2 GO 3CD 6 O a 5 M e ta l L a th and Plaster - M e ta l L a th and Plaster M e ta l L a th and Plaster M e ta l L a th and Plaster c- s c- w4Ou) $ u4) CCBD o ac c 5 a QG 5 .5 w ua ua0o A Xi Ju* 33 Computed from factors marked by * in Table 2. Thickness assumed to be % in.` Thickness assumed to be % in. 4Based on one a ir space w ith no flooring, and tw o a ir spaces w ith flooring. .The value of U w ill be the same if insulation is applied to under side o f joists and separated from la th and piaster ceiling by l>in. furring strips, A ir space faced on one side w ith b rig h t alum inum foil. T a b le 9. Coefficients of T ransmission (U ) of Concrete Construction Floors and Ceiling s'. Coefficients are expressed in B lu per hour per square foot per degree Fahrenheit difference in tem perature between the a ir on the tw o sides, and are based on s tiil a ir (no w in d ) conditions on both sides. Heating Ventilating Air Conditioning Guide 1939 110 Chapter 5. Heat Transmission Coefficients and Tables 1a2. |q^h.g5 .9 8|o fe >-S g *3 e uao 3*SW-.SS9Kiog.*1SS*-icEg5-85s-lSEi jiSSla*!2h cu ? b--. Tit 9 & 3= T a b l e 10. C o e f f ic ie n t s o k T r a n s m is s io n ( U ) o f C o n c r e t e F l o o r s o n G r o u n d w it h V a r io u s T y p e s o f F in is h F l o o r in g **. Coefficients ore expressed in B lu per hour per square fo o t per degree Fahrenheit difference n temperature between the ground and the a ir over the floor and are based on s till a ir (no w in d ) conditions. ' ' tOiOIOV dodo ss do tcoo-o# do V)> ooo " Computed from factors marked b y * in Table 2. ^Assumed in. thick. Assumed % in. thick. ^Assumed 1 in. thick. c x. c 5 -2 8 o 2 <a c waoT`$S3i 1.5 a> o HX c 5SeC *1 o6 a o UU S-? SI Is OJ =a Heating Ventilating Air Conditioning Guide 1939 Table 11. Coefficients of Transmission (U) of Various Types of Flat Roofs Covered with Built-Up Roofing* TYPICAL CONSTRUCTION ----- Without Ceilings Wits Metal Lath and Plaster Ceilings4 type of roof deck Thickness or Roof Deck (Inches) No. /tur AOOFlHGj -./`THt *Vt/PPfl[07^ ' 4t/una*.T/jr Precast Cement Tile W1 Chapter 5- Heat Transmission Coefficients and Tables Coefficients are expressed in Blu 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 mpK jd ja d 5 d ia0 1 8 55 55o a .2 3 | o & 0as J3 1 i 0a 1 1 *1 <2 5 o O 5 E 1 M O 2 N Jd Oo a a .oa a o B cD E FGH I Rigid Insulation (M in.) Rigid Insulation (2 In.) with metal lath and PLASTER CEILINGS4 d S 5 oa _as 0a . 1 9a I *T3 0 *aa aa 3 .2 i 1 Jrf 2 8 O O J K LMNO 3 CH , iJ03 1 O P 0.84 0.37 0.24 0.18 0.14 0.22 0.16 0.13 0.43 0.26 0.19 0.15 0.12 0.18 0.14 0.11 INJULATIONi koapmdi p CONCRETE.^ KSOfl Kin;DmLATntm>i flL-LidLrrr, eowaitTe.' |j^| Cl Concrete Concrete 22 43 04 IN/ULATlOIt/ ROOftMC* / myyyrjyyyr/i wopy NtmATtm ROOFirt^ UQiP'* Ld tuuno^ Wood Wood Wood Wood W 4k 5 7 8 iHjUL/nriott/ moping] / riam* eA IMJULAnun. jcapFiMCi. j fuA/rer. daup' ClXUlHG? Gypsum Fiber Concrete4 (2 in:) on Plaster Board {H in*) Gypsum Fiber Concrete* (3 in.) on Plaster Board hi in.) Gypsum Fiber Concrete* (2. in.) on Rigid Insulalatlon Board (H >n.)' Gypsum Fiber Concrete* (2 in.) on Rigid Insula tion Board (1 in.) WrouTlflfy iiiiiiii,nmii)iT?!l ^ yecK initfUTUMt/ wopwa /. rmnimimin tO l n atal r ye.**. j CE1L1HO ' 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. - `Computed from factors marked by in Table 2. ^Nominal thicknesses specified--actual thicknesses used in calculations. Gypsum fiber concrete--87H per cent gypsum, 12H per cent wood fiber. 2H 3H 2K 3 - 9 10 13 ' a 6.72 0.64 0.37 0.34 0.33 0.24 0.23 0.22 0.17 0,17 0.16 0.14 0.13 0.13 0.22 0.21 0.21 0.16 0.16 0.15 0.13 0.12 0.12 0.42 0.40 0.37 0.26 0.25 0.24 0.19 0.18 0.18 0.15 0.14 0.14 0.12 0.12 0.11 0.18 0.17 0.17 0.14 0.13 0.13 0.11 0.11 0.11; 0.19 0.37 0.32 0.23 0.28 0.24 0.22 0.17 0.20 0.18 0.16 0.14 0.15 0.14 0.13 0.11 0.12 0.19 0.11 0.17 0,11 0.16 0.096 0.13 0.14 0.13 0.12 0.11 0.12 0.32 0.11 0.26 0.10 0.24 0.091 0.18 0.21 0.19 0.17 0.14 0.16 0.15 0.14 0.12 0.13 0.12 0.11 0.10 0.11 0.15 0.10 0.14 0.097 0.13 0.087 0.11 0.12 0.10 0.11 0.095 0.11 0.092 0.096 0.082 0.40 0.25 0.18 0.14 0.12 0.17 0.13 0.11 0.27 0.19 p.15 0.12 0.10 0.14 0.12 0.097 0.32 0.22 0.16 0.13 0.11 0.15 0.12 0.10 0.23 0.17 0.14 0.11 0.097 0.13 0.11 0.091 0.26 0.19 0.15 0.12 0.10 0.14 0.11 0.10 0.20 0.16 0.13 0.11 0.09 0.12 0.10 0.087 0.080.19 0.15 0.12 0.10 0.09 0.12 0.10 0.16 0.13 0.11 0.09 0.08 0.10 0.09 0.077 0.95 0.39 0.25 0.18 0.14 0.23 0.17 0.13 0.46 0.27 0.19 0.15 0.12 0.18 0.14 0.11 nlast^r - ***** ** .us?a wltn suracient accuracy for wood lath and plaster, or plaster board and upper side oTthe wiJirig5811111^ t^at there *8 an ^ space between the under side of the roof deck and the 113 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 U ) o f P it c h e d R o o f 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 an outside w in d velocity o f 15 mph. Heating Ventilating Air Conditioning Guide 1939 0.049 0.045 | 0.070 | 0.062 j 0.056 | 6.080 | 0.071 | 0.19 | .0,18 | 0.14 | 0.11 | 0.098 0.048 0.044 : 0.092 | 0.078 | 0.069 | 0.089 INSULATION BETWEEN ROOF RAFTERS (Til K) - pitre (mi z) pjroquiOQ o ('"! M) "W Pn" ( "I Hi) l"W0 X (N 0.16 (mi H) P113 (*tn i) uopepsai pphx 0 e: fc(mi y) P0* (mi y) uoiiB|QU] paftu t- 04 oo | oW o8 (mi y) aoi^einsui pi3ry | 0.29 | 0.29 pas ^}\rj poo^\ o ( HI pno ri!K)Praia"nij u '0 8 01 C! %) 1 0.46 (pseodxg SmjBOON < o . 55 ' - r* | None. . - | B rig h t A lu m in u m Foil? J 0 .2 2 1 |1 0.21 1| 0.21 || 0 .1 8 0.14 . n 1, | tro 1 ZZO I in. F le xib le * 1 Il 0.13 I 0.12 | 0.12 i1 o . i i 1 | 2 in. F le x ib le * J 0.083 | 0.083 | , 0.075 | 0.068 so d otoo d CtoOO tto-oo 04 O o to 0o0 d. 0.063 0.062 0.058 0.058 i 0.32 j| 0 .3 2 1 | 0.23 | 0.17 | 0.11 cn to so dd 00 o d 04 ot> g o 0.059 | 0-H 1 . 0.11 I 0.064 i 0.064 | 0.087 | 0.13 n 04 o N ** 04 M 0o0 d 00 04 00 do 0.065 t 2 1 0.66 0.34 1 Z% in. R ock W ool* | None | | B rig h t A lu m in u m Foil* | IO o t- 00 o *o3 0 at c CO . ] 1 in. Flexible* j 2 in. Flexible* . o '"I SsE 3S SS2 *ra=t.gvX>l. .S g?a C4>cZ EC S-'SS jll 2 '*3 *o 3 S heathing^ Slate o r T ile . R oofing- on Wood Shingles, Com posltio n Roofing, or A sphalt Shingles, R igid'Asbestos W ood Shingles on W ood S trips6 x*'' TYPE OF ROOFING AND ROOF SHEATHING . . . . TYPICAL CONSTRUCTION ?* a r* *> *`Sao-Iost-faog^'SSS0-So"0 * rt`5ro m ,, j So 8^5 114 Chapter 5. Heat Transmission Coefficients and Tables 13 coefficients of Transmission (U) of Doors, Windows, Skylights ^abLE ` and Glass Walls ,. # tire based on a wind velocity of 15 mph, and are expressed in Btu per hour per square foot per CoeJfcijfNj* difference in temperature between the air inside and outside ofthe door, window, skylight or wall A. Windows and Skylights . Description ' V; Single--.............................. Nominal Thickness Inches 1 IK lH 2 2H 3 B. Solid Wood Doorsc Actual Thickness Inches 1H6 154s m m 2H 2H ' 1.13". . 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 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;/! = 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: ........................ Plaster (on wood lath, plasterboard, rigid insulation, form, or corkboard)_________________ ___________ ________ Slate (roofing)..................................... ............|1J Stucco on wire mesh reinforcing___ ______________ ;______ Tar and gravel or slag-surfaced built-up roofing.________ 1-in. lumber (S-2-S)______ _____________ ______;______ ;_____ 1/4-in. lumber (S-2-S)___________ ___ _________ __________ 2-in. lumber (S-2-S).................................... ............................. 2J4-in. lumber (S-2-S)_________ __________________ ; 3-in. lumber (S-2-S)............... .................................. ................. 4-in. lumber (S-2-S)................................................................... Finish flooring (maple or oak)__________:____________........ in. ' in. Hi Hi -1^6 - - 2mH - 2H - 3% --% 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. 115 Heating Ventilating Air Conditioning Guide 1939 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 Ucc . U=t,r + -^ (6) where U = combined coefficient to be used with ceiling area. Ux ~ 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. Stating the formula in terms of the total heat resistance of the ceiling and roof, u =* = 1 + 1 UT X n (7) In selecting the values to be used for Z7r and Z7ce 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 UT. In this case an approximate value of UT 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 tpp 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 of 32 F. Additional information on the inside and outside temperatures to be used in heat loss calculations is given in Chapter 7. 116 Chapter 5- Heat Transmission Coefficients and Tables references A S.H.V.E. Research Reports: ` ar9__ Ffleets of Air Velocities on Surface Coefficients, by F. B. Rowley, A. B. No- 80 Algren and J. L. Blackshaw (A.S.H.V.E. Transactions, Vol. 36, 1930, p. 123). . .. one__wind Velocity Gradients Near a Surface and Their Effect on Film Con ductance, by F. C. Houghten and Paul McDermott (A.S.H.V.E. Trans actions, Vol. 37, 1931, p. 301). 014__ Surface Coefficients as Affected by Direction of Wind, by F. B. Rowley IS' and W. A. Eckley (A.S.H.V.E. Transactions, Vol. 38, 1932, p. 33). Q,e__ Conductivity of Concrete, by F. C. Houghten and Carl Gutberlet (A.S. No' H.V.E. Transactions, Vol. 38, 1932, p. 47). qa4__The Heat Conductivity of Wood at Climatic Temperature Differences, by F. B. Rowley (A.S.H.V.E. Transactions, Vol. 39, 1933, p. 329). qqf!__ Insulating Value of Bright Metallic Surfaces, by F. B. Rowley (A.S.H.V.E. ' Transactions, Vol. 40, 1934, p. 413). xjn 1026__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). A S H.V.E. Research Paper--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). Insulating 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). Importance of Radiation in Heat Transfer Through Air Spaces, by E. R. Queer (A.S.H.V.E. Transactions, Vol. 38, 1932, p. 77). Radiation and Convection Across AirSpaces in Frame Construction, by G. B. Wilkes and C. M. F. Peterson (A.S.H.V.E. Journal Section, Heating, Piping and Air Con ditioning, August, 1937, p. 505). Radiation and Convection from Surfaces in Various Positions, by G. B. Wilkes and C M F. Peterson (A.S.H.V.E. Journal Section, Heating, Piping and Air Conditioning, July, 1938, p. 477). ' 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). Heat Insulation as Applied to Buildings and Structures, by E. A. Allcut, University of Toronto, 1934. House Insulation, Its Economies and Applications, 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 Williard, Revised Edition, 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 117 Heating Ventilating Air Conditioning Guide 1939 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. 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 J^-in. blanket insulation. 0.23 (Table 3, WaU 12L). 3 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; k for insulating material is 0.34. Calculate the value of U. - f\ = 1.65;/o = 1.65; a = 0.46 _L_ JLL _i_ 4. _JLR = 1.65 4- 0.34 4. 0.46 ^ 0.34 4. "+" 1.65, = 6.327 U= = 0.158 .4 What is the inside surface temperature of a. 6-in. solid concrete'wall? Inside air*.70 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. 12.0;/o = 6.0 . Over-all resistance i? = 3^- + ^- +-^ =1.27 . '1 Temperature drop, inside air to surface _ 1.65 , . Temperature drop, air to air 1.27 Temperature drop, inside air to surface = ^ =43 1.27 X 1.00 . . 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, . . 485 - (if.o + i) =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 hoiir 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 V for the roof is equivalent to the summation of coefficients for each individual section times its percentage of total area. Ur = (0.52 X 0.15) + (0.46 X 0.85) = 0.47. Ratio of roof area to ceiling = 1560 -r 1200 = 1.3. Substituting in Formula 6: 0.47 X 0.38 0.38 = 0.235 0,47 + 1.3 H = AU(ti - t0) = 1200 X 0.235 X 85 = 23,900 Btu per hour. 118 Chapter 6 air leakage M of Air Infiltration, Infiltration Through Walls, Window Leakage Door Leakage, Selection of Wind Velocity, Crack T-Inrrth used for Computations, Multi-Story Buildings, Heat 9 Equivalent of Air Infiltration - A IR leakage losses are those resulting from the displacement of heated J\ air in a building by unheated outside air, the interchange taking _lace 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. Mechanical ventilating systems are frequently designed to produce positive or negative pressures in an enclosure which are greater or lower than prevalent wind pressures. In such designs, if the rate at which air is specified to be introduced to or removed from the enclosure by positive means exceeds the infiltration rate, it is common practice to use the greater value in determining-the heating capacity to warm the outside air. 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. 119 X" Heating Ventilating Air Conditioning Guide 1939 A complete study of all of the factors involved in air movement through building constructions would be very complex. Some of the complicating 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 walls 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 3Table 1. Infiltration through Walls Expressed in cubic feet per square foot per hour Ttpb op Wall 5\ Worn Velocity, Miles per Hour 10 15 20 25 30 *" Brick Wall {plastered"" 1.7S 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.------- 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 piaster1*. 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. 120 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 an air space between them. : The amount of infiltration that may be expected through single 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 121 Heating Ventii^ating Air Conditioning Guide 1939 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 Fig. 3. Diagrau Illustrating Crack and Clearance . 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 pu^h 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. >' 122 Fig. 4. Infiltration through Sash Perimeter of Window with and without Storm Sash--Ht-iti. Crack and M2-1N. 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 Storm Sash--Jff-iN. Crack and H-in- Clearance '. 123 Heating Ventilating Air Conditioning Guide 1939 2Table . Infiltration Through Windows Expressed in Cubic Feet per Foot of Crack per Bour* Type or Window Remarks Wind Velocity, Miles feb Hour 5 10 IS 20 2S 30 ~ Around frame in masonry wall--not calked^ 3.3 8.2 Around frame in masonry wall--calkedb____ 0.5 1.5 14.0 2.6 20.2 3.8 27.2 4.8 34.6 5.8 ~ Around frame in wood frame constructionb__ 2.2 6.2 10.8 Double-Hung Total for average window, non-weather- Wood Sash Windows stripped, 16-in. crack and &-in. clearance,c Includes wood frame IpgAngEd . __ 6.6 21.4 39.3 (Unlocked) Ditto, weatheralrippedd 4.3 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- strippea, 26-in. crack and i6*io. clearance. Includes wood frame Icakagrti... 26.9 69.0 110.5 153.9 199.2 249.4 Ditto, weatherstrippedd 5.9 18.9 34.1 51.4 70.5 91.5 Double-Hung Non-weatherstripped, locked 20 45 70 96 125 154 Metal Non-weatherstrinoed. unlocked.... 20 47 74 104 137 170 Windowsf Weatherstripped. unlocked_______ __________ 6 19 32 46 60 76 Rolled Section Steel Sash Windowsk Industrial nivnted l4n rr*rV 52 108 176 Architectural projected, crackh______ 15 36 62 Architectural projected, 36*io. crackh______ 20 52 88 Residential easement l^-in crack! 6 18 33 Residential rswment V^-in rmcki 14 32 52 Heavy casement section, projected, 16-in. 3 10 18 Heavy casement section, projected l-in. 8 24 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 window*.. 30 88 145 186 221 242 The values given in this table, with the exception of those for double-hung and hollow metal windows, 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-iu. crack and 36-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 50 per cent efficiency of frame calking. A 3-in. crack and clearance represents a poorly fitted window, much poorer than average. (Windows tested in place in building. ^Industrial pivoted window generally used in industrial buildings. Ventilators horizontally pivoted at center or slightly above, lower part swinging out. - , ^Architectural projected made of same sections as industrial pivoted except that outside framing member is heavier, and it has refinements in weathering and hardware. Used in semi-monumental buildings such as schools. Ventilators awing in or out and are balanced on side arms. J6-in. crack is obtainable in the best practice of manufacture and installation, 36-in. crack considered to represent average practice. . *Of same design and section shapes as so-called heavy section casement but of lighter weight. )-in. crack is obtainable in the best practice of manufacture and installation, l-in. crack considered to represent average practice. JMade of heavy sections. Ventilators swing in or out and stay set at any degree of opening. )-in. crack is obtainable in the best practice of manufacture and installation, 16-in.- crack considered to represent average practice. kWith reasonable care in installation, leakage at contacts where windows are attached to steel frame work and at mullions is negligible. With 36*in. crack, representing poor installation, leakage at contact with steel framework is about one-third, and at mullions about one-sixth of that given for industrial pivoted windows in the table. * 124 Chapter 6. Air Leakage DOOH LEAKAGE vary greatly in fit because of their large size and tendency to *JO por a wen fitted door, the leakage values for a poorly fitted doubler^'wood window may be used. If poorly fitted, twice this figure should "ung , jf weatherstripped, the values may be reduced one-half. A T door which is frequently opened, such as might be found in a store, ^ Id have a value applied which is three times that for a well fitted jhou -j-jjjg 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. 3Table 3. Infiltration Through Outside Doors for Cooling Loads Expressed in Cubic Feet per Minute per Person in Room . Application Pair 36 in. Swinging Doobs, Single ENTBA-NCEb 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. ^Vestibules 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. ' 125 Heating Ventilating Air Conditioning Guide 1939 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 B 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 B case of heavy masonry walls, and other factors, to arrive at the most 1 accurate solution of the problem. Although heat capacity should be con- g sidered wherever possible, it is seldom possible to accurately determine the E worst combination of outside temperature and wind velocity for a given g 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 and Table 2 in Chapter 7). CRACK LENGTH USED FOR COMPUTATIONS In no case should the amount of crack used for computation be less i 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, j take the wall having the most crack; but in no case take less than half the 1 total crack. For a building having no partitions, whatever wind enters t 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. I The amount of air leakage is sometimes roughly estimated by 'assuming j 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 j a check on the calculations made in the more exact manner. ; MULTI-STORY BUILDINGS I 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 g levels may be somewhat abated by surrounding obstructions. Further- i more, the chimney effect is reduced in multi-story buildings by the partial | isolation of floors preventing free upward movement, so that wind and 1 s 126 ' l Chapter 6. Air Leakage Table 4. a r Changes Taking Place under Average Conditions Exclusive AIR 0F air Provided for Ventilation . Kino op Room or Building Rooms, 1 side exposed..........................................Rooms, 2 sides exposed------------------------- --------Rooms, 3 sides exposed........................................... Rooms, 4 sides exposed-----------------------------------Rooms with no windows or outside doors- Entrance Halls-.................................................. Reception Halls.------------- ----- ---------------------------Living Rooms----------------------------- --------------Dining Rooms............................-...................... Bath Rooms.----------------------------------- ---------Drug Stores----------------------------------------------Clothing Stores----- ---------------;-------------------Churches, Factories, Lofts, etc.......... ........ .. Number op Air Changes Taking Place per Hour 1 2 2' Hto a 2 to 3 2 1 to 2 1 to 2 2 2 to 3 1 Fi 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 used in connection with Tables 1 and 2 that will allow for both wind velocity and temperature difference: Mc = Vtf - 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 need be made for the chimney effect'. Instead, the greater wind move ment at the greater heights 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 arbitrary rule is to increase the heating surface on floors above neighboring 127 Heating Ventilating Air Conditioning Guide 1939 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 I 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 Ha = 0.24 Q d (ti -- t0) (3) Hs -- heat required to raise temperature of air leaking into building from to to (; 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. li = room air temperature, degrees Fahrenheit. to = 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 . . H\ = heat required to increase moisture content of air leaking into building from M0 to M'u 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: Mo -- 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. ' Ha = 0.018 Q (ti - h) lh = 0.0114 Q (Mi - Mo) -(5) (6) Changing the temperature and vapor subscripts in Equations 5 and 6 to (to -- U) and (M0 -- Mi) permits the use of these same formulas for determining the sensible and latent heat gains due to infiltration in cooling load computations. Chapter 6. Air Leakage , has more than one room which is divided by interior walls If a bund g su(^c;ently accurate to use half of the total infiltration or partition ' mjn;ng the total heat requirements. Where buildings losses tor a wa]]S) the infiltration losses are calculated by using "aVhalf of the total crack, in which case the entire infiltration loss should be considered. _____ REFERENCES a c H V E Research Reports: A XT " eQfi]__Air Leakage, by F. C. Houghten and C. C. Schrader (A.S.H.V.E. Trans- No. 686 actions, Voi. 30, 1924, p. 105). No 704-Air Leakage Around Wmdow Openings, by C. C. Schrader (A.S.H.V.E. Transactions, Vol. 30, 1924, p. oio). xr No. 786_-_^Ihnnfilrtraattmion^ThrMouag^haPrelat sItnegreedls and Unplastered Brick Walls, by F. C. (A.SH.v.E. Transactions, Vol. 33, 1927, xt am__ Air^Leakaee on Metal Windows in a Modern Office Building, by F. C. No. 803 houghten and M. E. O'Connell (A.S.H.V.E. Transactions, Vol. 34, 1928, XI,, ai__ Al^Leakaee Through a Pivoted Metal Window, by F. C. Houghten and No. E CTConnell (A S.H.V.E. Transactions, Vol. 34, 1928, p. 519). xr,, oof!__Air Infiltration Through Various Types of Brick Wall Construction, by No. 82b cl" Larson, D. W. Nelson and C Braatz (A.S.H.V.E. Transactions, Vol. 35, 1929, p. 183). No 851--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). No 909--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). No 936--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). . No 994--Wind Velocities Near a Building and Their Effect on Heat Loss, by F. C. ' Houghten, J. L. Blackshaw and Carl Gutberlet (A.S.H.V.E. Transactions, Vol. 40, 1934, p. 387). Neutral Zone in Ventilating, by J. E. Emswiler (A.S.H.V.E. Transactions, Vol. 32, 1926, p. 59). . 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). 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). 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). ... 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 (Healing, Piping and Air Conditioning, October, 1932). 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). 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 arid, 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 (A.S.H.V.E. Journal Section, Heating, Piping and Air Conditioning, July, 1937). 129 X' Heating Ventilating Air Conditioning Guide 1939 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 per cent of the calculated radiation in the bottom third, the normal amount in the middle third and the remainder in the top third. 5 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 months and the temperature as 15 F above the coldest recorded by the Weather Bureau during the preceding 10 years. \ 8 0 Show the probable combined effects of infiltration due to temperature difference and wind velocity on 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 = V12* + 1.75 X 100 = 17.8 mph At the 15th floor level it would be reduced to: Me = Vl2! - 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 locfcely fitted window from 185 to 90 cfh. 130 Chapter 7 HEATING LOAD Heat Demand Design Factors, Method o Procedure, Inside and Outside Temperatures, Wind Velocity Efiects, 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 Lrtnrs which govern this maximum heat demand--most of which are I actors w' Airor5.in .jKKrinm--inrludp thp fnllnwincr: 1. Outside temperature. 2. Rain or snow. 3. Sunshine or cloudiness. 4. Wind velocity. 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. Outside Conditions } (The Weather) 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 the 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.) 131 Heating Ventilating Air Conditioning Guide 1939 3. Select or compute the heat transmission coefficients for outside walls and glass- I also for inside walls, floors, or top-floor ceilings, if these are next to unheated space-1 ! include roof if next to heated space. (See Chapter 5.) '? 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 froij 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 j 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.) 3 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. j Item 7 represents the heat losses after the building is heated and under ! stable operating conditions in coldest weather. Additional heat is j required for raising the temperature of the air, the building materials and I the material contents of the building to the specified standard inside j temperature. I 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. .f This additional heat may be figured and allowed for as conditions re- { Table 1. Winter Inside Dry-Bulb Temperatures Usually Specified3 Trn or Builoixq Dto Fabb Trre or BmiDtxa Deg Pass Schools Class rooms................ Assembly rooms..__ Gymnasiums....... Toilets and baths_____ ________ Wardrobe and locker rooms__ Kitchens. Dining and lunch rooms.-.. Playrooms Natatoriums.............................. Hospitals-- Private rooms.-------- -------- ----Private rooms (surgical)---- Operating rooms.......... ............ WardsKitchens and laundries.. Toilets--------------------------Bathrooms_____ ___-...... 70-72 68-72 55-65 70 65-68 66, 65-70 60-65 75 Theaters-- Seating space........... ........... _... Lounge rooms; ToileFs. Hotels-- Bedrooms and baths Dining rooms_______ Kitchens and laundries______ .. Ballrooms.____________ Toilets and service rooms.............. 68-72 68-72 68 70 70. 66 65-68 68 70-72 70-80 70-95 68. 66 68 70-80 Homes. Stores Public buildings Warm air baths Steam raths Factories and machine shops. Foundries and roiled shops Paint shops 70-72 65-68 68-72 120 110 60-65 50-60 80 ine most comiorLaoie ary-buib temperature to be maintained depends on the relative humidity and (SttCfaapter 3) 6 """ factor* considere<i together constitute what is termed the effective temperature. 132 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. 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 50 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. 61. Heating Ventilating Air Conditioning Guide 1939 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 information*. . 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, the 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. JA.S.H.V.E. Report No. 958--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). A.S.H.V.E. Report No. 1011--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). 134 Chapter 7. Heating Load . The outside temperature to be assumed in the design of any heating 1 ne is ordinarily not more than 15 deg above the lowest recorded tern-. system ^ reported by the Weather Bureau during the preceding 10 Perat rQr tjje locality in which the heating system is to be installed. In ^h^case of massive and well insulated buildings in localities where the . um does not prevail for more than a few hours, or where the lowest m'orded temperature is extremely unusual, more than 15 deg above the rePimum may be allowed, due primarily to the fly-wheel effect of the heat ml" -tv of the structure. The outside temperature assumed and used in the design should always be stated in the heating specifications. Table 2 lists the6 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 trans 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/,, 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 135 Heating Ventilating Air Conditioning Guide 1939 Table 2. Climatic Conditions Compiled from Weather Bureau Records3 Col A Col B Col C Average State City Temp., Oct 1st- May 1st Ala_________ Birmingham____________ . 53.8 Mobile............ .......... ......... 58.9 Flagstaff _____ ____ 35.8 Phoenix-- ________ ;....... 59.5 Arlr. 50.4 Calif.. _ Little Rock........................ I.os Angeles 51.6 58.5 San Francisco___ _______ . 54.2 Coin. 38.9 Grand Junction_________ 38.9 Conn. New Haven_____________ 38.4 D. C.............. Washington . 43.4 Fla. 62.0 r,a. Atlanta 51.5 Savannah ............ 58.5 42.3 Pocatello._____ ;_________ 35.7 Ill- ............... Chicago 36.4 Springfield...... ................... 39.8 Ind--............. Evansville . ... 45.1 Indianapolis-___ 40.3 33.9 Sioux City......... .......... ..... 32.6 39.8 Dodge City_____________ 41.4 Ky 45.3 I 61.6 Shreveport______________ 56.2 Me................. Eastport........ ....... .............. 31.5 Portland. __ ____ ;........... 33.8 Md...... .......... 43.8 Mass. . 38.1 29.6 Detroit................ 35.8 Marquette____ _ _ 28.3' 24.3 Minneapolis 29.4 Miss..... ....... Vicksburg.___ ___ _______ .56.8 Mo- ............ St. Joseph______________ '40.7 St. Louis. _______ _____ _ 43.6 Springfield......................... 44.3 Mont............. Billings........... .................... 34.0 Havre......... .. ......... , 27.6 Nebr.............. 37.0 North Platte 35.4 Nev................ 39.4 N. H_______ N. J......... N. V.............. Winnemucca..................... Concord________________ Albany__________________ 37.9 33.3 41.6 35.2 Buffalo_______ :__________ 34.8 New York___________;___ 40.7 aUnited States data from U. S. Weather Bureau. Canadian data from Meteorological Service of Canada. 136 Col D Lowest Tempera* turn Ever Reported -10 -i --25 12 -- 15 -12 28 27 --29 -21 -15 -- 15 10 --8 8 --23 -28 --23 -24 -16 -25 --32 -35 --25 -26 --20 7 -5 -23 -21 -7 -- 18 --28 -24 -27 --41 -33 -1 -24 -22 -29 -49 -57 --29 -35 -- 10 -28 -35 --9 -24 -20 -14 1 Col E Average Wind Vel ocity Dee., Jao., Feb., Miles per Hour Col F Direction of Prevail ing Wind, Dec., Jan Feb. 8.5 10.4- 7.8 6.4 8.1 8.7 6.3 7.6 7.5 5.3 9.7 7.1 9.2 12.1 9.5 5.3 9.6 12.5 10.1 9.8 11.5 7.1 11.6 R1 9.8 9.9 8.8 8.9 12.0 9.2 7.8 11.2 12 4 12.7 11.1 12.6 11.3 8.3 9.3 11.6 10.8 9.5 in.5 8.5 10.0 8.7 6.6 15.9 8.1 17.2 17.1 N~ N sw E E . NW NE N s NW N NW NE NW NW E SE w NW S SW N\V NW s NW sw N SE W NW NW W w SW NW SW NW SE NW S SE W SW s W SF. NE NW NW s W NW Chapter 7. Heating Load Table 2. Climatic Conditions Compiled from Weather Bureau Records3-- (Concluded) Col. A State or Province Col B City Col C Average Temp., Oct UtMay 1st Santa Fe-- Raleigh.. Wilmington........ I. Dak.. Bismarck............. Devils Lake------ )hio...... Cleveland--------- Columbus.. Ikla-- keg--- Oklahoma City.. Baker__________ Portland.--.------- Philadelphia------ Pittsburgh-------- . I..... C___ Providence-------Charleston-------Columbia---------- Dak.. HuronRapid City.------ Knoxville---- ----- Memphis--...... El Paso________ Fort Worth------ San Antonio.-- Utah....... -- Modena.............. Salt Lake City.. Vt.. Burlington......... Va.. Lynchburg------- Norfolk--............ Richmond--------- Wash_ Seattle_________ Spokane.............. W. Va.. Elkins................. Parkersburg.----- Wis...... Green Bay......... La Crosse.-------- Milwaukee_____ Wyo... Lander................ Sheridan--.......... Alta...... Edmonton......... B. C___ Vancouver......... Victoria............... Man___ Winnipeg........... N. B..... Fredericton....... N. S___ Yarmouth_____ Ont...... London............... Ottawa.. Port Arthur-__ Toronto........ ..... P. E. I... Charlottetown... Que.... .. Montreal............ Sask__ Yukon.. Quebec...... ; Prince AlbertDa wson________ 38.3 50.0 54.2 24.6 20.3 37.2 39.9 47.9 35.2 46.1 42.7 41.0 37.2 57.4 54.0 28.2 33.4 47.9 51.1 53.5 55.2 60.6 36.3 40.0 31.5 46.8 49.3 47.0 44.8 37.7 39.4 42.6 30.0 31.7 33.4 30.0 30.7 23.0 42.0 43.9 17.5 27.0 35.0 32.6 26.5 . 22.4 32.9 29.0 27.8 . 24.2 . 15.8 . 2.1 United States data from U. S. Weather Bureau. Canadian data from Meteorological Service of Canada. 137 Col D Col E Lowest Tempera* ture Ever Reported Average Wind Vel ocity Dee., Jan., Feb., Miles per Hour -13 -2 5 -45 -44 -17 -20 -17 -24 -2 -6 -20 -17 7 -2 -43 -34 -16 -9 -5 . -8 4 -24 -20 -29 -7 2 -3 3 -30 -28 -27 -36 -43 -25 -40 -41 -57 2 - 1.5 -47 -35 -12 -27 -34 -37 -26.5 -27 -29 -34 -70 . -68 7.8 , 8.2 8.5 9.1 10.6 13.0 12.0 12.0 6.9 7.5 11.0 11.7 12.8 10.6 8.1 10.6 8.2 7.8 9.7 10.4 10.4 8.0 8.8 6.7 11.8 7.1 12.5 7.9 11.3 7.1 6.6 7.5 10.4 7.3 11.5 5.0 6.0 6.5 4.5 12.5 10.0 9.6 14.2 10.3 8.4 7.8 13.0 9.4 14.3 13.6 5.1 3.7 Col F Direction of Prevail ing Wind, Dm., Jam, Feb. NE SW SW NW W SW SW N SE S NW W NW SW NE NW W SW S NW NW NE W SE S NW N SW SE SW w sw sw s w sw NW SW E N NW NW NW SW NW NW SW SW SW SW W S . Heating Ventilating Air Conditioning Guide 1939 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 the 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 i 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 i 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 i Chapter 5 are based on a wind velocity of 15 mph and 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. I The Heating, Piping and Air Conditioning Contractors National Associ- ! ation. has devised a method5 for calculating the square feet of equivalent ; direct radiation required in a building. This method makes use >l ex- i 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 if *See Standards of Heating, Piping and Air Conditioning Contractors National Association. .38 Chapter 7. Heating Load ` ed in the room if the product being manufactured is not removed re tiUts temperature is the same as the room temperature. UI\f nower is transmitted to the machinery from the outside, then only .`.^t eauivalent of the brake horsepower supplied is used. In the the n Motor horsepower _ . first case the Btu supplied per hour Efficiency of motor ^ an<^ the second case Btu per hour = bhp X 2546, in which 2546 is the Rtu equivalent of 1 hp-hour. In high-powered mills this is the chief urce of heating and it is frequently sufficient to overheat the building "en in zero weather, thus requiring cooling by ventilation the year r The heat (in Btu per hour) from electric lamps is obtained by multioiying 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 ofthe 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 many types of construction under adverse conditions. The tempera- ir,,i -- ,... --. voi. jo, lyoU. p. 153). .uunuiug ijuiirfccs, uy raut is -. . ,.(,/i.o.n. v c inAifui.uuns, Sp<^i!,d'2saHon 'Slhln Wa,la' h* F- B- Rowley. A. B. Algren and C. E. Lund (A.S.H.V.E. Journal oection. Heal,ng, Piping and Air Conditioning, January. 1938). . 139 Heating Ventilating Air Conditioning Guide 1939 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 heat 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 Fig. 1. Elevation of Factory Building 1. Location------------- ----------------- ------------------------------ ------------------------------------------------------ Philadelphia, Pa. 2. Lowest outside temperature. (Table 2)...-- 6F 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 = . (-6 + 10) = + 4 F. 4. Direction of prevailing wind (during Dec., Jan., Feb.)______________ Northwest 5. FBreathing-line temperature (5 ft from floor)....60 6. Inside air temperature at roof: The air temperature just 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 11 = 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)'11.0 mph 9. jOver-all dimensions (See Fig. 1):________ _________ .Cl20 x SO x 16 ft 10. Construction: . Walls--12-in. brick, with M-in. plaster applied directly to inside surface. Roof--3-in. stone concrete and built-up roofing. 140 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)-----------------Roof--(Table H, Chapter 5, Roofs 2A and 3A)._ floor__(Table 10, Chapter 5, Floors 5A and 6A). Doors--(Table 13B, Chapter 5)--------------------------Windows--(Table 13A, Chapter 5)---------------------- 0.34 0.77 0.63 0.46 1.13 12 Infiltration Coefficients: . ' Windows--Average windows, non-weatherstripped, Ks-in. crack and 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 Width in Feet Height in Feet Net Sur face Area or Crack Length Coeffi cient North Wall: Brick. M-in plaster--------------Doors (2-in. wood)............ ...... H in. Crack- .................... -- West Wall: Brick- J4-m. plaster------------Glass (Single)..................... -- in. Crack- . ----------- .. South Wall_____________________ Eant Wall Roof. 3-in. concrete and slag surfaced built-up roofing.____ Floor, 5-in- stone concrete on Wn cinder concrete_________ 50 16 12 12 1 pair doors 656 144 60 120 16 15 x 4 9 Double Hung Windovrs (15) 1380 540 450 Same as North Wall Same as West Wall 50 120 6000 50 120 6000 0.34 0.46 0.90 0.34 1.13 0.45 0.77 0,63 Temp. Difp. . Total Btu 59.6 57.2 57.2 59.6 60.2 60.2 69.2 5b 13,293 3,789 1,544a 27,964 36.734 6.095a 18.626 70,793 319.704 18.900 Grand Total of heat required for building in Btu per hour___ 517,442 . ' "This building has no partitions and whatever air enters through the cracks on the windward aide must leave through the cracks on the leeward side. Therefore, only one-half of the total crack will he used in . computing infiltration for each side and each end of building. a ?, ^ temperature differential is commonly assumed to exist between the air on one side of a large oot laid on the ground and the ground. 141 Heating Ventilating Air Conditioning Guide 1939 PROBLEMS IN PRACTICE j 1 What is the relation between the sensible heat loss from a building and th heat required for humidification? .e 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 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 usin? 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. *i 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 X 3.415 = 12,294 Btu per hour.. : \ 6 A two-story, six-room, frame house, 28-ft by 30-ft foundation, has the j following proportions: 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. ' . ; > t I } > I i \ j 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 3 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, j Windows are single glass, double-hung, wood, without weatherstrips. The | second floor ceiling is metal lath and plaster, without an attic floor. The roof J 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: i (a) U for walls; (b) U for glass; (c) U for second floor ceiling; (d) U for roof; $ Chapter 7. Heating Load i* and roof combined; (f) air leakage, cubic feet per hour per foot (e) U for ceUl^c7 (g) air leakage, cubic feet per hour per foot of door crack, of window cr q 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). T Anta of Ouestion 6, calculate the maximum Btu loss per hour for 7 Using t~ionStructions, and show the percentage of the total heat which is Though each construction described. . rFnt rise in temperature for each foot in height. The average temperature Assume 2 per c ,, and 79 1 F for the second floor ceiling1. 0. Outside walls b. Glass c. Doors 1. Second floor ceiling e. Air leakage, windows /. Air leakage, doors 46,200 Btu loss 34,950 Btu loss 5,670 Btu loss 24,050 Btu loss 15,750 Btu loss 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 c. 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 ol 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. Uninsulated a. Outside walls............... ............. b. Glass.. c. Doors_____ ... d. Ceiling e- Air leakage, windows______ / Air leakage. Honrs 46,200 34,950 5,670 24,050 15,750 3,865 Insulated 26,650 17,000 5,670 12,420 11,400 2,795 Btu Saved Pqa Cent Saved 19,550 17,950 0 11,630 4,350 1,070 42.3 51.4 0 48.3 27.6 27.7 Heating Ventilating Air Conditioning Guide 1939 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 log, 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 tern, perature to be expected is --10 F, what thickness of rigid fiber insulation will ba required to prevent condensation? From Table 11, Chapter 5, U for the uninsulated roof = 0.72. From Table 2, Chapter 5, k 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, where U [80 - (-10) ] = 1.65 (80 - 65) V is the transmittance of the insulated roof. Solving the equation, U = 0.275. 1 The resistance of the insulated roof = = 3.64. 0.275 1 The resistance of the uninsulated roof = = 1.39. U.7* The resistance of the insulation = 3-64 -- 1.39 = 2.25. Resistance per inch of insulation = = 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 anfinsulated 4-in. concrete slab having a U of less than 0.275 from Table 11, Chapter 5. This if-in. concrete slab with 1-in. rigid insulation has a U of 0.23 which is safe. i* 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 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 not the maxi-i mums 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 rYork City from 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- temperatures^ The design . 145 Heating Ventilating Air Conditioning Guide 1939 Table 1. Design Dry- and Wet-Bulb Temperatures, Wind Velocities, and Wind Directions for June, July, August, and September State City Design Dhy-Bclb Design Wet-Bulb Summer Wind Velocitt MPH Prevailing Summer Wind Direction Mobile....................................... Ark. Calif. Colo...... ........ San Francisco.......................... Denver...................................... D. C. Fla. Ga. Tampa....................................... . Savannah.................................. 111. Peoria........................................ Ind.._ ........... Indianapolis____'..................... Ky. La. Md. Shreveport................................ Miss.............. Vicksburg-- ............................. Mr, St. Louis. - ............................ N. H. N. J. N Y. Buffalo...................................... NM N. C...... ....... N. Dak. . Ohio..... ....... OHa Asheville. ............................. Wilmington.............................. Cincinnati................................ Cleveland................................ Pa.~ RI s. c. .. S. Dak--.... Pittsburgh................................ Greenville................................. Sioux Falls...,__ ..................... Memphis.............. .................. 95 95 105 95 ' 90 90 95 95 95 95 95 94 95 95 95 95 95 . 95 95 100 95 95 100 90 95 92 95 95 95 100 95 95 95 95 90 95 92 93 95 90 90 95 95 95 95 101 90 95 95 93 95 95 95 95 95 78 80 76 78 70 65 64 75 78 78 78 79 76 78 65 75 76 76 77 75 76 79 78 73 78 75 75 75 78 76 78 67 75 65 73 78 75 75 75 65 75 79 73 78 ,* 7765 65 78 75 75 80 - 76 75 77 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 6.2 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' 6.6 9.9 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 S SW sw sw SE SW s sw sw s w NW SW S SW SW SE SE SW NW SW s s NW SW ' NW NW sw NE s SW SW 146 c Chapter 8. Cooling Load i Design Dry and Wet-Bulb Temperatures, Wind Velocities, and, TablEVVind Directions for June, July, August, and September (Concluded) Crrr Design Dry-Bulb Design Wet-Bulb Summer Wind Prevailing Velocity Summer Wind MPH Direction Texas.. Utah... Vt-----Va...... Wash.. VV. Va. WiscWyo... El Paso--....................................... Galveston--.................................. Houston........................................... San Antonio.................................. Salt Lake City.--...................... Burlington...................................... Norfolk.......................... -................ Richmond....................................... Seattle......... .................... ................ Spokane........................ ................ Parkersburg--............. -................ Madison....................... ................... Milwaukee..................................... Cheyenne.............-........ :............... 100 100 95 95 100 92 90 95 95 85 90 95 95 95 95 . 78 69 80 78 78 63 73 78 78 65 65 75 75 75 65 9.4 6.9 9.7 7.7 7.4 8.2 8.9 10.9 6.2 7.9 6.5 5.3 8.1 10.4 9.2 S E S s SE SE S S SW S SW SE SW S 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 located 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 i gain, that is, they tend to raise the temperature of the air within the : structure. The last three components not only produce sensible heat i gain but they may also tend to increase the moisture content of the air ; within the structure. i Normal Heat Transmission ' [ By normal heat transmission, as distinguished from solar heat trans- j mission is meant the transmission of heat through windows, walls, { partitions, etc. from without to interior of enclosure by virtue of difference'' etween outside and inside air temperatures." This load is calculated in a Are 1939Heating Ventilating Conditioning Guide p O oo o nj CM o o p O o anoH U3d ij os vid nig \ Oot X oz z; ^J0S << O 0Z* > 3' .fMcH^ z0 os a <z V) H 3 >5Ss Ow tHn D u o Chapter 8. Cooling Jjoad^. _ cimilar to that described in Chapter 7 (except that flow of heat is reversed)*by means of the formula: - Ht = AU (ta - t) (l) 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. - = outside temperature, degrees Fahrenheit. . TJ = coefficient of transmission of wall, glass, floor, etc., Btu per hour per square foot "" pgr degree Fahrenheit difference in temperature (Tables 3 to 13, Chapter 5). Solar Heat Transmission Calculations of the solar heat transmitted 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 are drawn from A.S.H.V.E. Laboratory data obtained by pyrheliometer, 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 from 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 the solar radiation impinging: against the outer surface fails to pass thrbugKTfKe wall. Instead it is delivered to the outside air by reflection, radiation, convection and conduction. A mathematical solution for the-determination 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 (I) for various hours Of the day on walls of various orientations and horizontal surfaces. These values are shown for north latitudes from 30 to 45;deg. : Since the. amount of solar intensity actually 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 `A.S.H.V.E. Research Report No. 923--Heat Transmission as Influenced by Heat Capacity and Solar Radiation, by F. C. Hbughten, J. L. Blackshaw. E. W. Pugh and Paul McDermott(A.S,H.V.E. Transactions. Vol. 38. 1932, p. 231). *A.S.HAf.E.- Research Report No. 853--Absorption of Solar Radiation in its Relation to the Tem perature. Color. Angle and Other Characteristics of the Absorbing Surface, by F..C. Houghten and'Carl Gutberlet (A.S.H.V.E. Transactions. Vol. 36. 1930. p. 137). ,, _________________ L______ ________;________ Heating Ventilating Air Conditioning Guide 1939 Table 2. Solar Radiation Impinging against Walls having several Orientations and a Horizontal Surface. ' . For SO Deg Latitude on the twenty-first of July. Sun Time Northeast 4:59 5:00 6:00 7:00 8:00 0 1 47 136 151 Intensity of Solar Radiation, Btu per Sq Ft per Hour East 0 1 51 160 205 Southeast South Southwest West Northwest Horizontal Surface 0 0.3 24 90 136 0 0.01 9 68 147 9:00 10:00 11:00 12:00 127 79 21 189 140 141 122 78 85 36 8 31 45 50 36 214 265 296 305 1:00 2.00 300 4:00 45 85 78 21 296 31 122 141 79 265 8 140 189 127 214 136 205 151 147 500 6:00 7:00 701 90 24 . 0.3 0 160 51 1 0 136 47 1 0. 68 9 0.01 0 Table 3. Solar Radiation Impinging against Walls having several Orientations, and A Horizontal Surface. ' . For SB Deg Latitude. on the twenty-first of July. . Sun Time Northeast 4:46 5:00 600 7:00 800 0 9 67 142 150 900 10:00 11O0 12:00 118 60 .2 1:00 200 300 400 Intensity of Solar Radiation, Btu per Sq Ft per Hour East 0 9 72 174 209 191 143 75 Southeast 0 3. 35 103 145 154 139 103 55 South Southwest \ 26 55 72 78 72.. 55 26 55 , 103 139 154 145 West Northwest Horizontal Surface 0 0.01 15 77 '# 151 ` .' -\ 214 264 291 . 300 75 2 143 60 191 118 209 150 291 264 214 151 500 600 700 7:14 103 ., 35 3 0 174 142 . 77 72- 67 15 99 0.01 00 0 Chapter 8. Cooling Load c p Radiation Impinging against Walls having several Orientations, Table 4. Solar and a horizontal Surface. i/i r INTENSITY of Solar Radiation, Btu per Sq Ft per Hour Sun Tims Northeast East 4:31 5:00 6:00 7:00 8:00 9:00 10:00 11KX) 12:00 0" 0 14 14 72 80 143 180 143 211 104 192 46 143 75 1:00 2:00 3.-00 4:00 5:00 6:00 7:00 7:29 Southeast 0 5 40 112 155 South 8 Southwest West Northwest Horizontal Surface 0 1 19 82 152 168 46 156 77 121 95 73 103 15 73 213 258 284 293 15 95 121 75 77 156 143 46 46 168 192 104 8 155 211 143 284 258 213 152 112 180 143 40 80 72 5 14 14 000 82 19 1 0 Table 5. Solar Radiation Impinging against Walls having several Orientations, and a Horizontal Surface. For 4B Deg Latitude on the twenty-first of July. SUN Time Northeast 4:26 0 5:00 25 6:00 89 7:00 149 8:00 140 9:00 10:00 11:00 12:00 92 33 1:00 2:00 3:00 4:00 5.-00 6:00 7KX) Intensity of Solar Radiation. Btu per Sq Ft per Hour East 0 24 99 194 219 194 144 75 Southeast South Southwest West Northwest Horizontal Surface 0 9 52 125 171 22 0 2 26 90 156 183 65. 171 98 139 121 91 128 32 91 210 251 274 282 32 121 139 75 274 98 171 144 33 . 251 65 183 194 92 210 22 171 219 140 156 125 194 144 52 99 89 9 24 25 90 26 2 151 Heating Ventilating Air Conditioning Guide 1939 heat transmission, to apply correction factors to the values of (7). Solar radiation factors and solar absorption coefficients have been determined1 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: . where HR - A F a I . . (2) //r = Solar heat transmission, Btu per hour. ' . A = Area of wall or roof, square feet. j F = Percentage (expressed as a decimal) of the absorbed solar radiation which is 1 transmitted to the inside (Fig. 2). o..= Percentage (expressed as aj decimal) of the incident solar radiation which is absorbed by the surface (Table 6). I = Iritensity of solar radiation striking1 surface, Btu per hour per square foot ('fables 2, 3, 4 and 5). ; ... Thd total amountjof heat conducted through a wall exposed to the sun is the sum of Ht an<| HR from Formulas 1 and 2. , II I t I; ; :. >. - - ---- ! Ii j :' : A Rational Heat Gain Method for the Determination of Air Conditioning Cdoling Loads, by F. H. Ffeustrfc. Levine;-and-F: O: UrbaiHA:SvH;V7E-. TRANSACTioiTOrVotr*t? l35rp^327)^------------------------ 152 Chapter 8. Cooling Load * Table d- cot a Absorption Coefficients for Different Building Materials so1**-* v ----------------- Surface Material . Absorption Coefficient (o) .-------------------------------- White atone i :~hr Colored Surfaces..............Very light colored cement Very Lignc White or light cream-colored paint 0.4 ---------------- Asbestos shingles Unpainted wood Brown stone wMejdi- um Dark uarx Surfaces..........................Brick and red tile cm Dart-colored cement Stucco Red. green or gray paint . 0.7 ---------- - Slate roofing xV.e,,ry, HUaarrKk Colored Surfaces...............VTearryrodoafrinkgpmainattaerials 0.9 The calculation of heat transmission through walls and roofs does not take into consideration the heat capacity of the structure nor the con sequent time lag in the transmission of heat. In the case of massive walls the time lag may amount to several hours4. 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 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 ip 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. Radiation Transmitted Through Glass Windows present a problem somewhat different from that of opaque walls, because they permit a large percentage of the solar energy to pass through, a small amount is reflected and the balance is absorbed by the glass. The amount absorbed depends upon the character and thickness of the glass and the angle between the sun's rays and the glass. The temperature of the glass is raised by the absorbed heat and this heat is then delivered to the air on the two sides of the glass in proportion to the the difference between the glass and air temperature.6 . Table 7. Time Lac in Transmission of Solar Radiation through Walls and Roofs Ttps and Thickness or Wall ob Roof Time Lao. Hours 2-in. pine___ 4-in. gypsum........................................................................... !................................................................. 3-in. concrete and 1-in. cnrk 2-in. iron and cork (equivalent to %-in. concrete and 2*.15-in. cork)................. 4-in. iron and cork (equivalent to 5f$-in. concrete and 1.94-in. cork)................ 3-in. iron and cork (equivalent to 16-in. concrete and 1.53-in. cork)................. 22-in. brick and tile wall : - ' ih 3 2^ 2 2'A 7'A 19 10 `Loc. Cit. Notes 1 and 2. . j' `Heat Absorbing Glass Windows, by W. W. Shaver (A.S.H.V.E. Transactions. Vol. 41. 1935, p. 287). Heating Ventilating Air Conditioning Guide 1939 Chapter 8. Cooling Load The A.S.H.V.E. tests6 indicate that a single pane of double strength j glass 0.127 in. thick absorbs approximately 11 per cent of the solar ? radiation passing through it when the impingement is normal. For smaller i angles of impingement, the glass retards percentages of the total radiant : energy approximately in proportion to the sine of the angle. Other ] experiments7 indicate a glass absorption of 16.7 per cent for one pane of ; glass and 37.5 per cent for two }4 in. panes separated by a 1% in. air space. ; The amount of solar radiation delivered to an unshaded glass surface ' may be obtained from Tables 2, 3, 4 or 5. These values must be used only 1 for the net glass area on which the sun shines and not the entire glass ' area. Tests at the A.S.H.V.E. Research Laboratory8 have determined j the percentage of heat from solar radiation actually delivered to a room 5 with various types of outdoor and indoor shading. The data in Table 8 l are taken from these tests. The percentage values in this table were obtained by dividing the total j amount of heat actually entering through the shaded window by the \ total amount of heat calculated to enter through a bare window (solar j Table 8. Solar Radiation Transmitted through Shaded Windows Ttpb op Appurtenance Finish ' Facing Sun 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.... Aluminum Buff Aluminum Aluminum Per Cent Delivered to Room 28 22 45 , 68 58 22 radiation plus glass transmission, based on observed outside glass tern- \ \ perature). For bare windows on which the sun shines, the transmission I l of heat from outside air to glass may be small or negative as the glass } ' temperature is raised by the solar radiation absorbed. On the other hand, f ; at times when the solar intensity is low, the heat gain as a result of solar ? : radiation may be less than that due to normal transmission. |; ' In calculating the total heat gain through windows.on the sunny side ! - of buildings, it is sufficiently accurate to figure the total heat gain to a 'j ; window as follows: l' Consider the total heat gain as that resulting from solar radiation and : neglect the heat transmission through the glass caused by the difference f ? between the temperatures of the inside and outside air. This method | jj should be used except at times when the calculated heat gain per square J | foot due to normal transmission exceeds the solar intensity. At such f < . times, solar radiation may be neglected and the total heat gain considered 2 | as resulting from normal transmission. . I |' A.S.H.V.E. Research Report No. 974--Radiation of Energy Through Glass, by J, L. Blackshaw and F. C. Houghten (A.S.H.V.E. Transactions, Vol. 40, 1934, p. 93). A.S.H.V.E Research Report No. 975 --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). tA.S.H.V.E. Research Report No. 924--Field Studies of Office Building Cooling, by J. H. Walker, ' jj \ 5 t S. S. Sanford, and E. P. Wells, (A.S.H.V.E. Transactions, Vol. 38. 1932, p. 285). - '\ Loc. Cit. Note 6. . . .. I ?; ; Jr 154 I- jar heat transmission through windows or skylights mav hp 1 ne . .1 . r^^niQ W - Solar radiation transmitted through a window, Btu per hour. Ha I Net area of glass exposed to sun's rays, square feet. Aa c> re of solar radiation (expressed as a decimal) transmitted to the } ~ inside (Table 8). For bare windows, / = 1. - Intensity of solar radiation striking surface, Btu per hour per square foot 1 " (Tables 2, 3, 4 and 5). Although the tests from which Table 8 was obtained showed that A*t -mately all of the heat from solar radiation is delivered to a room approxi w;ncjow glass, other tests9 have indicated that in the case of holding having floors of high heat capacity such as concrete floors on Veil the solar radiation falls, approximately one half of the heat entering w.1 e window is absorbed by the floor and does not immediately become 4 oart of the cooling load, but is delivered back to the air in the building at a slow rate over a period of 24 hr 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 paper19by the A.S.H.V.E. Research Laboratory it was shown that ordinary double strength window glass transmits no measureable amount of energy radiated from a source at 500 F or lower; that it transmits only g.O 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 _ 'A.S.H.V.E. Research Report No. 1002--Pooling Requirements of Single Rooms in a Modern Office Biulding. by F. C; Houghten, Carl Gutberlet, and Albert J. Wahl (A.S.H.V.E. Transactions, Vol. 41, 1935, p. 53). '. TMLoc. Cit- Note 6. : ' *- .' 155 Heating Ventilating Air Conditioning Guide 1939 requirements of different' sides of the building. The total cooling l0a(j | for a building exposed to the sun on more than one side is of course 1^; than the sum of the maximum cooling loads in the individual rooms since i 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- i 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 I 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. . Heat Introduced by Outside Air An allowance must be made for the heat and moisture in the outside "i 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 f 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 i 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 i volume of air required for ventilation exceeds that due to infiltration it is f 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 5 determined by the following formula: < ' Ha = 0.24 X 60 do Q (to - t) (4) | where / Ho - 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 toU> = 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 = 66 do Q (ho -- h) (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)- . Chapter 8. Cooling Load ho = heat content of mixture of outside dry air and water vapor, Btu per pound of dry air (at temperature fe)- .. h = heat content of mixture of inside dry air and water vapor, Btu per pound of dry air (at temperature t). The latent heat gain resulting from outside air introduced may be determined by the following formula: ' H\ ~ H ~ Ho (6) whHer\e = latent heat to be removed, Btu per hour. H = total heat to be removed, Btu per hour. Ho = sensible heat to be removed, Btu per hour. .. Heal Emission of Appliances Heat generating appliances which give off either sensible heat or both sensible and latent heat in an air conditioned enclosure may be divided into three general classes of equipment or devices: 1. Electrical appliances. 2. Gas appliances. 3. Steam heating appliances. In the first group may be found such devices as lights, motors, toasters, waffle irons, etc. The capacities of most electrical devices may be determined from the watt capacity indicated on their name plates. The Btu 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: ,, 746 (hp) . (7\ where P = motor input, watts. hp = motor load, horsepower, n = motor efficiency (expressed as a decimal). 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 Hobsepoweb VS to 3 3 to 20 Heat Gaik in Btu rra Hoys m Hosmrowxa Connected Load in Same Room 4250 3700 2950 Connected Load Outside of Room 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, . Heating Ventilating Air Conditioning Guide 1939 Table 10. Heat Gain from Various Sources SOUBCB Bto Pbb Hotjb Sensible Latent | Total Electric Heating Equipment Electric Equipment--Heating Water--Stewing. Boiling, etc-----------------------.--- J. 100% 80% 50% 3.4 3413 2546 90% 2000 1200 600 * * Plate Warmer--Per Cubic Foot of Volume______ _____ ____ _____________________ ..... - 8000 1025 300 850 3200 * Permanent Wave Machine in Beauty Parlor--24-25 w Units................................. 2050 2050 0% 20% 50% 0 0 10% 2000 600 * * 2000 0 800 0 1300 * * o 0 Gas Burning Equipment Gas Equipment--Dry Heat--No Water Evaporated .. .. ................ . Gas Equipment--Heating Water--Stewing, Bolling, 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 5> 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.................... .. ......... .......... ....................... Simmering Burner.................................................................................................................,......... Coffee Urn--Large, 18 in. Diameter--Single Drum.. -..................................................... Coffee Urn--Small, 12 in. Diameter--Single Drum Coffee Urn--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___ ___ ______ ________________________ ______ Curling Iron Heater .............................................................,,...................................................... Bunsen Type Burner--Large--Natural Gas.................... -.................... ^ ....................... Bunsen Type Burner--Large--Artificial Gas......................................................................... Bunsen Type Burner-Small--Natural Gas.......................... ...................... ........ .............. Bunsen Type Burner--Small--Artificial Gas...................................... .............................. Welsbach Burner--Natural Gas............. _.......................-...................................... ............ Welsbach Burner--Artificial Gas.... ............................................................................................ Fish-tail Burner--Natural Gas......... .................................. ........................... ......... .......... Fish-tail Burner--Artificial Gas.............................................................. .. .......... ........... Lighting Fixture Outlet--Large, 3 Mantle 480 C.PcF....................... ...... 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 500 2500 400 540 2250 2250 -* * .* * * _ 4500 2250 900 540 135 10% 33% 60% 1000 6000 5000 ,* * . * * * 5000 3000 500 2500 900 60 250 250 * *. * * * * * 500 250 100 60 15 Steam Heated Equipment Bare Pipes, Not Polished Per Square Foot of Surface___ ___________________________ Insulated Pipes, Per Square Foot________ ______ ______ ____________ _________ _____ _ Steam Table--Per Square Foot of Top Surface.................................................................... 330 130 80 400 220* 110 2000 1200 2500 300 0 o 0 0 0 0 2000 1200 2500 800 100% 100% 100% 3.4 3413 2546 100% 4000 2400 1200 3400 7500 10000 1025 1100 850 4500 4600 9000 2050 2050 100% 10000 18000 10000 12000 10000 18000 250 100000 100 250 2500 10000 6000 1000 5000 1300 G00 2500 2500 5000 3000 3000 1800 3000. 1800 5000 3000 . 5000 2500 1000 600 150 330 130 80 400 220 110 4000 2400 5000 1100 Miscellaneous. . Heat Liberated By Food per person, as in a Restaurant.... ............ ............................ 1 30 Heat Liberated from Hot Water used direct and on towels per hour--Barber Shops 100 30 200 Per cent sensible and latent heat depends upon use'of equipment; dry heat, baking dr boiling. GO 300 Cooling Load 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. GENERAL From the foregoing discussion it is obvious that the determination of the maximum cooling load is rather complicated by reason of the variable nature 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 at 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. _ Example 1. Determine cooling load requirements for a clothing store illustrated in rig. 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 = 033 liable 4, Wall 38 B, Chapter 5). cReoiloinfgc,oUnst=ru0ct.i2o6n,(T2abinle. c1o1n, cWreatell, 2 ], inC.hraigptider i5n)s.ulation, metal lath and Pplaster F'P^PaPle flooring on yellow pine, no ceiling below, U = 0.34 (Table 8 Wall i u, Chapter 5). WaU 77B^Chapter's)^ piaster on 1)01,1 sides of studding, U = 0.34 (Table 6, Show windows, provided with awnings and thin panel partition at rear. Front doors, 2 ft 6 in.x7 ft (glass paneled), U =1.13 (Table, 13 A, Chapter 5). Side door, 3 ft x 7 ft (solid, 1H 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. . 159 Heating Ventilating Air Conditioning Guide 1939 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, I = 211. I for the south side at 4:00 p.m. is 8. Because of the small amount of solar radiation transmitted through the south glass, it can be neglected and the total heat gain taken as that due to normal transmission. Assuming time lag in roof and walls to be 2 hours, the corresponding values for / 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 / = 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 througlKwhich 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 1H outside air changes per hour. On a basis of 1)4 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. . ' 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: SUBTACB 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 it)-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 Abba SO FT 155 205 399 21 1800 1404 360 V 1.13 0.33 0.33 . 0.51 0.26 0.34 0.34 Temp. Dipt. Deo F Bm pxs Houb 15 2.627 15 1,015 15 1.975 15 . 161 15 7,020- 5 2,387 8 979 16,164 Cooling Load S Wall \V Glass W Door \V Wall Roof 3(14 ft *6(0 + (8 ft x 6 ft) Abba SQ FT 205 300 21 399 1800 P 0.078 0.118 0.078 0.062 a 0.7 0.7 0.7 0.9 / 77 211 192 143 258 Shade Factor 0.28 Btu peb Houb 862 17,724 333 3,113 25.914 47.946 Outside Air Heat Gain: Sensible heal, H$ = 0.24 X 60 do Q (fo -- 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 0.07105 lb per cubic foot (Table 4, Chapter 1). Dew-point of outdoor air is 66 F (psychrometric chart). Pa(rTtiaabl lepr6e,ssCuhreapotferva1p).or is 0.64378 in. Hg. (Pressure of saturated vapor at 66 F' 0 022 (29.92 - (164378) = 0 0137 lb water vaPr Pr W = 0.622 (ife) . 1 f/iua v.vn/t do = 0.07105 X 0.986 = 0.0699 ib dry air per cubic foot outside air. H, = 60 X 500 X 0.0699 X 0.24 (95-80) = 7549 Btu per hour. Total heat, H - 60 do Q (Ao -- 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). 77 = 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 peb Houb Senmbte 16,164 47,940 7,549 11.250 14,*j35 97.244 1 Latent 10.300 17,325 Total Load: 97,244 + 17,325 = 114,569 Btu per hour. Heating Ventilating Air Conditioning Guide 1939 PROBLEMS IN PRACTICE s 1 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 tem- - 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? ; Hi + Hr U for roof F a I Hi + IiR foot per hour. = [ATJ {to -- I)] + [AFal] (Formulas 1 and 2). , = 0.64 (Table 11, Wall 4 A, Chapter 5). = 0.147 (Fig. 2). = 0.9 (Table 6). = 293 (Table 4). = [1 X 0.64 (95-80)] + [1 X 0.147 X 0.9X293] = 48.5 Btu per square ; i i < b. Maximum sun intensity occurs at noon (Table 4). Maximum effect in cooling load will occur at 3 p.m. (Table 7). : 2 a. What is the maximum rate of heat delivered to a room through a bare iwindow 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 = A g// (Formula 3). I = 205 (Table 2). , Ha = 1 X 1 X 205 = 205 Btu per square foot per hour. b. At 4 p.m. (Table 2). ' J. \ i c. 205 X 0.28 = 57.4 Btu per square foot per hour (Table 8). \ 3 What is the heat gain per cubic foot of outside air introduced, under the 1 following conditions if the barometric pressure is 29.5 in. Hg? Outdoor tem- i peratures, 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 i (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). ' -i W = 0.622 ( ^ = 0.622 (jjg gg46 ) = 0 015 lb water vaPr per pound dry } air (Formula 5a, Chapter 1). i T plus 0 015 = lb dry air per pound outside air. do = 0.0705 X 0.985 = 0.06944 lb dry ajr per cubic foot outside air. Heat content outside dry air at 75 F wet-bulb = 38.46 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. ;S | ] f .| ' ^ J 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 ares 10 a.m., outside 85 F and inside 77 F; 4 p.m., outside 95 F and inside 80 F. Latitude 40 deg. .10 10 a.m.: Hi -- 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 0.58 X 211 = 2570 Btu per hour (Tables 4 and 8). ' 162 . Chapter 9 COMBUSTION AND FUELS PWnciDles of Combustion, Classification of Coals, Firing Methods for Coals, Firing Methods for Coke, Dustless Treat- ent of Coal, Classification of Oils, Combustion of Oil, Classim fication of Gas, Combustion of Gas THE data given in the first part of this chapter are of general appli cation to the various fuels used in domestic heating which are coal, coke, oil and gas. The choice of fuel is a question of dependability, cleanliness, fuel availability, economy, operating requirements and control. fundamental principles of combustion Combustion may be defined as the chemical combination of a substance with oxygen with a resultant evolution of heat. The rate of combustion depends partly upon the specific rate of reaction of the combustible substance with oxygen and partly upon the rate at which oxygen is supplied and the surrounding conditions as they define the temperature. Complete combustion is obtained when all of the combustible elements in the fuel are oxidized with all of the oxygen with which they can combine. All of the oxygen supplied may not be utilized. Perfect combustion is defined as the result of supplying the required amount of oxygen for combination with all of the combustible elements of the fuel and utilizing all of the oxygen so supplied. The oxygen required for the process of combustion is obtained from air which is a mechanical mixture of oxygen, nitrogen and small amounts of carbon dioxide, water vapor and inert gases. These inert gases are generally included with the nitrogen, and for engineering purposes the values given herewith may be used. Bt Volume Per Cent Oxygen, 0,................................................................. Nitrogen, IV,............................................ i................. 20.9 79 1 Bt Weight Per Cent 23.15 76.85 The combination of oxygen with the combustible elements and com pounds of a fuel is in accordance with fixed laws. In the case of perfect combustion the reactions and resultant combinations are shown in Table 1. The most important condition governing the process of combustion is temperature. It is necessary to bring a combustible substance to its Chapter 9. Combustion and Fuels ' temperature before it will unite in chemical combination with ignition _r(Xjuce combustion. The ignition temperatures for several of the combustible constituents of fuels are presented in Table 1. heat of combustion As oreviously stated, the process of combustion results in the evolution f heat The heat of combustion, or calorific value, of a fuel is the amount f heat generated by the complete combustion of a unit of the fuel and is nstant for a given combination of combustible elements and compounds. 2?, . t,p,,t 0f combustion of the several fuel elements and compounds in their pure state is given in Table 1. ` The reaction of the carbon in the fuel with oxygen may result in the formation of carbon monoxide or carbon dioxide. In burning to carbon monoxide, the carbon is not completely oxidized and, as shown by the data the heat produced is considerably less than if it were completely oxidized. This fact is of greatest importance in considering the efficiency of combustion. The calorific value of a fuel is determined by direct measurement of the heat evolved during combustion in a calorimeter. As the calorific value, on a moisture and ash free basis, of coal from a given district or mine remains substantially constant the calculation of the calorific value of a particular lot of coal can be made if the lot is analyzed for moisture and ash. From a known reliable calorific value for coal from the same mine or district the calorific value on a "moisture and ash free'' basis, often called the H value, is calculated from formula (1). _ . , . , , , 100 X Calorific value (as received) ... Calorific value, moisture and ash tree = -------177070:--------(nMoro--is--t-u--r--e- 7+--Aj--srhr)------ - ('1)' If a dry or moisture free analysis is used it is necessary to correct for ash only to reduce to moisture and ash free basis. From the value ob tained by formula (1) the calorific value for the sample under consider ation can be calculated as follows: Calorific value = ^a^or`^c va^ue (moisture and ash free) X [100 -- (Moisture -I- Ash)) ^ `From In te rn a tio n a l C ritic a l Tables. In the above formulae moisture and ash are expressed in per cent. The H values for Illinois coals are published1 and it is to be expected that more data on H values for other coals will be available in the future. As practically all fuels contain hydrogen they produce a certain amount of water vapor as one of the products of combustion. The amount of water vapor produced increases as the hydrogen content of the. fuel increases. When the calorific value of a fuel is determined in a calori meter the 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 fuel. 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 a fuel is specified. In burning the fuel, however, the products of 164 165 Heating Ventilating Air Conditioning Guide 1939 combustion are not cooled cannot be obtained. to the dew-point and the higher calorific valUe \ FLAME The appearance of the flame or products of combustion may serve as an 1 approximate measure of the temperatures developed in the combustion s process. The luminosity of a flame is caused by the heating to incan- ; descence of unconsumed particles of combustible matter in the gases and - the higher the temperature of these particles the whiter the flame. Table l 2 gives some approximate flame temperature data. { AIR AND COMBUSTION i The weight of air required for the perfect combustion of a pound of fuel i may be determined by use of the ultimate analysis of the fuel as applied to ;i formulae 3 to 5. The various elements are expressed in percentages i by weight. Table 2. Flame Temperature Data Appearance: of Flame Red, visible in davlivht Tight red. ..... Orange-red........ Urange-vellow..,,. Vellow-white. Bright white. . ------------------------------ --- --_ Solid and Liquid Fuels: Temperature DeqF ` ....... ................ ' `* 975 1832 2012 2192 2372 2550 T+Pounds air required per pound fuel = 34.56 Gaseou Fuels: ^Pounds air required per pound fuel = 2.46 CO + 34.56 H, + 17.28 Cll< + 13.29 CiHt + 14.81 C,H, + 16.13 C,H, + 6.10 II,S - 4.32 0, (3) .. W When the analysis is given on a volumetric basis the formula is express ed as follows: Cubic feet air required per cubic foot gas = 2.39 (CO + Hi) i 9.56 Cl1, 11.98 C,H, + 14.35 CiH, + 16.74 C,Hi 4.78 Oi ,,, w Formulae 6 and 7 may be used as approximates methods of determining the theoretical air requirement for any fuel. PDound.s a.ir requi.red, per p'ound, f,ue,l = 0,,.755 X, -C--a--l-o--r--if-i-c---v--a--l-u-ets(xBa--tu -p--er p--o-u--n--d--)1000 m Cubic feet air required per unit fuel = Calorific value (Btu per unit) 100 CO Approximate values for the theoretical air required for different fuels are given in Table 3. It is customary to make use of the analysis of the products of com bustion to determine the amount of flue gas produced and the actual 166 1 Chapter 9- Combustion and Fuels abemeonuwnet lol fdeasircrsibuepdplmiedvaforiroucsompubbulsictiaotnio. nsTohfe tahneaBlyusriseaouf ff h, aJ in the literature and the details of Orsat manipuS {J?** a"d considered in this discussion. (See Chapter 45). P eed not buTshtioenwloesigshctaolcfudlartyionflsueangdasmpaeyr bpeoudnedteormf ifnueedl bbuyrnfoerdmula 8^ " Cm' Pounds .dry flue gas per pound fuel = ILCO, fm8ofTt +T-7c(oCOr---)- Nil x c (8) gaVs aaluneaslysfoisr CaOnd?, 0C isCOtheanwdeNig?hatreofoecracrebnotaisflrmern^d 0 umerfr0m t, ^e flue corrected for carbon in the ash burned Per Pound of fuel Solid Fuel -------------------- -- Anthracite.................. ;...................... Semi-bituminous coal... -......................... Bitujmnous coal.......................................... Lignite.......................................... Pounds Air Per Pound Fuel 9.6 11.2 10.3 6.2 11.2 Fuel Oil Commercial otanaara i>o. a-- -...... -...... Commercial otanaaru i>o. ................... --------- Gaseous Fuels Pounds Air Per Gallon Fuel 102.6 104.5 106.5 112.0 114.2 . Cubic Feet Air Per Cubic Foot Gas 10.0 4.4 4.4 2.1 5.2 EXCESS AIR Because the real measure of the efficiency of combustion is the relation existing between the amount of air theoretically required for perfect com bustion and the amount of air actually supplied a method of determining the latter factor is of value. Formula 9 will give reasonably accurate results, for most solid and liquid fuels, for determining the amount of air supplied per pound of fuel. Pounds dry air supplied per pound of fuel 3.036 N, (CO, A- CO) (9) Values for C02, CO and N are percentages by volume from the flue gas analysis and Cis the weight of carbon burned per pound of fuel corrected for carbon in the ash. ' 167 Heating Ventilating Air Conditioning Guide 1939 The relationship of the air supplied, as determined from the previous formula, to the theoretical air required indicates the per cent of excess air supplied. A formula that may be used to determine directly the per cent of excess air is expressed: 100 CO (*-)Per cent excess air = N, X 0.264 -O- 0\ )2 In this formula the symbols represent volumetric percentages of the j flue gas constituents as determined by analysis. \ The amount of excess air in its relation to the percentage of COi is i shown by the curves in Fig. 1 for several fuels. These are approximate values. It should be noted that in hand-fired furnaces with long periods j. between firings the combustion goes through a cycle in each period and >| the quantity of excess air present varies. CHAPTER 9. Combustion and Fuels tbheed.coTkeheiscCoOm,baunsdtiounndoefrtcheertvaoinlactiolendmitaiottnesrsaonmdethCeOCO If rfr0m 11, 16 cthoemlbibuesrtiaotniosnpaocfeforovmer 4th0etfoue6l0bpede.r cent o'f the heat.nn TMe ^ue Jn tJle airTthheataiisr athdamtipttaesdseosvtehrrothuegfhuethl ebefudeinl boerddeisr to buj.rstV-.t and the and CO is called secondary air. burn the vo!atl^ matter Table 4. Maximum CO, Valves -------- ---------- ------------ ----------------------------------- - Fuel ____ ----------------- " ~oke....r- \nthracite Bituminous coal ............. >latural gas ;oke oven gas... ,,............................................................... ' '. Peb Cent COt 21.0 20.2 18.2 15.5 11.5 9.25 This process of combustion is illustrated in Fig. 22. The free oxygen of ie air passes through the grate and the ash above it and burns the carbon i the lower three or four inches of the fuel bed forming carbon dioxide, his layer noted as the oxidizing zone is indicated by the symbols COi and 1 Snmp nf the carbon dioxide of the oxidizing zone is reduced to carbon ~A * isrliipin0r 7finP Fig. 1. EXCESS AIR. PER CENT CO ARelation Between i and Excess ir in Gases of Combustion Due to the different carbon-hydrogen ratios of the different fuels the maximum CO% attainable varies. Representative values for perfect com bustion of several fuels are given ih Table 4. In considering the factor of excess air it should be noted that a deficien cy 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. An excess of air is usually required-, however, to eliminate combustible losses occasioned by poor mixing of the fuel and air. It is considered good practice, under usual operating conditions, to supply from 25 to 50 per cent excess air, dependent upon the fuel utilized. SECONDARY AIR When a solid fuel is hand-fired in a furnace the volatile^ matter in the J] fuel distills off leaving coke on the grate. The product of combustion of' 1 168 bed are mainly carbon monoxide, carbon dioxide, nitrogen and very little free oxygen. Free oxygen is admitted through the firing door to burn carbon monoxide and the volatile combustible distilled from the freshly fired fuel. . 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 size of * * ------------I-- InAWAnoCi VIM fVl 'From Bureau of Mines Technical Paper No. 80. 169 Heating VentiIiAting Air Conditioning Guide 1939 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'! I?' increases with increase in rate of burning. | Size of the fuel is a very important factor in fixing the quantity 0f| | secondary air required for non-caking coals. With caking coals it is notf f so important because small pieces fuse together and form large lumps,! fc Fortunately a smaller size fuel gives more resistance to air flow through the fuel bed arid thus automatically causes a larger draft above the bed, which draws in more secondary air through the same slot openings.! f In spite of this, a small size fuel requires a larger opening of the door i t slots; for a certain size for each fuel no slot opening is required, and fori 5- larger sizes too much excess air gets through the fuel bed. 1 | 1 Ii 5 I E Fig. 3. 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 It is impossible to establish a single rule for the correct slot opening for I all types and sizes of fuels and for all rates of burning. Furthermore, the | effect, of slot opening is dependent on whether the ashpit damper is open j or closed. It is better to have too much than too little secondary air; the j opening is too small if there is a puff of flame when the firing door is opened. | The relationship of the slot opening, for a domestic furnace, to the size | of coke and the rate of burning is shown in Fig. 33. These openings are i 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 J period subsequent to a firing in order to consume the gases and to reduce j the smoke. The smoke produced is a good indicator, and that opening is | *From Bureau of Mines Report of Investigations, No. 2980. 170 ;bweislltcwoohlictheregdausceessbethloewsmthoekiegntoitioanmpinoimntu, man.d pTrooovemhuachrmspfimiNnnHf^fJ'^r beneficial. The following suggestions will be helpful- ' `nStead of hal1f.oIpnencoalldl twheattihmeer,. with high combustion rates,' the sseecronnndary,, a,,ir djamper s,hould be sho2u. ldInbevecrloysmediladllwtehaethtiemr,ew. ith a very low conmobust.ion raatien, the seconjdary air damper sho3u. ldFober tinemanpeinrateturrmesedbiaetweepeonsitvioenry. mild and very cold' e secndjary a.ir damper one4.hoFuorr. ordinary house operation, secondar'y air is needed aftreer. e,,ach. frirm g f,or about buIsntiotnheoffioelidl isofgednoemreaslltyicrehsetaritcintegdthtoe tuhsee loarfeseercosnedm*iTM ,n com' of oil burners used in large heating boilers This fa 'cot^mf.rcial types - * factor is discussed in Ol Oil UUMIUO W-vv- - w Chapter 11, Automatic Fuel Burning Equipment. The air that is supplied around the flame in a domestic heatinn eas burner is considered as secondary air. As it is drawn into the aDDliance by natural draft action, the need for proper draft control is evident 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 square foot of grate area per hour. 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 affect on the draft required to produce a given rate of burning. If the excess is caused by holes in the fuel bed or an extremely thin fuel bed it is often possible to produce a higher rate of burning by increasing the thickness of the bed. The thickness of the fuel bed should not, however, be increased too much because-the increased draft resistance will reduce the rate of primary air supply and the rate of burning. DRAFT REGULATION Because of the varying heating load demands present in most instal lations it is necessary to vary the rate of fuel burning. The maintenance of the proper air supply for the various rates of burning is accomplished by regulation of the drafts. Correct and incorrect methods of draft regulation are shown in Fig. 4. The air enters through the ashpit, firing door and by leaks in the setting, whereas the gases leave only through the up-take. By throttling the gases with the damper in the up-take all the 171 Heating Ventilating Air Conditioning Guide 1939 air entering by each of the three intakes is reduced in the same proportion. I If the ashpit door is closed the air admitted through the ashpit is reduced } and increased through the other two intake openings. * Methods of control of draft conditions when burning oil or gas are ] noted in Chapter 11, Automatic Fuel Burning Equipment. ' ; CLASSIFICATION OF COALS I 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 *' Fig. 4. Correct and Incorrect Methods of Draft Regulation in a Hand-Fired Furnace 1 J pound of coal, in the handling and storing properties, and in the burning ; characteristics. A description of the relationship between the qualities f. of coals and these characteristics requires considerable space; a treatment l applicable to heating boilers is given in Bureau of Mines Bulletin 276. i The classification of coals by rank involves several of the items indicated i in a proximate analysis of the coal. This analysis determines tlie content 1 of volatile matter, fixed carbon, ash and moisture. The calorific value and sulphur content are often reported w;ith the proximate analysis. Volatile f matter is the loss of weight when the coal sample is heated to 1732 F for 7 min. Fixed carbon is the difference from 100 per cent of the sum of ; other losses, not including sulphur. Ash is the incombustible impurity in < the coal and has no heating value. . Moisture is the inherent and ex- j traneous water in the fuel. $ A classification of coals is given in Table 5, and a brief description of the | kinds of fuels is given in the following paragraphs, but it should be f recognized that there are no distinct lines of demarcation between the I kinds, and that they graduate into each other. . | Anthracite is a clean, dense, hard coal which creates very little dust in handling. It jj is comparatively hard to ignite but it burns freely when well started. It is non-caking, 1 it burns uniformly and smokelessly with a short flame, and it requires little attention to j the fuel bed between firings. It is capable of giving a high efficiency in the common 1 172 1 Chapter Combustion and Fuels of hand-fired furnaces. A tabulation of the quality of the various anthracite t>. rpeVwm;j| be foouunnddlin Bureau oc f Mines Report of Investigations No. 3283. SIZeS * ihracite has a higher volatile content than anthracite, it is not as hard and more easily; otherwise its properties are similar to those of anthracite, ignites ^ js soft ancj friable, and fines and dust are created by handling it. r*?*'* mew|,at slowly and burns with a medium length of flame. Its caking pro- k '^increase as the volatile matter increases, but the coke formed is relatively weak. Table 5. Classification of Coals by Rank5* Legend* FC. = Fixed Carbon. V.M. = Volatile Matter. Btu = British thermal units. Grou? Liuits of Fixed Carbon or Btu Mineral-Matter-Free Baris Requisite Phtbical Properties 1. Meta-anthracite.-------- 2. Anthracite----------------- |. Anthracite-------3. Semi-anthracite-. Dry 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) Non-agglomerating* Dry F.C., 86 per cent or more and less than 92 per cent (Dry V.M., 14 per eent or tees and more than 8 per cent) II. Bituminous4-. 1. Low volatile bituminous coal... 2. Medium volatile bituminous coal 3. High volatile A bituminous coal.. 4. High volatile B bituminous coal.. 5. High volatile C bituminous coal.. Dry F.C., 78 per cent or more and Icbb than 86 per cent (Dry V.M,, 22 per cent or less and more than 14 per cent) Dry F.C., 69 per cent or more and less than 78 per cent (Dry V.M., 31 per cent or (ess and more than 22 per cent) Dnr F.C., less than 69 per cent (Dry V.M., more than 31 per cent); and moist* Btu, 14,000* or more ' Moist* Btu, 13,000 or more and less than 14,000* Moist Btu, 11,000 or more and less than 13.000* Either agglomerating* or non-weathering/ 1. Sub-bituminous A coal III. Sub-bituminous. 2. Sub-bituminous B coal 3. Sub-bituminous C coal Moist Btu, 11,000 or more and less than 13,000* Moist Btu 9500 or more and less than 11,000* Moist Btu 8300 or more and less than 9500* Both weathering and non-agglomerating* IV. Lignitic__ t. Lignite., 2. Brown coal.- Moist Btu less than 8300 Moist Btu less than 8300 Consolidated Unconsolidated This classification does not include a few coals which have unusual physical and chemical properties and which come within the limits of fixed carbon or Btu of the high-volatile bituminous and sub-bituminous ranks. AH of these coals either contain less than 48 per cent dry, mineral-matter-free fixed carbon or have more than 15,500 moist, mineral-matter-free Btu. *lf agglomerating, classify in low-volatile group of the bituminous class. Moist Btu refers to coal containing its natural bed moisture but not including visible water on the surface of the coal. * 4It 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, a^*^mnrweaUierinn0D*Wea^er'nB' Variety 2. agglomerating and weathering; Variety 3, non-agglomerating Philadd^h^ ^rm ^ST.M. Standards, 1937, Supplement, p. 145, American Society for Testing Materials, 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. jj .-^e tombituminous coal covers a large range of coals and includes many types having frnfi*!!? udifferent composition, properties, and burning characteristics. The coals range the high-grade bituminous coals of the East to the poorer coals of the West. Their , " PrPerties range from coals which completely melt, to those from which the raHneS a* ^rs a^e distilled without change of form, so that they are classed as non- g or Iree-burning. Most bituminous coals are strong and non-friable enough to 173 Heating Ventilating Air Conditioning Guide 1939 Chapter 9. Combustion and Fuels permit of the screened sizes being delivered free from fines. In general, they ig,,jt J I easily and burn freely; the length of flame varies with different coals, but it is long. Mm* ! it smoke and soot are possible especially at low rates of burning. *5 . Sub-bituminous coals occur in the western states; they are high in moisture whe mined and tend to break up as they dry or when exposed to the weather; they are liabj"1 t to ignite spontaneously when piled or stored. They ignite easily and quickly and have! ? medium length flame, are non-caking and free-burning; the lumps tend to break int 3 small pieces if poked; very little smoke and soot are formed. | ; I ; '. Lignite is of woody structure, very high in moisture as mined, and of low heatiiw `5 \ value; it is clean to handle. It has a greater tendency than the sub-bituminous coals to t 5 disintegrate as it dries, and it also is more liable to spontaneous ignition. Freshly mined I f lignite, because of its high moisture, ignites slowly. It is non-caking. The char left after I f the moisture and volatile matter are driven off burns very easily, like charcoal. Xhe' lumps tend to break up in the fuel bed and pieces of char falling into the ashpit continue 1 5 to burn. Very little smoke or soot is formed. ;V It is often desirable to learn about the properties of a coal, such as the various items - noted in the discussion of proximate analyses. As a guide for the consumer as to the) expected characteristics of coals several commercial publications are available and 3 numerous reports of the Bureau of Mines discuss the coals produced in individual state areas. S * CLASSIFICATION OF COKES |\ Coke is produced by the distillation of the volatile matter from coal. The type o( S coke depends on the coal or mixture of coals used, the temperatures and time of distil- 1 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. 5 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- J 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- \ merit have contained from 10 to 15 per cent volatile matter. In general, these cokes 5 ignite and burn more readily than high-temperature cokes. The properties of various I low-temperature cokes may differ more than those of the various high-temperature cokes f because of the differences in the quantities of volatile matter and because some'may be V light and others briquetted. | Petroleum, cokes, which are obtained by coking the residue left from the distillation of i petroleum, 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 f protect the grates from being burned! , .| . i ! FIRING METHODS FOR ANTHRACITE4 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. Stove size coal is the proper size of anthracite for many boilers and furnaces used for heating buildings. It burns 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 4Sce reports published by Anthracite Industries Laboratory. Primps, Delaware County, Pennsylvania. 174 be poked or disturbed, and the fuel should be fired deeply and ^rh^tnut size coal is in demand for firepots up to 20 in. in diameter, with jptrth 0f from 10 to 15 in. 3 p size coal is often an economical fuel to burn. It is relatively low . " When fired carefully, pea coal can be burned on standard grates, in pnce- small amount of a larger fuel on hand when.building Ic 1S *eps or wben filling holes in the fuel bed. Care should be taken to r^the grates only until the first bright coals begin to fall through the snake uel j,ed, after a new fire has been built, should be increased ?r:thickness by the addition of small charges until it is at least level with 'h 'll of the fire-door. This keeps a bed of ignited coal in readiness tbe time when a sudden demand for heat shall be made on the fgai" 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 cold- Table 6. Anthracite Standards tgg--- Classification Coal Size, Inches Through 3-M Through 2-ki6 Through 1-54 Through Through %6 Over 2-Jf e Over l-% Over `5f6 Over % 6 Over 6 air 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 burn on ordinary grates. Greater care 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 fire 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 conse quently 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 175 Heating. Ventilating Air Conditioning Guide 1939 Chapter 9. Combustion and Fuels then to attempt to burn the fuel at a high rate while warming up. A uni form 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. : No. 2 buckwheat anthracite, or rice size, is used only in domestic j stokers. No. 3 buckwheat anthracite, or-barley, has no application in I domestic heating. | The Anthracite Institute Standards of sizing are shown in Table 6 taken 1 from Anthracite Industries Manual, Report No. 2403. | I sufficient to burn the volatile matter represented by the shaded supply .. eacj1 j;ne The shaded areas above each horizontal line areas u ^ eacj1 ajr supply the loss from incomplete combustion of the rePr^ matter. The clear area under each horizontal line represents the volati excessive air. As the air supply increases the loss from incom1<fte combustion decreases but the loss from excessive air becomes larger. Th sum of the two losses is the least when the air supply is introduced lne te(j by the average line. It is evident that the sum of the losses for ^"average air supply is much larger in diagram B than in A which would indicate that small and frequent firings are better than large firings at long intervals. FIRING METHODS FOR BITUMINOUS COAL jj 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 i ignite the gases leaving the fresh charge. j! Air should be admitted over the fire through a special secondary air ]j 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. j> ' 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- Z 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 'j of gases and to reduce the quantity of secondary air required for smoke- fj less combustion. '1 It is well to have the bright fuel in the firebox so placed that the gases jj| from the freshly fired fuel, mixed with the air over the fuel bed, pass Si 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 I ignition temperature, thereby causing the gaseous matter to burn and preventing the formation of smoke.: f The importance of firing bituminous coal in small quantities at short intervals is discussed in the U. S. Bureau of- Mines Technical Paper, \ No. 80. Better combustion is obtained by this method in that the fuel supply is maintained more nearly proportional to the air supply.- This is demonstrated in Fig. 5 where diagram A shows the air supply and the distillation of the volatile combustible when the firings are 5 min apart; and diagram B indicates the same relationships when the firings are 15 min apart. In both cases the amount of coal fired per hour and the weight of volatile combustible distilled from the coal are the same. This weight of volatile conbustible is represented by the shaded area under the saw-tooth curve. The horizontal dotted lines represent the constant air 176 Wfc Necessary Air Supply 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 requiring stoking it may not be necessary to shake the grates, as the ash is usually dislodged, during stoking. It is acknowledged that it may be difficult to apply-the outlined methods to domestic heating boilers of small size, especially when frequent attendance is impractical. The adherence to these methods insofar as practical, however, will result in better combustion. 177 Heating Ventilating Air Conditioning Guide 1939 The output obtained from any heater with bituminous coal will usually exceed that obtainable with anthracite, since bituminous coal burns more rapidly than anthracite and with less draft. Bituminous 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. FIRING METHODS FOR SEMI-BITUMINOUS COAL | The Pocahontas Operators Association recommends the central cone i 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 r firing door. This allows the larger lumps to fall to the sides, and the fines i to remain in the center and be coked. The poking should be limited to s breaking down the coke without stirring, and to gently rocking the grates. ? It is recommended that the slides in the firing door be kept closed, as the ' thinner fuel bed around the sides allows enough air to get through. | FIRING METHODS FOR COKE Coke ignites less readily than bituminous coal and more readily' than anthracite and burns rapidly with little draft. 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 rapidly 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. In order to obtain tlje same interval of attention as with other fuels 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. The best size of coke for general use, for small firepots where the fuel depth is not over 20 in., is that which passes over a 1 in. screen and through a V/i in. screen. For large firepots where the fuel can 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. PULVERIZED COAL Although several pulverized coal burning units for domestic heating plant firing have been developed, none has attained extended, use. Two general methods, of adaptation have been employed, one where the coal is pulverized by the unit at the furnace and one where the coal is delivered to the home in pulverized form. " FURNACE VOLUME The principal requirements for a hand-fired furnace 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. . 178 i Chapter 9. Combustion and Fuels The furnace volume is influenced by the kind of coal used. Bituminous Is on account of their long-flaming characteristic, require more space Ca\vhich to burn the gases of combustion completely than do the coals jn jn volatile matter. For burning high volatile coals provision should h made for mixing the combustible gases thoroughly so that combustion '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. DUSTLESS TREATMENT OF COAL The practice of treating the more friable coals to allay the dust they create is increasing. The coal is sprayed with petroleum products, par ticularly the lighter oils, a solution of calcium chloride or a mixture of calcium and magnesium chlorides. The latter 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 coal in the bin. The coal is usually treated at the mine, but sometimes by the local distributor just before delivery. The salt solutions are sprayed under high pressure, using from 2 to 4 gal or from 5 to 10 lb of the salt per ton of coal, depending on its friability and size. Oil for the dustless treatment of coal is also applied under high pressure, in concentrations of 1 to 8 qt per ton of coal, depending upon the characteristics of the coal and oil. CLASSIFICATION OF OILS The Commercial Standard Specifications for Fuel Oils (CS 12-38) of the U. S. Department of Commerce are given in Table 7. These speci fications conform with American Society for Testing Materials Tentative Specifications for Fuel Oils D396-38T. The specific gravity of oil is of interest in its relationship to the calorific value and these data are given in Table 8. COMBUSTION OF OIL 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 and 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 (satu rated and unsaturated hydrocarbons, hydrogen, etc.) may be offset some what 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 179 T a b l e 7. D e t a il e d R e q u ir e m e n t s fo r F u e l O il s 8 N o. 2 Fuel o il-- a d is tilla te o il fo r use in burners requiring a moder ately volatile fuel. N o. 3 Fuel o il-- a d is tilla te o il fo r uSe in burners requiring a low vis cosity fuel. OP No. 5 Fuel o il-- an o il fo r use in b u r ners requiring a medium vis cosity fuel. Heating Ventilating Air Conditioning Guide 1939 V is c o s m Seconds 90 Per Cent Point End Saybolt Point 1 Universal | a t 100 F Saybolt Furol I a t 122 F d s 1 2 s 1 2 i s c ta^* 2 Hg KeS 2 1 a 410 560* 440 000 675 55 09 .009 40 45 CC .2*0 .5 O' % O v &! c O CO 51 8 o-S 8 33 .*2 522h 2g" E=-oa q Sg-; 1 1 S o Sav Igbd--woe"!gg! oc'tS *v*O* 11*1 g3*o08* w * OyC y2g Sfil sUl 1Cc e pc .: sgJ.Se!:p 52g|S||'!K| eg s Scf E g c cch 6-35 ,,,, Si^CongOOr. ca -- .J3 , 2O 5"S c** Sm-o 52 _53= i; =oca! A sh Paa Cent 10. ;Per Cent Point || M ax. || M ax. J oro 0.25 on 10% R e s id u u m / j 0.15 Straight 0.05 on 10% Residuum '1 Carbon Residue PEn Cent Max. Water and Se d im e n t Per Cent Pour Point D eo F F lash Po in t D eq F M in. | Max. | Max. j Max. j tb iO CD 'll 0 2 0 No. 1 Fuel o il-- a d is tilla te o il fo r use in burners requiring a volatile fuel. 100 or Legal Trace -110 or Legal 190 .15* o ro 900 no 1 or . 230 20* Legal 130 ! or Legal eJ3v,-3TJl>4,Ci4>^*25*i *-> O S,fiJ3*5 Oiox:^ a c S s-> `Ef rss S'0"^s 3.2 sg 5 2 * p= 0 0 0 Sj 5 --= 3~ r] 3 0U6 ,S- *Ve S23S u ^q 03 i 112 b^C i ^2 IrUoSlqOtos.ZOZOPg SK a :- 150 1 No. 6 Fuel o il-- an o il fo r use in b u r ners equipped w ith preheaters p e rm ittin g a high viscosity fuel. 2 E c w 3C si* --gk,--S2'20. O |s t ?ll ts f'3 j5 aCO--8vn s Iff !! ogs s| sis i dg .SfcS ri ) 41 tl O B g'3 rf 3U|g f-5r i i `i I Js u i! 8- 5S--lg,Si<jSod *C4COtOO _,5`Ci{ ododoo^USP: *!, wZZZZZ >, >0: ia O 3 us' Chapter 9. Combustion and Fuels Table 8. Approximate Gravity and Calorific Value of Standard Grades of Fuel Oil AESC1AL ABD NO. 1 2 3 5 6 Approximate Gravttt, Range Baumb 38-40 34-36 28-32 18-22 14-16 Calo&ipic Value Btu Per Gallon 136,000 138,500 141,000 148,500 152,000 eas 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 quantities. The air and oil vapor must be vigorously mixed to get a rapid and com plete 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 com pletion. 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. CLASSIFICATION OF GAS Gas is broadly classified as being either natural or manufactured. Natural gas is a mechanical mixture of several combustible and inert 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. Repre sentative properties of gaseous fuels commonly used in domestic heating are presented in Table 9. 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 CO2, and from 1 to 12 or 14 per cent of nitrogen. The heat values varies from 700 to 1500 Btu per cubic foot, the majority of natural gases averaging about 1000 Btu per cubic foot. Table 9 shows typical values for the four main oil fields, although values from any one field vary materially. Table 9 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 tricts, nor at successive times in the same district. COMBUSTION OF GAS The majority of gas burners utilized in central domestic heating plants are of the Bunsen type and operate with a non-luminous flame. In this type of burner part of the air required for combustion is mixed with the gas as primary air, the air and gas mixture being fed to the burner ports. 181 Heating Ventilating Air Conditioning Guide 1939 -------------------' . Chapter 9. Combustion and Fuels Additional secondary air is introduced around the flame by draft inspi ration. In the luminous flame burner, which is sometimes used, all of the air for combustion is brought in contact with the flame as secondary air The importance of bringing the secondary air into intimate contact with the gas is noted. Some makes of burners use radiants or refractories to convert some of the energy in the gas to radiant heat by utilizing the principle of surface Table 9. Representative Properties op Gaseous Fuels. Based on Gas at 60 F and 30 in. Hg. Gas Natural gas-- California Btt; per Co Ft High Low (Gross) (Net) Specific Am Required G&avitt, for Combus Air tion, 1.00 (Cu Ft) Products op Combustion Cubic Feet Total CO, HjO with N, Ulti mate CO, Dry Basis Theoretical Flame Tem- PERATCRg (dbg Farr) 1200 1087 0.67 11.26 1.24 2.24 12.4 12.2 3610 ? ]I 1 l ?5 f 1 | Natural gas-- Mid-Continental Natural gas-- Ohio Natural gas-- Pennsylvania Retort coal gas 967 1130 1232 575 873 0.57 1025 0.65 1120 0.71 510 0.42 9.17 10.70 11.70 5.00 0.97 1.92 10.2 11.7 3580 |\ 1.17 2.16 11.8 12.1 1.30 2.29 12.9 12.3 0.50 1.21 5.7 11.2 3600 | ii jj 3620 ; 3 V 3665 . a Coke oven gas 588 521 0.42 5.19 0.51 1.25 5.9 11.0 3660 1 Carbureted water gas 536 496 0.65 4.37 0.74 0.75 5.0 17.2 3815 1 Blue water gas 308 281 0.53 2.26 Anthracite pro- ducer gas 134 124 0.85 1.05 Bituminous producer gas 150 140 0.86 1.24 Oil gas 575 510 0.35 , 4.91 0.46 0.51 0.33 0.19 0.35 0.19 0.47 1.21 2.8 1.9 2.0 .5.6 22.3 3800 19.0 19.0 3000 3160 . 10.7 3725 |l 3 3> i ti '{ * tr combustion. The radiants also serve as baffles in directing the flow of the products of combustion. '* . Since one of the main functions of a gas burner is to properly proportion the air and gas, any marked change in the gas composition which affects the specific gravity necessitates a readjustment of the burner. It is necessary to supply a greater amount of air when the specific gravity of a gas is increased. The quantity of air given in Table 9 is that required for theoretical combustion, blit 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. ... .182 The air gas ratio has a decided effect upon flame propagation. It is 1 sarv that the gas will flow out of the burner ports fast enough so that cannot travel back into the burner head, i.e. flash back, but the elocity must not be so high that it blows the flame away from the port. The maximum and minimum flow speeds from burner ports which may he oermitted are known to be very close together when air-gas mixtures 'theoretical proportions are being supplied to the burner. As the air-gas "V- js lowered, and the mixture becomes more gas rich, the limiting eds become further apart, until with 100 per cent gas, in an all-yellow fkune flash back cannot occur and a much higher velocity, is needed to blow off the flames. REFERENCES Fuels and Their Combustion, Haslam and Russell (McGraw Hill Co., 1926). Principles of Combustion in the Steam Boiler Furnace, Arthur D. Pratt, (Babcock and Wilcox Co.). . Bureau of Mines Publications. . Bulletin No. 97, Sampling and Analyzing Flue Gases, by Henry Kreisinger and F. K. Ovitz. Report of Investigations (R;I. 2980), Coke as a Domestic Heating Fuel, by P. Nicholls and B. A. Landry. Bulletin No. 276, Five Hundred Tests of Various Coals in House-heating Boilers, by p. Nicholls, S. B. Flagg and C. E. Augustine. .. Report of Investigations (R.I. 3283), Quality of Anthracite as Prepared at Breakers, 1935. Technical Paper No. 80, Hand Firing Soft Coal under Power-Plant Boilers, by Henry Kreisinger. . Technical Paper No. 303, Value of Coke, Anthracite, and Bituminous Coal for Gener ating Steam in a Low-pressure Cast-iron Boiler, by John Blizard, Janies Neil and F. C. Houghten. .` Anthracite Industries Laboratories Publications: Report 2015, Comparison of Sizes, Egg, Stove and Chestnut Anthracite. Report 2018, Domestic Survey. ' Report 2062, Utilization of Anthracite for Domestic Heating. . Report 2204, The Crater Method of Firing. - Report 2403, Anthracite Industries Manual. An Experimental Investigation of the Use of Oil for the Treatment of Coal, by Ralph A. Sherman and J. M. Pilcher (A.S.M.E. Transactions, February, 1938). Handbook of Oil Burning, by Harry F. Tapp, American Oil Burner Association. Industrial Gas Series/Combustion, American Gas Association. . Comfort Heating, American Gas Association. . .. Tests of Gas Home-Heating Equipment, by R. B. Leckie and C. H. B. Hotchkiss (Purdue University, Engineering Bulletin Research Series No. 36). PROBLEMS IN PRACTICE 1 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 Uk k* ^uel 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. 183 Heating Ventilating Air Conditioning Guide 1939 2 Does the size of a fuel affeet 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. 3 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, and d. fusibility of the ash. ' 4 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' and 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. 5 4 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 off under high temperature, producing smoke. 6 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. -. 7 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 thewater 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. 8 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. - 9 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 efficiency is 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 firepot. 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. .ft , 184 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 cooler 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 Heating Ventilating Air Conditioning Guide 1939 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 mechanica] 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 10.Chapter Chimneys and Draft Calculations oressure, respectively. A mechanical draft system may be used either in conjunction with, or as an adjunct to, a natural draft system. Fig. 1. General Operating Characteristics of Typical Induced Draft Fan i 1 .- i : parts, (4) low cost of maintenance, (5) relatively long life, (6) relatively! t low depreciation, and (7) no power required to operate. The principal 1 I disadvantages are: (1) lack of flexibility, (2) irregularity, (3) affected! | by surroundings, and (4) affected by temperature changes. fp .' j Mechanical Draft . ,N 5 >; Artificial draft, or mechanical draft, as it is more commonly called, is a f l difference in pressure produced either directly or indirectly by a forced! f draft fan, an induced draft fan, or a Venturi chimney as the pressure; ?. transformer. The intensity of mechanical draft is dependent for the most| l part upon the size of the fan and the speed at which it is operated.. The! f element of temperature does not enter into the creation of mechanical J t 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| 1 which the pressure difference is the result of a blowing:. Mechanical draftj y systems tend to produce a vacuum or a plenum, as the system used in itsj | production creates a pressure difference below, or above, atmospheric* ?r- 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 186 187 fC Heating Ventilating Air Conditioning Guide 1939 not be confused with mechanical draft systems that create draft mechani-! cally, but which must also be automatically controlled. i The use of such a device to provide a more uniform and dependable t control of draft than could be maintained by manually operated dampers will produce better combustion of fuel. This higher efficiency of combusl > tion together with the reduced heat losses up the chimney by reason of! decreased gas velocity, results in fuel economy, with consequent lower 1 costs of plant operation. ^ CHARACTERISTICS OF CHIMNEYS ! In order to analyze the performance of a natural draft chimney, it may f 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 i 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 f equation for this net total available draft intensity of a natural draft i chimney with a circular section is as follows: | Da = 2.96HBo (j? IVA 0.00126 H^Tc/Z. Tc) D>B,,Wc (lit- where Z?a = available draft, inches of water. H = height of chimney above grate bars, feet. B0 ** barometric pressure corresponding to altitude, inches of mercury. W. = unit weight of a cubic foot of air at 0 F and sea level atmospheric pressure, pounds per cubic foot. W, = unit weight of a cubic foot of chimney gases at 0 F and sea level atmospheric i pressure, pounds per cubic foot. $ To = absolute temperature of atmosphere, degrees Fahrenheit. . * \ Tc = 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. t L length of friction duct of the chimney, feet. D = minimum diameter of chimney, feet. jr ` i The first term of the right hand expression of Equation 1 represents | the theoretical draft intensity, and the second term, the loss due to friction. { Example 1Determine the available draft of a natural draft chimney 200 ft in height ? and 10 ft in diameter operating under the following conditions: atmospheric tempera-1 ture, 62 F; chimney gas temperature, 500 F; sea level atmospheric pressure, B0 = 29.92 in. of mercury; atmospheric and chimney gas density, 0.0S63 and 0.09, respectively. . coefficient of friction, 0.016; length of friction duct, 200 ft. The chimney discharges .j 100 lb of gases per second. . 188 Chapter 10. Chimneys and Draft Calculations Substituting these values in Equation 1 and reducing: ,, ., /0.0863 0.09\ 0.00126 X 100* X 960 X 0.016 X 200 Dt = 2.96 X 200 X 29.92 X ^ 522 960 J 10 x 29.92 X 0.09 = 1.27 - 0.14 = 1.13 in. Fic 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 vailable draft is equal to 1.27 in. of water, the theoretical intensity. As die amount of gases flowing increases, the available intensity decreases til 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: where Ex = 62,737 logio Ei = altitude of plant above sea level, feet. (2) 189 Heating Ventilating Air Conditioning Guide 1939 .--^ r| In general, the barometric pressure decreases approximately 0.1 in. of mercury per XOO 1 ft increase in elevation. | 2. The unit weight of a cubic foot of chimney gases at 0 F and sea level barometric 1 pressure is given by the equation: Wc = 0.131 COt + 0.095 0, + 0.083 Nt \ {Z) \ hA '{ In this equation COt, 0% 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 l 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 3 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 1 f at the time the analysis of the operating chimney is made. The mean atmospheric ? V temperature in the temperate zone is approximately 62 F. }r 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 r 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 I infiltration due to open joints, the temperature of the gases throughout the chimney will 1. 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 s analysis of this section is predicated on the assumption of constant gas temperature and $ no air infiltration throughout the height of the chimney. I * :* ' \ * l > > 5. The coefficient offriction between the chimney gases and a sooted surface has been 1 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 f brick or brickr-fined chimney, but in time the inside surface of all chimneys regardless of I the materials of construction becomes covered with a layer of soot, and thus the coef- I ficient of friction has been taken the same for all types of chimneys and in general 5 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 j various special equations and charts shown'in this chapter. J l 1 , * ` r } l 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. | * l j \v > - The Reynolds number, a dimensionless ratio, may be stated as follows: 1 where C,r = ^ 11 (4) D -- chimney diameter, feet. V -- velocity of hot gas, feet per second, p = mass density of the chimney gas per cubic foot. p = 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 Cr Dy-g (5) 190 Chapter 10. Chimneys and Draft Calculations where W = weight of gas passed per second. g = acceleration of gravity. -n, | ,, of a for chimney gases is usually taken as that of air or nitrogen, and for the The vaiu p temperature, the Sutherland equation may be employed as follows, Srin PoUnds-seconPd per square foot: 11 " 140 Lrc L J_ [~273 + Cl T To "IIS + CJ 273 where Tc = chimney gas temperature, degrees Centigrade. ^ = gas viscosity at 0 C. C = constant for specific gas. n.inv International Critical Table values, for air po = 35.6 X 10-8; C = 124; for nitrogen po = 34.5 X 10-8; and C = 110. REYNOLDS NUMBER. IN THOUSANDS 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 different 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 2. 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: ' Cr W_ 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. 51. Inree curves are shown: A, B, and C, where the choice of the friction factor curve uepends on the relative surface roughness, and this for usual chimney construction may Set also Flow of Fluids in Closed Circuits, by R. J. S. Pigott (Mechanical Eneincerine, August, 1933). 191 Heating .Ventilating Air Conditioning Guide 1939 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 f[ upwards, Curve A. Thus for the previous example with Cf = 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. y Fig. 6. Chimney Performance Chart3 aTo 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: ' where w = CtGWtp 3600 (6) Cg = pounds of fuel burned per square foot of grate surface per. hour. G = total grate surface of boifers, square feet. Cg X G = total weight of fuel burned per hour. W'tp = 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. 192 Chapter 10. Chimneys and Draft Calculations p. g js a typical chimney performance chart giving the available draft t Cities for various amounts of gases flowing and sizes of chimney. TVs chart is based on an atmospheric temperature of 62 F, a chimney gas * oerature of 500 F, a unit chimney gas weight of 0.09 lb per cubic foot, tC level atmospheric pressure, a coefficient of friction of 0.016, and a f^tion duct length equal to the height of the chimney above the grate lei 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= 2MBa Dr_______________ WVV 0.184/H^cBo^ Tc) TCD (7) where D = 0.288 J. WTc " B0WCV (8) 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. D, = 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 193 y Heating Ventilating Air Conditioning Guide 1939 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 = xtHD where Q = volume of material, cubic feet. t = average wall thickness, feet. For all practical purposes, the value of it/ 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: '\ fwc ) where Ve = economical chimney gas velocity, feet per second. 00) 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 and 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 considerably for average operating conditions in an average size steam plant by assuming typical conditions. x Average chimney gas temperature, 500 F.............................Tc = 960 Mean atmospheric temperature. 62 F...... ........................ To = 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........ Ba = 29.92 . Substituting these values in Equations 10, 8 and 7, respectively, and reducing, the results are substantially: Fc = 13.7 W1/s (ID . D = 1.5W2'5 (12) . 17'= 190.0, (13) 194 ' Chapter 10. Chimneys and Draft Calculations it 7 gives the economical chimney sizes for various amounts of gases and for required draft intensities as computed from Equations 11, flowing They are based on the operating factors used in reducing c-2 Eons'7 8 and 10 to their simpler form. The sizes shown by the EqUps in the chart should be used for general operating conditions only, CUIfbr installations where the required data necessary for an exact deter- Fig. 7. Economical Chimney Sizes3 Diameter values also for gas temperatures of 400, 500 and 600 F mination are difficult or impossible to secure. Whenever it is possible to secure accurate data, or the anticipated operating conditions are fairly well known, the required size should be determined 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 producing plant may be stated as follows: 7>t - hf = kp + Ab + hBd + he + hBr + hv + ho + hE + Hr 195 (14) Heating Ventilating Air Conditioning Guide 1939 Chapter 10. Chimneys and Draft Calculations where Dt = theoretical draft intensity created by pressure transformer, inches of water. hi = draft loss due to friction in pressure transformer, inches of water. Iif = draft loss through the fuel bed, inches of water. Ab = 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. had = 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. hE = draft loss through the economizer, inches of water. hR = 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 c 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 `j * system, while the right hand member expresses the required draft in- '] ; tensity and is analogous to the total dynamic head in a water works i - system. For a general circulation of gases T '. Da = Dr where .. . Da = available draft intensity, inches of water. Dt = required draft, inches of water. (15) > : l' `i: . .. \ 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 f installations, the draft loss through the fuel bed is dependent upon the y : 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, i coarseness of fuel; (4) thickness of the fuel bed, rate of combustion; k ' (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 \ t obtained for every kind of coal and rate of combustion. Fig. 8 gives the i intensity of draft, or the vacuum in the combustion chamber required to .f] . burn various kinds of coal at various rates of combustion. Expressed in ?] other words, these curves represent the amount of draft required to force jj the necessary amount of air through the fuel bed in order to effect various fj . 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 j r large and the particles are not well broken up, as with bituminous coals, f 7 much less draft is required than when the particles are small and are well jj ~ 196 I: with bituminous slack and the small sizes of anthracites. In brokeniup. ^ loss through the fuel bed increases as: (1) the pergenerai, u volat;ie matter diminishes; (2) the percentage of fixed carbon centage o ^ thickness of the bed increases; (4) the percentage of ash increase. W ^ volume 0f the interstices diminishes. in?eamakinK the preliminary assumptions for the draft loss through the ihwl due allowances should be made for a possible future change in [h de of fuel to be burned and also in the rate of combustion. A value Table 1. Recommended Minimum Chimney Sizes for Heating Boilers and Furnaces3 Wash Aib Pubnao Capacity mSqln- or Lbadsb Pips Btbam Boileb Capacitt Sq Ft or Radi* ATION Hot Water Hbatbb Capacitt Sq Ft or Radi ation Nominal Dimen sions op Fibs Clat Lining in Inches Rectangolab FLub Actual Inside Dimensions of FLiirneinCglay in Indies Actual Area 8q In. 590 973 8Mxl3 7 xllH 81 1000 690 1,140 900 1,490 13x13 HKxUK 127 900 1,490 8Mx 18 6 x 16)4 110 1,100 1,820 1,700 2,800 13x18 11)4x16)4 183 1,940 3,200 2,130 3,520 18x18 15)4x15)4 248 2,480 4,090 20x20 17)4x17)4 298 3,150 5,200 4,300 7,100 4,600 7,590 20x24 17x21 357 5,000 8,250 24x24 21x21 441 5,570 9,190 24 x24b 576 5,580 9,200 6,980 11,500 7,270 12,000 24 x 286 672 8,700 14,400 9,380 15,500 28x286 784 * 10,150 16,750 30 x 306 900 10,470 17.250 28x326 896 Round Flub Inside Diam elitneirnogf in Inches 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 lation 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 case 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. 197 Heating Ventilating Air Conditioning Guide 1939 Chapter 10. Chimneys and Draft Calculations The draft loss through the boiler and setting {ha) also varies between wiri I limits and, in general, depends upon the following factors: e- 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 , the loss through one of three or four, passes. A poor design gr!ftelrf)ueh condition of the brickwork will increase the loss greatly, and 3 f a proper design and a smooth condition will keep the loss at a whereas joss through the boiler will be less when the breeching minimu ^ jocate(j at or near the top of the boiler than when it is located entraInear the bottom since the gases have a shorter distance to travel in the former instance. The draft loss through the breeching (hBr) is given by the general equatln' , 0.000194 W*TcfL hBr = ---- (16) where jy = the amount of gases flowing, pounds per second. X = absolute temperature of breeching gases, degrees Fahrenheit. f = coefficient of friction. L = length of breeching, feet. A = area of breeching, square feet. B = atmospheric pressure corresponding to altitude, inches of mercury. . if = 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. 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 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 (Ay) is given by the equation 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 anil 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 of 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 i , 0.000194fF*rc hv = A'BffWc ~ (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 (hud) 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: . 0.000194 W'TC hBi A'B0Wq (18) 198 I 199 Heating Ventilating Air Conditioning Guide 1939 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: 0.000194fircW,,7V he = A\BqWc (19) where Kc = coefficient of sudden contraction based on ^-p1 , the ratio of the areas of the smaller to the larger section = 0.5 ^ 1 -- ^ As = 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: 0.000194^oH/,7'c ho = A\B0Wc (20) where Ka = coefficient of sudden enlargement based on At' the ratio of the areas of the smaller to the larger section = ^ 1 -- ^2 When the flue or passage through which 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. The draft loss through the economizer (Ae) should be obtained from the manufacturer but for general following general equation: purposes it may be computed from the 1 = GSWlNTc Ae To5 (21) j 200 10. Chimneys and Draft Calculations where .. .. . unds of gases flowing per hour per linear foot of pipe in each economizer Wo Psect.ion_. .. .. . N = number of economizer sections. . An economizer in a steam plant affects the draft in two ways, (1) it ffVrs a resistance to the flow of gases, and (2) it lowers the average h'rrmev eas temperature, thereby decreasing the available intensity. In kcase of a natural draft installation, both of these factors result in a Strive increase in the height of the chimney and, in the case of a large lant they may add as much as 20 or 30 ft to the height. The decrease tiie 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 s*s 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. Fire-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. f s`ze or area * ?ue l>n*n8 or of brick flue for warm-air furnaces depends on height olehimney and capacity of heating system. For chimneys not less than 35 ft in height aoove grate line, the net internal dimensions of lining should be at leiast 7 x liyz in. 201 Heating Ventilating Air Conditioning Guide 1939 for a total leader pipe area up to 790 sq in. Above 790 and up to 1,000 sq in. of lead*? pipe area the lining should be at least 11J4 x 11)4 in. inside. In case of brick flueg less than 35 ft in height with no linings, the internal dimensions should be at igJ?| 8 x 12 in. up to 790 sq in. of leader area, and at least 12 x 12 in. for leader capacities 1,000 sq in. Chimneys under 35 ft in height are unsatisfactory in operation and henSv should be avoided. CHIMNEYS FOR GAS HEATING j The burning of gas differs from the burning of coal in that the f0rc^ 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 off 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-l 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 t " -I* Table 2. Suggested General Dimensions for Vertical Back-Draft Diverter I Chapter 10. Chimneys and Draft Calculations < A study of a typical back-draft diverter shows that partial or complete . ney stoppage will merely cause some of the products of combustion "Te Vented out into the boiler room, but will not interfere with com bustion. In fact, gas-designed appliances must perform safely under such condition to be approved by the American Gas Association Laboratory. Other functions of the back-draft diverter are to protect the burner and nilot 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 .GA. Table 3. Suggested General Dimensions for Horizontal Back-Draft Diverter Pipe . ' Size A B .3 4 .5 6 7. 8 9 10 'll 12 33 44 55 66 7' 7 8. 8 99 10 10 11 11 12 12 c 5.5 7.2 9.4 11.5 13.5 15.5 17.5 19.7 22.2 24.7 D E 7.0 3.8 9.5 5.0 10.8 5.3 12.0 5.6 13.9 6.4 15.8 7.1 17.5 7.7 18.8 7.9 20.7 8.4 22:2 . 8.7 F 0.7 1.0 .1.5 1.9 2.3 2.7 3.1 3.6 4.3 5.0 .G 4.4 6.0 8.0 9.8 11.6 13.4 15.2 17.2 19.6 22.0 H 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 1 I J K L M| 1.5 2.5 0.7 1.5 2.3 I 2.0 3.5 1.0 2.0 3.0 | 2.3 4.0 0.9 2.4 3.51 2.5 4.5 0.8 2.7 4.01 2.9 3.2 5.3 6.0 0.9 1.0 3.1 3.5 45-- 61i 3.5 6.7 1.0 4.0 5- I 3.8 7.3 1.0 4.3 6.2 i 4.1 8.0 1.5 4.6 6.6 4.4 8.5 1.7 5.0 7.01 202 Pipe Size A B C D E F G H J K L M.' 3 4 .5 6 8 ,,9 3 4 3 4 6 1.5 4.8 8 2.0 4.8 3.8 1.4 5.0 1.9 2.5 2.5 2.5 2.1 0.6. 1.8 3.4 3.4 3.4 2.9 0.8 2.3 5 6 7 8 9 10 11 12 5 10 6 12 7 14 8 16 9 18 10 20 11 . 22 12 24 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 4.8 4.8 4.8 4.8 4.8 4.8 4.8' 4.8 6.3 7.5 8.8 10.0 11.3 12.5 13.8 15.0 2.4 2.9 3.4 3.9 4.4 4.9 5.4 5.9 4:2 5.0 5.9 6.7 7.5 8.4 9.2 10.0 4.2 5.0 5.9 6.7 7.5 8.4 9.2 10.0 4.2 3.5 09 2.9 5.0 4.3 1.1 3.5 5.9 5.0 1.3 4.1 6.7 5.6 1.5 4.7 7.5 6.4 1.7 5.3 8.4 7.0 1.9 5.8 9.2 7.8 2.1 6.4 10:0 8.5 2.3 7.0 203 X 1939Heating Ventilating Air Conditioning Guide 10.Chapter Chimneys and Draft Calculations 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 (S03). Sulphur usually bums 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) HBtGHT or Chimnet Feet 100 Gab Consumption in Thousands or Btu per Hour i i 200 300 400 500 750 1000 1500 2000 `j 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 fori; 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. 1 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 shoulckbe 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. .5 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 ofj 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 noj openings at the joints. Cement mortar should be used for the entire! chimney. ml - Table 4 gives the minimum cross-sectional diameters of round chini-J 204 evs (in inches) for various amounts of heat supplied to the appliance, "nd for various chimney heights. This is in accordance with American Gas Association recommendations. PROBLEMS IN PRACTICE 1 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 pate bar level and the temperature difference between the chimney gases and the atmosphere. 2 ^ What two kinds of draft need be considered? Natural draft caused by temperature differences, and artificial draft caused by me chanical forcing. ' j ^ 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. 41 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 ft 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 # a. Name the principle advantages of natural draft. b. Name the.principle disadvantages of natural draft. o. 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 tern- perature changes. ' How is mechanical draft created? By forced draft, by induced-draft fans, or by a Venturi chimney. ^ Distinguish between theoretical and available draft. ivhpnI?|t-Ca* <!f*ft `s difference in pressure inside and outside the base of a chimney draft |S Un.u PeratlnS> temperatures but when there are no gases flowing. Available * 'the chimiT5 *aeorehcal draft by the friction loss .due to the flow of gases through 205 Heating Ventilating Air Conditioning Guide 1939 -r--- 11 Explain the term efficiency of a natural draft chimney. ` The efficiency of a chimney is the ratio of the work it does in moving gases to the theo retical amount of power it generates. . 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 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? . 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 t Is it possible to state an average value for the draft loss through a boiler and its setting? .- 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 infdrmation.17 18 19 20 17 Of what significance is the COj content of stack gases in establishing draft loss? The COj content of the exit gases is a measure of the completeness of the combustion and the amount of excess air supplied. Low CO* indicates' a high excess of air and hence a high draft loss. . 18 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 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 i What is the purpose of aback-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. 206 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 of solid, 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 stoker^. These stokers receive fuel at the front of the grate in a layer of uniform 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 bum 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 main tain ignition until the fuel is fully consumed. A typical traveling-grate stoker is illustrated irt 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. 207 Heating Ventilating Air Conditioning Guide 1939 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 . voiatile gases are released, are mixed with air, and pass through the fie where they are burned. The ash may be continuously discharged as the small stoker or may be accumulated on a dump plate and periodi- in., discharged. This stoker requires no arch as it automatically pro- "dgS for the combustion of the volatile gases. . Fig. 3. Overfeed Inclined Grate Stoker 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 208 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. Stokers also may be classified according to their size based upon coal feed rates. The following classification has been made by the United States 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. . - ' 209 Heating Ventilating Air Conditioning Guide 1939 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. Chapter 11. Automatic Fuel Burning Equipment 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 Departr fnent 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. ; .. Fig. 5. Underfeed Screw Stoker, Hopper Type Fig. 6. - Underfeed Screw Stokf.r with Automatic Ash. Removal 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 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. 210 Operating Requirements for Anthracite Stokers Efficiency. The over-all efficiency of the unit at all points above 50 per cent of maxi mum coa| feed shall be above 50 per cent when installed in a round sectional cast-iron boiler having three intermediate sections and 1 Yl in. of asbestos insulation or its equiva 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. , r ., . , ; Ash Loss. Combustible in ash shall riot 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. Subsequent to the issuance of these standards the Society adopted a Code1 which should be followed iri 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. Combustion Rate. 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 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 of 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 interpiediate sections and the uq ivalent of 1 /2 in. of asbestos insulation'. However, in no case shall the maximurii -^S-H-V.E. Standard Section, Heating. Piping Code and A for. Testing Stoker-Fired ir Conditioning. September, Steam-Heating 1938, p. 613). Boilers (A.SiH.ViE. Journal 211 Heating Ventilating Air Conditioning Guide 1939 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 coq. 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 in. holes and over a similar screen having 5^6 in- holes. The undersizing should not exceed 15 per cent and the oversizing should not exceed 10 cent. A No. 2 buckwheat (rice) should pass through a round mesh screen having holes 5^6 in- >n diameter and over a like screen having holes of ${6 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 pa 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 arid 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 i This class is used extensively for heating plants in apartments and i 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, j 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 i plunger. .The drive for the coal feed may be an electric motor, or a steam J or hydraulic cylinder. With an electric motor, the connection between j the driver and the coal feed may be through a variable speed gear train j which provides two or more speeds for the coal feed; or it may be through j 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 i cylinder, the power piston is connected directly to the coal feeding ? plunger. .1 212 .Chapter 11 Automatic Fuel Burning Equipment The stokers in this class vary also in their retort design according to the f Is and load conditions. The retort is placed approximately in the U'Hdle of the furnace and is provided with tuyere openings at the top on "n 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, j -rj,ese stokers also differ in the grate surface surrounding the retort, tn 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 tvoe 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 airadmitting and some stokers have shaking grates. These grates permit a large part of the ash to be shaken into the ashpit beneath, while the dinkers<are removed through the fire doors. With this type of grate, the 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 as 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 burn bituminous coal, types are available for 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 Tlo*,w' er rate. . Class 4 Stokers, Medium Commercial pi; '. V. These stokers are usually of the screw feed type without auxiliary ;j)lungers or other means of distributing the coal. Rectangular retorts ^'th sectional tuyeres and dead plates without air ports are employed. 213 Heating Ventilating Air Conditioning Guide 1939 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: . a. 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. 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 aind a reduced air pressure under 214 Chapter 11. Automatic Fuel Burning Equipment . ^teTvTs cjofftr tro>f .tMheineriautem. oTfh8e^se ssqtofkt.ers va^ry in size from aPpPproxi- roa*u ost prevalent type of rear cleaning underfeed stoker, is the i Se'retort design. Occasionally double or triple retort side cleaning 'a feeds are made. The multiple retort underfeed stoker is made for underteeo jj0iiers for large industrial plants and central stations, xif- toker has reached a very fine stage of development mechanically T"s.s Mg matter of air supply and control. In some instances zoned air ana ,n ^ ^een applied both longitudinally and transversely to the grate ^rface Ash dumps on smaller sizes are sometimes manually operated. The Combustion Process Due to the marked differences in design and operating characteristics f 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) nderfeed type, burning takes place within the stoker retort. The ash u j 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 dr 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 and 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. 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. . < 215 Heating Ventilating Air Conditioning Guide 1939 The ash layer becomes thicker with time and that near the retort, being i 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 removal of ash as clinker and clinker tongs are provided to facilitate this purpose. Typical representations of underfeed bituminous stoker i fuel beds are shown in Figs. 8 and 9. i The appearance of such fuel beds is very ragged at times, and large j masses of coke build up, surrounded by blowholes with intense white i flame indicating the presence of excess air. There is a natural tendency for users to disturb the fuel bed and make it conform to the conventional Fig.'8. Cross-Section of Fuel Bed with Weakly Coking Coal IFig. 9. Cross-Section of Fuel Bed with Strongly Coking Coal ' 3 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 tree 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 these being:- the type and design of stoker, the type and characteristics of the fuel, the method of stoker installation and the method of stoker operation. 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. 216 Chapter 11. Automatic Fuel Burning Equipment The standard that has been most commonly used for the proportioning t furnaces for bituminous coal stokers is the code of the Steel Heating gX lnsUtute (see Chapter 13). Furnace volume is not an important item in anthracite stoker instal' 1 tions. Due care should be exercised for both anthracite and bituminous tokers to prevent intense heat application on the metal surfaces of the combustion chamber. The installation of a baffle or adjustment in setting height of the stoker may be desirable in some cases. 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 iii 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 217 Heating Ventilating Air Conditioning Guide 1939. Chapter 11. Automatic Fuel Burning Equipment 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 of Combustion | W' As efficient combustion is based upon a certain percentage of excess air I it is possible to determine the results by analysis of the gases formed by 1 the combustion process. An Orsat apparatus can be used to determine the 1 percentage (by volume) of the carbon dioxide (COs), oxygen (02) and 1 carbon monoxide (CO) in the flue gases. Due to variations in the fuel bed i 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- 1 Iout an operating period of reasonably long duration should be used. . A COt 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 t ` 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 ? I f: bituminous coal stokers, care should be taken that the delivery of air by f the fan is great enough to avoid smoke. ~n Controls ' 'I 5 The industry developed by stokers in Classes 1, 2, 3 and 4 has been due | j" 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-l jt dential heating, a field wherein the majority of owners and users are not | f familiar with control problems or stoker operation. |i The usual controls applied are as follows: .| 2. METHOD OF OIL PREPARATION Vaporising--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 - , 0 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 0. Electric. (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. Gas. (1) Continuous--pilot light of constant size. (2) Expanding--size of pilot light expanded temporarily at the beginning of burner operation. '. ' Combination--electric sparks light the gas and the gas flame ignites the oil. Manual--by manually-operated gas torch for continuously operating burners. 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). 5. MANNER OF OPERATION a. On and off--burner operates only a portion of the time (intermittent). b. High and low--burner operates continuously but varies from a high to a low flame. c. Graduated--burner operates continuously but flame is graduated according to ' needs by regulating both air and oil supply. . 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 fire- a s pot 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 3 % the heating system. .. 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: 4' j}U.' 1. AIR SUPPLY FOR COMBUSTION a. Atmospheric--by natural chimney draft. b. Meckanical--electric-motor-driven fan or blower. c. Combination of (a) and (b)--primary air supply by fan or blower and secondary . air supply by natural chimney draft. . 218 A trade classification of oil burners consists of the following general types: (a) gun or pressure atomizing, (b) 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. " 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 characteristic yellow color. Combustion is-supported by means of a bowl-shaped chamber or hearth. The wall -name burner (Fig. 12) differs in that combustion takes place in a ring of ;219 Heating Ventilating Air Conditioning Guide 1939 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 Chapter 11- Automatic Fuel Burning Equipment - A that while the heavier grades of oil have a smaller heat value per tfound havei due to greater density, a larger heat value per gallon. ^i.Un lative 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 liable to the purchaser of this type of equipment. They are used for 3 nlacements as well as for new installations. This type of equipment rePi~jlv j,as more heating surface than the older coal-burning designs. Flue proportions and gas travel have been changed with beneficial results. smm- Fig. 10. Gun Type Pressure Atomizing Oil Burner Fig. 11. Center Flame Vertical Rotary Burner Fig. '12. Wall Flame Vertical Rotary Burner 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. 3. No. 3 oil is the heaviest and most viscous of the various grades mentioned. An oil burner satisfactory for No. 3 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 220 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 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, r 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 as 350 gal of oil per hour can be burned in these units, and frequently, they 221 Heating Ventilating Air Conditioning Guide 1939 are arranged in multiple on the boiler face, from two to five burners t I each boiler. . 0; The larger installations are nearly always started with a hand torch and are manually controlled, but the useof 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. - . ....... 14.Fig. Horizontal Rotating-Cuf Oil Burner ' I | % 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; 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 f hour: There are indications that at times much higher fuel-rates may be ' 222 Automatic Fuel Burning Equipment t t rv This in turn suggests that the value of 38,000 Btu per cubic ; satisfactory- . j^be adjusted according to good engineering judgment. 1 foot pef care should be taken to keep the gas velocity below 40 ft for best ^^ere cbeckerwork of brick is used to provide secondary air, ^Jwactice calls for about 1 sq in. of opening for each pound of oil good P jiouf Such checkerwork is best adapted to flat flames, or to fired pe jjjgg that can be spread over the floor of the combustion chamber. 4if1Ca oner bricking of a large or even medium sized boiler for oil firing is 6 rtant and frequently it is advisable to consult an authority on this unporta essential in combustion chamber design is to provide subjec ame jmpjngeinent upon either metallic or firebrick surfaces. M^ufacturers of oil burners usually , have available detailed plans for Anting 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 ner 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 gaseous 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 rill 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 riot 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 223 Heating Ventilating Air Conditioning Guide 1939 the chamber shall be as nearly air tight as is possible, except when th 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 supporI 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 onlv 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 j 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 fire brick 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 or inactive spaces 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 is 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 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 the change causes the per cent of excess air to decrease below allowable limits of the 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 2b (3) and 2b (4) listed in the previous classification table. Note that any change due to partial i 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 ^ . 224 .' Chapter 11- Automatic Fuel Burning Equipment oossible stoppage of the chimney and changes in draft resispurposes^^ due to partial stoppage of the flues), and (b) changes in air ^^adjustments to the fan. m f;. reCognized that a secondary source of air due to leakage in the `Lt-ting is present in many installations and it is highly desirable that i kaee be reduced to a minimum. Obviously the amount of air will be determined by the draft in the combustion chamber. leaKag tant tj,at this draft should be reduced as low as is consistent th theoroper disposal of the gases of combustion. When using mechanift burners with average conditions, the combustion chamber draft h Id not be allowed to exceed 0.02-0.05 in. water. An automatic draft regulator Is very helpful in maintaining such values. Measurement oi the Efficiency of Combustion Efficient combustion being based upon a clean flame and certain nrooortions of oil and air employed, it is possible to determine the results bv analyzing the gases formed by the combustion process. An Orsat aooaratifc is a device which measures the volume of carbon dioxide (CO ) oxygen (Oi) and carbon monoxide (CO) in the fluegases. Except m the case of a non-luminous flame it is usually sufficient to analyze only for carbon dioxide (COi). 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 COi Taking into account the potential hazard of oil or air fluctuations with low excess air (high COi) a setting to give 10 per cent COi 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 C02. 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 (b) 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 operation and greater uniformity of room temperature. Class (b) 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 (b) 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 225 Heatino Ventilating Air Conditioning Guide 1939 Automatic Fuel Burning Equipment the quantity of oil in the storage tank. For this purpose various types 0f , indicating or recording gages are used, the simplest forms being the gU.' f level gage, and a float-and-dial arrangement having a graduated dial faC(; f indicating the proportion of the tank containing liquid. Other raoi! I accurate and dependable devices are designed to operate by hydrauli j 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 5, connected with the tank by pipe or tubing. The quantity readings mav 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 I production of such a large number of different types of gas heating I systems and appliances that today there is probably a greater variety ol < them than there is for any other kind of fuel. Gas-fired heating systems may be classified as: follows: L 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. ; . .' . . . . s . II. Conversion Heating Systems. . . A. Central Heating Plants. v 1. Steam, hot water and vapor boilers. . 2. Warm air basement furnaces. , : ' . : . 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-Fixed 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 , . -nable in sizes from those sufficient to heat the largest residence are ob~" s;zes applicable to a single, room. The practice of installing a down to arate furnaces to heat individual rooms is peculiar to mild onumber urnaceSj frequently controlled by electrical valves cJimates. push-buttons in the room above, are often installed to heat actuatea e^e may ^ desired for an hour or so each day. These .100,118 are USed also for heating groups of. rooms in larger residences. (Urnasvstem of this type each furnace should supply a group of rooms in the heating requirements for each room in the group are similar as far*S t)ie period of heating and temperature to be maintained are con- ccrnfi^* , - . The same fundamental principle of design that is followed in the con st uction of boilers, that is, breaking the hot gas into fine streams so that Darticles are brought as close as possible to the heating surface, is equally applicable to the design of warm air furnaces. Codes for proportioning warm air heating plants, such as that formu- 1 ted by the National Warm Air 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 is well to have the control of the fan and of the gas so coordinated that there will 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 rooms 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 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. i 226 I Heating Ventilating Air Conditioning Guide 1939 around a drum or heating section, and out of the heater at or near the ton These heaters cause a continuous circulation of the air in the room during the time they are in 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. 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 and sizes 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 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. m Many conversion units are equipped with sheet metal secondary air 228 iit 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. jj,e Combustion Process 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 iri 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 Orsat apparatus. It is desirable to determine the percentage of carbon dioxide (COs), oxygen (02) and carbon monoxide (CO) in the flue gases. While ultimate COj 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 COs 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, 229 Heating Ventilating Air Conditioning Guide 1939 Chapter 11. Automatic Fuel Burning Equipment; water temperature, or furnace bonnet temperature to shut off the burne when the pressure or temperature becomes excessive, a device on tj/ 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 f0r 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. Ratings lor 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 American 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. 230 ;V jsv,1 fij- ,,iven by the American Gas Association Laboratory is not "^conservative rating when considered from the standpoint of only a e^cjencyi but is also a safe rating when considered from the capacity. physical safety to the owner or caretaker. The rating that standpoi Han appijance is limited by the amount of gas that can be is placea j^ut ^ production of harmful amounts of carbon monoxide. Si- a me limitation applies to all classes of gas-consuming heating **u. snrps that are tested and approved by the Laboratory. Gas boilers applian ratings up to 14,000 sq ft of steam, while furnaces with are av ^ ahout 500,000 Btu per hour are available. (See Chapter 20.) ffllUl' r _, .. . ` . REFERENCES . Stoker Information, Bulletin No. 5, Committee of Ten, 307 N. Michigan Ave., ^Domestic Burners for Pennsylvania Anthracite, Commercial Standard CS48-34 ti c Oepartmcnt of Commerce. U d r rmmrf Exoectancy of Domestic Underfeed Stokers for Anthracite, by Allen J A.IM.E., Coal Division, Vol.119,,1936). c J JL Relation of the Size of Bituminous Coals to Their Performance on Small Under- Stokers--The Relation of the Size in the Hopper to That Burned in the Retort, Pn . 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- -j Cfnkers___ Burning Tests on Four Typical Coals, by R. A. Sherman, E R. Kaiser and iflt Limbacher, Technical Report No. 1, Bituminous Coal Research, Inc. (July, 1937) Pt II Stoker Coals, Anonymous, Bulletin of Chesapeake and Ohio Railway Co., 1935. ASH.V.E. Research Report No. 907--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). ASH V.E Research Report No. 925--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 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). . Comfort Heating, 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, Heating Ventilating Air Conditioning Guide 1939 PROBLEMS IN PRACTICE . 1 List some factors which might account for higher efficiencies with stoke, 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. ve 2 Classify stokers ns to construction and operation. o. Overfeed flat grate, b. Overfeed inclined grate, c. Underfeed side cleaning type, and d. Underfeed rear cleaning type. '0 3 What main parts are found in an underfeed residential stoker? i 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. ' 4 O What is a dead-plate? '^ A dead-plate is a flat surface without air supply openings upon which the fuel rests while j combustion of the fixed carbon is completed. Generally the ash is removed from the dead-plate. 5 What features of furnace design are essential for the proper burning of | 1 the volatile coal gases above the fuel bed? yv 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. ,, 6 What methods of oil atomization are used? \ i 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. j' 7 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. - ' 8 # Which flame is considered better, the luminous or the non-luminous? Laboratory tests show that they are equally efficient in the usual installation. ; ' 9 # What CO, content should be attained in oil burning? Ten per cent COj is considered good practice, for it indicates the supplying of 50 per cent excess air. ' . ; : 10 9 Name five types of gas-fired space heaters. a. Parlor furnaces or circulators, 6. radiant heaters, c. gas-fired steam or hot water radiators, d. warm air radiators, and e. garage heaters. 11 9 How are gas heating units rated? . Gas-fired units are rated on the basis of output in Btu per hour. - 12 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. ' 232 Chapter 12 heat and fuel utilization Fuel Consumption Records, Calculated Heat Loss Estimation Method, Maximum Rate pf Fuel Burning, Degree-Day Method, Unit Fuel Consumptions per Degree-Day, Maximum Demands and Load Factors MANY methods are in use for estimating in advance of actual oper ation the anticipated heat or fuel consumption of heating plants over long or short periods. With suitable modification in procedure these general methods are frequently useful in checking the degree of effectiveness with which heat or fuel is utilized during plant operation. In applying any of these estimating methods to the consumption of a particular building plant it should be noted that (a) reliable records of past heat or fuel consumptions of this building will usually produce more trustworthy estimates of future consumptions than will any data obtained by averages or from other similar buildings; (b) where no past records exist useful data can sometimes be obtained from records of similar buildings with similar plants in the same locality; (c) records of consump tion which are averages from many types of plants in many types of buildings in various localities, can produce no better than an average estimate which may be far from accurate; (d) estimates based on com puted heat losses without the benefit of operating data are wholly de pendent.on how well the computation represents the actual facts. Where records of past consumptions are available they should be examined for reliability to be sure that the records show fuel or heat for the heating plant only, or else make a suitable allowance for fuel used for other purposes, such as heating service water. Weights and measures shown on invoices may not always agree with fuel used, for residues left in bins or tanks may represent a considerable fraction of the fuel charged to a building. Generally, plant operating records of fuel used are to be preferred to those obtained from accounting or bookkeeping offices from fuel invoices. ' . ' Records from similar buildings even in the same locality should be examined with care before being used as the basis of estimates. The type . of heating system, the quality of supervision in manual plants, the kind of control in automatic plants, and the attention given to the plant operation are all factors in fixing the consumption in any building. Many times these factors do not show up in superficial examination and are even -difficult to evaluate when known to be present. Especially check the 233 Heating Ventilating Air Conditioning Guide 1939 records to be sure that they do not include energy or fuel used for other purposes than heating the building. Estimates based on computed heat losses alone are frequently the only ones possible to obtain especially where new equipment is put into unusual buildings and there is a scarcity of records and an absence of experience data. Such estimates also have to be made where direct information is not obtainable as, for example, if a survey is being made without the assistance or knowledge of the building operator and thus without information as to the'kctual consumption. Estimates of this kind are also useful in some cases where a relative standard of performance is desired to serve as a base of comparisons in a campaign of fuel utilj. W: r Chapter 12. ' Heat and Fuel Utilization. CALCULATED HEAT LOSS METHOD Th's method is theoretical and assumes constant temperatures for very , i -te hours each day throughout the entire heating season. It does not It into account factors which are difficult to evaluate such as opening tf windows, abnormal heating of the building, sun effect, poor heating systems, and many others. - In order to apply this method the hourly heat loss from the building under maximum load, or design condition is computed following the 1 GROSS OUTPUT-THOUSAND 6 T.U.PER HOUR --i---1-'--- 1----1--- 1----1-- - 1----1---!-1--- GROSS OUTPUT - HUNORED FEET STEAM RAOIATION -l--I--I--I--i--i--r--1--i i i--1--1--1--1--I--I--I--1--1--ill"!--1- 5 10 15 20 25 GROSS OUTPUT- HUNDRED FEET WATER RAOIATION Fig. 1. Coal Fuel Burning Rate Chart zation. In such situations it can be plausibly argued that an estimate based on computed heat quantities is to be preferred to one which is related to operating methods. ' In interpreting and evaluating heat or fuel consumption estimates'as well as in their preparation, it is well to realize that any estimating method used will produce a more reliable result over a long period operation than over a short period. Nearly all of the methods in common use will give trustworthy results over a full annual heating season, and in some cases such estimates will prove consistent within themselves for monthly periods. As the period of the estimate is shortened there is more chance that some factor not allowed for in the estimating method will become controlling and thus give discrepant and even ridiculous results. . . Of the various estimating methods in use attention is directed in this discussion to but two as they are illustrative of all, viz: (1) calculated heat loss method, and (2) degree-day method. 234. ,------ 1------ 1------- 1------i------ 1-------1-------1-------1-------r---r----- r---t--------1------- 1-------1-------r---------r--i----- 1 02 4 6 8 10 12 14 16 18 20 ! GROSS OUTPUT - HUNORED FEET STEAM RAOIATION >, | '(--r" i i r- i t i i i i t- i i--i i i 'i i i "i--i i i..... * * -" it. i .o 5 10 15 20 25 30 GROSS OUTPUT - HUNDRED FEET WATER RADIATION Fig. 2. Oil Fuel Burning Rate Chart51 . This chart is based upon No. 3 oil having a heat content of 143,400 Btu per gallon. If other grades of oil are used multiply the value obtained from this chart by the following factors: No. 1 oil (139,000 Btu per gallon) 1.U32; No. 2 oil (141.000 Btu per gallon) 1.017; No. 4 oil (144.500 Btu per gallon) 0.992; No. 5 oil (146,000 Btu per gallon) 0.982; and No. 6 oil (150,000 Btu per gallon) 0.956. principles discussed in Chapters 5 and 6 and the method described and illustrated in Chapter 7. . . In some cases, however, depending on the presence of interior par titions, the computed heat loss is modified when used for estimating the heat or fuel consumption. If the building has no interior walls or par titions then, by the method of Chapters 6 and 7, the infiltration losses are calculated by using only half the total window crack. In such a building the calculated loss need not be modified in order to prepare heat or fuel estimates by this method. Where the building does contain interior walls or partitions instead of using as the calculated heat loss (77) which is equal to the sum of the transmission losses (77t) and the infiltration losses (Hi), it is more desirable to let H = Ht + 235 Heatino Ventilating Air Conditioning Guide 1939 In predicting fuel consumption for building heating by the Calculated Heat Loss Method, the general formula is: ' F= H{t - <a) N E (td - t0) C (1) where . F = quantity of fuel or energy required (in the units in which C is expressed). H = calculated heat loss, Btu per hour, during the design hour, based on t0 and (generally H = //t + Hi but may on occasion equal Hi + Hi'-) t = average inside temperature maintained over estimate period, degrees Fahrenheit. 1 ta = average outside temperature through estimate period, degrees Fahrenheit (Table 2, Chapter 7). r Id = inside design temperature, degrees Fahrenheit (usually 70 F). t0 = outside design temperature, degrees Fahrenheit (see Outside Temperatures Chapter 7). 1 N = number of heating hours in estimate period (for an Oct. 1--May 1 heatinr ' season, 5088). ' . ` E = efficiency of utilization of the fuel over the period, expressed As a decimal; not the efficiency at peak or rated load condition. C = heating value of one unit of fuel or energy. li Example 1. A residence in Philadelphia is to be heated to 70 F from 6 a.m. to 10 p.m. and 55 F from 10 p.m. to 6 a.m. The calculated hourly heat loss is 120,000 Btu per hour based on 70 F inside at --5 F outside. If the building is to be heated by metered steam, how many pounds would be required during an average heating season? . (i Solution. The heating value of steam may be taken at 1000 Btu per pound, and since it is purchased steam, the efficiency can be assumed as 100 per cent. From Table 2, Chapter 7, Ia -- 42.7 F. The average inside temperature is: s. (16 X 70) + (8 X 55) = 65 F. 24 Substituting in Equation 1: 120,000 (65 - 42.7) 5088 1.00 [70 - (-5)] 1000 181,239 lb. Example S. How much would the fuel cost to heat the building in Example 1 during an average heating season with coal at 88 per ton and with a calorific value of 11,000 Btu per pound, assuming that the seasonal efficiency of the plant was 55 per cent? Solution. F = 120,000 (65 - 42.7) 5088 = 30,013 lb = 15 ton, which, at 88 per 0.55 [70 - (-5)1 11,000 ton, costs 8120. j. Equation 1 can be expressed as: s- _ H_ (t - to) N P EC * (Id - to) (2) where the expression is the rate at which fuel is burned during the design hour. Values of this rate are plotted as ordinates in Figs. 1, 2 and '3 for coal, oil and gas. For a given efficiency, the rate of fuel burning is directly proportional to the load and therefore these charts can be ex tended by moving the decimal points the same number of digits .-in both vertical and horizontal scales. Use of these charts thus expedites the estimate. 236 Chapter 12. Heat and Fuel Utilization Table 1 Heat Carrying Capacity of Gravity Warm Air Furance 1AB ' Round Leader Pipes 180 F Register Temperature ---------- -------- * First nooi......... .......... Third floor--................. Leader Pipe Btu per Hr at Design Conditions ' per Sq In. op Leader Pipe ni 167 . 200 The charts are plotted.so that the load is expressed in three terms: (a) hourly.heat loss at design conditions, (b) square feet of steam radiator surface (240 Btu per hour), and (c) square feet of hot water radiator surface (150 Btu per hour). By entering the chart at the correct point on the abcissa corresponding to the calculated heat loss (H), following ver tically to the seasonal efficiency assumed and thence horizontally to the GROSS CALORIFIC VALUE .8 ' o B.T.U. PER CUBIC FOOT h * 500 ( 7 tP, ... V S si s > 200 3 200- 100 <r, A L> & *0 100 200 300 GROSS OUTPUT-THOUSAND aT.U PER HOUR 4 6 8 10 12 W GROSS OUTPUT - HUNDRED FEET STEAM RADIATION 10 15 20 25 GROSS OUTPUT-HUNDRED FEET WATER RADIATION Fig. 3. Gas Fuel Burning Rate Chart fuel rate, the rate of fuel burning during a maximum or design hour will be found along the left hand scale for various calorific values of the fuel. 1 In the case of gravity warm air heating installations, the load is usually expressed in square inches of leader pipe. This can be converted into hourly heat loss by multiplying by the factors in Table 1. Example. $. A building located in Salt Lake City with an oil-burning heating plant has a calculated hourly heat loss of 260,000 Btu per hour. The plant is designed to maintain a temperature of 70 F inside during all 24 hours of the day, the outside design temperature is -- 5 F, the average outside temperature 40 F, the heating season 5088 hours long, the assumed efficiency 60 per cent, and the oil has a calorific value of 143,400 otu per gallon. What will be the seasonal fuel consumption? 237 Heating VentiIiAting Air Conditioning Guide 1939 Solution. Enter Fig. 2 at 260,000 on the upper horizontal scale, move vertically to th 60 per cent efficiency curve, and horizontally to the vertical scale where the firing rate is found as 3.0 gal per hour. Substituting this in Equation 2 for m- c O A ,, (70 - 40) 5088 , . F = 30X 70 -(-5) = 6106gal~ Example 4: What would be the total gas consumption over a full heating season of a gas-fired gravity warm air furnace designed according to the Code1, and with four 12 in and two 8 in. round leaders to the first floor and six 10 in. leaders to the second floor, if the gas has a heating value of 500 Btu per cubic foot, the plant operates at a 70 per cent seasonal efficiency and is designed to maintain an average inside temperature of 65 F when it is 10 F outside in a city where the average outside temperature is 45 F and the heating season is 5088 hours long? Solution. The area of the round leaders is: 12 in., 113 sq in.; 10 in., 79 sq in.; and 8 in., 50 sq in. From Table 1 the total Btu transmitted is: First Floor: [(4 X 113) + (2 X 50)] X 111 = 61,272 Btu per hour. Second Floor: (6 X 79) X 167 = 79,158 Btu per hour. . ' . . Total 140,430 Btu per hour. Allowing 10 per cent for duct and furnace losses, the gross output would be 154,500 Btu per hour. , ' Enter Fig. 3 at 154.5 on the upper horizontal scale, move to the 70 per cent efficiency proximately 440 cu ft per hour ( H\ 1 -g J to be ap Substituting in Equation 2: (65 - 45) 5088 F ^ 440 X (70 - 10) 746,428 cu ft. Maximum Rate of Fuel Burning . . 1 The rate at which fuel is burned during the maximum, or design hour is frequently useful in setting, or adjusting, the fuel feed devices attached to stokers, oil-burners, and gas burners. This rate is and can be found from the charts of Figs. 1, 2 and 3 in the same way as outlined in the Examples 3 and 4. In using the charts for this purpose, however, it should be noted that the efficiency () is the overall efficiency of the boiler or furnace at the time of peak load. This efficiency is generally consider ably greater than the value selected for when the seasonal efficiency of utilization is used in making seasonal fuel estimates. Failure to dis tinguish between the two essentially different meanings attached to E may result in grossly inaccurate estimates. 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 , 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 Healing and Air Conditioning Association. 50 W. Broad St., Columbus, Ohio. 238 Chapter 12. Heat and Fuel Utilization llv introduce the fuel at a single fixed rate during the on periods and ^rate should be sufficient to carry the gross or maximum design load; . i the case of coal stokers, which are usually capable of variable rates of *n.111 jt |s desirable to operate at as low a rate as weather conditions will .firing. ^ maximum firing rate of the stoker should be sufficient *o carry the gross load. This rate may be determined by the same method as used for oil or gas. .... Frnmble 5. The estimated net load (including domestic hot water supply) as calcupH for^a residence is 1500 sq ft of hot water radiation. Determine the firing rates for latei"ll= mechanically fired fuels assuming an overall boiler efficiency of 70 per cent; var'pUpnal 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 'l500 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 charts in Figs. 1, 2 and 3 project vertically from the gross output value on the proper horizontal scale to the intersection of the 70 per cent efficiency line. From the ntersection 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. .. DEGREE-DAY METHOD This method is based on consumption data which have been taken from buildings in operation, and the results computed on a degreerday basis. While this method may not be as theoretically correct as the Calculated Heat Loss Method, it is of more value for practical use. . 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 Association2 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. : Recently the National District Heating Association studied the metered steam consumption of 163 buildings3 in 22 different cities and published data substantiating the fact that the 65 F base originally chosen by the gas industry is approximately correct. (See Table 2). ., If the degree-days occurring each day are totaled for a reasonably long period, the fuel consumption during that period as compared with another period will be in direct proportion to the number of degree-days in the two periods. Consequently, for a given installation, the fuel consumption can be calculated in terms of fuel used per degree-day for any sufficiently long period and compared with similar ratios for other periods to deter mine the relative operating efficiencies with the outside temperature variable eliminated.* * *Sfce 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. .. 239 Heating Ventilating Air Conditioning Guide 1939 Predictions of fuel consumption are generally based on the average number of degree-days which have occurred over a long period of years and such averages, by months, on a 65 F base, are given by months and heating season totals, for various United States and Canadian cities in Table 3. In general, attempts to apply the degree-day method to fue]' consumptions over a period of less than a month are of questionable value. Formula for Degree-Day Method The general formula for predicting fuel consumption by the Degree- Day Method is: . F = UX NXD (3) where P = fuel consumption for the estimate period. U = .unit fuel consumption, or quantity of fuel used per degree-day per building load unit. N = number of building load units. D = number of degree-days for the estimate period. . Values of D for use in Equation 3 are given in Table 3. Values of N depend on the particular building for which the estimate is being pre pared and must be found by surveying plans, by observation, or by measurement of the building. Values of U for use in this equation are the Unit Fuel Consumptions per Degree-Day and are obtained as a result of the collection of operating information. Certain of this information is presented later but before referring to these data attention is directed to the nature of the unit. Table 2. Base Temperature for the Degree-Day3 Tm o? BuildtNa Office...................... ....................................... ............ Office and Bank. ........................................_ ..... Bank.......................... ............................................... Office and Telephone Exchange........................... Office and Stores......... ............... ......................... Stores. ................................................................ Department Stores................................................. Hotels.............................................................>.......... Apartments.............................................................. Residences. ...................................................... Clubs.............................. ......................................... Lodges--.............................. .................. .......:......... Theatres.......................... ......................................... Churches............ ........................................f. Garages..................................................................... Auto Sales and Service.__________ , Newspaper and Printing,...................................... Warehouse and Loft. ______i Office and Loft........................................................ Manufacturing............... ............................................ Average for 163 Buildings________________ No. or Buildings Akaltzed* 60 4 3 2 6 11 12 7 14 8 4 5 3 2 2 4 3 3 2 8 Temperature F CobRESPONDS TO ZERO Steam Consumption 66.2 65.8 66.2 65.5 67.4 64.0 64.3 66.5 68.8 66.9 65.5 64.9 67.6 65.8 64.8 . 61.2 67.7 67.7 65.2 65.4 66.0 F Report of' Commercial Relations Committee, Proceedings, National DistrictHeating Association, 1932. 240 . Chapter 12. Heat and Fuel Utilization Unit Fuel Consumptions per Degree-Day The quantity of fuel used per degree-day in a given heating plant can he reduced to a unit basis in terms of quantity of fuel (or steam) per Jwree-day per square foot of radiator, per cubic foot of heated building " ace or per thousand Btu hourly heat loss at design conditions. A less frequently used basis is quantity of fuel per degree-day per square foot of ir flow area. In fact any convenient unit can be used to relate the con sumption to the degree-day and to the building. The choice of these units requires explanation and some discrimination and judgment. The use of heated space in preference to the gross building cubage used by architects is obviously more accurate for this purpose. The architects' cubage includes the outer walls and certain percentages of attic and basement space which are usually unheated. The net heated space is usually about 80 per cent of the gross cubage and can be calcu lated 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. Use of equivalent radiator surface figures is fundamentally the same as using a calculated heat loss and therefore units in terms of fuel per degreeday per equivalent square foot of calculated radiator surface, per 1000 Btu of calculated heat loss, or per Btu of heat loss at design conditions are all of equal accuracy and desirability. It is doubtful if installed radiator surface as determined by count should be used at all. Radiator ` units are also of questionable value where there is fan coil surface or warm . air systems. In view of all these considerations it is believed that the unit based on thousands of Btu of hourly calculated heat loss for the design hour is probably the most desirable although the one most widely used seems to' be units of fuel (or heat) per degree-day per square foot of equivalent direct radiator surface. Since this unit is the one most widely used at present the unit fuel con sumptions given in succeeding paragraphs of this chapter make use of this unit to a considerable extent, although it should be understood that most of these units of consumption can be transposed as desired. Estimating Gas Consumption Values of the Unit Fuel Consumption Constant (IT) for gas are given in Table 4 for various gas heating values, and different types and sizes of ; heating plants. They are based on an inside design temperature of 70 F and an outside design temperature of 0 F and apply only to these conditions. For other design conditions corrections must be made as given in Table 5. Estimates for industrial buildings where low inside temperatures are maintained cannot be made from this table. The factors in Table 4, as corrected if necessary, are satisfactory for regions having 3500 to 6500 degree-days per heating season. In regions with less than 3500 degree-days the unit gas consumption is higher than given; where over 6500, the unit is less than given. Ten per cent addition or deduction in these cases is recommended by -American Gas Association publications. _ '' : . " For gas heating values other than those given In Table 4, simply inter- ' rpolate or extrapolate. It will also be noted that Table 4 applies only to Heating Ventilating Air Conditioning Guide 1939 Chapter 12. Heat and Fuel Utilization Table 3. Degree-Days for Cities in the United States and Canada* State ClTT . Jan. . . Mat June July Auo. Sept. Our. Ala.... Birmingham- 589 521 260 69 318 Mobile............. 428 311 152 186 Ariz... Flagstaff.......... 1153 969 896 654 465 171 40 252 577 840 Tucson........--. .459 325 257 87 252 Ark-- Little Rock..... 719 582 353 78 47 381 Calif.. Los Angeles.... 326 266 239 159 90 123 San Francisco. 465 356 353 264 195 202 186 114 146 261 Colo.. Col. Springs.... 1085 991 852 369 90 162 502 789 Denver............. 1079 918 800 267 72 428 759 Conn. New Haven.... 1110 1011 899 223 39 360 693 D. C Washington...:. 970 848 694 25 251 594 Fla.. Jacksonville.-- 285 207 56 75 Ga.._ Atlanta____ __ 682 557 388 132 96 396 Savannah___ 409 316 167 201 Idaho Boise........... -- 1097 848 651 236 102 434 738 III.-.. Chicago_____ 1262 1095 911 .. 248 3 353 756 Springfield..... 1181 1008 760 366 56 282 681 Ind. Evansville..:.. 949 854 620 276 155 528 Indianapolis... 1128 969 756 384 59 298 687 I owa.. Des Moines... 1392 1173 890 441 118 357 798 Sioux City..... 1435 1260 967 164 33 415 870 Kans. Dodge City... 1116 890 688 47 276 672 Topeka._....... 1221 980 747 270 699 ,Ky- Lexington.-- Louisville....... 973 868 648 939 801 589 25 245 612 186 552 La.. New Orleans. 332 230 59 102 Me. Eastport--..... 1380 1232 1110 Portland........ 1321 1168 1017 543 300 143 136 276 543 843 329 39 120 443 780 Md. Baltimore...... 955 843 701 22 223 567 Mass. Boston............ 1150 1042 908 245 48 363 693 Mich. Detroit........... 1252 1134 973 226 42 400 777 Marquette..... 1500 1361 1249 496 186 43 225 567 960 Minn. Duluth......:.... 1727 1473 1277 524 198 37 261 620 1062 Minneapolis... 1609 1400 1094 236 93 481 963 Miss;.. Vicksburg-- 521 384 195 252 Mo. Kansas City.. 1094 958 676 12 214 612 St. Louis---- 1060 854 657 205 597 Mont. Billings.--...... 1318 1120 955 316 60 189 524 909 Havre--.......... 1624 1450 1169 369 144 270 620 1041 Nebr.. Lincoln--........ 1311 1131 840 99 316 753 Omaha......... . 1355 1126 868 84 329 780 Nev-;. Reno............. 1042 823 753 366 90 144 453 714 N:;H.. Coricord.......i. 1349 1240 1011 N; Jv : Atlantic City: .992 904 806 Trenton.... 1014 941 735 298 54 220 81 168 484 846 254 ' 588 242 588 n.m.: Santa Fe....:j. 1110 902 775 N. Y.. Albany.....--... .1287 1142 980 298 ; 3 183 120 459 780 72 446 774 Buffalo....--.... 1240 1156 1032 335 12 - 75 '419 .774 New York--.-- 1060 960 837 155 276 618 Utica.,--.......... 1248 1181 989 253 482 430 781 N.C..: Raleigh:iLr..:..:v 722 .630 446 130 429 Wilmington.-.v. 555 468 322 19 .303 N.D.. Bismarck.:....r .1807 1548 1283 338 45 222 626 1113 Ohio... Cincinnati..'--:. 'ion 871 679 19 248 615 Cleveland--:.. '1181 1075 930 220 27 366 732 Columbus.--.; 1113 980 778 . 87 313 690 Okla.. Oklahoma City 865 742 465 105 459 Ore..... Portland__ ... 806 644 558 245 90 105 332 558 Salem------ 778 633 586 285 111 102 350 600 3242 5298f Si i' 87003 5999" 61311 5892| .73533 5176? 4933| 6063,25347,: 36131 sj 4469-jre^' 1 npTREE-DAYS FOR CITIES IN THE UNITED STATES AND CANADA* (Concluded) Table 3. lww________________________________ _______________________________________________ ____ -- Jan. Feb. Mar. Apr. Mat June JULY Aug. Sept. Oct. Nov. Dec.- 1001 893 756 402 68 242 588 905 4855 Pittsburgh....... 1054 944 787 423 78 Providence-- 1 lift 1070 890 558 251 Charleston....... 487 372 242 36 Spartanburg- 7*25 622 431 147 Sioux Falls-- Memphis........... J547 1358 1045 744 599 384 564 96 217 Nashville........... 812 675 477 180 Austin.-.............. Dallas-........... Houston.......... 487 330 133 617 493 267 2fifi 277 65 9 Sari Antonio.. 3ft 1 274 74 Logan........---- Salt Lake City 1262 1110 1072 885 893 722 525 453 329 236 Burlington.......... 1429 1294 1088 654 273 48 3 313 669 967 5235 63 348 693 1026 6015 207 425 1769 121 429 716 3191 93 484 945 1404 7657 62 402 663 2950 136 483 744 3507 201 434 1585 303 567 2256 114 335 1157 126 347 1202 114 468 819 1218 6748 18 388 723 1020 5555 144 481 861 1287 7514 Fredericksburg 887 820 583 303 223 .549 877 4242 Norfolk.--..... 738 650 521 246 Richmond........ . 825 703 552 240 99 411 685 3350 158 483 766 3727 Seattle.............. 775 652 623 465 319 168 40 43 192 403 570 716 4966 Spokane.--....... 1172 952 778 504 285 81 192 515 819 1057 6355 Morgantown.... 1026 944 713 414 78 295 648 977 5095 Parkersburg...... 995 907 679 360 47 282 630 1048 4948 Fond du Lac.-- 1507 1322 1048 603 276 117 493 921 1330 7617 Green Bay........ 1538 1358 1125 600 322 132 505 921 1324 7825 LaCrosse.......... 1535 1265 1033 528 183 96 462 909 1311 7322 Milwaukee------ 1383 1201 1023 648 350 39 '84 450 846 1221 7245 Wyo... Cheyenne!........ 1215 1075 995 720 446 126 240 605 900 1144 7463 Pbovinc* ClTT. . Jan. Fbb. Man. .Apr. Mat Skit. Oct.. Nov. Drc. Total B. C....... .. Kamloops...... .... - Alb.___ _ Sask--____ Qu 'Appelle. :.----- Winnipeg...... ........... Que........-- 1615 1409 1219 720 309 190 N. B.......... N. S............ Yarmouth................ P. E. Charlottetown__ LJ 5777 5976 6724 '8152 11,261 11,166 10,803 7732 372 961 1422 8417 8628 9099 7694 8485 - `Abstracted by permission from Degree-Day Handbook (Second Edition, 1937)-, by - C. Strock and C. H. B. Hotchkiss. ` : small installations. In general the .larger the installation the smaller the unit gas consumption becomes and the values in the. table should-be used with care, if at all, in large gas-burning installations. .......... Example 6. What would be the estimated average gas consumptioh of a residence Ifi with 650 sq ft ohsteam radiation surface if the outside design temperature is --10 F, if 70 F is to be maintained inside and if 535 Btu per cubic footrgas Is available? Find the value of U from Table 4 under, Steam, 300 to 700 sq ft, opposite .535 to.be 0.215. Since the outside design temperature is other ithan O F. finchthe'.cor- rection factor from Table 5 to be (opposite --10 F) 0:875. : Multiplying 0.215 by. 0.875 243 Heating Ventilating Air Conditioning Guide 1939 the corrected U is 0.188. The average number of degree-days in Albany, from Table 3 for a full average heating season is 6580, and the number of building load units is 650' Substituting in Equation 3: ' F = 0.188 X 6580 X 650 = 804,076 cu ft of gas. Estimating Oil Consumption Unit fuel consumption factors for oil, similar to those for gas in Table 4 are given in Table 6. The factors in Table 6 apply only to an inside design temperature of 70 F and an outside design temperature of 0 F. For other Table 4. Factors for Estimating Gas Consumption Btu Value ' or Gas perCu Ft 500 535 800 1000 Hot Water Steam ' Warm Air ' Cu Ft Gas per Degree-Day per Sq Ft Radiator Up to 500 Sq Ft 500 to 1200 Sq Ft Over 1200 Sq Ft Cu Ft Gas per Degree-Day per Sq Ft Radiator Up to 500 Sq Ft 300 to 700 Sq Ft Over 700 Sq Ft Cu Ft Gas per Degree-Day per 1000 Btu Hourly Design Heat Loss Gravity Fan Systems 0.142 0.132 0.089 0.071 0.135 0.126 0.085 0.068 0.128 0.120 0.081 0.065 0.242 0.226 0.151 0.121 0.231 0.215 0.144 0.115 0.220 0.206 0.137 0.110 0.855 0.800 0.534 0.428 0.820 0.766 0.513 0.410 i n 1 Therm 100,000 Btu Gas Consumption in Therms per Degree-Day 0.000708 0.000675 0.000642 0.00121 0.00115 0.00110 0.00428 0.00409 "Abstracted from Comfort Heating, American Gas Association, 1938. Table 5. Correction Factors for Outside Design Temperatures Outside Design Temp. Deo F Inside Design Temp. Deg F Multeplt Values in Tables 4, 6 and 7 bt -20 -10 0 . +10 +20 . 70 70 70 70 70 \ 0.778 0.875 0.000 1.167 1.400 outside design temperatures, the constants in Table 6 must be multiplied by the values in Table 5 as explained under Estimating Gas Consumption. is Table 6 assumes the use of oil with a heating value of 140,000 Btu per I gallon. For other heating'values, multiply the values in Table 6 by the ratio of 140,000 divided by the heating value per gallon'of fuel being used. Example 7. What would be the estimated seasonal oil consumption of a boiler- burner unit in Minneapolis of a building having a calculated heat loss of 192;000 Btu per ^ hour, burning 144,000 Btu per gallon oil and operating at a seasonal efficiency of 60 jj per cent, if the outside design temperature for Minneapolis is --20 F, and the inside design temperature is 70 F? "- Solution. From Table 6, under 60 per cent efficiency and opposite the bottom column, 13 -find the uncorrected V to be 0.00476 gal per 1000 Btu hourly heat loss. ' 244 n Chapter 12. Heat and Fuel Utilization r- Tnhle 5 the correction multiplier for --20 F outside design temperature is 778OD1Solving, 0.778 X 0.00476 = 0.00370. Making a further correction for the heating 0.0iw03f7t nA/ 144 000 = 0.0036 gal per 1000 Btu per hour calculated heat loss per degree- dparoyF*Fb-irleomm Table 3, the average degree-days for Minneapolis pj 1Q2. Substituting in Equation 3: number 7850, and from the F = 0.0036 X 7850 X 192 = 5426 gal. Table 6. Unit Fuel Consumption* Constants for OiLb . Unit Eppicienct in Per Cent 40 50 60 70 80 Gal Oil per Sq Ft Steam Radiator.. 0.00172 0.00137 0.00114 0.00098 0.00086 Gal Oil per Sq Ft Hot Water Radiator........... .............. .................. 0.00108 0.00086 0.00072 0.00062 0.00054 Gal Oil per 1000 Btu per Hour Heat Loss........... ............................... 0.00715 0.00571 0.00476 0.00409 0.00358 "Based on a heating value of 140,000 Btu per gallon. ' ' bAbstracted by permission from Degree-Day Handbook (Second Edition, 1937), by C. Strock and C. H. B. Hotchkiss. Table 7. Unit Fuel Consumption* Constants for CoALb . Unit , 40 Lb Coal per Sq Ft Steam Radiator.. 0.0200 Lb Coal per Sq Ft Hot Water Radiator..... _ ................................. 0.0125 Lb Coal per 1000 Btu per Hour Heat Loss.......................................... 0.0825 Eppicienct dt Per Cent 50 0.0160 60 0.0133 70 0.0114 0.0100' 0.0084 0.0072 0.0666 0.0550 0.0471 80 0.0100 0.0063 0.0412 Based on a heating value of 12,000 Btu per pound. bAbstracted by permission from Degree-Day Handbook, (Second Edition, 1937), by C. Strock and C. H. B. Hotchkiss. Estimating Coal or Coke Consumption Coal or coke consumption estimates can be made in exactly the same way as for oil. The uncorrected values of U are given in Table 7. These constants apply only to inside design temperatures of 70 F and an outside design temperature of 0 F, and correction must be made for other con ditions by use of the multiplying factors in Table 5. Table 7 is based on 12,000 Btu per pound coal and for other heating values of coal, values in Table 7 must be multiplied by the ratio of 12,000 divided by the heating value of fuel used. . Estimating Steam Consumption .. . . In estimating steam consumption the efficiency is not' ordinarily a factor and is assumed at 100 pier cent. Ordinarily low pressure steam 245 Heating Ventilating Air Conditioning Guide 1939 Table 8. Steam Consumption for Various Classesof Buildings3 , (Heating Season Only) Building Classification No. or Buildings Listed Steam Consumption . Pounds per Degree-Dat--65 F BasisS Per M Cu Ft Per M Sq Ft of Heated of Radiator Space Surface Per M Btu jHPeatHLor sobf Apartments........................................... :............. :. Hotels....... ............................................................. Residences.......................... .................................. Retail Stores..... .... Theatres. 1....................... ..................................... Loft and Mfg.............. ...................................... Banks..................... ....................... ........................ Department Stores........... :.................'............... Offices (Total)......... ............................................. Offices (Heating only)............................ ............ 16 10 . . 172 - - 10 18 6 16 - - 7 8 6. 14 6 35 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 r .65.4 0.359~ 0.371 6.268 0.498 0.283 6.238 6.283 . 0.256 Includes steam for heating domestic water for heating season only. - > bHeat losscalculated 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. ' with a heating value of 1000 Btu pier pound is used so that no correction is necessary for heating value in the usual case. In comparing values from'different cities, correction should, be made for design temperature (see. Table; 5) when the unit figures are in terms of square foot of radiator or 1000 Btu per hour calculated heat loss, but not when the values are in terms of building volume or floor space. -; .Consideration has been, given to the difference, in steam utilization of different types of buildings and Table 84 shows actual average units for these various'types. These figures are obtained from operating results in Table 9. Building Load Factors and Demands of. Some .Detroit Buildings3 Building Classification >... Lb of Demand per Qb ' ' Load Factob per Sq Ft of Equivalent Installed Radiator Surface Offices_____________ ..................... ________ :............. Apartments____ _______:........ ..................... .......... Retail Stores__ ................ ........................................... Auto Sales and Service. ::................................ Banks........._____ _____ ............................................... Churches...__:.__........................ ........... .......:......... Department Stores....................................................... Theatres...... .................. ................................................ 0.318 0.316 0.287 0.263 ' : 0.255 0.238 0.223 0.203 0.158 0.138 0.126 . . 0.184 0.207 0.217 0.209 0.225 0.182 0.248 0:158 0.152 , 0.145 0.151 Report`of. Commercial Relations Committee, Proceeding?, National District Heating Association, 1932. ` 4The Heat Requirements of Buildings,' by J. H. Walker arid G. 'H. Tuttle (A.S.H.V.E. Transactions, cVol. 41, 1935;p. 171). . ; . : : J . / . . . . ` .. . - 1246 or buildings located in 21 different cities in the United States. Being ees and for small groups in each type, the figures may need con- a-aeraWmodification to allow for local variations. It should be especially twl that the steam used for heating hot water is included in the values . jn Xable 8, but in the case of office buildings, the steam for heating ^1'[e is also shown. Presentation of the unit consumption in three ways n mits making the estimate if either the calculated heat loss or the ^ume of net heated space in the building is known. maximum demands and load factors In one form of district heating rates, a portion of the charge is based on 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 9. ' 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 to the maximum load and is an index of the utilization habits. Thus, in Table 9, 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. . ' PROBLEMS IN PRACTICE 11 What will be the estimated fuel cost per year of beating 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 seasonal efficiency will be 75 per cent. The heating plant will be thermostatically, controlled, and a temperature, of 55 F will be maintained from.ll 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: ' ^ = (Z^;)2iJ55X.8)_ 663 1, ... : The maximum hourly heat loss will be: . . ;, H = 92,000 26,000 = 79,000 Btu. .' M= 79,000 (66.3 - 36.4) X 24 X 210 100,000 X 0.7S X (72 - 0) = 2204.6 hundred thousand Btu. 2204.6 X 0.07 = $154.34 = estimated fuel cost per year of heating building. '247 Heating Ventilating Air Conditioning Guide 1939 2 0 What factors should be taken into consideration when determining tk efficiency at which a fuel will be burned? . e Manufacturers' catalogs usually give equipment efficiencies obtained under test cod ditions. These values do not allow for poor attendance, defects in installation, or pooi draft. Such efficiencies do not consider heat radiated from the outside of the equipment but in many cases this heat is utilized. Neither do they allow for the fact that the ef* ficiency under less than rated capacity is frequently lower than at the rating point 3 Make an estimate of the gas required to heat a building located in Chicago 111., assuming that the calculated heating surface requirements are 1000 sq of hot water radiation based on design temperature of 0 F and 70 F. Chic has 800 Btu mixed gas, and 6290 degree-days. Using Equation 3 and Table 4, the fuel consumption for a design temperature of 0 F with 800 Btu gas is found to be 0.085 cu ft of gas per degree-day per square foot of hot water radiation. 0.085 X 1000 X 6290 = 534,650 cu ft. 4 A building in Marquette, Mich., has an hourly heat loss at design con ditions of 240,000 Btu per hour. If the inside design temperature is to be 70 F and the outside design temperature is --10 F, what will be the estimated normal seasonal coal consumption for heating if 12,000 Btu per pound fuel is burned at a 50 per cent seasonal efficiency, and what part of the total will be used during November, December, and January? 1 VII; From Table 7, U, uncorrected, is 0.0666 lb of coal per 1000 Btu per hour heat loss. Correcting for the outside design temperature, Table 5, the corrected value of U is 0.875 X 0.0666 = 0.0583. From Table 3, D is 8693 and from the problem N is 240. Substituting in Equation 3: F = 0.0583 X 240 X 8693 = 121,632 lb. Fuel used over any period is, according to the theory of the degree-day, proportional to the number of degree-days during the period. From Table 3, the average number of degree-days for November, December, and January in Marquette are 960, 1302, and 1500, a total of 3762. The yearly total is 8693, so that during these three months the estimated consumption is: } ! 3762 X 121,632 = 52,638 lb. 8693 5 Careful estimates of the probable fuel consumption of a building in Balti more based on average degree-days as shown in Table 3 indicated that the fuel consumed should total 13,600 gal of oil in a normal year. The first heating j season the building was in operation, the winter was cold and the degree-days totaled 4741 and the oil consumed totaled 14,500 gal.. Was the plant performing according to the estimate or not? From Table 3, the average number of degree-days in Baltimore is 4533. During the period under consideration the degree-days were above normal, so that the calculated consumption would have been: t X 13,600 gal = 14,223 gal. t t* Since the building consumed 14,500 gal the operating performance was slightly worse than expected after allowance was made for the severe winter. 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. . . 5 L Chapter 13 HEA TING BOILERS Cast-Iron Boilers, 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, s 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. CAST-IRON BOILERS Cast-iron boilers may be of round 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 iri 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 as fire -tube or water tube; second, with regard to arrangement of furnace and 249 Heating Ventilating Air Conditioning Guide 1939 Chapter 13. Heating Boilers flues, as (1) horizontal return tubular (HRT) boilers, (2) portable (self contained) 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 tube boilers the water is circulated within the boiler tubes, heat being applied ex ternally to them. The HRT 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 % in. to 14 in- Water3 t 2 Kind of 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 i 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-of Coal per Sq Ft Grate per Hour . 3 ~~ . 3K ; 4 "S -V 4H 5 5 514 : 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 suspended from structural columns and beams independent of'the brick setting. Small HRT boilers sometimes are supported by brackets resting on the brick setting. . Portable firebox boilers are the more generally used type of steel heating, boilers, their outstanding .characteristic being the water-jacketed firebox which eliminates virtually-allbrickwork. They are shipped in.one piece from the factory and come to the job ready, for immediate hook-up to piping. They may be of welded of 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 m frequently used. They usually.require more headroom than other types of boilers but require considerably .less .floor space and-make possible a 250 - a h'srher rate of evaporation per square foot of heating surface, with . much nig , baffling and draft. Water tube boilers used for heating proper ^ e;ther completely supported, insulated and encased in steel, purpose, k ^ supported on structural steel columns and have the brick r encased in an insulated steel housing to prevent air infiltration and setd"gjmize beat losses. For large heating loads at a high rate of evaporam nun boilers sbouid be operated at pressures above 15 lb per square '^ch'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 , giined for the burning of small sizes of anthracite and coke. These re built of both cast-iron and steel, and liave a large fuel carrying 3 pacity which results in longer firing periods than would be the case with fhe standard types using buckwheat sizes of coal. Special attention must be riven 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 of 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 fs 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 theiform of the initial gas pressure) /draft losses,through gas boilers are low. See,Chapter 11. - ^ . ` I .: . , 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 F. Direct water heaters in some cases are designed to burn refuse and. garbage. ; . : . ;!. . 251 Heating Ventilating Air Conditioning Guide 1939 . Indirect heaters generally consist of steam boilers in connection with' heat exchangers of the coil or tube types which transmit the heat from th steam to the water. This type of installation has the following advantages* 1. The boiler operates at low pressure. 2. The boiler is protected from scale and corrosion. _ 3. The scale is formed in the heat exchanger in which the parts to which the seal 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. * CCI 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 ? f" usually is obtained from an indirect heater placed below the water line of ` the boiler. j ' FURNACE DESIGN f 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 com- bustion of all the volatiles. On account of the small amount of volatiles { contained in coke, anthracite, and semi-bituminous coal, these fuels can : . be burned efficiently with less furnace volume than is required' for bi tuminous coal, the combustion space being proportioned according to the- amount of volatiles 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 l' purpose. The furnace temperature must be maintained sufficiently high f. to produce complete combustion, thus resulting in a higher CO% content ; . and the absence of CO. Hydrocarbon gases ignite at temperatures ( . varying from 1000 to 1500 F. ' 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 i; . 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- 5 mately 1 cu ft for each developed horsepower, and it is approved by % most smoke prevention organizations. _ fj 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 >i . passing through the incandescent fuel bed. The design of the.boiler also i ` may affect the setting height, since in certain types the gas enters the i: 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. . 2; 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 | 4 252 Chapter 13. Heating Boilers water line conditions and headroom permit, to raise the boiler on a hrick6 foundation setting. c gkeless combustion of the more volatile bituminous coals is furthered use 0f mechanical stokers. (See Chapter 11.) Smokeless com- h don in hand-fired boilers burning high volatile solid fuel is aided (1) hvthe use of double grates with down-draft through the upper grate, (2) h the use of a curtain section through which preheated auxiliary air is Produced 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 able 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 . Practical rates of heat transfer in heating boilers will average about 3300 Btu per sq ft per hour for hand-fired boilers and 4000 Btu per sq ft ,,*c Bureau of Mines Bulletin No. 18, The Transmission of Heat into Steam Boilers-.,.. .' Heating Ventilating Air Conditioning Guide 1939 Chapter 13. Heating Boilers per hour for'mechanically fired-boilers when operating at design load When operating at maximum load2 these values will run between. 5000 and I 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. . ' TESTING AND RATING CODES The. Society has.adopted three solid .fuel testing codes, a solid fUe[ rating code and; an oil fuel testing code. A.S.H.V.E. Standard: and Short IForm Heat Balance Codes for Testing Low-Pressure Steam Heating Solid Fuel Boilers--Codes 1 and 2--(Revision of June 1929)3, are intended | I. |r 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)8 is intended for use With A.S.H.V.E. Code for Rating Steam Heating Solid Fuel Hand-Fired Boilers4. 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 and performance of the boiler/ The A.S.H.V.E. Standard Code for Testing Steam Heating Boilers Burning Oil Fuel 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 their physical characteristics and expressed in square feet of steam or water radiation or in Btu per hour as given in Table 2. The following requirements are included in this Code: -i 1. One square foot of steam radiation is to be considered equal to the emission of 240 Btu per hour and one sqiiare foot of water radiation is to -be considered equal to emission Of 150 Btu.per hour/: ; v .r ; . 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. . .. . ; : r ............ . 'r 7 , 3. The.rating of a boiler expressed in square feet of steam radiation in which solid fuel mechanically; fired, or in which: oil or ga& is burned, ;is bas^d on the amount equal to 17 times the-heating surface of the boilerin 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 brie side and water on the other. . In. measuring surfaces, the .onter .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 lower 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: , ;. . , . iI For boilers with ratings 1800.sq ft to 4000 sq ft of steam radiation: V'Grate Area = Catalogue Rating (in square feet steam radiation) -- 200 : ; : . .. 25.5 . .. aFor definitions of design load and maximum load see pages.237 and 238. "See A.S.H.V.E. Transactions, Vol. 35, 1929. p. 12. Also Chapter 45. <See 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. Chapter 45. 254 (1) Table 2. Standard Steel Heating Boiler Ratings3 HiSD Fired Capacitt Rating Water plritatiOD Rajifttion Sq Ft' "risr 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 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 Heating Bto per Hr Surface Sq Ft 432,000' 528,000 624.000 720.000 840.000 960.000 1,080,000 1,200,000 1.440.000 1.680.000 2.040.000 2.400.000 3.000.000 3.600.000 4.200.000 4,800,000 6.000.000 7.200.000 8.400.000 129 158 186 215 250 286 322 358 429 500 608 715 893 1,072 1,250 1,429 1,786 2,143 2,500 Mechanically Fired Capacity Rating Grate Steam Water Area Radiation Radiation Sq Ft Sq Ft Sq Ft Bto per Hr Furnace Volume Bituminous Coal CuFt 7.9 8.9 9.7 10.5 11.4 12.2 13.4 14.5 16.4 18.1 . 20.5 22.5 25.6 28.4 30.9 33.2 37.4 41.2 44.7 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 3,500 4,280 5,050 5,840 6,800 7,770 8,750 9,720 11,660 13,600 16,520 19,440 24,280 29,150 34,000 38,860 .48,570 58,280 68,000 525,600 643,200 : 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 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 of Standards, United Stales Deportment of Commerce Simplified Practice Recommendation R IS7-S5. For boilers with ratings 4000 sq ft of steam radiation arid larger: = VGrate Area Catalogue Rating (in square feet steam radiation) 16.8 1500 (2) 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 arboiler, with a rating 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 riot to be less than that determined graphically in Fig. 1 or mathematically by the following forhiula: . ytyitm +V; where H = average furnace height, inches as determined by the following formula: H =* 12F _ 12F A ~ WI. . .. .. . . R -- stoker fired boiler rating, square.foot steam radiation. A -- planarea of firebox, square: feet measured at the bottom of-the fuel bed.'F = furnace volume, cubic feet. 255 (3) Heating Ventilating Air Conditioning Guide 1939 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 ? bridge wall, the total length of the furnace may be used except that this InnTM? = is not to exceed 2H W. BOILER OUTPUT b Boiler output as defined in A.S.H.V.E. Performance Test Code f0r Steam Heating Solid Fuel Boilers (Code No. 3) is the quantity of heat 1 available at the boiler nozzle with the boiler normally insulated. \ 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 for Stoker Fired Boilers and Bituminous Coal Rated in Square Feet Steam Radiation Rating Steam Heating, Solid Fuel, Hand-Fired Boilers, the perrffo^rcmmaance 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 boiler will perform in actual service. The output of large heating boilers is frequently stated in terms of boiler horsepower instead of in Btu per hounor square feet of equivalent radiation. 256 Chapter 13. Heating Boilers , Horsepower: The evaporation of 34.5 lb of water per hour . aigl2 F which is equivalent to a heat output of 970.2 X 34.5 = 33471.9 Btu per hour. w' -valent Evaporation: The amount of water a boiler would ^^ate in pounds per hour, if it received feed water at 212 F and evapor^.^ ^ same temperature and at atmospheric pressure. vaj*. USUally considered that 10 sq ft of boiler heating surface will pro , U a rated boiler horsepower. A rated boiler horsepower in turn "uce,,rry a design load of from 100 to 140 sq ft of equivalent radiation. I?1? aDparent, therefore, that 1 sq ft of boiler heating surface can carry a '-gP load of from 10 to 14 sq ft of equivalent radiation, or somewhat de^eif 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 Solti 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 arid grate is the ratio of the heat absorbed by the water and steam in the boiler per pound of fuel as 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 in 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 on 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 Association6. 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 amount 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. *A.S.H.V.E. Research Report No. 907--Study of the Characteristics of Oil Burners and Heating wders, by L. E. Seeley and E. J. Tavanlar (A.S.H.V.E. Transactions. Vol. 37,1931. p. 617). A.S.H.V.E. axsRARCH Report No. 925--A Study of Intermittent Operation of Oil Burners, by L. E. Seeley and J. H. rowers (A.S.H.V.E. Transactions. Vol. 38, 1932, p. 317). of t Minimum Requirements tor the Heating and Ventilation of Buildings (Edition 257 Heating Ventilating Air Conditioning Guide 1939 Chapter 13. Heating Boilers 3. The estimated heat emission in Btu per hour of the piping connecting the radiati and other apparatus to the boiler. . 0,1 Estimated Maximum Load: Construed to mean the load stated ;n Btu per hour or the equivalent direct radiation that has been estimated bv the purchaser to be the greatest or maximum 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.) The estimated maximum load is given by8: 4. The estimated increase in the normal load in Btu per hour due to starting up 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. LowWarming-up Allowances-for Pressure Steam and Hot Water Heating Boilers*1. b.c Design Load (Representing Summation op Items 1, 2, and 3,d Btu per Hour Equivalent Square Feet of Radiationd PercenftoabgeWCarampaincgittUpto Add 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. *>See also Time Analysis in Starting Heating Apparatus, by Ralph C. Taggert (A.S.H.V.E1 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 Sabin Crocker {Heating, Piping and Air Conditioning, March, 1932). oThis table refers to hand-fired, solid fuel boilers. A factor of 20 per cent over design load is adequate when automatically-firedfuels are used (see Fig. 3). ' ' <1240 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,* 258 *Loc. Cit. Note 7. 258 . use at all places at the same time, or in any one place at all times. Fo"a further discussion of this subject see Chapter 6. g0t Water Supply Load When the hot water supply (Item 2) is heated by the building heating Wnei __ , intrt rnnciHpratinn in sizinff flip hnilpr. The f5000 . 500 BOILER DATA -- ORATE AREA,SO FT- IB.O HEATING SURFACE,SQ.FT. 254 WEIGHT, LB. 9160 FUEL CAPACITY. LB. 651 FUEL AVAILABLE, LB. FUEL OCPTH.IM - 414 10 FUEL--BITUMINOUS 3/4* LUMP ANALYSIS-- VOLATILE MATTER 34.ee/, . FIXED CARBON 55-44 . ASH 9.67 SULPHUR 2.66 MOISTURE . 3*00 BTU PER LB. 13,655 Fig. 2. Typical Performance Curves for a 36tIn: 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. Kping 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 andcovered 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 259 Heating Ventilating Air Conditioning Guide 1939 Chapter 13. Heating Boilers and return lines, but better practice, especially when there is much ba pipe, is to compute the emission from both bare and covered pipe surfa^ 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 appljc" able to automatically-fired heating.plants using steam radiation. YVith 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 bV 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 Fuel 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 Steam 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 from soot deposit, poor fuel or inefficient attention. ' 260 ; f" i _ejectj0n Based on Heating Surface and Grate Area urtipre performance curves are not available, a good general rule for WD tinnallv-designed boilers is to provide 1 sq ft of boiler heating eonven ^ sq ft 0f equivalent radiation (240 Btu per square foot) ^rp^ented by tbe design load consisting of connected radiation, piping rePres% jQjnestic water heating load. As stated in the section on Boiler nftout this is equivalent to allowing 10 sq ft of boiler heating surface per horsepower. In this case it is assumed that the maximum load ludine the warming-up allowance will be provided for by operating the holier in excess of the design load, that is, in excess of the 100 per cent rating on a boiler-horsepower basis. Due to tie wide variation encountered in manufacturers' ratings for hollers of approximately the same capacity, it is advisable to check the prate area required for heating boilers burning solid fuel by means of the following formula: . ." G = C X FX E (4) where . G = grate area, square feet. S = 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. r 500,000 " 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 257 and 258. 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 commercial burner recommended by the boiler manufacturer. If the heat loss from the piping system exceeds 20 per cent ofthe installed radiation, the excess is to be considered as a part of the net 261 Heating Ventilating Air Conditioning Guide 1939 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.A. factors will be the minimum . Table 4. Boiler. Ratings Based on Net Load3 Hand Fired Ratings Steam Radiation Sq Ft Net Loadb 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 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 Mechanically Fired Ratings Steam Radiation Sq Ft Net Loadb Steam Radiation Sq F 2,190 1,695 2,680 2,089 3,160 ..... . 2,461 3,650 . 2,853 4,250' 3,335 4,860 3,830 5,470 4,330 6,080 4;834 . 7,290 . - 5,850 8,500. . 6,885. 10,330 8,490 12,150 : 10,125, 15,180 12,650V 18,220 . 15,183 21,250 17,708 24,290 20,242 30,360 25,300 36,430 30,359 42,500 - 35,417 "Adopted by the Steel Heating Boiler Institute in cooperation with-the Bureau of Standards, United States Department of Commerce Simplified Practice Recommendation R 157SS. - * bThe net load is made up by the sum of the estimated design load, items l and2 (pages 257 and 258). A1J net loads are expressed In 70 F. For hand-fired boiler ratings less than 1800 sq ft of steam 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. ' .. . x' ; ' 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! conversion job is that the boiler is installed and probably will not be made larger; 262 Chapter 13. Heating Boilers f re it is a matter of setting a gas-burning rate to obtain best results .there* > iiabie surface. Assuming a combustion efficiency of 75 per r for a conversion installation the b'oiler output would be 2 X 0.75 l tjmes the connected load, which allows 50 per cent for piping tax H ickup. In converting large boilers, the determination of the re-, a? *1 Btu input should not be done by an arbitrary figure or factor but Ih^ld be based on a. detailed consideration of the requirements and' characteristics of the connected load. . An efficient conversion installation depends upon the proper size of fl e connection. Often the original smoke breeching between the boiler nd chimney is too large for gas firing, and in this case, flue orifices can be ased They are discs provided with an opening of the size for the gas H ' usecj jn this boiler. The size should be based on 1 sq in. of flue area for each 7500 hourly Btuinput. , jf 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 back draft 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 263 Heating Ventilating Air Conditioning Guide 1939 Chapter 13, Heating Boilers 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 the 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 ceilin 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 is- recommended 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.M.E. 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. /.P.5.9 if the gage is more than 5 ft from the boiler connection, and also in any case where the connection is less than 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 glass. 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.* 264 A-S.Af.E. Code. Identification of Piping Systems. 264 u/h re a return header is used on a cast-iron sectional boiler to distribute 1 ' turns to both rear tappings, it is advisable to provide full size the r, tees instead of elbows where the branch connections enter the plugg tappingS. This facilitates cleaning sludge from the bottom of the ^sections through the large plugged openings. An equivalent clean- "t lug should be provided in the case of a single return connection. ^Mow-off or drain connections should be made near the boiler and so Janeed that the entire system may be drained of water by opening the A^n cock. In the case of two or more boilers separate blow-off connec.ral must'be provided for each boiler on the boiler side of the stop valve Pii'the main return connection. ' Water service connections must be provided for both steam and water hollers 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 the A.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 not 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 yThe directions of the boiler manufacturer always should be read before -"'the 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: . I' Ther? should be provided proper and convenient drainage connections for useif the boiler is not in operation during freezing weather. f ' 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. -\ ^kect 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 dr other refractory material. : Condensation must flow back to the boiler as rapidly and uniformly as possible. Ketum connections should prevent the water from backing out of the boiler. "tt5; Automatic boiler feeders and low water cut-off devices which shut off the source Heating Ventilating Air Conditioning Guide 1939 Chapter 13. Heating Boilers of heat if the water in the boiler falls below a safe level are recommended for boiler, mechanically fired. 615 Boiler Troubles A complaint regarding boiler operation generally will be found to bg due to one of the following: 1. The boiler fails to deliver enough heal. The cause of this condition may be: (a) draft; (6) poor fuel; (e) inferior attention or firing; (d) boiler too small; (e) improper piping; (/) 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: (a) grease and dirt in boiler; (6) water column connected to a very active section and, therefore, not showing actual water level in boiler; and (e) 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; (i) 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; (b) 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 ievel 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; (6) inferior fuel; (c) inferior attention; (d) accumulation of clinker on grate; and (e) boiler too small for the load. 6. Boiler requires too frequent cleaning offlues. This may be due to: (a) poor draft; (6) smoky combustion; (e) too low a rate of combustion; and in firebox causing chilling of gases. (d) too much excess air s i 7. Boiler smokes through fire door. This may be due to: (a) defective draft in chimney ] or incorrect setting of dampers; (6) air leaks into boiler or breeching; (c) gas outlet from % firebox plugged with fuel; (d) dirty or clogged Hues; and (e) improper reduction inj breeching size. | - '- .. ' d . 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 j 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. I 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 i 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 134 in. nominal'pipe size with outlet s 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| 266 essure recedes close valve and repeat process adding water at intervals J..t* maintain proper level. As a final operation bring the pressure in the r to about 10 lb, close blow-off, draw the fire or stop burner, and open 5l-n 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 are effective, but special instructions on the proper cleaning compound and directions for itTuse 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 proper 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. AlUieating 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 pevent 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 accessories of the boiler carefully to see that they are in good working order. In this connection, oil all door hinges, damper bearings and regulator parts. BOILER INSULATION , Insulation for cast-iron boilers is of two general types: (1) plastic m iff bk'cks wired on, cemented and covered with canvas or duck; f 's^e.ets or plastic material covered with a metal jacket j.unushed by the boiler manufacturer. Self-contained steel firebox boilers . sually are insulated with blocks, cement and canvas, or rock wool Diankets; HRT boilers are brick set and do not require insulation beyond. at provided in the setting. It is essential that the insulation on a boiler 267 Heating Ventilating Air Conditioning Guide 1939 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 depend 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 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 taken to make sure a proposed heating installation will work properly? a. Select the right size and type of boiler. 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.6 6 # 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. 268 Chapter 14 RADIATORS AND GRAVITY CONVECTORS ' Heat Emission of Radiators and Convectors, Types of Radi ators, Output of Radiators, Heating EfEect, 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 having 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 AllJjetiting 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 sometimes known as slim tube radiation. The tubes in these radiators are materially smaller, and they are compactly assembled in less space than those of the standard radiator. , 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 269 Heating Ventilating Air Conditioning Guide 1939 in factory buildings, but now wall type radiators are most frequently uSC(j for this service. When coils are used, the miter type assembly is to be 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 true index of output. (The engineering unit of outputs 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 and for hot water service 150 Btu per hour per square foot. Table 1. Variation in Dimensions and Catalog Ratings of 10-Section Tubular Radiators (Steam) No. of Tubes____ __ Width of Radiator -- Length per Section. __ -------_Jnches .Inches 3 4.6-5.1 2.5 4 6.0-7.0 2.5 5 8.0-8.9 2.5 6 9.1-10.4 2.5 , 7 11-.4-I2A 2.5-3.0 Height with 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 28.5 20.0-22.5 25.0-31.2 30 25 30.0-33.9 35 25.0-27.5 32.5-39.8 37.5-40.0 33.3-35.0 40.0-48.6 50 40.0-42.5 50.0-56.5 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 70.0-754 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 but are 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 Btu per 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 level 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. 270 Chapter 14. Radiators and Gravity Convectors - Output f PiPe The heat emission of pipe coils placed vertically on a wall with the iDes horizontal is given in. Table 2. This has been developed from avail- Medata and does not represent definite results of tests. For such coils' fhe heat emission varies as the height of the coil. The heat emission of Sch pipe of ceiling coils, placed horizontally, is about 126 Btu, 156 Btu, and 175 Btu per linear foot'of pipe, respectively, for 1-in., lJ4-in.t and 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) ' Size of Pips 1 In. IK In. IH In- OlA. --....... . 132 252 440 567 651 732 812 162 312 545 702 796 907 1005 185 348 616 793 907 1020 1135 Effect of Paint The prime coat of paint on a radiator has no material effect on the heat output, but the finishing coat may influence the radiation emission and thus affect the heat output. Within the range of temperatures at which radiatore/operatc, color has no appreciable influence on the radiation emitted^ Thus, finishing coats of oil paints of various colors will give the same results. However, a bronze paint, applied as the finish coat will change the character of the surface and reduce the amount of heat emitted by radiation. No paint has a noticeable effect on the portion of heat which is given off by convection. The larger the proportion of direct radiating surface, the greater will be the effect of any finish coat of paint which changes the character of the surface. Available tests are on oldstyle column type radiators which give results as shown in Table 3. Table 3. Effect of Painting 32-in. Three Column, Six-Section Cast-Iron Radiator3 Radiatob No. i 2 3 4 Finish Bare iron, foundry finish........ One coat of aluminum bronze.......... : Gray paint dipped........... ............ One coat dulhblack Pecora paint.... Area Sq Ft 27 27 27 27 Coefficient of Heat Trans. Btu Relative Heating Value Per Cent 1.77 100.5 1160 90.8 1.78 101.1 1.76 100.0 19277p 41) Kaaiator pmisnes. Dy w. H,: SeverTM (A.S.H.V.E. Transactions. Vol. 33. 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; he decrease is probably small for low temperatures of superheats and . 271 Heating Ventilating Air Conditioning Guide 1939 Cold room temp in deg f -22 3 552 Q> Test R-E2. 5-tube rad -22 z -2.7 s -25 5 62 >b Test R-E61,3-tube rad 542 lb Test R*10, l-tube panel rad 550 Test R-2c. (Bui 223) waD rad I 1 2 3 - -5 6- . 7 8 Net lb of steam condensed per hour ~~2 3 4 5 6 ~ 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 ait. temperature of 69 F is maintained at the 60-in. level. additional tests are necessary with varying degrees of superheat to establish accurate comparisons for all types of radiators and convectors*. 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 radiator1.* 272 668 lb Test R-E56. S-tube rad. 6.48 lb Test R-E20,3-tube rad. 6.12 tb Test R-E58,1-tube panel rad. 55.0 (b Test R-2c. (Bui. 223) wall rad. 1 2 3 4 56 Net tb of steam condensed per hour HEIGHT ABOVE FLOOR IN FEET Fio 2 Room Temperature Gradients and Steam Condensing Rates for Fouh Types op 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 lemperalurt 0/ $8 F is maintained at the 80-in. level. 'Tests of Radiators with Superheated Steam, by R. C. Carpenter (A.S.H.V.E. Transactions. Vol. 7. 190*The Heating Effect of Radiators, by Dr. Charles Brabbei (A.S.H.V.E. Transactions. Vol..33.Wg. p. 33). A.S.H.V.E. Research Report No. 962--The Application of the Eupatheoscope for Mrasunnj the Performance of Direct Radiators and Convectors 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). 272 iifiaaaa Chapter 14- Radiators and Gravity Convectors -ti, results of tests conducted at the University of Illinois are shown in .nH ?,* For the four types of radiators shown, the following con- fFuigssio. nlsaanrue g:iven. 1 The heating effect of a1 radiator cannot be judged solely by the amount-of steam aller^oor-to^eiling temperature differentials can be maintained with long, low, direct radiators, than is possible with high, direct radiators. _ thin, direc portion of the floor-to-ceiling temperature differential in a room of y^age ceiling height heated with direct radiators occurs between the floor and the breathing J^f-ort ievel (approximately 2 ft-6 in. above floor) is below the breathing line . I ionroiimately 5 ft-0 in. above floor), and temperatures taken at the breathing level' lapP indicative of the actual heating effect of a radiator in the room. The "ne f rt indicating temperature should be taken below the breathing line level. CO-c Hi,,h column radiators placed at the sides of window openings do not produce as comfortable heating effects as long, low, direct radiators placed beneath window openings5. Fig. 3. Chart Showing the Steam Demand Rate for Heating Up a Cast-Iron Radiator with Free Air Venting and Ample Steam Supply HEATING UP THE RADIATOR AND CONVECTOR The maximum condensation occurs in a heating unit when the steam is first turned on8. Fig. 3 shows a typical curve for the condensation rate in pounds per hour for the time elapsing after steam is turned into a cast^ iron radiator. The data are from tests on old-style column type radiators. In practice the rate of steam supply to the heating unit while heating up is frequently retarded by controlled elimination of air through air valves or traps. Automatic control valves may also retard the supply of steam. Vacuum types of air venting valves may be used to reduce the length of the venting periods. `A.S.H.V.E. Research Report No. 905--Steam 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). `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). . *Tbe 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 Atr Conditioning, April, 1937, p. 251). 273 X Heating Ventilating Air Conditioning Guide 1939 14. Radiators and Gravity Convectors ENCLOSED RADIATORS The general effect of an enclosure placed about a direct radiator is t0 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: 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. 8 v 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 (5), with a poorly-designed enclosure (C), and with a cloth cover (D) will illustrate the relative s: t. . f r." -Ir 'iff >' the room is between 25 and 40 per cent. This source of supply of ; 'noisture 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 or other enclosure so that the greater percentage of heat is conveyed to the 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- ? Fig. 4. Steam Consumption of Exposed and Concealed Radiators \J II j; 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 same heating effect. Curve (C) shows the unsatisfactory, effects produced by improperly designed enclosures. Curve (D) shows that the 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 jj |j \j J\ \t {j f, |: f |> \\ j , 'University of Illinois, Engineering Experiment Station Bulletins 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). ^University ,of Illinois, Engineering Experiment Station Bulletin No. 230, p. 20. . i j 274 ; Fig. 5. Typical Concealed Convector Using Specially Designed Heating Unit 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 arid 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 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 room 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 275 Heating Ventiuiting Air Conditioning Guide 1939 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 its ratings and has compiled ai tentative . 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 and 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. When more than one heating unit is used, one mounted. above the other in the same cabinet, the output of the upper unit or units will be materially less than that of the bottom unit. RADIATOR AND CONVECTOR SELECTION The capacity of a radiator varies as the 1.3 power, and that of a con vector10 as the 1.5 power of the temperature difference between the heating medium and the surrounding air in the case of the radiators, and the entering air in the case of the convector. It is obvious that for conditions other than the basic ones with the heating medium at a temperature of 215 F, and the room temperature at 70 F in the case of a radiator, and the 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). . ,#A.S.H.V.E. Research Report No. 998--Factors Affecting the Heat Output of Convectors, by A. P. Kratz, M. K. Fahnestock, and E. L. Broderick (A.S.H.V.E. Transactions. Vol. -10, 1934, p. 443/. 276 Chapter 14. Radiators and Gravity Convectors Table 4 Correction Factors for Direct Cast-Iron Radiators and lA ' Convector Heaters3 AM Heating SS. Medium Factors for Direct Cast-Iron Radiators Factors ros Convectors 101. Tbmp.F Steam Room Temperature F Inlet Am Temperature F AteLb per Sq In- OB Water 80 75 70 65 60 55 50 80 75 70 65 60 55 50 - 3.7 4.7 6.0 ` ' 7.5 9J 11.5 150 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 1.59 170 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 1.40 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 15.6 215 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 21 230 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 30 250 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 42 270 0.70 0.68 0.66 0.64 0.62 0.60 0.58 0.70 0.68 0.65 0.63 0.60 0.58 0.56 67 300 0.58 0.57 0.55 0.53 0.52 0.51 0.49 j- 0.56 0.54 0.53 0.S1 0.49 0.48 0.47 To determine the size of a radiator or a convector 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 radiator or a convector under conditions other than the basic ones with the heating medium at a temperature of 215 F, and the room temperature at 70 F in the case of a radiator and the inlet air temperature at 65 F in the case of a convector, divide the heating capacities at the basic conditions by the proper factor from the above table. . .. inlet air temperature at 65 F in the case of a convector, the heat emission will be other than 240 Btu per square foot of rating. Table 4 shows factors by which radiation requirements, as determined by dividing heat load by 240, shall be multiplied to obtain proper radiator or convector 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 - 70y-3 \ h--h ) For convectors: where /215 - 65\i-5 \ h~U ) Cs = correction factor. Is = steam temperature, degrees Fahrenheit. (r = room temperature, degrees Fahrenheit. li = average inlet air temperature, degrees Fahrenheit. 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) , 1931, and (Hot Water), 1933, see also (A.S.H.V.E. Transactions, Vol. 41. 1935, p. 38). .. 277 S f-*---".,/v'W-'ST ~t ;>-;5-Sv -.-, -,T- .* .'/.. Heating Ventilating Air Conditioning Guide 1939 For steam services the actual condensation weight is taken without anv allowance for heating effect; for hot water services the weight of circu lated 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 steam pressure of 1 lb gage 15.6 lb per sq in. absolute (215 F) or an average hot water temperature of 176 F and a room temperature of 70 F (5 ft above floor) for radiators or an inlet air temperature of 65 F for convectors. The heating capacity of a steam radiator or steam convector is determined as follows: . lh = W'aftfg where . Hi Btu per hour under test conditions. W% = condensation in pounds per hour. ^fg -- 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: For radiators: 215 . Te - TrJ f 145 \1.3 1<TS- Tr) (2) 10 ' to 1 CO 1 For convectors: '215 - 65\1.5 , 7V -Ti) 1^ Ts - Ti ) . (3) The output under standard conditions will be: . where Hs = CBHt C8 = correction factor. . T6 .= steam temperature during test, degrees Fahrenheit. Tt = room temperature during test, degrees Fahrenheit. Ti = inlet air temperature during test, degrees Fahrenheit. . . Hg = heat emission rating under standard conditions, Btu per hour. '. \ ... Similarly, for hot water convectors, the output under.test conditions may be determined as follows: . H = w (0, - e,) ^ ' (5) where . '. H -- Btu per hour under test conditions. ... W =' pounds of water handled during test. 0i = average temperature of inlet water, degrees Fahrenheit. 0, = average temperature of outlet water, degrees Fahrenheit.- t = duration of test, seconds. ' , uLoc. Cit. Note 9. ' ' **Loc. Cit. Notes 9 and 10. 278 ;v. Chapter 14. Radiators and Gravity Convectors To convert test results to standard conditions, the following correction factor is used: f 170 - 65___ \yl--5s // 105 l + 0 T. I =1 01 + 0 --------- r7 2 y* T. ) r7 (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 SYSTEMS The heating units for this system are usually of the extended surface type for steam or hot water, and are installed about as shown in Fig. 6. The temperature and volume of the air leaving the register must be great enough so that in cooling to room temperature the heat available will just equal the heat loss during the same time. 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 temperature, by a system of vent flues or ducts. As the air flow is maintained by natural draft and this gravity head is very slight, it is necessary to make all ducts as short as possible, expecially the runs from the heating units to the base of the vertical warm air flues. Gravity-indirect arrangements, such as illus- "Loc. Cit. Note 10. 279 Heating Ventilating Air Conditioning Guide 1939 trated in Fig. 6, are not to be generally recommended for hot water sy$. . terns unless the water temperature can be maintained at a reasonably high temperature and rapid circulation of the water can be .obtained PROBLEMS IN PRACTICE 1 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 arid brass, or copper and aluminum, as well as entirely of cast-iron. ' 2 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. 3 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. 4 How are fins of convectors attached to the tubes or prime surface? Tubes or a solid core may be forced through 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. 5 What is the procedure in selecting a convector when the required amount of radiation is known? 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 6 Given a room to be heated to 80 F with outside temperature at 0 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 80 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 C9. C` ~ 1,215 - 70/ \215 - 70 / `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. . 280 ' Chapter 15 STEAM HEATING SYSTEMS Gravity and Mechanical Return, Gravity One-Pipe Air-Vent, ' Gravity Two-Pipe Air-Vent, Air Line Heating, One-Pipe Vapor, . Two-Pipe Vapor, Atmospheric. Condensation Return, Vacuum, Sub-Atmospheric, Orifice, Zone Control, Condensation Return Pumps, Vacuum Heating Pumps, Traps THE essential features of the common types of steam heating systems are described in this chapter together with some of the characteristics which influence their successful design and operation. The combination of-equipment and piping by which steam is used for space heating, or to warm air for use in ventilating or air conditioning, is known as a steam heating system. They may be classified according to (a) the piping arrangement, (b) the service performed, such as the split system where direct radiators are used for space heating and the heat exchanging units are onlvmsed for central fan ventilating or air conditioning, (c) the accessories-used, (d) the method of returning the condensate to the boiler, Je) the method of expelling air from the system, or (/) the type of control employed. The above classifications are used both where a boiler is included in the system and where the steam supply is from a district heating system. After the selection of the most suitable type of steam heating system is made on the basis of its operating characteristics, the design of the system should be considered under four headings, namely, (1) determination of load and selection of heating units, (2) the arrangement of the general piping scheme, (3) the sizing of the piping, and (4) the details of con nections. Specific information concerning the design and layout of steam heating systems will be found in Chapter 16. GRAVITY AND MECHANICAL RETURN ' When systems are classified according to the method of returning the condensate from the system to the boiler they are known as gravity or mechanical systems. In gravity systems the condensate is returned to the boiler by gravity due to the static head of water in the vertical portion of the return pipes or mains. The elevation of the boiler water line must be sufficiently below the lowest heating unit, steam pipe or dry return pipe to . Permit the return by gravity. The water line difference forming the static -head must be sufficient to overcome the maximum pressure drop in the system, including the pressure drop due to the condensing effect of the -radiation. When radiator and drip traps are used, as in two-pipe vapor ' 281 lipilUj.j..,11?%?? Heating Ventilating Air Conditioning Guide 1939 systems, the static pressure must also exceed the operating pressure of the boiler. The pressure drop caused by condensing rate of the radiation is especially important during those portions of the operating periods where changing pressure conditions prevail, as for example, when the system is being initially filled with steam. In systems where the condensate is wasted to the sewer no water line difference is required as is the case with closed systems. However, the waste of condensate may introduce con ditions which warrant the use of an appropriate mechanical system. Whenever the conditions of a heating system are such that the returns from the radiation cannot gravitate to the boiler they must be returned by some mechanical means. In mechanical systems the condensate flows to a receiver by gravity and is then forced into the boiler against its pressure. In all instances the Chapter IS. Steam Heating Systems ter than what are regarded as more expensive systems because of - b ?r creased cost of labor and materials for the relatively larger pipe sizes - '"red. As seen by Fig. 1, the steam piping rises to a point as high as ' reqU;bIe at the boiler, and pitches downward from this location until the fnd of the main is reached. At the low points and the far ends, drips ^aken off and sealed below the water line before being connected to Aj^er drips and brought back to the boiler through a wet return. The diators are supplied with steam by risers branched off the main or ra- s the steam passing up the riser and the condensation flowing down P jn'the riser, steam and condensation flow in opposite directions, but ..' ter condensation enters the steam main it flows in the same direction as the steam and is removed from the main through the drip. Short mains are sometimes arranged for the condensate to flow in a direction opposite the steam by sizing them so the critical velocity is not exceeded. Ih buildings of several stories it is customary to drip the heel of each riser to avoid counter-flow of the steam and condensate in the riser spring piece so as to improve steam circulation, but in buildings of one or two stories Up to radiator or riser -- pitch___________ Steam main 5 ft approximately Fig. Typical Steam Runout where Risers are not Dripped Fig. 3. Typical Steam Runout where Risers are Dripped Fig. 1. Typical Up-Feed Gravity One-Pipe Air-Vent System preferable practice is to provide for gravity flow even where ai vacuum pump is used. The lowest parts of the supply side of the system must be kept sufficiently above the water line of the receiver to insure adequate drainage of water from the system, and as long as this condition is ob-. tained,.,,the relative elevation of the boiler water line is unimportant. There are three general types of mechanical return devices in common use, namely, (1) the mechanical return trap, (2) the condensation return pump, and (3) the vacuum return line pump. GRAVITY ONE-PIPE AIR-VENT SYSTEM This'system is the most common of all methods of steam heating, especially for small size installations, due largely to its low cost and ^ g. simplicity. With larger sized systems the cost of one-pipe systems may " '282 the condensate is carried back into the steam main instead of being emptied into the wet return through a riser drip. Both types of risers are shown in Fig. 1. Horizontal branches to radiators and risers should be pitched not less than Yi in. per foot downward toward the riser or vertical pipe. Hori zontal branches from steam mains should be graded at least this amount toward the main, except where the heel of the riser is dripped. Where the heel of the riser is dripped the direction of pitch should be toward the riser drip. (Figs. 2 and 3). Drips carried above the boiler water line or overhead should grade toward the boiler. They must be water sealed before being connected to another dry drip. Wet drips should preferably pitch toward the boiler so they may be completely drained if the building is to be left unoccupied in freezing weather. Wet returns or drips need not be pitched toward the boiler to maintain steam circulation and may be pitched in the opposite direction. In any case provision for drainage is important. As the one-pipe system is relatively sluggish because of the slowness with which air is released from the system, provision should be made to promote it by providing air vents at the ends and at intermediate points where the steam main is brought to a higher elevation. Venting at drip point of mains is especially important.. It. is desirable to install the air.vent valves about a foot ahead of. the drips, as indicated in Fig. 1, to 282 .. 283 Heating Ventilating Air Conditioning Guide 1939 prevent possible damage to their mechanisms by water as may occur if the valves are installed directly above the drips. The air valves may bg .manual or automatic, with or without a. check. Air:vent valves with checks prevent the ready re-entrance of expelled air. The radiator valves may be the angle-globe, corner pattern or gate type Straight-globe type should not be used since the damming effect of the raised valve seat would interfere with the flow of condensation through the valve. Graduated valves cannot be used since the steam valves on this system must be fully open or fully closed to prevent the radiators filling with water and creating a dangerous water line condition. An ob jection to the one-pipe steam system is that the heat cannot be regulated at the radiator. Regulating at the radiator is possible only by having the heat all on or all off, or by setting the valve in an intermediate position. Improved systems and devices are now available which make it possible to obtain a modulating effect from one-pipe heating systems. This is accomplished by the use of special one-pipe regulating plates and auto matic control of the rate of steam supply which permits varying rates of steam supply and gives fair control during average and severe winter weather. Steam pressure at Boiler steam pressure end of main mL tti Water line of boiler. . Return water 'Riseswater tine difference :--- Level -- ywctfi Fig.. 4. Difference in Steam Pressure on Water in Boiler and at End of Steam Main It is important to keep the lowest points of the steam mains and heating units sufficiently above the water line of the boiler to prevent flooding. Usually a distance of 18 in. is sufficient but construction limitations frequently make shorter distances necessary. The minimum distance which may be used can 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 pressure on 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 friction of the steam in passing from the boiler 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 (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 H lb. and utilizes an Underwriters' Loop 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 H of 28 in., or 3^ in.' Adding 3 in. to this for the flow through the return main and 6 in. as a factor of safety gives 12> in. 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 Yi lb, and with a check in the- '") 284 Chapter 15. Steam Heating Systems . WOuld require H of 28 in., or 14 in., for the difference in steam pressure, 3 in. for fcflo'w through the return, 4 in. to operate the check, and 6 in. for a factor of safety, tin? a total of 27 in. as the required distance. Higher pressure drops would increase Xdistance accordingly. down-feed gravity one-pipe air-vent system The overhead down-feed system varies basically only from the up-feed systems in the location of the steam main. The steam supply is taken from the boiler and carried to the top of the building, as near the boiler as possible as shown in Fig. 5. If the run to the main riser is long;, or the Fig. 5. Typical Down-Feed Gravity One-Pipe Air-Vent System Fig. 6. Steam Runouts Dripping Main . Fig. 7. Steam Runouts with Main Dripped at End Only riser extends several stories, the bottom of the riser should be dripped into the wet return. The horizontal main extends from the top of the riser and grades down from it toward all the drops or down-feed risers. The con nections to the risers are taken from the bottom of the main, and each drop carries its share of the main's condensation (Fig. 6). 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 to drain the entire main. The overhead main does not carry condensation from the radiators. The air vent may be located on the main before the last drop (Fig. 5) but the preferable location is at the bottom of the drop below the last radiator 285 Heating Ventilating Air Conditioning Guide 1939 connection and sufficiently above the water line of the boiler to prevent 5 flooding. The radiators, radiator valves, air valves and radiator runouts, as back as the risers, are arranged the same as for the up-feed, system. GRAVITY TWO-PIPE AIR-VENT SYSTEMS The gravity two-pipe system indicated in Fig. 8, is now considered obsolete although many of these systems are still in use in older buildings The same general principles governing its piping design are used when connecting radiators as in other types of gravity systems where they must discharge their condensation to the wet return pipe. Separate supply and return mains and connections are required for each heating unit. Radi- Fig. 8. Typical Up-Feed Gravity Two-Pipe Air-Vent System ator valves are required in both the supply and return connection to the radiator, and air valves are instated on the heating units and the mains. The radiator valves are the same qs 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 connect ed into a separate return line system which has the base of the risers sealed either by carrying them down to a wet return below the boiler water line or by a water seal. 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 through water seals about 36 in. deep, as shown in Fig. 9, to prevent steam from one riser or radiator entering another through the outlet tapping and closing the air valves on the nearest radiator. 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 286 Chapter 15. Steam Heating Systems feed one-pipe gravity system. The drips at the bottoms of the ani drops and the runouts to the radiators are similar to those shown ?teFi,, g for the up-feed gravity two-pipe system. On the return side of *hp system, the piping is arranged in exactly the same manner as the up-feed gravity two-pipe system. AIR LINE HEATING SYSTEMS Both one-pipe and two-pipe systems are at times provided with air valves, which instead of venting to the atmosphere direct, vent to a return nipe of small size. This pipe is then finally vented to atmosphere or connected to a vacuum pump. These are known as one-pipe and two-pipe air line systems depending upon the omission or provision of a return pipe for the condensate. Where the air line is exhausted by a vacuum pump Return tram radiator*-* -*---Pitch - =---------------- H T I^Ory return S t 1 Clean out J S7777T. a.floor *JSSSsr1}S//SS SffS Fig. 9. Method of Connecting Two-Pipe Gravity Returns to Dry Return Main they are most generally termed one-pipe or two-pipe vacuum air line systems. Actually the one-pipe air line system has two pipes, the supply pipe and the air pipe (line) while the two-pipe air line system actually has three pipes. Such systems, when making use of a vacuum pump have, in the past, been termed vacuum systems. The history of steam heating reveals that the term vacuum has been very loosely used. ONE-PIPE VAPOR SYSTEM The one-pipe vapor system operates under pressures at or near atmos pheric and returns its condensation to the boiler by gravity. In this system the automatic air valves are of special design to permit the ready release of air and prevent its ready return after it is expelled and the steam radiator valves are a type which, when opened, give a free and unob structed passageway for water. The piping is the same as for the one-pipe gravity system so designed as to permit operation at a few ounces pressure. TWO-PIPE VAPOR SYSTEM . Tworpipe vapor systems use separate supply and return pipes. In present practice the radiators discharge their condensation through ther- 287 Heating Ventilating Air Conditioning Guide 1939 mostatic traps to the dry return. They operate at a few ounces pressur and above, but those with mechanical condensate return devices mav operate at pressures upward of 10 lb atmospheric, pressure. Other essen tials are packless graduated valves on the radiators, thermostatic traps to drip the ends of steam mains or to vent them where they are dripped to a wet return, and means of venting the system to the atmosphere. In the simplest cases the vent consists of a % in. pipe with a check valve opening outward. Certain systems employ special patented forms of vent valves designed to allow the air to readily pass out of the system and to prevent its return. These systems contemplate control of the radiator by varying the opening of the graduated radiator valves. The boiler pressure is . Chapter IS. Steam Heating Systems . , ;De is run up into the bottom of the return trap, which is usually verUt^ the bottom about 18 in. above the boiler water line. Some locatea constructej go that they will operate when they are installed ^wheir bottom as close as 8 in. above the boiler water line. On the "jTM side of this connection a second check valve is installed in the main P f Crn just before it enters the boiler. Fig. 11 shows a typical connection for a automatic return, trap. . Up-Feed Two-Pipe Vapor System In the up-feed system the supply piping is carried to a high point directly at the boiler and is graded down toward the end or ends of the Air vent and check Fig. 10. Typical Up-Feed Vapor System with Automatic Return Trap2 Proper piping connections are essential with special appliances for pressure equalizing and air elimination. maintained at substantially constant pressure slightly above but close to atmospheric pressure. . These systems may be classified as-(l) closed systems, consisting of those which have a device to prevent the return of air after it has once been expelled from the system, and which can operate at both super and subatmospheric pressures for.a period of,four to eight hours depending upon the tightness of the system and rate of firing, and (2) open systems, com- . prising those which have the return line constantly open to the atmos phere without a check or other means to prevent the return of air. The open systems are not so popular because they have the disadvantage of not holding heat when the rate of steam generation is diminishing. The two-pipe vapor system is shown in Fig. 10. Systems of this design should preferably be equipped with an automatic return trap to prevent water from backing out of the boiler and when so equipped have sometimes been known as return heating systems. In installing the return trap a check valve is inserted in the return main at a point near the boiler and a 288 . Fig. 11. Typical Connections for Automatic Return Trap' 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 radiator above, these being graded back toward the steam main; they are not dripped at the bottom of the riser, or toward the riser if the riser heel is dripped. Both types of connections are illustrated in Figs. 2 and 3. . . The return risers are connected to each radiator on its return end through thermostatic traps. These are connected to the return main . through runouts which slope toward the return main. The return main is run dry and slopes back toward the boiler. Wet returns, if used, are installed in the same manner as for one-pipe gravity systems. If the dry return becomes a wet return it should be vented at that point. 289 V; Heating Ventimting Air Conditioning Guide 1939 Down-Feed Two-Pipe Vapor System In the down-feed two-pipe vapor system the steam is carried to the ton 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 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 Chapter 15. Steam Heating Systems ATMOSPHERIC SYSTEM '7 'The distinguishing features of the atmospheric system are gravity ' t n to the boiler or to waste, graduated or ordinary radiator valves, no tUmatic air valves on the radiators, thermostatic traps on the radiator ^turns and the venting of all air from the system by means of pipes open `the atmosphere. The returns are open to the atmosphere at all times, 40 lly by extending the return risers to the top of the building where thev are either connected together in groups and carried through the roof r extended through the roof individually. Atmospheric systems, either p-feed or down-feed, are often used where the condensation is not return, drip trap may be omitted) Fig. 12. Detail of Drip Connections at Bottom of Down-Feed Steam Drop 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 and the normal size of drop required is 1 in. or less. The bottom of the steam drops should terminate with a dirt pocket 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 watersealed 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 for the up-feed system already described. 290 , Fig. 13. Typical Atmospheric System with Automatic Return Trap3 Properpiping connections are essential with special appliances for pressure equalizing and air elimination. 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. 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- 291 Heating Ventilating Air Conditioning Guide 1939 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 atmospheric re-enters through the open vent pipe retarding the inflow of steam and cooling the radiator. CONDENSATION RETURN HEATING SYSTEMS When an automatic condensation return pump is substituted for the gravity return of a two-pipe vapor system they are quite generally known Steam Heating Systems VACUUM SYSTEMS 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. The pump is usually controlled by a vacuum regulator which operates the pump to maintain the vacuum within limits and operates in response to a pressure difference between the atmosphere and the return to control the vacuum in the return main. ^The source of steam supply may be from a low pressure boiler as shown in Fig. 15, or a high pressure line through a pressure reducing valve. - The supply main slopes down in the direction of flow; the runouts pitch down toward the riser if it is dripped (Fig. 3) or upward toward the riser ,r " '1r,nnf>fl 'Fie- 2>- The dripping of the risers depends largely on Fig. 14. Typical Installation Using Condensation Pump as return systems or return pump heating systems. A typical installation of a motor driven automatic condensation unit is illustrated in Fig. 14. It will be noted that the returns are graded to cause flow by gravity to 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 feed water heater or to raise the water to any higher elevation or pressure than that of the return line. A useful application 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 height of the riser. Ordinarily risers less than three stories high are not dripped) while those more than four stories high are usually dripped. 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 runouts from the dripped risers slope back toward the riser. Where graduated manual control of the radiators is desired, graduated valves may be used to control the supply of steam to the radiator. Angle or corner pattern radiator valves may be used,. The radiators must be drained through thermostatic traps which pass air and water but prevent the passage of steam. Combination float and thermostatic traps are preferable for draining mains and risers. The return risers are connected in the basement into a common return main which slopes downward toward the vacuum pump. The vacuum 293 Heating Ventilating Air Conditioning Guide 1939 pump withdraws the air and water from the system, separates the a` from the water and expells it to atmosphere and pumps the water back t the boiler, or other receiver, which may be a feed-water heater or hot well. It is essential that no connection be made from the supply side to the return side at any point except through a trap. The best practice demands a return flowing to the vacuum pump by an uninterrupted down ward slope. In some instances local conditions make it necessary to dron the return below the level of the vacuum pump inlet, before the pump can be reached. In such an event one of the advantages of the vacuum system is the ability to raise the condensate to a considerable height by the suction of the vacuum pump by means of a lift connection or fitting Chapter IS. Steam Heating Systems nown-Feed Vacuum System 1 , jng arrangement for the down-feed vacuum system is similar V T"e gjnply side to the down-feed vapor system in that it has similar on tne_ J^ator valves, drips on the bottom of the steam drops, and 'UfUenient of the drops for the lower radiator connections. The return en>a* tjjC syStem is exactly the same as the up-feed system except that l 'team riser drips at the bottom are connected into the return line l ueh thermostatic traps. It is preferable to take the runouts for the rs from the bottom or at a 45-deg angle down from the steam main 6) so that they may serve as steam main drips. When this is done t's practical to run the steam main level if a runout is located at every Fig. 16. Method op Making Lifts on Vacuum Systems when Distance is Over 5 ft Fig. 17. Detail of Main Return Lift at Vacuum Pump eccentric reducing [COUPLING. -a Fig. 18. Method of Changing Size of Steam Main when Runouts are Taken from Top . inserted in the return. The height the condensate can be raised depends on the steam pressure and the amount of vacuum maintained. It is preferable to limit lift connections ter a single lift at the vacuum pump. A still more preferable arrangement is the use of an accumulator tank, or receiver tank with a float control for the pump, at the low point of the return main located adjacent to the vacuum pump. When the vertical lift is considerable, several lift fittings should be used in steps (Fig. 16). This permits a given lift to be secured with a somewhat lower vacuum than where the vertical distance is served by a single lift. Where several lifts are present in a given system at different locations, the lifting cannot occur until the entire system is filled with steam. A lift connection for location close to the pump, where the size may be above the commercial stock sizes, is shown in Fig. 17. It is desirable that means be provided for manually draining the low point of the lift fittings to elimi nate from the return piping all water in danger of freezing in case the system is shut down for a considerable length of time. \ 294 change in pipe size, or if eccentric fittings are used (Fig. 18). A slight pitch in the steam main, however, should be used when possible. . An overhead vacuum down-feed system is shown diagrammatically in Fig. 19. SUB-ATMOSPHERIC SYSTEMS Sub-atmospheric systems are similar to vacuum systems but, in con trast, provide control of building temperature by variation of the heat output from the radiators. The radiator heat emission is" controlled by varying the pressure, temperature and volume of steam in circulation. These systems differ from the ordinary vacuum system in that they main tain a controllable partial vacuum on both the supply and return sides of the system, instead of only on the return side. In the vacuum system, 295 Heating Ventilating Air Conditioning Guide 1939 t steam pressure above that of the atmosphere exists in the supply mains and radiators practically at all times. In the sub-atmospheric system atmospheric pressure of higher levels exists in the steam supply piping and radiators only during the most severe weather. Under average winter temperature the steam is under partial vacuum which in mild weather may reach as high as 25 in. Hg., after which further reduction in heat output is obtained by partially filling the radiation with steam. The rate of steam supply is controlled by a control valve in the steam main or by thermostatically controlling the rate of steam production in the boiler. The control valve may be of the automatic modulating 0r. floating type governed thermostatically from selected control points in the building or it may be a special pressure reducing valve which will maintain the desired sub-atmospheric pressures by continuous flow into the heating main. At all radiator supply tappings are radiator valves incorporating adjustable orifices or equipped with regulating orifice plates. The sizes of orifices used are larger than for orifice systems because for equal radiator sizes the volume flowing is larger. Radiator traps and drips are designed to operate at any pressure from 15 lb gage to 26 in. of Hg. Unit heaters, unit ventilators, cast-iron direct radiators and con vectors may be used together in the sub-atmospheric system. A vacuum pump capable of operating at high partial vacua is preferable to promote accuracy in the distribution of steam throughout the system, particularly in mild weather. This vacuum is partially self induced by the conden sation of the steam in the system under conditions of restricted supply for reduction of the radiator heat emission. The vacuum pump regulator is a diaphragm device subjected to the difference in pressure between the supply and return sides of the system. It starts the pump when the pressure drop through the system falls to a minimum and stops it when the pressure difference increases to a fixed maximum. The actual pres sure difference (drop) maintained is only enough to secure adequate circulation and is often about 2 in. of Hg. The low pressure difference maintained permits the use of a wider range of sub-atmospheric pressure in the radiators and supply pipe and more precise control of distribution. This method of operation results in a diminution in heat output from steam mains and risers (as well as radiators) and gives a measure of control over this portion of the total system output. The decrease in condensation in the piping, as the temperature of the steam is reduced under vacuum, assists in securing control of building temperature and promoting economy. The orifices function to distribute steam propor tionately when both complete and partial filling of the radiators is being employed in the cycle of heat output reduction. Individual thermostatic radiator control may be used with this system. With individual thermo static radiator control the individual control makes fewer operations and the radiator follows a more even temperature without fluctuating from extreme hot to extreme cold, since operating the system with steam temperature inversely with the outside temperature removes a part of the load from the radiator temperature control. The returns must grade downward constantly and uninterruptedly from the radiator return outlets to the inlet of the receiver of the vacuum pump. One radical difference between this system and the ordinary vacuum system is that no lifts should be made in the.return line, except 296 Chapter 15. Steam Heating Systems , vacuum pump. The receivers may be placed at a lower level than at t"e mo and are equipped with float control so the pump may operate d*6 Pgturn pump during night operation. The system may be operated f5 game manner as the ordinary vacuum system when desired. m T convert an ordinary vacuum return line system to a sub-atmospheric 10 a control valve is inserted on the steam main near the boiler or ^boiler is automatically controlled. The steam supply to each radiator . rovided with a flow proportioning device, such as an orifice, a high*S Puum pump is substituted for the ordinary type and is supplied with a va^_ure difference control, and traps are placed on the radiators and drip Pr.nts which will operate satisfactorily throughout the wide pressure and vacuum range. steam for- heating domestic hot water should not be taken from the heating system side of the control valves of this system. It should be taken from the boiler header back of the control valve so that pressures sufficiently high for heating the water may be maintained on the heater. The sub-atmospheric method of heating can be used for the tempering and heating coils of ventilating and air conditioning systems. The flexible control of heat output secured by this method materially reduces the required size of by-pass around the heaters. Sub-atmospheric systems are proprietary. ORIFICE SYSTEMS Orifice systems of steam heating may have piping arrangements identi cal with vacuum systems. Some of these systems omit the radiator thermostatic traps but use thermostatic or combination float and thermo static traps on all drip points. A return condensation pump with the receiver vented to atmosphere is generally used to return the condensation to the boiler, or place of final disposition, such as a feed water heater or hot well. They contemplate varying the heat emission from the radiators by varying the pressure maintained in the steam supply piping while the radiator pressure remains substantially equal to that of the atmosphere. The principle on which they operate is based on the well known fact that the steam' flow through an orifice will vary 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 flow will be obtained as a result of the increased pressure difference. If an orifice is so designed in size as to exactly fill a radiator with 2 lb gage on one side and , M lb gage on the other, the absolute pressure relation is: 14 7 4_ n 95 . I on = -9 ^ 90 per cent. . Should the steam pressure be dropped to x/i lb on the supply pipe, the pressure on each side of the orifice would be balanced and no steam flow would take place. From this it will be apparent that if an orifice of a given diameter will fill a given radiator with steam when there is a given pressure on the main, reducing this steam main pressure will permit filling various desired portion of the radiator down to the point where the main pressure equals the back pressure in the radiator provided the supply pipe pressures may be controlled sufficiently closely. If orifices are designed on 297 Heating Ventilating Air Conditioning Guide 1939 a similar basis for a given system and proportioned to the heating capacitv of the radiators they serve, all radiators will heat proportionately to the steam pressure. The range of pressure variation is limited by the per. missible noise level of the steam flowing under the pressure difference required for maximum heat output. The control of the steam supply js obtained by a valve placed in the steam main, which maintains a deter mined pressure. These valves are frequently manually set from a remote location, guided by temperature indicating stations in the building; 0r thermostatically controlled from a thermostat on the roof, which auto 1S% r% matically measures the differential of outside and inside temperatures; or a Iby a boiler pressure control. Since the range through which the pressures ifmay be varied is limited, usually from 0 to 4.0 lb gage, the control should hbe capable of maintaining close regulation to maintain the desired space m temperatures, particularly in mild weather. 3l Some systems use orifices not only in radiator inlets but also at different points in the steam supply piping for the purpose of balancing the system to a greater extent. In this manner the difference between the initial and terminal pressure in the steam main may be compensated to a great extent. For example, if the initial pressure was 3 lb gage and the pressure at the end of the main was 2 lb,.an orifice could be used in each branch for the purpose of obtaining a more uniform pressure throughout the system. Such a provision may be particularly, useful in this system for branches close to the boiler where the drop in the main has not yet been produced. Orifice systems are proprietary. Chapter 15. Steam Heating Systems _____ ------------------------- ' , Qn stiH days the heat demands vertically will vary little, but on Hv days there will be a marked difference in the heat requirements for different horizontal sections at different elevations. An arrangement "ie rovi(je for difference in heat requirement for exposure and chimney would give 12 zones; namely, north, east, south, and west lower e*eC~s. similar middle zones; and similar top zones. Every type of steam h ting system may be zoned. The extent to which any system may be js governed by the limitations of the given installation and the Zrticular type of system. Zone control is used principally with subatmospheric, orifice and vacuum heating systems. Each zone should constitute an individual and separate system with its own control valve (controlled by thermostats in its respective zone), steam supply and return piping and preferably its own return pump or vacuum pump. It is possible for a single vacuum pump to serve several zones with a controller for each section connected in parallel so that the zone in which the lowest differential or vacuum is produced may start the pump. Zoning has advantages even where individual thermostatic radiator control is installed, whether this he of pneumatic, electric, or the self contained radiator valve type. The control secured by zoning in supply ing heat in parallel with its outside temperature and wind fluctuations removes a large part of the load from such individual thermostatic controls; they operate less frequently and the radiators follow a more even temperature instead of fluctuating from extreme hot to extreme cold. ZONE CONTROL CONDENSATION RETURN PUMPS Often certain portions of a building may require more heat than others . Condensation return pumps are used for gravity systems when the even if occupied for the same daily periods and the same maintained local conditions do not permit the condensation to return to the boiler temperatures exist. Sometimes an entire building is on one general under the existing static head. The return of the condensate permits the control, which results in overheating some sections when sufficient heat is water to repeatedly go through the cycle of vaporization, with subsequent supplied to accommodate the coldest portion. By separating a building into zones, each with its own piping system, each zone may be controlled separately. Systems are zoned to care for ex posure, hours of occupancy, stack effect and the requirements of occu pancy activity. In large buildings it is important to consider zoning for exposure because of the varying effects of the wind and sun. With the prevailing winter winds from the northwest, for example, a simple zoning would sIfi' i1 Vj; i `r i?' 1! 'f ; | condensation and return to the boiler. During such repeated cycles any incrustants or other substances in. solution are precipitated and the water de-activated to a considerable extent so that corrosion of a serious nature is seldom ever encountered where the condensate is repeatedly used. Serious corrosion is more frequently found in systems where the conden sation is not repeatedly used but is wasted and fresh make-up water is continually being introduced. The most generally accepted condensation pump unit for low pressure ' place the north and west sides of the building on one zone and the south 41 heating systems consists of a motorrdriven centrifugal pump with receiver and east sides on another. If the size of the building justifies the expendi and automatic float control.. Other types in use include rotary, screw 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 and reciprocating pumps with steam turbine or motor drive, and directacting steam reciprocating pumps. fourth. 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 operation is to be secured. 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 to the boiler and at the same time not so small as to cause too frequent In high buildings it is often important- to consider zoning for stack or operation of the unit. The usual unit provides storage capacity between chimney effect, caused by the difference in density between the warm air stops in the receiver of approximately 1.5 times the amount of condensate on the inside of a building and the colder air on the outside. Where the returned per minute and the pump generally has a delivery rate of 3 to 4 lowest eight or ten stories are protected from winds by surrounding times the normal flow. This relation of receiver and pump size to heating buildings, it may accentuate the need for zoning to correct for the chimney i* ' 298 ?* system condensing capacity takes account of the peak condensation rate. 299 \? -I:'. Heating Ventilating Air Conditioning Guide 1939 VACUUM HEATING PUMPS On vacuum systems, where the returns are under a vacuum, and sub. atmospheric systems, where the supply piping, radiation and 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 dispose of the condensation. 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. In general, however, these have been replaced by the automatic motor-driven return line heating pump especially developed for this service. Steam turbine drive is also frequently used where steam at suitable pressures is available, the steam being used afterward for building heating. The usual vacuum pump unit consists of a compact assembly of exhausting unit for withdrawing the air-vapor mixture and discharging the air to atmosphere and a water removal unit which discharges the condensate to the boiler furnished complete with receiver and separating tank and automatic controls mounted as an integrated unit on one base. 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. Under special conditions such as installations where it is necessary to return the condensate to a high pressure boiler, auxiliary water pumps may be supplied. In some instances separate air and water pumps may be used. , Practically all automatic motor-driven return line vacuum .heating pumps make use of a portion of the condensate to operate either as a liquid piston pump or as a kinetic exhauster (which operate on a modified ejector principle) to withdraw the air and condensate from the system, discharge the air to atmosphere and return the condensate to the boiler..' Some type of hydraulic action is utilized to produce the suction. Such hydraulic evacuating devices may be classified as: a. Water ring centrifugal displacement pumps. b. Water piston pumps. c. Stationary kinetic exhauster pumps. . d. Rotary kinetic 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 genera! classifications: o. 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-condensable 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. ' 300 Chapter IS. Steam Heating Systems . jjjg second classification, the air and condensate are first separated Her vacuum by means of the receiver which is directly connected to tb returns. The hydraulic evacuator withdraws only the air and nonndensable vapors from the top of the receiver and delivers them to ?mosphere. 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 essure 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. For rating purposes1 vacuum pumps are classified as low vacuum and high vacuum. Low vacuum pumps are those rated for maintaining 5)^ in. Fig. 20. Method of Discharging High-Pressure Apparatus into Low-Pressueb Heating Mains and Vacuum Return Mains through a Low-Pressure Trap Hg. vacuum on the system, and high vacuum pumps are those rated to maintain vacuums above 5j/2 in. .The vacuum maintained in the returns of a system is affected by the steam pressure being carried on the system. Thus when pressures in the upper ranges used in low pressure steam heating are carried, the tempera ture at which the condensate enters the return piping increases. A portion of the condensate in flowing through the traps, upon entering the lower pressure region of the returns re-evaporates because it is at a temperature higher- than the saturation temperature for the pressure existing in the return piping. This vaporization tends to increase the pressure existing in the return piping (reduce the vacuum). The amount vaporizing is proportional to the difference between the heat content of the condensate at the temperature it leaves the radiator and that corresponding to the vacuum in the return piping. This action also frequently results in the inability to produce as high vacuums in systems having covered return piping as would otherwise be the case even though the same steam pres sure is carried on the radiation. It is obvious that conditions may be u Stand:,,d Code for Testing and Rating Return Line Low Vacuum Heating Pumps, (A.S. n.v.E. Transactions. Vol. 40. 1934, p. 33). . 301 Heating Ventilating Air Conditioning Guide 1939 obtained which limit the vacuum the pump can produce even though the traps are in normal operating condition and the system is reasonably J tight. It is for this reason the condensate from equipment using steam at - high pressures should not be connected directly to a vacuum return line | but should drain to a receiver through a high pressure trap. The receiver should have an equalizing connection to a low pressure steam main and drain through a low pressure trap to the vacuum return main as indicated 1 in Fig. 20. Vacuum Pump Controls ' . S i ' In the ordinary vacuum system the pump is controlled by a regulator \ which cuts in when the vacuum drops to the lowest point desired and cuts out when the vacuum has been increased to the desired high point to economize on current consumption. The cut-in point is usually about 3 in. and the cut-out point approximately 8 in. This is done largely to eliminate frequent starting and stopping of the vacuum pump which would otherwise occur without serving any particular purpose in the ordinary vacuum return line system. In addition to this vacuum control, a float control is included which automatically starts 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 and to permit continuous operation if desired. In sub-atmospheric systems the vacuum pump control maintains a pressure difference between the supply and the return piping which is held within relatively close limits. Such limits pernfit securing higher vacua on the supply piping as the upper limit of the pump's vacuum is ap proached. A pilot switch is also provided to enable operation as a con densation pump or to give continuous operation. In those cases where the condensation returns at a level lower than the pump, an accumulator tank is provided with a float control, to start and stop the pump whenever sufficient condensate accumulates. 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. . 302 Chapter IS. Steam Heating Systems TRAPS Trans are generally classified as to function as (o) separating traps, (h) return, lifting or vacuum traps, and (c) air traps. Separating traps av be either float operated, thermostatically operated or float and thermostatically operated. Return traps for low pressure service have heen referred to previously as alternating receivers in this chapter. . Return traps may also operate to receive condensate under a vacuum and return it to atmosphere or a higher pressure. Air traps are generally float operated. Separating traps are used to release water of condensation but to retain steam. The thermostatic, and float and thermostatic types release both condensate and air but retain steam. Separating traps are used for draining condensate from radiators, indirect air heaters, steam piping systems, kitchen equipment, laundry equipment, hospital equipment, drying equipment and many other kinds of apparatus. Air traps release air but retain water. Devices known as quick vents and vent valves are, in principle, traps which allow the passage of air but prevent the passage of either water or steam. Return 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 also be classified according to the principle-of operating device which supplies the power to cause them to function as (1) float, (2) bucket, (3) thermostatic, (4) float and thermostatic, (5) impulse, or (6) tilting 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- tmuous since the height of the float, and consequently the area of the outlet, is propor tional to the amount of water present. * 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 me 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 th h s."r .ce f tbe water in the bucket to force the water to a discharge opening. When e bucket is emptied it rises and closes the valve and another cycle begins. The discharge irom this type of trap is intermittent. , In the inverted bucket trap, steam floats the inverted submerged bucket and closes the 303 . Heating Ventilating Air Conditioning Guide 1939 valve. Water entering the trap fills the bucket which sinks and through compounj leverage opens the valve, and the trap discharges. It is impossible to install a wat<2 gage glass on an inverted bucket trap, but if visual inspection is necessary, a gage g|j? can be placed on the line leading to the trap. No air relief cocks can be used 6ut this j! 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. 8 Thermostatic Traps. Thermostatic traps are of two types, those in whjch 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. Float and thermostatic traps have both a thermostatic element to release air and a float element to release the water. Impulse traps operate with a moving valve actuated by a control cylinder. When the trap is handling condensate, the pressure required to lift the valve is greater than the reduced pressure in the control cylinder and consequently the valve opens allowing a free discharge of condensate. As the remaining condensate approaches steam tempera ture, flashing results, flow through the valve orifice is choked and the pressure builds up in the control chamber closing the valve. 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. . 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. Tilting traps 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. 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. 304 Chapter IS. Steam Heating Systems How many types OI cumiuuu uicuuauiuii Tthhereye**. Ill the ,,mechanical return trap, (2) the condensation return pump, and (3) the vacuum pump. f In the ordinary vacuum system of steam heating, where does the vacuum usually exist. _ . re(Urn side of the system only, between the radiator trap and the vacuum pump, tfrhe radiator supply valve is closed off, the vacuum may extend back through the H'ator as far as the supply valve; if an inadequate supply of steam is furnished to 1?a"vstem, some vacuum may be developed in the steam main, but neither of these can betermed 'normal operation. ' 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 dosed vapor system has an automatic device on the air vent so that air once expelled fiom the system through the vent cannot re-enter via this route. g I Qn 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. 61 How does the sub-atmospheric.system differ in 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 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, or 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? . X *LSy.re ^e-return Qf condensate to the boiler when the operating condition is such that the bouer 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? r*'-?P Heating Ventilatwg Air Conditioning Guide 1939 A'system equipped with such valves builds up a vacuum and holds the heat 10Q With proper controls on the boiler, lower radiator temperatures can be maintained^* 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 drii*. an automatic return trap to prevent water from backing out of the boiler. -' 13 Why must the automatic return trap on two-pipe vapor systems be about 18 m. above the boiler water line? * That height is necessary to overcome water line difference owing to pressure drop and friction in pipe and fittings. I -306 1 ifc Chapter 16 PIPING FOR STEAM HEATING SYSTEMS Operating Characteristics, Steam Flow, Pipe Sizes, Tables for Pipe Sizing, One-Pipe Gravity Air-Vent Systems, Two-Pipe Gravity Air-Vent Systems, Two-Pipe Vapor Systems, Vacuum, Orifice, Atmospheric and Sub-Atmospheric Systems, Steam Supply Sources, Piping Connections and Details, Boiler and Radiator Connections, Piping for Indirect Heating Units, Dripping IT is important that steam piping systems not only distribute steam at full or design load but during excess and partial loads. Usually the average winter steam demand is less than half of the demand at the design outside temperature. Moreover, in rapidly warming up a system, the load on the steam main and returns may exceed the maximum operating load for severe weather and even in moderate weather due to the necessity of raising the temperature of the metal in the system to the steam tem perature and the building to the design indoor temperature. Investi gations of the return of condensation have revealed that as high as 143 per cent of the design condensation rate may exist under conditions of actual operation. The functions of piping are to supply the heating units with steam and to remove the condensation as well as the air in the case of those systems where both air and condensation are returned. To accomplish this effectively, the distribution of the steam should be rapid, equitable and without noise. To attain this result the release of air from the system should be facilitated as much as possible, as an air bound system will not heat readily nor properly. In designing the piping arrangement for a steam system it is desirable to maintain equivalent resistances in the supply and return piping to and from a radiator. Arranging the piping so the total distance from the-boiler to the radiation is the same as the return piping distance from the heating unit back to the boiler, tends to obtain such a result. The condensation which occurs in steam piping as well as in radiators must be drained to prevent impeding the ready flow of the steam'and air. The effect of back pressure in the returns, and ex cessive revaporization such as occurs where condensation is released from pressures considerably higher than the vacuum or pressure in the return must be avoided. The piping design of a heating system is. greatly influenced by','its operating characteristics. Heating systems do not operate under affixed condition as they are continually changing due to variation in load. :As the system is being filled with steam the pressure existing an- various '307............................... ' ''' '" Heating Ventilating Air Conditioning Guide 1939 Table 1. Flow of Steam in Pipes P = loss in pressure in pounds. d = inside diameter of pipe in inches. L = length of pipe in feet. D -- weight of 1 cu ft of steam. W = pounds of steam per hour. VoW = 5220 PDd* P = 0.0000000367 ( 1 + PasaaOBB . Loss IN Ounces Col. 1 Pipe Size s V^ Actual 22 Nominal Internal Diameter Internal Area op Pipe Sq Inches Col. 2 Steam Press. bt Gage Col. 3 VT Length or Pips IN Feet Col. 4 V? 0.2S 65.28 0.50 92.28 1.00 ' 130.5 2 184.6 3 226.0 i IK IK 2 2K 1.049 1.380 1.610 2.067 2.469 0.864 1.496 2.036 3.356 4.788 0.536 --1.0 0.187 1.178 -0.5a 0.190 1.828 0:0 0.193 3.710 0.3 0.195 6.109 1.3 0.201 20 . 2.240 40 1.580 60 1.290 80 1.120 100 1.000 4 261.0 3 3.068 7.393 11.183 2.3 0.207 120 0.912 5 291.8 3K 3.548 9.887 16.705 5.3 0.223 140 0.841 6 319.7 4 4.026 12.730 23.631 10.3 0.248 160 0.793 7 345.3 4K 4.506 15.947 32.134 15.3 0.270 180 0,741 8 369.1 5 5.047 20.006 43.719 20.3 0.290 200 0.710 10 412.7 6 6.065 28.886 71.762 30.3 0.326 250 0.632 12 452.0 7 7.023 38.743 106.278 40.3 0.358 300 0.578 14 488.3 8 7.981 50.027 149.382 50.3 0.388 350 0.538 16 522.0 9 8.941 62.786 201.833 60.3 0.415 400 ' .0.500 20 583.6 10 . 10.020 78.854 272.592 75.3 0.452 450 0.477 24 639.3 12 12.000 113.098 437.503 100.3 0.507 500 0.447 28 690.5 14 13.250 137.880 566.693 125.3 0.557 600 0.407 32 738.2 16 15.250 182.655 816.872 150.3 0.603 700 0.378 40 48 80 160 320 480 825.4 904.1 1167.2 1650.7 2334.5 2859.1 Column 1 X 2 X 3 X 4 a lb of steam 175.3 per hour that will flow through a straight pipe for a given condition. 200.3 Example 1: 1 oz drop -- 2 in. pipe -- 1.3 lb press. -- 100 ft equivalent length: 0.645 0.685 800 0.354 900 0.333 1000 ' 0.316 130.5 X 3.710 X 0.201 X 1 = 97.2 lb per hour. 97.2 X 4b = 388.8 sq ft equivalent radiation. . 1200 0.289 Table 1 does not allow for entrained water in low-pressure steam, condensation in covered pipe and roughness in com 1500 mercial pipe as found in practice. ' 2000 0.258 0.224 Pounds per square inch gage = 2.04 in. Vacuum. Mercury Column. '' bThe factor 4 is the approximate equivalent in square feet of steam radiation of 1 lb of steam per hour. 308 Chapter 16. Piping for Steam Heating Systems ; may be different than those which exist for appreciable periods locations^ ot^er ]ocations and which under constant pressure may have f nations that are approximately the same. In designing piping it is of cn . . importance to arrange the system to preclude trouble caused by ^^messure differences. The systems which readily release the air persucn P .jorm pressures to be attained in much shorter time intervals "those which are sluggish. Results are given in Fig. 1 from investi01 . i t0 determine the rate of condensate and air return from a two -rarity heating system. Variations in the steam pressure during the P'P6 Up period when the rate of air elimination and condensation is highare clearly indicated in these curves. It is evident that the condensation flow during the initial warming up period reaches a peak which is greater than the constant condensation rate which is eventually reached when the pressure becomes uniform. Moreover, the peak condensation rate is obtained when the system steam pressure is lower than that existing during a period of constant condensing rate. It will also be noted that the peak rate of air elimination does not coincide with the higher condensing rate. 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 has been established by Babcock in the formula given at the top of Table 1. In Columns 1, 2, 3, and 4 of this table, the numerical values of the factors for different pressure losses, pipe diameters, steam densities and lengths of pipe have been worked out in convenient form so that the steam flowing in any pipe may be calculated by multiplying together the proper factors in each column as shown in the example at the bottom of the table.* 309 `A.S.H.V.E. Research Report No. 954--Condensate and Air Return in Steam Heating Systems, by F. C. Houghten and J. L. Blackshaw (A.S.H.V.E. Transactions, Vol. 39. 1933, p. 199). 309 Heating Ventilating Air Conditioning Guide 1939 PIPE SIZES The determination of pipe sizes for a given load in steam heating depends on the following principal factors: 8 1. The initial pressure and the total pressure drop which may be allowed between th source of supply and the end of the return system. e 2. The maximum velocity of steam allowable for quiet and dependable operation of the system, taking into consideration the direction of condensate flow. 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- . 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; and (4) the equivalent head due to pressure drop does not exceed the difference in level, for gravity return systems, between the lowest point on the steam main, the heating units, or the dry return, and 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 2 and 3 for vertical risers arid in Table 4 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 Chapter 16. Piping for Steam Heating Systems maximum Allowable Capacities of Up-Feed Risers foe One-Pipe 1 . Low Pressure Steam Based on A. S. H. V. E. Research Laboratory Tests VBIiOCTTT Fbet Pbb Second Pressure Drop O0NCE8 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.S7 0.54 0.48 0.44 0.39 . Sq Ft Radiation D 45 98 152 288 464 799 1144 1520 Capacitt Btu per Hour E 10,961 23,765 36,860 69,840 112,520 193,600 277,000 368,000 . Uj 8team per Hoar F 11.3 24.5 38.0 72.0 116.0 199.8 286.0 380.0 INSTRUCTIONS for using TABLE 2 1 Capacities given in Table 2 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 pij^^hould be well reamed and free from constrictions. Fittings should be up to size. (See Tables 5 and 6). - Table 3. Maximum Allowable Capacities of Up-Feed Risers for Two-Pipe ' Low Pressure Steam Based on A. S. H. V. E. Research Laboratory Tests Pipe Size Inches Velocttt Feet per Second Pressure Drop Ounces per 100 Ft .A K l 1J4 1J4 2 ty. 3 3y 4 ; B 20 23 27 30 35 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 Capacitt' Btu per Hour E 9550 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 3 1. The capacities given in this table should never be exceeded on two-pipe risers. ' 2. Capacities are based on 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 5 and 6.) ' ' ' 311 Heating Ventilating Air Conditioning Guide 1939 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 pjpe 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 5). 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 6). 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 Table 4. Comparative Capacity of Steam Lines at Various Pitches for Steam and Condensate Flowing in Opposite Directions3 Pitch of Pipe in Inches per 10 Ft Pitch or Pipe K m. Pipe Site Inches Sq Ft Rad. Based on 240 Btu a H in- Sq Ft Rad. Based on 240 Btu y 3 S 1 IN. Sq Ft Rad. Based on 240 Btu e a IMm. Sq Ft Rad. Based on 240 Btu 3 3 S 2 IN. Sq Ft Rad. Based on 240 Btu . 3 IN. Sq Ft Rad. Based on 240 Btu 3* 4 IN. Sq Ft Rad. Based on 240 Btu a 5 m. Sq Ft Rad. Based on 240 Btu 3 S % 25.0 12 30.3 14 37.3 18 40.4 19 42.5 20 46.1 21 47.5 22 49.3- 23 l 45.8 12 52.6 15 63.0 17 70.0 20 75.2 22 83.0 23 87.9 25 90.2 26. IH 104.9 18 117.2 20 133.0 23 144.5 25 154.0 27 165.0 28 172.6 29 178.2 31 1M 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 Data from American Society of Heating and Ventilating Engineers Research Laboratory. on which Table 5 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. 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 7 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. 312 ' Chapter 16. Piping for Steam Heating Systems . Pkh Cent Difference in Capacity for Carrying Steam and Condensate Tables- pUE TO Variation of Pipe Size and Smoothness3 Maximum Condensation, Lb per Hour Size of Pipe- Minimum-- Maximum---------Per cent variation.. Kin.14.00 15.20 8.6 1 In. 24.89 30.08 20.8 IK In. 45.42 52.08 14.7 IHln. 70.50 82.00 16.3 from American Society of Heating and Ventilating Engineers Research Laboratory. Table 6. Effect of Reaming Entrance to One-Inch One-Pipe Risers3 Maximum Capacity op Rlbeb Reamed entrances......--................................. --Rounded entrances.--.......................... ------------- Squared entrances................................................... Three wheel cutter............ ...................................... Single wheel cutter-- ............................--.......... 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 Peb Cent Decrease 0.0 3.2 10.1 22.2 28.7 Data from American Society of Heating and Ventilating Engineers Research Laboratory. Table 7.' Length in Feet op Pipe to be Added to Actual Length op Run-- < Owing to Fittings--to Obtain Equivalent Length Sue op 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 8 9 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 3 25 3 33 4 39 5 45 7 57 9 70 10 82 12 94 13 105 15 118 18 140 20 160 9 12 16 19 22 28 32 37 42 47 52 63 72 Example of length in feet of pipe to be added to actual length of run. i*..... MEASURED LENGTH. - BZ.-O 4"GATE YALtE. - 5.-0* * 4ELBOWS. - 56-0 : EQUIVALENT LEN6TH 193'-O' 313 Heating Ventilating Air Conditioning Guide 1939 TABLES FOR PIPE SIZING2 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 8 and 9, worked out for determining pipe sizes, have their col umns lettered continuously, Columns A through L being in Table 8, and M through EE in Table 9. 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 lb (4 oz) of steam per square foot of equivalent direct radiation3 (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. Table 8 may be used for sizing piping for steam heating systems by1 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 I 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 9 where pipe capacities for wet, dry, and vacuum return lines are shown for the pressure drops per 100 ft corresponding to the drops in Table 8. It is customary to use the same pressure drop on both the steam and return sides of a system. Example 2. What pressure drop should Jbe 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 Yo lb, while if the total drop were 'A. lb, the drop per 100 ft . *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 iogical unit based on the Btu. The new terms to express the equivalent of 1000 Btu (Mb), and 1000 Btu per hour (Mbn), have been approved by the A.S.H.V.E. . 314 Chapter 16. Piping for Steam Heating Systems ij he Ho lb. In the first instance the pipe could be sized according to Column D for 4h oer 100`ft, and in the second case, the pipe could be sized according to Column C K* lb On completion of the sizing, the drop could be checked by taking the longest for 734 a*ctuajjy calculating the equivalent length of run from the pipe sizes determined. ^dilated drop is less than that assumed, the pipe size is all right; if it is more, it is If tnbeable th_antr#th* earneuanruesaunalunusmubael rnoufmfibtteinr gosf fiinttvinoglvsedin,vaonlvdeedi,thaenrdtheeithlienretshme ulinstes must P^rticrhtened or the column for the next lower drop must be used and the lines resized. gd&y resizing will be unnecessary. Table 8. 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 op Heating and Ventilating Engineers. CAPACITIES OF STEAM MAINS AND RISERS Direction or Condensation Flow in Pipe Line Special Capacities for One-Pipe Systems Onlt Pipe With the Steam io Ooe-Pipe and Two-Pipe Systems Vs* lb */*4 lb Vie lb HIb Mlb Mlb Two-Pipe Only WOz HOt 1 Oz Drop Drop Drop 2 Oz 4*0z Drop . Drop 8 0s Drop Vertical Hori* zontal Risers UpFeed Radiator Radiator and Connections Riser Run- AB C D B F G Io : /b K Lc %` 1 39 46 30 56 79 in 30 157 56 Wi 87 100 122 173 245 346 122 134 155 190 269 380 538 190 2 273 315 386 546 771 1,091 386 2Vs 449 518 635 898 1,270 1,797 635 3 822 948 1,163 1,645 2,326 3,289 1,129 3M 1,228 1,419 1,737 2,457 3,474 4,913 1,548 4 1,738 2,011 2,457 3,475 4,914 6,950 2,042 5 3,214 3,712 4,546 6,429 9,092 12,858 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 80j171 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 -- 26 58 95 195 395 700 1-.150 1,700 3,150 -- 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 AQ Horizontal Mains and Down-Feed Risen Up. Feed Risers Mains and Un dripped Run- . outs Up. Feed Risers Radiator Con- nections Run outs Not Dripped Mote.--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 8. Copyright [ American Society or Heating and-Ventilating Engineers I Not to be Reprinted Wlth- 1 Beating, Piping and Air ConditioninQ Contractors National Association f out Special Permission 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 now in the same direction, use 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. Heating Ventilating Air Conditioning Guide 1939 1,977 3,390 5,370 11,300 18,925 30,230 45,200 62,180 109,300 175,100 190 1.400 450 2.400 990 3,800 1,500 8,000 3,000 13.400 21.400 32.000 44.000 77.400 124,000 190 450 990 1,500 3,000 700 1,200 1,900 4.000 6,700 10.700 16.000 22,000 38.700 62,000 : i ! !i OTf'O^OOOOOO-O'-^ONOWOQO e-t Cl fO IOXJQ i:jII OCW-IMOOOOOk O-O0OOO v-l fO 00iq O1rt0* O10 j 190 570 ....... 450 976 ....... 990 1,547 ....... 1,500 3,256 ....... 3,000 5,453 ........ 8.710 ____ ,13,0201....... 17.910 ____ 190 450 990 1,500 3,000 i: 22 is* xs: X. f Not to bo Reprinted Without Specie! Porntloolon Chapter 16. Piping for Steam Heating Systems 3 For up-feed steam risers carrying condensation backfromtheradiators, 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. g 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 lb. The return piping sizes should correspond with lie 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 Table 10. Pipe Sizes foe One-Pipe Up-feed System Shown in Fig. 2 . PiBT or SYSTEM 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 toe c tod d toe e to / / tog g to h h to j f to k ktom m to n n to p Radiation Supplied (Sq Ft) Theoretical Pipe size (Inches) Practical Pipe size (Inches) 100 2 2 50 ik IK 200 2 2 300 2H 2 'A 400 2M 2K 500 3 3 .600 3 3 600 3 H 3K 600 3 3 600 3 600 IK 2 600 1 2 600 1 2 600 1 2 1 50 I 1 50 14a. ft r^Uft Fig. 2. Riser, Supply Main and Return Main of One-Pipe System Column C (it will be noted that if Column H is used the drop would exceed the limit of Ke lb); the dry return from Column R; and the wet return from Column Q. With a %-lb drop the sizing would be the same as for >4 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 3. Size the one-pipe gravity steam system shown in Fig. 2 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 K lb P Pcr 100 ft will be slightly less than 3d6 lb. It would be well in this case to use zs4 lb, and this would result in the theoretical sizes indicated in Table 10. These theo- Heating Ventilating Air Conditioning Guide 1939 retical sizes, however, should be modified by not using a wet return less than 2 in. wh'I, the main supply, g-h, if from the uptake of a boiler, should be made the full size of tii 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. 111 Notes on Gravity One-Pipe Air-Vent Systems . 1. Pitch of mains should not be less than Vi in. in 10 ft. 2. Pitch of horizontal runouts to risers and radiators should not be less than Vi 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 5. Where supply mains are decreased in size they should be dripped. 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 Y2 lb the drop per 100 ft would be "XA or Ys lb; therefore, Column D would be use' d for all steam mains where the condensation and steam flow in the same direc tion. If a total drop of Y lb is desired, the drop per 100 ft would be lb and Column B would be used. If the total drop were to be 1 lb, the drop per 100 ft would be A 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 Vi* lb or 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 G, 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 9 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. 318 . . Chapter 16. Piping for Steam Heating Systems TWO-PIPE VAPOR SYSTEMS V iin-ije many manufacturers of patented vapor heating accessories have h'r own schedules for pipe sizing, an inspection of these sizing tables H'cates that in general as small a drop as possible is recommended. The m sons for this are: (1) to have the condensation return to the boiler by reafJjty (2) to obtain a more uniform distribution of steam throughout gystem, especially when it is desirable to carry a moderate or low fae and (3) because with large variation in pressure the value of gradu ated valves on radiators is destroyed. Por 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 x/% lb to Y lb, if possible. Thus, for a 400 ft equivalent run the drop per 100 ft should be not over x/i lb divided by 4, or Y lb. In this case the steam mains would be sized from Column B; the radiator and undripped riser runouts from Column I; the risers from Column B, because Column H gives a drop in excess of Yi 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 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 Vi in. in 10 ft. 2. Pitch of horizontal runouts to risers and radiators should not be less than H 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 2x/i 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, ORIFICE, SUB-ATMOSPHERIC SYSTEMS Vacuum, atmospheric, sub-atmospheric and orifice systems are usually employed in large installations and have total drops varying from Y to Vi lb. Systems where the maximum equivalent length does not exceed 319 Heating Ventilating Air Conditioning Guide 1939 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 sy$! tern with 1200 ft longest equivalent length of run would employ a drop per 100 ft of 34 lb divided by 12, or At lb. In this case the steam main would be sized from Column C, and the risers also from Column C (Column 1{ could be used as far as critical velocity is concerned but the drop would exceed the limit of At lb). Riser runouts, if dripped, would use Column C but if undripped would use Column I; radiator runouts, Column 7; 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^-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 A in. in 10 ft. 3. Pitch of horizontal runouts to risers and radiators should not be less than A 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 slipiild not be less than 2A 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. 7. No lifts can be used in orifice and atmospheric systems. In sub-atmospheric systems the lift must be at the vacuum pump. STEAM SUPPLY SOURCES Steam heating systems may be supplied from boilers used exclusively for heating or which provide steam both for heating and other purposes. Low pressure boilers are widely used because in modern practice steam heating systems usually operate at low pressures, usually not exceeding 15 lb gage. Frequently the heating boiler serves the heating system and the domestic hot water supply (See Chapter. 43). If the boiler plant supplies steam for other purposes requiring pressures exceeding 15 lb gage, a pressure reducing valve is the means used to lower the steam to the pressure required for use in heating. In some installations there may be separate zones used to supply steam for (a) direct steam heating, (b) pro cess work, (c) air conditioning or ventilation, and (d) domestic water heating. Each of these may require different steam pressures and con sequently individual pressure reducing valves are needed. 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 320 Chapter 16. Piping for Steam Heating Systems pctly and installed with care may be rendered defective by the use of noer connections, such as runouts that do not allow for expansion, mostatic traps unprotected from scale, pressure-reducing valves without strainers, and lack of drips at required points. BOILER CONNECTIONS supply Boiler headers and connections have the largest sizes of pipe used in a tem Cast-iron, horizontal-type, low pressure heating boilers usually have several tapped outlets in the top, the manufacturers recommending dieir 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 Fig. 3. Old Style Standard Boiler Connections Fig. 4. Approved Method of Boiler Connections 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 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 321 Heating Ventilating Air Conditioning Guide 1939 pipe, is dropped down into the boiler return, or into the top of the Hart- ft. ford Loop, which is described in a following paragraph. As a result, anv 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 arh 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 inches4. 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. 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 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 4Scc method of calculating height above water line for gravity one-pipe systems in Chapter 15. 322 .Chapter 16. Piping for Steam Heating Systems '-'c The difference in size between the vertical uptakes from the horizontal main or runout is compensated for by the use of ' "-`Return connections to boilers in gravity systems are made the same return main itself. Where the return is split and connected to ;- -.-Size 'tapLIp1Vin" gs on t.he same. ibo*ilie_.r., lbo.,thi. c__on-n___e__c__t__i_o__n___s___a___r_e_ m___a__d_ie. *t.hi. e_ rfuiltl s_ize ' iTthe return line. Where two or more boilers are in use, the return to < h may be sized to carry the full amount of return for the maximum load i'-'which that boiler will be required to carry. Where two boilers are used, ' 0f them being a spare, the full size of the return main would be ''`Tarried to each boiler, but if three boilers are installed, with one spare, the Fig. 6. The Hartford Return Connection 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. 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. Boiler header and piping sizes should be based on the total load. 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 323 Heating Ventilating Air Conditioning Guide 1939 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 redudm, 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 Table 11. 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 2X 3 3X 4 5 6 Pounds Steam per 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 SRadiation q Ft at K 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 Equitalbnt Direct Radiation Sq Ft at H 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: A X V X 3600 X .50 144 X 3.88 pound9 per hour passed by orifice. where 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 10^-lb gage. ) i 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 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 324 Chapter 16. Piping for Steam Heating Systems -8 er of the initial pressure, that the orifice efficiency is approx- lv 70 per cent, and that 20 per cent more is allowed for a factor of *?tv then the pressure reducing valves will have the working capacities jn Table 11. If the valve, when fully open, does not give an orifice S"Weaual to that of the pipe on the inlet side, then the capacities will be ^oortional to the percentage of opening secured, taking the pipe area ^lOO Der cent. More frequently, difficulty is encountered from the use 0ressure reducing valves which are too large in size instead of being * small. Where valves are large in size, the valve tends to work close fbthe 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 oressure 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 Less trouble from expansion leaks will occur when the bypass valve is on the same center line as the pressure reducing valve Bypess (same size as high pressure supply line) ' lobe valve High pressure steam Drip Low pressure steam Gate valve T.-~i~W|ve Pressure reducing valve Pilot line Fig. 6. Typical Pressure-Reducing Valve Installation 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 as double-disc valves, but the single disc is preferable where dead-end valves are necessary, such as on short runs to thermo statically controlled hot water heaters, central fan heating units and unit heaters. The correct "installation (Fig. 6) 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- 325 Heating Ventilating Air Conditioning Guide 1939 r 'Chapter 16. Piping for Steam Heating Systems 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 K;ve much better regulation than the larger one on light or normal loads. It js advisable to install a safety valve on the low pressure side of a pressure reducing valve set at 15 lb gage where the initial pressure exceeds 50 lb 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. Radiator Connections Radiator connections must not only be properly pitched at the time they are installed but must be arranged so that the pitch will be main tained under the strains of expansion and contraction, the variation of the riser or drop length with expansion and contraction, and the changes resulting from shrinkage, as in the case of frame buildings, and settling. In a three story building the change in the building height may some times amount to 1 in. or more. The riser run outs and the spring pieces from mains to risers are made by swing joints which permit the expansion or contraction to occur under heating and cooling without bending of pipes. In longer risers expansion joints of commercial construction or comprised of a series of swing joints alternating with properly spaced anchors are placed in intermediate lengths of the risers. These are basic requirements for radiator connections in all types of steam heating sys tems. The simplest radiator connection is for a one-pipe system in which only one radiator connection is necessary. Where the runouts must come above the floor, the runouts can project out into the room only a short distance and with standard length of radiator legs the vertical space is small. If the runouts are located under the floors there is frequently more space available to permit making a swing joint with ample pitch. Fig. 7 illustrates two satisfactory methods of making runouts for one-pipe gravity air vent systems for either the up-feed or the down-feed type. Where the vertical distance is limited and the runouts must run above the floor the radiator may be set on pedestals or high leg radiators. A method of connecting a unit heater to a one-pipe air-vent steam heating system is illustrated in Fig. 8. Where radiators are located below the level of the steam main the drop to the radiator is dripped into the wet return. An air veiit is used to vent the end of the radiator, or the radiator may have a return connection for the condensate at the end opposite the supply end. If connected in this latter manner a check valve should be placed in the condensation return connection. The method of making two-pipe connections for radiators of the old steam type is shown by Fig. 9. If the hot water type is used, which is the more recent practice, the supply tapping is at the top instead of at the bottom, as shown in Fig. 10, the runouts remaining as shown in Fig. 9. 326 - ,, 0f radiator connection is satisfactory for radiator connections cThis.-typ . y T vacuumi sub-atmospheric, and orifice systems of qff'atmo P fe^d ancj down-feed types. Short radiators, not exceeding in sections may be supplied and drained from the same end as 8 *9 1 . pj ' On down-feed systems the bottom of die supply 'must be dripped into the return somewhat as illustrated in Fig. 12. . ^riser m ^-Runout below floor PLAN jjpmji ll|l,l||Fl!jp Radiator 1 L Air valve-- r.Floor Runout below floor ELEVATION Fig. 7. One-Pipe Radiator Connections Fig. 8. Unit Heater Connected to One-Pipe Air-Vent System Radiators which are located below the level of the steam main have the drop from the supply pips dripped into the wet return, the return radiator connection drips to the wet return arid is vented through an air line to the overhead return line through a radiator trap or air line valve, as illustrated in Fig. 13. The same method is used for connecting concealed heating. units such as indirect radiators and the steam coils of air conditioning or 327 iili Heating Ventilating Air Conditioning Guide 1939 ventilating units where they are located at an elevation lower than th dry return pipe. Radiators located below the supply main but above th* dry return main may have the drip on the steam drop to the radiato omitted if an overhead valve is used, as shown, in Fig. 14. If they are located above the dry return pipe, they are connected in the manner shown by Fig. 15, which follows the same method as direct radiators similarly located. . Convector Connections Convectors are often 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 connections for a convector with the inlet and outlet at the same end are shown in Chapter 16. ' Piping for Steam Heating Systems ~ , _. 21 is suitable for atmospheric, vapor, vacuum, sub-atmospheric, ^d onfice systems. pipe Connections for Indirect Heating Units The coils or heat exchangers used to temper the air for ventilation and conditioning are supplied with steam using the same piping principles ^ use<j for connecting radiators for the given type of system. If the ring coil is located at an elevation lower than the dry return piping, the connection would be as shown by Fig. 22 for a two-pipe vapor system. For a one-pipe system the air line through the thermostatic trap would be omitted and the usual air vent substituted. Fig. 9. Connections to Steam-Type Radiator for Two-Pi pe System Fig: 10. Top and Bottom Opposite End Radiator Connections Fig. 11. Top and Bottom Radiator Connections leg M ton S' lon( Fig. 12. Top and Bottom Opposite End Radiator Connections Fig. 13. Connections to Radiator Hung on Wall . Fig. 14. Connecting Drop Riser Direct to Radiator . ' ? Fig. 16. 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, 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. 17. 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. 18. A convector located in the basement and supplying air to a room on the floor above may be piped as pictured in Fig. 19 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. 20. j , > \ \ J > ;. : J 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 ' 328 Dirt pocket Fig. 15. Piping Connec tions to Indirect Radiators Fig. 16. Convector Con nections Same End Fig. 17. Horizontal Fin-Type Heating Unit \T Cabinet \ type Fin radiator Fig. 18. Heating Unit Valves Behind Grille Fig. 19. Heating Unit with Valves in Basement Fig. 20. Fin-Type Heat ing Unit in Cabinet Where a building is served by a vacuum system or a sub-atmospheric system the air heaters should be piped in the usual manner and traps of large capacity, preferably of the combination float and thermostatic type, should be used. In an orifice system, traps should be used on the returns so that a pressure above that of the atmosphere may be secured on the heaters. A similar connection may be used for a closed two-pipe vapor system using a condensation pump with receiver. In connecting air heaters a branch steam main is directed to the fan room and a single branch is connected to each row of heating units. Each of these branches is split into as many connections as are needed for each row, governed by the number of stacks and width of stacks. Each stack must have at least one steam connection. Wide stacks are more evenly heated with two steam connections, one at each end, the stacks being divided and a return connection provided for each steam connection. The return connection should use. a nipple full size of the outlet tapping and reduce the pipe size to the normal return size as required by use of a reducing elbow as shown in Fig. 23. 329 Typical connections to manifold coils having more than 8 pipes Fig. 21. Typical Pipe Coil Connections 330 Chapter 16. Piping for Steam Heating Systems 'piping shown in Fig. 24 is for small stacks and has the steam con%-v, , .pj at only one end. On the return side all of the returns are collected 11 fuer through check valves and are passed through blast traps which ' togein ^ected ^ vacuum return or to an atmospheric return. The air freCthe 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 tapping is made to the lower portion of one of the middle sections, in the manner illustrated in Fig. 25, to prevent air collecting at this point. ip Fig. 24. Supply and Return Con nections for Heating Units of Central Fan Systems Strainer Blast trap ' tit- 1 1 3 Return Fig. 25. Typical Connections to Central Fan System Heating Units Exceeding 12 Sections 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 i connections to each stack. . where _ <2 X 60 X (ft - le) Q X (tl (eV EDR - 55.2 X 240--------= 220.8 (1) EDR = equivalent direct radiation, square feet. Q = volume of air, cubic feet per minute. fe = the temperature of the air entering the row of heating units under con . sideration, degrees Fahrenheit. ft = 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. Example 4- 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 331 HI i- Heating Ventilating Air Conditioning Guide 1939 65 F, and in the third row from 65 to 80 F. What is the load in EDR on each and return connection? , ^7 The pipe sizes would then be based on the length of the run and the pressure dmdesired, as in the case of radiators. It generally is considered desirable to place theij Chapter 16. Piping for Steam Heating Systems heating units on a separate system and not on supply or return lines connected to ^general heating system. DRIPPING A steam main in any type of steam heating system may be dropped to a lower level without dripping if the pitch is downward, and with the direc tion of steam flow. Any steam main in any heating system can be elevated 7 dripped- Fig. 27 shows a connection where the steam main is raised and the drain is to a wet return. If the elevation of the low point is above a drv return it may be drained through a trap to the dry return in two-pipe vapor, return, vacuum return line and sub-atmospheric systems. Hori- Fig. 27. Dripping Main Where it Rises to Higher Level Fig. 28. Looping Main Around Beam. Fig. 29. Looping Dry Return Main Around Opening Fig. 26. Typical Piping for Atmospheric and Vacuum Systems with Thermostatic Control (Central Fan System) . Solution. For row 1, ,, 50,000 X (40 - 0) _ ^ R = ---------- 2208-------------- 9058 SQ ft' For row 2, _ 50,000 X (65 - 40) R = ---------- 2208---------- = 5661 Sq ft` For row 3, o 50,000 X (80 - 65) _ R = ------------ 2263----------------- 3397 811 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 LoAob (EDR) 2265 or 1132 1415 or 708 849 or 425 . One quarter of total row load. . ' bQne half of stack load if two steam connections are made: otherwise, same as stack load. Fig. 30. Methods of Taking Branch from Main To find length C-muiUpty A by constant tor angle B Fig. 31. Constants for Determining Length Offset Pipe out pocket 1 V * ' Wet return Fig. 32. Dirt Pocket Connection zontal steam pipes may also be run over obstructions without a change in level if a small pipe is carried below the obstruction to care for the con densation (Fig. 28). Horizontal return pipes may be carried past door ways and other obstructions by using the scheme illustrated in Fig. 29. It will be noted that the large pipe, in this case, runs below the obstruction and the smaller one over it; in vacuum systems it is well to have agate 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 333 Heating Ventilating Air Conditioning Guide 1939 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 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. 3^ 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 s= Water Reducing coupling Cooling teg it ^leasts* tong 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 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. 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 1 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 permissible to maintain a pressure in the farthest radiator. The length of run in sizing piping is important and it is generally considered 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. *x 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. 334 Chapter 16. Piping for Steam Heating Systems *'i * # What are the major factors to be considered in determining the flow of ftearn in pipes? ....... ~ The initial steam pressure available and the total pressure drop allowable between the * ` irce 0f steam supply and the end of the return system. The pressure drop should ever exceed one half of the initial pressure. . -. .r-jjg maximum steam velocity allowable. When condensate is flowing against the - ^gam 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 j ater 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. . 0. Provision for the distribution of suitable quantities of steam to the various heating units. . 1. 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. 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 1 reducing valve? b. How should such'valve be installed? - . 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. . 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. ? * Whnt is the usual expansion allowance and how it is compensated for in beating system supply risers? ft nf |,;..r z *------ unveil ds a 74 tu a 72 in. per 1UU If. 01 pipe With a five story budding a double swing connection between the riser and the mam 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 wpansion loops or nser offsets are used which are capable of handling a length of riser alfprln? - stor,.es ln either direction from the joint. The risers are anchored at each te. 0 stor>es- AH radiators must have double swing connections, and those con- eciea above where the nser is anchored must be given greater pitch to insure their Having proper grade when the riser is heated. .- Heating Ventilating Air Conditioning Guide 1939 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 than the invert of the pipe at the top of the loop. Chapter 17 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. HOT WATER HEATING SYSTEMS AND PIPING 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 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 Bowing 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 O 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. 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 of 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. 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 no 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. 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 usedfor many years for rating purposes in both steam and hot water systems, but Us use, especially in hot water systems, has always resulted in compli I 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 336 337 Heating Ventilating Air Conditioning Guide 1939 In designing a piping arrangement for a hot water heating system, it ;snecessary 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, one- pipe 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 rcorrectly 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 338 Chapter 17. Hot Water Heating Systems and Piping 1 neest. 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 naths leading through the three radiators shown in Fig. 2 are practi- J^Hy 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 at 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. rtn. "Ll!-, 4J-- -- -------!>-- tTTL .im pxi, ji -- --i-- H -J Fig. 1. A Direct Return System Fig. 2. A Reversed Return System The modern 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 dcfuSl 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 339 Heating Ventilating Air Conditioning Guide 1939 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 systerns 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, blit 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 . ; j al 'll 340 rr- Chapter 17. Hot Water Heating Systems and. Piping ulation system. They are designed for installation directly into the hating main and require no other support. The common practice is to -fgU them in the return line but where desirable there is no objection to iocation in the supply line. Gate valves should be installed in either Vie 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 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 341 Heating VentiiiaTing Air Conditioning Guide 1939 Difference of the Water in the Flow and Return Lines .' For other temperature drops the pipe'caparities 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. 342 Hot Water Heating Systems and Piping '' . t0 design a satisfactory forced circulation system than a satis'fectcHy gravity circuiation 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 : Jjg 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 151ft 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 in a 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. Havingdetermined 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 relationship7between 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. miao {Journal of Ike New England Water Works Association. Vol. XLIV, No. 4, 1930). '. Heating Ventilating Air Conditioning Guide 1939 .Table 1. Capacities for Black Iron Pipe A = Carrying capacities inMbh B = Velocity in inches per second Head Loss. Ft Milinch Friction Loss Per Foot ok Pipe 720 480 360 300 240 180 160 144 120 96 90 80 ' 70 60 Equivalent Length of Pipe in Feet (Longest Circuit) 2 2M 3 3K 4 4H 5 5M 6 6H 7 m 8 SH 9 9H 10 10M . 11 11H 12 Nominal Pipe Size, In. 33 50 66 42 62 84 50 75 100 59 87 117 67 100- 133 75 112 149 83 125 167 92 137 183 100 150 200 108 162 217 116 175 233 124 187 249 133 200 266 142 212 283 150 225 300 159 237 317 167 250 333 175 262 349 183 275 366 192 287 383 200 300 400 80 100 120 140 160 180 .200 220 240 260 280 300 320 340 360 380 400 420 440 460 480 100 133 125 167 150 200 175 233 200 266 225 300 250 333 275 366 300 400 325 433 350 465 375 500 400 533 425 566 450 600 475 633 500 666 525 700 550 733 575 766 600 800 150 188 225 167 208 250 200 250 300 250 312 375 270 333 400 300 375 450 340 428 510 400 500 600 263 300 338 291 350 437 463 525 593 333 400 500 533 600 685 374 450 562 593 675 758 700 800 900 375 416 500 625 666 750 860 Togo 413 450 457 500 550 600 6S7 750 713 809 825 923 900 1030 1100 1200 488 525 563 540 580 623 650 700 750 812 875 937 843 975 1088 933 1050 1200 973 1125 1252 1300 1400 1500 600 666 800 1000 1070 1200 1370 638 706 850 1062 1103 1275 1417 675 750 900 1125 1200 1350 1540 1800 713 750 789 950 1187 833 1000 1250 1233 1425 1577 1333 1500 1715 1000 788 872 1050 1312 1363 1575 1737 2100 825 .916 1100 1375. 1466 1650 1885 2200 863 955 1150 1437 1533 1725 1897 2300 900 1000 1200 1500 1600 1800 2030 2400 Capacity of Pipes Mbh With a 20 F* Drop A 20 16 14 13 11 10 9 9 8 7 7 6 6 6 B 27 22 19 17 16 18 12 It 10 9 9 8 8 7 A . xB 43 35 30 27 24 21 19 18 17 15 14 13 12 ll 33 25 23 21 18 16 16 14 18 11 11 10 9 9 A 85 70 60 54 48 41 39 36 33 30 28 27 25 23 l . B . 89 32 27 25 22 19 18 17 16 13 13 12 11 10 A IX B 180 145 125 115 98 85 80 75 ' 68 60 58 55 51 47 SB 89 S3 SO 27 28 21 20 19 16 16 15 IS It A . 285 230 195 180 160 135 125 120 110 96 92 88 82 75 ' ix B H ss 88 34 50 26 BS 28 21 19 18 17 16 H A 2B 540 .435 370 340 300 255 240 230 205 180 175 165 150 140 <4 62 SB SO 86 ''SO 29 27 is 22 21 . 80 19 17 A 2M B 890 720 610 550 480 420 '390 370 330 300 280 270 250 74 60 60 SB 41 85 S3 31 28 24 BS 22 21 A 1650 1340 1130 1000 900- 7C0 . 720 670 600 540 520 480 450 3 B. 88. 70 60 BS SB. St 88 . 86 33 29 28 26 84 A 3X B 2500 2000 1700 1500 1350 1150 1080 1000 900 800 760 720 670 99 78 66 60 - BS SO SB so 86 : 32 . SI 29 27 230 19 410 t 620 t5 A V 3500 2800 2400 2200 1900 1600 1520 1440 1300 1150 1100 1050 960 m 4B no 87 7S 66 68 60 S7 SB 40 85 ss 82 so V A 7000 5600 4700 4300 3700 3200 3000 2750 2500 2200 2100 2000 1800 1700 5 B_^ '.182 106 90 80 70 80 66 68 SB SB 41 88 5-J SB A 12.000 9200 7800 7000 6200 5200 4800 4600 4100 3600 3500 3300 3000 . 2800 6B 156 m 104 BS 82 69 64 61 55 SB so ss S' fFor other temperature drops the pipe capacities may be changed correspondingly. *:For example. with i temperature drop of 30 F. the capacities shown-in this table are to be multiplied by 1.5. ' 344 Chapter 17. Hot Water Heating Systems and Piping Table 2. Capacities for Type L Copper Tube A = Carrying capacity in Mbh * B -- Velocity in inches per second Milinch Friction Loss per Foot of Tube HEAD LOSS 720 600 480 360 300 240 180 150 120 90 Equiv uhnt LENGTB Gif Tube in Feb1r (Long SST ClRC*un) -- 2 2H 3 . 50 ~ 3H~ 4 *x 75 5 6 100 40 50 60 70 80 90 100 110 120 108 130 117 140 IK 125 150 133 160 142 170 9 150 180 10X 159 190 167 200 175 210 183 220 192 230 12 *200~ 240 Nominal Size. In. 50 63 75 88 100 113 125 138 150 163 175 188 200 213 225 238 250 263 275 288 300 67 80 100 133 160 83 100 125 167 200 100 120. 150 200 240 200 267 250 333 300 400 117 140 175 233 280 133 160 200 267 320 150 180 225 300 360 350 467 400 533 450 600 167 200 250 333 .400 183 220 275 367 440 200 240 300 400 480 500 667 550 733 600 800 217 260 325 433 520 233 280 350 467 560 250 300 375 500 600 650 867 700 933 750 1000 267 320 400 283 340 425 300 360 450 533 640 567 680 600 720 800 1067 850 1133 900 1200 317 380 475 633 760 950 1267 333 400 500 667 800 1000 1333 350 420 525 700 840 1050 1400 367 440 550 733 - 880 1100 1467 383 460 575 767 920 1150 1533 400 480 600 800 960 1200 1600 Capacity of Tubes Mbh With a 20 F* Drop 75 60 320 400 400 500 480 600 560 700 640 800 720 900 800 1000 880 1100 960 1200 1040 1120 1200 1300 1400 1500 1280 1360 1440 1600 1700 1800 1520 1900 1600 2000 1680 2100 1760 1840 1920 2200 2300 2400 A XB 10 9 8 27 BS 21 6.8 18 6.2 16.6 5.4 14 4.6 IS 4 11 3.6 3 2.8 10 8.6 8 A 20 18 16 13.5 12 10.8 9 8 7 6 XB 38 SO 26 21 19 17 16 18 12 . io 5.4 9 A XB 36 30 26 22.1 .. 20 37 SS 30 BS 21 17.8 19 15 17 13.1 16 11.8 18 9.9 11 9 10 A 51 46 40 34 31 28 23.2 20.5 18.1 15.3 13.9 isX B 42 38 S3 27 BS 21 19 . 17 12 11.6 A " 104 94 82 70 63 56. ' 47 42 37 32 28 1B SB 46 89 ss 50. 26 22 19 17 146 18 A 185 169 149 125 112 100- 84 75 66 56 50 IX B 66 61 46 89 85 SO 26 22 19 17 16 A 300 270 235 200 180 160 134 120 105 IX B 62 67 61 S3 89 86 . . 80 26 22 90 81 19 .17 A 625 560 495 420 375 335 280 250 200 188 170 2B 76 68 69 61 47 SB 86 82 27. 22 20 A 1130 1010 890 750 680 600 500 ' 450 395 335 305 2X B 90 80 69 58 SB S7 SB 87 38 26 28 -A A 3>$ B 1840 1650 1450 1210 98 90 80 66 2750 2480 2170- 1840 110 loo .89 76 1100 59 1650 66 980 62 1450 67 820 S7 1210 51 740 42 1100 46 650 86 980 . 4 550 SO . 820 36 490 27 740 SO A 3900 3505 3100 2600 120 108 96 88 2350 75 2090 1760 68 . - 66 1580 SB 1390 . ss 1180 37 1080 34 2.4 7 4.7 8 7.9 9 12.1 10 25 12 44 IS 71 16 150 18 270 21 420 28 650 26 950 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 1.5 345 Heating Ventilating Air Conditioning .Guide 1939 Table 3. Iron Elbow Equivalents* 1 90-deg elbow............. ................................................................ ..... ..................................... ^ 1 45-deg elbow.............. .........................................................--........... ................................... q 7 1 90-deg long turn elbow._.................................... ................... ............................................... q\j 1 open return bend._................................................:............................ ................................... j q 1 open gate valve........................................................-............................. --.................... ........ Qcj 1 open globe valve....,,........................................ ........................ ..................... ......... .--.____ 12q 1 angle radiator valve........................... :_______________________________ __________ ___ 2*0 1 radiator.........................;................................................... ......... ...... ................................. 3q 1. boiler or heater................................................................................................................. ..... 3 q 1 tee .................................................................................... ..............:.......................................(Noteb) The loss of head in one elbow can be expressed in terms of the velocity head by the formula: * 2g ) the loss of head in feet, v = the velocity of approach in feet per second, and 2g = 64.4 ft per second per second. bThe loss of head in tees when water is diverted at light 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 los9 of head. in elbow equivalents, may be expressed as follows: : ** _ t > where . . ;. ' ht = the loss of head in elbow equivalents, v\ -- the velocity of approach, . p* = the velocity of water diverted at right angles. . ' . * Values in elbow equivalents for the most common percentages of water diverted in a Ixlxl 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 45-deg elbow... ......;............ 1 90-deg long turn elbow..... 1 open return bend :............ 1 open gate valve.................. 1 open globe valve.......:....... 1 radiator valveL.__1 radiator.... ............. .......-- 1 boiler or heater.____ 1.... 1 tee........... ......... --.. -- __ 1.0 -..... 0.7 ...._ 0.5 ___: i.o __ : o.7 ...... 17.0 3.0 ___ 4.0 ....., 4.0 ..(Noteb) aThe loss of head in an.elbow can be expressed in terms of the velocity head by the formula: i - (3) where - ' ' ,. h = loss of head in milinches, v -- velocity in inches per second, and g . . in. per second-per second). . - . .. acceleration of gravity (386 bThe loss of head in cppper tees: .V 0.7 (4) where - - ................. N -- number of elbows that would cause the same los3 as the tee when the velocity of water in the connecting pipe is v. ' . -' pi -- velocity of the water in the pipe entering the tee, and pi = 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 _ 50 per cent.... 30 per cent__ 25 per centTM .1.2 . 4.0 . 16.0 . 20.0 346 chapter 17. Hot Water Heating Systems and Piping pjpe s;zes may be selected from Fig. 4 or from Table 1 which has been derived from supply main of the longest circuit first. Section AB carries 98 Mbh. From . 4*it will be noted that at 240 milinches per foot, a 1K in. pipe carries 98 Mbh. nr Sore use lM in- P>Pe in Section AB. Section BO carries 40 Mbh. A 1 in. pipe 48 Mbh at 240 milinches per foot. Use a 1 in. pipe. Section OP carries 20 Mbh ^d'this will require % in. pipe. Section PQ carries 10 Mbh and requires l/i in. pipe. T* size the return start from the boiler and proceed backwards. Section IR carries zflMbh and from Fig 4 a 1 in. pipe is required. Section RS carries 30 Mbh which is only v* | over the capacity of a % in. pipe, so use % in. Section ST carries 20 Mbh and S uires a % in. pipe. The radiator branches are.determined in the same manner. It is ^dent 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 roper p0;nt. 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 1M 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 Friction Milinches Total Loss Milinches Supply Main AB 98 BC 58 CD 38 DE 23 EF 11 fg 4 37 1 240 9600 9,600 2 4 IK 90 1080 10,680 16 11 155 2790 13,470 9 0 K 220 1980 15.450 12 0 K 240' 2880 18,330 16 1 K . 50 850 19,180 HI 98 1J 58 JK .54- KL 47 LM 35 MN 20 5 11 16 11 9 15 '-5 ` 1 1 0 .0 1 IK IK . 1. 1 .1 K 240 90 300 230 140 . 170 Radiator Circuits . CN 20 Supply * Return DM 15 Supply Return EL 12 Supply Return . FK 7 Supply Return . GJ 4 Supply Return 3 .4 , 13 2 .K .K 3 19 4 . 17 K K 14 20 15 20 K K 3 19 4 . 17 . K 8 ; - * 5 9 . 17 - K K 170 170 420 96 270 _ 270 100 100 50 50 347 4320 1260 5400 2530 1260 2890 . 4.320 5,580 10.880 13.410 14,670 17,560 3910 1190 9250 2880 9180 , 9450 2200 2100 650 1300 5,100 . 12,130 18,630 . 4,300 1,950 Heating Ventilating Air Conditioning Guide 1939 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 ? 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 tU 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. A 10 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 S. 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 1M in. tubing. Sections CD and 1J supply 67.2 Mbh and require 1)4 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 Yz 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 head 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 fje supplied by additional resistance in the first riser. : Chapter 17- Hot Water Heating Systems and Piping Table 6. Friction Heads (in Milinches) of Central Circular Diaphragm. Orifices in Unions . Velocity or Water in Pipe in Inches pes Second or Ounces (Inches) * 3 "^1 - 10 12 18 %-in. Pipe - 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 1-in. Pipe 0 an 0 0 so n ss n 60 0.65 900 2000 3500 7800 14,000 22,000 32,000 460 .1000 1800 4000 7200 12,000 17,000 37,000 65,000 270 570 1000 ' 2300 4100 6400 9300 21,000 37,000 160 330 580 1400 2300 3700 5400 12,000 22,000 50,000 190 330 750 1300 2200 3000 7000 13,000 28,000 200 440 800 1300 1800 4200 7400 17,000 120 260 460 720 1100 2400 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 1 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 0.85 850 1900 3300 '600 1300 2300 400 850 1500 260 600 1100 180 400 760 300 540 200 380 1 Pipe 7400 5400 ,3600 2600 1800 1200 860 13,000 8600 7200 4400 3000 2200 1600 21,000 16,800 10,400 7000 5000 3200 2300 30.000 21.000 14,000 10,000 . 7000 5000 3000 50|000 30,000 21,000 14,000 10,200 7800 53,000 39,000 28,000 19,000 45,000 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 37,000 9500 20,500 5800 .12,500 3700 7900 1910 4200 1375- 3100 38,000 23,000 49,000 14,000 30.000 8100 16,800 4400 8850 losses of head for the orifices in the 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 ts a function of the ratio of the diameter of the pipe to that of the orifice. This had been found to be ^.cally true in the tests to determine the losses of head in orifices in K-in*. I-in., and IH-in. pipe, con ducted by the Texas Engineering Experiment Station, and also in the tests to determine the losses of head * m *"*n- 6-in., and 12-in. pipe, conducted by the Engineering Experiment Station of the University of Illmois.(Btt//iB 109. Table 6. p.-38. Davis and Jordan>. . ` Heating Ventilating Air Conditioning Guide 1939 This resistance can be supplied by a calibrated and adjusted modulating valve or k an orifice resistor in a union. If the orifice resistor is to be used, its size may be selpor j from Table 6. . 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 350 Chapter 17. Hot Water Heating Systems and Piping t. , ii |,e [es5| probably about 41,700 milinches, which is approximately 10 per cent head ^'an the required resistance. This is permissible and the 0.35 in. orifice is selected. S:zes 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 oportional 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 mam will be about 2 in. According to Table 7 Column 2, a 2 in. elbow is equivalent to 'ion r an(^ 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^ 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 V/i in. pipe Heating Ventilating Air Conditioning . Guide 1939 too large. The solution is to use some 2 in. and some 2)4 in. pipe. Since the 2U : . nearer the correct size than the 2 in., select 2 in. pipe for the first 50 or 60 ft fromu,13 boiler and 2)4 in. for the remaining pipe back to the boiler. Tables 8 and 9 may be used to design the fadiator risers and connections. Accord' to Table 8, for 12 Mbh the flow riser should be 54 in. and the return riser 1 in., and to'riser branches should be 1 in. and 1)4 in., respectively. Note that according Table n both radiator tappings should be 1 in. To simplify the construction, select 1 in. a a' risers with 1 in. riser branches and 1 in. radiator tappings. Also select 1)4 in. retu risers with 1)4 in. riser branches, and 1)4 in. radiator tappings. Similarly, for 18 Mm? select 1)4 in. flow and return risers and riser branches, and 1)4 in. radiator tapping 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 i 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. 352 Chapter 17. Hot Water Heating Systems and Piping v Capacities of Mains in Mbh, for One-Pipe and for Two-Pipe Direct Tab^Jt'uiin Gravity Circulation Systems with a Total Friction Head RET of 0 6 In., a Temperature Drop of 35 F, when the Mains ' are 4 Ft Above the Center of the Boiler Pot Sot , (ISCKZS) Equivalent Length or Pif* (Feet11) Equivalent Total Length of Pipe in Feet in Longest Circuit 100 150 175 200 250 500 Unit Friction Head, in Miuncbes 48.0 87.5 33.0 30.0 27.0 25.0 22.2 20.2 18.7 88.0 78.0 63.0 57.0 51.0 48.0 42.0 38.0 35.0 4.5 140.0 115.0 100.0 90.0 81.5 75.4 67.2 61.0 66.0 5.0 884.0 204.0 175.5 160.0 143.0 133.0 110.0 107.5 100.0 5.5 847.0 300.0 260.0 236.0 214.0 200.0 177.0 160.0 146.0 6.0 490.0 422.0 370.0 334.0 297.0 278.0 248.0 223.0 205.0 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 A B and IA, which supply 105.6 Mbh, a 3 in. pipe is tod large and a 2)4 in. pipe is too small: hence, select 2)4 in. rather than 3 in. as noted in Fig. 8 for Section AB and 3 in. for Section 1A. For Sections BC and HI, which supply 76.8 Mbh, a 2)4 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, 1)4 in. flow and return risers will supply 26.0 Mbh; if the return riser is increased to 1)4 in., the capacity will be increased to 34.0 Mbh. This is considerably larger than necessary, and 1)4 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 )4 in. flow and a 54 in. return riser is used, the capacity will be 8.0 Mbh; if both risers are )4 in., the capacity will be 14.0 Mbh. The 54 m. 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 54 in. flow and 1 in. return is 9.1 Mbh, and that of 353 Heatino Ventilating Air Conditioning Guide 1939 Table 8. Maximum Capacities of Risers3 in Mbh, and Velocities of Water Pipes in Inches Per Second for One-Pipe and for Two-Pipe Direct 10 Return Gravity Circulation Systems with a Drop of 35 F Through Each Radiator- Pipe Size (Inches) Flow Return Equivalent Length of Pipe (Feetc) 1st Floob* Vel (In. per Seed) Mbh Flow Return 2nd Floor Mbh 3rd and 4th Flo( Mbh XX X XX X1 11 1 Hi m ix ix ix. IX iy2 1.0 1.5 2.0 3.0 3.5 9 2.3 2,3 IS 3.2 2.0 18 2.5 2.5 SI 3.0 2.0 S6 3.0 3.0 84 4.0 2.5 48 3.0 3.0 5 6.4 10.1 1S.8 SO S5.S 43 6:s 8.0 14-0 17.1 S6.0 84 55 "This table is based on pressure heads 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. * nair*a>The riser branches, the piping which connects the risers to the mains, are to be one size larger thanv tkhuc* cApproximate length of pipes in feet equivalent to one elbow in friction head. This value varies 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 % 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 of Pipe (Feet) 1st Floor Mbh 2nd, 3rd, and 4th Floors ' Mbh XX XX XX X' 1 11 1 ix ix IX 1.0 1.5 2.0 3.0 4-1 5.S 7.0 9.1 1S.6 17.5 SS.3 5.9 7.5 10.5 13.0 17.8 SS.S SS.S Approximate length of pipe in feet equivalent to one elbow in friction head. This value varies with, the velocity. ` Chapter 17- Hot Water Heating Systems and Piping t .Eat available for the fourth set. The velocity in the riser branch is `. ngf,second (see Table 8) and, therefore, according to Table 6, an 3 P orjfice in a 1J4 in. union should be used. This will provide a ' tarice of about 420. milinches. In the same manner it is found that ?'es1^ e sec0nd set of risers a resistance of 240 milinches is required and htan 0.70 in. orifice in a 1J4 in. union will provide a resistance of 285 'Inches- 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 volurne 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 Vent --h Overflow and vent 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), thewater 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 355 Heating Ventilating Air Conditioning Guide 1939 of about 32 lb per square inch must be maintained in the expansion ^ , if the water in the highest radiator is to be heated to 225 F without dan? * of boiling. ger The type of expansion tank used in a heating system, whether open 0 closed, has no influence on the operation of the system. The only functic/ 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 riot be less than the tank sizes indicated in Table 10 and in addition provisions must be made for draining it without emptying the system. 8 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 10. Expansion Tank Sizes for Hot Water Heating Systems Tank SizeGallons Equivalent Direct Radiation Installed Sqin Ft Capacitt Direct Radiation Installed m 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 oh 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 an excessive pressure rise above the valve setting. . Chapter 17. Hot Water Heating Systems and Piping A relief valve should be of the diaphragm-operated or gravity-weighted A without guide.wings below the seat. Provision should be made for ^uai 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 rate often provided the tank is of adequate size. It is essential that ^ 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 brandnes 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, i.e., 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 [ess 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 Heating Ventilating Air Conditioning Guide 1939 connection must be nearer the heater than the return connection. In a correct! designed two-pipe system, the pressure in the flow main is higher than that in the retu^' main, and a slight variation in the distances of the flow and return connections from th heater is not material; but it is generally best to have the two connections about eauaU distant from the heater. uuauy In some cases it may be advisable to take the flow connection off the top of the mai and the return connection from the side, but in most cases both connections should beat an angle of 45 deg. This method shortens the lines and substitutes 45-deg ells f,, 90-deg ells. or Preferably, connection of the flow riser to a radiator should be to the upper tappin,, 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 mav then be taken out of the radiator at either end. . y 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 (b) give more beat? 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 to358 358 Chapter 17. Hot Water Heating Systems and Piping . retard circulation. For a given pipe the friction varies approximately as the prevent velocity, and for given fittings, valves, heaters, and radiators, the friction 1.7 pow ^jjjjnately. as the square of the velocity. It is therefore sufficiently accurate vanes app friction in fittings, valves, heaters, and radiators in terms of the friction oTSndard elbow, as shown in Table 3. . . Ia g|ngle radiator located 10 ft above a boiler is connected with a flow and black iron pipe, what is the pressure head maintaining the circulation if the^*ter *n l^e return riser is at 180 F and that in the flow riser is at 200 F? . * found from Table 7, Chapter 2, that 180 F water weighs 60.61 lb per cubic foot and inoV water weighs 60.13 lb per cubic foot. The pressure head is independent of the size fthe pipe. If the two risers were each 1 ft square, the water in the flow riser would l Vh 601-3 lb and that in the return riser would weigh 606.1 lb. Thus the water in the W?um riser would weigh 4.8 lb mdre than that in the flow riser. Consequently, the resulting pressure head is 4.8 ib 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 ip. terms of 190 F water. Such water weighs 60.39 lb per cubic.foot, and to <iJ-ure a pressure of 4.8 Ib 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 0 In the elementary system of Question 3, if tbe radiator dissipates 14,000 Btu per hour, what is the velocity of tbe water in the pipe line, if the pipes are 1 in. in diameter? .What, if thfey 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. From 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. It appears from Table 3 that the friction head in one elbow is ~- , 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 359 Heating Ventilating Air Conditioning Guide 1939 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 willS less than 190 F, the radiator should be larger than the size given in Question 4. 7 Should n 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 used when 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 -- TO)*-* is to (190 -- 70)'-*. This ratio works out to 1.28. 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 sanie in both cases. \ 360 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 MPORTANT considerations in the selection and installation of pipe I 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. . . Nought-Iron Pipe. Wrought-iron pipe is considered to be more corro sion-resisting than ordinary steel pipe and therefore its somewhat higher 361 Heating Ventilating Air Conditioning Guide 1939 first cost can be justified on the basis of longer life expectancy. Wrought iron 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 in. 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 JPIPE 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 in., 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 362 Chapter 18. Pipe, Fittings. Welding ` l- knesses listed. In sizes 14 in. and upward, pipe is designated by its ' utside diameter (O.D.) and the wall thickness is specified. While the demands for pipe for the heating and ventilating industry are sonably well served by the standard-weight and extra-strong pipe, !fmands for pipe for higher pressures and temperatures in industry "suited jn the use of a multiplicity of wall thicknesses for all sizes. Even [n heating installations, the erection of piping by welding was deemed to . Table 1. Dimensions of Welded and Seamless Steel Pipe Nominal Wall Thicknesses for Schedule Numbers PPSSOB Diam. Schedule Schedule Schedule Schedule Schedule Schedule Schedule Schedule Schedule Schedule 10 20 30 40 60 80 100 120 140 160 Yb , y* 3d 7A Wd. lit 3 5 $ 8 10 12 14 0. D. 16 0. D. 18 O. D. 20 0. D. 24 0. D. 30 0. D. 0 40S 0.068* 0.095* 0 S40 0.088* 0.119* 0.675 0.091* 0.126* n 840 0.109* 0.147* 1 050 0.113* 0.154* 1.315 0.133* 0.179* 1.660 0.140* 0.191* 1.900 0.145* 0.200* 2.375 0.154* 0.218* 2.875 3.500 ______ 0.203* 0.216* 0.276* 0.300* 4.000 0.226* 0.318* 4.500 0.237* 0.337* 0.437 5.563 0.258* 0.375* 0.500 6.625 0.280* 0.432* 0.562 8.625 0.250 0.277* 0.322* 0.406 0.500* 0.593 0.718 10.75 12.75 0.250 0.307* 0.365* 0.500* 0.593 0.718 0.843 . 0.250 0.330* 0.406 0.562 0.687 0.843 1.000 14.0 0.250 0.312 0.375 0.437 0.593 0.750 0.937 1.062 16.0 0.250 0.312. 0.375 0.500 0.656 0.843 1.031 1.218 18.0 0.250 0.312 0.437 0.562 0.718 0.937 1.156 1.343 20.0 0.250 0.375 0.500 0.593 0.812 1.031 1.250 1.500 24.0 0.250 0.375 0.562 0.687 0.937 1.218 1.500 1.750 30.0 0.312 0.500 0.625 -------- --..... 0.187 0.218 0.250 0.250 0.281 0.343 0.375 0.437 0.531 0.625 0.718 0.812 0.906 1.000 1.125 1.125 1.312 1.250 1.406 1.437 1.562 1.562 1.750 1.750 1.937 2.062 2.312 -- -......... All dimensions are given in inches. The decimal thicknesses listed for the respective pipe sizes represent their nominal or average wall dimensions'&hd 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 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. 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 363 Heating Ventilating Air Conditioning Guide 1939 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 totai 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 nf 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, arid Table 2. Nominal Weights of Welded and Seamless Steel Pipe Nominal Pipe 8m 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 SCHED. 60 Plain Ends SCHED. 80 Plain Ends 8ched. 100 Plain Ends SCHED. 120 Plain Ends SCHED 140 ` Plain Ends Scan. 160 Plus End# H M % H 1 1M 2" 2 3 3H 4 5 6 8 10 12 14 O. D. 16 0. D. 18 O. D. 20 O. D. 24 O. 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* 14.7* 14.9* 20.8* 19.0* 19.2* 28.6* 25.0* 28.6* 28.8* 35.7. 43.4* 50.9 35.0* 40.5* 41.2* 54.8* 64.4 77.0 45.0* 53.6 55.0 73.2 88.6 108.0 63.3 85.0 107.0 131.0 82.8 108.0 137.0 165.0 105.0 133.0 171.0 208.0 123.0 167.0 209.0 251.0 171.0 231.0 297.0 361.0 19.0 27.1 36.4 60.7 89.2 126.0 147.0 193.0 239.0 297.0 416.0 1.31 1.94 2:85 3.77 4.86 7.45 10.0 14.3 22.6 33.0 45.3 67.8 74.7 105.0 116.0 140.0 161.0 171.0 190.0 224.0 241.0 275.0 304.0 342.0 374.0 484.0 536.0 Weights are given in pounds per linear foot and are for pipe with plain ends except for sizes which art.. 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 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. 364 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 Nouinal Pipe Sot Vs Vs Vs 14 V. l Wi l 'A 2 t)4 3 3K 4. 5 6 8 10 ' 12 14 0. D. 16 0. D. 18 0. D. 20 0. D. Outside Diameteb 0.405 0.540 0.67S 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* o.m* 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 o nos* n i??* o m* 0 151* 0 157* n i5* 0 105* 0 ?Od* 0 775* n 787* 0 306* 0 575* 0 544* n .58.5* 0 441* n 5in* 0.606 n 70? 0.750 <Umeao<M^1?rtl,'^ii,^neSS'3,ilisted IoI the.,fesI?!ctive pipe sires represent their nominal or average wall *Thi an lnc ut^e an allowance for null tolerance of 12.0 per cent under the nominal thickness. with an asterisk.in Schedules 30 and 40 are identical with thicknesses for standard- inPipe former lists1161 ^8ts* t^ose 111 Schedules 60 and 80 are identical with thicknesses for extra-strong The Schedule Numbers indicate approximate values of the expression 1000 x P/S. . 365 Heating Ventilating Air Conditioning Guide 1939 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 Pipe Size (Inches) VL Vt. l 1 Vi m 2 m 3 3H 4 5 6 8 10 12 14 O. D. 16 O. D. 18 0. D. 20 O. D. SCHED. SCHED. 10 20 Plain Plain Ends ' Ends 36.0 41 3 46 5 44.8 51.4 57.9 77.0 Schedule 30 Schedule 40 Schedule 60 Plain Threads Plain Threads Plain ' Knrtft Couplings Ends Couplings F.nris 24.7* 34.3* 43.8* 53.6 61.4 80.5 103.0 25.6* 35.0* 45.0* -- 0.25* 0.25* 0.43* 0.43* 0.57* 0.57* 0.86* 0.86* 1.14* 1.14* 1.68* 1.69* 2.28* 2.29* 2.72* 2.74* 3.66* 3.68* 5.80* 5.82* 7.58* 7.62* 9.11* 9.21* 10.8* ,10.9* 14.7* 14.9* 19.0* 19.2* 28.6* 28.8* 40.5* 41.2* 53.6 55.0 ' 62.2 81.2 103.0 115.0 ............ 54.8* 73.2 87.6 111.0 136.0 0.32* 0.S4* 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 . 104.0 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 fists. ^ . 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: . Lt = Lo [i + a (4oor) + b (w) ] (1) where > Lt = length at temperature t degrees Fahrenheit, feet. Lo = length at 32 F, feet. I = final temperature, degrees Fahrenheit. a and b are constants as given on the next page. ,, 366. 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 fflay 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) Permissible Actual Nominal Outside Diam Sob. In. eter, Variation in Mean Outside Dumeter. In. In. Annealed Hard Drawn WALL THICKNESS, IN. Clam 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 Class Class KLM Vs Vi 0.500 0.0025 0.001 0.049 0.004 0.035 0.0035 0.025 0.0025 0.269 0.198 0.144 0.625 0.0025 0.001 0.049 0.004 0.040 0.0035 0.028 0.0025 0.344 0.285 0.203 1 Vi 0.875 0.003 0.001 0.065 0.0045 0.045 0.004 0.032 0.003 0.641 0.455 0.328 1.125 0.003S 0.0015 0.065 0.0045 0.050 0.004 0.035 0.0035 0.839 0.655 0.464 lVi 1.375 0.004 0.0015 0.065 0.0045 0.055 0.0045 0.042 0.0035 1.04 0.884 0.681 iy2 1.625 0.0045 0.002 0.072 0.005 0.060 0.0045 0.049 0.004 1.36 1.14 0.94 2 2.125 0.005 0.002 0.083 0.005 0.070 0.005 0.058 0.0045 2.06 1.75 1.46 VA 2.625 0.005 0.002 0.095 0.005 0.080 0.005 0.065 0.0045 2.92 2.48 2.03 3 3.125 0.005 0.002 0.109 0.005 0.090 0.005 0.072 0.0045 4.00 3.33 2.68 3H 3.625 0.005 0.002 0.120 0.005 0.100 0.005 0.083 0.005 5.12 4.29 3.58 4 4.125 0.005 0.002 0.134 0.006 0.110 0.005 0.095 0.005 6.51 5.38 4.66 5 5.125 0.005 0.002 0.160 0.006 0.125 0.006 0.109 0.005 9.67 7.61 6.65 6 6.125 0.005 0.002 0.192 0.006 0.140 0.006 0.122 0.005 13.87 10.20 8.91 From Standard Specifications for Copper Water Tube of the American Society for Testing Materials, AS.T.M. Designation B8S-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- 367 Heating Ventilating Air Conditioning Guide 1939 tinued turning in the threaded joint may in time result in a leak, par I ticularly when the pressure is high. The amount of elongation which a 1 i gth when hot from the length when cold shall not disarrange the normal and orderly provisions for drainage of the branches. swivel joint can take up is controlled by the length of the swing employed and by the lateral displacement which is permissible in the long pipe runs. . It is especially necessary with light-weight radiators so to anchor the icing and so to give it freedom for expansion that no strain therefrom *hall be allowed to distort the radiators. When expansion strains from Probably the most economical method of providing for expansion of piping in a long run is to take advantage of the directional changes which the pipes, are permitted to reach these light metal heaters they usually emit sounds of distress which are exceedingly troublesome. : must necessarily occur in the piping and proportion the offsets so that sufficient flexibility is secured. Ninety-degree bends with long, straight Table 6. Thermal Expansion of Pipe in Inches per 100 Ft* tangents in either a horizontal or a vertical plane are an excellent means {For superheated steam and other fluids refer to temperature column's 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 SiTUBlTSD SrBAM Elongation in Inches per 100 FT FROm - 20 F cp Saturated Steam Elongation in Inches per 100 FT FROM --20 F UP Pressure Tem ygftnrm Pounds perature lodttf of Hg- Degrees Square Fahren Inch heit Gage CastIron Pipe Steel Pipe Wrought Iron Pipe Copper Pipe Pressure Pounds ,, per Square Inch Gage Tem perature Degrees Fahren heit CastIron Pipe Steel Pipe Wrought Iron Pipe Copper Pipe -20 0 0 0 0 664.3 500 3.847 4.296 4.477 6.110 0 0.127 0.145 0.152 0.204 795.3 520 4.020 4.487 4.677 6.352 20 0.255 0.293 0.306 0.442 945.3 540 4.190 4.670 4.866 6.614 40 0.390 0.430 0.465 0.655 1115.3 560 4.365 4.860 5.057 6.850 29.39 60 0.518 0.593 0.620 0.888 1308.3 580 4.541 5.051 5.268 7.123 Offset U bend 28.89 27.99 26.48 80 100 120 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 2041.3 600 4.725 5.247 5.455 7.388 620 4.896 5.437 5.660 7.636 640 5.082 5.627 5.850 7.893 Fig. 1. Measurement of L on Various Pipe Bends 24.04 _______ 140 20.27 ........ 160 1.051 1.209 1.265 1.794 2346.3 1.200 1.368 1.427 2.008 2705 660 5.260 5.831 6.067 8.153 680 5.442 6.020 6.260 8.400 j is relatively complicated1. The following approximate method, however, 'j has been found to give reasonably good results and is deemed to be 14.63 6.45 _____ 180 200 2.5 220 10.3 240 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 2.960 700 5.629 6.229 6.481 8.676 720' 5.808 6.425 6.673 8.912 740 6.006 6.635 6.899 9.203 760 6.200 6.833 7.100 9.460 it sufficiently accurate for most heating work. ij Fig. 1 shows several types of expansion bends commonly used for 20.7 260 34.5 280 52.3 300 1.931 2.183 2.279 3.189 2.085 2.350 2.465 3.422 2.233 2.519 2.630 3.665 780 6.389 7.046 7.314 9.736 800 6.587 7.250 7.508 9.992 820 6.779 7.464 7.757 10.272 taking up thermal expansion. The amount of pipe, L, required in each of iJ these bends may be computed from the following formula: Jj 74.9 320 103.3 340 138.3 360 2.395 2.690 2.800 3.900 2.543 2.862 2.988 4.145 2.700 3.029 3.175 4.380 840 6.970 7.662 7.952 10.512 860 7.176 7.888 8.195 10.814 880 7.375 8.098 8.400 11.175 1 180.9 380 2.859 3.211 3.350 4.628 900 7.579 8.313 8.639 11.360 L = 6.16 ^ D A (2) | 232.4 400 3.008 3.375 3.521 4.870 920 7.795 8.545 8.867 11.625 293.7 420 3.182 3.566 3.720 5.118 940 7.989 8.755 9.089 11.911 366.1 440 3.345 3.740 3.900 5.358 960 8.200 8.975 9.300 12.180 where . . 451.3 460 3.511 3.929 4.096 5.612 980 8.406 9.196 9.S47 12.473 ' . L = length of pipe, feet. - ' )' ; j, ^ 550.3 480 3.683 4.100 4.280 5.855 1000 8.617 9.421 9.776 12.747 D = outside diameter of the pipe used, inches. A = the amount of expansion to be taken up, inches. ^ ^ "From Piping Handbook, by Walker and Crocker. This table gives the expansion from -20 F to the ^ j temperature m question. To obtain the amount of expansion between any two temperatures take the r v attterence between the figures in the table for those temperatures. For example, if a steel pipe is installed at a temperature of 60 F and is to operate at 300 F. the expansion would be 2.519 -- 0.593 = 1,926 in. 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 PIPE THREADS 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 All threaded pipe for heating and ventilating installations uses the American Standard taper pipe thread which is made with a taper of l.in or with arcs of circles having radii five to six times the pipe diameter. Tv,mejSUret^ -n tlie diameter of the pipe so. as to secure a tight joint. 1 nreads of fittings are tapped to the same taper. The number of threads ru All risers must be anchored and safeguarded so that the difference in Per'nch varies with the different pipe sizes. All threaded pipe should be made up with a thread paste suitable for the service under which the; Piping Handbook', by Walker and Crocker, and A Manual for the Design of Piping for Flexibility, by the Use 01 Graphs, by E. A. Wert, S. Smith, and E. T. Cope; published by The Detroit Edison Company- pipe is to be used. .. 368 . 369 Heating Ventilating Air Conditioning Guide 1939 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 pietB 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 3}^ 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 lb (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, 370 Chapter 18. Pipe, Fittings. Welding aV have the smaller connection tapped eccentrically to permit free drainof 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- nression 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. Wfhile no effort has been made to standardize dimensions of flared tube fittings, manufacturers have quite generally used S.d .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 SOIDER-TYPE FITTING FIARED-TUBING 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.A 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 Heating Ventilating Air Conditioning Guide 1939 threads are used. To facilitate drainage, some elbows have the thread tapped at an angle to provide a pitch of the connecting pipe of jn>. 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 J^-inch raised face! The standard facing for steel flanged fittings for 150 and 300 lb is a }^f6-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 temperature 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 ejectric arc welding, both of- which are com monly .used to produce acceptable welds. , " 372 Chapter 18. Pipe. Fittings. Welding 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 Tbbs, and Crosses (Straight Sizes) for 125 Lb Cast-Iron Screwed Fittings ELBOW A Nominal Pits Size Center to End, Elbows, Tees and Crosses c B B. Center to End, 45 Deo Elbows Length or Thread Min. Width or Band, Min. P .G H Inside Diameter ' or Fitting Min. Max Thickness, Min. Outside . Diameter... or Band. Min. X X H X 1 iX ix 2 zX 3 iX 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 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 10763 13.12 15.47 16.94 19.30 AH dimensions given in inches. all of the responsibility. Thus the employer should select his welding mechanics with good judgment, provide them with first-class equipment and tools, arrange for their training and use of acceptable workmanship standards, and at regular intervals subject their work to prescribed tests, industry will not accept the employment of mechanics of undetermined ability nor on the basis of past experience. Neither does industry accept tne statement that a weld is only as good as the workman who makes it. ine control Codes now in process of adoption will be the law governing Heating Ventilating Air Conditioning Guide 1939 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 f short and long radius flanged fittings. Some typical types of these fittings am 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 Nominal Pm SnEA-b A AA ` Center-to Face Tees and Crosses b-c Face to Face Tees and : Crosses b-c Diameter . or Flange . Thickness or Flanqb, ; Min. Metal . Thickness or Body, Min. . i IK i ik 2 2K 3 3K 4 5 6 8 10 12 14 O.D. 16 0:D. 18 O.D. 20 O.D. 24 O.D. 30 O.D. 36 O.D. 42 O.D. 48 O.D. 3K ' ' 7 4K 3K 4 i m .m 8, 5 Kb % He Kg ` h* " V* 4K : 9 6 % He 5 10 7 Kb 5K 6 11 12 m\ 8K M Kb HHe 6K 13 9 15Ae H m, 8 15 16 10 11 1He - 1 K He 9 18 13K IK ' K 11 22 16 1He K 12 24 '' 19 IK 1He 14 28 21 IK He 15 30 23 K 1He 1 16K 33 25 1He IK 6 18 36 27K 1 'He IK 22 44 32 IK IK 25 50 38K 2K IKe 28 56 46 2K IK 31 62 53 2K ilK 34 . 68 59K 2K 2 Ail 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, ire made in two lengths, depending on the size of the outlet. eTees 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. - -. ' 374 90 DEG. LONG RADIUS 45 DEG. reducing side outlet Nominal Pipe Sob A Center to Face Elbow b-o-d B Center to Face Long Radius Elbow b-o-d c Center to Face 45 Deg Elbow e Diameter or Flange Thickness or Flange, Min. Metal Thickness or Body, Min. i IK IK 2 2K 3 3K 4 5 6 S 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. . 3K 3M 4 4K . 5 5K 6 6K 7K 8 9 11 12 14 15 16K 18 22 25 28 31 34 5 5K 6 6K 7 7K 8K 9 10K UK 14 16K 19 21K 24 26K 29 34 41K 49 56K 64 IK 2 2K 2K 3 3 3K 4 4K 5 ,5K 6K 7K 7K 8 8K 9K 11 15 18 21 24 4K 4K 5 6 7 7K 8K 9 10 11 13K 16 19 21 23 K 25 27K 32 38K 46 53 59K He K He K Kb K Kb Kb Kb 1 IK 1Kb IK IK 1Kb 1Kb 1 Kb IK 2K 2K 2K 2K Kb Kb Kb Kb Kb Kb Kb K K Kb K K Kb K 1 1Kb IK IK 1Kb i'K ^Kb 2 "Size of all fittings listed indicates nominal inside diameter of port. enrrbjy "S"8 elbows ?nd fide outlet elbows carry same dimensions center to face as straight size elbows corresponding to the size of the larger opening. as rivSTfTM fe* elbow's, ranging from 1 to 45 deg, inclusive, have the same center to face dimensions fac* Him.TM- des elbows and those over 45 deg and up to 90 deg, inclusive, shall have the same center to line flow r?.??3 X *`ve" loJ 80 deg elbows. The angle designation of an elbow is its deflection from straight uue now and is the angle between the flange faces. ide outlet elbows shall have all.openings on intersection center-lines. 375 Heating VentiijATing Air Conditioning Guide 1939 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 valve is open or closed, although space limitations may prevent its "*c -phe globe valve is less expensive to manufacture than the gate US) e but its peculiar construction offers a high resistance to flow and vaJV 'event complete drainage of the pipe line. These objections are of jocular importance in heating work. " rheck 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 1 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 i..Tee 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 valyes 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 376 NOMINAL' Pips . Sos Diameter or Fla noe Thickness . or Flo. Min. Diameter or Hub 0 0 .y Hub Diam. Beginning or Champer B Length Thru Hub Y Diam. roa Standard Pipe A 1 ix lA 2 2A 3 3A 4 5 6 8 10 12 14 0. D. 16 0. D. 18 0. D. 20 0. D. 24 0. D. 4)4 4)4 5 6 7m m 9 10 11 13)4 16 19 21 23)4 25 27)4 32 Me A Me A 'Me M 'Me 'Me 1Me 1m 3Me m1mm14ee 'm'Me 1'Me 2Me 2Me 3Me 3Me *x *'Me 5Me 6Me 7Me 9'Me 12 14A ISM 18 19)4 22 26)4 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 2Me 2M 2Me vA 2M 2M 2 'Me 3 3)4 3)4 4 4 4)4 5 5 5)4 S'Me 6 1.05 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 sy 3'A 3A 4M s'A 6 7 7)4 m 9)4 11M 14M 17 18)4 21)4 22M 25 29)4 . No. OP Bolts 4 4 4 4 4 4 8 8 8 8 8 12 12 12 16 16 20 20 8izb OP Bolts A A A A A A A A M M M A A l l 1)4 1)4 1)4 AU dimensions given in inches. A raised face of 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 back of the chamfer in order to reduce the heat transfer while welding. the two sides of the valve. The two principal kinds of check 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 377 Heating Ventilating Air Conditioning Guide 1939 handles are often supplied to indicate the relative opening of the valve' any position. Standard roughing-in dimensions for angle-type v=i. are given in Table 12. P alves Automatic control of steam supply to individual radiators can ^ Table 11. Proposed Dimensions of Steel Welding Neck Flanges for Maximum Steam Service Pressure of 300 Lb per Sq In. (Gage) at a Temperature of 750 F Nominal Pip Size *2 2% 3 3% 4 5 6 8 10 12 14 O. D. 16 O. D. 18 O. D. 20 O. D. 24 O. D. Diam. or Flange Thick ness or Flange Min. 0Q Diam. or Hus X Hub Diam. Beginning or Chamfer H 6% 8K 9 10 11 12M 15 17M 20M 23 25M 28 30% 36 % 3%e 1 3% m 4% 1%6 5M m 3% 1% 7 IHe m mm i % 12% 2 14%, 2% 16% 2H 19 2% 21 W. 23% m 27% 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 Thhu Hub F 2% 3 3% 3iKfi 3% 3Vs 3% 4% 4% 5% 3% 5% . 6% 6% 6% Diam FOB Standard Pipe Diam. ros Extra Strong Pipe Diam. or Bolt Circle AA 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 1.94 2.32 2.90 3.36 3.83 4.81 5.76 7.63 9.75 11.75 5 3% 6% 7% 7Vs 9% 10% 13 ISM 17M 20M 22M 24M 27 32 No. or Bolts 8 8 8 8 8 8 12 12 16 16 20 20 24 24 24 Sob or. Bolts M % % % ZA % % r iM iy IK i% i% iH *For sizes below 2 in. use dimensions of 600 lb flanges. . All dimensions given in inches. A raised face of V6 in. is included in thickness offlange minimum. is recommended that the taper of the hub should not exceed 6 deg for a reasonable distance back of the chamfer m 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 He-in. hole through the web forming the seat to insure sufficient circulation to prevent freezing when the valve is closed. Valves made particularly 378 --s'. Chapter 18. Pipe, Fittings. Welding hot water heating systems are of less complex design, one type (or us *" a sjmpJe butterfly valve, and another of a quick opening type ^"which a part in the valve mechanism matches up with an opening Sn the valve body. ... ., I one-pipe steam-heating systems, automatic air valves are required fiie radiators. Two common types of air valves available are the 3t imm type and the straight-pressure type. Vacuum valves permit the 'llsion 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 c j3-l Size or Valve M % l 1M 1M 2 Tolerance Dimension A Steam and Hot Water Angle Valves and Union Elbows Effective January 1,1926 2M 2M 3 3M 3M 4M M Dimension a Modulating Valves . ' Effective January 1, 1926 Dimension A Return Line Vacuum Valves Effective . January 1,1925 2M 2M 3 3% 3M 4M M 3M -- _____ --------' -- _____ ' ---. .. All dimensions given in inches. ' Connecting ends shall be threaded and gaged as to threading according to the American (Taper) Pipe Thread Standard. AS.A. No. B2--1919. 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 Volr 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 379 . Heating Ventilating Air Conditioning Guide 1939 internal pressure within the radiator closely approaching atmospheri At such times, the vacuum valve will not vent the system any mo rapidly than the ordinary type. Automatic air valves are provided with* . float to close them in case the radiator becomes flooded with water becau^ 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 . -i 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 i surfaces are in contact with gas-laden condensate. . k . Another possible cause of corrosion is a flow of'electric current some- ^ times resulting from faulty electrical circuits which should be corrected. !i Electrolytic corrosion also may occur because of the presence of two dis- " similar metals, such as brass and iron, but the condensate in practically `i 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, an attempt should be made to minimize such leakage. \ . S I. V <i { 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. ; f | / 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 {Keating and Ventilating, May, 1933). A.S.H.V.E. Research Report No. 983--Corrosion 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). A.S.H.V.E. Research Report No. 1037--Corrosion Studies in Steam Heating systems, by R. R. Seeber, F. A. Rohr- man 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. Healing, Piping and Air Conditioning, June. 1937, p. 387). . 380 * ; Chapter 18. Pipe. Fittings. Welding amount of gas in solution depends upon the partial pressure of that T the atmosphere above the surface of the solution, in accordance ^h'the well known physical law of Henry and Dalton*. The exact 1'cation of this law, however, assumes equilibrium conditions which dP not always exist under the flow conditions prevailing in a heating ^Distinction should be made between corrosion in heating systems proper d in the condensate discharge lines from other apparatus using steam, an. as water heaters, kitchen equipment, and sterilizers. Experience has shown that in heating systems the partial pressures of the gases do ot 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 District Heating Associa tion has perfected a corrosion tester for measuring the inherent corrosive ness pf 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 steamsupply 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 *Sotrie Fundamental 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). 31 Heating Ventilating Air Conditioning Guide 1939 this type of corrosion than the ferrous metals, and considerable attentio is now being given to corrosion-resistant linings for. ferrous pipe. Cast0 iron pipe, sometimes alloyed with other metals, also deserves mn 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 O 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 # 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. V25-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 9 What fittings are.generally used for threaded connections in low pressure heating systems? .. ' Cast-iron 382 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 of 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. 'Ail figures and much of the engineering data which follow are from University of Illinois, Engineering Experiment Station Bulletins Nos.* 141, 188. 189 and 246; Warm Air Furnaces and Heating Systems, by A. C. Willard. A. P. Kratz. V. S. Day. and S. Konzo. . 383 Heating .Ventilating Air Conditioning Guide 1939 7. Size of furnace necessary to supply the warm air required to overcome the he,/ loss from the building. This size should include square inches of leader pipe area whS, the furnace must supply. It is also desirable to call for a minimum bottom fire-iS diameter in inches, which is the nominal grate diameter. .8 Area and dimensions in inches of chimney and smoke pipe. If an unlined chimnev 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 SITES 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 findesign 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: Leader areas for first floor, square inches = jjj = approximately 0.009// (1) H Leader areas for second floor, square inches = -- approximately 0.006// (2) Leader areas for third floor, square inches- = ^qq = approximately 0.005H (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 = -gg- = approximately 0.012H (4) 'H Leader areas for second floor, square inches = = approximately 0.007H (5) Leader'areas for third floor, square inches = = approximately 0.006H (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. 384 Chapter 19- gravity Warm Air Furnace Systems A deviation from these conditions requires a modification of the conused in Equations 1, 2, and 3. The temperature drop in leaders of ^dus lengths at three different register temperatures is shown in Fig. 2, V3d should be used to obtain new register temperatures, lower than 175 F, 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 X to 3 nor should leaders less than 8 in. in diameter be used. It J --A "--"".mji nraftirp in snecifv 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 is1 required by the application of the equations, smooth transition fittings, and duct insulation are recommended. 385 X" Heating Ventilating Air Conditioning Guide 1939 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 vi, agisters used for discharging warm air into the rooms should have f h6or net area not less than the area of the leader in the same run of a. The free area should be at least 70 per cent of the gross area of ^'register. No upper-floor register should be wider horizontally than h wall stack, and it should be placed either in the baseboard or side wall, Tthis can be done without the use of offsets; First-floor registers may be - -i----- .u^crvl or floor tvne. with the former location preferred. High 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 3H in. For such requirements either multiple stacks, or stacks having larger cross-sectional area (placed in 6 in. studding spaces) will be required. . 386 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 387 Heating Ventilating Air Conditioning Guide 1939 the air stream must change direction or shape, streamline fittings should be employed. Horizontal ducts should pitch at least }/$. in. per 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 Illinois1, resulted in the following conclusions: Fig. 4. Heating Effect at Registers for Various Stacks with 10-in. Leader 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 388 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. . . of Warm Air Furnaces and Heating Systems. Part IV. by A. C. Willard. A. P. Krat*, and V. S. Day (University of Illinois, Engineering Experiment Station Bulletin No. 189). 389 Heating Ventilating Air Conditioning Guide 1939 _ The grate area will depend on several factors of which four are ve important. First of all, the air temperature at the register for wh'T the plant has been designed must be determined. Usually, this temper ture is taken at 175 F. Second in importance is the combustion rat* which must always correspond with the register air temperature, as is show*' by a set of typical furnace performance curves (Fig. 7) for a cast-iro" circular radiator furnace with a 23 in. diameter grate and 50 in. diamete' casing. The third factor is efficiency, which is a function of the <x,m 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 > . , , .rnc,rp is 62 per cent. Under this condition the capacity at the 0f;the *u. t per square foot of grate is 43,200 Btu per hr and per .furnace, do orate is 300 Btu per hr, the required area of the grate in ^ inches in this case will be -|jj^ = 0.0042 H. It should be , .jjat a larger grate area is required if the furnace is to deliver air "fa lower register temperature. a_. ..mlral oerformance curves shown in Fig. 7 are not applicable to <3 J No. 3 ------No pitch No. 5 No. 6 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 11^- 0,03411. 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 390 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: R= GXftX/XE, XEiX 0.866 144 (7) Standard Code Regulating the Installation of Gravity Warm Air Heating Systems in Residences. This code has been sponsored by the National Warm Air Heating and Air Conditioning Association, the National Association of Sheet Metal Contractors, and the American Society of Heating and Ventilating Engineers. It is recommended that the installation of all gravity warm air heating systems m 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, 60 W. Broad St., Columbus, Ohio. 391 Fig. 9. First-Floor Plan, Research Residence 392 Chapter 19. Gravity Warm Air Furnace Systems where . . - q - grate area, square inch. p = combustion rate, pound coal per square foot o{ grate per hour. . f = 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. 0866 = factor of safety to allow for contingencies under service conditions such as accumulations of soot and ashes, ineffective firing methods, etc. fl = 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 tests* 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: . G= ________________ 144 X H___________ P X / X , X j X~ 0.866 [I + 0.02 (R-20)} 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. G = 7.5 X __ 12,790 X 0.55 144 X R X 0.75 X 0.866 [1 + 0.02 (R-20)J (9) G = 0.004205 [1 + H 0.02 (R-20)] GO) 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 an 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 tUinois. Engineering Experiment Station Bulletin No. 246. by A. C. Willard, A. P. Kratz. and & Konao. Chapter X, pp. 126-146. `Loc. Cit. Note 3. , 393 X Heating Ventilating Air Conditioning Guide 1939 394 Ja a n L Chapter 19. Gravity Warm Air Furnace Systems h Warm Air Research Residence of the National Warm Air Heating Air Conditioning Association erected at the University of Illinois6. Leaders, Slacks and Registers. (Direct Method) Living Room, 1st floor: 17 250 -5- 1U = 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, Snd floor: 15 030 -5- 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. ' p._;qter area = 90 sq in. net area. Gross area = net area -5- 0.7 = 12 X 12 g . . 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. (Code 7 Method. See Art. 3, Sec. 1, 2, 3) Living Room(Glass = 90, Net wall =405, Cubic contents - 2405) , / 90 , 405 , 2405 \ . ... Leader = .(i2 + 60+wy9 = 1S5sq,n- .. Register, same as Direct Method. Owner's Room (Glass 68, Net wall = 394, Cubic contents = 2275) . ,Leajder = (/ 6V82 +, 3W94+, W2275A) .6 = 90 Sq m. ` 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 floor not heated. TLoc. Cit. Note 3. University of Illinois, Engineering Experiment Station Bulletin No. 120, p. 129. 395 Heating Ventilating Air Conditioning Guide 1939 Chapter 19. Gravity Warm Air Furnace Systems Table 1. Summary of Data Applied to Waem Air Research Residence Rooms From Chapter 7 Estimating Heat Losses Btu Heat Losses H First Floor Living_______ Dining.______ Breakfast___ Kitchen_____ Sun_________ Hall and stair Second Floor Owner's_____ S. W. Bed.__ Bath_____ N. Bed.. ___ Third Floor E. Bed... .. W. Bed______ 17250 6810 2300 9210 25710 12570 15030 9800 2450 14800 8220 8220 Leader Area Sq In. Stack Area Sq In. 0.7 X LA = 0.0097? 155 61 21 83 230 113 = 0.0067? 90 59 15 89 = 0.0057? 41 41 __ _ _ .... _ _ 63 41 10 62 29 29 Leader Diameter Inches Stack Size Net ReSgiziseter Gross ---- 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 5 X 12 9 314 X 12 8 3 X 10 11 or 12 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 or oil burners are running and to stop automatically when the burners shut down. The booster equipment is most 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 identical8. University of Illinois, Engineering Experiment Station Bulletin No. 141, p. 79, and No. 246. PROBLEMS JN PRACTICE 5 1 What may prohibit the use of a gravity warm air system in a large house having several exposed wings? L $ [' 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 f 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 9 A first story dining room has a calculated heat lossof 12,000 Btu per hour. a. What size leader pipe should be used for 175 F register air temperature? b. What size register? 396 - Leader area = = 103.1 sq in. Use leader with diameter of 12 in. 108 J 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 = ^qq ' = 60 sq in. Use leader with diameter of 9 in. b Stack area = 0.7 X 60 -- 42 sq in. Use stack 3^ in. by 12 in. c. Register gross area = Jy = 85.7 sq in. Use register 8 in. by 12 in. 4 g 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. Corubustion rate = 7.5 lb per sq ft per hr. ftatio 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 9 Name the items involved in the design of a furnace heating system, o.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. t. 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 9 Discuss the design features of recirculating ducts. a. Their area should be equal to or greater than that of the supply ducts. b. 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. . 397 Heating Ventilating: Air Conditioning Guide 1939 e. The return line should be pitched downward toward the furnace. It should b* designed to minimize friction. e- /. The top of the shoe or boot should never be above the grate level. 8 t Discuss the use of a booster fan. What effect has a booster fan at lo 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. Chapter 20 mechanical warm air furnace SYSTEMS Furnaces, Fans and Motors, Sound Control, Sprays and Filters, Air Distribution Design, Automatic Controls, Design of 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 the difference 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 sprays 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. 5 s `See University of Illinois, Engineering Experiment Station Bulletin No. 266 by A. P. Kratz and S. Konzo or details of tests conducted in Warm Air Research Residence. f v. 398 Heating Ventilating Air Conditioning Guide 1939 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. 8 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 grafe 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. It 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 combustion 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 sheet iron liners, extending from the grate level to the top of the furnace and spaced from 1 in. to lj'f! 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 400 Chapter 20. Mechanical Warm Air Furnace Systems , many manufacturers recommend the use of special baffles to restrict *hfree area within the casing and to force impingement of the air against h heating surfaces. The method of making these baffles for furnaces Mn horseshoe radiators and for furnaces with back crescent radia nsillustrated 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 A. Lintr, 1 in. from casing. B. Hole to vent baffle. C. Baffle, dosed top and bottom. D. Outer casing. 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. .V 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 401 Heating Ventilating Air Conditioning Guide 1939 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. 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). FILTERS 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 orifes. 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). 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 mixes with the cold air dropping off from the exposed walls. This may be accomplished by the use of a supply register placed closeto an outside wall in such-a position that thewarm air sweeps Chapter 20. Mechanical Warm Air Furnace Systems the cold wall surface. The ducts leading to supply registers which are ` located on 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 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 bf.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- taes over the face area of the. register by, means of diffusers, are illustrated' r`8- Merely to use a larger'register may not result.;in materially reduced velocities unless diffusers are used. ........ ' .... v 'Loc. Cit. Note 1. ' `s 403 Heating Ventilating Air Conditioning Guide 1939 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 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 Chapter 20. Mechanical Warm Air Furnace Systems To have a sufficient supply of heat available at all times to avoid lag when the mniii 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. 7 To provide quick response to the thermostat, with protection against overrun. S. 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 burners. This location ^Sjd 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. Fig. 4. Diffusers in Transition Fittings to Equalize Velocities Through Register Faces 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 the equiva lent round pipe size in the case of rectangular ducts. 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 fire 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. t 'Automatic Controls for Forced-Air Heating Systems, by S. Konzo and A. F. Hubbard (A.S.H.V.E. Transactions, Vol. 40, 1934. p. 37). c 404 Squeeze Fig. S. Three Types of Dampers Commonly Used for Trunk and Individual Duct Systems . 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. 3. A protective limit control located in the bonnet to shut down the system inde pendently of the thermostat if the bonnet temperature exceeds 200 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. 405 X Heating Ventilating Air Conditioning Guide 1939 Chapter 20. Mechanical Warm Air Furnace Systems . 4. Determine equivalent length of duct for each register, allowing 10 diameters f straight pipe as equivalent to each 90 deg elbow having an inner radius not less than th diameter of the round pipe or the depth of the rectangular pipe. ne 5. Select a value for temperature of the air at the furnace bonnet. It is customarv to use some value lying between 150 to 165 F. Use lower value if larger number of ai recirculations is desired. It is recommended that the number of air recirculations should be in excess of 5 per hour. 0 6. Determine approximate value of temperature reduction in each duct caused bv 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 leneth* up to approximately 60 ft. s 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: ' ' n= H V 60 X 0.24 X d {I, - 65) 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. tz = 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: Q = H X Factor (2) in which the values of the Factor may be obtained from Table 1. 9. Determine register size from the air volume delivered to each room by the following formula: . i Free area of register, square feet = -2- (3) AH able 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 fpm. High sidewall = not less than 600 fpm. ................. ` 10 Duct systems for forced-air installations may consist of either trunk systems or individual duct systems. r nk Systems. Determine duct sizes and friction losses as outlined in Chapter 29, that for residence applications the velocities in the main duct and in the various tj,e system should approximate the values recommended in Table 2. ^Individual Duct Systems. An individual duct system is one having separate ducts ndine from the heating unit to each register. In designing such a system select first fhduct having the greatest equivalent length. Select a reasonable velocity using Table 9sa euide. From friction chart on page 584 determine unit friction loss per 100 ft of i 3 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. Table 2. Recommended Velocities Through Ducts and Registers . Description Low Velocitt Ststbh (ppm) Medium Velocitt Stbtem . (ppm) - Hios Velocitt ` Ststsm ' (ppm) .. Main ducts.......................... .................-- Branch ducts....... .................................... Wall stacks............................................... Baseboard registers (max.).............. Wall registers above 5 ft (min.)._....... 500 450 350 300 500' . 750 600 500 350 550 itioo ' : 750 : 600 400 600 Gross area of register, square feet -- Free Area. (4) 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 fit where - . .. ' used in the longest duct and to balance the system by employing dampers in the shorter ducts. . ... r,.: , .() '^ required air volume, cubic feet per minute. Return duct systems are designed making use of the same principles as those used in !Jii V = velocity at register face, feet per minute. : . R = ratio of free area to gross area of register. : 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 1. Factors Corresponding to Register Temperature for Equation 2 .. ... - Register Temperature . , . Factor . - : :: 110 120 . 130 140 : .- 150 : . 3 160 170 : 0.0221 0.0184 0.0158 0.0140 0.0125 0.0114 : 0.0105 11. Determine frictional resistance in: o. 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. .... v 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 ^ 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 406 Heating Ventilating Air Conditioning Guide 1939 fan will be capable of delivering air against pressures that may not have been foresee during the design of the duct system. ^eo 12. Select a furnace capable of delivering heat at the register outlets equal to th total heat loss of the structure to be heated. e The following formula may be used for coal burning furnaces: where H G= fXpXEi X . [1 + 0.02 (R - 20)] (5) 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. Ei = 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 5, Chapter 9). p = 7.5 lb. Ei = 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 be added to the normal heat loss of the building to determine the load which the heating plant must carry through the warming-up process, ft 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 manufacturer's Btu ratings of furnaces designed for exclusive use with oil, and select a burner with liberal excess capacity. ,N 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 formifla: where H ft = 0.9 H = total heat loss from building, Btu per hour. R = official A.G.A. output rating of the furnace, Btu per hour. (6) 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: 7 = 1.59 H (7) 408 Chapter 20. Mechanical Warm Air Furnace Systems where / = Btu per hour input. . ' 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 f system Specify controls including location of all thermostats. Arrange for proper mtrol 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 furnishings.. Temperatures and relative humidities should be governed within the 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 409 / Heating Ventilating Air Conditioning Guide 1939 . Chapter 20. Mechanical Warm Air Furnace Systems h- h this latent heat of evaporation can be taken, such heat is supplied . which ajf There is, therefore, a trend in present practice toward ^T'ne the water in addition to heating the air. Equipment for doing if' may make use of sprays, or it may take the form of water circulating f olaced within the combustion chamber and connected by pipes to c humidifier pans where a constant water level is maintained by some Separate float device. (See Chapter 25.) Snrays for residence systems may be provided in separate housings be installed on the inlet or outlet side of the fan, or they may be tecral with the fan construction. They operate at water pressures of -f?om 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. . Sprays 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. Sprays used in connection with commercial'or heavy duty plants should be a regulation type of commercial spray. Residence Requirements The principles underlying humidity requirements and limitations for residences are summarized in University of Illinois Bulletin No. 2304, as follows: " 1. Optimum comfort is the most tangible criterion for determining the air conditions within a residence. . 2. An effective temperature of 65 deg6 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, arid 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 conclusions were drawn from the experimental results reported in the aforementioned bulletin: . 1. None of the typesof 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 huniidity in a residence similar to the Research Residence when the outdoor temperature approximated zero degrees Fahrenheit. . <Sre 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. ' ... ....... i . . . .. . ; . -. .. 411 Heating Ventilating Air Conditioning Guide 1939 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 21 and 23). 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. T 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. ' A.S.H.V.E. Research Report No. 947--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)! A.S.H.V.E. Research Report No. 979--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). 412 L. 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 i value of from 65 to 70 F was found satisfactory. 3 Determine indoor cqnditions 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 21). . 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 ind 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. ., S. 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 24. 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, haring 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 furaace 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: r _ ________ 225,000 ' ,. , , 12,000 X 7.5 X 0.65 X 0.85 ~ 4 53 sq ft of grate area' , A furnace having at least 4.5 sq ft of grate area should therefore be selected. Why should secondary surface be designed for easy cleaning? IIcomjU3tin `s nt perfect, soot is formed immediately above the fire and is apt loiorm 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 zSL, owjn these to form an insulation between the hot gases of combustion and the Wrtii I furn!?ce; consequently, these should be readily cleaned. If the passages are ai^e largel.y self-cleaning of ash, but provision should be made for easy and ough cleaning of the collection chamber below them. 413 Heating Ventilating Ain Conditioning Guide 1939 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 k baffles of one form or another to bring it in contact with the hot surfaces so it will sZ pass through the casing unheated. On the other hand, if the air is held against a h0t surface too long it might become overheated, for the average register temperature e% fan system should not exceed 120 F. QTi a 4 What practical points should be observed in designing a fan system in 0pj to eliminate noise? rQer 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 sprinw material according to the principles given in Chapter 30, provided, of course, that such insulation is of value. ' 01 d. See that the air velocity is not too high in the ducts. Properly designed splitters fo the elbows will avoid high velocities at the turns in cases where the velocity through the ducts themselves is not too high. e e. Use canvas connections between the ducts and any running equipment. /. Be sure the ducts have a relatively smooth interior and are rigid. 5 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 bum as gases, and as much as 60 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 4 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. 12oo Air-pass velocity = --= 400 fpm. o Air-pass area = --= 4 sq ft = 576 sq in. 7 0 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) Area of air pass .. . 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. - .- , ,, ' 40.4 - 30.0 eo. . , Gap = --,, ,--- = 5.2 in. = approximately 5J4, in. .. Chapter 21 CENTRAL SYSTEMS FOR COMFORT AIR CONDITIONING Types of Systems for Heating, Humidifying, Cooling, Dehumidifying with Modifications, Design Details, Load Calcula- 1 . tions. Selection of Equipment ACENTRAL system for comfort air conditioning includes a central fan with complete supply and recirculating duct system which is designed to serve one or more conditioned spaces from one central appa ratus. The air conditioning equipment includes the heating and cooling coils, humidifying and dehumidifying apparatus, air cleaning equipment, and the controls, all designed so that the air introduced to the space will maintain the desired temperature and humidity in that space after it has been affected by the losses and gains in heat or moisture which occur in the space. This chapter is intended to serve as a general guide in the selection and design of the central system for year-round air conditioning for commercial installations. References are made to other chapters which give complete data and discussion on certain portions of the work. Many systems will not include all of the functions of the complete year-round system and it is impractical in the space allowed here to show all the different combinations of equipment which could be used for central system work to suit special conditions or the preferences of the designing engineer. In January, 1938 the Society adopted an application Code1 for the design of comfort air conditioning installations which was prepared by a Joint Committee of the American Society of Heating and Venti lating Engineers and the American Society of Refrigerating Engineers. In some states and municipalities local codes have been prepared giving specific design requirements for those localities and the engineer should refer to these standards if they are in existence.. . CLASSIFICATION OF SYSTEMS Central systems which are designed to produce dehumidification by the use of cold surfaces or sprays may be classified as: ` , 1. Central unit with heating and cooling coils and humidifying sprays (refer to Fig. 1). This system is very common and used extensively for summer and winter conditioning. `Code of Minimum Requirements for Comfort Air Conditioning (AiS.H.V.E. Journal Section, Heating, rtping and Air Conditioning, April, 1938, p. 276). Reprints of this'code are available at $.10 a copy.: Heating Ventilating Air Conditioning Guide 1939 2. Central unit with preheating coil, washer and reheating coil (refer to Fig. 2). fi. system is widely used for winter conditioning on larger installations and summer co0 ditioning is accomplished by using cold water in the washer. COn" 3. Blow through system with heating and cooling coils and mixing dampers (refer Fig. 3). This system is used where several different zones are served from one central system and the conditioning of the entering air for each zone is determined ly mivj varying quantities of air after passing through the conditioner. ~g Fig. 1. Central Unit with Coils and Sprays Central Systems for Comfort Air Conditioning Fig. 3. Blow Through Systems with Coils and Mixing Dampers 4. Central outside air conditioning units with unit recirculating conditioners (refer to Fig. 4). This system is used on installations having large zones requiring independent control to meet local requirements for office and apartment buildings, hotels, etc. 5. Central conditioning unit either washer or coils with booster reheating coils (refer to Fig. 5). This system is used for special zone arrangements where there is considerable variation in requirements of different zones such as hospital operating rooms or an auditorium served in conjunction with office and store cooling systems. An entirely different method of dehumidification is used in some installations where the extraction of moisture is accomplished by methods of adsorption or absorption. Materials which are commonly.used for these ..Fig. 5. Central Unit with Either Air Washer or Coils and Booster Coils Heating Ventilating Air Conditioning Guide 1939 systems are silica gel, lithium chloride, activated alumina and calcin chloride. These systems accomplish dehumidifying entirely separat* from sensible heat cooling. The air passing through the material gives i,6 its moisture to the material and there is a conversion of latent heat enerev to sensible heat energy so that the temperature of the air leaving th equipment is considerably higher than the entering air. These system! can be used for dehumidifying outside air only, or for a mixture of outsit and recirculated air, or for recirculated air only. The sensible heat cooW is accomplished by directing the air over a cooling coil. For further details of this method refer to Chapter 23. DESIGN OF SYSTEM In designing a complete air conditioning system it is logical to consider several factors which, for convenience, may be enumerated herewith- 1. Design conditions a. Outside dry-bulb temperature for winter. b. Outside dry- and wet-bulb temperatures for summer. . c. Inside dry-bulb temperature and relative humidity. 2. Design heating load a. Heat transfer through windows, walls, partitions, doors, floors, sky-lights ceilings and roofs. ' b. Heating capacity to warm incoming outside air. c. Heat required to evaporate moisture for humidification. d. Heat loss through ducts and casings. . e. Allowances for heat emitting sources. 3. Design cooling load a. Heat transfer through windows, walls, partitions, doors, floors, sky-lights, ceilings and roofs. b. The sensible and latent heat gains from occupants. c. Heat emission of electrical, chemical, gas, steam, hot water or other devices, apparatus or lights. d. Transfer of solar radiation through windows, walls, doors, sky-lights or roofs. e. The sensible and latent heat to be removed from incoming outside air. f. Heat gain through ducts, casings and fans between conditioning unit and enclosure. 4. Design of distribution system a. Establish the temperature of air leaving the supply inlets. b. Calculate the quantity of air to b'e circulated. c. Estimate the temperature rise or loss in the duct system. d. Calculate the heating or cooling requirements of apparatus. e. Design the duct system including the air inlets and outlets;, f. Consider noise control problems. - . g. Design the control system. , h. Calculate total static pressure of the system. i. Select the air filtering equipment. . j. Select the fan, motor, drive and auxiliary equipment. . - Design Conditions The design outside dry-bulb temperature in various localities for use in computing the winter heating requirements may be referred to in Chapter 7. In computing the summer cooling requirements for various cities recommended design outside dry- and wet-bulb temperatures may be 418 Central Systems for Comfort Air Conditioning , jn chapter 8. Recommended inside temperatures and relative humidities tfoorr winter and summer conditions and for various ty^pes of load Calculations for Heating Complete tabular information is given in Chapter 5 for determining the heat loss through windows, walls, partitions, doors, floors, sky-lights, ceilings and roofs. . .. ' The heating capacity required for warming the outside air which enters hv uncontrolled infiltration should be calculated according to the infor mation given in Chapter 6. Mechanical ventilation systems are frequently designed which produce either positive or negative pressures within an enclosure that are greater or less than the outside prevailing wind pres sure. Under such circumstances uncontrolled infiltration is over or under balanced by the supply or exhaust ventilation system. If the rate at which air is specified to be introduced to or removed from the enclosure by positive means exceeds the estimated .infiltration rate it is common practice to use the greater rate in heating capacity calculations. The heat required for warming the outside air introduced for venti lation purposes should be calculated according to the basic data given in Chapter 3, and the methods outlined in Chapter 6. The first requirement for any air conditioning system is to provide satisfactory ventilation and the design should err on the side of being liberal in the amount of outside air introduced for the purpose of maintaining good ventilation without objectionable odors. Code2 requirements state that the assumed rate at which air is to be positively introduced into the enclosure per occupant, when the con tamination of air within the enclosures results entirely from respiratory process shall not be less than 10 cfm per stated number of occupants which is indicated as being the maximum number of people within the enclosure when the sum of the remaining loads are a maximum. The Code further states that the assumed ventilation rates shall not be less than 15 cfm per stated number of occupants in enclosures where smoking is customarily permitted, and that provision shall be made for air removal from the enclosure either by natural or mechanical means at not less than the assumed ventilation rate. For the purpose of the Code air quality or purity are assumed to be met if means are provided for the positive introduction of outside air in the amounts previously mentioned and for removal of 95 per cent by count of all dust particles over 10 microns in diameter from all air delivered to the enclosure. The heat required to evaporate the necessary water required for winter humidification and superheat the resulting vapor in order to raise the moisture content of the outside air assumed to enter the enclosure by infiltration or positively introduced for ventilation should be calculated according to the information included in Chapter 1. The heat loss through the ducts and casings between the condition unit and the treated space may be determined from data given in Chapter 39. The heat gain due to lights and people or other heating sources in the conditioned space may be calculated as referred to later in this Chapter.- 'Loc. Cit. Note 1. 419 U r I'l r. ifit I I i k- Heating Ventilating Air Conditioning Guide 1939 This heat gain is then used as a credit against the heat loss calculation In general, however, the design for heating disregards these gains as f most cases these values are not a continuous or uniform source of heat an!) the heating system must be adequate to maintain the required tempera11 ture at all times including nights, Sundays and holidays, when the space is not in normal use. p ce The summation of these heat losses will give the total heat to be supplied by the air entering the conditioned space and the additional heat necessary to be added to the conditioning unit to provide the prescribed entering air temperature. Load Calculations for Cooling The heat gain through the windows, partitions, doors, floors, sky. lights, ceilings or roofs of the enclosure due to the air dry-bulb tempera-ture difference assumed to exist between the air on the opposite sides of the construction may be determined from data given in Chapter 5. The heat gain from occupants may be calculated from data given in Chapter 3, which gives the metabolic rate for people engaged in various activities. In addition charts are included which give a separation of the sensible and latent heat losses from the body which should be item ized separately in all calculations. The heat emission from various appliances should be calculated ac cording to the information and data given in Chapter 8, with special consideration being given to the division of latent and sensible heat requirements of the apparatus. Complete details may also be found in Chapter 8 for determining the heat gain resulting from electric lights and. motors within the enclosure. The transfer of solar radiation through windows, walls, doors, sky lights or roofs of enclosures may be determined from the charts and tables in Chapter 8. . _ The heat to be removed from the outside air in cooling load calculations is determined in exactly the same manner as described previously under Load Calculations for Heating. The minimum ventilation requirements should be carefully considered. The heat gain through ducts, casings and fans between the conditioning unit and the treated space may be determined from information in Chapter 39, and'such calculations demonstrate the value of insulation in applications of this type. . Air Distribution System for Heating The total heating load to be supplied by the central system is determined from the several components of the load listed under Item 2. The quantity, air motion, and temperature of the treated air and the method of introducing it to the conditioned space should be designed so as to limit the variation in dry-bulb temperature to 3 F or less at a 5 ft level throughout that portion of the enclosure which is normally frequented by persons. It is desirable to avoid air velocities exceeding 50 linear feet per minute in the occupied zone between the floor and the 5 ft level. When architectural or other construction requirements necessitate the location of a supply or return grille below the 5 ft level in an occupied Ii j\ { rIf \ i| ? |. l[ jjl 420 Central Systems for Comfort Air Conditioning ' snecial consideration should be given to the air velocities in that Spa,<on to avoid uncomfortable drafts. re1. . durable to use reasonably low temperature differences between , U * tering air and room conditions where possible. Air temperatures f 6 680 to 90 F will generally be satisfactory, although where the quantity t0 be circulated is kept at a minimum and where the arrangement of inlets permits adequate mixing with the room air before reaching the hreathing zone, higher temperatures from 100 to 120 F can be used. Having selected the desired temperature of the entering air, the quantity of air is determined as follows: H ^ = 6Od X 0.24 (iy - 0 ^ where Q = volume of air to be introduced, cubic feet per minute. H = sensible heat loss of space to be conditioned, Btu per hour. i = density of air, pounds per cubic foot. ty = outlet temperature at the grille, degrees Fahrenheit. ( =.- design room temperature, degrees Fahrenheit. If the air quantity calculated is excessive, it may be decreased by using a higher entering temperature. If the quantity is too small to provide adequate distribution and ventilation, it may be increased by using a lower entering temperature. Air motion has a cooling effect on the individual, and ordinarily the air quantity circulated should provide an overall air change in the conditioned space in not less than 5 min or more than 12 min. Best results are secured when the entering air temperature and method of distribution permit uniform mixture of air without excessive motion in the occupied zone. . The temperature drop between the heating element and the supply grille may be calculated according to the following formula: where . __ _______ Hd_______ w 60 d X 0.24 X Q <d = temperature drop, in degrees Fahrenheit. Hd = heat loss in ducts, etc., Btu per hour. . /n\ 1 . The temperature drop /d is added to the grille outlet temperature to determine the air temperature leaving conditioning unit heating coil. In general, duct losses will vary from 2 to 5 F and if greater than 5 F special consideration should be given to insulation. The duct distribution system is designed using velocities as recom mended in Chapter 29, and grille locations as discussed in Chapter 28. In most installations it is advisable in order to permit economical heating prior to occupancy to design the return duct system of sufficient area to convey 100 per cent of the air handled by the fan. Also in mild weather certain economies of operation may be affected by designing the outside air duct of sufficient area to convey approximately the total quantity of air handled by the fan and means should be provided for the escape of this air quantity. In every case, however, the outside air duct should be of sufficient area to permit the minimum ventilation requirements to be met. 421 Heating Ventilating Air Conditioning Guide 1939 --Rafter 21- Central Systems for Comfort Air Conditioning Air Distribution System ior Cooling ' . . or simple cooling coil will not produce the desired combination of The total cooling and dehumidifying load to be supplied by the centr I system is determined from the several components of the design 1<J!! listed under Item 3. The entering air temperature is determined bv selecting the proper relationship between the quantity of air to be handled" the heat gain in the conditioned space, and the location of the air inlets' In cooling applications it is desirable that the difference between the temperature of air currents in the space frequented by occupants and the average temperature in such space, be not greater than 2 F for air velo cities of 40 linear feet per minute and over and not greater than 3 F f0r velocities of less than 40 linear feet per minute. . There is a fairly wide range of permissible entering air temperatures .With high velocity jets or diffusing nozzles, located at some distance froni the occupied space, entering air temperatures may be as much as 30 F " -sber dew-point temperatures for the air leaving the apparatus, elative amount of dehumidification can be increased by reducing the *. er, -ty through the dehumidifier,, and by reducing the temperature |^.;v dehumidifier. In some cases, it is necessary to add a reheating coil : . order to obtain the desired combination of dry-bulb-and dew-point - temperatures. .. ... The design of a duct distribution system for cooling is accomplished in th same manner as that previously described for heating installations. F r cooling spaces prior to occupancy, it is also desirable to design the ajr ducts of sufficient area to convey 100 pier cent of the air handled - jjjg ^ and the same recommendations with regard to the outside air :. as referred to in the heating design would be applicable for summer air conditioning. . below room temperature. Where the air is introduced through supply inlets fairly close to the occupied zone the entering air should be within ; CORRELATION OF SUMMER AND WINTER DESIGN 10 to 15 F of a desired room temperature. The problem of . preventing Frequently the quantity of air required for the central system in drafts in summer air conditioning is important as air, cooler than room summer conditioning is considerably greater than the quantity required air, tends to fall without diffusing and proper design must consider the for winter conditioning. In practice, volume control should be provided relationship between temperature and diffusion to secure satisfactory results. ' . using a speed regulator on the fan, or dampers, so that the air quantify may be changed for the cooling and heating cycles. Sometimes a recalcu The quantity of air circulated for cooling may be determined from lation using different entering air temperatures will permit using the same Equation 1 which was given previously for heating. However, in this quantity of air all year round. There is no fixed rule or method for case H is the total sensible heat gain of the space to be conditioned. - determining the most practical design for air quantity and the engineer Having established the entering dry-bulb air temperature and quantity, should use discretion to a large extent in working out a balanced system. the relative humidity is then determined. If there is no moisture gain When air is introduced above room temperature it tends to rise, while in the room (i.e., no latent heat gain) the dew-point of the entering air incoming air below room temperature tends to fall. It is therefore will be the same as that of the room air, as all of the necessary air cooling common to introduce air for heating only through baseboard or low air will be used for removing the sensible heat. If there is a latent heat load inlets; and air for cooling is introduced through high side-wall inlets or to be absorbed in the room then a procedure as outlined herewith may be ceiling inlets. Uniform diffusion is the important part of the design, and used for determining the entering air wet-bulb temperature: successful installations have been made introducing cold air from low outlets and warm air from high outlets. An overall air change in the Total all the latent heat gains in the room and convert them to equivalent grains of moisture. Divide the total grains of moisture by the number of pounds of air delivered to the room which will give the difference in weight of moisture between the entering air treated space of once in 5 to 8 min prevents stratification. In a system designed for all year-round operation, the overhead diffusing openings are I and room air conditions. Subtract this amount from the grains of moisture corresponding to the dew-point temperature in the room and refer it to psychrometric charts or tables used for supply air with very satisfactory results. Particular care is taken in locating the exhaust or. recirculating grilles to prevent short- la I to establish the required dew-point temperature of the entering air. The intersection of this new dew-point condition with the dry-bulb temperature line of the entering air at the supply inlet to the room will establish the entering wet-bulb temperature condition. circuiting of the supply air directly to the exhaust. Special care is also taken to prevent cold down-drafts from outside windows sweeping across a room during the heating season. This subject is covered more thoroughly The temperature rise from the air cooling equipment to the supply inlet in Chapter 28. may be determined from Equation 2. Obviously, the dry-bulb air tem perature leaving the apparatus must be lower than the supply inlet SELECTION OF EQUIPMENT temperature by the difference in temperature rise calculated. These duct gains will usually be from 1 'to 3 F and if greater than .3 F special con sideration should be given to the application of insulation. The system to be used is selected to meet the requirements of the . installation. There are numerous modifications which can be made to any of the systems mentioned. Recirculating air is used in both heating With the dew-point of air leaving the air cooling apparatus as previously and cooling for the sake of economy. However, in many cases the system determined and the dry-bulb air temperature as established from the is designed for 100 per cent outside air with no recirculation and an temperature rise in the duct system, a wet-bulb temperature of air leaving exhaust system added to remove the air to complete the circuit. In the. apparatus may be determined from a psychrometric chart which also planning any system, it should be remembered that there is always some shows the total heat of the air. In some instances, a conventional air - -exfiltration through door cracks, windows, and even through building 422 423 Heating Ventilating Air Conditioning Guide 1939 materials, so that it is not possible to recirculate or exhaust all of the a' mechanically. If the conditioned space is practically air tight, 90 per ce*J of the air can be recirculated, but in ordinary construction it is better n , to assume more than 80 per cent. On the same basis exhaust fans a sized for 75 to 80 per cent of the supply fan capacity, where recirculatl^6 is not used. n In some localities, the cooling is accomplished by evaporative coolina without any mechanical refrigeration or dehumidifying equipment. This is practical where the outside air dry-bulb is high and the relative humi dity is low, as the washer temperature will tend to equalize at the outsi<je wet-bulb temperature and will deliver saturated air at this temperature * for cooling. There is no change in the wet-bulb temperature of the air going through the conditioner and therefore no change in the total heat but the rapid circulation of the cold, moist air is often considered sufficient for comfort. These systems do not use recirculation. . In making the selection between spray and surface dehumidifiers certain characteristics of each should be considered. A spray dehumidi fier, (i.e., a dehumidifying air washer) will deliver practically saturated air, the temperature of which is determined by the temperature of the air washer water. The control in this case is the control of the water tempera ture and cooling effect can be accomplished by an external water cooler, a natural cold water supply, or coils directly installed in the washer. The washer system is used in the winter time for humidifying in the same way; that is, by controlling the water temperature, water can be evapo rated into the air. This may require preheating the 'air before entering the washer, or the use of an external water heater, or steam coils directly in the washer. Air washers also have the ability to eliminate certain kinds of dirt and dissolved gases and some odors. Surface coil dehumidifiers seldom deliver saturated air. Most comfort conditioning systems require that the air be delivered at low dew-point and relatively high temperatures. It is often simpler to produce this condition with a so-called dry coil than with an air washer. Surface coils can be used with cold water in the tubes or with direct-expansion refrig erant. When dehumidifying, the coil surface is wet due to the condensed : moisture, and this water has some small cleaning effect and does absorb " some gases and odors. These coils must be kept clean, however, as the water condensed is not sufficient to wash off the accumulations of dirt, and in the course of time a stale odor may be continuously added to the air stream from dirty coils. The relationship between sensible and latent heat is given in Table 1 for typical classes of comfort conditioning and the required entering air condition. Unfortunately, there is yet no uniform practice in the state ment of this -ratio, and hence in Table 1 several ways of stating the load ratio are given. Examples of the solution of a typical problem of treating air to produce the room conditions of 80 F dry-bulb and 50 per cent relative humidity are presented in Table 2. In these examples it is assumed that as the air is discharged into the room and diffuses with the room air, it will absorb the sensible and latent heat in the ratio indicated and thus arrive at the designed condition. These are grille or outlet conditions which will not be the same as the condition leaving the de humidifier. 424 Central Systems for Comfort Air Conditioning The heating coils may be selected as indicated in Chapter 24. It is tomary to use heating coils of convenient shape to fit the balance of the Conditioning equipment, using 1, 2, or 3 rows of coils as needed. Qn comfort cooling installations, the 4-row cooling coil, is most widely . a]though some installations use 3-row coils and some 5 rows or more, Heoending upon sensible-latent ratio, air quantity and refrigerant temnerature. With any given face velocity, the resistance to air flow increases Sdth the number of rows of depth of coil. (See Chapter 24). If a system using an air washer is selected, the washer is designed to fit the permissible space both as to width, height and length. Refer to Chapter 25. . If the surface coil system is used, winter humidifying may be accom- Table 1. 1 Room Heat Load Ratios for Typical Summer Comfort Conditioning Ttpical Classes or Room Service or Load Room Heat Load Ratios* Sensible Heat Total Heat 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 Total Heat Sensible Heat 1.00 1.11 1.25 1.43 1.67 Latent Heat Total Heat 0 0.10 0.20 0.30 0.40 Total Heat Latent Heat 10.00 5.00 3.33 2.50 Sensible Heat Latent Heat 9.00 4.00 2.33 1.50 Latent Heat Sensible Heat 0 0.11 0.25 0.43 0.67 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. * ` Table 2. Dry-bulb Temperature of Air at Room Inlets To Maintain Typical Room Conditions of 80 F Dry-bulb, 60 per cent Relative Humidity Sensible Heat Total Heat 1.00 0.90 0.80 0.70 0.60 Air entering saturated*1 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 demJwl!!!^ ^ conditions leaving the central conditioner are: With spray dehumidifier, 0 to 2 F wet-bulb 10 F wet-bulb depre^o^7156 1 to 6 F wet-bulb depression. With by-pass or reheat, 4 to 425 Heating Ventilating Air Conditioning Guide 1939 plished with a separate humidifier system. On small installations, th ' simplest method is to use a warm water spray through atomizing nozzles6 using a pressure of 15 to 25 lb and sufficient nozzles to atomize abour twice the amount of water needed for humidifying. The grains of moisture to be added to the incoming air at outside design temperature to bring it up to the required room dew-point are calculated. This is converted to total pounds of water per hour for the system and sprays designed for twice this amount. Cold water will not vaporize as completely as warm water, and water temperatures from 120 to 150 F are commonly used Another method is to install a water tank in the air stream with a steani coil submerged in the tank, the humidification being accomplished by the steam boiling the water into vapor, which in turn will be absorbed by ' the passing air. In both of these systems there is a tendency to deposit lime and other impurities on any surface the water touches, and this scale should be cleaned regularly before it becomes excessive. Water spray should not touch the steam heating coils as they will quickly become coated with scale. The preferred practice is to install sprays between coils and eliminator plates. Sound Control Problems of sound control should be jointly considered by the acous tical and air conditioning engineer for satisfactory results. Many installations require noise levels which are relatively low and for that reason equipment must be selected having a very low noise rating. In central systems consideration should also be given to the lining of ducts for the reduction of noise levels within an enclosure;' Often reduced speeds of equipment and low air velocities are helpful in eliminating undesirable noise conditions. Information is given in Chapter 30 with regard to acceptable noise levels for various types of rooms and methods are outlined for computing length of duct lining materials. Automatic Control The control of an air conditioning system is very important. A simple comfort cooling or heating installation requires a minimum of control, whereas a more complex installation justifies a more complete control. In this connection, it should be mentioned that there are many patents allowed and pending on air conditioning equipment including control, and the designer should consider these factors in selecting all of the equip ment. Refer to Chapter 37. 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. ' . X. Outside air inlet, comprised of screen, louver and short duct, may have a loss of 0.2 in. of water. Central Systems for Comfort Air Conditioning VW 4 . ? ^ typical viscous filter at rated capacity and velocity has a drop of 0.25 in. water. ` ]oss 0f 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. i h standard humidifier at rated velocity may have a loss of about 0.35 in. water. . g '-yhe loss through one row of a standard make reheater equals 0.12 in. water. Ply ^ faif assumption for duct losses on a simple system is 0.25 in. water. \p' 8 The static pressure for a nozzle type outlet may be taken as 0.1 in. water. ... The sum of these values equals 0.2 + 0.25 + 0.09 + 0.10 + 0.35 'tf 0 12 + 0-25 + 0.1 = 1-46 in. which is the static pressure against which the system must operate. ' Fans, Motors and Filters jjje 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. Complete information is given in Chapter 26 for the selection of all types of air filtering equipment. SPECIAL CONSIDERATIONS In designing a central system for air conditioning there are a number of special considerations not referred to previously which must be considered. Certain features of building constructions are important. The building must be suitable in construction so that the conditions designed can be maintained economically. For instance, excessive sun load on roofs or glass windows may not only cause excessive heat gain to be absorbed by refrigeration, but direct sun radiation heating converts a surface into a panel heater. This radiant heat is not absorbed until it strikes another mass such as a building wall, or a person. It is therefore possible to have comfortable air conditions surrounding a person, and yet have him uncomfortably warm from radiant heat from a hot wall, window, or ceiling near him. As another example, it is much better to provide hoods over steam tables, coffee urns, etc., than to try to remove this heat by mechanical refrigeration. Another problem is presented with winter conditioning for maintaining satisfactory relative humidity. If 30 to 40 per cent is desired at all times, no matter how cold it is outside, excessive condensation may collect on single glass windows, or on hardware which connects to the outside such as latches and hinges. Condensation on windows can sometimes be pre vented by applying a small amount of local heat under the window. In other cases double glass or storm window construction is used. Refer to Chapters 5 and 7 for condensation temperatures. In many cases, different zones of a building will require entirely different treatment. In some buildings where offices are exposed on all four sides to sun and wind effect, cooling is required on the sunny side and heating is required on the shady side simultaneously, in spring and fall seasons. The central system must be carefully zoned to apply cooling or heating as they may be needed for each zone, independent of other zones. In many existing buildings, the central system will be added to a radiation system of heating. The designer should take full avantage of 427 Heating Ventilating Air Conditioning Guide 1939 this radiation for heating the outside walls and windows. At the same time, it must be controlled to prevent overheating the whole system. ^ few uncontrolled radiators will often change the heat balance and cause excessive overheating of the whole zone, without occupants near the radiators realizing the source of the trouble. All radiation used locally in connection with the control system should be equipped with automatic control to prevent overheating. The apparatus should be placed for minimum piping and duct work but it must be accessible for maintenance, repair, and cleaning. The air conditioning unit should be designed to provide access for cleaning coils drip pans, eliminators and for very easy maintenance on filters. This equipment will be in operation for many years, probably for the life of the building, and a little thought spent in the plan will simplify maintenance and assure successful results. Example 1. With the assumed values as indicated perform the essential calculations, to determine the design loads for heating and cooling and the necessary factors for'designing the distribution system. Solution: Design Conditions from Item 1. Outside air dry-bulb, winter..................... Outside air dry-bulb, summer.................. Outside air wet-bulb, summer.................. Inside air dry-bulb, winter......................... Inside air wet-bulb, winter...... .................. Inside air relative humidity, winter....... Inside air dry-bulb, summer..................... Inside air wet-bulb, summer.................... Inside air relative humidity, summer.-- 200 people--4 kw light load. . 0F .95 F .75 F .72 F .56 F .35 per cent .80 F .66.7 F .50 per cent Design Load for Heating from Item S. Sensible heat loss through walls, etc-..........................................200,000 Btu per hour Outside air--2000 cfm X 0.075 X 60 X 0.24 X(72 - 0) = 155,500 Btu per hour Humidification- -2-0--0--0---X----0--.0--7--5- ---X (470qq-q5)--X----6--0---X----1-0--4--0- = 46,9^00 Btu per thour Heat loss through ducts...... ........ ..................................................... 33,200 Btu per hour Heat gain from lights, etc......... .................... ...............Disregard Total heating capacity..................... .......... ......................................435,600 Btu per hour Design Load for Cooling and Dehumidifying from Item 3. \ Sensible Heat gain through walls, etc.......... .................... .... 128,160 Heat gain from occupants (200)........................ ..... 44,000 Heat emission from appliances........................... ..... 2,000 Heat gain from lights (4 kw).....................:........ ..... 13,840 Heat gain from solar radiation!.......................... ..... 12,000 Latent 36,000 Totals, .......................................................... .... 200,000 36,000 Btu per hour Outside air: 2000 X 15 X 0.075 X 0.024 X 60 -_____ 2000 X 0.075 X (110 - 80) X 60 X 1040 7000 , Heat gain through ducts..................................... ..... 22,200 40,100 Totals. --.............................................................. ..:..254,550 428 76,100 Btu per hour 21. Central Systems for Comfort Air Conditioning Total Cooling Capacity = 330,650 Btu per hour Tons'Cooling Effect- = 27.5 . ._ . Heat Load Ratio 200,000 ,,,,,, 236,000 '85 Design Distribution System for Heating a. Total heating loss in space Using 72 F plus 18 F n =' 200,000 200,000 Btu per hour 90 F entering air 10,300 cfm b Total heat loss in ducts between unit and grilles 33,200 to = 60 X 0.075 X 0.24 X 10;300 c. 90 F plus 3 F Design Distribution System for Cooling 33,200 Btu per hour 3F 93 F temperature leaving coil a. Total sensible heat gain in space Using 80 F minus 18 F 200,000 060 X 0.075 X 0.24 X 18 10,300 cfm 200,000 Btu per hour 62 F entering air 770 lb Latent heat gain -- 36,000 Btu per hour = 600 Btu per minute . . = 4020grains perminute = 5.2grainsper pound Room condition = 80FDB, 66.7 FWB, 50% RH, 60 FDP, = 77.3 grains Entering air = 62 FDB, 59.5 FWB, 87% RH, 58 FDP, = 72.1 grains b. Duct gain 22 200 to = 60 X. 0.075 X 0.24 X 10,300 = 22,200 Btu per hour * = 2 F temperature rise Leaving coil = 60 FDB, 58.7 FWB, 58 FDP These calculations are based on maximum load conditions as set forth in the design. For intermediate loads the calculations may show entirely different relationship. For example, the entering air temperature will approach the space temperature as the sensible heat gain or loss decreases, due to outside temperature change, entrance or exit of people, use of artificial lighting, direction and intensity of sun's rays. The entering dew-point will remain much more uniform as it is affected by changes in room moisture gain only and this does not fluctuate greatly. If intermediate load conditions are im portant the calculations should be repeated for those loads. PROBLEMS IN PRACTICE ' 1 Consider a central heating 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. Reduction in power input = = 1-83 hp. Annual energy saving = 1.83 X 0.764 X 4000 = 5480 kwhr. 2# 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 of 34,200 Btu per 429 Heating Ventilating Air Conditioning Guide 1939 hour on the basis of 0 F outdoors and 70 F room temperature, is to be heated h a recirculating central heating system with air entering the rooms at 11$ J How many cubic feet per minute, measured at 70 F, will be required? ' Substitute in Equation 1. H = 110,100 + 34,200 = 144,300 Btu per hour; ty -- llgp. / = 70 F; Q = 144,300 60 X 0.07492 X 0.24 (116 - 70) = 2900 cfm. 3 In the preceding question, if the warm air loses 4 F between heater and roomnss., how many pounds of steam per hour at 1-lb gage will the heatinc sections condense? Q 2900 cfm, from solution of Question 2; At = 116 + 4 -- 70 = 50 F; hfg = Btu, from steam table in Chapter 1. W 60 dQ X 0.24 X Al _ 60 X 0.07492 X 2900 X 0-24 his 968 4 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. .. 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 4. 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. 6 t 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? . 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. . 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 dry- bulb temperature of the resulting mixture.^ 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. . 430 *>\ tr ' Chapter 22 UNIT HEATERS, VENTILATORS, AIR CONDITIONING, COOLING UNITS Classification of Unitary Equipment and Related Systems, ' Unit Heaters, Unit Ventilators, Split and Combined Systems, Cooling Units, Air Conditioning Units, Heating, Humidifying and Dehumidification, Filtering, Location of Units, Air Dis tribution, Residential Central System Units, 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 Equipment1, 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 tinction to the generally accepted term of a field fabricated central station system. The manufacturer of the unit is responsible for the output and [Prepared by a Joint Committee of the American Society of Refrigerating Engineers, American Society Heating and Ventilating Engineers, Refrigerating Machinery Association, National Electrical Mann* fadwers' Association and Air Conditioning Manufacturers' Association. . '' 431 Heating VentiiiATing Air Conditioning Guide 1939 performance of the unit under rated conditions, whereas the contracts ` installing the complete unitary system is normally held responsible f0r 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 mate, 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. s- 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 equips . 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. Self-contained Air Conditioning Units are classified1 according to the method of rejecting condenser heat (water cooled, air cooled, and evaporatively cooled), method of introducing venti lation air (no ventilation, ventilation by drawing air from outside, ventilation by ex hausting room air to the outside, or ventilation by a combination of the last two methods), and method of discharging air to the.room (free delivery or pressure type). 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. *Loc. Cit. Note 1. ^ . ... ^Proposed Standard Method of Rating and Testing Self-Contained Air Conditioning Units for Comfort Cooling prepared by a Joint Committee of the American Society of Refrigerating Engineers, American Society or Heating and Ventilating Engineers. Refrigerating Machinery Association, National Electrical Manufacturers' Association, and Air Conditioning Manufacturers' Association. 432 Chapter 22. Unit Heaters. Ventilators, Air Conditioning. Cooling Units 10 A Pressure Typo Unit is for use with one or more external elements which impose ail resistance. 1 There has grown up in the industry definite branches, in which the neering 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 hv 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-commercial 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 healer 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 rate 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. . 8. Provide a means of saving floor area or room'space due to.the compactness of the . equipment and flexibility of application. 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 , 433 Heating Ventilating Air Conditioning Guide 1939 30 ft to as much as 200 ft from the unit. This makes possible the locatio of these units at considerable distances from each other, thus reducin'1 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 JHaJG/ TU ^ ----- -SUPPLY )R l 5 X. L=k RETURlr Fig. 1. Suspended Unit Heater, Propeller Type Fan Fig. 2. Floor Mounted Unit Heater, Housed Type Fan 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 code4 governing the number of sizes of propeller type unit heaters offered for sale by a manufacturer, as well as a standard method of specifying outlet air velocities has been adopted. 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. . 'Standards for Propeller Type Unit Heaters prepared and adopted by the Industrial Unit Heater Asso> ciation, June. 1938. 434 ~~ Znn hottHeaters. Ventilators. Air Conditioning, Cooling Units ,,chapter^- ;_ <f AIR TEMPERATURES5 % p. r recirculating heaters with intakes at.the floor level, the temperature h maintained in the room should be considered as the temperature of -air entering the heater. Where outside air is introduced, the tem- "Xure Qf tjjC mixture must be calculated and used as the entering air f^oerature tQ heater. Where suspended heaters are used without te*v 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- ^With suspended unit heaters taking air at some distance above the floor the temperature variation from floor to ceiling may reach as much ks 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 Fig. 3. Suspended Type Unit Heater, Housed Type Fan 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. 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 rating6. The capacity of a heater increases as the steam pressure increases, and decreases as the entering air temperature . *A.S.H.V.E. Research Report No. 968--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). . A.S.H.V.E. Research Report No. 1011--Tests of Three Heating Systems in an Industrial Type of Build"*8. by G. L. Larson, D. W. Nelson, and John James (A.S.H.V.E. Transactions, Vol. 41, 1935, p. 185). Standard Code for Testing and Rating Steam Unit Heaters (A.S.H.V.E. Transactions, Vol. 38.1930,,p. 165). 435 Heating Ventilating Air Conditioning Guide 1939 Unit Heaters. Ventilators. Air Conditioning. Cooling Units Note.-- 'To d e te rm in e c a p a c ity a t a n y etearo pressure and e n te rin g te m p e ra tu re ,' m u ltip ly co n sta n t fro m ta b le b y ra te d c a p a c ity a t 60 F e n te rin g and 2 lb preaaure. ses The heat capacity for any condition of steam pressure and *ncre^n,, jir temperature may be calculated approximately from any given en.t.er* bv the use of factors in Table 1. This table is accurate within 5 P^Jrdt heaters are customarily rated as free delivery type units. If - t ide air intakes, filters, or ducts on the discharge side are used with the ?u t 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 . acteristics 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 widi 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 f 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. 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. 436 437 Heating Ventilating Air Conditioning Guide 1939 It is unwise to install a single unit heater as the sole load on anv boiler, particularly if the unit heater motor is started and stopped bv 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 Steam supply jDry return and valve ==&= ^ Steam supply 5 ,j^-G-rHrAP_TE__K 00 U__n__i_t__H__e_a_;ters. Ventila.tors. Air Conditioning, Cooling Units 7': . j t0 a dry return instead of a wet return it is necessary to provide a nec pocket or loop about 5 ft in depth to prevent steam passing into the return and thus into other equipment. - A method of connection is shown in Fig. 5, where there is a wet return d a dry return. In this case the condensate from the heater and the f. from the supply main drop to the wet return by gravity, while the . passes upward through the traps to the dry return and is vented from the system at any suitable location. 'A sketch of an arrangement where there is a dry return line through hich both air and condensate pass to be handled by some suitable means, sWuch as a condensation pump and receiver is given in Fig. 6. The return line is not subjected to vacuum, and consequently all arrangements must facilitate gravity flow of the condensate toward the receiver. Traps must =<1 Drip Scale pocket SV^ ,,nk|nUnmn-*W vr~Water line of boiler Water line of boiler' .Wet return Fig. 4. Unit Heater Connection to One-pipe Gravity Steam System Fig. 5. Gravity Unit Heater Connected to System With Wet and Dry Returns 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. PIPING CONNECTIONS : Piping connections for unit heaters are similar to those for other types of fan-blast heaters. The piping around the unit heaters must strictly conform to the system requirements while at the same time permitting the heaters themselves to function as intended. Some of the more frequently encountered piping arrangements are illustrated in Figs. 4, 5, 6 and 7. Unit heaters may be applied to one-pipe gravity and vapor systems if the piping connections are arranged with proper care and attention. A method of connecting a unit heater to a one-pipe gravity system is illustrated in Fig. 4. In those cases where the unit heater is to be con- 438 . Fig. 6. Unit Heater Connection for Fig. 7. Method of Connecting Unit . Vacuum or Vapor System Discharging Heater to High Pressure Return < .. Condensation into Dry Return pass air and condensate rapidly to keep the return piping only partially full of water. : ; Since unit heaters are often constructed with sufficient strength to . resist high pressures, use of high pressure steam in them is a common practice. In Fig. 7 the condensate and air reach the return overhead through traps, and check valves are located in the return piping. For two-pipe closed gravity return systems, the return from each unit .^should be fitted with a heavy duty of blast trap, and an automatic air ' valve should be connected into the return header of each unit. Pressure . .drop must be compensated for by elevation of the heater above the water ' 4ine of the boiler or of the receiver. V In pump and receiver systems the air may be eliminated by individual z .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 ^.-atmosphere, provided all units, drip points, and radiation are properly ^trapped to prevent steam entering the returns. 439 Heating Ventilating Air Conditioning Guide 1939 Unit Heaters. Ventilators. Air Conditioning. Cooling Units On vacuum or open vented systems the return from each unit should h a urine, with which the use of heated air in rapid circulation with fitted with a large capacity trap to discharge the water of condensatio and with a thermostatic air valve for eliminating the air, of with a heavy1 duty trap for handling both the condensation and the air, provided th f rm distribution is of particular advantage. They may be used for UrU ture absorption, such as fog removal in dye-houses, or for the pre- 01f. 0f condensation on ceilings or other cold surfaces of buildings in air finally can be eliminated at some other point in the return system 6 orocess moisture is given off. When such conditions are severe, it For high pressure systems the same kind of traps may be used as with ecessary that the heaters draw air from outside in enough volume to vacuum systems, except that they must be constructed for the pressure **rovide a rapid air change and that they operate in conjunction with ! 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 . ntilators or fans for exhausting the moisture-laden air. (See discussion ^condensation in Chapter 7). I the condensate through the high-pressure return trap, with some danger 1 of return pipe corrosion and the problem of its elimination at some other UNIT VENTILATORS7 point in the system. Unit ventilators while designed primarily for ventilation must incor OTHER TYPES OF UNITS porate controlled heating. A typical unit ventilator is illustrated in Fig. All Electric The foregoing discussion relates generally to units in which steam or hot water is used as the heating medium. Electric unit heaters are ap plied where electric power is abundant and cheap and where other forms of fuel are scarce and expensive. The low first cost, easy control, and inexpensive installation of this type of heating have also accounted for many other installations in which electricity has conveniently provided heat for short periods of time. (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 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. Fig. 8. Typical Unit Ventilator Showing One of Many Arrangements of Dampers and Heating Coils 8. 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 "firing 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. 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 440 The primary functions of a unit ventilator are: ' fA roof vmtilntnr For information on roof ventilator*, see 441 . Heating Ventilating Air Conditioning Guide 1939 1. To supply a given quantity of outdoor air for ventilation or to mix indoor = . outdoor air. (See A.S.H.V.E. Ventilation Standards, Chapter 45). an<* 2. To warm the air to approximately the room temperature if the unit is intended f ventilation only, or to a higher temperature if it is intended to take care of all or a nan of the heat transmission losses from the room. 1)311 3. To control the temperature of the air delivered so as to prevent both cold draft and overheating. (See Chapter 37). 8 4. To deliver air to the room in such a manner that proper distribution is obtain-, 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. SPLIT AND COMBINED UNIT VENTILATOR 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. Thd split system permits the heating of the room during failure of electric current, 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 blit 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 corner 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. 442 ;fCHAPTER22- UnitHeaters. Ventilators. Air Conditioning, Cooling Units Table 2. Typical Capacities of Unit Ventilators for an Entering Air Temperature of Zero Cubic joiuMimn 600 750 1000 1200 1500 Total Capacity in Square Feet op Equivalent Direct Hrating Surface (Radiation) Capacity Available for Heat ing the Room in Square Feet of Equivalent Direct Heating Surface (Radiation) Final Air Temperatube (Deo Fabr) EDR Mbh EDR Mbh 285 68 95 350 . 84 115 455 110 150 565 136 , 190 70S 169 235 23 28 36 46 56 105 105 105 105 105 VENTS8 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 witii 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 venti 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 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 P *A.S.H.V.E. Research Report No. 936--Investigation of Air Outlets in Class Room Ventilation, by Larson, DAV. Nelson, and R. W. Kubasta (A.S.H.V.E. Transactions. Vol. 3S, 1932, p. 463). h,, Research Report No. 1017--Air Supply to Classrooms in Relation to Vent Flue.Openings, y r. L. Houghten. Carl Gutberlet, and M. F. Lichtenfels (A.S.H.V.E. Transactions. Vol, 41.1936, p. 279). 443 Heating Ventilating Air Conditioning Guide-1939 select the unit best adapted to the heating and ventilating load. Typi^ capacities are given in Table 29. If no direct heating 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, Ht = 0.24 W (ty -- to) (1) W = d 60 Q (2) H ,, ^ " 0.24W + (3) where . d = density of air, pounds per cubic foot. . H = heat loss of room, Btu per hour. .. Hy = heat required to warm air for ventilation, Btu per hour. . Ht = total heat requirements for both heating and ventilation, Btu per hour = H + Hy. Q = volume of air handled by the ventilating equipment, cubic feet' per minute. ' t 1 temperature to be maintained in the room. t0 = outside temperature. . ty = temperature of the air leaving the unit. 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 (1 -- 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; t = 70 F; to = 0 F. Substituting in Equation 4: - Ht = 24,000 + 0.24 X 0.075 X 60 X 1000 (70 -0) = 99,600 Btu h ~ 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 = 0.24W0 (ty - to) + 0.24 Wi (ty - t) where W0 = weight of air, pounds per hour taken from out-of-doors. Wi = weight of air, pounds per hour taken from the room. (5) Wo = do 60 Q0 Wi = di 60 <2i (6) (7) A.S.H.V.E. Standard Code for Testing and Rating Steam Unit Ventilators (A.S.H.V.E. Transactions, Vol. 38, 1932. p. 25). 444 Chapth*22' unit Heaters. Ventilators, Air Conditioning. Cooling Units inhere ,. ^ _ density of air, pounds per cubic foot at temperature la- dj = density of air, pounds per cubic foot at temperature t. O = volume of air taken in from the outside, cubic feet per minute. q? = volume of air taken in from the room, cubic feet per minute. , ^ = 0.24 (W0 + Wi)+` (8) . Ht = H + 0.24 do 60 Qo (t-- to) (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 24,000 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.-f = 59,200 Btu. Units designed and operated 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 (ty - 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: Hr = 0.24 W (ty - to) (11) In this case ty should be equal to or slightly higher than t. 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 f the volume of air that will be delivered at a certain temperature ty for an initial temperature of to. Therefore a certain amount of heat (Hh) 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 steani or hot water. They are normally installed within the space to be served, or at. 445 Heating Ventilating Air Conditioning Guide 1939 Chapter 22. Unit Heaters. Ventilators, Air Conditioning. Cooling Units least closely adjacent thereto. Occasionally they are provided to receive outside air in which case this air is invariably filtered or washed to prevent product. Cooling units are normally constructed of galvanized steel or non-ferrous material in order to reduce the corrosive effect of their any possible contamination of the product. constant wetted condition. Cooling units are provided in two major types similar to unit heaters Cooling units are often called upon to operate in rooms where a tempera either floor mounted with housed fan, or suspended with`propeller typ* fans. Normally, air outlet velocities are lower than for heating, due largely to the effect of high velocities on the product. Cooling units are 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 normally of the free delivery type although they occasionally are sup. defrosting. Such defrosting is accomplished by the following methods: plemented with duct work to provide more careful air distribution. Product cooling originally was accomplished by means of stationary C When the room is above freezing the source of refrigeration is cut off and the fan allowed to operate until the unit has defrosted. pipe coils. This was later supplemented with the forced fan bunker systems in which air was passed over banks of coils. The present trend 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 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-buib temperature is controlled separately from the control of humidity, thus classifying these units as cooling units. if . Fig. 9; Ceiling Type Cooling Unit . 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 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 pbjectionable in this industry. Typical cooling units are shown in Figs. 9 and 10. 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. 10 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 446 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. rh n rude[ 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. 10, but equipped with a pump for recircu- .447 ' Heating Ventilating Air Conditioning Guide 1939 lating brine over the coil as shown in Fig. 11. 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 tons of refrigeration and should specify the quantity, temperature and.humidity of the air entering the unit with a stipulated refrigerant temperature 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 1 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: 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 or 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 448 Unit Heaters, Ventilators, Air Conditioning, Cooling Units tern is where the spray water is furnished from a constant water source, hch 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 socalled 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. . 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 therate 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.o.ther 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 Dehumidiiication Those units that employ recirculated water sprays will undoubtedly use such sprays as. their means of cooling-and dehumidificajtion by urmshmg refrigeration: to the water in circulation. Occasionally where 449 Heating Ventilating Air Conditioning Guide 1939 an adequate source of cold well water is available, this may be used as a direct spray and run to waste. Other methods of dehumidificatiori accomplished by direct contact with the transfer medium are by means of the so-called adsorption and absorption systems. (See Chapter 23). 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 chloride 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 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 riot 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 23. However, they may be divided into the following groups: . 1 2 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: a. Cold well water. ' b. Cold city water. e. Artificial refrigerated water provided by direct expansion of refrigerant in a water cooler, direct steam jet refrigeration, or. by the melting of ice. 450 T-Chapter 22. Unit Heaters. Ventilators. Air Conditioning. Cooling Units Fatering-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 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. 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 of Air Conditioning Units . .; The characteristics of the conditioned space, the building construction, the type of system employed, the duct connection, the accessibility of the unit for servicing, as well as the source of power, piping and refrigeration . influence directly the location of air conditioning units., . . '. Fundamentally, there are two types of unit air conditioners. The first type is entirely the self-contained. These units are usually finished in decorative cabinets designed to harmonize with the interior finish of residences, stores, and small commercial establishments. They are, however, sometimes located outside the conditioned space with small lengths of ducts transmitting the conditioned air to the space where it is required. The primary problem in locating units within the conditioned space is to insure proper air distribution. If ventilation air is required, or if the condenser is of the air cooled type, the proximity to a source of fresh air should be considered when locating the units. Units with water cooled condensers should be placed close to the water supply and drain, and care must be exercised that the ambient temperature is never below 32 F, to prevent freezing the water in the condenser. . Proper care should be observed to locate the unit so that all parts are easily accessible in case of trouble. . . The second type of unit is the air conditioner which is designed for connection to some remote source of refrigeration. In the smaller sizes these units are sometimes placed within' the conditioned space. The 451 Heating Ventilating Air Conditioning Guide 1939 larger sizes are frequently located externally to the occupied and con ditioned 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 source of refrigeration or outside air or both It frequently permits the use of the basement or of space less valuable than that on the level or floor of the occupied zone. The design then approaches that of a Central System, (see Chapter 21). 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 dis charge and return grilles which are designed so as to correspond to the decorative scheme of the room. Air Distribution . With self-contained units, or any units exposed within the conditioned space, the aiir distribution is usually through grilles or louvres built into the equipment. The grilles or louvres are usually adjustable to assist in directing the air properly. The discharge of the air from this type of unit is usually directed upward at some angle with respect to the horizontal so that the cool air is not directed at the occupants, but at the same time is. carried to the most remote part of the room. In general, the air discharge should be designed to distribute cool air over the entire zone, dropping slowly and returning to 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 air flow and on its uniformity of temperature. 4 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 <jf 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 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. . : TYPE* 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 oi application:and .superior construction... It will. be.impossible to cover in 452 Chapter 22. Unit Heaters. Ventilators. Air Conditioning, Cooling Units this chapter the many types of construction on the market. Illustrations 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. 12. 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 Fig. 12. Floor Type Heating and Cooling Unit heating and cooling without manual control. When the unit is used for summer conditioning only, the heating coil may be omitted for the 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. i^11 eniirely different arrangement shown in Fig. 13 places both the air <n et and the discharge at the top of the unit. The fan at one side dis- arff|S the air downward to the bottom where it turns and passes hori zontally through an atomizing spray air washer. The path then, con- 453 ~S -f .' ' ' Heating Ventilating Air Conditioning Guide 1939 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 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. 14. Such units are equipped with either a direct expansion coil or U CHAPTER 22. Unit Heaters. Ventilators. Air Conditioning. Cooling Units eating compressor driven from a motor located iii the base. This comoressor 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 ;J it 1 1* Fig. 14. Suspended Propeller Fan Type Cooling Air Conditioning Unit Fig. 13. Conditioning Unit with Top Inlet and Outlet . (3f if'- one for chilled water or brine circulation. The outer cabinet is sometimes constructed of a well polished wood, but more commonly is made of wood-grained steel or baked enamel and is insulated from the cool air 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. 15. 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 special motor andfan assembly. Refrigeration is furnished by a recipro- , 454 ' Fig. 15. Portable Self-Contained Conditioning Unit for Cooling the occupied space during the winter season .when cooling is not needed. The portable air-cooled units are now available in sizes up to and in cluding 34 hp. . 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, in order to reduce the starting load, one model has two separate motors Drought on to the line at delayed.intervals thereby decreasing the initial 455 Heating Ventilating Air Conditioning Guide 1939 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. A new type of self-contained air conditioning unit has achieved promi- . nence, recently, for application in small commercial establishments. These units range in capacity from 2 to 10 tons, and are designed pri marily for use in the conditioned space. They are enclosed in steel casings, designed and finished to harmonize with the interior of com ' mercial establishments. These units generally use water-cooled con densers and are designed for use with 100 per cent recirculated air and free discharge although both fresh air connections and discharge ducts can be used with the units. DISCHARGE (msASrcE Chapter 22. Unit Heaters. Ventilators, Air Conditioning. Cooling Units These units usually provide for the addition of a heating coil as an tional item and some units also have available humidifying equipment as accessory equipment for winter operation. Remotely located conditioning units vary widely in details of con traction. Figs. 17,18 and 19 indicate one type built-in sections thereby oermitting interchangeability of application with a minimum change in oarts. The vertical unit shown in Fig. 17 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 eliminating the vertical type drip pan and substituting a horizontal drip pan, this unit is converted into a horizontal suspended type conditioning 1 ! Fsn !! 1 >! Mocw ! Fig. 16. Self-Contained Fig. 17. Vertical All-Year- Air Conditioning Unit Round Conditioning-Unit Fig. 18. Spray Type Air Conditioning Unit A typical unit of this type is illustrated in Fig. 16. In this particular unit the air enters a grille located at the front of the unit, passes through a throw-away type filter, then through the cooling coil and is discharged by a blower through an adjustable discharge distributor head. The air is discharged in such a manner to insure good distribution'without being directed at the occupants. The air may be discharged from the front only or from the front and either (or both) side. The refrigerating effect is furnished by a reciprocating compressor belt connected to a motor, all mounted on a resilient base to reduce vibration. The heat dissipated by the condensing unit is removed by water cooling. Panels are remov able for servicing and replacement of filters. The motor starter and other controls are mounted inside the enclosure and the unit may be operated either as a cooling unit or circulating unit by using the manual switches mounted on the side panel, or it may, be automatically controlled by means of a time switch or thermostat. . . ; 456 Fig. 19. Horizontal Remote Type All-Year-Round Conditioning Unit unit for connection to duct work, both with and without filters, as shown in Fig. 19. A spray type conditioning unit is illustrated in Fig. 18. This spray type unit, which is similar to the arrangement given in Fig. 17, 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. 18, 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 or commercial 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. \: j 457 Heating Ventilating Air Conditioning Guide 1939 In Fig. 20 is shown a conditioning unit which may be operated i,, conjunction with a hot water or steam boiler. Heat generated in th boiler is supplied to an exchanger which raises the air temperature a! it is circulated through the unit. The connection of a cooling coil to a source of refrigeration will provide year-round air conditioning. This type of system is particularly adaptable to a split system in which a ' Chapter 22. Unit Heaters, Ventilators, Air Conditioning. Cooling Units t 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 1 through the use of unitary equipment, material costs can be kept to a minimum, SmVy effort should be made to simplify installation. * 2 Self-contained units in the small sizes now available, probably represent the lowest t individual installations. They have, however, their limitations. ,, ^jje floor type all-year-round air conditioning units for the occupied space with a motelv controlled compressor, heating sources being either the existing heat system or Seam connections to the unit, probably afford the lowest cost all-year-round service for most individual rooms. 4 For multiple rooms or offices, the remotely located unit with connecting ducts obably represents the most economical installation. The larger self-contained air conditioners are particularly adaptable to stores, residences and small commercial installations. Fig. 20. Residential Conditioning Unit with Steam Boiler 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. ' Gas-fired winter conditioning units are available equipped with appa ratus 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 oil-fired conditioning unit is given in Fig. 21. A circulating fan forces the filtered air over a heat exchanger through which the combustion gases from the oil burner are being directed. A cooling section may be placed in the air inlet, with cold water, or re frigerant being circulated through the cooling element. . . 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 458 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. It is difficult to make any comparison of operating costs of cooling vs. heating equipment because the relative operating expense depends upon many factors including climatic conditions; i.e., in the South the cost of operating "cooling equipment greatly exceeds the operating cost of heating equipment, whereas in colder climates where cooling equipment is used about two months per year, the heating costs are probably higher than those for cooling. The more rapid growth of air conditioning,' at present, has been along commercial lines where it has represented an actual profitable investment resulting in increased business returns and where the first cost and operating cost per occupant is con siderably less than in the residential type of application where comfort cooling is still considered a luxury by the ordinary home owner. . 459 Heating Ventilating Air Conditioning Guide 1939 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. Unit Window Ventilators Window ventilators consist of filters and motor-driven fans enclosed in a cabinet to be mounted on the window sill of homes or offices. These units accomplish ventilation, air cleaning and air circulation. The di rection of air discharge is manually adjustable for seasonal operation 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 J/g in. 0f water, disc or propeller fans are generally used instead of the blower or housed types. The fans should have quiet operating characteristics, and 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 atticfans, 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. i ' ! i 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: Installation cost......... Fan data_______ ___ __ Operating period........ Power consumption_ $75 to $400, average $250 9000 cfm average, 280 ipm 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 - 460 "Cha"pTte_r 92 Unit Heaters, Vej_n_t_i_l_a_t_o_r_s__, _A_i_r__C_o__n_d_i_t_io__n_i_n_g_.__C_o_o__l_in_g__U__n_i_t_s Humidifiers . Humidifying units may be installed as part of an air conditioning unit tern or may be installed individually to furnish additional humidity. FV 23illustrates a humidifying unit for installation in connection with a ^ rm 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 die air delivered to the air distribution system. In other cases, imilar 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. 24. This unit is normally placed at some central location on the INTAKE Fig. 23. Humidifying Unit foe Warm Air Furnace Fig. 24. 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. PROBLEMS IN PRACTICE 1 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. . . 461 Heating Ventilating Air Conditioning Guide 1939 2 Is it satisfactory to install one unit heater as the total load on a cai fired boiler? Such an arrangement is impractical if the unit heater is sorted 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. 3 t 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 speed. For a given fan, slower speeds mean less noise. ' 4 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. ' 5 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. 6 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 methl surface units. 7 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.8 8 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 temperature and constant wet-bulb temperature of entering air, the wet-bulb depression of the leaving air increases, and since jt is this depression which determines the maintained relative humidity it must be carefully considered when selecting the unit. . 462 Chapter 23 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 he 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. Heating Ventilating Air Conditioning Guide 1939 DEHUMIDIFICATION PROCESSES Dehumidification may be accomplished in any of three ways, or by a suitable combination of them: y 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, 464 Chapter 23. Cooling and-Dehumidification Methods . jn operation is not of paramount importance, space is available or n<j`lively cheap, and the cooling system is to a great extent separate or ^dependent of other mechanical equipment. By contrast, air condition!n IqJ. space cooling and comfort work in office buildings, theaters and taces 0f public assemblage requires special consideration of all these f rtors. 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. o. 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 arid 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 cited. 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- 465 Heating Ventilating Air Conditioning Guide 1939 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. Low Pressure Saturated Gas N Heat of Compression Added to Gas _L Compressor High Pressure Superheated Gas -V Hot In HeatAiidedto Refrigerant by Substance,Cooled Cold Out Evaporator or Cooler Expansion Valve for Reducing Pressure Condenser Heat Taken from Refrigerant by . Condensing Medium High Pressure Saturated Liquid .. Fig. 1. Mechanical Refrigeration System 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. 466 Chapter 23. Cooling and Dehumidification Methods theoretical Mechanical Refrigeration Cycle The complete mechanical refrigeration cycle may be illustrated on the rature-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 omoressor at a and compressed at constant entropy (adiabatically) and then delivered to the condenser at b. Condensation occurs at constant temperature 7j from b to c with a contraction from the vapor to the rauid 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 b bi . so a5 So SPECIFIC VOLUME. CU FT PER LB Fig. 2. Theoretical Dichlorodifluoromethane (Fu) 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 t)ie 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 a{). Moreover, expansion may start either with a mixture of liquid and vapor or with a sub-cooled liquid, as at Ci, with expansion to ei. It is obvious that this latter is desirable as it increases the refrigerating effect. Area aibicdaaj represents the work of such a superheated cycle, while the area eiUigi/ie] 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 ' 467 . Heating Ventilating Air Conditioning Guide 1939 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 ternperature 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. , ( <,S ; 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 Ha is known, and also the entropy Sa. Since point b lies near the saturation curve it is customary to assume Sa = Sb and with Tt given, Hb can be determined. If W = work in foot-pounds per pound of refrigerant, then W = (Hb- Ha) X 778 (l) 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. iy = ir^iXP`7>[(lf)!^J-1] . r <2> 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 r 1 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 pier 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. 468 Chapter 23. Cooling and Dehumidification Methods Refrigerating Effect per Pound The refrigerating effect per pound is computed by the same method, rdless of the type of refrigeration system. The solution is indicated n the temperature-entropy diagram of Fig. 2. Assuming that the vapor Paying the evaporator is saturated, the refrigerating effect in Btu per und is obtained by subtracting from the heat content of the vapor at temperature Ti, the heat content of the liquid at Tt, or if the liquid is sub-cooled, the liquid temperature. Thus, the refrigerating effect in Btu per pound is equal to Ha - Hc - fla - He (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 ton, 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. = - T' i\ -- 11 (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 aibiCCie&i. However, the vapor during compression actually follows line atbt 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 bibigihibi 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 ,,e rat* theoretical cycle work to the actual work represents the over all efficiency. It should be noted that area a-ibtbiai is considered as part 469 Heating Ventilating Air Conditioning Guide 1939 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 ' Sources of loss which are usually recognized as reflected by the overall efficiency referring particularly to reciprocating and rotary systems aro 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). y 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 Dichlorodifluoromethane (Fh) 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 r* .-- 1J (6) where c = clearance volume. . d = 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. - 470 Chapter 23. Cooling and Dehumiditication Methods The mechanical efficiency of a reciprocating and rotary compressor be multiplied by the superheat volumetric efficiency to give the derail efficiency of the compressor. Eff.overall = Mech. Eff. = Super. Vol. Eff. X Mech. Eff. . (7) Normally, the volumetric efficiency of a compressor varies with the tio of compression, while the mechanical efficiency remains virtually feed Good standard practices for dichlorodifluoromethane compressors are: Vol. Eff-reexp*. Vol. Eff.super Vol. 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 and air mix with the -impelling steam on the discharge side of the jet. The total mixture of 471 Heating Ventilating Air Conditioning Guide 1939 entrained air, evaporated water, and impelling steam is discharged into surface condenser at a pressure which permits the available condense* medium to condense it. The resulting condensate is removed from th^ condenser by a small pump, from which it can be discharged to the sewe* Fig. 5. Steam Ejector Temperature-Entropy Diagram 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 472 Chapter 23. Cooling and Dehumidification Methods olication, however, the amount of working fluid is different for one 3 rtion of the cycle than for the other. Dry saturated steam under high P ure, 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 "Mansion WOuld occur along isentropic line ab. Actually, however, most, ozzles are only about 90 per cent efficient, the real expansion being along the line obi. Since the exact path of the line abi is not known, the work -rea 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 cxdfgc\ is used in express ing the efficiency of the ejector, the line Cid 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: M^primary -f- MVsecondary = M^'mixture (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. 200 lb per sq In. Steam press. 22 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. Steam press. 12 lb per sq in. Condenser temp. 105 F Steam rate 40 lb per hour per ton Steam rate 70 lb per hour per ton 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 "> Figs. 6 and 7. The rapacity of the reciprocating and rotary compressor varies slowly -with a change of evaporator temperature, and the variance of power Heating Ventilating Air Conditioning Guide 1939 requirements, in the air conditioning range of Operation, is small f0r . 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 23. Cooling and Dehumidification Methods _ water is rather high in temperature;; From Fig. 6 it is evident h t steam jet refrigeration is better suited dor 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, . ........... " jyr 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 qf 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- 474 Fig. 7. Performance Characteristics of Compression Refrigeration Machines at Constant Speed obtain, as for instance in railway air conditioning.1^ 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. Heating Ventilating Air Conditioning Guide 1939 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 froirh 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. 476 Chapter 23. Cooling and Dehumidification Methods Evaporative, Due to the high cost of city water for condenser purposes and due to rdinances in some localities prohibiting the discharge of large quantities f 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 . 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 477 3 & ;:SgaaS : E 1 1 Heating VentiIiAting Air Conditioning Guide 1939 with the cooling coils. Another common and efficient method of coolinp 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 a 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 conseauently 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 -A suction piping should be selected so that the pressure loss is between 2 g 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 ^ 478 Chapter 23. Cooling and Dehumidification Methods .. should be limited to approximately 4 lb per square inch pressure roc All pressure drops mentioned are total system losses and not only include the piping losses, but also the pressure losses in the valves, fittings and coils. . ,. .. ., 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. All 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 condition ing systems to obtain economical results. 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 loadsj but the operating cost ner 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. W. the system may consist of several condensing units and evaporators which are cut in or out, depending upon the demand, or (2) condensing 479 Heating Ventilating Air Conditioning Guide 1939 Table 1. Pressure Losses in Dichlorodifluoromethane Discharge or Hot Gas Lines Capacity BTU pbb Hour Pressure Dkop m Pounds pbb Square Inch per 100 Fib Lxnb Sizes, Inches 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 X 2.3 4.9 8.5 X 1.0 2.0 3.4 5.3 7.5 .X 0.6 1.0 1.7 2.6 3.6 6.4 9.8 IX m IX m 0.6 0.9 1.2 2.1 0.5 0.7 3.1 4.4 6.0 1.0 1.3 1.9 0.5 0.7 0.9 8.0 10.2 2.5 3.1 3.8 1.1 1.4 1.7 0.5 6.0 8.5 11.6 2.6 3.8 5.1 6.7 ip.4 0.7 1.0 1.3 1.7 2.6 3.7 6.7 10.5 2M 0.6 0.9 1.2 2.2 3.5 5.0 9.0 iX -- - 0.5 0.9 1.5 2.1 3.8 5.8 9.5 0.7 1.0 1.8 2.9 4,4 6.4 11.3 *Soft annealed copper tubing up to and including j in. outside diameter. Hard copper pipe % in. outside diameter and larger. bLength of tubing includes the average number of fittings. unit capacity may be reduced by using back pressure regulating valves, by-pass valves, or variable speed compressors. 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. 480 Chapter 23. Cooling and Dehumidification Methods Table 2. Pressure Losses in Dichlorodifluoromethane . Liquid Refrigerant Lines -- Pressure Drop m Pounds per Square Inch per 100 Ft* Capacttt BTtJ pen Hour Pipe Sizes, Inches X IX IX IX _ ---- ' 100,000 0.6 125.000 0.9 150,000 1.3 175,000 1.8 200,000 2.3 0.6 " 225,000 250,000 275,000 300,000 2.9 3.6 4.3 5.1 0.8 1.0 1.2 1.4 325,000 350,000 375,000 400,000 5.9 . 6.9 7.9 9.0 1.6 1.8 2.1 2.3 0.8 450,000 500,000 550,000 2.9 3.5 4.3 1.0 1.3 1.5 0.7 600,000 700,000 800,000 5.0 6.7 8.7 1.8 2.4 3.1 0.8 1.1 1.4 900,000 1,000.000 1,200,000 3.9 4.7 . 6.7 1.7 2.1 3.0 1,400,000 1,600,000 1,800,000 9.0 4.0 5.1 6.3 2.000.QOO 2,200,000 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. Bemuse 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 "ot drop with a rising discharge pressure as fast as the refrigerating effect is reduced. 481 Heating Ventilating .Air Conditioning Guide 1939 Table 3. Pressure Losses in Dichlorodifluoromethane Suction Refrigerant Lines Copper Pipe Actual O.D. Inches Capacity BTU peb Hour Pressure Drop in Pounds per Square Inch per 100 Ft* FRefrigerant Temperature Deq -10 . 0 10 20 30 40 SO 3A m' 2,000 4,000 6,000 8,000 10,000 12,000 14,000 16,000 18,000 20,000 7,000 10,000 15,000 20,000 25,000 35,000 0.3 1.3 2.8 4.8 7.4 10.5 14.0 0.3 1.0 2.2 3.8 5.8 8.4 11.0 14.5 0.4 0.3 1.0 6.7 1.9 1.5 3.3 2.6 5.0 4.0 9.7 7.7 0.2 0.8 1.8 3.1 4.8 6.8. 9.1 12.0 15.0 0.3 0.5 1.2 2.1 3.2 6.2 0.2 0.7 1.5 2.6 3.9 5.6 7.6 9.8 12.3 15.0 0.2 0.5 1.0 1.7 2.7 5.1 0.2 0.6 1.2 2.1 3.3 4.7 6.4 8.3 10.4 12.7 0.2 0.4 0.8 1.4 2.2 . 4.3 0.1 0.5 1.0 1.8 2.8 4.0 5.4 7.0 8.7 10.7 0.2 0.3 0.7 1.2 T .9 3.6 04 (Li 0.9 23 3.3 4.5 5.8 7.2 8.9 0.1 0.3 0.6 1.0 1.6 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 -. ,. .m 10,000 15,000 20,000 30,000 40,000 50,000 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 2.6 2.1 1.6 1.3 1.1 .0.9 0.8 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 30,000 40,000 , 50,000 10.0 1.6 2.7 4.2 7.8 14.0 '\ 6.2 , 11.0 1.3 1.0 2.1 1.7 3:2. .' 2.5 5.0 8.7 13.5- 0.8 1.4 2.1 4.2 . 7.3 11.3 0.7 1.1 1.7 3.5 3.0 6.2 5.2 9.5 8.2 0.6 0.5 0.9 0.8 1.4 1.2 60,000 6.1 . 4.5 3.6 2.9 2:4 2.0 1.7 m . . 70,000 8.7 6.3 4.8 '3.8 3.1 2.6 2.2 80,000 ; 8.4 6.3 4.9 4.0 3.3 2.8 90,000 100,000 120,000 ; .140,000 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 9.5 7.9 *Length of tubing includes the average number of fittings. 482 Chapter 23. Cooling and Dehumidification Methods Table 3. Pressure Losses in Dichlorodifluoromethane Pressure Drop, in Pounds per Square Inch peb 100 Ft* Copfw n? ACTUAL O.U. INCBS3 Capacity BTU peb Hour ------- -------- 50,000 100,000 150,000 . -10 0.7 2.6 . 5.6 Refrigerant Temperature Deg F 0 10 20 30 40 0.5 0.4 0.3 0.3 0.2 1.8 1.4 1.1 0.9 0.8 3.9 3.0 2.4 2.0 1.6 50 0.2 0.7 1.4 200,000 9.8 6.7 5.2 4.1 3.4 2.8 2.4 250,000 14.8 10.3 8.0 6.3 5.1 4.2 . 3.6 300,000 14.5 11.3 9.0 7.2 6.0 5.0 350,000 400,000 19.5 15.3 19.6 12.0 15.3 9.7 12.5 7.8 10.0 6.7 8.5 50,000 100,000 150,000 0.2 0.2 0.1 0.1 0.1 0.1 0.1 0.7 0.6 0.5 0.4 0.3 0.2 0.2 1.6 1.2 1.0 0.8 0..6 0.5 0.4 200.000 250,000 300,000 2.8 2.1 1-.7 4.3 . 3.4 2.6 6.1 4.5 3.7 1.4 1.1 2.1 . 1.7 3.0 2.4 0.9 0.7 1.3 i.i1.9 1.5 2% 350,000 8.2 6.0 5.0 4.0 3.2 2.5 2.0 400,000 7.8 6.5 . 5.1 4.2 3.3 2.7 450,000 7.7 6.4 5.3 4.0 3.5 500,000 550,000 600,000 7.8 6.4 5.0 4.2 7.7 6.2 5.1 7.4 6.2 200,000 300,000 400,000 1.2 1.0 0.8 0.6 0.5 0.4 0.4 2.6 .2.0 1.6 1.3 1.0 0.8 0.7 : 4.5 3.4 . 2.6 2.1 1.7 1.4 1.3 500,000 7.3 5.4 4.1 3.3 2.7 2.2 1.9 3ys 600,000 8.1 6.0 4.7 3.8. .3.1 2.7 700,000 8.4 6.5 5.2 4.2 3.5 800,000 , 900,000 1,000,000 8.6 6.8 5.5 4.6 8.7 7.0 5.9 8.9 7.3 300,000 400.000 500,000 1.2 . 0.9 0.7 0.6 0.5 0.4 0.3 2.0 1.6 1.3 1.0 0.8 0.7 .0.6 3.2 2.5 1.9 1.6 1.3 1.0 0.9 600,000 4.6 3.6 2.8 2.2 1.8 1.5 1.3 700,000 6.4 4.9 3.8 3.0 2.5 2.0 1.7 800,000 8.7 6.4 4.9 3.9 3.2 2.5 2.2 3 900,000 8.2 6.2 4.9 3.9 3.2 2.7 1,000,000 7.7 6.1 4.9 4.0 3.3 1,100,000 9.4 7.3 5.8 4.8 4.0 1,200.000 1,300.000 1,400,000 8.7 6.9 5.6 4.8 8.0 6.6 5.6 9.3 7.6 6.4 `Length of tubing includes the average number of fittings.' Heating Ventilating Air Conditioning Guide 1939 Table 3. Pressure Losses in Dichlorodifluoromethane Suction Refrigerant Lines (Concluded) 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 hjgh air temperature, some effort is made to keep the humidity lower than usual. . Fig. 9. Open Solid Material Adsorption System 484 Chapter 23. Cooling and Dehumidification Methods Silica Gel Silica gel has two applications when used to replace refrigeration. In h one principally used, the air from which moisture is to be extracted is t ken 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 laves at a lower dew-point and a higher sensible temperature than, those t 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 mount 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 applied 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 first 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 485 Heating .Ventilating Air Conditioning Guide 1939 the weight of the adsorber. The time allowable for reactivating is equal to the time occupied by the second unit adsorbing alp.ne, 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'actiyated 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- Conditioned air Dry bulb dependentupon cooling medium * 580.p. Recirculated. {liquid 82 ------------------1---- "'"Liquid distributor - /Liquid in tank 89 Regenerated liquid 100; Unconditioned air Inlet 90 D. 8. 75 W. B. 66 D. P. Liquid, distributor Regenerator . .. 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 rrtargin 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 form of water from the water vapor that is iti 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 furictiori of the amount of water vapor condensed from the air stream. . 4&6 Chapter 23. 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 mall 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 ooint 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 ^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. This type of system is not limited to lithium chloride, as calcium, zinc or barium chloride and various combinations of halogen salts may also be used. . CLOSED ABSORPTION SYSTEMS The fundamental rule governing the absorption (in a dosed system) of a gas by a liquid is Raoult's Law, which states that at any given temp erature the ratio of the partial pressure of a volatile component in a solution to the vapor pressure of the pure component at the same temp erature 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 487 . 1 I. Heating Ventilating Air Conditioning Guide 1939 present in the solution are equal. Actually, no such solutions exist that deviations from Raoult's Law are always found in practice. T^ deviation is called positive when the observed pressure is greater than th t calculated from Raoult's Law, while the term negative deviation refe to the opposite case. Negative deviations are found wherever chemical attraction exists between the solvent and the solute. Positive deviatio occurs when there is a difference in the internal pressure of the comn 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 refriv erant in the liquid absorbent, because, the larger the negative devia tion, the greater is the amount of refrigerant that can be cycled, usin(j 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 Fig. 11. Closed Absorption System and the absorbent. Only the latent heat of the refrigerant can be recovered for useful work. Many refrigerant-absorbent combinations have been -proposed and quite a number have been.tested. Fig. 11 is a diagrammatic representation of a typical closed absorption system. In this system a mixture of refrigerant and absorbent is evaporated in the generator, passes to an analyzer and rectifier where it is purified, and then to a condenser where the refrigerant and remaining absorbent is condensed. It then passes. through an expansion valve to an evaporator, where heat is absorbed from a cooling load. From the evaporator the vapor and residual ab sorbent passes to an absorber" where it meets absorbent which is ini tially low (weak) in refrigerant concentration. The absorbent absorbs the vapor, and the strong absorbent liquor is transferred to the generator through, an interchanger with the weak liquor returning from the generator. A cooling medium, ordinarily water, is used in the absorber to remove . 488 Chapter 23. Cooling and Dehumidification Methods ^ heat of absorption and maintain the absorptive power of the absorber at a maximum. , T ke the steam ejector system, the absorption system compares most Urably when a cheap source of cooling water and steam or other Lt source is available. Unlike the ejector system, the comparative rformance 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 /j) water and ammonia and (2) monofluorodichloromethane 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. Evaporative cooling is being used advantageously in many parts of the country. By using all outside air in sufficient volume to increase the air motion in an occupied space and to limit the temperature rise of the air to approximately 8 F an entering wet-bulb temperature as high as 70 F will result in effective evaporative cooling. 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 tefnperature 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, - T, where Ti = absolute temperature of evaporator. Fi = 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 489 Heating Ventilating Air Conditioning Guide 1939 and 4 or 5 times practically, as the work put in. There are a number 0f limitations, however, the most serious of which is the lack of ready availability of a practical source of heat. 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 The use of ice for air conditioning is becoming more adaptable particu larly for the smaller commercial installations where first cost is paramount and where the operating period is limited to only a few hours per day. Restaurants serving only one or two meals per day, tea rooms, meeting halls and other comparable installations have found ice to be advan tageous in comparison with other methods. Local ite manufacturers will furnish complete data for this type of system. . i f i PROBLEMS IN PRACTICE . .\ . 1 Electrically .driven dichlorodifiuoromethane 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 fuU load at speed. At Vi speed, full load is y2 total bhp of full load speed. `. - ' ' 490 23.Chapter Cooling and Dehumidification Methods Discuss the considerations involved in making a decision as to whether a single nit with a 20 hp motor of the 2 speed type would be used in preference to -10 hp constant speed units. The cost of 2-10 hp 10 ton units in excess of 1-20 hp, 20 ton unit with 2-speed motor, is 1830.00--1210.00 or $620.00, increased first cost. At 15 per cent fixed charges, this jfpresents 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 H 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'witb the following data on partial load operation, determine the seasonal power cost at 2 cents per kwhr: 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 Wh'-Bclb Thmpibatubs F Ton-Hours . Kwhr - 80 79 - 75 74 - 70 69-65 64-60 59 - 55 54-50 Totals 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 = 1,860 181,824 ton-hours 158,627 kwhr 491 Heating Ventilating Air Conditioning Guide 1939 The 158,627 kwhr at 2 cents per kwhr will cost 83,173. . . 158,627 kwhr .. The average consumption will be igl 324 ton-hours ~ '873 kw ^ ton' 3 Using the data from Question 2, if city water costs 20 cents per thousan(> gallons, and if 1,25 gallons are used per minute per ton, estimate the ann^ water cost. 60 X 1.25 *= 75 gal per ton-hour. 181,824 ton-hours X 75 -- 13,620,000 gal per year. 1--3',-6--2--0-.-0--0--0---X----$--0--.-2--0- -- $2,7T2O4. the year.ly coo.l.ing wat. er cos.t. . 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 dichloro? difluoromethane refrigeration system if the final temperatures of the Water leaving the cooling tower and the kilowatt input per ton are the folloviog. Tons Temperature of water leaving tower, F Kw input per ton 284 233 183 157 144 79 37 86.7 81.8 76.5 72.1 66.4 61.3 55.6 1.10 0.94 0.85 0.80 0.74 0.59 0.62 Wet-Bulb Temperature P 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 Kwbr X 1.10 X 0.94 X 0.85 X 0.80 X 0.74 X 0.59 X 0.62 = 1,875 21.900 43,300 41.400 29,500 7,370 1,200 Totals181,824 ton-hours146;545 kwhr* 5 6 The 146,545 kwhr at 2 cents per kwhr will cost $2,931. The average consumption will be ^gihours " 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 per 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 dehumidifying in j 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 coils or by mixing with by-passed air. .* For a set air velocity and a set mean refrigerant temperature, a given cooling cos! 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-buib temperature of the conditioned space. This means then that * the final dew-point will vary somewhat depending on entering air conditions. t Summarizing then, the air washers permit close control over both final dry-bulb and c final dew-point temperatures, while the surface coolers permit close control over the } final dry-bulb only. - I - . `j. 492 Chapter 24 heat transfer surface coils Coil Applications, Construction and Arrangement, Steam Coils, Water Coils, Direct-Expansion Coils, Flow Arrangementis, Applications, Calculation of Heat Transfer, Air Flow Resistance, Coil Performance, Selection THE coils described in this chapter are used in air conditioning sys tems for heating or cooling an air stream under forced convection. The surface coil equipment may be made up of a number of batiks assembled in the field, or the entire assembly may be factory constructed. The applications of each type of coil are limited to the field within which it is rated. Other limitations are imposed by code regulations, by proper choice of materials for the refrigerants used and the condition of the air handled, or by an economic analysis of the possible alternates on each installation. . For heating service, these coils are used as preheaters, reheaters or booster heaters, (see Chapters 21 and 22). The function of the coils is air heating only, but the apparatus assembly may include means for humidi fication and air cleaning. Steam or hot water are the usual heating media, although others are used in special cases such as, reheating by means of discharge gas from a refrigerating system. Coils are used for air cooling with or without accompanying dehumidi fication. Examples of cooling applications without dehumidification are precooling coils using well water or other relatively high temperature water to reduce the load on the refrigerating machinery, or water cooled coils to remove sensible heat in connection with chemical moistureabsorption apparatus. By proper coil selection it is possible to handle both sensible cooling and dehumidification together as further explained later. The apparatus assembly usually includes an air cleaning means to protect the coil from accumulation of dirt and to keep dust and foreign matter out of the conditioned space. Although cooling and dehumidi fication are the usual functions, there are cases of cooling coils purposely wetted as an aid to air cleaning and odor absorption. The usual cooling media used in surface coils are cold water and volatile refrigerants such as dichlorodifluoromethane and methyl chloride, but others are used in special cases. Brines are seldom required for the range of applications covered by this chapter, although there are cases where low entering air temperatures with large latent heat loads require a refrigerant temperature so low that water becomes impractical. Some- 493 Heating Ventilating Air Conditioning Guide 1939 times, also, brine from an industrial system already installed, is the only convenient source of refrigeration. For combined cooling and dehumidifying, surface coils present an alter nate to spray dehumidifiers. For many applications it is possible, by proper selection of apparatus, choice of air velocities, refrigerant temperatures etc., to perform the same duty with either. 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 considered. 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 the dew-point, and hence a dew-point control can be arranged by using a simple duct thermostat. Spray dehumidifiers have the advantage over unwetted coils of a certain degree of air cleaning and odor absorption. On the other hand, coils make possible a closed and balanced cooling water circuit, obviating the unbalanced pumping head, the complication of water level control, and danger from possible floods incidental to multiple-spray dehumidifiers, especially if located on different levels. The use of coils often makes it possible for the same surface to serve for summer cooling and winter heating by circulating cold water in the one season and hot water in the other, with consequent saving in apparatus and piping. Surface-coil dehumidifiers seldom deliver saturated, air, and wet bulb depression of 0.5 to 4 F (or more) is usual. Another, advantage is that where the surface coil system can be used with direct expansion of refrigerant, it is comparatively low in initial and operating costs. Of course the safety of the occupant must be kept in mind in comfort con ditioning applications. Some localities have refrigeration codes which restrict the use of direct-expansion coils in the air stream, and hence local codes should be consulted by the engineer before a system employing direct expansion methods is designed. The choice between spray dehu midifiers and coils depends upon the necessities and the economic aspects of each case arid no general rule can be given. There are many instal lations in which either can be used. COIL CONSTRUCTION AND ARRANGEMENT Coils are basically of two types,-those consisting of bare tubes or pipe and those of extended surface construction. The former are little used for the applications covered by this chapter, but are often employed where conditions cause frost accumulation, and for cooling surface within spray dehumidifiers. - The heat transmission from air passing over a tube to a refrigerant flowing within it, is impeded by three resistances. The same is true when the air is being heated by steam or hot water in the tube. The first resistance is from the air to the surface of the tube, usually called the outside surface resistance or air-film resistance. Second is the resistance to the flow of heat by conduction through the metal itself. Finally there is another surface or film resistance to the flow of heat between the inside, surface of the metal and the fluid in the tube. For the applications under consideration both the resistance of the metal wall to heat conduction, , 494 Chapter 24. Heat Transfer Surface Coils and the inside surface or film resistance are usually low as compared with the air-side surface resistance. This is especially the case where sensible heating or cooling only is accomplished. Where dehumidification accom panies sensible cooling, or where the external surface of the tube is sprayed with large quantities of water, the resistance to heat flow between the tube and the air flowing over it is much decreased. In the case of the water spray, the surface resistance depends on the amount and the method of application of the water. Economy in space, weight and cost make it advantageous to decrease the external surface resistance, where it is proportionately large, to approach that of the tube wall, and that from tube to refrigerant. This is accomplished in heating coils by increasing the external surface by means of fins. For cooling or dehumidification without external water spray, fin surface is also commonly used. With water spray the external resistance is already low, and the fins are less useful for increasing the overall heat transfer. Sometimes water spray is Spiral fins o o S' "S r> o Z o o z _ i1 1 I m1.1 o o Flat corrugated fins Flat square fins Fig. 1. Types of Fin Coil Arrangement applied to the same type surface as would have been used without it. The overall heat transfer is not necessarily increased much by such an arrangement, but the water spray may serve other purposes than to in crease the flow of heat, such as air and coil cleaning. In fin or extended surface coils the external surface of the tubes is known as primary and the fin surface is called secondary. The primary surface consists generally of round tubes or pipes. In some cases these are staggered and in others in line with respect to the air .flow. The staggered arrangement gives a somewhat higher heat transfer value but also a higher resistance to air flow and in some cases makes the header and return bend arrangement more complicated. A number of types of fin arrangement are used, the most common of which are spiral, flat arid flat-crinkled or corrugated, all as shown in Fig. 1. While the spiral fin surrounds each tube individually in all cases, the flat types may be con tinuous (including several rows of tubes), or they may be round or square, with individual fins for each tube. All of these, as well as other less types are in use, the selection for a particular installation being a- jn econ?mic considerations, space requirements and resistances of individual designs of coils. A most important factor in the performance ol extended surface coils is the bond between the fin and the tube. An intimate contact is assured in a number of ways. The assembled coil may ue coated with tin, zinc, etc., after fabrication. The spiral type fin may oe knurled into a shallow groove on the exterior of the tube. The tube 495 Heating Ventilating Air Conditioning Guide 1939 may be expanded after the fins are assembled, or the tube hole flanges of flat or corrugated fin may be made to override those in the precedm* fin and sc compress them upon the tube. There are also types of co 8 struction where the fin is formed out of the material of the tube itself, f any case the successful performance of a fin surface depends upon" th bond between fin and tube being secure and remaining so in service6 For heating coils the materials most generally used are copper, steel and aluminum. Sometimes aluminum or brass fins are used on copne tubes. Steel is uncommon except in special cases. Some types of heatme coils are made of cast-iron. There are sufficient practical installations of each of these to demonstrate that they can all give good service. The . Chapter 24. Heat Transfer Surface Coils all space demand, but the resistance, both over the surface and through Sf?1 tubes, is higher than with larger tubes and more widely spaced fins. Moreover, too close a fin spacing may result in trouble from dirt accumul tion especially on dehumidifying coils, and may also cause trouble la 'water hold-up between the fins, particularly with air flow ertically upward. This condition increases the air resistance and de ceases the capacity of the coil. Water hold-up sometimes causes flooding trouble in vertical air flow units by accumulating too much water for the drain to handle all at once when the fan is stopped. Steam Coils , For proper performance of steam heating coils, condensate and air must be continually eliminated and the steam must be evenly distributed to the individual tubes. This distribution is usually accomplished by individual orifices in the tubes, by distributing plates and orifice in the steam header, or by perforated internal steam-distributing pipes extending Fig. 2. Various Water Circuit Arrangements copper coils are frequently tin-dipped and steel coils galvanized to protect them from corrosion and to assure a bond between fin and tube. For heating applications copper tubes and fins are the most commonly used. Cooling coils for water or for volatile refrigerants are most frequently of copper, both fin and tube. The coil may or may not be tin-dipped, depending on the type of bond between tube and fin. Aluminum fins on copper tubes are also used. For brines such as sodium or calcium chloride and for ammonia, steel fins and tubes are common. Although there are many variations for special cases, tube and fin sizes and spacings for air conditioning coils, both heating and cooling, fall within fairly narrow limits. The tubes are usually %, }/, or % in. OD, and the fins spaced from 4 to 8 per inch, 6 per inch being a.common design. The tube spacing generally varies from about lj/g to 2 in. on centers. Small tube size and close fin spacing give large capacity with 496 Fig. 3. Direct-Expansion Coil with Flooded System Fig. 4. Direct-Expansion Coil with Thermal Valve System into the individual tubes. The latter arrangement has the advantage of distributing the steam throughout the length of each tube, and is con ducive to uniform delivered air temperatures. The tendency for freezing of condensate at the bottom of the coil with cold entering air and light heating loads is also minimized. This is especially valuable for outside, air preheaters. Methods of air and condensate elimination are discussed in detail in Chapters 15, 16 and 22. Water Coils The performance of water coils, for heating or cooling, depends on the elimination of air from the system and proper distribution of water. Air elimination is taken care of in the system piping as described in Chapter 17. To assure a pressure drop sufficient for adequate distribution but at the same time to provide against excessive pumping head where large water quantities are handled, water coils are provided with various water circuit arrangements. For instance, a typical coil 18 tubes high and 6 tubes deep in the direction of air flow can be arranged for 6, 9, 18 or 36 parallel water circuits as conditions may require. Orifices in individual tubes are occasionally employed blit are usually unnecessary as the Heating Ventilating Air Conditioning Guide 1939 resistance of individual water circuits is generally sufficient to effect a satisfactory distribution. In cases such as well water precooling coils where there may be considerable sand and other foreign matter in the water, provision for cleaning of individual tubes is of advantage. It js important to arrange water coils for drainage if located where they will be exposed to freezing. For this reason the circuits should be so laid out that there are no pockets to hold water. Fig. 2 shows such construction. The drains may be provided in the water piping although they are often arranged in the coil headers. Direct-Expansion Coils Coils for volatile refrigerants present more complex problems of fluid distribution than do water, brine or steam. It is desirable that the coil be effectively and uniformly cooled' throughout, and necessary that the Chapter 24. Heat Transfer Surface Coils through the coil per thermal valve to keep the pressure drop through the refrigerant circuit within practical limits and to reduce the corresponding penalty in increased evaporating temperature. At the same time the coil must be so arranged that the required suction superheat can be attained with a minimum sacrifice in the performance of the coil as a whole.' It is general practice to attain this superheat. within the coil itself and not by the use of external heat exchangers or other auxiliary devices. With thermal expansion valves it is advantageous to keep the pressure drop through the refrigerant feeds as low as possible. The feeds are laid out to expose each to the same mean temperature difference so that it handles the same refrigerating load. A distributing means is imposed Air flow Fig. 5. C Types of Refrigerant Feed Distributing Heads compressor be protected from entrained, unevaporated refrigerant. There are two types; namely, flooded systems, and thermal expansion valve systems, as shown in Figs. 3 and 4. With flooded control the coils are supplied with liquid by the same type\of circulation that exists in a water tube boiler, while the level in the surge drum is maintained by the action of the float regulator, or by properly charging the plant in the case of the high pressure float drainer. The thermal expansion valve system depends upon the thermal valve automatically feeding just as much liquid to the coils as is required to maintain the superheat at the coil suction .outlet within predetermined limits which ' vary from about 6 to 20 F. The thermal valve arrangement is in common use for the type of coils covered by this chapter, while the flooded system is comparatively rare. With the flooded system the refrigerant distribution through the tubes depends on properly selecting the length of the feeds and the head of liquid imposed upon the liquid inlets. No auxiliary distributing devices are required. With the thermal valve system there are two factors to consider. There must be, generally, more than one refrigerant feed 498 Fig. 6. Arrangement for Superheating at Air Outlet Fig. 7. Arrangement for Superheating at Air Inlet between valve and coil liquid inlets to divide the refrigerant equally among the feeds. Such a distributor shall be effective for distributing both liquid and vapor, since the. entering refrigerant is a mixture of the two. Fig. 5 shows three typical types of distributors. In distributor A the liquid and gas mixture from the thermal valve is led tangentially into a chamber. The coil feed connections extend outward radially at the top of this chamber. In distributor B the refrigerant is discharged at a high velocity through a central jet against the end plate, forming a uniform mixture of gas and liquid within the distributor, from which individual connections are led as shown. In type C the refrigerant enters at high velocity from the thermal valve and is discharged against the end plug in which the individual liquid feeds are closely arranged. These distribu tors can be used in either vertical or horizontal position. Although there 499 Heating Ventilating Air Conditioning Guide 1939 are other forms of distributors the above are typical examples. Xh individual liquid connections from the distributor to the coil inlet ar* commonly made of small diameter tubing and are all of the same leneth and diameter in order to impose the same friction between the distribute and the coil. Since the thermal valves act in response to the superheat at the coil outlet, this superheat should be produced with the least pos sible sacrifice of active evaporating surface. Where conditions require a coil which is thin in the d.rection of air flow, with large quantities of air per ton of refrigeration, the temperature difference between leaving air and refrigerant is large and it is, therefore, practical to feed the coil in the direction of the air flow as shown in Fig. 6. If the refrigerant temperature Chapter 24. Heat Transfer Surface Coils s of relative flow in common use. Fig. 10A shows parallelflow in which tuP7ir and the medium in the tubes proceed through the coil in the same d?e ctjon pig. 10B shows counter-flow in which the media in the tubes oceed in a direction opposite to the flow of air. Fig. IOC shows crossg"; ^ which the air and heating or cooling media pass at right angles to 0ther. Parallel-flow is often used in coils fed with volatile refrigerant eaCjt is characterized by a fall of refrigerant temperature in direction of flow dUe to the pressure drop through the refrigerant circuit. Cross%ru> is common in steam heating coils, the temperature within the tubes heine substantially uniform, and the mean temperature difference the came whatever the direction of flow, relative to the air. Cross-flow is also used in very thin coils with brine or water or volatile refrigerants, it being impractical to arrange these coils any other way. The counter-flow arrangement or some modifications of it is used almost universally in is high and the air quantity per ton low so that the leaving temperature difference becomes small, it.is expedient to arrange the circuits so that the refrigerant is brought back to the air inlet side pf the coil to take ad vantage of the large temperature difference at that point for. superheating, as in Fig. 7. Sometimes a single thermal valve is used per coil. In other cases multiple valves are used, with the coil divided across the air flow or parallel to it as shown in Figs. 8 and 9. The arrangement of Fig. 9 has the disadvantage of unequal load on the two parallel circuits. The choice between face or thickness division is dictated by the type of auto matic temperature and humidity control used. Flow Arrangements The relative direction of flow of the air outside the tubes and the media within them influences the performance of the surface. There are three brine or water coils which are deep in the direction of air flow, to take advantage of the highest possible mean temperature difference for given entering'water and air temperatures. Counter-flow is frequently used in coils fed with volatile refrigerant to take advantage of the higher air temperature for superheating the leaving gas. This arrangement permits complete evaporation. of the refrigerant and proper operation of the thermal expansion valve. Applications Heating coils in field assembled banks are used for a number of pur poses as described in Chapter 21. They may be arranged with the air flow vertical or horizontal, although the latter is more common. For steam heating the coils may be set with the tubes vertical or horizontal. In the latter case the coil should be sloped to provide for condensate drainage. Because of the multi-circuit feed arrangement and the neces sity for avoiding air and water pockets, water heating coils are generally arranged with the tubes horizontal. Certain precautions must be taken against freezing. Where steam coils are used with entering air below 501 Heating Ventilating Air Conditioning Guide 1939 freezing temperature, throttling the steam supply may result in freezing the condensate in the bottom of the coil if the tubes are of the variety noj provided with internal distributing pipes, or an equivalent arrangement If these are used, there is little danger of freezing the condensate as long as the leaving air temperature is not allowed to fall below about 40 F As an added precaution with both steam and water coils the outside air inlet dampers are often closed automatically when the fan is stopped to avoid trouble caused by very cold outside air drifting in during off periods. A typical arrangement of water cooling coils is shown in Fig. 11. Some means should be provided to filter all the entering air to keep dirt and foreign matter from accumulating on the coils. The assembly is provided with a drip-pan to catch the condensate during summer dehumidifying duty and to collect the non-evaporated water from the humidifying sprays Chapter 24. Heat Transfer Surface Coils r the first tyPe a set of spray nozzles is arranged for intermittent cleaning. The operator can wash the coils off as frequently as necessary. These 1 ravs are not operative when the system is in use and no recirculating SP p is provided. The second arrangement requires a collecting tank ^nd a recirculating pump. The water is in circulation whenever the noaratus is in operation, and assists in keeping the coil clean and in absorbing odors. Fig. 13 illustrates such an arrangement. Wherever air by-pass65 are used around a coil on summer duty for control purposes, it is of advantage to direct only return air through the by-pass rather than a mixture of return and outside air. The casing should be arranged accordingly. To maintain the air quantity handled by the fan reasonably crnstant, and to assure the required design quantity of by-passed air Drain ^Insulation Drip pan Fig. II. Typical Arrangement of Cooling Coils in a Central System in winter. The drip connection should be made ample in size and liberally provided with plugged, tees and crosses for cleaning; It should not be exposed to freezing temperatures in winter if the apparatus is used on winter humidifying duty. Access doors should be provided for servicing filters, humidifying nozzles, and fan bearings and for cleaning the coils. With certain designs of coils when.used for dehumidifying, eliminators must be used beyond the coil to catch any water which may be blown into the air stream. It is customary to include these eliminators when the air velocity exceeds about 450 fpm with the individual fins and about 600 fpm for the continuous flat fin type. Where a number of coil sections are stacked one upon another, and where the velocities are low, so that eliminators need not be used, occasional trouble results when water splashes down from one coil to the next and blows out into the air stream. In such cases drip troughs as shown in Fig. 12, are used to collect this water and conduct it to the condensate pan. .. Sometimes finned surface coils on summer cooling and dehumidifying duty are provided with water sprays. These sprays are of two types. . 502 m. Drip tube to condensate pan Fig. 12. Coil Arranged with Drip Trough . Fig. 13. Recirculating Spray System for Cleaning Coils when the by-pass damper is open, cooling coil banks are frequently furnished with both face and by-pass dampers as shown in Fig. 11. Although both heating and cooling coils are made of sufficient strength' to take up expansion and contraction arising within themselves, care should be taken to avoid imposing strains from the piping on to the coil connections. (See Chapters 16 and 17). HEAT TRANSFER AND AIR FLOW RESISTANCE The transfer of heat between the heating or cooling medium and the air stream is influenced by several variables: 1. The magnitude of the driving force, i.e., the temperature difference. 2. The design and surface arrangement of the coil. 3. The velocity and character of the air stream. 4. The velocity and character of the medium in the tubes. The driving force is usually taken as the logarithmic mean temperature difference for heating or cooling without dehumidification. For combined 503 s- Heating Ventilating Air Conditioning Guide 1939 cooling and dehumidification, a special measure of the propelling force i used as described later. Logarithmic differences are generally employed in practice although there are special flow relationships used, such as cross-flow, where they do not strictly apply. With volatile refrigerants there is often an appreciable pressure drop and corresponding change in evaporating temperature through the refrigerant circuit. The problem is further complicated by the fact that the refrigerant is evaporating in part of the circuit and superheating in the remainder. In spite of this heat transfers and ratings for coils using volatile refrigerants are usually based in practice on a refrigerant temperature corresponding. to the pressure at the coil outlet. ; The design and surface arrangement of the coil includes such items as : materials, type, thickness, height and spacing of the fins, and the ratio of this surface to that of the tube, the use of the staggered or in-line tube arrangement, and provisions to increase the air turbulence such as the ' use of corrugated as against flat fins. Staggered tubes increase the total, heat transfer as against the in-line arrangement and corrugated fins are more effective than flat. Of especial importance is the bond between fin and tube. The velocity of the air usually considered is the coil face velocity. This bears a varied relation to the actual velocity over the surface, de pending upon the individual coil design. As long as a fixed design of coil is under consideration face velocities may be used, but they may be unsatisfactory in comparing different designs, as it is the actual surface velocity that is significant. The air volume is often based on standard air' at 70 F and a barometric pressure of 29.92 in. Hg. The use of air volume in coil rating information may be misleading. The significant value is mass velocity in pounds per minute and not cubic feet per minute, because for a fixed volume the corresponding weight may vary widely, depending upon the air density, temperature and barometric pressure under consideration. . ; : At the same mass air velocity, varying performance can be obtained depending upon the turbulence of the air flow into the coil and upon the uniformity of distribution of air over the coil face. The latter is very im portant in obtaining reliable test ratings and in realizing rated performance in practical installations. The resistance through the coils will assist in properly distributing the air, but where the inlet duct connections are brought in at sharp angles to the boil face, the effect is frequently bad and there may even be reverse air currents through the coils. This reduces the capacity, but can be largely avoided by proper layout or by the use of directing baffles. " . : ; ] The heat transfer depends also upon the velocity of the medium in the tubes and upon its character, whether flowing water, condensing steam or evaporating volatile refrigerant. In the latter case, the effect is complex because of the combination of evaporation and superheating, and because of the influence of pressure drop in the refrigerant circuit. Heat transfer rates expressed as Btu per square foot of internal surface per degree logarithmic mean effective temperature difference between the fluid and tube wall are, for example, about 150 to 300 for evaporating dichlorodifluoromethane, about 350 to 1200 for water at 2 and 6 fps and about ] j . Chapter 24. Heat Transfer Surface Coils 1900 for condensing steam. The influence of the medium in the tubes on overall heat transfer rate is, therefore, apparent. Because of these variables, reliable rating and performance information i any design of coil must be based on actual tests on that coil under the nected conditions of operation. A comparison between the perfor mance f two designs, unless based on such tests on each, may lead to entirely erroneous conclusions. Heating and Dry Cooling Coils To find the surface requirements for heating or dry cooling coils, the heat transfer coefficient U and the dry-bulb mean temperature difference mi'st be known. It has been found that U can be expressed as an ex ponential function of the mass air velocity. If Ui is known at a given velocity Vu its value at another velocity V3, can then be found by the Equation 1. t/./CT, = (V,/V,) (1) This relationship can also be represented on logarithmic paper as a straight line of slope n. The value n must be determined by test as it is dependent upon the coil design. For coils in common use, n ranges from about 0.4 to 0.8. For a given design, n will depend upon the coefficient of heat transfer from the fluid in the tubes to the tube wall, so that n will be higher as the water velocity in the tube increases, and will be higher for condensing steam than for water at low velocities. A coil that is several rows deep will have a higher n than one of the same design with fewer rows. For heat transfer information as well as values of n for typical coils, see Table 1. To avoid the labor of coil selection by use of heat transfer coefficients and mean temperature differences, the ratings of heating and dry cooling coils are frequently set up in tables from which, for known conditions, a coil can be selected directly. Dehumidifying Coils When air passes through a cooling coil, the temperature of which is lower than the dew-point of the air, there is a removal of both sensible and latent heat. The sensible heat transfer process is exactly the same as in heating and non-dehumidifying cooling coils. The moisture passes from the air to the cold surface by diffusion. . It is evident that the coil may be wet throughout or, because of tem perature gradient through fins or temperature range in the refrigerant, may be partially dry and partially wet. In this case, part of the coil acts as dry and part as dehumidifying surface. Various approximations are used for this condition as the percentages of wet and dry surface and the temperatures applying to each are difficult to ascertain. One approxi mation is to assume that for ratios of total to sensible heat of 1.10 or more the coil is to be treated entirely as wet, and for ratios less than 1.10 entirely dry. ' Although much research has been already conducted and more is in progress, there is no general agreement as to the most satisfactory and convenient manner in which to rate dehumidifying coils. A large number of methods are now in use, most of them combinations of theory and 505 Heating VentiiiAting Air Conditioning Guide 1939 &ag$ ^fafa ooooooooooooooo ooos>o:ftHcoHHOooio (QOOOOOOOOOQO)0)N<O os co "JWhoos^ cdoOOOt>lNW5^;^ o u Un . 2 . 'SUZ D u 06 u; ; 06 w .a- Is o O fe. Mag o~ US '5Z HQ as * '-1 ' 2H .< -3 i-S 5s afa cn as .a H o tL, & D g'O. CO 00 t- t- b- !Nt> : b- CD ! : b- ICQb-b'. :tc* : i : : r-t ^ co jco*H ; : t-H i i-H rH ' |A kQ lO l| tQ U) NNWWNN CO O CO CO CO CO 00000*0 ! CO CO CO iooo SCO CO ido o o- a> 0) C/5 C/3 :I <cv < bcco bo t*> bh-*-> -> 4(-01 4t-O1 cd ' rt rt -rW c -M W C/5 --C/5 C/5 Cu/5c(oJp^- L) cd cd uu ^C^COCOCO^*--IC^---(t-HCOr . _ . - . _ ! 4> <U u QJ CJ 4)'D iO bo.Qj3 bojD bi bo b/tja to bo bo bo . cbdo bcdo bcdo bcod bcdo brot bcoo bcdo bcdo . di <m'iq loiouoiddjiototdc^ojioio EEEEEEEE'EEEEEES cOd cdvcod cvd ocd ocd ocd-vcdccdjucd icidiocd ucd ocdocd ,C/5i75(/5C/5C/5C/5C/5C/5C/5(y5COC/5COC/5C/5 v _j *-- l co 4 , j, 4) C<DO <(AU__JJ 4C>O C4O> _J. . ;H.2 J--i --t^cd f-Hi -i ^cd --i *0.0 ; <u,o a3-<B o b -"u uo u JGJS OO JC -C DUo 2 S: 1U). wldSeeidEb S.OmEo Eo,oEmw Eo o ospsuuupsoi* vco oto CEc oco o<to5 EeC eCE 11 D O D 1) O O &04U&P4UU f-UNCO^tOOt^COOfiOi-cC^CO-^iO 506 t^OOCJOt>.bCOcOK - ^^ - co^^b-b-cocON fiO ub.tO c<MococNJoCbO-tbo-tto^tt^obrn; oooooooo ' co co. ; <n O -h co -d< ride .2.2.2 ..... cco Sc5 *5c3 aid aerf aofamoer.f 2g- Sg3- 5g wnnnnWUW cd cd cd cd cd . .J- cd [cd 2dj-cj^Ju3 uauiauiJo3 EEfeE!3EES EEaHEES UOUoOaC>OCi>P^COUUOO.Cv Chapter 24. Heat Transfer Surface Coils moirical presentations of test data. Information is given, usually in the form of tables or curves to determine the total cooling capacity, with * inplementary devices to ascertain the proportions of sensible and latent. Sometimes the presentation of data is simplified, often at the expense of. flexibility and coverage, by setting up tables covering limited and specific air and refrigerant conditions, in which total, sensible and latent capacities are set forth directly. Some of the methods now used require trial and error solutions and others are of very questionable accuracy, although the grror may be small when applied within narrow limits of the several variables. It is hoped that investigations now in progress will lead to a convenient and reasonably accurate method of rating which can be widely adopted. ' In rating dehumidifying coils, there are two requirements.. The total capacity must be determined and the proportion of sensible and latent heat transfer ascertained. These determinations often involve an average coil surface temperature. This may be determined experimentally by the use of thermocouples or calculated theoretically from other test data. Sometimes, a fictitious temperature is used, determined by the point of intersection between the saturation curve on the psychrometric chart and a straight line drawn through points representing the entering and leaving air conditions. '. The total cooling capacity is determined in a variety of ways, of which the following are the most usual: 1. The use of surface or overall heat transfer coefficients in conjunction with dry-bulb mean temperature differences. The result is corrected for dehumidification by means of functions for: (X) the temperatures differences, (2) the expected total to sensible load ratio, and (3) empirical factors determined from test. 2. The use of surface or overall coefficients for combined sensible and latent heat removal with a wet coil, using as the driving force the difference between heat content of the entering air and that of saturated air at either the surface or the refrigerant temperature. 3. The calculation of sensible and latent capacities separately. The sensible is based on dry-bulb mean temperature difference and heat transfer while the latent is deter mined using a dew-point mean difference and a corresponding latent heat transfer value. 4. The use of a contact factor or ratio of heat removed to heat removable. This factor, is a function of coil depth and air velocity, is experimentally determined for each design' and used in.conjunction with a so-called surface temperature. The total capacity is influenced by the factors already enumerated and, as with dry cooling or heating coils, the air velocity correction is an exponential function of the mass air velocity. Unless the sensible and latent capacities have been separately calculated as in item 3 above, various means are used to determine these. The slope of a straight line on the psychrometric chart connecting points representing the entering and leaving air conditions gives a direct means of fixing the proportions of sensible and latent heat removal. Such a line is termed the load-ratio line. 'For given entering air conditions and a required proportion of sensible and latent cooling, the load ratio line may therefore be drawn, its slope being determined by the temperature and moisture content coordinates of the psychrometric chart used. . ; To satisfy the performance requirements, the point representing the' leaving air conditions for a coil chosen to give the necessary total cooling capacity must also fall on this line. 507 Heating Ventilating Air Conditioning Guide 1939 Some of the common methods of coil rating are based on the assumption that the load ratio line for a given coil under given operating conditions not only passes through points representing the entering and leaving air conditions, but also intersects the saturation curve at a temperature fictitiously referred to as the coil surface temperature, see Fig. 14. This surface temperature is higher than the refrigerant temperature by an amount proportional to the total cooling load, and determined by tests for each design of coil. For a selected coil, therefore, the load ratio line can be determined after such tests have been made. The chosen coil will not satisfy the required performance unless the coil load ratio line coin tides with that of the required duty, a condition requiring a trial and error process. This entire method is not suitable when the proportion of latent heat load is high, because the true load ratio line fails to intersect the saturation curve. Tangent to saturat on line TSaturat on line hr ring airLoad r; tio line. DRY-BULB TEMPERATURE Fig. 14. Load Ratio Line on PsYCHROMETRIC CHART DRY-BULB TEMPERATURE Fig. 15. Approximate Maximum Load Ratio or Latent Heat Load Having selected a coil for which the load ratio line and total capacity meet the estimated load requirements, the condition of the leaving air can be located on the load ratio line by separately determining from rating tests and psychrometric information, any quantity which will give an intersection with the load ratio line, such as: 1. The dry-bulb temperature of exit a^r. 2. The wet-bulb temperature of exit air. 3. The dew-point temperature of exit air. 4. The relative humidity of exit air. . 5. The wet-bulb depression of exit air. 6 The ratio- I *`ne ^rom *n*et to e*** conditions ' ' Length of line from inlet to saturation curve" . " (This is frequently called the ratio of heat removed to heat removable). \ As it is evidently impossible to dehumidify with a cooling coil, with no removal of sensible heat, there must be a limit to the possible ratio of total to sensible heat removal.- A common approximation is to limit this ratio to that corresponding to a load ratio line drawn through the entering air condition and tangent either to the saturation curve or to an arbitrarily selected relative humidity line not far from saturation. (See Fig. 15)- 508 Chapter 24. Heat Transfer Surface Coils The resistance to air flow for a given coil is usually greater for a wetted than for a dry coil, the difference being dependent upon the coil design and the facility with which the water of dehumidification is removed. The effect of water is greater with close than with wide fin spacing and for some designs is greater with upward vertical than with horizontal air flow. For typical coils, the air resistance of the wet coil is about 30 per cent greater than the resistance of the dry coil, although this depends also on the heat load ratio. Air resistance is usually taken as proportional to the square of the mass air velocity, although the 1.8 power is sometimes used instead of the square. . . COIL PERFORMANCE AND SELECTION In the selection of a coil it is necessary to consider several factors: 1. The duty required--heating, cooling, dehumidifying. 2. Temperature of entering air--dry-bulb only if there is no dehumidification, dryand wet-bulb if moisture is to be removed. 3. Available heating and cooling media. 4. Space and dimensional limitations. 5. Air quantity limitations. 6. Allowable resistances in air circuit and through tubes. 7. Peculiarities of individual designs of coils. 8. Individual installation requirements, such, for example, as type of automatic con trol to be used. The duties required may be determined from information in Chapters 5, 6, 7 and 8. There may or may not be a choice of cooling and heating media, as well as temperatures available, depending upon whether the installation is new or is in combination with present sources of heating or cooling. Space limitations are dictated by the requirements of individual cases. The air quantity is influenced by a number of considerations. The air quantity through heating coils is often made the same as that necessary to handle the summer cooling load. The air handled may be fixed by the use of old ventilating ducts as an air distribution system for new air conditioning apparatus, or may be dictated by requirements of satisfac tory air distribution or ventilation. The resistance through the air arcuit influences the fan horsepower and speed. This resistance may be limited to allow the use of a given size of fan motor, or to keep the opera ting expense low, or it may be limited by the maximum fan peripheral velocity which requirements of quietness may permit. The friction through the water or brine circuit may be dictated by the head available from a given size of pump and pump motor. As the fan and pump motor inputs represent a refrigerating load on cooling installations, it is eco nomical to keep" them low. Proper performance of a surface heating or cooling coil depends upon correct choice of the original equipment and upon certain other factors. The usual coil ratings are based on a uniform face velocity or air. If the air is brought in at odd angles or if the fan is located so as to block part of the air flow, the performance as given in the Manufacturer's Ratings cannot usually be obtained. To obtain this performance it is necessary also that the air quantity be adjusted on the job to that used in deter mining the coil selection, and must also be kept at this value. The most common causes for a reduction of air quantity are the fouling of the filters . 509 Heating Ventiuiting Air Conditioning Guide 1939 and collection of dirt in the coils. These difficulties can be avoided bv proper design and proper servicing. There are a number of ways in which coils may be cleaned. A common method is to wash them off with water They can sometimes be brushed and cleaned with a vacuum cleaner. |[| bad cases of neglect, especially on restaurant jobs where grease and dirt have accumulated, it is sometimes necessary to remove the coils and wash off the accumulation with steam, compressed air and water, or hot water The most satisfactory solution, however, is to keep the filters serviced' and thus make the cleaning of the coils unnecessary. , ' The proper selection of coils requires an understanding of the necessities of each case and should be based on an economic analysis of the plant design as a whole: No general rule can, therefore, be laid down for the selection of heating or cooling coils. It is possible, however, to point out the limits of usual practice and to indicate the influence of the variables involved in the coil selection. , Heating Coils Steam and hot water heating coils are usually rated within these limits: Air Face Velocity--200 to 1200 fpm, sometimes up to 1500 fpm. ' Steam Pressure--2 to 200 lb, sometimes up to 350 lb per square inch. Hot Water Temperature--150 to 225 F. Water Velocity--2 to 6 fps. . Individual cases may deviate widely, but the tabulation given herewith will serve as a guide to usual heating practice: ` Air Face Velocity---500 to 800 fpm face, 500 being a common figure. Delivered Air Temperature--varies from about 72 F for ventilation only to about 150 F for complete heating. , Steam Pressure--2 to 10 lb, 5 lb being common. Hot Water Temperature--150 to 225 F. Water Velocity--2 to 6 fps. Water Quantity--Based on about 20 F temperature drop through a hot-water coil. Air Resistance--The total resistance through heating coils is usually limited to from % to % in. of water gage for public buildings, to about 1 in. for factories. ` The selection of heating coils is relatively simple as it involves dry-bulb temperatures and sensible heat only, without the complication of simul taneous latent heat loads, as in cooling coils. For a given duty, entering air temperature, and steam pressurelt is possible to select several arrange ments of the same design of coil depending upon the relative importance of space, cross-sectional area, and air resistance. Table 2 shows an example. , ________________________ Table 2. Several Heating Coil Arrangements Selection 123 Temperature of-air entering coil, deg F........ Temperature of air leaving coil, deg F. Coil face area, sq ft. Goil rows deep... ....................... _.............. Face velooitv, fpm. . Air friction, in. water................................. 5 40 129 10*000 33 3 2 300 0.044 '5 40 129 10,000 12.5 . 3 800 . 0.396 5 40 129 10,000 7.50 4 1330 1.077 510 Chapter 24. Heat Transfer Surface Coils Cooling Coils The usual range of ratings for cooling and dehumidifying coils are enumerated herewith: Entering Air Dry-Bulb--60 to 100 F. . Entering Air Wet-Bulb--50 to 80 F. Air Face Velocities--300 to 800 fpm, (sometimes as low as 200 and as high as 1200). Volatile Refrigerant Temperatures--25 to 55 F, at coil suction outlet. Water Temperatures--40 to 65 F. Water Quantities--2 to 6 gpm per ton, or equivalent to a water temperature range of from 4 to 12 F. Water Velocity--2 to 6 fps. The ratio of total to sensible heat removed varies in practice from 1.00 to about 1.65, i.e., sensible heat is from 60 to 100 per cent of total, de pending on the application. (See Chapter 21, Tables 1 and 2). Required ratios may demand wide variations in air velocities, refrigerant tempera tures, and coil depth, so that general rules as to these values may.be misleading. On usual comfort installations air face velocities between 400 and 600 fpm are frequent, 500 being a common value. Refrigerant temperatures will ordinarily vary between 40 and 50 F where cooling is accompanied with dehumidification. Water velocities will range from 2 to about 6 fps. ' When no dehumidification is desired, for which condition the dew-point of the entering air will be equal to or lower than the cooling coil tempera^ ture, the coil selection is made on the basis of dry-bulb temperatures and sensible heat transfers only, the same as with heating coils. It is.possible also to choose various arrangements of face area, depth, air velocity, etc., for the same duty, as illustrated in Table 2 for a steam coil. Dehumidifying Coils . The selection of coils for combined cooling arid dehumidifying duty is more involved than for heating or sensible cooling and requires con sideration of both dry- and wet-bulb air temperatures. It is further complicated by the fact that the proportional amount of dehumidification required is also highly variable. The methods outlined previously under Heat Transfer and Resistance may be used to determine whether it is possible for a coil to perform the duty required. If entering and leaving Table 3. Various Cooling Coil Arrangements Selection 1 Total cooling capacity, tons........ 100 Sensible cooling capacity, tons... 69 Latent cooling capacity, tons. 31 Ratio total to sensible heat--.....: 1.45 Air quantity, cfm.. _ .................. 47,800 Cfm per total ton........................... 478 Face velocity, fpm.......................... 325 Resistance, in. water... .................. 0.11 Coil face area, sq ft.. __________ 147 Coil rows deep 4 Coil evaporator temp, deg F-- 45 2 .3 100 69 31 1.45 41,700 417 423 0.27 99.0 6 45 100 69 31 1.45 37,100 371 500 0.51 74.2 8 45 4. 100 69 31 1.45 46,800. 468 600 ` 0.37 78.1 4 38 Heating Ventilating Air Conditioning Guide 1939 air conditions are arbitrarily specified, the corresponding duty sometimes cannot be obtained at all without the use of reheat. As with heating and sensible cooling coils, there are combinations of face areas, depth, air velocity and refrigerant temperatures which will give the required per formance. This is illustrated in Table 3. It is possible as shown in Table 3 to perform approximately the same duty at a given refrigerant temperature with small face area and large thickness or vice versa. The large face area coil will give low air velocity and resistance but high air quantities per ton. The coil of small face area and great depth will require small air quantities per ton of refrigeration high resistance and high air velocities. As shown also in Table 3 the same sensible, latent and total cooling capacity may be obtained with various refrigerant temperatures by proper choice of coil. This makes it possible Chapter 24. Heat Transfer Surface Coils latent heat capacity. On installations controlled from dry-bulb temlirature the operating time will be shortened because of the added senPfje cooling capacity. The result will be less moisture pick-up than s'Iculated, and higher relative humidity. If an oversize condensing unit 's installed the opposite situation will take place. The relative humidity will be lower than estimated. This is not generally a disadvantage except that it results in a greater load from outside air than calculated, as well as in increased power consumption. Balances to illustrate these cases appear in Fig. 17- If oversize equipment is furnished, a balance should be made to assure that the ratio of total to sensible capacity is the same as in the estimated load. . Sometimes arbitrary air quantities are specified for ventilation or other reasons independent of' the selection of the cooling coil. As shown in Fig. 16. Balance of Evaporator Temperature Conditions with Condensing Unit Capacity to keep the evaporating temperature high enough to carry the load with a chosen size of condensing unit. High evaporating temperatures with correspondingly small compressor operating expense can be attained but at the expense of coil surface, air quantity or both. The choice will be determined by the necessities of individual installations. For a given quantity and condition of entering air the evaporating temperature of a volatile refrigerant coil will be determined by a balance between the condensing unit and the coil. The total, sensible and latent cooling capacity can then be determined from the coil rating information. Fig. 16 shows typical balances. If the condensing unit and cooling coil have been properly balanced for the required load and, due to miscalcu lated duct resistance or improper choice of fan speed, the air quantity is reduced, the total cooling capacity will also be reduced. The decrease is generally in the sensible capacity. This is the effect also when the air by-pass or volume control is used. ' It is necessary that not only the total capacity but also the sensible and latent cooling requirements both be met. The installation of an excess of coil will result in an increase in total capacity, but not a proportional gain 512 Fig. 17. Balancing Conditions for Excess Coil and Condensing Unit Capacities Table 3, the coil selection can be altered to take care of various air quantities for the same duty. ' ' Where coil and condensing unit are selected for the peak load condition, and the sensible load partially disappears due to fall of outside tempera ture or other cause, the condensing, unit and coil rebalance. This may result in more sensible capacity than required at the light load condition and less latent in proportion, with an increased relative humidity in the conditioned space. Such a condition, for a typical installation, is shown in Table 4: If approximately 40 per cent of the total air is by-passed, the condition will be improved as indicated. The situation could be entirely avoided by using reheat. . With sufficient reheat, it is possible to handle any ratio of sensible and latent loads.and. maintain-the design temperature'and humidity. '. Gare should be taken to avoid, freezing at light loads. In general, freezing occurs when the coil surface temperature falls to 32 F. With 513 X Heating Ventilating Air Conditioning Guide 1939 Table 4. Capacity Balances for Maximum and Minimum Load Conditions Required at peak load conditions.......... ............. Required at minimum load conditions............... Peak load equipment balance................................... Same equipment balanced at minimum load conditions.............. ......................................................... Same equipment balanced at maximum load conditions with 40 per cent by-pass.________ Same equipment balanced at minimum load conditions with 38,800 Btu per hour reheat Capacity in Tons Total 10.90 6.62 10.90 Sensible 7.90 3.36 7.90 Latent 3.00 3.26 3.00 9.85 6.58 3.26 8.38 5.05 3.33 6.62 3.36 3.26 Ratio -I otal SbnsuSJ usual coils for comfort installations, this will not occur unless the evapo rating temperature at the coil outlet is about 20 to 25 F, The exact value depends on the design of coil' and the amount of loading. Although it is not customary to choose coil and condensing units to balance at low tem peratures at peak loads, there is danger of this occurring when the load decreases. This is further aggravated if a by-pass is used so that less air is passed through the coil at light loads. It may be even worse if.the control is arranged for decrease of inside temperature with fall of that outside. Freezing can be avoided'by making the full load balance a high evaporating temperature and checking the balance at the minimum load condition. REFERENCES A.S.H.V.E. Research Report No. 997--Heat Transfer from Direct and Extended Surfaces with Forced Air Circulation, by G. L. Tuve and C. A. McKeeman (A.S.H.V.E. Transactions, Vol. 40, 1934, p. 427). . A.S.H.V.E. Research Report No. 1029--Performance of Fin-Tube Units for Air Heating, Cooling and Dehumidifying, by G. L. Tuve (A.S.H.V.E. Transactions, Vol. 42, 1936, p. 99). . ' A.S.H.V.E. Research Paper--Performance of Fin-Tube for Air Cooling and Dehu midifying, by G. L. Tuve and C. A. McKeeman (A.S.H.V.E. Journal Section, Heating, Piping and Air Conditioning, June 1937, p. 379). , A.S.H.V.E. Research Paper--Performance of Surface Coil Dehumidifiers for Comfort Air Conditioning, by G. L. Tuve and L. J. Seigel (A.S.H.V.E. Journal Section, Heating, Piping and Air Conditioning, September, 1938, p. 605). .. ' Heat Transmission in Cooling Air with Extended Surfaces, by W. L. Knaus (Refriger ating Engineering, January, 1935, p. 23, February, 1935, p. 82). . Rational Development and Rating of Extended Air Cooling Surface, by H. B. Pownall (Refrigerating Engineering, October 1935, p. 211); Dehumidification of Air with Coils, by William Goodman (Refrigerating Engineering, October, 1936, p. 225). . .. Graphical Method of Determining Finned Coi^ Capacities Described, by E. P. Wells (Heating, Piping and Air Conditioning, December, 1936, p. 665). : Extended Surface Cooling Units, by R. H. Swart (Refrigerating Engineering, February, 1938, p. 107). . : . PROBLEMS IN PRACTICE 1 Why are extended surface coils used in preference to plain tube coils and where is the advantage greatest and least? - Extended surface is used to increase the flow of heat between an air stream and the external surface of a tube, where the resistance through the tube wall and from tube wall 514 Chapter 24. Heat Transfer Surface Coils edium flowing in the tube are proportionately low. Where the latter resistances are t meu^ ^ compared to the external resistance, as with dry air flowing over tube con- vefX water at high velocity, it is economical to use large ratios of extended to tube 441 f' ce Where the external resistance is already low, as where large quantities of water ^re sprayed over the surface, lower ratios are used, sometimes even plain tube coils. j Qn what one feature of construction does the performance of extended Surface coils largely depend? An intimate and permanent bond between tube and fin. 3 What is the maximum number of fins per inch, and why? Eieht fins per inch is the usual practical maximum. A closer fin spacing causes trouble with dirt accumulation and by holding up water between the fins when on dehumidifying duty. 41 What is the purpose of the liquid distributor in volatile refrigerant coils? The distributor is used to apportion the incoming liquid arid gas mixture as evenly as nossible between the individual refrigerant circuits through the coil, at the same tiine making it practical to arrange these circuits for a low refrigerant pressure drop. 5 # What.is the usual practice as to the relative direction of flow of air over the tubes and the liquid or vapor in the tubes? With water and brine, counter-flow is used wherever possible. Volatile refrigerant coils are generally arranged for parallel-flow although cross-flow and combination arrange ments are also used. Steam heating coils are. usually arranged for cross-flow. ; 6 # What factors influence the transfer, of heat from the air to fluid in the tubes? .` : The magnitude of the propelling force or temperature difference. The design and surface arrangement of the coil. The velocity and character of the air stream. The velocity and character of the fluid in the tubes. ' 7 What effect has air velocity on the heat transfer? It has been found that the relation between total heat transfer coefficient and mass air velocity can be represented as a straight line on logarithmic paper. The slope varies with the coil design, number of rows deep and the fluid in the tubes. 81 Why do practical coil applications sometimes fall short of rated capacity? To attain rated capacity it is necessary that the incoming air be uniformly distributed over the coil face. Sometimes this is not attained due to poor layout of apparatus and air connections. . 91 What are the three general conditions of operation to which cooling coils are subjected in practice? . The coil may be entirely dry, part dry and part wet, or wet throughout, the conditions being based upon whether or not any, part or all of the coil surface is below the dew-point temperature of the air passing over it. 10 f What is the load-ratio line for a cooling and dehumidifying coil? It is a straight line drawn on a norfi-logarithmic psychrometric chart through points representing the entering and leaving air conditions. The slope of this line gives directly the relationship between the sensible and latent cooling corresponding to the selected entering and leaving air conditions. 11 Upon what does the selection of a heating or cooling coil depend? An economic analysis of each case should be made together with the relative importance of space, air resistance and quantity, and available or desirable temperatures of heating and cooling media. For a specific design of coil there are a number of possible arrange ments for the same duty. 516 Heating Ventilating Air Conditioning Guide 1939 12 Can a cooling and dehnmidifying coil be selected for any arbitrarily spec!, fied conditions of entering and leaving air? ' No. Although sensible and latent cooling effects may be obtained simultaneously, and in varying ratios, there is a limiting ratio of total to sensible cooling effect, for any gjven entering air conditions which cannot be exceeded without the use of reheat regardless of the coil design or refrigerant temperature. 13 What precautions must be taken in selecting a condensing unit and cooling coil to operate together? ` . - The total refrigerating capacity and the ratio of total to sensible heat load will be deter mined by the evaporating temperature at which the coil and condensing unit balance. It is possible that, unless a check is made at this balance point, the resultant ratio of totai to sensible may differ considerably from that required. An oversized coil, for instance is likely to result in the desired dry-bulb temperature but excessive relative humidity of the air discharged. r 14 What precautions as to the air circuit should be taken to assure the proper performance of a coil? . .' The air conditions should be adjusted to obtain those upon which the selection was based; the filters should be kept clean, and the incoming air should be distributed evenly over the coil face. , 15 * What are the usual causes of freezing in the case of a volatile refrigerant coil? ,. Freezing is caused by a reduction or stoppage of air flow due to dirty filters, clogged coil or sticking of automatic dampers. Or the selection of equipment may have been made for so low an evaporating temperature at peak load that the balance between condensing unit and coil at light loads causes the coil temperature to fall below 32 F. . Chapter 25 SPRAY EQUIPMENT FOR HUMIDIFICA TION 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. Scrubber-plate types of washers are 517 Heating Ventilating Air Conditioning Guide 1939 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 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 ol - the;"air aetossithe: chamber section above the level of the water'in'the 5i8 ^apter 25. Spray Equipment for Humidification &. Dehumidification mn- moderate velocities qf air flow, 300 to 600 fpm in the spray cham*ur- an adequate amount of spray water broken up into a fine mist throughout the air stream; sufficient length of air travel through the ater spray and over thoroughly wetted surfaces, and the elimination 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 uivalent to a number of washers in a series arrangement. Each stage }S 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 2J4 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 dry-bulb temperature of the air passing through the washer is about the maximum that should be anticipated. For greater decrease in dry-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 Am 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 recircut 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 (he total heat of the air and water-vapor mixture is unchanged. 'Moisture is added 5l Heating Ventilating Air Conditioning Guide 1939 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 take' place. Theoretically the spray water and the dry- and wet-bulb tetnS 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) 100 eh ti -- t' 0) where eh = humidifying efficiency, per cent, fi = initial dry-bulb temperature, degrees Fahrenheit.. It = final dry-bulb temperature, degrees Fahrenheit. I' -- 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 ........1..................................................................... 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-bulb1 temperatures and lowers the relative humidity, but not 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 aiid the use of a reheater when such is necessary. ; !: Method 3 -involves heating the spray water to a temperature equal 520 ^O^jtprzR 25. Spray Equipment for Humidification & Dehumidification 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 1 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 efficjency 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 O 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. Air Washer with Spray Water Heating Arrangement Solution. From Example 2, Chapter 1, the final dew-point temperature is 44.5 F, W\ -- 0.000548, Wt = 0.00618, and Wt -- Wi = 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 preheated 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) J = 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) ] -- (0.005632 X 4.5) = 6.11 Btu per pound of dry air. 1 APPARATUS FOR DmECT HUMIDinCATipN 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;,;aind! (3) Combined direct and indirect. ';;:'' . . ; .............. 521 Heating Ventilating Air Conditioning Guide 1939 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 30.1b 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 them selves and is drawn constantly to the atomizer by aspiration when com 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 522 '^cbapterZS- Spray Equipment for Humidification & Dehumidification ping un;t. The spray-generating nozzle which is of the impact type located in a cylindrical casing.' A drainage pan provides for the collec*? an(j return of unevaporated water which flows through a return pipe ya 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 sation 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 arid 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. 523 25.^gaPTER Spray Equipment for Humidification & Dehumidification AIR DEHUMIDIFICATION WITH WASHERS Moisture removal from an air-vapor mixture can be accomplished by of an air washer so long as the temperature of the spray medium is |i than the dew-point of the air passing through the unit. The final drv-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 dehumidibcation 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. 4l. 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 r'Teaiperature of Water Available for Industrial Use' In the United States, by W. D. Collins (U. S. Otofogicoi Survey, Water Supply Paper No. 520 F). ' ; - - : :: 525 1939Heating Ventilating Air Conditioning Guide Table 1. Average Maximum Water Main Temperatures3 State ClTT Ala______ Ariz_____ Calif...--. Colo... Conn.. d. c.: Del...: Fla.... Ga- IIl.-.. Ind.~....... Iowa._ Kans.. Ky.. La... Me--.. Md-- Birmingham__ Mobile............. . Phoenix.____ Tucson.. Anaheim._......... Berkeley.... ........ Fresno.... ........ ... Fullerton--_____ Glendale............ Los Angeles...... Oakland........ .. Ontario...:.......... Pasadena...:...... Pomona.. Riverside............. Sacramento'........: San BernardinoSan. Diego______ San Francisco__ Whittier............... Denver................ Bridgeport........... Hartford--........... New Haven........ Waterbury.......... Washington___... Wilmington......... Jacksonville....:_ Miami.. Tampa......... Atlanta____ ; Macon______ Chicago____ Cicero-......... Evanston..... Peoria.. Rockford............. . Springfield___ _ Evansville_______ Gary..... ........ I....... Indianapolis--...... South Bend.. Terre Haute:____ Cedar Rapids--:_ Des Moines....... . Sioux City-........ . Concordia:_______ Kansas City--:___ Topeka-.________ Wichita--___ -- Louisville.........: Baton Rouge...: New Orleans...: Augusta....^___ Baltimore... Temp. F State Te. $ 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 6182 v -78 77 62 57 . 86 ` 88 72- ' 85 85 . 85 v 60 75 Mass__ Mich___ Minn.. Boston________ Cambridge____ Fall River.___ .,, Lowell............... Lynn................. New Bedford.. Salem.....__ --. Worcester.____ Detroit....... ..... Flint.................. Grand Rapids... Highland Park;. Jackson... ............ Kalamazoo...___ Lansing.. Saginaw.... .......... Duluth-____:..... Minneapolis....... 80 ' 70 76 50 68 70 68 76 77 70 84. 77- . 56, 53 64 82 55 . 80 Mo..... St. Paul___ .:___ Jefferson City.... Kansas City....: St'. Joseph_____ ; St. Louis_______ 77 82V 84 84. 85 Nebr___ Springfield.......... Lincoln.._.l 70 87 Nev___ Omaha.:...... :...... Reno.:__ _______ 87 61 N. H.._,, N. J._... Manchester........ Jersey City_____ 76 63 Newark--___ ___ 74 Paterson...........1........ 78 Trenton. .79 N. Y.._...... Albany...... ................ 68 Buffalo.......____ 75 56 Mt. Vernon________ '74 .New Rochelle.___ . 75 New York--______j... 72 Rochester_____ ____ .70 Schenectady--:.......... 60 74 Utica: __. 69 Yonkers................. .... . 70 N. C....:._... Asheville--__J___ _ . 74 Charlotte.:....... --. .: 85: Winston-Salem__.... 82 N. M_____ Albuquerque_______ 65 Ohio._ ....:. 76 Canton..................... . 50 Cincinnati. ____ 84 Cleveland;_____..C 74 Columbus.____ _____ . 82 60 Lakewood--....... . ' 82 Toledo..-- : 83 , sThese averages taken from various city water main locations, with some actual values slightly higher and some'lower than values shown. "............. - .. ; . 1 ; . . ,, 526 V CHAP"'TZELR on Spr_a_y__E__q_u_i_p_m_e__n_t__f_o_r__H__u_m__id__if_i_c_a_t__io__n__&__D__e_h_u_m__i_d_if__ic_a__t_io__n_ Table 1. Average Maximum Water Main Temperature3 (Concluded) Crrr Temp. F State Crrr Temp. F Oklahoma City.. Tulsa--................ Eugene................. Portland............... Altoona-............. Erie....................... Johnstown........... McKeesport-....... Philadelphia.--.... Pittsburgh........... Providence.......... Charleston.......... Greenville--......... Spartanburg....... Rapid City-....... Chattanooga...... Knoxville....:....... Memphis.--...... Nashville--...... Amarillo.............. Austin.................. Beaumont.... ....... Dallas.................. Fort Worth........ Galveston--......... Houston.............. Port Arthur....... 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 Utah 44 Salt Lake City-- ...... 60 Va.................. Fredericksburg._____ 75 Lynchburg................... . 73 Norfolk............ --........... 80 Wash............ Olympia.......................... 58 Seattle. ......................... 62 Spokane.......................... 51 Tacoma........................... 57 W. Va - ... 85 Huntington................... 78 Wheeling....... ................ 78 Wis. 54 Madison......................... 58 Milwaukee.................... . 70 Racine............... :............ 68 Province Alta.--..... Calgary........................... B. C. Toronto........................... P. E. I......... Charlottetown.......:... Que--....... . Quebec............. ........ :.... 64 60 50 63 48 78 68 * These 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 527 Heating Ventilating Air Conditioning Guide 1939 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, atnios. 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, the 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. Iii 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 & 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 designof 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, arid 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 normal maximum, the limiting temperature of the ammonia in the condenser is 96 F. Should the ammonia tempera- tufe go above this figure the head pressure Will exceed 185 lb and power consumption increases. To obtain this head pressure, the temperature of ' ' 528 ' i------------rr^AV Equipment for Humidification & Dehumidification Chapter #>___________________________________________________________________________---------------------- circulating water leaving the condenser must always be less than 96 F Kan amount depending upon the size and design of the condenser, the antity of water being circulated, and the refrigerating tonnage being ^mduced. A condenser having a large surface per ton of refrigeration be designed to operate satisfactorily with the leaving hot water imDerature 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 ' res for which commercial condensers are designed. Internal combustion engines have limiting hot water temperatures of 125 F to 140 F. The ctjling 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 Maximum Pressure Desired in Condenses Gas Temperature in Condenser Deg P Leaving Hot Wateh TEitfEHArtJsB Deo F Brat Condenser Design| Arera^eCtodeoser 28 in. vacuum.......... 27 in. vacuum.......... 26 in. vacuum.......... 185 lb gage head pressure------ Carbon dioxide . '10301b gage - head pressure........ Methyl 102 lb gage chloride.......... head pressure------ Dichlorodi- 117 lb gage fluoromethane head pressure....... 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 92 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 529 Heating Ventilating Air Conditioning Guide 1939 975 hours represent a third of the summer period, cooling equipm based upon the noon average July wet-bulb of 68 F would be inadequatDt Commercial practice is to choose a wet-bulb temperature for refrigerati e` design purposes which is not exceeded during more than 5 to 8 per ce of the summer hours (75 F for New York City), with somewhat lowe! requirements for steam turbines and internal combustion engines, difference is made because the heaviest load on a refrigerating plant ;* coincident with high wet-bulb temperatures, whereas the heaviest electn' power demand occurs either in the winter or after nightfall in.summey when the wet-b__u_lb__t_e_m_ ,p_e__ra_--ture .i.s. tl'o-jww. Txaa.buliec i1,, cCmhaapprteerr 8,, sshhoowwssddeessiiggnn wet-bulb temperatures wwhhiicchh wwiillll nnmot- btoe exceedejd -m---o--r--e'than 8" per ce8nt 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___ Spray Towers........................................ Deck or Atmospheric Towers_________ Mechanical Draft -- ----------------- ' CooUNO PEfficiency-- eb Cent Minimum 30 40 35 35 Usual 45 to 55 45 to 55 50 to 70 55 to 75 Maximum* 60 60 90 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 1 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 m m design wet-bulb temperature, the quantity of water required can be ilfc 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...... ....................... 220 to 270 Btu per minute per ton. , Condenser turbine_______________........ ..... 950 to 980 Btu per pound of steam. Steam jet refrigerating apparatus1030 to 1150 Btu per pound of steam. Diesel engine.:-------------- ---------------------------2800 to 4500 Btu per horsepower 530 '.cSfc'.e- * fe S---"Tot: spray Equipment for Humidification & Dehumidification Chapter "_________ __________________________ _______ _______________ r 'cooUng Ponds . '1-S.. arUral pond is often used , as a source of condensing water. The ^ water should be discharged close to the surface at the shore line. 5m- ral air movement over the surface of the water will cause evaporation .y*tu jy aWay heat. Because increased density due to the loss of heat - cooled water to sink to the bottom of the pond, the suction ?u ectjon for intake water should be placed as far below the surface as oon"ble 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 ito the air, the difference in temperature between the water and the wet- bulb 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 531 Heating Ventilating Air Conditioning Guide 1939 corner in passing through the fence, and the heavier drops of water are' thrown back, owing to their inertia. The louvers also restrict the flow 0t air, particularly at the higher wind velocities, and thus further reduce the possibility of water being carried off. The height of an effective ferice should be equal to the height of the spray cloud. Louver boards are' preferably of red gulf cypress or California redwood supported on cast- * iron, 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 p0rKjs , 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]4 to gal of hot water. About 10 parts of permanganate should be used per million parts of cooling water. 5 The permanganate attacks the algae, forms a brown covering over it, 1 and causes it to settle. Enough of the permanganate solution should be j added periodically to cause the water to have a pink color for a period of j from 15 to 20 min.' Small additions of the permanganate daily do not \ give concentrations which are effective. The best results are obtained i when sufficient quantities are added periodically at intervals of several 1 weeks, the time intervals being dependent upon local operating conditions.: i The chemical is non-poisonous and is non-corrosive when used as directed. j1 Spray Cooling Towers j ` 1 Where not more than 30,000 Btu per minute are to-be-dissipated, the spray cooling tower is a satisfactory apparatus. The word lower in this ' connection is somewhat of a misnomer as the apparatus is essentially a 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 -1 distance that the nozzles are elevated above the water basin. Heights j range from 6 ft to 15 ft and the total width of a structure is not usually ;j greater than its height. Spray cooling towers occupy less space on small N jobs than spray ponds of equivalent capacities because the towers have i 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 ,i to the cooling air. Natural Draft Deck Type Towers 5 In past years most of the atmospheric water cooling on refrigeration i; 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 y: the basin. The object of the decks is to arrest the fall of the water so as to j; present efficient cooling surfaces to the air, which passes through the j 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, J too many decks are a detriment. ?: 532 &Spray Equipment for Humidification Dehumidification jo 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 one 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 0f 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 must 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 and 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 533 Heating Ventilating Air Conditioning Guide 1939 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-fifle,} 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 " Cost. Area.. Height. Weight per square foot .----------Independence of wind velocity.. Drift nuisance.. Make-up water required. Pumping head...... ....... i--. Maintenance.. Suitability for congested districts.......... Water quantity required for definite result_________________________________ Cooling Sprat Pond z2 '5 4 I2 -z Z 63 16 16 l2 2I z5 Sprat Deck Tower Tower i3 32 3 4-5 13 45 54 54 3 4-5 34 43 6 5 4 1-2 *Not 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 . Sincd the atmospheric water cooling equipment performs its functions chiefly by evaporating a portiori^of the water 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. 534 on Corby Equipment for Humidification & Dehumidification ^chapter zo. _____________ ____ ______________:-- -----------------------:-- Winter Freezing - If atmospheric water cooling equipment is operated in freezing weather, h water may be cooled below freezing temperature so ice forms and 11 ts untn its weight causes damage. To obviate freezing during con- *? uec[ operation, the efficiency of the apparatus may be lowered. This ^"done on the spray pond and the spray cooling tower by reducing the ,s antity 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 vstem put in service midway down the height of the tower. The water mil be kept above freezing, because it will have shorter contact with the r xhe 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 be 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. 51 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. 535 1939Heating Ventilating Air Conditioning Guide 7 Why do cooling towers give best results when the humidity of the air is i01f. The cooling of the water by dropping it through the air depends mostly upon the evatvw ation of the water. If the relative humidity of the air is low, the water vapor wilji^ readily absorbed and carried away, while if the relative humidity is high, its capacitvt pick up water vapor is less and the water is cooled less with the same exposure to the ah 8 ( What are some of the advantages and disadvantageous of a forced draf cooling tower compared with a natural draft wind tower? 1 Advantages: a. Does not depend on wind, b. Less space required, and c. Less drift los and less make-up. . 085 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 9 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 9 What chemical is used to kill algae formation in spray ponds? Potassium permanganate. .. 12 9 What is the usual amount of spray water 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 9 About how much water is lost by evaporation in atmospheric cooling? About 1 gal per 1000 gal for each degree of cooling range. 14 9 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 not freeze so readily. . 536 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 THE removal of impurities from air brought into.a building, or from air 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 1 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 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). 537 Heating Ventilating Air Conditioning Guide 1939 SvChapter 26. Air Cleaning Devices percentage relationship expressing dust, removal efficiency at capacity, (4) reconditioning power, the energy necessary to operat^k^ mechanism of an automatic air cleaning device, and (5) dust-hotr s capacity, the amount by weight of standard dust which a non-autom '! air cleaning device will retain before reconditioning is necessary. atlc CLASSIFICATION OF AIR CLEANERS j,e viscous and dry type air filters which are part of many ventilating and air conditioning systems. F r removal of dusts, smokes and fumes from stack gases. Prevention of atmos2- l'P pollution from this source is of ever increasing importance, sometimes forced legally and frequently used in order to obtain increased efficiency. For removal and collection of industrial dusts from the point of their production through exhaust systems. VISCOUS TYPE FILTERS According to the Code, the following four classifications are given ti, * devices: Class A. Automatic Type: In general all air cleaning devices which use pow , ^ automatically recondition the filter medium and maintain a non-varying resistan/ 0; airflow. "nee to; The principle of air cleaning used in viscous filters is that of adhesive 'mpingement. Dust and dirt in the air, especially soot and carbons, are trapped and retained by successive impingements on coated surfaces. "Vhile 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. cleaning device. _ Class C. Medium Resistance Non-Automatic Type: Air cleaning devices for system, 1 IV in which a maximum of not more than 0.5 in. water gage is available to move air throiVk * 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. ** ' 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. i 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. - 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. " 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 capillarity, or ability to wet and retain the dust. 6. Evaporation should not exceed 1 per cent. 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. 7. It should be fireproof. 8. It should be odorless. ' Viscous Unit Filters b. For unit ventilators. Filters of 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 stnd Diesel engines. f. For compressed air lines. Unit type visepus-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 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. 538 539 Heating Ventilating Air Conditioning Guide 1939 The resistance of a well-designed unit filter of the adhesive imping, 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 Chapter 26. Air Cleaning Devices localities. Wide variations are also found due to different seasons of th'e ar as well as the tirrie of day and the direction of the wind. A chart lowing the increase in resistance of a unit filter of the viscous impinge ment type, when tested with the standard test dust described in the code8, . given in Fig. 1. The resistance to air flow of three typical clean viscous `moingement 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 toe. Cit. Note 1. 540 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 and 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 toe. Cit. Note 1. 541 Heating Ventilating Air Conditioning Guide 1939 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 it. 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 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 J^-in. water gage at an air velocity of 500 fpm measured at the filter entrance. Automatic viscous filters are made upin units which are delivered either fully assembled or in parts to be assem bled at the point of installation. . DRY AIR FILTERS Dry 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 affected 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 542 Chapter 26. Air Cleaning Devices tides. However, new types have been developed which appear to have ^Libilities for applications where the air to be cleaned is extremely j?Vtv or where a higher degree of cleanliness is desired than can be ob?*'ned with a conventionally designed air washer. Information on air Crashers 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: 1. The filter must be of ample sire 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. AH doors on the clean air side should be lined with felt to prevent infiltration of unclean air. All 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- 543 Heating Ventilating Air Conditioning Guide 1939 tides in separators, either gravitational or centrifugal, thus preventing clogging and overloading of the filters or precipitators used lor 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 T4 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 544 Chapter 26. Air Cleaning Devices e of usefulness is indicated in Fig. 1 of Chapter 4. They have wide nolication 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 a 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 It 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 o'f construction are available which combine quick interchangelability 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 plateswhere 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 arcing voltage for the particular conditions. The discharge electrode should be negative because with this charge higher voltages may be carried without arcing. 545 Heating Ventilating Air Conditioning Guide 1939 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). A.S.H.V.E. Research Report No. 843--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 (Heating, Piping and Air Conditioning, January, 1932, p. 35). L 546 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). Testine 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. 277). The Dust Problem in Air Conditioning, by F. B. Rowley (A.S.H.V.E. Transactions, Vol. 41, 1935, p. 375). An Alternate Method 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 X 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 dirty? 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 and 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? An 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. 547 / Heating Ventilating Air Conditioning Guide 1939 7 What instruments and apparatus are required for determinins th. ,, < concentration in air by means of the settling method? PUen 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 bv 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. \ 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? vefodtyVr0 F'S' Th6 resistance is substantially proportional to the square of the Ri Vf R, Vf 0.4 0.16 200* Vf Vi = 126.5 fpm Q = AV 1000 = 126:5 A . A = Si = 7 91 *ft- The filter area would be increased from 5 sq ft to 7.91 sq ft. ' \ 548 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) axial flow 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. Radial flow or centrifugal fans 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 549 Heating Ventilating Air Conditioning Guide 1939 laws apply to installations comprising any type of fan, any given pin;n 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 cfm 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 (500\2 J = 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 tbe density. ' ' Example 2. 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? Static pressure = 1 X ^= 0.80 in. 0.07492 0.06015 Power = 4 X 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? . JSpeed = 400 X 0J.07492 = 446 rpm ,06015 Capacity = 12,000 X x J-TM.07492 \ o..l06015 = 13,392 cfm (measured at 200 F) V-sPower = 4 X ,07492 = 4.46 hp 0.06015 6. For a constant weight of air: ' . (a) 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? . . 0 074Q2 ` Speed = 400 X 0^5= 498 Tpm . 0.07492 Capacity = 12,000 X Q Q6015 = 14,945 cfm (measured at 200 F) 550 Chapter 27. Fans . , ^ 0.07492 , . Static pressure - 1 X 0 06015 l-25 m- 0.07492 \2 Power = 4 X (006015) . 20 p 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: ,, , cfm X total pressure in inches of water . Air Horsepower1 = ------------------ --------- ------------------------ ,,. (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 fen 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: M,,ec,han.ica,l or _To.ta,l e,,ffic.iency,1 = c--f-m-----X- 6--t3-o-5-t-6a---lX--p--r-eH--so-s-r-us--re-e-p-i-on--w--ien--rc--hi:-ne--ps--u-o-tf--w--a---t-e--r (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- *See Standard Test Code for Centrifugal and Axial Fans, Third Edition of 1938. Heating Ventilating Air Conditioning Guide 1939 centages of their wide-open capacity. Variations in efficiency accompanv variations in pressures and power consumption which are characteristic of the individual designs and which are influenced particularly by the shat* 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 Centrifugal and Axial Fans* prepared jointly by the American Society of Heating and Venti lating Engineers and the National Association of Fan Manufacturers' The results of tests are plotted in different ways: the abscissae may be 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. I. Operating Characteristics op an Axial Flow Fan 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 pres sure 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. . .93^Wri'ES'S 1938, 2923' P- 407' 552 ,, .in A:S H V E- Transactions. Vo 37 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. Heating Ventilating Air Conditioning Guide 1939 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 fan 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 cneed may necessitate somewhat heavier construction and more operating ttention or service. The dimensional bulk for a given duty often is 150 pet cent t^at 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 Fig. 3. Operating Characteristics of a Fan with Blades Curved Forward The forward curved multiblade 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- 554 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. 555 1939Heating Ventilating Air Conditioning Guide 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 2 3 4 5 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. 556 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 pace 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, msatisfactory 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 Vi %. 14 Vt K % l IK m m 2 2K 2)4 3 Outlet Velocity Fbbt peb 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 . Tip Speed Feet peb Minutb 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 the full length of the performance curve. 557 Heating Ventilating Air Conditioning Guide 1939 In exhaust ventilating systems where the air column moves toward th fan, noise due to the higher tip speeds and outlet velocities will not h! < so readily transmitted back through the air column to the building ^ when the air column is moving toward the rooms. Therefore high? 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 supp]v 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 Prfbsurb Inches of Water M Vt Vl % H %. l m m 1M 2 2M 2K 3 Outlet Vblocitt. 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 moisture- proof 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 558 Chapter 27. Fans ~ 1H In drying, these fans may be used with unit heaters where not much duct work is required and where air is to be delivered against 400 sure since the noise developed from the high peripheral speed of these fens is not ordinarily objectionable in process work. Centrifugal fans of the multiblade type generally are selected to supply . 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 `nee 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 559 Heating Ventilating Air Conditioning Guide 1939 Be* . ISS -1*I!s*s! fc 1w? 555=38 ^ feg? geo- ssj SS-g 560 Chapter 27. Fans increased supply of air in summer over that needed for winter is demanded Experience is required m deciding whether speed-control or dampercontrol shall be used for specific cases. Where noise is a factor, it mav 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 yithout change tn 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 " iiation is clockwise, the fan, blower, or blast wheel will be designated as clockwise. Nthe proper direction of rotation is counter-clockwise, the designation will be counterjiShMse. (The driving side of a single inlet fan is considered to be the side opposite {beiSet regardless of the actual location of the drive.)' This method of designation will apply to all centrifugal fans, single or double width, gad 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 gad 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 a3 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 speci6ed. In orderto 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. 561 Heating Ventilating Air Conditioning Guide 1939 Justification for liberal power provision exists also in the possibil'hF- of varying demand due to changes in ventilation requirements, inten of occupation, and weather conditions. 7 The motive power of fans should be determined in accordance with tli Standard Test Code for Disc and Propeller Fans, Centrifugal Fans Blowers, as adopted by the American Society of Heating and Venti ! eating 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). . Section 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. 1 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 What information must be supplied to the manufacturer when ordering a centrifugal fan? o. Size 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.). . . Chapter 27. Fans <V selecting fans for quiet operation in public buildings: ! * * gj,ould the outlet velocity of the fan be limited? ghould the tip speed of the fan be limited? se all commercial fans operating at pressures suitable for this class of work ' *" wMie considered noisy if the fan were to discharge directly into the room, and soald lue duct system on the fan discharge is depended upon to absorb a reasonable .bap115? r ^ noise, it is desirable to have a moderate run of duct work with some bends ^afoows included as sound deadeners. Where this duct is of necessity very short, the I t velocity must be kept down to the lower limits recommended in this chapter or iBU n efficient sound absorber must be used. The experience of the engineer must be y*guide in determining the allowable outlet velocity in each individual case. speed should not ordinarily be limited, because different types of fan blades have f;rJy different allowable tip speeds for quiet operation. A fan having a backward hi de 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 . ;s 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. ( 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: 1 a. What is the static efficiency? b. What is the total efficiency? 0. 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. * 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. 563 ; 'j j > j j Heating VentijjAtjng Air Conditioning Guide 1939 9 V 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 i will be least. Produced \ 10 In Fig. 3, a static pressure of 85 per cent of blocked tight pressure responds to three different volumes, namely 11 per cent, 30 per cent and 48Ct* cent of wide open volume. . What will determine which volume the fan deliver** The fan can operate only at the intersection of its pressure-volume curve and the syste characteristic. The type of system, together with the specification of the volume at certain static pressure, completely defines the system characteristic. a As illustrated in Fig. 5, a given system characteristic will intersect the fan curve in one point. only 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 will not have the same resistance at any ot volume. \ 564 Chapter 28 air distribution Definitions, Grille Locations, Standards for Satisfactory Con ditions, Factors Affecting Distribution tor Cooling and Heat ing, fur Outlet Noises, Selection of Supply Outlets, Balancing System CORRECT air distribution 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; (o) distribution to the various spaces served by the system, (6) distribution in these spaces. This discussion is primarily limited to division (6), reference being made to the duct system only insofar as it affects the performance of the air distribution Outlets. ' Definitions 1. Supply Opening: Any opening through which air is delivered into a space which is being heated, or cooled, or humidified, or dehumidified, Or ventilated. 2. Exhaust Opening: Any opening through which air is removed from a space which is being heated, or cooled, or humidified, or dehumidified, or ventilated. 3. Outside Air Opening: Any opening used as an entry for air from outdoors. 4. Grille: A covering lor any opening and through which air passes. 5. Damper; A device used to vary the volume of air passing through a confined cross-section by varying the cross-sectional area, 6. Multiple Louvre Damper: A damper having a number of adjustable blades. 7. Single Louvre Damper: A damper having one adjustable blade. 8. Face: A grille with provision for attaching a damper. 9. Register: A face with a damper attached. . 10. Flange: The portion. (either integral or separate) of a grille, face, or register extending into the duct opening for the purpose of mounting. 11. Frame: The portion (either integral or separate) of a grille, face, or register extending around the duct opening for the purpose of mounting. 12. Margin: The margin of a grille, face, or register is one-half of the difference between the duct dimension and overall dimension measured either horizontally or vertically. r 13. Fret: The member separating the openings of a grille, face, or register. 14.Free Area: The total minimum area of the openings in the grille, face, or register through which air can pass. 15.Core Area: The total plane area of the portion of a grille, face, or register bounded by a line tangent to the outer edges of the outer openings through which air can pass. 16. Mean Area: The total of the core and free areas divided by two. 17.Duct Area: The area of a cross-section of the duct based on the inside dimensions at the point where the grille, face or register is mounted. Heating Ventilating Air Conditioning Guide 1939 18. Percentage Free Area: The ratio of the free area to the core area expressed percentage. "V 19. Dimensional Ratio: The ratio of length of the core of a grille, face or to the width. ^'Ster 20. Throw: The distance air will carry measured along the axis of an air stream from the supply opening to the position in the stream at which air motion reduces to 50 fpjJ1 21. Envelope: The outer boundary of an air stream. ' 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 Chapter 28. Air Distribution 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 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 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 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. 566 Fig. 3. Elevation View Ceiling Supply Outlet with Return Wall Outlet Fig. 4. Elevation View Ceiling Supply and Return Outlet 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 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 567 . Heating Ventilating Air Conditioning Guide 1939 temperature of 83 F would be cold.. In general, other conditions be' equal, for the range of temperatures normally encountered in i;vJn^ quarters on cooling installations, the permissible deviation from averap8 room temperature varies from approximately 1 F at the low end of thC range to about 3 F at the high end of the range. In this matter, it ^ important to consider the particular problem in the light of the type *f occupancy. For instance, greater deviations from room temperature and higher velocities may be permitted in a garage or a hotel hallway tha would be permissible in an office or living room. The velocity which mav be considered the permissible maximum differs with the temperature deviation for a given installation, but an absolute maximum under anv conditions might be considered that which would produce a mechanical Chapter 28. Air Distribution e ;s counteracted to a certain extent so that an individual may be peraw tQ higher velocities of warm air without the feeling of disSU f rt occasioned by the same velocities of cool air. In every case, it cp|l he the purpose of the designing engineer to keep the conditions ih'n the zone of occupancy as nearly uniform as possible, securing W' 'mum temperature deviations and low velocities. The air velocity Tall points in the room should be at least 25 fpm for good results. 8 It is impractical to measure momentary temperature differences with v degree of accuracy in the field, but in checking a given installation it 11 generally be found satisfactory to measure velocity only, since on - doling installations high velocities normally occur with low temperatures, d 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 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 Fig. 5. Elevation View Correctly Located Return Outlet Fig. 6. Elevation View of Improperly Located Return Outlet 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 qccupancy 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- 568 Fig. 7. Plan View Correctly Located Return Outlet Eliminating Stagnant Space 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 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 569 Heating Ventilating Air Conditioning Guide 1939 be contributed by fans, motors, duct work, and other items of condition' ^ equipment. The control of noise from these sources is another proble^f (see Chapter 30). Where sound control is important, the actual nx,1" '? sound level without conditioning equipment should be known p ' feasible, the contribution of the conditioning equipment, less outlet should be estimated to secure the working sound level. If this correctio ' 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 the outlet noise is greatest. A tentative standard:listening point relative to the outlet is suggested later in this discussion, and it is assumed that the outlet noise data are taken 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 short- circuit to the return air outlet, or 1, " - 3. It may spill into the center of the room. 5 570 Chapter 28. Air Distribution V In the first case, the system fails for lack of uniform distribution and the /. ence Qf C01J areas. In the second case, the standards as to velocity '^dtemperature difference in the zone of occupancy may be satisfactorily .,a" t but air distribution and circulation throughout the entire room is not 'mplished, with the result that the end of the room away from the atlet would not be satisfactorily conditioned. In the third case, the hortcomings 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 s a maximum and a minimum length of room which can be satisfactorily ' 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 upon 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. In addition to disturbances due to the construction of 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 and about 5 deg for two-sided expansion. Frqm 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 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- 571 Heating Ventilating Air Conditioning Guide 1939 stream, are obtained with the arrangement shown in Fig. 9. The latt may be corrected by inserting a turning member in the elbow back of outlet face as shown in Fig. 10. The importance of straightening the stream and affecting uniform distribution over the entire face of the outW cannot be over-emphasized. le* 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 Fig. 8. Effects of Expanding Duct Fig. 9. Unequal Face Velocities Fig. 10. Effect of Turning Member 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 U 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 ' 1 ; ^ i 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 enclosure, 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 proportional to the rate at which sound energy is generated and inversely .,,* :: ^ ; J fi 572 Chapter 28. Air Distribution rtional to the number of sound absorption units (sabins) in the PrP~ if would thus appear that doubling the sound absorption of the would halve the intensity and result in a noise level decrease of 3 db. Hwever, it is not satisfactory to consider the grille noise on this basis (herein the sound power received directly from the source is small rnDared with that received by reflection) since in practice the occupants ? jjjg roorn may be quite close to the grille. The nearer the listener is to ihe 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 centimeter*. 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 weighing network intended to approximate the response of the human ear. `American Tentative Standards for Noise Measurement, American Standards Association. Heating Ventilating Air Conditioning Guide 1939 If the published ratings are in terms of decibels per square foot cn rection must be made for area to secure to total sound level of outlets *1 more or less than one square foot area. This can be done by use 0{ following formula: e Decibel Addition = 10 logTM A where: , A = core 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 and 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 Chapter .28. Air Distribution 12 Thus, if the absorption is 200 sabins, a correction of +1.3 db he'made and the permissible velocity becomes that corresponding to - ajr , ioudness level of 31.3 decibels or approximately 750 fpm. If the 3 * is highlyreflecting and has an absorption of less than 100, correction fm (_j1 more important. For instance, for 35 sabins a correction of -- 3 db 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 predetermined total loudness at a predetermined rate of flow expressed in cubic feet per minute. The values used are arbitrarily chosen for the purpose of discussion and do not necessarily represent data referring to any particular make of grille, register or air outlet. It is assumed that Fig. 11 is based on a room having 100 sabins of sound absorption. In such a room the sound level due to 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 oh the basis of a room absorption of TOO 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 574 must be made and the maximum velocity corresponding to 27 db total loudness chosen; thatjs, approximately 550 fpm. Where more than one 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 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- 575 Heating Ventilating Air Conditioning Guide 1939 ling this problem, and one which errs in the direction of safety, is to tre the room as though all the air were being supplied by one outlet. Tli if two outlets, each supplying 1000 cfm are used, the value 2000 ct' should be used with Fig. 11. Although this method may place an 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 t justify a more complicated though more exact procedure. 0 In general, return grilles are selected for velocities about half the supnlv 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 a suitable supply air temperature selected, the Fig. 13. Plan View Typical General Office 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 576 Chapter 28. Air Distribution pooling problem, using numerical values which have no reference particular make of outlet. 1 The load calculations have been made; a suitable temperature differential has been ted (it is to be understood that the data referred to from this point on are based on s' temperature differential), and the volume of air required determined. Assume that tr 13 represents a small general office having a noise level of 40 db and that 2500 cfm oust be supplied for proper conditioning. 2 Select a tentative location for the outlet or outlets, having in mind the type of `He most likely to effect proper distribution. In this particular case, two outlets ^ying a wide spread appears to be a logical choice. o Qata from which to determine velocity which corresponds to 2500 cfm and a noise tine 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 nracti'ce 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 He selected may be used at velocities up to 700 fpm without exceeding 35 db; that is, 5db below the noise level of office. 4. Having determined the velocity, the core area becomes fixed at 3.57 sq ft or 257 sq iri. 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, register 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 series 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 577 Heatino Ventilating Air Conditioning Guide 1939 draw a small proportion of the room air into the air spreader where ' mixes with the conditioned air before it is discharged. 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 th 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. e 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 on the return grilles. 3. Dampers in the supply ducts. '4. Dampers in the return ducts. 578 Chapter 28. Air Distribution :r-V--; Reducing the effective area of some outlets by blank-offs. : ' Combinations of dampers in both supply and return air. i Dampers on the supply grilles themselves are objectionable because of effect on the air stream. Dampers on the return grilles are frequently ' h fnful in building up a static pressure in the room to prevent infiltration f outside air, and at the same time reduce the volume of incoming air. However, it is frequently impossible to sufficiently reduce the incoming ' . . this method alone. A damper in the supply duct some distance T'.'&Anf the outlet forms a very satisfactory means of regulating the flow. -- -without disturbing distribution across the outlet face. . A damper in the r.jTLrn air duct has the advantage over one immediately behind the grille ' in that it does not tend to create high localized velocities through the " zrille as the latter might do if nearly closed. Blank-offs consisting of ; Sgces 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 1 conveniently accomplished as with dampers. Dampers in both supply "and return air form the most flexible means of controlling the supply to the Vbom 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 oi 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 11 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, but also the air must be properly distributed within the enclosed space to give complete satisfaction. 2 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 # What factors in grille design affect the length of air throw? o. 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. i How does the height of a supply outlet affect the temperature differential within a room? 579 Heating Ventilating Air Conditioning Guide 1939 In general, the higher the outlet is above the floor, the greater may be the differen between room air and incoming air temperatures. ence 5 Under conditions prevalent in a large room, how does the intensity of sound develop at an air outlet vary? 4 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. 18 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 stationa.ry air. 7 What type of system is generally used in a large continuously operated theatre? Most targe continuously operated theatres are provided with a complete downward system of 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 # 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: a. 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. v 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 //v 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 II, 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 therefore, where : -gy = 62.4 . Ay d ; 12 ,. (N iri II -tS hy' ; d \5 V = 1096.5 - 7 : 1 . a) V = velocity in feet per minute. Ay = 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: . = 4005 V^ (2) 581 Heating Ventilating Air Conditioning Guide 1939 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 Losses 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 Fig. 2. Corve Showing Loss of Pressure in Square Elbows 582 Chapter 29. Air Duct Design , , ^mes the velocity head. The pressure loss in elbows must also be 'flowed for. in the design. It is customary to express dynamic losses in. tims 0f the percentage of the velocity head; in other words, the per1 ntage of that pressure corresponding to the average velocity in the duct ^hich 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 on 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 1% 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 cent for square ducts. Very little advantage is gained in making elbows with a radius of more than two diameters2. 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) vy 4005/ For rectangular ducts "r * pi*)*.-* (**)(*) (3) (4) where kL = loss of head, inches of water. (7 \2 J -- velocity head, inches of water. V = velocity of air, feet per minute. L = length of pipe D = diameter of pipe } all in feet. a, b = sides of rectangular duct :f = coefficient of friction. / \ \ii \ ..'"'I C =-j- = length of pipe in diameters for one head loss. For all practical purposes C varies only with the nature of the pipe surface: C = 60 for perfectly smooth pipe; = 55 for pipeas used in planning 'Loss of Pressure Due to Elbows in the Transmission 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 (Healing, Piping and Air Conditioning, July. p. 365, August, p. 427, September, p. 483, 1936). . 583 Heating Ventilating Air Conditioning Guide 1939 Friction in Inches of Waterper 100 Ft. Fig. 3. Friction of Air in Pipes 584 Chapter 29. Air Duct Design ... gxhaust systems; = 50 for heating and ventilating ducts; = 45 for ml` th and 40 for rough conduits of tile, brick or concrete. However, tr'tzsche states (and numerous tests check very closely) that / varies .eTse\y as the 2/7 power of the pipe diameter, and inversely as the 1/7 m wer of the velocity, or inversely as the 1/7 power of capacity, which is same thing. Thus Formula 3 may be revised as follows, based upon a of one velocity head (at 2000 fpm) in a length equal to 50 diameters f 24-in- galvanized swedged pipe: ----jMi The preceding formulae are based on standard air, and for other conHitions the friction varies directly as the air density and inversely (apnroximately) 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 to H 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 585 Chapter 29. Air Duct Design D iam eter of Branch Pipe F ig . 4. M a in an d B r an c h P ipes for E q uaL F r ic tio n per F oot of L en g th (1 to 20 P e r C e n t C a p a c it y ) ir nt within the available pressure difference. This pressure difference in ` irhanical ventilation is that derived from the fan, while in gravity ntilation the aspirating effect due to the temperature and height of the ^{utnn of heated air causes the pressure difference. funeral Rules . 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 toLl.) Procedure lor 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 siipply 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, 587 D iam eter of Branch Pipe (20 t o ioo P e r C e n t C a p a c it y ) Heating Ventilating Air Conditioning Guide 1939 588 Chapter 29. Air Duct Design aximum velocities with good construction and design may be as high. m 2000 or 2200 fpm in main ducts, with suitable reduction in branches ^d outlets. With these velocities first-class duct construction is essential. Proportioning the Size for Friction By means of Figs. 4 and 5 the diameter of branch pipes necessary to rarry 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 sire of branch pipe required to carry 50 per cent of the total air in the main. Find 50 ner cent at the left of the chart, move right to the 60-in. diagonal line and note directly Jibove 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 <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 17J4 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 &DS RECTkSQOlAR 8 8.5 9 9.5 10 10.5 ii 11.5 12 12.5 13 13.5 14 14.5 15 15.5 Deep 16 3 . 3.5 4 4.5 5 5.5 5.2 5.4 5.5 S.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 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 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 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 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 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 10.1 589 X s '3 8 2 a a 2 3 2 2 2d 2 22 Ov "22 00 Heating Ventilating Air Conditioning Guide 1939 5522- M<0 0>N """2 o 00 00 00 o> 2222 i ""23 590 6.9 8.8 7.3 9.3 7.7 9.8 8.0 10.2 7.4 7.6 | 7.9 1 8.2 10.0 10.7 11.4 12.0 12.6 13.2 10.4 11.1 11.8 12.5 13.1 13.7 14.3 10.8 11.5 12.3 12.9 13.6 14.3 14.9 15.4 11.1 11.9 12.7 13.4 14.1 14.7 15.3 16.0 222 2 NO 2288 2322 88S8 883S S8S3 8.4 9.5 i 10.5 11.4 12.3 13.1 13.8 14.5 15.2 8.6 9.8 10.8 11.8 12.6 13.5 14.2 15.0 15.7 8 .9 10.0 11.1 12.1 1 1 1 13.8 14.6 1 15.4 16.1 9.1 10.3 11.4 12.4 S:Si 14.2 ! 15.0 15.8 16.5 9.3 10.5 9.7 11.0 10.0 11.4 10.4 11.8 = 222 12.7' 13.6 14.5 15.4 16.2 17.0 13.2 14.2 1 15.2 16.1 16.9 17.8 13.8 14.8 j 15.8 16.8 17.6 18.5 U .3 15.4 16.4 17.3 18.3 19.2 12.2 12.6 12.9 13.2 14.8 15.2 15.6 16.1 15.9 16.4 16.9 17.3 17.0 17.5 18.0 18.5 18.0 18.5 : 19.1 1 19.6 19.0 19.5 ; 20.1 1 20.7 19.8 20.5 21.1 21.6 15.8 16.3 16.8 17.2 17.6 18.5 19.3 20.0 20.7 21.4 22.0 22.6 16.5 17.0 17.4 17.9 21.5 22.2 22.9 23.5 17.1 17.6 18.1 1 18.6 19.0 19.9 20.8 21.6 ; 19.7 20.6 21.5 22.3 22.4 23.1 23.8 24.4 18.7 19.2 1 19.8 I 19.8 20.4 20.9 ; 20.3 21.3 , 22.2 j 23.0 1 20.9 21.9 ; 22.8 23.8 21.5 22.5 23.5 24.4 ; 23.9 24.7 25.4 26.2 24.6 1 25.3 : 25.4 26.2 26.2 27.0 26.9 27.7 22.0 23.1 24.0 25.1 26.0 26.8 27.7 28.5 ! 23.6 24.2 24.7 25.2 26.4 25.7 26.3 27.5 26.6 27.3 27.5 28.2 1 1 28.4 29.1 29.2 30.0 2222 11.9 13.6 12.2 13.9 12.5 14.3 12.7 14.5 16.4 17.7 19.0 20.1 21.2 22.2 23.2 24.2 25.1 26.0 ; 26.8 27.7 28.5 29.3 30.0 30.8 32.2 16.8 17.2 18.2 18.6 19.4 19.8 20.6 i 21.7 21.1 1 22.2 22.8 23.3 23.8 24.4 24.8 25.4 25.8 26.4 26.7 1 27.5 27.3 28.2 28.4 29.1 29.2 29.9 30.0 30.8 30.8 31.6 31.5 32.4 33.1 33.9 17.6 19.0 20.3 21.6 22.7 23.8 24.9 25.9 26.9 27.9 28.8 29.8 30.7 31.4 32.2 33.0 34.5 44 13.0 14.8 16.4 18.0 19.4 20.7 22.0 1 23.1 24.3 25.4 26.5 ` 27.5 1 46 , 13.3 15.1 16.7 , 18.4 i 19.8 ; 21.1 i 2 1 -* 1 23.6 24.8 25.9 1 27.0 28.1 48 13.5 15.4 1 17.0 18.7 20.1 21.5 22.8 24.1 25.2 1 26.4 27.5 28.6 50 13.7 15.7 17.3 19.0 20.4 21,9 23-2 24.5 25.7 | 26.9 28.0 29.2 1 I 29.5 30.3 i 31.2 30.1 31.0 i 31.9 30.5 31.6 32.5 31.3 32.2 33.1 32.1 32.8 33.4 34.1 1 33.7 i 34.6 35.2 35.9 35.3 36.2 37.0 37.6 13.9 15.9 17.6 19.2 20.8 22.2 23.6 24.9 14.1 16.1 ; 17.9 19.6 21.1 22.6 24.0 25.3 14.3 16.3 18.2 19.9 21.5 22.9 24.4 25.7 14.6 16.6 18.4 20.2 21.8 23.3 24.7 26.1 28.5 29.6 30.7 i 31.8 32.9 33.8 34.7 35.6 36.5 38.3 29.0 30.1 31.2 1 32.3 33.4 34.4 35.3 36.3 37.2 38.9 28.3 29.5 30.6 31.7 | 32.8 33.9 34.9 35.9 36.9 37.8 39.6 28.7 30.0 31.1 32.2 33.3 34.4 35.4 36.4 37.4 38.4 40.3 14.7 16.8 18.7 20.4 22.1 23.6 25.1 -26.5 27.8 29.1 15.0 17.0 19.0 20.7 22.4 24.0 25.5 ! 26.9 28.2 29.5 15.1 17.3 19.2 21.0 22.7 24.3 25.9 27.3 28.6 29.9 15.3 17.5 19.5 : 21.2 23.0 24.6 26.2 27.7 29 30.3 - - 5 X 5 * -_______ 1 4.9; 4 X 6 5.4; 4 X 7 5.8; 5.5; 5 X 6 6.3; 5 X 7 39.1 40.9 1 1 1 41:.!6 -- IN 00 ssssi $33 SSSSS . s'sissj .S3'sis; 333 .. ssss T a b l b 1 . C ir c u l a r E q u iv a l e n t s o p R e c t a n g u l a r D u c t s f o r E q u a l F r ic t io n -- (Concluded) Heating Ventilating Air Conditioning Guide 1939 592 F ig . 0. T y p ic a l L a y o u t op A ib D is t k 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 S. 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 7j^-minute air change (8 air changes per hour) is assumed for proper ventilation, giving 22,935 cfm as the air required. , # 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 dear 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 16M 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 in the main pipe will be 1340 fpm. Using the friction pressure loss method' this 56-in. 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 jolume 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. ' Voluub or Am (CFM) 22,935 12,510 10,425 8,340 6,255 4,170 2,085 Table 2. Pipe Sizes for Example 3a Pee Cent or Total Volume 100.0 54.6 45.4 36.3 27.2 18.2 9.1 Dumsteb or Pipe (Inches) 56 45 42 39 35 29H 23 Equivalent 8tsb or Rectangular Duct (Inches) 60 x 44 58x30 50x30 42x30 42x24 30x24 30x15 Velocity through diffusers (not shown) to be approximately 300 fpm. 593 Heating Ventilating Air Conditioning Guide 1939 The pressure at the outlets nearest the fan will be greater than at the pipes fartli along the run so that the former will tend to deliver more than the calculated amout air. To remedy this condition, volume regulating dampers should be located at the h of each riser and adjusted for proper distribution. At points where branches leave fh* main it may be advisable, depending upon the nature of the installation, to inst n adjustable splitters similar to that shown in Fig. 6 where the main duct divides intJ it 58 in. X 30 in. and 50 in. X 30 in. branches. The rectangular equivalents are selected from Table,1; the width to depth proporti will be determined by construction requirements and ease of fabrication. The cal n lation of the friction is as follows: ' cu- The longest run from the fan outlet to diffuser is 150 ft 0 in.; 150 ft of 56-in. Dine 150 x 12 vv equivalent to------^------------------------- --------------------------------------------- ------ .......... -- 32.2 diam Two 45-in., 90-deg elbows (2 X gg X 8.5)----------------------------- --_.................... 13.7 (j;am , (Assume each elbow equivalent to 8.5 diameters of duct, Fig. 1). .' ' oo ' . Two 23-in., 90-deg elbows (2 X gg X 8.5).--....................................... ................... 7.0 diam ' - 23 - Two 23-in., 90-deg elbows in riser (2 X gg X 30).----------r.------------- ............. 24.7 diam (Two bad elbows in riser, each equivalent to 30 diameters of duct). Total diameter of 56-in. pipe._________________________________ ____________ 77.6 The velocity 'head corresponding to a velocity of 1340 fpm is X( 14304005\)2 = 0.112 in. ,. . yy g Taking 50 diameters as one head loss, then -gg-- X 0.112 = 0.174 in. static loss in duct. Where the connection pieces are made with long easy slopes and the general work 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_____ _____________________________________0.111 in. Other friction losses are as follows: , (1) Fresh air intake 1000-fpm velocity (1)4 heads X.0.0625)............ (2) Tempering coil loss (from manufacturer's tables)__________________ (3) Air washer loss (from manufacturer's tables)_________________________ (4) Reheating coil loss (from manufacturer's tables)____________________ (5) Allowance for regulating dampers and diffusers______ _____________ .0.094 in. 0.100 in. 0.250 in. 0.100 in. 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 Centrifugal and Axial Fans1, will deliver 22,935 cfm at a static pressure of 0.755 in. and which has an outlet area of 16)4 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 *See Chapters 27 and 45. Chapter 29. Air Duct Design 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 damperuig in the risers and supply branches in order that equalization of air flow can be 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- Table 3. Pipe Sizes for Example 4a VOLUME or Ara (ctm) 16,800 11,550 9,450 5,250 4,200 3,150 2,100 Pbb Cent or Total Volume 100.0 68.8 56.2 31.3 25.0 18.8 12.5 DudOSTES or Pipe (Inches) 47 41 38 31 28.5 25.3 21.6 Equivalent Sieb or Rectangular Due* (Inches) 38x48 30x46 30x40 24 x 34 24x28 16 x 34 . 16x24 . Velocity through intake grilles (not shown) to be approximately 400 fpm. 595 Heating Ventilating Air Conditioning Guide 1939 rvw-- j: L -i SECTION /Top sheet _ These crossbreaks are -"never shown on a plan ELEVATION Reinforced cross seams Side sheet 'Bottom sheet Seams between adjacent panels or plain cross seams Fig. 9. Details of Seams Fig. 10. Method of Installing Heating Unit \ I* Fig. 11. Installation of Easement in Duct Around Obstruction 596 Chapter 29. Air Duct Design AU risers will require dampering as in Example 3.- The calculation of the friction b as follows: . The longest run from the intake grille to fan inlet is 100 ft. ....................... . . /100 X 12\ (X) Duct friction 100 ft of 47-in. pipe ^^----- J--------- 25.6 diam J...................................( 2 X 28.5 X 30 \ Two 28j4->n., 90-deg elbows in riser ^^-------- . (Two bad elbows in riser each equivalent to 30 diameter? of duct). One 28J$-in-t 90-deg elbow in horizontal run 8 5^......... ..........-- 36.4 diam 5.2 diam Total diameter of 47-in. pipe. .. 67.2 diam Velocity head corresponding to 1400 fpm is 67.2 X 0.122 Taking 50 diameters as one head loss, then 50 ----------- (2) Intake loss from grille (1)4 heads at a 400 fpm velocity 1)4 X 0.01)--------(3) Static pressure required to produce one velocity head at 1400 fpm-----------(4) Loss occasioned by step-up of velocity (0.20 X 0.122)__________________ (This toss 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). 0.164 in. 0.015 in. 0.122 in. 0.024 in. 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 = 4 diameters of 45-in. pipe. 45 The velocity head corresponding to a velocity of 1525 fpm is 0.145 and the discharge- side loss is 0----1455UX-----4 = 0.012 in. The total static pressu' re 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 597 Heating Ventilating Air Conditioning Guide 1939 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 pipjj 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 5. 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 having been designed for equal friction per foot of length, 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, which has a loss equivalent to 8.5 diameters of 20-in. pipe. This in turn is ?? 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 head, the loss is --gjp = 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 1.3J X 0.3 = 0.399 in. Table 4. Sheet Metal Gages for Rectangular Duct Constructions Gage Width or Duct Seam Reinforced Seam 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. W 20 61 in. to 90 in. W in. x in. in. x 1% in. m If 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 huild die 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 trans formation sections and splitters in elbows tends to maintain relatively uniform velocities with decrease in turbulence and in the noise produced. 598 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 Tabic 4. REFERENCES Fan Engineering, Buffalo Forge Co. . Heat Power Engineering, by Barnard, Ettenwood, 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. 2A79S).tudy 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 1 Determine tbe 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, and (t) 200 per cent of the pipe diameter. Assume 1 velocity head lost in 50 diameters. From Fig. 1 the per cent of velocity head 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 17.0 per cent X 50 = 8.5 diameters straight pipe. c. For 200 per cent radius is 14.5 per 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. 1 What determines which shape to use? Structural and space conditions. Because ducts are as a rule part of tbe building or structure, it is necessary to proportion their sizes to fit the spaces available. 599 Heating Ventilating Air Conditioning Guide 1939 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 vel is fixed for the main supply duct at the fan, and this velocity is gradually decreaJ?ty each branch or outlet is taken off the main supply duct. vasen ,, 6 Which system of duct design is to be preferred, the velocity method or friction pressure loss method? ' *** The friction pressure loss method can be used to advantage where no structural building conditions limit the shape of the ducts. Where these limiting conditions . the velocity method is to be preferred. est 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 increased from 20 to 50 per cent, depending on the design of the grille, to allow for til* loss of area caused by the construction of the face of the grille. lne 8 Where it is necessary to provide steel angle braces, how far apart should they be spaced? 1(3 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). 10 How does a splitter at a duct junction influence the volume of the air going through each branch? 8 A splitter facing the direction of air flow cuts off the air and delivers the desired amount to the branch. 11 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 9 What methods are used to keep large ducts from vibrating because of air pulsations, and from sagging because of their own weight? External bracing, such as standing seams, or structural shapes, like tees or angles, should be placed across the top and bottom. Exterior braces or cross buckling of metal sheets in diagonal panels may be used for the sides of large ducts. \ 13 What velocities of air. flow should be used in the trunk ducts of a venti lating system in a public building? 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 fpm. 600 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 acoustical 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 By a recently adopted international standard, two terms are used for noise measurement. The decibel (db) is the physical unit for expressing intensity or pressure levels. The phon is applied to what was formerly called loudness level; that is, the equivalent level in decibels of the equally loud thousand cycle tone- The decibel is defined by the relation iV = 10 log-^r-, where N is the number of decibels by which the intensity *0 ' flux /; exceeds the intensity flux Ia. The intensity flux is the measure of the energy contained in a sound wave and is defined in terms of micro watts per square centimeter of wave front in a freely traveling plane wave. It is usually more convenient to select an arbitrary reference intensity for IQ 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 601 Heating Ventilating Air Conditioning Guide 1939 this reference threshold is 10~10 watts. In a similar manner, when sound measurements are given in actual intensity or energy units, they can 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 noise 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. ' .. . ' 602 Chapter 30. Sound Control. . .wiedge necessary to its solution can be listed, the available infor- ation at present is lacking in certain respects. However, attention niay hi 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 lris based on these data, which represent the best opinion on the ' Table 1. Typical Noise Levels ' Rooms ; Noise Level in Decibels to be Anticipated Min. Representative .Max. Sound Film Studios..................;...................... ..............:..... Radio Broadcasting Studios...................... ......... :................... Planetarium...................................................................................................... Residence, Apartments, etc.........--.......... .......... .............. Theatres, Legitimate.-................... .......................,------- :.................. . Theatres, Motion Picture................................. ........................... Auditoriums, Concert Halls, etc................................................. Churches..........................-.................................. -............ --........................ Executive Offices, Acoustically Treated Private Offices Private Offices, Acoustically Untreated.......................... General Offices- ...............................................................i.................... 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.- .................................... ................ 10 10 15 25 25 30 25 25 25 35 45 25 30 30 45 40 40 50 40 50 50 60 . 60 14 20 : 14 20 20 25 35 40 30 35 35 40 30 40 30 35 33 40 45 50 55 60 40 55 35 45 40 45 55 60 50 60 . 50 55 60 70 50 60 60 . 70 55 60 70 80 70 80 Vehicles Railroad Coach............................................ ........... .......... . Pullman Car..................... ... Automobile........................................... .................................. Vehicular Tunnel....... ........................................................... Airplane........................... . 60* 55* 50 75 80 70 65 65 85 . 85 80 - 75 80 95 100 For train standing in station a level of about 45 db is-the maximum 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 603 'l Heating Ventilating Air Conditioning Guide 1939 existing spaces. They are, however, the noise levels of the room and n the noise levels of the ventilating or air conditioning equipment. If noise level at the room of the equipment is kept at the levels shown in th table the equipment will not add to the acoustical hazard existing witho it, provided the equipment noise is heard atone, but if both are hen*!! together the total noise level in the room will be increased about 3 dh This is usually considered an acceptable result. D' 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 measureable 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. 1 NOISE CHEATED 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 on 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. BINDS 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 the room as: 1. Noise transmitted through the building construction. 2. Noise transmitted through the ducts. It is convenient to further sub-divide these two methods of delivery as: 1. Noise transmitted through the building construction. a. From machine mountings as vibration. b. From equipment through roomvwall surfaces. . 2. Noise transmitted through the ducts. o. 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. Chapter 30. Sound Control noise THROUGH BUILDING CONSTRUCTION It is impossible to select ventilating equipment which will operate hnut producing some mechanical noise, and since the equipment must ounted in a building, it is probable that a part of this noise will be "e Emitted to the building itself to such a degree as to make noisy con joins in the rooms which are to be air conditioned. Much of this noise d v be transmitted by the duct if it is rigidly connected to the fan outlet. iTs common practice to make the connection between the fan and the Jit 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: v. r* + 4 **nV* + (1-Knm -- 2tcncl (1) where t1 = the so-called transmissibility 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 frequencv 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. VPhysical Renew, Vol. 32, 1928, p. 324). and A. L. Kimball, (Journal of the Acoustical Society of America, Vol.2, 1930. p. 297). ' 605 G 1939Heating Ventilating Air Conditioning uide 30.Chapter Sound Control 11 r, the mechanical resistance,- is very small, formula 1 may be written . .1 - ofany particular set-up. The value of c can be obtained by making static Pents 0f the amount of displacement of the compressed support eas" h additional unit of the compressing force. If this be done for a (or rLen of the flexible material of a certain thickness and area of.cros? sP? tjje compliance can be determined for any other thickness or area where o is the natural frequency of the machine upon the elastic pad, i^the relation that c will be directly proportional to the thickness and "rsely proportional to the area1 of the flexible support. . When the ' :. " = irVi wnal resistance r is not too large, it can be determined by observing the TLsive amplitudes of the free vibrations of a mass m which rests upon susccoeeci_m__e_n__o_ff tthtief (flWexiti-blilpe mmaatteerial,, aanndd ssolvingg-for r bvy the usual loeg-' -In most cases of design of resilient machine mounting the effect f frictional resistance is small, and Equation 2 may be used. In such case! it is only necessary to know the natural frequency of the elastic pado platform used under the desired loading and the transmissibility for anv vibrational frequency of the machine may be obtained. However th' 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.) ls Hecrement method. Or, if the damping be,so great that the free motion of - n0n-oscillatory, r can be obtained from measurements on the experi mentally-determined resonance curve of the forced vibrations of m, or om 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 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 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 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 compairison with the frequencies which are Table 2. Compliance and Resistance Data for TypicaL Specimkns of Flexible Materials generated by the machine. Thus, if the principal vibrations in the machine be of the order of 100 vibrations per second, the natural frequency The compliances and resistances given.in the table are for specimens 1 in. thick ; . and 1 sq cm in cross-section ' , 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 Material . Description op Material Approximate Upper Safe Loading in Pounds per Square Inch - Compliance c in Centimeters pep Dtne Resistance r- in AbsolutbUnits 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 Corkboard Corkboard 1.10 lb per 12 0.25 x 10- 0.15 x 10s board foot 0.70 lb per 8 0.50 x 10-* 0.25 x 10s 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. 1 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 above about a/---- 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 Fiber Board Fiber Board Fiber Board Fiber Board Fiber Board Anti-Vibro-BIock Sponge Rubber Soft India Rubber board foot .1.35 lb per board foot Carpet lining Insulating board Insulating board Insulating board . 25 lb per cubic foot 55 lb per cubic foot 4 to 6 10 12 15 15 . 5 1 to 3 3 to 6 0.60 x 10-* 0.40 x 10- 0.18 x 10- 0.16 x 10rS 0.12 x 10- 0.60 x 10- 3.0 x 10- 1.2 x 10~* 0.50 x 106 1.5 x 10s material and, when known, can be used to determine the insulation value From Architectural Acoustics,'by V. O, Knildsen, p. 278.` 606 607 Heating Ventilating Air Conditioning Guide 1939 of accuracy. Table 2 gives the values of c and r for a number of monly used flexible materials. Example 1. A machine weighing 1000 lb has a base area of 20 sq ft. Assume that th principal vibration of the machine has a frequency of 100 cycles per second (nZ? machinery vibrations are less than 150 vibrations per second, and the assumed frequen^ of 100 is cjuite representative of typical machines). Suppose that a 1-in. slab of board weighing 1.10 lb per board foot'be placed between the machine and the flor The loading on the cork will then be only 50 lb pier square foot, or slightly more tha yi lb per square inch. (It is assumed that the compliance c in centimeters per dyne for specimen 1 in. thick and 1 sq cm in cross-section is 0.25 X 10"* and the resistance . :* mechanical ohms is 0.15 X 10s.) ln The transmissibtlity 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 1(H.. Therefore, the compliance of the entire support, 1 in. thick and 20 sq ft in cross section, is 0.25 X 10_t X i gg ^ = 0.134 X 10"" cm per dyne, and the resistance of the entire support is 0.15 X 10s X 1.86 X 104 = 0.28 X 10* mechanical ohms (or absolute units). Therefore, V1 (0.28 X 10s)* + 4** X 100* X (0.134 X 10-")* (0.28 X 10s)* + ^(2t X 100 X 4.54 X 10s) - 1 2% X 100 X (0.134 X 10 4 10". 0.0784 X 10" + 4x* X 10* X 0.018 0.0784 X 10" + (,2* X .4.,54 X 10' - 10s y 2x 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 10~* X gjg = 0.39 X 10-* cm per dyne, and the resistance will be 0.15 X 10s X 645 = 0.97 X 10' mechanical ohms (or absolute units). Therefore , 4 (0.97 X 10')* + ,4-k* X 100* X (0.39 X 10-")* (0.97 X 10')* + ((2. X 100 X 4.54 X 10s) - ^TxTob xWxiiP))* 4' ' 10" 0.94 X 10" + 4x* X 0.1521 0.94 X 10" + ^2* X 4.54 X 10' - 10' 2rc X 0.39 0.0375 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- . 608 Chapter 30. Sound Control I tions, but also the importance of selecting the proper type and design of (Lihie 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, 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. \ ^ 4` Brick I 5- X *-g Plaster 1 Insulation Value*47 db 4* Hollow Clay Tile 1** 2* Furring Strips Paper and Metal Lath ^ Plaster Insulation Value * 52 db. s| p" Absorptive Blanket f Fibre Board B Plaster * I 'Staggered Wood hII Studs Insulation Value Greater than 50 db. ^Rough and Finish Flooring Absorptive Blanket ^Piaster on Lath Insulation Value * 50 db. Flooring Resilient Chairs _ ,, Concrete Slab 23^ Resilient Hangers "Plaster on Lath Insulation Value a GO 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). . . 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 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 609 Heating Ventilating Air Conditioning Guide 1939 material. ' Lagging material of similar'characteristics placed on the out side of ducts serves to prevent noise originating outside the ducts bein * carried inside the ducts and into the air stream. % A case where outside lagging is desirable occurs when ducts original at the fan in the equipment room and pass through this room on the wav 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 } Measurements in one laboratory have shown that the loss through a sheet of No. 22 gage metal is 24 db. When a sheet of rock wool insu lation 1 in. thick and weighing 1.4 lb per square foot is added to this, the insulation value is increased to 29 db. In general, however, adding a layer of insulation or pipe covering does not materially increase the sound insulation value unless the material is dense, or unless it is surfaced with another sound impervious layer such as metal or board. 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 traveling in a duct system; consequently some empirical method has to be used. - : Perhaps the commonest rule of thumb is that a length of duct should be lined which is equivalent to 10 to 15 diameters. If the duct is square, this may be interpreted to mean 10 times the average dimension. Tests have shown that this amount of lining will usually suffice to eliminate the majority of the high frequency noise which is prevalent. Since this is the more objectionable component of the noise, and since much of the low frequency noise is usually eliminated in passing through any extended supply system, this procedure is usually satisfactory except in severe conditions: It should be noted that the lining should be installed at or near the outlet, in order to effectively reduce all sounds which may be generated in the system up to this point. A more complete method of determining the necessary length of lining material has been described and is available for detailed reference4. Another empirical method uses 4The Nature of Noise in Ventilating Systems and'Methods for its Elimination, by J. S. Parkinson (A.S.H.V.E. Journal Section, Healing, Piping and Air Conditioning, March 1937, p. 183). . 610 Chapter 30. Sound Control duct lining factor evaluated by experience. 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 liningr factor (/) giving numerical values for use at various uipment 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 Duct lining factor f Noisy Equipment Average . Quiet 0 5 10 15 20 25 30 75 65 55 65 55 . 45 55 45 35 45 35 25 35 25 15 25 15 5 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. " ................................... 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 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. 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 611 Heating Ventilating Air Conditioning Guide 1939 length of the untreated duct system and the number of bends or elbows splitters should be considered, since the longer arid the more complex H?r system, the more reduction of noise level will occur before the. sound reaches the room grilles. Also the sound absorbing power of the roo TM 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 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. Fig. 3. Diagram of Branch Duct Treatment Where Length is Insufficient for Adequate Absorption 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 (/) X diameter of duct. Example S. 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 X 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 added5. For coefficients of commercial sound absorbent materials see Bulletin Acoustical Manufacturers' As sociation, 919 No. Michigan Ave., Chicago. 111. - 612 Chapter 30. Sound Control 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 have 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. 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 S. Assume a branch duct, as shown in Fig. 3, is 24 in. wide by 12 in. hieh and 42 in. long. Use a duct lining factor of 10. Case I. (No splitters). J-nnsth of lining = / X minimum dimension = 10 X 12 = 120 in. .Re Hurt should be lined for 120 in. which is obviouslv imnnssihle. Case II. (Two splitters). Results in 3 ducts 24 in. wide and 4 in. high. > Length of lining = / 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 traveling 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). . Patents exist covering the sub-dividing of ducts for installing sound absorbent materials. 613 Heating Ventilating: .Air Conditioning Guide 1939 Effect of Humidity upon the Absorption of Sound in a Room, by V. O. Knud (Journal of the Acoustical Society of America, July 1931). Also see report presented affu11 May 1933, meeting of 4.5. of A. ceaatthe Acoustics and Architecture, by P. E. Sabine. Architectural Acoustics, by V. 6. Kriudsen. Acoustical. Engineering, by West.. Modern Acoustics, by Davis. . , ............ . PROBLEMS IN PRACTICE 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 keen 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. 8 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? . ' a. ! High noise reduction. d. Fire resistance. ' b. Physical strength. . e.' Cleanliness, absence of loose fibers or pieces. c. Easy working and installation. ` /. Smooth surface to reduce air friction.' 7 Should a ventilating,duct be lagged or covered oh the outside? ' Yes, 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 can cross-talk be eliminated when one duct serves two or more rooms? Install proper filters adjacent to the grilled in each room, using splitters if the duct leads to the rooms are short. ... . v.' . 9 9 Space limitations and maximum air velocities for the introduction of air to a broadcasting Studio restrict the size of duct to 3Q 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'permissible 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 - --^2-- ^ 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. - 8 X 28 --Tx-- = 48.7, ft duct lining required to attenuate an average fan noise. - 614 Chapter 31 air conditioning in the treatment OF DISEASE Operating Rooms, Reducing Explosion Hazards, Post-operative Heat Stroke, Nurseries for 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 ojd 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- Heating Ventilating Air Conditioning Guide 1939 ordinary precaution is necessary for the safety of the patient and oner ting personnel. a' Copious ventilation, from 6 to 12 air changes per hour, is necessary t preclude accumulation of explosive mixtures and to reduce the conce tration of anesthetics to below the physiologic threshold so that th' surgeon and his personnel will not be affected. e 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 qu;te 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 t Table 1. Approximate Limits of Inflammability of Ethylene and Ethers Mixed With Air.......................................... Oxygen.................................. Nitrous Oxide..................... Ethtlene Lower limit Per Cent 3.0 3.0 Upper limit Per Cent 30* 80- Etheb Lower limit Per Cent 1.7 1.7 3.8 Upper limit rerCeat 5040* 26* - ^Limits of Inflammability of Gases and Vapors, H. F. Coward and G. W. Jones. U.'S. Dctartfam1 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, ^ind 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 'l i 1 i;i , 'The Hazard of Explosion of Anesthetics, by Y. Henderson. Report of the Committee on Anesthesia (Journal American Medical Association, 94:1491, 1930). 616 Chapter 31. Air Conditioning in the Treatment of Disease , ressed. The organism loses ability to regulate its own body tem' rature and becomes unusually sensitive to chilling and post-operative implications. In order to maintain a normal body temperature, a high ? temperature is necessary, as high as 90 F or higher in the case of ether j^esthesia, judging from experiments on animals2. guch },jgh temperatures are obviously uncomfortable for the operating rsonnel, and in' order to alleviate the condition the room temperature jf 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 reported* 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 investigator* 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 several 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 ho 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 heat waves, 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, 1:1015, 1923). ' `Post-operative Heat Stroke, by T. M. Martin (Journal Missouri Medical Association. July. 1923. Abstract Anesthesia and Analgesia, 8:23. 1929). 617 Heating Ventilating Air Conditioning Guide 1939 dicitis for,instance, which sometimes come with summer heatwaves j develop dangerously, unless promptly operated upon. Complete air,; ditioning of operating -rooms would therefore seem to be a necessity0" many sections of the United States. . " ln Satisfactory Air Conditions: ' Although the comfortable air conditi for the operatives are not identical with those of the patient, a comrT"8 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 cou weather will probably prove satisfactory. Additional heat may b furnished to the patient locally or by suitable covering according to bodv temperature in individual cases. ' 7 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:, (o) 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 the 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 1925)1 ir"Brne Infection and Air Control, by W. F. Wells (Journal Industrial Hygiene, 17:253. 'Sterilization of the Air in the Operating Room by Special Bactericidal Radiant Energy, by Deryl Hart (Journal Thoracic Surgery, 6:45, 1936). ' 618 31.Chapter Air Conditioning in the Treatment of Disease . jjeat regulating system is not fully developed; the metabolism is i 61 and the infants generally exhibit marked inability to maintain a *oWinaj body temperature by their own efforts. The resistance to infec- fion is low and the mortality rate, very high. Air Conditioning Requirements . .. The optimum air conditions for the growth and development of these ' fants were determined by extensive research at the Infants Hospital, Boston, Mass.,8 using four valid criteria, namely,-stability of body tematur'e, 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 extreme1 conditions. Importance of Humidity: Although external heat is an important factor in the maintenance of normal body temperature, humiditytappears 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 pier 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,. *The Premature Infant: A Study of the Effects of Atmospheric Conditions on Growth and.on Develco-' ment. by K.-D. Biackfan, C. P. Yaglou and K. McKenzie (American Journal Disease of Children. 46:1170' 619 Heating Ventilating Air Conditioning Guide 1939 persistent vomiting, diminishing gains or loss of body weight, and oth symptoms, were generally from two to three times as high unHfr iCr than under high humidity. w Finally, the mortality of premature infants was found to be greatl affected by humidity. In Table 2 is given the net mortality according t the humidity in which the derangement of body function began. In th old nurseries, prior to the installation of the air conditioning system th6 death rate from acute and chronic infections was 26.5 per cent as com6 pared with 9.7 per cent in the conditioned nurseries under low humiditv 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 Humidity* Infants Hospital, Boston, Mass. Unconditioned Nurseries (1923-1925) Conditioned Nurseries (1926-1929) Cause ot Death Natural Humiditt Acute and chronic infections_____ Congenital deformities: ................. Unclassified......................................... All causes............................................ Per Cent Mortality 26.5 1.2 1.2 28.9 Relatiyb Humiditt 25-49 Per Cent 50-75 Per Cent Per Cent Mortality Per Cent Mortality 9.7 0.0 4.8 00 0.7 0.0 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 620. Chapter 31. Air Conditioning in the Treatment of Disease hanisms 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 neriod of fever treatment varies with the type of the organism involved fr^m 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." 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 Gutbertet (A.S.H.V.E. Journal Section, Healing, Piping and Air Conditioning. February, 1937, p. 115). 621 Heating VentiIiAting Air Conditioning Guide .1939 . Extensive research is now.in progress to determine the usefulness anH limitations of fever therapy on a wide variety of pathogenic conditions While this form of therapy is rapidly gaining wide recognition, its apnli cation, according to the American Medical Association, should be strictlv a hospital procedure surrounded with the safeguards commonly employe^ 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 of 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 pppular 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 filtratiomof pollen, a ceftain amount-of cooling and dehumidification 622 Chapter 31. 'Air-Conditioning in the Treatment or Disease nears to be desirable. A comfortable temperature between 75 and 82 F * 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 of 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. AER 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 uThe 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). * 623 Heating Ventilating Air Conditioning Guide 1939 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 Der hour gives satisfactory results in patients with fever in a medium size tern 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. Bullowa (f/ro/l* Examiner 5:12, 19361. . 624 Chapter 31. Air Conditioning in the Treatment or Disease ethod 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 ^ministration 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 invdlves 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 11 Where has air conditioning in hospital wards proved itselfofsufficient 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. 625 Heating Ventilating-: Air Conditioning .Guide 1939. 2 # What is the major problem in conditioning hospitals? .. For general hospital wards, the major problem seems to be one of providing adeem f amounts of ventilation rather than-air conditioning, with , some provision for' cool^ 6 over-heated wards on unusually warm summer days. ; , 3 What are the usual requirements for ventilation of operating rooms? To preclude the accumulation of explosive mixtures and to reduce the concentration nf anesthetics below the physiologic threshold, it is desirable that ventilation to the extent of 6 to 12 air changes be provided. - c 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. e 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 warrh weather temperatures between 75 and 82 F and relative humidities well below 50 per cent are more conducive to comfort. 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- 627 Heating Ventilating Air Conditioning Guide 1939 centage of outside air should be kept as low as possible to maintain the ai in the proper condition in order to minimize the heat or cooling load. r 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 fij 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. of 2. One or two side ducts built on the turtle-backed or arched-roofed cars. outside of monitor-roofed cars, or on the inside 3. Free discharge at the end bulkheads, or by free discharge from a unit nlar<vi overhead m the center of the car, discharging toward the ends. ea 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.. 628 Chapter 32. Railway Air Conditioning ffc cleaning a || 0f the air circulated by the blower is filtered before passing over the ling coils. In some cars the outside and recirculated air are filtered oarately before mixing, while on others the air from the two sources is lxed before passing through a common filter. Filters in use are made of l^tal wool, cloth, spun glass, hemp, paper, hair, and wire screen. Most filters'have a viscous coating of oil for greater cleaning efficiency. Some tyoes may be cleaned, retreated, and returned to service while other ^pes are discarded when dirty. STEAM OR VAPOR HEATING EQUIPMENT Tfie 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 23 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 629 Heating Ventilating Air Conditioning Gtiide 1939 system is driven by an internal combustion engine operating on pronan Sufficient fuel for.several days' operation is carried in drums mounted a rack under the car. ln The refrigerant frequently used in the mechanical compression system is dichlorodifluoromethane. The condensers are cooled by blowing S large quantity of outside air over the dry condenser coils, or over the coif 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 aimount 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, butthe relative humidity obtained depends largely on the temperature of the evaporator, which should be below the 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 630 Chapter 32. Railway Air Conditioning -(he 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 utomatic 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., simplify the installation and operation. Generally, . -gparate 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. 631 Heating Ventilating Air Conditioning Guide 1939 Table 1. Electric Power Required to Operate System System Electro-Mechanical--........-......................... Direct Drive Mechanical--------------------- Internal Combustion Engine Mechanical Steam-Ejector...... ................................... _..... Ice-Activated.................................................... Koowjtts 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 1 10.24 hp from the car axle and the steam-ejector system requires 230 lb 1 steam per hour from the locomotive boiler for a 6-ton unit. The ice---' ' i activated system requires 463 lb of ice per hour and the internal com bustion engine drive mechanical requires 7.3 lb propane per hour. This - j 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 dirdct mechanical system, and upon the average efficiency of four mechanical drives and generators used lor 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 4- 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 equipment is not operating, which includes the horsepower required to operate ; ; : ' . : i. 632 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. pjg. 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, - .u comp 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 aerator load. The curve with the 4 kw generator is representative of a ir before air conditioning, and the curve with the 20 kw generator and tons added weight is representative of a car after air conditioning. 150 mph, the tractive resistances of these two cars are 520 lb and 745 lb spectively.or a difference of 225 lb. Then: -2-f ^ =29.7hp oO X 00VJUO required due to a 16 kw load and 5 tons added weight. Ten cars with a milar load would require 297 horsepower or roughly 10 per cent of the ipacity of a 3,000 hp passenger locomotive. 633 3*335535 Heating Ventilating Air Conditioning Guide 1939 Consideration must also be given to the power requirements f refrigeration while the car is standing or running at slow speeds. electrical energy required for the ice-activated, steam, and internal combustion engine drive mechanical systems is easily supplied from th 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 Ststem 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-Ejector3................... ....... ..................... 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 For Cent Non-Operation Electro-Mechanical.............................................. Direct Mechanical............ .................................. Internal Combustion Engine Mechanical....... Steam-Ejector..................................................... 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 a In 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 djive, the air conditioning system operates at reduced capac ity when the car is moving at speeds below 42 mph. .. 634 VV-VV-fe'. - : *v,;r 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 rominent 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 car-miles Maintenance Cost Operation Cost Total $3.33 2.33 $0.99 0.93 $12.97 14.61 3.30 2.15 0.97 1.99 1.02 5.29 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 = m (0.204) where FC = fixed charges, dollars per 1000 car-miles. A = gross installation cost, dollars. m = total number of car-miles traveled in one year. (1) 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 m MC = maintenance cost, dollars per 1000 car-miles. B -- total annual maintenance cost, dollars. ni = total number of car-miles traveled in one year. 635 (2) Heating Ventilating Air Conditioning Guide 1939 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 80.00493 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 84.42 per ton, 5. Propane on the car, at 80.039 per pound, c. Steam at 80.021 per 100 pound. . Fig. 3. Comparative Total Costs for Railway Passenger Cars The operation cost in dollars per 1000 car-miles is: OC = X + 0 56 F x G) + 1000 x25~ 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. 5 = 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. 636 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 Gars, 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 docs 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 f What is the effect of train speed upon the cooling requirements of a car? Requirements are slightly increased because of increased heat transmission. 5 O 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. 1 * 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. sSSrSSSnSS,? Heating Ventilating Air Conditioning Guide 1939 9,0 What cooling medium is used for condensing the refrigerant in a railrouj ^ air conditioning system? , "*^4 ; Outdoor air, sometimes with the aid of evaporative cooling. 10 O Iiow may adequate cooling of condensers be provided in hot desert regions? By evaporative cooling with water sprays. 11 O How is the temperature controlled in railroad cooling systems? By intermittent operation of the compressor, the steam jet or the ice water circulatii pump. . 12 9 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 9 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. \ 638 \ cr' S' 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. . 639 Heating Ventilating Air Conditioning Guide 1939 Table 1. Desirable Temperatures and Humidities for Industrial Processing Industry Process Temperature Degrees Fahrenheit 65 Baking...................... Cake mixing.................... ............................ ............... Dough fermentation room................................. Loaf cooling............................ .................................... Make-up room........................................................... Paraffin paper wrapping. .................................. Proof boxes......................................................... 1 Storage of flour............. ........................................... Storage of yeast........................................................ 70 75 80 70 75 to 80 75 to 80 80 80 to 90 70 to 80 28 to 40 Biological pRonircT.s below 32 38 to 42 . kxUTITJ Hronnrr bs Csht 40 50 65 76 to 80 60 to 70 55 to 70 55 to 70 55 80 to 95 60 60 to 75 Fermentation in vat room................................. Brewing.................. Storage of grains ,,................................................. 44 to 50 60 50 30 to 45 Ceramic.................. Drying of auger machine brick....................... Drying of refractory shapes............................ Molding room............................................................ Storage of clay......................................................... 180 to 200 110 to 150 80 60 50 to 60 60 35 Chemical................. 60 to 80 35 to 50 Confectionery.. Chewing gum rolling............................................ Chewing gum wrapping....................................... Chocolate covering............................................... Hard candy making. ............................................ Starch room......................;......................................... 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 to 65 Distillery............. General manufacture. --..................................... Storage of grains....................................................... 60 60 45 . 30 to 45 Drug............. _______ Storage of powders and tablets...................... 70 to 80 30 to 35 Electrical............ Insulation winding. .......................................... 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.................... ...... Butter making........................................................... Dairy chill room....................................................... Preparation of cereals.......................................... Preparation of macaroni ................................ Ripening of meats.........................................C....... Slicing of bacon......................................................... Storage of apples...................................................... Storage of citrus fruit............................................ Storage of eggs in shelL................. :..................... Storage of meats...................................................... Storage of sugar.. ................................................. 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 F UR..................... ......... Drying of furs.......................................................... Storage of furs............... .................... '...................... 110 28 to 40 25 to 40 640 Chapter 33. Industrial Air Conditioning - ,, i Desirable Temperatures and Humidities for Industrial Processing Table l- ^ _____________(Concluded) Indubtbt Process Temperature Degrees Fahrenheit Relative Humiditt ` Per Cent. Incubators.------- ------- ------------------Laboratory------- Chicken..................... ..................................... General analytical and physical_________ Storage of materials-------- -- ------------- 99 to 102 60 to 70 60 to 70 55 to 75 60 to 70 , 35 to 50 Leather.------------ Library-------------- Linoleum----------Matches------------ Drying of hides.............................. ........ 1....... Book storage (seediscussion in thischapter) Printing................. :----------------------------------- Manufacturing................................................ Storage of matches........................... :............. 90 65 to 70 80 72 to 74 60 70 38 to 50 40 50 55 Paint.................... Air drying lacquers.--................................. 70 to 90 Baking lacquers................ --...................... 180 to 300 Air drying of oil paints............. .................... 60 to 90 25 to 50 25 to 50 Binding, cutting, drying, folding, gluing. 60 to 80 Paper--,------------- Storage of paper.................. ............................ 60 to 80 25 to 50 35 to 45 Photographic-- Development of film................................... Printing--........................................................... Cutting............................................................... 70 to 75 75 to 80 70 72 60 50 70 65 Binding.............................................................. Folding........... -.................................................. Press room (lithographic)............................ Storage of rollers... ...................................... 70 77 75 60 to 75 60 to 80 45 65 60 to 78 20 to 60 35 to 45 Manufacturing.-------------- ---.........................Standard laboratory testa.--.................... 90 75 to 80 80 to 84 25 to 30 42 to 48 110 70 Textile____ :____ Cotton-- carding........... .......... 1.................... combing...... ................................... roving............................................. spinning...-......... ............................ weaving................................. ......... Rayon-- spinning.. ..................................... . twisting........................................... Silk-- dressing........................................... spinning.... .................................... : throwing.................... .................... weaving.......................................... Wool-- carding........ ................................... spinning-- ..................................... weaving.______ ............................. 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.......:................. Softening.... ...................................................... Stemming or stripping......... ................... 70 to 75 90 75 to 85 55 to 65 85 . 70 641 Heating Ventheating Air Conditioning Guide 1939 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 0r cooling to any desired temperature, and of providing ample air supply at all times. Refrigeration may or may not be required, depending Up0n natural conditions, the required relative humidity and the maximum 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. c 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: ' X. Control of Regain. ' ` 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 rate of production and upon the weight, strength, appearance and general 642 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 moisture 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 pf material. Regain is more specific and refers only to hygroscopic moisture. It is expressed as a percentage of the bone-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. ' ` 7<5.U .... ..... 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. 643 Heating Ventilating Air Conditioning. Guide 1939 Table 2. Regain of Hygroscopic Materials Moisture Content Expressed in Per Cent of Dry Weight of the Substance at Various Relative Humidities--Temperature. 75 P ClaseiflCATION Material Description PeaRelative Humiditt-- Cent - AoTBoain 10 20 30 40 so 60 70 80 90 Cotton Cotton Cotton Sea island--roving Americas-- cJotb Absorbent 2.5 3.7 4.6 5.5 6.6 7.9 95 115 14.1 Hartshome 2.6 3.7 4.4 5.2 5.9 6.8 8.1 10.0 145 Schloesing 4.8 9.0 12.5 15.7 18.5 20.8 2X8 24.3 255 Fuwa ~ Natural Textile Fibres Wool Silk Linen Australian merino--skein 4.7 7.0 8.9 10.8 1X8 14.9 17.2 19.9 23.4 Hartahoma Raw chevennee--ekein 3.2 55 6.9 8.0 8.9 10.2 11.9 145 185 Schloesiag Table cloth 1.9 2.9 3.6 4.3 5.1 6.1 7.0 8.4 10.2 Atkinson Linen Dry spun--yarn 3.6 5.4 6.5 7.3 8.1 8.9 9.8 11.2 135 Sommer Jute Average of several grades 3.1 5.2 6.9 8.5 10.2 12.2 14.4 17.1 20.2 Storch Hemp Manila and sisal--rope 2.7 4.7 6.0 7.2 8.5 9.9 11.6 13.6 15.7 Fuwa Rayons Viscose Nitrocellu lose Cupramonium Average skein Cellulose Acetate Fibre 4.0 5.7 6.8 7.9 9.2 105 1X4 14.2 16.0 Robertson 0.8 1.1 1.4 1.9 2.4 3.0 3.6 4.3 55 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 u. S. B.ofS. H. M. F. Writing Wood pulp--3% ash 3.0 4.2 5.2 6.2 7.2 85 9.9 11.9 14.2 o.aB.ois. Poper White Bond Rag--1% ash 2.4 3.7 4.7 55 6.5 75 85 105 13.2 0. 8. B.oia Com. Ledger Kraft Wrapping 75% rag--1% ash Coniferous 3.2 4:2 5.0 5.6 6.2 6.9 8.1 105 13.9 a. a b. ota a a3.2 4.6 5.7 6.6 7.6 8.9 105 1X6 14.9 u. b. ot Leather Sole oak--tanned 5.0 8.5 11.2 13.6 16.0 18.3 20.6 24.0 29.2 Phelps Catgut Raequet strings . 4.6 7.2 8.6 10.2 12.0 145 175 195 21.7 Fuwa Glue Mlsc. Organic Rubber Materials Wood Hide Solid tire Timber (average) 3.4 4.8 5.8 6.6 7.6 9.0 10.7- 115 125 Fuwa 0.11 0.21 0.32 0.44 0.54 0.66 0.76 0.88 0.99 Fuwa 3.0 4.4 5.9 7.6 95 115 14.0 175 22.0 Forest P. I*b. Soap White 1.9 3.8 5.7 7.6 10.0 1X9 16.1 195 235 Fuwa Tohacco * Cigarette 5.4 8.6 11.0 13.3 16.0 19.5 25.0 335 50.0 Ford White Bread 05 1.7 3.1 4.5 6.2 8.5 11.1' 145 19.0 Atkinson Crackers 2.1 2.8 3.3 3$ 5.0 6.5 8.3 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 2X1 Atkinson 2.6 4.1 '55 6.5 8.0 9.9 1X4 15.4 19.1 Bailey Starch ' 2.2 3.8 5.2 6.4 7.4 85 9.2 10.6 1X7 Atkinson Gelatin 0.7 1.6 2.8 3.8 4.9 6.1 7.6 95 11.4 Atkinson Asbestos Fibre Finely divided 0.16 0.24 0.26 0.32 0.41 0.51 0.62 0.73 054 Fuwa Silica Gel Miss. / Inorganic Domestic Coke Materials Activated Charcoal Steam activated Sulphuric Acid HtSOi 5.7 9.8 1X7 15.2 17.2 18.8 20.2 2t.S 22.6 Fuwa 0.20 0.40 0.61 0.81 1.03 1.24 1.46 1.67 1.89 Selvig 7.1 145 22.8 26.2 28.3 29.2 30.0 31.1 3X7 Fuwa 33.0 41.0 47.5 5X5 57.0 615 67.0 73.5 8X5 Mason 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- oerature 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 general, 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 mdisture 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). ' 645 Heating Ventilating Air Conditioning Guide 1939 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 arJ 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 REACTIONS 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 and 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, such 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 646 Chapter 33. Industrial Air Conditioning kin cured and colored, after which the fruit is cooled to maintain as slow sKLte 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 rocess, 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 die 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 the 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, .. ; 647 Heating Ventilating Air Conditioning Guide 1939 REFERENCES . Effect of Air Conditioning upon Munitions, by J. I. Lyle (A.S.H.V.E. Transactions Vol. 23, 1917, p. 383). s' Air Conditioning for Sausage Manufacturing Plants, by M. G. Harbula (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 (Heatini 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. S. Department of Agriculture, Circular No. 278). Reactions of Lithographic Papers to Variations in Humidity and Temperature, by C. G. Weber and L. W. Snyder (V. S. 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 AgricultureJTechnical 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 11 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-. 648 Chapter 33. Industrial Air Conditioning 2 0 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 paper 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. 3 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 tbe regain and moisture content of the tobacco? The regain, from Table 2 17.75 X 100 The moisture content = 100 + 17.75 17.75 per cent. 15.1 per cent. 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. ' W ... ' 15 gg = regain = 15 per cent = ^ 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 lb 0 74 Regain = Q 26 ^ per cent* From Table 2, the proper relative humidity required is 60 per cent. 6 # 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 atmospheric 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 -or . 8.5 iooo ~w ~ regam =8 S per cent " loo 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 drier 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 drier 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 Heating Ventilating Air Conditioning Guide 1939 cent humidity line, move horizontally, to the right to the intersection with the 14n p 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 cunT and read 97.5 F dry-bulb, which will be the temperature of the air leaving the drier * Moisture per cubic foot at 97.5 F and 70 per cent relative humidity = 13.2 g--; 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 = 1685 cfm. 24 X 60 X 4.9 " 4.9 grains No allowance is made for heat lost in the transmission to and from the drier or for the heat required to raise the product from its entering temperature to that maintained in the drier. This would necessitate a trial and error solution common to all drying problems \ 650 Chapter 34 INDUSTRIAL EXHA UST 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 651 Heating Ventilating Air Conditioning Guide 1939 breathing zones. The objective to keep in mind in all cases is to tak advantage of the natural tendency of the material to move upward o downward. r 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-creatine 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 systeih. 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 riot 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. . . . 'For more detailed requirements see Safe Practice Pamphlets Nos. 32 and 37. published by the National Safety Council, Chicago. ' 652 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 for Wood-Working Machinery Type of Machine Diameter of Connections in Inches 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---------- 1------------------------------------- ----------------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............................................................ 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 Heating Ventilating Air Conditioning Guide 1939 Chapter 34. Industrial Exhaust Systems 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 1}^ in. thick____ 10 in. to 16 in., " ` 2 in. ` ____ 17 in. to 19 in., " " " 3 in. " ........ 20 in. to 24 in., " " " 4 in. " ....... 25 in. to 30 in., " " " 5 in. " ____ Buffing-- 6 in., or less, not over 1 in. thick................ ,......... 7 in. to 12in., inclusive, notover 1)4 in. thick. 13 in. to 16in., " " " 2 in. " . 17 in. to 20in., " " " 3 in. " . 21 in. to 27in., " " " 4 in. " . 27 in. to 33in., " " 5 in. " . Max. Grinding Surface Sq In. - 19 43 101 180 302 472 19 57 101 189 338 518 Min Dim, Branch Bipes in Inches 3 3)4 4 4)4 5 6 3)4 4 4)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 ll/2 to 5 in. water displacement in a f/-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 Tng or Installation -. Static Suction in Inches or Wateb . Exhausting from grinding and huffing wheels . Exhausting from tumbling barrels y Exhausting from wood-working machinery--light duty Exhausting from wood-working machinery--heavy duty Shoe machinery exhaust....................................-i......................................... Flint grinding exhaust..................... ......................... ................................. ......... Fur and felt machinery exhaust . . Exhausting from textile machinery.................................................................. Exhausting from elevating and crushing machinery 1H-5 2 2 2-4 2-3 2 2 2 2-4 2-3 2-3 2 3-5 a 1 i I *! r . n 200 fpm at the point of origin. For granite dust generated by neumatic devices, Hatch et al2 give velocities from 150 to 200 fpm, Heoending on the type of hood used, as sufficient for safe control. Con'dering 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: r._ 01 Q ** + 0.1 A (1) where V = velocity at point, feet per minute. A = area of opening, square feet. x = 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 hood5. Control of the Silicosis Hazard in the Hard Rock Industries. I. A Laboratory Study of the Design of Dost 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). The Control of Industrial Dust, by J. M. DallaValle (Mechanical Engineering, Vol. 55, No. 10, October 1933). ^Studies in the Design of Local Exhaust Hoods, by J. M. DallaValle and Theodore Hatch (A.S.M.E. Transactions, Vol. 54, 1932). Velocity Characteristics of Hoods under Suction, by J. M. DallaValle (A.S.H.V.E. Transactions, Vol. 38. 1932, p. 387). 655 Heating Ventilating Air Conditioning Guide 1939 Further, the velocity contours are identical for similar hood sha when the hoods are reduced to the same basis of comparison. These f8 are applicable to all hood problems so that when the velocity conta*8 distribution is known, the air flow required can be determined. Rip [ shows the contour distribution in two axial planes perpendicular to ti/ sides of a rectangular hood with a side ratio of one-half. The distrib 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 a*** expressed as percentages of the velocity at the opening. ' re 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: where Q = 4005/4 y/~h ` (2) ' Q -- volume of air flow, cubic feet per minute. A' = area of connecting duct, square feet. ftt = 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. 656 Chapter 34. Industrial Exhaust Systems An average value of/ is 0.71, although for a well-shaped opening a value 0{ 0 8 may be used. The factor / is determined from the equation: '-Vfc where hv 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 tp 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 sub-divided 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: <?.= 1.4PDV (4) where 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 plating6, 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 Win. Blum (U. S. Public Health Report, Vol. 43, No. 20, September 7. 1928). 657 Heating Ventilating Air Conditioning Guide 1939 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 f0j a distance of more than 18 in. and the level of the solution should be kent 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 ment of Labor and of spray booths, Industry. 1926, see Special Bulletin Harrisburg. Pa. No. 16. Spray Painting in Pennsylvania, Depart- 658 Chapter 34. Industrial Exhaust Systems ocularly those used in buffing and polishing, are connected by short branch pipes to the main duct which renders proportioning impractical. Construction phe ducts leading from the hoods to the exhaust fan should be con tracted 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 pTAMKTtra or Duct Gaos or Metal 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 preferably have a throat radius of at least one and one-half times the diameter of the pipe. Every pipe should be kept open and 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. .. ' 659 Heating Ventilating Air Conditioning Guide 1939 Table 6. Air Speeds in Ducts Necessary to Convey Various Material Material Grain dust_______________ Wood chips and shavings. Sawdust_________________ Jute dust_________________ Rubber dust. Lint Metal dust (grindings)___ Lead dusts_______________ Brass turnings (fine)_____ Fine coal 2000 3000 2000 2000 2000 1500 2200 5000 4000 4000 At the point of entrance of a branch pipe with the main duet, 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 5 and 5a may be used as tests to determine the conveying efficiency of a system1. 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 --pr <f. s+1 (5) For horizontal ducts: where V = 6000 ~ . " s+1 (5a) V -- air velocity in duct, feet per minute. ' j specific gravity of particles. d = average diameter of largest particles conveyed, inches. Example 1. 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 0.37w 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. DallaValle (A.S.H.V.E. Journal Section. Heating. Piping and Air Conditioning, September. 1932, p. 639). 660 Chapter 34. Industrial Exhaust Systems Table 6 Loss Through 90-Deg Elbows fcsow Center Lot Radius in Per Cent or Pipb Diameter 50 ' 100 150 200 to 300 Loss in Per Cent or Veloott Head 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. pud 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 1H 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 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 : ^=013(i)2 '6) where . Ac = 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, 661 Heating Ventilating Air Conditioning Guide 1939 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 ;s.... 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 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 hood?, (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. 662 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 Gases3 Substance Spec. Gkav. or Gas ob Vapor (Am 1) Inflammable Limits (%> Physiological Action Maximum Allowable Concentration (ppm) .Chlorine........................... r.------ ... Ozone......... ............ :................... Hydrogen chloride................ Sulphur dioxide...................... Carbon monoxide.................. Hydrogen sulphide............... Benzene .................................... Methanol............ ....................... Carbon tetrachloride.......... . 2.486 5.5 1.2678 2.2638 0.9671 1.190 2.73 1.1 5.3 non-infiamm. do do do 12.5-74 4.3-46 1.4-7.0 7.5-26.5 non~inflamm. irritant do do do asphyxiant do anesthetic do do 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. DallaValle (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 W34, p. 353). 663 Heating Ventilating Air Conditioning Guide 1939 Table 8. Materials to be Used for the Protection of Exhaust Systems Against Corrosion2 Ttpb or Fume Conveted Protective Material to be Used Chlorine.___________________ Rubber lining or chrome-nickel alloys Hydrogen sulphide________ Aluminum coated iron, aluminum, high chrome-nickel alloys Iron or steel ^ Sulphurous gases__________ High chrome-nickel alloys Hydrochloric acid_________ Rubber lining, chrome-nickel alloys 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 t 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; D = 30 in. *= 2.5 ft; V = 60 fpm. Hence, Q = 1.4 X 24 X 2.5 X 60 = 5040 cfm. 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 twaTimum diameter particle transported at this velocity? . Using Equation Sa, 2700 = 13,300 X ||| X <?>" from which d = (0.281*-TM = 0.11 in. 5 t What special materials may be used to resist chemical corrosion in a Bystem 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. 664 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, or 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. 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. 665 / Heating Ventilating. Air Conditioning Guide 1939 T3 0) > '&> U OV O'C B-0 O re *o5 2o 33 O a* 0-0 BV U C 2 UJ sSs c >. -- l_ as. !' to 00 4_, --o 5i tD'O ti c S2 d E. S*D 3 "ere 8 5re bcC O -- '-y fe Vu re d --d ?-c II St: a oa v3 2 cu `CT3 <D C .$* * to a E 3. a 3 a> Out! a j: d E d *r s* ^ 4-> o fcu_ (I).5 be a; X) -2 .3C* CTO=T5O >45 45 2> " e xZM 3 o b 25 c c > is P ou Jar> 4d_t 45 C IS 8 4) C E oo tcogE- Ss >4* a sir u-o E'S 88 w5S >vg* E g-3 a2- re w 3 te 6 rey 3a> o C" X3J <2c -Q-.2 *O2 r3e gll to juo^rj E " -1 2u ! CD T=3 J1 iS ! <0,1 E > 3 d3 Ec d _ -t> O. E"^ o fdlj g^TO HC (/) 45 O S E E5 da,Q*-* w'o ^ S<3a o9w i--< w CO g 8 w WU5 og . CO u E *U3- +d4j) <C/1 c 6 *2 o U- dQ> < C/5 __ :i+aJoio E-I <u 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 Am under curve end show oven temperature represents useful heL Area between oven end room temperature represents heat in vented err EufflpW When r h supplied to oven at temperature CD gh Useful hut eou*ls arc* Vented heat equals area RCOE BGHJ - TbeT ABJK T a b l e 1. D r ier s fo r E v a p o r a tio n of W a te r oc cS *jjas st3 *Vo o c -.So. o fe 4> O (S-E 8(O .r*e lO3>H 5- 2 c/5Q Ht- HHCO gCQ X3 iS% TO U d 'u tn 01 o dQ 1~5< aoo>.. U.Qcd Jw=-Sc U 3 re -S c'o OG UU3. c1 ;<D -<ovu tn2n are 2a> L)(/)r 4oJ 'G *" u X0?)45 >' 55 d >2>E d 2 Q.45 feO C/)CJ bOT; eS Wc <uu EO,' . d <u a-u, 3a ssai a) V ad *+crjt '2e5 <u 3 JJ i-T m" 4ar>t. CCcd a->< 3Q 30) 4-) 45 O Uff5 4O=-i a3 -*o r0e) Ou >a. J-g ao wt- "'e3 rOt.4a-> v 0) o 45 <2 UE 45 to U3 . *3 ei di_ 3 o U<y J3Uo. re re *o .E --3-- uu, .S' 3 i-J (75 s'S sasx sv 0d-H04U5 '`d o s'i a, ci 0d-C4J5 Eu 41 4) 41 .S*o dc ,`r d 0-i0d. .g2 ocn. CO 5rT5eO *4) IH St UO *a %u. C I 0 oo 01 u HU O ^ ft) CO ^ 666 --Room temperature Fig. 1. Relation Between Useful and Total Heat Supplied PER CENT WATER. DRY BASIS Fig. 2. Rate of Drying i 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 667 Heating Ventilating Air Conditioning Guide 1939 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 modern 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 drying 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 sufficiently low that sub-surface drying starts almost immediately after the conclusion of the constant rate period. Thus the 668 Chapter 35. Drying Systems intermediate state of unsaturated 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 kinds 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 Humidity Air Velocity `Air direction Thickness of Materia] D&tinq 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 Drying rate increases as humidity is decreased No effect until equilibrium con tent is reached; drying then ceases Drying rate varies approximately as the 0.6 power of the velocity No effect Drying rate increases the more nearly the air blows perpendicular to surface; for dead air film becomes thinner No effect 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 unsaturated 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. 3l shows the equilibrium moisture content of wood. . lU. S. Department of Agriculture Bfdletin, No. 1136. 669 Heating Ventilating Air Conditioning Guide 1939 Chapter 35. Drying Systems 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 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 5 : recirculating the air in a closed system which includes a suitable dehu-: f 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 23 on Cooling and Dehumidification Methods. Air Circulation Xs 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 %l %< regulation of temperature, humidity, and velocity in the different zones. Vji. i. { ,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, and 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. Fig. 3. RELATIVE HUMIDITY IN ATMOSPHERE, PER CENT 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 dr 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 670 I $.a 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 and 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 of 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 671 Heating Ventilating Air Conditioning Guide 1939 8IV AUd 81 83d dOdVft 831VM 81 `AUGIWnH 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 nietal (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 out 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. DEG F PER LB DRY AIR . TEMPERATURE, DEG F F ig . 4. H u m id it y C h a r t o S 831VAA 81 83d 18 0 C0O1 i 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 (H) 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 (<!>) 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 %H= ------ X <*> 29.92 - p (1) , Ps -- vapor pressure of water, inches mercury; at dry-bulb temperature, degrees Fahrenheit. P = top* . 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 673 X Heating Ventilating Air Conditioning Guide 1939 Table 3. Drying Time and Conditions for Representative Materials*' Material .Temperature Deo F. . Per Cent Relative Humiditt Drying Timb Banana Food in. Thick..-------:-------- ----------------- Cores, Oil sand for molding.______ Vi--1 in. thick Black sand with goulic binder/ o about 0.6 of time....---------- ---jj ^ck Cores, Radiator (in continuous ovens) Enamels synthetic......................................................... 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 300 480 480 700 525-600 275-450 150 180 225 290-425 225 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 6 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 2 Hrs + Air Dry 1 Hr 3 Hrs Furs. ....1....------------------ .......--...... . Glue bone, thin sheets on wire trays... 200 90-95 450 225-300 250 150-180 85-110 140 110 110 70-90 .70-90 r.nt ............. :........... Gypsum board % in. thick.......... ........ f Start Wet Finish Gypsum block........................................... Hides heavy........................... ............................ ............. 150 350 275 350-190 180-200 150-190 120 140-180 90 70-90 40-50 1 Hr 18-36 Hrs 1 Hr 30-350 Min 1.5 Hrs . ' 20-30 Min 2-6 Hrs 6-9 Days 2 Days 4 Hrs 60 Min 8-16 Hrs 1 Hr 2 Hrs 2-4 Hrs j 4-6 Days See references at end of chapter. 674 Chapter 35. Drying Systems Table 3. Drying Time and Conditions for Representative Materials*--Con. Material Temperature Deg F. Per Cent Relative Humidity Drying Time 120-180 70-300 japan beds........................................................................................ 300 300-450 200 140-180 78-95 90 80 110-145 Lithographing on tin color work......... ............................. 250-270 350 100-180 160-220 90-110 140-180 Matrix.. ............................................-...... ........ ............................ 350 Milk and other liquid foods spray dried....................... 135-300 95 Moulds green sand C.I. flasks (onef 8 in. thick surface only exposed)..::\ 13 in. thick 600 700 180 -250 90-95 75-140 150 150 350-140 Paper, machine dried_______ ____ ______ ,....... ................ . 180 Paper, air dried__________ ___ ____ :............ ........................... 90-200 140 Paper wall, varnished.................. ............................................ 140-160 150 135 140 150 Potatoes sliced-- ........ :..................................................... 85 Potatoes steamed................................. ............. ......................... Prunes ' 170 140 180 Rice 140 150 Rubber ' 300 85-90 Rugs....... 140-200 190 Salt.... . . 350 300 Shade cloth. "...........................i........... .. ........... .. ...... 110 240 Shirts... 120 Soap...................................................................................................... 100-125 Starch ...... ' 180-200 Stock feed mixed.............................. ............ ........... -____ :. Storage battery plates.................................... 180-220 100-110. Suear_... : - 250 150-200 1.5-2 Hrs 1.5 Hrs 30 Min 85 70 10-30 4 Days 2-3 Days 6-10 Hrs 18-25 Min 3-180 Days 2-14 Days 7.5-8 Hrs 15 Min Instantaneous 6 Hrs 13 Hrs - 1 6.5 Hrs 24 Hrs 35 8-24 Hrs 22-30 45 15 Min - 1-2 Min 26 Hrs 24 Hrs 6 Hrs -i 4 Hrs 6.5 Hrs' 10 Hrs 8 Hrs 6-12 Hrs : 1-2 Hrs 4-8 Hrs . . Rotary Drier 10-15 Min 90 for Low for 1-2 Hrs 20 Min 12-72 Hrs 1-4 Hrs 20-30 Min 24 Hrs 6 Hrs , 20-30 Min See references at end of chapter. 675 i i I Heating Ventilating Air Conditioning Guide 1939 Table 3. Drying Time and Conditions for Representative Materials3__ Con Material Tanin and other chemicals (spray dried)...... Terra Cotta (air drying in conditioned room). Tobacco leaves Tobacco sterna_________________ ________ ____ Varnish refrigerator boxes. Varnish steering wheels_______ __________...... Veneer J4 in. 3-ply._________ ______ __ _____ _ tKs in. 5-ply. 114 in. 5-pfy-- Vitreous Enamel sheets before firing________ Wallboard pasted plywood____ ______________ Wallboard fiber insulating, roller type drier. Wallboard fiber insulating, truck type drier. Walnuts._____ ! Wheat, com, oats, rice, barley______________ Wire cloth Japan............ ...................... .............. Wool_______________________ _______ _________ Tempera tube Deo F Peb Cent Relative Huhiditt Di!TING Tims 250-300 150-200 85-130 180-200 110 110-140 120-130 120-130 120-130 170 300 300-385 300-385 100 180 200 105 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-^8 Hrs 24 Hrs 20 Min See 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. 676 Chapter 35. Drying Systems I = air temperature. ., t< = stock temperature. ' = average stock temperature over short time interval, in a batch drier. ^ = wet-bulb temperature. s' = specific heat of the stock. B = total radiation and conduction losses per unit time, ui = pounds of water per pound of dry stock. r = heat of evaporation of water. s = humid heat of air, heat necessary to raise 1 lb of dry air + II lb of steam 1 F. 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 (Hi - Hi) = S(u>, - to,) (2) Table 4. Gas Combustion Constants3 Gas Carbon Hydrogen 4 ^ 31 53 si Ofc.. a sS S sec- Cu Ft peb Lb C 12.000 Heat or Combustion ' Bta per Lb Gross Net 14,140 14,140 Lbs peb Lb or Combustible Required for Combustion Oi Hi Air Flue Products COi HaO N, 2.667 8.873 11.540 3.667 -- 8.873 Hi 2.015 187.723 61.100 51,643 7.939 26.414 34353 8.939 26.414 Oxygen Oi 32.000 11.819 Nitrogen- Hi 28.016 13.443 Carbon Monoxide CO - 28.000 13.506 4,369 4,369 0.571 1.900 2.471 1.571 __________ 1.900 Carbon Dioxide 'Methane Ethane Propane COi 44.000 8.54S cha 16.031 23.565 23,912 21,533 3.992 13.282 17.274 2.745 C,H, 30.046 12.455 22.215 20.312 3.728 12.404 16.132 2.929 C,Ha 44.062 8.365 21.564 19334 3.631 12.081 15.712 2.996 2.248 13382 . 1.799 12.404 1.635 12.081 Sulphur Dioxide SOt 64.060 5.770 Water Vapor HtQ 18.015 21.017 Air 28.900 13.063 All gas volumes corrected to 60 F and 30 in. mercury barometric pressure dry. 677 Heating Ventilating Air Conditioning Guide 1939 In discontinuous driers, c.g., compartment driers, the drying operation is given by the equation: " G(H,-H0 = S'g In the continuous drier, the heat consumption per unit time is: = Gsxih - h) + G(r, + /,-?,) (Hi - H,) + 5(1', - +wl) +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 eonditions, 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, I 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' (<", - <",) (s' - >,) . ... : - and in the second term l1, be replaced by "' :, t\ + .. : " . .' Theoretically these periods should be very short and the equation integrated. Practically the error introduced by using a small number of long periods and employing1 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 678 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 679 Heating Ventilating Air Conditioning Guide 1939 brought up to 50 per cent humidity at 150 F. The drier is to use room air, the 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 7ff F rises quickly to the wet-bulb temperature of the air, with which it is in Fig. 9. Temperature Humidity Relations in a Drier Fig. 10. Core Drying Time Temperature Relations Vent 33} per cent t 422 F / Rectrculetion 66 per cent ( et 422 F'Y lb IS (b product of perfect l combustion per pound fuel t> > Excess air for combustion X lb at 70 F Fig. 11. Core Drying Diagram of 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, may be assumed proportional to the moisture content. The moisture content of the entering stock, in the units here employed, is: ti 40 per cent water 60 per cent dry stock 0.6667: wt = 5 per cent water 95 per cent dry stock 0.0527 680 Chapter 35. Drying Systems = A to = 0.614 lb water evaporated per pound of dry stock. Since the air Ipaving the drier is 50 per cent saturated at 150 F from Fig. 4, H, = 0.105. Similarly, Jr _ 0.008, corresponding to 50 per cent humidity at 70 F. Consequently H, -- Hi - 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, tv = 95 F. Hence the wet-bulb depression, t -- t*, = 150 -- 95 = 55 F. The assumption made regarding the relation between stock temperature and moisture content in this range may be formulated: Aw . t - tw - 0.25 At the point w = 0.15, At' = 33 F, /' = 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 681 Chapter 35. Drying Systems. Heat in 1 lb fuel oil = Heater Loss (10 per cent) = 1883 Duct Loss (5 percent)- = 942 18,830 Btu 2,825 Btu 16,005 Btu available to heat oven. Heat content of gases in 1 lb fueloil 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 (5m - Sm) + X (S8J5 - 57o) = 12930 Y = 2 (X + 15) for 66.7 per cent recirculation. . (4) where . . S = 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). . . .. 5m - = 190 - 91 . = 99 ' . . 5m - 5,o = 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 + 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 (5m - 5,o) = 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 H- 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 (5m -- Sm) .= 41.3 (127 -- 8.6) = 4,880 Btu per pound fuel. ,, . Heat available for heating material = 16,005 -- 4,880 = li,125 Btu. Fuel used in second hour = 1,072,008 -t- 11,125 = 96.5 lb oil = 14.3 gal. Total oil used per load = 25.6 + 14.3 = 39.9 gal. - 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. . . . . ... 682 683 Heating Ventilating Air Conditioning Guide 1939 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). 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 R. S. 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). .\ 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 Nostrarid & Co., 1901). Drying in Industrial Plants, by J. O. Ross. Elements of Chemical Engineering, by Badger and McCabe (McGraw Hill Co., 1931). Fan Engineering, Buffalo Forge Co. Fuels and Their Combustion, by Haslam and Russell (McGraw Hill Co., 1926). Heat Transmission, by W. H. McAdams (McGraw Hill Co., 1933). Modem Drying Machinery, by H. B. Grenshaw, London, 1926. . . Principles of Chemical Engineering, by Walker, Lewis, McAdams (Chapters on Evaporation, Humidity and Drying, 2nd edition, (McGraw Hill 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). 684 Chapter 35. Drying Systems PROBLEMS IN PRACTICE X # 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? 0. 9507; -- 1 = 2 lb water per pound dried product. b. Water entering = gg = 233 per cent on bone dry basis. Water leaving = ^5 = 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. /. 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. .cy ... >? Heating Ventilating Air Conditioning Guide 1939 Leaving Air: Humidity, H = 0.0355 ib water vapor per pound dry air. Per Cent Humidity, % H = 32. Water pick up = 0.0355 -- 0.01 = 0.0255 Ib per pound bone dry air. Bone dry air circulated per hour = 250 -5- 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 4- (0.46 X 0.5) = 13.87 cu ft = 1 lb dry air + vapor. Volume handled by fan at 80 F = 9?00_X_yL87 _ 2260 cfm. 60 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) .. Xh r- k) X 5 = Btu for evaporation . (/,' - 130) X 0.2425 = 27.43 h = 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, pa = 9.65 in. Hg (From Table 6, Chapter 1) p = <f>ps = 0.496 X 9.65 = 4.78 ' 29.92 _ 9.65 29 92 -- 4 78 ^ -' ' ~ 0-40 or 40 per cent absolute humidity. \ 686 Chapter 36 NATURAL VENTILATION Wind Forces, Stack Effect, Openings, Windows, Doors, Sky? lights. Roof Ventilators, Stacks, Principles of Control, General Rules, Measurements, Dairy Bam Ventilation, Garage Ven. ! . , tilation ' VENTILATION by natural forces, supplemented in certain cases by wind-actuated devices finds 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, . (a) wind forces, and (b) the difference in temperature between the air inside and outside the building, or a combination of the two-. The results that are obtained by natural ventilating systems- are variable, as they depend on wind action and temperature difference. 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, trees, etc. . . 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. . . .. ,' Heating Ventilating Air Conditioning Guide 1939 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: . Q-EAV (1) where Q = air flow, cubic feet per minute. A = free area of inlet (or outlet) openings, square feet. V = wind velocity, feet per minute, = miles per hour X 88. B = effectiveness of openings. (B should be taken at from 50 to 60 per cent if the inlet openings face the wind and from 25 to 35 nr cent if the inlet openings receive the wind at an angle.) - * wcr 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. i). 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 when the outdoor tempera ture is lower 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) Q = air flow, cubic feet per minute. A = free area of inlets or outlets (assumed equal), square feet. ' . H = height from inlets to outlets, feet. t = average temperature of indoor air in height H, degrees Fahrenheit. to = temperature of outdoor air, degrees Fahrenheit. 9.4 = 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. . *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, Voi. 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). ' .. 688 Chapter 36. Natural Ventilation TYPES OF OPENINGS Types of openings may be classified as: (1) windows, doors, monitor openings and skylights, (2) roof ventilators, (3) stacks connecting to registers, and (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, bottom or side. The proper distribution of the air in spaces to be ventilated is as im portant as that of sufficient air quantity. Advantageous pivoting of sash is very useful for securing good air distribution. Deflectors are sometimes used for the same purpose, and these devices should be considered a part of the ventilation system. _ Roof Ventilators The function of a roof ventilator is to provide a storm and weather proof air outlet. If it is of a type which is sensitive to wind action addi- 689 Heating Ventilating Air Conditioning Guide 1939 Oscillating Ventilators Fig. 7 Fig. 8 . Rotating Ventilators 690 Fig. 9 Chapter 36. Natural Ventilation tional flow capacity will be produced. 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 and the duct work offers to air flow, (3) the height of draft, and (4) the efficiency of the ventilator in utilizing the kinetic energy of the wind for inducing flow by centrifugal or ejector action. For maximum flow induction, a ventilator should be located on that part of the roof which receives the full wind without interference. (See pig. 1.) This does not mean that any 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 value in these locations, and hence their size should be increased proportionally. The base of the ventilator 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). . If a grille is provided at the base of a ventilator it should be oversized as compared with the ventilator size. Air inlet openings located at lower levels in the building should be at least equal to, and preferably larger than the combined throat areas of all roof ventilators. The air discharged by a roof ventilator depends on wind velocity and temperature difference, but due to the four capacity factors already mentioned, no simple formula can be devised for expressing venti lator capacity. . Several types of roof ventilators are shown in Figs. 2 to 9. These may be classified as stationary. Figs. 2 to 4, pivoted or oscillating. Figs. 5 to 7, or rotating. Figs. 8 and 9. 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. . Natural ventilation units may be used to supplement power-driven supply fans, and under favorable weather conditions it may be possible to shut dpwn the power-driven units. Where low operating costs are very important, such a combination has great advantages. Controls Gravity ventilators may have dampers controlled by (1) hand, (2) thermostatic, and (3) wind velocity, in combination with a fan. 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 or vertical flues are really chimneys and utilize both the inductive effect of the wind and the force of temperature difference (the so-called 691 Heating Ventilating Air Conditioning Guide 1939 gravity action). Like the roof ventilator, the stack outlet should be located so that the wind may act upon it from any direction. 60 With little or no wind, chimney effect depending on temperature differ ence and lower outdoor temperature will produce a removal of air from the rooms where the inlet openings are located. HEAT REMOVAL In problems of heat removal, 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: where ~ VH " c 60 (t -- to) % (3) c = 0.24 = specific heat of air. V = specific volume of the air, cubic feet per pound, about 13.5. (See Chapter 1.) H = heat to be carried off, in Btu per hour. Q = air flow in cubic feet per minute. / = inside temperature, degrees Fahrenheit. <o = outside temperature, degrees Fahrenheit. For disposing of odors or other air impurities, the amount of outside air to be introduced must be of such quantity to dilute the impurities to.a . degree that they are no longer objectionable. See Chapter 3 for the minimum of outside air necessary for ventilation. 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): ` 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 velocity5, this resistance becomes a limiting factor as the flow through the openings is increased, Recent investigations*4 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. *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 V14 for moderate to low velocities, and with the first Power of the velocity for very low velocities through small openings. 692 Chapter 36. Natural Ventilation Example l Assume a drop forge shop, 200 ft long, 100 ft wide, and 30 ft high. The Weal content is 600,000 cu ft, and the height of the air outlet over that of the inlet is 2! ft Oil fuel of 18,000 Btu per lb is used in this shop at the rate of 15 gal per hour n 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: H = 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: 0 =_____1"____ = 13.5 X 2,092,500 = 196,172 cfm. v c 60 (f - to) 0.24 X 60 X 10 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 196,17J cfm are to be circulated by the force of the temperature difference alone, the area of opening would be, by Equation 2: Q 9.4 V H (I - to) 196,172 9.4 V 30 X 10 1,205 sq ft. 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 - EA V = 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 in the building 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 to be ventilated. - 693 Heating Ventilating Air Conditioning Guide 1933 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 to 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. 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. (See Chapter 44). . 694 Chapter 36. Natural Ventilation r.: : DAIRY BARN VENTILATION5 A successful barn ventijating system is one which continuously supplies the proper amount of air required by the stock, with proper-distribution hnd 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. .. Barn temperatures below freezing and above 80 F affect milk produc tion. Milk producing stock should be kept, in a barn temperature, be tween 45 and 50 F. Dry stock, at reduced feeding, may be kept in a barn 5 to 10 deg higher. Calf barns 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 barn volume is within the limit that can be heated by the stabled animals, the air supply need not be heated. The air should be 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 bam 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 temperattire zone, vary between 0.043 and 0.066 Btu per hour per cubic foot of barn space, and 0.197 to 0.305 Btu per hour per square foot of barn exposure. GARAGE VENTILATION 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 oh 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 `Dairy Barn Ventilation, by F. L. Fairbanks (A.S.H.V.B. Transactions. Vol 34, 1928,' p, 1S1). 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. .. ; 695 Heating Ventilating Air Conditioning Guide 1939 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.6 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 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 in the following statements: 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' variatibns 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 60 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. '. Code for Heating and Ventilating Garages (A.S.H.V.E. Transactions, Vol. 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). . A.S.H.V.E. Research Report No. 874--Carbon Monoxide Concentration in Garages, by A.S. Langsdorf and R. R. Tucker (A.S.H.V.E. Transactions, Vol. 38, 1930, p. 511). A.S.H.V.E. Research Report No. 935--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). . A.S.H.V.E. Research Report No. 934--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). * A.S.H.V.E. Research Report No. 967--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. Trans actions, Vol. 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). 696 Chapter 36. Natural Ventilation PROBLEMS IN PRACTICE X 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, j Variation in wind velocity. c. Inability to clean incoming air. j 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 usage, and the best utilization of natural ventilating forces. The general rules referred to in this chapter apply particularly to these factors. j Windows with swinging sash and openings with deflectors may be used to direct air to the points desired. 9 0 a. What is the best location for ventilating openings? b. How are the sizes of ventilating openings determined for proper air supply? a. Inlet openings should be low and facing the prevailing winds where possible. Outlet openings should be high and on the side opposite the prevailing winds. ' 4. For simple openings use Formula 1 : Q = EAV and for stacks use Formula 2: Q = 9.4 A V H (i -- fo) 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. 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 venti lator, or wind velocity control designed 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 venti lating system? Wind velocity and air velocities through openings, determined by suitable anemo meters; outdoor air temperatures, measured by a shaded thermometer not near objects 697 Heating Ventilating Air Conditioning Guide 1939 heated by the sun or near exhaust air openings; indoor air temperatures, measured at various heights to secure 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, v c60(I-Io) _ 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 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. 0.05 X 50 X 100 250 sq ft of window area. This area should be evenly distributed along two sides of the building. 698 Chapter 37 AUTOMATIC CONTROL Purpose of Automatic Control, Definitions of Control Units and Terms, Types of Control, Centred 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, PURPOSE 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. 699 Heating Ventilating Air Conditioning Guide 1939 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 .. Bi-Metallic .. 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. 700 Chapter 37. Automatic Control Humidity Controls: Humidity controls are defined as automatic devices reacting to1 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 tiirough 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 ne&ls 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. 701 Heating Ventilating Air Conditioning Guide 1939 TYPES OF AUTOMATIC CONTROL Operating Media or Source of 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. In self-contained control systems, the primary source of operation is the vapor pressure of a volatile liquid in the closed thermal system of the controller, which is increased or decreased in direct proportion to variation of the temperature in the controlled medium. These pressure changes are transmitted directly to the control valve or damper motor. Application's consist of valves or dampers to regulate the flow of heating or cooling media to coils, radiators, or liquid tanks, 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 ito the space under the control of the thermostat in order to 702 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 a't 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 pf 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. Where this type of control is 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, care should be taken that the control point and operating char acteristics of the regulator are such that the valve is fully open at temper atures below freezing, to avoid the possibility of freezing condensate in the bottom of the coil. Division of 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 703 Heating Ventilating Air Conditioning Guide 1939 other form of control is the type of automatic system regulated entirely 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 Ti located in the outdoor air intake is set just above 704 Chapter 37. Automatic Control freezing, and controls valve Vi on the first heating coil. This valve must 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 Vi are controlled by thermostat T2 located in the discharge duct from the fan. If the temperature of the discharge air increases, through the action of Ti the damper is moved automatically to admit more cold air. Should this not reduce the temperature sufficiently, the valves V2 and V% on the heating coils will be closed gradually and in sequence until the correct temperature is reached. The control of the damper and valves V2 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-tip 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 (Tt 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. . . - ;; 705 Heating Ventilating Air Conditioning Guide 1939 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 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- 706 Chapter 37. Automatic Control troller 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 mfist 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 witfi 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 arid humidity of the treated space are measured and govern, through coritrol of the cooling means, the temperature and . the humidity of the air leaving the conditioner. In FigJ 4 is represented one of the most simple ceritral fan types of cooling system. Thermostat T measures the temperature within the treated space arid 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 humidity in central fan cooling systems, which are: :\ . 707 Heating Ventilating Air Conditioning Guide 1939 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, and 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. 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. Roorn thermostat ' Air intake " w I\ Cooling | 1 ! / ----- 1------------1------------------------ Fan Fig. 4. }- Compressor Diagram of Simple Cooling System Control Thermostat 7\ 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 coojing coil so as to maintain the temperature in the space being conditioned at the point which has been set up by thermostat T,, 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 708 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 airdischarge during both cycles. Complete automatic control of all year systems incorporates an auto matic change-over between the cooling and heating cycles. If the instal 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 heatipg 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. |~~p,Room thermostat Insertion p- " I ; op___________ Outdoor eir 1 i 1 i Cooling i coil i i Control va,ve"^^^ \\ V Fan / [--Refrigerant supply 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. Fi 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 Fj 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 Fj which, in turn, modulates the flow of water to the cooling coil so as to maintain a fixed temperature in the space. Humidity control ,?/* 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 Ts acts as a low limit. It assumes command of control valve Ft whenever it is necessary to prevent the air 709 Heating Ventilating Air Conditioning Guide 1939 discharge temperature from falling below a minimum point. Thermostat Ti may also be arranged to act as a low limit during the cooling cycle if the conditions of the installation make it desirable. - . Thermostat Ti 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 H3 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. . . . Thermostat T, must be set at a loiter temperature than thermostat T2 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 Fand 7* 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 central 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 710 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 unit heaters 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 711 Heating Ventilating Air Conditioning Guide 1939 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 22. 712 IP'.'l'.*'. 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.1 7. Operation of the control equipment is as follows: ; 1. During the Heating Cycle. Combination controller Ti measures the temperature in the space being conditioned and opens control valve Vt 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 T\ 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 7Y 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 T\ must be set at a lower point than that of controller Tt in order to provide for the automatic change-over between the cooling and heating cycles. As an example, controller Ti might be set at 72 F and controller Tt 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 7Y would be set at a lower point than that of controller Tt. As an example, Ti might be set at 35 per cent and Tt at 60 per cent. . Heating Ventilating Air Conditioning Guide 1939 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 and 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. Modulating controls and controls providing a high and low fire are also available for gas burners. For purposes of preventing abnormally high temperatures in the bonnet of gas-fired 714 Chapter 37. Automatic Control furnaces or in the temperature of 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 regulators 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 mechanism. 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 by the 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 riinder the command of a room thermostat and through chain linkage,- operates the draft and check dampers of a boiler or warm air 715 Heating Ventilating Air Conditioning Guide 1939 furnace. Such installation should be protected against excessive tem 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 or 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 therqiostat 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 tem perature 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. 716 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 cooling 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 by a temperature controller which will in turn operate a twoposition.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 tem perature controller and control valve. 717 Heating Ventilating Air Conditioning Guide 1939 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 self- contained 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 arid the humidity control may be electrically wired in parallel with a fan motor, and be subject to the temperature limit switch. . ' .: 718 *31^1jV Wi 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 recipro cating 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. . 719 Heating Ventilating Air Conditioning Guide 1939 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 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 720 38.Chapter 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. 721 w Heating Ventilating Air Conditioning Guide 1939 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 and the 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. 722 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, normal 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 to automatic 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. 723 Heating Ventilating Air Conditioning Guide 1939 Current Table 1. Classification of Motors Speed Charac teristics FuU. VOLTAOS Starting Torque Starting Current Hr Range Tt*b or Application oeb Footnote* 1. Shunt Direct 2. Compound 3. Series Constant Spud Drives Constant Medium Medium All Constant High or Variable Medium All (a) Fans and (c) Centrifugal Pumps (M. (c) (e) Recipro cating Pumps and frequentor handstarting Variable High Medium Small (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 C4) Reciprocating' Pumps () and Compressors started loaded 7. Automatic Start Constant High High Torque Low 3 Times Medium (4) Reciprocating Pumps () and Compressors started- loaded 8. Slip Ring Wound Rotor Constant High Low All 1-3 Times with sec ondary control (a) and Hoists (4) Reciprocating Pumps (c) and Frequent () or Hand Start 9. Synchronous High Speed Constant Medium Medium Medium (o) Fans and Cen \ 5-7 Times Large trifugal Pumps 10. Synchronous Low Speed Constant Low Low Medium [a) Reciprocating 3-4 Times Large Compressors Start- ` mg Unloaded Single PHASE 11. Capacitor Constant High Normal Medium (4) Pumps and Small Compressors * "Applications: .' . Drives having medium or low starting torque and Inertia (WR1) such as fans and centrifugal pumps or reciprocating pumps and compressors started unloaded. . Drives having high starting torques, such as reciprocating pumps and compressors started loaded. c. Similar to (o) except where frequent or hand starting (large WR*) requires a higher starting and accelerating torque. d. Fans direct connected. e. Stoker drives. - 724 Chapter 38. Motors and Controls Current Table 1. Classification of Motors--(Continued) . TYPE Charac teristics Fou, Voltage Starting Torque Starting Current Hp Range Tn>a or Application See Footnote* Single phase 12. Capacitor Fan Constant High Medium Medium (a) Fans--belted Small 13; Capacitor Fan Constant Low Medium Medium (<f) Fans--direct Small 14. Capacitor Start Constant Any Induction Run Medium Medium (a) Fans Small (4) Pumps and Compressors 15. Repulsion Induction Constant High Medium Medium (a) Fans Small (4) Pumps and Compressors 16. Repulsion Start Constant High Induction Run Medium Medium (a) Fans Small (4) Pumps and Compressors 17. Split Phase ' Constant Medium and Adjusttable Medium Frac tional () Fans () Pumps and Compressors Adjustable Speed Drives 18. Shunt Field Adjustment Constant Medium Medium All Direct 19. Shunt Armature Variable Medium Medium All Resistor (o) Fans and (e) Centrifugal Pumps (a) Fans and (e) Centrifugal Pumps Poly phase 20. Squirrel Cage Variable Medium Medium Medium (a) Fans High Slip, Small Tapped Winding 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 Ail (a) Fans (4) Pumps and (c) Compressors Heating Ventilating Air Conditioning Guide 1939 Current Table 1-. Classification of Motors--(Concluded) TYPE Speed . Charao TERiancs Full Voltage Starting Torque Starting Current Hp Range Ttpe OP Application See Footnote* Poly PHASE Single phase 23. Wound Rotor, Variable Slip, Ring, Ex-; terrial 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 id) 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. N 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 power 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. 726 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 secondaiy 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: 1. 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. c. Establish current and add overload and low voltage protective devices. (1) Not used. (2) Not used. 727 $ iiyii ilili Heating Ventilating Air Conditioning Guide 1939 (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 thermostat. When this type of thermostat is .used it will lie 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 dr 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. 728 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 729 Heating 'Ventilating Air Conditioning Guide 1939 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 bestarted 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 controllers 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 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 slightly 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 Heating Ventheating Air Conditioning Guide 1939 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 When using direct current motors: a. What tlu-ee types are available as regards their windings; b. - What four -types are available with reference to their speed characteristics? : a. Shunt wound, compound wound, and series wound. K Constant speed, adjustable speed, adjustable varying speed, and varying speed. 732 Chapter 38. Motors and Controls 3 9 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) low 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 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 0 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 (*'.e., 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 there are no standards for 733 Heating Ventilating Air Conditioning Guide 1939 connecting of loads on the power line and they are likely .to vary with different power companies. * 11 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 in load as a result of speeding up the unit. 12 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). \ 734 Chapter 39 PIPING AND DUCT INSULATION Meat 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 Btu per hour per linear foot per degree Fahrenheit difference in temperature between the pipe and surrounding still air at 70 F Nominal Pips Sob (Inches) X H l W 2 2X 3 3X 4 *X 5 6 8 10 12 120 F . -- Hot Water * 150 F 180 F 210 F 227.1 F (5 Lb) Temperature Difference 50 F. 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 6.62 110 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 7.46 157.1 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 Steam 297.7 F (50 Lb) 227.7 F 0.742 0.886 1.084 1.345 1.520 1.866 2.215 2.641 2.972 3.312 3.655 4.030 4.755 6.120 7.592 8.900 337.9 F (100 Lb) 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 9.670 735 Heating Venturing Air Conditioning Guide 1939 Fig. 1. Chart for Estimating Dollar Value of Heat Loss from Barb Iron Pipes. (See Table l)a This chart Is based on 100 linear feet per 1000 hours. 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. . 736 ' Chapter 39. Piping and Duct Insulation Table 2. Heat Loss from Horizontal Bare Bright Copper Pipe Expressed in Btu per hour per linear foot per degree Fahrenheit between the pipe and surrounding still air at 70 F Nominal Pipe Size (Inches) ' Hot Water (Type K Copper Tube) Steam (Standard Pipe Sue Pipe) 120 F I50F 180 F . 210 F 227.1 F (5 Lb) 297.7 F 1 337.9 F (50 Lb) 1 (100 Lb) Temperature Difference a M 1 m i lA 2 2H 3 3'A 4 m S' 6; 8, S0F 0.180 0.236 0.290 0.340 . 0.390 0.490 0.580 0.680 0.760 0.940 1.020 1.160 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 1.255 1.410 1.820 140 F 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 Table 3. Heat Loss from Bright Copper Pipe Given One Thin Coat of Clear Lacquer Expressed in Btu per hour per linear fool per degree Fahrenheit between the pipe ana surrounding still air at 70 F Nominal Pipe Size - (Inches) A % l m m 2 2 'A 3 3A 4 m 5 6 8. Hot Water (Type H Copper Tube) . Steam (Standard Pipe Sue Pipe) 120 F 150 F 180 F 210 F | 227.1 F 1 (5 Lb) 297.7 F (50 Lb) 337.9 F (100 Lb) Temperature Difference 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 6.937 1.025 1.250 1.400 1.685 1.936 2.500 HOF 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 0.3070.414 0.507 0.614 0.714 0.892 1.085 1.270 1.442 1.556 1.965 2.272 2.854 157.1 F- 227.7 F - 0.401 -6.461 0.477 6.571 0.598 ' 6.681 0.700 6.812 1.208 0.966 1.005 1.164 1.178 1.361 1.400 1.625 1.580 1.845 1.750 2.040 1.910 -2.240 2.130 2.415 2.450 2.810 3.120 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 41. 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 *Heat Los from Copper Piping, by R. H. Heilman {Heating Piping and Air Conditioning, September, 1933. p. 458). r ........................... ' _ .. . -. 737 -1 Heating Ventilating Air Conditioning Guide 1939 Table 4. Heat Loss from Horizontal Tarnished Copper Pipe Expressed in Btu per hour per linear fool per degree Fahrenheit . between the pipe and surrounding still air at 70 F Hot Water (Type K Copper Tube) Steam (Standard Pipe Size Pipe) . ' Nominal. ' i 120 F Pipe Size (Inches) 150 F 180 F 210 F 227.1 F (5 Lb) Temperature Difference 297.7 F (50 Lb) 337.9 F (100 Lb) 'K k i IK iK 2 2K 3 3K 4 4K 5 6 8 50 F 0.250 0.340 0.440 0.500 0.580 0.730 0.880 1.040 1.180 1.460 1.600 1.840 2.400 80 F . 0.287 .0.381 0.475 0.559 . 0.656 0.825 1.000 1.175 1.350 1.500 L i 8i2 2.125 2.685 no 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) K: K 1 iK IK Surface Area (Sq Ft) 0.22 0.275 0.344 0.435 0.498 Nominal Pipe Size (Inches) 2 2K 3 3K 4; ; Surface Area (Sq Ft) ' 0.622 0.753 h.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) K K. . l ' IK IK ' ' Surface Area (Sq .Ft) Tube Size . . (Inches) 0.164, '2 0.229 2K. 0.295 . 3 0.360 3K 0.426 4 Surface Area (Sq Ft) 0.S56 0.687 0.818 0.949 1.080 Tube Sim . (Inches) i -5 6 8' - Surface Area (Sq Ft) 1.342 1.604 2.128 ' Chapter 39. Piping and Duct Insulation Table 7. Areas of Flanged Fittings, Square Feet11 Nominal Pipe Size (Inches) i IK IK 2 2K 3 3K 4. , 4K 5 6 8 10 12 . Flanged Coupling -90 Deg Ell Long Radius Ell Tee Cross Standard Extra Heavy Standard Extra Heavy Standard Extra Heavy Standard Extra Heavy Standard Extra Heavy 0.320 0.438 0.795 i.015 0.892 1.083 1.235 1.575 1.622 2.07 0.383 0.510 0.957 1.098 1.084 1.340 1.481 1.925 1.943 2.53 0.477 0.727 1.174 1.332 1.337 1.874 1.815 2.68 2.38 3.54 0.672 0.848 1.65 2.01 1.84 2.16 2.54 3.09 3.32 4.06 . 0.841 1.107 2.09 2.57 2.32 2.76 3.21 4.05 4.19 5.17 0.945 1.484 2.38 3.49 2.68 3.74 3.66 5.33 4.77 6.95 1.122 1.644 2.98 3.96 3.28 4.28 4.48 6.04 5.83 7.89 1.344 1.914 3.53 4.64 3.96 4.99 : 5.41 7.07 7.03 9.24 , 1.474 2.04 3.95 5.02 4.43 5.46 - 6.07 7.72 7.87 10.07 1.622 2.18 4.44 5.47 5.00 6.02 6.81 8.52 8.82 10.97 1.82 .2.78 5.13 6.99 5.99 7.76 7.84 10.64 10.08 13.75 2.41 3.77 6.98 9.76 8.56 11.09 10.55 14.74 13.44 18.97 3.43 5.20 10.18 13.58 12.35 15.60 15.41 20.41 19.58 26.26 4.41 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 tori of coaLper 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 kTable 8. Conductivities ( ) of Various Types of Insulating Materials ; for Medium and High Temperature; Pipes Types op Insulating Material . 100 F 85 per cent Magnesia Type....... .......... :__ L_.:. ft. 425 Corrugated Asbestos Type.______ 1.......... ,o:.53o (4 Plies per 1 in', thick) i Corrugated Asbestos Type. ... .(.... ... .. .. 0.480 (8 Plies per 1 in. thick) Laminated Asbestos Type................ :__ 0.360 (30-40 Laminations'per 1 in. thick) ; Laminated Asbestos Type.............. 0.545 (20 Laminations per X in. thick) Rock Wool Type .......................................... 0.350 High Temperature Type._____ ............................. 0.515 (Diatomaceous Earth and Asbestos) Brown Asbestos Type.______ _____ ;................ 0.600 (Felted Fibre) .; . . Mean Temperature 200 F 0.465 0.650 0.555 300 F 0.505 0.770 0.630 400 F 0,550 0:890 0l705 0.415 0.470 0(525 0.605 0.665 0.725 0.410 0.470 0(530 0.545 0.575 0:605 0.640 0.675 0.715 500 F 0.590 0.585 0.785 0.590 0.635 0.750 R. H. Heilman, Mechanical Engineering, Vol. 46 (1924),p.593\ Heating Ventilating Air Conditioning Guide 1939 Table 9. Coefficients of Transmission (U) 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 air at 70 F Thickness ' OF INSULATION (Inches) i v ik 2 Nominal PtPB 8m (Inches) K K l ik ik 2 2H 3 3K 4 m 5 6 8 10 12 120 P 50 P ; 0.744 0.672 0.613 0.562; 0.532 0.500 0.475 0.455 0:441 0.429 0.420 0.411 0.402 0.387 0.375 0.369 Hot Water 150 F 180 F 210 F 227.1 F (5 Lb) Temperature Difference 80 F 110F 140 F 157.1 F 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 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 0.779 0.701 0.641 0.589 0.557 0.523 0.497 0.477 0.462 0.449 0.440 0.430 0.422 0.405 0.393 0.386 Steam 297.7 F (50 Lb) ~ 337.9 F ' (100 Lb) 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 K .K l ik ik 2 2ft 3 m 4. 4K 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 0.566 0.511 0.465 0.436 0.405 0.382 0.362 0:347 0.337 0.328 0.320 0.311 0.295 0.284 0.279 0.642 0.573 0.518 0.472 0.442 0.410 0.386 0.367 0.351 0.341 0.332 0.324 0.315 0.299 0.288 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 0.285 0.665 0.596 0.540 0.490 0.459 0.4270.401 .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 0.342 0.333 0.316 0.304 0.299 K 0.543 K 0.484 1 : 0.433 IK 0.393 IK 0.365 2 0.338 2K 0.316 3 0.297 3K 0.284 4 0.275 4K 0.266 5 0.258 6 0.250 8 . 0.236 10 0.224 12 0.219 0.551 0.490 0.439 0.398 0.370 0.343 0.320 0.301 0.288 0.278 0.270 0.262 0.254 0.239 0.227 0.222 0.558' 0.497 0.445 0.403 0.376' 0.347 0.324 0.305 0.292 0.282 0.273 0.265 0.257 0.242 0.230 0.225 0.565' 0.503 0.451 0.409 0.381 0.351 0.328 0.309 0.295 0.285 0.276 0.268 0.260 0.245 0.233 0.228 0.569 0.507 0.454 0.412 0.384 0.354 0.331 0.312 0.297 0.287 0.278 0.270 0.262 0.247 0.235 0.230 0.587 0.523 0.467 0.424 0.397 0.364 0.341 0.321 0.306 0.296 0.286 .6.278 0.270 0.255 0.242 0.237 0.597 0.532 0.476 0.432 0.402 0.370 0.347 0.326 0.311 0.301 0.290 0.283 0.274 0.258 0.246 0.240 i 740 T Chapter 39. Piping and Duct Insulation (U)Table 10. Coefficients of Transmission 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 ' OF; * Insulation (Inches) , | i IK , .! 2: !. Nominal Pipe 8n - - (Inches) K K l m IK .2 2K 3. 3K 4 4K ;5 6 8 10 12 Hot Water 120 F; 150 F; 180 F 210 F 227.1 F (5 Lb) . Temperature Difference 50 F 80 K 110 F 140 F 1S7.1 F 0.890 0.803 0.731 0.671 0.635 0.595 0.567. 0.544 0.527 0.513 0.502 0.490 0.480 0.462 0.447 0.441 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 297.7? (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 K M l. 0.737 0.657 0.594 i K 0.542 IK 0.507 ` 2 0.471 2K 0.443 3 0.421 3K 0.403 4 0.393 4K 0.383 5 0.372 6 0.362 -8 . 0.343 10 0.328 12 0.323 0.762 0.679 0.614 0.559 0.524 0.487 0.458 0.435 0.417 0.405 0.394 0.384 . 0.374 0.354 0.339 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 K M l IK ; IK 2 : 2K 3 3K 4 4K ;s 6 i8 . 10 12 : 0.648 0.578 0.518 0.469 0.438 0.404 0.379 0.356 0.339 0.328 0.318 0.308 0.299 0.282 0.267 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 0.527 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 0.314 337.9 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 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 6.810 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 0.325 741 Heating Ventilating Air Conditioning Guide 1939 Table 11. Coefficients of Transmission (/) for Pipes Insulated with Corrugated Asbestos Type Insulation (8 Plies Per Inch Thickness) These coefficients are expressed in Blu per hour per square foot of pipe surface per degree Fahrenheit difference in temperature.behveen pipe.and surrounding still air at 70 F Thickness . of Insolation (Inches) - Nominal ' Pipe 8ieb (Inches). ' - \ \ :l - ' K K l : ik. .2 : 2K 3 ; 3a : 4 : 4H ; 5. 6, 8.. ' ,, : io 12 ; 120 F Hot Water 150 F 180 F 210 F 227.1 F (5 Lb) !- Temperatube Difference 50 F 80 F 0.801 0.723 0.658 0.606 0.573 0.538 0.511 0.489 0.474 0.461 0.451 0.442 0.432 0.416 0.402 0.397 0.820 0.739 0.673 0.619 0.586 0.550 0.523 0.501 0.485 0.472 0.462 0.452 0.442 0.426 . 0.412 0.406 110F 0.838 0.756 0.688 0.633 0.599 0.562 0.534 0.512 0.496 0.482 0.472 0.462 0.452 0.436 0.421 0.415 140 F 0.857 0.773 0.704 0.647 0.612 0.575 0.546 0.524 0.507 0.493 0.482 0.473 0.463 0.446 0.430 0.424 157.1 F 0.868 0.783 0.713 0.655 0.619 0.581 0.553 0.531 0:514 0.500 0.489 0.479 0.468 0.451 0.435 0.429 Steam 297.7 F (50 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 . 337.9 F (100 Lb) 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 i m . . K. ;1 ; IK : IK ' 2: : 2K 3 3K - 4' 4K 5 i .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 0.679 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 0.695 0.621 0.560 0.510 0.478 0.444 0.418 0.396 0.380 0.369 0.360 0.350 0.341 0.324 0.310 0.306 0.711 0.636 0.573 0.522 0.490 0.455 0.428 0.405 0.388 0.378 0.368 0.358 0.349 0.332 0.318 0.313 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 2 ------- - :K K 1 : IK IK 2 -2K 3 3K :4 4K :' 5 6 8. 10 . ____ _____ li........... 0.585 0.599 0.613 0.627 0.520 0.533 0.545 : 0.558 0.465 0.476 0.487 0.498 0.422 0.432 0.442 ; 0.452 0.394 0.403 0.412. 0.422 0.364 0.372 0.380 0.388 0.339 0.347 0.355 0.363 0.319 0.327 0.334 0.342 0.304 .0.311 0.318 0.326 0.295 0.302 0.308 0.315 .0.285 0.292 0.299 0.306 0.278 0.284 0.290 0.297 ,0.269 0.275 0.282 0.288 0.253 0.259 0.265 0.270 0.240 0.245 0.251 0.257 ..0.236... , Q..24L- -0.247... .0,253 .. 0.635 0.565 0.504 01458 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 0.277 742 Chapter 39. Piping and Duct Insulation 12 U)Table . Coefficients of Transmission ( 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 of Insulation (Inches) : 1. . Pipe Size (Inches) K K l IK IK 2 2K 3 3K 4 4K 5 6 8 10 12 - 120 F S0F 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 Hot Water 210 F | 150 F 180 F 227.1 F (S Lb) Temperature Differencr 80 F HO F 140 F 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 Steak 297.7 (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) 267.9F 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 IK ........... K M l IK IK 2 2K 3 3K : 4 4K 5 :6 "8 10 12 . 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 0.514 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 0.27O 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 K- 0.442 0.453 0.464 0.475 0.481 0.508 0.523 K 0.392 0.402 0.412 0.422 0.428 0.452 0.465 1 0.352 0.360 0.369 . 0.378 0.383 0.405 0.417 IK 0.319 0.327 0.335 0.343 0.348 0.367 0.379 IK 2 0.297 0.304 0.311 0.319 0.323 0.341 0.352 0.274 0.280 0.287 0.294 0.298 0.314 0.324 2K 0.256 0.262 0.269 0.275 0.279 0.293 0.302 3 0.243 0.249 0.254 0.260 0.264 0.277 0.285 2 3K 0.231 0.236 0.242 0.248 0.251 0.265 0.273 4 0.223 0.228 0.234 0.240 0.243 0.257 0.265 4K 0.216 0.222 0.227 0.233 0.236 0.249 0.256 5 0.210 0.215 0.220 0.225 0.228 0.241 0.248 6 0.203 0.208 0.213 0.218 0.221 0.233 0.240 8. - 0.191 0.196 0.201 0.206 0.209 0.220 0.227 10 0.182 0.187 0.192 0.196 0.199 0.210 0.215 12 0.178 0.183 0.187 0.192 | 0.195 0.205 0.210 Heating Ventilating Air Conditioning Guide 1939 U)Table 13. Coefficients of Transmission ( for Pipes Insulated with Laminated Asbestos Type Insulation (Approximately 20 Laminations Per Inch Thickness) These coefficients are expressed in Bln 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 (IsCHIB) 1 ; 1J* 2 Nominal Pipb Sees (Inches) Vi Vi l m i vi 2 m 3 3Vi 4 4Vi 5 6 8 10 12 Vi Vi 1 IVi IVi 2 2Vi 3 3Vi '4 4Vi 5 6 8 10 12 . Vi -% 1 IVi lVi 2 2Vi 3 3Vi 4 4Vi 5 6 8 10 12 120 F 50 F 0.910 0.823 0.748 0.686 0.649 0.610 0.581 0.558 0.539 0.524 0.514 0.503 0.492 0.473 0.458 0.452 0.755 0.674 0.607 0.553 0.517 0.481 0.453 0.429 0.412 0.400 0.390 0.380 0.369 0.351 0.337 0.332 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 Hot Watbb 150 F 180 F 210 P j 227.1 K (5 Lb) Temperature Dipfebencb 80 F no f 140 F 157.1 F 0.925 0.836 0.760 0.698 0.659 0.620 0.590 0.567 0.548 0.532 0.522 0.511 0.500 0.480 0.465 0.459 0.940 0.850 0.773 0.710 0.671 0.630 0.600 0.576 0.557 0.541 0.530 0.519 0.509 0.488 0.473 0.467 0.956 0.863 0.785 0.721 0.682 0.640 0.609 0.585 0.566 0.551 0.539 0.528 0.517 0.497 0.481 0.475 0.964 0.871 0.792 0.728 0.688 0.647 0.615 0.591 0.571 0.556 0.544 0.533 0.522 0.502 0.485 0.478 0.767 0.685 0.618 0.562 0.527 0.490 0.460 0.436 0.419 0.407 0.396 0.386 0.375 0.358 0.344 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 0.356 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 0.675 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 Steam 297.7 F~~ 337.9 F (50 Lb) (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 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 0.732 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 0.296 267.9 F 1.022 0.921 0.840 0.771 0.731 0.685 0:651 Of. 626 0.604 0.589 0.575 0.565 0.553 0.532 0.514 0.507 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 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 0.302 744 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 or . Insulation (Inches) Nominal Pipb 8ro (Inches) Vi Vi 1 m IVi 2 2Vi 43 1 3Vi 4 4Vi 5 6 8- 10 12 Vi Vi 1 .m l Vi 2 2)i 3 lVi 3Vi 4 4Vi 5' 6 '8 10 12 2 . Vi % 1 iVi l Vi 2 2 Vi 3 3Vi 4 4Vi 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 Watsb 150 F 180 F HOF 227.1 F (5 Lb) Temperatube Difference 80 F 110 F 140 F | 1S7.1 F 0.644 0.581 0.529 0.486 0.460 0.431 0.411 0.394 0.381 0.371 0.363 0.356 0.348 0.335 0.324 0.320 0.658 0.593 0.541 0.497 0.470 0.441 0.420 0.402 0.389 0.379 0.371 0.364 0.356 0.342 0.331 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 Stbam 297.7 F (50 Lb) 337.9 F (100 Lb) 227.7 F 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 0.355 267.9 F . 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 0.468 0.421 6.383 0.359 0.333 0.314 0.296 0.286 0.278 0:270 0.263 0.257 0.244 0.235 0.230 0.534 0.477 0.430 0.391 0.366 0.340 0.320 0.302 0.291 0.284 0.276 0.269 0.262. 0.249 0.240 0.234 0.545 0.487 0.440 0.399 0.375 0.348 0.327 0.310 0.298 0.290 0.282 0.275 0.267 0.254 .0.245 0.239 0.556 0.497 0.449 0.407 0.383 0.356 0.335 0.317 0.304 0.296 0.287 0.280 0.273 0:260 0.250 0.245 0.563 0.503 0.455 0.412 0.387 0.360 0.339 0.321 .0.307 0.300 0.291 0.284 0.277 0.263 .0.253 0.247 0.590- . 0.528 0.477 0.433 0.407 0.378 0.355. 0.337 0.323 0.315 0.305 0.298 0.290 0.276 0.265 0.260 0.606 0.542 0.490 0:444 0.419 0.389 0.365 0.347 0.332 0.323 0.313 0.305 . 0.297 0.283 0.272 0.267 0.461 0.409< 0.366 0.333 0.310 0.286 0.268 0.252 0.241 0.232 0.225 0.218 0.213 0.200 0.189 0.185 0.471 0.418 0.374 0.340 0.316 0.292 0.274 0.257 0.246 0.237 0.230 0.223 0.217 0.204 0.193 0.190 0.481 0.427 0.382 0.347 0.323 0.298 0.279 0.262 . 0.251 0.242 0.235 0.228 0.221 0.208 0.197, 0.194 0.491 0.436 0.390 0.355 0.330 0.304 0.285 0.268 0.257 0.247 0.240 0.233 0.226 0.213 0.201 0.198 0.496 0.441 0.395 0.359 0.334 0.308 0.289 0.272 0.260 0.250 0.243 0.236 0.228 0.215 0.204 0.200 0.520 0.463 0.415 0.377 0.351 0.323 0.302 0.284 0.272 0.262 0.255 0.247 0.239 0.225 0.214 0.210 0.534 0.475 0.427 0.387 0.360 0.331 0.310 0.292 0.280 0.269 0.262 0.253 0.245 0.231 0.220 0.216 745 Heating Ventilating Air Conditioning Guide 1939 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, V/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 weather 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 brighter 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: . - f, ] (l) The heat given up by the air in the' duct is: .. .--- - B -- 0.24 M (h - Ij) = 14.4 A V d (t, - U) " 746 (2) Chapter 39. Piping and Duct Insulation Equating 1 and 2 enables the determination of the temperature drop in the duct: kPL^(^Ji^ -/,] = 14.4 4 Vd (tx- t,) lx+t,-2h 28.8/4 Vd tx-h kP L :,r 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. ...... - tx = temperature of air entering duct; degrees Fahrenheit. tt = temperature of air leaving duct, degrees Fahrenheit. - t, = temperature of air surrounding duct, degrees Fahrenheit. M = weight of air per hour through the diict,' 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. A more exact formula2 is. available for determining the heat loss from a duct in case the duct is exceedingly long. . 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 Vi 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, . k + 120 - (2 X 40) = 28.8 X 6 X 1200 X 0.07423 h - 120 0.516 X 10 X 70 ........................ ......... <1 + 120 - 80 = 42.62 (f, - 120) : f, + 40 = 42.62 tx -- 5114 ... 5154 = 41.62*, . _______ : 123.8 - tx ............ Performance Tests of Asbestos Insulating Duct, by R. H. Heilman and R- A. MacArthur (A.S.H.V.E. Journal Section. Heating, Piping and Atr ('tjnditioning. February.lStSS, p. 127). ..... .. ................. 747 . Heating Ventilating Air Conditioning .Guide 1939 Based on 123.8 F entering air temperature the new mean temperature difference will be 81.9 F and the new transmission coefficient will be 0.515. Resubstituting in Formula 3, <i becomes 123.9 F, which value is evidently exact within one tenth of one degree. Substituting in Formula 1, H - 0515 X 10.X 70 . 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 Conductivities ' Values are expressed in Btu per hour per square foot of flat surface per degree Fahrenheit difference in temperature between air inside and still air outside at 90 F for cold air and 50 F for warm air in ducts Conductiyitt OP Insulation at 86 P Mean Temp 0.200 0.250 0.300 0.35U 0.450 0.550 Thickness or Insulation (Inches) 40 F 50 P Cold Aib 60 P 30 F ' 80 F 90 F Warm Am 120 F ISO F Temperature Difference 10 F 40 F 70 F 100 F k 1 m 2 0.319 0.175 0.121 0.092 0.323. 0.177 0.122 0.093 14 0.382 0.387 i 0.214 0.217 114 0.149 0.151 2 0.114 0.115 14 1. i)4 2 0.440 0.252 0.176 0.135 0.445 0.255 0.178 0.137 )4 1 1)4 .2 0.494 0.499 0.286. 0.289 0.202 0.204 0.156 0.158 )4 0.596 1 0.356 1)4 0.254 2 0.198 )4 1 i)4 2' 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 0.6Q2 0.360 0.257 0.200 0.688 0.422 0.305 0.239 0.324 0.178 ............. 0.390 0.218 0.448 0.256 0.502 0.290 0.599 0.358 0.685 0.418 0.330 0.181 0.125 0.397 0.221 0.154 0.457 0.260 0.181 0.511 0.295 0.208 0.610 0.364 0.259 0.699 0.425 0.307 0.337 0.184 0.127 0.404 0.225 0.156 0.466 0.264 0.184 0.521 0.300 0.211 0.621 0.370 0.263 0.714 0.432 0.312 180 F 130 F 0.344 0.188 0.129 0.412 0.229 0.159 0.475 0.268 0.187 0.530 0.306 0.215 0.633 0.376 0.267 0.730. 0.440 0.317 For round ducts less than 30 in. diameter, increase heat transmission values by the following percent ages: . Thickness of Insulation (Inches) .. x 1 IX 2 21 to 30 in. Duct DiameterTM-------------.--------------------------- i% 3% 2% 6% "" 9%: ' Chapter 39. Piping and Duct Insulation 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 of 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, release1 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 permissible 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 temperaturedifference. 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 to 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. latiori necessary to take care of still water in pipes at various water and 749 Heating Ventilating Air Conditioning Guide 1939 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- aSoIve problems by drawing lines as indicated by dotted line, entering chart at lower left band 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 750 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 Rates of heat transmission given in Btu per hour per degree Fahrenheit temperature difference between fluid in pipe and surrounding still air Based on materials having conductivity, k = 0.30 - ' Nominal Pipe Sizes (Inches) Ice Water Thickness Thickness of . Insolation (Indies) Bto Per Linear Foot Btu Per Sq Ft Pipe Surface H 1.5 1.6 1 1.6 1.6 m 1.5 2 1.5 2M 1.5 3 1.5 3J4 . 1-5 4' 1.7 S 1.7 6 1.7 8 1.9 10 1.9 12 ' 1.9 0.110 0.502 .0.119 0.431 0.139 -0.403 0.155 0.357 0.174 0.351 0.200 0.322 0.228 0.303 0.269 0.293 0.295 0.282 0.294 0.248 0.349 0.239 0.404 0.233 0.455 0.201 0.559 0.198 0.648 0.194 Brink Thickness 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 Hravt Brine Thickness Thickness of Insulation (Inches) Btu Per linear Foot' Btu Per Sq Ft Pipe Surface 2.8 2.9 3.0 3.1 3.2 3.3. 3.3 3.4 3.5 3.7 3.9 4.0 4.0 4.0 4.0 0.087 0.094 0.104 0.113 0.118 0.134 0.147 0.162 0.176 0.182 0.202 0.228 0.263 0.309 0.364 0.394 0.340 0.294 0.260 0.238 0.214 0.197 0.176 0.167 0.154 0.138 0.130 0.116 0.110 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 but 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 1939 (L. B. McMillan, Proc. Notional Dist. Heating Assn., Vol. 18, p. 138). Fig. 3. Chart for Determining Economical Thickness of Insulation 752 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 Association3. ' 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 waterproofing membrane 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 resulf.of theories4 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). 753 Heating Ventilating Air Conditioning Guide 1939 Table 17. Data for Estimating Requirements to Prevent Freezing of Water in Pipes Nominal Pipe Sob (Inches) H ii l)6 | 2 J 3 4I 5I 6| 81 10 II 12 2 0.42 0.83 1.40 1.94 3.25 4.55 5.92 7.35 10.05 13.00 15.80 Ncubes op Hours ro Cool Water to Freezing Point Water Required to Flow to Prevent Freezing, Pounds per Linear Foot op Pipe per Hour 5 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 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 3 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 (Lb Gage) or Conditions 0 to 25 25 to 100 100 to 200 Low Superheat Medium Superheat High Superheat Steam Temperatures Degress Fahrenheit 212 to 267 267 to 338 338 to 388 388 to 500 500 to 600 600 to 700 Thickness or Insulation Pipes Larger Than 4 In. 1 in. 1}4 in. 2 in. 2)6 in. 3 in. Z)6 in. Pipes 2 In. to 4 In. 1 in. 1 in. 1)6 in. 2 in. 2)6 in. 3 in. Pipes HIn. to 1)4 In. 1 in. 1 in. 1 in. 1)6 in. 2 in. 2 in. "All piping located outdoors or exposed to weather is ordinarily insulated to a thickness N 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) or Conditions Steam Temperatures Degress Fahrenheit Minimum Thickness or 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 25 to 125 267 to 352 Above 125, or superheat 352 to 500 m 2 2H 2 m 3 2^ 3 m m in Minimum Between AND Return i 1H 754 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 Yi 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 O 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 1.677 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 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) 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 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 *A closely approximate solution of this problem may be quickly made by use of the estimating chart given in Fig. 1. . Heating VenthiAting Air Conditioning . Guide 1939 found to be 0.622 sq ft. The total annual loss through the-insulation = 89.04 ?< 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. Solution of the problem by use of Fig. 3 results in a required thickness of approximately 1.05. in. The nearest commercial thickness procurable is standard thick (lJlh in.) magnesia. . (It is of interest to note that the use of Fig. 3 will generally result in solutions 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 wool felt 2.4-in. thick is sufficient to prevent condensation. The nearest commercial thickness procurable is 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 factor of safety is thus obtained. 756 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 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 pf the heatafter 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 into1 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 757 Heating Ventilating Air Conditioning Guide 1939 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 arid 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 healers, 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. 758 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 manrier 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 -Reflector Incandescent " element ^"^r-Cord . /7777Z7777777>777Z; Fig. 1. Typical Radiant Heater "I r;/, JDeflector 1 Elements*;! T &. Perforated***** case 1/ V 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 fail 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 for 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 near 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 elements an automatic control panel, a thermostat, and a master hand 759 Heating Ventilating Aik Conditioning Guide 1939 switch. All heaters shguld 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. Portable unit heaters are useful for temporary work, such as drying out damp rooms, or for warming rooms during construction. . Chapter 40. Electrical Heating 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 and 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. 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 Fig. 3. Ceiling Mounted Unit heater Fig. 4. Wall Mounted Unit Heater Thermal / Power supply Fig. 5. Floor Mounted Unit Heater Fig. 6.- Wiring Diagram for Unit . Heater 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- 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). 760 Fig. 7. Wiring Diagram of a Selecting Control for a Fan System constant unless some compensating action is performed by control. Auto matic variation of the electrical heat input synchronized properly with the air flow has been successfully applied to central fan systems. A typical wiring diagram of an automatic modulating system for central fan heating is indicated in Fig. 7. . Electric'heaters are useful in balancing the heat distribution in central fan'heating systems. Even in those instances where steam is the principal heat source, the temperature of individual rooms can be controlled locally by separate electric booster heaters. These heaters can be installed in branch ducts or behind the air outlet grilles in each room. With this arrangement, the central heating unit distributes air at an average temper ature, controlled from a thermostat centrally located, such as in the main return duct. The electric booster heaters may be controlled by thermo stats mounted in each individual room Which permits the occupant to maintain any desired temperature independent of the rest of the building. 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 761 Heating Ventilating Air Conditioning Guide 1939 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 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 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 762 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 SUPPLY1 Electric water heaters of the automatic storage typie 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.. ------: '' / : lTeet Results of Electric Water Heaters, by C. G. Hiilier (A.S.H.V.E. Journal Section. Heating, Piping and Air Conditioning, November, 1936, p. 632). . . Fourth Annual Survey, by B. J. Martin (Electric Light and Power, March, 1937). 763 Heating Ventilating Air Conditioning Guide 1939 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. Safety valve 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 fteating element is usually con nected to the line so that in case the supply of hot water in the tank becomes exhausted the tbp 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 764 . 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 23. 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 *Cooling 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 /. 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 Section, Heating, Piping and Air Conditioning, October. 1935. p. 497). `. Heating Ventilating Air Conditioning Guide 1939 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 . 3415 kw rating of required electric heating (1) For comparison with steam radiation: 3415 BtUJne kWhr) = 142 stJ ft of steam radiation 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 vo.lts, which, can only be used economically for small heaters. : Usually 766 Chapter 40. 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? a. 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. t. 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 hot 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. *. 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. /. As booster heaters in central fan systems to permit local temperature control in individual rooms. 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. .................... 1939Heating Ventilating Air Conditioning Guide 3 At what rate for electric power is electric heating feasible? o. 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? a. Better distribution of heat to the floor level. b. 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 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 selective electrical control which will automatically compensate for variations in the volume of air flow. This cannot be done by mixing dampers alone as in a steam system. 6 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. 768 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. . . ' 769 Heating Ventilating Air Conditioning Guide 1939 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. ' . 1A.S.H.V.E. Research Report No. 830--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). 770. Chapter 41. Radiant Heating The loss by evaporation, which depends on the air temperature, aif movement and humidity, together with the loss by respiration makes upthe 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 oyer 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 arid 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; -[(*)* -)4] <> where ...(ir)" *()"" x (r- - r.)"" Hr = heat loss by radiation, Btu per square foot per hour. . * i?c = heat loss by convection, Btu per square foot per hour. r,, = absolute temperature of the body surface, degrees Fahrenheit. rw = absolute temperature of the walls, degrees Fahrenheit. ra = absolute temperature of the air, degrees Fahrenheit. 7m tb + tb 2 D = diameter of cylinder, inches. e = the ratio of actual emission to black body emission. If it is assumed that a normal adult has an average height of 5 ft 8 in. December 1928) -- ' *** iviisceuaneous ^oiiecuons, vol bl, jno. 6, iASME- **"* 771 Heating Ventilating Air Conditioning Guide 1939 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 environ ment 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: 1. 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. A.S.H.V.E. Research Report No. 962--Application of the Eupatheoscope for Measuring the Per formance of Direct Radiators and Convectors in Terms of Equivalent Temperatures, by A. C. Willard, A. P. Kiatz, and M. K. Fahnestock (A.S.H.V.E. Transactions, Vol. 39, 1933. p. 303). . 772 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 cot- I m Fig. 1. Pipe Coils Located in Interior Wall Surfaces Fig. 2. Arrangement of Continuous Pipe Coil in Floor Construction strutted 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 a^d ceiling U"der ^ flr may be brger than those erabedded in the plaster walls 3. By circulating warm air through shallow ducts under the floor. In this design the entire floor surface of a room is heated as in method 2. This method while being more 773 Heating Ventilating Air Conditioning Guide 1939 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. These 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 healed 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 thelatter 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 ' 774 Chapter 41. Radiant Heating Table 1. Total Black Body Radiation to.Surroundings at Absolute Zero3 Boor OB Mean Radiant Temper ature Deg Fahr Radiation ip Btu per square foot per hour . emitted to surroundings with a tempera- ' ture of absolute zero by bodies at various temperatures and with emissivity factor e6 e 1.00 0.9S 0.90 0.80 : Boot OB' Mean Radiant Temper ature Deg ' Fahr Radiation in Btu per square foot per hour emitted to surroundings with a temperature .of absolute zero by bodies at various temperatures and with emissivity .factor e . - 9, .e 1.00 , : : 0.95 9 0.90 9 0.80 . 30 99.3 35 103.5 40 107.6 45 . 112.1 46 112.9 47 113.9 48. 114.8 49 . 115.6 50 116.5 51. 117.5 52 118.4 53 119.4 54 120.2 55 121.1 56 122.1 57 123.1 58 124.0. 59 124.9 60 125.8 61 126.6 62 127.7 63 128.6 64 129.6 65 130.5 66 131.6 67 132.5 68 133.5 69 134.5 70 135.5 94.3 98.3 102.4 106.5 107.3 108.2 109.1 109.9 110.6 111.6 112.5 113.4 114.2 115.1 116.0 117.0 117.8 118.6 119.5 120.3 121.4 122.2 123.1 124.0 125.0 125.9 126.8 127.8 128.8 89.4 93.2 96.8 100.9 101.6 102.5 103.4 104.1 104.9 105.8 106.5 107.4 108.2 109.0 109.9 110.9 111.6 112.4 113.4 114.0 114.9 115.8 116.7 117.5 118.4 119.3 120.1 121.1 121.9 79.4 82.8 86.1 89.7 90.4 91.1 91.9 92.4 93.2 94.0 94.7 95.5 96.2 96.9 97.7 98.5 99.2 99.9 100.7 101.4 102.2 102.9 103.7 104.4 105.4 106.0 106.8 107.6 108.4 71 72 73 74 , 75 . 80 85 90 100 110 120 130 140 150 160 170 .180 190 200 210 220 250 300 350 400 450 500 550 600 136.5 137.4 138:4 139.6 141.0 146.6 152.3 157.9 169.6 181.6 . 194.8 210.1 223.2 237:1 251.1 270.5 288.0 306.5 325.2 348.0 371.5 437.8 575.0 740.0 942.1 1176.0 1464.0 1791.0 2405.0 129.6 130.5 131.5 132.6 133.9 139.4 144.6 149.9 161.1 172.5 185.0 199.6 212.1 225.2 238.8 257.0 '273.8 291.0 309.0 330.6 353.0 415.9 546.1 703.0 895.0 1117.0 1390.0 1701.0 2284.0 122:9 109.3 123.6 109.9 124.5 110:6 .125.6 ' 111.7 126.9 . 112.8 132.0 117.4 137.1 . 121.9 142:1 126.4 . 152.6 135.7 163.5 145.4 175.4 155.9 189.1 168.1 201.0 178.5 213.5 189.7 226.0. 201.0 243.5 216.4 259.1 230.4 .275.8 245.1 292.8 260.3 313.1 278.4 334.4 297.1 394.0 350.2 517.5 460.0 666.0 592.0 847.5 753.5 1059.0 941.0 1318.0 1171.0 1613.0 1434.0 2165.0 1925.0 These factors are calculated from the formula where , /Q ( 0.1723 X T*\ \ 100 000.000 0 =* total black body radiation, Btu per square foot per hour. e "** emissivity. .. . T " 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. 775 Heating Ventilating Air Conditioning Guide 1939 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 pier 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, theltype 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 Btii per. square foot per hour. The total emission of radiation into the .room from that surface would there fore be4 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--ait aj, Os,--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, and 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 tern-., perature'maintained. If it will not, additional convection surfaces must I be introduced to make up the deficiency. . . , . 776'.' Chapter 41. Radiant Heating Table 2. Subface Areas, Temperatures and Emissions for a Room of 5760 Cu Ft External Wall..................... Glass-.................................... inner Wall........... _............. Ceiling................................... Floor.. .................................. Total--.......................... Arica Sq Ft 297 279 480 480 480 2016 Assumed Subta.ce Temperature (Deo Fahb) 50 45 55 55 55 Heat Emission (Btu Per Sq Ft per Hour) Total Heat Emission from Area (Btu per Hour) 110.6 106.5 115.1 115.1 115.1 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, aind, 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 o'f 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, arid 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.. Heating Ventilating Air Conditioning Guide 1939 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.II.V.F. 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). ... What Will be the Future Development of Heating and Air Conditioning, by W. H. Carrier (Healing, 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). . 778 S-y' 'S*-' 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 f Where did radiant heating derive its name? ' The term radiant heating 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 convected warm air. 2 0 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 0 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 0 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 0 When and why does 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 0 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. 779 Heating Ventilating Air Conditioning Guide 1939 8 9 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 9 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 9 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) = (142-X-l 1.1) = 7. 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 9 Give a simple formula to calculate radiant heating surface required, and explain. ,, (142 -- X -- 11.1) A 6" B ' where S -- 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 9 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 feel$ 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. . Chapter 42 DISTRICT HEATING Steam Distribution Piping, Selection of Pipe Sizes, Provision for Expansion, Capacity of Returns with Various Grades, Conduits for Piping, Pipe Tunnels, Inside Piping, Steam Re quirements, Fluid Meters and Metering, Rates, Utilization, Automatic Temperature Control. 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 probletns in connection with institutions and factories. Some data are included to cover the piping peculiar to heating systems which are to be supplied with purchased steam.. A com plete district heating installation should not be attempted without a thorough study of the entire problem by men competent and experienced in that industry. STEAM DISTRIBUTION PIPING 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. Having 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. Miscellaneous steam requirements such as laundry, cooking, or process should be individually calculated. . The steam requirements for water heating should be taken into account, ' 781 Heating Ventilating Air Conditioning Guide 1939. 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 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 upon (1) boiler pressure, (2) whether exhaust or live steam, (3) pressure require ments of apparatus to be served. If steam has been passed through electrical generating units, the pressure will be considerably lower than if live steam, direct from the boilers, is used. The advantages of low pressure distribution (2 to 30 lb per square inch) are (1) smaller heat loss from the pipes, (2) less trouble with traps and valves, (3) simpler problems in pressure reduction at the buildings, and (4) general reduction in maintenance costs. 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 value 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 is one of several formulas which may be used. Unwin's formula, which gives pressure drops slightly larger than actual test results, is as follows: 0.0001306 W'L (l -f P= dD> 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. (1) This formula is similar to the Babcock formula given in Chapter 16. 782 Chapter 42. District Heating Information on provision for expansion will be found in Chapter 18. Where steam and return piping are installed in the same conduit, the return piping usually follows the same grade as the steam piping. In general, the condensation is pumped back under pressure. Where the condensation returns by gravity, Table 1 gives the sizes of the return piping. It is evident that at points where the grade is great, smaller pipes can be installed. 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 affecting 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 or cast steel set in concrete. In general, cast steel is preferable to struc tural steel. Table 1. Capacity of Returns for Underground Distribution Systems in Pounds of Condensate per Hour 8heb" or Pipe In. i IK IK 2 3 4 5 6 8 10 12 6* 448 1740 2700 4980 13900 30900 54800 90000 190000 344000 555000 1' 998 2490 4190 7380 . 22500 44800 79800 138000 277000 . 498000 798000 Pitch or Pipe per 100 Ft r 1890 3990 5740 10700 30900 64800 120000 187000 404000 724000 1148000 3' 2240 4880 7480 13900 37400 79700 144800 237000 508000 900000 1499000 5' 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 .............. . ___________ -- aSize of pipe should be increased if it carries any steam. . In laying out underground conduits the following points should be borne in mind: , .1. The depth of the buried conduit should be kept at a minimum. Excavation costs are a large factor in the total cost. 2. An expansion joint, offset, or bend should'be placed between each two anchors. 3. 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. 4. 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. 5. For longer lines, manholes must be located according to experience, physical con ditions and the expansion value of the type of expansion joint or bend that is used. The 783 Heating Ventilating Air Conditioning Guide 1939 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. 6.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 test pressure should be one-and 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. . There are many types of conduits, some of which are manufactured products and some of which are built in the field. The styles and con struction of conduits commonly used may be classified as follows. Some of the more common forms are illustrated in Fig. 1. Fig. 1. Construction Details of Conduits Commonly Used 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 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 below. 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 placed 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. 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 784..' Chapter 42. District Heating 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 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 on 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, hollow 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 water-proof jacket enclosing 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. 785 Heating Ventilating Air Conditioning Guide 1939 aV- J. **?-**; Fig. 2. Connections for Reducing Valves of Size Less than 4 In. 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 to accommodate miscellaneous other services or provide underground passage between buildings. OVERHEAD DISTRIBUTION In some industrial and institutional applications, the distribution piping may be installed, entirely or in part, above ground. This method of construction has the advantage of requiring no excavation and being easily maintained. Fig. 4. _ float trap Steam Supply Connection when Using Two Reducing Valves INSIDE PIPING 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 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 until repairs are made. Fig. 4 shows a typical installation used for high pressure steam service. The first reducing valve, effects the initial pressure reduction. The second reducing valve reduces the steam pressure to that required. 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. 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. ' Return main Fig. 3. Connections for Reducing Valves of Size 4 In; and Larger, and for Expanded Valves 786 787 Heating Ventilating Air Conditioning Guide 1939 788 -n...u .... ,: .-. - . . . , -. ,,.jaSSSSS5^^P^ Chapter 42. District Heating 1. Provision should be made for conveniently shutting off the steam supply at night and at other times when heat 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 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 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 coil, or as is more frequently done, by a water heating economizer (see Fig.-5) which preheats 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 economizer. The supply to the hot water heater passes through the economizer, ab sorbing heat from the condensate. If the hot water system in the building is of the recirculating type, the recirculating connection should be tied in between the economizer and the water heater proper, not at the economizer inlet, because the recirculated hot water is itself at a high temperature. The number of square feet of heating surface in the economizer 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 condensate if storage capa city is provided for the preheated water. Frequently a type of economizer 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 temperature controls of various, types or by orifice systems. Another method which is very simple is the use of an ordi nary vacuum return line system in which the pressure in the radiators is varied between a high vacuum and a few pounds pressure, thus producing some control over the heat output of the heating system by varying the temperature of the steam in the radiators. Several proprietary systems are on the market which accomplish this automatically, either with outdoor or indoor controls or a combination of both. One form of control which appears to be well suited for controlling district steam service to a building is the weather compensating control. It regulates the steam supply automatically ac cording 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. This type of control can be equipped with time clocks and thermostats to provide a warmingup period in the morning. 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 daytime hours only. The setting of a switch may provide no service, continuous service, or periodic service. For the latter, by means of several intermittent settings, steam will 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. 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 inter mittent supply called for by the day switch setting, or may be set to interrupt the opera- 789 / Heating Ventilating Air Conditioning Guide 1939 tion 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. . The maximum in economical operation and satisfactory heating can only be obtained by the use of some automatic temperature control system. FLUID METERS The perfection of fluid meters has contributed more to the advance ment of district heating than any other one thing. These meters may be . classified as follows: 1. Positive Meiers: 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: 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 sub-divisions of these two general classifications can be made as follows: { KS" P Positive - Quantity Volumetric { Fluid Meters Quantity - Current - Turbine Differential Rate of flow Head (Kinetic) Venturi Flow nozzle Orifice Pitot tube {Area (Geometric) Orifice and plug Cylinder and piston Head area (Weir) [ 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. 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. (b) Installation cost. (cj 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. * 790 Chapter 42. District Heating 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 condensation meters. 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 tilting 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 Fig. 7. Geavity Installation for Condensation Meter Using Vented Receivers 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. Fig. 7 illustrates a gravity installation using a vented receiver ahead of the meter, while Fig. 8 shows a vacuum installation without a master trap. Flow Meters Steam flow meters are available in many types and combinations. 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 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. 9 shows a typical orifice-type meter connection and indicates typical requirements-in the installation of this type of meter. 791 Heating VentiIiAting Air Conditioning Guide 1939 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. A 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. ' Chapter 42. District Heating by using a consumption of 0.0025 lb per day per cubic foot of heated space for office buildings, and 0.0065 lb per day per cubic foot for apartment houses. Additional data on steam 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 on the investment. However, there are Fig. 8. Vacuum Condensation Meter Installation without Master Trap 2. Reservoirs should always be on the same level and installed in accordance with the instructions of the meter company. ' 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 REQUIREMENTS Steam requirements for heating various types of buildings are given in Chapter 12. Steam requirements for water heating can be satisfactorily estimated 792 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. 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 lay man 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 hourly load to the 793 Heating Ventilating Air Conditioning Guide 1939 maximum hourly 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). . . ' . 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 thousands of pounds 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 advantage 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. N' 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. The Doherty rate is divided into three elements: (a) A charge based upon demand. (b) A charge based upon steam consumed. (c) A customer charge. , In the Hopkinson rate, the last two elements are combined into one element, 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. 794 '`W- Chapter .42. * District Heating They are of.benefit to utility companies and to consumers because the investment and operating icosts 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. Demand rates are an advantage to the customer in that the use of such a rate reduces the rate per thousand pounds to the long-hour user. - . : . 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 pride of fuel, it is also desirable to add a defiiiite 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 changing1 of the whole rate, structure. .. - UTILIZATION ............... Considerable savings can be made by the proper arid intelligent oper ation of heating systems. It should be borne, in mind-that a heating system, is designed to heat a building to 70 F; inside when the outside temperature is at its lowest point for that particular locality. There is a tendency to overheat the building at any time the outside temperature is above the design temperature unless, some method of regulation is used, either automatic or manual. . . . -' The.general rules for economical operation are as follows: . . . ! - . * 1. Weatherstrip all windows, and calk all window frames. .. .. 2. Provide revolving or vestibule doors on all 'entrances. Separate shipping and receiving. rooms by partitions so that the ever-open large doors will not ventilate, the entire building. .... ... 3. Keep the.radiation near the outside walls, under the windows, if possible. 4. Eliminate all unnecessary ventilation/ Ventilating equipment is sized to.meet extreme requirements.. Do not supply ventilation to a theater or auditorium adequate for an audience of 2000 when there are only 200 present. . <. . 5. Determine the hours that heating is required during the day and see that the steam is shut off for the maximum time at night, on Sundays, and holidays. .. 6. Shut steam off entirely in unoccupied sections of the building, taking care to avoid freezing the water in the plumbing system. -- . 7. Shut off steam during the day whenever possible. During the year steam can be shut off about 55 per cent of the total daytime, the saving is proportional. An automatic control will do it, but it can be done by hand with amazingly good results. -- 8. Determine the temperature required for the occupancy of the building. Do not heat a storage garage or a furniture warehouse to the temperature required in a hospital ward. . . ' . ... ` . '. . 9. Provide some good means of temperature control............. . 10. In a hot water heating system keep the temperature of the water down to corre spond with existing outdoor temperatures. - 11. In a vacuum system maintain a high vacuum. If this is not possible, locate and eliminate all. leaks., . 12. Install separate lines for those parts of the building that require long-hour or all-night heating. It is much cheaper than heating the entire building all night. 13. See that the entire system responds rapidly when steam is turned on. Locate and eliminate the cause of any sluggish circulation. Balance the radiation, provide adequate air elimination, and correct any trapped run-outs to provide quick system drainage. 14. Keep the system in good repair. Worn, damaged, or defective valves and traps will not function properly. 15. Insulate all steam pipes not used as heating surface. . ,. . 16. Do not obstruct radiators or prevent the free circulation of air around them; to do so seriously reduces the heating capacity of a radiator. 17. Extract the heat in the condensate for hot water or some other, useful purpose. 18. Provide thermometers and recording pressure gages so that the engineer can operate the system with full knowledge of what he is accomplishing. . 795 . Heating Ventilating Air Conditioning Guide 1939 19. Make all valves and controls convenient and accessible, either direct or through remote control. It is only human nature to delay and avoid doing that which is incon venient. 20. Keep a daily record consistently, based on weather requirements, and watch it every day. 21. Control the heat supplied to water tanks located on or above the roof. Such tanks require heat to prevent freezing. No heat is required when the temperature in the tank is above 32 F. . 22. Investigate every complaint of no heat by tenants; find the cause and correct it. Do not overheat an entire building to correct a local condition in one room. AUTOMATIC TEMPERATURE CONTROL As stated in Chapter 37, automatic control properly applied to heating, ventilating and air conditioning systems makes possible the maintenance of desired conditions with maximum operating economy. In addition to the large possibilities for economy, the use of adequate temperature control provides more healthful, comfortable, and efficient working conditions in the buildings because through its use the building is uniformly heated with correct temperatures and drafts from open windows and over-heating are eliminated. There are many types of temperature control available, each adaptable to a particular type of building, but all require uniform distribution of steam and proper venting. Before the installation of any type of modern temperature control equipment, it is necessary to see that the heating system is put in good operating condition. In general, the heating system in a building is not given the attention that other mechanical equipment is given because it will continue to function, after a fashion, even though changes in piping, location of radiation, settlement of piping, and the normal wear and tear or other changes have taken place. Through all this depreciation of the system, it becomes more and more costly to operate and parts of the building have to be greatly overheated in order to prevent underheating in a small section of. the building. Vents, traps, vacuum pumps, and valves should be given a careful inspection and replaced or repaired if required. The piping should be of adequate size and graded properly. The return piping should have a careful inspection, and any pockets or lifts removed and properly vented. These inspections and repairs are not costly and prevent a much greater outlay in future years. In most cities district heating companies will be willing to make a survey of heating, systems and offer recommendations as to operation and changes in piping layout. The selection of control equipment depends upon the type and size of building and the degree of saving possible. 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 Diata 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). 796 Chapter 42. District Heating 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 Flow Meter Calculations, (N.D.H.A. Proceedings, Vol. XIII, pp. 183-193). . Testing of Steam Meters, (N.D.H.A. Proceedings, Vol. XIV pp. 272-276). ' 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.H.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). Utilization (Principles of Economical Heating, N.D.H.A., and N.A.B.O. & H.). PROBLEMS IN PRACTICE 1 # a. What are the advantages and disadvantages of a low pressure distribu tion system? " . b. High pressure? a. 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, and (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, and (2) de- . creased field of usefulness owing to small pressure range. b. The advantages of a high pressure system are: (1) smaller pipe sizes, and (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, (3) extra heavy fittings are required, and (4) usually two reducing valves or some form of emergency relief is necessary to protect the building piping system. 2 # What- points should be borne in mind when laying out an underground steam conduit? The conduit should be reasonably water-proof, 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. 3 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 onehalf 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 100.1b per square inch. 4 What are the common methods for salvaging heat in condensate? The most common methods are: (1) the use of a water heating economizer for pre heating the hot water supply to the building, and (2) the use of a cooling radiator. 797 Heating Ventilating Air Conditioning Guide 1939 5 tie the steam'consumption less' in a huilding 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 results in lower heat loss from the building, and less heat need therefore be supplied. 6 What are the common methods used to graduate the heat supply, accordr ing to variations in outside temperature? .. , . . .: - a. Thermostats controlled by building-temperatures and operating a motor valve. b\ A "Weather compensating thermostat will regulate the steam supply according to outside temperatures. These controls can be arranged to give short intervals of inter mittent steam supply. Tbose without time clocks can. be.equipped with suitable timing arrangements. . y - - . .. c. .-Another; method which is very. simple is the use of an ordinary;;vacuum return line system in whicrh the pressure in the radiators is varied between a high vacuum and a few pounds to produce some control oyer the heat output. There are.systems on the market which will do this automatically. : ` . d. The'use of orifice systems1 insures proper distribution and graduation of heat supply. e. 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 pf minutes for each successive setting 'of-the switch, steam being shut off during the balance of the period. This type pf 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. .. :. 7 0 What .is the common method of determining the size of mains in a dis tribution system? . . Oh 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. 8 O Determine the size of pipe from the following data using Unwin's formula s length of pipe, 600 ft; steam to be carried, 90,000 lb per hour, dry saturated; initial pressure, 100 lb per square inch, gage; arid final pressure, 40 lb per square inch, gage. ` '' The pressure drop, P 100 -- 40 = 60 lb per square inch. 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 Tables: ... 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 (1): 0.0001306 X 1500* X 600 ( 1 + 60 ='-- 0.1932 X Di D.= 7.35 in. Therefore, an 8-in. pipe should be.used.-. 798 . ( ' 1 .TT 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* ing Requirements OMESTIC 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 forinulae employed may have been derived on sound technical basis the assumptions are often in error. ....... To arrive at a safe standard, the approximate rate.1 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 ou 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. .. . 799 Heating Ventilating Air Conditioning Guide 1939 sectionalizing is for the purpose of avoiding excessive pressures 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. 800 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 Futures ' Colo Water (Gallons per . Minute) Hot Water (Gallons per Minute) Water-closets, flush valve............. ... . Water-closets, flush tank ......... ..... Urinals, flush valve................... Urinals, flush tank.__ __ . Urinals, automatic tank............................................-..L,.,............ Urinals, perforated pipe per foot Lavatories..__________________ ____ __ ________________ Showers, 4 in. heads, V6 in* inlets : - Showers, 6 in. heads or larger ... Shampoo spray__________;........................................ Liver spray______ ............. ... . - Manicure table. .................. Kitchen sink___ ____ ' Pantry sink, ordinary ... Pantry sink, large bibb....,.......... ,.............,................................... Wash* trays......__ t__........................... ^....................... Laundry tray.....................................;..................... Garden hose bibb._.......................................................................... 45* 10 30* 10 1 10 3 3 6 1 2 5 4 2 6 6 3 6 10 0 0 0 0 0 0 3 3 6 30 1 2 m 5 4 ' 2 6 6 3 0 0 ---------------------------- , Actual testa on water-closet flush valves indicate 40 gpm as the maximum rate of flow with 30 lb prea^ sure at the valve; this would increase to 60 gpm (about 50 per cent) at 00 lb pressure. The 45 gpm has been taken as an average flow; 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 >m< manner.' 1 . * 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 haying the same maximum possible flow, qng cpmposed entirely of water closets and the other a mixed system of water 801 . T a b l e 2. Sc h e d u le o f Size s fo r D o w n -F e e d R is e r (Se e F ig . 2) Heating Ventilating; Air Conditioning Guide 1939 closets and smaller fixtures, the probability of a: given rate of flow is greater for the system. composed of water closets them for the mixed 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 than flush valve fixtures the curve has been extended for smaller maximum possible flow values. " '\ ' ' 802 r itx 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 yalve 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 gptn------------ 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. 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 gpmr Maximum possible.flow.__! 600 gpm i- Fig. 1 shows a factor of ` usage of 23 per cent. . : Maximum probable flow of hot . water is 600 X 0^3--__________ ...__ 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 rate 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 by 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,1 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. ' . 803 Heating Ventilating Air Conditioning Guide 1939 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 Sna or Pips (Inches) a Ye l m m 2 m 3 4 5 6 90-Deg Elbow 4 5 5 6 7 7 10 12 18 25 30 45-Deg Elbow 3 3 3 4 5 5' 7 8 13 18 21 Ttpb or Fitting or Valve Return Bend Gate Valve Globe Valve 8 2 48 10 3 60 10 3 60 12 3 . 72 14 4 84 14 4 84 20 5 120 24 6 144 36 9 216 50 13 300 60 15 360 Angle Valve 8 10 10 12 14 14 20 24 . 36 50 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 equivalent4ength 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 8. 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 Sressure which will be available for pressure drop will then be 60 lb -- (15 lb + 50 ft X .43 lb) = 60 lb - (15 lb + 21.5 lb) = 23.5 lb. To change this into drop per 100 ft: 200ft^-t-^lOtift = 7.8 lb per 100 ft. . The pifie 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. . 804 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. Table 4. Pressure Loss Through Water Disc Meters3 A. W. W. A. Standards ' Rats or Flow Gpm 5 10 15 20 25 30 35 40 45. 50 75 . 100 125 150 175 200 '250 300 350 400 500 600 800 1000 H 1.5 6.0 14.0 25.0 H 0.5 2.0 5.0 9.0 13.5 19.5 Approx. Pressure Loss Through Meters, SLb per q In. ' - Pipe Size (In.) ' 1 1M 2 ' 3 0.2 1.0 2.0 3.5 0.2 0:6 1.0 0.2 . 0.4 . 4' 6 5.5 8.0 11.0 14.0 1.5 2.0 3.0 4.0 . 0.6 0.9 1.0 1.5 18.0 22.0 5.0 . 6.0 14.0 25.0 2.0 2.5 5.5 10.0 0.7 1.5 2.8 1.0 15.0 22.0 4.0 6.0 8.0 10.4 1.5 2.2 3.0 4.0 1.0 16.0 23.0 1.5 2.2 3.0 4.0 6.5 9.0 16.0 25.0 S orMinimum izb Sebvice Recommended Sate Maximum Delivery op Metres Rate or Flow Gpm 1-20 20-30 30-50 50-100 100-150 Approx. Minimum Pipe Size or Service, Main to Meter (In.) Maximum Length (Ft) 30 75 100 150 200 Meter Size In. Ye Yd 1 i 1 Ys .H Y l 1 ia IA 1 l m m ia .1A \A 2 m ia 2 2 2 3 5 ia 2 2 IA VA 8 Capacity, Gpm Based on 25 Lb Loss Thbouge Meteh 20 34 53 100 160 315 500 1000 Pressure loss through compound and current meters are less than shown in table. Forexact information consult manufacturers. . ' - 805 *1 Heating Ventilating Air Conditioning Guide 1939 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 pneuniitic 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 means that if the total equivalent run to the farthest top fixtures supplied is 300 ft, the drop per 100 ft should not exceed * ^onri or 0-33 ^ 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? 1 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 1 lb X 100 600 0.16671b. 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 helow 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 806 Chapter 43. Water Supply Piping and Water Heating RATE OF FLOW IN GALLONS PER MINUTE Fig. 3. Chart Giving Pressure Drop for Various Rates of Flow of Water 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 lo_+ 4.'! lb -- 5.3 lb which, divided by the 600 ft equivalent run gives a drop per 100 ft of 5.3 X 100 600 = 0.9 lb 807 Heating Ventilating Air Conditioning Guide 1939 Fig. 4. Typical Layout foe Down-Feed System Water Line ------ 1--- House Tank-f' House Supply Fire Reserve __ i 197 ' 197 4* 8th. *- 4W.C.-F.V. 2U.-F.V. ^ Lav. ,, 166 ? 7 th. 4W.C.-F.V. 2U.-F.V. 3 Lav. . 145. 2 6th. ^ 4W.C.-F.V. 2U.-F.V. 3 Lav. 117 2 ,T 5th. 4W.C.-F.V. 2U.-F.V. 3 Lav. ` 9" 25 1` 4th. 10 Lav. 11 lias. 3rd. >- . 8 " -2nd 1 S. S. * 44 1st (I) 1S. S. 255 215 4- 6W.C.-F.V. 4 Lav. 5* ,,,, 211 21* 6W.t-F.V4 Lav. " 196 2F <>w.t-F.v. 4 Lav. 180 2" 6W.C-F.V. 4 Lav. . . 4W.C-F.V. 160 2 2U.-F.V. *3 . 2 4W.C.-F.V. 2U.-F.V. 3Uv` 98: 1? i-at 2W.C.-F.V. IU.-F.V. 1 Lav. 45 if lW.t-F.V. . (2) 122 ri i a a 4- ,2l 2 i as. - 120 t i a a ! 120 . 2` 1S.S. . 3W.C.-F.V. H9 2 1 Lav. _ IS.S. 2" 2 Lav. ,r 3W.C.-F.V. 89 2 1 Lav. i4 is. a (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 * . 2qq------ = 2.7 lb per 100 ft. This gives 6 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 fixtures noted on each floor. First this will be solved for a down-feed arrange-: ment assuming that the level of the water in the house 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. 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 6tb 7th 8th Fixtures on Floor 1 S. S. 1 S. S. 1 S. S. 10 Lav. 4 W. C. 2 U. . 3 Lav. 4 W. C. 2 U. 3 Lav. 4 W. C. 2 U. 3 Lav. 4 W. C. 2 U. 3 Lav. Gpm PER Fixture 4 4 4 3 45 30 3 45 : 30 3 45 30 3 45 30 3 Maximum Gpm on Floor Maximum Gpm ON Riser Probable Use (per 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 9 249 291 40 117 30 180 60 9 249 540 27 145 30 180 60 9 249. 789 21 166 30 180 60 9 249 1038 19 197 2 Pipe Size In. H 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 Risers Nos. 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 ft. 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. Heating Ventilating. , Air Conditioning Guide 1939 Table 6. Typical Calculation of Pipe Sizes on Down-Feed Riser with Flush Valve Water-Closets and Urinals (Riser. No. 8. Fig. 4) ' Floor of Bldg. Fixtures . ON Floor 1st 1 W. C. Gpm PER Fixture 45 Maximum Gpm . ON Floor Maximum Gpm on Riser Probable Use (per cent) Probable Demand Riser Gpm Allowable Drop Lb per 100 Ft 45 45 100 45 30 2nd . . 2 W. C. 1 U. . 1 Lav. .45. . . 30 .3 ... ., 90 30 3 123 168 58 98 . 30 3rd ... 4 W. C. 2 U. 3 Lav. . 45 ... 30 3 .180 60 9 249 417- 31 130 30 4th 5th 4 W. C. 2 U. 3 Lav. 45 30 3 6 W. C. 4 Lav. 45 3 180 60 9 249 27012 282 666 948 24 ; 19 160 . 180" 30 30 6th * . .V 7th 6 W. C. 4 Lav. 6 W. C. 4 Lav. 45 3 45 3 270 12 282 270 12 282 .1230____ 1512 16 .. 196 14 211 .30 30 8th 6W.C, 4 Lav. 45 3 270-12 282 1794 12 215 2 Pipe Size In. IK ..IK. 2 2 2 2K 2K 4. Then the allowable drop per 100 ft will be ^5-6 = 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 flow 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 810 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. 3. Fig. 4) Floor of Bldg. 1st 2nd 3rd 4th 5th 6th 7th 8th Fixtures on Floor 1 S. S. 3 W. C. 1 Lav. 2 Lav. 3 W. C. 1 Lav. 1 S. S. 1 S. S. 1 S. S. 1 S. S. 1 S. S. Gpm PER Fixture 4 45 3 3 45 3 4 4 4 4 4 Maximum Gpm on Floor Maximum Gpm on Riser Probable Use (per cent) Probable Demand Riser Gpm Allowable Drop Lb per 100 Ft 4 4 100 4 30 135 3 138 142 63 89 30 6 148 61 90 30 135 3 4 142 290 41 119 30 4 294 - 41 . . 120 30 4 298 40 120 30 4 302 40 121 30 4 306 40 122 2 Pipe . Size In. K IK IK 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 tarrying 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 Probable Gpm 187 255 282 Allowable Drop Lb per 100 Ft 2 2 2 Size of Main In. 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. 811 Heating Ventilating Air Conditioning Guide 1939 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 07 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. Riser No. 1 7th and below 8th 4 W. C. 2 U. 3 Lav. 10 10 3 789 40 20 9 69 858 21 166 20 172 30 . 2 3.3 4 Riser No. S 7th and* below 8th 6 W. C. 4 Lav. 10 3 1512 60 12 72 1594 14 211 14 ,223 30 2M 3.3 4 Riser No. 3 7th and below 8th 1 S. S. 4 302 4 306 40 121 40 122 30 2 3.3 3 . For the second arrangement of hot.water risers (Fig. 76), circulation lines are run back from the last fixture supplied to the main return circulation linein 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 <pp- and down-travel which the hot water must make. In the third and most common arrangement (Fig. 7c) all of the wateris 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 of 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 Riser 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 4 812 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. 2U.-F.V. 8th. 3 Lav. . 4W.G-FV. 24 2U.-FV. i * 3 Lav. 7th. 4W.C.-F.V. 24 2U.-F.V. 3 Lav. 6th. 4W.C.-F.V. 3" 2U.-F.V. t t 3 Lav. 5th. 3` 10 lav. 4th. 3' 1S.S. 3rd. 3' ias. 2nd. 3" 1S.S. 1st 3* 3" Main O) 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 tiie 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 813 Heating Ventilating Air Conditioning Guide 1939 Table 11. Typical Calculation of Pipe Sizes on Up-Feed Riser with Flush Valve Water-Closets and Urinals (See Fig. 5) Floor op Bldg. 8th 7th 6th 6th 4th 3rd 2nd 1st Fixtures ON Floor 4W.C. 2 U. 3 Lav. 4 W. C. 2 U. 3 Lav. 4 W. C. 2 U. 3 Lav. 4 W. C. 2 U. 3 Lav. 10 Lav. 1 s. S. 1 s. s. 1 s. 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 45 180 30 60 39 249 249 44 109 8.5 45 30 3 ..... . 180 60 9 249 498 28 139 8.5 45 180 30 60 39 249 747 22 164 8.5 45 180 30 60 39 249 996 18 179 8.5 3 30 1026 18 185 . 8.5 ......4 , 4 4 1030 , 4 1034 18 186 8.5 18 187 ' 8.5 4 4 1038 18 188 8.5 Pipe . Size In. 2H 2H 3 3 3 3 3 3 Table 12. Suggested Storage Tank Sizes for Homes and Apartments All Yeab Service Based on Boiler Wateh at 180 F Service Drama Hsatinq Season Based on Boilbb Water at 215 F Tank Capacity 30 35 40 50 60 72 80 100 125 150 200 250 300 400 500 . Piping Connections Boiler, In. i IK IK IK IK IK 2 2 2 2 2 2K 2K 3 3 Tank, In. K K K K l l l IK IK IK IK IK IK 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 Tank Capacity 30 40 v 52 66 82 100 120 144 160 200 250 300 400 500 600 Piping Connections Boiler, In. . Tank, In. iK iK iM IK l IK l IK l IK l IK l 2 IK 2 IK 2 IK 2 IK 2K 2 2K 2 3 2K Number of Baths or Families i i i 1-2 2-3 3 -4 5 6 6-7 7-9 9-11 11-15 15-18 18-21 814 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 160 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 water 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 ^ 1+ 1 i! ^1 t1 Supply. I 1 -^ >% . CQL. C3 &a. a. 3 *1 l ^ r*(B W 21 1 | H. \ /' * (a) (c) 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. 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 heatinjg purposes. 815 Heating Ventilating Aik Conditioning Guide 1939 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 Fig. 8. Hot Water Heating Coil Submerged in Storage Tank rating tables. The area of the inside surface of a he.ating coil may be determined from the following equation: where ,, Q X 8.33 (A, - ft) A ~ ~ K0 X An . .. {1) A = surface area of coil, square feet.: Q '= quantity of water heated, gallons per hour. ' j to = hot water outlet temperature, degrees Fahrenheit. A = 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. An is approximately = (A> + A)j , 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 816 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 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 817 Heating Ventilating Air Conditioning Guide 1939 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 ^'^24 ^ = gph but the peak hour will require Mo 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 u 116T capacity without cooling the tank excessively, will be q = 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. 818 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 surface (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. ' ->; v ' 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 =* 100 X 8.33 240 water heated 819 3.48 sq ft per gallon of Heating Ventilating Air Conditioning Guide 1939 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 60 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 are 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 Ttpso? Buildxnq Lavatories Private PubDo Batbs Showers Slop Sinks Kitchen Pantbt Sinks Sinks Foot Baths Wash Trats Av. Max. Use* Maximum Probable gph 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 25 75 50 67 100 100 100 67 67 ,. . _10_0 25 100 80 60 80 25 75 50 33 67 67 100 25 80 45 25 25 25 25 25 100 50 33 100 150 100 100 67 100 33 75 50 150 150 100 50 67 67 .... _ 100 _--_... 25 100 ..8.0. 100 70 90 100 __ ____ __ 20 100 25 25 75 50 33 100 50 33 67 33 50 . 50 100 50 ..6.0 50 25 25 100 100 100 07 67 100 100 80 75 Percentage of fixtures likely to be demanding maximum probable usage at any one time. 820 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. 1 inn non y 2 With a turnover ratio of twice in 24 hr, the heating capacity is: = 8333 gal per hour. The steam consumption would be: X 8970^ ~ ^ = 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 , Ttpb or Building Conditions Gallons -. Hotels Buildings Industrial Buildings Restaurants 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) Public bath or lavatory Public shower Public lavatory with attendant 150 (per day per fixture) 200 (per day per fixture) 200 (per day per fixture) Per office employee Per factory employee Cleaning floors 2 (per day) 5 (per day) 3 (per 1000 sq ft per day) $0.50 Meals $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) 821 rrT55? Heating Ventilating Air Conditioning Guide 1939 PROBLEMS IN PRACTICE - 1 9 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 - + = 100 [ISO - m+M] Q = 28.98 gal per hour, capacity of heater using water at a temperature of 180 F. 2 9 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 9 What is the purpose of zoning water supply systems in tall buildings? To avoid excessive pressures in the lower stories.. - : 4 9 Offing thft madmnm possible flow, the maximum probable flow, and the average probable flow. s ` V. 1 . 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 js 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 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 What methods of hot water circulation commonly are employed with hot water supply systems? o. Up-feed risers with returns having no connections paralleling the risers. b. Up-feed risers with returns in other locations, arid 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 O Which method of hot water supply generally is the most satisfactory? The single main up-feed riser supplying drop risers for all fixtures. 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 O 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. ............ 822 Chapter 44 TEST METHODS AND INSTRUMENTS Pressure Measurement, Temperature Measurement, Air Movemerit. 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 854 and 855. 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. 823 Heating Ventilating Air Conditioning Guide 1939 The following equation may be used to make corrections for temperature: h = fe, [I - 0.000101 (I, - <)] (1) where h = height of mercury column corrected to temperature /, inches. hi = actual height of mercury column, inches. ' t\ = 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 lube. 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 1 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 commercial forms may be used. . A gage which indicates pressures slightly abpve 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 manometers2 are available for the measurement of small pressure differen- `Fluid Velocity and Pressure, by J. R. Pannell (Edward Arnold and Co., London. 1924). 'Illinois Micromanometer, University of Illinois (Engineering Experiment Station Bulletin No. 120, p. 91). 824 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 1C = 0.00009 D (t, - (,). 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. (, = temperature of exposed mercury stem, degrees Fahrenheit. (2) Thermocouples* may be used to measure any range of temperatures up to 2900 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- A.S.H.V.E. Research Report No. 943--Study of the Application of Thermocouples to the Measure* ment of Wall Surface Temperatures, by A. P. Kratz and E. L. Broderick (A.S.H.V.B. Transactions, Vol. 39. 1933. p. 55). 825 *|PiiP51P Heating Ventilating Air Conditioning .Guide 1939 nected in series are called thermopiles. Thermocouples for the:measurement 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 pjatinum,.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. Themercurial 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 a concave^mirror or Tens-' .A sensitive galvanometer or potentiometer with "a'calibrated1 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). Thermoelectric pyrometers operate on the same principle . as thermocouples. - When measuring high temperatures; it is custorhaiy to hold the cold junction at-room temperature and this may cause somb 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 rice 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 exercisecl 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 sourcesuch 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.ope degree graduations. No ten degrees should `occupy a space of less than one-half, inch. The accuracy throughout the whole.scale must be within orie-half degree. The operator should take hold of the top and no part of the body, including the hand, should be nearer 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. : 1 ` . .; For measuring dUct temperatures a duct thermometer should be used,, with , the: bulb extending into the duel 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, acork 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 niay be given to temperature stratification. Other forms of 826 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 quantity, 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 als6 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 ... -. ..... . This usually consists of two tubes, one within the ether, which when properly held in the air stream will register the total or impact pressure and the static pressure, respectively. If these7 tubes are connected to opposite sides of a draft gage, or other type of U tube, the recorded presr 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 afe 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 Centrifugal and Axial Fans.4 .:. For precise work the shape, size and calibration of the Pitot tube are important considerations in the determination of the correct air flqw: r Vl. 29, 1923, p. 407. Amended June, 1931. Alao'see Standard Test Code for Centrifugal and Axial Fans. Ed tion of 19R8. ... ,. . ,rw. 827 Heating Ventilating Air Conditioning Guide 1939 Extensive test results comparing the characteristics of several Pitot tube types are available in the published reports6 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 Laboratory6. 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 cfm = CV A + 2 a or CVA (1 2 + p) (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. 546. National Advisory Committee tor Aeronautics, November. 1935. A S.H.V.E. Research Report No. 966--Measurement of the Flow of Air Through Registers and Grilles, by L. E. Davies (A.S.H.V.E. Transactions. Vo!. 36. 1930, p. 201. Vol. 37. 1931, p. 619. and Vol. 39. 1933, p. 373). 828 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 0.873 for all usual velocities7. 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 tdie 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 hjgh 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. 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 tem perature. Especially at low velocities it constitutes a useful instrument for readily detecting drafts. W Research Paper--The Flow of Air Through Exhaust Grilles, by A. M. Greene. Jr. and M. H. Dean (A.S.H.V.E. Journal Section, Heating, Piping and Air Conditioning, September, 1938, p. 619). 829 Heating Ventilating Air Conditioning Guide 1939 The instrument is essentially an alcohol thermometer with a bulb approximately 54 in- in diameter and x/i 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 tern- 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. Alt traces of. moisture must be removed from the dry Kata, before timing to eli'rtiinate error, introduced by evaporation. : V *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 arid 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 theNwick must still be moist. Standard psychrometric tables should be used8. 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 iriust.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; J. S. Department of Agriculture, Weather Bureau. Washington, D. Cl ' . 830 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 pf the duct, with two bulbs extendiftg; into the duct, Will be found very convenient. Owing to the velocity of the1 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 teinperatures, and others recording relative humidity directly. Any form of wetr 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 fpni is usually recommended but Velocities from 300 to 1000 fpm have been found suitable urider favorable conditions9. For .extremely low humidities, or for hurriidity rneasurements above 212 F, a thermal conductivity method is available10, . CARBON DIOXIDE DETERMINATION11 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 carbon 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 investiga tions. The principle involved is the measurement of a given volume of 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 Stafidard Methods for Examination of Air, American Public Health Asso ciation, Vol. 7, No. 1; American Journal of~ Public Health, Jan., 1917.) A "thermal cpridrictivity method may also be used to measure carbon dioxide in air over a range of 0 to 1.5 per cent12. ; ; , Where field conditions are such that this apparatus may riot 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 __________ . pp. 528-30). ----------- ---- W. . -. -r VOl. 0, 1NO. O, AUgUSt, lyiW, . . / .. . . lsGas Analysis by Measurement of Thermal Conductivity, by H. A. Dayned (CtAridgc. Press, 1933). nA.S.H.V.E. Research Report No. 959--Indices of Air Changes and'Air Distribution, by F..C. Hough* ten and J. L. Biackshaw (A.S.H.V.E. Transactions, Vol. 39, 1933, p; 261). . Loc. Cit. Note i0. .. ' 831 Heating Ventilating Air Conditioning Guide 1939 dust-counter, using a microscope, the impinger13, using chemical changes in water, and the Lewis sampling tube14, 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 code18 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 C0%. 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 of gas. The burette is connected by a manifold of glass to pipettes con taining liquids for absorbing COt, 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, If. 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. 277). UA.S.H.V.E. Standard Code for Testing and Rating Air Cleaning Devices Used in General Vehlilation Work (A.S.H.V.E. Transactions, Vol. 39, 1933, p. 225). '* 832 ' 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 Ringelmanfi 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 fluegas 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 notr 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-boxls and the guarded hot-plate17. 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-plate 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, p. 253), and Report of the Committee on Heat Transmission, National Research Council. "A.S.H.V.E. Research Report No. 685--Measuring Heat Transmission in Building Structures and a Heat Transmission Meter, by P. Nicholls (A.S.H.V.E. Transactions, Vol. 30, 1924. p. 65). 833 - 1939Heating Ventilating Air Conditioning Guide ,; 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 fl- 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? -.. ` . 1 . .- . : '-- - Substitute in-Equation; 1. h. -- 29.51 [1. 0.900191.(91 -- 32)}. . : , .ft; - 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. 6C 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 hot taken at the right time. .- '. - - : : 8 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. 834 Chapter 45 TERMINOLOGY Glossary of Physical and Heating, Ventilating and Air Conditioning 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. . , r: ' Acceleration: The rate of change of velocity. In the fps system this is expressed in units of one foot per second per second. . .. . V' ., . - . .... ., .; ' . 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- qr^ loss jpf. heat:. \Vheri a substance undergoes adiabatic expansion, since it does hot 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. ' . ;- . .... Air 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 Cbnditibning: The simujtahepug Control of all ot at least the first three of those factors affecting both the physical and chemical conditions of .the' atmosphere within any structure.' - These factbrsincludetempera- ture, humidity, motiondistribution, dust, bactefiay' odors, tokic gases, and ' ionization, - most of which affect in'greater" or lesser degree human health or comfort. ' '... '. , r v:.;: t.v. Air Washer i An enclosiife irF'Whicfipair; i4 forced . through .'a spray of water in order to cleanse, humidify, .'or dehurtiidify the' air: l; :: .Anemometer:' An instrument; for? meastiringithe velocity rot moving air* . -' - . i; '835 Heating Ventilating Air Conditioning Guide 1939 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 *s"jgQ f the 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 = 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 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 Chapter 21). Chimney Effect: The tendency in a duct or other vertical air passage fqr 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 wail, 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. 836 Chapter 45. Terminology 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 the resulting device is sometimes referred to as a concealed radiator. (See also definition of Radiator). (See also Chapter 14). . 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 foot, d = . 837 Heating Ventilating Air Conditioning Guide 1939 Dew-Point Temperature: The temperature corresponding to satura tion (100 per cent relative humidity) for a given moisture content. 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! (Top Outlet Enclosure):. The height of a gravity convectorbetween the bottom of the heating unit and the top of the enclosure. ' Drip: A pipe, or a steam trap and a.pipe, considered as a 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.spme water vapor included in air, and such water vapor, being a gas, is dry. .; , 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.'. .v..::/:; i i :.; ' U/' v:- `.-.r ; . , Effective Temperature': An arbitrary index of the degree of warmth'; or cold felt by the human body in response to temperature; humidity,f and movement of the air. - Effective temperature is a composite index which combines the' readirigs tof temperature, humidity, arid air: motion into a single value. .The'numerical , value ofixt-he' effective'itemperature: spale.has been fixed iby the/temperatute jol satilratetlgi? which .induces an identical sensation of warmth. -V; . Enthalpy: Total heat or thermal potential. ' ...... . ' 838' V I | . l ' \ : ; ; 1 , : , : ' ` r Chapter .45. Terminology. -r- Entropy: ..- A ratio, evaluated for practical purposes by dividingthe 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 peri hour, if it received feed water at 212 F and 2vaporized. it at the same temperature and atmospheric pressure. ' ,-s-v. ' Estimated Design Load: The load,-stated in Btu per hour or equiv alent direct radiation, as estimated by the purchaser for the conditions pf 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 actually installed plus the allowance for the heat'loss of the connecting piping plus the heat requirement for any apparatus reqnmng heat con nected with the system. (A.S.H.V.E. Standard Code for Rating Steam Heating Sblid Fuel Hand-Fired Boilers---edition of' April 1932). .2 1 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 maximum 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. Fan Furnace System: See Warm Air Heating System. force: The action on a body which tends to change its relative con di.ti.on as to rest or moti.on. F -- -W---V--. , _ 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 horizontal- return tubular boilers and water-tube boilers is the cubicalcontents 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 waste- heat 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 839 1939Heating Ventilating Air Conditioning Guide 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. 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). 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 Healing 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. Humidistat: A regulatory device, actuated by changes in humidity, used for the control of humidity. Humidity: Thewater 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 840 45.Chapter Terminology 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. 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. 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 energyof 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. m -- --W . -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 m 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. ' 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 boiler in the same circuit. 1These symbols were approved by the A.S.H.V.E., June. 1933. 841 1 Heating Ventilating Air Conditioning Guide 1939 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. . 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 thait.the heating process takes place mainly,by radiation from the wall, floor or ceiling surfaces to the objects in the room. 1 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. Psychro: metry: 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. , ' Relative Humidity: See,1 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 hea.ting units is returned along paths arranged so that all circuits composing the system or composing a major sub-division of the system are practically of equal length. ,, 842 Chapter 45. Terminology Roof Ventilator: A device placed on the roof of a building to facilitate 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. Smokeless Arch: An inverted baffle placed in an up-draft furnace toward the rear to aid in mixing the gases of combustion and thereby to reduce the smoke produced. 1; 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 = --j- = -==. - a- W 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 and 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 above1 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 vapbr tvhich 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 yapor.^.:Steam in: contact with the waiterdront which it has ibeen generated may be .dry.`saturated. steam";c>r.'.sitek:saturated',steam*. ' Thedatter. contains more or. less actual water in the form of mist. If steam is heated, and the pressure'maim: taiped.'the same as- when, it was vaporized, its temperature wilj.lncrease and it wi.ffcbecoine superheated, .i'f ; V.' , r` . Steam,Heating System: A. heating system'd.n^whichj.heat is -trjans; . 843 Heating Ventilating Air Conditioning Guide 1939 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. 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. Therm: Symbol used in the gas industry representing 100,000 Btu. Thermal Resistance: The reciprocal of conductance. Thermal Resistivity: The reciprocal of conductivity. 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 or radial pressure and the velocity pressure at the point of measurement. 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. 844 Chapter 45. Terminology 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, 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 V.ent Vapor System: A vapor heating system with air valves which do not permit re-entry of air. Vapor Pressure: Thg 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 the fps system it is expressed in units of one foot per second. V -- -j. Velocity Pressure: The pressure corresponding to the velocity of flow. It is a measure of the lanetic 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-burping 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 fan 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). 845 Heating Ventilating Air Conditioning Guide 1939 ABBREVIATIONS2 Absolute................................-___--*................................. Acceleration, due to gravity____ ................................. Acceleration, linear-________________ -................--....... Air horsepower.......................... ........ ............................... Alternating-current (as adjective)-..... ............. ......... Ampere._________ ____ ------------- -------------------------------- Ampere-hour....... ....................... -........................ -.......... Area_____;..... ................................................................ -- Atmosphere........ ........ ............. .........-------------------------- Average............. .................-........................ i.................... Avoirdupois: .................................... v.............. ---- Barometer.;.................. ....................................................... Boiler pressure-.......-1_____ --.................................-...... Boiling point.__________ ..................... r.--;------------------ Brake horsepower..........-........... ......... :-- -------- --- Brake horsepower-hour....... ..................................... British thermal unit.................. .---------................ Calorie_____ --____-____________ --J............ ......-- Centigram.....--............... .-------------------- ....................... Centimeter___:............................................ ......... ............ Centi meter-gram-second (system) ___ _-................. Change in.specific volume during vaporization:-- Cubic............................................ ..--....... ....................... : Cubic foot________ --..--................................... -- Cubic feet per minute................... 1--............ - Cubic feet per second....................--'-.................. -- Decibel :.i-7.1'^....................................... ....................-- Degree*................ ............................................. .................. Degree centigrade............. -.....................-..................... Degree Fahrenheit--....................................................... Degree Kelvin............................................. .................... Degree Reaumur:.---.. :____ --: ---- ........ Density, Weight per unit volume, Specific weight.. abs ----------- g .....___ a __air hp __ --a-c ,,....amp ..amp-hr ......A ____ atm -------------avg i...... i....avdp .......... ....bar. ........ bp --------- bp _____ --bhp .......,,bhp-hr ...______ Btu .....___--cal ------ eg __________l.,cm ........ ---cgs --------- Pfg ___ __________cu __________ .___ ;.CU ft ____ cfm cfs ...--:l.db .deg or ,............. ,,-.F ................... K ;..R ..d or p (rho) v. Diameter.....------- ;........... ......................-----......-----.......... or diam Direct-current (as adjective)..............:...............................-....... --,---------------- r-V---------- .....d-c Distance, linear................................ ......................................---,-r-------...------ *.*----- --------------------s Dry saturated vapor,' Dry saturated gas at saturation pressure and temperature, Vapor in contact: with;liquid........u-------script:g Entropy (The capital should, fee usedior any weight, and the small letter for unit . weight).---........................................ ............................................. S.or s Feet per minute-U^.-V--..-:.-...-........-------------------------- ------ :.:--fpm Feet per second-..:.:...U..------:---v.l..v:--.-.....1........................ -------i----------fps Fopt-pound*...-.--.....'.---.................. -...........--....... --------------------- ft"lb Fppt^pound-s^ond'Xsystem),..-......... Force, total ibad-.-i.i-....'.--::,.......v-.:'--............................ Freezing point--.:.ir.,,.l..j.i,.,,;...:...L--..:.:...i-::..:...-.L..L.....-'.---.:l'....:-j-:.r.->----::........fp . Gallons per minute.................................................................................... ----............ Gallons per second. ......-- ..............-.................................... --.........-^ps Gram^caforie.......a:^ -jI ----............................................................... Ig-iCal _________ is. v` . .V'v ..r'4 -"s^From cdmpilatibnsrdf abbreviations approved by the American Standards Association, 2,-10 a," c, f, and i/ As a general rule, the period .is? omitted in all.abbreviations except wbpre :;the omission results .in. the formation of an-English'word; rj':.'`V'* " /'--, V is recommended that the abbreviation for the-tehiperature scale.- F, 'C; K; be included in expressions for numerical temperatures but, wherever feasible, the abbreviation for degree bejomitted^as 68 F. j ^ ' Chapter 45. Terminology Head- ..H or h Heat content, Total heat,. Enthalpy. (The capital should be used for any weight and the small letter for unit weight). ..H or h Heat content of saturated liquid, Total heat of saturated liquid, Enthalpy of saturated liquid, sometimes called heat of the liquid- -hi Heat content of dry saturated vapor, Total heat of xiry saturated vapor, Enthalpy of dry saturated vapor. Heat of vaporization at constant pressure.__ h% ___ L or Afg Horsepower--...............................:-------------- ------- ------------ hp Horsepower-hour.----.-- ------- ..... __ Jipdir Inch.. Inch-pound _____________________________________ ------------------------------------------------ - in.-lb Indicated horsepower._____________________________ ______ _____________________ ___ '..... ihp Indicated horsepower-hour._____________ ____________ ____ihp-hr Internal energy. Intrinsic energy. (The capital should be used for any weight and the small letter for unit weight)---__________________________________________ U or u Kilowatt'-i.;......---------------i -----.-a-- ----------------- ------ ---------- _i_. kw Kilowatthoiir--J----------------------- ----------------1...............-__ --......... --____.:....................kwhr Length of path of heat flow, thickness......... ..................... ,.... ,,_.._L Load, totalsIS.________ _____ ____________-________ _____________ ......______________ ..... W Mass._____ ___ ____________ __ _____ _______..... ......................... 1.1,,.,,________________ _______m Mechanical efficiency________________________ em Mechanical equivalent of heat:___________ ;.....:.......... ....................................................... ..........7 Melting point________________________ _________ _____ _______ mp Meter__________________________________r____ ...................................-..........................................m Micron....................... (mu) Miles per.hour.______________________________ a.,,--__ -mph _ Minute...... ..............--................... ..................... .................................... .................... ....................min Molecular weight---________________________ ____ ___--..............:_______________ __ mol. wt Ounce_____ _______________________________________ oz Power, Horsepower, Work per unit time.:.----_____:; ............................ ........ JP Pressure, Absolute pressure,. Gage pressure, Force per unit area______________ ________ p Quantity (total) of fluid, water, gas, heat; Quantity by volume; Total quantity of heat transferred........... ~ Quality of steam. Pounds of dry steam per pound of mixture....................................... Revolutions per minute______ __________________ ___________ ___________ -..... ........ ........ ..rpm Saturated liquid at saturation pressure and temperature, Liquid in contact with vapor-........................ ................... ......................................... ....... .................Subscript f Specific gravity............. ,___________ ___________ --________ ..._____________ sp gr Specific, heat--*...... ..................................................................... ........ sp ht or c Specific heat at constant pressure..^____ __ ___________________________ __ ________.cp Specific heat at constant volume........ a--_______ ___ ....._____________ cv Specific volume, Volume per unit weight, Volume per unit mass.- ____--.r Square foot..____ .....................________ _________________________ ___ .....sq ft Square inch......................... .......... ...................... ........... ....... ..................-..... --_____sq in. Temperature (ordinary). F or C. (Theta is used preferably only when t is used for, : .Time in the same discussion)--.--_____________ _____________ ...__J.____ i or 0 {theta) Temperature (absolute) F abs or K. (Capital theta is used preferably only when small theta is used for ordinary temperature)._________________ T or {capital theta) Thermal conductance4 (heat transferred per unit time per degree),__ ;__________________C kA c = 1r = L h - h Thermal conductance per unit area,-Unit conductance (heat transferred per unit time per unit area per degree) .....______ _____ ______ :__________________ _ ...Ca ... : .. . __C 1 . . A , KA :q A(t, -/,) k L d ,. . Terms ending ivity designate'properties independent of size or shape, sometimes caW^Aspecific proper ties. Examples are--vonductivHy and resistivity. Terms ending ancc designate quantities depending not ontyvoq .the, material. hut: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. 847 Heating Ventilating Air Conditioning Guide 1939 Thermal conductivity (heat transferred per unit time per unit area, and per degree per unit length)k JL h __ --__ * . -1.) L . 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)_______________________________________________________________________--./ _9 A / 11 - f. (In general / is not equal to k/L, where L 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)---------------------- :.--....U 9 Thermal transmission (heat transferred per unit time)-................................ -................-.....q Thermal resistance (degrees per unit of heat transferred per unit time)................... ....... R Thermal resistivity.. Jl/k Vaporization values at constant pressure, Differences between values for saturated vapor and saturated liquid at the same pressure------------------------------------- Subscript fg Velocity.~~ V Volume (total)_______________________________________________ __________________ _______ V Volume per unit time, Rate at which quantity of material passes through a machine, Quantity of heat per unit time, Quantity of heat per unit weight---------- q Watt.. Watthour.. Weight of a major item, Total weight____________________________ ..whr __W Weight rate, Weight per unit of power, Weight per unit of time.. Work (total) ..W 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. . . Absolute temperature, expressed in centigrade degrees = centigrade degrees + 273.1. 1 848 Chapter 4S. .Terminology Power, Heat and Work i 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 ; Weight and'Volume lgal(U.S.) 1 British or Imperial gallon 1 cu ft l eu 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 (avdp) 1 bushel 1 short ton 1 long ton Pressure 1 lb per square inch 1 oz per square inch = (12,000 Btu per hour \200 Btu per minute = 143.33 Btu per pound ( 777.5 ft-lb =3 0.293 whr L 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 . 34.16 lb water raised 100 F 0.003968 Btu 3.085 ft-lb . 0.0011619 whr 1.3405 hp - 56.92 Btu per minute 44,252.7 ft-lb per minute - 0.746 kw = . 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 f 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 f 16 oz . \ 7000 grains = 1.244 cu ft = 20001b = 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 l 1.732 in. water at 62 F : v.:;. " Heating Ventilating Air Conditioning Guide 1939 1 atmosphere 1 in. water at 62 F ... . - - - , : \ i 1 ft water at 62 F . . . > 1 in. mercury' at 62 F Metric Units . . '; 1 cm' ` 1 in. 1m 1 ft l 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 ; 1 gram per square centimeter:. 1 kg per square centimeter (metric atmosphere) 1 gram per cubic centimeter " ' 1 dyne . 1 joule 1 metric horsepower ., ... 1 kilogram-calorie (large calorie) 1 kilogram-calorie per kilogram 1 gram-calorie per square centimeter 1 gram-calorie per square centimeter per centi meter " , V ' 1 gram-calorie per second per square centimeter for a temperature graduation of 1 deg C per centimeter ... ; 850 14.7 lb per square inch 2116.3 lb per square foot 33.974 ft water at 62 F 30 in. mercury at 62 F 29.921 in. mercury at 32 F : : ( 0.03609 lb per square inch | 0.5774 oz per square inch . . ( 5.196 lb per square foot ` ' " ' I 0.433 lb per square inch \ 62.355 lb per square foot 0.491 lb per square inch ' 7.86 oz per square inch 1.131 ft water at 62 F 13.57 in. water at 62 F '' 0.3937 in. 2.54 cm 3.281 ft 0.3048 m 0.155 sq in. . - 6.45 sq cm 10.765 sq ft 0.0929 sqm ...... : , 0.061 cu in. 16.39 cu cm 35.32 cu ft . ! -utKoci : 0.0283 cu m 1000 cu cm = 0.264 gal ......... 2.2046 lb ' ' " 0.4536 kg . : ,: 2205 lb (avdp) 980.59 dynes r= 0.002205 lb ` ' 0.6214 mph . iS . ! / 0.0290 in. mercury, at 0 deg C \ 0.394 in. water, at 15-C ' 14.22 lb per square inch1 ? > V f 0.03614 lb per cubic inch. : \ 62.43 lb per.cubic. foot ........ r 0.00007233 poundals / 10,000,000 ergs 10.73767 ft-lb v^ .. / 75 kg-m per second \ 0.986 hp (U. S.) - - 1000 gram-calories (small calorie) 3.97 Btu : 1.8 Btu per pound . . .. ... 3.687 Btu per square foot 1.451 Btu per square foot per inch ' (2903 Btu per hour per square foot | for a temperature graduation of l 1 deg F per inch of thickness. Chapter 45. Terminology SYMBOLS FOR HEATING. VENTILATING AND AIR CONDITIONING DRAWINGS6 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. ' 1. General . Piping ` 6. Air Piping ----- *------ *----- `------ `------ Piping 7. Vacuum ___ ______ _____------------ Piping ~, ' 3. Condensate Piping 4. Cold Water Piping 8. Gas Piping --------- -------------------------- 9. Refrigerant ,' Piping------ +--+---- 1-------+ -- 5. Hot Water . Piping - ' 10. Oil Piping _ .11. Lock and Shield Valve . 12. Reducing Valve . -op. 13. Diaphragm Valve 1 14. Thermostat 15. Radiator Trap Elevation 16. Radiator Trap Plan 17. Tube Radiator Plan H<8> C=3 18. Tube Radiator Elevation 19. Wall Radiator Plan PP = 20. Wall Radiator Elevation 21. Pipe Coil Plan DO 22. Pipe Coil Elevation 23. Indirect Radiator Plan ; : I; n ~ 24. Indirect Radiator - tv ~>i pi Elevation U_^l bl 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 0 0 A-I.L * 30. Vanes 31. Air Supply Outlet, 32. Exhaust Inlet , ~r , 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, Z14.2--1935). 851 Heating Ventilating Air Conditioning Guide 1939 33. Joint 34. Elbow--90 deg 35. Elbow--45 deg 36. Elbow--Turned Up rumii Screwed Bd and Spigot Welded Soldered -6-Hf- --f-- oo -o- r4 4r /f $ ( G>H-- Of-- QH- OX- G>-- 37. Elbow--Turned Down 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 60. Side Outlet Tee--Outlet Down 51. Cross <3 >-OB-- Of-- h G*-- o- 4 rf*rr 4 4 i. X-ff-^fb X+fl- X-tb^ff4r x X JL-fib -A- -Job -BOB- (r-*Oe fO -O* -BOB- -fOb -*G* -o- -ffiff- -4b -If4tt-H^fb X 4 4 852 Chapter 43. Terminology 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. Stop Cock 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 853 Heating Ventilating Air Conditioning Guide 1939 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 . Title . When Adopted Reference Air Cleaning Devices Air Conditioning A.S.H.V.E. Standard Code for Testing and Rating Air Clean ing Devices Used in General Ventilation Worka . Code of .Minimum Require ments for Comfort Air Con- ditioning3 ? Boilers (testing) Standard and Short-Form Heat Balance Codes for Testing LowPressure Steam Heating Solid Fuel Boilers (Codes 1 and 2)a Boilers (testing) A.S.H.V.E. Performance Test Code for Steam Heating Solid Fuel Boilers (Code 3)a b Boilers--Oil Fuel (testing) A.S.H.V.E. Standard Code for Testing Steam Heating Boilers ' Burning Oil Fuela Boilers A.S.H.V.E. Standard Code for Stoker-Fired Testing Stoker-Fired Steam (testing) , Heating Boilers3 Boilers (rating) A.S.H.V.E. Standard Code for Rating Steam Heating. Solid Fuel Hand-Fired Boiiers3 Concealed Gravity Type Radiation A.S.H.V.E. Standard Code for Testing and Rating Concealed Gravity Type Radiation (Hot Water Section)3 Convectors A.S.H.V.E. Standard Code for Testing and Rating Concealed Gravity Type Radiation (Steam Code)3 Ethics Code of Ethics for Engineers June, 1933 A.S.H.V.E. Transactions, Vol. 39, 1933, p. 225 January, 1938 A.S.H.V:E. Reprint June, 1929 A.S.H.V.E. Transactions, Vol. 35, 1929, p. 322 June, 1929 June, 1932 A.S.H.V.E. Transactions, Vol. 35, 1929, p. 332 a.s:h.v.e: Transactions, Vol. 37, 1931, p. 23 January, 1938 A.S.H.V.E. Reprint, January, 1929 Revised .. April, 1930 A.S.H.V.E. Transactions, Vol. 36, 1930, p. 42 June, 1933 . ... Revised January, 1935 A.S.H.V.E.' Transactions, . Vol. 39, 1933, p. 237 January, 1931 A.S.H.V.E. Revised ' Transactions, January, 1935 Vol. 37,1931, p. 367 January, 1922 A.S.H.V.E. Transactions, Vol. 28, 1922, p. 6 (See frontispiece The Guide, 1939) Fans Standard Test Code for Cen trifugal and Axial Fans3 1.938 Edition A.S.H.V.E. Reprint0 . aReprints available. - ' bOriginally adopted by the National Boiler and Radiator Manufacturers Association. eSee A.S.H.V.E. Transactions. Vol. 29. 1923. p. 407; Vol. 37. 1931. p. 363. 854 Chapter 45.. Terminology Subject . Title ....................... . When Adopted Garages ' .Code for .Heating and Ven-. . tilating Garages June, 1929 Revised .January, 1935 Heat Transmission Through Walls Standard Test. Code for Heat Transmission through Walls3 January; 1927 Reference A.S.H.V.E. Trans actions, Vol. 35, 1929, p. 355 A.S.H.V.E. Reprint A.S.H.V.E. Transactions, .'Vol. 34, i928, pi 253 Minimum Requirements Code of Minimum Require . merits for Heating and Ventila- tibn of Buildings, Edition-1929 June, 1925 a.s.h.v:e. Codes Radiators Code for Testing Radiators3 January, 1927 A.S.H.V.E. Transactions, Vol. 33, 1927, p. 18 Unit Heaters Standard Code for Testing and Rating Steam Unit Heaters3 d January, 1930 A.SiH.V.E. . Transactions, Vol. 36, 1930, p. 165 ; Unit Ventilators A.S.H.V.E. Standard Code for Testing and Rating Steam ; Unit Ventilators3 June, 1932 A.S.H.V.E. Transactions, Vol. 38, 1932, p. 25 Vacuum Heating Pumps A.S.H.V.E. Standard Code for Testing and Rating Return Line Low Vacuum Heating Pumps3 June, 1934 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 yENTiLATiNG Engineers : Subject . Title . Sponsored bt . J Reference . Air Standard Method: of Rating Conditioning 'and Testing Air Conditioning Equipment - Equipment3 American Society of Refrigerating ; Engineers;. A merican. Society of Refrigerating Engi neers, New: York, N. Y. . - ` Chimneys Standard Ordinance for Chim- National Board of Chapter 14, f . 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 Air 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 ConditioningA ssociation, Columbus, Ohio ^Adopted jointly by the Industrial Unit Heater Association, and the A.S.H.V.E. . eProposed 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. ' ^Adopted November, Safety Council. 1928, Sponsored by (1) A. meric.a..n....S. ociety o.f Mechan. ical Engine. ers. (2) Natio.nal.. 855 1939Heating Ventilating Air Conditioning Guide Table 1. Circumferences and Areas of Circles Diuona IN Inches Abba. 8q In. Sq Ft `H H 1lIHxx IX 2 2H 2H 2X 3 3X 3X 3X 4. 4X 4H 4X 5 SH 5H 6SH 6K 66Mx 7 1M 7H 7x 8 8X SH 8X 9 vK 9H 9H 10 10H ii 1li2H HX 13 13M 14 . 14H 15 15H 16 16H 17 I7X 18 18H 19 2109H 2210H 2221H 22H 23 ` MX 2U4H 25 2SH 26 26H 27 27X 0.049 0.196 0.442 0.785 1.227 1.767 2.405 3.142 3.976 4.909 5.939 7.069 8.296 9.621 11.04 12.57 14.19 15.90 17.72 19.64 21.65 ' 23.76 25.97 28.27 30.68 33.18 35.79 38.49 41.28 44.18 47.17 50.27 53.46 56.75 60.13 63.62 67.20 70.88 74.66 78.54 86.59 95.03 103.9 113.1 122.7 132.7 143.1 153.9 165.1 176.7 210818..17 213.8 226.9 240.5 254.5 268.8 283.5 298.6 314.2 330.1 346.4 361.1 380.1 397.6 415.5 433.7 452:4 471.4 490.9 510.7 530.9 551.6 572.6 593.9 0.0003 0.0014 0.0031 0.0054 0.0085 0.0123 0.0167 0.0218 0.0276 0.0341 0.0412 0.0491 0.0576 0.0668 0.0767 0.0873 0.0986 0.1104 0.1231 0.1364 0.1504 0.1650 0.1840 0.1964 0.2131 0.2304 0.2486 0.2673 0.2867 0.3068 0.3276 0.3491 6.3713 0 3942 0.4175 0.4418 0.4668 0.4923 0.5185 0.5454 0.6010 0.6600 0.7215 0.7854 0.8520 0.9218 0.9937 1.069 1.146 1.227 1.310 1.396 1.485 1.576 1.670 1.767 1.867 1.969 2.074 2.182 2.293 2.405 2.508 2.640 2.761 2.885 3.012 3.142 3.274 3.409 3.547 3.687 3.832 3.976 4.125 CoctncrEREKCE Inches Feet DUKETEa IN 1 Inches Abba ' Sq In. Sq Ft ClBCTOFEHEKCB Inches Feet 0.785 1.571 2.356 3.142 3.927 4.712 5.498 6.283 7.069 7.854 8.639 190..42215 10.99 11.78 12.57 13.35 14.14 14.92 15.71 16.49 17.28 18.06 18.85 19.64 20.42 21.21 21.99 22.78 23.56 24.35 25.13 25.92 26.70 27.49 28.27 29.06 29.85 30.63 31.42 32.99 34.56 36.13 37.70 39.27 40.84 42.41 43.98 45.55 47.12 48.69 50.27 51.84 53.41 54.98 56.55 58.12 59.69 61.26 62.83 64.40 65.97 67.54 69.12 70.69 72.26 73.83 75.40 76.97 78.54 80.11 81.68 83.25 84.82 86.39 0.0652 1 0.1309 0.1964 0.2618 0.3273 0.3927 0.4582 0.5236 0.5891 0.6546 0.7200 0.7854 0.8510 0.9160 0.9818 1.047 1.113 1.178 1.243 1.309 1.374 1.440 1.505 1.571 1.637 1.702 1.768 1.833 1.899 1.964 2.029 2.094 2.160 2.225 2.291 2.356 2.422 2.488 2.553 2.618 2.750 2.880 3.011 3.142 3 273 3.403 3.535 3.665 3.796 3.927 4.058 4.189 4.321 4.451 4.582 4.712 4.845 4.974 5.105 5.236 5.367 5.498 5.629 5.760 5.891 6.021 6.153 6.283 6.415 6.545 6.676 6.807 6.938 .7.069 7.199 28 28M 29 x 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 07 98 99 100 615.8 4.276 87.97 7.330 637.9 4.430 89.54 7.462 660.52 4.587 91.11 7.592- 683.5 ' 4.747 92.63 7.725 706.8 4.909 94.25 7.854 754.8 5.241 97.39 8.116 804.3 5.585 100.5 8.378 855.3 5.940 103.7 8.639 907.9 6.305 106.8 8.901 962.1 6.681 109.9 9.163 1018.0 7.069 113.1 9.425 1075.0 7.467 116.2 9.686 1134.0 1195.0 7.876 8.296 119.4 122.5 9.948 10.21 1256.0 8.727 125.6 10.47 1320.0 9.168 128.8 10.73 1385.0 9.621 131.9 10.99 1452.0 10.08 135.1 11.26 1521.0 10.56 138.2 11.52 1590.0 11.04 141.4 11.78 1662.0 11.54 144.5 12.04 1735.0 12.05 147.7 12.30 1810.0 12.51 150.8 12.57 1886.0 13.09 1S3.9 12.83 1963.0 13.64 157.1 13.09 2043.0 2124.0 14.19 14.75 160.2 163.4 13.35 13.61 ' 2206.0 15.32 166.5 13.88 2290.0 15.90 169.6 14.14 2376.0 16.50 172.8 14.40 2463.0 17.10 175.9 14.66 2552.0 17.72 179.1 14.92 2642.0 18.35 182.2 15.18 2734.0 18.99 185.4 IS.45 2827.0 19.63 188.5 15.71 2922.0 20.29 191.6 15.97 3019.0 20.97 194.8 16.23 3117.0 3217.0 21.65 22.34 197.9 201.1 16.49 16.76 3318.0 23.04 204.2 17.02 3421.0 23.76 207.3 17.28 3526.0 24.48 210.5 17.S4. 3632.0 25.22 213.6 17.80 3739.0 25.97 216.8 18.06. 3848.0 26.73 219.9 18.33 3959.0 27.49 223.1 18.59 4072.0 28.27 226.2 18.85 4185.0 29.07 229.3 19.11 4301.0 29.87 232.5 19.37 4418.0 30.68 235.6 19.63 4536.0 31.50 238.8 19.90 4657.0 32.34 241.9 20.16 4778.0 . 4902.0 33.18 . 245.0 34.04 248.2 20.42 20.68 5027.0 5153.0 34.91 35.78 251.3 254.5 20.94 21.21 5281.0 36.67 257.6 a 21.47 5411.0 37.57 260.8 21.73 5542.0 38.48 263.9 21.99 5675.0 39.41 267.0 22.25 5809.0 40.34 270.2 22.51 S945.0 41.28 273.3 22.78 6082.0 42.24 276.5 23.04 6221.0 43.20 279.6 23.30 6362.0 44.18 282.7 23.56 6504.0 45.17 285.9 23.82 6648.0 46.16 289.0 24.09 6793.0 47.17 292.2 24.35 6940.0 48.19 295.3 24.61 7088.0 49.22 298.4 24.87 7238.0 50.27 301.6 25.13 7390.0 51.32 304.7 25.39 7543.0 52.38 307.9 25.66 7698.0 53.46 311.0 25.92 7854.0 54.54 314.2 26.18 856 CATALOG DATA GIL Heating, Ventilating Air Conditioning 1939 INDEX TO ADVERTISERS PAGE 859 INDEX TO MODERN EQUIPMENT PAGE 1137  '.V In this Catalog Data Section of The Guide 184 manufacturers describe the most modern types of heating, ventilating and air con ditioning equipment and materials--259 pages of valuable data, profusely illustrated. Alphabetical arrangement of advertisers--on pages 859-864--permits ready reference to the product of a specific manufacturer. . Iy Various types of apparatus and materials are grouped in their respective classes, and may be located -readily by reference to the page headings--Boilers, Heaters, Insulation, Pumps, Valves, etc.--as on pages 865-1134. A classified Index to Modern Equipment--on pages 1137-1160--contains complete listings . of manufacturers whose products are described in the Catalog Data Section. . \ INDEX TO ADVERTISERS Heating Ventilating Air Conditioning Guide, 1939 A Page Acme Heating & Ventilating Co., The, 4224 S. Lowe Ave., Chicago, 111....... .............. 895 Aerofin Corporation, 410 S. Geddes St., Syracuse, N. Y....... .................................. 989-991 Air Conditioning & Oil Heat (a pub.), 232 Madison Ave., New York, N. Y........... 1056 ' Air Controls, Inc., 1937 West 114th St., Cleveland, Ohio................................................. 892 Air-Maze Corporation, 5002 Harvard Ave., Cleveland, Ohio............ -.................... 922--923 Airtemp, Division of Chrysler Corporation, Dayton, Ohio...................... :....... 1___ 896-897 Airtherm Manufacturing Co., 1474 S. Vandeventer, St. Louis, Mo.:............................ 981 Alco Valve Co., Inc., 2626 Big Bend Blvd., Si. Louis, Mo............................................ 1129 Alfol Insulation Company, Incorporated, 155 East 44th St., New York, N. Y....... 1011 Aluminum Aircell Insulation Co., 415 Curtis Bldg., Detroit, Mich....................... 1012 American Air Filter Co., Inc., First St. and Central Ave., Louisville, Ky._....... 924-925 American Artisan (a pub.), 6 N. Michigan Ave., Chicago, 111..... ................................. 1052 American Blower Corporation, Detroit, Mich............................................................. 866-867 American Brass Company, The, Waterbury, Conn..... ..................... .................... 1046-1047 American Coolair Corporation, 3604 Mayflower St., Jacksonville, Fla................ 968-969 American District Steam Company, North Tonawanda, N. Y..... ...................... 966, 1039 American Gas Products, Div. American Radiator Co., 40 West 40th St., New York, N. Y.............................................. ............. ................................ ;........ .. 900, 951 American Moistening Company, Providence, R. 1.............................................................. 865 American Radiator Co., 40 West 40th St., New York, N. Y................898-899, 940-941 American Rolling Mill Co., The, Middletown, Ohio........................................................ 1078 American Society of Refrigerating Engineers, 37 West 39th St., New York, N. Y... 1051 Anderson Products, Inc., Cambridge, Mass............................... _..................................... 1130 Anemostat Corp. of America, 10 East 39th St., New York City, N. Y...-................. 1067 Armstrong Cork Company, Lancaster, Pa.............................................................. 1013 Armstrong Machine Works, 851 Maple St., Three Rivers, Mich...................... 1082-1083 l Auer Register Co., The, 3608 Payne Ave., Cleveland, Ohio.TM............................. . Automatic Heat and Air Conditioning (a pub.), 1900 Prairie Ave., 1068 Chicago,III............................................................................ ,....................... ........... 1054-1055 Autovent Fan & Blower Co., 1809-23 N. Kostner Ave., Chicago, 111....... .................... 970 s, B Babcock & Wilcox Company, The, 85 Liberty St., New York, N. Y...... .............:...... 952 E. B. Badger & Sons Co., 75 Pitts St., Boston, Mass;:..................... ........................... 967 Baker Ice Machine Co., Inc., 1518 Evans St., Omaha, Nebr..... ........ .-............... . 868-869 '4 Barber-Coliiiaii Company, Rockford, 111........................................... .............:...... 1112--1113 Barber Gas Burner Company, The, 3704 Superior'Ave., Cleveland, Ohio.__.............. 901 $x Barnes & Jones, Incorporated, 129 Brookside Ave., Jamaica Plain, Boston, Mass... 1081 859 r Heating Ventilating Air Conditioning Guide 1939 B Page Barrett Co., The, 40 Rector St., New York, N. Y......................................................... 1014 Bayley Blower Company, 1817 South 66th St., Milwaukee, Wis................................. 971 Beaton & Cadwell Mfg. Company, The, New Britain, Conn............................ 1084-1085 Bell & Gossett Company, 3000 Wallace St., Chicago, 111............................................... 999 Bethlehem Steel Company, Bethlehem, Pa...... ............................................................... 1079 Bristol Company, The, Waterbury, Conn........................................................................ 1002 Brownell Company, The, Dayton, Ohio--........................................................................ 1104 Buffalo Forge Company, 450 Broadway, Buffalo, N. Y............................................ ..... 972 Buffalo Pumps, Inc., 450 Broadway, Buffalo, N. Y....................................................... 1061 Burnham Boiler Corporation, Irvington-on-Hudson, N. Y.................................... 942-943 C Carbondale Division, Worthington Pump & Machinery Corp., Harrison, N. J... 890-891 Carey, Philip Co., The, Lockland, Ohio........................................................................... 1020 Carnegie-Illinois Steel Corporation, Pittsburgh, Pa............................J......................... 1080 Carrier Corporation, Syracuse, N. Y............................,,.................................................... 870 Celotex Corporation, The, 919 N. Michigan Ave., Chicago, III........ ............... 1015-1017 Century Electric Company, 1806 Pine St., St. Louis^'Mo............................................ 1043 Chamberlin Metal Weather Strip Co., 1254 Labrosse St., Detroit, Mich 1018-1019 Champion Blower & Forge Co., Lancaster, Pa........ ........................................................ 973 Chicago Pump Company, 2330 Wolfram St., Chicago, 111....... .................................... 1062 Clarage Fan Company, Kalamazoo, Mich.............. ............,,............................................ 871 Cochrane Corporation, 3130 N. 17th St., Philadelphia, Pa.......................................... 1086 Combustion Engineering Company, Inc., 200 Madison Ave., New York, N. Y.... 1105 Cooling Tower Co., Div. of Fluor Corp., Ltd., 15 John St., New York, N. Y.......... 964 Coppus Engineering Corporation, 339 Park Ave., Worcester, Mass............................ 926 Crane Co., 836 S. Michigan Ave., Chicago, 111......................................................... 944-945 Curtis Refrigerating Machine Co., Division of Curtis Manufacuring Co., 1959 Kienlen Ave., St. Louis, Mo................................................................................ 872 D Davies Air Filter Corp., 390 Fourth Ave., New York, N. Y.._..................................... 927 DeBothezat Division American Machine & Metals, Inc., 100 Sixth Ave., New York, N. Y.................................. ................................................................................................ 974 Decatur Pump Co., Decatur, 111........................................................................................ 1063 Delco-Frigidaire Conditioning Division, General Motors Sales Corp., Dayton, Ohio.................................................... .......................................................... ,...... 902-904 Detroit Lubricator Company, Detroit, Mich........................................................ 1114-1115 Detroit Stoker Company, General Motors Bldg., Detroit, Mich................................ 1106 Domestic Engineering (a pub.), 1900 Prairie Ave., Chicago, 111........................ 1054-1055 C. A. Dunham Company, 450 E. Ohio St.f Chicago, 111............................... . 1000-1001 E Eagle-Picher Lead Company, The, Temple Bar Bldg., Cincinnati, Ohio................. 1021 Econ-O-Col Stoker Div., Cotta Transmission Corp., 2342 Eleventh St.; Rockford, I1L....... .......................................... .............................................................. 1107 Ehret Magnesia Manufacturing Co., Valley Forge, Pa.............................. :....... 1022-1023 Excelsior Steel Furnace Co., The, 118 S. Clinton St., Chicago, III--........................... 905 860 . Index to Advertisers F Page Farrar & Trefts Incorporated, Buffalo, N. Y.................................................................... 953 Fedders Manufacturing Co., 57 Tonawanda St., Buffalo, N. Y.................................... 982 Fitzgibbons Boiler Company, Inc., 101 Park Ave., New York, N. Y............ . 954-955 Foster Engineering Co., 114 Monroe St., Newark, N. J.--......................................... 1131 Frick Company (Incorporated), Waynesboro, Pa............................................................ 873 Julien P. Friez & Sons, Div. of Bendix Aviation Corp., Baltimore, Md................... 1118 Fueloil Journal (a pub.), 420 Madison Ave., New York, N. Y................................... 1057 Fulton Sylphon Company, The, Knoxville, Tenn................................................ 1116-1117 G G & O Manufacturing Company, The, 138 Winchester Ave., New Haven, Conn.... 992 Gar Wood Industries, Inc., 7924 Riopelle St., Detroit, Mich............................... 906-907 General Electric Company, Bloomfield, N. J.............................. ............................. 908-909 General Electric Company, Schenectady, N. Y................................................... 1044-1045 General Insulating & Mfg. Company, Alexandria, Ind................................................. 1024 Grinnell Company, Inc., Providence, R. 1...................................................... 993-995, 1087 H William S. Haines & Company, 12th and Buttonwood Sts., Philadelphia, Pa........ 1092 Arthur Harris & Co., 210-218 N. Aberdeen St., Chicago, 111....................................... 1048 Hart & Cooley Manufacturing Co., 61 W. Kinzie St., Chicago, III................. 1070-1071 Heating Journals, Inc. (a pub.), 232 Madison Ave., New York, N. Y........ ............. 1056 Heating & Ventilating (a pub.), 140-148 Lafayette St., New York, N. Y.....".......... 1058 Heating, Piping and Air Conditioning (a pub.), 6 N. Michigan Ave., Chicago, 111... 1053 Hendrick Manufacturing Co., Carbondale, Pa...................................................;........... 1069 Henry Furnace & Foundry Co., 3471 East 49th St., Cleveland, Ohio................ 910-911 Henry Valve Co., 1001-19 N. Spaulding Ave., Chicago, 111........................................ 1132 Hershey Machine & Foundry Co., Motorstoker Div., Manheim, Pa........................ 1110 Hoffman Specialty Co., Inc., Waterbury, Conn............................. ..................... 1088-1089 I Ilg Electric Ventilating Company, 2880 N. Crawford Ave., Chicago, III................... 975 Illinois Engineering Company, Chicago, 111.......................................................... 1090-1091 Illinois Testing Laboratories, Inc., 422 N. LaSalle St., Chicago, III.......................... 1003 Independent Air Filter Co., 228 No. LaSalle St., Chicago, 111...................................... 928 Independent Register Co., The, 3747 East 93rd St., Cleveland, Ohio....................... 1074 Ingersoll-Rand Company, 11 Broadway, New York, N. Y................................... 874-875 * Insulite Company, The, Minneapolis, Minn......................................................... 1026-1027 Insul-Wool Insulation Corp., Wichita, Kansas............................. ........... `.................... T025 Internationa] Exposition Co., Grand Central Palace, New York, N. Y...................... 935 International Fibre Board Limited, Ottawa, Ont., Canada........................................ . 1028 Iron Fireman Manufacturing Company, Portland, Oregon............................... 1108-1109 Heating Ventilating Air Conditioning Guide 1939 J Page Jenkins Bros., 80 White St., New York, N. Y................................................................ 1133 Johris-Manville, 22 East 40th St., New York, N. Y........................................... 1030-1031 S. T. Johnson Co., 940-950 Arlington Ave., Oakland, Calif............................... 962-963 Johnson Service Company, Milwaukee, Wis................................... -................... 1120-1121 Jones & Laughlin Steel Corporation, Jones & Laughlin Bldg., Pittsburgh, Pa____ 1049 K E. Keeler Company, Williamsport, Pa..................... -......................................... i..... 956-957 Kelvinator Division of Nash-Kelvinator Corp., Detroit, Mich................... ......... 912-916 Kewanee Boiler Corporation, Kewanee, III.................................:............ -............... 958-959 Kieley & Mueller, Inc., 40 West 13th St., New York, N. Y....................................... 1093 L . Lau Blower Company, The, Monument Ave. at Barney, Dayton, Ohio.................... 893 Leeds & Northrup Company, 4941 Stenton Ave., Philadelphia, Pa.--....................... 1004 Liquidometer Corporation, The, 38-16 Skillman Ave., Long Island City, N. Y..... 1005 M Maid-O'-Mist, Inc., 180 N. Wacker Dr., Chicago, 111--..... .........-.......-.........-.............. 998 Manning, Maxwell, & Moore, Inc., 11 Elias St., Bridgeport, Conn., (formerly Consolidated Ashcroft Hancock Co., Inc.).............................................................. 1006 Marley Co., The., Fairfax & Marley Roads, Kansas City, Mo.................................... 965 Martocello, Jos, A & Company, 229-231 North 13th St., Philadelphia, Pa................ 877 McCord Radiator and Manufacturing Co., 2587 E. Grand Blvd., Detroit, Mich.... 983 McDonnell & Miller, Wrigley Bldg., Chicago, 111........................... -....................-- 938-939 McQuay Incorporated, 1600 Broadway, N.E., Minneapolis, Minri........................1--. 876 Mercoid Corporation, The, 4201 Belmont Ave., Chicago, 111....................................... 1119 Meyer Furnace Company, The, Peoria, III................................................................... . 917 Milwaukee Valve Co;, Milwaukee, Wis..................................................... -................... 1094 Minneapolis-Honeywell Regulator Company, Minneapolis, Minn................. 1122-1123 Modine Manufacturing Co., 17th and Holburn Sts.^Racine, Wis....................... 984--985 Motorstoker Division, Hershey Machine & Foundry Co., Manheim, Pa................. 1110 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.~...... 1095 Mundet Cork Corp., 65 S. Eleventh St., Brooklyn, N. Y...................................:....... 1029 N Nash Engineering Company, The, South IJforwalk, Conn;........................... --1064-1065 National Pipe Bending Co., 104 River St., New Haven, Conn............................... 988 Herman Nelson Corp., The, Moline, III............................................................ ................ 996 John J. Nesbitt, Inc., Holmesburg, Philadelphia, Pa..................................1...........1..... 997 New York Air Valve Corporation, 611-621 Broadway, New York; N. Y................. 1134 .Niagara Blower Company, 6 East 45th St., New York, N. Y..............:....................... 878 .. 862 ' Index to Advertisers O Page Oakite Products Inc., 22 Thames St., New York, N. Y.._........................................... 921 Owens-Corning Fiberglas Corp., Toledo, Ohio.................................................................. 929 P Pacific Steel Boiler, Div. U. S. Radiator Corp., Detroit, Mich--......... ....................... 960 Pacific Lumber Company, The, 100 Bush St., San Francisco, Calif.......................... 1034 Palmer Company, The, 2506 Norwood Ave., Cincinnati (Norwood); Ohio....... -..... 1007 Parks-Cramer Company, Fitchburg, Mass................................................................... 879 Penn Electric Switch Co., Goshen, Ind...... ............................................. ........................ 1126 Plumbing and Heating Trade Journal (a pub.), 515 Madison Ave., New York, N. Y....................................................... ; ---............................................................ 1059 Pomona Pump Co., 206 E. Commercial St., Pomona, Calif........................................ 1066 H. W. Porter & Co., 825 Frelinghuysen Ave., Newark, N. J...................................... 1040 Powers Regulator Co., The, 2719 Greenview Ave., Chicago, 111.................. .... 1124-4125 R Research Corporation, 405 Lexington Ave., New York, N. Y....................................... 880 Research Products Corporation, 1011 E. Washington Ave., Madison, Wis................ 930 Ric-wiL Company, The, Union Trust Building, Cleveland, Ohio............................... 1041 Ruberoid Co., The, 500 Fifth Ave., New York, N. Y............................ ............ 1032--1033 S Sarco Company, Inc., 183 Madison Ave., New York, N. Y............................1096-1097 Schwitzer-Cummins Company, Indianapolis, Ind.................................. ............... 894, 1111 Servel, Inc., Evansville, Ind................................................................................................. 881 Sheet Metal Worker (a pub.), 45 West 45th St., New York; N. Y........................... 1060 Smith Twin Tubular Boiler Co., Inc., State Rd. & Cottman St., Philadelphia, Pa... 961 H. J. Somers, Inc., 6063-69 Wabash Ave., Detroit, Mich.............................................. 931 Spence Engineering Co., 28 Grant St., Walden, N. Y............................... ................... 1127 Spencer Heater Division, Lycoming Mfg. Co., Williamsport, Pa...... .............. 946-947 Standard Lime & Stone Company, The, First National Bank Bldg., Baltimore, Md. 1035 Staynew Filter Corporation, 6 Leighton Ave., Rochester, N. Y...... .................... 932-933 B. F. Sturtevant Co., Hyde Park, Boston, Mass__ ;................................. ................... 980 T Taylor Instrument Companies, Rochester, N. Y................................................. 1008-1009 Torrington Mfg. Co., The, 50 Franklin St., Torrington, Conn............................. 976-977 Trane Company, The, 2021 Cameron Ave., LaCrosse, Wis--............................... 882-883 Tuttle & Bailey, Inc., New Britain, Conn.'..:............ .................. ......................... 1072-1073 863 r L t i - > Heating Ventilating Air Conditioning Guide 1939 U Page Underground Steam Construction Co., 75 Pitts St., Boston, Mass............................ 1042 Unit Heater and Cooler Co., The, Wausau, Wis.............................................................. 986 United States Air Conditioning Corp., Northwestern Terminal, Minneapolis, Minn... 884 United States Gauge Co., 44 Beaver St., New York, N. Y......................................... 1010 United States Gypsum Company, 300 W. Adams St., Chicago, 111........................... 1036 United States Radiator Corporation, Detroit, Mich............................................ 948-949 United States Register Co., Battle Creek, Mich............................................................. 1075 Universal Cooler Corporation, Detroit, Mich--.............................................................. 885 V Vilter Manufacturing Company, The, Milwaukee, Wis............................... .............886 Vinco Company, Inc., The, 305 East 45th St., New York, N. Y...................... . 936-937 W Warren Webster & Company, Camden, N. J........................................................ 1098-1101 Waterloo Register Company, The, Waterloo, Iowa............................. ..................... 1076 Weil-McLain Company, 641 W. Lake St., Chicago, 111.............................................. !... 950 Western Felt.Works, 4029-4117 Ogden Ave., Chicago, 111.--....................................... 1037 Westinghouse Electric & Manufacturing Co., Springfield, Mass--......... ........... 888-889 White-Rodgers Electric Co., 1209 Cass Ave., St. Louis, Mo....................................... 1128 Wickwire Spencer Steel Co., 41 E. 42nd St., New York, N. Y................................... 1077 Williams Oil-O-Mdtic Heating Corporation, Bloomington, 111...................................... 920 L. J. Wing Mfg. Co., 59 Seventh Ave., New York, N. Y...................................... 978-979 Wolverine Tube Co., 1411 Central Ave., Detroit, Mich--......................................... 1050 Wood Conversion Co., 155 First National Bank Bldg., St. Paul, Minn................... 1038 Worthington Pump & Machinery Corp., Harrison, N. J........................................ 890-891 Wright-Austin Co., 317 W. Woodbridge St., Detroit, Mich........................................ 1102 'i M `i i i ti i i i f i i t! Y Yarnall-Waring Co., 7600 Queen St., Philadelphia, Pa...... ............... .......................... 1103 York Ice Machinery Corporation, York, Pa--................................................................ 887 Young Radiator Company, Racine, Wis............... .................................................... ........ 987 Young Regulator Company, 4500 Euclid Ave., Cleveland, Ohio............ .................. :.. 934 864 Air Conditioning American Moistening Company Atlanta. Ga. Boston. Mass. Ebtabusbco 1888 Providence, R. I Charlotte, N. C. Gbebnyillb. S. C. 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 an 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. 865 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 For dehumidifying, 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. 866 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 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. 867 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, d irect-con- nected or V- belt drive. Baker Com Baker Ammonia Compressor pressors may be arranged in duplex or multiple installations for any desired capacity. Also equipped with double-suction, capacity reduction where conditions require utmost economy of operation. Baker Cold Stream Brine Spray Units-- Forced Draft Designed for applications requiring uni form control of tempera Baker ColdStream Brine Spray Unit--forced draft type tures and rela tive humidity. Equipped with slow-speed blowers mounted on ball bear ings. Fan speeds may be changed to suit air velocity requirements. Housing is of boiler plate construction. Baker Ammonia Type SelfContained Units Ranging in size from H- ton to 25-ton capacities, 24 different mod Baker Ammonia Type Self-Contained Unit els are included in the complete Raker line of ammonia type self-contained units. Com plete with motor, drive and control, mounted with condenser on rigid steel base. Two and four-cylinder models. 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. Both air cooled and water cooled models available. Baker Fan Type ColdStream Units Rigidlyconstructed' for compact, high- capacity, heavy duty service in refrigera ting and air condi tioning foods and other perishables re quiring positive con Baker Fan Type ColdStream Unit trol of temperatures * above the freezing point. Finned coil surfaces and air velocity designed for a correct combination of temperature and relative humidity. ' Baker ColdStream Brine Spray Units -- Gravity Flow Especially designed for cooling and air conditioning service in rooms which re quire absorption of excessive quantities of heat and moisture, such as are found in meat processing plants and pre-cool ing plants. Suction created by brine Baktr ColdStream Brine Spray Unit-- Gravity Flow Type spray jets draws warm air into grille open ings at top. Passing through these atomized brine sprays, air is cooled and dehydrated, forced downward and out through rust proof moisture eliminators near bottom of unit. . 868 Air Conditioning Baker Ice Machine Co., 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: 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 d uces water costs. Casing is of heavy metal, rigidly braced and thorough ly reinforced. Non-corrosive type elimi nators. Outdoor units are weatherproofed. Baker Shell and Tube Condensers Baker Four- Cylinder Freon Compression Units Baker 4-cyl inder vertical enclosed type Freon com pression unit, assembled on a Baker Four-Cylinder Freon rigid metal ' Compression Unit base with motor and . automatic control. Available in 30 to 60 hp. Timken anti-friction roller bearings, balanced bellows crankshaft seal, and builtin removablecartridge-typeoil filter. Auto matic pressure-type temperature control and high-pressure cut-out (thermostat type also available). V-belt drive. Compactly built, all parts easily accessible. Baker Booster Compressors Especially designed for quick freezing and low temperature work. Two and four cylinder models. Ar ranged for single or dual assembly, direct connected or V-belt drive. Positive lubri cation, Press-R-Seal, Timken tapered bearings. Baker Booster Compressor Made in all sizes up to 2500 sq ft of effec tive cooling surface. Vertical, horizontal, multi-pass or single pass types available, with diameters and tube lengths to fit any specification. and Tube Condenser Easily cleaned. Baker Liquid Coolers Designed to cool quickly large quantities . of water or brine. Hori zontal mul tipass shell and tube construc tion. Com plete range Baker Liquid Cooler of sizes. , Cooling ca pacity up to 150 tons each. Easily cleaned. Baker Dual Condensing Unit 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. Equipped with shell and tube type extra capacity condenser or for evaporative type condenser. Cut-away view shows position and length of tubes. 869 Air Conditioning Carrier Corporation Home Office and FACTORIES: Syracuse, N. Y. District Sales OFFICES: New York City Philadelphia Chicago Los Angeles L . |h 1 J Air Conditioning Refrigeration Heating Branch Offices AND DEALERS IN Principal Cities International DIVISION: Syracuse, N. Y. A Marine Division: 405 Lexington Ave. New York City Air Conditioning for FACTORY--BUSINESS--HOME CENTRAL STATION SYSTEM Fans, Humidifiers, Dehumidifiers, Heaters, Filters, Controls for large factories, * theatres, stoves, etc. . UNITARY EQUIPMENT Air conditioning equipment complete in single unit for room, home, business, factory, processing, product cooling Dehydrator (Silica Gel). SELF-CONTAINED EQUIPMENT Three-quarter, three and five ton units for summer air conditioning in rooms, offices and commercial installations. Refrigeration for AIR CONDITIONING--PROCESS--PRODUCT COOLING CENTRIFUGAL REFRIGERATION MACHINES 40-860 tons for Central Station and multi unitary air conditioning equipment, processing, and product cooling. Reciprocating Condensing Units, using Freon, Methyl Chloride, Ammonia for Central Station and unitary air conditioning equipment, processing and product cooling. EVAPORATIVE CONDENSER For.use with Refrigeration Units. .\ . . Unit Heating for FACTORY--BUSINESS DISC FAN TYPE of suspended unit. ` CENTRIFUGAL FAN TYPE--suspended or floor mounted. 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. 870 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, condi tioning 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 data on any Clarage product is invited. Write for Bulletins. Clarage Systems for complete air conditioning in public buildings and industrial plants. Mullitherm Units for complete conditioning, summer codling, or winter heating. ' Clarage Fan with Vortex (con stant speed) Volume Control for ventilation and air conditioning. with Syncrotherm Temperature Control for factory heating. 871 Unilherm Unit Coolers for pro duct cooling and refrigeration. Air Conditioning Curtis Refrigerating Machine Company Division of Curtis Mfg. Company 1959 Kienlen Avenue St. Louis, Mo. New York Office 30 Vesey St. Water Cooled (Shell and Tube Type) 3 Up up to SO ton capacity. GENERAL INFORMATION ABOUT CURTIS 90 models comprise the Curtis line of condensing units--45 air-cooled units in sizes from % to 5 hp; 45 water-cooled units from M to 30 hp. Available for either Freon (F12) or Methyl Chloride. MECHANICAL FEATURES OF CURTIS UNITS Curtis compressors employ "Centro-Ring" positive pressure lubrication--only one moving part--no gears or plunger. Timken Tapered Roller Bearings (models above M hp)... Cylinder Heads removable... Drop forged, alloy steel, heat-treated crank-shaft and connecting rods . . . Balanced sylphon bellows seal . . . .Unusually large receivers and condensers assure efficiency. TYPICAL CURTIS UNITS Air-Cooled Condensing Units--For commercial cooling. Extra large air-cooled condensers and con denser receivers. . Water-Cooled Condensing Units (Counter-flow Type)--For commercial and air conditioning work when water is free from salt or other mineral content. Water-Cooled (Shell and Tube Type) Condensing Units--With cleanable condensers having removable heads. Evaporative Condenser Receiver--Cleanable type, designed to provide economical condensing of refrig erant vapors for high water rates and nigh water temperature. Floor Type Cooling Units--Attractive appearance, efficient operation. Two models--one for comfort cooling, one for complete air conditioning. Comfort Ceiling Type Units--Each unit complete with filter, blower fan, efficient cooling unit. Furnished for cold and hot water circulation. Store and Office Cooler--A complete packaged air conditioning unit ^requiring only water and electrical connections to install. Cools, dehumidifies, circulates and filters the air. Adaptable for heating. Evaporative Condenser Receiver J to 20 ton capacity. Comfort Ceiling Type Unit--%. /H &nd 3 ton capacity. 872 Store and Office Cooler--3 and 5 ton capacity. Floor Type Cooling Units-->4 to lYt . ton capacity-. Air Conditioning Albany Atlanta Baltimore Boston Barreto Charlotte Chicago Cincinnati Dallas Detroit Frick Company (Incorporated) Air Conditioning, Refrigerating and Ice-Making Equipment Waynesboro, Penna. Distributors in 150 Principal Cities Kansas Crrr Lofl Angeles Memphis New Orleans New Yore Oklahoma City Palatka Philadelphia Pittsburgh St. Louis Seattle AIR CONDITIONING We furnish complete air conditioning sys tems as well as refrigerating machinery for use with equipment furnished by others. Upwards of a thou- sand installations attest the value of the various Frick systems of air con ditioning, some of which are patented, and of those made under the patents of the Auditorium Conditioning Corp. Ask for Bulletin . 505, describing the four principal kinds The Philtower and Philcade of systems; also' Buildings at Tulsa are Air Conditioned with 1000 Tone of Frick Refrigeration Bulletins 504 and 512, illustrating and listing typical jobs. Estimates cheerfully rurnished. FRICK FREON-12 REFRIGERATION Includes a com- plcte line of en closed type Freon-12 com pressors. Large capacity, ample gas passages, pressure lub rication from internal pump, patented FLEXO-SEAL 38 Schrafft'e Restaurant* Use a Total of 14$ Frick Machines for Air at shaft. Coils, Conditioning and Food Service coolers, conden sers and controls for Freon-12 systems. Bulletin 508. AMMONIA REFRIGERATION Machines in all capacities from 3^ ton up. Combined units, vertical enclosed type compressors, horizontal machines: complete high and low sides. 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 CARBON DIOXIDE REFRIGERATION Six sizes of enclosed CO* compressors: smooth running, efficient and reliable machines; condensers, coolers, etc. Bul letin 118. LOW PRESSURE REFRIGERATION 20-Ton Freon-12 Unitfor Air Conditioning Work Commercial units in more than 50 sizes and types, with motors of K 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. Enclosed Type Ammonia Compressor Frick Enclosed Freon-12 Compressor Enclosed Compressor for Carbon Dioxide S73 Low Pressure Refrigerating Units Air Conditioning Atlanta BIRMINGHAM Boston Buffalo Bum Chicago Ingersoll-Rand Company 11 Broadway, New York City Branches or Distributors the World Over Cincinnati Cleveland Dallas Dentes Detroit Duluth El Paso Hartford Houston Kansas Crrr Knoxville Los Angeles Newark . New York Philadelphia Picher Pittsburgh Pottsvtlle Salt Lake Citt San Francisco Scranton Seattle St. Louis Tulsa Washington PUMPS 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. Motorpump AIR COMPRESSORS There is an efficient, reliable IngersollRand pump for every purpose. Single stage 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 "Motorpump" is ideal for general service everywhere, ranging in sizes from ^ 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 floor, wall or ceiling. Capa cities 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 ex plosion-proof types. CONDENSATE RETURN UNITS Type "50" Troo-Staoe Comprettor 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 selfcontained plant, consisting of a compres sor, driving motor, air receiver and auto matic pressure control switch. The com pressor is either single- or two-stage, using I-R steel valves. Cylinders and inter cooler are air cooled. Capacities range from 1.2 to 102 cfm. Pressures range from 5 to 1000 lb per sq in. Ingersoll-Rand manufactures more than 1000 sizes and types of compressors in cluding a complete line of ammonia com pressors. OTHER I-R PRODUCTS "Motorpump" Condensate Return Units are designed to return condensation from radiation systems, heaters, steam coils, etc. Surface condensers; counter-current and ejector-jet barometric condensers; steamjet ejectors; vacuum pumps; centrifugal blowers; air aftercoolers and receivers; Diesel and gas engines; air and electric hoists; rock drills; and pneumatic tools of many kinds. 874 Air Conditioning Ingensoll-Rand 0 WATER-VAPOR REFRIGERATION I-R Water-Vapor Refrigeration uses water as the only refrigerating medium. There is no refrigerant to purchase or replace. The system operates entirely under vacuum, and may be opened up for inspection whenever desired. Water-Vapor Refrigeration gives low operating costs by saving refrigerant re placement and by economical operation at light as well as full loads. Of special value is its unusual ability to handle overloads. Full capacity is retained for the life of the machine. I-R Units arc ordinarily sold through reliable contractors for field installation as a part of air conditioning systems. Cooling is effected by direct evaporation of water at high vacuum. Steam-jet boosters maintain the vacuum and dis charge the evaporated water vapor into a surface condenser. (When desired, baro metric type condenser units can be fur nished). The heat carried away by the evaporation of the water vapor chills the main body of water as it is circulated through the unit. The I-R patented design has bdin specially developed to insure reliability and simplicity of operation. Steam-J^t Coolers are free from noise and vibration, and are easy to install and maintain. ' Standard sizes are available for capaci ties of approximately 10 tons upward for chilled water temperatures of 35 F and higher. Units are built for steam pres sures of 2 lb gauge and upward. 875 Air Conditioning McQuay, Inc. 1600 Broadway, N.E., Minneapolis, Minn. MANUFACTURERS OF AIR CONDITIONING EQUIPMENT Unit Heaters. Full floating, all copper heating elements. Improved bond, between fin and tubes. 26 sizes Evaporator Coils. For all phases of commercial re frigeration. Tailor-made to fit specific requirements. Air-Conditioning Unit. Suspended Type. New line, low priced, combining high efficiency of centrifugal fans and air filters. Cold water or Freon cooling medi um. Attractive cabinets, adaptable for fresh air con nection. Comfort Coolers. For direct expansion or water as cooling medium; also as combination cooling and heating units. Capacities for any requirements. Concealed and Cabinet Copper Radiation (Con vectors). Enclosure types, exposed floor and wall hung, fully or partially recessed. Removable panels and con cealed. All copper heating elements. Unit Coolers. For truck refrigeration, storage rooms, etc. All refrigerants. Nine sizes. Cabinet Room Coolers. Floor type for home or office. Attractive, compact. Water or direct expansion refriger ants. ESgf-J Suspended Cooling Unit. Blower Type. Com panion to floor type. Com bi n a t i o n cooling and heating. Air-Conditioning Coils. For central fan heating and cooling systems. For cool ing and dehumidifying. Direct expansion refrig erants or water for cooling, steam or hot water for heat ing. Sizes for any air con ditioning application. Floor Type Cooling and Heating Units. Six sizes, 3 to 50 tons cooling capacities. NEW DESCRIPTIVE BULLETINS ARE READY on all McQuay Products. 876 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 . Pipe Size Inches Part No. Diam. Orifice Inches Vi 1930 Vi 1910 `/ 1910 Double y. 1920 >/ 2300 2304 V. 2308 7/64 13/64 5/32 17/64 7/32 5/16 M/32 5 lb .22 .54 .86 1.48 1.98 2.66 3.59 10 lb .29 .77 1.18 1.96 2.63 3.77 4.87 Capacity, Gallons per Minute 15 1b .34 .96 1.46 2.38 3.15 4.71 5.92 201b .39 1.13 1.76 2.75 3.62 5.52 6.83 25 lb .44 ' 1.29 2.02 3.08 301b .49 1.44 2.24 3.36 4.05 6.24 7.62 4)44 6.87 8.33 35 lb .54 1.58 2.44: 3.60 4.80 7.47 8.98 . 401b .59 1.71 2.63 3.82 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 877 Air Conditioning Niagara Blower Company AIR ENGINEERING EQUIPMENT AND SYSTEMS General Sales Office: 6 East 45th Street, New York City Buffalo Rochester Pittsburgh Boston. Chicago Philadelphia Seattle Cleveland Atlanta Detroit 17 Years' experience in the engineering, design and installation of complete air conditioning PRODUCTS--Exact Control Air Conditioning, Humidifying, Dehumiditying, Drying, Moistening, Chilling, Comfort Systems, Niagara Air Con ditioners, High Humidity Spray Coolers, Fan Coolers, Fan Heaters, Cool ing Coils, Heating Colls, 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 Available both in floor mounted and space-saving sus pended types. Maintains constantly or makes any change required in temperature and relative humidity. NIAGARA AIR CONDITIONER, TYPE C (Illustrated) A year around air conditioning unit providing winter heating and humidifying and summer cooling and dehu- midifying. NIAGARA FAN COOLER and DISK FAN COOLER For comfort cooling, process cooling, low temperature Coil Air Conditioner, mannfac- storage for dairies, fruits, meats, food products, fur storage "ff "Zddf. vaults, etc. NIAGARA SPRAY COOLER For all cooling applications requiring high humidity or high capacity in small space. In 1-, 2-, 3-, and 4-fan units--seven sizes. Patented. NIAGARA "NO FROST" SYSTEM Using Niagara "No Frost" Liquid in spray coolers, prevents frosting of cooling coils, automatically keeps spray solution at proper concentration, gives freedom from brine troubles, corrosion. Constant efficient operation. Patented. . 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 CONDENSER (Illustrated) . Saves power and water cpst utilizing atmospheric air to remove heat of condensation. Patented. NIAGARA "DUAL" COOLERS Simultaneously cools a room and furnishes chilled water as a refrigerant. Saves coils and operating troubles in milk plants and elsewhere. Patented. NIAGARA FAN HEATERS arid DISK FAN HEATERS For heating and ventilating large areas. . .Units of the highest quality in engineering material and workmanship. NIAGARA AIR SUPPLY HEATER Balances exhausted air in factories when exhaust systems are operating, saves steam and power, gives more effective heating. Patent pending. 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. ' . 878 Air Conditioning Parks-Cramer Company Fitchburg, Mass. Charlotte, N. C. CERTIFIED CLIMATE Complete Air Conditioning Systems including Heating, . Cooling, Humidifying, De-humldifying, Air Changing, Refrigeration, Air Filtering and Air Washing AUTOMATIC REGULATION Merrill Process System of Hot Oil Circulation for Heating Industrial Materials Central Station High Duty Humidifier Psychrostat Pettifogger Central Station Air Conditioning A centrally located AIR WASHER supplying correct amount of moisture with positive pre-determined air change. Usually includes indirect radiation for heating --may include refrigeration and cooling. Features absolute control and centralized equipment. Helps in many industries, notably, Textiles (Cotton, Wool, Worsted, Silk, Rayon, Jute); Printing and Litho graphing; Cigar, Cigarette and Tobacco; Clothing; Paper and Envelope; Leather and Shoes; Wood Prod ucts; Cereals; Storage of Perishables; Ceramics; Celluloid; Glassine Paper; Starch and Dextrine; Cement; Confectionery. Installations similar in design are ef fective in Hospitals, Art Galleries, Auditoriums, and Restaurants... Nozzles for Central Station Air Washers. 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 three sizes of nozzles give flexible capacity for varying conditions. Circulation 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. Self-cleaning. Parks Automatic Airchanger ., For use with High Duty or Turbo Humidifiers. Insures fixed humidity and maximum evaporative cooling. 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. 879 Air Conditioning Research Corporation 405 Lexington Avenue, New York City RESEARCH SYSTEM OF AIR CONDITIONING (Patented and Patents Pending) The Research Corporation System of Air Conditioning features a direct method of chemical dehumidification, and may be applied to either comfort control or industrial processing. It functions either with or without the use of refrigeration, depending upon oper ating conditions. In the working unit, or Calorider, a moisture-absorbing salt solution is sprayed over copper extended surface . coils through which cooling water cir culates. This salt solution is automatically kept at a definite concentration by heat supplied at relatively low temperatures (e.g., by waste steam). The system makes possible the independent and yet simultaneous control of tempera ture and humidity over a wide range, at extremely low operating cost. Advantages of Research Corporation System of Air Conditioning 1. Installation costs are moderate, opera 4. Noise and vibration limited to that of ting costs are cut 50 to 80 per cent. main air supply blower. 2. Cooling water at 70 deg gives condition 5. Fully automatic control, all year 'round ed air with dew-point as low as 22 deg. 3. Maintenance is simple, cheap and in if desired; relative humidity may be held sfc 3 per cent at any point between frequent. No reciprocating machinery, 15 and 50 per cent. no gas to leak. The only moving 6. Equipment available in sizes of 1000, parts are fans, pumps and their motors. 3000, 6000, 9000, 12000 and 18000 cfm. COEY MULTISTAGE COOLING TOWERS (Patented and Patents Pending) "Water Saved is Money Earned" ~ The Coey Multistage Cooling Tower is constructed of a copper-bearing steel shell and corrosion resisting supporting members, Red Gulf Cypress wood baffles, a non-overloading reverse blade centrifugal fan rotor, and the Coey Spray Eliminator of copper-bearing steel or aluminum. Table of Capacities and Sizes j Modd No. ' Nominal Water Flow Cpm Height.above beams* 1 Diam l Operating W gt Pounds* Mech. Refrig. Tons | | Steam je t 1! | Refrig. Tons | Steam Condensing at 27 in. Vac. 115 F L b per hour a X o o 2 10 or 10-A 100 2.0 y- 0" 20-R 225 5.0 II'- 5' 35 or 35-R 375 7.5 14'- 2' 50 or 50-R 550 10.0 16'- 9* 85 or 85-R 850 15.0 18'- 8' 110 or liO-R 1100 20.0 21'- 7' 150 or 150-R 1400 25.0 22M0' 5'- O' 8'- 5' II'- 3' 13'- 3' 15'- O' 17'- 9' 20*- O' 4500 35 15 9000 75 35 15500 125 60 21500 165 90 30000 235 135 43000 375 175 56000 465 230 1,125 2,500 4,290 6,200 9.550 12,400 15.700 Compact, light in weight, spray free and quiet in operation, it is desirable for installation anywhere, but is especially well-suited for roof and basement installations in congested districts. Controlled Cooling. Sprayless Operation. Minimum Noise Level. Architectural Harmony. Complete information on Research Corporation products gladly sent upon request. Other Equipment: Cottrell Electrical* Precipitation Systems--Multiclone Dust Collectors--Impax Separators--Cottrell Royster Deodorizers--Royster Stoves for High Temperature Heat Exchange. 880 Air Conditioning Servel, Inc. Electric Refrigeration and Air Conditioning Division Evansville, Indiana AIR CONDITIONING Servel specializes in the manufacture of refrigerating machines for the air conditioning industry. Eliminating side lines and accessories, Servel concentrates its engineering and manufacturing facilities on this one all-important element in every complete, system. Backed by 17. years of experience in building heavy-duty low-pressure refrigerating machines, Servel units offer every modern feature, plus a record of proven dependability. SERVEL'S NEW PRODUCTS FOR 1939 Servel offers a fully integrated line of machine units, designed as a "family." This line is the result of a research program inaugurated early in 1935. Since that time, dozens of new materials, design features, manufac turing processes and practical selling ad vantages have been developed. All units have been moulded to the modern tread. While special stress has been placed on quiet operation and compactness, there has been no sacrifice of high capacity and overall efficiency. ' Remote Machines--For conventional central fan systems or room coolers, Servel . offers over twenty models, ranging from Yi ton to 20 tons and including air-cooled, . water-cooled and evaporative condenser types. Air-cooled models feature shrouded condensers with leaf-type "Streamair" fans. The larger water-cooled units have the economical counter-flow shell and tube condensers developed by Servel two-years ago. Machines for Self-Contained Units --For manufacturers or assemblers of selfcontained conditioners, Servel offers com ' pact assemblies of compressors, condensers and auxiliaries suited to this type of work from Yl. ton to 10 tons. Servel offers nine distinct compressors for use with units of Y ton to 20 tons capacity. All except the smallest are four or eight-cylinder compressors, insuring absolute balance and freedom from vibration. Manufacturers will find these compressors adaptable to almost any assembly program. Servel's engineers will be glad to supply technical data, specifications and other details to responsible firms. . Typical Compressor ` EVAPORATIVE CONDENSERS For sections of the country where water rates are high, or where there is a shortage of water supply or sewage facilities, Servel offers five economical evaporative condensers. Ranging in size from 5 tons to 20 tons, these evaporative condensers are shipped complete, including coil, blower, pump, receiver, eliminator, by-pass connec tion, motors, drives and control. Each model is designed to handle full capacity, with condensing temperature within 25 F of entering ' wet-bulb. . 881 Air Conditioning The Trane 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., Appleton, Wis., Atlanta, Ga., Aurora, 111., Baltimore Md , Birmingham, Ala., Boston. Mass., 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. Ia.. Detroit, Mich., Flint Mich., Gainesville, Fla., Grand Rapids, Mich., Greensboro, N. C., Greenville, S. C.. Harrisburg, Pa., Houston. Tex., Indianapolis, Ind., Jackson, Miss., Juneau, Alaska, Kalamazoo. Mich., Kansas City, Mo., Knoxville, Tenn., LaCrosse Wis.", Lake Charles, La., Little Rock, Ark., Livingston. Mont., Los Angeles, Calif., Louisville, Ky., Memphis, Tenn., Miami, Fla., Milwaukee, Wis., Missoula, Mont., New Haven, Conn., Newark N J. New Orleans, La., New York City, Oklahoma City, Okla., Omaha, Neb.. Peoria. III., Philadelphia, Pa., Phoenix, Anz., Pittsburgh, Pa., Portland; Ore., Portsmouth. Ohio. Providence, R. I., Richmond, Va., Rochester, N. Y., St. Louis, Mo.. St. Paul, Minn., Salt Lake City, Utah, San Antonio, Tex., San Francisco, Calif., Seattle. Wash., Sioux City, la.. South Bend, Ind., Spokane, Wash.. Syracuse. N. Y., Toledo, Ohio, Washington, D. C., Westchester, N. Y., Wilkes-Barre. Pa., Zanesville, Ohio. In Canada: Trane Company of Canada, Ltd., Toronto, Ont. NON-FERROUS TRANE AIR CONVECTORS CONDITIONING MANUAL The Trane Non-Ferrous Con vector provides instant, even heat to any room space. Con structed in fifteen basic types and several hundred sizes,' the Trane Convector may be placed on the floor, partially or totally The Tranemark of High Quality in Heating. Cool ing and Air Conditioning A comprehensive handbook, and textbook covering the fun damentals of the science of air conditioning. For the engineer and architect. Straightforward. Unbiased. Price; $5.00. concealed in the wall, or hung completely exposed on the wall. This heating unit operates efficiently on all types of steam and hot water systems. Can be installed within range of cast iron UNIT HEATERS radiator prices. Projection Unit Heaters--A draw- through propeller type unit heater that taps the reservoir of heat at the ceiling, HEATING SPECIALTIES The Trane Heating Specialty line consists of Low, Medium, and High Pressure Bellows Traps; Thermostatic Drip Traps; Quick and Float Vents; Vent Traps; Her metic, Packless and Bellows Angle Valves; High and Low Pressure Float Traps; Direct Return Traps; Inverted Bucket Traps; Dirt Strainers; and Damper Regulators. projecting it down to the living zone. It may be used at heights from 10 to 60 ft. Available in single or multiple fan units in 6 sizes. (Illustrated center, above). Propeller Type Unit Heaters--A standard unit heater for all types of heat ing. Available in 60 sizes for steam pressures up to 150 Jb or positive circu lation hot water systems at 160 deg or higher. Incorporates refinements that eliminate strain and stress caused by expansion, and that direct heat to the floor line. (Left). Trane Heating Specialties are precision Torridor Blower Type Unit Heaters built and ruggedly constructed for out --A blower type draw-through heater for standing performance for any steam sys large space heating with a minimum of tem. The heart of Trane Heating Special units. Their high velocity makes them ties is the famed Trane Bellows. Trane desirable for duct work application. Avail is one of the few heating specialty manu able in belt or direct driven, standard or facturers who. actually fabricate this by-pass control units, floor, ceiling and important part. . wall types; 96 sizes. (Right). 882 The Trane Company Air Conditioning OTHER AIR CONDITIONING EQUIPMENT AIR CONDITIONING EQUIPMENT Climate Changers--The complete year around air conditioner for the home, apart ' meat and small building. Hot water or steam heating. Cooling with any standard medium. Humidification. Air circulation. . Dehumidification. In 12 sizes in hori zontal or vertical models. Commercial Air Conditioners--A compact unit for commercial application. Same features as the Climate Changer. A wide range of sizes and capacities in floor and suspended models. DeLuxe Air Conditioners--For use where attractiveness must be combined with functions of year around air condi tioning. Floor Type and Hotel and Office Models. Floor type Unit is a vertical unit of compact design available in 6 cabinet , sizes. The Hotel and Office Unit is a hori zontal unit for ceiling suspension. Primanly a summer air conditioner. 1. The Trane Evapora tive Condenser to condense refrigerants in any com pressor system. 2. The Trane Air Washer for humidification in the average commercial heating and ventilating system. '. 3. The Trane Type X Propeller Com fort Cooler, an inexpensive quiet propeller fan. draw-through unit. Intended for service with water as the cooling medium. 4. The Trane Product Cooler a compact unit used with refrigeration system pro vides proper temperatures for product storage. 5. Railroad Air Conditioning Equip ment includes the Trane Electro Mechani cal System for undercar installation and sub-cooler and railroad evaporative con densers to make other systems function more effectively. 6. Bus Air Conditioning Equipment for light weight unobtrusive installations. UNIT VENTILATORS HEATING AND COOLING COILS There is a Trane Ex tended Surface Coil to meet all heating or cool ing applications, com mercial or industrial. . 1. Type E Blast Coils for heating and cooling' using low and high pressure steam,' hot or cold water. Especially designed for duct work installations. 2. Type C though similar to Type E is not encased. Side channels provided for structural strength. 1 and 2 row sections and many sizes. Designed primarily for installation in self-contained units. 3. Type S for cooling with clean cold water. Available in single and-double row serpentine for varying water supplies. In 2, 3, 4, and 6 row depths and a multitude of sizes. 4. Type R for cooling with water where tube cleaning may be necessary. In 4, 6, and 8 row depths and a variety of sizes. 5. Direct Expansion Coils for cooling with standard refrigerants. 2, 3, 4, and 6 row depths and many sizes. 6. Welded Header Coils for steam pressures umto 250 lb. Particularly advan tageous fo^rdrying applications. 2-row depths and a variety of sizes. . 7. Booster Colls for booster type heat ing, ventilating and air conditioning in a central system. . Intended primarily for the school room, the Trane Unit Ventilator may be used wherever the combination of positive ventilation and heating is required. The unit is a draw-through type, attractively finished. Available in a variety of sizes and types in class room and auditorium models. GAS EQUIPMENT Trane Gas Equipment consists of Unit Heaters and Winter Air Condi tioners. The Unit Heater is an automatic unit, light in weight, one of thespeedi est heat makers ever de veloped. Can be used with natural or manufactured gas. The Winter Air Con ditioners are factory-assembled for duct or free delivery. Humidity, heating, air cleansing, and circulation obtained. May be equipped for summer cooling' ALLIED EQUIPMENT Includes Condensation and Circulating and Booster Pumps, Compres sors, Temperature Control Valves to maintain set temperatures on . convectors or radiators, and Washer and Atomizing Target Type Spray Nozzles. 883 Air Conditioning United States Air Conditioning Corporation A Complete Line of Air Conditioning Equipment 2121 Kenedy St., N.E. Minneapolis, Minn. Branch Offices or Agents in Principal Cities U. S. AIRCO Air Washers U. S. AIRCO Blowers Single inlet single width and double inlet double widthBlowers for both supply and exhaust. Sizes from 300 cfm to 100,000 cfm. Series 39 Unit Heater with U. S. AIRCO patented Deflecto-Grille, horizontal and ver tical blades both adjustable for per fect control of air volume and air dis tribution. Type A Blower, with backward1y c u rve d blade i m pel 1 e r. Both single and double inlet. Sizes from 1,000 to 70,000 cfm. Also Standard Model Unit Heaters with adjustable horizontal louvres. U. S. AIRCO Blower Type Unit Heaters Also light duty Blowers and BlowerFilter^nits for furnaces and self-contained air conditioners. Also Propeller (Exhaust) Fans. U. S. AIRCO Unit Coolers Ceiling suspension and floor models. Available with heating and cooling coils, humidifiers and filters. Also blast heat cores. Unit Cool ers for cold water or di rect expan sion. Range of sizes. Send for catalog showing complete line of U. S. AIRCO Equipment. 834 Air Conditioning UNIVERSAL COOLER CORPORATION Detroit, Michigan Automatic Refrigeration Exclusively Since 1922 Model W-1500, 15 hp Condensing Unit. A complete LINE of CONDENSING UNITS AND COMPRESSORS MANUFACTURERS: Universal Cooler condensing units are made for you. We sell to manufacturers only. Our product and our policy are suited to your business. Make our factory your factory. ARCHITECTS AND ENGINEERS: You may specify Universal Cooler refrigerating units with confidence. You can share the confidence that many outstanding, manu facturers of refrigerating and air conditioning equipment have expressed in our product. CONTRACTORS: Universal Cooler refrigerating units are available to you through our customers, the leading manufacturers of refrigerating and air conditioning equipment. We sell to manufacturers only. We do not compete with you in the field. . Complete data mailed on request. Universal Cooler Corporation. Detroit, Michigan. Universal Cooler Company of Canada, Ltd., Brantford, Ontario. Listed under Reexamination Service of Underwriters Laboratories, Inc. 885 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 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. Dry Coil UNIT AIR CONDITIONERS 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. 886 Air Conditioning York Ice Machinery Corporation York, Pennsylvania Factory Branches and Distributor Engineering and Sales Offices throughout the World. Air Conditioning and Refrigeration for maintaining proper atmos pheric conditions for human comfort and industrial processes. Installations of unit and central systems in a complete range of capacities and types for every design requirement. York Standard Dehumidifier with Coils York Water Cooling System Air Conditioning Units: A complete line of finned coil, dry coil wetted surface and spray type sectional air con ditioners for horizontal or vertical applications, designed to facilitate installation and the distribution of air. Standard units can be equipped with by-pass feature and arranged for cooling and dehumidifying, heating and humidifying, for year-round comfort. Finned Coils--For installations where capacities or sys tem arrangement prevent the use of standard York air conditioning units, York Fin Sections are especially applicable. Corrugated fin plates are pressed on seamless copper tubes, metal bonded and hot-dip coated, con struction being identical-with the heating and cooling surfaces manufactured for human comfort air condi tioners. Dehumidifiers--With or Without Coils. For central ' station systems where a large volume of air is to be handled and where control of humidity is an essential requirement, the York dehumidifier is especially applic able. Construction features insure a minimum space demand and maximum performance conditions. Stan dard washers, and those equipped with direct expansion coils, are available in a full range of capacities for human comfort or industrial installation. Air washers can be . furnished also for use as indoor condensing water cooling towers when specified1. The York Economizer--A combined forced-draft cooling tower and refrigerant condenser, is avilable for instal lations where prohibitive water costs or inadequate drainage facilities preclude the use of a water cooled condenser. Standard factory constructed and built-up units may be used singly or in multiple for applications of any specified capacity. Economizers for use with the refrigerant Freon-12 are furnished, as standard, with a liquid sub-cooling coil. Condensing and Water Cooling Systems--Standard systems are available for every application requirement up to 1,000 hp capacity using a single compressor. Self-contained units up to 150 hp feature the YORK line. These units are furnished with water cooled con densers or without condensers for economizer appli cations. " Automatic or manual capacity reduction by-pass valves can be provided for economical operation at reduced load. All materials and manufacturing methods employed, in the construction of the York Freon-12 Condensing and Water Cooling Systems conform to the high standards and efficient operating characteristics of all YORK pro ducts and carry performance guarantees based on Refrigeration Manufacturers' Association and Air Con ditioning Manufacturers' Association ratings. 887 ` /? Air Conditioning Westinghouse Electric & Manufacturing Co. Springfield, Mass. Sales, engineering and service available through Authorized Engineering Contractors in all principal cities UNIFIED Air Conditioning Equipment for Commercial Building Applications Westinghouse Electric & Manufacturing Co. Air Conditioning HOW TO SELECT--Fit equipment to meet the total Btu load according to capacities under local conditions as listed on Westinghouse performance data sheets. Consult your Westinghouse Engineering Contractor or write Westinghouse, Air Conditioning, Dept. 9004, Springfield, Mass., for data sheets. WHERE TO BUY--Consult classified telephone directory or nearest Westing house district office for name of Authorized Engineering Contractor. SELF-CONTAINED UNITS Capacities from 1 to 15 tons refrigeration APPLICATION--Westinghouse equip ment provides air conditioning for every building application. Every unit is engi neered by Westinghouse and matched in capacity and performance to operate in a Unified System. Equipment is applied in carefully engineered installations, with re sponsible maintenance service to assure continuing efficiency. FEATURES CONDENSING UNITS AND COM PRESSORS--Available in capacities from 1 to 100 tons. Exclusive Westinghouse Hermetically-sealed construction--no shaft seals, belts, pulleys or other visible moving parts. Compact and light in weight, they require unusually small floor space and maybe installed without special foundations. HEAT TRANSFER SURFACES-- Cooling surfaces for Freon or cold water-- heating surfaces for steam, hot water or vapor, in sizes to match all other Westing house equipment. Tubes and fins of pure Lake copper, soldered together for per manent contact and efficiency. All joints in Freon surfaces are silver-soldered. AIR CONDITIONING UNITS--Hori zontal and vertical types in sizes to match all Westinghouse compressors, cooling and/or heating surfaces. These units in corporate blower, heat transfer surfaces, humidifiers, dehumidifiers and filters. EVAPORATIVE CONDENSERS-- Westinghouse Aquamisers, combining the performance of water-cooled condenser, air-cooled condenser and cooling tower in a single compact unit that reduces water consumption by 95 to 98 per cent. ELECTRICAL EQUIPMENT-- Starters, circuit breakers, switches, con duit, etc., for every requirement. 888 Complete, self-contained unit of 15 tons capacity, only 6 ft 6 in. long by 5 ft 4 in- high and 8 ft 10 in. wide, for use with duct system. HOME HEATING AND AIR CONDITIONING A complete line of attractive, efficient heating-.and air conditioning equipment including gravity warm air furnaces (pipes . and pipeless types), coal-fired air condi tioning units, boiler-burner units, conversitJn oil burners, oil and gas-fired auto matic air conditioning units, oil and gas-fired gravity warm air furnaces, blower- filter units, Mobilaire room coolers and summer cooling units for use with duct systems. Full range of capacities meets all residential application requirements. Series 1100 oil-fired winter air conditioning unit, capacities from 101,000 to SSI.000 Btu at register. Weslingfeoiise Spiralaire conversion oil burner, capacities to 5 gph. Rotary wall burner also available. Boiler-burner unit for steam or hot water systems, oil or gas- fired. Steel and cast-iron gravity warm airfur naces in a total of 88 sites. 889 RU-90 summer coding unit for use with winter air conditioning units to form a year-round sys tem. Air Conditioning Worthington Pump and Machinery Corporation p Carbondale Division WORTHINGTON Atlanta Boston Buffalo Chicago 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 Cities of Foreign Countries Seattle Tulsa Washington CA9-1 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 or 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. Overall Dimensions Smallest: 22 ttt. long, 16 in. wide, 17 ioi. high Largest: 98 in. long, 40 in. wide, 41 in. high Medium Self-contained Units "Freon-12" ,,-JL^b or methyl chloride units, equip ped with ca pacity con trol; patented F e a t.h e r jrjc Valves; mo tors of 30, 40 __ __ _-.-J* and 50 hp. ^ Eight-cylin der units; motors of 75, 100 and 125 hp. Vertical Duplex Double-acting Compressors "Freon-12" ^ or ammonia; large tonnage compressors; force-feed lubrication; roller main bearings. Crankcase sealed from cylinders, preventing contamina tion of oil by refrigerant. Equipped with patented Feather Valves; automatic capacity control features. Crosshead in corporated in enclosed crankcase. 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 .160 tons in one unit. Overall Dimensions (Without Motor) Smallest: 2 ft 3 in. long, 2 ft Hn. wide, 3ft3li in. high Largest: 6 ft in. long, 5 ft wide, 7 ft 7f in. high Single and duplex; single-stage and twostage; 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. 890 Air Conditioning Worthington Pump and Machinery Corporation, Carbondale Division Carbon Dioxide Compressors Steam Jet Water Cooling Systems A series of convenient types and sizes for every re quirement is available. 15 to 600 tons. Either surface or barometric condenser may be fur nished. Air Conditioning Units For Direct Expansion or Water Circulation . Vertical and Horizontal Condensers horizontal; 500 to 15,000 cfm; -j -;\ -7j/" j;. - * large air pas sages ; slow speed, quiet rugged fans; heavy welded steel frames; separable sec =* -1- X*., tions; readily accessible. The design permits a wide degree of fle: ability in installation arrangements. *-L-_ Atmospheric drip type, for warm corrosive waters. Double-pipe for dosed systems, can be retubed without shutting down. Multi-pass for closed systems and space Shower Condensers saving. A combined con denser, receiver, Vertical Condensers and modified cool The Carbon- ing tower, in one as dale "Spira- sembly, for "Freon- Flo" posses 12" or methyl ses the ad chloride systems; vantages of 5 to 50 tons re both the at frigeration; built in mospheric separable sections; and double all parts easily ac pipe types. cessible. Saves 90 Usable with to 95 per cent in any kind of cost of water. water. Com Liquid Cooling Equipment pact ; instal led indoors, Various de- outdoors, or on the roof. Easily cleaned. si g n s 6 f horizontal Miscellaneous 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 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 circulating systems. request. 891 Air Conditioning (Accessory Units) Air Controls, Inc. Div. of The Cleveland Heater Co. 1933 West 114th Street, Cleveland, Ohio Manufacturers of REX-AIRATE Air Circulators, REX AIRPAK Blower Filter Units, REX A C Blowers and Blower Parts. REX-AIRATE VENTILATORS REX-AIRATE Summer Comfort Cool ing units are furnished in a wide range of styles and sizes for every type of com mercial cooling and ventilating. Quiet and economical in operation. Model S shown, stands 42 in. high. Capacity: 7,000 cfm. REX-AIRATE HOME COOLER A highly effective home cooling unit by means of attic ventilation. Complete (no extras to buy) with automatic' ceiling shutters, ceiling moulding, metal vent-box and canvas connector. Available in sizes for every type home. REX-AIR-PAK PACKAGE FURNACE BLOWER Model JR-100--A complete package blower filter unit for the small home owner and home renter. Easily detached from one furnace and quickly installed to another. New streamlined cabinet. Fourspeed pulley provides various air deliveries from 650 to 1000 cfm. Available in many colors. Other models in larger sizes. REX A C Blower parts such as blower wheels, housings, bearings, four-speed, etc., can be furnished to furnace manufacturers and sheet metal contractors. Write its for bulletins describing REX equipment illustrated on this page. 892 Air Conditioning (Accessory Units) The Lau Blower Company Monument Ave. at Barney, Dayton, Ohio Manufacturers of Furnace Blowers, Blower Wheels, Housings, Pulleys, Pillow Blocks and Complete Assemblies Self-Aligning Pillow Blocks Hold-down bolts cannot affect the freedom of the bearing. Oil tight steel housing; reservoir holds twice as much oil as cast iron housings; Durex bushing feeds oil to the shaft by capillary action and maintains a constant oil film even when shaft is not rotating. Spherical surface of bearing conforms to contour of housing, providing a universal joint action. 100 Series Assembly A complete blower assembly for manu facturers who fabricate their own casings (also available with top motor mounting) S-sizes; variable speed drive; automatic belt-tightening device; automatic cut-out on motor. Blower Wheels and Housings Squirrel cage, forward curve, multi blade type wheels. Double inlet, double width (or single inlet, single width). Dy namically balanced; sizes 4%-in. to 25-in. Blower housings available in 10 standard sizes--special sizes on request. 700 Series Package Unit Blower Steps-up efficiency of coal, gas and oil-fired furnaces. Complete with filters, blower cabinet, variable speed drive, blower and full size access doors on both sides. Motor and drive assembly are reversible . . . may be placed on the most convenient side-- on the job. 8 sizes; knock-down construction. BIo-Ette Package Unit A blower that will remedy the many thousands of existing unsatisfactory gravity jobs at a price so low that it is well within the reach of everyone. Top motor mounting; auto matic cut-out on motor; leak proof filter frames; 16 x 25-in. filters; high speed--low pres sure; large size access door. 3 sizes. 893 Air Conditioning (Accessory Units) Schwitzer-Cummins Company Indianapolis, Indiana, U. S. A. BLOWERFANS VENTILATING FANS HOME-VENTILATORS HY- DUTY BLOWER-FILTERS HUMIDIFIERS HY-DUTY BLOWERS A superior line of blower fans from 4J4 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. ATTIC VENTILATORS Made with HY-DUTY propeller type fans and HYDUTY blower fans. Models for every type installation including complicated home arrangements. 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. 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 1111) 894 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 of automatic stokers or oil burning equipment: a "* -<1 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. 'l,j " ' - - ,, Phantom View of Acme Healer Showing Flow of Gases and Air Travel. - Physical Data--Large Series 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 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. Dimensions Size No. Lgth Width Ht Grate sq ft Heat Surf, sq ft Free Area sq ft Min. Free Area sq ft Max. Wt. Lb Max. Capacity Btu . High Ratio of Heating Sur face to Grate Area: The radiator tubes are covered with extended 7 6'-6' y8 8f-l* VS' 10 IP-3* 4'-0* 7'-0* 10.31 260 4'-0" 4'^r 7'-0* T4T 11.91 13.06 340 430 4'Ar TJf 14.43 500 6.53 10.25 5900 900,000 7.73 12.50 7000 1,100,000 8.91 14.75 8000 1,300,000 15.82 22.62 9300 1,500,000 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 Junior Series surface of the combustion chamber, affords a remarkably high ratio of 2 4'-6,r 3'-6* 5'-8*' 3.9 136 4.7 4.7 3700 350,000 3 6'-0* 3'-6* 5'-8' 6.1 183 5.9 6.9 480(1 527,000 4 7'-6' y-6" 5'-8* 7.2 230 7.1 9.1 5000 634,000 5 vjy 3'-6* 5'-8' 9:3 .280 8.3 11.3 6000 800,000 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. 895 Air Conditioning /7/PTEMP 0/ V / S / O N OF CHRYSLER CORPORATION DAYTON, OHIO CHRYSLER'S AIRTEMP RADIAL COMPRESSOR Sizes range from 10 Hp to 75 Hp capacity for individual unit or multiple installation. In self-contained Con densing Unit models for city water or cooling tower appli cation or Compressor Unit models for use with evaporative type condensers. AIRTEMP "ALL-IN-ONE" AIR CONDITIONER The Airtemp "All-In-One" is a complete system, all in one cabinet . . . cools and dehumidifles, filters and circulates, with positive ventilation; for free discharge or duct distri bution of the conditioned air. Heating coil and humidifier can be furnished for connection to existing heating systems. Compact--Entirely self-contained and all working parts compactly enclosed within a finished metal cabinet. Two sizes and capa cities for single or multiple installation meet all requirements for dependable low-cost air conditioning in stores, shops, offices etc. Engineered Especially For Air Conditioning. Practically no vibration ... an in herent characteristic of radial design ... all parts balanced. . Direct connected ... no belts, no flywheel. Operates at standard motor speeds. Economical--high volumetric effici ency, large gas passages, large valves and ports, and low friction insures low operating costs at all loads. Forced-feed lubrication for smooth running and long life. Automatic starting unloader permits starting without load. Automatic capacity regulator keeps machine constantly balanced to vary ing load requirements while running at constant speed . . . economical. Operates at peak efficiency under all loads. Shipped completely assembled . . . easily installed. Write for Bulletin No. L-336. Model No. 3 SC 5 SC Hp Cap. 3 5 Free Air cfm 1200 2000 Approx Dimens, (inches) L W>H 33 20 1 89/2 34 20 | wy. Efficient--Unusually quiet, trouble-free operation assured because of the Airtemp hermetically-sealed Radial Compressor which is suspended from single rubber mounting. Readily Installed--Completely assembled and factory tested . . . delivered ready for installation. Approved by Underwriters Laboratories, Inc. 896 Air Conditioning, Automatic Healing Systems /9/PTEMP M 0/ tf/S/O/V OF CHRYSLER CORPORATION - DAYTON, OHIO AIRTEMP DIRECT-FIRED WINTER AIR CONDITIONERS Quality and Dependability at Low Cost Cut-away view of model 0-125 Winter Air Conditioner. A complete line of compact, dependable winter air condi tioners that heat, humidify, filter and circulate the air at cost of heating alone. These units are designed around a one-piece copper bearing steel furnace body that is gas tight and compactly enclosed in an insulated finished metal cabi net. Light in weight, eco nomical in floor space, with either oil or gas fired models. Model 0-125 Winter Air Con ditioner with enclosure Jacket. Model No. 0-123 0-163 0-200 0-250 OIL burning models Btu/hr. Output* Rating at Bonnet Floor Dimens, (inches) LW 100.000 130.000 160.000 200.000 40 y. 49% 55 28 35 37 41 Approx. Net Weight Lb 438 625 710 848 Model No. G- 87 G-125 G-163 G-200 C-250 GAS BURNING MODELS ACA Rating Input* Btu/hr- Floor Dimens, (inches) LW 87.000 125.000 163.000 200,000 250,000 18 40 45% 49'/* 55 26 28 35 37 41 Approx. Net Weight 310 418 605 685 828 Nominal Rating SO per cent Efficiency. Nominal Output 80 per cent of Input. Maximum efficiency and low operating costs are built into Air temp Boilers. Matched coordi nated design of boiler and burner, ample heating surface to insure full rated capacity and quick heating, fire chamber surrounded on all sides including bottom by water sections and jacket insu lated with rigid sheet asbestos surfaced with reflective alumi num foil. ' AIRTEMP OIL BURNING Steam Water Boiler Boiler Model Model No. No. Installed* Sq Ft Radiation Steam Water OS-2 OS-3 OS-4 OS-5 OS-6 OS-7 OW-2 OW-3 OW-4 OW-5 OW-6 OW-7 280 490 665 840 1010 1200 445 735 1000 1260 (540 1780 BOILERS GAS BURNING Steam Water Boiler Boiler Model Model No. No. Installed* Sq Ft Radiation Steam Water GS-2 GW-2 GS-3 GW-3 GS-4 GW-4 GS-5 GW-5 280 438 585 735 445 700 935 1175 Installed Rad. calculated equal to 70 per cent total EDR. AIRTEMP OIL BURNERS A high pressure, atomizer type burner for use in Winter Air Conditioners, Boilers, or Conversion work. Burns No. 3 fuel oil with adjustable oil pressures and air quantities. The quality and dependability of this burner is unique because of the High Velocity Blender which properly mixes the air and oil to give complete combustion, coupled with a Focused Flame tailored to fit the combustion chamber. Automatic, fuel control insures smooth, quiet operation and control of oil to the last drop at nozzle tip. Long Life flexible Duprene coupling minimizes wear on pump and motor. Available in four sizes ranging from I to 9.5 gallons of oil per hour. 897 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 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 no thermostatic traps are required on the return connections of the radiators. A thermostatic air eliminator is provided. If the pressure, through inadvertence, should exceed the design pressure, steam will enter the return lines, close the vent port of. the air eliminator, and 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. It can be used in^ny size building and has been installed in buildings requiring up to 60,000 square feet of radiation. "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-Ori fice may be adjusted per manently to "meter" the correct amount of vapor to each radiator according to its capacity, to effect balanced heating. 898 Air Conditioning, Automatic Heating Systems AMERICAN RADIATOR COMPANY division or American 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 898 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, leakproof, 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. ARCO AIR CONDITIONERS ARCO AIR CONDI TIONERS 101-B, 201-B ARCO AIR CONDITIONER Designed to be part of SERIES "RH" American Radiator Con ditioning Systems, Arco Air Conditioners add Fresh Air Ventilation, Humidification, Air Clean ing, Circulation to any radiator heated home or small building. Needing only simplified air mains, Arco Air Conditioners are especially suitable for modernization work. ARCO AIR CONDITIONER 1101-B Combines in one jacket No. 11 Oil Burning Boiler, Arco Air Conditioner and Taco Heater for domestic hot water. ARCO AIR CONDITIONER 301-B For larger homes--pro vides heat as well as air The Arco Conditioner, Series "RH," is a quiet, compact and economical air conditioning unit for residential and smaller com mercial buildings. The inherent simplicity and advanced features of design result in a unit flexible in application and constructed of' the best materials which will de liver the benefits of air condition ing at a cost comparable to that of an ordinary heating system. conditioning in conjunc ARCO HUMIDIFIER No. 8000 tion with steam or hot Adds correct moisture water boiler. to radiator heated homes. Needs only one 3 in. main. Easily con nected to any boiler. ARCO AIR FILTER 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 base ment wall or ceiling. Bjows humidified air through a7 short duct and outlet grille into the rooms above. (See also American Radiator Co. pages 940-941 and Subsidiaries) 899 Air Conditioning, Automatic Heating Systems American Gas Products Division of American Radiator Company 40 West 40th Street, New York, N. Y. Gas Fired Air Conditioners AGP AIR CONDITIONERS FEATURE: Space Saving Design. Factory As sembled FanMotor Unit. Factory As semb1ed Heating Sec tion of cored cast iron. Single Com b ustio n Chamber. Single Ther mo s t a t i c Pilot. Sirocco Type AC Fan. High Effi ciency. Quiet Opera tion. ' Counier-Flcno Type--Type 2-FE Parallel-Flow Type--Type 1-FP RATINGS--DIMENSIONS--DATA ACP Guaranteed Ratings Conditioner Number AGA Rating Input Btu/hour Output at Bonnet Btu/hour Output at Registers Btu/hour Conditioned Space Cu Ft Maximum Fan Cfm at 65 F Cfm < at Discharge Approx:mate Shipping Weight Lb 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-FE-I0-I00 2-FE-I0- 80 2-FE-I2-I00 2-FE-I2- 80 l-FP- 4 1-FP- 6 l-FP- 8 l-FP-12 90.000 100.000 M 2.500 125.000 135.000 150.000 180.000 200.000 225.000 2S0.000 270.000 300.000 56.000 85.000 100.000 150.000 72.000 80.000 90.000 100,000 108.000 120.000 144.000 160.000 180.000 200.000 216.000 240.000 44.800 68.000 90,000 >20.000 64.800 72,000 81.000 90.000 97,200 108.000 129.600 144,000 162.000 180.000 194.400 216.000 40.300 61.200 72.000 108.000 10.600 14.700 13.300 I8.40Q 15.800 22.000 21.100 29.400 26.600 36.600 31,700 44,000 8300 12,600 14,800 22.100 660 920 830 1150 990 1375 1320 1840 1660 2290 1980 2750 520 790 930 1380 785 1060 990 1325 1180 1585 1570 2120 1980 2640 2360 3170 600 910 1070 1590 1210 1210 1290 1355 1355 1420 1760 1775 2275 2315 2450 2500 510 627 813 1013 Note: AGP Guaranteed Ratings are based on thermal efficiencyof 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 Space 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 951) 900 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. 38-A catalog and price list. No. S. P.-15 Barber Burner Unit 12i~ No. P.13.-160 Burner Unit No. C. U.-90 Barber Burner with Safety Pilot Barber Gas Pres sure Regulators A.G.A. Approved Made in the following sizes: X'.H'.X*. AX *. r. iK'. IK'. 2". 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, Confect ioners' Stoves, Vulcanizing Machines, Pressing Machine Boilers, Japanning Ovens, CoreOvens, Banana Room Heaters, Other Appliances. Conversion Burner for Round Furnaces or Boilers Round Burners are adjustable as to diameter, on the job, to fit practically all grate sizes. 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. 324-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. 901 Air Conditioning, Automatic Heating Systems Delco-Frigidaire Conditioning Division General Motors Sales Corporation GENERAL MOTORS Dayton, Ohio A complete line of air conditioning and automatic heating products, in cluding: Condensing units, coils, self-contained room conditioners, selfcontained store conditioners, central system units, remote units, suspended units, evaporative condensers, oil burners, coal stokers, oil and gas fired boilers, oil and gas fired winter air conditioners, split system units, automatic water heaters. Write to Delco-Frigidaire, Dayton, Ohio for latest information and . detailed specifications, or consult local Delco-Frigidaire distributor whose address is listed in the classified section of your telephone directory. CENTRAL SYSTEMS COMPRESSORS Frigidaire automotive type air conditioning Con densing Units, which produce more cooling per dollar of water cost and per kilowatt of power consumed, are available from % to 50 hp in size, for use with : evaporative condensers, water towers or city water. Air cooled models available up to 3 hp. 10 hp Condensing Unit CENTRAL PLANT UNITS Frigidaire Central-Duct type Air Conditioners make available the advantages of a properly engi neered unit, built under strict factory control, to meet the requirements of centrahduct air conditioning systems. Available in vertical and horizontal models with a nominal capacity range of 6-24 tons. Heating coil optional for winter use. 6 Ton Central System Unit 40 Ton Evaporative Condenser EVAPORATIVE CONDENSERS Frigidaire Evaporative Condensers are designed for use with Frigidaire air conditioning condensing units. Their use reduces necessary water consumption, and makes it possible to provide economical and efficient installations in localities where water is scarce, of poor quality, available only ^t high rates, or where use is restricted. Available in six sizes with a nominal capacity range of 3-40 tons. 902 Delco-Frigidaire Air Conditioning, Automatic Heating Systems UNIT AIR CONDITIONING RSA Room Conditioner ROOM CONDITIONERS Frigidaire self-contained Room Conditioners, models RSA (air cooled) and SC-81 (water cooled) are designed for single room installations. Portable model RSA powered by famous Meter-Miser mechanism; can be used year 'round for filtering, circulation and ventilating in addition to true summer air conditioning; needs only power and window connection. Model SC-81 needs power, water and drain connections. Thermo static control furnished as standard equipment on both models. Both models nominally rated at ton capacity. STORE CONDITIONERS Frigidaire self-contained Store Conditioners are completely self-contained, incorporating the condensing unit, fans, coils, filters and controls within compact, attractive cabinets. Frigidaire Store Units provide cooling, dehumidification, fil tering and air circulation. A heating coil may be added to furnish a positive circulation of warm filtered air for winter service, if desired. Directional grilles on the 3 and 5 ton models provide proper distribution to meet the space require ments. Models are available with nominal ratings of 3, 5 and 10 tons. These can be installed either within conditioned area (except 10 ton model), or in adjoining space. Units are ideal for short leases, as they may be removed and reinstalled in new locations in but a few hours. 9-Ton Store Unit AUTOMATIC HEATING OIL BURNERS DelcoOil Burners employ the highly efficient pres sure atomizing method of breaking the liquid fuel into fine particles for complete combustion. In the Delco Oil Burner with the Rotopower unit, all rotating parts are built as an integral unit on the motor shaft. Available in 5 sizes in standard voltage characteristics with combustion rates from 1-30 gal per hour or a capacity range from 440-12,000 sq ft of steam, EDR. Residential Burner Typical Stoker COAL STOKERS Delco Stokers are designed to provide automatic firing for coal-fired domestic heating plants. Are of underfeed, screw type with intermittent coal feed. Two 30-pound and one 50-pound stokers, burning bituminous coal, make up the line. Automatic controls, sectional tuyeres; Coal Control; automatic air control, rubberlined corrosion-resistant hopper, hopper gas eliminator and sound insulated mechanism in deluxe models mini mize the time and effort of attention and provide unin terrupted heating service. 903 DelcO'Frigidaire Air Conditioning, Automatic Heating Systems AUTOMATIC HEATING AUTOMATIC BOILERS Delco Automatic Boilers coordinate the Delco oil burner or Delco gas burner with a boiler of special design and con struction for application on hot water, steam, or vaporvacuum heating systems. Most oil-fired models incor porate the famous Delco Oil Burner with the Rotopower Unit. Boilers are honey-combed with water-filled fins. When sections are fitted together, fins form a series of passes, exposing a maximum of water-backed surface to the heated gases. Two models, the DB3 and DB4 in corporate the exclusive Quik-Action Heat Transmitter which provides quick, radiant heating and renders the previous slow heating fire clay refractory lining of the combustion chamber unnecessary. Five oil fired auto matic boilers, with capacities ranging from 350-1,335 sq ft. of steam, DR, and one gas fired model with a capacity of 800 sq ft of steam, EDR, are available. DB-S Boiler HC-20 Conditioner "SPLIT SYSTEMS" Delco Residential Air Conditioning Units are furnished in two sizes and styles, the HC-20 and HC-40, and are particularly designed for use with Delco automatic boilers. Are of horizontal, sus pended type and operate in conjunction with a duct system. Units are designed for four major types of applications: (i) "Split System" heating and humidifying units in connection with an ex ternal source of steam or hot water, together with separate radiators; (2) as "Indirect" heating and humidifying units for use with external source of heat, where no radiation is used; (S) as year 'round units, requiring external heating and cooling sources; (4) HC-20 may also be used as a humidi fier, by substituting a tempering coil. CONDITIONAIRS The- Delco Conditionair is a compact, completely automatic unit, oil or gas fired, which provides, true winter air conditioning by circulating cleaned, humidi fied and properly heated air. Model DAO Delco oil Conditionair incorporates the new, exclusive QuikAction Heat Transmitter. Air flow resistance reduced to a minimum by tear drop design, heat transferred to the flowing air from a large heating surface, dotted with heat projectors, moisture then added by pan, cascade or spray type humidifier. Cooling attachment can easily be added for year 'round use. In Delco gas conditionairs there is a sufficient range in sizes to permit selection of the proper unit for applications ranging from a small six room house (85,000 Btu heat loss or less) to a large mansion (255,000 Btu heat loss or less). Delco Conditionairs, oil fired, range in size from 85,000 Btu heat loss to 280,000 Btu heat loss. 904 Smell Coitditionair Air Conditioning The Excelsior Steel Furnace Co. 118 S. Clinton Street Chicago, III. Brooklyn, N. Y. Branches St. Paul, Minn. Kansas City, Mo. EXCELSIOR WARM AIR HEATING EQUIPMENT UNIQUE OIL BURNING AIR CONDITIONER Made in three sizes: Bl--121,000 Btu. 670 to 1300 cfm. B2--141,000 Btu. 1160 to 2100 cfm. B3--161,000 Btu. 1160 to 2100 cfm. Unequalled for economy, heating efficiency and quietness. EXCELSIOR WARM AIR FURNACES ERA Cast iron.' Made in six sizes, rated 336 to 869 sq in.' warm air pipe capacity. SUPERLIFE Chrome-alloy cast iron of similar design with 20 year guarantee. FAMOUS Cast iron. Made in three sizes, rated 595 to 843 sq in. warm air pipe capacity. STEEL FURNACES Two models ranging from 461 to 1217 sq in. warm air pipe capacity. FAMOUS EXL-AIR Square cased Units with blower, blower switch and automatic humidifier. Made in three sizes, rated from 111,600 to 158,700 Btu and 670 to 2100 cfm. Standard model permits side stoker installation. EXCELSIOR FORCED AIR DUCTS AND FITTINGS Standardized, prefabricated ducts and fittings for forced air and air conditioning installations. Full information on our complete line of Warm Air Heating Equipment upon request. 905 Air Conditioning, Automatic Heating Systems Gar Wood Industries, Inc. AIR CONDITIONING DIVISION QafWxxf 7924 Riopelle St., Detroit, Mich. Licensed Distributors in All Principal Cities TEMPERED-AIRE UNIT The Tempered-Aire heating and air-conditioning equipment made in six (6) 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 b.y 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 is a steam tube within the firebox, assuring simple and prompt humidification. The new line of Tempered-Aire units (Models 101, 201, 301) have many improve ments including the new Model "O" oil burner and new cabinet design (see cut opposite). The oil burner starts, operates and cuts off smoothly even with widely varying draft con ditions. Combustion is clean, quiet and ef ficient, due to the improved manner in which the air and oil are mixed to make a sunburst shaped flame. CO? is exceptionally high, and even greater economy than previous models is assured. Tempered-Aire Ratings and Dimensions Btu 1 Hour at Bonnet........................................... Btu 1 Hour at Grilles............................................ Air Delivery CFM................................................. Air Temperature at Bonnet............................. . Oil Rate. Gallons 1 Hour....................................... Heating Surface. Sq Ft.......................................... Filter Area, SqFt.................................................. Motor Horse Power-Burner................................... Motor Horse Power-Blower................................... Over all Length. Inches......................................... Over all Width. Inches........................................... Over all Height. Inches.......................................... No. 101 No. 201 100.000 80,000 . 1,000 160 1.00 54% 30 1/6 1/5 771/2 32 54 135.000 110.000 1350 160 1.35 64 30 *i/5 82% 32 54 No. 301 200.000 160.000 2.000 160 2.00 86% 40 1/6 1/3 92% 32 54 No. 104 225.000 185.000 2.250 160 2.25 176 60 1/6 1/2 140% 38 64 No. 105 300.000 245.000 3.000 160 3.00 220 77 1/6 3/4 156% 38 64 No. 105-C 400.000 4.000 160 4.00 220 77 1/4 156% 38 64 GAS FIRED TEMPERED-AIRE Built in a single unit, it provides air filtering, blower circulation, humidifying and heating. Furnace is made, of heavy gauge copper bearing steel. Thermostatically operated. ________________________ Safety con No. 90 No. 120 trols give full protec tion. Ap proved 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. I............... 135.000 101,250 90.000 900-1425 34 l/s hp 250 Watts 96% 40 160,000 135,000 120.000 1200-1900 34 l/5hp 250 Watt* 96% 40 906 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 Water Load--Sq Ft.............. Maximum Gross Steam Load--Sa Ft................... Maximum Gross Hot Water Load--Sq Ft........... 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 RI000 D 3.25 1000 1600 1500 2400 84 37% 59!/, R1400 D 4.50 1400 2240 2100 3360 II8 37*% 66 . RI800 D 6.00 1800 2880 2700 4320 154 37% 60 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. Burns No. 3 fueloil. Fully auto matic. Separate tank.- Capacities: 200 and 300 gal per hour 100 F tem perature rise. Over all widths: 28% in.; 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 tern- L perature rise. Both || d-I' 1 types have vertical j. rotary burner with jV| only one moving ^ part and for use with No. 2 or lighter oil. Model S60 Model S40 Highly efficient for installation in- existing heating plants. Pres sure atomizing type. Simple in design. Han dle No. 3 fuel oil. Sturdy, quiet, easily accessible. Fit any shape of firebox. CONVERSION OIL BURNERS Model "W" 418-8500 sq ft net steam radiation. Model "K" 418-8600 sq ft net steam radiation. Model "H" Up to 686 sq ft net steam radiation. Air Conditioning, Automatic Heating Systems GENERAL ELECTRIC COMPANY AIR CONDITIONING PRODUCTS Air Conditioning Department, Bloomfield, N. J. G-E Oil Furnace--Four sizes, LA-3, LA-4, LA-6 and LA-7 designed * for steam, vapor, or hot water radiator systems and for indirect heating with air conditioners. Boiler output, LA-3, 417 sq ft steam; LA-4, 555 sq ft steam; LA-6, 665 sq ft steam; LA-7, 1,250 sq ft steam. Steel boilers constructed in accordance A .5. M.E. boiler code. Approved by Underwriters' Laboratory, Inc. Fully coordinated-boiler, burner/ domestic hot water, controls in one enclosed unit made and guaranteed by General Electric. Low standby losses. Automatic Night and Day temperature control available with all units. G-E Water Circulator available with hot water models. G-E Oil Burner--Conversion unit for existing or built-up heating systems. Consists of motor-compressor, fan, burner head, and controls enclosed in an attractive gray metal jacket: Flexibility makes it applicable to varying sizes of boilers and furnaces. Tailored flame to conform to fire-box giving maximum efficiency. Models available for steam, vapor, hot water, and warm air systems. Easily installed and serviced. Oil rates from % to 3 gallons per hour. G-E Warm Air Conditioner, Oil Fired--Three sizes, LB-3, LB-4 and LB-6 consisting of combustion-heat transfer unit, centrifugal fan, humidifier, filters, controls, and neces sary air, oil, water and electrical connections, all enclosed in an attractive chrome-trim gray cabinet. Of direct fired type, developed especially for residential air conditioning, it circu lates clean, warm, moistened air through ducts. Automatic Night and Day temperature control available with both units. Total outputs are: 100,000, 133,000 and 160,000 Btu per hour respectively. G-E Warm Air Conditioners, Gas Fired--Conventional and verti cal models. Consists of combustion heat transfer unit, gas burner, centri fugal fan, humidifier, controls, and necessary gas, water, and electrical connections enclosed in attractive cabinet. Direct-fired air conditioner, developed especially for residential and small commercial air conditioning, which circulates clean, warm, moisened air through the conditioned space. Numerous sizes available tp meet heating requirements from 35,250 --216,000 Btu per hour, output, with air flows ranging from 400--2700 cfm. Approved by A.G.A. 90S Air Conditioning, Automatic Heating Systems G-E Gas Furnaces--Designed for steam, vapor or hot water svstems and for indirect heating with air conditioners. Tv-op 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 * ft steam. Automatic pressure, low water and temperature limit rontrol Gas regulation is gas operated to assure positive action. Cast iron sectional boilers meet A.S.M.E. boiler code. Approved by >1 .C.A. G-E Unit Air Conditioner--Type FD-30 --Consists of an enclosed sound-proofed 3 hp condensing unit, water cooled condenser, four row cooling coil, fan, filters, adjustable air dis charge, and controls all enclosed in a golden bronze cabinet. The unit is designed to be installed quickly and easily within the air con ditioned space of a general office or small com mercial establishment. Outstanding features include simplicity in design, easy accessibility, quiet operation, and simple installation per mitting easy relocation. G-E Unit Room Air Conditioner--Type AF-i--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 enclosed in an attractive walnut cabinet. The unit features high cooling capacity, low operating cost, ease of. installation and pleasing appearance. G-E Air Conditioner for Winter--Type HW-1 designed for win ter air conditioning of radiator heated homes. Includes filters, humidifier, tempering coil and radial flow aphonic fan. G-E Air Circulator--Types HV1B, HV1D (illustrated), HV2A, and HV2B for attic ventilation, air circulation and exhaust appli cations. Type HV1D also available with pedestal mounting for air circulation. G-E Condensing Units--Available in sizes from 1 hp through 50 hp. Several air cooled 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. G-E Central Plant Air Conditioners--A complete line of factory designed air conditioners for summer, winter or year 'round applications. Types HD-50, 100, 200 and 300 units include aphonic radial flow fan, filters, humidifiers, cooling coils and heating coils in combi nations which meet a wide range of air conditioning functions and required capacities. The larger sizes, Types HD-400, 500,600, and 700 include filters, humidi fiers, cooling coils, heating coils, to meet requirements of large, single and multi-zone systems. (See also Pages 1044-1045) 909 Air Conditioning, Automatic Heating Systems The Henry Furnace & Foundry Company Manufacturers of MONCRIEF 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. 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. Oil Fired Air Conditioner "SPECIAL" OIL FIRED AIR CONDITIONERS Unit No. Size of casing: . Width........................................... Height........................................... 75 .76 28' 71' 6n0o)// 1/6 6120 915 2 75.000 100 1.02 28' 71' 60)// 112 V* 6120 1225 2 100.000 Per Hour SIZES, CAPACITIES--Aristocrat Oil-Fired Units. G&i Plenums c . Warm Cold O U Air Air A b c D E F G |H 7 K L M N 3O v oCd 03 a w2 F u CO X i >3 j: 'o CO si cXXco Z so V 'o .S " o etSPS- coU. Input 1 125 9. 60^ 28 W4 18 20 28 20 28 125.000 1525 M2 '/* 8925 4 16x25 1240 1.28 150 175 ft 56ft 28 16 24 28 24 28 150.000 1830 114 8925 4 16x25 1265 1.53 52/2 28 5iy. 43'/. 5% 18 24 32 24 32 175.000 2200 114 % 11088 4 16x25 1365 1.8 200 561/. 60% 52'/2 28 5iy. 43'/.13y, 18 24 36 24 36 200.000 2440 114 M088 4 16x25 1455 2.04 275 97 64Vl 64 59 38 5iy. 5l'/j5V, 18 30 40 30 40 275,000 3350 214 ft 13248 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 'cfm 1Required Sq In. Heating I Surface' \ Gas Line No. of Burners Unit No. Casing Dimensions Plenum Size Inches Warm Cold Air Air A B cD EK L M N G-8 75 20 54 1/2 13 (4 32 16 14 80,000 61.200 110 1/6 2 16x25 748 G-12 75 26 54 13 19 32 22 15 120,000 91,800 112 V. 3 16x25 1124 G-16 75 34 54 12 .26 34 30 12 160,000 122.400 112 A 4 16x25 . 1500 ft. G-20 75 41 54 1 Vf 12 32 34 37 12 200,000 153,000 114 4 16x25 1879 G-24 75 49 54 12 40 34 44 12 240,000 183.600 114 5 16x25 2244 G-32 G-40 75 68 54 75 78y. 54 m \ft 12 12 52 66 34 34 60 72 12 320,000 244,800 12 400,000 306.000 214 214 v> % 6 8 16x25 16x25 2994 3740 G-48 75 94'/, 54 i ft 12 80 34 88 12 480,000 367,200 214 9 16x25 4480 5410 8115 10820 13525 16230 21640 27050 32460 , 1' IV/ w 1'/.' N CO 3 U. 2__| 6' 3 6' 4r 5 8' 6 8' 8 10 9' itr 12 ii' 910 With Cast Heating Element. Unit Casing Dimensions-- Size inches No. A B c U Et Plenum Size Warm Cold air air K L MN Blower Size Motor Hp Sq In. Heating Surface Grate Area Sq In. Cfm Re quired No. of Filters Forced Air Register Btu Coal Hand- Fired Forced Air Register Btu Stoker Fired 4020 66/4 40V4 62*4 /. 28 soy. 30 28 30 18 4422 68V, 42V 623/4 48'/, 30 soy. 32 28 32 20 4824 70Va 44/, 623/4 41)'/, 30 soy, 34 30 34 20 5226 78>/4 46V4 66 44'A 34 503/4 36 34 36 22 M0 112 M2 M2 y. y. y. M 5021 214 967 5609 269 1157 6010 326 1330 6753 397 1580 2 73.800 85,200 3 88,300 101,800 3 101,600 117,300 4 120,400 139,000 5628 82V 48'/, 66 48'/, 34 soy. 38 38 38 24 114 7579 472 1840 5 140,300 162,000 With Steel Heating Element. Blower Size || | Motor Hp Sq In. Heating Surface Grate Area Sq In. Cfm Required No. of Filters Forced Air Register Btu Coal HandFired Forced Air Register Btu 1 Stoker Fired | Unit Size No. Casing Dimensions---inches A B c D EF G Plenum Size Warm Cold air air K LMN 2054 2254 68>/4 70% 40V4 44% 62V, 62V4 40'/, 401/4 78 30 50% so# 35V, 39% 30 30 30 30 34 34 16 18 HO 112 SI'/,2456 74% 46V4 66 40'/, 34 50% 41 'A 30 36 36 20 M2 2758 74V4 67V, 40'/, 34 50% 46V, 30 42 42 20 114 3060 86V 54'/. 69 48'/, 38 50% 49V4 36 42 42 24 212 3060J 90V. 54% 69 71 48% 363462 901/4 60`A 55'/,3462J 9f/2 60'/, 71 52V, 38 50V4 491/4 40 42 42 24 212 42 50% 55V4 48 48 24 214 54'/, 42 soy. 42 48 48 24 214 V. V, V. % V? %y. 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 5 138,600 160.000 5 171,000 197,300 5 180,300 208,000 6 213,600 246,700 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. 911 Air Conditioning, Automatic Heating Systems Kelvinator Division of Nash-Kelvinator Corporation SUMMER AND WINTER AIR CONDITIONING Factories in Detroit, Michigan and London, Ontario Boston New York Factory Division Offices in Atlanta Cincinnati Chicago St. Louis Dallas San Francisco Distributors in more than 200 Cities FACTORY BUILT AIR CONDITIONING EQUIPMENT FOR EVERY REQUIREMENT No matter what the requirements are, from a self-contained unit for air conditioning a single room to central system equipment for complete building installations, Kelvinator perfected equipment will exactly fit the need. Evaporative Condensing Units. These factory-built units are available in all standard sizes up to 50 hp. Installation costs are saved because of unit construction of evaporative condenser. Use of spray discs instead of spray nozzles eliminates need for pumps, lowers power costs, and avoids a common cause of service interruptions. Condenser can be in stalled in any unused over-head space above condensing unit or in machinery room. Facto ry-built, assembled and tested before shipment, it is ready for duty as soon as it is mounted in position and connected. Construction features include: an all-gal- vannealed steel cabinet built on a heavy angle-iron frame, with removable panels to make the interior easily accessible for cleaning: the quiet-operating, centrifugal-type fan has ample .capacity for circulating and cooling; Kelvinator Evaporative Condensing Unit and 0 hp Compressor. condenser coils are fin type with wide spacing that facilitates cleaning; the brass spray discs which distribute a finely divided shower over tl\e 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 are available in all standard sizes up to 50 hp; air-cooled types from % to 5 hp, inclusive. - The use of air-cooled condensing units in sizes as large as 5 hp is made possible.by the Kelvinator refrigerant-cooled head. Large condenser capacities in the air-cooled models make efficient operation possible with high temperature condenser air. All water-cooled units have water-cooled compressor cylinder heads. Formation of carbonized oil is prevented by maintaining the temperature of the cylinder head and valve plate below the carbonization temperature of the oil. Water-cooled models of 10 hp and larger are equipped with shell and copper tube cleanable condensers. The condenser water passages 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. 912 Kehinator Air Conditioning, Automatic Heating Systems 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. Kelvinator Central System Air Conditioning Unit. Kelvinator Air-Cooled Room Cooler; completely self-contained. Self-Contained Air Conditioners for Single Room Installations. Air-cooled models in ^ hp and 1 hp sizes. Watercooled models in H hp, 1 hp and 1 x/i hp sizes. Provide cooling, dehumidifying, cleaning, and circulation. Outside air intake standard on air-cooled models, winter-heating coils optional. All models can be equipped with thermostat for automatic operation. Kelvinator Room Coolers can be moved to a new location as easily as other office or household equipment. 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. Complete cooling, dehu midifying, filtering, and air distribution. Heating coil and humidifier can be included in sizes of 5 tons and larger. This equipment is designed for installation right in the room to be air conditioned. Eliminates costly duct work; ideal for business firms holding short-term leases. Kelvinator Type C Suspended Air Conditioner; condensing unit remote. 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 require about the same space and cost little more than the radiator they may replace. They are particularly suit able for air conditioning bedrooms, hotel Kelvinator Floor-Type .1 ir Conditioner; con denser remote. guest rooms, hospitals and office suites and other existing construction where duct installation expense would be prohibitive. Kelvinator Store Air Conditioner. Designed to provide simplified, low-cost air conditioning in a self-contained unit for the average business establishment. Can be easily adapted to a variety of different situations. Where air conditioning is desired for several Kelvinator Store Air Conditioner adjoining rooms, the unit can be installed at a convenient,, centrally located point and ducts run to the spaces to be air conditioned. Simplified provision for air return can be made by use of air grilles or louvers in inner office doors. Completely self-contained, factory-built, it can be installed easily and quickly; requires no expensive installation and can be readily moved to new quarters. 913 Keloinator Air Conditioning, Automatic Heating Systems Residential Air Conditioning and Automatic Heating Equipment 25 years of experience in manufacturing controlled temperature appliances is back of Kelvinator's year-Tound air conditioning and automatic heating equipment. Developed in the Kelvinator Research Residence, it has been proved in hundreds of Kelvin Homes throughout the country. These homes provide new scientific advances in year-'round comfort and household conveniences for families of moderate income. Year-'Round Air Conditioning System. Kelvinator's residential air conditioning system is of the indirect type. The air is heated by a steam coil in the conditioner. Steam is supplied by an automatic boiler. This boiler also furnishes heat to radiators for heating those parts of the house where conditioned air is not required. Kelvinator Exacl Selection Control Panel assures "Finger-Tip" Selection of Con ditions to be maintained. The illustration shows the auto matic oil-fired boiler (left), the air conditioner (above at center), and the con densing unit for summer cooling (inside the small room at right). The Conditioner. The conditioner contains a heating coil, cooling coil, filter, hu midifier 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 mechanical 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 humidistat in winter. Four sizes with air deliveries up to 2000 cfm pro vide for conditioning any size home. Multiple units .. Kelvtnator Type RC Conditioner. can be used for zoned systems in large residences. ' The Comfort Damper. The comfort damper, controlled by the Selector, permits outside air to be brought to the conditioner, filtered and circulated throughout the house. Mechanical cooling load is reduced and operating costs are cut in summer through the introduction of cool, night air and discharge of warm air. The comfort damper takes full advantage of the cool ness of night air. 914 Keloinator Air Conditioning, Automatic Heating Systems Pontrols Kelvinator residential air conditioning features the finger tip Exact Election control. However, desired temperature and humidity may be automatically 56 'ntained with the thermostat and humidistat. Beside these a conveniently located eSertor panel contains switches by which conditions to be maintained may be selected. 5?le | placing the three toggle switches in the up position establishes the system in iimer operation; placing them in the down position selects winter operation. The marv switch provides for (1) a completely off position for the air circulation system; a position in which the air circulation cycles under control of the thermostat; (3) com fort position which controls the comfort damper, stopping recirculation and allowing the ntroduction of 100 per cent outside air circulation. With this Selector it is not necessary to call a service man to change from summer to winter or winter to summer operation. Kel-O-Flame Oil-Fired Boiler. 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 work ing parts are easily accessible for adjustment or service. Each unit is complete with fully automatic controls, including a low-water cut-off for steam boilers, safety stack switch, safety limit control, summer hot water con 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/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 combina tion valve supplies gasf under constant pressure whenever the thermostat calls for heat. Jacket is fully insulated. Com plete automatic control equip ment is provided, including a Kelvinator Gas-Fired Unit Boiler. low-water cut-off, automatic elec- trie or gas-failure shut off, and an electric limit control. Kelvinator Oil-Fired Conditioner. Oil-Fired Conditioner. 4 lines with capacities from 100,000 Btu/hour to 250,000 Btu/hour. This conditioner filters, heats, humidifies and circulates the air to accomplish complete winter air conditioning, and to provide automatically a more comfortable atmosphere in the home. Kelvinator Conditioners are appropriate in their size and appearance for any home requirements. Completely factory-built for high efficiency and low operating cost. 915 Keloinator Air Conditioning, Automatic Heating Systems Gas-Fired Conditioner. Available in 3 lines, 4 models in each. Capacities from 90,000 Btu/hour to 200,000 Btu/ hour. The Kelvinator gas-fired conditioner is a completely automatic heating system making use of gas. This con ditioner maintains uniformly comfortable temperatures and also accomplishes a complete winter air conditioning effect by cleaning, humidifying and circulating the conditioned air throughout the house. The gas-burning unit is of the atmospheric, individual port, up-shot type with automatic gas valve pressure regu lator. Safety pilot prevents opening of main control valve in the event that flame should be extinguished. This insures absolutely safe operation. Kelvinator Oil Burners. Kelvinator conversion oil bur ners are especially developed to insure quiet, dependable, and efficient performance in con Kelvinator Gas-Fired Conditioner. ventional heating plants. They employ the pressure-atomizing principle. By means of a scientifically designed turbulator and air de flector, 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. Kelvinator Con Seven models of burners may be fired at oil rates from version OH Burner. 1.25 to 25 gal an hour with capacities up to 2,270,000 Btu/hour. Kelvinator Coal Stokers. Kelvinator Automatic Coal Stokers introduce important improvements in the automatic firing of bitumi nous fuels. They utilize the proved underfeed principle. Gases, ordinarily wasted, are scien tifically released and thoroughly burned over a slow-burning coke fire. Combustion is com plete and smokeless. Burner is made of nickel-steel tuyere seg ments, with special air vents which distribute air uniformly to the fuel bed. A controlled air- damper regulates air flow automatically, and holds the fire down when heat is not required. . Kelvinator Coal feed is by a cast steel tapered worm, full Automatic Coal Stoker. 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 accessible 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. Construction provides easy accessi bility of all working parts for adjust ment or service. Coal hopper of smaller, household size models, holds more than a day's supply of coal. 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/hour. Kelvinator water-cooled condensing unit for summer cooling. Kelvinator Condensing Unit See paragraph on Kelvinator Con densing Units under Commercial Air Conditioning Section. 916 Air Conditioning, Automatic Heating Systems he Me/er 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. Nbb. 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 Ratio Smoke Grate Htg. to Outlet No. Surface Grate Diam. (Sq Ft) Surface (In.) Gravity Circulation Casing Dimen. Rated Output Round Rect'lar At Reg. Pipe Area (In.) (In.) (Btu. Hour) (Sq In.) Fan Circulation Casing Dimen. (In.) Air RatedOutput Delivery . at register (CFM) (Bti/Hour) 621 1.26 624 1.78 628 2.32 630 3.08 633 3.82 636 4.74 MO 6.25 M4 7.60 22.7 18.5 10 10 10 10 10 12 12 52 54 58 65 67 47x50 50x52 54x56 56x64 56x66 54 400 73i600 94,100 119,000 138,000 160,000 400 541 47x90 1200 692 50x99 1600 875 54x103 2000 1015 56x110 2300 1160 56x118 2700 60x106 4000 64x114 5000 92,000 118,000 148,000 172.000 200.800 264,000 316.000 WEIR Oil Fired A ir 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.C.A. approved. No. Input at Burner (Btu/Hour) Output at Bonnet (Btu/Hour) Vent Diam. (In.) Dimensions W. L. R (In.) (In.) (In.) Air Delivery Va In.S.P. (CFM) Motor Size (HP) MEYER Gas Fired Air Conditioner 125-A 175-A 225-A E-I0 E>15 E-20 E-30 E-45 C-100 C-120 C-150 165.000 260,000 335,000 110.000 165.000 220.000 330.000 495.000 100,000 120.000 150,000 WEIR Oil-Fired Air Conditioner 125.000. 8 48 68 48 1700 175,000 8 56 68 48 2300 225,000 8 63 68 48 3000 a 1/3 1/2 MEYER Gas-Fired Air Conditioner 88.000 132.000 176.000 264.000 396.000 5 32 69 45 1200 6 41 69 45 1800 7 53 69 45 2400 9 69 69 45 3600 10 97 69 45 5400 >/ 1/3 1/3 1/2 3/4 MEYER Gravity Gas Furnace 75.000 90.000 112,500 5 6 38 42 38 42 60 67 Complete descriptive literature, including 6 42 42 67 cooling, upon request MEYER Gravity Gas Furnace The MEYER Gas Furnace--Efficient--Economical--All Steel, welded heating section, die-formed insulated casing. A.C.A. approval. ' 917 Branches St. Louis Memphis Omaha Minneapolis Salt Lake Cm 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 PrTTSBUBGH 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 Healing Systems Mueller Heaters For All Fuels A Complete Line for A11 Purposes Return Flue all-cast Fur nace. 18 in. to 30 in. firepots, single and double firedoor styles. Available in round, galvanized or square, 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. Available in sizes from six to twenty sections, with AGA output ratings from 216,000 to 720,000 Btu per hour. Gas Era Cast Iron air conditioning furnace. AGA input rating, 65,000 Btu per hour, per section. Wide range of sizes and air delivery capacities. Gas-fired air con ditioning furnace. AGA input rating, 45,000 Btu per hour, per section. Wide range of air deliveries. Muelleraire unit. Gas-fired with fan, filters, and humidi fier. 5 sizes--AGA input ratings, 72,000 to 180,000 Btu per hour. Series "A" Gas Boiler. AGA ratings, 180 to 1,260 sq ft steam; 290 to 2,015 hot water. Series 60 oil-fired air con ditioning furnace. Bur ner optional. Two sizes, 110,000 and 165,000 Btu per hour. Series "SA" stoker-fired furnace, with fan-filter unit. Any stoker may be used. Capacities, 110,000 and 175,000 Btu! Horizontal Tubular Heaters, for schools, churches and other large buildings. Three sizes, with cap acity range from 1,188,000 to 1,390,000 Btu per hour. Complete catalogs on each of above units available upon request. 919 Air Conditioning, Automatic Heating Systems Williams Oil-O-Matic Heating Corporation Manufacturers of Automatic and Manually Controlled Fuel Oil Burners Bloomington, Illinois Service to Architects and Builders Chicago. III.. 641 N. Michigan Avenue ' New York, N. Y., 2014 Graybar Building For Williams Ice-O-Malic Refri&erolion Equipment, see File Index A Complete Line Williams Oil-O-Matic offers sixOil-O-Matic burner models--a genuine Williams Oil-O-Matic for every size and type of house, for every apartment, public building or commercial structure. Also, thenew WilliamsHP-3 (high pressure) model. Complete boiler burner and furnace-burner units; a new typeof oil-burningauto- OnSflCmatic water heater; an oil burning range burner for heavy duty ranges are availal e. Oil-O-Matic Water Heaters 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 travel which transfers all possible heat to the water. See specifications lower left. Heating Capacities of the Various Williams _____________Oil-O-Matic Burners if!Model .c A e 1 J Gal*. Fuel Oil per Oper 5 c 4a & 1 . 1^ *c a. a. XX ating Hour Mini Maxi mum mum K-150 125 LK-3 k.-*/5 K-7 M800 145 170 175 255 295 115 (highpTM**ure) 29 30 33v3A'/j 45 50 30 ISK wmi/wmo 20K1!/I0]|800 2UW 22j|l/5 |l800 ny. 21^1/5 1800 20 24 1/2 1800 32 24 |l |l800 17 18 1/101800 Vi 1 2H 4 8 12 135 I'/i 3 47 /i 15 25 .3 Standard draft pipe IS in. I2-in. length draft pipe optional. Standard electric current is 110-volt. 60-cycle. 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 WHAT 600 57 22H 28 1/fOllSOO WHBf 885 75 23 WHC{ 1385 90 29 28 l/H I860 Vi 34 1/ICijisoo 1 iy. *Output: 90 F rise, 60 gal per hour. fOutput: w F nse. 120 gal per hour. {Output: 90 F nse, 210 gal per hour. .r 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, Evans Oil-O- * Matic, International Oil-O-Matic, Kruse Oil-O-Matic, Orr& Sembower Oil-O-Matic, Waterman-Waterbury Oil-O-Matic Boiler-burner units automatically pro vide domestic hot water supply the year 'round. Indirect heating coils may be included for either instantaneous or storage tank systems. Furnace-burner units pro vide winter air conditioning. Horizontal Boiler-Burner Unit A complete Oil-O-Matic product, con sisting of a boiler and Oil-O-Matic oil burner. It is furnished for both steam and hot water systems. The welded steel tank used meets A.S.M.E. code specifications for operating up to 15 lb pressure. Boiler capacities are: 610 sq ft equivalent direct steam radiation; 980 sq ft equivalent direct hot water radiation. 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 tip). . For exact detail data, see Oil-O-Matic Installation and Service Manual. Underwriters* Listing ' Listed as standard by Underwriters' Laboratories, Inc. Also approved by all important codes and governing bodies. Fuel Oil Range Burners Williams Oil-O-Matic fuel oil burner for use with heavy duty ranges in restaurants, hotels, hospitals, steamships, dining cars, resorts and clubs. 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. 920 Air Conditioning, Water Treatment Oakite Products, Inc. 22 Thames Street, New York, N. Y. Branch Offices and Representatives in All Principal Cities oj the U. S. OAKITE AIREFINER 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 of 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 sale, 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. 921 Air Filters The Air-Maze Corporation 5202 Harvard Avenue, Cleveland, Ohio ENGINEERS AND MANUFACTURERS OF AIR FILTERS EXCLUSIVELY Direct Factory Representatives in All Industrial Areas. 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 alt fields of application. low and 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 oper ations, 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 condi tioning and power equipment installations AIR-MAZE panel filters are effectively used in humidifiers, water eliminator units, 1 paint spray-booths, oil separators, ahd . other applications where specific problems ' and unusual requirements are easily han dled by adaptations of the panels. AIRMAZE panels will be made to fit frames of existing installations and can be furnished with locking handles and latches, or with flanged edges and lift handles. 4 in. Thick Panel t 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 \ Magnified Section of "Loaded" AIR-MAZE Air Filter Element. Note that dust has been quite evenly impinged on the wires. No obstructed spaces can be seen. This feature accounts for the Low Pressure Drop and Non-clogging characteristics ofAIR-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 lj^to 2^6 cfm per square inch. Thus, the capacity of a 20 x 20 in. panei is 600 to 1000 cfm. Normally, 2 cfm per square inch should be used. . . " 922 Air Fillers The Air-Maze Corporation 5202 Harvard Avenue, Cleveland, Ohio Resistance--For 2 in. thick panels the resistance varies from 0.089 in. to 0.10 in. H O when handling 2 cfm per square inch of'filter area (288 fpm velocity); and for 4 in thick filters the resistance varies from o 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-2A. 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 ar ranged with precision so as to create gradu ated and progressive density, and to positively embody the baffle impingement principle. The filter element is enclosed in a heavy gauge 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. 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; or spray with oil. Any inexpensive oil of S.A.E. 20 viscosity or heavier is suitable. If using the immersion method, panel should be removed from charging tank, placed on open end edge, and drained thor oughly. 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 constructed 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 to gether 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 dimen sions 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 adr dition to the panel types, Air-Maze Cor poration also manufactures a complete line of circular shaped air filters for use in various Railroad, Industrial and Auto motive applications. Literature Available--Bulletins GPB97, PPS-38, and PI-107R: covering com plete panel filter details. Graphs G-ll and G-12A: showing results of tests made with A.S.H.V.E. Code Test Apparatus. Folder RR-18: describing railroad air filters; and complete catalogs covering the entire AIRMAZE line. 923 Air Filters American Air^FilterCompany 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 biters, 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 M/W g Filler integral part of large central systems. These are usually of the fully automatic type such as the Multi-Panel filter, illustrated in the accompany- ingphotograph. There are now available to manufacturers ok 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 Throway Air Filler 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 arid 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 924 American Air Filter Co., Inc. Air Fillers easily removed without Jhe useof tools, and filter 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 oeriod 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 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 Sell-Clean ing Filter--Developed es- Armored 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-Panel filter curtain showing unique construction of new Armored Panel. Dark 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 Armored 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. Unimalic 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. 925 Air Filters Coppus Engineering Corporation 339 Park Avenue, Worcester Mass. MANUFACTURERS OF AIR FILTERS, STEAM TURBINES, GAS BURNERS, 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" (E, Figs. 1 and 2) and a retainer grid (J5, 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. All metallic parts are rust-proofed and Duco Painted. Davies Air Filter Corp. 396 Fourth Avenue, New York, N. Y. Air Conditioning, Process, Building, Industrial Filters DAVIES TYPE M FILTER Specially designed for ventilating and air conditioning systems where high ef ficiencies are required and space for air filters is small. Sturdily built frames, 14 eauee cold-rolled steel, rust-proofed under finishing coat of baked enamel. Other finishes or metals supplied on request. Two frames with patented interlocking members, hold the filtering medium on wire mesh and produce an air-tight joint. Large filtering area is a special feature. The two filter frames are placed in a gaskets prevent leakage and insure high efficiency. Type M filter medium is specially pro cessed cotton with large dust holding capacity--supplied in rolls sufficient for 15 complete refills, 21 feet each. Specifications--Type M Filter Filter Cell--overall........... -................... 24 x 24 x 8 in. Effective Filtering Area.......... .............. .......... 40 sq ft Capacity recommended................... .............. 1200 cfm Maximum Capacity..-............ .......................1500 cfm Resistance--clean filter { 12 !m W. G,' Cleaning Efficiency........................... -......................98% Fig. 8 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). Dimension?: 20 by 20 in. by 5jh in. Weight per'unit; 251b. . Fig. S Outstanding Advantages 1. It has an exceptionally high dust arrestance: 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 926 Cleaning Filter Elements- with Portable Vacuum Cleaner' Method of loading: Heavy loader rods carry the cotton material into place. After a Utile practice, a filter can be loaded in forty seconds--special mechanical knowledge is not required. AIRPLEX RENEWABLE FILTER Airplex filter medium is cotton fibre, specially processed and lightly glazed. Each filter contains 30 sq ft of filter medium and gives 500 to 1000 hours active service. Functions efficiently in temperatures below freezing and up to 200 F. Not affected by tem perature or hu midity -- will not disintegrate. Filters can be cleaned several times before they are discarded. Each filter is a completecartridge -- replacement can be made Segment of Airplex Filler quickly, hence is Shoioing Corrugated Spacers not neglected. WASHABLE FILTERS--TYPE HG Filter medium of fine spun hair glass closely packed and secured between two sheets of galvanized wire cloth; these long flexible glass fibres do not break and can not be drawn into the air stream. Filter element supported in a steel frame, rust proofed or galvanized as required. Glass wool, being chemically inert, is not attacked by gases or liquids, will not rust or disintegrate, will last many years. Water, hot or cold, with or without grease solvents, used for cleaning, depending on type of air pollution. Segment of H. G. Filter Showing Wire Mesh Holder Standard Sizes Airplex Filter Stock Sizes--Type HG Filter Process, Industrial, Building.,.............20 x 20 x 4 in. fb l \Air Conditioning Units {--gj Frame Size )9Vi * 19'/2 in. l9'/2 x I9|h in. 16 x 25 in. Depth Filtering Surface Capacity cfm 2 in. 3% in. 3'/z in. 460 1053 1053 500 1000 1000 Pressure drop .12 .12 .12 927 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. Cutaway view illustrates how front side of curtain impinges dust on up travel and rear side on down travel --an exclusive "DoubleDuty'1 feature, giving eight acute deflections of air through both curtains "DOUBLE-DUTY" Self-cleaning Non-clogging Automatic AIR FILTERS Designed for industrial plant and large building air filtration. Operates on the True Impingement principle. ' Dust particles are freely and completely released when curtain plates immerse in oil bath. Cannot clog. Constant air flow re gardless of dust content of air. . Oil entrainment impossible, due to angular design of steel louvre plates. Oil needs never be changed--merely replenished. Standardized sectional construction ` meets all capacity requirements. Write for Bulletin D-110-AS "KOMPAK" Low velocity Dry fabric Renewable medium AIR FILTERS For general ventilating and air conditioning systems. "KOMPAK" affords maximum area of filter medium in minimum space, large dust holding capacity, high cleaning efficiency, long useful life, low structural resistance to air flow and low refill cost. Each unit contains 28 sq ft of filtering medium. Frames are of rust-proofed steel construction. Changing of filter medium re quires less than 5 minutes per unit and is only necessary every 3 to 6 months, depending on dust content of air. Write for Bulletin K-120-AS 928 Air Filters Owens-Corning Fiberglas Corporation Toledo, Ohio FOR APPLICATION TO RESIDENTIAL, COMMERCIAL and INDUS air filters TRIAL HEATING, VENTILATING and AIR-CONDITIONING SYSTEMS "FIBERGLAS" MEDIUM - ADHESIVE-COATED - REPLACEMENT TYPE The Dust-Stop Air Filter consists of a series of non-combustible mats of Fiberglas, progressively 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-evapo rating fireproof adhesive having extraordinary wetting power, will retain viscosity under operating tenv peratures ranging from 15 F below to 300 F above zero, will not flow . off or charge the air with adhesive ... Dust-Stop Air Filters are engineered to provide high efficiency at low cost of instal lation 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 blow ers, gravity and forced warm air heating systems, and air conditioning equipment of all kinds. 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 in combinations to accom DU5T-5TO? TYPE " FRAME modate for any cfm and space re quirement. STANDARD SIZES FOR EQUIPMENT* Standard Sizes (Nominal) 1ST x 25' a 2' 20* * 20* * 2' 16' * 25' x 2' 16' x 20* x 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 0.095r0.l0 Vtioerrv -Fter w Minute VgLOCITy-eCSISTAMCE CUBVE Other standard sizes available. . .Write Owens-Corning Fiberglas Corpora tion for information and data. 929 Air Filters Research Products Corporation 1011 E. Washington Ave., Madison, Wisconsin WALTON AIR FILTERS High Dust Removal Efficiency--Low Air Resistance--Long Life Walton air filters operate on the im pingement principle, using an entirely new filter medium--expanded fibre. Large, uniformly distributed area holds large quantities of dust yet cleans effectively, with low air restriction. Air flowing through the filter impinges against more than 30,000 tiny baffles per sq ft, de positing dust, and changing direction 21 times. To prevent clogging and insure uniform deposit of dust, the filter is made in three sections--at the inlet, coarse open mesh; middle and outlet sections progressively finer mesh; in each section a sticky com pound is applied in progressive amount. Progressive mesh and progressive sticki ness reduce clogging and insure high holding capacity. Exposed surfaces are free from excess stickiness--clean to handle. The sticky compound will not drip or volatilize at high temperatures, nor gum at low temperatures, and is odorless. , Walton air filters have been used success fully on warm air furnaces, ventilating and air conditioning systems, automobile air conditioning, industrial . dust collectors and wherever a filter is required for re moving dust and pollen from the air. Diagrammatic cross section of Walton filter. Three sections with progressively finer mesh and Progressive stickiness. Large dust particles ore trapped' by the coarse section, finer particles by the finer mesh--deposited uniformly throughout the filter. HIGH DUST REMOVAL EFFICIENCY The Walton filter maintains high clean ing efficiency for all common dust sizes. Because of its controlled mechanical con struction, blow holes do not form and pass dirty air. Efficiency of the filter actually increases as it becomes laden with dust. Dust particles deposited on the baffle surfaces absorb the sticky compound, and, in turn, retain additional dust particles. Vibration cannot settle or pack the filter and thus reduce its efficiency. Particles cannot N,break off and blow into the air stream. WALTON AIR FILTER STANDARDS Walton air filters are made in five standard sizes to fit most commonly used frames, special sizes for special requirements, and to standard or special specifications. Standard Specifications .Recommended air capacity____ 250 to 350]cfm per sq ft of face area Average efficiency (depending on type of dost)..________ 86.5 to 100% Holding capacity (standard dust)132 grams per sq ft Resistance when replacement is necessary at - 250 cfm per sq ft of face area_................................. 0.18 in. water Resistance when replacement is necessary at 350 cfm per sq ft of face area..0.55 in. water Standard Sizes 20 x 25 x 2 in. 20 x 20 x 2 in. 16 x 20 x 2 in. 16 x 25 x 2 in. 15 x 20 x 2 in. Special sizes for any purpose. Research Products Corporation engineers will gladly submit recommen dations for any special applications that may be required. . Air Filters H. J. Somers, Incorporated Factory and General Office 6063 Wabash Avenue . Detroit, Mich. Somers Washable Air Filter All Welded Vee Type These filters eliminate the necessity, replacement. . 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 and lasts indefinitely in service. Water either hot or cold may be used to clean it, without impairing its efficiency, expense and the inconvenience of periodic Somers Washable Air Filter--All Welded Vee Type--Stock Sizes (Partial List) :Frame Size Height and Length In. 151/2 X 24*/2 155/6 X 24% 16 x 21 % 16 x 25 16 * 25 16 x 25 16 x 25 16 x 25 16'/, 1 24'/, 18 x 18 19 x 20 m,i54 l9'/4 X 20 I9y. x 19'/, 19'/? x 191/2 191/2 X 191/2 I9'/S x I9'/j 19'/, x l9'/2 20 x 25 20 x 30 20 x 20 20 x 30 20 x 20 20 z 20 20 x 20 20 x 20 20 x 20 20 x 25 2oy, x 20% Frame Depth In. * 3* 3% 3)6 3'/. 3/4 . 3I/4* 3% 336 3'/b 336 3J6 3% 3 3 3*/4 2 3 3'A 336 336 l\i 3 y/4 2 3 3 3% 3`/4 3 Filter Surface Sq-In. 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 1023 mo 816 1056 1632 1344 1440 864 600 864 1482 1039 1039 936 1053 480 936 1170 1800 1800 1040 1560 1200 480 840 960 1320 1560 550 ' Wet Application where water sprays are applied against filter for hu inidifying CFM 511 555 408 528 816 672 720 432 400 432 741 519 519 468 526 240 468 585 900 900 520 760 600 240 420 480 660 780 275 Other sizes from 9>ij x 30 to and inclusive of 31 in. x 23) also available. Send for complete stock size list. Frames zinc plated for 100 hour salt 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 Fillers Staynew Filter Corporation Air Filters for Every Purpose -------mu--------6 Leighton Ave. .....,, 0 . ,L 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 (X) 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 Mulli-VType Cells i,, 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 without 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......................... ,,..........19H x 19^ 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. Total Weight ................................................... .v~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 frame. 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 filtering area, or for reasons of economy. (Protectovent Window Ventilator, which supplies clean, fresh air to home or office, Multi- V- Type employs Multi-V-Type inserts). Complete spedfiSfc./C/Snf fications mailed promptly on request. 932 Air Filters Staynew Filter Corporation Air Filters for Every Purpose 6 Leighton Ave. Rochester, N. Y. Wire-Klad Filter Sizes 20 in. x 25 in. Wire-Klad Units: Unique method of construction permits a high efficiency filter at low cost. Fins are reinforced on both sides with screen cloth, producing a rigid, long-wearing, flame-resist ing filter that may be repeatedly cleaned with vacuum or com pressed air, or flushed with water or liquid solvents. Made in 2 in. and 4 in..deep units. . Specifications 2 in. and 4 in. Units Capacity--Wool Felt Capacity-- Jo. 6460 Cotton 800 cfm. 0.13 in. wg 600 cfm. 0.12 in. wg 600 cfm. @ 0.11 in. wg 1000 cfm. @ 0.12 in. wg 800 800 cfm. cfm. @1 0.08 0.075 in. in. wg wg 600 cfm. 3) 0.07 in. wg 1000 cfm. 3) 0.08 in. wg Filtering Area sq ft 2 in. 18.5 2 in. 16.5 2 in. 14.8 2 in. 23.0 4 in. 38.5 4 in. 38.5 4 in. 30.7 4 in. 48.0 PROTECTOMOTOR 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 y 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. A utomatic Filter Write for Catalog Mentioning Special Interests Diagram of Automatic Filter PROTECTOMOTORS ALSO MADE FOR INTERNAL COMBUSTION ENGINES, COMPRESSORS, TURBO-GENERATORS, AIR TRANSMISSION LINES, ETC. 933 Air Flow Regulators Young Regulator Company Department G 4500 Euclid Avenue, Cleveland, Ohio Representatives in Principal Cities THE "YOUNG" REMOTE CONTROL SYSTEM To Individually Control Volume of Air .This practical device is particularly adaptable for hotels, office buildings, residences, public buildings and other buildings to manually control a damper or register at a remote distance up to 100 ft or more. The damper or register is connected to the regulator by a stain- , less steel cable encased in control casing. We recommend that it be placed in a in. copper tubing. Knob sets damper or register at any' desired position. Knob is on a 2% in. by 5 in. escutcheon. The indicator shows position of damper or register. The damper or register operates by pulling on the cable. The stainless steel spring closes the damper or register and returns the cable when the indicator passes the "on** position. Patents Pending Multiple Blade Damper Installed in a Duct Behind the Grille . Fastening Remote Control Regulator to Butterfly Damper THE "YOUNG" REGULATOR The "YOUNG" Damper Regulator is made in % in. size only and has five important features: (1) It locks secure ly. (2) It is temper-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. . THE "YOUNG" VALCALOX REGULATOR AND THE "YOUNG" FLUSH CUP REGULATOR The "YOUNG" VALCALOX Regulator can be placed on partition wall or any location of duct. Adjusted and locked with a special wrench, the "YOUNG" Regulator. It is much cheaper than . loam The "YOUNG" Flush Cup Regulator is used where regulator must be flush with the wall and is operated E with a special wrench. We can also supply a concealed type regulator on which the plate must be removed in order to operate. 934 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. The next one will be Cleveland, January 22 to 26, 1940. . 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 150 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 Croup: 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, tools of all kinds, and equipment not specifically included 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........................... 474 Industrial Users, 49 classifications____________ 10,791 Professional and Service Organizations, 23 classifications___________ 2095 Public Utilities_____:_______________ 1459 Real Estate Management and . Operation, 10 classifications.......,,............ 1418 Educational Institutions 1935 Miscellaneous___________ 1466 Total______________________________ ____27,743 Occupations Executive (44 titles)_______._________ 12,437 Construction (16 titles and trades)-___ :____ Operation (44 titles and trades) 4316 Technical (64 titles).__________________________ 2606 4477 Not Classified including Educators, Pub lishers. Horae Owners, etc. 3907 Total^____________________________ 27,743 The registered attendance at the 1938 Exposition in New York was nearly 40,000, 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. Boiler Cleanser, Lea\ Seal, Soot Destroyer The Vinco Company, Inc. 305 East 45th Street ' New York, N. Y. 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. 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. 6, and 10 V> 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. Liquid Boiler Seal i 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 Li9u`d 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 that Virtco be Used--Correctly--in Every Heating System You ln Specify or Operate. _ Tafis Used by the Following Boiler Manufacturers on All Their Boilers, Prooer Specifications for Cleaning All New, Remodeled and Old Steam, Give r Vapor, and Hot Water Heating Systems. African RADWTOt!. COMM?!]: GILBERT 6 BARKER MANUFACTURING CCL International Heater Company Jnfirusviutfiiimffloo/a/omstrr (Face of Tag) RichmondRadiatorCo. WATERFILM BOILERS (Reverse of Tag) CAUTION Do not um $ cleansing gent aoda or any alkali, vinegar or any acid In this boiler. USC VINCO. UANTITTES OF VINCO (In Pounds REQUIRED FOR HEATING SYSTEMS Note that quantities are based on actual installed rai ation, not on boiler capacity. . For Steam on 'AMn/orHotW.tea Annually. To Re Vapor Systems To Heating -Systems move Rust Scale. Prevent or Cure Maintained at Ap- Dirt and for Priming and prozimateljr 200 (Gravity) Hot Foaming Deg or Above. * Water Systems DIRECTIONS FOR CLEANING * Altar the system la tested and tight, use the proper quantity ol VINCO listed on the reverie aide of this tag and follow directions gtvan on each can of VINCO. Satisfactory results will ba obtained In record time with minimum eapenso. {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. . For systems having: Up to 350 sq ft of radiation--___3 ------ 1M 351 * 600 " " _____ 5_____ --------------- 2H 601 " 1100 * " ___ 8.___ . ____ 4 1101 1400 * _____ 10.... -......... ._ 5 1401 1800 8 _____ 13____ . - 6H 1801 * 2100 " " ___ 15. -- . . m 2101 ".2700 " * " _____ 18-- 9 2701 3100 " " " --------20 - 10 3101 *3700 " _____ 23____--------------- 11H 3701 " 4200 * " ... --. 13 4201 " 4600 ` " * ___ .28 __ U 4601 " 5000 " " " _____ 30 __ - 15 5001 * 5300 " * 5301 * 5600 * * 5601 * 5900 * " " 31._ 15H -___ 32 . ................. 16 tt - ~16M 5901 " 6200 " " " -------- 34. ........ 17 6201 * 6500 * 6501 * 6800 " * T? ___ 36 --m -- 18 6801 " 7100 " " ` --37_ _ ----- 18H 7101 * 7400 * " 38_____--____ . 19 7401 7700 " * 39 - . . 19M '7701 ` 8000 " " " --------40. . . 20 8001 " 8300 " * * ......--41 . ............ 20M 8301 * 8600 * * 42___ -- -- 21 8601 " 8900 " " _____ 43___ -------------- 2IM 8901 * 9200 * " * .. 44 .-- 22 9201 " 9500 " ___ 45____ ' 22M 9501 9800 " * _____ 46. -- - . - -23 9801 *10100*" " * . ___ 47 -------- hy Above 10100 sq ft use an additional pound Vinco fot each additional 300 so ft of actual installed radiation. 937 Boiler (Feeders) M-DONNELL & MILLER Manufacturers of McDONNELL Boiler Water Level CONTROLS General offices: Wrigley Building, Chicago, 111. "Doing thing well" PRODUCTS: Boiler Water Feeders; Combined Boiler Water Feeders and Low Water Cut-offs; Low Water Cut-offs; Com bined Low Water Cut-offs and Pres sure Controls; Electric Water Valves; Pump Controls; Low Water Alarms; Constant Level Valves; Humidifier Water Valves; and related equip ment. Boiler Water Feeders--McDonnell Boiler Water Feeders (Nos. 47, 147, 51, 53 and 101) supply water to boilers when ever the boiler water level tends to drop to the danger zone. Their dependableoperation is assured by the McDon- nell"Cool Feed Valve" (Patent No. 1,934,486) which prevents lime and scale formation--by packless (belr lows) construc No. 47-S Com bined Feeder and Low Water Cut off with "QuickHook-Up" for automatically fired boilers below 5,000 sq ft capacity. No. 47 for handfired boilers in same range is identical except for the No. cut-off switch (See below). tion; stainless steel valves; the Mc Donnell "Quick-Hook-Up" (Patent No. 1,997, 785); built-in strain er and many other refinements fully described in the Mc Donnell literature. No. 6IS Combined Feeder and Low Water Cut-off for automat ' ically fired boilers above 5,000 sq ft capacity, No. 51, for hand fired boilers, is the same except for No. switch. No. 55 and No. 6S- are similar in appear ance but of heavier con ' struciion for higher, pres sures (See tables 1 and ). Feeders and Cut-offs Com bined--Nos. 47-2, 147-2,51-2 and 53-2 for automatically fired boilers, are the Nos. 47, 51 and 53 with the McDonnell No. 2 Switch as illus trated. In these combinations the feeder takes care of all normal opera tion, and the switch stands by to cut off the burner, if an emergency should arise such as ex- treme primingor foaming or failure of water supply. Another type of feeder cut-off combination meeting special conditions isfourid in the No. 67 with No. 101, as ex plained under the illustrations at the right. No. Low Water Cut-off' Switch used on Nos. 47, 147, 51 and 63 Safety Feeders. Has high voltage cut-off con tacts and low voltage alarm contacts. Can be furnished on feeders or installed easily after feeders are in place cn boilers. .. Low Water Cut-offs--The No. 67 takes care of all cut-off requirements for boilers with steam pressures up to 25 lb. Its operation is restricted to stop ping the burner when low water threatens the boil er. However it is furnished with an extra switch, as explained under No. 67- the illustration, .vanced de for operating the velopment in No. 101 Electric low water cut-off with Feeder so that the McDonnell Quick-Hook-Up. feeder may be Has extra switch which closes added at any time on Small drop of water line, without cutting off burner, to without price complete circuit to No. 101 penalty. For boilers with Electric Water Feeder (See No. 101). Note deep sedi ment chamber, removable pressures from 25 clean out plate, and tapping lb up to 150 lb, the McDonnell No. which provides for No. 13 Wireless Pressure Limit Control. \150 is the cut-off to use. It can be used as either a low water cut-off, a pump control, a low water alarm, or for any com bination of these three functions. Service recommendations covering Mc Donnell Boiler Feeders^ Low Water Cut offs and Feeder Cut-off Combinations are given in the table at the top of the opposite page which is followed by typical specifi cations. If there is any question as to the proper equipment or hook-up for handling a given condition, our engineering depart ment will be glad to work with you in helping you to arrive at the best solution to your particular problem. Complete installation instructions are packed with each McDonnell product. 938 McDonnell & Miller Boiler (Feeders) SERVICE RECOMMENDATIONS Boiler Size in Square Feet Steam Pressure McDonnell Product to Use Table 1--For Hand Fired Jobs Up to 5.000 Up to 5.000 Above 5.000 Any Any size Under 15 lb 15 to 35 lb Under 35 lb 35 to 75 lb 35 to 1501b No. 47 Water Feeder No. 147 Water Feeder No. 51 Water Feeder No. 53 Water Feeder No. 150 as a pump control Table 2--For Automatically Fired Jobs Water Feeder--Low Water Cut-off Combinations Up to 5.000 Up to 5.000 Up to 5.000 Above 5.000 Any size Any size Under 15 lb 15 to 35 lb Under 25 lb Under 35 lb 35 to 75 lb 35 to 1501b No. 47-2 Feeder-Cutoff ' Combination No. 147-2 Feeder-Cut-off Combination No. 67-101 Electric Feeder- Cut-off Combination No. 51-2 Feeder-Cut-off Combination * No. 53-2 Feeder-Cut-off Combination No. 150 as pump control and Cut-off Table 3--Low Water Cut-offs Any size Any size ) Under 25 lb No. 67 Low Water Cut-off 1 25 to 150 lb No. 150 Low Water Cut-off Low Water Cut-off--Pressure Control Combination Any size Off at 3 lb No. 67-13 Combined Cut-off On at I lb and Pressure Control Typical Specifications for Boiler Water Feederor Combined Feeder and Cu t-off Furnish and install complete in every essential detail for each boiler unit. Autoinatic 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 operation, subject to acceptance and approval of the architect's .................................................................. engineer. *If job is hand fired, insert: "No. 47," "No. 147," "No. 51," or "No. 53," as indi cated by service conditions in Table 1. *lf job is automatically fired, insert: "No. 47-2," "No. 67-101," "No. 147-2," "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 electri cal connections for low water switch to con trol fuel supply equipment, so that the fuel is automatically shut off by the low boiler water control. Control No. 101 mectric winng to be of Water Feeder for flexible armored *}se No- 67 cable. All wiring .& WN%% caf;o to meet the requirements of the City Electrical Inspection Department and ttnheP nNaatliinonnaCL ll Board of Fire Underwriters. ' ' that many mod- CT'Wboiler-burner - nuenU*tsl^ha,veW"ableurilCt-uint."offMs cwDhoicnh- may be used to operate No. 101. ^- tot has stainless steel aVgaai-n'sPt wsialivteer pPorwesesrufurel culopsutroe 150 lb. Typical Specifica tions for Low Water Cut-off Furnish and install on each boiler in accord ance with the manufacturer's ?-ls. fress,ure Limit Control _____ for quick and easy mounting on instructions, No. 67 Low Water Cut-off. Its a McDonnell plunger forces down the float of & Miller No l^e *ot' water cui~ff When ex( ______ .. v t * cess pressure develops, slopping (insertt) Low the burner until proper operaWater Cut-off, ting Pressure is restored. No to be float opera- M^y be on , i____, . V outlt-tn cut-offs which pro- ted and to have vide tapping for it. packless con struction. Control wiring to be of flexible armored ca ble. All wiring to meet the requirements of the City Elec trical Inspection Department and the National Board of Fire o. 150 Underwriters. Combina tion Low tlnsert at this point WaterCut- "No. 67" or "No. off. Pump 150" as indicated by Control and Low .Water Alarm service conditions in built to stand up in high Pres Table 3. sure service. Float operates two Literature contains switches. One closes pump cir complete descrip cuit when water level falls; the _ tions. capacity other cuts burner circuit and chart, installation completes alarm circuit..when - instructions, wiring water level falls to danger zone. diagrams, dimen Maximum steam Pressure, 150'- sions, etc. lb. 939 Boilers, Cast-Iron AMERICAN RADIATOR COMPANY .division orAmerican "Radiator a Standard Sanitary Corporation 40 West 40th Street, New York, N. Y. PRODUCTS FOR EVERY HEATING REQUIREMENT IDEAL OIL BURNING BOILERS Automatic oil burning boilers, available in three models, with standard jacket or extended jacket for concealing bur ner. All equipped with low-water control, air-cell in sulation and pro vision for yearround hot water supply. Ratings: Steam 355-2,460 sq ft; water 570 3,940 sq ft EDR. IDEAL WATER TUBE BOILERS Ideal Water Tube Sectional Boilers for homes as well as large buildings and commercial installations. Sec tional construc tion permits easy admittance through doorways and inexpensive installation. Low water line elimi nates digging of pits. For all fuels. Ratings: Steam 450-. 15,000 sq ft; water 720-24,000 sq ft E.D.R. IDEAL ARCO ROUND BOILER IDEAL REDFLASH BOILERS An unjacketed, low priced boiler. Uses hard or soft coal or coke. May be easily converted to automatic firing--coal, oil or gas fuel. Machine ground surfaces of .doors and sections prevent waste of heat. Ratings: Steam 200-800 sq ft; wa ter 320-1280 sq ft E.D.R. No. 7 IDEAL BOILER FOR COAL (STOKER OR HAND FIRED) OIL OR GAS 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 'Hand Fired water supply by screwed in Taco Heaters. Ratings: Steam 225-750 sq ft; water 360-1,200 sq ft E.D.R. A popular boiler for any kind or size of building from cottage to skyscraper. Red enamel jacket. Multi ply Asbestocel insu lation. Automatic damper regulator on all steam boilers and on smallest size hot water boiler. Ratings: Steam 220-10,370 sq ft; water 350-16,600 sq ft E.D.R. AUTOMATIC COAL-FIRED BOILERS , Designed especially for use with mechanical stokers, these boilers are recommended by leading stoker manu facturers. Efficient and economical operation. External or built-in hot water, supply. A com plete range of sizes and models. Ratings: Steam 375-8,445 sq ft; water 600-13,512 sq ft e.d.r: Write us for detailed information 940 . Boilers, Cast-Iron PRODUCTS FOR EVERY HEATING REQUIREMENT CAST IRON RADIATORS American Radiator manufactures a com plete line of cast iron radiators suitable for all types of heating. Complete ratings, dimen sions and data will be sent on request. A rco Convector WATER HEATERS Water heaters of all types are quickly available from branch warehouse stocks and wholesalers. Capacities range from 3000 gallons with the Arco High Test Tank Heater down to 65 gal lons with the Dome Type Heater shown on the right. A partial list of these heaters is given and complete information on them will be sent on request. Arco High Test Tank Heater Kolflash Water Heater Ideal Oil Burning Water Heater Old Line Water Heater Ideal Dome Type Water Heater Scuttle-a-Day Water Heater Excelso Water Heater Corto Hospital Type Arco Radiant Convector ARCO ACCESSORIES Arco Accessories permit the installation of completely integrated heating systems, backed by a single responsibility. Illus trated below are a few of the Complete Line of valves, vents, controls fpr steam, vapor or water. With new products being constantly made available and with changes and improvements being made to existing products, we suggest you write us for further information on all our equip ment. A complete list with ratings will be sent on request. Arco Radiators Peerless Wall Radiator No. 2001 Equatrol Perfection Pin Venlo Cast Iron Radiator (See also American Radiator Co. pages 898-899 and Subsidiaries) 941 Boilers, Cast-Iron 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 senes 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. Burn soft coal efficiently, withoutsmoke. 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^--Dome Top Hot Water Supply Boilers. Will keep 50 to 1500 gal tank always full of hot water. Guaranteed to - 120 lb working pressure. 10--Bumham-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. Nair rower. 3-tube type 3J in. wide. 4-tube typer in. wide. 5-tube type in, wide. 6-tube type in. wide; Can be recessed. 12--Fero Tube Radiators. All heights--3, 4, 5, 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. . * 942 Manufacturers of Cast Iron and Welded Steel Boilers, Cast Iron Radiators and Heating Accessories Irvington-on-Hudson, N. Y. rw____________ill- AU1 Branch Offices BOSTON; Philadelphia; Chicago; L. I.;queens Village, Long Island C , N. Y.;ity Baltimore; Springfield; Lancaster; Pittsburgh; Zanesville; N.Y.Elizabeth; Geneva, Plants N.Elizabeth, J.; Lancaster, Pa. N. Y.Zanesville, Ohio; Geneva. As jacketed for burning hand fired coal or gas. ' As jacketed for oil burning. Jacket extension easily removable. Its use is optional. BURNHAM ALL-FUEL YELLO-JACKET BOILER That Stings The Fuel Bill Its outstanding econo especially with oil and my point is the expanded stoker fired coal. combustion chamber, that It is equipped with a extends from the bottom fully bilt-in Taco hot water to the top of the boiler, supply heater. You have while still having the Burn the option of the Tankless ham basic, back and forth or Storage Tank type. The fire travel. The fire shine, jacket is a light dandelion or direct surfaces, are yellow, combined with greatly increased. Further black and a touch of chro efficiency is secured by the mium. It has an optional adding of fins. . removable extension for To prevent a too rapid completely enclosing an oil rush of fire travel gases, there is a balanced down draft, that overcomes the Showing how jacket extension can be easily lifted off. Handles pro vided for the purpose. burner. Can be easily converted from oil to coal, , or the reverse. cooling off losses, or heat lag, incident to the intermittance with I . Made in 7 sizes. automatic firing of coal, oil or gas. The main combustion chamber has the For steam: from 325 to 775 square feet. advantage of additional height, an essential, For water: from 520 to 1240 square feet. Boilers, Cast-Iron Crane Co. BOILERS, RADIATORS, VALVES, FITTINGS, PIPE, STEAM SPECIALTIES PLUMBING AND HEATING MATERIALS ' General Offices: 836 South Michigan Avenue, Chicago, Illinois Nation-wide Service'Through Branches, Wholesalers, Plumbing and Heating Contractors CRANE HEATING EQUIPMENT FOR RESIDENTIAL AND COMMERCIAL BUILDINGS Crane offers a single source of supply for a full line of heating equipment, automatic or manually operated, for both residential and commercial buildings. The advantages of a single responsibility for the whole system are obvious, and the reputation of the name Crane is your guarantee of quality and satisfaction. CRANE OIL AND GAS-FIRED BOILERS Crane Co. Boilers, Cast-Iron CRANE RADIATORS AND CONVECTORS CRANE cast-iron radiators Crane Radiators are available in a com plete range of sizes to meet every structural need Screw nipple construction enhances appearance and dependability. Optional equipment is Crane patented invisible shields which direct heat to "living zone. Enclosures are of heavy steel, with re movable grille sections of plastic or pressed steel. For completely or partially recessed free-standing, wall-hung, or plaster front installation. Crane advanced design and assembly method assure lasting efficiency. CRANE SUSTAINED HEAT OIL-BURNING BOILERS Combination boiler and burner unit with patented sustained heat principle which extracts more heat from the fuel; and down draft construction which prevents escape of gases into flue before their heat has been absorbed. CRANE FIN-TYPE OIL-BURNING BOILERS Specially designed for oil burning with any gun-type burner. Many integrally cast fins increase absorption of heat. Made with plain insulated jacket, or De Luxe jacket completely en closing boiler and burner. BASMOR GAS-FIRED BOILERS A wide variety of sizes avail able for every home. Its specially designed "Butter fly" Bunsen-type gas-saving burners assure proper com bustion. Immune to back firing. In Standard and-De Luxe Models with insulated jackets. CRANE COAL-FIRED BOILERS CRANE CONSERVOIL BURNERS A high efficiency burner with controlled air delivery, assuring proper mixture of air and oil--reducing combustion noises. Silent operation achieved through a simple yet efficient fan and two-stage fuel pumps operating on a single shaft--making only one moving part. VALVES AND FITTINGS CRANE AUTOCOAL STOKERS A worm-feed stoker, with five speeds. Every friction point is in transmission case and runs in oil bath. Burner is full coking type with sectional tuyeres of chromium alloy iron. Has thermal-overload pro tector switch. Worm tube is seamless, smooth. Also available for anthracite coal. HEATING CONTROLS CRANE SECTIONAL COAL BOILERS Crane Sectional Boilers are made in sizes to meet a wide range of load demands. Patented control of water circulation contributes to faster heating and higher efficiency. Available with or without insulated jacket. CRANE STOKER-FIRED BOILERS Identical to the Crane Sec tional (manually fired) Boiler with grates and shaking mechanism elimi nated. Available with special high base to obviate need of placing stoker in pit or raising boiler. 944 CRANE ROUND COAL BOILERS - A round boiler with excep tionally good flue travel and generous depth in fire pot. Available in range of sizes sufficient for small to me dium size home. Furnished with or without insulated jacket. Crane makes every type of valve, fitting, and steam specialty for heating instal lations. Backed by Crane experience of more than SO years in engineering, Crane piping equipment in any installation as sures greater efficiency--tighter and more workmanlike assembly. The Crane line of automatic controls in cludes room thermostats, primary oil burner and stoker controls, fan or circulator relays, water temperature and steam pres sure limit controls and regulators, furnace temperature controls of simplified design --precision-built throughout. 945 Boilers, Cast'Iron Spencer Heater Division Lycoming Manufacturing Company Williamsport, Pa. Sales Representatives in Principal Cities Spencer Automatic Magazine Feed Heaters are furnished in cast iron sectional types --and steel tubular types for larger buildings--for steam, vapor and hot water heating. There is a size and capacity for every type of building, to provide economical and con venient heat--safe, dependable, sure. The Spencer Automatic Magazine Feed Warm Air Furnace makes available 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 circu lation type. COMFORTABLE HEAT AT LOW COST Coal -- Coke -- Gas -- Oil -- Spencer J and L series heaters, M series boilers and W series furnaces are primarily designed to burn low cost No. 1 Buckwheat Anthracite or small size coke; the CN series Nut or Pea Anthracite, or Nut size coke. If at any time a property owner desires to burn more expensive fuels--oil or gas-- his Spencer Heater will show a' higher efficiency than can be secured with any ordinary boiler. ^ Thermostats--Thermostats and electric damper motors are furnished as optional equipment. Jacketed Covering--Attractive met allic jackets, as illustrated, are available for Spencer Cast Iron Heaters, either with or without the enclosing jacket doors. Spencer Jacketed Heater L-l Series Why Spencer Heaters and Furnaces per form so satisfactorily can best be explained by an inspection of their design and con struction. The Spencer principle, illus trated in the cross-sectional view, is simple: Once a day fuel (No. 1 Buckwheat Anthracite or small size by-product coke) 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 burning 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 fuel. These exclusive Spencer advantages are available in all types of the magazine feed heaters and furnaces. ' Spencer Heavy Duty Tank Heaters-- Of the magazine feed type, they are avail able in the capacities indicated. With the automatic magazine feed construction, they provide ample domestic hot water at lowest cost, and with a minimum of tank heater attention. Cutaway sectional view Spencer Cast Iron Heater 946 Spencer Healer Division Boilers, Steel SPENCER AUTOMATIC MAGAZINE FEED WARM AIR FURNACES Spencer Furnaces operate on the automatic magazine feed principle. Once fuel (No. 1 Buck wheat Anthracite or small size coke) is in the storage magazine, it feeds over the fire on the sloping grate in just the right amount for the heat required. Attention is necessary only once or twice a day. Unique in furnace design, the Spencer burns low cost No. 1 Buckwheat Anthracite or small OeLuxe Jacket size coke, and eliminates the dis advantages of ordinary furnaces Unjacketed ___n0 "hot spots," no furnace cement, no brick lined fire pot, no leaky joints. Assures an air-tight, gastight, leakproof, long life installation. Spencer Furnaces are compact, streamlined, and so designed that other air-condi tioning features can be readily added. Illustrated here is the attractive enameled metallic jacket. Galvanized casing also available, if desired. SPENCER STEEL TUBULAR MAGAZINE FEED BOILERS For large buildings we recommend Spencer Steel Tubular Magazine Feed Boilers, burning low cost No. 1* Buckwheat Anthracite or coke. In the cross-section diagram, 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 sec tions for ease in handling and installation--a great advantage on replacement jobs, eliminating the necessity of costly tearing out of wall or partitions. Combination water and fire tube construction; built to A.S.M.E. standards. Sud 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 do been building, in the opinion of experts, mestic hot water heating coils, either of the one of the most efficient, economical and storage tank or instantaneous type. dependable coal burning boilers on the market. With this back ground of experience, Spencer Engineers developed the Spencer Steel Tubular 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 both for the property owner and for the archi tect or engineer who specifies 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 Steel Boiler Type "A" Steel Boiler 947 UnitedStates Radiator (corporation General Oilices: Detroit. Michigan Branches and Sales Oilices in Principal Cities Detroit, Michigan Front Extended Jacket Performance Curve k ua MlS JO* -- -- ' V TK1 NO V r "i |i m ut iw ISM Output--% of Direct Standing Radiator Load Flue Gas Analysis CO2--12.5%; Oz--4.1%; CO--0.0%. CAPITOL THINTUBE RADIATORS 3-Tube Height* Per Section Heating Surface 19* 1.1 Sq Ft 22' l.3SqFt 25' 1.5 Sq Ft 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. CAPITOLAIRE DIRECT FIRED 4-Tube I9 MSqFt 22' 1.6SqFt 25' 1.8Sq Ft 5-Tube 20' l.8SqFt 23' 2.1 SqFt 26* 2.4 Sq Ft 6-Tube 19" 2.2 Sq Ft . 32- 3.85 Sq Ft 40 per cent less space needed for these graceful, efficient Capitol ThinTube Radiators. . . CONDITIONING UNIT An air conditioning unit especially de signed for oil firing. Streamline flue con struction in preheating and prime-heating sections insures high efficiencies. Deluxe jacket completely encloses all controls, heating unit, automatic humidifier, filter and fan. Other gravity and forced air furnaces available for gas, stoker or hand coal firing. 948 Boilers, Cast-Iron United States Radiator (corporation General Oilices: Detroit. Michigan Branches and Sales Oilices in Principal Cities Detroit, Michigan CAPITOL SQUARE BOILERS FOR ALL FUELS "A" Series Ratingi in Sq Ft Direct Cast iron Radiator Loads--Sq Ft Water-- 975-2475 260- 655 460-1085 "B" Series Steam--1200-3600 Water--1980-5940 550-2030 910-3350 "C" Series Steam--4700-10,500 Water--7760-17,325 1865-5805 3080-9580 CAPITOL RED CAP BOILERS For AH Fuels 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- ifirepot walls to assure a clean surface for better heat absorption. CAPITOLAIRE CONDITIONING UNIT FOR SPLIT SYSTEMS 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. A suspended unit, quiet in operation, using ducts to convey heated, humidified and filtered air to various rooms of the home. Heating supplied to the Unit heat exchange coil by a steam or hot water boiler. Floor model conditioning units with a wide range of heating capacities also available. SPECIFICATIONS Capacity--BTU/HR . Unit No. Heating* 200 2# H. W. Steam Cooling** 50* 40 Water Refrig. Air Capacity cfm S-| 34,000 28.000 14.000 15.000 S-2 48,000 39,000 19.000 21.000 S-3 65,000 54.000 26.000 28,000 S-4 99,000 >28.000 37.000 39.000 500 750 1000 1500 949 X' 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-McLain Boiler and Radiator service is made conveniently available through local stocks carried by WeQ-Mel i Distributors in most of the Important distributing centers. CLAln New AU-Fuel Boilers No. 67 and No. 77 Conversion type boilers with insulated enameled jacket. For hand or autCH matic firing. Connected Load Ratings: Steam 300 to 950 sq ft, Water 480 to 1,520 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. "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. 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 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. S-TU8E 6-IUBE Junior Radiators Occupy 40 per cent less space than conventional radiators of same rating. 3-tiibe, 3% in. wide; 4tube, 4^g in. wide; 5-tube, 5^ in. wide; 6-tube, 61%6 in. wide. Concealed Raydiant Partially Recessed Cabinet Raydiant Raydiant is a convector type all cast iron radiator made in Concealed, Partially Exposed and Cabinet Types. Raydiant Radiators, however, differ from conventional convectors in that they supply not only convected heat but also sun-like radiant warmth if-r-1 radiating "live" panel front. A second important advantage is their ability to hold heat longer^ This helps increase the comfort of (on and off) automatic heating and makes mixed installation of Raydiant and standard radiation practicable. 950 Boilers, Gas American Gas Products Division of American Radiator Company 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. Boiler Number 0-GS-4 0GS-5 0-GS-6 0-GS-7 0-GS-4-E 0-GS-5-E 0-GS-6-E 0-GS-7-E 0-GS-9-E 0-GS-I1-E IGS-4 1-GS-5 l-GS-6 l-GS-7 l-GS-8 i-cs-y 1-GS-tO 1-GS-ll 4GS-6 4-CS-7 4-GS-8 4GS-9 4-GS-10 4-GS-ll 4-GS-13 4-GS-15 4-GS-17 4-GS-I9 4-GS-2I 4-GS-22 4-GS-25 4GS-28 4-GS-31 4GS-33 4-GS-37 4-GS-4I Empire Ideal Standard Ideal Specifications for Empire and Standard Ideal Gas Boilers STEAM BOILERS WATER BOILERS A.G.A. Steam Rating Sq. Ft. Supplies Sq. Ft. Direct C.I. Radiation No. and Size of Tappings . Supply Return In. Water Boiler Number A.G.A. Water Rating Sq. Ft. Supplies Installed No. and Size of Tappings Gravity Accelerated. Supply In. Return In. 270 360 450 540 255 340 425 510 680 850 610 775 940 1105 1270 1435 1600 1765 2000 2400 2800 3200 3600 4000 4800 5600 6400 7200 8000 8400 9600 10800 12000 12800 <4400 16000 171 231 291 357 161 217 275 336 460 592 408 533 666 792 934 1055 1176 1298 1471 1765 2059 2353 2647 2941 3529 4118 4706 5294 5882 6176 7059 7941 8824 9412 10588 11765 2-2'/i . 2-2'A 2-2Vi 2-2Vz 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-* 2-6 2-6 2-6 . 4-6 4-6 4-6 4-6 4-6 6-6 6-6 6-6 6-6 8-8 8-6 . 8-6 M'/l , M'/i l-l'/a l-l'/a l-l'/a l-l'/a l-l'/a 1-l'/a M'/a -M'/a 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 5-5 3-5 4-5 4-5 4-5 4-5 5-5 5-5 5-5 l-GA-4 l-GA-5 l-GA-6 1-GA-7 2-GA-4 2-GA-5 2-GA-6 2-GA-7 4-GA-9 4-GA-ll 4-GA-13 l-GW-4 l-GW-5 l-GW-6 l-GW-7 l-GW-8 l-GW-9 1-GW-10 l-GW-l 1 4-GW-6 4-GW-7 4-GW-8 4-GW-9 *gw-io 4-GW-11 4-CW-13 4-GW-15 4-GW-17 4-GW-I9 4-GW-2I 4-GW-22 4-GW-25 4-GW-28 4-GW-31 4-GW-33 4-GW-37 4-GW-41 210 280 350 420 .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 126 167 210 253 253 342 434 527 724 931 1149 624 810 1007 1222 1410 1597 1778 1958 nr? 2667 3111 3555 4000 4444 5333 6222 7111 8000 8889 9333 10666 12000 13333 14222 16000 17778 131 175 220 265 265 359 455 554 761 980 1215 656 853 1063 1294 1493 1691 1882 2074 2353 2824 3294 3765 4235 4706 5647 6588 7529 8471 9412 9882 11294 12706 14118 15059 16941 18824 2-Wi 2-1'A m 1-21/z 1-2'A 1-2'/2 1-2<A 2-2(4 2-2i/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 8-6 2-11/2 2-11/2 2-l'/z 2-H/2 1-2'A 1-21/J 1-21/2 1-2'A 2-2(5 2-21/4 2-21/2 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 All BoUers except Type 4-G and Nos. 1-GSor W-llare available in either Standard or Empire Ideal models. (See also Page 900) 951 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 sires ranging from 691 to 6225 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. Floor to Face of Steam Outlet. Ft. In. Floor to Top of Boiler. F t. In. Size of Steam Outlet, In, |1 J I Widthof Settin If 1$ Two <s< I `S s = Single Boiter Boilers in .3C 8 & Ft. In. Batter) !s" X Ft. In. L Oil, 691 15-1 921 115; H-1 1382 I6i; 184: * 207- 2304 6-0 7-0 8-0 9-0 10-0 11-0 12-0 13-0 11-0 13-0 15-0 17-0 19-0 21-0 23-0 25-0 5-2 14-51/3 13-3% * * a a ** 877 17-8 6-0 1169 7-0 1462 8-0 H-l 1754 9-0 2046 2339 2631 * 10-0 11-0 12-0 2924 13-0 11-0 13-0 15-0 17-0 19-0 21-0 23-0 25-0 !4-5'/2 15-3% ** * 1063 20-2 6-0 1417 * 7-0 I//2 2126 H-3 248(1 2835 * * * 8-0 9-0 10-0 11-0 3189 12-0 3544 13-0 3898 * 14-0 4252 15-0 11-0 13-0 15-0 17-0 19-0 21-0 23-0 25-0 27-0 29-0 4-5% 14-5% 13-3% * " " * ** *** 1245 22-8 6-0 11-0 1660 7-0 13-0 !07H 149q m 8=0 15-0 9-0 17-0 H-4 !905f 10-0 ' 19-0 32ft * 11-0 21-0 1735 12-0 23-0 I50j * 13-0 25-0 (565 19801 14-0 15-0 27-0 29-0 4-1% 4-114 13-3% a a a a a a * ** Type H Stirling Boiler tcilh Babcock <fc Wilcox Chain-Grate Stoker 5 The advantages of the Babcock & Wilcox Type H Stirling Boiler may be sum a 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 5 * any condition of firing. 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 5 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. 6 The boiler is supported by a structural- 6 steel framework entirely independent of the brickwork. 5 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 6 6 be sent upon request. Simply ask for Bulletin G-8-C. 952 Boilers, Steel Farrar & Trefts Incorporated Buffalo, N. Y. heating and power boilers Bison Compact Boilers plrtbox R<=mreTubutar Boilers Locomotive Type Boilers ISTtch Marine Type Boilers Established 1864 STEEL PLATE CONSTRUCTION Storage and Pressure Tanka 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. TTiis 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 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 Healing 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 are 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 lb working pressure and of riveted construction for power purposes at 100, 125 and 150 lb. working Firebox Return Tubular Boiler 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 needed. 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 Bieon Two-Paee 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. 953 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'' air con ditioning to lower floor, and radiator heat to rest of house, with year-'round tankless domestic hot water. The BOILER-AIRGONDITIONER 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 GAS-EIGHTY--for gas. Jacketed. Ratings, Steam--12 Sizes--425 to 2680 sq ft. The STOKER-EIGHTY--For bituminous firing. Jacketed. Stoker may be installed at either side if desired, to allow free access for inspection through door in front. Ratings, Steam--6 Sizes--485 to 1100 sq ft. The GOAL-EIGHTY AUTOMATIC--For anthracite stoker firing. Jacketed. Pro vision for installing stoker at either side as well as front. Supplies year-'round hot water with or without tank as desired. Approved by Anthracite Institute. Ratings, Steam--12 Sizes--425 to 2680 sq ft. 954 | X pHmihbons 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 R-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.M.E. Code. Ratings, steam--1800 to 15,000 sq ft BOO 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. 955 ft! 1 Boilers, Steel E. Keeler Company Williamsport, Pa. 75TH ANNIVERSARY Builders of Better Boilers Since 1864 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. Anaconda Copper 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 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 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. 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. Also manufactured in Canada by Canadian Vickers, Ltd., Montreal. 956 Ketoanee Boiler Corp. Ss.S rt O gH.I'.: Sbo 3. TM ij -- .O JJ Um^ 0 o S2 Sl-S 1: " | rt aO. &S !- S .. tilrt i 8 2a a> t"S " ~ l-S8! -- vu -- <u c ^Vn3 V.. O **60 j| B a> u ^ aj >--Oi kbj 2=8 2 s, 6 aj fn W -- -C m V *--' -- * h " EL-t* & c 1C 4> <u o <$ O cr^> ss * 8 m-s || sk| >---3iS C. - 5 O + 5 <u ~. y s^t-.'-si5g.3os-8s-8 X 958 1 t u 9 H1 38 B o ile r N o ....................................... Rated Steam Capacity: C oal.....................................Sq F t O il, Ga or Stoker............ Sq F t 1 20 20000 1 24290 72x18-0 107 SS& ' 20000 Boilers, Steel 13 14 15 18 > oo ~ SS2&SS8 M 90 20R |sS8 inc kSiaN-- K "S < go **Nn^~s--g2*>'0oo|g$o~ *" "" -- go gSiiSJRP 16 K. 1 SS-s-'ll iil^li 14K 15K j a 1k|3:8!1 11 12K 5^ _St'd gS^N--88 ^ ` ss=^_ o S~iv.--8 S^ t^sO'O;n-cfoN'?O o s5_<s --fS.J^3 w'^5 u^>o"^ 1 55K 6 6K w00 *3 i 808<A=K-^5corSot o op<So-0O~"*!A>0UW-1'I o0eO<N <*"> ooo ` oo ~ f--M>iocCiM^N-*KN m o fN al in n 82 <A O oN'rhoo>rTfftNOo"o' fO W idth and Length .. .In . x F t In. Overall Height Shell.................In. Height of Approxim Water Line ate Weight: ...C...o..a.l..........ILn.b O il. . ... .Lb fCeicanec Boiler Corp. Boilers, Steel 35000 1 42500 84x23-4 125 105 36100 33800 lo ss t9*o> &00y tO9o0OO0^Q0 gis|SS CSs? liiggil 0243_____r_s-- wSo'*o S3 ?S25,,88 8Sog 33- 22 ^-SR--~ r-.ao J* .- Cm00*<0^N0 lg=SR|l 9kf0t 0^0 oo 8tS^5H00v*s. --S^|| 578 1 579 =8S 8gJooL_ S?J*K?a 1 577 to -SSt-le>.^u3!- n J-S& o-J.sp^ _31M |?oSor=s-S s"S-l'!S os &: 583 483 586 l 486 | 485 17500 21250 72x17-0 113 94 | 22000 20300 30000 36430 84x20-7 125 105 32300 3020Q iS^in^SB Nmoroi OO O.*p^i in -nmJOoOO sea--n^osasa NNg gs^stas snOO <qAS->'<?rti^O<=^ogo ssOO <! SS*2-<!oo " S. St-<S8 gs^sssa s *A 8orSs =* CT'CT'PJfT StOrtSSO5wOm vO'V'oNSr^^iN-, 0*7 _ o R<m!?^8ris> ss O8C8O^O0CO0N8f*8-- SSciooSS 782 783 2782 2783 785 2785 788 2788 789 2789 790 2790 vOs\vVrsn ' J--* fi--r*-iv----n- eN&rNrAs.NVrr CO S wi '* So j 83"i(~-- *res\-rfN co o^ 000 og-No S3s rJ"re8* "* NN- iaSso III gsa-- E-ill'fJeJ 787 2787 17500 21250 72x12-1* (18 101 16600 16100 13800 786 2786 *? iariSs; 5Rco h -- ^ 000 g?s OVs0O--0^_--v0IHS0 2--.. 05w0i-Ho Nm^O0^ NNO >0 ilo5^ss o11o1-- J2 .*p$ .5 QfcoSccM 784 2784 2924 3300 774 2774 775 776 I 2775 i 2776 I 778 | 2778 1 750 I | 2780 | t'R rre* a 5000 6080 42x9-2 111- gsS^. N50*09K O-Of>. gOs&Mr>g.XcosjO5^t>, lal&j W\ <N co 0. 8 c1o *?;^c-s^rs ^ - vv8si^SrsjO*i^ifs>s..*-oo' OtnvOs-voKsrts-s.-O 88^^?^ v&tv--sj^Ststs,. 111 ggg "0V --0<B0 gttsfs.grN-.g---o tt>o tt>o 6500 6300 5400 III >o VSU-. 888 v\ Vs -J- 90 t> ts 3 vs-Seo-'--* <8 to 3 to gVl*gSgN o t*3< S* 8 cOrssvSs vvss o - S CQ (N ts X o :5 u !S 1737 :-gJ :.r-ss-o-v. ;. g .: 2 wO 90 SS ^w2 onsos 22 :vs^?sg wto NVSOO Sm 52 j3f 5^CQ "ftiNVVsSNO0' 2<SS vsF :sf?Sg X 9e0o --.O --O-'t0vss5rtMo>< .,.t>N>o-?iA>o-rivv*s0ss(V--Nns 3"a *390to06 (O rS--s SN--RNVxS . NWgoSvsttOlN' S^n 0tsoo6 Eg aVo Cri ES c<Njl JrJt II fr-* 3o' W r*t --OO--0' <vvmMss ..toJ-,'cViwSoVosSCmrN._y 0two6 ll 5 S iJ.**- sraCA O----i---nrvvMVMsS s<sgx 5 gsss- t9o0 ...vS0sv*a<roNvOsN}^VQ: -- sf o-s'3. tZ3 ou X 83 ggi :gsS 80 a vs W u 0 ttii-sijjj t-K jrjf-;;;; :. 5 E<3C6 Toj<o0-3 . `A sg-5 uo*r! u: ."SsS3 CSjAis*J3 0 9b 05 -* 3 jii `u St 2 tf>S^ J4 9' X 15^2 ^ 6 4d!s*'54 | Z u Sgl is^l -j 0 & &S(5i-<- ` In Ea X *S8 XB w-s -X0 2a B o ile r N o ...................................... 1 Rated Steam Capacity: C o a l;.....................Sq F t 2200 Oil. Gas or Stoker.Sq F t 2680 W idth & Length. In jtF t in. 36x5-10w Overall Height Shell... In. Height of Water Line. .In. Approximate Weight: /0 0 Series, C oal........L b 1 2700 Series, C o a l... .Lb 3400 O il ....... Lb 2900 B o ile r N o ........................ B o ile r N o ................................... Rated Steam Capacity: C oal................................ Sq F t Oil, C a t or Stoker........ Sq F t W idth and Length .In . x F t In. Overall H eight S h e ll........... In. H eight of W ater L in e ...........In. Approximate Weight: C oal. Lb O il...Lb 959 Boilers, Steel Pacific Steel Boiler Division United States Radiator Corporation General Offices: Detroit, Michigan . Sales Offices In Principal Cities . A Complete Line of Low Pressure Steel Heating Boilers. All Pacific Boilers are built using the A.S.M.E. Boiler Code Standards as mini- mums. '; LOW WATER LINE SERIES Built in the following capacities for steam: Coal Burning Sizes--1800 to 35,000 sq ft. Mechanically Fired Sizes--2190 to 42,500 sq ft. High Fire Box for Stoker Firing--Sizes-- 2190 to 42,500 sq ft. All Pacific Boilers are built, inspected, andtested under the supervision of the Hartford Steam Boiler Inspection and Insurance Company. TWO-PASS FRONT SMOKE OUTLET Built in the following capacities for steam: Coal Burning Sizes--4000 to 30,000 sq ft. Mechanically Fired Sizes--4860 to 42,500 sq ft. All Pacific Boilers .are made of steel with . each joint and seam electrically arc-welded --built to last a life-time. SINGLE-PASS REAR SMOKE OUTLET Built in the following capacities for steam: Coal Burning Sizes--1800 to 6000 sq ft. Mechanically Fired Sizes--2190 to 7290 sq ft. PACIFIC THREE-PIECE CONSTRUCTION Made up of three parts, shell, firebox and base, Pacific Boilers are particularly adapt able to replacement work. Where necessary Pacific fireboxes can be split (as illustrated) allowing the boiler to be taken into the building in four pieces and erected without welding on the job. Descriptive Bulletins on Pacific Steel Boilers will be mailed on request. 960 Boilers, Steel Smith Twin Tubular Boiler Co., Inc. State Road and Cottman Street Philadelphia, Pa. MANUFACTURERS STEEL HEATING BOILERS Smith Sectional Steel Boilers have rained favor with Architects and Engineers Hue to their compact construction and adaptability for installing in boiler rooms of building through existing doors or oenings. Built on foundations or f.o.b. / t>__ , f nr ni| firinv. All the outstanding advantages of both the water tube and fire tube boilers with out complicated baffle construction. Faster steaming and higher efficiency obtained by rapid water circulation due to water tube construction that comprises 50 per cent of the boiler heating surface. Write for circular for Domestic Boilers especially designed for Oil or Stoker firing. SPECIFICATIONS--SMITH SECTIONAL-STEEL HEATING BOILER . J&irsJmCfr7<nRePuaipiepwctn {jxxrstmctii oFo/f&temrro/GoHt nv fIvC/rvr.erprp7jtucc.s-t' SUPfiKS--.. ' COr-USUSTlQrt ***=?. jfr&PiPO i . 7*OHrCr*a3HPlCT l CO8U31tGM PiDRrGSOUoP/HMM7cPUT*ff/CPH/ny.SOoCzJ}; 3ctfL?tjatrrmt/0tTsO r//77P> 7U&S3 Number of Boiler 1 2-60 2-72 2-84 2-96 2-108 3-84 3-96 3-108 3-120 4-108 4-120 4-1324-144 5-1325-144 5-156 |- 4800 5800 6800 7800 8800 10000 11400 12800 14200 16000: I7SOO 1960021400 24800 27100 29300 785 343 401 458 525 589 >72 753 135 944 1050 1154 1262 1462 1593 1724 Water Line In................ 6* 65 65 65 65 71 ; 1 71 71 78 78 76 78 85 85 85 42 42 42 42 42 42 42 42 42 46 4b 46 46 50 50 50 SI 63 75 88 100 93 108 124 139 161 181 201 221 253 279 304 60 72 84 % 108 84 96 108 120 108 120 132 144 132 144 156 Width of Shell In. B SI 51 51 51 51 61 61 61 61 71 71 71 71 81 81 81 Height bottom Sec. C 31 31 31 31 31 42'/, 42V, 42'/, 42'/, 48>/, 48*/, 48V, 48>/, M'/, 33'/, 33'/, Height 1 op bee. D 28 28 28 28 28 26'/, 26V? 26'/, 26'/, 30'/? 3oy, 30V? 30*/2 34'/, 34'/, Length 1 op bee. L 60 72 84 96 108 84 96 108 120 108 120 132 144 132 144 156 Length of Boiler In. F 84 % 108 120 132 no 122 134 146 136 148 160 172 160 172 184 Width of Boiler In. G S6 56 56 56 56 66 66 66 66 76 76 76 76 86 86 86 Height of Boiler In. H 72'/? 72'/, 72'/, 72'/, 72'/, 78V, 78V, 78'/, 78V, 84'/, 84'/, 84'/, 84'/, 92 92 92 Height 1 op Header 1 84 84 84 84 84 90 90 90 90 98 98 98 98 107 107 107 No. & btze Uutlets In... 1-8 1-8 1-8 1-8 1-8 1-8 1-8 1-8 18 1 10 1-10 1-10 1-10 1-10 1-10 1-10 No. & Size of Returns In. 1-4 1-4 1-4 1-4 M 1-4 1-4 1-4 1-4 1-6 1-6 1-6 1-6 1-6 1-6 1-6 Dia. Smoke Collar I 70 20 70 20 20 24 24 24 24 30 30 30 30 36 36 36 Height Stack Ft Length of Pit In. M Width foundation N Length Foundation 0 Width Ash Pit K Length Ash Pit L SO SO 56 62 44 50 55 60 65 70 65 70 75 80 75 80 85 90 85 90 95 62 74 86 9ft 68 . 80 92 104 9? 104 116 128 104 128 140 56 56 56 56 66 66 66 66 76 76 76 76 86 86 86 74 86 98 no 86 98 110 122 no 122 134 146 134 146 158 44 44 44 44 54 54 54 54 64 64 64 64 74 74 74 50 56 56 62 52 58 64 64 56 64 70 70 64 64 70 Steam R. (Hand-Fired) 4000 4800 5600 6400 7200 8250 9400 10500 11700 13200 14700 16700 17700 20500 22400 24000 Grate Size In.......... 46x48 46x4f 46x5< 46xV 46x61 56x5< 56x6056x66 56x66 66x6( 66x66 66x72 66x72 76x66 76x66 76x72 Grate Size Sq Ft........... 15.3 15.3 17.3 17.3 19.4 21.0 23.3 25.6 25.6 27.5 30.0 33.0 33.0 34.8 34.8 37.3 Standard Ratings conforming with the Industries "Simplified Practice Recommendations." Special High-furnace Boilers furnished for CHI Burners or Stokers. 961 ________ ______ __________________ Burners, Oil . S. T. Johnson Go. 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 complete line from small domestic to large industrial units with manual or full automatic ignition and control, burnings from the lighter fuel oils to the heaviest grades ... it includes combination oil-arid^ 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 55,600 sq ft steam radiation or its equi valent). The three commercial types of Johnson Rotary Oil Burners are of the same basic construe- 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. . - rfMH SPEED CENTRIFUGAL FUEL ATOMIZING CUP POSITIVE FUEL SUPPLY FROM OI.LBPUURMNPERON AIRCOOLED MOTOR FAN AND MOTOR MOUNTED ON SHAFT SUPPORTEO BY BALL BEARINGS. INSURES SILENT CAREFREE OPERATION TYPE 30-AV AND 30-AVH FULLY AUTOMATIC The 30-AV uses up to No. 5 Dimensions and Capacities of Types 28, 30AV and 30AVH Burners Burner Size No. l'/i 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 13 Wi 696 17 F 15 m 4Vi 150Vl i'/l 1400 2775 4150 5550 6950 13900 20900' 27800 50 100 150 200 3 15 6 30 9 45 12 60 Vi 250 300 y. 400 470 I Vi 460 525 2 475 540 320 16% isy. 10'/. 8'/, 171/2 l5'/2 505 17 l9>/2 13 9% 21 19'/, 560 21 Vl 21 Vl 13 II 24 20 575 21 Vl 21 Vl 13 II 24 20 6Vl 8325 41700 300 24 90 3 525 575 625 2V/i 21'/z 13 ii 25 20-/2 r/2 18500 55600 400 40 120 3 725 2IV4 24 14 n 25 201/2 Boiler output. Type 28 Burner available without built-in pump in same capacities. 962 5 f. Johnson Co. Burners, Oil fuel without pre-heating. Johnson-built viscosity compensating control valve furnishes constant flow of fuel to burner, regardless of fuel temperature or vis cosities and without excessive pressure on lines or undue strain on pump or motor. Built in six sizes, up to 41,700 sq ft steam radiation. 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. Built in six sizes, up to 41,700 sq ft steam radiation. Type 28 Semi-Automatic Burner, manually ignited, is made for heating boilers up to 55,600 sq ft of steam radiation or 400 boiler horsepower. Built in seven sizes, with built-in oil pump, and seven 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 trouble-free. It furnishes heat or domestic hot water or both in combination at low cost. Made in 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 4J4 ft, 5 ft, and 5)4 ft respectively. 'Laddi' Du-All 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. The Pressure Atomizing Burner used with the "Laddi" is available as a conversion bur ner for all types of furnaces and boilers. It is built in four sizes, covering a range from % to 7)4 gal per hour, equivalent to 300 to 3100 sq ft of steam radiation (E.D.R.). 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. ' "SeUclair" Capacities and Dimensions of SELECTAIR Units Size Max. Rating* No. Btu per hour 1 125,000 Cu Ft Air per min. </4S.P. 1,485 Heat Exchanger Size Stack Oil Rate Btu per hour . Connection Cal per hour 105,000 . 7' 1 to l'/4 Cabinet Width IT Dimensions Length Height 60' 54' . 2 200,000 2,320 166,000 ' ' . 8' l'/4 to 2 3r 69' 63' 3 300.000 1 3,300 235,000 .9" \ 2 to 2J/4 33" 86' 69' *Total output includes steam to heat exchanger, heat for domestic hot water, and heat available for installed radiation if used. 963 Cooling Towers The Cooling Tower Company, Inc. 15 John Street, New York, N. Y. A DIVISION OF THE FLUOR CORPORATION, LTD. 909 E. 59th St., Los Angeles, Calif.--Mail Address: P. O. Box 128, Station K. Los Angeles, Calif. Representatives in Principal Cities Manufacturers of Aerator Type 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.* Fluor Aerator Type Cooling Towers Mechanical Draft Cooling Towers ' Our successful Aerator type design is such that no straight line passage of air or water through the cooling tower is pos sible. This results in (1) undisturbed water dis tribution through the tower, (2) elimination of windblown spray, and (3) uniform cooling per formance. Structurally, these towers are 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 sturdy. California Redwood, the structu ral material, is selected because of its characteristic strength, durability and long life, as well as its low maintenance cost. The tower is rigidly cross-braced trans versely and longitudinally with full cross section beams, providing equal strength in tension or compression. Architecturally, the completed tower is an outstanding example of modern industrial design. The distribution system of the tower consists of a longitudinal pipe header with openings in the top connecting to two large trans verse distributing arms in each bay. Water distribution is effected by double staggered bowed panel type deck surfaces, effecting perfect water filming with fastest dissi pation of heat. Wind pressure drop through 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. the tower is negligible with wind velocities under six miles per hour. Successful opera tion at any outside temperature, in any location, with any wind velocity, is assured. Aerators are standard on all Fluor Towers, from the smallest to the largest. Towers (2) Freedom from interruption of opera tion. x (3) Automatic drain and flushout valve. (4) Well designed spray fence for protec tion against spray dirt. are built in any sizes from five gallons per minute upward. ' Indoor Cooling Towers 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. 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. 964 Cooling Towers The Marley Company (Fairfax and Marley Roads,) Kansas City, Kansas Branches or Agents in Principal Cities Spray Nozzles and a Complete Line of Water Cooling Equipment HARLEY Standard Water Cooling Xoszles for Spray Pond L'se. and Cooling Towers, MARLEY Small t-Piece Noz zles for Brine Spraying, Air Washing and Similar uses. MARLEY Ice Melting Nozzle for cooling systems using ice. MARLEY Humi difying Nozzleadds moisture to air in open rooms or duct system. MARLEY PATENTED NON-CLOG SPRAY NOZZLES Made in scores of types and sizes. Practically any metal or alloy the purpose may demand. Bulletin 100. MARLEY ATMOSPHERIC SPRAY TOWERS For all industrial water cooling services, refrigeration, Diesels, etc. Virtually unlimited range of sizes. Entirely shop fabricated. Rugged, efficient. Low initial maintenance and operating costs. Many exclusive MARLEY advantages. Bulletin 200. Large MARLEY Double-Cased Redwood Forced-Draft Tower. MARLEY Steel Forced-Draft Tower typical of roof installations for air conditioning. MARLEY STANDARD FORCED DRAFT TOWERS For heavy-duty heat-dissipating services of all kinds. Any capacity. MARLEY patents cover a variety of important features for extreme operating flexibility, high efficiency and economy. Bulletin 85. MARLEY STANDARD INDUCED DRAFT TOWERS For same types of service as above but where the induced draft principle is more desirable or efficient. Same MARLEY patented features and engineering. MARLEY "SMALL SERIES'* STEEL INDUCED DRAFT TOWERS For jacket water cooling of engines, compressors and other small equipment. Popular in refrigerating and air condi tioning, 3 tons and up. 28 standard models for any space or capacity requirements. Vertical style for outdoor service, Bulletin 500. Horizontal style for indoor service, Bulletin 502. Also MARLEY Spray Coll Towers, Large Induced Draft Coil Towers, Deck-Type Atmospheric Coil Towers, Spray Ponds and Related Equipment. 965 Expansion Joints 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 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. V The element is a series of welded U-rings ' 1 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. 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. : 1 : Red Diamond Brand Casing 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 worlang 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. 35-86G. ADSCO Vertical Steam Trap ADSCO HEAT EXCHANGERS Made in various sizes and capacities to heat or 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, economizers, condensate coolers or special units. Write for Bulletin No. 35-75BG, 35-76G. ADSCO In^laneous Water Beiur 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 Rotary Condensation Meter . city. Write for Bulletin No. 35-80AG. {See also Page 1089) 966 Expansion Joints E. B. Badger & Sons Co. General Office: 75 Pitts Street, Boston, Mass. Representatives Atlanta, Ga... Charlotte N. CChicago, Ili~................... Cincinnati, Ohio........... Cleveland, Ohio........... Denver, Colo.._............ Detroit, Mich................ Houston, Texas............. Indianapolis, Ind......... Kansas Cttt, Mo........... Los Angeles, Calip..-- 140 Edgewood_Ave. ..... 1408 I'nde' pend'ence Bl"dg. ....... 1307 So. Michigan Ave. .1801 Carew Tower ___ Guardian Bldg. ..725 Denver National Bldg. ................. .424 Book Bldg. --4421 Rusk Ave. ............ 825 Occidental Bldg. 1332 Oak St. .............609 So. Anderson St. Minneapolis, Minn........................ -.732 Builders Exchange Montreal, Quebec...................................... 1411 Crescent St. New Orleans, La... ....................... 916 Union St., Room 203 New York, N. Y........ ...........................,,271 Madison Ave. Philadelphia, Pa........................................... 1500 Walnut St. Pittsburgh, Pa___ 302 Benedum Trees Bldg., Fourth Ave. Salt Lake City, Utah..................................... _Kearas Bldg. San Francisco, Calif.........................................Sharon Bldg. Seattle, Wash .......................................... .Smith Tower St. Louis, Mo...... ..................................4060 W. Pine Bird. Washington, I). C._....................1103 Vermont Ave., N. W. ENGINEERS AND MANUFACTURERS Manufacturers of Copper and Stainless Steel Badger Corrugated Expansion Joints; Engineers and Manufacturers of Chemical Apparatus; Engineers on Process Work; Designers of Complete Plants. Forty years' experience in design, manufacture and application are back of Badger Expansion Joints. Over the years, many improvements in design have been brought out, resulting in better construction and longer life. Every advantage has been taken of controlled heat treatment throughout fabrication to obtain its benefits. The Directed Flexing feature, one of the more recent developments, assures full distribution of flexing stresses by progressively controlled flexing. The all-curve corrugations and corre spondingly shaped equalizing rings provide this. The adoption of Stainless Steel, another recent'development, solves the problem of using a "packless" type expansion joint under high temperatures, high pressures and special corrosive conditions. Badger Expansion Joints.are of the packless type, requiring no maintenance during their long life. This ' feature makes them particularly useful in crowded quarters or in underground tunnels where space is at a pre mium. They are com pact and easily installed and insulated. They do not have to be serviced after installation. Three distinct de signs are available, each described in an illus trated bulletin. Copies of bulletins will be sent on request. Bulletin No. 100 Directed Flexing, Self-Equalizing List prices, weights and dimensions of copper and stainless steel expansion joints together with installation data on this design which is used for traverses ranging from fractions of an inch up to 6 inches single and 12 inches double; for pressures ranging from vacuum to 200 pounds (cop per) and 300 pounds (steel); for tempera tures from sub-zero to 500 F (copper) and 900 F (stainless steel). Bulletin No. 200 Non-Equalizing . List prices,, dimensions, weights of cop per and stainless steel expansion joints and other data on the design which is used principally to absorb vibrations or lateral displacement between piping and equip ment or between connected equipment. Traverse is limited to in. or less and line pressure to 25 pounds or less. Stan dard shapes: round, square, rectangular, or oval; special shapes to order. ' Bulletin No. 300--Flexible Seal Dimensions and other data on a modification of the standard Badger Non-Equalizing Joint for use on pipe lines passing through walls, foundations, decking, bulkheads, etc. Its function is to allow for line movements such as expansion, contraction, lateral dis placement or vibration yet completely seal the opening so that water or other liquids will not work back along the line into buildings or compartments. Made standard in carbon steel; other metals to order. List prices on application; 967 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. '> ,' ifferentiate clearly D between coo"ling and' ven*ti 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 theoutstanding 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 openings 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 Coolair Home Cooling and Validating Installation Standard Type--Front View Diameters Six to Nine Feet Performance Data on Request Description COOLAIR Belt Drive Fans meet the ventilating and coqling 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. 968 American Coolair Corporation Fans Performance Data--Coolair Belt Drive Fans Fan Size Hp Fan RPM Cu Ft Air per Min "% 448 4600 2 t% 535 5500 tt 'A 595 6100 "% 395 t M 432 2% t% 495 tt % 567 7500 8200 9400 10700 % 308 10000 tH 335 10800 3 t% 394 12800 tt % 440 ' 14200 ttl 485 15700 t$ 244 294 3% t% 325 ttl 358 tfl% 410 - Over-All Dimensions (In.) tk 211 248 4 t% 290 Height and . Siw width Depth ttl ttl% 320 366 12500 15000 16600 18300 21000 15500 18200 21300 23500 26800 2 2Vz 3 V/g 4 A'/i 5 6 7 8 9 30% - 36% 42% 49 55% 61% 67% 75% 87% 99% Ml 12 12 12 16 17% 18% 161% 28 34/2 34 34 -% 210 t% 236 4% tl 260 ttl% 298 tt2 328 '% 175 t V, 201 5 tl 222 ti% 254 tt2 280 ft3 321 21600 24500 27000 30900 34000 24600 28200 31200 35700 39300 45100 'Standard type frames. Note: Depth Approximate. Advantages Vfery quiet. tQuiet. ttlndustrial. Data in accordance with Standard Code Test, American. Society of Heating and Ventilating Engineers. Coolair Direct Drive Fans (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) Rubber insulated motor support. Adjustable to belt tension. (6) Equipped with SKF ball bearings in dustproof, grease-packed housings. . (7) Easy to install. The steel blades and frame are durable, yet light in weight (8) Standard motors. Enclosed when specified. No vent holes are necessary to keep them cool. Coolair Direct Drive--10 in. to Si in. Data on Request Covered by U. S. Patent No. 1,855,660, designed for maximum air per horsepower with minimum noise. Type "B" Direct Drive COOLAIR Fans (9) Blades are individually mounted, inexpensive to replace. (10) Coolair Belt Drive units, when equipped with ball bearing motors, are suitable for operation in any position. (11) Residence units are light, spring suspended for ultra-quiet operation. 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 Susper, ion covered by U. 5. Patent No. I,99S.tlS. 969 Autovent Fan & Blower Company 1809-23 N. Kostner Ave., Chicago, Illinois FANS--BLOWERS UNIT HEATERS Member National Association of Fan Manufacturers and Industrial Unit Heater Associations Coolvent Fan--Belt Driven Propeller Fan for com mercial and industrial applications as well as residential attic fan installations where large volume of air is required with quiet operation at low initial and oper ating costs. Sizes from 24" to 54" diameter. Bulletin No. 204-A sent on request. Autovent "31" Series Propeller Fans--Will not churn air or overload the motor. Especially recommended for economical ventilation. Ruggedly con structed. Capacities from 500 to 38,000 cfm. Write for bulletin No. 200. Acid-moisture and Explosion Proof Fans--The acid-Moisture proof units are equipped with fully en closed motors and specially constructed fan wheels. The vapor-explosion proof units designed to handle ex plosive dusts and gases have underwriters label "Class 1 --group D" motors and non-ferrous fan wheels to meet the requirement, bulletin No. 201. x Write for AUTOVENT "31 SERIES" PROPELLER FANS Constant or Two Speed--Alternating Current--Multiphase-- 220 or 440 Volts--60 Cycle Size Type Motor HP Clin Max. Appr. Rpm Max. Appr. Shpg. Wt. Lb Size Type Motor Hp Cfm Max. Appr. Rpm Max. Appr. whi i I6HMN I6HMR I8HMN 18HMR 20HMN 20HMR 24HML 24HMN 24HM 1/8 1700 1140 64 1/5 1950 1725, 66 1/8 2350 1140 > 77 I/'t 2950 1725 90 1/4 3450 . 1140 115 1/4 3550 1725 115 1/6 ! 3850 850 145 1/4 4500 1140 150 1/3 5250 850 175 30HML 30HMN 36HMT 36HML 42HMT 48HMT 54HME 60HME 72HME 1/3 Vi Vi Va 1.0 l'/z 2 2Vz 3 7100 850 8100 1140 10000' , 690 12500 850 13500 690 18900 690 21500 575 26500 480 38000 480 210 220 335 390 510 650 890 1200 1500 - i ,,* V 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 f\ow 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. 102. The Complete Line of AUTOVENT Propeller Fans is tested and rated in accordance with the Standard Test Code adopted jointly by the National Association of Fan Manu facturers and the American Society of Heating and Ventilating Engineers. * 970 A Fans Bayley Blower Company 1817 S. Sixty-Sixth Street Branches in Principal dries Milwaukee, Wig. 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, drying systems, forced and induced draft systerns. 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. Aeroplex Fan: 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: Type "B" exhaust fan is for heavy duty, hand ling refuse from industrial and textile plants. Type "SE" is used in handling smoke, fumes and dust laden gases. Type "H" for high-pressure work. These units are highly efficient and of high class design and workmanship. Bayley Turbo Air Washers, Humidifiers and De-Humidifiers: The Turbo Atomizer used in the Bayley Washer pro duces a steady, fine spray. Water at low pres sure is deliv ered . to the The Bayley Turbo Air Waeher Show- center Of a rapidly re ing Turbo Atomizer and Eliminator volving cone-shaped rotor provided with atomizing pins set in its periphery. This 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. 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) the lower chamber, ris ing through %-in. pipes located within the 1^-in. pipes leading from the upper chamber. Condensation takes place in the larger pipes, the water falling into the 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 . knocked down in the larger units. May be installed in horizontal or vertical position. Bayley Chinookfin Heating Sections: Are the same design as the Chinook Heaters, using heavy gauge copper fin tubes. . As compared with Chinook it is much lighter and occupies less space. Bayley Plexfin Unit Heaters: This unit in corporates Chinookfin radiation and Plexiform or Aeroplex fans. The fan assem bly including top plate and motor is re movable as a unit for main tenance and inspection. The heating element is a re movable unit. Casing all welded extra heavy gauge. This is an exceptionally high grade unit at a moderate price. 971 Buffalo Forge Company 450 Broadway, Buffalo, N. Y. Branch 1 Albany. N. \...... _______ 611 Standard Bldg. Atlanta. Ga........ ..16tb Floor, 22 Marietta Bldg. Baltimore. Md.,, 404 St. Paul St. Boston. Mass..... .............. ..........486.Main St. Chicago. Ill......... __JO North Waeker Drive Cincinnati, Ohio. _.626 Broadway Cleveland. Ohio. 418 Rockefeller Bldg. Dallas,. Texas. _____ 702 Tower Petroleum Bldg. Davenport, Iowa--D. C. Murphy Co., 305 Security Bldg. Denver, Colo.--Hcndrie A Bolthofl Mfg. A Supply Co., 1635 Seventeenth St. Des Moines, Iowa--D. C. Murphy Co., 214 Old Colony Bldg. Detroit, Mich.--Cood DeVisscr Co., 2051 W. Lafayette Blvd. Greenville, S. C_______ 312 Franklin National Life Bldg. Houston, Texas.Kansas Citt, Mo... TM713 Bankers Mortgage Bldg. _428 Dwight Bldg. Kitchener, 6nt., Canada-- Canadian Blower A Forge Co., Ltd Knoxville, Tbnn.--C. F. SextonTM.......... 702 Empire Bldg Los Angeles, Calif.................. _708 Pershing Square Bid* Minneapolis, Minn................................. 2102 Foshay Tower Nashville, Tbnn.--Southern Sales Co., 117 Fifth Ave. South New Orleans, La.--Devlin Bros___ .?1003 Maritime Bids New York, N. Y._..............39 Cortlandt Bldg., Room mo Philadelphia, Pa--............ .......................703 Cunard Bldg. PirreBtmo, Pa-------------------------------------- ---431 Fulton Bldg; \ Richmond, Va--T. Spencer Williamson, Jr., Inc., Mutual Bldg > San Francisco, Calif.--Moore Machinery Co., . 1625 Van Ness Sk St. Louis, Mo... ...1598 Arcade Bldg Seattle, Wash... ..500 First Ave. South Toledo, Ohio..-..................................1922 Linwood Avenue Washington, D. C.--820 Woodward Bldg., 15th and H Sts., N. W Wilkes-Barre, Pa.--Power Engrg. Corp., 517 Brooks Bldgi 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 cool ing 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 venti lating fan mounted on the silent, float ing fan base eliminates all motor and fan vibration. Buffalo Unit Heaters Buffalo Unit Heaters are built in a wide range of sizes and types for the efficient and econom ical handling of any heating problem. Oper ate with either low or high Breezo-Fin Steam Unit pressuresteam. We also offer a wide selection of Gas Unit Heaters that are fully automatic and equipped with every necessary safety device. Buffalo Unit Coolers Quiet unit coolers for use 'with cold water, brine, methyl chlo ride or Freon. Compact, simple, inex pensive. A vailable in both sus pended and floor types. Buffalo Air Washers Buffalo Air . Washers are in use in thousands of build ings, many for more than 30 years. Bulle tin 480 gives details. . 972 Champion Blower & Forge Co. Manufacturers and Engineers Plant and General Offices: Lancaster, 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 fiat 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. Type "S" Double Width . Belt Driven Fans Built in sizes up to 60 in. Wheel for Ven tilating and Air Conditioning. Type "CE" Electric Driven Fans For use in Forced Draft and small venti lating work. Built in sizes up to and including 18 in. dia. Wheel. 973 DeBothezat Ventilating Equipment Division American Machine and Metals, Inc. Etecutive and sales offices: 100 Sixth Ave., New York, N. Y. Factories: EAST MOLINE, ILL. Branch Offices and Agents in All Principal Cities Type H. Disc Pressure Fan. 14 in., hp, 1140 rpm, 6170 cfm against H in. static pressure. Bifurcator. Efficient unit for use where fumes of excessive temperature, corrosive or explosive character, are to be removed. Motor outside air stream. Two-Stage Duplex-Rotation Impeller Blower, with part of housing cut away to show construction. Large volumes of air against high static pressures at low lip speeds. Extremely high efficiencyover entirerangeofoperation. Fans and Blowers are guaranteed to have non-over-^ loading power characteristics. Complete operating safety under varying working conditions. .. Disc Pressure Fans (Direct and Belt Drive)__ Three types: H for high static pressures; HL, for moderate; and L for low--designed to meet all pressurevolume 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. &\ %% 1i in $ & 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. . Bifurcators--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 airstream 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. Roof Ventilators--Assure positive ventilation under all atmospheric conditions. Built in 14 to 48 in. diameters (special sizes on specification) with capacity ranges from 925 to 52,300 cfm of free air. Totally enclosed motor, ball bearing mounted. Also furnished in Bifurcator Type, i.e., motor isolated from air stream. Attic Fans--DeBothezat attic fans adaptable to every type house. Built in 18 in., 24 in., 30 in. and 36 in. diameter. Steel construction, insulated, with four-bladed fan rotating on rubber-mounted-ball bearings. Catalogs--Descriptive catalogs sent upon request. 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 Ilg-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 Ilg 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 "BC" 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. Ilg-built throughout. For steam or hotwater. 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 3^ ton cooling capacities 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. 975 The Torrington Mfg. Co. 50 Franklin Street, Torrington, Conn. Manufacturers of Alt-Aluminum Blower Wheels and Disc Propeller Type Fan Blades. Air impellers for every purpose. AIQISTCCRAT * --r - - Quiei frnpeltei Fan Bladn ' JORRiNGTOM] BLOW'ERW'HEELS 1 AUTUm : Single Inlet Blower Wheel Double Inlet Blower Wheel Pot. 1.700.017 Special Design Blower Wheel Torrington Aluminum Blowerv 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 --saves power. Every wheel is perfectly balanced by hand and given a running test. 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. to 15 in. diameter in ail 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--The ^ one piece cup construction is economical for production and the design is efficient and sturdy. Ideal where maximum air delivery and minimum power is required. Used for automobile heaters, windshield defrosters, small hair dryers, hand dryers, ice box and refrigerator circulators, win dow ventilators, exhausters, etc. Made ` for either clockwise or counter clockwise rotation, of steel or aluminum, in the following sizes: il r: '"4 \ ' r. Cup Type Blower Wheel . Pats. 1.513.763 and 1.648,060 {Produced under license from American Blower Co.) Dia. Blade Width 3 in. 3^ in. 4H in. 4H in. 5 in. 5 in. Iti in. 21J%6 in. in. 3 in* 2M in. 3 in. . Dia. Blade Width 6 in. . ti6 in. in. 6 in. 7H in. 9 in. H. in. 1% in. 2% in. 3H in. 4Hi in. in. ` I 976 The Torrington Mfg. Co. Fans AIRISTOCRAT Quiet Propel ler Fan Blades are beautiful, orna mental ultra quiet, modern as the year 1939 'Designed for free air applications /desk fans, air circulators, etc.) Perform well at moderate pressures. Used for window ventilators, unit type air condi tioners unit heaters, refrigeration devices, etc Blades are hand set for alignment, statically balanced and packed in special containers for protection in transit. Clock wise rotation only. Aluminum alloy blades, steel center. Finishes as follows: 1. Plain. 9 Blades with no finish; spider and hub with cadmium plate or black lacquer. 3 All black lacquer, with or without center button. 4. Buff and lacquer blades, black lacquer spider and hub, with or without center button. Bulletin No. 123738 gives detailed dimensions and guaranteed per formance curves recorded under NEMA code tests at various speeds. De Luxe /Model--The round, convex centerplate adds to the beauty of this ultra quiei 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 spider instead of round center disc. A sturdy and beautiful blade which has withstood extreme laboratory breakdown tests. Sizes 8 in., 10 in., 12 in., 14 in., 16 in. and 18 in. Priced lower than DeLuxe Models. Air Circulator Model--The design of this blade is the result of two years of laboratory experiment to produce a better air circulator blade. At recommended speed these blades produce a high velocity air stream effecting deep penetration with unusual quietness. Sizes 20 in., 24 in. and 30 in. (Larger sizes ready soon). Airislocrat DeLuxe Model Airislocrat Standard Model Pats. 2,072,882 and 2,021,707 Airislocrat Air Circulator Model AUTOCRAT Fan Blades--For auto heaters, windshield defrosters, etc. Have been standard ever since these devices were first marketed. Made in sizes 3 in., 4 in., 4^ in., 5 in., 5% in., 5^ in., 6 in., 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. K 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. Autocrat Fan Blade 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. 977 Branch Offices in Principal Cities L. J. Wing Mfg. Co. 59 Seventh Avenue, NeW York, N. Y. Factory; NEWARK' N- 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 Bring the realization of a heating method that pro duces live heat--the pleasant, healthful effect of com fortably warmed air in motion. . No hot spots, cold spots or drafts because the circu lating air is continually changing direction. 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 Detail of Wino Featherfin Heating Element showing Compression Union Tube Connection WING Unit Heaters. Tested at 1000 lb pressure. Bulletin HS-1. . Wing Variable Temperature Heating Sec tions permit precise control of air temperature without b^-passing and without throttling steani. No freezing. VariaMe Temperature Heating Section. Bulletin HS-1. Wing Garage Heaters For effective and economical heating of garages. Sometimes cut heating costs in half. Bulletin G-l. Wing Door Heaters For instantaneously heating inrush of cold air at large doorways of industrial buildings. Bulletin D-l. 978 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-\ 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 FE-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-7. 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 System of Controlled Combustion For low-pressure heating boilers. In creases capacity and permits use of lowestcost fuel. Eliminates necessity of frequent firing, allowing inter vals as great as 24 hours in some cases in zero weather. Bulletin M-76. Wing Turbine-Driven Blowers Applied to hand, stoker, oil or pulverized fuel fired boilers, increase boiler capacity, maintain 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) Applied to high pressure boilers, produce high static pres sures 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 applications. Bulletin COS. 979 X Akron, O. Albany, N. Y. Atlanta, Ga. B. F. Sturtevant Co. Baltimore, Md. Boston, Mass. Hyde Park, Boston, Mass. Buffalo, N. Y. Camden, N. J. Chicago, 111. Slurlevanl Cincinnati, O. Cleveland, O. Columbus, O. Detroit, Mich. 1 Paso, Tex. Grand Rapids, Mich. Greensboro. N. C. Hartford, Conn. Indianapolis, Ind. Kansas City, Mo. Little Rock. Ark. Camden, N. J. PLANTS LOCATED IN - Hyde Park, Mass. Framingham, Mass. Los Angeles, Cal. Sturtevant, Wis. Galt, Ont. Berkeley, Calif. Louisville, Ky. Mansfield, O. The Cooling and Air Conditioning Division Milwaukee, Wis. of B. F. Sturtevant Company Minneapolis. Minn. New York, N. Y Phoenix, Ariz. * ' Pittsburgh, Pa, Portland, Ore. St. Louis. Mo. Salt Lake City, U San Francisco Cal Seattle, Wash. Spokane, Wash Springfield, Mass Syracuse, N. Y. Toledo, O. * Toronto, Ont. Washington, D. C A. M. Lockett & Co. New Orleans, La Houston. Texas Dallas. Texas Galveston. 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 Catalog No. . 291 Pneumatic Collecting and Con veying Systems. -. 377 Unit Ventilators. ' *' 395 Rexvane Speed Heaters (Floor type unit heaters). ' 396 Speed Heaters (Suspended Type Unit Heaters). 443 Design 8 Propeller Fan (Specially designed to operate against duct and wind resistance). COOPERATION 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 suitable for any prospective installation. VENTILATING FANS Catalog No. , 271 Multivane Fans (Forwardly curved blade type). 414 Rexvane Fans (Radial blade type). 400 Direct-connected Fans and Blow ers (Propeller Fans; Window Fans for kitchens and offices; Centri fugal Fans from 80 to 6460 c.f.m.; Portable Gas - . Engine - Driven Fans; Coal Burning Blowers; Forge Blowers; Dust Blowers). 422 Roofvane Ventilators. 435\ Silentvane Fans (Backwardly 442/ curved blade type). AIR CONDITIONING EQUIPMENT Catalog No. ' 295 Air Washers. AC 101 Industrial Air Conditioning. 378 Filticooler (Compact, high ef ficiency air washer. For filter ing, washing, humidifying, cool ing, dehumidifying. Used prin cipally for public buildings and factories). 398 Comfort Air Conditioning. 401 Railway Air Conditioning. 424 ' Fans and Air Washers for Theatres. 425 Air Conditioning Apparatus-- Fans and Accessories. VACUUM CLEANERS Catalog No. 368 Industrial Vacuum Cleaning Systems. ' 373 Vortex Furnace Cleaner. 397 Central-Vacuum Cleaning Systems. (Commercial Buildings). 413 Vortex Portable Vacuum Cleaners. 980 Heaters, Unit Airtherm Manufacturing Company 1474 South Vandeventer, St. Louis, Mo. THE ENGINEERED LINE OF UNIT HEATERS AIRTHERM IMPROVED UNIT HEATERS are backed by thirty years experience in unit heater construction, and are recognized for their many new, and exclusive features. Sound engineering principles, highest quality materials and workmanship, plus modern design and styling make Airtherm Units the logical choice. It is significant that most sales of Airtherm Heaters have been made to those concerns maintaining engineering staffs of their own, many of whom are engaged in heating and allied industries. THE AIRBLANKET. Propeller Fan Type . . . with a patented method of air direction control to hold warm air in the heating zone. THE AIRBLANKET. Centrifugal Fan Type . . . with the exclusive Airblanket Principle. Airblankets are designed so that a stream of cool air of high velocity is delivered just above a stream of warm air at less velocity. The cool air stream retains and distributes the warm air stream in the lower portions of a building, pre venting unnecessary heating above the breathing level ... it thus produces an artificial ceiling or blanket of cool air above the breathing line. THE DIRECTHERM. Newly De signed Direct-Fired Unit for Gas, Oil or Coal (Hand or Stoker). ENGINEERING SERVICE. The Airtherm Manufacturing Company Engi neering Department and District Representativcs are al all times available for consultation. At your request we will place experienced engineering aid at your dispo sal. Representatives in all principal cities. THE AIRHEATOR. The Airtherm blower fan type unit heater for floor or ceiling mounting. . THE AIRVECTOR. (Not illustrated). A propellor type fan unit for ceiling sus pension or for mounting from the floor on recirculation stack. Heaters, Unit Fedders Manufacturing Co. HEAT TRANSFER SPECIALISTS SINCE 18% 57 Tonawanda Street, Buffalo, N. Y. Branches and Representatives in All Principal Cities Unit Heaters, Air Conditioning Surface and Unit Conditioners, Unit Coolers, High Capacity Thermostatic Expansion and Constant Pres sure Valves, Commercial and Household Refrigeration Equipment Fedders Series 4 Unit Heaters New, exclusive Series 4 Double Headers for' unusually free steam flow, improved Full Floating Mountings, tubes with aerodynatni- cally correct 3 to 1 streamline ratio and patented saddle fins prevent differential expansion stresses, improved mono-piece cabinet design with integral mouldings, those are some of the features of Fedders New Series 4 Unit Heaters Complete line with single, two and three speed standard and explosion proof motors. ' Write for Bulletin 573. ' 3UI 3143 3141 3183 3311 3261 3273 3353 3311 3374 3372 (4,1 100 125 ISO 175 200 225 250, 275 300 325 350 ,7, 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 correct distribution of cooling and heating medi`um. Engineered and cataloged on a package basis. Write for Bulletins. Fedders High Capacity Thermostatic Expansion and Constant Pressure Valves Patents: 1,974,831 1,987,948, e,011,379 Model 37 Ther mostatic Expan sion Valves have 8, 12, 16 and 20 Tons capacity with Freon. Model HCP38 Constant Pres sure Valves up to 60,000 Btu/hr with 26.7 lb per sq in. Pressure Drop, Freon. 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. 982 Healers, 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 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 PRODUCTS 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 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. 983 . X Heaters, Unit Modine Manufacturing Company Heating and Air Conditioning Division General Offices: 17th and Holburn Sts., Racine, Wis. Factories at Racine, Wis. and La Porte, Ind. Branches in all Principal Cities Complete information on the following products including engineering data and prices, can be secured by writing to the Modine General Offices at Racine, Wisconsin--or by communicating with nearest Modine representative. Unit Heaters--Capacities and Dimensions (Kn Inches) 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 effective, economical distri bution of heat: (1) Expansion Bend, given each tube of the condenserbefore 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 stream, assures greatest possible throw consistent with comfortable heating. (3) Direct Pipe Suspension facilitates horizontal redirection of the heated air stream, permitting full 360 deg rotqtability. Also means easier installation at less cost-- no brackets, pipe rods or straps being nec essary. Write for Unit Heater Catalog 138. AU above models are available with variable speed motors. Units for hot water application also available MODINE COPPER CONVECTORS (Deluxe Type) The new Modine Deluxe 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 'vsystems. 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.--Catalog 238. (Standard Type) The popular copper radiators for commer cial and public buildings, low cost houses, etc.--wherever the benefits of copper con vector heating are desired. Attractive 984 jtfodine Manufacturing Company Healers, Unit enclosures with remov able fronts. High capacity copper heating units. Enclo sures available in three types of Recessed and Floor and Wall Cabinet types. Cata log 238-A. UNIT COOLERS (PropeUor) This unit is intend ed for cooling stores and offices in the sum mer--and heating them in the winter. Cold water is the cooling medium. In expensive and easy to install. No ducts or change in building construction required Bulletin 438. INSTITUTIONAL TYPE UNIT COOLERS (Blower) Designed for use where special construc tion features, common to institutional heating, are specified. This line incorpo rates many features which have hereto fore been con sidered "expensive'spe cials." Avail able in two types of Re cessed and in Wall Cabinet. Cat. 238-A. For stores and offices. This unit cools, cleans, dehumidifies and circulates the air. Equipped with powerful, yet quiet blower, extra deep cooling coils and large-area air .filters. May be installed with or without duct work. Choice of cold water or Freon cooling coils. Bulletin 438-A. MODINE BLAST HEATERS Made in over 250 sizes, types and ca pacities to meet the specific demands for heat transfer ser vice. Outstanding featuresare: (1) Ex pansion Bend. (2) All steam carrying passages are cylin drical for greatest possible strength. (3) From inlet to outlet condenser is of copper or copper alloy. (4) Copper fins are bonded metallically to tubes. Cat. 338. AIR CONDITIONER (Apartment House Type) A compact unit performing every func tion of complete winter and summer air conditioning--for apartments, hotel suites, residences, offices, and shops. Its com pactness allows installation in a closet above shelving or in a hall above a false ceiling. Uses steam or hot water for heating; cold water or Freon for cooling. Two sizes. Bulletin 638-B. AIR CONDITIONER (Large Central Type) MODINE COOLING COILS For residential For use in central and commercial system cooling and year-'round air con air conditioning ditioning--may be plants, Modine Cool used in straight air ing Coils, Cold Water conditioning or split Type, are installed systems. Uses with a blower fan and steam or hot water duct work. Adapt for heating and cold able where cold water water or Freon for or non-corrosive brine is used as the cooling. cooling medium.--Catalog 538. | 638-A. Catalog 985 Heaters, Unit The Unit Heater and Cooler Co. Wausau, Wisconsin Offices In Principal Cities MANUFACTURERS OF THE GRID UNIT (patented) 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 hinal Temp. Weight Supply Return 1000 16 12'/. m 16 0.85 1200 18 l4'/2 it'/. !7>/2 1.04 515 23'/i 18 ll'/2 20 1.67 1500 23'/z 18 ll'/2 20 1.67 1520 27 18 ll'/2 20 2.2 520 27 23'/. II1/2 2l'/2 2.8 .2000 27 23'/. ll'/2 2l'/2 2.8 2025 32 23'/. ll'/2 2l'/2 3.6 525 32 28'/2 II'/2 28 4.5 2504 32 28'/2 ll'/2 28 4.5 2500 32 28'/2 11'/2 28 4.5 2530 36 28'/2 ll'/2 28 5.3 530 38 33 133/. 29. 6.5 3000 38 33 13'/. 29 6.5 3000 38 33 13'/. 29 "Varies with type of motor. 6.5 1/20 1/20 1/10 1/10 1/10 1/6 1/6 1/6 1/2 1/4 1/2 1/2 1/2 1/2 l'/2 1700 1700 1750 1750 1750 1150 1150 1150 1150 1150 1150 1150 1150 850 1150 578 711 1290 1450 1700 2500 2500 2875 4200 3200 4200 4650 5300 6350 8100 29,400 .46,000 59,600 77,500 104,000 102,300 148,000 177,000 166,400 210,000 225,000 282,000 260,500 341,000 394,000 107 . 119 102 109 113 97 114 115 94 . MS 108 115 105 109 104 90 120 180 210 250 280 320 370 390 400 440 ' 500 600 690 725 . i'/." i'/." I'/.". i'/2" l Vi" 2" 2" 2" 2" 2" 2" 2" 2'/2" iVi" VA" i'/." i'/." i'/," i'/," i'/." i'/." iv." i%" i'/." i'/." i'/." i'/." i'/." i'/." i'/." 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. 986 Heaters, Unit YUpNG RADIATOR \jompamt~ Offices J , all Principal Cities Racine, Wis. Write For Literature Engineering Information At Request , Model SH Unit Healer STREAMA1RE Convector Type FC Healing Units Blast Units-- Commercial Units Air Conditioning Unit ' . Air Conditioning Units--are made in five physical sizes for home and industrial, installations. Designed to do a complete air-conditioning job, heating, cooling; hu midifying, and dehumidifying. Unit Heaters--Model SH and TH. A complete line of single and twin fan sus pended units, 28 sizes ranging in capacities fr0m 18,000 to 658,000 Btu per hr. Unit Coolers--A complete line of sus pended units, 9 models varying in capacities from .39 to 2 tons. Designed for use with water brine, or any common refrigerant. STREAMAIRE Convectors--are avail able in six distinct types of cabinet enclossures--free standing, wall hung, partially recessed, fully recessed, bathroom cabinets, and plastered-in enclosures. Designed to operate on one pipe steam, two pipe steam, vapor, vacuum and gravity hot water heating systems. "FH" Unit Heaters--ten models rang ing in capacities from 120,000 to 800,000 Btu per hr. These units are equipped with two, three, and four blower type fans, driven by single or variable speed motors. "FC" Heating Units--combine the appearance of a STREAMAI RE convector with the higher capacity of YOUNG Unit Heaters. Available in four physical sizes, equipped with single and two speed motors. Cooling Coils--Type "W" with con tinuous tubes, type "K" with removable headers for use with water or brine. Evaporators--Designed for mechanical refrigeration systems using Freon or methyl chloride. . Commercial Units--Designed for use in connection with heating, cooling, and air-conditioning units where a compact, efficient, heating surface is desired. Blast Units--as encased heating sur face for use in connection with forced air, heatiifg, and cooling systems. 987 Unit Cooler Model FH Unit Heater Type "K." Cooling Coil S' The National Pipe Bending Company Incorporated 1883 104 River Street, New Haven, Conn. Instantaneous Water Heaters Caustic Liquor Heaters Feed Water Heaters Fuel Oil Heaters Storage Heaters Head-Exchanger* Coils, Pipe, Tub* Welded Heaters NATIONAL HOT WATER HEATERS :% Instantaneous . * Water Tube Type ' Heats water as it flows, either continuously or intermittently. Built for steam pressures up .to 150 lb per sq in. U-Bend copper tubes expanded into steel tube plate and enclosed in steel shell. Made in sizes from 210 to 30,000 ga! of hot water per hr at temperatures of from 40 to 180 F.. NATIONAL SUPER-SERVICE STORAGE HEATERS This heater embodies exclusive, new features of design and construction which make possible the utmost in hot water heating efficiency. Outstanding among these features: Provides for intimate contact of all water with all heating sur faces at all times. En tering water passes di rectly into bottom of casing completely en closing heating ele ment. No short cir cuiting. Note Heating Element is Completely Enclosed by-Casing NATIONAL FEED WATER HEATERS COIL TYPE Type BW. Coils are internal manifold type encased in cast iron or steel shell with ends brazed into bronze manifolds. Coils rigidly secured by copper straps to bar-iron supports to prevent vibration, abrasion of tubes and electrolytic' action. Heads having steam and drip connections are bolted to shell; either cast iron or flared and dished steel. FACILITIES FOR COILS AND BENDS Designs, specifications and estimates submitted for any require ments. All "National" Coils are continuous, without couplings, or screwed fittings, unless specified. Iron and steel coils have electrically welded joints; brass and copper, brazed joints. Heating and Cooling Surface (Fan System) /4rofin Corporation 410 So. Geddes Street Syracuse, N. Y. Aero fin Standardized Light-weight Heat Exchange Surface Branch Offices CHICAGO, NEW YORK, PHILADELPHIA, DETROIT, 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. AH 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 tem plate punched for bolting together adjacent Units, or for duct connection. Fig. 8 Flexitube Aerofin (Fig. 2) is distin guished from all other developments by its off-set tubes, so arranged as to absorb all expansion and contraction strains. Headers--Cast bronze or aluminum. Tubing--5^ in. O.D. copper, admiralty or aluminum. Joints--Whereadmiralty 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 galvan ized iron. Design--Constructed with headers on opposite ends making possible installation of units with tubes horizontal or vertical. Fig. l Aerofin Non-freeze heater (Fig. 1) is non-freeze, non-stratifying spiral fin coil built into casing for air conditioning units or for installing in ducts. May be installed horizontally or vertically. Used on any two-pipe steam system for preheating or re heating. Modulating control on preheaters. Available in 13 lengths and 3 widths,, from net face area of 2.76 sq ft to 26.28 sq ft. - Tubing 1 in. O.D. Innertube % in. O.D. Headers--Cast Brass. Fins--spiral, turned copper. Fig. S Universal Aerofin (Fig. 3) is distin guished by its "S" bend construction of 989 Aerofin Corporation Heating and Cooling Surface (Fan System) tubing, units designed with steel headers on opposite ends, the ends of the "S" bends being connected thereto by com pression nuts, the bends taking care of the expansion and contraction of the tubing. Recommended where close control is desired. Headers--Pressed steel. Tubing--1 in. O.D. Copper, admiralty or aluminum. ' Casings--Copper, aluminum or galvan ized iron. . Casings--Copper, aluminum or g*\ vanized iron. *' Aerofin Encased Booster Units* (Fig. 5). For horizontal or vertical air flow. Six sizes, 150 to 1624 cfm. For either horizontal or vertical air flow Fig. 6 Fig. 4 High Pressure Aerofin (Fig. 4) is of continuous tube design, being recommend ed where extremely high pressures of steam are used. . Headers--Pressed steel. Tubing--rl in. O.D. Copper, aluminum or admiralty. Casings--Copper, aluminum or gal vanized iron. ' Narrow Width Aerofin: (Fig. ' 6) 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. 5 Fig. 7 Booster Aerofin (Fig. 5) is of the con tinuous tube design, recommended where small volumes of air are used, or to.raise the air temperatures in branch ducts, etc. Headers--Cast iron. Tubing--% in. O.D. Copper or alumi num. Aerofin Continuous Tube Water Coils (Fig. 7) are designed for air cooling by circulating cold water through the Aerofin and air over extended fin surface. Made for either horizontal or vertical air flow. Tubes and fins are copper, completely tinned with permanent metallic bond 990 Aerofin Corporation Healing and Cooling Surface (Fan System) between fin and tubes. Headers are made ,,f one-piece cast bronze and casings of heavy galvanized iron or copper. Urutf tested to 1000 lb hydrostatic Fig. 8 Aerofin Cleanable Tube Units (Fig. 8) for cooling only and all made with headers removable to permit cleaning out tubes. Recommended for use where sedi ment or scale forming chemicals are present in the cooling water. Headers--Cast iron. Tubing--Copper or admiralty. Casings--Copper or galvanized iron. Fig. 9 - End plate removed showing distributing and suction headers.. ' Aerofin Direct Expansion Units: (Fig. 9) 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. Fig. to Aerofin Direct Expansion Units: (Fig. 10). 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 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. ContinuousTube: 13standard 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 phamplet on Cleanable Type Aerofin for cooling. . Heating and Cooling Surface The G & O Manufacturing Company 138 Winchester Avenue New Haven, Connecticut GdO SQUARE FIN 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. . STANDARD SIZES 0.0. Fin Surface Fu> Spicing of Tube Size l Foot 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. j/.' *) >/.' W r'A v Wt" r'd. '/.* iy* 1. r 1'h" *0. 6 6 6 6 6 0.80 sq. ft. 0.60 at], ft. 1.55 aq. ft. 2.40 aq. ft. 4.00 aq. 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-10B Send for Catalog High Pressure No. 10 992 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. Offices. Plants and Branches Cleveland, Ohio (Branch) Columbia. Penna. (Plant) Columbus, Ohio Dallas, Texas (Brandi) Detroit, Mich. Kansas Cm, Mo. Long Island Cnr, N. Y. (Branch) Milwaukee, Wia. Minneapolis, Minn. (Branch) Newark, N. j. Nbw Orleans, La. New York, N. Y. Philadelphia, Penna. (Branch) Pittsburgh, Penna. Providence, R. I. (Plant and Foundry Rochester, N. Y. St. Louis, Mo. (Branch) St. Paul, Minn. (Branch) Warren. Ohio (Plant and Foundry) toe Angeles, Cal. (Branch) GRINNELL COMPANY OF THE PACIFIC Oakland, Cal. (Branch) San Francisco. Cal. (Branch) ^ Seattle, Wash. (Branch) GRINNELL COMPANY OF CANADA, LTD. f On*. (Branch) Montreal vd*- v Vancouver. B. C. (Branch) Toronto. Ont. (Plant and Foundry) Oshawa. 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 Equiflo 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 Thermollers (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. MaUeable 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 BuUdings, Schools, Churches, Stores, etc. For Data on Thermoflex Traps an Grinnell Equiflo Valves For Forced Hot Water Heating Equiflo Valve The designing of forced circulation hot water heating systems is so simplified by the Grinnell Equiflo 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. Equiflo Data Book sent to interested parties. Heating Specialties, see page 1087 Grinnell Company, Inc. Heating and Piping Systems, Industrial Thermouer Patented THE GRINNELL UNIT HEATER De Luxe, Industrial and Factory Tyoes--. 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 THERMOSTATIC ^ --,, "b--............. ~ 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 Model Nos. 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 80L Btu per Hour 90,700 67,100 104,800 77,700 129 500 110,100 142,000 117,000 164,600 139,300 Model Nos. - 90 90L 100 I00L 110 110L 140 . 140L 180 180L . - 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 ExchangeStreet, Providence. R. I. 994 Grinnell Company, Inc. Healing and Piping Systems, Industrial GRINNELL ADJUSTABLE PIPE HANGERS AND SUPPORTS n e of the chief advantages of Grinnell Adjustable Hangers is that they permit .tment of pipe lines after installation, thus obviating the necessity of turnbuckles or h ^moval of hangers. Their time and trouble-saving qualities during installation are llv exceptional. Below are shown a few Grinnell Hangers and Supports of particidar 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 1 $ in. 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. 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., ^ in., % in. or % in. rod as required. Nuts automatically lock by means of V-type teeth on both insert and nuts. - Fig. No. t8i CB-Univertal Insert GRINNELL WELDING FITTINGS 90 Elbow, 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 ^6 in. square end on inside of fitting. Angles of bevel other than 45 deg. can be furnished on special orders. Welding Outlet Wdding Tee Lap Flanged Wdding Neck 995 Threaded Outlet Heating and Ventilating Units The Herman Nelson Corporation General Offices and Factories at Moline, Illinois Sales and Service Offices in all Principal Cities Herman Nelson Air Conditioners for Schools hiJet Heaters for Industrial and Commercial Buildings Automatic Heat and Air Conditioning for The Home New Herman Nelson' Air Conditioner For Schools 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 vend- 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. Propeller-Fan Type Herman Nelson hiJet Heaters The Herman Nelson Corporation manu factures a complete line of hiJet Unit Heaters in two types--propeller fan and blower fan, for use with, steam or hot water systems. . Propeller-Fan Type hiJet Heater Available in 18 different-sizes and a complete range of capacities for full, medium or slow speed operation. Blower-Fan Type hiJet Heater Manufactured in 1&models and a com plete range of capacities. High or low capacity heating element available. Di rect-connected motor or V-belt drive. Blower-Fan Type i: - i. Herman Nelson Automatic Heat and Air Conditioning Oil Burning Air Conditioning Furnace Gas Burning Air Conditioning Furnace Conversion Oil Burner Oil Burning Boiler Automatic Stoker Coal Burning Air Conditioning Furnace Self-Contained Cooling Unit Year Around Air Conditioning Unit CATALOGS AVAILABLE on The New Herman Nelson Air Conditioner for Schools Herman Nelson hiJet Heaters . . . Herman Nelson Automatic Heat and Air Condi tioning. Write to THE HERMAN NELSON CORPORATION, MOLINE, ILLINOIS. 996 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 and NESBITT SERIES H HEATING SURFACE, sold by leading manufacturers of fan-system apparatus; WEBSTER-NESBITT UNIT HEATERS (for details see page 1101), 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. For engineering data, get Publi cation No. 225; for "The Story of Syncretized Air," Publication No. 231. Nesbitt Series B Thermovent For heating and ventilating auditoriums, gymnasiums, assembly halls, and similar gathering places. Publication No. 227. Nesbitt Series H Heating Surface ALL COPPER A lightweight, enduring, highly efficient blast-coil heating surface of tube-and-fin construction, made entirely of copper and copper alloy, designed for use with steam pressures up to 200 lb gauge. Large headers of seamless copper tubing with collars extruded from the header body, providing large areas to which the condensing tubes are silver brazed. Seven types, each in eight fin widths and up to six teen finned lengths--a total of 784 sizes from which to select. Sold by leading manufacturers of fan-system apparatus (list upon request). Send for Publication No. 232 for complete engineering data. 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 sup ply ; eliminating temperature stratification; preventing tube freezing without pre heaters; giving ideal system results. The illustration above shows a cut-away view of 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 leading manufacturers of fansystem apparatus (list upon request). Send for Publication No. 229-1 which contains full particulars and engineering data. 997 Humidifiers Maid-O'-Mist, Inc. 180 N. Wacker Drive, Chicago, 111. HUMIDIFIERS, WATER-LINE CONTROL VALVES AND AIR VENTS No. 855 Micro Boiler Protector Feeder and Cut-out Water-Boy Safety Feeder No. 7 Amo-Vent Air Eliminator for Hot Water Lines No. 00 Auto-Vent Air Relief Valve for Hot Water Radiators All Maid-O'-Mist Products are built entirely of Monel metal, brass, nickel silver and copper with nickel plated finish. They are low in price. The "Micro" Boiler Prelector is small in size and finished to conform with the modern jacketed boiler. They are for steam pressure up to 15 lb. No. 200 Auto-Vent for hot water radiation. Will operate on pressures up to 25 lb Size \Yi in. x 3^ in. No. 7 Auto-Vent is used on concealed radi ators, over head hot or cold circulating water lines on pressures up to 75 lb. Shells are brass N.P. finish, size 2}/% in. x 4 in. No. 95 Auto-Vent Humidifiers for low pressure steam heating quickly vent radiator and supply humidity as well. It may be connected in series for commercial installation. The amount of humidity is adjustable. N.P. finish, size 12in- x 4J4 in. The Zephyr Humidifier is designed for forced air circulation. The patented wings deflect the heated air over the water surface. The pan is built of bronze. Made in eleven styles, 26 in. and 36 in. lengths. Midget Water Feeders are made in eight types for humidifying and air con ditioning. Self closing, metal to metal or Neoprene seats. Length 7 in. over all. N.P. finish. These valves can be furnished with a 2% ih. x 2% in. x 6 in. enameled reservoir and cover, saddle valve and copper supply tubing. Send for Catalog G for complete information. Auto Vent Humidifier for Steam Radiators Automatic Expansion Tank open or closed f. j'v J Water Pan Feeder Length 7 in. over all Made in 8 types 998 Zephyr Humidifier for Warm Air Furnaces rip [' i : J||,: Heating Systems (Hot Water) Bell and Gossett Company 3000 Wallace Street Chicago, 111. HOT WATER SYSTEMS AND SPECIALTIES B & G MONOFLO HEATING SYSTEMS A genuine advance in con trolled and economical heat ing is offered by the B & G Monodo System. In conjunction with forced circulation, the B & G Monoflo Fitting makes possible a thoroughly practical, well balanced single main hot water instal lation. In over 30,000 installations, the B & G Monoflo System has demonstrated its desirability in homes, apartments, factories and institutional build ings. The equipment lends itself ideally to zoning, yet is exceedingly simple in application. EQUIPMENT REQUIRED B & G Booster An electrically- driven centrifugal pump, which me chanically circulates hot water through the system -- distin guished by genuine oil lubrication, patented water-tight seal and precision manufacture throughout. . B & G Indirect Water Heater Any one of five B & G Heater types can be in stalled to furnish year around do mestic hot water at smallest pos sible cost. B & G Angle Flo-Control Valve This valve, in stalled in the main, controls circulation of hot water to radia tors, permitting summer opera tion of the' In direct Water Heater. It also helps maintain a uniform room temperature during the heating season. B & G Monoflo Fitting A correctly engineered fit ting, installed in the main at radiator connections, which di verts water into the radiators. Its design assures a balanced distribution of water without introducing excessive resist ance. Simplex Relief Valve For boiler protection. See Current B & G Catalog for Complete Engineering Data 999 . Heating Systems (Sub'Atmospheric Steam) G. 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 CONDITIONING uMinfin C. A. Dunham Co., Ltd., (Of the United Kingdom) Morden Road, London, S.W. 19, England The accumulated experience of the entire Dunham Organization is put at the disposa of the Heating Ventilating and Air Conditioning Engineer. This cooperation is available for Modernization Work, as well as for new construction in industrial, commercial, housing and other projects.. " "Dunham Heating Service** in local classified telephone directory in all principal cities. . Dunham Sub-atmospheric Steam Heating is provided by a simple two-pipe heating system in which all the essentials of circulation, distribution and control are coordinated. Steam volume and temperature resulting from variation of pressure are the fundamentals of the Sub-atmospheric System. Control of the temperature of the steam in the radiators is accomplished by controlling the pressure or vacuum of the steam in the supply piping and radiators. The Dunham Sub-atmospheric Sys tem distributes a varying supply of heat equally, automatically and continuously through the heated space. Desirable building temperatures are automatically maintained under varying weather con ditions. A positive continuous circulation is maintained as a fundamental function of the system. This maintains unusually constant temperature levels throughout the building. At a control station which may be located in the boiler room, remote . readings of building temperatures and operating conditions may be taken. The Control Is fully automatic. Beginning with a maximum radiator heatoutput obtained by steam circulation at a pressure of 2 pounds and a temperature of 218 F or more as required, the output is progressively reduced according to the demands of the weather, by a reduction in the rate of steam admission to the system, which automatically causes a reduction in steam pressure and temperature so that steam may be circulated at varying terntemperatures down to about 133 F. Further reduction in heat-output is ob tained by partial filling of radiators with sub-atmospheric steam until the point is reached at which the need for heat ceases and the supply of steam is completely shut off. Measuring Heat Demand. The de mand for heat is measured by the resis tance thermometer principle. Resistance thermometers measure and indicate tem peratures or temperature changes, they are uniquely sensitive, accurate and long lived, operating without moving parts or wear. Variations in temperature at control points create variations in electrical resis tance in control circuits. The supply of heat is varied with the demand by using these variations in electrical resistance through Wheatstone Bridge circuits to actuate the control valve which governs steam supply. The distribution of the steam supply is automatically maintained under all variations in supply by the coordinated functioning of .the Traps, Pump, Differential Controller and Regu lating Orifices at radiator inlets. Can also be installed for manual control. 1000 c. A. Dunham Company Heating Systems (Sub'Atmospheric Steam) The RT (Resistance Thermometer) control equipment, which is an integral part of the System, is available in three models. Model T (which is illustrated) Models RS, TRSand TRST. The Model T for indicating and con trolling steam supply in proportion to the demand as measured by room temperatures, consists of a Panel, a Control Valve and one or more Thermostats. It gives: 1. Temperature control so sensitive that a fraction degree F change at the Thermo stat changes the valve opening a slight amount. . 2. Temperature control so stable that the control valve cannot take sudden swings of full opening or closing under automatic control. 3. Thermostat setting at the Panel and not at any other point. 4. Room temperature indication at the Panel. 5. An Operating Guide permanently attached to the Panel. The MASTER SWITCH with 10 selective stations provides: ' Automatic Control Stations 1. * Day Temperature--Range 68 to 86 F. 2. Night Temperature--Range 50 to 68 F. . 3; Clock used when Time Switch is added to. automatically switch ' from Day Temperature to Night Temperature. Semi-Automatic Control Station 4. Remote control of Valve position--Range 0 to 100% open. Manual Control Stations 5. Rapid opening of Control Valve. 6. Rapid closing of Control Valve. Indicating Stations 7. Room temperature--Upper Range 68 to 86 F.. 8. Room temperature--Lower Range 50 to 68 F. 9. Valve Position--Range 0 to 100% of full open. 10. "Off" Station--All control and indicating functions discontinued. Model RS for indicating and controlling steam supply with balance between the demand as measured by the Selector (window thermostat) and supply as measured by the Heat Balancer (heat-rate thermostat) consists of a Panel, a Control Valve a Selector and a Heat Balancer. ' Models TRS and TRST for indicating and controlling steam supply in proportion to the demand as measured by room temperatures within the limits established by Heat Bal ancer and Selector, consist of a Panel, a Selector, a Heat Balancer and one or more room thermostats. These are the only controls on the market that provide fully automatic control in response to the effect of outside weather and to building heat loss. TWO O+HER OUTSTANDING PRODUCTS A compact, efficient and JemfutfcaZ&c attractive all purpose humidity it dehumidifies and cools. The change from heating to cooling is made by Heating and Cooling Unit for the home, switching from a boiler connection to a store or office. Whether for winter or sum chilled water supply or a refrigerating unit mer service or both the Temperator may be which may be at a remote point. installed with access to outside atmosphere. Imwinter service this unit may be used with sub-atmospheric heating or with pressure steam or hot water system, providing clean, properly warmed and correctly hu midified air with quiet air movement. In summer service instead of adding heat and Sav'T'heat System (using gas fuel). A practical, efficient and economical method of residential heating and air con ditioning. May be installed as an air conditioning system, as a vapor radiator system, as a hot water system or a com bination of these. 1001 / Inslrumenls 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 RECORDING* INDICATING AND CONTROLLING TRADE-MARK BRISTOL'S ABO. VI. 6. PAT. OFFICE 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. 1250. Right: Thermo-!!umidigroph. Model 4069 Electric Flew Meter. Model MI040 M Recording Pressure Gouge, Model 40M Mechanical Flow Meter. Model illfiM 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. 101J+. 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 ' 4B40M Recording Thermometer. 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 rear oblique, right side and left side angle forms. Also portable stem thermometers with ring top, ring handle top, or adjustable stem handle forms. Fenestrated guard or plain bulb. Catalog No. 1250. Straight Form 1002 Instruments Illinois Testing Laboratories, Inc. 422 N. LaSalle Street, Chicago, Illinois TESTING ENGINEERS AND MANUFACTURERS Pyrometers--Portable--Wall Type--Surface Temperatures Distant Reading Resistance Thermometers Automatic Temperature Controllers Air Velocity Meters "ALNOR" VELOMETER The Only All-Purpose Air Velocity Meter Velometer with averaging jet used for checking velo city from supply grille. Th; Velometer is a versatile direct reading air velocity meter which gives instantaneous readings of the speed of air measured in feet per minute. Anyone can use the Velometer. No mathematical calcu lations, no leveling--no timing. As its movement is actuated by the pressure or impact of the air against a swinging vane, it is essentially a pressure instrument--thus it can be scaled to not only read velocities directly, but also to read static or total pressures when using suitable jets. Made in three standard ranges for velocity readings from 20 fpm to 6000 fpm and 3 in. static or total pressure. Special ranges available up to 18,000 fpm velocity and 20 in. pressure. Jets--Several standard jets are offered providing a wide application. Spot jets--for velocities over very small area. . Averaging jets--for obtaining average velocities over a definite area or grille face. Duct jets--for determining velocities directly within ducts or pipes. Static pressure jet--for static pressures in inches of water. Total pressure jet--for total pressure in inches of water. Other jets--Standard jets offered in several lengths and sizes. Special jets--can be designed for unusual applications. . Ask for Bulletin No. 2448-B "Alnor" Distant Reading Electric Thermometers The use of "Alnor" multi-point resistance. type thermometers is rapidly increasing not only in air-conditioning installations, but also for heating plants. The instrument can be located in the machinery room or boiler room with the elements located on various floors in any part of the building, or outdoors, thus providing the engineers with constant and convenient temperature readings. "Alnor" thermometers are made in several styles and sizes, both portable and mounted types. Ask for Bulletin No. 2451-A "Alnor" round type multi-point resist ance thermometer with built-in switch. Leeds & Northrup Company General office and Works: 4941 Stenton Avenue, Philadelphia, Pa Branch Offices: Boston Buffalo Chicago Cincinnati Cleveland Detroit Hartford Houston Los Angeles New York Pittsburgh St. Louis San Francisco Tulsa RUGGED, NULL-TYPE INSTRUMENTS THAT ARE RELIABLE - 'K Model S Micromax Recorder Record* Jrom t to 16 point* on a angle itripchart. Extremely open record. Can operate tignal*. (About I/loth size) Model R Micromax Recorder Record* 1 or t tjoint* on a round-chart. Ha* extremely readable diaL Can operate signal*. (About l/15th tie*) Switchboard Indicator ' Hand-operated. Can & connected through ftfrlor switches to any number of point*. (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 The facts needed to operate a modem heating plant so as to save fuel, to protect equipment, and to operate efficiently at varying loads are provided reliably by of distance and disregards all tempera rugged L&N instruments. Readings can 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 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 water lines. They are connected by instruments control automatically. 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. This equipment is fundamentally re liable. Instruments and Thermohms are 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, ancKhas a giant indicating dial that can be read at a glance. The switchboard in dicator provides intermittent checks on conditions at one or several points. 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 In the heating plant, L&N measuring, signalling or controlling equipment is used for: minimum maintenance. Thermohms and instruments are interchangeable, and can be replaced without disturbing wiring or returning anything to the factory. 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. Metermax Combustion Control. Furnace Pressure Control. Smoke Density Analysis. Flue Gas Analysis (Percent COi). Flue Gas Temperatures. Steam and Water Temperatures. Boiler-Furnace Temperatures. Electrolytic Conductivity of Water. J-N-225C2) 1004 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^bd' 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 Liquidometer Recorder 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 or1 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. Large Model Levelometer In this instrument the tank liquid traps and com presses air in an "air chamber"--the pressure de pends upon the height of liquid in the tank, and this ,. pressure is transmitted through tubing to a metal ^aciumcicr 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 lor the pump, thus providing a continuous reading gauge. /rel."eters are made in a number of different models to suit various tank capacities na desired dial calibrations. Models for tanks under pressure also are available. i: welcome the opportunity to make recommendations for perplexing liquid level gauge problems. 1005 X Instruments Manning, Maxwell & Moore, Inc. Bridgeport, Conn. BRANCHES IN PRINCIPAL CITIES Makers of AMERICAN INDUSTRIAL INSTRUMENTS--Since 1851 Manufacturers of Indicating and Recording Gauges; Gauge Testers: "U" 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; Absolute Pressure Gauges. Also manufacturers of Bronze, Cast Steel and Forged Steel Valves, Engine Room Clocks; Barometers; Mercury Column Gauges; Gauge Boards. Ashcroft American Gauges--Ashcroft American Gauges are made in all sizes from 2H 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 4H in., 6 in. and 8H 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 3% 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 3% 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 Thermometer (mercury-filled) 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 20 to 475 F. For hot water service tanks, water heaters, etc. Size of valve must be speci fied. Write for R-59 Bulletin. 1006 Instruments The Palmer Company Mam 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 THERMOMETERS for Heating and Pocket Thermometers Air-Conditioning with "Red-Reading- Every engineer should carry Mercury". this accurate type thermome Industrial Style Thermometers. ter around at all times. 7 in., 9 in. and 12 in. case. STRAIGHT and various ANGLE forms. Fixed thread fitting, Union connection, Separable Socket. Also Flanges: Fixed, Union and 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. adjustable. Accuracy Guaranteed. Wall Thermometers Built sturdy for long service. Standard Ranges: Can be used inside and out doors. This style made of -20 + 120F. -f 30 +240F. 0 -fl OOF. + 30 + IS0F. +50 +400F. +200 +550F. * +200 +750F. Stem Length: 3Yi in. including thread. Longer lengths furnished. Finishes: Nic 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. No. 827 kel-plate, chromeplate, Polished Laboratory Ther brass, Instrument-black, mometers etc. PALMER thermometers show a bright RED column,' seen at a great distance, through steam, smoke, dust, etc. For Genuine mercury thermometer with RED col umn, Specify: PALMER. For tests to be made at any time, these ther No. 18240 mometers are very valuable. ROUND or LENS glass. From 6 in. to 16 in. length. Also longer lengths. All ranges furnished, with the RED column. Made of selected glass. Every ther mometer PALMER furnishes is Psychrometers For testing moisture annealed and treated so as not No. 2120 Thermometer to change with age or use. It pays to buy the best. the air, this Sling Psychro- meter is necessary for all Air conditioning jobs. Pocket style, in leather case, with wet- and drybulb. Convenient for making daily tests. Because the mercury column in the tubes show a bright RED column, it is much easier to read than plain mercury, after swing ing. Range: +30 +110F. If you want a good- reliable., Precision Thermometers Have on hand a reliable test ther mometer in Fractional Divisions, so as to make very close and accurate tests. In H deg, H deg and Ho deg divisions. With Test Certificate^ Easy to read with PALMER "RedReading-Mercury" feature. The mer cury thermometer with a wide RED column. . thermomefer^' thoroughly aged for permanent accuracy, specify: PALMER Repairs to all makes of ther mometers with "Red-ReadingMercury" at no extra charge. No. IJfioo Write for FREE catalog. A trial order will convince you! 1007 No. 10042 Instruments *TcujJjor IndrAJummi GompxmieA Rochester, N. Y., U. S. A. ' IN CANADA--Taylor Instrument Companies of Canada, Ltd.. Toronto NEW YORK CHICAGO PHILADELPHIA PITTSBURGH LOS ANGELES INDIANAPOLIS ST. LOUIS CINCINNATI DETROIT ATLANTA BOSTON CLEVELAND SAN FRANCISCO TULSA 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 bine in the same case an HmilorThermometers--with new "BINOC,t Tubing . electrically - operated temperature controller --This line of thermome with an indicating ther ters includes many styles mometer. One tube sys and scale ranges with tem operates both units. bulbs for every applica tion. Suitable for air The New Taylor' ducts, kiln temperatures and oven tem "Fulscope" Recording Controller--Ai] . peratures. But these thermometers con air-operated .controller that gives practi tain a new and radical develop cally any character of process control ment of tremendous importance 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 toad lacking in industrial thermome- changes or ! M ffl ters. lt BINOC" Tubing more badly balanced i s III tkan doubles the angle of vision operating con I p|U within which readings can be ditions exist, HPoliil made. Because of the patented the Taylor Triple-lens construction, its " D ub l-Re Rgjjjr Bjg broad, contrasting mercury col- sponse Control umn can be read easily and ac Unit" is the curately with both only positive j&jil eyes at close range means of main ] ag 11 and also at greater taining con SS I than normal dis trol-point. tances. Bore reflec- Wrilefor . 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 piake 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. 1008 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 (Direct- Reading)-^ 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 The rmometer 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 PsychromTM eter---The advantage of this form of Wet- and Dry-Bulb Hygrometer over the stationary form is the facility with which tests can 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 Anemofneter--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 in struments and others designed for healing, ventilating and air conditioning, send to any of the offices listed on the previous page for new Taylor Catalog Number Five. 1009 U. S-, fhidixuitLnfyxmd, Tlsu^xdiiu^ rMAAuM. Qou^jia. 44 BEAVER STREET NEW FACTORY - ItlktltVllK MNNSYIVAN1A AMCHES- NEW YOBK CNICAOO-PHUADSlPtUA boston Cleveland Detroit st. touts HOUSTON - SEATTLE - LOS ANOELfS- MONTREAL 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 8)4, 10 and 12 in. sizes for pressures from 1 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. S. 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 ranges from -- 40 F to 800 F. Furnished with rigid connection bulb or with flexible capillary tubing up to 100 ft long. Alfol Insulation Company Incorporated 155 East 44th St.,1'New York, N. Y. Agents in Principal Cities Insulation INSULATION for INSULATION for Houses Buildings Radiators Air-Conditioners Ducts Dehumidifiers Blowers Boilers ALFOLBoiler Jackets Hot Water Tanks At temperatures up to 1200 F. PAT. IN 34 COUNTRIES Refrigerators Refrigerator Cars Refrigerator Trucks . Cold Storage Rooms Buses and Coaches Passenger Cars Locomotives Ships Ovens Ranges Tanks Stills Towers Pipes TECHNICAL DESCRIPTION OF ALFOL Alfol consists of one or more sheets of pure aluminum foil installed to build up heat insulation by providing barriers against the passage of heat. Sheets of Alfol block air currents and seal against moisture. The metallic surfaces reflect heat radiation and eliminate 95 per cent of this form of heat flow. Alfol has the dual advantage of being light in weight and low in heal absorption, and conduction through the separated layers of foil is negligible. Alfol is also furnished combined with other materials such as aircell asbestos for specialized applications. - PERMANENCE The outstanding quality of Alfol is its permanence. It resists fire and water, it is not affected by vibration, shrinking, settling, bulging, warping. Alfol is a lasting material. Every aluminum surface oxidizes as soon as it is formed. The oxide is transparent and forms a protective film. On the pure aluminum of which Alfol consists, this film is continuous and forms a coating which protects against atmospheric conditions. The reflectivity of Alfol with this oxide film is 95 per cent. After years of service, Alfol tests at 95 per cent reflectivity. EFFECTIVE AS VAPOR BARRIER Alfol is a recognized vapor barrier. Being pure metal it cannot absorb moisture and moisture cannot penetrate it. Alfol is a dry insultaion. SERVICE EXPERIENCE The first large applications of Alfol were made in this country in 1931 and in Europe four years earlier. Eight years here and twelve years abroad have proven Alfol's reliability and permanence. Millions of square feet of Alfol aluminum foil in ships, refrigerators, refrigerator cars, trucks, locomotives, pipes, ovens, houses, etc., prove as efficient today as when installed. The high insulating efficiency of Alfol is constant. Data on Heat Savings Effected by Alfol Construction ' Heat Transmission Btu/Hour/Sq Ft/F ` Not Insulated Wood Stud Wail--4-tn. studs.................................... Sin. Brick Wall--Furred........................................... Wood Shingle Roof (no lath and plaster)............... Concrete Roof--6-in. slab--suspended ceiling .... Composition Shingle Roof (no lath and plaster).. 0.25 .30 .62 .46 .35 .56 1 layer ALFOL O.lf .12 .13 .13 .13 .15 2 layer ALFOL 0.09 .09 .10 .09 .10 .11 Heat Transfer Stopped ... % layer ALFOL 56% 60 79 72 63 73 2 layer ALFOL 64% 70 84 '81 72 81 Alfol Actively and Instantly Reflects Radiant Heat insulation Aluminum Aircell Insulation Go. Curtis Bldg., Detroit, Mich. INSULATION FOR INSULATION FOR Air Conditioners Brooders Buildings Chicken Houses Dairy Barns Fruit Storage Homes Hot Houses Incubators Refrigerated Rooms Licensed under Patents: 1,757,479--1,890,418--1,934,174 others pending Automobiles Beehives Busses Floral Shipping Boxes Heaters Ovens Ranges Shipping Containers Trailers Trucks Heat Transmission Btu/Hour/sq ft/F Reflect-O-Cell Saves per cent Wood Stud Wall--4 in. studs....................... Open Attic Floor............................................. Wood_Shingle Roof (no lath and plaster).. Not Insulated 0.26 0.69 0.56 1 layer 2 layers Reflect-O-Cell Reflect-O-Cell 0.13 0.09 0.19 0.12 0.18 0.10 1 layer Reflect-O-Cell 50 69 68 2 layers Reflect-O-Cell 65 82 81 Thermal Efficiency determined at the University of Detroit under humidity conditions prevailing in actual use and also at the University of Toronto, Toronto, Canada. REFLECT-O-CELL is the modern insu lating material based on the famous Dewar Principle of insulation, the outstanding example of which is the efficient Thermos Bottle. Light In Weight, not depending on thickness nor density, REFLECT-O-CELL employs this Dewar Principle by means of its polished Aluminum Foil backed by corrugated Hermetex paper. (Hermetex paper was formerly used ALONE as an insulator by leading refrigerator manu facturers). The Structure of Reflect-O-Cell per mits both surfaces of the foil to reflect radiant heat. Moisture Sealing, which effectively reduces summer dehumidifying load and winter humidifying requirements by pre venting vapor pressure losses. Windproofing all studding spaces simi lar to metallic window weatherstrip effect. Soundproofing provided by high hys teresis air cel! construction. Especially Indicated for exposed appli cation to eliminate air-conditioning shock and to reduce cooling load. REFLECT-O-CELL is used in the pro duction of insulated Buses, Trucks, Trail ers, Ranges, Heaters and others. Similar satisfactory service has also been rendered in residences, industrial buildings and pro cessing equipment. REFLECT-O-CELL is supplied in con veniently scored continuous Roll Sheets or in Packs and is easily installed between wall studs, ceiling joists and roof rafters by stapling through its flanged edges. Weighs only 38 lb per 1000 sq ft. Single layer wall application. Also installed in two layers. 1012 Insulation (Cork) Armstrong Cork Company Building Materials Division Lancaster, Pennsylvania Aidant Atlanta Boston Buffalo Charlotte Chicago Branch Offices Cincinnati Cleveland Columbus Dallas Des Moines Detroit Houston Indianapolis Jacksonville Kansas Cm Louisville Milwaukee Minneapolis New Yoax Omaha Pittsburgh Rochester St. Louis Distributors Appleton, ^^western Asbestos and Cork Insulation Co. Baltimore. Md._ _.John R. Livezey Boston. M_a_ss. _________ T. R. Nunan Company W. Va----------- Capitol City Supply Company Cleveland, OhioClark Asbestos Company Denver, Colo___Stearns-Roger Manufacturing Company Eau Claire, We..______------------HoreLGeorce Company Evansville, Ind_____ Tri-State Asbestos & Magnesia Co. Green AT^or^wes^ern Asbestos and Cork Insulation Co. Jamestown, N. Y_____Laco Roofing & Asbestos Company Joplin. MoJoplin Cement Company Kingsport, Tenn---------------- ---- --Kingsport Lumber Co. Little Rock, Ark...-Fischer Cement & Roofing Company Los Angeles,-CalifVan Fleet-Freear Company W .Manitowoc, s _ Northwestern Asbestos and Cork Insulation Co. 'Memphis, TennGrant Brothers, Inc. New Orleans, La_______________ __H. T. Steffee Oklahoma Cm, Okla..........Kelley Asbestos Products Co. Philadelphia, Pa_____________________ John R. Livesey Portland, Oregon................... -Asbestos Supply Company Providence. R. I_______ Rhode Island Covering Company Richmond, Va.......................................... . JohnR. Livesey San Angelo, Texas___San Angelo Building Materials Co. San Francisco, CalifVan Fleet-Freear Company Seattle, Wash.-----------:Asbestos Supply Company Spokane, Wash---------------------------------------Asbestos SupplyCompany Springfield, Mass.............. ...... Johnson Asbestos Company Springfield, MoSouthwestern Insulation Company Tacoma. Wash__________________________ Asbestos SupplyCompany Terre Haute, Ind.........................The Hartmann Company Tulsa. Qkla._____ ___Kelley Asbestos Products Company Washington, D. C___John R. livesey Wichita, Kuna.___________ Ludeman Insulations Company For detailed technical information, samples, and descriptive literature, ask any office or representative. Complete specifications appear in each of Sweet's Catalog files. 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. Corkboard Insulating Efficiency The thermal conductivity of Armstrong's Corkboard, depending on the density, is 0.27 to 0.29 Btu per hour, per degree tem perature, per inch thickness at 90 F mean temperature (U.S. Bureau of Standards). The value of adequate and efficient insu lation is covered in (Chapter 5) of this book and the tables on .pages 102 to 114 indicate the savings which can be effected by using 1% in. or 2 in. of corkboard in standard wall and roof construction. Armstrong's Dl Corkboard is recom mended for the insulation of ducts where the problem is to prevent condensation. It is furnished in sheets 12 in. x 36 in. x H in. and has a waterproof mastic finish on one face. 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., 1)^ in., 2 in., 3 in., 4 in., and 6 in. 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 rigid and * are designed to fit accurately standard ammonia and extra heavy fittings, both screwed and flanged, of all types. Vibracork Armstrong's Vibracork, made in two densities, is ideal for the elimination of noise and vibration transmission and is of pri mary importance in air conditioning work. It does not take a set, is not affected by atmospheric moisture, and will not deteri orate in service. 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 Arm strong Cork Company, Building Materials Division, Lancaster, Pa. Insulation 40 Rector Street New York, N. Y. The Barrett Company 2800 So. Sacramento Ave., Chicago, III. Fairfield, p. o. Birmingham, Ala. BATTS: Paper-backed and Stand- ard. Full thick, and semi-thick, 15 in. x 48 in. and 15 in. x 23 in. Also Demi-Batts, full thick, 9 in. x 16 in. Jr'jM GRANULATED: For pneumatic applica tion. Weight per bag, 35 lb. LOOSE LONG FIBRE: For hand pack ing and irregular spaces. Weight per bag, 35 lb. CHARACTERISTICS Barrett Rock Wool is a mineral wool made by melting a high silica limestone. The resulting liquified rock, at between 2500 and 3000 F, is "blown" with a jet of steam, forming a fibrous, wool-like ma terial which contains over 90% dead air cells. These cells, which resist penetration by cold, heat and sound, give Barrett Rock Wool unusually low conductivity. The Barrett Company, with a background of 85 years of building experience, believes with many architects, engineers and build ers that this type of Rock Wool offers high insulation value for all types of buildings. PERMANENT . . . LIGHT WEIGHT . . . SAFE Barrett Rock Wool will not de, teriorate with age. It is fireproof vermin-resistant, odorless, clean, and a non conductor of electricity. It is approved by the Underwriters' Laboratories, Inc. Its light weight and rigidity assure ease and economy in handling. It is supplied only in high and uniform quality---free from impurities and extraneous material. VB BATTS Barrett VB Batts are furnished with a special water-repellent, vapor-resisting paper backing which has a 1j^-inch flap on all edges for lapping over adjacent batts and building framing to assure a vapor seal. (See cut.) These improved-type batts represent the last word in dependable, efficient insulation. . SPECIFICATIONS FOR APPLICATION Detailed specifications for furnishing and installing Barrett Rock Wool Batts and Barrett Granulated Wool by the pneumatic method will be furnished upon request. `Phone, wire or write our nearest office for complete information. Barrett's new Paper-Backed VB Bait. Overlapping flange permits easy application to studding. Special water-proof and vapor resistant Barrett Building Paper anchored to wool extends 1 in. beyond the edge of bolt on all four sides. Granulated Barrett Rock Wool for pneumatic instal lation. Exceptionally light weight promotes easier handling, more economical application. Ideal for insu lation of existing buildings and other enclosed areas. 1014 Insulation The Reldtex Horrora-tion 919 N. Michigan Ave., Chicago, Illinois Mills: MARRERO. LA. AND METUCHEN, N. J. Boston. Mass. Minneapolis, Minn. Philadelphia. Pa. LONDON. ENGLAND CJeiloteX BRAND INSULATING CANE BOARD RKG. U. t, PAT. OFF . Seattle, Wash. Sydney, Australia Paris, France London, England Buenos Aires. Argentina Durban, South Africa Builds - Protects - Insulates - Decorates - Subdues Noise Building Board Lath ,. Vapor-seal Sheathing Vapor-seal Lath Finish Plank Tile Board Roof Insulation Vapor-proofed Low Tem perature Insulation Insulation Blocks Cemesto . Thermax Ornaments-Mouldings Key Joint Units C-X Rock Wool Products Celotex Products also include Roofing . . . Gypsum . . . Asphalt Impregnated products . . . Hardboards . . . Flexcell Expansion Joint . . . Pottsco. 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 alt 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-Build- ing Guarantee. Same thickness as the wood sheathing it replaces--1 in.--S2S to 25/32. 4 ft wide; 7 ft, 8 ft, 8H ft, 9 ft, 9M ft, 10 ft and 12 ft long. . . Celotex Vapor-seal Insulating Lath In combination with Celotex Vapor-seal Insulating Sheathing this insulating plaster base,, with a vapor-seal on the warm side of the wall, protects against harmful moisture condensation within the walls. All the superior qualities of Celotex Insulating Lath are. retained in this material. Size: 18 in. x 48 in.; in., 1 in. thicknesses. 1015 The Celolex Corporation 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.; in., A in. and 1 in. thicknesses. Backed by Celotex written 10 point Life-of-Building Guarantee. Insulation 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. ,1}^ in., 2 in. or any multiple of A in. up to and including 4 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. }/% in. and 1 in. thick. Sizes: 4 ft wide and 4 ft, 5 ft, 6 ft, 7 ft, 8 ft ft, 9 ft, 9ft, 10 ft and 12 ft long. Backed by Celotex written 10 point Life-ofBuilding Guarantee. 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 A in. thick.. Also furnished laminated in thicknesses, 1, 1A, 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 Insulating Tile and Finish Plank Tile Board and Finish Plank--For square edges; otherwise the same as Type attractive wall and ceiling treatments . . . Double-A. Type Double-A joint Yi in. may be applied over existing plaster or as tftick only, and 1 in. thick on special order. a new finish. Neutral tan color or several Sizes range from 12 in. x 12 in. to 24 in. x pleasing tints on reverse side that simplify 48 in. Celotex Finish Planks, ]/z in. thick. decoration. Type Double-A joint permits Sizes: 6 in. to 16 in. wide; 8 ft to 12 ft alternated surfaces if desired. Type A, long. Backed by Celotex written 10 point furnished A in. and 1 in. thick has beveled 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 Rot and Termites (White Ants). It is not manufactured under the exclusive Ferox a surface treatment--it is integral--in Process(patented) and therefore effectively soluble in water--non-volatile--odorless-- resist damage by Fungus Growth, Dry permanent. 1016 7% Celotex Corporation Insulation Celotex Cemesto Celotex Cemesto is composed of genuine Celotex Cane Fibre Insulation Board core with a surface coating of Vs in- cement- asbestos adhered to one or both sides with a moisture-proofed adhesive. It forms a rieid board designed to assure permanent insulation and resistance to fire, moisture and weather. It is used for homes, pa vilions, cabins, garages, filling stations; vent ducts, conditioning rooms, dyers, kilns ovens, spandrels; steel frame build ings and hangars. The standard insu lation 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 tem perature insulation. The Celotex core in Cemesto is Dry Rot and Termite Proofed A dryer built of 1 in. SS Cemesto. Bolted to steel by the exclusive (patented) Ferox Process framing. and the hard asbestos-cement coating pro vides 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 wide; 4 ft, 6 ft, 8 ft, 10 ft and 12 ft long; in., 1 A in., \% in. and 2'A in. over-all thickness, when surfaced (SIS) on one side; and ZA in., A in., lA in- and ~x/l in. over-all thickness, when surfaced (S2S) on both sides. Thermax Structural Insulating Slab Application of Thermax Structural Insulating Slabs. A fire-resistant insulating slab suitable for wall sheathing--furring, partitions, ceilings and load-bearing roof decks. Ther mal conductivity 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 auditorium spaces, the under side is often. left exposed for sound absorption treat ment. Thermax is manufactured of shred ded wood fibres bound together with fire-resistant cement. It is nailed, sawed or set in masonry walls by ordinary mechanics with ordinary tools. Standard sizes: 1 in., 2 in., and 3 in. thicknesses in slabs 20 in. wide x 32, 48, 64, 72 and 96 in., long. Special lengths up to 9 ft can be furnished on request. ' - Celotex Key Joint Units New, improved insulating interior finish units, grooved on all edges with splines furnished. These splines form a joint that becomes part of the ceiling and wall deco ration. Designed for speedy and low cost application, the units are adaptable to standard framing practices and offer the advantages of less noticeable nailing and self-alignment of units. Paint cracks are less discernable at the joint because of depth of joint and resulting shadow. Cutting and fitting is reduced to a minimum and no special tool work is necessary. The units come in interchangeable sizes, permitting innumerable designs, even on small areas. Sizes: 16 in. x 16 in., 16 in. x 4 ft, 16 in. x 8 ft, 4 ft x 4 ft, 4 ft x 8 ft. Thickness: % in. 1017 Insulation (Weather Strips) Insulation Chamberlin Metal Weather Strip Co., Inc Chamberlin Metal Weather Strip Co., Inc. General Offices, Detroit, Mich. Factories, Detroit, Mich., Peru, IU Factory Sales- -Installation Branches * General Offices, Detroit, Mich, Factories, Detroit, Mich., Peru, 111, Atlanta, Ga. Baltimore, Md. Dallas, Texas Denver. Colorado Milwaukee, Wis. Minneapolis, Minn. CHAMBERLIN HEAT-SAVING PRODUCTS Boston, Mass. Detroit, Mich. Newark. N. J. yji. ftlO. r Buffalo, N. Y. Indianapolis, Ind. New Haven, Conn. San Francisco, Cal Chicago, III. Kansas City, Mo. New York, N. Y. Schenectady, N Y Cincinnati, Ohio Los Angeles, Cal. Philadelphia. Pa. Washington, D. c. Cleveland, Ohio Louisville, Ky. Pittsburgh, Pa. 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 CHAMBERLIN HEAT-SAVING PRODUCTS Rock Wool is one of the most efficient Weather Strips, Calking, In-Dor-Seals, Insulation and Insulate-Windows insulations available today. Long in fibre 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 Oldest and most extensively successful ' weather strip principle--tongue in groove. > 80 to 95 per cent efficient. No failure or upkeep. and clean of "shot", it insures effective insulation with low density and light weight. It is available in several forms At-c V;, 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 b $; 0.04 per cent sulphur. Its loss on ignition is less than 0.1 percent. Wherever pos sible pneumatic application, by means of Typical Chamberlin Insulation unit. Equipped with Powerful. gas-Powered, pneumatic blower capable ofpro jecting granular grade "A" rock wool a minimumdistance of more than 00 ft through a large rubber hose. 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 At right--near view of ` 'insulated'' performance in the art of application-- residential metal '.VY '! 41 - the hidden factor that means so much in obtaining the utmost efficiency from insu casement windows. Chamberlin Insu late-Windows on lation. outside. Below-- battery of Insulate- standard details arid specifications. Con sult nearest branch for equipments, sur veys, quotations. Calking Chamberlin Plasti-Calk 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. 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 buildings, 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 Windows showing how they can be hinged. AU 5 units can b.e unlatched from within the room by simply opening the two casement venti lators. 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. raised the instant door opens. 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. See Chamberlin exhibits in The Home Building Products Building at the New York World's Fair. 1018 1019 Insulation The Philip Carey Company Manufacturers of Heat Insulation and Asbestos Products Lockland Atlanta, Ga. Baltimore, Md. Boston. Mass. Buffalo, N. Y. Charlotte, N.C. Chattanooga. Tenn. Chicago. III. Cincinnati, Ohio Cleveland, Ohio Dallas, Tex. Detroit. Mich. Indianapolis. Ind. Kansas City. Mo. Cincinnati, Ohio Offices Knoxville, Tenn. Los Angeles, Cal. Louisville, Ky. Memphis, Tenn. Minneapolis, Minn. Nashville, Tenn. New York. N.Y. Norfolk, Va. Philadelphia, pA Pittsburgh, Pa. ' St. Louis, Mo Seattle, Wash Wheeling, W Va Standard 90 deg Elbow assembly. Left: Core opened to show duct rones. Right: The completed fitting. 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, is an excellent insulator, and has a definite sound deadening effect. Careyduct fittings are made from standard sections of duct, and may be made in the field with compara tive ease by men without special training. A simple mitre cut plus a few standard accessories make a complete fitting thus keeping costs at a minimum. Prefabricated fit tings may be ordered from the fac tory if desired. Two standard 90 deg Elbows nested in a larger standard section to form a tee. The telescopic assembly method practically eliminates leaks that are commonly found in other construc tion. 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 a combination of ells and straight duct. Standard 1 in. and \in. thick Careyduct sections with core extended. Grilles and dampers are installed according to the accepted standard practice. Careyduct gives high in sulating value. It materially reduces the transmission of extraneous and equipment noises. Careyduct costs decidedly less than properly insu lated metal duct and compares very favorably with sheet metal duct of standard quality. * For more detailed information and prices, write for illustrated catalog. 1020 Insulation The Eagle-Picher Lead Company General Offices: Temple Bar Building, Cincinnati, Ohio Offices In All Large Cities PICKER 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 batt form, it is extreme ly lightweight, non-corrosive, fireproof. ' According to U.S. Bureau of Standards tests, Eagle Insulation in applied thickness of m. 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 Eagle Insulation literally "seals" furnace heat inside the home. Records show that 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 Unlike many insulating materials which are described as "fire-sale" or "fire-resis tant", Eagle Insu lation is fireproof to 1200 F. It will not burn. Fire haz ard is greatly re duced. .Hollow spaces in walls, which ordinarily act as flues once a fire starts, are com pletely filled with a material that even a blow torch can not ignite. Eagle Insulating fVoot easily blown into spaces between wall studdings The Bureau of Buildings of the City of New York has given full approval to use of Eagle Insulation where fire-retarding is required under the Building Code and the Multiple Dwelling Law. Also approved by Underwriters' Laboratories, Inc. as being a non-conductor of electricity. 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 --will not deteriorate. It passes the most severe settling tests. 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 building alterations are necessary, whether the structure is of frame, brick veneer or stucco construction. Work is done by skilled authorized contractors. Type H-3. Batts for New Construction Eagle Insulat ing Batts are rec tangular pads in suitable sizes to fit snugly between studding and joists. Equipped with a water proofed paper back. Batts are easily cut to fit Eagle wall-thick baits quickly installed in new construction . irregular spaces when necessary. Data and Specifications For complete specifications and tech nical data on Eagle Home Insulation, see 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 "66" Plastic Insulation provides remarkable heat-saving efficiency for temperatures as high as 1800 F. Trowels easily on all large or irregular surfaces. 100 lb give 50-55 sq ft 1 in. thick dry coverage. Eagle Blanket Insulation is Eagle Insulating Wool felted and secured be tween metal fabrics. Easy to cut and fit. Other products are pipe insulation, roll and felted wools for air conditioning ap purtenances and other industrial. uses, insulating cements and loose wool. For specifications and technical data on Eagle Industrial Insulation, see Sweet's Engineering or Power Plant Catalog. 1021 X' Insulation Ehret Magnesia Manufacturing Go. Valley Forge, Pa. Rln im _H JLi. ... llJ J .. INSULATIONS DURANT SYSTEM Hermetically Sealed Insulated Pipe For Underground and Outdoor Use Ehret's DURANT SYSTEM insures unquestionable protection against moisture and soil conditions. Even if submerged, no water can ever penetrate through to the insulation. Since no foundations, underdrains, etc. are required, the installation is simply and quickly accomplished. Ehret's DURANT SYSTEM is a fac tory made product and is shipped complete with the pipe, in special or mill lengths. Any size and specification of pipe or tubing can be used. . Many large installations of Ehret's DURANT SYSTEM are * in successful use by Federal 'Housing Projects, United States Navy and Coast Guard, and other Government departments, as well as by numerous rail roads, public utilities and in dustrial concerns. A list of these installations will be fur nished upon request. 1022 Ehret Magnesia Manufacturing Co. Insulation A pure, high melting point asphalt is melted and cast around the insulated pipe, using an accurately spaced metal jacket as the mould. This results in a continuous, seamless and jointless protection which is exceedingly durable. The thickness of the asphalt is usually one in. for underground lines and K in- *or outdoor lines. The insulation consists of Ehret's 85% Magnesia which is the most dependable and efficient insulation material in its field. The thickness will depend upon the conditions. It is practical for both low, or cold temperature lines, as well as for heat piping- Insulation loses its efficiency if moist or wet and the heat losses are greatly increased by outdoor air currents. Perma nent and dependable protection from underground soil conditions and outdoor weather is most important. The absolutely impervious nature of Asphalt, surrounding the insulated pipe in a solid casing,thor oughly seals it against moisture or air infiltration from one end to the other. 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 fitted-together and cemented joints which might crack open, if the piping is forced out of line, permitting water to seep in. Since each pipe line is separately treated, it can be used as individual units. In the event that it becomes necessary to make changes in any line, such as replacing worn out return piping, the work can be done without disturbing any parallel piping. Also, in case that any pipe must be replaced by identical sizes, all that it is necessary to do is to tack with the welding apparatus a new piece, of pipe to the old piece to be removed, pull the old piece out of the insulation and the new piping will be inserted and ready to be installed in the original line. The only new insulation and waterproofing necessary, will be where the new pipe is joined to the original. Since the DURANT SYSTEM will not leak, even if placed in standing water, there need be no concern regarding, the type of soil it is to be buried in. Backfilling of the trench can be effected in one opera tion as the loose soil can be settled down into place by flooding the trench with water. Step One Fitld joint ready for inspection. Step Two Joint covered with standard pipe insulation. Step Three Special Durant joint casing in place ready for Asphalt. Step Four Asphalt Poured in slot--a perfect seal. 1023 Complete installations are quickly made and field joints and connections are easily and perfectly sealed. As shown in the illus trations at the left, the method of treating joint and fitting connections actually extends the as phalt casing along the en tire pipe system in an absolutely seamless manner. .. The heat of the melted asphalt poured around the joints thor oughly fuses into the asphalt cast around the insulation. Insulation General Insulating & Mfg. Company Engineering Offices and Main Plant: Alexandria. Indiana Executive Offices: St. Louis. Missouri %rock WOOL 5 Branch Plants: Dover. N. J. Dubuque. I0\va INSULATION Gimco Sealal Bats, furnished with waterproof paper back ing. fit between standard stud- dings and joists. Gimco Sealal Rock Wool Bats--Gimco Rock Wool Bats are made from long, tough rock wool fibres annealed and treated specially by the patented Gimco process. Installed 3% 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 are furnished with 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 25H sq ft; 10 large bats insulate approximately 55 sq ft. Present homes are easily arid 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. 330 Insulating Cement can be easily and quickly applied to any surface. It dries quickly with little shrinkage and has a smooth, hard surface. Cost per square foot coverage is unusually low. . 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. . 1024 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 "InsulWool" 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-Wool" method of chemical treatment makes Insul-Wool thoroughly ver min proof and fire proof. 11 has been approved by the National Board of Fire Underwriters, "INSUL-WOOL" 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 5. Does not pack or settle and outlasts the insulating material. building in which it is installed. 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. 6. Does not draw moisture. 7. Cuts fuel costs and reduces Summer temperatures, indoors. 8. Meets U. S. Government requirements on Federal Construction with a thermal conductivity of 0.24 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. 1 4 D. Wt. Per cu. ft. 2.5 C. Conductivity 0.24* 0.067** *Kansas City Testing Laboratory, Inc., February 25, 1938. J. C. Peebles, Armour Institute of Technology, April 8, 1937. Complete data on Insul-Wool Insulating Product will be sent upon request. 1025 Insulatton The Insulite Company General Offices 1100 Builders Exchange, Minneapolis, Minnesota Sales Solicitors Offices New York--101 Park Avenue Chicago--205 W. Wacker Drive San Francisco--475 Brannan St St. Louis--1206 S. Vandeventer TWENTY-FIVE YEARS PROVED DURABILITY 1939 marks the 25th Anniversary of The Insulite Company. For 25 years engineers and architects have specified Insulite materials in walls, ceilings, floors, roofs, and for duct lining to achieve insulation, acoustics, and sound control. Insulite materials have proved themselves practical through their performance on the job. You are invited to consult any Insulite office for cooperation on problems concern ing insulation, acoustics, and sound control. Modem Materials for Modern Building Ins-Lite--Natural surface wood fiber board, the color of natural wood. Burlap texture one surface--linen the other. Ther mal conductivity: 0.33 Btu/hour/square foot/inch/F, based on a density of 16 lb/cu ft. Thickness--in. for following sizes: 4 to 8^ ft wide by 6 to 14 ft long with-square edges and also 4 x 6 ft up to 4 x 14 ft beveled two long edges of linen textured side. Thicknesses ^ and % in. for following sizes: 12 x 12 in. to 18 x 48 in. with V-W joint on four edges and 6 to 16 in. wide by 8 to 12 ft long with V-W joint, beaded, on long edges. Used on interior walls and ceilings, also as sub-flooring. Graylite--Asphalt-containing wood fiber board with natural surface and neu tral gray-brown color. Burlap texture one surface--linen the other. Thermal con ductivity 0.35 Btu per inch thickness. Available in same thicknesses, sizes, and joint fabrication as Ins-Lite. Used on interior walls and ceilings, also as a sub flooring. furnished with V-W joint all edges. Fol lowing sizes are furnished with V-W joint--beaded, long edges: widths 6, 8, 10, 12, and 16 in.--lengths 8, 9, 10, and 12 ft. Used on interior walls and ceilings. Smoothcote--A pre-finished wood fibr board with a smooth, hard surface in a .pleasing light cream color. No decorative treatment is required over the surface, however, if desired, the board may be painted. Available in same thickness, sizes, and joint fabrication as Satincote. Thermal conductivity same as Ins-Lite. Used on interior walls and ceilings. Lok-Joint Lath--An insulating plaster base, fabricated from Ins-Lite. Has a patented "lok" that firmly locks the sheets together between supporting members. Thicknesses: Yi in., % in., and 1 in. Size: 18 in. x 48 in. Used as a plaster base for walls and ceilings. Satincote--A wood fiber board with primed and sealed surface in a rich light color. The surface is smooth, hard and durable and offers resistance to abrasion. The sealed surface receives paint finishes without further treatment but may be used in its natural finish if desired. Ther mal conductivity the same as for Ins-Lite. Thickness 3^ in. Sizes 4 x 6 ft up to 4 x 14 ft are available either square edged or beveled on long edges of finished surface. Sizes 12 x 12 in. up to 18 x 48 in. are Insulite for Interior Walls and Ceilings Bildrite Sheathing Bildrite Sheathing is an asphalt-contain ing wood fiber board manufactured under an exclusive process which provides in-' creased strength and moisture resistance. It is*2%2 in. thick and has a distinctive gray-brown color. Thermal conductivity: 0.36 Btu per inch thickness. Each sheet is marked to indicate proper nail spacing. Available in sizes 4 x 8 ft up to 4 x 12 ft. Used as a structural sheathing board and as a roof boarding. The Insulite Company Insulation INSULITE WALL OF PROTECTION ^ Coefficients of Transmission (U) of various types of frame construction. Interior Finish Exterior Finish * and Sheathing No Insulation Between Studding Insulation Between Studding &mis a. a0 6-0 sS CL -O 1 0e <-> .c a m == g 3&I ,, 35-s S-2 L 5 *.c0i6 -2'5 SK o -->co thickness. Used as insulation on all types of roof decks under built-up roofing. Graylite Roof Insulation An asphalt-containing wood fiber board of gray-brown color. The asphalt treat ment not only provides added strength and moisture resistance to the board but also a better natural bond with the bi tumen used on the job. Available in the same thicknesses, size, and edge treat ments as Ins-Lite Roof Insulation. Ther mal conductivity: 0.35 Btu per inch thickness. Used as insulation for all types of roof decks under built-up roofing. Wood Siding in. Bildrite Sheathing 0.20 0.16 0.074 The above values are typical of results which can be obtained by utilizing Insulite materials in frame construction. For further (U) values refer to Chapter 5, pages 106 andl07. ' Ins-Lite Cold Storage Insulation Fabricated from special low density wood fiber board, 12 lb per cu ft. Average thermal conductivity is 0.30 Btu per inch thickness. Available in eleven standard sizes of 12 x 18 in. up to 24 x 48 in. Thick nesses: 1, 2, 3, and 4-in. For use as insulation on walls, floors, and ceilings of ice houses, cooler rooms, storage plants, breweries, and wherever low temperature control is necessary. Sealdslab Cold Storage Insulation Fabricated frdrn the same low density material as Ins-Lite Cold Storage Insu lation; however, the board is given an additional treatment consisting of a con tinuous impregnation of especially pre pared asphalt to a uniform depth of %2 in. on all faces and edges which, with the addition of the final asphalt coating applied on the job, provides a superior seal against moisture and vapor. Available in same sizes and thicknesses as Ins-Lite Cold Storage. Insulation. Used as insulation on walls, ceilings, and floors of ice storage plants, cooler and freezer rooms, and wherever low temperatures are maintained. Ins-Lite Roof Insulation Fabricated from wood fiber board. Size: 22 x 47 in. with either offset or square edges. Thicknesses: 3^ L 1)^, and 2 in. Thermal conductivity: 0.32 Btu per inch A pplifing Insulite Roof Intulation Insulite Fiberock Insulite Fiberock Insulation is a rock wool product, treated for moisture resis tance. It has a low percentage of shot and sufficient resiliency to prevent it from settling. Thermal conductivity: 0.26 Btu per inch thickness. Used as insulation in the intermediate spaces in walls, ceilings, floors, and roofs. Available in six forms: Loose Fill, for hand packing; Granulated Fill, for pouring into place; Batts, thicknesses 2 and 3% in.; Wall-Seal Batts, thicknesses 2 in. and wallthick; Pads, wall thick; and Pre-packed, roughly 2 in. thick. The Batts are 15 x 23 in. and 15 x 48 in. in size, and the Wall-seal Batt is lined on one side with a waterproofed, vaporproofed kraft paper, flanged on all four edges. Pads and Pre-packed forms are 15 x 9 in. in size. Hard Pressed Boards Bronzelite materials are tough, durable, grainless, pressed wood fiber boards with a hard, smooth surface. Available in a range of densities, from 37 to 68 lb per cu ft, and degrees of hardness. Thick nesses are from 3/io to Yg in. and sizes from 4 x 2 ft to 4 x 12 ft. 1027 1nsuldliQn International Fibre Board Limited Sales Offices OTTAWA--MONTREAJL--TORONTO--WINNIPEG Administrative Offices and Mills: GATINEAU, QUE. London Office THE TENTEST FIBRE BOARD CO. Ltd. Astor House, Aldwych, London, W. C. 2., England ft 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 Ks 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 Ks 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 Ms in board, and the pull registered in an Olsen Testing Machine. Authority: Columbia University Testing Laboratories, New York. 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 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, % in. to 1 in. thick or laminated to any desired thickness. ' 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. or laminated to any desired thickness. 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. or laminated to any desired thickness. TEN/TEST Ashlar Block. For interior decoration and acoustical correction. Can be supplied in a variety of designs and sizes to harmonize with any decorative treatment. \TEN/TEST Acoustical Tile and Panels with sound absorption coefficients ranging up to 0.53 at 512. Specially de signed for churches, schools, auditoriums, theatres, etc. 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. 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. ` 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. Mundet Branches Dallas, Texas Detroit, Mich. Los Angeles, Calif. Memphis, Tenn. Philadelphia, Pa. St. Louis, Mo. Houston. Texas New Orleans, La. San Francisco, Calip. Kansas City, Mo. No. Cambridge (Boston). Mass. Syracuse. N. Y. Mundet Agents Baltimore. Md-------------------The McCormick Asbestos Co. Norfolk, VaF. H. Corn. Buffalo, N. Y...----------------------------- Claiton Asbestos Co. Oklahoma Citt, Okla__ Standard Roofing & Material Co. Charlotte, N. C-------------------------- --^__Oeo. A. White & Co. Cleveland, Ohio------------------ Standard Asbatos Mfg. Co. Portland, Oregon------------- Pacific Asbestos & Supply Co. Richmond, Va__ Virginia Insolation Co. Richmond, Va--------------------- -Virguua Insulation Co. Salt Lake Cm, UtahLouis A. Roeer Hartford, Conn-------------- -The Hartford Cement Co. Minneapolis, Minn---------Asbestos Building Materials Co. Seattle, Wash-----------------------.Pioneer Sand & Gravel Co. Tulsa, OklaStandard Roofing 6 Materials Co Nashville. Tenn-------------------- John Bouchard & Sons Co. Utica, N. Y____ __ _____________ _George Weisenberger Engineering and Specification Service .lines. The three thicknesses in which it is Our engineering department is at the service of Architects and Engineers at all times to assist and advise in the prepara tion of specifications pertaining to cork. This service is also available to any one -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. who has a cold insulation or a vibration isolation problem, and is rendered without Mundet Cork Vibration Isolation obligation. Our complete catalogue is filed in Sweet's Architectural Catalogue, The transmission of machine vibration can be easily and permanently prevented and will be sent on request. It is replete with valuable information and data that by the use of Mundet cork isolation. The machines commonly associated with the should always be within reach of every specification writer whose field touches our products. heating and ventilating industry are best isolated with Mundet Natural Cork . Isolation Mat. This form of isolation is Mundet Contract Service fabricated from blocks of pure cork. These blocks are held together within a We contract for the erection of our rigid steel frame or bound with asphalt products. In this way we may be certain paper applied with hot asphalt top and that our material is installed in accordance bottom. Steel bound isolation mat is 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. Mundet "Jointite" Corkboard Mundet "Jointite" Corkboard is 100 . per cent pure cork, fabricated in accor dance with the U. S. Government Master Specification, and is unsurpassed in its ibott u thorn a SUd Bound Mur.dtt Natural Cart Itolnticn Mat. Natttha natural cork ttripi within the tiedframe. 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., 1 % 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 , Mundet "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., 1% in., 2 in., 3 in., 4 in. and 6 in. thicknesses, depending on class of service. 1029 /nsulation Johns-Manville Executive offices: 22 East 40th Street, New York, N. Y. Offices tn All Large Cities Johns-Manville Home Insulation Johns-Manville Home Insulation is a light, fluffy mineral wool, highly efficient in heat-proofing practically any building, old or new. It is durable, rot-proof, fire-proof and odorless, and will not corrode or settle. Full stud thickness of this material will cut fuel costs up to 30 per cent in winter, and, help keep rooms up to 15 deg cooler in hottest weather. J-M Home Insulation is furnished in two forms: for new construction, in easily handled batts; for existing buildings, in loose, nodulated form to be installed pneumatically. to fill completely the space between studs, joists and rafters on the usual 16 in! centers. Type B batts are backed with waterproof, vapor-resistant paper, extend ing on the long sides in a in. wide flange, by which the batt is fastened in place and which also aids in sealing the joints. This backing protects against pene tration of moisture from wet plaster and also resists infiltration of moisture vapor from the house into the wall. * Junior Batts are similar to Type- B batts except that they are not paper backed and are furnished only in size 12 x 15 in. by full stud thickness. * Type C Home Insulation is an improved form of loose wool,' in pieces 8 x 15 .in., without paper backing; which readily fluffs to full wall thickness when installed. Both Junior Batts and Type C can be readily installed in irregular spaces since, they are easily cut or torn with the hands. Applying J-M Type B batts in new home For New Construction Types B, C and Junior Batts Type B Home Insulation is furnished in pre-fabricated batts of uniform density, in both full stud thickness and semi-thick, in sizes 15 x 23 in. and 15 x 48 in., designed For Existing Homes and Buildings Type A "Blown" Rock Wool 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 3in.; density does not exceed 10 lb per cubic foot. This type of insulation is installed only by Approved J-M Home Insulation Contractors, who are equipped with the necessary apparatus and trained crews. Write for Details Complete information on all types of J-M Home Insulation will be furnished on request. 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. 1030 Johns-Manoilh Insulation Johns-Manville Pipe ind Boiler Insulation 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, for all com mercial pipe sizes. JtM Superex Combination J-M Pre-Shrunk Asbeslocel Pipe Insulation 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, and in block forms. J-M Pre-Shrunk Asbestocel Pipe Insulation J-M Asbestocel Sheets and Blocks 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, minimizes objectionable shrinkage. 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, for all commercial pipe sizes.* 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 in. to 4 in. thick, for all commer cial pipe sizes.* 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 H in. % in., 1 in., Double in., and Double % in., for all commercial pipe sizes.* . 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 in. to 4 in. thick. J-M Rock Cork Sheets and Pipe Insulation J-M Rock Cork is made of mineral wool and a moisture-proof binding ingredient molded into sheets for insulating refriger ated rooms and air conditioning ducts; and into sectional pipe insulation with an integral waterproof jacket, for all low tem perature service. It is strong, durable, and will not support vermin. Because of its unusual moisture resistance, its high insu lating efficiency is maintained in service. Furnished in sheets 18 in. by 36 in., in IMj, 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 brine thicknesses, for all commercial pipe sizes. Details on Request Write for complete information on any Johns-Manville insulating material. *J-M Magnesia, Pre-Shrunk Asbestocel and Pre Shrunk Wool Felt can also be supplied in sections to fit straight runs of copper pipe or tubing with the following outside diameters: % in.. in., ii in., }i in.. 1 hi in., 1% in.. \% in.. 2H in., 2% in., 3>i* in., 3% in., in., 5hi in., and 6% in. 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 Hi-Temp Pyrfelt Ari*to Spouse Felt 65% Magnesia Imperial Watcocell Air Cell Woolfelt Anti-Sweat Frost-proof Temp. Limit 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 ISO F to 120 F 30 F to 100 F Suggested Use Protective inner layer for low temperature insulations. Breechings and flues -- withstands vibration. _ tS? ?**. "d co~tan"c,val of innJatioo. For a low-cost, medium pressure industrial steam line. ForccW^n(MsotiteMinet^RjecomnKTM3ed especially for air conditioning work. Air Cell Pipe Conering--A low-cost insulation for resi dential use. Woolfclt Pipe Covering-- For the insulation of pipes carrying hot or cold water-- also preventj\ 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 woAosl baensdtoVseCrmeimcuelintets. --Factory Prepared --Grades 203, AA, A, HF. Asbestos Cements--Mine Run-- Grades 115, 214. Magnesia Cement--85% Magnesia. High Temperature Cement-Grade H.MT.ineral Wool Cement--Grade R-W. Vermiculite Cement--Grade A-ll. 1032 The Ruberoid Co. Insulation RU-BER-OID Insulating Products for Residential Use RU-BER-OID AIR-MET Reflective Type Ruberoid also offers AIR-MET, a reflec tive insulation consisting of two sheets of pure aluminum. Has 4 reflective surfaces, 4'air spaces and 3 vapor barriers. Instal lation does a three-fold job--turns back 95 per cent of the radiant heat striking its aluminum surfaces; the air cells retard heat losses by convection; its light weight re duces the loss by conduction to a minimum. Moisture and verminproof. Simple to apply- Made in folded strips opening up like an accordion. Strips are 80 to 100 ft with scale of feet and inches indicated. Flanges are readily tacked to the sides of studs, joists or rafters. Cartons 8 in. x 18 in. x 31 in., weighing approximately 40 lb, contain enough material for 1000 sq ft of area. AIR-MET can be stocked in a small space. Twenty cartons provide the insu lation coverage of a carload of rock wool. Its insulation value is equal to the best and satisfies the government specifications, as well as meeting the thermal conductivity factors required by heating and air con ditioning engineers and public utilities. Type 2 AIR-MET has one layer of foil, 2 reflective surfaces, with a water-repellent vapor-resisting paper cemented to the opposite side. Suitable for sidewall insu-' lation and can be applied very rapidly. RU-BBR-OID AIR-MET Reflective Insulation Giant Bats RU-BER-OID Rock Wool RU-BER-OID ROCK WOOL Mass or Fill Type Bats--Loose--Granulated This indestructible wool is an efficient insulating material. Absolutely fireproof, verminproof and inert toward moisture. Affords excellent sound-deadening and acoustical qualities. RU-BER-OID Kraflined Rock Wool Bats are carefully fabricated. They are well tailored, uniform and easily handled. They are clean and sufficiently dense to prevent dusting and deterioration. Each bat is backed with a moisture-resistant paper that prevents the infiltration of vapor into the insulated space. RU-BER-OID Kraflined Bats provide "four flap" pro tection--each edge having an extension that allows adjoining bats to be covered preventing any exposed seam, thus effec tively resisting the vapor flow. Recommended for all exposed spaces, such as sidewalls of new houses or under the roof, either in the roof rafters or the floor joist over the top floor ceiling. Bats without the Krafliner can be furnished if desired. Packages Contain Kraflined Standard Bat........................................ 15 in. x 23 in. J : wall thickness.................................... 8 bats--19.16 sq ft 27 lb Kraflined Demi-Bat..............................................15 in. x 23 in x 2 in. thick............................................12 bats--28.75 sq ft 30 lb Kraflined Giant Bat.............................................. 15 in. x 48.in.: wall thickness................................... 5 bats--25 sq ft 45 lb Kraflined Giant Demi-Bat..................................... 15 in.- x 48 in. t 2 in. thick.......................................... 8bats--40 sq ft 45 lb RU-BER-OID Wal-Pac Pads are insu lating units 9 in. x 15 in. that can be fluffed up when applied to nearly fill the studding space. Furnished in cartons weighing 25 lb containing 20 pads that should cover 20 sq ft area. RU-BER-OID Loose and Granulated Rock Wool is also available. Furnished in paper bags containing 35 lb each. 1033 Insulation Insulation The Pacific Lumber Company 100 Bush Street San Francisco PALCO WOOL INSULATION 59 E. Van Buren St. Chicago 5225 Wilshire Blvd. Los Angeles 122 East 42nd St. New York The Standard Lime & Stone Company First National Bank Building Baltimore, Maryland Manufacturers of Capitol Rock Wool Home fnsulatlons Franchised Distributors in all Principal Cities WHAT IT IS 8 PROPERTIES 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 insulatingmaterial 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 20 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. 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 Fiat 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. . The Standard Lime and Stone Company, prominent in the building materials industry since 1888, manu factures Capitol Rock Wool Insulations, all types of lime products, fluxing and crushed stone, Capitol Port land Cement, etc. '. ' A new manufacturing technique produces a refined, longer, more flexible fibre--a more effective form of Rock Wool. ' CAPITOL ROCK WOOL IS EFFICIENT Transmission of both heat and sound is virtually eliminated by the effective tiny dead air cell structure of Capitol Rock Wool. CAPITOL ROCK WOOL WILL NOT BURN. Capitol Rock Wool in Existing Homes Capitol Rock Wool Grade "A" Blowing Fibre is pneu matically introduced into the wall air spaces and between rafters or joists in roofs or attic floors of homes already built, whether the construction is shingle, clap board, brick veneer, stucco or half-timbered. This "blown" installation is the same for any type of con struction and is performed by franchised blowing con tractors. Installation leaves no telltale marks. Installing CAPITOL ROCK WOOL BATTS in a New Building CAPITOL ROCK WOOL BATTS A Distinctive Product Moisture-proofed. The processing of Capitol Rock Wool Batts gives the fibres a moisture resisting characteristic. Vaporproofing Membrane. To pro tect the exposed surface of the Batts against moisture from wet plaster and excessive interior humidity, a tested membrane is enclosed separately in each carton. It is 17H in. wide to make tacking quick and easy, and of sufficient length to give a smooth continuous membrane-protected surface without open joints between Batts. Cuts Cost. 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 Capitol Rock Wool in New Structures maximum efficiency; also 2 in. thickness. New homes or. buildings are generally insulated at the time of erection by placing prefabricated Batts between the studding and roof rafters. Many new structures how ever, are effectively insulated by pneumati Permanency. Capitol Rock Wool is permanent,, non-deteriorating. It brings lasting efficiency, fire-protection and com fort to the home with fuel savings that?ultimately return the investment many times over. cally installing Grade "A" Blowing Fibre after the scratch coat of plaster is applied. Send for catalogs and samples of Capitol Rock Wool Home Insulations. Look for the Capitol Dome on every package." 1034 1035 Insulation United States Gypsum Company 300 W. Adams Street, Chicago, 111. Sales Offices in Principal Cities Strip Wool Bat Wool Junior Bat Wool Granulated Wool PRODUCTS Insulating Building Board Insulating Lath Metal Reinforced Insulating Lath Insulating Tile. Insulating Plank Insulating Mouldings Roof Insulation Asphalt Coated Sheathing RED TOP INSULATING WOOL Description Red Top Insulating Wool isan extremely light, fluffy mineral fiber insulation--a fireproof material. The nature of the raw materials used, permits accurate manufacturing control-- the product is uniform and long-fiber wool. It contains a minimum of non-insulating materials. It is springy and resilient. Low Thermal Conductivity The heat conductivity of Red Top Insu lating Wool 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). Light Weight (Density) In its standard density, Red Top Insu lating Wool weighs but \-x/i lb per cubic foot. It is furnished in full and semi thickness. WEATHERWOOD BOARD Weatherwood Insulating Board is a felted wood fiber product that has been treated to make it highly moisture re sistant. It is a homogeneous board, free from laminations and tendencies to split through the center. Low Thermal Conductivity The average established in tests is 0.33 Btu per hour, per square foot per inch thickness, per degree Fahrenheit difference in temperature. ,* , Resistance to Moisture Tests show that this board, after being submerged in water for a period' of two (2) . hours, has an average water absorption of less than 15 per cent. Structural Strength The tensile strength is over 300 lb per square inch, and the modulus of rupture, over 500 lb. Durability There is nothing in this board that will deteriorate and impair the original insula-tion value. The Moisture Resistant chemi cal makes the board distinctly distasteful to rodents and insects. Uniformity Adequate laboratory control and mill inspection assure uniformity in density and structural strength. 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 law 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. Applying Red Top Strip Wool between studs. Strip Wool has a waterproof paper backing with a in. flange for nailing to studding. Used as shown it prevents the entrance of moisture into (he insulation. 1036 Applying Asphalt Coaled Sheathing Showing how Western Felt is used as mounting material at base of motor and blower units to reduce vibration and subdue noises. 1037 Insulation Wood Conversion Company First National Bank Building, St. Paul, Minn. New York Chicago Tacoma Dallas BALSAM-WOOL AND NU-WOOD INSULATIONS BALSAM-WOOL Sealed Insulation Acoustical Blanket Sound Deadening Industrial Insulation Refrigerator Insulation NU-WOOD Interior Finish Plank Tile Board Sheathing NU-WOOD Lath Roof Insulation Industrial Insulation Refrigerator Insulation KOLOR-TRIM Pre-decorated Moldings BALSAM-WOOL--The Original Moisture Barrier Insulation ' The Moisture Barrier, which is universally recom mended by engineers and architects, has been incor porate in Balsam-Wool for 16 years. This Barrier, improved as construction and equipment demanded, now'consists of double layers of asphalted kraft--a heavier liner being used on the warm side. Encased between this protective covering is. an insulating mat of fleecy wood fibres, chemically treated to resist fire, rot,'termites and vermin. 92 per cent of the mat voliinje.is. dead air. Balsam-Wool SEALED Insulation is fabricated at the*factory to a controlled density of 2.2 ib per cubic foot. The mat has a coefficient of .25 Btu per hour, per square foot, per 1 degree F difference in tem perature, per 1 in. thickness. As applied, factory efficiency is assured. The Spacer Flange* on each edge folds over and is fastened to framing members with' a staple hammer, assuring important air space, front and back. . Balsam-Wool is available in x/l and l.in. thick nesses in widths of 12, 16, 24 and 33 in.--Wallthick in widths of 12, 16, 20 and 24 in. Pat. Applied For. Balsam-Wool Spacer Flange* Application is quick and easy NU-WOOD INTERIOR FINISH -- STRUCTURAL INSULATION Nu-Wood Interior Finish (Tile, Plank, Board and Wainscot) is applicable either to new construction or to existing build ings. It offers varied and pleasing7 dec oration, also insulation 'and acoustical value. . Nu-Wood Insulating Lath has several times the bonding strength of wood lath-- continuous surface eliminates dirty lath marks, reduces cracks. V-joint resists trowel pressure in both directions--assures unbroken insulation value. Nu-Wood Insulating Sheathing is surfaced oh both sides with double coats of special moisture proofingcompound. Large boards, marked for nailing--speed erec tion--stronger, wind proof, insulated con struction. 1038 Insulation, Underground PRODUCTS ,or STEAM service American District Steam Company North Tona.wanha.NX 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. The pipe supports are held in fixed posi tion on reinforced conduit sections. They do not pierce the conduit wall and are suitable for use with sectional molded insu lation or filler insulations, particularly ADSCO-Corning Filler Insulation. Write for Bulletin No. 35-67AG. 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 Internolly-Exiernally Guided Type INTERNALLY-EXTERNALLY GUIDED JOINT A completely guided slip type joint. Both ends of slip guided throughout entire length of travel by an internal guide ring ana 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 rings in the guide ring attached to the inner end of the slip hold the line pressure, enabling the jointto 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 966) 1039 Insulation, Underground H. W. Porter & Co. INCORPORATED Newark, New Jersey Permanent Protection and Insulation for Underground Pipe Lines BALTIMORE, MD. CHARLOTTE. N. C. RICHMOND. VA. WASHINGTON, D. C. T/ffterm-O-Ti/c, #ec uS.P*rorr STEAM CONDUIT SYSTEMS For Central Heating--Therm-O-Tile is a complete conduit system for the per manent support, protection, and insulation of underground mains of a central heating ter, and with 5 different size base tiles they produce 27 different conduit cross sections. 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. Insulation--Either sectional pipe cov ering or Thermobestos 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 econom ical thickness recommended; for multiple pipe lines, a filler type of insulation is usually more economical in first cost. Pipe Saddle. Permits full thickness of insulation between pipe and roller. Waterproofing-- Under normal soil conditions, this conduit is waterproof. If, marshy ground or partially submerged conditions are encountered, the ponmiit may be made completely waterproof by the use of membrane waterproofing applied under the slab on a sub-base and carried completely over the tile envelope. Anchor Block. Fits directly in line with Base Tiles. Pipe Support for Single Pipe. Pipe Support for Three Pipes. 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. 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. , Representatives--Therm-O-Tile is also sold and installed locally by Johns-Man* ville Construction Units. * .Single or DouMe Pipe Lines Using Sectional Pipe Insulation. Multiple Pipe Lines Using Filler Type Insulation. 1040 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 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 high efficiency 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, alignment guides, filter cloth, 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, a prefabricated, ready-to-inetaU rail. ISM ft long, including conduit (Armco Iron), pipe, insulation, and accessories. Ideal for speed and economy on district heating projects. 1041 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. 1042 Century Electric Company 1806 Pine Street, St. Louis, Mo. Offices and Stock Points In Principal Cities Motors Century motors have been developed specially to meet the exacting require ments of the Air Conditioning Industry --Quiet Starting--Quiet running--Re markably free from vibration. CENTURY MOTORS For Compressors, Pumps, Fans, Blowers, Refrigerators, Stokers, Oil Burners Type of Motor SCH--Squirrel Cage SC--Squirrel Cage SCN--Squirrel Cage Hone Power I Starting I Range I Duty Remarks POLYPHASE MOTORS Applications 3 to 200 Heavy Low Starting Current High Starting Torque Refrigerators. Piston or Plunger Pumps, Com pressors. etc. 1/8 to 600 Medium 7Vi to 200 ' Medium Normal Starting Current Normal Torque Lower Starting Current titan SC Normal Torque General Purpose Motors, Blowers. Pumps. AS--Automatic Start SI--Slip Ring 1 to 60 1 to 350 Heavy Heavy Lower Starting. Current than SCH High Refrigerators. Piston or Starting Torque Plunger Pumps, Com pressors. etc. Far Frequent Starting and/or Speed Control Fans, Blowers. Centrif ugal Pumps, Com pressors. etc. SINGLE PHASE MOTORS RS--Brush-Lifting 1/8 to 40 CPH--Cap. Start and Run 1/8 to 10 CSH--Cap. Start- 1/8 to 3/4 Heavy Heavy Heavy Low Starting Current, High Starting Torque High Starting Torque High Starting Torque Piston or Plunger Pumps, Refrigerators, Stokers, Compressors, etc. CSN--Cap. Start 1 to 10 CPX--Cap. Start and Run 1 to 10 Medium Light. Normal Starting Current Must be Loaded to at Least 50 per cent Capacity Fans (Belted or Direct Connected) Centrifu- fugal Pumps, etc. SP--Split Phase SP--Split Phase 1/20 to 1/3 Medium Unrestricted Starting Current. 1/20 to 1/3 Light Restricted Starting Current. Oil Burners, Unit Heat ers, Blowers. Fans, Small Tools, etc. DM-DN-R Shunt Wound Constant Speed DM-DN-R Compound Wound Varying Speed DN-R Shunt Wound Adjustable Speed.. 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. Starting Current is 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. Size Range up to 600 horse power 1043 Motors and Controllers GENERAL ELECTRIC COMPANY SCHENECTADY, N. Y. SALES OFFICES. WAREHOUSES. SERVICE SHOPS and DISTRIBUTORS in PRINCIPAL CITIE8 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 guiet-oPerating induction motor on sound-isolating base. Type MB Capacitor fractional-hotsc power 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 ate 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 Fans and Centrifugal Pumps Reciprocating Pumps and Compressors 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 Constant or 3^peed Constant or 2-Speed Constant or Multispeed Shunt . Compound Resistance Split Phase Reactance Split Phase Low Torque Capacitor High Torque ^ Capacitor Repulsion Induction Squirrel Cage (Low Starting Current) B & CD B A CD KH KX KC KC KC SCR KorKB KF 1/8-200 1/8-200 1/40-1/3 1/6-I/3 1/50-10- 1/4-10 i/a-io 1/8-10 1/4-1000 Wz-l5 Direct Current Single Phase Alternating Current Reciprocating Pumps and Compressors (High Starting Torque) KC 3-100 Polyphase Alternating Current Pumps. Compressors. Fans Constant or Adjustable Constant Wound Rotor Synchronous . Mi MB i/HOOO TS 25-2000 This Company will gladly assist in the solution of any electrical problems in relation to heating and ventilation 1044 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: 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- duction motors [CR1061 fractional-horsepower i motor starling 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 908 and 909 Pipe and Fillings, (Copper) The American Brass Company General Offices: Waterbury, Conn. Manufacturing Plants: N. Y. Mica.Aksonu, Conn. Torrinoton, Conn. Watersuht. Conn. Bottalo, Detroit, Kenosha, Wis Offices and Agencies in Principal Cities ANACONDA 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: Low Friction Loss--Because the inside surfaces of copper tubes are inherently smoother than those of pipe and tubes made of ferrous materials and also because they 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 less heat than black iron pipe of the same size. Ease of Installation--In many places the flexibility of copper tubes simplifies connections that ordinarily would be awk ward 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 ahe installed and apply a coat of clear lacquer or similar substance. This keeps the tubes bright and makes an installation of which both 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. TypejL tubes are suitable for interior plumbing. ' \. -V 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 of approximately 18 in., throughout every coil or straight length gf tube. Specifications for Type M tubes include hard. drawn tubes only. Pipe and Fittings, (Copper) The American Brass Company 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 ]/ ;n are furnished soft in 30, 45 and fiOTft coils; also hard and soft in 20-ft straight lengths. Sizes over 1M in. are fur nished, hard or soft, in straight lengths only. 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-X, 11th Edition. Copies will be mailed to 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" per sq in. air pressure under water, which is the equivalent of 400 to 450 lb per sq in. water pressure. They are so designed as to offer a minimum of re sistance to flow. i 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 refrigerants demands 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 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 in. to 12 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, any usual type of connection can be made 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 Copper Sili con Alloy 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. Arthur Harris & Co. 210-218 N. Aberdeen (formerly Curtis) Street Chicago, 111 ENGINEERS -- FABRICATORS OF NON- " FERROUS 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. ' Coils We have special equipment for making coils in all shapes and sizes from pipe or tubing--copper, brass, aluminum, stain less steel, monel, block tin and pure nickel. Standard or special fittings. Send sketch, blue-print or old coil. Metal Floats Cylindrical Flat Cylindrical Ball Cylindrical Column Made of copper, plain steel, stainlessisteel, aluminum, brass, monel, pure nickel, and Everdur, 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. Floats in special sizes and pressures--made to order. Stainless steel ball floats in. to 12 in. for high pressure and corrosion carried in stock--special stainless steel floats made to order--stain less steel ball floats larger than 12 in. diameter can be made up specially. Float catalog sent on request. Copper Expansion Joints For low pressure and vacuum. Made in two styles^--convex and concave. Sizes 4 in. to 60 in. diameter. Cast iron op steel flanges. Flanges drilled to American standard unless otherwise ordered. Bends We make bends in every shape from all sizes of pipe and tubing in copper, brass, aluminum, stainless steel, monel, tin and nickel. Standard or special connections. U-bends for storage water heaters. . Also special pipe work for industrial installations, plumbing, heating and brewing. Perforated pipe, double pipe coolers, etc. . 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. The steel pipe produced 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. 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 galvanized coating 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 quality that is essential to successful coiling and bend ing, 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-- make this product especially adapt able 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. It makes J & L Boiler Tubes stronger yet more pliable and, therefore, more easily formed in a cold state. Other j & L Tubular Products J & L also manufactures Reamed arid 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. Also J & L Flat Galvanized Sheets for Air Conditioning and Ventilating Work Pipes, ducts, stacks and trunk lines made of J & L Flat Galvanized Sheets give a lasting, neat looking job. These sheets have a tight galvanized coating that will not spall or flake off during forming operations. J & L Flat Galvanized Sheets provide uniform resistance to corrosion. Because of their uniform ductility, even surface and flatness, J & L Flat Gal vanized Sheets meet the most exacting specifications for severe bending and form ing operations. 1049 j! Ui ill M!l ;( Pipe and Tube Wolverine Tube Company SEAMLESS COPPER, BRASS AND ALUMINUM Main Office and Mill: 1411 Central Avenue, Detroit, Mich. Atlanta, Ga..................................... Baltimore, Md_________________ Boston (Cambridge), Mass... Chicago, III___ _' Cleveland, Ohio______________ Dallas, Texas................................ Dayton, Ohio.................................. Denver, Colo.................... ............ Long Island City, N. Y........... Los Angeles, Calif.................... Louisville, Kt_______ Milwaukee, Wis._______-_____ New York Office: 420 Lexington Avenue Sales Offices _______631 Spring St. 121 a Gay St 195 Albany St. ....129 S. Jefferson St. __ 1740 East 12th St _____2813 Canton St ________ Route No. 9 .....1210 California St ____ .47-31 31st Place __ 1015 East 16th St. _______ 125 S. 5th St ,,..647 W. Virginia St. Minneapolis, Minn........................ Newark, N. j. _ Philadelphia, Pa.._....................... -............ nortn 12th St Pittsburgh, Pa........ .............. ......... .1000 Columbus Ave. N S Portland, Ore.................................. 524 V. W. 14th AvL St. Louis, Mo. .................4565 McRee Av* San Francisco, Calif................... ------7 Front St Seattle, Wash........ ......................... 1005 E. Pike St Washington, D. C........................... .... ;...................1108 16th St Toronto, Ont. ....... 137 Wellington St., W. Winnipeg, Man................................ 80 Lombard St. EXPORT: H. M. Robins Co., 120 Madison Ave., . Detroit, U.S.A. The experience of over 20 years of seamless tube manufacture,, the use of fine, up-to-date equipment, and strict adherence to Government and customer specifications, are responsible for the uniform, high quality of Wolverine products. ' ' Immediate Shipment From Large Stocks DEOXIDIZED COPPER WATER TUBE Government Type K Recommended for Air Conditioning, Refrigeration, Oil Burner, and Plumbing and Heating installations. Also for Gas, Steam, Oil Lines, and industrial uses and where water conditions are severe. WOLVERINE COPPER T ** WATER TUBE Types K, L, and M (made to U.S. Government WW-T-799 and A-S.T.M. B 88-33 Specifications), for air conditioning and refrigeration installations, make this product suitable for piping in accordance with all refrigeration codes. Government Type L For Oil Burner, Air Conditioning, Re frigeration, and general plumbing uses. Suitable for normal water conditions. Types K and L furnished in hard or soft temper in straight 20 ft lengths; soft temper in SO, J+5, and 60 ft coils. Government Type M Suitable for Air Conditioning and Re frigeration installations and for interior plumbing and heating purposes. f Furnished in hard temper in straight 20 ft lengths only. Wolverine copper air conditioning tube is the Standard for Air Conditioning work --Now available with cellophane caps and dfecs telling size and type. Type K--Orange Type L--White v Type M--Green WOLVERINE WROUGHT COPPER FITTINGS These new Wolverine Fittings are of the straight-line design (ends not expanded). They make stronger, neater joints, more quickly made, give trouble-free service and longer life. A complete range of sizes is available. Write for Catalog B 1050 Publications American Society of Refrigerating Engineers 37 West 39th Street, New York, N. Y. refrigerating data book REFRIGERATING ENGINEERING T RHE '39-'40 edition of the Refrigerating Data Book achieves an excellence matched by few engineering or scientific efrigerating Engineering in its 37th volume continues to be the periodical source of authoritative information on all books. The compilation of the work of phases of the arts and sciences of refrig many experts in refrigeration, heat, power eration. In its most solid aspects it carries and manufacturing, as well as authorities the Journal of the /LS.R.E., a living record from the field of biology, it contains all the of the technical advance of practice and fundamental data on the art of refriger research in its field. The larger portion of ation and air conditioning. It is presented its pages is, however, devoted to material in the simplest possible style so that parts of wider appeal, with original articles, none may be used the less au by those of thoritative, any degree but written of technical in a journal interest. istic style to This fourth enable the edition of the reader to get Data Book the back contains over ground of 600 pages in each subject 50 chapters and an un divided into derstanding eight sections of it that will separated stick. Refrig by contents erating Engi pages with neering also thumb tabs. prints news, Contents out features, line is shown write-ups of inside the interesting cover for personalities, ready reference. It includes a catalog and and carries detailed reports of local and list of manufacturers, distributors and en national meetings of The American Society gineers. There are several inserted charts. of Refrigerating Engineers. This volume is specifically devoted to Refrigerating Engineering has long been principles and refrigerating machinery. unique in its field not alone for the origi Another volume, appearing two years nality and authority of its contents, but hence, will be devoted specifically to the for its coverage of all phases of refrigera many applications of refrigeration. Thence tion both as to machinery and application forth the Data Book will be in two volumes. problems. The applications of this art The price of each is 84 with express are, of course, very numerous, and Refrig charges collect. erating Engineering keeps pace as the A series of pamphlets on the application scope of refrigeration is widened. of commercial refrigeration to such uses The rate has been reduced to 83 for as fur storage, vegetable coolers, farmers 1939. locker plants and the like will appear in 1939. CODES AND STANDARDS MEMBERSHIP ACTIVITIES IT is the policy of the /LS.R..E. to treat in its meetings current subjects touching THE newest standards to be published include the Safety Code for Mechanical Refrigeration, a test code for Rating Re upon all phases of the art of refrigeration. frigerant Expansion Valves and the (joint) Membership is in four grades with dues Code of Minimum Requirements for Com from 87.50 to 817.50. Sections hold fort Air Conditioning. Others cover the meetings in the following cities: Boston, testing and rating of mechanical condensing New York, Philadelphia, Detroit, Chicago, units and the testing and rating of air Milwaukee, St. Louis and Los Angeles. conditioning units. The Society partici The Society holds its 35th Annual Meeting pates in fifty or more standardizing pro January, 1940, in Chicago. jects under current study. Publications American Artisan . Published by KEENEY PUBLISHING COMPANY 6 North Michigan Avenue, Chicago, III. American ARTISAN, now in its 60th 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 the market study called "What's What and Who's Who in Air Conditioning." For further information about this study, write to the address above. 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 rales furnished upon request. 1052 Publications Heating, Piping and Air Conditioning Published by KEENEY PUBLISHING COMPANY 6 North Michigan Avenue, Chicago, 111. 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 inlating Engineers 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 shown in a recently prepared market study titled "What's What and Who's Who in Air Conditioning" which will be presented to interested manufacturers upon request. Heating, Piping and Air Conditioning is a member of the A. B. C. and A. B. P. Subscription rates--$2.00 per year; $3.00 for two years in U. S., Canada, Mexico, Central and South America. Foreign, $4.00 per year. Advertising rales furnished upon request. 1053 Publications Domestic Engineering Publications 1900 Prairie Avenue Chicago, Illinois DOMESTIC ENGINEERING More than a half century devoted to serving the plumbing and heating industry . . . serving it faith fully and serving it well . . . that's the record of Domestic Engineering. This record provides the sound foundation upon which Domestic Engineering has achieved and maintained its commanding po sition of leadership over this long period ... a leadership based upon all points by which a business publication may properly be judged. The reader audience of Domestic Engineering is comprised of the top group of merchandisers who ar$ responsible for the major portion of the business in the huge plumbing and heating market. These a'r* the men who look upon Domestic Engineering as^the outstanding publication in their industry, who depend upon it to keep them informed on all matters pertaining to their business. They have utmost con . fidence in Domestic Engineering and this confidence in turn is carried over to the advertising pages. * Complete data concerning Domestic Engineering and the industry it serves is available i "Selling the Plumbing and Heating Market." Write for your copy. PLUMBING AND HEATING NEWS Further expanding its service to the plumbing and heating field, Domestic Engi neering is supplemented by Plumbing and Heating News, which reaches every known factor in the industry in. mid month. In tabloid form Plumbing and Heating News has filled a void in the industry by bringing up-to-the-minute news of current developments and new products. This news content has made it the newspaper of the industry. Because of its universal circulation in the industry, it has aided in welding into one vast selling force, the factors that sell this huge market. At an exceptionally low per-line-perreader rate Plumbing and Heating News enables the manufacturer to blanket the entire industry with his sales message. Write for complete details, rates, etc. 1054 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 areMarketing and Research Bureau . also available to aid sales and advertising executives in obtaining full information on markets and in building sales forces. DOMESTIC ENGINEERING CATALOG DIRECTORY Now enlarged and extended to incorporate automatic heating and air conditioning and related products, Domestic Engineering Catalog Directory has taken another forward step in keeping abreast of the industry. This new edition is specifically designed for buyers, specifiers, specifying engineers, wholesalers, general contractors, air condi tioning consulting engineers those whose duty it is to purchase and specify plumbing; heating and air conditioning equipment. Wholesalers, engineers and contractor-dealers, particularly, will appreciate the wealth of quick- reference purchasing and specifying data the 1939 Catalog Directory makes available to them. As a method of presenting their catalog material, manu facturers, too, will welcome the consolidation of all of this buying and specifying data in a single volume which is placed in the hands of the top notch plumb ing, heating and air conditioning buyers and speci fying engineers. . Due to the trend of distribution of air conditioning equipment, Domestic Engineering Catalog Di rectory as now extended and enlarged, fulfills an opportune desire of the trade . . . and the industry is ideally situated to accept and use this all-purpose, comprehensive buying and specifying guide. An interesting 8 page folder presenting the Catalog Directory acceptance and preference among whole salers will be sent upon request. 1055 Publications Air Conditioning & Oil Heat 232 Madison Ave. Lex. 2-4566 New York, N. Y. rhtfflgo 903 Merchandise Mart Delaware 9389 San Francisco Don Harway & Co. 155 Montgomery St. Exbrook 6029 Los Angeles Don Habway & Co. 318 W. Ninth St. Tucker 9706 Baltimore Candler Bldg. Plaza 7065 PRIOR to 1935, this publication was known as "OIL HEAT" and its edi torial content consisted entirely of articles about the manufacture, sale and instal lation of oil burners. The title was expanded to its present form in 1935, and inspired a change in the oil burner field. The oil burner manufacturers and dealers are a naturally progressive group, else they would not be in the oil burner business at all. They understood the modern mer chandising and technical problems pre sented by the sale of air conditioning equipment, and they entered vigorously into this new activity. The result is that today (January 4, 1939) a total of 44.2 per cent of the oil burner manufactures are selling (many of them also manufacturing) air conditioning equipment. And 6698, or 54.4 per cent of the 12,298 oil burner dealers now are selling some form of air conditioning. Editorial content includes articles on "Air Conditioning Schools," "Win ter Air Conditioning Equipment-- Sale, Installation and Service;" "Sum mer Air Conditioning--Application, Sale, Dealer Problems;" "Oil Burner Service; Dealer Problems; Selling and Installing;" News items about all forms of heating, air conditioning and firing equipment. A complete cover age of the industry's activities each month. Subscription price $2 per year. Surveys and publications available: 16- page booklet on4 `Answers to your Questions About Winter Air Conditioning;" 16 page booklet entitled "What the Air Condi tioning-Oil Burner Dealers are Thinking and Doing About Sheet Metal Shops, Ducts, Registers, Blowers, Etc.;" January, ,1939, Annual Forecast & Statistical Issue --a report on 1938 and intelligent opinions about 1939; Directory of Oil Burner and Air Conditioning Manufacturers, giving equipment specifications, officers' names, trade names, etc. . Circulation of this paper: * (Publisher's Statement) ' Air Conditioning & Power Oil Burner Mfrs-- 423 ' Additional Mfgr. Executives.--............................ 183 Air Conditioning & Oil Burner Accessory Mfrs...... ........................ -...... ..................................... 445 Mfgs. Branch Offices & Field men................... .. 148 Air Conditioning Depts. of Public Utilities..- 107 Combination Power Oil Burner and Air Con ditioning Dealers--.................................................. 6698 Additional Power Oil Burner Dealers (not yet handling air conditioning)................................... 5600 Additional Air Conditioning Dealers (not yet handling oil burners)......................... 1040 Wholesalers and Distributors of Air Condi tioning, Oil Burner and Heating Supplies & Accessories........................ -- ..................... -- 1,172 Advertisers, Agencies, Unclassified...... .........-- 1300 Total............ ..................................................... - 17,116 "Our two previous ads in AIR CON DITIONING & OIL HEAT secured us approximately $30,000 of new busi ness." Dewey-Shepard, P. 53, May, 1938, issue. "We have been pleasantly surprised with the tremendous response to our ads in the August and September issues of AIR CONDITIONING & OIL HEAT." Eds-Wil Burner Corp., Chicago, Sept. 9, 1938. AIR CONDITIONING & OIL HEAT also has a Mailing Service, under which, for very low cost, literature may be rnaiied to all of the groups indicated in the Circulation Listing, above. 1056 Publications OILHEAJFINGGi /fr / air1onkIiTtIig>hning TUBlaU N 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 modem 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 1938, the average oil heating dealer got only 28.7 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. 1938 gross dollar volume of the average dealer was divided : Conversion burner units........ 28.7 per cent Heating equipment, in cluding boiler-burner units..26.2 per cent Fueloil..... .......... 28.5 per cent Winter airconditioning, including furnace-burner units............_.......,.............16.6 per cent In 1938, 42 per cent or 57,141 conversion oilburners were sold with new cast iron or steel boilers. In addition, dealers sold 10,934 boiler-burner units. Total boiler sales by oilheating dealers increased 11 percent over 1937. These dealers did a winter airconditioning dollar volume in 1938 of $21,324,383. SERVICES FOR ADVERTISERS Key Market Studies. 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, the 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 (June 30, 1938) shows: Power oilheating and airconditioning dealers anddistributors....... -......... 10,764 Key heating contractors, plumbing and heating contractors, and engir neers.................................... ........................ 1,866 Fueloil distributors, selling fueloil and range oil. andtheir branches._______ 3.107 Accessory and heating supply dis tributors......... ...... 1,075 Total dealers and distributors.-'............ Power oilheating and airconditioning manufacturers and their executives, Accessory manufacturers______________ 16,812 587 428 Total manufacturers.-___ ________ Total dealers and manufacturers, Per cent of total circulation.............. Other miscellaneous................................... 1,015 17,827 ' 97.27 501 Grand totalTM............................................... 18,328 Fueloil Journal circulation covers the automatic heating field at the minimum rate per thousand copies. It will pay you well to get full details. Write, wire or telephone. .. 1057 Publications HEATING 6-- VENTILATING 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 ofoutstanding 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 oi 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. 1058 Publications Plumbing and Heating Journal Published by THE ANGUS CO., INC. 515 Madison Ave., New York City Plumbing 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. 1059 Publications Sheet Metal Worker Published by Edwin A. Scott Publishing Company 45 West 45th Street New York ' I HE January 1939 * issue of Sheet Metal Worker will be its Sixty-Fifth Anni versary and Directory Number. It is the old est publication in its field and ig of vital im portance to men in terested in sheet metal work--air conditioning --warm-air heating and ventilation. Founded and published to 1909 by David Williams Company; 1909 to 1920 by United Publishers Corp.; since 1920 by the present publisher, the Edwin A. Scott Publishing Co. Sheet Metal Worker is today a monthly merchandising, business and tech nical journal basic to the use of sheet metal. It serves the various unified mer chandising and installing branches of the industry, consuming sheet metal for the erection, maintenance and operating equip ment of homes and buildings, including central air conditioning equipment, warmair heating, ventilating, dust and refuse removal, and systems for handling material by air; kitchen and restaurant work; a wide variety of interior and exterior work for commercial, industrial, institutional, and residential buildings. Subscribers are mainly merchandising contractors purchasing practically all pro ducts and equipment which they fabricate, erect or install. Manufacturers, jobbers and distributors also subscribe. The market has three main divisions. (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 and the Associated Business Papers. It has a uni form distribution, with the greater part of its circulation centered in states showing the greatest industrial ac tivity. Readers of Sheet M etal Worker are made up of warmair heating, air condi tioning and sheet metal contractors and dealers. Also wholesalers, manufacturers, branch offices and salesmen. For further details send for ABC statement. EDITORIAL Sheet Metal Worker has been out standing in the editorial service it has rendered the trade and is noted for the practical usefulness of its articles and the timeliness of its editorials. Its editor is a noted author in this field and the author of several well-known books. Sheet Metal Worker also publishes- books on heating, ventilating, sheet metal work, air conditioning, etc. . The Annual Issue published in January, contains a comprehensive and valuable Directory Section. ADVERTISING Sheet Metal Worker has an enviable record of long term advertising and is proud of its long list of regular advertisers. Because of its intimate contact with this field, Sheet Metal Worker is well quali fied to cooperate with manufacturers in their sales and advertising programs. Subscription rates--$2.00 per year, U.S., Mexico and Canada; Foreign, $3.00. Advertising rates on request . 1060 Pumps Buffalo Pumps, Inc. 450 Broadway, Buffalo, N. Y. Branch Offices Albant, N.' V., 61! Standard Bldg.. H. S. Johnson Atlanta, Ga., 16th Floor, 22 Marietta Bldg., J. J. O'Shea Baltimore, Md., 404 St. Paul St., E. E. Thompson Boston, Mass., P. 0. Box11, Melrcee,Station. E. D. Johnson Chicago, III., 20 N. Wacker Drive, L. D. Emmert Cincinnati, Ohio. Building Industries Bldg., F. W. Twombly Cleveland, Ohio. 418 Rockefeller Bldg., T. A. Weager Dallas. Texas, 702 Petroleum Bldg. Davenport, Iowa, 305 Security Bldg.. D. C. Murphy Co. Inc. Denver. Colo., 1718 California St.. Stearns Roger Mfg. Co. Dbs Moines, Iowa, 214 Old Colony Bldg., D. C. Murphy Co., Inc. Detroit, Mich., 2051 W. Lafayette Blvd., . Coon-De Visser Co., T. E. Coon Greenville. S. 0., 312 Franklin National Life Bldg., R. A. Stipp'. Houston, Texas, 713 Bankers Mortgage Bldg. Kansas Cm. Mo., 428 Dwight Bldg., T. H. Anspacher * Loa Angeles, Cali?., 708 Pershing Sq. Bldg.. P.R. Adrians Minneapolis, Minn., 2102 Foshay Tower, E. F. Bell. Nashville, Tbnn.. 154 Second Ave., No., Buford Bros. New Orleans, La., Devlin Bros. 1003 Maritime Bldg. New Yore, N. Y.. 39 Cortland St.. W. S. Kiothan Philadelphia, Pa., 703 Cunsrd Bldg.. Davidson & Hunger Pittsburgh, Pa., 431 Fulton Bldg., H. L. Moore Richmond, Va., T. Spencer Williamson, Jr., Inc. Mutual Bldg San Francisco, Calip., 1625 Van Ness St., Moore Machinery Co.. J. G. Scott Seattle, Wash., 500 First Ave., So.. A. T. Forsyth Sr. 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 bt 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, easilyserviced 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. gal 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) All 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. 1061 w Chicago Pump Company 2330 Wolfram Street BRUnswlck 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 for Duplex Sets of Pumps. "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. BIOS--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 270. 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 unitsi Duplex units are alternated in their operation by the Auto matic Alternator. Complete data in Bulle tin 250. '- Vertical Condensation Pumps for Low and Medium Pressure for Systems from 500 to 100,000 Sq Ft Radiation . Close-Coupled Pumps Boiler Feed, Circulating, Tank Filling,' Water Supply Fig. 2130--Close-Coupled, side suction pump. Capac ities range from 8 to 600 Gpm against heads up to 189 ft. Motors from 1/6 to 20 Hp. Discharge 1 to $ in. Both dosed and open type impellers. 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 Bulletins 245 and 255. 1062 Pumps Decatur Pump Co. Decatur, 111. BURKS SUPER TURBINE PUMPS AND WATER SYSTEMS PUMPS 8^ apa rv Burks Heavy Duty Self Priming Super ' Turbine Pumps VT Pressures to 100 lb per square inch. % -Capacities to 1,700 ga! per hour. Only one . moving part, the bronze impeller. A general utility pump suitable for many r 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-A. 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 haying many outstanding features. Capa cities to 24,000 gal per hour. Ask for Bulletin No. U5-A. Burks Super Turbine Condensation Return Units Furnished with receiver tanks construeted 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-C covering complete.line return units. 1063 'i I! I St $ ij. i; 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 BuUelin 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. Compute data in Bulletin No. 290 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 constriiction, and combine receiving tank, pump and driving motor in a single assembly. Bronze fitted throughout, with Tobin bronze shaft. 1 mpeller 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 1J4 to 225 gpm of water. For serving from 1,000 up to 150.000 sq ft of equivalent direct radiation. CompUU data in BuUelin No. 241 on request. 1064 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 lj^, 1H, 2,3,4,6,and 8 in.sizes with capacity up to 2000 gpm. Heads up to 300 ft. Compute data in Bulletin No. 155 on request. Suction Sump and Sewage Pumps Jennings Suction Sump Pumps are self priming centrifugals Tor 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. These pumps will handle air or gas with liquid being pumped, and because of self priming feature are installed entirely outside of pit. This affords perfect accessibility for inspection or cleaning. Capacities to meet all requirements. Compute data in BuUetins 159, 161 and 275 on request. .. - 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 dean 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 27 in. of mercury. Equipment furnished for any capacity. Special equipment for higher vacuums and pressures. Compute data in Bulletins Nos. 252, 255, 258 arid 282 on request. 1065 Pomona Pump Co. Manufacturing Plants ST. LOUIS. MISSOURI POMONA. CALIFORNIA New York Branch Offices Chicago Los Angeles Atlanta San Francisco Houston Pumps PRODUCTS Pomona Deep Well Turbine Pumps; Niagara Low and Medium Lilt Pumps Column Pipe: Welded copper-bearing steel made to Pomona specifications and standardized in interchangeable 20-foot lengths. Seamless steel couplings. Column pipe ends fit bronze bearing retainer, in suring straightness and correct alignment with Tine shaft. Drive Shaft; High tensile, cold rolled steel with stainless metal Sleeves at all bearing points. Open line shaft. Underground Bearings: Patented $esilient revolvable rubber bearings held in precision bronze bearing retainers. Low coefficient of friction. Minimum wear. Water lubricated. Self flushing. Impellers: Semi-open bronze, adjusta ble for capacity from the top of pump. Applications: Pomona Turbine Pumps are used for air-cooling and washing service. Being water lubricated, they oper ate most successfully in conjunction with water softeners for building water supply. Pomona Niagara Pumps are used for flood protection, condenser service and any other purpose where large volumes of water must be moved rapidly. Sizes: Pomona Deep Well Turbine Pumps are made in all sizes for wells of any diameter from 4 in. to 32 in. or larger and for any depth to 1000 feet or over. Bowls: Special Pomaloy cast iron made in the Company's own foundry under laboratory control. Especially designed for resistance to graphitization, abrasion and other forms of corrosion. Packing Gland: Located at the lower part of the pump head, above ground, fully accessible. Non-reversing Ratchet: Located ' a^oye the motor at the top of the drive shaft. Positively prevents damage to line shaft or couplings in case of accidental reversal of rotation from any cause. Capacities: 15 gpm to 10,000 gpm, 3 to 1000 hp. { NIAGARA PUMPS Drive: Normally by unidrive integrally I For low or medium lifts. Capacities built electric motor, for any current char acteristic; 3-phase induction; 3-phase slip from 900 gpm to 100,000 gpm. Made in two types; propeller and Mixfiow. Propel ring; 3-phase synchronous; single-phase repulsion induction; single-phase capaci ler type is for heads up to 15 feet. The Mixnow type is for heads from 15 to 70 tor; 2-phase. Voltages 110 and 220 on feet or higher. single-phase; 220, 440, 550, 2200 and 4400 Pomona Pump Co. has distributors and . on 3-phase. Direct connected steam tur service men in important cities throughout bine drive can be furnished. Simplified I the world. Write us for the name of your construction makes automatic control easily ' nearest distributor. accomplished. Registers and Grilles Anemostat Corporation of America 10 East 39th Street, New York City, N. Y. THE ANEMOSTAT HIGH VELOCITY AIR DIFFUSER The Anemostat High Velocity Air Diffuser is a ceiling outlet consisting of a series of circu lar diverging metal cones opening- outward from a central circular neck which may be attached directly to the main or branch duct. The Anemostat assures draftless distri bution of air at any duct velocity. Various standard sizes from 2 in. to 38 in. neck diame ter will distribute volumes of air between 10 cfm and 25,000 cfm and will handle any velocities between 300 fpm and 4000 fpm. When introducing large quantities of air into a room air motion results. The series of cones which form the Anemostat discharge the air in definite proportions in all directions in a series of planes. This diffusion together with the as piration (suction) effect causes prompt equal ization of temperature and therefore, humidity throughout the room, horizontally, and defi nitely prevents air pockets and dissipates the evaporation aura around the human body. The air-mixing effect of the Anemostat causes the predetermined room temperature to be established at a point well above the breathing level, which permits the use of higher temperature differentials. This in turn results in smaller volumes of air to be conditioned and therefore in smaller plants, reduced operating expenses and smaller ducts, while the high velocities which may be employed because of the draftless diffusion, result in further reduction of duct sizes and simplifica tion of duct layouts. . At the different velocities recommended for rooms used for different purposes the increase in decibel ratings through the use of Anemostats is negligible. The Anemo-lite which is an Anemostat combined with a built in lighting unit is an ideal solution to the combined problem of Air Distribution and Lighting. (See Figure 1). Pendent lighting fixtures may be hung directly from the center cone of the Anemostat if desired. (See Figure 2). Particularly suitable for theatres and auditoriums is the Anemostat combined with the indirect lighting unit. (See Figure 3). With this combination unusual and effective results are easily obtained. . Complete technical information on the Anemostat combined with lighting fixtures is available upon request. Fig. 1 Fig. 3 "No Air Conditioning System is better than its Air Distribution" '*=553^ 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 ........... lfe===== -..... -Him W t ilLi______ V -V. _____ _-- .< ..tfuJHB Fin-Flex No. 5030 Register with Band Iron Frame Flexible fins % in. on center offer satisfactory one time adjustment. Adjusting tool furnished with every order. Horizontal fins, furnished as standard. Ver tical fins furnished ifspecified. Same design furnished also without valve, as a return. Fin-Flo No. 9030 Register with Band Iron Frame Horizontal Fin-Flo for upward and downward deflection is standard. Vertical Fin-Flo for two-way side defieclic n also furnished. Same design furnished also without valve, as a return. The Auer line of registers and grilles for heating and air conditioning systems is modern and complete, offering a wide choice of styles for every purpose. Only a few representative models are shown on these pages. Fin-Flex Registers and Grilles are made with either vertical or horizontal fins which are easily adjusted at time of installation for single or multiple air current in any direction. Ample free air capacity for modern forced air systems. Dura-Flo Registers and Grilles are also furnished with blades adjustable for any desired air flow. Fin-Flo Registers and Grilles are furnished with either vertical or horizontal fins for any specified air flow, and are not adjustable. DuraBilt Floor Registers and Cold Air Faces are assembled with steel cross-bar construction, all cross joints locked and mortised. These should be specified whereever extra strength is required. They come in medium or narrow mesh. The Auer Classic face has wide popu larity for air conditioning and heating uses. It is an unusually attractive face, appropri ate to most interior decorative schemes. All Auer models are designed with due. regard for air capacity, and supplied in all required sizes and finishes. Complete Catalog 39, showing all typra for air con ditioning and gravity heating, furnished 'on request. Registers and Grilles Hendrick Manufacturing Company Hendrick Perforated Metal Grilles 48 Dundaff Street, Carbondale, Pa. Sales Offices in Principal Cities--Consult Telephone Directory PRODUCTS--Hendrick Perforated Metal Grilles; also Mitco Open Steel Floor ing, Mitco Armorgrids and Mitco Shur-Site Treads. Hendrick Perforated Metal Grilles: To engineers, architects, contractors, building owners, Hendrick offers a large variety of grille designs. In addition to those patterns which have become stand ard, the Hendrick line includes many exclusive designs. All Hendrick Grilles are characterized by clean-cut perforations and fine finish. They are given a special flattening operar tion which makes for easy and pleasing installation. or with prime coat, with lacquer or duco finish in any color, with natural polish or with any standard electroplate finish. Furnished from 16 gauge to Xa in. thick, up to 90 in. wide and almost any length, dependent only on rolling mill limits. They come with invisible access doors, angle frames, hinged grilles, etc. Hendrick Grilles are available in alumi num, brass, bronze, copper, Monel, stain less steel, steel and other commerciallyrolled metals. They are supplied unpainted M. No. 9; 67% Open Area. Hendrick Nozzle Grille; Recommended for air ot- ditioning systems requiring grilles for high velocities; Particularly efficient in minimizing the danger of noise from air passing through the grille. Fabricated from oZurntnum, bronze, stainless steel or steel in gauges not exceeding .078 in. thick and in sizes not exceeding 48 in. x ISO in. % in. diameter hole is the most popular perforation but this nozzle grille can be furnished in many other sizes. Dura-Flo No. 8132 Register--No Frame Adjustable bars H ,n- on center. Also furnished with horizontal bars (adjustable). Small, convenient adjusting tool furnished with each order. Same design furnished also without valves, as a return. 106S Classic No. 2030 Register (with Valve) Band Frame Doors type. Fixed Louvre Grille;-installed in a door ihts grille permits air circulation but prevents vision from any angle through the grille. Regularly fur nished in No. 18 U. S. Gauge Steel with prime coal, enamel or electroplate finished. On special order can be furnished in aluminum, solid bronze or stainless steel .06 in. thick only. ' M. No. 7 (Design Patent No. 91,66) 47% Open Area. Send for a copy of new, 192 page handbook, "Hendrick Grilles." 1069 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 Seven Complete Lines of Air Conditioning Registers and Grilles in Five Distinct Price Groups. THE ACE OF AIR CONDITIONING GRILLES No. 90 DESIGN Dual Control Directional Flow No. 90 Design--Made up of a number of thin strips which are shaped into a series of grooves--straight or curved--as shown. The assembled strips form an exceptionally attractive grille with openings of 34 in. and a depth of 1 in. A wide range of deflec tions is available. The tubular shape of the openings insures positive control of air flow with all deflections. Price Group E. , CHARACTERISTICS OF No. 90 DESIGN 1. Dual Control of Air Flow--The air is controlled in two planes; horizontally as well as sideways. Thus, on high sidewall installations, the air is prevented from striking the ceiling, thus avoiding discoloration and loss of directional flow. ' WWW 2. Resistance--Curved shape of tubes eliminates tur bulence; hence, resistance is remarkably low. 3. Noise--The absence of turbulence likewise eliminates Straight Curved the greatest cause of noise in the grille. See H & C Catalog No. 37AC for Acoustica Ratings. 4. Concealment of Duct--The 1 in. depth of the grille, plus the tubular shape of the openings, results in exceptional concealment of the duct. 5. Free Area--The free area of No. 90 Grille is exceptionally large. See Page 39 of H & C Catalog No. 37AC, or Page 74 of Catalog No. 37 for Actual Free Areas. 6. Types of Directional Flow--Practically any deflections or combination of de flections are available. See Page 9 of H & C Catalog No. 37AC, or Page 65 of Catalog No. 37 for standard types of deflections. .................................. iiimiimiiimiiiiiiiiiif No. 68 Design--A very inexpensive grille combining ample free area, attractive appearance and effective concealment' of the duct. Openings are % inches by % inches with inch frets. Price Group AA. iimiiiiiiiiiMiiiiiimin No. 88 DESIGN . Perforated Plain Lattice .. No. 72 Design--Combines rigid bar type con struction, neat appearance, maximum free area with low cost. Depth of bars is in. Price Group A. 1070 No. 7 DESIGN Non-Adjuslable Vertical Bar Open Mesh Hart & Cooley Manufacturing Co. Registers and Grilles Nos. 84 and 85 De signs--Adjustable deflection grilles with bars % in. in depth and spaced 34 in. apart--bars are con nected in 2 in. sections, No. S4 DESIGN a. llowing_ sectional. ad- _N__o_.__S__o__D_ _E__S_IGN Adjustable Vertical Bar Close Mesh justment^ The Unique Adjustable Horizontal Bar Close Mesh construction assures positive directional control of air flow with quick adjustability to any combination of deflections desired. Depth of bars and close spacing combine attractive appearance and concealment of the duct. Price group D. Nos. 77 and 78 Designs--Fixed air flow. Similar in appearance to Nos. 84 and 85 Designs. Price Group B. REGISTER AND GRILLE FRAMES Any of the grille designs shown are available with any of the installation frames listed below. OUTER MEMBER 333fr No. 3 SIDEWALL STUD FRAME (Left) Installations when made as recom mended with this frame are perma nently streakproof. The frame provides a positive plaster lock, preventing the plaster from pulling |NMEB f away from the frame. The register face overlaps the frame 34 in. on all sizes. The Sponge Rubber Gasket which is furnished attached to the register face, forms a seal between the wall and the register face, pre venting air leakage at this point. The frame has rigid supporting arms of sufficient length on all sizes to fasten directly to the studs. The stackhead is bent over the outer member of the frame and held in place by means of the inner member. No. 8 BASEBOARD STUD FRAME (Right) Extension arms fasten directly to studs. Stackhead is attached to frame either by forming over inner member or by clamping it between the outer and inner members. May be used with any H & C one-piece Baseboard Register, all of which are furnished with Sponge Rubber Gas ket as standard to prevent streaking. Frame insures a solid foundation for register and protects stackhead. In expensive, easy to install. Schedule of Class Numbers for Use in Specifying H&C Registers, Grilles, and Intakes Type of Frame Design No. 68 1 72 77 78 84 85 90 Grille only, or Return Air Intake. Flat................ Register without installation frame....................... Sidewall Register with No. 2 Band Iron Frame.. Sidewall Register with No. 3 Stud Frame............ Baseboard Register with Integral Frame............ Baseboard Register with No. 5 Stack Frame.. .. Intake with 7/g-tn. projection.................................. Baseboard Register with No. 8 Stud Frame........ 680 1 720 770 780 840 850 900 681 771 781 841 851 901 772212682 772 782 842 852 902 683 ! 723 773 783 843 853 903 684 j 724 774 784 844 854 904 685 i 725 775 785 845 855 905 687 1 727 688 i 728 777 778 787 788 847 848 857 858 907 908 Complete Separate Catalogs on Air Conditioning Registers and Grilles or Warm Air Registers Available on Request. 1071 Registers and Grilles Tuttle & Bailey, Inc. New Britain, Conn. Branch Offices: Boston. New York. Chicaco. Philadelphia Air Conditioning Grilles. Registers and Intakes Air Control Devices Ornamental Grilles Cast or Wrought Metals Convection Heaters iimiiiiiiiiBiiiiiiBiiiiiiiiiiiiiiiiiiiiiii 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. COMBINATION VERTICAL AND HORIZONTAL DEFLECTION A series of individually operated louvers is placed directly behind the face of the grille. Deflector louvers run in a direction opposite to that of the fan bars. . Mcknight registers A scientifically designed register for com mercial air conditioning work. Provides positive control of air volume at the outlet. Volume control louvers are operated by means of a special key furnished with each register. For complete information on Tuttle & Bailey's entire line of air conditioning products, write for copy of latest Catalog No. 39. 1072 ________' ____________ Registers and Grilles Tuttle & Bailey, Inc. New Britain, Conn. REMOTE CONTROL An outstanding development. Ideal for hotels, office buildings, large public buildings. Makes possible individual control of air volume by the mereturning of a knob in every room throughout the building. A real advance in air conditioning for commercial buildings, yet comparatively inexpensive to install. SANTROLS 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. iiiui ' -- -----1 minitinmnitniHMiinn. n.ni|jr DUCTURNS Ducturns are composed of scientifically designed turning blades. When installed in. a duct system they eliminate the necessity for long radius turns and allow the use of right angle elbows throughout. Ducturns greatly simplify the layout of duct work and furnish a much more attractive and finished installation.. 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 actual job installations, 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. 1073 Registers and Grilles The Independent Register Go. Established 1898 3747 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 Horizontal Grille Bars With "Independent" Adjustable Directed Air Flow Registers and Grilles the Engineer is in com plete control of the direction of air flow. The directional adjustment can be made at the time of installation--or after the system is operating, to meet unforseen or changed con No. SU-A--Air Flow Downward Adjustable from straight to 4b deg. ditions. Patented The method of adjustment is simple as shown, and many directions and combinations can be developed to suit the need. Each interior No. 321-A--ADJUSTABLE DIRECTED AIR FLOW grille bar is ad justed individ With Vertical Grille Bars ually. Standard registers are furnished with single valves;--they are also made with "Multiple Valves" operating in unison--also with rear "Deflecting Vanes" which can be adjusted individually--with which the Engineer is given a dual control of the'air flow--being able to secure right and left together with up and down deflection at the same time. - Patented Grille Bars set for straight, right and left deflection. The grille bars are set in a firm tension, yet easily adjusted, with the tool sent with , each order. No. SS1-A--Showing a combination of Adjustments \ Ceiling Outlets are furnished in several sizes--both Round and Square styles. Ceiling Outlet No. 1860-R No. Slt-A--Knob Control Ceiling Outlets offer one of the most flexible units for ventilation and distribution of cooled or heated air. The ceiling outlet grilles are of perforated metal. The Nos. 311-A or 321-A Regis ters can be furnished with either Lever, Knob, Key, Chain or Pull Rod Control. You should have the Independent Register Catalogues--Yours for the Asking* . 1074 Registers and Grilles United States Register Company General Offices: Battle Creek, Mich., U. S. A. Branches: Minneapolis, Minn., Kansas City. Mo., Albany, N. Y.. New York, N. Y., San Francisco, Calif. Air Conditioning Registers, Vents and Grilles Style i 4o Style 153--New "Louvre-Tvpe" 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 Directional Flow, Horizontal or Vertical Styles. For com plete Reference Refer to 1939 Edition General Catalog No. 27. Also furnished with all styles of setting frames, and with INSET PANELS. Style 145--U. S. Adjustable Bar Air Conditioning Registers specially designed for Summer Cooling and Cold-weather Warming. Bars adjust from 60 deg Up- Flow to 60 deg Down-Flow by a lever operating Pin that is removable after Adjustment. Doesnot MARorINJURE Register finish. Can be furnished with Box Band Frames or Studding Frames, and INSET PANELS. ' Also furnished in Vertical Adjustable Bar Styles for Right or Left Adjusted Setting of Diffusions. Style 158 Style 177 V. V. I. or 145 V. V. 1. Letters V. V. I. used as suffix to an Air Condi tioning Vent or Grille Style Number means this Grille is equipped with Vertical Deflector Back Blades that can be set individually in any desired Angle and Locked in that fixed position with Set Screw at end of each Blade. This setting may be changed by adjusting De flector Back Blades after Grille is installed. Horizontal Back Blades are designated by Letters 1075 Letters V. V. L. used as suffix to an Air Conditioning Register Style Number means that this Register is equipped with Vertical Group Operated Valves that swing to complete Closing Position and to any desired practical angle of Deflection. Can be furnished with Knob-Operators, ChainOperators with Pulley, also Pole Operating.' The Style Number indi cates the Style of Register Face and the suffixing Letters, for Example, V. V. L. means vertical Lever Operated Valves. Letters H. V. L. means Horizontal Valves. Further Data may be had in Latest General Catalog! 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. , Many other grilles and air control devices for air conditioning applications are illus trated in Waterloo Catalog No. 18. Engineering and Performance data are published in a separate bulletin. Both are available from main office or representatives. Registers and Grilles Wickwire Spencer Steel Company 41 E. 42nd St., New York, N. Y. Buffalo Worcester Los Anceles Chicago San Francisco WISSCO STAMPED GRILLES WICKWIRE SPENCER PERFORATED METALS Wissco Grilles are manufactured in a great variety of designs--50 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 and 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 rjirjirjir.i AnAuu rjir-irjiiyi Airjirjirj grille area. In Wickwire Spencer plants, modern machinery produces grilles as heavy as %e in. in thickness, and in AMru-IAMAM any size or shape up to 60 in. x 156 in., in one piece. Larger sizes in two or more pieces suitable joined so that the joint is virtually invisible on the front of the grille. Dai`n 8e0 MATERIALS - Design 850 Wissco Bronze, an alloy sheet metal of high tensile strength, is specially recom mended for Wissco 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. Wissco 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-- Wissco grilles are perforated in sheet steels ranging from Ji in. thick to 16 U. S gauge and in bronzes and aluminum in. to 16 B. & S. gauge. 6 6' FINISH In the Wickwire Spencer finishing plant any type of finish may be supplied -- electro- Clated, japanned, uffed, or painted; special finishes matched or supplied as desired. When a paint finish is desired it is recommended that grilles be shipped from the manufactory with installed*' n'y finishi"g COat tQ be aPPlied where Grille Design-1,7 SPECIAL FEATURES Invisible doors, hinged grilles, angle frames, or other special features supplied as required. Other sheet metal designs and specialties produced as desired. A copy of the New Catalog on Wissco Grilles, giving detailed analysis of Grille layouts and specifications, will be sent upon receipt of your written request. 1077 The American Rolling Mill Company Executive Offices, Middletown, Ohio Atlanta, G*., 1437 Citizens and Southern National Bank Bldg. Boston, Mass.!201 Devonshire St. Buffalo, N. Y504 Seventeen Court St Bldg. Cbicaoo, li i. __________________ 310 S. Michigan Bldg. Cleveland, Obio..............,,................1516 B. F. Keith Bldg. Dallas, Texas............... -.......................1111 Santa Fe Bldg. Detroit. Mich.--___ ________ 5-261 General Motors Bklg. Indianapolis, Ind____________________ ______ Circle Tower Kansas Citt, Mo----------------------------------- 7100 Roberts St, Miodletown, Ohio------------------------- .-----------703 Curtis St, Minneapolis, Minn......... .................--171-27th Ave., S. E New Orleans, La-------------------------------3501 S. Carrollton Ave! New York, N. Y.----------------- ---------------------------- 50 Church St Philadelphia, Pa-------------------- 1808 Lincoln-Liberty Bid*. Pittsburgh, Pa...-----------------------------------1632 Oliver Bldg.' San Francisco, Calif.--------------------------- ,,_46S 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. Send for complete information. - Hot Rolled (Sheets and Strip) Fan Blades Blower Casings Fuel Oil Tanks Unit Conditioners Stoker Hoppers - Armco Zincgrip A special galvanized sheet that can be severely formed without peeling or flaking of the zinc coating. . Cold Rolled (Sheets and Strip) Furnace Casings Room Unit Casings . 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. N Stainless Steel ` (Sheets, Strip and Plate) Combustion Chambers Heat Flues and Tubes Furnace Casing Trim Grilles Corrosion Resistance Fan and Blower Blades Heat Resistance without destructive scal ing up to 1600 F. or higher. 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. Sheets (Copper Steel) Bethlehem Steel Company General Offices: Bethlehem, Pa. 1 BETHLEHEM STEEL COMPANY, GENERAL OFFICES: BETHLEHEM, Pa. DISTRICT OFFICES: ALBANY, Atlanta, Baltimore, Boston, Buffalo, Chicago. Cincinnati, Cleveland, Columbus, Dallas, Detroit, Honolulu, Houston, Indianapolis, Johnstown, Pa.. Kansas City, Mo., Los Angeles, Louisville, Ky., Milwaukee. Nashville, New Haven, New York, Philadelphia, Pittsburgh, Portland. Ore., St. Louis, St. Paul, Salt Lake Citv. San Antonio, San Francisco, Savannah, Seattle, Syracuse. Toledo, Tulsa, Washington, Wilkes-Barre, York. Export Distributor: 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 charts at the right summarize the results to date; com pare the life, in atmosphere, of the four most generally used materials. These tests are worth remembering when buying or specifying iron or steel--they show one material, copper-bearing steel, to be defi nitely superior. - Beth-Cu-Loy, Bethlehem's copper-bear ing steel, is of the identical composition as that shown by the lower bar of each 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 2 to 2^ times the resist ance to rust. It costs considerably less than open-hearth or copper-bearing iron. A.S.T.M. Test of 22-gage sheets Years to average first failure of 4 materials 2 4 6 8 10 12 Sheets exposed April 21, 1926; tests still under way (see Proceedings of A.S.T.M.--Committee A-5. Vol. 38). *No failures in copper-bearing steel sheets at last report. BETHLEHEM MAKES: Sheet Steel--all types, hot-rolled (black), coldUrolled, and galvanized-- available in Beth-Cu-Loy. Steel Pipe--all sizes and weights, buttwelded and lap-welded--available in BethCu-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. Available in Beth-Cu-Loy. 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. 2 4 6 8 10 12 Sheets exposed April 19, 1917; test discontinued April 16, 1928 (see Proceedings of A.S.T.M.-- Committee A-5. Vol. 28). . Only 10 of 61 copper-bearing steel sheets had failed when test was discontinued. | I I M | 1 f~T I | I I I I j T'T'T I | I II I /It ANNAPOLIS Copper-bearing Steel _L _L I _L 5 10 15 20 25 Sheets exposed October 17, 1916; tests still under way (see Proceedings of A.S.T.M.--Committee A-5. Vol. 38). Only 9 of 78 copper-bearing steel sheets had failed at last report. . A new booklet, ``Beth-Cu-Loy Sheets," gives the story of these tests. A copy is yours for the asking. 1079 Sheds (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 RUST-RESISTING U-S-S COPPER STEEL GALVANIZED SHEETS Copper steel is an alloy made by adding copper to molten steel, thereby increasing the resistance of steel to rust. Metallurgists, railroad construction engineers and independent research laboratories have tested US'S Copper Steel and discovered that it lasts two to three times as long as plain steel when subjected to atmospheric corrosion. When you specify U'S'S Copper Steel Sheets for air-conditioning ducts or equipment, you get the advantage of 100 per cent to 200 per cent longer life for about 5 per cent more cost. Duct work is so costly to replace that Copper Steel should be considered for any worthwhile job. * U * S* S Copper Steel 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 air-conditioning engineers, architects and contractors. . , '- . Gauges of Steel Sheets Used for Duct Construction HEATING AND VENTILATING Round Ducts Rectangular Ducts ' Diam.. Inches Cauge Width, Inches Gauge 6 to 19 20 to 29 30 to 39 40 to 49 30 and above 26 4 to 18 24 19 to 30 22 31 to 60 20 61 to 118 18 11 tt and above 26 24 22 20 18 Other Exhaust Systems . - 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., 1^ in. seams on widths over 48 in., 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.). U*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. 1080 ' Specialties, Heating frames cJones Boston, Mass. New York Office: 101 Park Avenue Barnes and Jones Vapor and Vacuum Systems of Steam Heating; Modulation Valves, Packiess 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 Sixe....................... '/, In.' Cap.Sq Ft Rad... 30 (8 o* pressure). With non-tarnishable indicating dial, non-rising stem, re newable disc seat. Tail piece extra heavy to prevent breakage--extra- long to facilitate connection to radi ator. Three models:. ndle and lock shield. >/, In.. 60 1 In. 100 1'/. In. 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 refilaced without special tools; lift out old unit and insert a new one. Available in sizes to fX almost any make of trap. Symbol 120 12 124 134 13 14 I i % k iCapacity.C. L Rad., w 400 rr 1200 Capacities based on 1^6\b 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. ATo. 32 Condensator No. Capacity u> Sq Ft 31 700 32 1,600 33 3.500 34 6.000 35 10,000 36 16,000 37 32,000 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., and ini, 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 1^3 in. and 2 in. sizes. Capacities to 5,000 lb of water per hour. 2 lb pressure differential. 1081 Specialties, Heating Armstrong Machine Works 851 Maple Street Three Rivers, Mich. Exclusive Manufacturers of Armstrong Inverted-Bucket Steam Traps ARMSTRONG Atlanta, Ga., J. M. Tull Metal & Supply Co., Inc., 285 Marietta St., N.W. Baltimore, Md., Milby & McKinney, 116 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., 10S-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, 307 Securities Bldg. 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.. 311 W. Cumberland Ave. 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. REPRESENTATIVES Milwaukee, Wis., Hamacher & Williams 2540 W. Wells St. ` Minneapolis, Minn., Albert C. Price Co. 257 Fourth Ave., South. '* Montreal, Quebec, Preston, Phipps Inc 955 St. James St. W. * New Orleans, La., Louisiana Steam Equipment Co., 109 Tchoupitoulas St. New York, N. Y., Advance Engineering Co. 69 Dey St. ' Philadelphia, Pa., Brogan & Co., 810 Race St. Phoenix. Ariz., John W. Ladlow, Box 1784. 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 S: 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, 404 Morgan 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., 6$ Higgins Ave. . Wooster, Ohio, Steam Economies Co., 1011 Beall Ave. . Armstrong offers two types of traps for heating, air conditioning, and steam distri bution service. Standard Inverted Bucket Traps, the type originated by Armstrong, are non airbinding and self-scrubbing. They are used for Tow, medium, and high pressure duty where relatively little air must be handled along with the condensate. Their free-floating lever design makes it possible to open very large discharge orifices com pared with the size and weight of the trap itself. . Armstrong Blast Traps are used where large amounts of air must be vented quick ly when steam is first turned on. The Armstrong Blast Trap (illustrated on next page) consists of a standard inverted bucket trap with a large auxiliary air vent controlled by a piece of rustless thermo static bi-metal. When the trap is cold, the Auxiliary vent is wide open, allowing air and condensate to blow right through the trap. When steam reaches the trap, the auxiliary vent closes, allowing the bucket to float and close the main valve after the condensate has been discharged. The Armstrong Blast Trap has several advantages over the conventional float and thermostatic trap, 1. The Armstrong Blast Trap has but a single orifice to be maintained tight against the full pressure differential. The pressure differential across the auxiliary air vent amounts to only 1 ini. to 4 in. of water. 2. Positive action. The discharge valve in an Armstrong Blast Trap is either wide 1082 Armstrong Machine Works Specialties, Heating open or tight shut. Fast opening and fast closing prevent wire-drawing. 3. Handles dirt. There are no dead spots in an Armstrong Trap in which dirt can settle and interfere with the operation of the trap. No blow-down valves are necessary and ordinarily no strainers are required ahead of Armstrong Traps. 4. The wearing parts in all Armstrong Traps are identical in design, material, and precision workmanship with parts used in Armstrong Forged Steel Traps for pres- . . sures up to 1500 lb gage and total tempera tures of 850 F. At ordinary heating pressures, Armstrong Traps last many . years without any maintenance expense whatever. Armstrong Steam Trap Book. This 32 page book gives complete information on all sizes and types of Armstrong Traps. It also contains 15 pages of data on the subject of trap selection, installation, and maintenance. A free copy will be mailed no request. ; Service Organization. Satisfactory se lection and operation of all Armstrong Traps is assured by 43 district representa tives in the United States, Canada, and Hawaii. Stocks of. Armstrong Traps are carried in all large cities.. THE ARMSTRONG BLAST TRAP The above picture shows how the Arm strong Blast Trap works when steam is first turned on. Note that the auxiliary vent in the top of the bucket is wide open. Air and water are free to rush straight through until steam comes in and causes the bi-metal strip to bend upward closing the auxiliary vent with the small flat disc. Thereafter it works the same as the standard trap. Sizes, Capacities and List Prices of Armstrong Traps -'Trap Size Pipe Connections................ List Price (Regular)............. List Price (Blast Trap)......... Telegraph Code (Regular)... Telegraph Code (Blast Trap), Diameter............................... Weight.................................. Maximum Pressure............... 5 2 50Continuous discharge capacity in U> of water per hour at pressure indicated. For more complete information, see the a 1150 20 30 Capacity Chart in the Armtrong Steam Trap Book. a. 70 a 100 J125 'If Yi in. connections are 150 desired, order No. 202 for 200 straight way of No. 203 for 250 angle. No. 200 and 201 450 560 640 690 500 600 660 650 660 No. 21 840 1000 1080 890 970 840 940 880 960 820 900 N6. 212 1560 1900 2060 1800 2050 1840 2030 1840 2040 1530 1680 No. 213 No. 214 No. 215 No. 216 3000 3500 3900 3100 3600 3750 3700 3400 3880 3500 3200 3500 r $29.00 $31.50 I'orli// li//or 2* $38.00 $55.00 $40.50 $60.00 Hemlock Larch Tamarack Hemlette 7W 32 Lb 250 Larette 14' 8i// 47 Lb 250 Tamrette 16VV 10*/ 76 Lb 250 4600 5600 6300 5900 6600 6200, 6100 6300' 6700 5900 5400 5700 7600 9100 10,000 8500 9800 8900 9200 10,400 10.900 9500 9500 10,200 14.300 17,200 19,000 18,200 17,600 18,200 18.500 18,500 20,400 18,600 17,400 19,000 Specialties, Heating The Beaton & Cadwell Mfg. Company Main Office and Factory: New Britain, Conn. CADWELL No. 45 UNIT FOR 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 bring methods, as 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 above 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. 6. 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 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. 35 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. Cadwell relief and pressure valves 25, .85 and 85 F have A.G.A. approval. Complete catalog sent upon request. 1084 The Beaton & Cadwell Mfg. Company Specialties, Heating CADWELL THERMOSTATIC AIR VALVES FOR ONE PIPE STEAM AND VACUUM SYSTEMS "PERFECTION" FLOOR AND CEILING PLATES No. I No. Sk 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~l in. flange--sizes yi in. to 12 in. No. 2--Same as No. 1 with set screw instead of springs. No. &--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 H in. to 8 in. No. 6--Sectional floor and ceiling plate cast iron or brass--1 in. flange--with set screw, in. high--size ^2 in. to 4 in. No. 6A--Solid floor plate cast iron or brass--size ^ to 5 in.--with or without set screw. No. 7---Same as No. 1--But with 1^ in. flange. Size H in. to 4 in. No. 9--Same as No. I but with 2 in. flange--size ^ in. to 4 in. No. 10 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 3 in. tube sizes. All plates can be furnished in plain, nickel or chromium plated finishes, as specified. Complete Catalog Upon Request 1085 Specialties, Heating Cochrane Corporation 3130 North 17th Street, Philadelphia, Pa. Branch Offices in 40 Principal Cities COCHRANE HEAVY-DUTY STEAM TRAPS A high pressure unit for condensate drainage of steam lines, separators, coils, evaporators, etc., and for conditions invol ving relatively high drainage rates. Rec ommended for pressures up to 400 lb. Simple construction. No levers, con stricted passages or stuffing boxes to be come clogged with sediment or scale. All parts are readily accessible. Action is quick and positive, avoiding wire drawing and erosion. Discharge capacities may be conveniently altered by easy change of valve seat. Write for publication No. 2850. 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 ribs which guide it into a direct unrestric ted fall, ana 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 For information on other Steam.Specialties -write for individual publications. 1086 Specialties, Heating GRIN NELL 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 ; . 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 pound Gauge, Thermoflex Damper Regu lator. 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 34 in. inlet and 34 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 99S-995) 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 Hoffman-Economy Vacuum and Condensation Pumps, and Hot Water Controlled Heat Equipment. 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. VACUUM VALVES The Nos. 2, 77 and 78 Vacuum Air Valves operate on a similar principle as described, but in addition feature the Hoffman Double Air Lock consisting 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. No. S Vacuum Vent Valve with Double Air Locks and Adjustable Vent Port HOT WATER CONTROLLED HEAT EQUIPMENT The Hoffman Tempera ture Controller is con nected by capillary tubing to the Outdoor Tempera ture Bulb, and to the Water Temperature Bulb installed in the supply main. Variations in out door and circulating water temperatures are instantly transmitted by these two Bulbs to the Temperature Controller which electric ally opens or closes the Control Valve. Temperature Controller The Hoffman Control Valve. Admission of hot water from the boiler into the circu lating system is con trolled by this valve. It is opened and closed elec trically when actuated by de mands for more or less heat from the Hoffman Tempera t ure Controller. Outdoor Temperature Bulb located on exterior of building ' Hoffman Circulator Water Tempera ture Bulb The Hoffman Circulator is a centrifugal pump of large capacity, low power con sumption and furnished in all standard sizes. It is installed in the return main and operates continuously except when outdoor temperature rises above 65 deg. 1088 - Hofman 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 aid 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 Valve SUPPLY VALVES Besides the No. 7 Adjustable Orifice Modulating Valve the Nos. 37 and 47 series (not illustrated) represent a complete line of Packless 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 arid 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--K in 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 5^ 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. No. 60 Series Trap 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. 1089 y Specialties, Heating ILLINOIS ENGINEERING COMPANY General Offices and Factory: Chicago Branches and Representatives in Principal Cities Illinois Motorized Valves (on and off) 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 installationsthis 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 % in. 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 open or tight ........... closed. No 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 Vertical Standard Separators horizontal type and have a removable baffle plate to facilitate clean ing of baffle and keep ing the separator's effi ciency at the highest point. Write for Bulletins 1090 Specialties, Heating ILLINOIS ENGINEERING COMPANY General Offices and Factory: Chicago Branches and Represen tatives In Principal Cities Illinois Selective Pressure Control Systems Illinois Selec tive Controller 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 inves tigation. Ask for Bulletin 16. Illinois Thermo Radiator Traps Illinois Thermo Ra diator Traps for vacuum, vapor and low pressure heating sys tems. Has Series G 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 Series 7C Unsurpassed for draining ventilating units, unit heaters, and for dripping mains arid risers-- wherever it is desira ble quickly to vent air from the main as well as handle the water of condensation in quantity, whether hot or cold. Illinois Flow Control Valves Type I In large installations where process steam or zoning require ments do not permit, the vari able control of combustion, and in housing projects or on Central Station service, Illinois Flow Control Valves are used. They are of the full floating type, giving complete regulation of steam flow. Furnished for manual, pneumatic or electric operation. Ask for Bulletin 517. Illinois Return Trap Automatic ally returris the condensa tion to the boiler, regard less of pressure on the boiler up to 8 lb, at the same time 4 # 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 1091 Specialties, Healing 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 and Blast Type v Traps, Combined Float and Thermostatic Traps, Air Eliminators, High Pressure Thermostatic Traps, Boiler Return Traps, Packless Radiator Valves and Modulating Supply Valves. HAINES RADIATOR TRAPS HAINES F & T TRAPS The operating thermo stat in all Haines Traps is a specially con structed Bourdon tube, charged with a volatile fluid and hermetically sealed. It is the expansion and contrac tion of the fluid, under varying tem peratures, that furnishes the operating power. The ther mostatic element is outboard the valve seat closing the valve against the flow of steam. This trap is designed for handling large quantities of conden sation such as occur at main line drip points, unit heaters, hot water generators, etc. This trap cannot become air bound as it has a ther mostatically controlled bypass. It is light enough to be supported in the pipe line. HAINES BOILER RETURN TRAPS HAINES MODULATING VALVES The seat and carrying member construc tion assures positive leak proof perfor mance. Less than- a full turn of the handle com pletely opens or closes the valve. This valve is packless and made in sizes from yi in. to 2 in. Can be fur nished with wheel or lever handle or lockshield. For vapor and atmospheric heating sys tems. Prevents cracked boilers. Assures positive circulation by venting the air and returning the water of condensation to the boiler irrespective of boiler pressure. Weighted valve mechanism pre vents wiring drawing of valves. This trap has no stuffing boxes or packed joints to leak air or water. All Haines material is ruggedly constructed to assure long life and accurately designed for economical operation. Each device is individually tested, factory adjusted and guaranteed. 1092 Specialties, Heating Kieley & Mueller, Inc. BsUMilhu) 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 fivuuovi & o----- v anvs Pilot Reducing, Back Pressure, Tank Control. ncguiaiIW5t 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. (AH 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; ball bearing spindle and easy-to-pack stuffing box; rotary or sliding valve. Write for special bulletin C-3. 1093 Specialties, Heating Milwaukee Valve Company Milwaukee Wisconsin Manufacturers of the Complete Line of Vapor and Vacuum MILVACO Heating Specialties -- APPROVED Bronze Valves Each unit is scientifically designed and constructed by precision methods, and carefully inspected and pre-tested to insure, uniformity, higher quality and finer workmanship. MILVACO representatives, located in principal cities, render intelligent, courteous service. 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 Fig. No. S50-6 Diaphragm Thermo static Trap. Positive seat ing accuracy; sensitive oper ation. 15 lb pressure to 25 in. vacuum. Nickel finish rough body and polished cover, tailpiece and nut. Sizes % in.'and% in. Cap. 200-400 sq ft E.D.R. Fig. No. 25-2ST Straight Through Bellows Type Trap. Size in. Finish same as No. 25-4. Cap. 200 sq ft. Bellows Type Thermo static Trap. Phosphor bronze bellows, hydrau lically formed. MILVACO cage construction employed. 25 in. vacuum to 25 lb pres sure. Nickel rough body with polished trimmings. Sizes yk in- ad % >n* Cap. 400 sq ft. Fig. No. 209 Packlesis Radiator Angle Valve. Lever handle, grad uated. Regularly furnished with rough nickel plated body,' finished nickel plated trimmings. Designed for low pressure and vacuum heating systems. Sizes Yi in. to 2 in. inch MILVACO RadiatorValves and Thermostatic Traps are also available in chrome finish. Fig. No. 18 Series Float and Thermostatic Trap. Self-aligning float valve with reversible monel metal seat. Diaphragm ther mal element. Baffle plate prevents condensate from flowing directly on ball float. Sizes % in. to 2j^ in. inch Cap. 200 lb to 8000 lb per hr. at 2 lb press, differential. Fig. No. 215 Packless Radiator Angle Valve. Finish same as No. 209. Also available in lock and shield pattern. MIL VACO Radiator Valves cam not bind or stick in opera tion. Sizes in. to 2 in. inch For complete detailed information send fo'r condensed catalog of Milvaco Heating Specialties. ' 1094 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 No. 617--Duplex quantities, our Duplex type protects Up to ttfiOQ Sq FU the boiler against flooding. AH 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. No. il9--Vp to 50 a. No. til--Up to 160 lb. Sieet yitoS in. Valves are sealed with sev eral inches of water, making theescapeofsteam impossible. Inverted Bucket No. til--For Preuurea Up to 160 lb. Si*e$ Mtotin. 1095 Specialties, Healing 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 comer 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. Bellcnos- 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 Vi in. to 1J4 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. N-100 Medium Pressure Trap 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. Floot-Thermostelic 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 l/i in. to 2 in. for pressures up to 900 lb. Catalog HV-165. See Sarco Catalog HV-45 for all heating specialities 1096 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. Catalog HV-45. 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 . 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 or brine for temperatures ranging from 0 to 400 F. Catalog HV-52. Type TR-Hl Standard for hot water storage tanks, fan units, etc. Type KR-14 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. Room Thermostat SARCO WATER BLENDER AND TEMPERING VALVES For mixing hot and cold water to deliver auto matically water at any desired temperature. Two models are available, type IB for showers, wash basins, etc., and type DB, a tempering valve for use with submerged heating coils or tankless heaters. Catalogs HV-140 and 839. See Sarco Catalog HV-45 for all heating specialities 1097 Water Blender Tempering Valve Specialties, Heating WARREN WEBSTER & COMPANY Pioneers of the Vacuum System of Steam Heating -since t888 pc Systems of Steam Heating Main Office and Factory: Camden, New Jersey 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 Central Control Systems results in (1) increased comfort because over-heating and underheating are minimized and (2) lower fuel or steam costs. 1098 Fig S. Webster System Radiation Warren Webster & Company Specialties, Heating WEBSTER SYSTEM RADIATION Sylphon Packless--A high quality Concealed, non-ferrous type for use valve incorporating a Sylphon Bellows exclusively with Improved Webster Sys completely enclosing a non-rising stem tems. Is unique in that it combines in a and fully meeting "bellows packless" spe single unit, a light-weight heating element cification. Made in angle model in sizes of of high efficiency with an orificed radiator A, %, 1, 1 ]ri, 13^ and 2 in. Right-comer, supply valve, a radiator trap and supply left-corner and straightway single-union and return piping connections. Metal models in sizes of 3^2, and 1 in. Choice enclosures for installation within the wall of lever, wheel, lockshield, chain wheel or and exposed metal cabinets are available. extended stem handles. Webster System Radiation and enclosures Type "B"--A good are so designed that the entire heating quality valve. Quick element can be quickly removed without opening. Non-rising damage to plaster or paint. Space require stem. Molded ring ments reduced to a minimum and instal packing meets usual lation greatly simplified. "packless" specifi 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 cation. Made in angle model in sizes of 3^, If 1%, 1XA 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 lA, % and 1 in. Choice of whe.e..l, lever, lockshield, chain wheel and extended stem handles. 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 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. 7. Metering Orifice Inserted in Union Connection of a Webster Supply Valve 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. 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 oftypes to fit both new and installed radiator supply valves of Webster or other make. Made in angle mod- ! RETURN TRAPS el in sizes of %, I Sylphon--Per 1 and 134 in. Right- | fected thermo corner, left-corner, static bellows trap, straightway single fully compensated union and double for pressure. Stain union models in se less steel valve lected sizes. Choice piece and renew of wheel, iever,lock- able seat. Factory Pig. 6. Webster Packless Valve . shield, chain wheel adjusted. Made in orextended handles. angle, right- Fig. 8. Webster BOS Sylphon Trap 1099 Warren Webster & Company Specialties, Heating corner, left-corner, vertical, and straight way bodies. Sizes: 34, M and 1 in. Normal operating pressures up to 15 lb per sq in. Maximum occasional pressure 25 lb per sqlin. Series "7M" --Perfected dia- ph ragm-type thermostatic trap, fully com pensatedfor pres sure. Uses M on e 1 Metal Fig. 9. Webster Size 70S-Si Trap diaphragm, Stainless Steel valve piece and seat insert. Renewable seat. Factory ad justed. Made in angle, right-corner, left- comer, vertical, and straightway bodies. Sizes: 34, M and 1 in. Normal operating pressures up to 25 lb per sq in.; maximum occasional pressure 50 lb per sq in. Series 7 with phosphor-bronze dia phragm can be used where normal opera ting pressures do not exceed 15 lb per sq in. piece and seat insert. Angle model only. Sizes: %, 34. M 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. Pig. 10. The Webster Site 0026-T Drip Trap is 'Rated 700lb Water per Hour at gib 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 Me t a 1 d i a - phragm. Stainless Steel valve Fig u Webster Size 7SS Trap Rig. IS. Size S4C-1 Webster Boiler Protector with Law Water Electrical Cut-out Switch. Size 34 has 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. 1100 Warren Webster & Company Specialties, Heating 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 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. All ratings of Webster-Nesbitt Unit Heaters are based on tests made in accord ance with the standard test code of Industrial Unit Heater Association and A.S.H.V.E. Pig. IS. Webster-Nesbitt Unit Heater. Propeller-fan Type GIANT HEATERS Centrifugal-Fan Type for the eco nomical heating or large areas. Floormounted, wall-mounted, horizontal-sus pended and inverted types; in sizes and capacities, from 3330 to 16,000 cfm, and from 125,000 to 1,008,000 Btu, with 2 lb steam, 60 deg entering air. With or with out Thermadjust Temperature Control Damper which prevents overheating and stratification, and effects fuel savings. Also available with Nesbitt Steam-distri buting Tube Heating Surface for instal lations employing modulating steam valve control. Quality throughout, from the sturdy, efficient copper tube-and-fin radi ators to the fans, motors, and durable, attractive casings. Giants of efficiency and endurance. Send for catalog W-N 104. Seven unit sizes--air capacities, at maximum fan speed, from 495 cfm to 4580 cfm. Three types of heating element for each size, affording wide range of final temperatures and permitting flexibility in selection. Modern casing of heavy furni ture steel, die-formed and welded, rounded corners, black featherweave finish, stain less steel trim. AU-copper heating ele ment of tube-and-fin construction, guar anteed for working steam pressures up to 150 lbs gauge. Steam and return headers of heavy seamless steel tubing. Freedom for expansion, because heating assembly is held in casing by snugly fitted angle guides. Center steam and return connections permit four smaller units to be suspended direct from steam piping. Quiet fans of four-blade type; four smaller units have extra wide overlapping blades for especially quiet service. Rub ber-mounted motors; and Adjustable discharge louvres. . Send for Catalog W-N 100. SERIES F UNIT HEATERS Centrifugal fan units for quiet and efficient circulation of heated air in offices, stores, showrooms, restaurants, halls vesti bules, etc. Four casing sizes, each with two radiator sizes; capacities (60 deg entering air; 2 lb steam) from 94 sq ft EDR to 423 sq ft EDR; 282 cfm to 1355 cfm. Send for Publication W-N 105. 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 and condensate. , Union connections make them easy to connect up. Also, furnished with screw con nections when desired. They save money for fittings and instal lation . labor, by having straight through horizon tal pipe connec tions. The Cub sizes are made in-. % in., 1 in. Especially suitable for in dividual unit drainage on heating and process equip ment. Also three "Master" sizes H in. to 2 in., for general service. "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- 5 zontal or vertical pipe o 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 "Combination" Steam Trap Float Type with internal thermo static air bypass and strainer. A modemly design ed. and very suc cessful trap for vacuum and pres sure heating. "Victor" Low Pressure Steam Trap A heavy duty trap for large volumes of con densation at low pressures. We make separators of every type and all sizes for all pressures. 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. 1102 Specialties, Heating Yarnall-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 cord 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 P--Valve C--Bonnet K--Control Chamber D--Control Cylinder L--Control DUe G--Valve Seat H--Tat Plug J--Body . Advantages Light Weight--Yarway traps need no support--H in. trap weighs only 1% lb. 2 in. trap weighs 8% lb. Small Size--They practically eliminate radiation losses--can be installed in cramped quarters--'A in. trap measures Vyi in. long--2 in. trap, in. long. Will not air bind. ..Require no priming. Insure quick heating. Operate on exclusive Impulse principle (U. S. Patents No. 2,061,782 and 2,127,649.) Low Price--Often cheaper than re pairing old traps. . Factory set to operate at all pressures up to 400 ib (or 600 lb) without change of valve seat. Prices, Weights and Dimensions Trap No. Prices Size In. 400 ib 6001b 6001b Trap 450 F 550 F 750 F Complete 60 70 Va 61 1 63 71 73 IV, 64 74 1'/2 66 - 76 2 67 77 120 $15.00 12! 22.00 123 31.00 124 48.00 126 68.00 127 90.00 Wt Lb iy* 2 2Va 4 6 8y For further information send for descriptive bulletin T-1734. 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 400.1b pressures. For additional details send for bulletin EJ-1906. 1103 Stokers The Brownell Company Established 1855 Dayton, Ohio Manufacturers of BROWNELL BOILERS AND STOKERS Representatives in All Principal Cities Power Boilers of various Fire Tube Types; Steel Heating Boilers; Underfeed Stokers and Steel Plate Work. 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 Brownell 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 1104 Stokers Combustion Engineering Company, Inc. All Types of Fire and WaterTube Boilers Mechanical Stokers Complete Steam Generating Units Pulverized Fuel Systems 200 Madison Avenue, New York, N. Y. Offices in all principal cities of the United States and Canada More than 14,000 C-E Itokers installed to date .wear are readily accessible for inspection, adjustment or replacement, when neces sary. Rate of fuel feed and air supply may . be regulated over a wide range and are readily adaptable to automatic control. Applicable to boiler units from about 100 hp up. - C-E SKELLY STOKER UNIT A compact, self-contained unit adapted to burn either anthracite or bituminous coal. Alternate fixed and moving grate bars assure lateral distribution of fuel. An integral forced-draft, fan, with vortex inlet control, permits positive regulation of aircoal ratio. Automatic control is standard equipment. Approximateapplication range --20 to 200 rated boiler hp. C-E SPREADER STOKER A simple, rugged stoker designed to burn a wide variety of coals. Hopper, feeding and distributing mechanism, variablespeed drive and motor are combined in a compact unit. A series of rotating spreader blades feeds coal into the furnace in criss crossing streams which assure uniform distribution. Fines are burned in sus pension and the rest of the coal is burned on a grate which may be of either the stationary or dumping type. Grate surface is toned for regulating air admission and to facilitate cleaning. All parts subject to TYPE E STOKER A single-retort, underfeed stoker with an established reputation of many years* standing for dependable service. Designed to burn a variety of bituminous coals under boilers up to about 600 rated hp. Available with either steam, electric or hydraulic drive. OTHER C-E STOKERS Type K Stoker--A single-retort, under feed stoker for burning bituminous coals under boilers in the upper size range of the C-E Skelly Stoker Unit. C-E Multiple Retort Stoker--For burning bituminous and semi-bituminous coals under boilers up to the largest sizes. C-E Traveling Grate Stokers -- Including both Coxe and Green types. Available with grate surfaces suitable for anthracite, coke breeze, lignite or bitumi nous coal, as required. Chain grate types are built for either forced- or natural-draft application. C-E BOILERS All fire tube and water tube types in sizes ranging from 25 hp up to the largest. Standard and special designs to suit all conditions of fuel, load and space. In cluded are all types formerly known by the trade names "Heine," "Walsh & Weidner," "Casey-Hedges," "Ladd" and "Nuway". Detroit Stoker Company Sales and Engineering Offices General Motors Bldg., Detroit, Mich. Main Offices and Works at Monroe, Mich. District Offices in Principal Cities Built in Canada at London, Ont. Since 1898 Detroit Stokers provide the Economical Method of Burning Coal. Built in many types and capacities for all heating and power requirements. Features embodied in the various designs represent 40 years' experience in Stoker manufacture exclusively Complete Line to Meet Every Need: Detroit LoStoker, Detroit UniStoker, Detroit Single Retort Stoker, Detroit Double Retort Stoker, Detroit Triple Retort Stoker, Detroit Multiple Retort Stoker and Detroit RotoStoker. ' Recommendations covering individual requirements submitted upon request. District Offices located in principal cities; or write Detroit Stoker Company, Detroit, Michigan. Detroit LoStoker, showing motor driven Detroit LoStoker Many grate area sizes and capacities to fit fur naces of all types of boilers. Side cleaning, with pro vision for admitting air under the dumping grates at each side to burn out the combustible prior to dumping ashes. Com- ' pact, easily installed, re sponsive and automatic. Highly efficient, saves coal. Successfully burns less ex pensive grades of coal. Detroit LoSlokers are mechanically driven through machine cut worms and gears fully enclosed, run ning in oil, require little power for oper ation. Large active fuel bed to fit the furnace and provide sufficient grate area to carry heavy loads and still operate economically with light loads. COAL V DISTRIBUTION ADJUSTMENT CONNECTING ROO ' COAL PLUNGER ADJUSTING BLOCjC Detroit LoStoker Advantages: Continuous Adjustable Plunger Feed with control of the quantity of coal fed and its distribution. Heavy Mechanical Drive of simple design, requires little power. Side Cleaning with dumping grates, ashes removed through doors provided in the Stoker front. No hand cleaning. Agitator in coal hopper for continuous coal feed, cannot stick or jam with wet coal. Automatically Controlled. Motor or steam turbinedriven, controlled from steam pressure, water temperature or thermostat. 1106 EC0N-0-C0L STOKER DIVISION OF COTTA TRANSMISSION CORP. MAIN OFFICE AND PLANT ROCKFORD, ILLINOIS N PRINCIPAL CITIES THROUGHOUT AMERICA Streamline Domestic Model Finished in smart green and black with chrome trim. A high quality pro duct, now giving complete satisfaction in thousands of homes throughout America. Three sizes. Bin-Feed Models . Two styles: "Transfer" or "Pull-Thru." Install delivery tube above or below floor. Use. in new or old homes.. . Domestic and Commercial Models Six sizes ranging from 18 to 200 lb per hour. For homes, apartments, stores, offices, factories, etc. to supply heat and small power: require ments. Industrial Models Open hopper stokers for heavy-duty heat or power re quirements of schools, apart ments, hotels, factories, etc. Rugged, long-life mechanism materially reduces fuel bills. A PIONEER LINE--22 MODELS DE LIVERING 10 TO 1250 LB PER HOUR Developed by Cotta Transmission Corp. --long and favorably known for "precision" transmissions in the heavy automotive and oil industries--Econ-O-Col Stokers are de signed and made to give exceptional per formance over a long period of years with little or no upkeep costs. The line is com plete--a model for every purpose from the heating requirements of a bungalow up to heavy-duty powerrequirementsofa modern factory. Equipped with nationally-known motor and controls. Adaptable to steam, vacuum, water, or warm air systems. A stoker that gives much more for a little more, rather than much less for a little less--Econ-O-Col! YOU GET ALL THESE FEATURES Continuous-feed, Free-rolling. Auto motive-type Transmis sion--Made to exacting tolerances from extra heavy, long-wearing ma terials. Tripleheat-treated gears cut from electric furnace, chrome-nickel steel --diamond point tested. Ball and roller bearings. Motor--Spring or rubber mounted. Quiet. Aero-Dynamic Fan--Delivers double required capacity. No whine. Copper-Bearing Steel--Used in all parts contacting coal to resist corrosion. Straight Flight Feed Screw--Requires less power, saves electricity. "Marvel" Air Volume Control-- Really works--not just a damper. Retort--Thick, strong. Keeps coal out of air chamber and scientifically distributes air. . .. Electric Safety "Shear Pin" Switch --Shuts off both motor and fan when ob struction stops flow of coal. Write for Special Bulletin# Giving Complete Specifications on other Models 1107 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 plant efficiency in four major ways: ( 1) Cuts fuel costs; (2) Reduces labor costs; (3) Provides steady, Typiccl Installation Down even heat or 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 Construc 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 stoker 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) Sect.io__n_a_|l, ,seilcf-cleanmg tuyere blocks. . r , .. P Typtcal 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 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 |jgfl||IBII stops the stoker rS 3JUJT motor at the com- `H'l TTTn\ mand of the II [ 1111( Syncro-Stat or fjp' ; other directing controls. In the case of the larger fctSrT stokers a magnetic Typical ,,,staUation operating switch works in conjunc Cast Iron Boiler 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 binfeed models for both bituminous and anthracite coal. Anthracite models have been tested and ap proved by The Anthracite Insti tute. Typical Installation Domestic Furnace 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, Low Bridge Wall 1108 Commercial Installation--Coal Flow model that carries coal direct from bunker to fire Air Spreader Model--For High Pressure Boilers Industrial "Poweram" Model--For Heat or Power 1109 Motorstokor Division Hershey Machine & Foundry Co. Factory and Home Office Manheim, Pa. MOTOR STOKOR Installation and Service by factory-trained dealers in all anthracite burning areas. DEFINITION A complete stoker, burner, and optional ash-removal system for automatic com bustion of buckwheat or rice anthracite. Applicable to coal, gas or oil furnaces or boilers for providing warm air, hot water, or steam. Especially designed for auto matically heating buildings and providing year-round hot water. RANGE OF TYPES Standard installations in all sizes include direct-from-bin feed with ash removal, direct-from-bin feed with pit collection, hopper feed with ash removal, and hopper feed with pit collection of ashes. RANGE OF SIZES Available in 9 models, providing a com plete range. The smallest is the new domestic MOTORSTOKOR No. 10 cap able of heating average small homes. It feeds up to 20 lb of anthracite per hour, is rated at 640 sq ft of steam and 1020 sq ft of water radiation. The largest are MOTORSTOKORS No. 2 and No. 3, feeding up to 100 lb of coal per hour and rated at 2800 sq ft of steam or 4480 sq ft of water radiation. ADVANTAGES Simplicity: Entire mechanism func tions intermittently, including coal feed controlled draft, and ash removal. A portion of the combustion air is fed with the coal, preventing dust and back draft. Worm feed. Concentric dustless ring burner needs no cleaning-. Revolving bar breaks all clinkers. Efficiency: Fixed air mixture for uni form combustion. Floating worm assures uniform, trouble-free coal feed. Flexibly mounted motor operating intermittently and using little current. Quiet, directmounted, self-compensating fan. Ruggedness: Heavy cast parts, with lavish use of chrome-moly, monel, nickel,.-and special alloys. Oil-submerged gears reduce all operations to very slow wearfree motions. Extraordinary structural and metallurgical protections against cor rosion. Safety: Floating coal screw minimizes stoppage or jams. Air feed through coal prevents back draft and escaping gas. Automatic release-clutch cuts off current when over-loaded. Minneapolis-Honeywell controls. 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. T0K0L 61 STOKOL MODELS for burning bituminous and anthracite coal--capacities range from 12 lb per hour on . domestic sizes to 600 lb per hour on commercial Models. . .Both bituminous and anthracite Models are - made in hopper type and bin feed construc tion. All STOKOLS are "underfeed" type. ", SUPERIOR FEATURES Schwitzer-Cummins Company pioneered many basic improvements important to the success of small Stokers--the Hydraulic Trans Model mission, Automatic Air Control, and Universal Dome. stic Bin Feed are outstanding. Superior STOKOL features are STOKOSTAT, hydraulically operated "Holdfire" control-- STOKOL AUTOMATIC AIR CONTROL for metering air delivered by the blower--STOKOLARM, an automatic device for signaling notice of obstruction in feed screw--AIR-TIGHT HOPPER with low- door for convenient filling--HY-DUTY multi-blade blower fan--AUTOMATIC ASH REMOVER for anthracite models. An unusual engineering feature is the STOKOL Hydraulic Transmission--An oil pump located on the fan and drive pulley shaft, draws oil from the reservoir in the bottom of the case and forces it into the hy draulic cylinder. The pressure of oil moves -the piston forward and with it a lever which turns a ratchet wheel attached to a main shaft which drives the coal feed screw. Turning a simple valve varies the rate of oil flow from the cylinder, and gives an unlimited number of coal feeds. Oil used to operate the piston is diverted to flood every moving part, assuring perfect lubrication and long life. STOKOL-HEAT Stoker-fired Furnace or Winter Air Condi tioner, embodying a welded steel furnace-- automatic coal stoker, either hopper type or binfeed--Blower-filter--and Humidifier. Capacities from 75,000 Btu at bonnet to 300,000 Btu at bonnet. The new MOTORSTOKOR No. 10 marks its manu facturer's new low in the first cost of completely automatic anthracite equipment. MOTORSTOKOR SAP for heavy-duty service in apartments, office buildings, etc. Bin-feed pipe at. left. Ash removal system at right. 1110 (See also Page 894) 1111 Bituminous Binfeed .;r _______'_____________________________________ Temperature Control Barber-Colman Company Rockford, Illinois AUTOMATIC Fleetrie 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. i Thermostats. All types--room, duct, immersion and air-stream. For snap-action, floating and proportioning controls. Hygrostats. Room, and duct types. Motor-Operated Valves. Packless, packed, single seat, pilot piston, vee-ported, balanced, three-way, four-way, and butterfly. For shut-off, throttling and proportioning service. Solenoid Valves. For air, oil, water, gas, and refriger ants. Damper Control Motors. Unidirectional, or rever--' sible, fixed or adjustable speed. For positive and proportioning service. 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. Temperature Control Barber-Colman Company Rockford, Illinois GRILLES REGISTERS Uni-Flo grilles and registers are designed especially for air conditioning installations involving both heating and cooling. Dimensions and core arrangement may be selected to give desired directional' flow and throw without increasing the noise level or causing drafts. Various sizes and shapes are available including curved surfaces. Registers are same construction as grilles, with the addition of spring loaded, positive closing, chain or key-operated dampers. Finish: Plain metal, gray prime coat, clear lacquer, or any of the following electroplated finishes: Gunmetal, brushed bronze, plain zinc, buffed zinc, brushed zinc, and satin copper. UNI-FIN Uni-Fin grilles and registers are designed especially for residential warm air installations. Available in standard sizes and prime coat or electroplated finishes. VENTURI-FLO Venturi-Flo' is a ceiling outlet of modern design, attractive in appearance, available for a wide range of capacities. - Write for descriptive literature on all types of out lets and accessories. Uni-Flo Grille Uni-Flo Register Uni-Fin Register Ceiling Grille 1112 Venluri-Flo 1113 Uni-Flo-Lite Temperalure Control Detroit Lubricator Company Detroit, Michigan, U. S. A. New York, N- Y., 40 West 40th Street Chicago, III., S16 S. Michigan Avenue Los Angeles, Calif., 320 Crocker Street - Canadian Representative: Railway and Engineering Specialties Limited, Montreal. Toronto, Winnipeg Division of American Radiator Cf Standard Sanitary Corporation Detroit Thermostatic Expansion Valve No. 673 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. Detroit valves are scientifically designed to keep evaporators completely refriger ated under all conditions. Orifice sizes available from Vii in. to in. with capacities up to `ix/i tons on Dichloro- dinuoromethane or 6 tons on Methyl or Sulphur. Detroit Ther mostatic Ex pansion Valves Nos. 781-783 and 785 Differential Thermostat . No. 691 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 Duct Damper Motor No. 431 stallations. Capacities up to 20 tons on Dichlorodifluoromethane and 35 tons on Methyl. Line Strainer illustrated avail able for large valves. An inexpensive 'means of provid itnemg pienrdaitvurideucaonl trol for zones or groups of rooms. Is quiet and can be mounted Pressure Control directly on the duct. Furnished with auxiliary switch to control heating equip ment. Neat in appearance and easily Ii installed. rtthar Hnnfrolr (Model RB-3) Controls low side pressure. . Available with high pressure cut-out to protect against high head pressures. Also available to control temperatures; 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. , 1114 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 bred. 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 a few oz. pressure. Beyond that the AUTOMATIC MODULATOR reduces port area so as not to jeopardize subse quent 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 Y 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 adjustment. 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 half its arc increases or decreases port area just 50%--moving the lever through a quarter of the arc changes port area 25%. Two.straight shank valves designated as the 302 and 303 Multiports are .furnished for concealed or "convector" type radiators. They have the same construction as the No. 300, except for the shank'and all metal jacket. The No. 302 has a Y in. connection and the No. 303 a % in. connection. ' ` SOS Straight Shank Multiport Experience with one pipe steam jobs has shown that such troubles as uneven heating, hard-to-heat rooms, etc., are fundamentally due to inadequate venting. Putting the No. 300 Multiport on each radiator and one or more No. 861 Hurivents oh the main, eliminates all this and also improves fuel economy. Whenever a conversion burner or a new boiler is installed, all radiator and vent valves should be replaced to avoid complaints and dissatisfaction. ' 1115 Temperature Control [ Temperature Control The Fulton Sylphon Company The Fulton Sylphon Company Manufacturers of Sylphon Automatic Temperature Controlling Instruments and Packless Expansion Joints No. 889-E Unit Ventilator Control PRESSURE REGULATORS Knoxville, Tenn. An electrically and mechanically opera No. 955--Sylphon Inter Sales Representatives In Principal Cities ted dual valve devel locking Valve is a safety appli oped for use in unit ance protecting oil-fired fur ventilators. The elec naces by shutting off oil How 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 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 tric side of the valve utilizes the same "heat motor" as used i? Sy'phon Electric Radiator Valves and (Electrically 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 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 Volvo HOT WATER SUPPLY No. 923 Temperature Regulator Valves. ' energizes a low voltage desired temperature during period of "ther For controlling tempera GENERAL INFORMATION electric heater coil surround ing a bulb containing a mal balance." Mechanical side of valve is operated by a thermostat bulb placed in dis ture of water in heaters, open or closed tanks and 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 volatile liquid. This liquid expansion causes pressure on a bellows in the 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. 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 No.vts ftjjSSr various types of equipment. Operation is unaffected by temperature fluctuations at the valve, either above or below bulb temperature. Neat. Compact. All parts, except steel adjustment spring, made of non-ferrous metals. May be installed in any position. Ranges from 40 -- 80 F to 290 - 330 F. Bulletin HVG-20. temperature control and heating special ties known everywhere for outstanding service and quality. No. 7 Temperature Control A self-contained, self-powered regulator A positive type motor for on-and-off control of dampers. Operation Bdoxo No. 908 Sylphon Thermortatic Water Mixer--H to tSl SPACE HEATING AND AIR CONDITIONING CONTROL for controlling unit heaters, wall or ceiling type radiators, heating coils in duct-type heating systems, etc. Sylphon Damper Motore (Sey-operating and electric typer) may be controlled by thermostat, hand switch, motor starting 0pm depending on voter procure. No. 885 Automatic Radiator Valve A stu rdy con trol, quickly installed, holds switch, or other means. Motor, safety type, closes on current For exposed radiation. Small, neat, finely finished, adjustable to room tem temperatures within close limits. Valve is n failure. Write for literature. perature desired. Simply replace ordinary placed in steam line to ' radiator valves with these Sylphon Automatic Regu lators--no wiring, piping or auxiliary equipment are ,, . . ,, ,,,, required. These valves A^SL rJvL ?nswer the demand lor an Volte inexpensive means of pro viding accurate, depend able space temperature control in rooms, 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. . ~ * Refrigeration Controls No. 94S-Z iRegulator Showing detail of u,freezeproof' valve Adaptable wherever brine is used as the refrigerant. Latest development is a "freeze-proof" valve (illustrated at left on the popularSylphon No. 945-Z Reg ulator). Bulletin HVG-20. temperaturefrom cold to a tafe maximum temp erature of hot voter. sections or throughout large buildings, No. 928-C Temperature Regulator PACKLESS EXPANSION JOINTS 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. A compact regulator, especially suited to con trol of duct temperatures. Bulb is a series of copper coils, sensitive to slightest change in air temperature. Sylphon No. 988-C Dud Temperature Begufaior Convenient adjustment. Three types for 15, 50 and 75 lb steam pressures and temperatures not exceeding 170 F. 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. Ho. no Sylphon Ezpantiqn 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 1116 Joint 5 to 131 gpm. Bulletin HVG-40. 1 1117 Temperature Control Julien P. Friez & Sons (Division of 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 Psychrometer--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. ` NEW! Hydraulic Action Remote Reading Temperature and Humidity Recorder--Electrically opera ted; humidity uniquely recorded from distant location directly in percent rela tive. Exclusive. Bulletin R. ' Limit controls for fans, furnaces, hot water, ovens, refrigeration. A new line of controls for long reliable service. Bulletin LG and Data Sheet 225. Write for Bulletins MODERN ADVANCED CONTROLS FOR MODERN NEEDS 1118 . Temperature Control The Mercoid Corporation SOLE MANUFACTURERS OF THE MERCOID SWITCH Main Office.and Factory, 4201 Belmont Ave., Chicago, 111. Branch Offices: New York, N. Y. 330 W. 34th St. Philadelphia, Pa. 3137 N. Broad St. Distributors and Jobbers in all Principal Cities Boston, Mass. - 25 Ivy St. 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. 200AS. SENSATHERM Extremely sensitive ther mostat which requires no artificial stimulation to main tain an even room tempera ture. Operates on tempera ture variation of H deg above or below point set (total dif ferential I F). Small in size, neat in appearance and un failing in performance. TRANSFORMER-RELAY A reliable low voltage mer cury contact relay which also acts as a transformer inducing low voltage (24 volts) on the pilot circuit. Does away with all hum and chatter. Available-for 110 or 220 volts, 60, 50, or 25 cycle. PRESSURE AND TEMPERATURE LIMIT CONTROLS These instru ments have 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 n making the neces-. sary operating adjustments. Available for steam, hot water and warm air furnaces. These controls are also used for various industrial applications. , COMBINED PRESSURE AND LOW WATER CONTROL Type DA-121 low water and pressure controls have the new double adjustment feature which saves guess work and time in installation. Pre vents firing into dry boiler and building up excessive steam pressure. ... ranges available. Various 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. These controls offer positive protection against flame or ignition failure. STOKER CONTROLS A stoker fire-maintaining timer which ' eliminates over heating and waste of fuel. Has interlocking mechanism which prevents timer from operating, immediately after thermostat shuts off. AH adjustments are easily made without the use of tools. Write for bulletin No. 124 AS. Temperature Control Johnson Service Company AUTOMATIC TEMPERATURE AND AIR CONDITIONING CONTROL General Offices and Factory Milwaukee, Wis. Branch Offices In all Large Cities Johnson Temperature Regulating Co. op Canada. Ltd., 113 Simcoe St., Toronto, Ont. Montreal, Qub. 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 fornon-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. Pilot operated valves for "smooth" gradual control, independent of fluctuating pressure and friction. 1120 Room Humidostat- Johnson Service Company Temperature Control Humldostats 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 per 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 lor cooling and heating. Four-Point Insertion Insertion and immersion thermostats in one, two, three, and Thermostat four-point patterns for operating valves and dampers suc cessively at different temperatures. ' Remote readjustdble 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 temperature 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 apparatus. Zone Control Johnson "Duo-Stats" to regulate the flow of heat in a group of radiators constituting a "heating zone" by maintaining the proper relationship between outdoor and radiator temperatures. Summer- Winter Thermostat Process Control Remote Readjustablc Duct Thermostat 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 tempera tures. . Modulating Attach ment for Expansion Valves "Proportioning" Damper Motor Rubber 'Diaphragm ' Coil Valve 1121 Johnson "Duo-Stat" x 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 and Distributing Offices....... .............. ........*Stock carried Albany. N. Y. Allentown Atlanta* Baltimore Birmingham Boston* Bridgeport. Conn. Buffalo* Butte* Charlotte, N.C. Chicago* Cincinnati Cleveland* Columbus Dallas Dayton Denver* . Des Moines Detroit* East Orange Eau Claire. Wis. El Paso, Texas Fargo, N.D. Hartford* . Harrisburg, Pa. Haverhill, Mass. Houston Indianapolis* Jackson, Mich. . Kalamazoo Kansas City* Los Angeles* Louisville, Ky. Mason City, Iowa Milwaukee* Minneapolis-- St. Paul* . New Orleans New York* Oklahoma City Omaha* Peoria Philadelphia* Pittsburgh* Portland* Providence* St. Louis* Salt Lake City* San Antonio* San Francisco* Scranton Seattle Sioux Falls, S.D Springfield, Mass. Syracuse* Toledo Tulsa* Wabash, Ind. Washington,D.C.* Wichita* Worcester, Mass. Youngstown In Canada: Montreal, Toronto,* Calgary, Vancouver, London, Winnipeg In Europe: Amsterdam, Holland;* London, England * Stockholm, Sweden* Minneapolis-Honeywell is. ready to assume the complete responsibility for the supply and installation of automatic controls and instruments specified for any building that y6ii design. M-H serivce is complete. Through our nationwide organization, we are pre pared to make complete installation, supervise installation, provide periodic service or supply control equipment. Minneapolis-Honeywell can offer unbiased advice on your control requirements--manufacture and install complete electric control systems, complete pneumatic control systems, or a combination of the two. Each Minneapolis-Honeywell office maintains a factory trained engineering personnel. Your Minneapolis-Honeywell engineer will be glad to furnish you with recommended control layouts and cost estimates. He is trained to recommend control results before installation of equipment and to produce control results after the installation has been completed. THE MODUTROL SYSTEM OF ELECTRIC CONTROL Duct Type Tempera The Modutrol Systenk designation is applied to" any combination ture Controller of Minneapolis-Honeywell 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 Modu trol System extremely flexible as to the selection of control equipment to produce the desired results. Modulating Motorized Valve Complete electric control systems are available for those instal lations where precise, flexible and dependable results are required. Electric controls of the Modutrol System provide a dependable means of effecting modulation through the use of the "Series 90" control circuit. All electric motor power units used in this system are completely oil immersed in order to insure quiet operation and years of trouble-free service. 1122 Minneapolis-Honeywell Regulator Company Temperature Control THE GRADUTROL SYSTEM OF PNEUMATIC CONTROL Minneapolis-Honeywell offers a complete line of pneu matic controls. To such features as "Helmet Seal" Ther mostats and Metaphram construction of valve and damper motors has been added the accurate and infinite positioning of the Gradutrol Relay. For commercial air conditioning and space heating installations, the Gradutrol System offers a truly remarkable advance in pneumatic control. COMBINATION ELECTRIC AND PNEUMATIC SYSTEMS The outstanding advantages of both the electric Modu trol System and pneumatic Gradutrol System of control may be combined in a single installation. Thus maximum flexibility and low installation cost are obtained. Minne apolis-Honeywell can offer either an electric or pneumatic system, or a combination of the two. This is your guaran tee of an unprejudiced recommendation. Gradutrol Motor and Damper 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 modern 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. Brown Portable Recorder In addition to Resistance Thermometers, The M-H Brown Instrument Division manufactures: Thermometers Hygrometers Pressure Gauges . Vacuum Gauges Potentiometer Pyrometers Flow, Meters CO2 Meters Tachometers Liquid Level Gauges Protectoglo System RESPONSIBILITY FOR ENTIRE CONTROL SYSTEM Minneapolis-Honeywell Regulator Co. is equipped to assume the entire responsibility forany control installation, thereby eliminating the difficulties and misunderstandings which division of responsibility may create. Brown Recording Resistance Thermometer 1123 Temperature Control The Powers Regulator Co. 48 Years of Temperature and Humidity Control Offices in 47 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 ot 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. The Powers Regulator Co. Temperature Control Three of the Many Types of Powers Self-Operating Regulators 1124 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-eight years of experience in fur nishing and installing temperature and 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. . 1125 Temperature Control Penn Electric Switch Co. Goshen, Indiana Offices--New York, Boston, Philadelphia, Detroit, Dayton, Chicago, Moline, (III.), St. Lome Export--100 Varick St., New York City Representatives--Garland-Affolter Engrg. Corp., San Francisco, Los Angeles, Seattle, Portland* Monarch Sales, Denver; Forslund Pump and Machinery Co:, Kansas City; * Vincent Brass and Copper Co., Inc., Minneapolis. . In Canada--Powerlite Devices Ltd., Toronto, Ont. . Distributors and Jobbers in All Principal Cities' Automatic Controls for Heat ing, Air Conditioning, Refriger ation, Pumps, Air Compressors. 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. Temlrols 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. . Illustrated are only a few Penn units for oil, stoker and gas heating, industrial temperature regulation, refrigeration, air conditioning and pressure control. Where temperature, pressure, liquid level or hu midity control problems are to be solved, consult Penn engineers. Water Valves and Regulators Immersion Temperature Controls 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. Steam Pressure CoTitrols Refrigeration Controls .. Remote Immersion . Temperature Control Oil Burner Warm Air Fan Slack Switches . and Limit Controls Penn control engineers have simplified design and production problems for others! Let them assist you. -. 1126 Temperature Control Spence Engineering Company, Inc. 28 Grant Street, Walden, N. Y. sFeNGE METAL DIAPHRAGM "DEAD END" REGULATORS Advantages of Spence Regulators ' Dead-end Shutoff--Spence Regulators -4 are guaranteed to hold a dead-end. V./ Single Seat--Spence design makes .^"possible a balanced single seat even in Z -enlarge sizes. fv'W Metal Diaphragms--Under normal ~;f^~conditions never require replacement. Accurate Regulation--Regardless of '' fluctuations in either load or initial pressure. SECO Metal--Guaranteed to resist the wiredrawing action of steam. Interchangeable Pilots--Any type of pilot will fit any size main valve. Accessibility--Pilot is connected to main valve with unions. No Stuffing Boxes--AH main valves and most pilots are packless. 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. 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 operatiohs, 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. 1127 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. Temperature Control White-Rodgers Electric Company 1209 Cass Avenue, St. Louis, Mo. Chicaco 844 N. Rush St. Superior 1336 New York 245 W. 55th St. Circle-1235 Cleveland . 14104 Lakota Orchard 7542-W Distributors In Principal Cities Cincinnati 457 E. 6th Main 4175 120-240 v. A-C. The basis of all White-Rodgers line voltage controls is the stainless steel seam-welded diaphragm, and the "solid liquid charge" obtained through a new method of evacuating all traces of air and gas from the liquid. The greater pressure available through the expansion of the liquid charge permits the use of a snap-action switch of unusually sturdy construction. This has resulted in Underwriters' approved ratings of 25 amp 120 v. A-C, 15 amp 240 v. A-C, and 1J4 hp Send for latest condensed control catalog. LOW VOLTAGE THERMOSTAT available. The appearance of this extremely sensitive instru ment permits it to harmo nize with the modern American home. An accu rate thermometer and tem perature selector are con cealed behind a hinged cover. Anticipating and non-anticipating types are Ivory finish with chrome trim. LINE VOLTAGE THERMOSTAT This "Hydraulic Action" control is ideal for air-condi tioning and heating instal lations in schools, hospitals, stores, theatres, etc. and for use with unit heaters. Due to high rating shown above, several unit heaters may be handled by only one control. Two finishes available--ivory and chrome, and black and chrome. STOKER TIMER This modern de signed stoker control employs a warp switch relay, thereby assuring at'all times quiet oper ation and absence of annoyance due to ther mostat chatter and relay hum. Also avail able with fused line switch and for automatic night set-back. ELECTRIC GAS VALVE This quick opening diaphragm valve is actuated by a bi-metal pilot valve to give noise less operation at all times. Available in %, in., 1 in., in. and ll/i in. sizes. DUAL IMMERSION CONTROL It is possible to obtain many economical combina tions of two switches in a single housing, such as Com bination Blower and Limit Controls and Dual Immer sion Controls. The latter control (as illustrated) elimi nates the need for an extra boiler tapping. . \ PRESSURE CONTROL Pressure, warm air and hot water limit controls are all heavy-duty line or low voltage instruments offering positive safety service on steam boilers and warm air and hot water furnaces. The quick response of these con trols to rapid changes in temperature or pressure pre vents dangerous over-run. 1128 Voices 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 up-to 11/\ 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 )4in., n., 1 in., in., 1^6 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 1129 Valoes, Air Anderson Products, Incorporated Cambridge, Massachusetts Vent-Rite Radiator Air Valves. The Vent-Rite Balancer. Originators of "Balanced Radiation by Controlled Venting.** The complete Line of Vent-Rite Air Valves comprises nine valves of various types, sizes, outlets and venting capacities. All are noiseless in operation, positive in action, close thermo statically under temperature. Vent-Rite Vacuum Valves do not depend upon a ball or disc to maintain vacuum in a system. Vacuum is maintained by means of a sensitive and positive acting bellows. This bellows is internally subjected at all times to atmospheric pressure which elongates the bellows, and closes the vent when the internal pressure in the valve is less than the atmospheric pressure. Venting takes place through an adequate, straight line . venting orifice, which is accurately set by means of a modu lating adjustment of the valve pin, toward or away from the valve seat. The adjustment is underneath the valve--out of sight; cannot be disturbed by accident or meddlesome fingers. These Vent-Rite features insure Permanent, "Balanced . Radiation'* of any one-pipe steam system, which means--the , quick, uniform transfer of steam to all radiators regardless of their number, sizes or distances from the boiler. All Vent-Rites are made of the finest non-rusting--non corroding materials throughout to insure years of trouble-free service. Bases are Brass Forgings, Valve Pins are nickel silver. Valves are of attractive modern design, finished in chromium. Vent-Rites can be taken apart for examination or cleaning and can be tightly reassembled. Union couplings with special heavy copper-asbestos gaskets insure leak-proof joints. Only Vent-Rites can be taken apart for thorough cleaning THE VENT-VAC SYSTEM Increases the Performance of One-Pipe Steam Heating-- : . Automatically Fired--To Its Highest Efficiency The Vent-Vac System functions as an Open Atmospheric and Vacuum System combined, retaining only the Desirable, Practical Features of the two systems. It enlarges the scope of one-pipe steam heating and makes it practical for schools, hospitals, apartment houses, etc., as well as residences. The Vent-Vac System modernizes old, one-pipe jobs into new, highly efficient heating systems; eliminates lagging radiators and overheated spots/ : ^ Write for new, illustrated booklet which gives complete information on Vent-Rite Valves and the Vent-Rite Balancer which makes possible the Vent-Vac System. 1130 Valves FOSTER ENG l/tf^E RING 114 Monroe Street, Newark, New Jersey Agencies in All Principal Cities in the United States and Canada The Foster Engineering Company manufactures selected types of automatic valves and regulators for controlling high and low, saturated or superheated steam, liquid, or gas pressures for the widest range of services, and maintains a staff of thoroughly experienced engineers for the best solution of problems pertaining to automatic regulation or control. -- Type 38-U TP*r--e---s---s---u----r--e-* Reduc*ing -Regulators flow . . . internally balanced; un Type 38-U. For intermittent and dead-end service on water or air; for initial pressures up to 300 lb with special constructions for affected by variations in pres sure. Sizes Y to 12 in. Temperature Regulators higher pressures. Pilot or direct- Types 34-T and 34-T2. Type acting diaphragm-actuated 34-T is a pilot-operated self- valves manufactured for low de contained, single-seated regula livery pressures. Built in bronze tor for dead-end service. Built and semi-steel; sizes Y to 20 in. in sizes of Y through 3 in. for Types 37-AI and A2. These pressures of 10 to 200 lb, this regulators offer every advantage regulator maintains temperatures of double spring loading. The of gases or liquids within plus or Type. 37-A1 is single seated for minus one degree Fahrenheit. dead-end service where initial Double-seated in sizes of 3Y pressure is constant and is built to 8 in. The Type 34-T2 is a in sizes of Y through 12 in. The direct-acting double-seated regu Type 37-A2 is double seated for lator built in sizes of Y to b in." continuous flow ... an internally for pressures 0 to 125 lb. balanced regulator unaffected by Float Valves variations in line pressure! Built in sizes of Y to 12 in. Types 37-B1 and B2. Sensi tivity at low reduced pressures is assured by these weight-loaded regulators. The Type 37-B1 is single-seated for dead-end service where the initial pressure is con stant and is built in sizes of Y through 12 in. The Type 37-B2 is double-seated for continuous Auxiliary Operated Float Valves. Extremely sensitive valves for hot or cold water ser vice, actuated by the pressure in the supply line. A tied-in aux iliary operated type has the pis ton loosely connected to the stem, combining the auxiliary and direct action. Both auxiliary and direct acting types made in sizes % to 12 in., angle and globe. Type 37-At Type 37-Bg Type 34-T 1131 A. 0. Float Valves Henry Valve Company 1001-19 North Spaulding Ave., Chicago, 111. Manufacturers of complete line of Dryers, Strainers and Large Line Valves for Freon and Methyl Chloride. Also Ammonia Valves and Forged Steel Fittings. ABSO-DRY PRESSURE SEALED DRYERS For Refrigeration and Air Conditioning HENRY STRAINERS There is a size and type of Henry Strainer for every installation requirement. Exclusive Henry vacuum process first re moves every trace of moisture,then thedryer is charged with dehy drated air. Loosening seal cap produces hiss ing sound, a guarantee of original factory dryness. Type 895 Strainer With sold er fittings for use with cop per pipe. Exceptional design. Welded steel construc tion. Negligible pressure OTHER FEATURES OF HENRY drop. Screen can be taken DRYERS--Perforated Dispension tube is out for cleaning without connected to inlet port and exposes entire removing strainer from line. Very large volume of dehydrant to penetration by screen area. Light weight. Baffle prevents refrigerant. Minimum pressure drop. No heavy particles injuring screen. channelling. Compression Spring, main tains uniform tension on dehydrant at all times and compensates for changes in volume. Soldered or Flanged Snells-- models are available with either soldered cap or flanged end shells. Flange is dis tortion-proof. Shells not exceeding 5H in. in length are drawn in dies, so that they have only one joint. ' Strainer and Liquid Indicator Has sight port for determining suffi ciency of refrigerant in system. Gas bubbles, passing Types 8 f* *iJt ug?ldaesrs,siSinhdt icPaotret shortage. Sight port is capped. FIVE DEHYDRANTS--Choice of follow ing dehydrants at same price: Activated Alumina, Calcium Chloride, Calcium Oxide, Drierite and Barium Oxide. WING CAP VALVES Designed especially for Freon and Methyl Chloride. Have patented rotating self aligning stem disc. Special resilient packing. . Type 774 May be re Cartridge packed under Dehydrator pressure. Wing cap can -- A flanged shell be inverted dehydrator with replaceable cartridge. and socket used for oper Type 721 Dehydra- Tector ating valve. Screw end, soldered and flanged con Combination dryer with capped liquid nections. sight port for determining sufficiency of refrigerant in system. Three sizes avail able with dehydrant capacity of 13.5, 31.5 FREE CATALOG and 47.2 cu in. It describes the AUTOMATIC RELIEF VALVE Angle type with push rod for emergency reseating. Available pressure settings: 90 to 250 lb. Approved for use under many refriger ating and air conditioning safety codes. complete line of Henry Dryers, Strainers and large line valves used in refriger ation and air con ditioning. ASK FOR IT. 1132 Valves Jenkins Bros. BRONZE - IRON - STEEL VALVES Mechanical Rubber Goods \ White St., New York. N. Y.; 524 Atlantic St., Boston, Mass.; 376 Spring St., Atlanta, Ga.; 133 N. Seventh St., Philadelphia, Pa.; 1514 Fulton St., Chicago, III.; ' 1112 Walnut St., Houston, Tex. Bridgeport, Conn. (Office and Factory) Jenkins Bros., Ltd.: London, W.C. 2; Montreal, Que.. (Works and Main Office). fig. 106A ' Brents Globs, Bsasoabls Comp. Disc Fig. 960 Bronzs Globs, Regrind-Renew Fig. 148 Iron Body Globs Fig.m Fig. StS . Bronts Gets Iron Body Gals Fig. 869 Radiator Offset Globs 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, Stainless Steel 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 GOOD SUPPLY HOUSES EVERYWHERE Valves New York Air Valve Corporation Since 1898 Chicago Boston 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 of 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. - lontion 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 ft in., ft in.. ft in.. Straight and ft in. Quick Vent. cowtrolI 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 where price Valve, will maintain is a consider vacuum on ation. one pipe Made also in ft in.,' ft in.. ft in.. Straight Shank and ft in. Quick Vent. gravity steam jobs over very long, periods. Made in angle and quick vent types only. Fig. 'No. 1 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. Fig. No. 8 GIANT n Three Speed Air ELIMINATOR For Rapid Air Elimi nation from Large Mains -- Coils-- Air Conditioning Units --Unit Heaters, etc. 3 Speed control--H in-. ft in.. ft in.--Secured by removing screw from speed size desired. ft in. Size for load up to 1500 ft. ft in. Size for load of 1500 ft to 3000 ft. ft in. Size for load of 3000 ft up. Mode in regular Venting and Vacuum Valve 6ft Actual Height. 1134 Fig. No. 80 INDEX TO MODERN EQUIPMENT In the Index to Modern Equipment are com plete detailed listings o 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 1137-1160, 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 859-864 will be found an alphabetical list of manufacturers whose products are shown in the Catalog Data Section of The Guide. INDEX TO MODERN EQUIPMENT Heating, Ventilating, Air Conditioning Guide, 1939 AIK CLEANING EQUIPMENT Carrier Corporation. 870 Delco - Frigidaire Conditioning (See also Filters, Air) Clarage Fan Company, 871 Div.. General Motors Sales Air-Maze Corporation, 922-923 Curtis Refrigerating Machine Corp., 902-904 Airtemp Div. 896-897 ' American Air 924-926 Chrysler Corp., Filter Co., Inc., - Curtis Manufacturing C. A. Dunham Co., 1000-1001 Co., 872 . Fedders Manufacturing Co., 982 Davies Air Filter Corp., 927 Fitzgibbons Boiler Co.. 954-955 Delco-Frigidaire Conditioning Frick Company 873 American Blower Corp., 866-867 .American Radiator Company. 898-899, 940-941' ; Autovent Fan & Blower Co.. 970 -r Buffalo Forge Company, 972 Burnham Boiler Corp., 942-943 Carrier Corporation, 870 Clarage Fan Company, 871 Coppus Engineering Corp., 926 . Davies Air Filter Corp., 927 Div., General Motors Sales Corp., 902-904 C. A. Dunham Co., 1000-1001 Excelsior Steel Furnace Co., 905 Fedders Manufacturing Co., 982 Fitzgibbons Boiler Co., 954-955 Frick Co., (Inc.), 873 General Electric Co., 908-909. 1044-1045 Grinnell Co.. Inc., 993-995. 1087 General Electric C- o . 908-909. 1044-1045 Grinnell Co., Inc., 993-995. 1087 Henry Furnace & Foundry Co 910-911 Ilg Electric Ventilating Co.. 975 Ingersoll-Rand Co., 874-875 Kelvinator Division of Nash- Kelvinator Corp., 912-916 McCord Radiator & Mfg'co 983 Delco - Frigidaire Conditioning Henry Furnace & Foundry Co., McQuay, Incorporated. 876 * Div., General Motors Sales t. Si91} . x. ... ,, Modine Mfg. Co., 984-985 Corp.. 902-904 ' IcJ8mleTtllc vnW*ting Co.. 975 Herman Nelson Corp., 996 * C. A. Dunham Co., 1000-1001 S. T. Johnson Co., 962-963 Niagara Blower Company, 878 . Fitzgibbons Boiler Co., 954-955 Kelvinator Division of Nash- Parks-Cramer Company, 879 'Gar Wood Industries, Inc., 906 Kelvinator Corp., 912-916 - 907 . Kewanee Boiler Corp., 958-959 Research Corporation, 880 Servel. Inc.. 881 . ''General Electric Co., 908-909, Lau Blower Co., 893 H. J. Somers, Inc., 931 1044-1045 McCord Radiator & Mfg. Co., 983 . Independent Air Filter Co.. 928 McQuay, Incorporated, 876 . Kelvinator Division of -Nash?,. Meyer Furnace Company, 917 Kelvinator Corp.,. 912-916 " Modine Mfg. Co., 984-985 Hartocello, Jos. A. & Co., 877 L. J. Muller Furnace Co., 918-919 ` L. J.\Mueller. Furnace Co., 918 Herman Nelson Corp., 996 ' . 919 \ - Niagara Blower Company. 878 Owens-Corning Fiberglas Corp., Parks-Cramer Co., 879 929 . . Servel, Inc., 881 Parks-Cramer Company, 879 H. J. Somers, Inc., 931 ... Research Corporation, 880 Spencer Heater Division, 946-947 . Research Products Corp., 930 . H. J. Somers, Inc., 931 . Schwitzer-Cummins Co.. 894, 1111 ` Staynew Filter Corp., 932-933 T4 rlaunuec Cvvoimnppaaniqy,, Tmhee,, 808024--808030 B. F. Sturtevant Co., 980 Trane Company, The, 882-883 United States Air Conditioning Corp., 884 . Unit Heater & Cooler Co., 986 Universal Cooler Corp.. 885 Vilter Manufacturing Co., 886 Westinghouse Electric & Manu facturing Co., 888-889 L. J. Wing Mfg. Co., 978-979 York Ice Machinery Corp., 887 Young Radiator Company, 987 AA _I_R DIFFmUSERS - / B. F. Sturtevant Co., 980 United States Air Conditioning American Blower Corp., 866-867 . Unit Heater and Cooler Co., 986 Corp., 884 Anemostat Corp. of America, United States Air Conditioning Unit Heater and Cooler Co.. 986 . Corp., 884 Universal Cooler Corp., 885 Uer Register Co., The, 1068 Westinghouse Elec. & Mfg. Co.. Weil-McLain Company, 950 Barber-Colman Co., 1112-1113 888-889 Westinghouse Electric & Manu- Hart & Cooley Mfg. Co., 1070- - AIR COMPRESSORS (See Com pressors, Air) . facturing Co.. 888-889 _ l071 Williams Oil-O-Matic Heating Independent Register Co.. 1074 Corporation. 920 Tuttle & Bailey, 'Inc.. .1..0..7..2..-.1..0..73 AIR CONDITIONING CON York Ice Machinery Corp., 887 United States Register Co., 1075 ' TROLS, (See ..Controllers and .- ` Control Equipment, Humidity Controls) ^ AIR CONDITIONING GRILLES (See Grilles, Registers) Young Radiator Company, 987 AIR COOLING AND DEHUMIDIFYING APPARATUS Aerofin Corporation, 989-991 Airtemp Div. Chrysler Corp., Waterloo Register Co., 1076 AIR DUCTS (See Ducts) AlR ELIMINATORS American Radiator Co., 898-899 940-941 . AIR CONDITIONING REG- 896-897 Armstrong Machine Works. 1082 'ISTERS (See Grilles, Registers) American Blower Corp., 850-851 1083 t AIR CONDITIONING UNITS 'Airtemp Div. Chrysler Corp., 896-897 American Blower Corp., 866-867 'American Gas Products Div., American Radiator Co., 900, * 951 . , rAmerican Radiator Company, 898-899, 940-941 . **' 'Autovent Fan & Blower Co.. 970 ; Baker Ice Machine Co., .868-869 ^Buffalo Forge Company, 972 Burnham Boiler Corp.,<J942-943 -j-Capjb,,ondaley',,D--iv-.", W .o..r..t.h...i.n. g. ton American Gas Products, Div., American Rad:ator Co., 900, 951 American Moistening Co., 865 Autovent Fan & Blower Co., 970 Baker Ice Machine Co., 868-869 Bayley Blower Company, 971 Buffalo Forge Company, 972 Carbondale Div., Worthington Pump & Machinery Corp., 890 891 Carrier Corporation, 870 Chicago Pump Co., 1062 Clarage Fan Company, 871 Crane >C>ov., 944-945 Beaton & Cadwell Mfg. Co., The 1084-1085 Burnham Boiler Corp., 942-943 Hoffman Specialty Co.. Inc, 1088-1089 Illinois Engineering Co.. 1090 1091 Maid-O-Mist, Inc., 998 Milwaukee Valve Co., 1094 \ Mueller Steam Specialty Co., Inc., 1095 New York Air Valve Corp., 997 Sarco Company, Inc., 1096-1097 Trane Company, The, 882-883 Wtuarren W'e'bst' er &` C` o., 1098- TV Lji.,np " Machinery Corp., 890- Curtis Refrigerating Machine Co., 1101 . ` 891 . Div. of Curtis Mfg. Co., 872 Wright-Austin Co., 1102 Numerals following Manufacturers' Names refer to pages in the Catalog Data Section 1137 1939Heating Ventilating Air Conditioning Guide Index to Modern Equipment AIR FILTERS (See Filters, Air, Niagara Blower Company, 878 BLOCKS, Asbestos also Air Cleaning Equipment) Parks-Cramer Company, 879 Carey, Philip, Co., 1020 . H. J. Somers, Inc., 931 AIR MEASURING AND RE B. F. Sturtevant Co., 980 CORDING INSTRUMENTS Trane Company, The, 882-883 Ehret Magnesia Manufacturing Co., 1022-1023 e Johns-Manville, 1030-1031 American Moistening Co., 865 United States Air Conditioning Ruberoid Co., The, 1032-1033 Babcock & Wilcox Co., 952 Bristol Company, The. 1002 Julien P. Friez & Sons, Div. of Bendix Aviation Corp., 1118 Corp., 884 Unit Heater and Cooler Co., 986 Vilter Manufacturing Co., 886 York Ice Machinery Corp., 887 BLOWERS, Fan (See Fans, Suppi# and Exhaust) BLOWERS, Forced Draft Grinnell Co., Inc., 993-995, 1087 Illinois Testing Laboratories, Inc., 1003 Johnson Service Co., 1120-1121 Minneapolis-Honeywell Regulator Company, 1122-1123 Palmer Co., 1007 Parks-Cramer Company, 879 Powers Regulator Co., 1124-1125 Taylor Instrument Companies, ' 1008-1009 ALARMS, Water Level Illinois Engineering Co., 1090 1091 McDonnell & Miller, 938-939 Mercoid Corporation, 1119 Minneapolis-Honeywell Regulator Co., 1122-1123 Mueller Steam Specialty Co., 1095 Warren Webster & Co., 1098 American Blower Corp., 866-867 American Coolair Corp., 968-969 Autovent Fan & Blower Co., 970 Bayley Blower Company, 971 Buffalo Forge Company, 972 Champion Blower & Forge Co 973 " Clarage Fan Company, 871 Coppus Engineering Corp., 926 Curtis Refrigerating Machine Co., Div. of Curtis Manu AIR MOISTENING APPARA TUS (See Humidifiers) AIR PURIFYING APPARATUS Air-Maze Corp., 922-923 American Air Filter Company, Inc-, 924-925 Buffalo Forge Co., 972 Burnham Boiler Corp., 942-943 Carrier Corporation, 870 Coppus Engineering Corp., 926 Davies Air Filter Corp., 927 Delco - Frigidaire Conditioning Div., General Motors Sales 1101 Wright-Austin Company, 1102 Yarnall-Waring Company, 1103 ALGAE PREVENTION (See also Slime Prevention) Oakite Products, Inc., 921 AMMONIA COILS (Sec Coils, Ammonia) . ANEMOMETERS Julien P. Friez & Sons, Div. of Bendix Av*ation Corp., 1118 Illinois Testing Laboratories, facturing Co., 872 DeBothezat Division American Machine & Metals, Inc., 974 , Henry Furnace & Foundry Co 910-911 Lau Blower Co., 893 Schwitzer-Cummins Co., 894 1111 Servcl, Inc., 881 B. F. Sturtevant Co., 980 L. 3. Wing Mfg. Co., 978-979 BLOWERS, Heating and Venti lating Corp., 902-904 Ilg Electric Ventilating Co., 975 Independent Air Filter Co., 928 Niagara Blower Company, 878 Inc., 1003 Taylor Instrument 1008-1009 . Companies. . Air Controls, Inc., 892 American Blower Corp., 866-867 American Coolair Corp., 968-969 Autovent Fan & Blower Co., 970 Owens-Corning Fiberglas Corp., ASBESTOS PRODUCTS (See Bayley Blower Company, 971 929 also Insulation) Buffalo Forge Co.,. 972 - . Research Products Corp., 930 Carey, Philip, Co., 1020 _ - Champion Blower & Forge Co.. H. J. Somers, Inc., 931 Ehret Magnesia Manufacturing 973 . Staynew Filter Corp., 932-933 Co., 1022-1023 Clarage Fan Company, 871 Westinghouse Elec. & Mfg. Co., Johns-Manville, 1030-1031 DeBothezat Division American 888-889 H. W. Porter & Co., 1040 Machine & Metals, Inc., 974 L. J. Wing Mfg. Co., 978-979 Ric-wiL Company, The, 1041 C. A. Dunham Co., 1000-1001 AIR RECEIVERS (See Receivers, Air) AIR TUBING, Flexible Metal (See Tubing, Flexible Metallic) AIR VELOCITY METERS (See Meters, Atr Velocity) AIR VELOCITY REGULATORS Johnson Service Co., 1120-1121 Powers Regulator Co.,- 1124-1125 ' Young Regulator Company, 934 Ruberoid Co., The, 1032-1033 Fedders Manufacturing Co., 982 ATTIC FAN COOLERS Ventilators, Attic) . Henry Furnace & Foundry Co., (See 910-911 Ilg Electric Ventilating Co., 975 AUTOMATIC FUEL BURNING Lau Blower Co., 893 EQUIPMENT (See Burners, McCord Radiator & Mfg. Co., 983 Automatic; Coal Burners, Auto McQuay, Incorporated, 876 matic; Furnace Burners; Gis Meyer Furnace Co., The, 917 Burners; Oil Burners; * L. J. Mueller Furnace Co., 918 Stokers) 919 Herman Nelson Corp., 996 AUTOMATIC SHUTTERS (See Schwitzer-Cummins Co., 894, Shutters, Automatic) 1111 AIR WASHERS AUTOMOBILE HEATER FANS Air-Maze Corp., 922-923 1 American Blower Corp., 866-867 American Coolair Corp., 968-969 Torrington 977 Mfg. Co., The, 976 American Radiator Company, BACTERIA CONTROL 898-899, 940-941 Oakite Products, Inc., 921 Autovent Fan & Blower Baker Ice Machine Co., Co., 970 868-869 . BEARING, Bronze' Bayley Blower Company, 971 Arthur Harris Co., 1048 B. F. Sturtevant Co., 980 Trane Company, The, 882-883 United States Air Conditioning Corp., 884 Westinghouse Elcc. & Mfg. Co., 888-889 . Williams Oil-O-Matic Heating Corp., 920 L. J. Wing Mfg. Co., 978-979 Buffalo Forge Company, 972 Clarage Fan Company, 871 Cooling Tower Co., Div. of Fluor Corp., Ltd., 964 " Delco - Frigidaire Conditioning Div., General Motors Sales Corp., 902-904 Henry Furnace & Foundry Co., 910-911 Meyer Furnace Company, 917 L. J. Mueller Furnace Co., 918 919 . ' BENDS, Pipe Baker Ice Machine Co., 868-869 Crane Co., 944-945 Frick Company, 873 Grinnell Co., Inc., 993-995, 1087 Arthur Harris & Co., 1048 -National Pipe Bending Co., 988 Vilter Manufacturing Co., 886 York Ice Machinery Corp., -887 BENDS, Return (See Pipe, Return Bends) BLOWER HOUSINGS Lau Blower Co., 893 , BLOWER MOTORS (See Motors, Electric) BLOWERS, Pressure American Blower Corp., 866-867 American Coolair Corp., Autovent Fan & Blower Co., 970 .Bayley Blower Company. 971 Buffalo Forge Company, 972 Please mention THE GUIDE 1939 when writing to Advertisers gfS-Champion Blower & Forge Co., 973 Clarage Fan Company, 871 ;PeBothezat Division American ; Machine & Metals, Inc., 974 Henry Furnace & Foundry Co., 910-911 Ilg Electric Ventilating Co.. 975 BOILER TUBES (See Tubes, Boiler) BOILER WATER TREATMENT Cochrane Corp., 1086 Research Products Corp., 930 Vinco Company. Inc., 936-937 BOILERS, Cast-Iron Burnham. Boiler Corp., 942-943 Crane Co., 944-945 Delco - Frigidaire Conditioning Div., General Motors Sales Corp., 902-904 Farrar & Trefts, Inc., 953 . Fitzgibbons Boiler Co., 954-955 Gar Wood Industries, 906-907 TI1ueIBlower "co 893 " "rtX j"A A Co.. 877 American Gas Products Div., General Electric Company, 908 ***" 9' 909, 1044-1045 Henry Furnace & Foundry Co., McCord Radiator &'Mfg. Co.. 983 American Radiator Company. 910-911 i Schwitzer-Cummins Go., 894, 1111 - B F. Sturtevant Co., 980 j'L. J. Wing Mfg. Co., 978-979 4. BLOWERS, Turbine uf&Coppus Engineering Corp., 926 %'General Electric Co., 908-909. 1044-1045 vb. F. Sturtevant Co., 980 Sr'L. J. Wing Mfg. Co., 978-979 898-899, 940-941 . Burnham Boiler Corp., 942-943 Crane Co., 944-945 Delco - Frigidaire Conditioning Div., General Motors Sales Corp., 902-904 .. L. J. Mueller Furnace Co., 918 919 Spencer Heater Division. 946-947 E. Keeler Company, 956-957 Kewanee Boiler Corp., 958-959 L. J. Mueller Furnace Co., 918 919 Pacific Steel Boiler Div., U. S. Radiator Corp., 960 Smith Twin Tubular Boiler Co., 961 Spencer Heater Division, 946-947- ti ^BLOWERS, Warm Air Furnace y.Air Controls, Inc., 892 / American Blower Corp., 866-867 American Coolair Corp., 968-969 ? Autovent Fan & Blower Co., 970 United States Radiator Corp., 948-949 Weil-McLain Company, 950 Westinghouse Elec. & Mfg. Co., 888-889 United States Radiator Corp., 948-949 Weil-McLain Company, 950 Westinghouse Elec. & Mfg. Co., 888-889 "Buffalo Forge Company, 972 BOILERS, Down Draft . BOILERS, Magazine Feed ` /Champion Blower & Forge Co., 973 ^.Clarage Fan Company, 871 ^DeBothezat Division American Machine & Metals, Inc., 974 ^General Electric Co., 908-909, " 1044-1045 WHenry Furnace & Foundry Com- f pany, 910-911 . a Lau Blower Co., 893 j^Meyer Furnace Company, 917 *L. J. Mueller Furnace'Company, 918-919 Brownell Company, 1104 Crane Co., 944-945 Farrar & Trefts, Inc., 958 Fitzgibbons Boiler Co., 954-955 Henry Furnace & Foundry Co., 910-911 E. Keeler Company, 956-967 Kewanee Boiler Corp., 958-959 Pacific Steel Boiler Div. U. S. Radiator Corp., 960 'United States Radiator- Corp.. 948-949 Burnham Boiler Corp., 942-943 Spencer Heater Divsion, 946-947 Weil-McLain Company, 950 BOILERS, Oil Burning Airtemp Div., Chrysler Corp., 896-897 American Radiator Company, 898-899. 940-941 . Babcock & Wilcox Co., 952 Brownell Company, The, 1104 Burnham Boiler Corp., 942-943 1 Herman Nelson Corp., 996 BOILERS, Gas Burning Crane Co., 944-945 Schwitzer-Cummins Co., 894. 1111 Trane Company. The, 882-883 Airtemp Div. 896-897 . Chrysler . Corp., Delco - Frigidaire . Div., General Conditioning Motors Sales ggj Westinghouse Elec. & Mfg Co., mr- 888-889 jpV.-L, J. Wing Mfg. Co., 978-979 American Gas Products Div., American Radiator Co., 900, 951 Corporation. 902-904 . Farrar & Trefts, Inc., 953 Fitzgibbons Boiler Co., 954-955 || BOILER-BURNER VAirtemp Div., Chrysler Corp., -: 896-897 ^/Burnham Boiler Corp., 942-943 J^'Carrier Corporation, 870 g~^Crane Co., 944-945 `X Delco - Frigidaire Conditioning 3. Div., General Motors Sales r,* Corp., 902-904 .... rGar Wood Industries, Inc., 906J 907 -[General Electric Co., 908-909, , 1044-1046 . EHenry Furnace & Foundry Co.. g&- 910-911 ^.S. T. Johnson Co., 962-963 >Kelvinator Division of Nash- Kelvinator Corp., 912-916 I Herman Nelson Corp., 996 `^Westinghouse Elec. & Mfg. Co., t-. 888-889 Bjs. Williams Oil-O-Matic Heating ** Corp., 920 American Radiator - Company, 898-899, 940-941 Brownell Company, 1104 Burnham Boiler Corp., 942-943 Crane Co., 944-945 Delco - Frigidaire Conditioning Div., General Motors Sales Corp., 902-904 C. A. Dunham Co., 1000-1001 Farrar & Trefts, Inc., 953 Fitzgibbons Boiler Co., 954-955 Genera! Electric Company, 908 909. 1044-1045 E. Keeler Company, 956-957 Kelvinator Division of Nash- Kelvinator Corp., 912-916 Kewanee Boiler Corp., 958-959 L. J. Mueller 'Furnace Co., 918 919 Pacific Steel Boiler Div., U, S. Radiator Corp., 960 Spencer Heater Division, 946-947 United States Radiator Corp., 948-949 Gar Wood Industries, Inc., 906 907 General Electric Company, 908 909, 1044-1045 S. T. Johnson Co., 962-963 E. Keeler Company, 956-957 Kelvinator Division of Nash- Kelvinator Corp., 912-916 Kewanee Boiler Corp., 958-959 L. J. Mueller Furnace Co., 918 919 Herman Nelson Corp., 996 ' Pacific Steel Boiler Div., U. S. Radiator Corp., 960 Smith Twin Tubular Boiler Co.. 961 . Spencer Heater Division, 946-947 United States Radiator Corp., 948-949 Weil-McLain Company, 950 BOILERS, Steel Babcock & Wilcox Co., 952 Brownell Company, The, 1104 [^BOILER COMPOUNDS (See Westinghouse Elec. & Mfg. Co., Burnham Boiler Corp., 942-943 Compounds, Boiler) S 888-889 Combustion Engineering Co.; .^BOILER COVERING (See Cov BOILERS, Heating ering. Pipes and Surfaces.! American Gas Products 1105 - Farrar & Trefts, Inc., 953 Div., Fitzgibbons Boiler Co., 954-955 BOILER FEED PUMPS (See American Radiator Co., 900, Frick Company, 873 ' . Pumps, Boiler Feed) . ' 951 ' . Gar Wood Industries, 906-907 HbOILER FEEDERS (See Feed American Radiator Company. S. T. Johnson Co., 962-963 ers. Boiler) 898-899, 940-941 Brownell Company, 1104 E. Keeler Company, 956-967 Kewanee Boiler Corp., 958-959 . Numerals following Manufacturers' Names refer.to pages in.the Catalog Data Section 1139 1 Mi Heating Ventilating Air Conditioning Guide 1939 Pacific Steel Boiler DivI, U. S. General Insulating & Mfg. Co., McQuay, Incorporated, 876 Radiator Corp., 960 1024 National Pipe Bending.Co. gc* Smith Twin Tubular Boiler Co.. Johns-Manville, 1030-1031 Trane Company, The, 882-883 961 Ruberoid Co.. The, 1032-1033 Unit Heater and Cooler Co gse Spencer Heater Division, 946-94? Standard Lime & Stone Co., 1035 Vilter Manufacturing Co., 87g United States Radiator Corp., 948-949 BOILERS. Water Tube Babcock & Wilcox Co., 952 Burnham Boiler Corp., 942-943 Combustion Engineering Co., 1105 Fitzgibbons Boiler Co., 954-955 Frick Company, 873 E. Keeler Company, 956-957 Smith Twin Tubular Boiler Co.. 961 Spencer Heater Division, 946-947 CHAIN PULLEYS (See Pulleys. Chain) CIRCULATORS. Hot Water Heating . Bell and Gossett Co., 999 General Electric Company, 908 909, 1044-1045 Minneapolis-Honeywell Regulator Co.. 1122-1123 Westinghouse Elec. & Mfg. Co.. 888-889 CLEANERS, Air (See Air Clean Worthington Pump & Machin^ Corp., 890-891 17 Yarnall-Waring Co., 1108 York Ice Machinery Corp., 337 Young Radiator Company,'987 COILS, Brass ' Aerofin Corporation, 989-981 E. B. Badger & Sons Co.. 967 Carrier Corporation, 870 ' Crane Co., 944-945 Grinnell Co., Inc., 993-995, 1087 Arthur Harris & Co., 1048 National Pipe Bending Co.. 988 BREECHINGS AND ing Equipment) B. F. Sturtevant Co., 980 CHIMNEYS COAL BURNERS, Automatic. COILS, Pipe, Copper Farrar & Trefts, Inc., 953 E. Keeler Company, 956-957 Young Regulator Company, 934 BURNERS, Automatic (See also Coal Burners, Stokers) Airtemp Div., Chrysler Corp., 896-897 ., Crane Co., 944-945 Delco - Frigidaire Conditioning Div., .General Motors Sales Corp., 902-904 Detroit Stoker Company, 1106 Econ-O-Col Stoker Div. of Cotta Transmission Corp., 1107 General Electric Company, 908 909, 1044-1045 Iron Fireman Mfg. Co., 1108 1109 S. T. Johnson Co., 962-963 Kelvinator Division of Nash- Kelvinator Corp., 912-916 MotorStokor Div., Hershey Ma chine & Fdy. Co., 1110 Herman Nelson Corp., 996 Schwitzer-Cummins Co., 894, 1111 Westinghouse Elec. & Mfg. Co.. 888-889 Williams Oil-O-Matic Heating Corp., 920 ' Anthracite Buffalo Forge Company, 972 Crane Company, 944-945 Combustion Engineering Co., 1105 Henry Furnace & Foundry Co., 910-911 Iron Fireman Mfg. Co., 1108-1109 Meyer Furnace Company, 917 MotorStokor Div., Hershey Ma chine & Fdy. Co., 1110 Scbwitzer-Cummins Co., 894, 1111 Spencer Heater Division, 946-947 COAL BURNERS, Automatic, Bituminous Brownell Company, 1104 Crane Company, 944-945 Combustion Engineering Co.. 1105 Delco - Frigidaire Conditioning Div., General Motors Sales Corp., 902-904 Detroit Stoker Company, 1106 Econ-O-Col Stoker Div. of Cotta Transmission Corp., 1107 Henry Furnace & Foundry Co., 910-911 Iron Fireman Mfg. Co., 1108-1109 Kelvinator Division of Nash- Aerofin Corporation, 989-991 American Brass Co.. 1046-1047 American Radiator Company .898-899, 940-941 E. B. Badger & Son Co.. 967 Baker Ice Machine Co., Inc 868 869 Bell and Gossett Co., 999 Carrier Corporation, 870 Crane Co., 944-945 Curtis Refrigerating Machine Co., Division of Curtis Manu facturing Co., 872 Fedders Manufacturing Co.. 982 Frick Company, 873 ` Grinnell Co., Inc., 993-995, 1087 Arthur Harris & Co., 1048. Kelvinator Division of Nash- Kelvinator Corp., 912-916 Kewanee Boiler Corp., 958-959 McQuay, Incorporated, 876 Niagara Blower Compapy. 878- Serve!, Inc., 881 .; York Ice Machinery Corp., 887 Young Radiator Company. 987 1 COILS, Pipe, Iron E. B. Badger & Sons Co., 967 Bayley Blower Company, 971 Clarage Fan Company, 8?1 Crane Co., 944-945 ' BURNERS, Coal (See Coal Kelvinator Corp., 912-916 Frick Company, 873 Burners) Meyer .Furnace Company. 917 ' Grinnell Co., Inc., 993-995. 1087 BURNERS, Burners) Gas (See Gas Herman Nelson Corp., 996 Schwitzer-Cummins Co., 894, Arthur Harris & Co., 1048 National Pipe Bending Co., 988 1111 * Vilter Manufacturing Co., 886 BURNERS, Oif (See Oil Burners) COILS, Aluminum York Ice Machinery Corp., 887 CALKING, Building Aerofin Corporation, 989-991 COILS, Tank Chamberlin Metal Weather Strip Baker Ice Machine Co., Inc.. 868 American District Steam Co.. Co.. 1032-1033 869 N . 966, 1039 CASTINGS, Bronze and Dairy Delco - Frigidaire Conditioning American Radiator Company, Metal , , -. Div., General Motors ' Sales .898-899, 940-941 . Arthur Harris & Co., 1048 Corp., 902-904 E. B. Badger & Sons Co.. 967 CEMENT, Asbestos . Carey, Philip, Co., 1018-1019 Eagle-Picher Lead Co., 1021 Ehret Magnesia Manufacturing Co., 1022-1023 Johns-Manville. 1030-1031 Ruberoid Co., The. 1032-1033 Arthur Harris & Co., 1048 McQuay, Incorporated, 876 National Pipe Bending Co., 988 Niagara Blower Company, 878 B. F. Sturtevant Co., 980 Trane Company, The, 882-883. Unit Heater and Cooler Co., 986 Young Radiator Company, 987 Baker Ice Machine Co., 868-869 Bell and Gossett Co., 999 Clarage Fan.Company. 871 Crane Co., 944-945 Frick Company, 873 Arthur Harris & Co., 1048 Kewanee Boiler Corp., 958-959 McQuay, Incorporated, 876 CEMENT. Refractory fractories) (See Re COILS, Ammonia Aerofin Corporation, 989-991 National Pipe Bending Co., 988 Unit Heater & Cooler Co.. 986 ' Vilter Manufacturing Co.. 886 CEMENT, Rock Wool Baker Ice Machine Co., 868-869 York Ice Machinery Corp., 887 Carey, Philip, Co., 1020 . Eagle-Picher Lead Co.,. 1021 Carrier Corporation, 870 Crane Co.. 944-945 COLUMNS, Water Ehret Magnesia Manufacturing Frick Company, 873 Brownell Company. 1104 Co., 1022-1023 . . G & 0 Manufacturing Co., 992 Crane Company, 944-945 Please mention THE GUIDE 1939 when writing to Advertisers 1140 Index to Modern Equipment Detroit Lubricator Co., 1114-1115 Baker Ice Machine Co., 868-869 Independent Register Co., 1074 gjeley & Mueller, Inc., 1093 Carbondale Division Worthington Johnson Service Co., 1120-1121 Mueller Steam Specialty Co., 1095 Pump & Machinery Corp., 890 Minneapolis-Honeywell Regulator Wright-Austin Company, 1102 891 Co.. 1122-1123 yarnall-Waring Company, 1103 Carrier Corporation, 870 Tuttle & Bailey, Inc., 1072-1073 -COMBUSTION CHAMBERS Babcock & Wilcox Co., 952 Combustion Engineering Co., 1105 COMPOUNDS, Asphalt, for Con duits Ruberoid Co., 1032-1033 COMPOUNDS, Boiler Vinco Co., Inc., 936-937 COMPOUNDS, Boiler and Radi - . ator Sealing Vinco Co., Inc., 936-937 COMPOUNDS, Cleaning Oakite Products. Inc., 921 Vinco Co., Inc., 936-937 COMPOUNDS, Soot Destroyer Curtis Refrigerating Machine Co., Div. Curtis Manufacturing Co.. 872 Delco - Frigidaire Conditioning Div., General Motors Salts Corp., 902-904 Fedders Manufacturing Co., 982 Frick Company, 873 G & O Manufacturing Co., 992 General Electric Company, 908 909, 1044-1045 Ingersoll-Rand Company, 874-875 Kelvinator Division of Nash- Kelvinator Corp., 912-916 McQuay, Incorporated, 876 Modine Mfg. Co., 984-985 National Pipe Bending Co., 988 Niagara Blower Company. 878 Servel, Inc., 881 Waterloo Register Co., 1076 Young Regulator Company, 934 CONTROL EQUIPMENT. Combustion Barber Gas Burner Co., 901 Bristol Company, The, 1002 Detroit Lubricator Co., 1114-1115 Fulton Sylphon Co., 1116-1117 Leeds & Northrup Co., 1004 Mercoid Corporation, 1119 Minneapolis-Honeywell Regulator Co., 1122-1123 Penn Electric Switch Co., 1126 Spence Engineering Co.. 1127 Westinghouse Elec. & Mfg. Co., 888-889 White-Rodgers Elec. Co., 1128 L. J. Wing Mfg. Co., 978-979 Vinco Co., Inc., 936-937- B. F. Sturtevant Co., 980 CONTROLLERS AND CON COMPRESSORS. Air . Baker Ice Machine Co., 868-869 Curtis Refrigerating Machine Co., Division of Curtis Manu facturing Company, 872 Frick Company, 873 General Electric Company, 908 909, 1044-1045 . Trane Company, 882-883 Unit Heater'and Cooler Co.. 986 Universal Cooler Corp., 885 Vilter Manufacturing Co., 886 Westinghouse Elec. & Mfg. Co., 888-889 York Ice Machinery Corp.. 887 Young Radiator Company, 987 TROL EQUIPMENT (See also Humidity and Temperature Control) American Radiator Company, 898-899, 940-941 Barber-Colman Co., 1112-1113 Barber Gas Burner Co., 901 Bristol Company, The, 1002 Ingersoll-Rand Company, 874-875 CONDENSER CLEANER Carrier Corporation. 870 Nash Engineering Co.; 1064-1065- .Oakite Products, Inc., 921 Detroit Lubricator Co., 1114-1115 B. F. Sturtevant Co., 980 Worthington Pump & Machinery Corp., 890-891 . CONDUIT, Flexible Metallic Trane Company, 882-883 C. A. Dunham Co., 1000-1001 Julien P. Friez & Sons, Div. of Bendix Aviation Corp., 1118 COMPRESSOR MOTORS (See ' Motors, Electric) COMPRESSORS, Refrigeration Airtemp Div., Chrysler Corp., r 896-897 Baker Ice Machine Co., 868-869 `Carbondale Div., Worthington t Pump & Machinery Corp., 890h 891 Carrier Corporation, 870 .Curtis Refrigerating Machine t)' Co., Division Curtis Manu- CONDUITS. Underground Fittings American Brass Co., 1046-1047 American District Steam Com pany. 966, 1039 E. B. Badger & Sons Co., 967 General Electric Company, 908 909, 1044-1045 H. W. Porter & Co., 1040 Ric-wiL Company, The, 1041 Underground Steam Construction Co.. 1042 Fulton Sylphon Co., 1116-1117 Hoffman Specialty Co., Inc., 1088-1089 Illinois Engineering Co., 1090 1091 Illinois Testing Laboratories, Inc., 1003 Johnson Service Co., 1120-1121 Kieley & Mueller, Inc., 1093 Leeds & Northrup Co., 1004 Manning, Maxwell & Moore, Inc., 1006 Minneapolis-Honeywell Regulator - facturing Co., 872 CONDUITS. Underground Pipe Co.. 1122-1123 Delco - Frigidaire . Conditioning American Brass Co., 1046-1047 Parks-Cramer Company. 879 ' fu Div., General Motors Sales American District Steam Com Penn Electric Switch Co., 1126 Corp., 902-904 pany. 966. 1039 Powers Regulator Co., 1124-1125 .Fitzgibbons Boiler Co.', 954-955 E. B. Badger & Sons Co., 967 Sarco Company, Inc., 1096-1097 ;TVick Company; 873 Ehret Magnesia Manufacturing Spence Engineering Co., 1127 "General Electric Company, 908 Co.. 1022-1023 Taylor Instrument Companies, 909. 1044-1045 Frick Company, 873 Ingersoll-Rand Company. 874-875 Johns-Manville, 1030-1031 1008-1009 Warren Webster & Co., ' 1098 ^Kelvinator Division of Nash*' Kelvinator Corp., 912-916 Herman Nelson Corp., 996 Servel, Inc., 881 Trane Company, The, 882-883 Jones & Laughlin Steel Corp., 1049 H. W. Porter & Co.. 1040 Ric-wiL Company, The. 1041 Underground Steam Construction 1101 Westinghouse Elec. & Mfg. Co., 888-889 White-Rodgers Elec. Co.. 1128 Young Radiator Co., 934 - ^Universal Cooler Corp.. 885' Co., 1042 CONVECTION HEATERS Vilter -Manufacturing Co., 886 Westinghouse Elec. & Mfg. Co., v. 888-889 Williams Oil-O-Matic- Heating ' Corp.. 920 . .York Ice Machinery Corp., 887 CONNECTIONS, Flexible Charg ing . Henry Valve Company, 1132 CONTROL, Air Volume Damper Anemostat Corp. of America, American Radiator Company, 898-899, 940-941 Crane Co., 944-945 ' C. A. Dunham Co.,' 1000-1001 Grinnell Co., Inc., 993-995, 1087 McCord Radiator & Mfg. Co., . COMPRESSOR TUBING. Flex 1067 983 ible (See Tubing, Flexible Auer Register Co., The, 1068 McQuay, Incorporated. 876 7- Metallic) '` Barber-Colman Co., 1112-1113 Modine Mfg. Co., 984-985 CONDENSERS . Aerofin Corporation, 989-991 Airtemp Div., Chrysler CoTp., 896-897 Fulton Sylphon Co., 1116-1117 Hart & Cooley Mfg. Co., 1070 1071 Illinois Engineering Co., 1090 1091 John J. Nesbitt, Inc., 997 Trane Company, The, 882-883 . Tuttle A Bailey, Inc.. 1072-1073 United States Air Conditioning Corp., 884 Numerals following Manufacturers* Names refer to pages in the Catalog Data Section 1141 x Heating Ventilating Air Conditioning Guide 1939 United States Radiator Corp.. COOLING EQUIPMENT, Water Carey, Philip, Co., 1020 948*949 (See also Water Cooling) Warren Webster & Co., 1098-1101 Aerofin Corporation, 989-991 Eagle-Picher Lead Co., 1021* Ehret Magnesia Mfg. Co 1099 Weil-McLain Company, 950 Young Radiator Co., 987 Airtemp Div., ChrysleT Corp., 1023 ' 896-897 General Insulating & Mftr r American Blower Corp., 866-867 1024 L'0-' COOLING EQUIPMENT, Air Aerofin Corporation, 989-991 Baker Ice Machine Co., 868-869 Insul-Wool Insulation Corp., 1025 Buffalo Forge Company, 972 International Fibre Board * 1 Carbondale Div. Worthington 1028 a- Air Controls, Inc., 892 Pump & Machinery Corp., 898 Johns-Manville, 1030-1031 Airtemp Div., 896-897 Chrysler Corp., 891 Carrier Corporation, 870 Mundet Cork Corp., 1029 Owens-Corning Fiberglas Com American Blower Corp., 866-867 American Radiator Co., 898-899, 940-941 Autovent Fan & Blower Co., 970 Cooling Tower Co., Div. of Fluor Corp.. Ltd., 964 Delco - Frigidaire Conditioning Div., General Motors Sales 929 v'.' Pacific Lumber Co., The, 1034 Ruberoid Co., The, 1032-1033 Standard Lime & Stone Co., 1035 Baker Ice Machine Co., Inc., 868 Corp.. 902-904 Western Felt Works, 1037 869 Fedders Manufacturing Co., 982 York Ice Machinery Corp., gg-j Buffalo Forge Company, 972 Carbondale Division Worthington Pump & Machinery Co., 890 891 Frick Company, 873 Ingersoll-Rand Company, 874-875 Marley Co., The, 965 McCord Radiator & Mfg. Co., 983 CUT-OFFS, Low Water Detroit Lubricator Co., 1114-1115 Maid-O-Mist, Inc., 998 Carrier Corporation, 870 McQuay, Incorporated, 876 McDonnell & Miller, 938-939 Champion Blower & Forge Co., 973 Clarage Fan Company, 871 Modine Manufacturing Co., 984 985 National Pipe Bending Co., 988 Minneapolis-Honeywell Regulator Co., 1122-1123 Penn Electric Switch Co., 1126 Curtis Refrigerating Machine Co., Div. of Curtis Manu facturing Co., 872 .DeBothezat Division, American Machine & Metals, Inc., 974 Delco - Frigidaire Conditioning Div., General Motors Sales Corp., 902-904 . Fedders Manufacturing Co., 982 Fitzgibbons Boiler Co., 954-955 Frick Company, 873 General Electric Company, 908 909, 1044-1045 Henry Furnace & Foundry Co., 910-911 Ilg Electric Ventilating Co., 975 Kelvinator Division of Nash- Kelvinator Corp., 912-916 Lau Blower Co., 893 McCord Radiator & Mfg. Co., 983 McQuay, Incorporated, 876 Meyer Furnace Co., 917 Modine Mfg. Co., 984-985 National Pipe Bending Co., 988 Herman Nelson Corp., 996 Niagara Blower Company, 878 Research Corporation, 880 Servel, Inc., 881 B. F. Sturtevant Co., 980 Trane Company, The, 882-883 . Unit Heater and Cooler Co., 986 United States Air Conditioning Corp., 884 Vilter. Manufacturing Co., 886 Westinghouse Elec. & Mfg. Co., 888-889 Williams Oil-O-Matic Heating Corporation, 920 L. J. Wing Mfg. Co., 978-979 York Ice Machinery Corp., 887 Niagara Blower Company, 878 Research Corporation, 880 DAMPER REGULATORS, Boiler (See also Regulators) B. F. Sturtevant Co., 980 Trane Company, The, 882-883 American . 898-899, Radiator 940-941 Company Unit Heater and Cooler Co., 986' Barber-Colman Co., 1112-1113 . Universal Cooler Corp., 885 Barnes & Jones', Inc., 1081 Vilter Manufacturing Co., 886 Detroit Lubricator Co.,` 1114-1115 Westinghouse Elec. & Mfg. Co.. Fulton Sylphon Co., 1116-1117 ,, 888-889 Yarnall-Waring Co., 1103 York Ice Machinery Corp., 887 Hart & Cooley Mfg. Co., 1070 1071 '. Henry Furnace & Foundry Co., Young Radiator Company, 987 910-911 ; COOLING TOWERS, Atmos pheric, Mechanical Draft, Forced Draft, Induced Draft (See also Cooling Equipment, Water) Baker Ice Machine Co., 868-869 Buffalo Forge Company, 972 Cooling Tower Co., Div. of Fluor Corp., Ltd., 964 Marley Company, 965 Research Corporation, 880 Unit Heater & Cooler Co., 986 York Ice Machinery Corp., 887 Hoffman Specialty Co., Inc!,- 1088-1089 . Illinois Engineering Co., 1090 1091 . Kieley & Mueller, Inc., 1093 : Leeds & Northrup Co.; 1004 Minneapolis-Honeywell Regulator Co., 2122-1123' Powers Regulator Co., 1124-1125' Sarco Company, Inc., 1096-1097 Spence Engineering Co., 1127 Taylor Instrument Companies, 1008-1009 Trane Company, The, 882^883 CORROSION, Treatment of Warren Webster & Co., 1098 Oakite Products, Inc., 921 Vinco Company, Inc., 936-937 1101 Westinghouse Elec. & Mfg. Co., COVERING, Pipe 888-889 Young Regulator Co., 934 Alfol Insulation Co., Inc., 1101 Armstrong Cork Company, 1013 Baker Ice Machine Co., 868-869 Carey, Philip, Co,, 1020 Eagle-Picher Lead Co., 1021 Ehret Magnesia Mfg. Co., 1022 1023 - Frick Company, 873 Grinnell Co., Inc., 993-995, 1087. DAMPER REGULATORS, Furnace - Barber-Colman Co., 1112-1113, Detroit Lubricator Co., 1114-1115 Julien P. Friez & Sons, Div. of Bendix Aviation Corp., 1118 Fulton Sylphon Co., 1116-1117 Hart & Cooley Mfg. Co., 1070 Young Radiator Company, 987 General Insulating & Mfg. Co., 1024 He1n07ry1 Furnace & Foundry ,,Co., COOLING EQUIPMENT, Oil Aerofin Corporation, 989-991 Carbondale Div. Worthington Pump & Machinery Co.,. 890 891 Johns-Manville, 1030-1031 Mundet Cork Corp., 1029 Owens-Corning Fiberglas Corp., 929 H. W. Porter & Co., 1040 ' Frick Company, 873 Ric-wiL Company, The, 1041 G & O Manufacturing Co., 992 Ruberoid Co., The, 1032-1033 Niagara Blower Company, 878 Standard Lime & Stone Co., 1035 Servel, Inc., 881 Unit Heater and Cooler Co., 986 COVERING, Surfaces ' Universal Cooler Corp., 885 Alfol Insulation Co., Inc., 1011 York Ice Machinery Corp., 887 Armstrong Cork Company. 1013 Young Radiator Company, 987 . Baker Ice Machine Co., 868-869 910-911 Kieley & Mueller, Inc., 1093 Leeds & Northrup Co., 1004 Manning, Maxwell & Moore, Inc., 1006 , Minneapolis-Honeywell Regulator Co., 1122-1123 Powers Regulator Co., 1124-1125 Sarco Company, Inc., 1096-1097 Spence Engineering Co., 1127 Tuttle & Bailey, Inc., 1072-1073 United States Register Co., 1075 Young Regulator Co., 934 Please mention THE GUIDE 1939 when writing to Advertisers Index to Modern Equipment -PAMPERS, Air Volume Control S.Air Controls, Inc., 892 7^'Anemostat Corp. of America, 1067 '"-'Auer Register Co., The, 1068 ^Barber-Colman Co., 1112-1113 ^Champion Blower & Forge Co., "% 973 ''Excelsior Steel Furnace Co., 905 Hart & Cooley Mfg. Co., 1070- DISTRICT HEATING (See also rC-o--r-r-o--s- i-o--n-----T--r--e--a--t-m---e--n*t of--Ex pansion Joints -- Insulation, Underground--Meters, Pipe) American District Steam Co., 966, 1039 H. W. Porter & Co., 1040 Ric-wiL Company, The, 1041 noOR rottom qp *1 c DOOR BOTTOM SEALS Carbondale Div. Worthington P-u--m---p &- ~Mach*inery -Corp., --89-0- 891 Carrier Corporation, 870 . Curtis Refrigerating Machine Co., Div. Curtis Manufacturing Co., 872 Delco - Frigidaire Conditioning Div.,. G-e...n..e..r.al Motors Sales Corp.. 902-904 .it 1071 ^Hendrick Mfg. Co., 1069 Chamberlin Metal Weather Strip Fedders Manufacturing Co., 982 1018-1019 Frick Company, 873 ^'Independent Register Co., 1074 DRAFT APPARATUS (See General Electric Company, 908- vJohnson Service Company, 1120- Blowers, Forced Draft) 909, 1044-1046 1121 DRYERS Refriff-mnt ifMinneapolis-Honeywell Regulator jjenry Valve Co^nnanv 1132 $ Co., 1122-1123 Henry Valve Company, 1132 Kelvinator Division of NashKelvinator Corp., 912-916 McQuay, Incorporated. 876 *3?Tuttle & Bailey, Inc., 1072-1073 DRYING EQUIPMENT Servel, Inc., 881 .'^Waterloo Register Co., 1076 JiYoung Regulator Co., 934 American Blower Corp., 866-867 B- p* Sturtevant Co., 980 American Coolair Corp., 968-969 Tr*ne Company, The, 882-883 ^DAMPERS, Flue ^Henry Furnace & Foundry Co., American Radiator Company, Heater & Cooler Co., 986 898-899, 940-941 Vilter Manufacturing Co., 886 Autovent Fan & Blower Co., 970 Westinghouse Elec, & Mfg. Co., & Bailev Ine lOTS-ifm Buffalo Forge Company, 972 feoung Regulator Company, 934 jjrrier. Coloration, 870 888-889 _ Xork lc* Machinery Corp., 887 -DAMPERS, Mechanical ^Air Controls, Inc., 892 ^Barber-Colman Co., 1112-1113 IClhhaammnpiiAonn BRlower &f. EFVoi*r.#g-e Co., Young Regulator Company, 987 973 _ _ EXHAUST HEADS (See Heads, Clarage Fan Company, 871 Exhaust) Delco - Frigidaire Conditioning ^Buffalo Forge Company, 972 Div., General Motors Sales EXHAUST TUBING, Flexible ^Carrier Corporation, 870 Corp., 902-904 (See Tubing, Flexible Metallic) g__C__l&_ ra.g,,e Fan Com.pa.n.y,.871 G & O Mfg. Co., The, 992 EXPANSION JOINTS ' ^Fulton Sylphon Co., 1116-1117 Ilg Electric Ventilating Co., 975 American District c.,,.,p 1-Hart & Cooley Mfg. Co., 1070- McQuay. Incorporated, 876 mb Steam Co" ft 1071 - B. F. Sturtevant Co., 980 JjgHenry Furnace & Foundry Co., Trane Company, The, 882-883 P t. rgaker fc^* MacWne S Cg68 869 H 910-911 Unit Heater and Cooler Co., 986 rncnn^iVinn a* 868-869 /Johnson Service Co.. 1120-1121 L. J. Wing Mfg. Co., 978-979 c", 870 ^inneapoHs-HoneyweU ReguW York Ice Machinery Corp., 887 Fulton Sylphon Co., HI6-I117 J^Powers Regulator Co., 1124-1125 Dl7C,TS' Prefabricated (? also DrinneH Co., Inc., 993-995, 1087 J&&YTIoniutFngr1 RsetgautelasRtoergCisotemr pCaony, 190374*; ExcSeiltstiionrgsS,teAelirFuDruncatcse, FCuor.,na9c0e5) Ainrtjh"u`rs HEanrrgisine&erCinog., 1C0o4.8, 1090- ^DAMPERS, Back Draft (Sec OUST COLLECTING Dampers, A.i.r .V.o.lume C- ontro-l) EQUIPMENT Ric-wiL Company, 1041 Underground Steam Construction ' ^DEHUMIDIFIERS ^Aerofin Corporation, 989-991 ^Airtemp Div. Chrysler Corp., U- 856-897 . American Blower Corp., 866-867 ^Carrier Corporation, 870 sa^CIarage Fan Company, 871 ;%Grmnell Co., Inc., 993-995, 1087 Parks-Cramer Co., 879 EResearch Corporation,.-880 . . H. J. Somers, Inc.,-931 jTrane Company, The, 882-883 ^Westinghouse Elec. & Mfg. Co., American Air Filter Co., 924-925 American Blower Corp., 866-867 Buffalo Forge Company, 972 Clarage Fan Company, 871 DInadveiepsenAdeirntFAiltierr FCiloterpr., C9o2.7. 928 Owens-Corning Fiberglas Corp., 929 Research Corporation, 880 Research Products Corp., 930 Staynew Filter Corp., 932 B. F. Sturtevant Co., 980 Emt Heater & Cooler Co., 986 Co., 1042 Warren-Webster & Co., 1101 Yarnall-Waring Co., 1103 rETXPPOOQSIiTTIOinNvcS 1098- International Exposition Co., 935 FANS, Attic Air Controls, Incl, 892 ' Airtherm Manufacturing Co., 981 American Blower Corp., 866-867 American Coolair Corp., 968-969 American Radiator Company, <&. 888-889 'kYork Ice Machinery Corp., 887 Westinghouse Elec. & Mfg. Co., 889-899, 940-941 888-889 Autovent Fan & Blower Co., 970 ^{DEHYDRATORS, Refrigerant i^Henry Valve Company, 1132 &DEHYDRA-TECTORS, Refrigerant |Renry Valve Company, 1132 Idehydrants " ^Henry Valve Company, 1132 DUST COLLECTORS, Cloth Type Alfol Insulation Co., 1011 Bayley Blower Company, 971 Buffalo Forge Company, 972 Champion Blower & Forge Co., American AAmmeerriiccaann ABBllioor wwFeeilrrterCr.o^Crpno..,, 924-925 866 Davies Air Filter Corp., 927 Staynew Filter Corp.. 932-933 Independent Air Filter Co.. 928 Clarage_Fan Compan,,y,,, 8e7v1i Coppus Engineering Corp., 926 DeBothezat Division American Mac-h'Finreigi&daLMee' tal^sC, oInndcS..io9n7in4g ^DEODORANTS lOakite Products, Inc., 921 DESTROYERS, Soot (See Soot &Destroyer) DIESEL ENGINES koines, Diesel) (See ' En-. miiDDnonno' . . .. PDIFFUSERS, Air (See Air Dxf- -%fuser$, and Ventilators, Floor EJECTORS, Steam Jet Ingersoll-Rand Co,,. 874-876 ENGINES, Diesel Ingersoll-Rand Co., 874-875 pvaporator^ EVAPORATORS Aerofin Corporation, 989-991 Baker Ice Machine Co., Inc., 868- 869 Div., General Motors Sales Corp., 902-904 ' - General Electric Company, 908 909, 1044-1045 Henry Furnace & Foundry Co., 910-911 . Lau Blower Co., 898 ` jMuce>yerr rFuurnrnaaccee cCoommppaannyy,, s9i17L. J. Mueller Furnace Co., 918- 919 and Wall) Buffalo Forge Co., 972 . John J. Nesbitt, Inc., 997 Numerals following Manufacturers* Names refer to pages in the Catalog Data Section Heating Ventilating Air Conditioning Guide 1939 Niagara Blower Company, 878 Clarage Fan Company, 871 DeBothezat Division America*. Schwitzer-Cummins Co., 834, Henry Furnace ft- Foundry Co., Machine & Metals, Inc., g-j 1111 910-911 Delco - Frigidaire Conditioning B. F. Sturtevant Co., 980 Lau Blower Co., 893 Div., General Motors Sai Torrington Mfg. Co., 976-977 Meyer Furnace Co., The, 917 Corporation, 902-904 Trane Company, The, 882-883 L. J. Mueller Furnace Co., 918 General Electric Company United States Air Conditioning 919 909, 1044-1045 Corp., 884 Schwitzer-Cummins Co., 894, Henry Furnace ft Foundry fv> Westinghouse Elec. & Mfg. Co., 1111 910-911 Wo- 888-889 Torrington Mfg. Co., 976-977 Lau Blower Co.. 893 L. J. Wing Mfg. Co., 978-979 Trane Company, The. 882-883 Meyer Furnace Company. 917 . Westinghouse Elec, ft Mfg. Co., L. J. Mueller Furnace Co.. 9ig. FAN BLADES 888-889 American Blower Corp., 866-867 L. J. Wing Mfg. Co., 97B-979 John J. Nesbitt, Inc., 997 American Cooiair Corp., 968-969 Niagara Blower Company, 878 Buffalo Forge Company, 972 FAN MOTORS (See Motors, Schwitzer-Cummins Co., 894 Champion Blower & Forge Co., Electric) 1111 ' 973 Clarage Fan Company, 871 DeBothezat Division American Machine & Metals, Inc., 974 Serve!, Inc., 881 Schwitzer-Cummirva Co., 894, FANS, Portable American Blower Corp., 866-867 American Cooiair Corp., 968-969 Autovent Fan ft Blower Co., 970 Bayley Blower Company, 971 H. J. Somers, Inc., 931 B. F. Sturtevant Co., 980 Torrington Mfg. Co., 976-977 Trane Company, The. 882-883 United States Air Conditioning Corp.. 884 8 1111 Torrington Mfg. Co., 976-977 Buffalo Forge Company, 972 Westinghouse Elec. & Mfg. Co Champion Blower ft Forge Co., 888-889 " Westinghouse Elec. ft Mfg. Co.. 973 L. J. Wing Mfg. Co., 978-979 ooo_oqo Coppus Engineering Corp., 926 L. J. Wing Mfg. Co., 978-979 FANS. Centrifugal Air Controls, Inc., 892 American Blower Corp., 866-867 General Electric Company, 908 909, 1044-1045 Henry Furnace & Foundry Co., 910-911 Ilg Electric Ventilating Co.. 975 FEED WATER HEATERS (See Heaters, Feed Water) FEED WATER REGULATORS (See Regulators, Feed Water) > American Cooiair Corp., 968-969 Torrington Mfg. Co., 976-977 FEEDERS, Boiler - . Autovent Fan ft Blower Co..-970 Bayley Blower Company, 971 Buffalo Forge Company, 972 Carrier Corporation, 870 Champion Blower & Forge Co., 973 Clarage Fan Company, 871 General Electric Company, 908 909, 1044-1045 Henry Furnace ft Foundry Co., 910-911 Ilg Electric Ventilating Co., 975 Lau Blower Co., 893 ' Meyer Furnace Company,- 917 Niagara Blower Company, 878 Schwitzer-Cummins Co., 894, 1111 Westinghouse Elec, ft Mfg. Co., 888-889 L. J. Wing Mfg. Co.. 978-979 FANS, Propeller Air Controls, Inc., 892 American Blower Corp., 866-867 American Cooiair Corp., 968-969 Autovent Fan ft Blower Co., 970 Buffalo Forge Company, 972 Champion Blower & Forge Co., 973 Clarage Fan Company, 871 Coppus Engineering Corp., 926 DeBothezat Division American Machine & Metals, Inc., 974 General Electric Company. 908 Crane Co., 944-945 ' ` Kieley & Mueller, Ipc.r 1093 Maid-O-Mist, Inc., 998 . McDonnell ft Miller, 938-939. Milwaukee Valve Co., 1094 \ Mueller Steam Specialty Co., ' 1095 Spence Engineering Co., 1127 Warren Webster ft Co., 1098-1101 Westinghouse Elec, ft Mfg. Co.; 888-889 Wright-Austin Co., 1102 FEEDERS, Water Decatur Pump Co., 1063 Kieley & Mueller, Inc., 1093 Maid-O-Mist, Inc., 998 B. F. Sturtevant Co., 980 909, 1044-1045 . McDonnell ft Miller, 938-939 Torrington Mfg. Co., 976-977 Henry Furnace ft Foundry Co.. Milwaukee Valve Co., 1094 Trane Company, The, 882-883 910-911 Mueller Steam Specialy Co., 1095 L. J. Wing Mfg. Co., 978-979 Ilg Electric Ventilating Co.. 975 Wright-Austin Co., U02 FANS, Electric Airtherm Manufacturing Co., 981 American Cooiair Corp., 968-969 Autovent Fan ft Blower Co., 970 Buffalo Forge Company, 972 Champion Blower & Forge Co., 973 Clarage Fan Company, 871 Coppus Engineering Corp., 926 DeBothezat Division, American Machine ft Metals, Inc., 974 General Electric Company, 908 909, 1044-1045 Henry Furnace ft Foundry Co., 910-911 Torrington Mfg. Co., 976-977 Westinghouse-Elec, ft Mfg. Co., 888-889 L. J. Wing Mfg. Co.. 978-979 Marley Co., The. 965 Schwitzer-Cummins Co., 894, 1111 Serve], Inc., 88l B. F. Sturtevant Co., 980 Torrington Mfg. Co., 976-977 Trane Company, The, 882-883 United States Air Conditioning Corp., 884 Westinghouse Elec, ft Mfg. Co.. 888-889 L. J. Wing Mfg. Co., 978-979 FANS, Supply and Exhaust Air Controls, Inc., 892 Airtherm Manufacturing Co., 981 American Blower Corp., 866-867 American Cooiair Corp.. 968-969 American Radiator . Company, 898-899, 940-941 FELT, Sound Deadening Barrett Company, 1014 Carey, Philip, Co., 1020 Ehret Magnesia Mfg. Co., 1022 1023 Johns-M$nville, 1030-1031 Ruberoid Company, 1032-1033 Western Felt Works, 1037 ?ELT, Insulating (See Insula tion, Felt) FILTERS. Air (See also Air Cleaning Equipment) Air-Maze Corporation, 922-923 American Air Filter .Co., Inc., 924-925 American Radiator Company, 898-899, 940-941 Coppus Engineering Corp.. 926 FANS, Furnace - Air Controls, Inc., 892 American Blower Corp., 866-867 ` Autovent Fan ft Blower Co.. 970 Buffalo Forge Company, 972 Champion Blower & Forge Co.. 973 Autovent Fan & Blower Co.. 970 Bayley Blower Company, 971 Buffalo Forge Company, 972 Champion Blower & Forge Co., 973 ' Clarage Fan Company, 871 Coppus Engineering Corp., 926 Davies Air Filter Corp., 927 independent Air Filter Co.. 928 Dwens-Corning Fiberglas Corp., 929 Research Products Corp., 930 H. J. Somers, Inc., r. c____ ..... Pi'lin, 931 ftO0_Q95 Please mention THE GUIDE 1939 when writing to Advertisers 1144 Index to Modern Equipment FIREBRICK, Insulating Babcock ft Wilcox Co., 952 'FITTINGS, Air Ducts, Furnace Excebior Steel Furnace Co., 905 'United States Register Co., 1075 FITTINGS, Pipe, Flanged Marley Company, 965 Research Corporation, 880 Unit Heater & Cooler Co., 986 York Ice Machinery Corp., 887 FURNACE-BURNER Delco - Frigidaire Conditioning Manning, Maxwell ft Moore, Inc 1006 Minneapolis-Honeywell Regulator Co., 1122-1123 Spence Engineering Co., 1127 Taylor Instrument Companies. 1008-1009 '^American Rolling Mill Co., 1078 Baker Ice Machine Co.. 868-869 Div., General Corp., 902-904 Motors Sales United States Gauge Co., 1010 -Carnegie-Illinois Steel Corp., 1080 Crane Co., 944-945 prick Company, 873 Grinnell Co., Inc., 993-995, 1087 Arthur Harris ft Co,, 1048 Henry Valve Company, 1132 United States Register Co., 1075 ;ViIter Manufacturing Co., 886 York Ice Machinery Corp., 887 FITTINGS, Pipe, Screwed Baker Ice Machine Go., 868-869 Crane Co., 944-945 Frick Company, 373 Grinnell Co., Inc., 993-995, 1087 Henry Valve Company, 1132 United States Register Co., 1075 Vilter Manufacturing Co., 886 York Ice Machinery Corp., 887 FITTINGS, Pipe, Solder Gar Wood Industries, Inc., 906 907 General Electric Company, 908 909, 1044-1045 Henry Furnace ft Foundry Co., 910-911 Meyer Furnace Company, 917 L. J. Mueller Furnace Co., 918 919 Herman Nelson Corp., 996 Westinghouse Elec, ft Mfg. Co., 888-889 Williams Oil-O-Matic Heating Corporation, 920 FUEL BURNING EQUIPMENT. Automatic (See Burners, Auto matic; Coal Burners, Auto matic; Furnace Burners; Gas Burners; Oil Burners;.Stokers) GAGE GLASSES American Radiator Company, 898-899, 940-941 Beaton ft Cadwell Mfg. Co., The, 1084-1085' Crane Co., 944-945 Jenkins Bros., 1132 Yarnall-Waring Co., 1103 GAGES, Altitude American Radiator Company, 898-899, 940-941 Bell and Gossett Company, 900 Bristol Company, The, 1002 Crane Co., 944-945 Mercoid Corporation, III9 Minneapolis-Honeywell Regulator Co., 1122-1123 New York Air Valve Corp., 1134 Taylor Instrument Companies. American Brass Co., 1046-1047 FURNACE FITTINGS 1008-1009 Crane Co., 944-945 Wolverine Tube Co., 1050 Excelsior Steel Furnace Co.. 905 PITTINGS, Pipe, Sweat FURNACE PIPE .American Brass Co., 1046-1047 . Excelsior Steel Furnace Co.. 905 American Radiator Co., 893-899, 940-941 FURNACE REGULATORS (See Regulators, Furnace) 'Crane Co., 944-945 Wolverine Tube Co., 1050 FURNACES, Electric United States Gauge Co., 1010 GAGES, Ammonia Baker Ice Machine Co., 868-869 Crane Company, 944-945 Martocello, Jos. A. ft Co., 877 Mercoid Corporation, 1119 United States Gauge Co.. 1010 Vilter Manufacturing Co., 886 -FITTINGS, Welding General Electric Company. 908 York Ice Machinery Corp., 887 American Rolling Mill Co., 1078 'Crane Co., 944-945 Grinnell Co., Inc., 993-995, 1087 .York Ice Machinery Corp., 887 909, 1044-1045 Westinghouse Elec, ft Mfg. Co., 888-889 FURNACES, Warm Air GAGES, Compound American Radiator Company. 898-899. 940-941 C. A. Dunham Co., 1000-1001 FITTINGS, Wrought Copper Acme Heating ft Ventilating Co.. Hoffman Specialty Co., Inc.. American Brass Co., 1046-1047 895 1088-1089 Wolverine Tube Co., 1050 ;FLOATS, Metal (See Trap and Valve) Arthur Harris ft Co.,- 1048 .Wright-Austin Co., 1102 Airtemp Div., Chrysler Corp., 896-897 Airtherm Manufacturing Co.. 981 American Gas Products Div.. American Radiator Co.. 900. 951 Illinois Engineering Co., 1090 1091 Manning, Maxwell ft Moore, Inc.. 1006 Sarco Company, Inc., 1096-1097 Spence Engineering Co., 1127 FLOOR AND CEILING PLATES American Radiator '''Company, 898-899. 940-941' 'Beaton & Cadwell Mfg. Co., ^ 1084-1085 .Carnegie-Illinois Steel Corp., 1080 :'Crane Co.. 944-946 Grinnell Co., Inc., 993-995, 1087 Carrier Corporation, 870 . United States Gauge Co., 1010 Delco - Frigidaire Conditioning Warren Webster ft Co., 1098-1101 Div., General Motors Sales Corp., 902-904 . GAGES, Hot Water Excelsior Steel Furnace Co.. 906 American Radiator Company. Fitzgibbons Boiler Co., 954-955 898-899, 940-941 Gar Wood Industries, 906-907 Bell and Gossett Co., 999 General Electric Company, 908 Bristol Company, 1002 909. 1044-1045 Frick Company, 873 Henry Furnace ft Foundry Co.. Julien P. Friez ft Sons, Div. of FLUE GAS ANALYSIS 910-911 Bendix Aviation Corp., 1118 {-Julien P. Friez ft Sons, Div. of Bendix Aviation Corp., 1118 Leeds & Northrup Co., 1004 ^Minneapolis-Honeywell Regulator ( Co., 1122-1123 S. T. Johnson Co., 968-969 Kelvinator Division of Nash- Kelvinator Corp., 912-916 Meyer Furnace Co., The, 917 L. J. Mueller Furnace Co., 918 919 Manning, Maxwell ft Moore, Inc., 1006 Mercoid Corporation, 1119 Minneapolis-Honeywell Regulator Co., 1122-1123 New York Air Valve Corp., 1134 FORCED-AIR DUCTS and FIT- Herman Nelson Corp., 996 Taylor Instrument Companies, ,, TINGS (See Ducts, Fittings) Spencer Heater Division, 946-947 1008-1009 ^FORCED DRAFT COOLING TOWERS (See also Cooling V Towers, Induced Draft, Mech- anicoi Draft) Baker Ice Machine Co., 868-869 Buffalo Forge Company, 972 Cooling Tower Co.. Div, of Fluor ' Corp., Ltd., 964 United States Radiator Corp., 948-949 Westinghouse Elec, ft Mfg. Co., 88S-8S9 GAGE BOARDS Baker Ice Machine Co., SCS-S69 Bristol Company, The, 1002 Frick Company, 873 . United States Gauge Co., 1010 GAGES, Liquid Level ' Henry Valve Company, 1132 Liquidometer Corp., 1005 . Taylor Instrument Companies, 1008-1009 Minneapolis-Honeywell Regulator. Co., 1122-1123 Numerals following Manufacturers' Names refer to pages in the Catalog Data Section Heating Ventilating Air Conditioning Guide 1939 Index to Modern Equipment GAGES, Pressure American Radiator Company, 898-899, 940-941 Anderson Products, Inc., 1130 Baker Ice Machine Co., Inc., 868 869 Bell & Gossett Co., 999 . GAGES, Vapor . Bristol Company, The, 1002 Burnham Boiler Corp., 942-943 C. A. Dunham Co., 1000-1001 Hoffman Specialty Co., Inc., 1088-1089 Illinois Engineering Co., 1090 Mueller Steam Specialty r* Inc., 1095 - Schwitzer-Cummins Co sqa 1111 ' Spence Engineering Co., 1127 Warren Webster & Co., 1098-1101 Wright-Austin Co., 1102 Bristol Company, 1002 Crane Co., 944-945 Manning, Maxwell & Moore, Inc., 1006 . Mercoid Corporation, 1119 Minneapolis-Honeywell Regulator Co., 1122-1123 New York Air Valve Corp., 1184 Spence Engineering Co., 1127 Taylor Instrument Companies, 1008-1009 . Trane Company, The, 882-883 United States Gauge Co., 1010 1091 Manning, Maxwell & Moore, Inc., 1006 Mercoid Corporation, 1119. Minneapolis-Honeywell Regulator Co., 1122-1123 New York Air Valve Corp., 1134 Spence Engineering Co., 1127 United States Gauge Co., 1010 Warren Webster & Co., 1098-1101 GAGES. Water American Radiator Company, 898-899, 940-941 GRATES FOR BOILERS ANn FURNACES . American Coolair Corp., 968-969 Combustion Engineering Co 1105 ' Fitzgibbons Boiler Co., Inc., 954. 955. E. Keeler Company, 956-957 Kewanee Boiler Corp., 958-959 L. J. Mueller Furnace Co., 918_ 919 Unit Heater and Cooler Co., 986 GRILLES, REGISTERS AND GAGES, Steam American Radiator Company, 898-899, 940-941 Anderson Products, Inc., 1130 Bristol Company, 1002 - ' Crane Co., 944-945 ' C. A. Dunham Co., 1000-1001 Hoffman Specialty Co., Inc., 1088-1089 . . Illinois Engineering Co., 1090 1091 Manning, Maxwell & Moore, Inc., 1006 Mercoid Corporation, 1119 Minneapolis-Honeywell Regulator Co., 1122-1123 New York Air Valve Corp., 1134 Spence Engineering Co., 1127 - Taylor Instrument Companies, 1008-1009 . United States Gauge Co., 1010 Warren Webster & Co., 1098-1101 Baker Ice Machine Co., 868-869 Bristol Company, 1002 Crane Co., 944-945 Detroit Lubricator Co., 1114-1115 Frick Company, 873 Julien P. Friez & Sons, Div. of Bendix Aviation Corp., 1118 Manning, Maxwell & Moore, Inc., 1006 Mercoid Corporation, 1119 Minneapolis-Honeywell Regulator Co., 1122-1123 New York Air Valve Corp., 1134 Wright-Austin Co., 1102 Yarnall-Waring Co., 1103 GAS BURNERS Airtemp Div. Chrysler Corp., 896-897 American Gas Products Div., American Radiator Co., 900, 951 Barber Gas Burner Co., 901 ' ORNAMENTAL METAL WORK (See also Registers) American Blower Corp., 866-867 American Coolair Corp., 968-969 Anemostat Corp. of America 1067 Auer Register Co., The, 1068 Barber-Colman Co., 1112-1113 Carrier Corporation, 870 Hart & Cooley Manufacturing Co., 1070-1071 Hendrick Mfg. Co.,' 1069 ` Independent Register Co., 1074 L. J. Mueller Furnace Co.", 918 919 Trane Company, The, 882-883 . Tuttle & Bailey, Inc., 1072-1073 United States Air Conditioning Corp., 884 United States Register Co.. 1075 Waterloo Register Co., 1076 Wickwire Spencer Steel Co., 1077 GAGES, Tank Coppus Engineering Corp., 926 HANGERS, Pipe Crane Co., 944-945 . American Brass C6., 1046-1047 Detroit Lubricator Co., 1114-1115 Delco- Frigidaire Conditioning Baker Ice Machine Co., 868-869 Frick Company, 873 - Div., General Motors Sales Beaton and Cadwell Mfg. Co., Julien P. Friez & Sons, Div. of Corporation, 902-904 . The, 1084-1085 Bendix Aviation Corp., 1118 Henry Furnace & Foundry Co., Crane Co., 944-945 - Liquidometer Corp., 1005 910-911 . .# Frick Company, 873 Minneapolis-Honeywell Regulator Spencer Heater Division, 946-947 Grinnell Co., Inc., 993-995, 1087 Co., 1122-1123 . Taylor Instrument Companies, 1008-1009 Wright-Austin Co., 1102 GASKETS, Asbestos Crane Co., 944-945 . Ehret Magnesia Manufacturing Co., 1022-1023 . . Ric-wiL Company, The, 1041 Vilter Manufacturing . Co., 886 Wolverine Tube Co., 1050 HANGERS, Radiator GAGES, Vacuum . Anderson Product?, Inc., 1130 . Bristol Company, 1002 Burnham Boiler Corp., 942-943 Frick Company, 873 . Jenkins Bros., 1133 . Johns-Manville, 1030-1031 Ruberiod Co., The, 1032-1033 Burnham Boiler Corp., 942-943 Crane Co., 944-945 Grinnell Co., Inc., 993-995, 1087 HEADS, Exhaust Crane Co., 944-945 GASKETS, Cork A C. A. Dunham Co., 1000-1001 Julien P. Friez & Sons, Div. of Bendix Aviation Corp., 1118 Hoffman Specialty Co., Inc., 1088-1089 Armstrong Cork Company, 1013 Crane Co., 944:945 ' Johns-Manville, 1030-1031 Mundet Cork Corp., 1029 Illinois Engineering Co., 1090 ..GASKETS, Felt 1091 Western Felt Works, 1037 Manning, Maxwell & Moore, Inc., 1006 GASKETS, Rubber Mercoid Corporation,' 1119 - Crane Co., 944-945 Minneapolis-Honeywell Regulator Ehret Magnesia Manufacturing Co., 1122-1123 .. Co., 1022-1023 :. New York Air Valve Corp., 1134 Frick Company, 873 - Spence Engineering Co., 1127 Jenkins Bros., 1133 . Taylor Instrument Companies, . Johns-Manville, 1030-1031 1008-1009 : Trane Company, 882-883 GOVERNORS, Pump United States Gauge Co., 1010 Crane Co., 944-945 Warren Webster & Co., 1098-1101 ' kieley & Mueller, Inc., 1093 Crane Co., 944-945 Kieley & Mueller, Inc., 1093 Wright-Austin Co., 1102 HEADS, Sprinkler . Grinnell Co., Inc., 993-995, 1087 HEAT SURFACE, Fan System Aerofin Corporation, 989-991 American Blower Corp., 866-867 Buffalo Forge Company, 972 C. A. Dunham Co., lOOOTOOl Fedders Manufacturing Co., 982 G & O Manufacturing Co., 992 General Electric Company, 908 909, 1044-1045 McCord Radiator & Mfg. Co., 983 McQuay, Incorporated, 876 Modine Manufacturing Co., 984 985 ' . Please mention THE GUIDE 1939 when writing to Advertisers ) John J. Nesbitt, Inc., 997 f^Nis8a^a Blower Company, 878 tir.B. F Sturtevant Co., 980 i/Trane Company, The, 882-883 . /'Unit Heater & Cooler Co., 986 Westinghouse Elec. & Mfg. Co., 888-889 L. J* Wing Mfg. Co., 978-979 ' York Ice Machinery Corp., 887 i Young Radiator Company, 987 Spencer Heater Division, 946-947 Williams Oil-O-Matic Heating Corp., 920 Westinghouse Elec. & Mfg. Co., 888-889 . Young Radiator Company, 987 HEATERS, Blast Aerofin Corporation, 989-991 American Blower Corp., 866-867 American Radiator Company, Delco - Frigidaire Conditioning Div., General - Motors Sales Corp., 902-904 General Electric Company, 908 909, 1044-1045 ' Kewanee Boiler Corp., 958-959 Meyer Furnace Co., 917 National Pipe Bending Co.. 988 Williams Oil-O-Matic Heating Corp., 920 ' .' HEATERS, Air 898-899, 940-941 HEATERS, Gas . ' Acme Heating & Ventilating Autovent Fan & Blower Co., 970 American Gas Products Div., Co., 895 Aerofin Corporation, 989-991 Bayley Blower Company, 971 Buffalo Forge Company, 972 . American Radiator Co., 900. 951 ' Airtherm Manufacturing Co., 981 Carrier Corporation, 870 Crane Co., 944-945 American Blower Corp., 866-867 Clarage Fan Company, 871 Burnham Boiler Corp., 942-943 ;1 American Gas Products Div., C. A. Dunham Co., 1000-1001 C. A. Dunham Co., 1000-1001 American Radiator Co., 900, Fedders Manufacturing Co:, 982 General Electric Company, 908 : .951 4. . American Radiator Cogipany, 898-899., 940-941 ^. I Autovent Fan &-Blower Co., 970 : Baker Ice Machine Co., 868-869 G & O Manufacturing Co., 992 McCord Radiator & Mfg. Co., 983 McQuay, Incorporated, 876 Modine Mfg. Co^, 984-985 John J. Nesbitt, Inc., 997 909, 1044-1045 . Kewanee Boiler Corp., 958-959 Meyer Furnace Company, 917 United States Radiator Corp., 948-949 Buffalo Forge . Company, 972 Niagara Blower Company, 878 "Burnham Boiler Corp., 942-943 B. F. Sturtevant Co., 980 HEATERS. Hot Water Service .-Carrier Corporation, 870 Trane Company, The, 882-883 American District Steam Co., C Clarage Fan Company, 871 Unit Heater & Cooler Co., 986 966, 1039 Combustion Engineering Co,, L. J. Wing Mfg. Co., 978-979 American Gas Products Div., 1105 Young Radiator Company, 987 American Radiator Co., 900, Delco - Frigidaire Conditioning Div., General Motors Sales HEATERS, Cabinet Corp., 902-904 American Radiator Company, C. A. Dunham Co., 1000-1001 898-899, 940-941 Excelsior Steel Furnace Co., 905 Burnham Boiler Corp., 942-943 Fedders Manufacturing Co., 982 ~- Delco - Frigidaire Conditioning Gar Wood Industries, Inc., 906 Div., General Motors Sales 907 Corp., 902-904 951 . American Radiator Company, 898-899, 940-941 Bell & Gosset Co., 999 Brownell Company, 1104 Burnham Boiler Corp., 942-943 Crane Company, 944-945 Fitzgibbons Boiler Co., Inc., 954 General Electric Company, 908- 909' 1044-1045 ffigSfr Grinnell Co., Inc., 993-995. 1087 Henry Furnace & Foundry Co., C. A. Dunham Co., 1000-1001 Fedders Manufacturing Co., 982 General Electric Company, 908 909, 1044-1045 955 Henry Furnace & Foundry Co., 910-911 S. T. Johnson Co., 962-963 m 910-911 f Ilg Electric Ventilating Co., 975 8ig| McCord Radiator & Mfg. Co., 983 ;? McQuay, Incorporated, 876 Meyer Furnace Company, 917 Ipj. Modine Mfg. Co., 984-985 Henry Furnace & Foundry Co., 910-911 S. T. Johnson Co., 962-963 McCord Radiator & Mfg. Co., 983 McQuay, Incorporated, 876 Modine Mfg. Co., 984-985 . Kewanee Boiler Corp., 958-959 L. J. Mueller Furnace Co., 918 919 National Pipe Bending Co.. 988 Pacific Steel Boiler Div.. U. S. Radiator Corp., 960 &S Herman Nelson Corp., 996 John J. Nesbitt, Inc., 997 Trane Company, The, 882-883 Spencer Heater Division, 946-947 Trane Company, Inc., 882-883 Unit Heater & Cooler Co., 986 Westinghouse Elec. & Mfg. Co., Weil-McLain Company, 960 888-889 Young Radiator Company, 987 HEATERS, Indirect HEATERS, Electric Aerofin Corporation, 989-991 Autovent Fan & Boiler Co., 970 American District Steam Co., Burnham Boiler Corp., 942-943 966, 1039 General Electric Company, 908 American Radiator Company, 909, 1044-1045 . . 898-899, 940-941 Grinnell Co., Inc., 993-995. 1087 Bell & Gossett, 999 Ilg Electric Ventilating Co., 975 Fedders Manufacturing Co., 982 B. F. Sturtevant Co., 980 ' Fitzgibbons Boiler Co., Inc., 954 Weil-McLain Company, 950 ' . 955 Westinghouse Elec. & Mfg. Co., Kewanee Boiler Corp., 958-959 888-889 . McQuay, Incorporated, 876 f|p John J. Nesbitt, Inc., 997 ` Young Radiator Company, 987 Niagara Blower Co., 878 Unit Heater and Cooler Co., 986 L. J. Wing Mfg. Co., 978-979 SWfr.'B. F. Sturtevant Co., 980 HEATERS, Feed Water Trane Company, The, 882-883 Brownell Company, 1104 HEATERS, Instantaneous - Unit Heater and Cooler Co., 986 Cochrane Corp., 1086 . National Pipe Bending Co.. 988 ^United States Air Conditioning Worthington Pump & Machinery & Corp., 884 . Corp., 890-891 V, Westinghouse Elec._&'Mfg. Co., General Electric Company, 908 | 888-889 " . 909, 1044-1045 |_-L. J. Wing Mfg. Co., 978-979 National Pipe Bending Co., 988 York Ice Machinery Corp., 887 Westinghouse Elec. & Mfg. Co., Young Radiator Company, 987 888-889 ' HEATERS, Automatic Hot HEATERS, Fuel Oil Water, Domestic American District Steam kj. American Gas Products Div., 966, 1039 3'- American Radiator Co., 900, Bell and Gossett Co., 999 Co., HEATERS, Refuse Burning Kewanee Boiler Corp., 958-959 L. J. Mueller Furnace Co., 918 919 ' . HEATERS, Storage American District Steam Co., 966, 1039 . American Gas Products Div., American Radiator Co., 900, . 951 Bell & Gossett Co., 999 . 951mW AmerNicuamn eraRlasdfoialtloorw-in.CgoMmpaannuyf,acturers* Names refer to pages in the Catalog Data Section l| 898-899, 940-941 . Crane Co., 944-945 '. 1147 |& Delco - Frigidaire Conditioning %V:- Div., General Motors Sales Ssjj Corp., 902-904 ' K Fi9tz5g6ibbons Boiler Co., Inc., 954- I Gar Wood Industries, Inc., 906- IPV07 Heating VENTIIiATING Air Conditioning Guide 1939 Brownell Company, 1104 Burnham Boiier Corp., 942.943 Crane Co., 944-945 General Electric Company, 908 909, 1044-1045 National Pipe Bending Co., 988 HEATERS, Tank American District Steam Co.. 986, 1039 American Gas Products Div., - American Radiator Co., 900. 951 American Radiator Co.. 898-899, 940-941 . Bell & Gossett Co., 999 Burnham Boiler Corp., 942-948 AiTternp Dw., Chrysler Corp., 896-897 Airtherm Manufacturing Co., 981 American Blower Corp., 660-867 American Gas Products Div., American Radiator Co., 900, 951 Autovent Fan & Blower Co., 970 Buffalo Forge Company, 972 Burnham Boiler Corp., 942-943 Carrier Corporation, 870 Clarage Fan Company, 872 Delco Frigidaire Conditioning Div.. General Motors Sales Corp., 902-904 . C. A. Dunham Co., 1000-1001 Excelsior Steel Furnace Co., 905 Herman Nelson Corp., 995 Research Corporation, 880 Sarco Co., Inc., 1096-1097 Schwitzer-Cammins Co., 894 Ull Spence Engineering Co., 1127 Spencer Heater Division. 946 947 Trane Company, The, 882-888 United States Radiator Com 948-949 Westinghouse Elec. & Mfg. Co 888-889 " Williams Oil-O-Matic Heating Corp., 920 Warren Webster & Co., 1098-noi L. J. Wing Mfg. Co., 978-979 Fittgjbbons Boiler Co., Inc., Fedders Manufacturing Co.. 982 954-955- Gar Wood Industries, Inc., 906 HEATING SYSTEMS. Furnace Grinnell Co., Inc., 993-995, 1087 907 Acme Heating & Ventilating S. T. Johnson Co., 962-963 General Electric Company, 908 Co., 895 Kewanee Boiler Corp.,* 958-959 909. 1044-1045 Airtherm Manufacturing Co., 981 I>. J. Mueller Furnace Co., 918 Henry Furnace & Foundry Co., American Gas Products Div., 919 910-911 American Radiator Co., 900 Pacific Steel Boiler Div., U. S. S. T. Johnson Co., 962-963 951 ' Radiator Corp., 960 -Kelvinator Division of Nash- Carrier Corporation, 870 Spencer Heater Division, 946 Kelvinator Corp., 912-916 Delco - Frigidaire Conditioning 947 Meyer Furnace Co., The, 917 United States Radiator Corp., Modine Mfg. Co., 984-985 - Div., General Motors Sales Corp., 902-904 ' 948-949 L. J. Mueller Furnace Co., 918 Excelsior Steel Furnace. Co., 90S Weil-McLain Company, 950 919 . Gar Wood Industries, Inc., 906 Westinghouse Elec. & Mfg. Co., Herman Nelson Corp., 996 907 .' 888-889 . John J. Nesbitt, Inc., 997 General Electric Company. 908-. HEATERS. Unit Niagara Blower Company, 878 909, 1044-1045 ^ Spender Heater Division, 946-947 Henry Furnace & Foundry Co., Airtherm Manufacturing Co., 981 B. F. Sturtevant Co., 980 ` American Blower Corp., 866-867 Trane Company, The, 882-883 910-911 S. T. Johnson Co., .962-963 Autovent Fan & Blower Co., 970 Unit Heater and Cooler Co., 986 Kelvinator Division of Nash- Bayley Blower Company, 971 United States Radiator Corp., Kelvinator Corp., 912-916 Buffalo Forge Company, 972 Burnham Boiler Corp., 942-943 948-949 Meyer Furnace Company, 917 Westinghouse Elec. & Mfg. Co.. L. J. Mueller Furnace Co.. 918 Carrier Corporation, 870 Clarage Fan Company, 871 888-889 L. J. Wing Mfg. Co., 978-979 919 Herman Nelson Corp., 996 . Crane Co., 944-945 . Young Radiator Company. 987 Schwitaer-Cummins Co., 894. Delco - Frigidaire Conditioning York Ice Machinery Corp., 887 1111 Div., General Motors Sales Spencer Heater Division, 946-* Corp., 902-904 HEATING SYSTEMS, Auto 94? C. A. Dunham Co., 10QO-1Q01 matic United States Radiator Corp., Fedders Manufacturing Co., 982 Airtemp Div., Chrysler Corp., 948-949 '* Grinnell Co., Inc., 993-995. 1087 Ilg Electric Ventilating Co., 975 896-897 American Gas Products Div.. Westinghouse Elec. & Mfg. Co., 888-889 r McCord Radiator & Mfg. Co.. 983 American Radiator Co., 900, Williams Oil-O-Matic Heating McQuay, Incorporated, 876 Modine Mfg. Co., 984-985 ' Herman Nelson Corp., 996 John J. Nesbitt, Inc., 997 Niagara Blower Company, 878 B. F. Sturtevant Co., 980 Trane Company, The, 882-883 Unit Heater and Cooler Co., 986 United States Air Conditioning Corp., 884 United States Radiator Corp., 948-949 '' Warren Webster & Co., 1098-1101 L. J. Wing Mfg. Co;, 978-979 Young Radiator Company, 987 HEATERS, Unit, Gas Fired Airtherm Manufacturing Co.. 981 American Gas Products Div., American Radiator Co., 900, 951 Buffalo Forge Company. 972 Crane Company, 944-945 951 . American Radiator Company, 898-899, 940-941 Anderson Products, Inc., 1130 Burnham Boiler Corp., 942-943 ' Carrier Corporation, 870 Crane Co., 944-945 . Delco - Frigidaire Conditioning Div., General \Motors Sales Corp., 902-904 . C. A. Dunham Co., 1000-1001 Gar Wood Industries, Inc., 906 907 General Electric Company, 908 909, 1044-1G45 Henry Furnace & Foundry Co., 910-911 Hoffman Specialty Co., Inc., 1988-1989 - Illinois Engineering Co., 1090 1091 S. T. Johnson Co., 962-963 Kelvinator Division of Nash- Corp., 920 HEATING SYSTEMS, Gas Fired Acme Heating & Ventilating Co., 895 Airtemp Div., Chrysler Corp., 896-897 Airtherm Manufacturing Co., 981 American Blower Corp.. 866-867 American Gas Products Corp., 900, 951 Barnes & Jones, Inc., 1081 Burnham Boiler Corp.. 942-943 Carrier Corporation, 870 Crane Co., 944-945 Delco - Frigidaire Conditioning Div., General Motors Sales Corp., 902-904 C. A. Dunham Co., 1000-1001 Fitzgibbons Boiler Co., 954-955 Gar Wood Industries, Inc.. 906 907 ' General Electric Company. 908 L. J. Mueller Furnace* Co., 918 Kelvinator Corp., 912-910 919 * " Meyer Furnace Company, 917 . 909, 1044-1045 Henry Furnace & Foundry Co., Trane Company, The, 882-883 HEATING SYSTEMS, Air MotorStokor Division, Hersbey Machine & Fdy. Co., 1110 . 910-911 S. T. Johnson Co.^962-963 , Kelvinator Division of Nash- Acme Heating & Ventilating L. J. Mueller. Fvrnace Co., 918 Co., 895 919 Kelvinator Corp., 912-016 Please mention THE GUIDE 19J9 when writing to Advertisers 1148 Index to Modern Equipment h. J- MuellerVurnace Co 918- "EATIN SYSTEMS. Steen. United " Airtherm... MAria.aniiuugfCaIcCtiu.UrrimngK Coo., 9y8o1i 948-949 Spencer Heater Division, 946-947 American Gas Products Div., Warren Webster & Co., 1098-1101 T-r--a--n--e-- Compa`nVy,> T1hIIeC,, 800812.--0^0"0' United States Radiator Corp. Anem, erica* n Radiator C---o-'., 9vv0v0.. AlI . . ,. Westinghouse Elec, & Mfg. Co., 888-889 ' 948-949 American Radiator Company. Williams Oil-O-Matic Heating Westinghouse Elec. & Mfg. Co. 898-899. 940-941 Corporation, 920 888-889 . Anderson Products, Inc., 1130 Barnes & Jones, Inc., 1081 HEATING SYSTEMS, Vapor HEATING SYSTEMS, Hot Water Bell & Gossett Co., 999 American District Steam Co.. Burnham Boiier Corp., 942-948 966. 1039 American Blower Corp.. 866*867 A__m__e__r_i_c__a__n Gas .Pirvouduuvcwts Div1 American Radiator Co., 900,* 951 American Radiator Company, 898-899, 940-941 Beaton and CadwelJ Mfg. Co., The, 1084-1085 . Bell & Gossett Co., 999 Burnham Boiler Corp., 942-943 Crane Co., 944-945 CSr>a-l_fr_rrn_i_eerrri-%CCoo-`-rrpp9oo-4rr4"aa`*9tt-iu4o5inr , 3-70 _tV_-_ * 4* TMgidaire uCuounrdniutiuonniinngs Div., General Motors Sales Corp., 902-904 C. A. Dunham Co,, 1000-1001 Gar Wood Industries, Inc., 906 907 General Electric Company, 908 909, 1044-1045 William S. Haines & Co., 1092. American Gas Products Div.,. American Radiator Co., 900, 951 * American Radiator . Company, 898-899, 940-941 Barnes & Jones, Inc., 1081 Crane Co., 944-946 Delco - Frigidaire Conditioning Div., General Motors Sales Corp., 902-904 C. A. Dunham Co., 1000-1001 D_e_DD_lc_iiVvo..-, F__r_Gig_e_idn__ear.iar..eIl. Conditioning Moto---r-s< *-S'ales Corp., 902-904. Gar Wood Industries, Inc., 906- * 090077 . General Electric Company, 908- 909. 1044-1045 Ho1f0fm88a-1n089Specialty Co;, Inc., ' Gar Wood 907 Industries, Inc., 906 Illinois Engineering Co., 10901091 g^ x. Johnson Co., 962-963 ,Kre,lv-.invautonrusvD-iii*v\iss*ji.oi nyoo-yfo<iNash- General Electric Company, 908 909, 1044-1045 William S. Haines & Co., 1092 Hoffman Specialty Co., Inc., Kelvinator Corp., 912-916 1088-1089 *' Henry Furnace & Foundry Co., 910-921 Hoffman Specialty Co., Inc., 1088-1089 Kewanee Boiler Corp., 958-959 Milwaukee Valve Co., 1094 L. J. Mueller Furnace Co., 918 919 Illinois Engineering Co., 1090 1091 S. T. Johnson Co., 962-963 ' Kelvinator Division of Nash- S. T. Johnson Co., 962-963 Herman Nelson Corp.,.9.96 L. J. Mueller Furnace Co. 918-' Ric-wiL Company,. The, 10941 Kelvinator Corp., 912-916 Milwaukee Valve Co., 1094 919 -- *' S--p_e_n_c_e_r ~Hea*ter ~ADTiIvViIsDiIoUnII., 93*4\63--947 Trane Company, The, 882-883 United States Radiator Corp., 948-949 ' Sarco Company, Inc., 1096-1097 Spence Engineering Co., 1127 S--*pencer Heater Di/4iv>isaiiounu, 946-947 Trane Company, The, 882-883 Unit Heater & Cooler Co., 986 L. J. Mueller Furnace Co., 918 919 Herman Nelson Corp., 996 Sarco Company, Inc., 1096-1097 Spencer Heater Division, 946-947 Westinghouse Elec. & Mfg. Co., 8__8_8_-_8_8_9 Williams Oil-O-Matic Heating United States Radiator Corp. 948-949 Xa*!Fn ,Webster & Co.. 1098-1101 Trane Company, The, 882-883 United States Radiator Corp., 948-949 . Corp., 920 Westinghouse Elec. & Mfg. Co.. Warren Webster & Co., 1098-1101 L. J. Wing Mfg. Co., 978-979 888-889 Williams Oil-O-Matic Westinghouse Elec. & Mfg. Co., Heating 888-889 HEATING SYSTEMS, Oil Fired Acme Heating & Ventilating Corp., 920 L- J` ' `Wins Mfg. Co., 978-979 Williams Oil-O-Matic Heating Corp., 920 Co., 985 HOSE, Flexible Metallic (See Airtemp Div., Chrysler Corp., 896-897 Airtherm Manufacturing Co., 981 American Blower Corp., .866-867 Barnes & Jones. Inc., 1081 ./Carrier Corporation^.870 C__r_a_n_e C__o_._, 944^94--5 Delco - Frigidaire Conditioning HEATING SYSTEMS, Vacuum also Conduit, flexible; Tubing, American Gas Products .Div., flexible) American Radiator Co., 900, American Brass Co.. 1046-1047 951 American Radiator 898-899, 940-941 Company, BOSE, fSee Refrigerant Charging . Hose, Flexible Metallic) uBaarmnes a&t *Jounnees, mInec., 1U08M1 HOT WATER HEATING SYS Beaton and Cadwell Mfg. Co;, TEMS (See Heating Systems, Div., General Motors Sales The, 1084-1085 Hot Water) Corp., 902-904 Excelsior Steel Furnace Co., 905 Gar Wood Industries, Inc.. 906- Burnham Boiler Corp., 942-943 Crane Co-, 944-945 Delco - Frigidaire Conditioning HUMIDIFIERS Air-Maze Corp., 922-923 q9077 General Electric Company, 908 tt9,,09,' 1044-1045 H9l0 9l1" & Foundry Co., 910-911 S. T. Johnson Co., 962-963 Kelvinator Division of <tJash- Kelvinator Corp., 912-916 Meyer Furnace Co., The, 917 L. J. Mueller Furnace Co., 918 919 ' Herman Nelson Corp., 996 . Trane Company, The, 882-833 United States Radiator Corp., 948-949 Westinghouse Elec. & Mfg. Co.,- -D*iv., G' eneral Motors ~Sa'les Corp.. 902*904 C. A. Dunham Co., 1000-1001 Gar Wood Industries, Inc.. 906 907 General Electric Company, 908 909. 1044-1045 William S. Haines & Co., 1092 Hoffman Specialty Co.. Inc., 1088-1089 Illinois Engineering Co., 1090 1091 Milwaukee Valve Co., 1094 ' L. J. Mueller Furnace Co,, 918 Ne9w19York Air Valve Corp., 1134 American Blower Corp., 866-867 American Moistening Co., 865 American Radiator Company,' 898-899, 940-941 Armstrong Machine Works, * 1082-1083 * Baker Ice Machine Co., 868^869 Buffalo Forge Company, 972 Burnham Boiler Corp., 942-943 Carrier Corporation, 870 Clarage Fan Company, 871 Crane Co., 944-945 Delco - Frigidaire Conditioning Div., General Motors Sales Corp., 902-904 General Electric Company, 908 888-889 , Sarco Company, Inc., 1096-1097 909, 1044-1045 Williams Oil-O-Matic Heating Spencer Heater Division, 946-947 Grinnell Co., Die.. 993-995. 1087 Corp., 920 Trane Company, The, 882-883 Henry Furnace & Foundry Co.. 910-911 Numerals following Manufacturers' Names refer to pages In the Catalog Data'Section 1149 Heating Ventilating Air Conditioning Guide 1939 Ilg Electric Ventilating Co., 975 HUMIDITY CONTROL Palmer Co., 1007 Johnson Service Co., 1120-1121 American Moistening Co., 865 Powers Regulator Co., 1124 119. Maid-O-Mist, Inc., 998 McQuay, Incorporated, 876 Barber-Colman Co., 1112-1113 Bristol Company, The, 1002 Taylor Instrument Compand 1008-1009 "names. Meyer Furnace Co., The, 917 Carrier Corporation, 870' United States Gauge Co.. 1010 L. J. Mueller Furnace Co., 918 Cochrane Corp., 1086 . . Westinghouse Elec. & Mft? 919 Delco - Frigidaire Conditioning 888-889 *' v'- Niagara Blower Company, 878 Div., General Motors Sales INSULATION, Building Parks-Cramer Company, 879 Corp., 902-904 Schwitzer-Cummins Co., 894, Detroit Lubricator Co., 1114-1115 1111 Julien P. Fries & Sons, Div. of Alfol Insulation Co., Inc 1011 Aluminum Aircell Insulation Co. H. J. Somers, Inc., 931 B. F. Sturtevant Co., 980 . Trane Company, The, 882-883 United States Air Conditioning Corp., 884 Unit Heater & Cooler Co., 986 Weil-McLain Company, 950 Westinghouse Elec. & Mfg. Co.. 888-889 HUMIDIFIERS, Central Plant Acme Heating & Ventilating Co.. 895 ' American Blower Corp., 866-867 Baker Ice Machine Co., 868-869 Bayley Blower Company, 971 Buffalo Forge Company, 972 Carrier Corporation, 870 Clarage Fan Company, 871 Delco - Frigidaire Conditioning Bendix Aviation Corp., 1118 Fulton Sylphon Co., 1116-1117 Armstrong Cork Company, 1013 Barrett Company, 1014 ' General Electric Company, 908 Carey, Philip, Co., 1020 909, 1044-1045 , Grinnell Co.,- Inc., 993-995, 1087 Henry Furnace & Foundry Co., 910-911 . ' Celotex Corporation, The 101 a 1017' ' Chamberlin Metal Weather Strin Co., 1018-1019 p Johnson Service Co., 1120-1121 Manning, Maxwell & Moore; Inc., 1006 Mercoid Corporation, The, 1119' Minneapolis-Honeywell Regulator Eagle-Picher Lead Co., 1021 Ehret Magnesia Manufacturing Co.', 1022-1023 K General Insulating & Mfg Co 1024 '- " Co., 1122-1123 Niagara Blower Company, 878. Parks-Cramer Company, 879 Penn Electric Switch Co., 1126 Powers Regulator Co., 1124-1125 Taylor Instrument Companies, Insulite Company, The, 1026-1027 Insul-Wool Insulation Corp., 1025 .International Fibre Board Ltd 1028 " Johns-Manville, 1030-1031 Mundet Cork Corp., 1029 1008-1009 Owens-Corning Fiberglas Corp . Div., General Motors -Sales Corp., 902-904 Gar Wood Industries, Inc., 906 907 General Electric Company, 908 909, 1044-1045 llg Electric Ventilating. .Co., 975 Johnson Service Co., 1120-1121 Meyer Furnace Co., The, 917 Niagara Blower Company, 878 Parks-Cramer Company, 879 Powers Regulator Co., 1124-1126 Research Corporation, 880 H. J. Somers, Inc., 931 B. F. Sturtevant Co., 980 * Trane Company, Inc.; 882-883 . United States Air Conditioning Corp., 884 Westinghouse Elec. & Mfg. Go., 888-889 York Ice Machinery Corp., 887 HUMIDIFIERS, Unit . HUMIDITY Indicators RECORDERS and ' 929 " Pacific Lumber Co., The, 1034 Ruberoid Co., The, 1032-1033 Bristol Company, The, 1002 Standard Lime & Stone Co.. 1035 Julien P. Fries & Sons, Div. of United States Gypsum Co., 1036 Bendix Aviation Corp., 1118 Western Felt Works, 1037 Leeds & Northrup Co., 1004 . Wood Conversion Company, 1038 Minneapolis-Honeywell Regulator Co., 1122-1123 INSULATION, Felt Palmer Co-, 1007 Barrett Company, 1014 Powers Regulator Co., 1124-1125 Carey, Philip, Co., 1020 Taylor Instrument Companies, Ehret Magnesia Mfg. Co., 1022 1008-1009 _ ' 1023 General Insulating & Mfg. Co., HYGROMETERS (See also Hu 1024 midity Recorders and Indi Johns-Manville, 1030-1031 cators) Ruberoid Co., 1032-1033 American Moistening Co., 865 Standard Lime & Stone Co., 1035 Detroit Lubricator Co'., 1114-1115 Western Felt Works, 1037 Julien P. Friez & Sons, Div. of Bendix Aviation Corp., 1118 Grinnell Co., Inc., 993-995, 1087 Johnson Service Co., 1120-1121 INSULATION, Pipes and Sur faces (See Coverings, Pipes and Surfaces) Airtemp Div., Chrysler Corp., Palmer Company, 1007 INSULATION. Magnesia - 896-897 American Blower Corp., 866-867 American Moistening Co., 865 Armstrong Machine Works, 1082-1083 . Buffalo Forge Company, 972 Burnham Boiler Corp., 942-943 Taylor - Instrument Companies. 1008-1009 ' INDUCED DRAFT COOLING TOWERS (See also Cooling Towers, Forced Draft, Mech anical Draft) Carey, Philip, Co., 1020 Ehret Magnesia & Mfg. Co., 1022-1023 Johns-Manville, 1030-1031 Ruberoid Co., The. 1032-1033 INSULATION, Refractory Carrier Corporation, 870 Baker Ice Machine^Co., 868-869 Babcock & Wilcox Co., 952 Clarage Fan Company, 871 Buffalo Forge Company, 972 ' Carey, Philip, Co., 1020 Crane Co., 944-945 ^ __ Cooling Tower Co., Div. of Fluor Johns-Manville, 1030-1031 Delco - Frigidaire .Conditioning Div., General Motors Sales Corp., 902-904 General Electric Company, 908 909, 1044-1045 Grinnell Co., Inc., 993-995, 1087 Maid-O-Mist, Inc., 998 Marley Company, The, 965 McQuay, Incorporated, 876 Niagara Blower Company, 878 Parks-Cramer Company, 879 B. F. Sturtevant Co:, 980 ` Trane Company, The, 882-883 Tuttle & Bailey, Inc., 1072-1073 Unit Heater and Cooler Co., 986 United States Air Conditioning Corp., 884 Corp., Ltd., 964 Marley Company, 965 Research Corporation, 880 Unit Heater & Cooler Co., 986 York Ice Machinery Corp., 887 INSTRUMENTS, Indicating and Recording ' Bristol Company, ,The, 1002 Cochrane Corp., 1086 Julien P. Friez & Sons, Div. of Bendix Aviation Corp., 1118 Illinois Testing Laboratories, Inc., 1003 Leeds & Northrup Co.,. 1004 Minneapolis-Honeywell Regulator Co., 1122-1123 ,, INSULATION, Sound Deaden ing (See also Felt, Sound Deadening) .- Alfol Insulation Co., Inc.. 1011 Aluminum Aircell Insulation Co., 1012 Armstrong Cork Company, 1013 Barrett Company, 1014 Carey, Philip, Co., 1020 Celotex Corporation, 1015-1017 Eagle-Picher Lead Co., 1021 Ehret Magnesia Mfg Co., 1022 1023 - General Insulating & Mfg. Co- 1024 ,, Insulite Company, The, 1026-1021 Please mention THE GUIDE 1939 when writing to Advertisers Index to Modern Equipment __ il-Wool Insulation Corp., 1025 /'international Fibre Board Ltd., 5.-: 1028 r ^Johns-Manville, 1030-1031 Mundet Cork Corp., 1029 ^Owens-Corning Fiberglas Corp., 929 f-pacific Lumber Co., The, 1034 gH. W. Porter & Co., 1040 ^Ruberoid Co., The, 1032-1033 ^Standard Lime & Stone Co., 1035 ^.United States Gypsum' Co., 1036 ^Western Felt Works, 1037 PWood Conversion Company. 1038 Spence Engineering Co., 1127 METERS. Feed Water Taylor Instrument Companies, Minneapolis-Honeywell Regulator 1008-1009 ' Co., 1122-1123 LIQUID LEVEL GAGES (See METERS, Flow Gages, Liquid Level) American District Steam Co., LOUVERS American Coolair Corp., 966, 1039 968-969 Bristol Company, The, .Cochrane Corp., 1086 1002 Anemostat Corp. of America, 1067 Auer Register Co., 1068 Autovent Fan & Blower Co., 970 SBuhfafamlopFioornglefoCwoemTp^a'ny, 972 Co.. Leeds & Northrup Co., 1004 Minneapolis-Honeywell Regulator Co., 1122-1123 Taylor Instrument Companies, 1008-1009 . ' ^INSULATION, Underground 973 METERS, Steam : Steam Pipe - Clarage Fan Company, 871 American District Steam Co.. wAlfol Insulation Co., Inc., 1011 ^American District Steam Co.. Hart & Cooley Mfg. Co., 1070 1071 . 966, 1039 Cochrane Corp., 1004 I. 966, 1039 |-E. B. Badger & Sons Co., 967 Hendrick Mfg. Co., 1069 Minneapolis-Honeywell Regulator Henry Furnace & Foundry Co., Co.. 1122-1123 ^Carey, Philip, Co., 1020 910-911 MOTORS, Electric ^Eagle-Picher Lead Co., 1021 ^Ehret Magnesia Mfg. Co., 1022 p 1023 (^General Insulating & Mfg. Co., -1024 . ^Johns-Manville, 1030-1031 kOwens-Corning Fiberglas Corp., %' 929 Independent Register Co., 1074 Trane Company, The, 882-883 Tuttle & Bailey, Inc., 1072-1073 Unit Heater & Cooler Co., The, 986 United States Register Co., 1075 Waterloo Register Co., 1076 Young Regulator Company, 934 Barber-Colman Co., 1112-1113 Century Electric Co., 1043 General Electric Company, 908 909, 1044-1045 B. F. Sturtevant Co., 980 . Westinghouse Elec. & Mfg. Co., 888-889 Williams Oil-O-Matic Heating |H. W. Porter & Co., 1040 Ric-wiL Company, The, 1041 ^Ruberoid Co., The, 1032-1033 ^Standard Lime & Stone Co., 1035 ^Underground Steam Construction ' Co., 1044 MANHOLE COVERS, For Underground Systems American Coolair Corp., 968-969 American District Steam Co., .. 966, 1039 . ' Corp., 920 NOISE ELIMINATORS (See also Hose,, flexible; Tubing, flexible; Sound Deadeners; Vibration Absorbers) |Wood Conversion Company, 1038 Ric.wicPComrpfnyCTh1e04?041 NOZZLES, Spray (See Spiap $INSULATION, Ventilating Ducts $Alfol Insulation Co., Inc., 1011 ^Aluminum Aircell Insulation MECHANICAL DRAFT AP PARATUS (See Blowers, Forced Draft) Nozzles) . OIL BURNER EQUIPMENT Airtemp Div., Chrysler Corp., 896-897 Co., 1012 MECHANICAL DRAFT COOL American Radiator Company, ^Armstrong Cork Company, 1013 ING TOWERS (See also Cool 898-899. 940-941 gBarrett Company, 1014 ing Towers, Forced Draft, In Crane Co., 944-945 ^Carey, Philip, Co., 1020 duced Draft) Delco - Frigidaire Conditioning sCelotex Corporation, 1015-1017 Baker Ice Machine Co., 868-869 Div., General -Motors Sales ja^*.E--ag-le----P--i-c--h--e-r---L--e--a--d-BCuoff.a, lo102F1orge Company,. 973 Corp., 902-904 g^Ehret Magnesia Mfg. Co., 1022- Cooling Tower Co., Div. of Fluor Detroit Lubricator Co., 1114-1115 . 1023 Corp., Ltd., 964 General Electric Company, 908-' General Insulating & Mfg. Co., Marley Company, 965 909, 1044-1045 . & 1024 Research Corporation, 880 S. T. Johnson Co., 962-963 glnsulite Company, The, 1026-1027 Unit Heater & Cooler Co., 986 Herman Nelson Corp., 996 . ^International Fibre Board Ltd.. York Ice Machinery Corp., 887 Kelvinator Division of Nash- r 1028 Kelvinator Corp., 912-916 g'Johns-Manville, 1030-1031 IMundet Cork Corp., 1029 METALS, Perforated (See Per L. J. Mueller Furnace Co., 918 forated Metals) 919 SOwens-Corning Fiberglas Corp., |v 929 . ^Pacific Lumber Co., The, 1034 ^Ruberoid Co., The, 1032-1033 - ^Standard Lime & Stone Co., 1035 ^Western Felt Works, 1037 |Wood Conversion Company, 1038 METERS, Air Bristol Company, The. 1002 Julien P. Friez & Sons, Div. of Bendix Aviation Corp., 1118 Minneapolis-Honeywell Regulator TaCyolo.,'r 11l2n2s'-t1r1u2m3 ent Companies, Spencer Heater Division, 946-947 Westinghouse Elec. & Mfg. Co., 888-889 . Williams Oil-O-Matic. Heating Corp., 920 OIL BURNERS Airtemp - Div., Chrysler Corp., ' ^LIQUID LEVEL CONTROLS 1008-1009 IpAlco Valve Co., Inc., 1129 METERS, Air Velocity ^Bristol Company, The, 1002 , g^Cochrane Corp., 1086 ' ^Detroit Lubricator Co., 1114-1115 Ef'Foster Engineering Co., 1132 jjjp'Frick Company, 873 Anderson Products, Inc., 1130 Julien P. Friez & Sons, Div. of Bendix Aviation Corp., 1118 Illinois Testing Laboratories, 1003 VJohnson Service Co., 1120-1121 -^Kieley & Mueller, Inc., 1093 -gLiquidometer Corp., 1005 Minneapolis-Honeywell Regulator Co., 1122-1123 Powers Regulator Co., 1124-1125 Maid-O-Mist, Inc., 998 ^McDonnell & Miller, 938-939 Minneapolis-Honeywell Regulator Taylor Instrument 1008-1009 Companies, % Co., 1122-1123 . ' METERS, Condensation ^-Mueller Steam Specialty Co., American District Steam- Co., Inc., 1095 966. 1039 896-897. Babcock & Wilcox Co., 952 Combustion Engineering Co., 1105 .. Crane Co., 944-945 . Delco - Frigidaire Conditioning -Div., General -Motors Sales Corporation, 902-904 Gar Wood Industries, Inc., 906 907 General Electric Company, 908 909, 1044-1045 S. T. Johnson Co., 962-963 Kelvinator Division of Nash- Kelvinator Corp., 912-916 L. J. Mueller Furnace Co., 918 919 . Numerals following Manufacturers' Names refer to pages in the Catalog Data Section 1151 1939Heating Ventilating Air Conditioning Guide Meyer Furnace Co., 91? Herman Nelson Corp., 996 Spencer Heater Division, 946-947 Westinghouse Elec. & Mfg. Co., 888-889 Williams Oil-O-Matic Heating PIPE. Copper American Brass Co., 1046-1047 American Radiator Company, 898-899, 940-941 Crane Co., 944-945 Wolverine Tube Co., 1050 E. B. Badger & Sons Co 957 Grinnell Co., Inc., 993-995 inoH. W. Porter & Co., 1040 8< Ric-wiL Company, The, 1041 Underground Steam Constructs Co., 1042 . tlon Corp., 920 OIL BURNER MOTORS (See Motors, Electric) OIL BURNER TUBING, Flex ible (See Tubing, Flexible Met allic) OIL TANK GAGES (See Tank Gages, Oil) PIPE* Copper Bearing Steel Bethlehem Steel Co., 1079 Carnegie-lllinois Steel Corp., 1080 * Crane Co., 944-945 Jones & Laughlin Steel Corp., 1049 PIPE, Furnace (See Furnace Pipe) PITOT TUBES (See Air Measur ing and Recording Instru ments) ' PLASTER BASE, Fire Retard ing * Armstrong Cork Company, 1013 Gelotex Corporation, 1015-1017 Johns-Manville, 1030-1031 United States Gypsum Co., 1039 ORIFICES, Flow Meter PIPE, Return Bends PLASTER BASE, Insulating - Bristol Company, The, 1002 Cochrane Corp., 1086 Taylor Instrument Companies, 1008-1009 . ORIFICES, Radiator Barnes & Jones, Inc., 1081 Bell and Gossett Co., 999 American Brass Co., T046-1047 Crane Co., 944-945 Frick Company, 873 Grinnell Co., Inc., 993-995. 1087 Arthur Harris & Co., 1048 Vilter Manufacturing Co., 886 PIPE. Steel Armstrong Cork Company, 1013 Celotex Corporation, 1016-1017 Insulite Company, The, 1026-1027 International Fibre Board Ltd 1028 * Johns-Manville, 1030-1031 . United States Gypsum Co., 1036 Detroit Lubricator Co., 1114-1115 American Rolling Mill Co., 1078 PLASTER BASE. Sound Dead Hoffman Specialty Co., In'c., Carnegie-lllinois Steel Corp., ening 1088-1089 Illinois Engineering Co., 1090 1091 Milwaukee Valve Co., 1094 New York Air Valve Corp., 1134 .Sarco Co., Inc., 1096-1097 1080 Crane Co., 944-945 Grinnell Co., Inc., 993-995, 1087 Jones & Laughlin Steel Corp., 1049 Vilter Manufacturing Co., 886 Armstrong Cork Company, 1013 Barrett Company, 1014 Celotex Corporation, 1015-1017 ` Insulite Company, The, 1026-1027 International Fibre Board Ltd 1028 " Spence Engineering Co., 1127 Trane Company, The, 882-883 Warren Webster & Co.. 1098-1101 PIPE, Wrought Iron Crane Co., 944-945 Grinnell Co., Inc., 993-996, 1087 Johns-Manville, 1030-1031 United States Gypsum Co., 1036 PLATES, Iron PACKING Asbestos Vilter Manufacturing Co., 886 American Rolling Mill Co., 1078 Barrett Company, 1014 Ehret Magnesia Mfg. Co., 1022 1023 Johns-Manville, 1030-1031 PIPE ANCHORS American District Steam Co., 966, 1039 E. B. Badger & Sons Co., 967 Carnegierlllinois Steel Corp., 1080 PLATES, Stainless Steel American Rolling Mill Co., 1078 Carnegie-lllinois Steel Corp., 1080 PANELS, Insulated Alfol Insulation Co., Inc., 1011 Aluminum Aircell Insulation Co.. 1012 Carey,- Philip, Co., 1020 Celotex Corporation, 1015-1017 Crane Co., 944-946 Grinnell Co.. Inc., 993-995, 1037 H. W. Porter & Co.. 1040 Ric-wiL Company, 1041 Underground Steam Construction Co., 1042 PLATES. Steel American Rolling Mill Co., 1078 Carnegie-lllinois Steel Corp., 1080 Jones & Laughlin Steel Corp., 1049 General Insulating & Mfg. Co., PIPE BENDING 1024 Insulite Company, The, 1026-1027 International Fibre Board Ltd.. 1028 United States Gypsum Co., 1036 Baker Ice Machine Co., 868-869 . Crane Co., 944-945 Frick Company, 873 Grinnell Co., Inc., 993-995. Inc., 1087 PRESSURE REDUCING VALVES (See Regulators, Pressure) PROPELLER FANS (See Fans, Propeller) PERFORATED METALS Arthur Harris & Co., 1048 PSYCHROMETERS (See also Auer Register Co., The, 1068 Hendrick Mfg: Co., 1069 Parks-Cramer Co., 879 Vilter Manufacturing Co., 886 Air Measuring, Indicating and Recording Instruments) Tuttle & Bailey, Inc.. 1072-1073 U. S. Register Co., 1075 Wickwire Spencer Steel Co., 1076 PILLOW BLOCKS Lau Blower Co., 893 PIPE, Asbestos Eagle-Picher Lead Co., 1021 Ehret Magnesia Mfg. Co., 1022 1023 Johns-Manville, 1030-1031 Standard Lime & Stone Co., 1035 PIPE CONDUITS (See.Conduits, Underground Pive) PIPE COVERING (See Cover ing, Pipe) . . PIPE FITTINGS (See Fittings, Pipe) ` PIPE GUIDES ' E. B. Badger & Sons Co., 967 Crane Co., 944-945 H. W. Porter & Co., 1040 Ric-wiL Company, The, 1041 American Moistening Co., 865 Bristol Company, The, 1002 Julien P. Fries & Sons, Di\, of Bendix Aviation Corp., 1118 Johnson Service Co., 1120-1121 ' Leeds & Northrup Co., 1004 palmer Company, The, 1007 Parks-Cramer Company, 879 Taylor Instrument Companies, 1008-1009 PUBLICATIONS Air Conditioning--Oil Heat, 1056 PIPE, Brass ` American Brass Co., 1046-1047 Crane Co., 944-945 Wolverine Tube Co., 1050 Underground Steam Construction American Artisan, 1052 Co., 1042 . American Society of Refrigerat PIPE HANGERS (See Hangers, ing Engineers, 1051 Automatic Heat and Air Condi Pipe) tioning, 1054-1055 PIPE, Cement Johns-Manville, 1030-1031 Ruberoid Co., The, 1032-1033 Standard Lime & Stone Co., 1035 PIPE SUPPORTS, ground Conduit American District 966. 1039 For Under Steam Co.. Domestic Engineering, 1054-1055 Fueloil Journal, 1057 Heating & Ventilating, 105* Heating Journals, Inc., 1055 Dease mention THE GUIDE 1939 when writing to Advertisers 1152 Index to Modern Equipment Heating, Piping and Air Con , ditioning, 1053 i Plumbing and Heating Trade Journal, 1059 Sheet Metal Worker. 1060 PUMPS, Condensation American Radiator Company, 898-899, 940-941 Buffalo Pumps, Inc., 1061 . Chicago Pump Company, 1062 RADIATION, Cast-Iron American Radiator Company, 898-899, 940-941 Burnham Boiler Corp., 942-943 Crane Co., 944-945 PULLEYS, Chain Decatur Pump Company, 1063 C. A. Dunham Co., 1000-1001 Hart & Cooley Mfg. Co., 1070- Hoffman Specialty Co., Inc., r 1071 1088-1089 . United States Register Co., 1075 Ingersoll-Rand Co,, 874-875 PULLEYS, Speed Types ' Nash Engineering Co., 1064-1065 Pomona Pump Co., 1066 ! Lau Blower Co., 893 Trane Company, The, 882-883 Unit Heater and Cooler Co., 986 United States Radiator Corp., 948-949 . Weil-McLain Company, 950 RADIATION, Copper Aerofin Corporation, 989-991 American Radiator Company, i PUMPS, Air and Gas Worthington Pump & Machinery 898-899, 940-941 Co., 890-891 C. A. Dunham Co., 1000-1001 Curtis Refrigerating Machine G & O Manufacturing Co., 992 ; Co., Div. of Curtis Manu- PUMP MOTORS (See Motors, McCord Radiator & Mfg. Co., 983 . facturing Co., 872 Electric) McQuay, Incorporated, 876 ; Ingersoll-Rand Company, 874-875 Modine Mfg. Co., 984-985 Nash Engineering Co., 1064-1065 PUMPS, Steam John J. Nesbitt, Inc., 997 Buffalo Pumps, Inc., 1061 B. F. Sturtevant Co., 980 PUMPS, Ammonia Ingersoll-Rand Co., 874r875 Trane Company, The, 882-883 Worthington Pump & Machinery Corp., 890-891 Scmhwiitzer-Cummins Co., 894, Tuttle & Bailey. Inc., 1072-1073 Warren Webster & Co., 1098-1101 ' York Ice Machinery Corp., 887 Trane Company, The, 882-883 Young Radiator Company, 987 PUMPS, Boiler Feed Buffalo Pumps, Inc., 1061 Chicago Pump Co., 1062 Decatur Pump Company, 1063 Ingersoll-Rand Company, $74-875 Nash Engineering Co., 1064-1065 * Trane Company, The, 882-883 V Westinghouse Elec! & Mfg. Co., t 888-889 . Worthington Pump & Machinery , Corp., 890-891 f PUMPS, Brine Baker Ice Machine Co., Inc.. : 868-869 ; Buffalo Pumps, Inc., 1061 Carbondale Div., Worthington Worthington Pump & Machinery Corp., 890-891 PUMPS, Sump Buffalo Pumps, Inc., 1061 Chicago Pump Co., 1062 Ingersoll-Rand Co., 874-875 Nash Engineering Co., 1064-1065 Pomona Pump Company, 1066 Worthington Pump & Machinery Corp., 890-891 PUMPS, Turbine Decatur Pump Company, 1063 Hoffman Specialty Co., Inc., 1088-1089 Ingersoll-Rand Co., 874-875 Nash Engineering Co., 1064-1065 RADIATION, Plain and Ex tended Surface Aerofin Corporation, 989-991 American Radiator Company, 898-899, 940-941 Buffalo Forge Company, 972 Crane Co., 944-945 G & O Manufacturing Co., 992 General Electric Company, 90S- 909, 1044-1045 Grinnell Co., Inc., 993-995, 1037 Modine Mfg. Co., 984-985 ' John J. Nesbitt, Inc., 997 B. F. Sturtevant Co., 980 Trane Company, The, 882-883 Weil-McLain Company, 950 Young Radiator Company, 987 -Pump & Machinery Co., 890 Pomona Pump Company, 1066 RADIATOR ENCLOSURES 891 AND SHIELDS Chicago Pump Co., 1062 PUMPS. Vacuum American Radiator Company. ' Decatur Pump Company. 1063 Chicago Pump Co., 1062 898-899, 940-941 . Frick Company, 873 Curtis Refrigerating Machine Auer Register Co., The, 1068 ! Ingersoll-Rand Company, 874-876 Co., Div. of Curtis Manu Crane Co., 944-945 Nash Engineering Co., 1064-1065 facturing Company, 872 Modine Mfg. Co., 984-985 Trane Company, The, 882-883 C. A. Dunham Co., 1000-1001 H. J. Somers, Inc., 931 Worthington Pump & Machinery Hoffman Specialty Co., Inc., United States Register Co., 1075 'Corp., 890-891 1088-1089 Wickwire Spencer Steel Co,, 1077 PUMPS, Centrifugal ' ^ Bell and Gossett Co., 999 ` Buffalo Pumps, Inc., 1061 Chicago Pump Co., 1062 ' ; Decatur Pump Company. 1063 >. C. A. Dunham Co., 1000-1001 Frick Company, 873 * Ingersoll-Rand Co., 874-875 l Nash Engineering Co., 1064-1065 i;.; Scnhwilitzer-Cummins Co., 894, < Trane Company, The, 882-883 . Worthington Pump & Machinery ; Corp., 890-891 Ingersoll-Rand Co.. 874-875 . Nash Engineering Co., 1064-1065 Worthington Pump & Machinery Corp., 890-891 PYROMETERS, Portable and Stationary Bristol Company, The, 1002 _ Illinois Testing Laboratories, Inc., 1003 - Leeds & Northrup Co., 1004 Minneapolis-Honeywell Regulator Co., 1122-1123 Taylor Instrument Companies. 1008-1009 RADIATORS. Cabinet American Radiator Company. 898-899, 940-941 Burnham Boiler Corp., 942-943 Crane Co., 944-945 C. A. Dunham Co., 1000-1001 Grinnell Co., Inc., 993-995,. 1087 McQuay, Incorporated, 876 Modine Mfg. Co., 984-985 . John J. Nesbitt, Inc., 997 Trane Company, The, 882-883 Tuttle & Bailey, Inc., 1072-1073 Unit Heater and Cooler Co., 986 United States Radiator Corp., 948-949 PUMPS, Circulating Bell and Gossett Co., 999 ' Buffalo Pumps, Inc., 1061 ; Chicago Pump Co., 1062 Decatur Pump Company, 1063 Ingersoll-Rand Co., 874-875 Nash Engineering Co., 1064-1066 Pomona Pump Company, 1066 : Schwitzer-Cummins . Co., 894. * J- im Trane Company, The, 882-883 RADIATION, Aluminum Aerofin- Corporation, 989r991 McQuay, Incorporated, 876 Trane Company, The, 882-883 Unit Heater and Cooler Co., 986 Warren Webster & Co., 1098-1101 RADIATION, Brass Aerofin Corporation, 989-991 G & O Manufacturing Co., 992 McQuay, Incorporated, 876 Warren Webster & Co., 1098-1101 Weil-McLain Company, 950 Wickwire Spencer Steel Co., 1077 Young Radiator Company, 987 RADIATORS, Concealed American Radiator Company, 898-899, 940-941 Burnham Boiler Corp.. 942-943 Crane Co., 944-945 C. A. Dunham Co., 1000-1001 Grinnell Co., Inc., .993-995, 1087 . Numerals following Manufacturers* Names refer to pages in the Catalog Data Section 1153 Heating Ventilating Air Conditioning Guide 1939 McQuay, Incorporated, 876 Modine Mfg. Co., 984-985 - REFRIGERATION CONTROLS REFRIGERATION (See also Controls) EQUIPMENT, Water Vap,,r John J. Nesbitt, Inc., 997 Trane Company, The, 882-883 Tuttle & Bailey, Inc., 1072-1073 Unit Heater and Cooler Co., 986 United States Radiator Corp., 948-949 Warren Webster & Co., 1098-1101 Weil-McLain Company, 950 Young Radiator Company, 987 RECEIVERS, Air Baker Ice Machine Co., 868-869 Brownell Company, The, 1104 Crane Co., 944-945 . Curtis Refrigerating Machine Co., Div. Curtis Manu facturing Company, 872 Farrar & Trefts, Inc., 953 Illinois Engineering Co., 1090 1091 Ingersoll-Rand Co., 874-875 Kewanee Boiler Corp., 958-959 Parks-Cramer Company, 879 Warren Webster & Co., 1098-1101 Alco Valve Company. 1129 American Blower Corp., 866-867 Barber-Colman Co., 1112-1113 Bristol Company, 1002 Carrier Corporation, 870 Detroit Lubricator Co., 1114-1115 Fedders Manufacturing Co., 986 Julien P. Friez & Sons, Div. of Bendix Aviation Corp., 1118 Fulton Sylphon Co., 1116-1117 Illinois Engineering Co., 1090 1091 Illinois Testing Laboratories Inc., 1003 . Johnson Service Co., 1120-1121 Leeds & Northrop Co.,`1004 Manning, Maxwell & Moore, Inc., 1006 Minneapolis-Honeywell Regulator Co., 1122-1123 Penn Electric Switch Co., 1126 Powers Regulator Co., 1124-1125 Sarco Company, Inc., 1096-1097 Taylor Instrument Companies, Ingersoll-Rand Company, 874-875 REGISTERS (See also Grilles Registers, etc.) * American Blower Corp., 866-867 American Coolair Corp., 968-969 Anemostat Corp. of America 1067 ca* Auer Register Co., The, 1068 Barber-Colman Co., 1112-1113 Carrier Corporation, 870 Hart & Cooley Manufacturing Co., 1070-1071 g Hendrick Mfg. Co., 1061 Independent Register Co., 1074 L. J. Mueller Furnace Co 918 919 Trane Company, The, 882-883 Tuttle & Bailey, Iiic., 1072-1073 - United States Air Conditioning Corp., 884 * United States Register Co., 1075 Waterloo Register Co., 1076 Wickwire Spencer Steel Co., 1077 RECEIVERS, Ammonia Baker Ice Machine Co., 868-869 Carbondale Div., Worthington Pump & Machinery Corp., 890 891 Frick Company, 873 York Ice Machinery Corp., 887 RECEIVERS, Condensation Baker Ice Machine Co., Inc., 868-869 Chicago Pump Co., 1062 Crane Co., 944-945 Illinois Engineering Co., 1090 1091 Nash Engineering Co., 1064-1065 Sarco Company, Inc., 1096-1097 Trane Company, The, 882-883 Warren Webster & Co., 1098-1101 RECEIVERS, Water Vapor American Blower Corp., 866-867 Illinois Engineering Co., 1090 1091 Warren Webster & Co., 1098-1101 1008-1009 REGULATORS, Air Volume Westinghouse Elec. & Mfg. Co., Anemostat Corp. of America 888-889 1067 ` REFRIGERATING EQUIPMENT, Centrifugal Barber-Colman Co., 1112-1113 Hart & Cooley Mfg. Co., 1070 1071 Airtemp Div., Chrysler Corp.,' Minneapolis-Honeywell Regulator 896-897 Co., 1122-1123 Carrier Corporation, 870 Tuttle & Bailey, Inc., 1072-1073 Trane Company, Inc., 882-883 United States Register Co., 1075 Young Regulator Company, 987 REFRIGERATING EQUIPMENT, Steam Jet REGULATORS, Damper Barber-Colman Co., 1112-1113 American Blower Corp., 866-867 Barnes & Jones, Inc., 1081 Carbondale Div., Worthington Carrier Corporation, 870 Pump & Machinery Corp., 890 Detroit Lubricator Co., 1114-1115 891 Julien P. Friez & Sons, Div. of Carrier Corporation, 870 Bendix Aviation Corp., 1118 Ingersoll-Rand Company, 874-875 Fulton Sylphon Co., 1116-1117 Universal Cooler.Corp., 885 General Electric Company, 908 Westinghouse Elec. & Mfg. Co:,- 909, 1044-1045 888-889 William S. Haines & Co., 1092 REFRIGERATING MACHINERY Hart & Cooley Mfg. Co., 1070 1071 . Henry Furnace & Foundry Co., RECORDERS, Humidity, Temperature . Airtemp Div., Chrysler Corp., 910-911 896-897 . Hoffman Specialty Co., Inc., Baker Ice Machine Co., 868-869 1088-1089 Bristol Company, The, .1002 Carbondale Div., Worthington Illinois Engineering Co., 1090 Julien P. Friez & Sons, Div. of Pump & Machinery Corp., 890 1091 ' Bendix Aviation Corp., 1118 891 , Johnson Service Co., 1120-1121 Carrier Corporation, 870 Johnson Service Co., 1120-1121 < Kieley & Mueller, Inc., 1093 Leeds & Northrop Co., 1004 Curtis Refrigerating Machine Leeds & Northrop Co., 1004 Manning, Maxwell & Moore, Co., Div. of Curtis Manu Manning, Maxwell & Moore, Inc., 1006 facturing Company, 872 ' Inc., 1006 Minneapolis-Honeywell Regulator Delco - Frigidaire Conditioning Minneapolis-Honeywell Regulator Co., 1122-1123 Div., General Motors Sales Co., 1122-1123 Powers Regulator Co., 1124-1125 Corp., 902-904 Powers Regulator Co., 1124-1125 Taylor Instrument Companies, Frick Company, 873. Sarco Company, Inc;, 1098-1097 1008-1009 General Electric Company, 908 Spence Engineering Co., 1127 . 909, 1044-1045 Taylor Instrument Companies, REFRACTORIES, Cements, Ingersoll-Rand Company, 874-875 1008-1009 ____ Materials Kelvinator Division of Nash-; Trane Company, The, 882-883 . Babcock & Wilcox Co., 952 Carey, Philip, Co., 1020 ` Combustion Engineering Co., 1105 . Eagle-Picher Lead Co., 1021 Ehret Magnesia Mfg. Co., 1022 1023 Johns-Manville, 1030-1031 Ric-wiL Company, 1041 Ruberoid Co., The, 1032-1033 1 Kelvinator Corp., 912-916 Servel, Inc., 881 Trane Company, Inc., 882-883 Universal Cooler Corp., 885 Vilter Manufacturing Co., 886 Westinghouse Elec. & Mfg. Co., 888-889 Williams Oil-O-Matic Heating Corporation. 920 York Ice Machinery Corp.. 887 Tuttle & Bailey, Inc., 1072-1073 United States Register Co., 1075 Warren Webster & Co., 1098-1101 White-Rodgers Elec. Co.. 1128 Young Radiator Co., 934 REGULATORS, Feed Water Beaton & Cadwell Mfg. Co., 1084-1085 Kieley & Mueller, Inc., 1093 Please mention THE GUIDE 1939 when writing to Advertisers . Index to Modern Equipment ;.'Maid-0-Mist, Inc., 998 McDonnell & Miller, 938-939 .3 Mueller Steam Specialty Co., J Inc., 1095 ^Powers Regulator Co., 1124-1125 ; Spence Engineering Co., 1127 ^Westinghouse Elec. & Mfg. Co., ; 888-889 i Wright-Austin Co., 1102 f REGULATORS, Furnace RELIEF VALVES (See Valves, Relief) SAFETY VALVES (See Valves, Safety) SCREENS (See Perforated Metals) SEALS, Inside Door Bottoms ` Chamberlin Metal Weather Strip Co., 1018-1019 SHEETS, Lead Coated Copper American Brass Co., 1046-1047 SHEETS, Pure Iron American Rolling Mill Co., 1078 SHEETS, Special Finish American Rolling Mill Co., 1078 Carnegie-Illinois Steel Corp., 1080 SHEETS, Stainless Steel '*' Air Controls, Inc., 892 Barber-Colman Co., 1112-1113 SEALS, Flexible Pipe Line .^Detroit Lubricator Co., 1114-1115 E. B. Badger & Sons Co., 967 American Rolling Mill Co., 1078 Carnegie-Illinois Steel Corp., 1080, Jones & Laughlin Steel Corp., ^ Fulton Sylphon Co., 1116-1117 1049 Hart & Cooley Mfg. Co., 1070 SEPARATORS, Dust % 1071 Air-Maze Corp., 922-923 SHEETS, Steel "Henry Furnace & Foundry Co., ; 910-911 ^Minneapolis-Honeywell Regulator Co., 1122-1123 Penn Electric Switch Co., 1126 Spence Engineering Co., 1127 American Air Filter Co., 924-925 American Blower Corp., 866-867 Buffalo Forge Company, 972 Coppus Engineering Corp., 926 Research Corporation, 880 Staynew Filter Corp., 932-933 American Rolling Mill Co., 1078 Bethlehem Steel Co., 1079 Carnegie-Illinois Steel Corp., 1080 Jones & Laughlin Steel Corp., 1049 T&"-Tuttle- & Bailey, Inc., 1072-1073 B. F. Sturtevant Co., 980 SHUTTERS, Automatic . Elf White-Rodgers Elec. Co., 1128 < REGULATORS, Gas Unit Heater and Cooler Co., 986 Air Controls, Inc., 892 Westinghouse Elec. & Mfg. Co., American Coolair Corp., 968-969 888-889 Autovent Fan & Blower Co., 970 American Gas Products, Div. American Radiator Co., 900, s 951 SEPARATORS, Oil Air-Maze Corp., 922-923 Barber Gas Burner Co., 901 g: Crane Co., 944-945 | Detroit Lubricator Co., 1114-1115 fj',Jenkins Bros., 1133 , - Cochrane Corp., 1086 Crane Co., 944-945 Frick Company, 873 Henry Valve Company, 1132 2^ Mercoid Corp., 1119 " Kieley & Mueller, Inc., 1093 * i Minneapolis-Honeywell Regulator mf Co., 1122-1123 Staynew Filter Corp., 932-933 Warren Webster & Co., 1098-1101 IpsPenn Electric Switch Co., 1126 Wright-Austin Co., 1102 !% White-Rodgers Elec. Co., 1128 SEPARATORS, Steam Barber-Colman Co., 1112-1113 Champion Blower & Forge Co., 973 Ilg Electric Ventilating Co., 975 B. F. Sturtevant Co., 980 L. J. Wing Mfg. Co., 978-979 SLIME PREVENTION (See also Algae Prevention) Oakite Products, Inc., 921 SMOKE DENSITY RECORDING . REGULATORS, Humidity Humidity Control) (See Cochrane Corp., 1086 Crane Co., 944-945 Kieley & Mueller, Inc., 1093 Bristol Company, The, 1002 Leeds & Northrop Co.. 1004 Westinghouse Elec. & Mfg Co., j-REGULATORS,. Pressure *$ American Radiator Company, , 898-899, 940-941 Beaton & Cadwell Mfg. Co., SSy: 1084-1085. '%.BeIl & Gossett Co., 999 ji* Bristol Company,. The, 1002 ^ Crane Company, 944-945 Warren Webster & Co., 1098-1101 Wright-Austin Co., 1102 SHEETS, Aluminum Foil Alfol Insulation Co., 1011 Aluminum Aircell Insulation Co., 1012 Ruberoid Co., The, 1032-1033 888-889 ' SOOT DESTROYER Vinco Company, Inc., 936-937 . SOUND DEADENING, Flexible Hose American Brass Co., 1046-1047 Detroit Lubricator Co., 1114-1115 gri&C. A. Dunham Co., 1000-1001 SHEETS, Asbestos, Corrugated Flat and SOUND DEADENING, Insula-. tion gCFedders Manufacturing Co., 982 Carey, Philip, Co., 1020 ^Foster Engineering Co., 1131 Eagle-Picher Lead Co., 1021 ^.Julien P. Friez &_ Sons, Div. of Ehret Magnesia Mfg. Co., 1022 ar* Bendix Aviation Corp., 1118 1023 Ig: Fulton Sylphon Co., 1116-1117 Johns-Manville, 1030-1031 1* General Electric Company, 908- Ruberoid Co., The, 1032-1033 jg 909, 1044-1045 isT-Henry Furnace & Foundry Co., SHEETS, Black, Galvanized ^ 910-911 American Rolling Mill Co., 1078 J Illinois Engineering. Co., 1090- Carnegie-Illinois Steel Corp., 1080 1091 Jones & Laughlin Steel Corp., p^Jenkins Bros., 1133 1049 Alfol Insulation Co.,.. Inc., 1011 Aluminum Aircell Insulation Corp., 1012 Armstrong Cork Company, 1013 Celotex Corporation, The, 1016 1017 Eagle-Picher Lead Co., 1021 Ehret Magnesia Mfg. Co., 1022 1023 Insulite Company, The, 1026-1027 Insul-Wool Insulation Corp., 1025 St Kieley & Mueller, Inc., 1093 SHEETS, Copper International Fibre Board Ltd., Minneapolis-Honeywell Regulator Co., 1122-1123 American Brass Co., 1046-1047 1028 Johns-Manville, 1030-1031 ^Mueller Steam Specialty ` Co., SHEETS, Copper Alloy Mundet Cork Corp., 1029 . af"_ Inc., 1095 . American Brass Co., 1046-1047 Pacific Lumber Co., The, 1034 Electric Switch Co., 1126 Carnegie-Illinois Steel Corp., 1080 Ruberoid Co., The, 1032-1033 Powers Regulator Co., 1124-1125 8Spence Engineering Co., 1127 SHEETS, Copper Bearing Steel ^.Taylor Instrument Companies,American Rolling Mill Co., 1078 SSk. 1008-1009 ` . Carnegie-Illinois Steel Corp- 1080 Warren Webster & Co., 1098-1101 Jones & Laughlin Steel Corp, Standard Lime & Stone Co., 1035 United States Gypsum- Co., 1036 Western Felt Works, 1037 SPRAY EQUIPMENT . . ^White-Rodgers Elec. Co., 1128 1049 Cooling Tower Co., Div. of Fluor REGULATORS. Temperature SHEETS, Felt (See Temperature Control) Western Felt Works, 1037 Corp., Ltd., 964 Unit Heater & Cooler Co., 986 Martocello, Jos: A. & Co., 877 * Numerals following Manufacturers* Names refer to pages In the Catalog Data Section Heating Ventilating Air Conditioning Guide 1939 SPRAY NOZZLES American Blower Corp., 866-867 Baker Ice Machine Co., 868-869 Bayley Blower Company, 971 Buffalo Forge Company, 972 Clarage Fan Company, 871 Cooling Tower Co., Div. of Fluor Corp., Ltd., 964 Marley Co., The, 965 Martocello, Jos. A. & Co.. 877 Hoffman Specialty Co., Inc., 1088-1089 . Mueller Steam Specialty Co., Inc., 1095 Sarco Company, -Inc., 1096-1097 Spence Engineering Co., 1127 Trane Company, Inc., 882-883 Warren Webster & Co., 1098-1101 Wright-Austin Co., 1102 STRAINERS, Oil TANKS, Storage American Radiator 898-899, 940-941 Company, E. B. Badger & Sons Co.. 9B7 Bethlehem Steel Co., 1079 Brownell Company, The, 1104 Burnham Boiler Corp., 942-941 Farrar & Trefts, Inc., 953 Frick Company, 873 Kewanee Boiler Corp., 958-959 Niagara Blower Company, 878 Parks-Cramer Co., 879 B. F. Sturtevant Co., 980 Trane Company, Inc., 882-883 Westinghouse Elec. & Mfg. Co., 888-889 . Yamall-Waring Co., 1103 York Ice Machinery Corp., 887 Crane Co., 944-945 Detroit Lubricator Co., 1114-1115 General Electric Company, 908 909, 1044-1045 Kieley & Mueller, Inc., 1093 Milwaukee Valve Co., 1094 Mueller Steam Specialty Co., Inc., 1095 TEMPERATURE CONTROL American Radiator Comnanv 898-899, 940-941 y* Barber-Colman Co., 1112-1113 Barnes & Jones, Inc., 1081 Beaton & Cadwell Mfg. Co 1084-1085 " Bell & Gossett Co., 999 SPRAY NOZZLE COOLING SYSTEM American Blower Corp., 866-867 Baker Ice Machine Co., 868-869 Bayley Blower Co., 971 Buffalo Forge Co., 972 Clarage Fan Company, 871 Cooling Tower Co.. Div. of FIuot Corp., Ltd., 964 . Marley Company, 965 Niagara Blower Company, 878' B. F. Sturtevant Co., 980 Trane Company, The, 882-883 York Ice Machinery Corp., 887 Sarco Company, Inc., 1096-1097 Spence Engineering Co.. 1127 Staynew Filter Corp., 932-933 Wright-Austin Co., 1102 STRAINERS, Refrigerant Henry Valve Company, 1132 STRAINERS, Steam Crane Co., 944-945 Detroit Lubricator Co., 1114-1115 Illinois Engineering Co., 1090 1091 Kieley & Mueller, Inc., 1093 Milwaukee Valve Co., 1094 Mueller Steam Specialty Co.; Bristol Company, The, 1002 Cochrane Corp., 1086 Carrier Corporation, 870 Delco - Frigidaire Conditioning Div., General Motors . Sales Corp., 902-904 Detroit Lubricator Co., 1114-1115 C. A. Dunham Co., 1000-1001 Foster Engineering Co., 1131 Julien P. Friez & Sons, Div. of Bendix Aviation Corp., 1118 Fulton Sylphon Co., 1116-1117 General Electric Company, 908 909, 1044-1045 Illinois Engineering Co., 1090 STACKS, Steel Bethlehem Steel Co., 1079 Brownell Co., 1104 E. Keeler Company, 956-957 Inc., 1095 . Powers Regulator Co., 1124-1125 Sarco Company, Inc., 1096-1097 Spence Engineering Co.. 1127 Trane Company, The, 882-883 1091 Illinois Testing Laboratories. Inc., 1003 Johnson Service Co., 1120-1121 Kieley & Mueller, Inc., 1093 STEAM HEATING SYSTEMS (See Heating Systems, Steam) STOKERS. Mechanical, - Anthracite Babcock & Wilcox Co., 952 Combustion Engineering Co.. 1105 Iron Fireman Mfg. Co., 1108-1109 MotorStokor Division, Hershey Machine &. Fdy. Co., 1110 Schwitzer-Cummins Co., 894, 1111 STOKERS, Mechanical. Bituminous Babcock & Wilcox Co., 952 Brownell Company, 1104 Combustion Engineering Co., Wright-Austin Co., 1102 STRAINERS, Water Crane Co., 944-945 Detroit Lubricator Co., 1114-1115 Illinois Engineering Co., 1090 1091 Kieley & Mueller, Inc., 1093 Maid-O-Mist, Inc., 998 . McDonnell & Miller, 938-939 Milwaukee Valve Co.,_ 1094 Mueller Steam Specialty Co., Inc., 1095 Powers Regulator Co., 1124-1125 Sarco Company, Inc., 1096-1097 Spence Engineering Co., 1127 Staynew Company, Inc., 932-933 Wright-Austin Co., 1102 TANK COILS (See Coils, Tank) Leeds & Northrup Co., 1004 Manning, Maxwell & Moore. Inc., 1006 Mercoid Corporation,1 The. 1119 Minneapolis-Honeywell Regulator Co., 1122-1123 Penn Electric Switch Co.. 1126 Powers Regulator Co., 1124-1125 Sarco Company, Inc., 1096-1097 Spence Engineering Co., 1127 Taylor Instrument Companies, 1008-1009 Trane Company, The, 882-883 Warren Webster & Co., 1098-1101 White-Rodgers Elec. Co., 1128 L. J. Wing Mfg. Co., 978-979 Yarnall-Woring Co., 1103 Young Regulator Co., 934 THERMOMETERS, Distance 1105 TANK COVERING (See Cover Type Delco Frigidaire Conditioning ing, Pipes and Surfaces) Bristol Company, The, 1002 Div., General Motors Sales Julien P. Friez & Sons, Div. of Corp.. 902-904 TANK. GAGES, Oil Bendix Aviation Corp.. 1118 Detroit Stoker Co., 1106 Liquidometer Corp., 1005 Illinois Testing Laboratories, Econ-O-Col Stoker Div. of Cotta Transmission Corp., 1107 ' TANK HEATERS (See Heaters, Inc., 1003 ........... Johnson Service Co.. 1120-1121 Iron Fireman Mfg. Co., 1108-1109 Tank) Leeds & Northrup Co., 1004 Kelvinator Division of NashKelvinator Corp.; 912-916 Meyer Furnace Company, 917 Herman Nelson Corp., 996 Schwitzer-Cummins Co., 894, 1111 TANKS, Blow-off Brownell Company, The, 1104 Farrar & Trefts, Inc., 953 Kewanee Boiler Corp., 958-959 TANKS, Pressure . Liquidometer Corp., 1005 Manning, Maxwell & Moore, Inc.. 1006 ,, Minneapolis-Honeywell Rcgula-or Co., 1122-1123 Powers Regulator Co., 1124-11Z& STOKER MOTORS (See Motors. Electric) Baker Ice Machine Co., 868-869 Bell and Gossett Co., 999 Bethlehem Steel Co., 1079 Sarco Company, Inc., 1096-1097 Taylor Instrument Companies, 1008-1009 '^ STRAINERS, Dirt Barnes & Jones, Inc., 1081 Crane Co., 944-945 Grinnell Co., Inc., 993-995, 1087 Henry Valve Company, 1132 Brownell Company, The, 1104 . Burnham Boiler Corp., 942-943 Farrar & Trefts, Inc., 953 Frick Company, 873 Kewanee Boiler Corp., 958-959 United States Gauge Co., 101 THERMOMETERS, Indicating Bell and Gossett Co., 999 Bristol Company, The, 1002 Please mention THE GUIDE 1939 when writing to Advertisers Index to Modern Equipment Julien P. Friez & Sons, Div. of Crane Co., 944-945 Grinnell Co.. Inc., 993-995, 1087 Bendix Aviation Corp., 1118 C. A. Dunham Co., 1000-1001 William S. Haines & Co., 1092 Illinois Testing Laboratories, Hoffman Specialty Co., Inc., Hoffman Specialty Co., Inc.. Inc., 1003 1088-1089 1088-1089 Johnson Service Co., 1120-1121 Illinois Enginering Co., 1090 Illinois Engineering Co., 1090 Leeds & Northrup Co., 1004 1091 1091 Liquidometer Corp., 1005 Kieley & Mueller, Inc., 1093 Kieley & Mueller, Inc., 1093 Martocello, Jos. A. & Co., 877 Milwaukee Valve Co., 1094 Milwaukee Valve Co., 1094 Minneapolis-Honeywell Regulator Mueller Steam Specialty Co., Mueller Steam Specialty Co., Co., 1122-1123 Inc., 1095 Inc., 1095 palmer Company, The, 1007 Sarco Company, Inc., 1096-1097 Sarco Company, Inc., 1096-1097 powers Regulator Co., 1124-1125 Trane Company, The, 882-883 Powers Regulator Co.. 1124-1125 Sarco Company, Inc., 14)96-1097 Warren Webster & Co., 1098-1101 Trane Company, The, 882-883 Taylor Instrument Companies, Wright-Austin Co.. 1102 Warren Webster & Co., 1098-1101 1008-1009 Wright-Austin Co., 1102 United States Gauge Co., 1010 TRAPS, Float and Thermostatic Yamall-Waring Co., 1103 THERMOMETERS, Recording American District Steam Co., 966, 1039 TRAPS, Thermostatic Bristol Company, The, 1002 Armstrong Machine Works, 1082 Julien P. Friez & Sons, Div. of 1083 . Bendix Aviation Corp., 1118 Barnes & Jones, Inc., 1081 Leeds & Northrup Co., 1004 C. A. Dunham Co., 1000-1001 Liquidometer Corp., 1005 Grinnell Co., Inc., 993-995. 1087 Manning, Maxwell &Moore. William S. Haines & Co., 1092 Inc., 1006 Hoffman Specialty Co., Inc., Minneapolis-Honeywell Regulator 1088-1089 J Co., 1122-1123 Illinois Engineering Co., 1090- powers Regulator Co., 1124-1125 1091 Taylor Instrument Companies. Milwaukee Valve Co., 1094 1008-1009 Mueller Steam Specialty Co., United States Gauge Co., 1010 Inc., 1095 Barnes & Jones, Inc., 1081 C. A. Dunham Co., 1000-1001 Grinnell Co., Inc., 993-995, 1087 William S. Haines & Co.. 1092 Hoffman Specialty Co., Inc., 1088-1089 Illinois Engineering Co., 1090 1091 Milwaukee Valve Co., 1094 Powers Regulator Co., 1124-1125 Sarco Company, Inc., 1096-1097 Trane Company, The, 882-883 Warren Webster & Co., 1098-1101 VnpuuncTATQ Powers Regulator Co., 1124-1125 THKKMUbTATS Sarco Company, Inc.. 1096-1097 TRAPS, Vacuum American Radiator Company, Trane Company, The. 882-888 ' 898-899, 940-941 - Warren Webster & Co., 1098-1101 Barber-Colman .Co., 1112-1113* Wright-Austin Co., 1102 Bell & Gossett Co., 999 Carrier Corporation, 870 TRAPS, Radiator itroit Lubricator1 Co., 1114-1115 Armstrong Machine Works, 1082'Julien P. Friez &. Sons, Div. of 1083 T Bendix Aviation Corp., 1118 Barnes & Jones, Inc., 1081 ' Fulton Sylphon Co.. 1116-1117 C. A. Dunham Co., 1000-1001 General Electric Company, 908- William S. Haines & Co.. 1092 . 909, 1044-1045 Hoffman Specialty Co., Inc., Illinois Engineering Co., 1090- 1088-1089 ; J091 Illinois Engineering Co., 1090- Johnson Service Co., 1120-1121 1091 Manning, Maxwell & Moore. Milwaukee Valve Co., 1094 Inc., 1006 Sarco Company, Inc., 1096-1097 Mercoid Corporation, The, 1119 Trane Company, The, 882-883 Minneapolis-Honeywell Regulator Warren Webster & Co., 1098-1101 Armstrong Machine Works, 1082 1083 Barnes & Jones, Inc., 1081 . C. A. Dunham Co., 1000-1001 William S. Haines & Co., 1092 Hoffman Specialty Co., Inc., 1088-1089 Illinois Engineering Co., 1090 1091 Kieley & Mueller, Inc., 1093 Milwaukee Valve Co., 1094 Mueller Steam Specialty Co., Inc., 1095 Sarco Co., Inc., 1096-1097 Trane Company, The, 882-883 Warren Webster & Co., 1098-1101 Wright-Austin Co., 1102 ? Co., 1122-1123 Penn Electric Switch Co., 1126 TRAPS, Return TUBES, Boiler Powers Regulator Co., 1124-1125 Barnes & Jones. Inc., 1081 Babcock & Wilcox Co., 952 'Sarco Company, Inc., 1096-1097 Crane Co., 944-945 Bethlehem Steel Co., 1079 White-Rodgers Elec^Co.. 1128 C. A. Dunham Co., 1000-1001 Carnegie-Illinois Steel Corp.', 1080 fnwmp y, o ,. William S. Haines & Co., 1092 Jones & Laughlin Steel Corp., TOWERS, Cooling (See Cooltng Hoffman Specialty Go.. Inc., 1049 l oxoers) 1088-1089 TRAPS, Bucket Illinois Engineering Co., 1090- TUBES, Pitot (See Air Measur ing and Recording Instru Aim|trong Machine Works, 1082- Kieley & Mueller, Inc., 1093 ments) . . 1083 Cochrane Corp., 1086 Crane Co., 944-945 C. A. Dunham Co., 1000-1001 Illinois Engineering Co., 1090i 1091 Kieley & Mueller, Inc., 1093 Milwaukee Valve Co., 1094 Mueller Steam Specialty Co., Inc., 1095 - Sarco Company, Inc., 1096-1097 Trane Company, The, 882-888 Warren Webster & Co., 1098-1101 TUBING, Aluminum ' Wolverine Tube Co., 1050 TUBING, Brass American Brass Co., 1046-1047 Wolverine Tube Co., 1050 Mueller Steam * Specialty Co., TRAPS, Scale - Inc., 1095 Sarco Company, Inc., 1096-1097 Trane Company. The, 882-888 Wright-Austin Co., 1102 ^TRAPS, Float Henry Valve Company, 1132 TRAPS, Steam American District Steam Co., 966, 1039 Armstrong Machine Works, 1082 TUBING, Copper American Brass Co., 1046-1047 Wolverine Tube Co., 1050 TUBING, Fabricated American Brass Co., 1046-1047 American District- Steam Co., 1083 966, 1039 Barnes &' Jones, Inc., 1081 Bethlehem Steel Co.. 1079 Carnegie-Illinois Steel Corp., 1080 Armstrong Machine Works, 1082- Cochrane Corp., 1086 Jones & Laughlin Steel Corp., k 1088 Crane Co., 944-945 1049 Barnes & Jones, Inc., 1081 C. A. Dunham Co., 1000-1001 Wolverine Tube Co., 1050 Numerals following Manufacturers' Names refer to pages In the Catalog Data Section 1157 Heating Ventilating Air Conditioning Guide 1939 TUBING, Flexible Metallic (See VALVES, Automatic Frick Company, 873 also Conduit, flexible; Hose, Alco Valve Co., Inc., 1129 Grinnell Co.. Inc., 993-995, log? flexible) American Radiator Company, Henry Valve Company 1132' American Brass Co., 1046-1047 898-899, 940-941 HHnois Engineering Co., 1090- American Radiator Company, Anderson Products, Inc., 1130 898-899, 940-941 Bethlehem Steel Co., 1079 Carnegie-Illinois Steel Corp., 1080 Baker Ice Machine Co., 868-869 Barber-Colman Co., 1112-1113 Beaton & Cadwell Mfg. Co.. Jenkins Bros., 1133 Manning, Maxwell Inc., 1006 & Moore- TUBING, Steel Babcock & Wilcox Jones & Laughlin 1049 Co., 952 Steel Corp.,- 1084-1085 Bell & Gossett Co., 999 Bristol Company, The, 1002 Detroit Lubricator Co., 1114-1115 Fedders Manufacturing Co., 982 Milwaukee Valve Co., 1094 Warren Webster & Co., 1098-lim York Ice Machinery Corp , 887* VALVES. Diaphragm TURBINES . Foster Engineering Co., 1131 Alco Valve Co., 1129 Coppus Engineering Corp., 926- Frick Company, 873 Bristol Company, The, 1002 B. F. Sturtevant Co., 980 Julien P. Fries & Sons, Div. of Illinois Engineering Co man Westinghouse Elec. & Mfg. Co., Bendix Aviation Corp., 1118 1091 ** 888-889 Fulton Sylphon Co., 1116-1117 Johnson Service Co., 1120-1121 L. J. Wing Mfg. Co., 978-979 Johnson Service Co., 1120-1121 Kieley & Mueller, Inc., 1093 UNDERGROUND PIPE CON DUITS (See Conduits, Under ground Pipe) Kieley & Mueller, Inc., 1093 : Manning, Maxwell & Monr Manning, Maxwell & Moore, ` Inc., 1006 ' Inc., 1006 Minneapolis-Honeywell Regulator Minneapolis-Honeywell Regulator Co., 1122-1123 UNIT HEATERS (See Heaters, Co., 1122-1123 Powers Regulator Co., 1124-1125 Unit) New York Air Valve Corp., 1134 - Taylor Instrument Companies UNIT VENTILATORS (See Powers Regulator Co., 1124-1125 1008-1009 1 Ventilators, Unit) Sarco Company, Inc., 1096-1097 UNITS, Air Conditioning Air Conditioning Units) (See Spence Engineering Co., 1127 Trane ` Company, The, 882^883 V-BELT DRIVES American Coolair Corp., 968-969 Frick Company, 878 Worthington Pump & Machinery Corp., 890-891 VALVES, Back Pressure Baker Ice Machine Co., 868-869 Cochrane Corp., 1086 .. ' Crane Co., 944-945 ' Foster Engineering Co., 1131 Illinois Engineering Co., 1090 -VACUUM HEATING SYSTEMS 1091 (See Heating Systems, Vac Jenkins Bros.,- 1133 uum) Kieley & Mueller, Inc., 1093 VALVES, Air American Radiator Company, 898-899, 940-941 Anderson Products, Inc., 1130 Beaton & Cadwell Mfg. Co., 1084-1085 Bell &' Gossett Co., 999 Bristol Company, The, 1002 Burnham Boiler Corp., 942-943 Curtis Refrigerating Machine Co., Div. of Curtis Manu facturing Company, 872 Detroit Lubricator Co., 1114-1115 Hoffman Specialty Co., Inc., 1088-1089 Jenkins Bros., 1133 . Kieley & Mueller, Inc., 1093 Mueller Steam Specialty Co., 1095 Spence Engineering Co., 1127 Taylor - Instrument Companies, 1008-1009 Warren Webster & Co., 1098-1101 York Ice Machinery Corp., 887 VALVES, Balanced Crane Co., 944-945 ' Foster Engineering Co., 1131 Illinois Engineering Co.,' 1090 1091 Jenkins Bros., 1133 Kieley & Mueller, Inc., 1093 Mueller Steam Specialty Co., 1095 - Spence Engineering Co., 1127 Maid-O-Mist, Inc., 998 Manning, Maxwell & Moore. Inc., 1006 Milwaukee Valve Co., 1094 . New York Air Valve Corp., 1134 Spence Engineering Co., 1127 Trane Company, The, 882-883 Wright-Austin Co., 1102 . VALVES, Blow-off Cochrane Corp., 1086 Crane Co., 944-945 . Detroit Lubricator Co., 1114-1115 Henry Valve Company, 1132 Jenkins Bros., 1133 Kieley & Mueller, Inc., 1093 Manning, Maxwell & Moore. VALVES, Expansion Alco Valve Co., Inc., 1129 Crane Co., 944-945 Delco - Frigidaire Conditioning Div., General Motors Sales Corp., 902-904 Detroit Lubricator Co., 1114-1115 Fedders Manufacturing Co., 982 Foster Engineering Co., 1131 Frick Company, 873 Fulton Sylphon Co., 1116-1117 Henry Valve Company, 1132 Spence Engineering Co., 1127 York Ice Machinery Corp., 887 VALVES, Float . Alco Valve Co., Inc., 1129 Anderson Products, Inc., 1130 Baker Ice Machine Co., 868-869 Beaton & Cadwell Mfg. Co., 1084-1085 ' Cochrane Corp.,' 1086 . . Crane Co., 944-945 Detroit Lubricator Co., 1114-1115 Foster Engineering Co., 1131 Frick Company, 873 General Electric Company, 908 909, 1044-1045 " .- Illinois Engineering Co., 1090 1091 Kieley & Mueller, Inc., 1093 Maid-O-Mist. Inc., 998 McDonnell & Miller, 938-939 Mueller Steam Specialty Co., 1095 Spence Engineering Co., 1127 Trane Company, The, 882-883 York Ice Machinery Corp., 887 VALVES, Angle, Globe and Cross . Inc., 1006 .' Yarnall-Waring. Co., 1103 American Brass Co., 1046-1047 VALVES,; By-Pass " Baker Ice Machine Co., 868-869 Burnham Boiler Corp.; 942-943 Carbondale Div., Worthington Pump & Machinery Co., 890 Crane Co., 944-945 Henry Valve Company, 1132 Jenkins Bros., 1133 Johnson Service Co., 1120-1121 891 . Crane Co., 944-945 .' .Detroit Lubricator Co., 1114-1115 Frick Company, 873 Kieley & Mueller, Inc., 1093 Manning, Maxwell & Moore, Inc., 1006 Grinnell Co., Inc., 993-995, 1087 VALVES, Check Henry Valve Company, 1132 ' Cochrane Corp.-, 1086 Jenkins Bros., 1133 . - Crane Co.,- 944-945 . Milwaukee Valve Co., 1094 * Fedders Manufacturing Co.. 982 York Ice Machinery Corp.-," 887 Foster Engineering Co., 1131- VALVES. Flow Control' Bell & Gossett Co., 999 Bristol Company, The, 1002 C. A. Dunham Co., 1000-1001. Foster Engineering Co., 1131 Frick Company, 873 General Electric Company, 908 909, 1044-1045 Hoffman Specialty' Co., Inc* 1088-1089 . Illinois Engineering Co., 1090' 1091 - Kieley & Mueller, Inc., 1093 Manning, Maxwell & Moore Inc., 1006 Please mention THE GUIDE 1939 when writing to Advertisers Index to Modern Equipment Minneapolis-Honeywell Regulator Burnham Boiler Corp., 942-943 Trane Company, The, 882-883 -Co., 1122-1123 Crane Co., 944-945 ork Ice Machinery Corp., 887 Mueller Steam Specialty Co., Detroit Lubricator Co., 1114-1116 .Inc., 1095 . powers Regulator Co., 1124-1125 Spence Engineering Co., 1127 Taylor Instrument Companies, 1008-1009 t^Warren Webster & Co., 1098-1101 Valves. Gate "American Brass Co., 1046-1047 Crane Co., 944-945 ^Detroit Lubricator Co., 1114-1115 'Grinnell Co., Inc., 993-995, 1087 Jenkins Bros., 1133 ' ^Manning, Maxwell & Moore, pif. Inc., 1006 .- ^Milwaukee Valve Co., 1094 C. A. Dunham Co., 1000-1001 Fulton Sylphon Co., 1116-1117 Grinnell Co., Inc., 993-995, 1087 William S. Haines & Co., 1092 Hoffman Specialty Co., Inc., 1088-1089 Illinois Engineering Co., 1090 1091 Jenkins Bros., 1133 Milwaukee Valve Co., 1094 New York Air Valve Corp., 1134 Sarco Company, Inc., 1096-1097 Trane Company, The, 882-883 Warren Webster & Co., 1098-1101 VALVES, Radiator, Electric VALVES, Safety American Radiator Company, 898-899, 940-941 Baker Ice Machine Co., 868-869 Beaton & Cadwell Mfg. Co., 1084-1085 Crane Co., 944-945 . Detroit Lubricator Co., 1114-1115 Frick Company, 873 Henry Valve Company, 1132 Jenkins Bros., 1133 Manning, Maxwell & Moore, Inc., 1006 New York Air Valve Corp., 1134 Spence Engineering Co., 1127 Motor Operated |VALVES, Hydraulic Barber-Colman Co., 1112-1113 VALVES, Solenoid jCrane Co., 944-945 Bristol Company, The, 1002 Alco Valve Co., Inc., 1129 s,Foster Engineering Co., 1131 Julien P. Friez & Sons, Div. of Anderson Products, Inc., 1130 ^Jenkins Bros., 1133 Bendix Aviation Corp., 1118 Barber-Colman Co., 1112-1113 ^Manning, Maxwell & Moore. Fulton Sylphon Co., 1116-1117 Detroit Lubricator Co., 1114-1115 grf Inc., 1006 General Electric Company, 908 Frick Company, 873 lYarnall-Waring Co., 1103 909, 1044-1045 Julien P. Friez & Sons, Div. of ^VALVES, Magnetic Jenkins Bros., 1133 Bendix Aviation Corp., 1118 Minneapolis-Honeywell Regulator Fulton Sylphon Co., 1116-1117 SAlco Valve Co,. Inc., 1129 . Co., 1122-1123 General Electric Company, 908 'Barber-Colman Co., 1112-1113 Sarco Company, Inc., 1096-1097 909, 1044-1045 i?Detroit Lubricator Co., 1114-1115 Minneapolis-Honeywell Regulator JFrick Company, 873 VALVES, Radiator Orifice Co., 1122-1123 Bjulien P. Friez & Sons, Div. of American District Steam Co.. Penn Electric Switch Co., 1126- g Bendix Aviation Corp.,-1118 966, 1039 Spence Engineering Co., 1127 'General Electric Company, 908 Barnes & Jones, Inc., 1081 Trane Company, The, 882-883 909, 1044-1045 Bell and Gossett Co., 999 ^Minneapolis-Honeywell Regulator Detroit Lubricator Co., 1114-1115 VALVES, Stop and Chech (See Co., 1122-1123 C. A. Dunham Co., 1000-1001 Valves, Non-Return) pPenn Electric Switch Co., 1126 Grinnell Co., Inc., 993-995, 1087 'Spence Engineering Co., 1127 ;<. . William S. Haines & Co., 1092 Hoffman Specialty Co., Inc., |VALVES, Mixing, Thermostatic 1088-1089 SBarber-Colman Co., 1112-1113 Illinois Engineering Co., 1090 jFulton Sylphon Co., 1116-1117 1091 . ^Johnson Service Co., 1120-1121 Milwaukee Valve Co., 1094 ppowers Regulator Co., 1124-1125 New York Air Valve'Corp., 1134 ['Sarco Company, Inc., 1096-1097 Sarco Company, Inc., 1096-1097 Trane Company, The, 882-883 ^VALVES, Non-Return Warren Webster & Co., 1098-1101 ?'Crane Co., 944-946 jFedders Manufacturing Co., 982 |Foster Engineering Co., 1131 VALVES, Radiator, Diaphragm Pneumatic |Frick Company, 873 ' Bell and Gossett Co., 999 - ^Illinois Engineering Co., 1090 Bristol Company, The, 1002 ' 1091 ._ . Johnson Service Co., 1120-1121 ^Jenkins Bros.,. -1133 Minneapolis-Honeywell Regulator IKieley & Mueller, Inc., 1093 Co., 1129-1123 ' ^Manning, Maxwell & Moore, Powers Regulator Co., 1124-1125 "'Inc., 1006 Taylor Instrument Companies, . 1008-1009 HALVES, Pressure. Reducing' (See Regulators, Pressure) VALVES, Relief Baker Ice Machine Co., 868-869 VALVES, Thermostatic . Alco Valve Co., Inc., 1129 Barber-Colman Co., 1112-1113 Barnes & Jones, Inc., 1081 Beaton & Cadwell Mfg. Co., The, 1084-1085 Detroit Lubricator Co., 1114-1115 Fedders Manufacturing Co., 982 Foster Engineering Co., 1131 Julien P. Friez & Sons, Div. of Bendix Aviation Corp., 1118 Fulton Sylphon Co., 1116-1117. General 'Electric' Company, 908-^ 909, 1044-1045 Grinnell Co., Inc., 993-995, 1087 Illinois Engineering Co., 1090 1091 Johnson Service Co., 1120-1121 Manning, Maxwell & Moore,. Inc., 1006 Minneapolis-Honeywell Regulator Co., 1122-1123 New York Air Valve Corp., 1134 ' jVALVES, Pump ^Crane Co., 944-945 |Jenkins Bros., 1133 ' ^Trane Company, The, 882-883 Beaton & Cadwell Mfg. 1084-1085 . Bell and Gossett Co., 999 Cochrane Corp., 1086 Crane Co., 944-945 Co., - Penn Electric Switch Co., 1126 Powers Regulator Co., 1124-1125 Sarco Company, Inc., 1096-1097 Spence Engineering Co., 1127 Taylor Instrument Companies, ^VALVES, Purge JjHenry Valve Company, 1132 Foster Engineering Co., 1131 Frick Company, 873 Henry Valve Company, 1132 ' 1008-1009 Trane Company, The, 882-883 White-Rodgers Elec. Co., 1128 ^VALVES, Radiator - Illinois 1091 Engineering Co., ; 1090 .Yarnall-Waring Co., 1103 ` rAmerican District Steam Co., Kieley & Mueller, Inc., 1093 VALVES, Water Regulating 966, 1039 . Manning, Maxwell & Moore, Beaton & Cadwell Mfg. Co., {American Radiator 'Company, Inc., 1006 898-899, 940-941 Milwaukee Valve Co., 1094 The, 1084-1085 Bell and Gossett Co., 999 . ^Anderson Products, Inc., 1130 Mueller Steam Specialty Co., Crane Co., 944-945 rBarnes & Jones, Inc., 1081 Bell and Gossett Co., -999 . Inc.. 1095 Detroit. Lubricator Co., 1114-1115 New York Air Valve Corp., 1134 Foster Engineering Co., 1131 Numerals following Manufacturers' Names refer to pages in the Catalog Data Section Heating Ventilating Air Conditioning Guide 1939 Fulton Sylphon Co., 1116-1117 Johnson Service Co., 1120-1121 Kieley & Mueller, Inc., 1093 Manning, Maxwell & Moore, Inc., 1006 Mueller Steam Specialty Co., 1095 -Penn Electric Switch Co.. 1126 Powers Regulator Co., 1124-1125 Spence Engineering Co., 1127 VENTILATORS. Roof Air Controls, Inc., 892 Airtherm Mfg. Co., 981 American Coolair Corp., 968-969 Autovent Fan & Blower Co., 970 DeBothezat Division, American Machine & Metals, Inc., 974 General Electric Company, 908 909, 1044-1045 Ilg Electric Ventilating Co.. 975 Kelvinator Division of NashKelvinator Corp., 912-916 Marley Co., Inc., 965 Servel, Inc., 881 Trane Company, Inc., 882-SS3 Universal Cooler Corp,, 885 Vilter Manufacturing Co.. 886 Westinghouse Elec. & Mfg. Co., 888-889 York Ice Machinery Corp., 887 York Ice Machinery Corp., 887 Johns-Manville, 1030-1031 B. F. Sturtevant Co., 980 VAPOR HEATING SYSTEMS WATER COOLING TOWERS (See Cooling Towers. Water) (See Heating Systems, Vapor) VENTILATORS, Unit WATER FEEDERS (See Feeders, VENTILATORS, Attic (See also Fans, Electric, Propeller and Exhaust) American Blower Corp., 866-867 American Coolair-Corp., 968-969 Autovent Fan & Blower Co., 970 Buffalo Forge Company, 972 Water) ' . ~-*-** loee neat ers, Hot Water Service) Air Controls, Inc., 892 American Blower Corp., 866-867 American Coolair Corp.. 968-969 Autovent Fan & Blower Co., 970 Barber-Colman Co., 1112-1113 Buffalo Forge Co., 972 Burnham Boiler Corp., 942-943 Davies Air Filter Corp., 927 Ilg Electric Ventilating Co., 975 Herman Nelson Corp., 996 John J. Nesbitt, Inc., 997 Staynew Filter Corp., 932-933 Schwitzer-Cummins Co.. 894, 1111 WATER TREATMENT American Blower Corp.. 866-367 Cochrane Corp., 1086 Oakite Products, Inc., 921 Research Products Corp., 930 Vinco Company, Inc., 936-937 Champion Blower & Forge Co., B. F. Sturtevant Co., 980 973 Trane Company, The, 882-883 Clarage Fan Co., 871 L. J. Wing Mfg. Co., 978-979 WEATHER INSTRUMENTS. Indicating and Recording Coppus Engineering Co., 926 Young Radiator Company, 987 Bristol Company, The, 1002 DeBoihezat Division, American Julien P. Fries & Sons. Div. of Machine & Metals, Inc.. 974 Delco - Frigidaire Conditioning Div., General Motors Sales Corp.. 902-904 Gar Wood Industries, Inc., 906* 907 General Electric Company, 908 909, 1044-1045 Ilg Electric Ventilating Co.. 975' Lau Blower Company, - 893 Schwitzer-Cummins Co., 894, 1111 VENTILATORS. Window American Air Filter Co., 924-925 American Coolair Corp., 96S-969 Autovent Fan & Blower Co., 670 Buffalo Forge Company, 972 Coppus Engineering Corp., 926 Davies Air Filter Corp.; 927 Ilg Electric Ventilating Co.. 975 H. J. Somers, Inc., 931 Staynew Filter Corp., 932-933 B. F. Sturtevant Co., 980 _ Bendix Aviation Corp., 1118 Johnson Service Co., 1120-1121 Leeds & Northrop Co., 1004 Minneapolis-Honeywell Regulator Co., 1122-1123 Palmer Company, The, 1007 Powers Regulator Co., 1124-1125 Taylor Instrument Companies. 1008-1009 . WEATHERSTRIPS. Metal Chamberlin Metal Weather Strip B. F. Sturtevant Co., 980 Torrington Mfg. Co.. 976-977 VIBRATION, Absorbers (See Co., 1018-1019 United States Air Conditioning also Sound Deadening) WELDING FITTINGS (See Fit Corp., 884 American Brass Co., 1046-1047 tings, Wtiding) Westinghousc Elec. & Mfg. Co., 888-889 WARM AIR FURNACES (See WELDING ROD L. J. Wing Mfg. Co., 978-979 Furnaces. Warm Air) American Brass Co., .1046-1047 Camegie-IUinois Steel Corp., 1080 VENTILATORS, Floor and Wall WARM A'R HEATING SYS Wickwire Spencer Steel Co.,1097 American Blower Corp.. 866-867 American Coolair Corp., 968-969 Anemostat Corp. of America, 1067 Auer Register Co., The, 1068 .Barber-Colman Co.. 1112-1113 Coppus Engineering Corp., 926 Hart & Cooley Mfg. Co., 1070 1071 Hendrick Mfg. Co., 1069 Independent Register Co., 1074 L. J. Mueller Furnace Co., 918 919 B. F. Sturtevant & Co., 980 Tuttle & Bailey, Inc., 1072-1073 United States Register Co.. 1075 Waterloo Register Co., 1076 Young Regulator Company, 934 VENTILATORS, Mushroom TEMS (See Heating Systems, Furnace) WHEELS, Blower Air Controls, Inc., 892 WATER COOLING (See also American Blower Corp., 866-867 Cooling Equipment, Water; Autovent Fan & Blower Co., 970 Cooling Towers) Bayley Blower Company, 971 Aerofin Corporation, 989-991 Airtemp Div., Chrysler Corp-, Buffalo Forge Company, 972 Champion Blower & Forge Co., 896-897 , Baker Ice Machine Co., 868-869 Carbondale Div., Worthington 973 . Clarage Fan Company, 871 Henry Furnace & Foundry Co., Pump & Machinery Corp., 890 910-911 891 Carrier Corporation, 870 Lau Blower Co.. 893 L. J. Mueller Furnace Co., 918 Cooling Tower Co., Div. of The Fluor Corp., Ltd., 964 Curtis Refrigerating Machine 919. ^ . Niagara Blower Company. 878. Schwitzer-Cummins Co., 894, Co.. Div. of Curtis Manu facturing Company. 872 Delco - Frigidaire Conditioning 1111 B. F. Sturtevant Co., 980 Torrington Mfg. Co., 976-977 American Blower Corp., 866-S67 Clarage Fan Company, 871 L. J. Mueller Furnace Co., 918 919 . Tuttle & Bailey, Inc., 1072-1073 Div,, General Motors Sales. Corp., 902-904 Fedders Manufacturing Co., 982 Frick Company, 873 . WINDOWS, Supplementary Sash ' Chamberlin Metal Weather Strip Ingersoll-Eand Company, 874-875 * Co., 1018-1019 Please mention THE GUIDE 1939 when writing to Advertisers Roll of Membership American Society of HEATING and VENTILATING ENGINEERS 1939------- Contains Lists of Members Arranged Alphabetically and Geographically, also Lists of Officers and Committees, Past Officers and Local Chapter Officers Corrected to January 1,1939 Published at the Headquarters of the Society 51 Madison Avenue, New York, N. Y. COMMITTEE ON RESEARCH F. C. Hooghten, Director One Year W. A. Danielson C. E. Lewis D. W. Nelson C. Tasker C.-E. A. Winslow W. L. FleisheR, Chairman J. H. Walker, Vice-Chairman A. C. Fieldner, Ex-Officio Member Two Years H. E. Adams A. E. Stacey, Jr. G. L. Tdve J. H. Van Alsburg J. H. Walker Three Years M. K. Fahnestock W. L. Fleisher R. J. Tenkonohy T. H. Urdahl B. M. Woods W. A. Danielson Executive Committee W. L. Fleisher C. Tasker J. H. Walker C.-E. A. Winslow Technical Advisory Committees, 1938-1939 Relations of Air Conditioning to Human Health and Comfort--W. L. Fleisher*, General Chairman. (a) Sensations of Comfort---C. Tasker*, Chairman; Thomas Chester, F. E. Giesecke Elliott Harrington, R. E. Keyes, Dr. W. J. McConnell, A. B. Newton, J. R. Parsons' C. P. Yaglou. . . .' (b) Physiological Reactions---C.-E. A. Winslow*, Chairman; Dr. T. Bedford, Dr. E. F. DuBois, Dr. R. W. Keeton, Andre Missenard, Dr. R. R. Sayers, C. Tasker.* (e) Treatment of Disease--Dr. T. L, Hazlett, Chairman; Dr. C. J. Barone, Dr. B. Z. Cashman, Dr. M. B. Ferderber, Dr. E. V. Hill, C. S. Leopold, Dr. C. D. Selby, Dr. W. O. Sherman, Dr. A. W. Sherrill, Dr. H. F. Smith, R. J. Tenkonohy*, Dr. B. L. Vosburgh. . .. (d) Climate and Season--J. H. Walker*, Chairman; Dr. H. A. Abramson, O. W. Arm- spach, Ellsworth Huntington, Dr. C. A. Mills, Andre Missenard, T. H. Urdahl*, E. L. Weber. . ._ (e) Air Conditioning in Industry--A. E. Stacey, Jr.*, Chairman; Philip Drinker, Dr. Leonard Greenburg, H. P. Greenwald, A. M. Kinney; J. W. Kreuttner, L. L. Lewis, Dr. W. J. McConnell, Dr. C. P. McCord, P. A .McKittrick, Dr. R. R. Sayers. Air Cleaning and Atmospheric Impurities--H. C. Murphy, General Chairman. . () Mechanical Procedures--Dr. Leonard Greenburg, Chairman; J. J. Bloomfield, W. H. Carrier, R. S. Dill, Theodore Hatch, C. E. Lewis* A. L. Simison, W. O. Vedder. () Electrical Precipitation and Sterilisation--Dr. E. B. Phelps, Chairman; H. E. Adams?, R. D. Bennett, L. W. Chubb, L. R. Roller, G. W. Penney, W. F. Wells. Radiation and Comfort Winter and Summer and Effect of Varying Humidity on Radiant Heating and Cooling--J - C. Fitts, Chairman/ A. A. Adler, A. H. Barker, W. D. . Fleming, R. P. James, Dr. C. A. Mills, D. W. Nelson*, W. R. Rhoton, W. f\V. Timmis, G. R. Wait, S. L. Warren, C.-E. A. Winslow* C. F. Wpod. Weather Design Conditions--T. H. Urdahl*, Chairman; J. C. Albright, F. S. Cornell, John Everetts, Jr., E. W. Goodwin, A. C. Grant, J. H. Kincer, O. A. Kinzer, J. W. . O'Neill, L. S. Ourusoff. V . Transportation Air Conditioning--J. H. Van Alsburg*, Chairman; W. I. Cantley, T. R. Crowder, A. G. Dixon, C. C. Elmes, L. H. Laffoley, E. A. Russell, W. E. Zieber. Radiation with Gravity Air Circulation--M. K. Fahnestock*, Chairman; B. C. Benson, H. F. Hutzel, J. P. Magos, J. W. McElgin, J. F. Mclntire, D. W. Nelson*, T. A. Novotney, W. A. Rowe. _ Heat Transfer of Finned Tubes with Forced Air Circulation--G. L. Tuve*, Chairman; W. E. Heibei, H. F. Hutzel, R. F. Norris, R. H. Norris, C. H. Randolph, L. P. Saunders, C. F. Wood. Cooling Load in Summer Air Conditioning--J. H. W. alker*, Chairman; C. M. Ashley, John Everetts, Jr., F. H. Faust, A. E. Knapp, L. S. Morse, A. E. Stacey, Jr.*, R- M. SolidStFriukeellse--atWhe.r.A. Danielson*, Chairman; H. N. Eavenson, A. C. Fieldner, A. J. Johnson, Percy Nicholls, V. F. Parry, H. J. Rose, J. E. Schoen, L. E. Seeley, E. T. Selig, R. A. Sherman, R. Templeton Smith, C. Tasker*. Member of Committee on Research. 4 Summer Air Conditioning for Residences--M. K. Fahnestock*, Chairman; E. A. Brandt, John Everetts, Jr., Elliott Harrington, H. F. Hutzel, E. D. Milener, K. W. Miller, R. E. Robillard, F. G. Sedgwick, J. H. Walker*. Air Distribution and Air Friction--J. H. Van Alsburg*, Chairman; S. H. Downs, M. K. Fahnestock*, F. J. Kurth, R. D. Madison, L. G. Miller, D. W. Nelson*, C. H. Randolph, Ernest Szekely, G. L. Tuve*. Heat Requirement of Buildings--P. D. Close, Chairman; W. H. Badgett; E. F. Dawson, W. H. Driscoll, E. K. Campbell, H. M. Hart, H. H. Mather, F. B. Rowley, R. J. J. Tennant, J. H. Walker*. Air Conditioning Requirements of Glass--M. L. Carr, Chairman; F. L. Bishop, A. N. Finn, S. O. Hall, E. H. Hobbie, R. A. Miller, F. W. Parkinson, Harold Perrine, W. C. Randall, L. T. Sherwood, J. T. Staples, C. Tasker*, G. B. Watkins, F. C. Weinert. Insulation--W. A. Danielson*, Chairman; E. A. Allcut, R. E. Backstrom, H. C. Bates, Wharton Clay, H. C. Dickinson, J. D. Edwards, W. V. Hukill, E. C. Lloyd, Paul McDermott, W. E.- McMullen, R. T. Miller, W. T. Miller, E. R. Queer, T. S. Rogers, F. B. Rowley, W. S. Steele, R. J. Tenkonohy*, G. B. Wilkes. Sound Control--J. S. Parkinson, Chairman; C. M. Ashley, G. F. Drake', A. M. Greene, Jr., A. L. Kimball, V. O. Knudsen, R. F. Norris, C. H. Randolph, J. P. Reis, W. P. Roop, A. E. Stacey, Jr.*, G. T. Stanton, F. R. Watson. Cooling Towers, Evaporative Condensers and Spray Ponds--B. M. Woods*, Chairman; J. C. Albright, S. C. Coey, E. R. Goodrich, E. H. Hyde, E. H. Kendall, S. R. Lewis, O. W. Ott, E. H. Taze. Psychrometry--F. R. Bichowsky, Chairman; C. A. Bulkeley, J. A. Goff, A. M. Greene, Jr., F: G. Keyes, D. W. Nelson*, W. M. Sawdon. Corrosion in Steam Systems--A. R. Mumford, Chairman; H. E. Adams*, J. F. Barkley, W. H. Driscoll, T. J. Finnegan, R. M. Palmer, R. R. Seeber, F. N. Speller, C. M. Sterne. Corrosion in Air Conditioning Equipment--A. E. Stacey, Jr.*, Chairman; A. F. L. Anderson, G. L. Cox, M. L. Diver, W. R. Heath, C. E. Lewis*, R. M. Palmer, F. N. Speller, C. M. Sterne, J. H. Young. Member of Committee on Research. Officers of Local Chapters, 1938-39 Atlanta , Headquarters, Atlanta, Ga. Iowa-Nebraska Headquarters, Omaha, Nebr. Metis: First Tuesday in Month President, C. L. TemPLIN 348 Peachtree St., N. E. Secretary, T. T. TUCKER 260 Peachtree St., N. W. , Meets: Second Tuesday in Month President, W. R. White. 4339 Larimore Ave., Omaha, Nebr. . Secretary, Henry Kleinkauf 1726 St. Mary's Ave., Omaha, Nebr. . Kansas City Cincinnati Headquarters, Kansas City, Mo. Meets: Second Monday in Month Headquarters, Cincinnati, Ohio Meets: Second Tuesday in Month President, O. W. Motz 2524 Moundview Dr., Norwood, O, Secretary, R. E. Kramig, Jr. 222 East 14th St. President, A. L. Maillard 3740 Washington St. Secretary, C. A. Flarsheim P. O. Box 56. Manitoba .. Headquarters, Winnipeg, Man. . Meets: Fourth Thursday in Month . . Golden Gate Headquarters, Saa Francisco, CaliS. Meets: First Tuesday in Month President, G. M. Simonson . 74 New Montgomery St., San Francisco, Calif. Secretary, G. J. Cummings113 Tenth St., Oakland, Calif. Illinois President, William Worton 50$ Scott Bldg. Secretary, E. J. Argue Ste. 11, Estelle Apts. . . Massachusetts . Headquarters, Boston, Mass. Meets: Third Tuesday in Month President, James Holt Massachusetts Institute o Technology, Cambridge, Mass. Secretary, H. C. Moore ' 69 Massachusetts Ave., Cambridge, Mass. Headquarters, Chicago, IU. Michigan Meets: Second Monday in Month President, J. R. Vernon 511 1355 Washington Blvd. T Secretary, M. W. Bishop 228 N. La Salle St * - Headquarters, Detroit, Mich. Meets: First Monday after the 10th of the Month President, F. J. LiNSknmkyer . University of Detroit Secretary, G. H. Tuttle 2000 SeCond Ave. . 5 Officers and List of Chapters, 1938-3--(Continued) Western Michigan Headquarters. Grand Rapids, Mich. Meets: Second Monday in Month President, C. R. McConneb. 1904 Waite Ave., Kalamazoo, Mich. Secretary, W. G. SChlichting 141? W. Lovell St., Kalamazoo, Mich. Minnesota . Headquarters, Minneapolis, Minn. Meets: Second Monday in Month President, J. E. Swenson 800 Hennepin Ave.. Minneapolis, Minn Secretary,M. H.'Bjbrken r ..................... 4952-17th Ave.. S., Minneapolis, Minn. . Montreal Headquarters. Montreal. Que. Meets: Third Monday in Month President, F. J. Friedman 1221 Osborne St. Secretary, C. W. Johnson 630 Dorchester St., W. New York . Headquarters. New York, N. Y. Meets: Third Monday in Month President, H. G. Mbinke Rm. 1500, 4 Irving PI., New York, N. Y. Secretary, T. W. Reynolds 100 Pinecrest Dr., Hastings-on-Hudson, N. Y. - Western New York Headquarters, Buffalo. N. Y. Meets: Second Monday tn Month President, J. J; Landers 701 Crosby Bldg. Secretary, W. R. Heath. 119 Wingate Ave. Northern Ohio Headquarters, Cleveland, Ohio Meets: Second Monday in Month President, J. P. Jones 448 Terminal Tower Secretary, C. M. H. Kaercher 3030 Euclid Ave. . Oklahoma Headquarters, Oklahoma City, Okla. Meets: Second Monday in Month President, E. W. Gray Box 1498 Secretory, A. A. Hoppe 1941 Northwest 17th St. Pacific Northwest Headquarters, Seattle, Wash. Meets: Second Tuesday in Month President, C. W. May 1201 Smith Tower Secretary, R. D. Morse 1534 First Ave., S. Philadelphia Headquarters, Philadelphia. Pa. Meets: Second Thursday in Month President, H. H. Erickson 1124 Spring Garden St. Secretary, H. H. Mather __ lOOO Chestnut St. __ Pittsburgh Headquarters, Pittsburgh, Pa. Meets: Second Monday in Month President. R. A. Miller 2200 Grant Bldg. Secretary, T. F.` Rockwell Carnegie Inst. Tech. St. Louis Headquarters, St. Louis, Mo. Meets: First Tuesday in Month President, E. E. Carlson 1010 Louderman Bldg. Secretary, D. J. Facin __ a. 3017 Olive St. . ' , Southern California Headquarters, Los Angeles, Calif. Meets: Second Tuesday in Month President, H. M. Hendrickson 5051 Santa Fe Ave. Secretary, A. J. Hess 2616 West 70th St. - ' - North Texas Headquarters, Dallas,'Texas Meets: Second Monday in Month President, C. L. Kribs, Jr. 4209 Shenandoah Ave., Dallas, Tex. Secretary, L. S. Gilbert 1314 Liberty Bank Bldg., Dallas, Tex. * _ South Texas Headquarters, College Station/Texas President, R. F. Taylor . . | 911 Bankers Mortage Bldg., Houston, Tex. Secretary, W. H. Badgett . Texas Engrg. Experiment Station, College Station, Tex. Washington, D. G. Headquarters. Washington. D. C. Meets: Second Wednesday in Month President. S.'P. Eagleton 3522 MS" St.. N. W. Secretary, E. V. Fineran 411 Tenth St.. N. W. Ontario . Headquarters, Toronto, Ont. Meets: First Monday in Month President, H. B. JBNNBY Royce and Lansdowne Aves. Secretary, H. R. Roth 57 Bloor St., W. ' Wisconsin . Headquarters, Milwaukee, Wis. Meets: Third Monday in Month' * ' President, D. W. Nelson ` University of Wisconsin, Madison, Wis. Secretary. T. M. Hughey 906 N. Fourth St. 6 1*011 ot Membership American Society of Heating and Ventilating Engineers 1939 (Corrected to January 1, 1939) HONORARY MEMBERS BALDWIN, WM. J. (1915), New York, N. Y. (Deceased May 7, 1924.) BILLINGS, DR. 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. GORMLY, JOHN (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) (M 1923; A 1918; J 1916) indicates. Election as Member 1923; Associate 1918; Junior 1916. (Pres. 1923) indicates. Elected President in 1923 and is now a Presidential Member. ADLER, Herman (S 1938) Purchasing Agent, ABBOTT, Thomas J. (Af 1938) Vice-Pres. (foT mail) Geo. C. Abbott, Ltd., 119 Harbord St., and 42 Ardmore Rd., Toronto, Ont., Canada. ABRAMS. Abraham (M 1927; J 1924) Pres.. Abbey Heating Co., Inc., 81 Centre Ave., and . (for mail) 100 Clove Rd., New Rochelle, N. Y. ABRAMSON, Ralph (A 1938) Estimating & Installation Engr., Hipskind Heating & Plumbing . Co., 1725 Winter St., and (for mail) 719 Union St., Fort Wayne, Ind. - ACHESON, Albert R. (M 1919) Consulting Engr. (for mail) 501 Eckel Theatre Bldg., and 852 Ostrom Ave., Syracuse, N. Y. ' ADAM, Ray W. (A 1938) Plbg. and Htg- Con- . tractor (for. mail) 8810 Grinneil Ave., and 5911 l CourviUe Ave., Detroit. Mich. ADAMS, Bruce P. (A 1936) Gen. Mgr. (for mall) McDonnell & Miller, 400 N. Michigan Ave., and 1432 Rascher Ave., Chicago, III. ADAMS, Eugene E. (A 1938) Sale9 Engr. (for mail) Garden City Fan Co., Room 1508 A, 55 W. 42nd St., New York,.and 35-46 79th St., Jackson Heights, L. I., N.Y.' . ADAMS. Harold E. (M 1930) Chief Engr. (for mail) Nash Engineering Co., Wilson Rd.. South Norwalk and Merrill Heights, Norwalk, Conn. ADAMS, Nell D. (M 1929; A 1925: J 1922) (Council. 1938) Supt. (for mail) Franklin Heating Station, 220-2nd Ave., S.W., and 836*8th Ave., S.W., Rochester, Minn. ADDAMS, Homer {Charter Member', Life Member) (Presidential Member) (Pres., 1924; 1st Vice- Pres.,' 1923; Treas., 1915-1922; Council, 1925 Armo Cooling & Ventilating Co., 30 West 15th St., and (for mail) 485 Central Park West, New York, N. Y. ' ADLER, Jack C. (A 1937; J 1936) 110-07 73rd Rd., Forest Hills, L. 1., N. Y. ADSHEAD. Bernard (J 1936) Tech. Dir., National Air Conditioning & Humidifying Co.. Ltd.. 46 Brittanic Bldg., Manchester, and (for mail) 53 Shamrock Rd., Birkenhead, Cheshire, England. AEBERLY, John J * (M 1928) (Council, 1937 1938) Chief of Div. of Htg., Vtg. and Ind. Sani tation, Chicago Board of Health, 707 City Hall, and (for mail) 6225 N. Newcastle Ave., Norwood Park P. O., Chicago, 111. AKEARN, William J. (M 1929) Htg. and Vtg. Engr., 21 Lake Rd., Cochituate. Mass. AHLFF, Albert A. (M 1923; A 1918) 43 Rockglen Rd., Overbrook Hills, Philadelphia, Pa. AIRMAN, Joseph M. (M 1936) Consulting Air Cond. Engr., 944 B. Cuyler Ave., Chicago, III. AKERMAN, Joseph Reid (J 1937) Htg. and Air Cond. Engr. (for mail) Phoenix Oil Co., 700 Twiggs SL, 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. 3, Birming- ' ham, Mich. , ALBRECHT, Henry P. (J 1937) Engr. (for mail) Reinhard Bros. Co., Inc., 11 S. Ninth SL, and 3521 Park Ave., Minneapolis, Minn. ALBRIGHT, C. Barton (J 1938) Consulting Air Cond. Engr. (for mail) Albright and Anderson, Military Park Bldg., Newark, and 26 Elizabeth St., Caldwell. N. J. 1925) Pres. Kewanee Boiler Co., Inc., and Fitzgibbons Boiler Co.. Inc., 101 Park Ave., New York, N. Y. . ADDINGTON, Herbert B. (M 1938) Consulting ALEXANDER, Samuel W. (M 1935) Mgr., Htg. Div., James Morrison Brass Mfg. Co., Ltd., and (for mail) 124 Kingsxnount Park Rd., Toronto, Ont., Canada. Engr., 25 Lafayette Ave.. Brooklyn, N. Y. ALFAGEME. Braulio (if 1935) Engr., Mgr., B. ADLAM, T. Napier (M 1932) Vice-Pres. and Gen. Mgr., Sarco Mfg. Co., 183 Madison Ave., New York. N. Y., and-(for mail) 64 Wellington Ave., Alfageme, Almagro 1. Madrid, Spain. ALFERY, Henry F. (M 1938) Chief Engr. ((ot mail) Milwaukee Gas Specialty Co., 2025-W. West Orange, N. J. Clyboum St., and 1819-W. Center St., Milwau kee, Wis. Heating Ventilating Air Conditioning Guide 1939 ALFSEN, Nikolai (Af 1933) CivU Engr., Alfsen & Gunderson, A/S Oslo, Prinsensgate 2b, and (for mail) Utsigtsveien 22, Stabekk, Norway. ALGREN, Axel B.* (Af 1930) Asst. Prof. Mech. Engrg., Exp. Engrg. Lab., University of Minne sota, and (for mail) 5l09-17th Ave., S., Minne apolis, Minn. ALLAIRE, Lucien (7 1937) Asst. Engr. of the Town of Vald'or, and (for mail) 2182 Sherbrooke St., East Montreal, P. Q., Canada. ALLAN, William (A 1937) Pres. & Treas. (for mail) Allan Engineering Co., 724 E. Mason St., and 2735 N. Farwell Ave., Milwaukee. Wis. ALLCUT, Edgar A.* (M 1937) Prof, of Mech. Engrg. (for mail) University of Toronto, and 48 Foxbar Rd., Toronto, Ont., Canada. ALLEN, A. Walter (Af 1936) Sales Engr., Pease Foundry Co., Ltd., Toronto, and (for mail) 161 Glen Ave., Ottawa, Ont., Canada. ALLEN, Car! V. (Af 1937) Sales Engr. (for mail) Mid-States Industrial Corp., 2401 Eleventh St., and 901 Garfield Ave., Rockford, III. ALLEN, DeWltt M. (M 1936; 7 1922) Dist. Mgr. llg Electric Ventilating Co., 310 Board of Trade Bldg., and (for mail) 5700 Olive St., Kansas City, Mo. ALLEN, William A. (A 1938) Sales Engr., Electric Products Corp., 5624 Penn Ave., and (for mail) ANGERMEYER, Albert H. (A 1936) Owner (fnr mail) 119 N. Commercial St., and 705 E. Forget Ave., Neenah, Wis. es* ANGUS, Frank M. (Af 1937) Branch Mgr. (for * mail) General Refrigeration Sales Co., 1730 Grand, and 4936 Booth Ave., Kansas City Kan ANGUS. Harry H.* (Af 1918) (Council, 1927ll92m Consulting Engr., 1221 Bay St., and (for mail) 34 Farnham Ave., Toronto, Ont., Canada. ' ANNAS, Henry C. (A 1937) (for mail) Annas- Brady Co., 413 Murphy Bldg., and 361 Covins, ton Drive, Apt. 306, Detroit, Mich. ANSPACHER, Thomas H. (7 1936) Dist. Mgr Buffalo Forge Co., 702 Tower Petroleum Bid**' . Dallas, Tex. " ANTHES, Lawrence L. (A 1935) Pres (for main Imperial Iron Corp., Ltd., 30 Jefferson Ave., and 117 Dowling Ave., Toronto, Ont., Canada. APT, Sanford R. (Af 1935) Chief Mech. Engr New York Worlds Fair 1939. Inc., Worlds Fih New York, and (for mail) 36-20 168th St' Flushing, N. Y. * ARCHER, David M. (Af 1934) Sales Repr. (for mail) Sarco Co., Inc., 143 Federal St., Boston, and 87 Cabot Ave., Braintree, Mass. ARDEN, Irwin L. (7,1937) Engr., Edw. A. Lutz Co., 85 East Ave., and (for mail) 105 Oak Hill Ave., Pawtucket, R. I. ARENBEKG, Milton K. (A 1920) Pres, (for mail) 106 N. Fremont, Bellevue, Pa. Robert Barclay, Inc., 122 N. Peoria St., Chicago, ALLEN. William W. (A 1936) Pres, (for mail) and Wildwood Lane, Highland Park, 111. American Coolair Corp., Box 2300, Jacksonville, ARGUE, Edgar J. (A 1935) Sales Engr., Anthes ' and DaVind St., Venetia, Fla. ALLENSWORTH, James E. (S 1939) Student Foundry, Ltd., Saskatchewan Ave., and (for mail) Ste. 11, Estelle Apts., Winnipeg, Man., (for mail) Box 290, Carnegie Institute of Tech nology, Pittsburgh, Pa., and Amsterdam, O. ALLONIER, Howard R. (A 1936) Dist. Sales Mgr., Ohio Div. (for mail) J. J. Nesbitt Co., 425 W. Town SL, Columbus, and R. R. No. I4 Powell, O. ALLSOP, Rowland P. (7 1934) Engr. (for mail) Mathers & Haldenby, 96 Bloor St., West, and Canada. ARMBRUSTER, Frank T. W. (Af 1936) Pro fessional Engr., The Portsmouth Supply Co., 1532-1534 Gallia Ave., Portsmouth, and (for mail) 105 First Ave., Waverly, O. '. ' ARMISTEAD, William C. (Af 1937) Sales Engr. (for mail) William C. Armistead, 205 Church St., and Murfreesboro Rd., Nashville, Term. ARMSPACH, Otto W.* (Af 1919) Vice-Pres. and 89 Neville Park, Toronto, Ont., Canada. Chief Engr., Kroeschell Engineering Co., 215 ALT, Harold L. (Af 1913) Mech. Engr., Voorhees, W. Ontario St., Chicago, and (for mail) 205 S. Gmelin & Walker, 101 park Ave.. New York, and Summit Ave., Villa Park, 111. . (for mail) 115-27 225th St., St. Albans, L. I. N. Y. ARMSTRONG, Edward T. (S 19391 Student (for AMES, Charles S. (7 1937) Jr. Mech. Engr., State mail) Massachusetts Institute of Technology,. of California, Division of Highways, l805-34th St., M. I. T. Graduate House, Cambridge, Mass., and (for mail) 1127-39th St., Sacramento, Calif. and 7901 Tenth Ave., Brooklyn, N. Y. AMMERMAN, Andrew S., Jr. (J 1937) Engr., Chicago Office (for mail) Aerofm Corp., Room 704, 111 W. Washington St., and 4737 ^N. Hermitage Ave., Chicago, 111. ; \' AMMERMAN, Charles R. (Af i916) Consulting ARMSTRONG, Robert W. (7 1937; S 1935) 2809 E. Lake of the Isles Blvd., Minneapolis, Minn, ARMSTRONG, Walter J. (Af 1938) Consulting Engr. (for mail) 1010 St. Catherine St., West, Montreal, and 15 Willow Ave., Westmount P. Q. Engr. (for mail) 772 Century Bldg., and 3908 Guilford Ave., Indianapolis, Ind. . ANDEREGG, R. H. (Af 1920) Vice-Pres., The Trane Co., and (Sot mad) 420 N. Losey Blvd., ARCNanDaTda, -Heinrich W. ' (A 1935) Mgr., Plbg. and Htg. Dept., Sears Roebuck & Co., 732 Broad SL, and (for mail) 1816 Wrightsboro Rd., Augusta, LaCrosse, Wis. ANDERSON, Carroll S. (Af 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) Mgr., Sales Engrg. Dept., Wood Conversion Co., 1981-lst Nat. Bank Bldg., and (for mail) 1999 Pinehurst Ave., St. Paul, Minn. ANDERSON, George A. M. (7 1936) Secy, (for mail) King Ventilating Co., and 717 S. Cedar, Owatonna, Minn. ANDERSON, John W. (7 1937) Engrg. Dept., The Conditioning Co., Carrier Air Conditioning Distributors, 368 Broad St., Newark, and (for mail) 548 Westminster Ave., Elisabeth, N, J. ANDERSON, P. Russell (7 1938) Radio Electric, Inc., Chester, Pa., and (for mail) 17 East 25th St., Wilmington, Del. ANDRESEN, Garwood C. (7 1938; S 1936) ARNOLD, Robert S. (A 1926: 7 1922) Proprietor, RobL Arnold Sales & Eng. Co., 2221 N. Broad \ St., and (for mail) 6391 Sherwood Rd., Phila delphia, Pa. ARNOLDY, William F. (A 1930) Branch Mgr. (for mail) Minneapolis-HoneyweJLRegulator Co, 415 Brainard SL, DetroiL and 520 SL Clair Ave. v Grosse Pointe, Mich. ARROWSMITH, John O. (Af 1934) Plant Engr. (for mail) Canadian Kodak Co., Ltd., and 9 Humberview Rd., Toronto 9, OnL, Canada. ARTHUR, John M,, Jr. (Af 1923) Commercial Sales Mgr. (for mail) Kansas City Power & Light Co., 1330 Baltimore Ave., 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 Brattfe Rd., Syracuse, N. Y. ASHLEY, Edward E. (Af 1912) Consulting Engr. (for mail) 10 East 40th SL, New York, N. Y. Branch Engr., York Ice Machinery Corp., 471 St. Paul, and 55 Somershire Drive, Rochester, N. Y. ' and Middlesex Rd., Noroton Heights, Conn. ATHERTON, Alfred E. (A 1937) Company Dir. ANDREWS, George H. (A 1934) Partner and (for mail) A. E. Atherton & Sons Pty-, Ltd., 383 Supt., Frank P. Andrews & Son, 354 Neshanock Latrobe St., Melbourne, C. 1, and 39 Ormond Ave., and (for mail) 213 Meyer Ave., New Castle, Esplanade, Elwood, S. 3, Melbourne, Australia. Pa. ' 8 Roll or Membership ATKINS. Thomas J. (Af 1931) Consulting Engr., 68 Cathedral Ave., Nutley, N. J. AUCHMOODY, Frank W. (A 1938) Chief Engr. (for mail) E. R. Squibb Institute for Medical Research, Georges Rd., New Brunswick, and 422 Magnolia St., Highland Park, N. J. AUGHENBAUGH, Harry E. (Af 1935) York Ice Machinery Corp., and (for mail) 481 Madison Ave., York, Pa. AUSTIN, William H. (S 1937) Sales Engr., York Ice Machinery Corp., 200 Causeway St., Boston, and (for mail) 630 Adams St., Milton, Mass. AVERY, Ledyard (A 1939) Mgr. Air Cond. Dept, (for mail) Schumacher-Mackenzie, Ltd., 334 Main St., and 2$8 Broadway, Winnipeg, Man., Canada. AVERY, Lester T. (Af 1934) Pres, (for mail) Avery Engineering Co., 2341 Carnegie Ave., and 21149 Colby Rd., Shaker Heights, O. 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. Campbell SL, Williamsport, Pa. . BAKER, Howard C. (Af 1921) Pres, (for mail) The Howard Baker Co., 128 S. SL Clair St., and 4604 Manorwood Rd., Toledo, O. BAKER, Irving C. (Af 1921) Vice-Pres. in Charge of Sales (for mail) Airtemp Inc., 1119 Leo SL, and Mad River Rd., Dayton, O. BAKER, Lome P. (7 1937) Air Cond. Engr. (for mail) Canadian General Electric Co., Ltd., Royce Ave. Works, 830 Lansdowne Ave., and 115 Wembley Rd., Toronto, Ont., Canada. BAKER, Roland H. (Af 1928; A 1924) Pres., R. H. Baker Co., Elkins, N. H. BAKER, Thomas (Af 1938) Suburban Air Con ditioning Corp., 7 Depot Plaza, White Plains N. Y. BAKER. William C. (Af 1938) Pres, and Treas. (for mail) Electric Appliances, Inc., 155-7th Ave., N., and Westover Drive, Nashville, Tena. BAKER, William H., Jr. (A 1935) Standard Air Conditioning Corp., 40 West 40th SL, New York, N. Y. BALDI, G. (A 1936) Engr. (for mail) Copagnia B Italiana Westinghouse, Via Pier Carlo Boggio 20, and Corso Racconigi 39, Torino, Italy. - BACHMAN, Fred (Af 1936) Contractor (for mail) 3004 North 21st St., Philadelphia, and 906 Bell Ave., Yeadon, Pa. BACHOFER, Henry A., Jr. (7 1938) Mgr. Htg. and Air Cond. Dept., Mid-West Plumbing Co., Ill South 5th St., and (for mail) 534 South 8th SL, Salina, Kan. BACKSTROM, Russell E.* (A 1931; 7 1928) Mgr., Ind. Sales Dept, (for mail) Wood Con version Co., First National Bank Bldg., and 1655 Hillcrest, St. Paul, Minn. BACKUS, Theodore H. L. (Af 1916) (for mail) Schumacher & Backus, 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, Mexico, Mo. - BADGETT, W. Howard* (Af 1937; 7 1932) Research Asst., Texas Engrg. Experiment Station, P. O. Box 213 Faculty Exchange, College Station, Tex. * BAENDER, Frederick G. (Af 1937) Consulting Engr., Drexel, Mo. . BAGGALEY, Walter (Af 1938) Asst. Chief Mech. Engr. (for mail) The Austin Co., 16112 Euclid Ave., Cleveland, and 3390 Glencairn Rd., Shaker Heights, O. - BAHNSON, Frederic F.* (Af 1917) Vice-Pres. Secy, (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, Albert E., Jr. (A 1938) Sales Engr., Frigidaire Div., General Motors Sales Corp., No. 29.Franklin Rd., and (for-mail) 1624 Patterson Ave., S. W., Roanoke, Va. BAILEY, Edward P. (M 1925) Sales Engr., Detroit Stoker Co., General Motors Bldg., Detroit, and (for mail) 151 Crocker Blvd., Mt. Clements, Mich. BAILEY, W. Mumford (Af 1930) Managing Dir., Mumford Bailey & Preston, Ltd., and Joint Managing Dir., British Trane Co., Ltd. (for mail) "Newcastle House" Clerkenwel) Close, London; E. C. 1, and "Oldbury Court," Dainesway, Thorpe Bay, Essex, England. BAIRD, S. Alan (M 1935) Consulting Engr. (for mail) 621 Commercial National Bank Bldg., and 421 W. Melbourne Ave., Peoria, 111. BAKER, C. T. (Af 1935) Consulting Engr. (for mail) 713 Glenn St., S. W., and 31 The Prado, Atlanta. Ga. - BAKER, George R. (M 1936) Pres, (for mail) G. R. Baker Co., Ltd.. 224 Adelaide St. W,, ana 37 Lappin Ave., Toronto, Ont., Canada. BAKER, Harold S. (A 1937) Sales Engr., Re frigeration, 2015 Chester Ave., and (for mail) 241 Jefferson St., Bakersfield, Calif. BAKER, Harry L., Jr. (7 1935) Sales Engr. for mail) American Blower Corp., 50 West 40th St., New York, and 9935 Third Ave., Brooklyn, N. Y. BALDWIN, Karl F,, Jr. (7 1938) Engr. (for mail) McCrea Equipment Co., 324 Independence Ave., S. W., Washington, D. C., and 4810 Cedar SL. Decatur Hts, Hyattsville, Md. . BALDWIN, William. H. (Af 1921) Sales Engr. (for mail) C. A. Dunham Co., 5757 Cass Ave., and 2432 Atkinson Ave.. Detroit, Mich. BALL, William (A 1936) Pres, (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 840, and 141 Bedbrook Ave., Montreal, West, P. Q., Canada. BALLMAN, William H. (M 1937) Chief Engr. Air Cond. Div. (for mail) Nash-Kelvinator Corp., Long Island City, N. Y. BALSAM, Charles P. (Af 1932) 324 Fourth St., Brooklyn, N. Y. ' BAMOND, Manuel J. (Af 1936) Engr., Reynolds Corp., 1400 Wabensia Ave., and (for mail) 4715 Magnolia Ave., Chicago, 111. BANKS, John B. (A 1937) Branch Mgr. (for mail) Minneapolis-Honeywell Regulator Co., 2405 N. Maryland Ave., and 2928 N. Maryland Ave., Milwaukee, Wis. BANNER. Francis L. D. (Af 1937) Branch Mgr. (for mail) Minneapolis-Honeywell Regulator Co., 378 Saunders-Kennedy Bldg., and 5523 Corby St., Omaha, Nebr. BANNON, Lucas E. (A 1935) ArchL, 16 Church St., Paterson, N. J, BANOWSKY, Aubra B. (Af 1938) Director of Commercial and Industrial Sales, United Gas Corp., Rusk Bldg., and (for mail) 3735 Ingold, Houston, Tex. BARBIERI, Patrick J. (7 1936; 5 1933) Engr., Armo Cooling & Ventilating Co., 30 West 15 SL, and (for mail) 2166 Belmont Ave., New York, N. Y. - BARNARD, M. Everett (A 1931; 7 1929) Sales Engr. (for mail) Carrier Corp., 12 S. 12th SL, and 341 Vernon Rd., Philadelphia, Pa. BARNES, Arthur F. (Af 1920) Owner (for mail) Texas Engineering Co., 726 Electric Bldg., and 3015 Jarrard SL. Houston, Tex. BARNES. Arthur R. (Af 1924) Chief Engr. (for mail) U. S. Supply Co., 1315 West 12th St., and 326 East 70th Terrace, Kansas 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., Hamilton, Ont., Canada. BARNES, Lewis L. (7 1937) Air Cond. & Refrig. Engr., Carrier Atlanta Corp., 348 Peachtree St., and (for 'mail) 3995 N. Stratford Rd., Atlanta, Ga. :. 9 Heating Ventilating Air Conditioning Guide 1939 BARNES, Walter E. (M 1933) Pres., Barnes & Jones, Inc., 128 Brookside Ave., Jamaica Plain (Boston) and (for mail) 7 Woodlawn Ave., BEAN, George S. (A 1935) Mgr. Stoker Div Stoker Engr. (for mail) North Western Fuel* 4E9.4192-1036thFAirsvte.N, Sa.ll,.MBinannekapBoldlisg,.,MSint.nPaul ' ana Wellesley Hills. Mass. " BARNEY, William E. (Af 1936) Mgr. (for mail) Hydraulic-Press Brick Co., South Park, and 4929 E. 108th St., Cleveland. O. BEARMAN. Alexander A. (M 1937) En*r (f*r mail) 20th Century-Fox Film Coro.. 444 ur 56th^St- New York, and 47 Edward St., Baldwin, BARNSLEY, Frank Richard (A 1936) Mgr.. Air Cond. Div. (for mail) Canadian General Electric Co., Ltd., 1000 Beaver Hall Hill, and 5245 Byron Ave., Montreal. P. Q., Canada. BARNUM, Marvin C. (M 1930; A 1928) Eastern Repr. (for mail) Waterman-Waterbury Co.. P. O. Box 284, Suffern, and Cherry Lane, Tallman, N. Y. BARNUM, Willis E- Jr. (Af 1933; 7 1930) Mgr., Air Cond. Div., York Ice Machinery Corp.r . Roosevelt Ave., and (for mail) 35 N. Rockburn St.. York, Pa. BARR, George W. (Life Member; Af 1905) (Board of Governors, 1910) Dist. Mgr., Aerofin Corp., 2030 Land Title Bldg., Philadelphia, and. (for mail) Woods End, Villa Nova. Pa. BARRY, James G., Jr. (Af 1933) Vice-Pres. (for mail) EJJiott & Barry Engineering Co., 4060 W. Pine Blvd.. and 5051 Queens Ave., St. Louis, BEAULIEU, Adrian A. (Af 1937) Utilization Engr., Boston Edison Co., 39 Boylston St Boston, and (for mail) 535 N. Elm St. W * Bridgewater, Mass. *" BEAURRIENNE, Auguste* (Af 1912) Consulting Engr. (for mail) 25 Rue des Marguettes, and 18 Avenue du Petit Val, Lucyen Brie Setoise Paris, France. ' BEA VERS, Georg R. (M 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 4766 Rapid Run Pike, Cincinnati O. * BECK, Don (7 1938) Supvr. Air Cond. Sales, York Ice Machinery Corp., 6051 Santa Fe Ave., and (for mail) 310 N. Orange Drive, Los Angeles, mo. BARRY, Patrick I. (Af 1920) (Peace Commis sioner) M.I.H.V.E. Managing Director (for mail) M. Barry, Ltd., 4 Marlboro St., and 8 Sidney Park, Cork, Ireland. BARTH, Herbert E. (Af 1920) Vice-Pres- (for . mail) American Blower Corp., 6000 Russell St., and 829 Warden, 15 E. Kirby. Detroit. Mich. BARTLETT, Amos C. (Af 1919) Mgr. Htg. and Vtg. Dept, (for mail) B. F. Sturtevant Co., Damon St.. Hyde Park, and 30 Hollingsworth Ave.. Braintree, Mass. BARTLETT, C. Edwin (Af 1922) Pres.. Bartlett & Co.. Inc.. 3223 Arch St., and 3111 \V. Coulter Calif. BECKER, Roger K. (M 1938) Dept. Mgr.. Ohio Valley Hardware 8c Roofing Co., and (for mail) 1017 E. Powell Ave., Evansville, Ind. BECKER, Walter A. (Af 1935) Sales Engr. (for mail) Grinnell Co., Inc., P. O. Box 292, and 215 Maple Terrace, Oconomowoc, Wis. BEEBE, Frederick E. W. (A 1915) Johnson Service Co., 28 East 29th St., New York, N. Y. BEERY, Clinton E. (Af 1913) Owner Pres, (for mail) Heat & Fuel Engineering Co., 646 N. Michigan Ave., and 3750 Wayne Ave., Chicago, 111. ` BEGGS, William E. (Af 1927) Owner, W. E. St., Philadelphia, Pa. BARTLEY, Henry E. (Af 1938) Dir. and Works Mgr., Matthews & Yates, Ltd.. Swfnton, Man chester, and (for mail) "The Grange." Hospital Rd., Pendlebury, Lancs.. England. BARTON, Jay (Af 1937) Mgr., National Manu facturing & Engineering Co., 628 E. Forest Ave., and (for mail) Box 221, Detroit, Mich. BASSETT, James W. (A 1938) Sale3 Engr. (for mail) McQuay, Inc-, 2832 E. Grand Blvd., Detroit, and Birmingham. Mich. BASTEDO, Albert E. (Af 1910) Vice-Pres. and Treas.. Burnham Boiler Corp., Irvington, N. Y. BASTEDO, George R. (7 1937) Lab. Asst.. Standard Air Conditioning, Inc., New Rochelle, and (for mail) 102-36 86th Rd., Richmond Hill, Beggs Co., 907 Lloyd Bldg-, and (for mail) 3639 Palatine Ave., Seattle, Wash. BEIGHEL, H. 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 3930) Mgr-, Air Cond. Div.; Combustioneer Corp., 409 10th St.,. S. W- and (for mail) 1213 Hamilton St., N. W., Washington, D. C. BELDING, Harry H. (A 1937) Chief Engr., Gathright, Inc., 1840 W. Broad St., and (for mail) 2616 Cnambertayne Ave.. Richmond, Va. ' BELING, Earl H* (Af 1936; A 1930; 7 1925) Owner, Beling Engineering Co., 405 State Trust Bldg., and (for mail) 242S-13th St., Moline. 111. BANU. EYR. , Albert E. (Af 1935) Engr., United States . BELL, E. Floyd (Af 1933) Mgr. (for mail) Bell 8t Eiss, Inc., 2102 Foshay Tower, and 5337 Girard Air Conditioning Corp., 2101-N, E. Kennedy, Minneapolis, and (for mail) 59 S. Victoria St., Ave., SBELSKY, GMeinonregaepAol.is(,AMi3n9n3.7) Air Cond- Engr., St. Paul, Minn. . . BAUGHMAN, L. R. (Af 1935) Htg. Engr., Helms & Baughman, 103 N. Sheridan Rd.. Waukegan, and (for mail) 2706 Eschol Ave., Nash Kelvinator Corp., 27th St. and Pearson PI., Long Island City, and (for mail) 53 N. Grove St., Valley Stream. L. I., N. Y. BELT, Newton O. (Af 1929) Engrg. Dept, (for Zion. 111. * BAUM, Albert L. (Af 1916) Member of Firm (for mail) Jaros, Baum & Bolles, 415 Lexington Ave., mail) . I. Du Pont de Nemours & Co., and 824 West 10th St.. Wilmington, Del. BEMAN, Myron C. (Af 1926) (Council 1934-1938) N and 600 West 111 St., New York, N. Y. ' BAUMGARDNER, C. M. (Af 1928) Mgr., Chicago Branch (for mail) United States Radiator Corp., 3254 N. Kilbourn Ave., Chicago, and 602 Michi Consulting Engr. (for mail) Beman & Candee, 374 Delaware Ave., and 699 Richmond Ave., Buffalo. N. Y. .,v BENHAM, Colin S. K. (7 1937) Dir. (for mail) gan Ave., Evanston, III. BAXTER, William E. (A 1939) Vtg. and Air Cond. (for mail) H. E. Baxter, Ltd., 87 Vitre, W., Montreal, and 89-51st Ave., Lachine, P. Q., Benham & Sons, Ltd., 66 Wigmore St., London W. 1, and 31 Ormonde Terrace, London N. W. 8. BEENngHlaAnMd., Ford C., Jr. (7 1938) Sales _Engr. (,for Canada BAY, Charles H. (A 1938) Salesman (for mail) The Detroit Edison Co., 2000 Second Ave., and mail) c/o C. H. Ruebeck Co., P. O. Box 141, and 1106 N. 16th St, Waco. Tex. BENNETT, Charles A. (M 1936) 1751 Kilbourae 17323 Wildemere St., Detroit, Mich. BAYSE, Harry V. (M 1923) Pres, (for mail) Place, N. W., Washington, D. C. BENNETT, Edwin A. (Af 1936; 7 1929) Sales American Furnace Co., 2710-31 Delmar Blvd., Engr. (for mail) American Blower Corp., 50 W. and 6959 Hancock Ave., St. Louis Mo. 40th St, New York, and 45 Pondfield Rd., W., BEACH, Walter R. (A 1936) Sales Engr. (for mail) Cleveland Electric Illuminating Co., 75 Public Bronxville, N. Y. BENNITT, George E. (Af 1918) 44 Cedar St, Sq- Cleveland, and 1185 Yellowstone Rd., Cleveland Heights, O- - Wakefield, Mass. 10 Roll or Membership BENOIST, LeRoy L. (M 1934) Mgr. (for mail) Benoist Bros. Supply Co., 117 S. Tenth St., and 1500 Main St. Mt Vernon, III. . BENOIST, Raymond E. (Af 1936) Partner. Benoist Bros, and Secy.-Treas., Benoist Bros. Supply Co., 117 South 10th St, and (for mail) 811 North 12th St.. Mt. Vernon, III. BENSEN, Clarence L. (7 1935) Chief Engr. (lor mail) McQuay, InC- 1600 Broadway, N. E., and 2722 Benjamin St, N. E., Minneapolis, Minn. BENSINGER, Mark (7 1936) Asst. Mech. Engr. (Htg. & Air Cond.) War Dept., U. S. Govern ment. Room 2347. Munitions Bldg., and (for mail) 2737 Devonshire PL, N. W-, Washington. D.C. BENSON, Bernard C. (Af 1937) Sales Promotion - Mgr.,- -Chicago- Branch- (for' mail) American Radiator Co., 820 S. Michigan Ave., and 8127 Clyde Ave., Chicago, 111. BENSON, Merrill L. (Af 1938) Mgr., Air Cond. Coil Div. (for mail) McQuay, Inc., 1600 Broad way, N. E., and 4521 Harriet Ave., S- Minne apolis, Minn. BENTLEY. Clyde E. (Af 1937) Consulting Engr., 216 Pine St., San Francisco, 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. BERGAN, John R. (7 1937) Dist. Repr. (for mail) Minneapolis-Honeywell Regulator Co-, 1220 Madison Ave., Toledo, and 525 W. Broadway. Maumee. O. BERMAN, Louis K. (Af 1908) Pres, (for mail) Raisler Corp., 129 Amsterdam Ave., and 285 Central Park West, New York, N. Y. BERMEL. Alfred H. (A 1933; 7 1928) Estimator and Engr., August Arace 8t Sons, Inc., 642~3rd Ave., Elizabeth, and (for mail) 16 William SL, No. Arlington, N. J. BICHOWSKY, F. Russell (Af 1935) Consulting Engr. (for mail) Dow Chemical Co- 309 S. State St- and 1508 Granger, Ann Arbor, Mich. BIGELOW, Edward S. (Af 1938) Mgr.. Air Cond. Div- Trilling & Montague. 2409 Walnut St., Philadelphia, and (for mail) 413 Jericho RdMontgomery Co., Abington, Pa. BILLINGSLEY, Oliver F- 2nd (7 1937) Owner and Engr- Foo Hobbylab, 424 N. St. Mary's St and (for mail) P. O- Box 1740, San Antonio, Tex. BINDER, Charles G. (Af 1920) Mgr- Htg. DeptWarren Webster & Co- 17th & Federal St., Camden, and (for mail) 115 Oak Terrace, Merchantville, N. J. BIRD. Charles (A 1934) Treas. & Gen. Mgr. (for .mail) .The Doermann-Roehrer Go- 450 E. Pearl St- and Box 179, D Section Rd- R. R. No- 6, Cincinnati, O. BIRD, George L. H. (7 1937) Chief Engr. (for mail) Refrigeration & Allied Products, Ltd- 92 Buckingham Palace Rd- London, S. W. 1, and No. 9 Holmefield Court, London, N. W. 3, England. BISHOP, Charles R. (Lift Member; Af. 1901) 22 Sagamore Rd- Bronxville, N. Y. BISHOP, Frederick R. (Af 1921) Mgr. of Sales, The Brundage Co- Kalamazoo, and (for mail) 8011 Dexter Blvd- Detroit, Mich. BISHOP, Joseph W. (Af 1939) Mgr. Air Cond. Div- Toronto Dist. (for mail) Canadian General Electric Co- Ltd., 214 King St., W,, Toronto, and 62 Highland Crescent. York Mills, Ont.,. Canada. BISHOP, Marion W- (7 1935) Sales Engr. (for mall) American Blower Corp- 228 N- LaSalle St- and 7024 Sheridan Rd., Chicago, 111. BJERKEN, Maurice H. (Af 1937; A 1927) Sales Engr- Hoffman Specialty Co- and ((or mail) 4952-17th Ave- S- Minneapolis, Minn. BLACK, Edgar N- 3rd (A# 1922) Philadelphia BERNERT, Lawrence A. (A 1937) Mgr., Htg. & Air Cond. Dept. The Maag Co., 831 N. Mil waukee St., Milwaukee, Wis. Mgr., Fitzgibbons Boiler Co- Inc- 927-28 Land Title Bldg- Philadelphia, and (for mail) 111 Woodside Rd- Haverford, Montgomery Co- Pa. BERNHARD, George (Af 1935; A 1929) Managing BLACK, F. C. (Life Member; Af 1919) Pres, (for Engr., Associated Heating & Power Corp., 1 mail) F. C. Black Co- 622 W. Randolph St- and Hanson PI.-, and (for mail) 985 Park Place, Brooklyn. N. Y. BERNSTROM, Bert* (Af 193Q) Consulting Engr., B. Bemstrom Air Cond.Consultant, 2853 Dickens Ave., Chicago. IU. 4535 N. Ashland Ave- .Chicago, III. BLACK, Frank M. (A 1937) Chief Engr- U. S. Government, Army Medical Center, Washington, D. C- and (for mail) P. O. Box 164, Silver Spring, Md. BERRIDGE, Winston W. (Af 1938) Sales Engr. (for mail) McCoU-Frontenac Off Co., Ltd., Dominion Square Bldg., and 5169 Westbury Ave., Montreal, P. Q.. Canada. BERRINGER, Sidney H. (M 1926) Chief Engr., Holly Heating & Mfg. Co., 21 S.. Chester, Pasadena, and (for mail) 2083 Malden Lane. Altadena, Calif. BERZELIUS. Carl E- (Af 1936) Captain, Com manding Officer, CCC Camp (for mail) Co. 784 CCC, and 101-Wisconsin, Neodesha, Kan. 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) Sr. Mech. Engr., Htg. & Vtg. (for mail) Dept, of Buildings, City of Minneapolis, 213 City Hall, and 4923 S. Russell Ave., Minneapolis, Minn. BLACK, Harry G. (Af 1917) Prop, (for mail) p. Gormly Co- 155 N. 10th St- and 927 N. 65th St- Philadelphia, Pa. BLACKBURN, E. C- Jr. (Af 1929) Mech. EngrCrow, Lewis & Wick. Archts- 200 Fifth AveNew York, and (for mail) 5 Kenwood RdGarden City, N. Y. BLACKHALL, W. R. (Af 1922) Partner (for mail) McKeller & Blackball, 1104 Bay St- and 332 Waverly Rd- Toronto, Ont., Canada. BLACKMAN. Alfred O. (Af 1911) Htg. and Vtg. Engr- 145 W. 45th St- and (for mail) 450 W. 24th St- New York, N. Y. BLACKMORE, F. H. (Af 1923) Mgr., Mfg. Dept, (for mail) U. S. Radiator Corp- 1056 Natl. Bank Bldg., Detroit, and 515 Tooting Lane, Birming ham, Mich. BETZ, Harry D. (Af 1928) Pres., Betz Air Con? BLACKMORE, George C. (Chorler Member; Life ditioning Corp., Six West Ninth St., and (for Member) Pres, (for mail) Automatic Gas Steam mail) 1610 Valentine Rd., Kansas City, Mo. BEVINGTON, Curtis H. (Af 1936) Mgr. (for Radiator Co- 301 Bru&htoa Ave- and Cathedral Mansions, Pittsburgh, Pa. mail) C. H. Bevington Co., 600 S. Michigan Ave., Chicago, and Park Ridge, IU. BEWS, John (A 1938) Dist. Sales Mgr. (for mail) Canadian Ice Machine Co., Ltd., 628 Craig St., West, and 5546 Trans Island Ave., Montreal, P. Q- Canada. . BIANCULLL Vincent A. (7 1937) Draftsman, Navy Dept., Brooklyn, and (for mail) 557 Broome St- New York, N. Y. BIBER, Herbert A. (A 1937) Engr. (Htg- Air Cond. Refrigeration) Mellon National Bank, 542 Smithfield St- Pittsburgh, and (for mail) 323 Barnes St., Wilkinsburg, Pa. BLACKMORE, J. J * (Charter Member; Life Mem ber) 32 West 40th St- 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) "X" Laboratories and Bell & Gossett, 4006 Papin, St. Louis, and 312 S. Fillmore, EdwardsviUe, III. BLACKSHAW, J. L* (M 1937; J 1929) Air Cond. Engr., Air and Refrigeration Corp- 11 West 42nd St- New York, and (for mail) 59 Joralemon St- Brooklyn, N. Y. Heating Ventilating Air Conditioning Guide 1939 BLAKELEY, Hugh J. (AT 1935) Consulting Engr. (for mail) Hubbard Rickerd & Blakeley, Con sulting Engrs., 275 Orange St., and 5 Doty- Place, New Haven, Conn. BLANDZNG, Robert L. (Af 1938) Vice-Pres. (for mail) Taco Heaters, Inc., 123 South St., and 1385 Smith St., Providence, R. I. BLANKIN, Merrill F. (Af 1927; A 1926; J 1919) Pres, (for mail) Haynes Selling Co., Inc., S. E. Cor. Ridge Ave., and Spring Garden St., and 528 E. Gates St., Roxboro, Philadelphia, Pa. BLAS, Romualdo J. (Af 1936) Sanchez & Co., Apartado Postal 1006, Caracas, Venezuela, South America. BLEDSOE, Raymond P. (J 1937) Sales Engr., Madison Gas & Electric Co., and (for mail) 531 N. Pinckney St., Madison, Wis. BLOOM, Louis (M 1935) Partner, Freeport Plumbing and Heating Engineers, 84-A, Broad way, Freeport, N. Y. BLUM, Herman, Jr. (J 1926) Engr. (for mail) C. Wallace Plumbing Co., 2224 Summer St., and 5912 Elliot St., Dallas, Tex. BLUMENTHAL, M. I. (Af 1936) Engr. in Charge , Refr. & Air Cond. (for mail) National Schools, 4000 S. Figueroa, and 648 W. Santa Barbara, Los Angeles, Calif. BOALES, William G. (Af 1936; A 1923) Owner (for mail) Wm. G. Boales & Associates, 6439 Hamilton Ave., Detroit, and 195 McMillan Rd., . Grosse Pointe Farms, Mich. BOCK, Bernard A. (A 1929; J 1927) Mech. Draftsman, 57 Elizabeth Ave., Arlington, N. J. BOCK, 1.1. {A 1934) Pres, (for mail) Carrier-Bock Corp., 2022 Bryan St., and 2500 South Blvd., Dallas, Tex. BODEN, Walter F. (A 1937) Branch Mgr. (for mail) Modine Mfg. Co., 420 E. Wells St., Mil waukee, and 606 Milwaukee Ave., South Mil- BODINGER, Jacob H. (Af 1931) Pres, (for mail) Bodinger & Co., Inc., 530 Tenth Ave., New York, and 1429 East 19th St., Brooklyn, N. Y. BODMER, Emmanuel (Af 1937) Engr,, Head of Tech. Dept., Ets. Dieny & Lucas, 223 Boulevard Pereire, and (for mail) 20, rue Leon, Paris (18e), France. BOESTER, Carl F., Jr. (A 1938) Air Cond. Engr., 101 E. Essex, Kirkwood, St. Louis, Mo. BOGATY, Hermann S. (M 1921) 735 B. PhiJ- EUena St., Philadelphia, Pa. BOLAND, Roy O. (A 1938) Mgr., Insulation Div. (for mail) Alexander Murray ,& Co., Ltd., 4035 Richelieu St., Montreal, and 348 Kensington Ave., Westmount, P. Q., Canada. BOLS1NGRR, R. C. (M 1916). (Council, 1936, . 1937, 1938) Dist. Repr., General Stokers, Inc.' Philadelphia, Pa., and (for mail) 238 E. Madison Ave., CoUing8wood, N. J. BOLTON, Reginald P.* {Honorary Member', Life Member; M 1897) (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, Harry H. (M 1938) Partner (for mail) Edward E. Ashley, Cons. Engr., 10 East 40th. St., New York, and 141-49 181st St., Springfield, L. I., N. Y. BOND, Horace A. (M 1930) Dist. Mgr., Warren Webster & Co., 152 Washington Ave., and (for mail) 12 Ramsey PI., Albany, N. Y. BONTHRON, Robert C. (A 1935) Headquarters Syndicate Repr., Air Cond. Sales (for mail) Westinghouse Electric & Mfg. Co., 150 Broad way, New York, and 44 Ingraham Blvd., Hemp stead, L. ]., N. Y. BOOT, Arthur (M 1938) Mgr.. Air Cond. Div. (for mail) Boot & Co., 115 W. Fulton St-, and 928 Orchard Ave., S. E., Grand Rapids. Mich. BOOTH, Charles A. (M 1917) Vice-Pres. & Sales Mgr. (for mail) Buffalo Forge Co., 490 Broadway, and 142 Summit Ave., Buffalo, N. Y. BORAK, Eugene (M 1937) Chief Draftsman (for mail) Buensod-Stacey Air Cond. Corp.. 6o Knc, 42nd St., New York, N. Y., and 261 Manhattan Ave., Jersey City, N. J. . BORG, Elmer H. (Af 1938) Partner (for mail) Proudfoot Rawson-Brooka & Borg, Archts is Hubbell Bldg., and 3101 Easton Blvd. 'dm Moines. Ia. * BORK.AT, Philip (J 1936) 3116-18th St.. N W Washington, D. C. '" BORLING, John R. (A 1934) Engr.-Custodian (for mail) Chicago Board of Education 214 N Lavergne Ave., and 953 East 84th Place, Chicago* BORNEMANN, Walter A. (M 1924; J 1923) Sales Engr. (for mail) Carrier Corp., 12 South 12th St., Philadelphia, and 123 W. Wharton Ave Glenside, Pa. ** BORNSTEIN, William (A 1937) (for mail) Wm Bernstein & Son, 5424 Third St., N. W., Wash ington, D. C., and 222 Chestnut Ave.. Tafcoma Park, Md. BOTELHO, Nanto J. (A 1937) Engr. and Mgr,, Ceibrasil Representacoes Ltda- Rua General* Camara, 64-70 andar, Rio de Janeiro, Brazil (S. A.) BOTTUM, Edward W. (J 1938) Engr., Kel- vinator Engrg. Dept., Nash Kelvinator CoTp., 14250 Plymouth Rd., and (for mail) 2051 W. Grand Blvd., Detroit, Mich. BOUEY, Angus J. (A 1937; / 1930) -Sales Engr. (for mail) The B. F. Sturtevant Co., 681 Market St- and 4810 Fulton St., San Francisco, Calif. BOUILLON, Lincoln (M 1933) Consulting Engr. (for mail) 1411 Fourth Ave. Bldg., and 2211 32nd South, Seattle, Wash. BOWEN. Harold C. (A 1938) Treas., Joseph A. Bowen Co., 100 Pleasant St., and (for mail) Box 202. Warren, R. I. BOWEN, John C. (A 1938) Sales Engr.. Lennox Furnace Co., Marshalltown, la., and (for mail) 421 S. 17th St.. La Crosse, Wis. BOWERMAN, Everett L. (A 1937) Sales Engr., Francis Hankan and Co., Ltd., 165 Spadina Ave., and (for mail) 274 Belsize Dr., Toronto, Ont- Canada. . BOWERS, Arthur F.' (A 1919) Pres., Industrial Heating & Engineering Co., 828 N. Broadway, Milwaukee, Wis. BOWLES, Edmund N. (A 1937) Northwest Air Cond. Supvr. (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., 757 Pacific St.. Stamford, and Box 61, New Canaan, Conn. BOXALL, Frederick (M 1937) Mgr. of Air Cond. Dept, (for mail) J. H. Vivian .Co., Box 301, Johannesburg, South Africa, and Carbondale Div., Worthington Pump Co., Harrison, N. J. BOYAR, Sidney L. (J 1937) Estimating Supvr., Sears Roebuck & Co., 925 S. Homan Ave., Chicago, and (for mail) 1515 Schilling Ave., Chicago Heights, 111. BOYD, Spencer W. (M 1937; J 1931) Consulting Engr. (for mail) Newcomb & Boyd, Trust Co. of Georgia Bldg., and 1505 Fairview Rd., Atlanta, Ga. BOYD, Thomas D. (M 1937) Sales Engr. (for mail) Johnson Service Co., 1113 Race St., and 4220 Erie Ave., Cincinnati, O. BOYDEN, Davis S * (M 1909) (Pres. 1937; 1st Vice-Pres.. 1936; Treas., 1933-1934; Council, 1917, 1930, 1937, 1938) Engr-, Boston Edison Co., 39 Boylston St., Boston, Goodrich St., Lunenburg, and (for mail) Box 386 Shirley, Mass. BOYKER, Robert Owen (J 1935) Contractor, Mac Boyker & Son (for mail) 220 1st Ave., and 100 Kennebeck Ave., Kent, Wash. BOYLE, John R. (M 1935) Traveling Sales Mgr- Westerlin & Campbell Co., 1113 Cornelia Ave.. and (for mail) 6858 Osceola Ave., Chicago, 1U. BOZEMAN, Richard (M 1936; J 1929) Chief Instructor, AJr Cond. Div. (for mail) Jourden Diesel Schools, Inc., 2831 N. Broad St- and 709 Church Lane, Germantown, Philadelphia, Pa. 12 Roll of Membership BRAATZ, Chester J.* (M 1930) Sales Mgr., Temperature Control and Uni-Flo Dept., BaibeiColman Co-, and (for mail) 1819 Clinton SL, Rockford, 111. BRABBEE, Dr. Charles W.* (M 1925) 50 Lincoln Ave., Tuckahoe, N. Y. BRACKEN, John H. (M 1927) Mgr., Industrial Uses Dept, (for mail) The Celotex Corp., 919 BROCKINTON, G. E. (A 1937) Sales Engr. (for mail) Advanced Refrigeration, Inc., 350 Peachtree St- and 756 Elkmont Dr- N. E- Atlanta, Ga. BRODERICK, Edwin L.* (M 1933) Research Asst, in Mech. Engrg. (for mail) University of Illinois, 213 M. E. Lab- Urbana, and 909 S. First St- Champaign, 111. ' N- Michigan Ave., and 455 Oakdale Ave., BRODNAX, George H., Jr. (M 1938) Htg. Engr. Chicago, 111. (for mail) Georgia Power Co- Electric Bldg- and BRADFIELD, William W. (M 1926) Mech. 1564 Westwood Ave- S. W- Atlanta, Ga. Engr. (for mail) 341 Michigan Trust Bldg., and BROKAW, George K. (5 1938) Student, Uni 1352 Franklin St., S. E- Grand Rapids, Mich. versity of California, and (for mail) 2634 B BRADFORD, Gilmore G. (M 1936) Mgr.. Frigid- College Ave- Berkeley, Calif. aire Div., General Motors China Ltd., 408 Holland House, Hong Kong. China. BRADLEY, Eugene P. (Af 1906) Pres, (for mail) Hester-Bradley Co., 2835 Washington Ave., and 6935 Pershing Ave., St. Louis, Mo. BRADLEY, J. M. (A 1938) Chicago Repr. (for mail) Airtherm Mfg. Co., 312 N. Loomis St., and 1352 Astor St., Chicago, 111. BRANDI, O. H. (M 1930) Dipl. log., Rud. Otto Meyer, Hamburg 23, and (for mail) Reinbek b. Hamburg, Hamburgerstr 14, Germany. BRANDT, E. IL, Jr. (M 1928) Pres, (for mail) Reliance Engineering Co., Inc., P. O. Box 1292, BRONSON, Carlos E* (M 1919) Chief Mech. Engr- Kewanee Boiler Corp- Kewanee, 111. BROOKE, Irving E. (M 1937) Consulting Engr. (for mail) 189 W. Madison St- Chicago, and 830 Keystone Ave., River Forest, 111. BROOM. Benjamin A. (M 1914) Sales Pro motion Engr- Weil-McLain Co- 641 West Lake St- and (for mail) 1534 Fargo Ave- Chicago, 111. BROOME, Joseph H. (A 1936) Sales EngrMinneapolis-Honeywell Regulator Co- 604 Cen tral Ave- East Orange, and (for mail) 89 Edgemont Rd., Montclair, N. J. and U01 Providence Rd., Charlotte, N. C. BROWN, Alfred P. (Af 1927) Vice-Pres. (for mail) BRASHAW, Clarence J. (A 1938) Sales Engr., J. F. Stampfer Co., 8th & Main St., and (for Reynolds Corp., 1400 Wabansia Ave- Chicago, and 439 Maple St- Winnetka, 111. mail) 765 Chestnut St- Dubuque, la. BROWN, Aubrey I.* (Af 1923) Prof, of Htg. and BRATT, Hero D. (M 1937) Sales Engr., Warren Vtg. (for mail) Ohio State University, and 169 Webster & Co., 228 Ottawa Ave- and (for mail) Richards Rd- Columbus, O. 2259 Stafford Ave- Grand Rapids, Mich. . BROWN, David (M 1936) Owner (for mail) 67 BRAUER, Roy (M 1926) Mgr., Pittsburgh Office (for mail) The Trane Co., Magee Bldg., and 576 Cooper Square, and 54 West I74th St- New York, N. Y. Austin Ave., Mt. Lebanon, Pittsburgh, Pa. BRAUN, John J. (Af 1932) Factory Mgr., The United States Playing Card Co., and (for mail) 4305 Floral Ave., Norwood, O. BRAUN, Louis T. (M 1921) Executive Secy. (for mail) Chicago Master Steamfitters Assn., 228 N. LaSalle St., and 1548 Pratt Blvd- Chicago, 111. . BRAYMAN, Albert I. (J 1937) Draftsman and Estimator, Edward Brayman, Htg, Contractor, 81 Chamber St- Boston, and (for mail) 340 Boulevard, Revere, Mass. BRECKENRIDGE, L. P.* (Honorary Member; Life Member; M 1920) Prof, of Mech, Engrg., Emeritus Yale University (for mail) "The Brackens," North Ferrisburg. Vt. BREDESEN, Bernhard P. (A 1931) Engr. (for mail) Reese 8c Bredesen, 403 Essex Bldg- and . 3319 Knox Ave.. N- Minneapolis, Minn. ` BRENEMAN, Robert B. (A 193H J 1927) Sales Engr. (for mail) Armstrong Cork Co., 191 Orchard Lane, Columbus, O. BRIDE, William T. (M 1928; J 1925). Supt. Engrg- Bride-Grimes Sc Co., 9 Franklin St. (for mail) P. O. Box 777, Lawrence, and 28 Albion St., Methuen, Mass. BROWN, Foskett* (M 1926) Pres, (for mail) Gray & Dudley Co- 222 Third Ave- N- and 2314 West End Ave., Nashville, Tenn, BROWN, John S., Jr. (J 1937) Sales Engr- Smith Distributing Co., and (for mail) 2230 Talbott Ave- Louisville, Ky. BROWN, Joy S. (M 1938) Mgr.. Air Cond. & Refrig. Dept, (for mail) J. P. Baldwin Co., 1304 W. Washington Blvd- and 5706 E. Circle Ave*, Chicago, 111. BROWN, Mack D. (Af 1938; J 1936) Mech. EngrHtg. and Vtg. (for mail) Northup & O'Brien, Archts- 602-03 Reynolds Bldg- and 915 East 21st St- Winston-Salem, N. C. BROWN, Maurice W. (J 1938) Sales Engr. (for mail) American Blower Corp- 619 Mercantile Bldg- and 1201 E. 7th, Dallas, Tex. BROWN, Tom (Af 1930) Vice-Pres. & Gen. Mgr*, (for mail) Autovent Fan & Blower Co- 1805-27 N. Kostner Ave- and 5325 N. Laramie Ave- ` Chicago, III. BROWN, William H. ( A 1923) Mgr., Brown Bros- Inc., 3015 North 22nd St- Milwaukee, Wis. BROWN, W. Maynard (A 1930) Warren Webster & Co., 17th and Federal Sts- Camden, N. J. BRIERLY, Keppel (J 1938) Air Cond. Engr Public Service Co. of Colorado, 900 15th St- and (for mail) 1378 Dexter St., Denver, Colo. BRIGHAM, Clare M. (M 1925) Vice-Pres. in charge of Sales (for mail) C. A. Dunham Co450 E. Ohio St- and 420 Maple Ave- Winnetka, 111. BROWNE, Alfred L. (Af 1923) 253 Highland Ave., South Orange, N. J. BRUNETT, Adrian L. (M 1923) Mech. EngrU. S. Supervising Architects Office, Treasury Dept- Washington, D. C- and (for mail) P, O. Box 36, Rockville, Md. BRUST, Otto (Af 1930) Consulting Engr- Wil- BRINKER, Harry A. (M 1934) 2521 University Ave., Kalamazoo, Mich. - BRINTON, Joseph W. (M 1920) Mgr- Boston Dist. (for mail) American Blower Corp., 1003 Statler Bldg., Boston, and 42 Gleason St., West Medford, Mass. BRISSETTE, Leo A. (M 1930) Treas. (for mail) Trask Heating Co- 4 Merrimac St- Boston, and 168 Florence St., Melrose, Mass. BRITTAIN, Alfred, Jr. (M 1938) Engr. Weathermakers (Canada) Ltd- 593 Adelaide St- and (for mail) 138 Wheeler Ave- Toronto. Ont., Canada. BROCIIA, John F. (Ax 1S36) Buyer of Plbg. and Htg- Montgomery Ward & Co- 619 W. Chicago Ave- and (for mail)-5475 Hirsch St- Chicago, 111. mersdorfer Strasse 95, Berlin-Charlottenburg 4, Germany. BRYANT, Alice Gertrude, A.B- M.D., F.A.C.S., AS-E.E. (Life Member; M 1921) Otologist and . Laryngologist, Physician and Surgeon, 405 Marl borough St- Boston, Mass. BRYANT, Percy J. (Jf 1915) Chief Engr. (for mail) Prudential Insurance Co. of America, 763 Broad St- Newark, and 754 Belvidere AveWestfield, N. J. BUCK, David T. (A 1936) Chairman (for mail) Buck Engineering Co- Ltd- 37-41 Marcy St and 116 W. Main St., Freehold, N. J. BUCK, Lucien (Af 1928) Engr- Proctor & Schwartz, Inc- 7th St. & Tabor Rd- Philadelphia and (for mail) 101 Waverly Rd- Wyncote, Pa. 13 Heating Ventilating Air Conditioning Guide 1939 BUCKERIDGE, Victor L. (A 1938) Partner (for mail) H. Buckeridge & Son, 15108 Kerchival Ave., and 601 Fisher Rd., Grosse Pointe, Mich. BUCKLEY, Malcomb L. (A 1939) Estimator 8c Supt., Pbillips-Gctschow Co., and (for mail) CABOT, Mathew A. (7 1937) Mech. Engr (fOT mail) College of Engineering, University Kentucky, and 316 Mentelle Park, Lexington, 4542 Beacon St., Chicago, til. BUENGER, Albert* (Af 1920; 7 1917) (Council, 1934-37) Mgr., National Business Dept, (for mail) Delco-FrigidaireCond. Div.,General Motors Sales Corp., 300 Taylor St., and 224 Schantz Ave., Dayton, O. BUENSOD, Alfred C. (Af 1918) Pres., Buensod- Stacey Air Conditioning, Inc., 60 East 42nd St., and (for mail) 33 Fifth Ave., New York, N. Y. CADY, Edward P. (7 1937) Engr., 1003 Euclid Ave., Syracuse, N. Y. uata CAIRNS, John H. (A 1936) Asst. Sales Engr Frigidaire Corp., and (for mail) 127 Scarboro Rd., Toronto, Ont., Canada. CALDWELL, Arthur C. (Af 1930) Engr. and Estimator, P. Gormly Co., 155 N. Tenth St. and (for mail) 550 South 48th St., Philadelphia', BULKELEY, Claude A. (Af 1923) Consultant & Sales Engr. (for mail) 2045 N. Broad St., Phila- CALEB. David (Af 1923) Engr. (for mail) Kansas - delphia,.Pa...and Newton, N. J._ _ _ `. BULLEIT, Charles R. (Af 1932: 7 1930), 1811" City...Power 8c Light Co., 1330 Baltimore Ave - and 141 Spruce St.. Kansas City, Mo. *' Bayard Park Drive, Evansville, Ind. CALL, Joseph (M 1938; 7 1936) Air Cond. Enzr BULLER, Charles R. (A 1938) Asst. Chief Engr., Elliott-Lewis Co., 2518 N. Broad St., and (for Oil Burner Div., The Heil Co., 3000 W. Montana mail) 669 Jamestown St., Roxborough, Phila Ave., and (for mail) 2650 S. Shore Drive, Mil- delphia, Pa. CALLAHAN, Peter J. (Af 1934) Inspecting Engr. BULLOCK, Howard H. (A 1933) Commerical Engr. (for mail) General Electric Co., 212 No. Vignes St., Los Angeles, and 2442 Cudahy St., Huntington Park, Calif. ' BULLOCK, Thomas A. (Af 1930) 35 Everett St., Arlington, Mass. BUR, Julien R. C. (A 1936; 7 1931) Chief Engr. (for mail) Bur 8c Co.. 10 rue du Chapeau Rouge, and 1 Place Francois Rude. Dijon. France. BURCH, Laurence A. (Af 1934) Sales Mgr., R. L. Deppmann Co., 957 Holden Ave., Detroit, and (for mail) 78 Amherst Rd., Pleasant Ridge, Royal Oak, Mich. BURKHART, Elder M. (7 1935) Sales Engr.. Overly Mfg. Co., 574 W. Otterman St., and (for mail) 529 E. Pittsburgh St., Greensburg, Pa. BURNAM, C. M., Jr. (M 1938; A 1937) Engrg. Editor (for mail) Heating, Piping and Air Con ditioning, 6 N. Michigan Ave., and 10563 S. Hale Ave., Chicago, 111. BURNETT, Earle S. (M 1920) Senior Mech. Engr., Petroleum and Natural Gas Div., U. S. Bureau of Mines, Amarillo Helium Plant, P. O. Box 2025, and (for mail) 4223 W. Eleventh Ave., Amarillo, Tex. ` BURNS, Edward J. (Af 1923) Harris Bros. Plumb ing Co., 217 W. Lake St., and (for mail) 4716 Aldrich Ave., Minneapolis, Minn. BURNS, John R. (J 1936; 5 1933) Htg. Dept., Crane Co., 279 Madisorr Ave., New York, N. Y. and (for mail) 504 N. Main St., Wallingford, Conn. BURR, Griffith C. (Af 1937) Engr., Modem Automatic Heat Co., 14 Wood Lane, Hyde Park, N. Y. BURR, Kimball (A 1936) 320 Crocker St., Los Angeles, Calif. BURRITT, Charles G. (A 1916) Mgr., Minne apolis Office (for mail) Johnson Service Co., 922 2nd Ave., S., and Minneapolis Athletic Club, Minneapolis, Minn. BUSHNELL, Carl D. (A 1921) Pres, (for mail) The Bushnell Machinery Co., 311 Ross St,, Pittsburgh, and 94 Pilgrim Rd., Rosslyn Farms. Carnegie, Pa. BUSSE, Herbert (Af 1938) Chief Engr.. Fisher & Co., Fisher Bldg. Div., W. Grand Blvd., and (for mail) 16771 Burgess, Detroit, Mich. BUTLER, Peter D. (Af 1922) Salesman, U. S. Central Hanover Bank & Trust Co., 60 Broad way, New York, and (for mail) 4057 Amboy Rd Great Kills, Staten Island, N. Y. '* CALVER. Robert W. (A 1937) Prop, (for mail) P. O. Box 832, and 77 Queen St., Kirkland I -q w Ont., Canada. . CAMERON, Robert T. (5 1938) Asst., Alex Cameron, Inc.. 5035 Forbes St., Pittsburgh, Pa., and (for mail) 98 Herrick Rd., SouthamDton. N. Y. '' CAMERON, William R. (A 1936) Dist. Mgr.. L. J. Mueller Furnace Co., Milwaukee. Wls., and (for mail) 3337 Highland Ave., Kansas City, Mo. CAMPBELL, Alfred Q., Jr. (7 1933) Engr., E. K. Campbell Heating Co., Kansas City, Mo.', arid (for mail) 1083 Meriwether Ave., Memphis, Tenn. CAMPBELL, Andy O. (7 1939) Engr. (for mail) Oklahoma Gas 8c Electric Co., Room 408, and 2749 N. W. 21st St., Oklahoma City. Okla. CAMPBELL, Bowen (Af 1938) Engr. (for mail) Campbell Heating Co., 3127 Dean Ave., and 2404 E. 29th, Des Moines, la. CAMPBELL, Everett K.* (Af 1920) (Council, 1931-1933) Pres, (for mail) E. K. Campbell Heating Co., 2445 Charlotte St., and 3717 Harrison, Kansas City, Mo. CAMPBELL, E. Klrker, Jr. (Af 1938: 7 1930) Secy.. E. K. Campbell Heating Co., 3420 Hayaie, Dallas. Tex. CAMPBELL, Frank B. (A 1927) Sales; Engr., American Radiator Co., Old Hermitage Jld., Richmond, Va. CAMPBELL, George S. (7 1937) Sales Engr., John Bouchard & Sons, Nashville, and (for mail) 1906 Ivy St., Chattanooga, Tenn. CAMPBELL, Ralph L. (A 1937) Sales Engr., ' Chrysler Airtemp, 1316 Nicollet Ave., S., and (for mail) 5241 Knox Ave., S., Minneapolis. Minn. CAMPBELL, Robert E. (7 1935; S 1934) Sales ''Engr., Consolidated Air Conditioning,' 114 East 32nd St., New York, and (for mail) 3520 Newkirk Ave., Brooklyn. N. Y. CAMPBELL, Thomas F, (Af 1928) (for mail) T. F. Campbell Co.. 1013 Penn Ave., and R. D. No. 1, Wilkinsburg, Pa. CANDEE, Bertram C. (Af 1933) Partner, Beman & Candee, 374 Delaware Ave., Buffalo, apd (for mail) 19 Tremont Ave., Kenmore, N. Y. CANON, Herbert A. (A 1938) Mgr., Carrier Dept, Radiator Corp., Detroit, Mich., and (for mail) (for mail) Dravo Corp., 300 Penn Ave., and 604 127 Edgewater Rd., Cliffside Park, N. J. BUTT, Roderick E. W. (A 1936: 7 1930) Air Cond. Mgr., Refrigeration & Allied Products, Olympia Rd., Pittsburgh, Pa. CAPLE, Ira (5 1938) Sr. in Mech. Engrg., Univer sity of Minnesota, and (for mail) 318 Harvard Ltd., 92 Buckingham Palace Rd., and (for mail) 605 Beatty House, Dolphin Square, London, S. W. 1., England. , BYRD, Tom (A 1938) Market Development Div. (for mail) The American Rolling Mul Co., and 2403 Fleming Rd., Middletown, O. BYSOM, Leslie L. (Af 1915) Mech. Engr., Puget Sound, Navy Yard, P.S.N.Y., Public Wks. Dept., and (for mail) 1214 8th St., Bremerton, Wash. S. E., Minneapolis. Minn. CAPPS, Edgar Lee (A 1937) (for mail) .Capps & Sutherland, 619 W. 35th St,, and 619 Pennsyl vania Ave., Norfolk, Va. ' CARBONE, James H. (Af 1937) Htg.-Vtg. .In spector, City of New York, New York, and (for mail) 121-13 198th St.. St. Albans. L. I.. N. Y. CAREY, James A. (Af 1928) . Carrier Corp., Syracuse, N. Y., and (for mail) Villa Nova, Pa. 14 Roll or Membership CAREY, Paul C. (Af 1930) Consulting Engr. (for mall) Runyon & Carey. 33 Fulton St., Newark, and 31 Claremont Drive, Maplewood, N. J. CARLE, William E. (Af 1926) Pres, (for mail) CASPERD, Henry W. H. (A 1938; 7 1930) Engr., Carrier Co., Ltd., 24 Buckingham Gate, London, and (for mail) 21 Robin Hood Lane, Sutton, Surrey, England'. Carle-Boehlirtg Co., Inc., 1641 W. Broad St., and 2220 Floyd Ave., Richmond, Va. CASSELL, John D * {Life Member; Af 1913) Retired, 2008 Walnut St., Philadelphia, Pa. CARLOCK, Marion F. (Af 1936) Dist. Repr., American Foundry & Furnace Co., and (for mail) 505 Henry, Alton, III. CARLSON, C. O. (A 1937) Owner (for mail) C. O. CASSELL, William L. (Af 1936) Owner (for mail) William L. Cassell Mechanical Engr., 2501 Telephone Bldg., Kansas City, and R. F. D. No. 6. Independence, Mo. Carlson Htg. Co., 1627 Washington Ave., N., and 1806 Thomas Ave., N.. Minneapolis, Minn. CAWBY, Elmer L. (A 1938; 7 1935) Sales Engr. (for mail) Carrier Corp., 748 E. Washington CARLSON, Conrad V. (7 1937) Air Cond. Engr. (for mail) Realty Syndicate, 1321 Sharp Bldg., Lincoln, and Axtell, Nebr. CARLSON, Everett E. (Af 1932; A 1929) Branch Mgr. (for mail) The Powers-Regulator Co.,-1010- ` Louderman Bldg., and 6652 Washington Ave., St. Louis, Mo. CARNAHAN, John H. (7 1937) Design Engrg. Dept., Oklahoma Gas and Electric Co., 321 N. Harvey St., and (for mail) 3116 N. W. 26th St., Oklahoma City, Okla. CARON, Hector (A 1938) Mgr.-Owner (for mail) Heating & Air Conditioning, 421 S. 3rd St., Rochelle, 111. CARPENTER, Raymond D. (S 1938) California Polytechnic, San Lui9 Obispo, and (for mail) 534 Bay St., Santa Cruz, Calif. CARPENTER, R. H. (Af 1921) (Council. 1930 1935) Mgr., New York Office (tor mail) Nash Engineering Co., Graybar Bldg., 420 Lexington Ave., New York, and 20 Jefferson Ave., White Plains. N. Y. CARR. Maurice L.* (Af 1931) Director, Pitts burgh Testing Laboratory, Stevenson & Locust Sts.. Pittsburgh, Pa. CARRIER. Earl G. (Af 1936: 7 1929) Supvr. Engr., Carrier Corp., Philadelphia Savings Fund Blvd., and 2315 S. Flower St., Los Angeles, Calif, CHALMERS, Charles H. (M 1925) Gen. Mgr. (for mail) Chalmers Oil Burner Co., 1234 Central Ave., and 523-7tb St., S. E., Minneapolis, Minn, CHAMBERS. Fred W. (Af 1936) Pres: (for mail) F. W. Chambers 8c Co., Ltd.. 96 Bloor St., West, and 122 Garfield Ave., Toronto, Ont,, Canada. CHAMPLIN, Robert C. (A 1938) Assistant to Air Cond. Engr., Timken Silent Automatic Div., 100-400 Clark Ave., Detroit, and (for mail) 152 Cortland Ave., Highland Park, Mich. CHAPIN, C. Graham (Af 1933) Treas. (for mail) Hopson & Chapin Mfg. Co., 231 State St., and 66 Faire Harbour Place. New London, Conn. CHAPIN, Harvey G. (Af 1935) Sales Engr. (for mail) Westerlin 8c Campbell Co., 1113-15 Cornelia Ave., and 8151 Inglesiae Ave., Chicago. 111. CHAPMAN, William A., Jr. (Af 1936) Sales Planning Div. (for mail) Delco-Frigidaire Cond. Div., General Motors Sales Corp., 300 Taylor St., and 2515 Shafor Blvd., Dayton, O. CHARLES, Paul L. (Af 1938) Mgr. (for mail) Walsh 8c Charles, 406 Tribune Bldg., and 145 Ash St., Winnipeg, Man., Canada. CHARLES, Thomas J. (Af 1934) Engr.. 209 West 38th St., New York, and (for mail) 175 Marine Ave., Brooklyn, N. Y. Bldg.. Philadelphia, Pa., and (for mail) 228 Robineau'Rd.; Syracuse, N. Y. CARRIER, Willis H.* (Af 1913) (Presidential Member) (Pres., 1931; 1st Vice-Pres., 1930; 2nd Vice-Pres., 1929; Council, 1923-1932) Chairman of the Board (for mail) Carrier Corp., and 2570 Valley Drive, Syracuse, N. Y. CHARLET, Louis W. (Af 1934) Branch Mgr. (for mail) Kewanee Boiler Corp., 37 W. 39th St., New York, and 427 Rich Ave., Mt. Vernon, N. Y. CHARTERS William A. (A 1937) Salesman and Field Engr., Canada Foundries & Forgings, Ltd., Brockville, and (for mail) 57 Newton Ave., Hamilton, Ont., Canada. CARROLL, Arthur F. (Af 1938) Development Engr., Automatic Products Co., 2450 N. 32nd St., and (for mail) 5525 Brooklyn PL, Milwaukee. Wis. CARROLL, William M. (7 1938) Sales Engr. (for mail) Tom Dolan Heating Co., 614 W. Grand, and 908 East Drive, Oklahoma City, Okla. CHASE, Arthur M., Jr. (Af 1938) Sales Engr. (for mail) York Ice Machinery Corp., P. O. Box 359, and 5124 Ennis St., Houston, Tex. CHASE, Chauncey L. (Af 1931) Partner (for mail) Edward E. Ashley, Consulting Engr., 10 East 40th St., New York, and 8829 Fort Hamilton Pkwy., Brooklyn, N. Y. CHASE. Louis R. (Af 193S;7 1931) Mgr. Air Cond. CARTER, Alexander W. (7 1936) Htg. Engr. (for mail) Monarch Brass Mfg. Co., Ltd.. 71 Browns Ave., and 2178 Queen St., E., Toronto, Ont., Canada. CARTER, Doctor (Af 1934) Consulting Engr., 34 Dept, (for mail) The Carter-Waters Corp., 2440 Pennway, and 4915 Bell. Kansas City, Mo. CHEATWOOD. William H. (7 1937) Commercial Engr. (for mail) Air-Rite Corp., 3123 Holmes St., ana 1815 Grand Ave., Dallas, Tex. Cunningham Ave., St. Albans, Herts England. CARTER, John H. (Af 1936) Special Repr. (for mail) Frick Co., 100 N. Broadway, St. Louis, and 529 Atlanta Ave., Wesbter Groves, Mo. CHEESEMAN, Evans W. (7 1937; 5 1934) Engr., Perfection Stove Co., 7609 Platt Ave., and (for mail) 2200 Prospect Ave.. Cleveland, O. CHEN, Sarcey T. (Af 1936) Vice-Pres. and Gen. CARY, Edward B. (Af 1935) Partner (for mail) Mgr. (for mail) American Engineering Corp., John Paul Jones Cary & Millar, Consulting Engrs., 448 Terminal Tower, Cleveland, and Chillicothe Rd.. Aurora, O. CASE. Delbert V. (Af 1937) Owner, Case Engi neering Co., 428 Dwight Bldg., and (for mail) 2005 East 33rd SL, Kansas City, Mo. 989 Bubbling Well'Rd., and 45/24 Great Western Rd., Shanghai. China. CHENEVERT, J. Georges (Af 1938) Consulting Engr. (for mail) Arthur Surveyer & Co., Con sulting Engrs., Room 1003-1010 St. Catherine St., W.. Montreal, and 536 Outremont Ave., CASE, Roy H. (A 1936) Resident Mgr. (for mail) Outremont, P> Q.. Canada. 417 Central Bldg., and 3322 Hunter Blvd., Seattle, Wash. CHENOWETH, Dale M. (7 1938; 5 1936) 1000 Washington St., South Braintree, Mass. CASE, Walter G. (A 1930) Asst. Mgr., Ideal Boilers & Radiators, Ltd., Ideal House, Great Marlborough St., London, W.I.; and (for mail) 66 The Ridgeway, Kenton, Harrow, Middlesex, England. CASEY, Byron L. (Af 1921) Sales Engr. (for mail) Ilg Electric Ventilating Co., 182 N. LaSalle St., Chicago, and 307 Vine Ave., Park Ridge, 111. CASKEY, Lutber H., Jr. (S 1938) Student (for mail) Carnegie Institute of Technology, Box 310, Pittsburgh, Pa., and 513 N. Queen St., Martinsburg, W. Va. CHERNE, Realto E. (M 1938; 7 1929) Engrg. Supervisor, Carrier Corp-. and (for mail) 606 Charmouth Drive, Syracuse, N. Y. CHERRY, Lester A.* (Af 1921) Consulting Engr. (for mail) Industrial Planning Corp., 271 Dela ware Ave., and 155 Euclid Ave., Buffalo, N. Y. CHERRY, Virgil H.* (Af 1937) Instructor, Uni versity of California, Dept, of Mech. Engrg.. and (for mail) 1269 Hearst Bldg.. Berkeley, Calif. . CHESTER, Thomas* (Af 1917) Consulting Engr., c/o Davidson & Co., Ltd., Central House, Kingsway, London, England. Heating Ventilating Air Conditioning Guide 1939 CHEYNEY, Charles C. (A 1913) Asst. Sales Mgr. (for mail) Buffalo Forge Co.. 490 Broadway, and 255 Lincoln Parkway, Buffalo, N. Y. CHILDS, Lewis A. (M 1933) Dist. Sales Mgr. (for mail) Clarage Fan Co., 520 Commercial Trust Bldg., and 1320 Foulkrod St., Philadelphia, Pa. CHRISTENSON, Harry (A 1931) Partner (for mail) Hunter-Prell Co., 38 S. Madison St., and 121 Sunset Blvd., Battle Creek, Mich. CHRISTMAN, William F. (A 1932; 71931) Engr. (for mail) Kroeschell Engineering Co., 215 W. Ontario St., and 5649 Artesian Ave-, Chicago, 111, CHRISTOPHERSON, Andrew E. (Af 1935) Engr.-Custodian (for mail) Board of Education, Spalding School, 1628 Washington Blvd,, and 2923 N. Kilpatrick Ave., Chicago, 111. CHRONE. Robert E. (AT 1938) Chief Engr., R. F. Taylor, Consulting Engr., 909 Bankers Mortgage Bldg., Houston, Tex. CHURCH, H. J. (Af 1922) Mgr. (for mail) Darling Brothers, Ltd., 137 Wellington St., W., Toronto, and 358 Main St, N., Weston, Ont, Canada. CITRON, Daniel J. (S 1938) 2055 Ryer Ave., New York, N. Y. GLAR, Robert, Jr. (A 1938) Sales Engr. (for mail) United States Radiator Corp., 127 Campbell Ave., and Lee Crest Apartments, 2nd Blvd. at. Blaine, Detroit, Mich. CLARE, Fulton W. (Af 1927) 935 Plymouth Rd., N. E., Atlanta, Ga. CLARK, E. Harold (Af 1922) Manufacturer's Agent, 600 Michigan Theatre Bldg., and (for mail) 2539 Lakewood, Detroit, Mich. CLARK, Lynn W. (A 1938) Engr. and Salesman (for mail) Hall-Neal Furnace Co., and 737 West. 32nd St., Indianapolis, Ind. CLARKSON, John R. (S 1938) David Ranken Jr. School of Mech. Trade, Air Cond, Dept., 4431 Tinney Ave., and (for mail) 4620-A New berry Terrace, St. Louis, Mo. CLAY, Wharton (A 1938) Secy, (for mail) National Mineral Wool Assn., 1270 Sixth Ave., New York, and 127 S. Broadway, Nyack, N. Y. CLEGG, Carl (Af 1922) Dist. Mgr. (for mail) American Blower Corp., 311 Mutual Bldg., ana 3513 Gillham Rd., Kansas City, Mo. CLEVELAND, Clyde C. (A 1936) Htg. Engr., Johnson & Cleveland, 192 Main St., and (for mail) 64 E. Main St., Bradford, Pa. CLIFTON, John A. (A 1938) Salesman, Warden King, Ltd., 299 Adelaide St., W., and (for mail) 369 Belsize Drive, Toronto, Ont.. Canada. CLINE, Edward A. (Af 1937) Consultant on Air and Water Conditioning, Room 512, Architects Bldg., 816 West 5th, Los Angeles, Calif. CLOSE, Paul D * (Af 1928) (for mail) The Celotex Corp., 919 N. Michigan Ave., Chicago, and 564 Meadow Rd., Winnetka, IH. CLOSE, Robert (Af 1938) Chief Air Cond. Engr., National Broadcasting Co., 30 Rockefeller Plaza, New York, N. Y. and (for mail) 199 Ames Ave., Leonia, N. J. CLOSNER, J. J. (7 1938) Sales Engr. (for mail) Robischung-Kiesling, Inc., 4848 Main St., and 4435 Jefferson, Houston, Tex. COCHRAN, Charles C. (A 1935) Asst. Sales Mgr., Chicago Office, Minneapolis-Honeywell Regulator Co., 433 East Erie, Chicago, and (for mail) 840 S. Clifton Ave., Park Ridge, 111. COCHRAN, Lex H, (Af 1934) Sales Mgr., Western Div. (for mail) American Blower Corp., 625 Market St, and 130 Camino Del Mar, San Francisco, Calif. COCHRAN, William B. (7 1936; S 1935) Air Cond. Engr. (for mail) Cochran Air Conditioning Co. (Westinghouse) 1303 .Lamar Ave., and 3316 Telephone Rd., Box 16, Houston, Tex. ` COCKINS, William W. (7 1937) Sales Engr. (for mail) The Trane Co., 1129 Folsom St, San Francisco, and 576 The Alameda, Berkeley, Calif. CODY, Henry C. (M 1930) Sales Engr., Pierce Butler Radiator Corp., 19th & Glenwood Ave., and (for mail) 7336 North 21st St, Philadelphia, Pa. COGHLAN, Sherman F. (A 1937) Metronome Water Dist of Southern Calif., 306 W. TlfirdSt1' Los Angeles, and (for mail) 414 Ninth St Santa Monica, Calif. t* COHAGEN, Chandler C. (If 1919) Archt 211 Hedden Bldg, (for mail) Box 2100, and Avenue G., Billings, Mont. ** COSHt.ECNl,evHealarnrdy, (O7. 1937; S 1936) 3630 East 1*4U0tUhl COHEN, Philip (Af 1932) Dist Mgr. (for main B. F. Sturtevant Co.. 401 E. Ohio Gas 3d* and 7100 Euclid Ave., Suite No. 6, Cleveland n* COLBY, Clyde W. (Af 1915) Vice-Pres, and Gen* Mgr., Air Devices Corp., 70 Britannia St knd (for mail) 167 Buckingham St, Meridan Conn COLCLOUGH, Otho T. (A 1933) Custodian American Legation, and (for mail) 726 Parkdai* Ave., Ottawa, Ont., Canada. COLE, C. Boynton (7 1937) ChiefEngr. Air Cond. Dept., The Murray Co., Howell Mili*Rd P. O. Box 1517, and (for mail) 3843 Ragler Ave ' N. E.. Atlanta, Ga. ' COLE, Grant E. (A 1925) Vice-Pres. & Gen. Mgr Trane Co. of Canada, Ltd., 4Mowat Ave!' Toronto, Ont., Canada. ' COLEMAN, John B. (Af 1920) Chief Engr. (for mail) Grinnell Co., Inc., 260 West 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 Bellevue Ave., Westmo'unt, P. Q. Canada. 4 ' COLLE, Samuel S. (A 1938) Engr. & Owner (for mail) Air Conditioning Engineering Co., 361 You* ville Square, and 1489 Atwater Ave., Montreal, * P. Q.f 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) Supervisorof Steam Utilization (for mail) Allegheny County Steam Heating Co., Philadelphia Co. Bldg., 435 Sixth Ave., and 827 N. Euclid Ave., Pittsburgh, Pa. ' COLMENARES, Gaspar Vlzoso (A 1938) Vice- Pres. .& Gen Mgr. (for mail) Castel-Vizo, Re- frigeradon y Aire Acondicionado S. A., Obrapia 407. P. O. Box 210, and 19th St, No. 1001, Vedado, Havana, Cuba. COMB, Fred R., Jr. (7 1938; S 1937) Sales Engr., Delco-Fridigaire Conditioning Div., 2446 Uni versity Ave., St. Paul, and (for mall) 2425 Bryant Ave., S., Minneapolis, Minn. COMPTON, Warren E. (7 1930; S 1935) Engr., 904 W. Green St., Urbana, HI. . . COMSTOCK, Glen M. (A 1926) Sales Repr. Engrg. (for mail) L. J. Wing Mfg. Cov 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., North Tonawanda, and 1306 Delaware Ave., Buffalo, N. Y. CONE, William E. (7 1937) Air Cond. Engr. (for mail) Shook & Fletcher Supply Co., 1814 1st Ave., N., and 1037 10th Ave., S., Birmingham, CONNELL, Harold (Af 1935) Engr., Armo Cooling & Ventilating Co., 30 West 15th St., New York, and (for mail) 163 Arlington Ave., Mariners Harbor, S. I., N. Y. CONNELL, Richard F. (Af 1916) Mgr., Capitol Testing Laboratory (for mail) U. S. Radiator Corp., 1056 National Bank Bldg., and 2970- Burlingame, Detroit, Mich. CONNER, Raymond M. (Af 1931) Dir. Testing Laboratories (for mail) American Gas Asso ciation. 1032 East 62nd St., Cleveland, and 271 East 216th St., Euclid, O. CONRAD, Roy (Af 1935) Salesman, Carrier Corp., 748 E. Washington, Los Angeles, Calif., and (for mail) 3416 Colfax "B'\ Denver, Colo. CONROY, Martin J. (A 1938) Dealer,-Link-Belt Co., Stoker Div.;''Lycoming at Broad St., Phila. delphia, and (for mail) 122 Kent Rd., Upper Darby, Pa. 16 Roll of Membership CONSTANCE, John D. (7 1937) Draftsman, York Ice Machinery Corp., 42nd St. & 2nd Ave., Brooklyn, N. Y., and (for mail) 407 27th St., North Bergen, N. J. CONSTANT, Earl S. (7 1935) Air Cond. Sales Engr., P. H. Hensarling Co., 713 Bankers Mortgage Bldg., and (for mail) 2802 Bagby St., Houston, Tex. COOK, Arthur L. (A 1938) Engr., Power Plant, A. &. M. College of Texas, and (for mail) P. O. Box 248, College Station, Tex. 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) Pres, (for mail) AirConditioning, Inc., 2324 Hampden Ave., St. Paul, and 2115 Blaisdell Ave., Minneapolis. Minn. COOK, H. Dale (A 1938) Temp. Control Engr. (for mail) R. L. Deppmann Co., 957 Holden St., Detroit, and 73 East 10th St., Holland, Mich. COOK, Ralph P. (Af 1930) Asst. Supt.. Engrg. & Maintenance Dept, in charge of Engrg. Div. (for mail) Eastman Kodak Co., Kodak Park, and 663 Seneca Parkway, Rochester, N. Y. COOKE, Thomas C. (A 1937) Htg. & Air Cond. Engr. (for mail) Tomlinson Co., Inc., 400-402 E. Peabody St-, P. O. Box 217, and 1118K Eighth St., Durham, N. C. COOLEY, Edgerton C. (Af 1937) Mfrs. Agent, Chicago Pump Co. and Ross Heater & Mfg. Co. . (for mail) 625 Market St., San Francisco, and P. O. Box 789 B Route 1, Los Altos, Calif. COOMBE, James (A 1932) Vice-Pres. (for mail) William Powell Co., 2525 Spring Grove Ave., ana 2363 Grandin Rd., Cincinnati, O. COON, Thurlow E. (Af 1916) Pres, (for mail) The Coon-DeVisser Co., 2051 W. Lafayette, and 826 Edison Ave., Detroit, Mich. COOPER, Albert W. (Af 1935) Branch Mgr. (for mail) Johnson Service Co., 1230 California St., and 639 Cook St., Denver, Colo. ' COOPER, Dale S. (Af 1938; A 1937) Chief Engr. & Vice-Pres. (for mail) Air Conditioning Co., 4304 Main St., and 6528 Rutgers, Houston, Tex. COOPER, John W. (Af 1932; A 1925; 7 1921) Repr. (for mail) Buffalo Forge Co., 1598 Arcade Bldg.. St. Louis, and 612 Hawbrook Drive, Kirkwood, Mo. COOPER, Tom E. (7 1937; S 1936) 309 West 50th St., Minneapolis, Minn. COOPER, William B. (7 1937) Head of Pre fabricated Filtering Dept., Mueller Furnace Co., 2005 Oklahoma Ave., and (for mail) 3825 N. Newhall, Milwaukee, Wis. 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) Engr., 40 Sias Lane, Milton, Mass. CORNWALL, Charles C. (7 1935) Research Engr., The Bahnson Co., 1001 S. Marshall St., . and (for mail) 473 Carolina Circle, WinstonSalem. N. C. CORNWALL, George I. (Af 1919) Sales Engr., Burnham Boiler Corp., Elizabeth, N. J. CORRAO, Joseph (A 1936; 7 1933) Engr., City of San Francisco, Dept, of Works, Engrg. Dept., City Hall, and (for mail) 854 31st Ave., San Francisco, Calif. CORRIGAN, James A. (7 1935; 5 1930) Engr. (for mail) Corrigan Co., 2501 St. Louis Ave., and 6130 McPherson Ave., St. Louis, Mo.. COST, George W. (S 1938) Johnson Service Co., 1238 Brighton Rd., and (for mail) 5210 Forbes St., Pittsburgh, Pa. COVER, E. B. (Af 1937) Sales Engr., York Ice Machinery Corp., 115 S. 11th St., St. Louis, and (for mail) 3252 Waverly, East St. Louis,-III. COVER, Richard R.- (A 1936) Engr., Carrier Corp., 4th & Channing, N. E., and (for mail) 1302 Gallatin St., N. W,, Washington, D. C. COWARD, Charles W. (Af 1935) Pres, (for mail) Coward Engineering Co., 411 Cooper St., Cam den, and 812 Lincoln Ave., Palmyra, N. J. . COWELL, Robert J. (Af 1922) Consulting Engr., 769 Seventh Ave., New York, N. Y. COX, Harrison F. (A 1930) Htg. & Air Cond., 243 Carroll St., Paterson, N. J. COX, Philip E. (Af 1938) Engr., Sodete des Cine-Theatres d'Indochine, ana (for mail) 50 Boulevard Dongkhank, Hanoi, Tonkin, French Indo China. COX, Thomas M., Jr. (7 1937) Refrigeration and Air Cond, Dept. Head (for mail) Neal & Massy Engrg. Co., Ltd., 61 Edward St., and Maravol, Port of Spain, Trinidad, B. W. I. COX, William W. (Life Member; Af 1923) Pres, and Mgr. (for mail) Heating Service Co., Inc., 326 Columbia St., and 6232 31st Ave., N. E., Seattle, Wash. CRAMER, Wesley G. (A 1938) Dist. Sales Mgr. (for mail) The Marley Co., 1801 Carew Tower, and 3174 Portsmouth Ave., Cincinnati, O. CRANE, Robert S. (Af 1938) Dist. Engr. (for mail) Air Cond. Frigidaire Div., General Motors Sales Corp., 4 Cummin Station, and 301 32nd Ave., S., Nashville, Tenn. CRANSTON, William E., Jr. (Af 1931) Vice-Pres. & Gen. Mgr. (for mail) Thermador Electric Mfg. Co.. 2821 E. Pico St., Los Angeles, and 240 Hacienda Drive, Arcadia, Calif. CRAWFORD, Arthur C. (A 1938) Sales Engr., Potomac Electric Power Co., 10th & E. St., N. W., and (for mail) 429 Butternut St., N. W., Washington, D. C. CRAWFORD, John H., Jr. (A 1936; 7 1930) Air Cond. Engr., Hitchen Co., 441 Lexington Ave., New York, N. Y., and (for mail) 289 Reynolds Terr., Orange, N. J. CRIBARI, Hugo E. (A 1937) Salesman, American Radiator Co., 40 West 40th St., New York, and (for mall) 468 N. Fulton Ave., Mt. Vernon, N. Y. CRICHTON, Howard C. (S 1936) 769 Beaver Ave.. Midland, Pa. CRIQUI, A. A * (Af 1919) Chief Engr., Htg. & 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. Southport Ave., and 1320 N. State St., Chicago, 111. CRONE, Thomas E. (Life Member; Af 1920) Apt. E-24. Highland Hall, Rye, N. Y. CRONEY, P. Alfred (Af 1938) Chief of Mech. Section, U. S. Housing Authority, Interia Bldg., N., Washington, D. C., and (for mail) 21 Phila delphia Ave., Takoma Park, Md. CROPPER, Robert O. (Af 1938) Operating Engr., War Dept., c/o Quartermaster, Fort Knox, and (for mail) Vine Grove, Ky. CROSBY, Edward L. (Af 1936) Pres, (for mail) Henry Adams Inc., Consulting Engrs., 1263-1269 Calvert Bldg., and 5323 Belleville Ave., Balti more, Md. ' CROSS, Freeman G. (Af 1936) Sales Mgr Controls Div. (for mail) Fulton Sylphon Co., and 31 Nokomis Circle, Knoxville, Tenn. CROSS, Robert C.* (Af 1937) Fuel Engr. (for mail) B&ttelle Memorial Institute, 505 King Ave., and 1178 Virginia Ave., Columbus, O. CROSS, Robert E. (Af 1938; A 1931) Dist. Mgr. (for mail) Minneapolis-Honeywell Regulator Co., 271 Columbus Ave., and 68 Kimberly Ave., Springfield, Mass. CROSS, Roy A. (A 1938) Jr. Engr., Buffalo Forge Co., 490 Broadway, Buffalo, and (for mail) 66 Enola Ave., Kenmore, N. Y. CROUT, Marvin M. (Af 1939; A 1938) Branch Mgr. (for mail) York Ice Machinery Corp., 412 Houston St., and 2392 Hurst Drive, Atlanta, Ga. GRUMP, Alvin L. (Af 1937) Sales Engr. (for mail) Powers Regulator Co., 2720 Greenview Ave., Chicago, and 2701 Payne St., Evanston, 111. CUCCI, 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) Partner (for mail) Culbert-Whitby Co., 2019 Rittenhouse St., Philadelphia, and 929 Alexander Ave., Drexel Hill, Pa. . Heating Venturing Air Conditioning Guide 1939 CULLEN, Augustine G. (A 1936) Pres, (for mail) Cullen, Inc.. 20 L St.. S. W., Washington, D. C. CULLIN, William W. (Af 1938) Chief.Engr., Home Insulation Div., Johns-Manville Sales Corp., 22 East 40th St., and (for mail) 2995 Botanical Sq., New York, N. Y. GUMMING, Ford J. (Af 1936) Pres, (for mail) Beecher-Cumming, Inc., 820 2nd Ave., S., Minne apolis, and 120 Interlachen Rd., 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) Mgr. (for mail) Industrial Appliance Co. of New England, 110 Arlington St., Boston, and 41 Edgehill Rd., ... Chestnut.Hill,.Mass... _ . ______ _ ' CUMMINGS, G. J. (Af 1923) Vice-Pres. & Secy, (for mail) The Scott Co., 113-10th St., and 2001 Hoover Ave., Oakland, Calif. CUMMINS, George H. (Af. 1919) Dist. Mgr.. . Aerofin Corp., 918 United Artists Bldg., and (for mail) 16210 Ashton Rd., Detroit, Mich. CUMNOCK, H. (A 1938) Secy. & Treas. (for mail) Little Rock Refrigeration Co., 417 W. Capitol Ave., and 609 Rock, Little Rock, Ark. CUNNINGHAM, John S. (7 1937; S 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. CURRIER, Charles H. (Af 1919) (for mail) Ross Heater & Mfg. Co.. Inc.. 1407 west Ave., and Park Lane Apts., 33 Gates Circle, Buffalo, N. Y. CURRY, Roger F, (S 1938) Template Dept., Curtiss Wright Corp., Robertson, and (for mail) 3142 Sutton Blvd., Maplewood, Mo. CURTICE, Jean M. (A 1936) Htg. Engr. and Dist. Mgr., Citizens Utilities Co., 15 W. Fourth St., La Junta, Colo. CURTIS, Herbert F. (A 1934) Chief Engr. (for mail) Henry Furnace & Foundry Co., 3471 East 49th St., Cleveland, and 59 Fourth Ave., Berea, O. CURTIS. Walter A. (7 1938; 5 1936) Sales Engr.. B. F. Sturtevant Co., 220 Delaware Ave., and (for mail) 37 E. Morris Ave., Buffalo. N. Y. CUSHING, Charles F. (Af 1938) Mgr. Air Cond. Sales, Bryant Heater Co. (for mail) 17825 St. Clair Ave.. Cleveland, and 2204 Edgerton Rd., Cleveland Heights. O. . CUTHBERTSON, Merle W. (A 1937) Supt. Mech. Equip, and Bldgs., Hardware Mutual Insurance Co., 2344 Nicollet Ave., Minneapolis, and (for mail) 1466 Hague Ave., St. Paul, Minn. CUTLER, Joseph A. (Af 1916) (Council. 1920 1926) Pres. and Gen. Mgr. (for mail) Johnson Service Co., 507 East Michigan St., and 4811 N. Lake Drive, Milwaukee. Wis. DANIELSON, Ellsworth H. (7 1938) Dist. Mgr Minneapolis-Honeywell Regulator Co.. 283t* Center St., Des Moines, la. DANIELSON, Lloyd C. (7 1938; S 1936) Sales* Mgr., Home Service Co., 821 Main St., Russell Kan. ' DANIELSON, WMmot A. (Af 1935) Lt. Col Quartermaster and Constructing Quartermaster' U. S. Army, Quartermaster Corps, Fort Knox Kv' DARBY. Marion H. (A 1938:7 1930) Chief Engr Air Cond. Dept, (for mail) General Electric' S. A., Caixa Postal 109, and Alberto de Camnos 299, Apt. 6. Rio de Janeiro, Brazil. DARLING, Arthur B. (A 1929) Asst. Sales Mgr (for mail) Darling Bros. Ltd., 140 Prince St * . Montreal, and 4326 Sherbrooke St., W., West! mount, P. Q., Canada. DARLINGTON, Allan p; (Af 1930) Sales'Eng^. Power Apparatus (for mail) American Blower Corp., 6000 Russell St., and 5200 Haverhill Detroit, Mich. ' DARTS, John A. (Af 1919) Kewanee Boiler Co Inc., 101 Park Ave., New York, N. Y. '' DASING, Emil (Af 1937) Designing Engr., Sears Roebuck & Co., 925 S. Homan Ave., and (for mail) 4729 N. Talman Ave., Chicago, III. DAUBER, Oscar W. (Af 1937) Consulting Engr. (for mail) 224 S. Michigan Ave.. Chicago, and 366 Winnetka Ave., Winnetka, IU. DAUBERT, LeRoy L. (7 1937) Branch Mgr., Sidles Co., Airtemp Div., 805 Walnut St., and (for mail) 2315 Grand Ave., Des Moines, la. DAUCH, Emil O. (Af 1921) Secy.-Treas. (for mail) McCormick Plumbing Supply Co., 1675 Bagtey Ave., Detroit, and 729 Bedford Rd., Grosse Pointe, Mich. DAUMAN, Arnold (S 1938) 1700 Grand Con course, New York, N. Y. DAVEY, Geoffrey I. (Af 1937) Consulting Engr., Haskins & Davey, 60-66 Hunter St., Sydney, M C U7 A llQf ralta DAVIDSON, John C. (7 1936) Air Cond. In spector, City of Minneapolis, 213 City Hall, and (for mail) 44l2-46th Ave.. S.. Minneapolis. Minn. DAVIDSON, L. Clifford (Af 1927) Associate Dist. Mgr. (for mail) Buffalo Forge Co'., 220 S. 16th St., Philadelphia, and 322 Winding Way, Merion, Pa. * * DAVIDSON, Philip L. (Af 1924; 7 1921) Con sulting Engr. (for mail) 1600 Walnut St., Phila delphia, and Radnor, Pa. - DAVIES, George W. (Af 1913) Mgr.. G. W. Davies & Co., 19 Maclaggan St., Dunedin, C. 1. (for mail) P. O. Box 390, Dunedin, N. 2., and Colina- wood, Macandrew Bay, New Zealand. DAVIS, Arthur C * (Af 1920) Supt. of Main tenance. The Port of N. Y. Authority, 111 Eighth Ave., New York, N. Y., and (for mall) 73 Preston St., Ridgefield Park, N. J. DAVIS, Arthur F. (Af 1934) Pres, (for mail) D Johnson & Davis Plumbing & Heating Co., 2235 Arapahoe St., and 1901 Ivanhoe St., Denver, Colo. DAFTER, Edwin H. (Af 1938) Dist. Chief Engr.(for mail) Carrier Corp., 12 S. 22th St., and 236 Henley Rd., Penn Wynne, Philadelphia, Pa. . 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. 1., N. Y. DAITSH, Abe (7 1937) Student Engr., York Ice Machinery Corp., 42nd St. & Second Ave., and (for mail) Y. M. C. A., 357 Ninth St., Brooklyn, DAVIS, Bert C. (Lift Member; Af 1904) (Council, \1917) Pres, and Treas. (for mail) American Warming 8t Ventilating Co., 317 Pennsylvania Ave., and 603 W. Church St., Elmira, N. Y. DAVIS, Calvin R. (Af 1927) Branch Mgr. (for mail) Johnson Service Co., 2328 Locust St., and 7534 Westmoreland Drive, St. Louis, Mo. DAVIS, Charles (Af 1938) Engr. (for mail) Rathe Heating Corp., 598 Grand Concourse, and 281 Wadsworth Ave., New York, N. Y. DAVIS, Edward J. (7 1938) Sales Engr. (for mail) Gurney Foundry Co., Ltd., 4 Junction Rd., N. Y. DAKIN. Harold W. (7 1934) 169 Park Ave., Toronto, and Lakeview, Ont., Canada. . DAVIS, George C. (7 1936) Vice-Pres. (for mail) Dalton, Mass. DALY, Robert E. (Af 1931) Dir. of Engrg. (for mail) American Radiator Co., 40 W. 40th St.. New York, and 270 Bronxville Rd., Bronxvttle, Northern Public Service Corp., Ltd,, 307 Power Bldg., and 923 Somerset Ave., Winnipeg, Man., Canada. - ,, DAVIS, George L., Jr. (A 1938) Estimator (for DAMBLY. A- Ernest (Af 1924; 7 1921) (for mail) 901 Architects Bldg., Philadelphia, Pa., and Harvey Cedars, N. J. DANIELSON, E. B. (A 1936) Owner-Mgr. (for mail) Home Service Co., 132 West St., and 819 Main St., Russell, Kan. mail) L. L. McConachie Co., 1003 Maryland Ave., and 1300 Waybum St., Detroit, Mich. * DAVIS, Joseph ( Af 1927; A 1926) Owner, Heating & Refrigeration Contractor (for mail) 70 West Chippewa St., and 166 Huntington Ave., Buffalo, N. Y. . 18 Roll of Membership DAVIS, Keith T. (Af 1937) Engr. Dept, (for mail) L. J. Mueller Furnace Co., and 1445 N. 40th, Milwaukee, Wis. DAVIS, Otis E. (M 1929; A 1925) Sales Engr.. Hoffman Specialty Co., Waterbury, Conn., and (for mail) Box 98, Scottsbluff, Nebr. DAVIS. Rowland G. (A 1921) Sales Repr., 887 Nela View Rd.. Cleveland Heights, O. DAVISON, Robert L. (Af 1934) Director of Housing Research (for mail) John B. Pierce Foundation, 37 West 39th St., New York, and DE SOMMA, Anthony E. (7 1937) Engr.; Heating, Ventilating & Air Cond., Worlds Fair, Flushing, and (for mail) 2052 Homecrest Ave., Brooklyn, N. Y. . DES REIS, John F. (Af 1936) Regional Mgr., Carrier Corp., and 102 Century Drive, Syracuse, N. Y. DETERLING, William C. (A 1937) Salesman (for mail) General Electric Co., 570 Lexington Ave., New York, and 32 W. Milton St., Freeport, N. Y. Meadow Glen Rd., Fort Salonga, L. L, N. Y. DAWSON, Eugene F. (Af 1934) Assoc. Prof, of Mech. Engrg. (for mail) University of Oklahoma, and 225 E. Frank St., Norman, Okla. DAWSON, Thomas L. (Af 1930) Pres, (for mail) -Thoznas-L.-Dawson~ Co., 2035 Washington St., Kansas City, Mo., and Shawnee Mission Rd., Rosedale Station, Kansas City, Kan. DAY, Harold C. (A 1934) Mgr. (for mail) Ameri can Radiator Co., 1807 Elmwood Ave., Buffalo, and 223 Woodcrest Blvd., Kenmore, N. Y. DAY, Irving M. (A 1936) Sales Engr. (for mail) 709 Mills Bids., Washington, D. C., and 405 Cumberland Ave., Chevy Chase, Md. DAY, V. S.* (Af 1924) Director Dealer Engrg. DEVER, Henry F. (Af 1936; A 1935) Branch Mgr.. Minneapolis-Honeywell Regulator Co.. Wayne & Roberts Ave., Philadelphia, and (for mail) 502 Merwyn Rd., Narberth, Pa. DeVILBlSS,.Parker T.-(A 1937) Htg. and Air 'Cond. Engr.. 11V$ N. Lee Ave., Oklahoma City, Okla. DEVORE, Angus B. (A 1937) Sales Engr. (for mail) James A. Messer Co., Inc., 1206 K St., N. W., Washington, D. C., and 2016 Queens Chapel Rd. (Avondale) Hyattsville, Md. DEWEY, Ritchie P. (Af 1934) Mgr., Temperature Control & Uni-Flo Depts. (for mail) BarberColman Co., River & Loomis Sts., and 2301 Oxford St., Rockford, III. (for mail) Carrier Corp., and 306 Highland Ave., Syracuse, N. Y. DeWILDE, Marlnus Pieter (7 1938) Ing. M. P. DeWilde. M. T. S. H., N. V. Ind. My. Gebr. DAYNES, Joseph H. (Af 1938) Application Engr. Van Swaay, Banka Straat 134, Den Haag (The (for mail) Canadian General Electric Co., Ltd-. Hague) Holland. 212-214 King St., W., and 469 Soudan Ave.. DeWITT, Earl S. (A 1936) Branch Mgr., Wash Toronto, Ont., Canada. ington Office (for mail) American Blower Corp., DEAN, Carl H. (Af 1936) Air Cond. Engr. (for 438 Woodward Bldg., Washington, D. C., and mail) Oklahoma Natural Gas Co., P. O. Box 871, 3224 Oliver St., Chevy Chase. Md. and 1007 North Main, Tulsa, Okla. DIAMOND, David D. (7 1937) Design Engr., DEAN, Charles L. (Af 1932) Asst. Prof. Mech. Engrg., University of Wisconsin, 305 University Extension Bldg., and (for mail) 102 Grand Ave., Madison, Wis. Twin City Furnace Co., 13 S. 3rd St., Minne apolis, and (for mail) 118 E. Congress St., St. Paul, Minn. DIBBLE, S. E.* (Af 1917) (Presidential Member) DEAN. David (Af 1937) Sales Engr.. New York Plumbers Specialties Co., Inc., 334 E. 98th St., New York, and (for mail) 171 Radford St,, Yonkers, N. Y. DEAN, Frank J., Jr. (7 1935; 5 1934) Sales Engr., Gustin-Bacon Mfg. Co., 1412 West 12th St., and (for mail) 6028 Walnut St.. Kansas City, Mo. DEAN, Marshall H. (71938; 51936) Secy.-Treas., Dean-Hagny Corp., 14th & McGee St., and ((or mail) 1030 W. 55th St., Kansas City, Mo. DEE, Leo H. (7 1937) Junior Engr., Carrier Corp., International Div., and (for mail) 1026 W. Onodaga St., Syracuse, N. Y. DEGLER, Howard E. (Af 1938) Prof, of Mech. Engrg. (for mail) University of Texas, and 1405 Hardovin Ave., Austin, Tex. DeLANU, Charles W. (M 1924; 7 1923) Secy.Treas. (for mail) C. W. Johnson, Inc., 211 N. Desplaines St;, and 2021 Estes Ave., Chicago, HI. (Pres., 1925; 1st Vice-Pres., 1924; 2nd Vice-Pres., 1923; Council, 1921-1926) Supt., Thomas Ranken Patton School, Elizabethtown, Pa. DICK, Andrew V. (7 1935) Pres., A. V. Dick Heating Co., 14J Jay St., Albany, N. Y. DICKASON, Gray D. (Af 1938) Pres, (for mail) Genesee Heating Service, Inc., 950 Mercantile Bldg., and 140 Windemere Rd., Rochester, N. Y. DICKENSON, Frederick R. (Af 1936; A 1934) Asst. Sales Mgr. (for mail) American Blower Corp., 6000 Russell St., Detroit, and 715 Pilgrim Rd., Birmingham, Mich. DICKENSON, Malcolm E. (Af 1936) Vice-Pres. & Mgr. (for mail) Livingston Stoker Co., Ltd., 78 Catharine St., N. and 964 Cumberland Ave., Hamilton, Ont., 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. DELANY, John V. (S 1938) Worcester Poly technic Institute, and (for mail) 34 Fruit St., Worcester, Mass. . DELAVAN, Nelson B. (Af 1938) Senior Partner DICKINSON, Robert P., Jr. (7 1938) Warehouse Mgr. (for mail) Burnham Boiler Corp. of Ohio, 301 Brushton Ave., Pittsburgh, and 219 Meade St., Wilkinsburg, Pa. (for mail) Delavan Engineering Co., 414 12th St., and 338 42nd St., Des Moines, la. DELL'ORTO, Luciano (7 1938) General Engr., Ing. Giuseppe DeU'Orto, 18 Via Merano, Milano (139) Italy. . DEMAREST, Richard T. (7 1938) Air Cond. Sales Engr., Eastemoil Inc., 133 Marginal Way, and (for mail) 64 Deering St., Portland, Me. DEMPSEY, Stephen J. (A 1938) Pres.-Treas.. DICKSON, George P. (Af 1919) Pres, (for mail) B. F. Sturtevant Co., 89 Broad St., Boston, Mass., and P. O. Box 22, Canterbury, N. H. DICKSON, Robert B. (Af 1919) Pres, (for mail) Kewanee Boiler Corp., Franklin St., and Q Tracks, and 145 E. Division St., Kewanee. 111. DICKSON, Robert W., Jr. (7 1938) Sales Engr., American Blower Corp., 1433 Oliver Bldg., Pittsburgh. Pa. Stephen J. Dempsey Co. (for mail) 79 Harvard, Battle Creek, Mich. DENISE, John R. (A 1937: 7 1935) Development Engr. (for mail) Surface Combustion Corp., 400 Dublin Ave., and 136 E. Broad St., Columbus, O. DENNY, Harold R. (A 1934) Eastern Mer chandise Mgr. (for mail) American Blower Corp., 50 W. 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., and 13201 Cloveriawn Aye., Detroit, Mich. DIETZ, C. Fred (Af 1937) Sales Engr. (for mail) Haynes Selling Co., Inc., 1124 Spring Garden St., and 1215 Allengrove St., Philadelphia, Pa. D'lMOR, Elton J. (Af 1933) Factory Repr., U. S. Air Conditioning Corp., 750 Union Ave., and (for mal!) 2102 Cowden Ave., Memphis, Tenn. DION. Alfred M. (Af 1937) Sales Engr. (for mail) Trane Co. of Canada,. King & Mowat Sts., and 356 Bloor St., E., Toronto, Ont., Canada. DISNEY, Melvin A. (A 1934) Pres, (for mail) Disney-Leffet Co., Inc.. 3323 Main St., and 6648 Kenwood, Kansas City, Mo. Heating Ventilating Air Conditioning Guide 1939 DISTEL, Robert E. (7 1938) Distel Heating Equipment Co., 404-6 Kalamazoo Plaza (for mail) Post Office Box 133, Lansing, and 547 Bailey St., East Lansing, Mich. DIVER, M. L'. (Af 1925) Consulting Engr., P. O. . Box 1016, San Antonio, Tex. - DIXON, Arthur G. (Af 1928) Sales Mgr. (for mail) Modine Mfg. Co., and 442 Wolff St., Racine, Wis. DIXON, Meridith 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, P.Q., Canada. DODDS, Forrest-F. (Af 1920) Mgr., K. C. Branch (for mail) American Radiator Co., 1023 Grand Ave., and Park Lane Hotel, 4600 Mill Creek Pkwy., 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, F. L. (Af 1919) Salesman, American Radiator Co., Richmond, and (for mail) 238 Boston Ave., Lynchburg, Va. DOERR, Carl F. (5 1938) Draftsman, American Can Co., 13th Ave. & St. Charles, and (for mail) 1118 N. 8th Ave., Maywood, III. 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 & Belt, 908 S. Michigan Ave., and (for mail) 46 Hawkins Ave., Chicago, 111. ` DOME, Alan G. (A 1938; 7 1936) Engr., Elliott- Lewis Co., 2514-18 N. Broad St., and (for mail) 7129 Chew St., Philadelphia, Pa. DONELSON, William N. (7 1937) Htg. Engr. (for mail) T. J. Conner, Inc., 3290 Spring Grove, and 795. Ludlow, Cincinnati, O. DONNELLY, James A.* (Life Member; Af 1904) (Treas., 1912-1914) Largent, W. Va. . DONNELLY, Martin A. (7 1937) Sub-Inspector, Frankford Arsenal, 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 23 Primrose St., Roslindate, Mass. DONOVAN, William J. (A 1930) 2239 North 27th St., Philadelphia, Pa. DORFAN, M. I. (if 1929) Dust Control Specialist, Pangborn Corp., 604 Chamber of Commerce Bldg., and (for mail) 1217 Malvern Ave., Pitts burgh, Pa. DORNHEIM, G. A. (Af 1912; 7 1906) 15 Hamilton 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. and Secy., The Tomngton Mfg. Co., 70 Franklin Sl, Tonington, Conn. DOUGHTY, Charles J. (Af 1925) Pres.-Managmg 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. and Htg. Engr. (for mail) Southern California Edison Co., 601 W. 5th 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. West, and (for mail) 9 Prince Arthur Ave., Toronto, Ont., Canada. DOWNE, Edward R. (Af 1927) Vice-Pres., Ameri can Gas Products Corp., 40 West 40th St., New York, and (for mail) 35 Howell Ave., Larchmont, n; y. . DOWNES, Alfred H. (A 1937) Draftsman. English & Lauer, 1978 S. Los Angeles St., and (for mail) 1342Bond St., Los Angeles, Calif. DOWNES, H. H. (Af 1923) DisL Mgr.. Mgr Navy Equip. Div. (for mail) American Blower Corp., 438 Woodward Bldg., Washington, D. C . and 4621 Chevy Chase Blvd., Chevy Chase Md* DOWNES, Nate W. (Af, 1917) Chief Engr Supt. of Bldgs., School Dist. of Kansas City Mo., 317 Finance Bldg., Kansas City, Mo ' DOWNING, Clarence B. (A 1938) Secy.-Treas N. B. Downing Co.. Jefferson Ave., and (for main Clark Ave., Milford, Del. DOWNS, Charles R. (Af 1936) Pres., Calorider Corp., Old Greenwich, Conn., and (for main .50 E. 41st St., New York, N.JkT. DOWNS, Sewell H. (Af 1931) (Council, 1937-1938) Chief Engr., Clarage Fan Co., and (for mail) 211 Creston Ave., Kalamazoo, Mich. DOXEY. Harold E. (A 1937) Safety Engr. (for mail) Ocean Accident & Guarantee Corp., Ltd 308 Phoenix Bldg., and 4251 Quincy St., N. Ei* Minneapolis, Minn. . *' DOYLE, Bernard J. (A 1938) Sales Engr., Weil- McLain Co., and (for mail) 1430 Collingwood, Detroit, Mich. '' DOYLE, William J. (Af 1920) Designing Engr. . Williamson Heater Co., 337 W. Fifth .St., Cia^ cinnati, and (for mail) P. O. Box 52, Goshen O DRAKE, George M. (7 1936) Vice-Pres. (for miilj George H. Drake, Inc., 218 Lexington Ave., Buffalo, and 163 Renwood Ave., Kenmore, N. y! DREHER, Louis F. (S 1938) Student of Air Cond., David Rankin Jr. School of Mech. Trades, and (for mail) 4816 Margaretta Ave., St. Louis, Mo DRESCHER, Francis E. (A 1938) Sales Engr., Straus-Frank Co., and (for mail) 117 Estelle, Houston, Tex. DRESSELL, Russell E. (A 1938) Mech. Engr., Riggs Distler Co., Inc., 216 N. Calvert St., and (for mail) 918 E. Preston St., Baltimore, Md. DRIEMEYER, Ray C. (7 1937) Sales Engr., Air- therm Mfg. Co., 1474 S. Vandeventer, and (for mail) 5410 Vernon Ave., St. Louis, Mo. - DRINKER, Philip* (Af 1922) Prof, of Industrial Hygiene (for mail) Harvard School of Public Health, 55 Shattuck St., Boston, and 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. - DRISCOLL, William H.* (Af 1904) {Presidential Member) (Pres., 1926; 1st Vice-Pres., 1925; 2nd Vice-Pres., 1924; Treas., 1923; Council, 1918 1927) Vice-Pres. (for mail) Carrier Corp., Syra cuse, N. Y., and 50 Glenwood Ave., Jersey City, N. J. DROPPERS, C. J. (A 1937) Partner, Wichita Insulation Co., and (for mail) 566 W. Douglas Ave., Wichita, Kan. DU BOIS, Louis J. (Af 1931) Air Cond. Engr., York Ice Machinery Corp.. 117 S. 11th St., St.. Louis, and (for mail) 7451 Bland Drive, Clayton, Mo. . DUBRY, Ernest E. (Af 1924) Asst. Supt., Central \ Heating, Detroit Edison Co., 2000 Second Ave., and (for mail) 9116 Dexter Blvd., Detroit, Mich. DU CHATEAU, Manuel F. (7 1938) Sales Engr. (for mail) Crane Co., 824 Broadway, and 7 Briarwood Lane, Greeahills, Cincinnati, O. DUFAULT, Felix H. (A 1936) Mgr. Furnace Div.. Quebec & Maritime Provinces (for mail) General Steel Wares, Ltd., 2355 Delisle St., and 2275 . Visitation St., Montreal, P. Q., Canada. DUGAN, Thomas M. (Af 1920) Sanitary-Htg. Engr., National Tube Co., Fourth Ave. and Locust St., and (for mail) 1308 Freemont St., McKeesport, Pa. DULL, Edgar J. (A 1937) Engr.-Contractor (for mail) 218 Water SL, and 3614-3rd St., Brooklyn, Baltimore. Md. DULLE, Willferd L. (7 1936) Asst. Secy.. E. E. Souther Iron Co., 1952 Hienlen Ave., St. Louis, and 2910 Lincoln Ave., Normandy, Mo. DUNCAN, James R. (Af 1923) Sales Engr., Air Cond., Carrier Corp., Room 408, Chrysler Bldg., New York, N. Y. . 20 Roll of Membership DUNCAN, William A. (A 1930) Mgr., Process Sendee (for mail) Dominion Oxygen Co., Ltd., 159 Bay St., W., and 71 Jackson Ave., Toronto, Ont-. Canada. DUNHAM, Clayton A.* (Af 1911) Pres, (for mail) C. A. Dunham Co., 450 E. Ohio St., Chicago, and 150 Maple Hill Rd.. Glencoe, III. DUNNE, Russell V. D. (Af 1937) Chief Engr., International Div., Air Cond. & Ref. (for mail) Carrier Corp, S. Geddes St., and 216 Robineau Rd., Syracuse, N. Y. DUPUIS, Joseph R. (A 1936) Dist. Mgr. (for mail) Trane Co. oi Canada, Ltd., 660 St." Catherine, W., Montreal, and 331 Clarke Ave., Westmount, P. Q., Canada. PURKEE, Merritt E. (A 1936; 7 1931) Com- merical Sales, Dallas Gas Co., Harwood and Jackson Sts., and (for mail) 1830 Moser St., Dallas, Tex. : DUTCHER, Harvey S. (A 1938) Design Div., A. L. Hart, Inc., 315 Vanderbilt Ave., and (for mail) 430 Clinton Ave., Brooklyn, N. Y. DWYER, Thomas F. (Af 1923) Chief of Htg. & Vtg. Div. (for mail) Board of Education, 49 Flatbush Ave. Ext., Brooklyn, and 1163 Clay Ave., New York, N. Y. - DYKES, James B. (7 1936) Estimator (for mail) T. A.'Morrison & Co., Ltd., 1070 Bleury St., and Apt. No-. 2, 3141 Maplewood Ave., Montreal, P. Q., Canada. DYKMAN, John G. (A 1938) Owner, John G. Dykman, 205 Lane Ave., S. W., Grand Rapids, Mich. EDGE, Alfred J. (Af 1938) Engr. In charge Htg. & Air Cond. (for mail) c/o John F. Reynolds, Consulting Engr., Room 316 Duval Bldg., and 2051 Herschel St., Jacksonville, Fla. EDWARDS, Arthur W. (Af 1936) Branch Mgr., The Trane Co., 626 Broadway, and (for mail) 3423 Paxton Ave., Cincinnati, O. EDWARDS, Daniel F. (Af 1920) Pres, (for mail) D. F. Edwards Heating Co., 2340 Pine SL, SL Louis, Mo., and R. R. No. 1, Millstadt, 111. EDWARDS, Eton J. (A 1933) Vice-Pres. (for mail)/ General Heat & Appliance Co., 596 Common wealth Ave., and 8 Devon Terrace, Boston, Mass. EDWARDS, Henry B. (7 1935) (for mail) c/o W. A. Ramsats, Ltd., P. O. Box 1721, Honolulu, T. H. EDWARDS. Junius D. (Af 1936) Asst. Dir. of Research (for mail) Aluminum Research Labora tories, Aluminum Company of America, P. O. Box 772, New Kensington, and 536 Sixth St., Oakmont, Pa. EDWARDS, Lawrence V. (Af 1938) Engr., Buensod-Stacey Air Conditioning, Inc., 60 E. 42nd St.,' New York, N. Y., and (for mail) 1631 Edmund Terrace, Union, N. J. EDWARDS, Paul A. (Af 1919) Pres, (for mail) The G. F. Higgins Co., 608 Wabash Bldg., Pittsburgh, and 3074 Pinehurst Ave., Pittsburgh (16). Pa. .' EGGLESTON, Herbert L. (Af 1938) Mgr., Gas & Ref. Depts., Gilmore Oil Co., 2423 E. 28th St., Los Angeles, and (for mail) 1017 Cumberland Rd., Glendale, Calif. E EHLERS, Jacobus (7 1937) Engr. (for mail) Carrier Engineering South Africa, Ltd., Box 7821, ft EADE, Hugh R. (Af 1935) Archt. (for mail) Eade & Co., 2 Imperial Bank Bldg., and 163 Cheriton Ave., North Kildonan, Winnipeg, Man., Canada. EADIE, J. G. (Af 1909) Consulting Engr., Eadie, Freund & Campbell Co., 110 West 40th St., New York, N. Y. EAGLETON, Sterling P. (Af 1936) Group Supt., U. S. Government, Room 2070, Interior Bldg., and (for mail) 3522 "S" St., N. W.t Washington, D. C. X EARL, Warren (A 1936) Vice-Pres. & Gen. Mgr., E. S. Ko Mfg. Corp. and (for mail) 515 Fargo Ave., Houston, Tex. . EARLE, Frederic E. (Af 1937) Sales Engr. (for <$ mail) 520 Howard Ave., Bridgeport, and 1536 Main St., Stratford, Conn. -. ; *f' EASTMAN, Carl B. (Af 1932; 7 1929) Sales Epgr. % (for mail) C. A. Dunham Co., 1500 Walnut'SL, Philadelphia, and 530 Brookview Lane, Brook line, Pa. EASTWOOD, E. O. (Af 1921) Head of Dept, of Mech. Engrg. (for mail) University of Washing ton, and 4702-l2th Ave., N. E., Seattle, Wash. EASTWOOD, Harry F. (Af 1925) Mgr. Anthracite V: Industries, Permanent Exhibit, Architects Sam ple Corp., 101 Park Ave., New York, and (for mail) 157 Frankel Blvd., Merrick, L. I., N. Y. EATON, Byron K. (Af 1920) Zone Mgr., Delco- Frigidaire Conditioning Div.,. General Motors Sales Corp., 1420 Wisconsin Ave., Dayton, O., a11n1.d (for mail) 240 S. Brain: ard Ave., LaGrange, and Jacwal Court, Quartz SL, Johannesburg, South Africa. EHRLICH, M. William* (Af 1916) Chief Engr., Commodore Heaters Corp., 11 West 42nd St., . New York, N. Y., and (for mail) 56 Ridge Rd., Lyndhurst, N. J. EICHER, HuBert C. (Af 1922) Chief, Div. of School Plant, Pennsylvania State Dept, of Public Instruction, State Capitol, and (for mail) 207 North 30th St., Harrisburg, Pa. EILS, Lee C. (7 1936) Zone Mgr., Barton D. Wood, Inc., 206 Balter Bldg., New Orleans, La., and (for mail) 3223 Kennett Sq.p Pittsburgh, Pa. EISELE, Dudley E. (A 1938) Owner (for mail) Eisele Engineering Co., 121 N. Appleton SL, and 1735 N. Morrison SL, Appleton, Wis. EISELE, Lewis G. (A 1937) Secy, (for mail) Eisele Automatic Heating Co., Box 309, and 602 W. Hughitt St., Iron Mountain, Mich. EISELE, William S. (A 1937) Supervising Engr. (for mail) Ideal Heating & Air Conditioning Co., 551 Seneca St., and 836 Tacoma Ave., Buffalo, N. Y. EISS, Robert M. (M 1933; 7 1930) Engr., Kim berly-Clark Corp., P. O. Box 31, and (for mail) 714 Hewitt St., Neenah, Wis. EKINGS, Robert M., Jr. (Af 1938) Engr., Air Cond. DepL, General, Electric Co., 5 Lawrence SL, Bloomfield, N. J., and (for mail) 132 S. Oakhurst Drive, Beverly Hills, Calif. EKLUND, Karl G. (Af 1938) Consulting Engr. (for mail) Karl G. Eklunds Ingeniorsbyra, EATON, William G. M. (A 1934) Sales Engr., Pease Foundry Co., Ltd., 227 Victoria St., and ' (for mail) 300 Wellesley SL, Toronto, OnL, '<> Canada. ' . . EBERT, William A. (Af 1920) Mech. .Contractor Brunkebergstorg 15, Stockholm, and Storangen, Sweden. ELBERT, Ben F. (7 1937) Sales Engr., Sidles Co., Airtemp Div., 425 Stuart Bldg., Lincoln, Nebr., and (for mail) 1008 Eighth St., Des Moines, la. (for mail) 1026 W. Ashby, and 2151 W. Kings Highway, San Antonio, Tex. ECKART, John H. (A 1938) Salesman, Htg. Dept., Sears Roebuck & Co., 6339 Market SL, ELLINGWOOD, Elliott L. (Af 1909) Cons. Mech. & Elect. Engr. (for mail) 124 W. 4th St., Los Angeles, and 210 S. Los Robles Ave., Pasadena, Calif. and (for mail) 6012 Lawndale Ave., Philadelphia, 'i Pa. ECKSTEIN, Jacob E. (A 1938) Pres, (for mall) ELLIOT, Edwin (Af 1929) (for mail) Edwin Elliot & Co., 560 North 16th SL, Philadelphia, and 403 W. Price SL, Germantown, Philadelphia, Pa. . J. E. Eckstein Co., 22 Penn Ave., and 1323 Denniston Ave., Pittsburgh, Pa. EPELMAN, Bernard P. (A 1935) Asst. Sales Mgr. (for mail) U. S. Air Conditioning Corp., 2101 Kennedy St., N. E., and 4338 Nicollet Ave., l Minneapolis, Minn. ELLIOT, Gerald B. (Af 1938) Sales Engr., Francis Hankin Co., Ltd., and (for mail) 4971 Victoria Ave., Montreal, P. Q., Canada. ELLIOTT, Irwin (A 1937) Chief Engr., Universal Oven Co., 271 Broadway, New York, and (for mail) 103 Penfield Ave., Croton, N. Y. Heating Ventilating Air Conditioning Guide 1939 ELLIOTT, Louis B. (Af 1932) Consulting Mech. Engr. (for mail) Ebasco Services Inc., 2 Rector St., and 33 Washington Square West, New York. N. Y. ELLIOTT, Norton B. (A 1934) Branch Mgr., American Blower Corp., 1011 Majestic Bldg., Milwaukee, Wis. ^ ELLIS, Frederic R. (2f 1913) Buerkel & Co., Inc., 18-24 Union Park St., Boston, and (for mail) 131 Beacon St., Hyde Park, Mass. ELLIS, Frederick E. (2f 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, Gerahom P. (Af 1935) Chief Engr. (for mail) Board of Public Education, 341 Bellfield Ave., and 6601 Dalzell Place, Pittsburgh, Pa. " ELLIS,' Harry W: (Life Member; 2/ 1923; A 1909)' Pres.-Gen. Mgr., Johnson Service Co., 507 E. Michigan St., Milwaukee, Wis. ELLIS, Lester W, (A 1938) Sales Engr., Disney- Leffel Co., Inc. (for mail) 3323 Main St., and 3835 Main St.. Kansas City, Mo. ELWOOD, WilUs H. (M 1936) Branch Mgr., Holland Furnace Co., 209 King St., Ithaca, N. Y. EMERSON, John J. (J 1938) Soles Engr., 424 Sherbrooke St., W., Apt. 35, Montreal, P. Q.. Canada. ',, EMERSON, Ralph R. (if 1922) Pres., Emerson Swan Goodyer Co.. 107 Arlington St,, Boston, and (for mail) 44 Whitney Rd.. Newtonville, Mass. ,.v 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 mall) University of Michigan, 221. W. Engrg. Bldg., and 1303 Granger. Ann Arbor, Mich. ENDERS, Clarence E. (A 1938) Pacific Coast Factory Repr. & Engr. (for mail) Electro!, Inc., 424 E. Burnside, and 1813 S. E. 60th Ave., Portland, Ore. . ,_ . ENGDAHL, Richard B. (J 1938) Special Research Asst, (for mail) University of Illinois, 102 Mech. Engrg. Lab., and 1108 W. Stoughton, Urbana, 111. ENGLE, Alfred (A 1923) Secy, (for mail) Jenkins Bros.. 80 White St., 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., Frontier Engineering Corp., 986 Ellicott Square Bldg.. Buffalo, and (for mail) Revere Drive, Derby. N. Y. ... EPPLE, Arnet B. (/ 1934) 201 Benjamin Ave., S. E., Grand Rapids, Mich. ERICKSON, E. Vincent (M 1936) Mgr., New York Export Office, Carrier Corp., 405 Lexington . Ave., New York, N. Y. ERICKSON, Harry H. (A 1929) Sales Engr. (for mail) Haynes Selling Co., 1124 Spring Garden St., and 217 W. Tulpehocken SL. Philadelphia, 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. ERISMAN, 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 matt) The Heil Co., 3000 W. Montana, and 2646 N. 45th St., Milwaukee, Wis. ESCHENBACH, Samuel P. (J 1935) Sales Engr. (for mail) American Blower Corp., 135 Spring St., and 268 Dartmouth St.. Rochester. N. Y. ESKELL, Joseph E. (S 1939) Student, Columbia University, New York, and' (for mail) 18-27 21st Rd., Astoria, L. I., N. Y. ESTEP, Leslie G. (2/ 1936) Asst. Mgr., Technical & Training Dept., Kelvinator Div., Nash-Kelvinator'Corp., 14250 Plymouth Rd., and (for mail) 14909 Marlowe Ave., Detroit, Mich. ESTES, Edwin C. (A 1936) Mech. Draftsman" (for mail) Railway Transportation, Rm. 820 Northern Pacific Ry., Gen. Office, SL Paul, and Victoria Ave., Mendota, Minn. ETLINGER, Martin J. (J 1936) Sales Mgr., The Bradley Press, Inc., 103 Lafayette St., and 2979 Marion Ave., New York, N. Y. EUTSLER, Eugene E., Jr. (J 1938) Engr. (for mail) Buffalo Forge Co., 490 Broadway, and 179 ' Lexington Ave.. Buffalo, N. Y. EVANS, Bruce L. (2/ 1938; A 1937) Designing Engr. (for mail) Oil Heat, Inc., 3217 Locust St.. and 6322 Pershing Aye., St. Louis, Mo.__ - EVANS, Edwin C. (M i919) Mgr., Syracuse Office, (for mail) B. F. Sturtevant Co., 504 Eckel Bldg., and 307 Montgomery St.. Syracuse, N. Y. EVELETH, Charles F* (M 1911) Air Cond. Engr., Smith & Oby Co., 6107 Carnegie Ave., and . (for mail) 2030 East 115th St., Cleveland, O. EVEREST, R. Harry (Af 1935) Sales Engr., Sheldons, Ltd.. Galt, and (for mail) 235 Waterloo SL, Preston, Ont., Canada. EVERETTS, John, Jr.* (2/ 1938; A 1935; J ig29) Engr. (for mail) Air & Refrigeration Corp., 11 West 42nd St., New York, N. Y., and 55 Sound Beach Ave., Old Greenwich, Conn. EWENS, Frank G* (M 1937) Instructor in Mech. Engrg. (for mail) University of Toronto, Mechan ical Bldg., University of Toronto, and 83 Madison Ave., Toronto, Ont., Canada. ' EZZ EL DIN, Karaal (J 1938) Engr., Ministry of Public Works, and (for mail) 78 Helwan St., Mounirah, Cairo, EgypL F FABER, Dr. Oscar (2/ 1934) Consulting Engr. (for mail) Romney House, Marsham St., West minster, London and Hayes Court, Kenley, Surrey, England. FABLING, Walter D. (A 1937) Sales Mgr., (for mail) Sterling Electric Motors, Inc., 5401 'Trie- graph Rd., and 2121 Glendon Ave., Los Angeles, 4 Calif. FAGIN, Daniel J. (2/ 1932) Htg. Engr., Laclede Gas Light Co.. 1017 Olive St., St. Louis, Mo. FAHNESTOCK, Maurice K.* (2/ 1927) Research Asst. Prof, (for mail)University of Illinois. 214, M. E. Laboratory, and 701 W. California St. Urbana. 111. FA1LE, Edward H. (M 1934) Designing and Con struction Engr. (for mail) 608 Fifth Ave., New York. N. Y., and R. F. D. 1, Westport, Conn. FAIRBANKS. Frank L. (2/ 1937) Prof. Agr. Engrg. & Agr. Eng. in 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, Detroit, and 809 E. Kingsley SL, Ann Arbor, Mich. FALTENBACHER, Harry J. (2/ 1930) Pres.. Harry J. Faltenbacher, Inc., 235 E. Wister St., Philadelphia, Pa. FALVEY, John D. (2/ 1922) Consulting Engr.. 316 N. Eighth St., St. Louis, and (for mail) 6636 Pershing Ave., University City, Mo. FAMILETTI, A. Robert (M 1938; J 1930) CWef Engrg. Draftsman, Industrial. Dept., NavyYaro, and (for mail) 6735 Guyer Ave., Philadelphia, Pa. FARBER, Louis M. (J 1936) Engr. (for mail) Natkin & Co., 1800 Baltimore, and 3714 Flora Ave., Kansas City, Mo. FARLEY, W. F. (2/ 1930) Salesman, American Radiator Co.. 40 West 40th St., New York, and (for mail) 28 Elm St.. New Rochelle, N. Y. FARNES, Bert W. (A 1938) Vice-Pres. & Sato Mgr. (for mail) Control Equipment Co^ 404 Selling Blvd., and 3565 N. E. Hollyrood Court. Portland, Ore. 22 Roll of Membership FARNHAM, Roswell (2/ 1920) (Council, 1927 FENKER, Clement M. (2/1937) Designing Mech. 1933) Dist. Mgr., Engrg. Sales (for mail) Buffalo Forge Co., P. O. Box 985, and 5 Clarendon Place, Buffalo, N. Y. . Engr. (for mail) Edward J. Shulte, Archt., 920 E. McMillan, Cincinnati, and 2268 Feldman Ave., Norwood, O. . FARRAR, Cecil W. (2/ 1920; A 1918) (Treasl, FENNER, Everett M, (Af 1936; A 1928) Htg.-Vta. 1930; Council, 1930) Vice-Pres. (for-mail) W. A. Engr., 387 High St., rail River, Mass. Case & Son Mfg. Co., 31 Main SL, and 29 Oakland Place, Buffalo, N. Y. FENNER, N. Paul (A 1928) (for mail) John G. Kelly, Inc., 210 East 45th St., New York, and 15 FARROW, Ernest E. (A 1938) Pres., E. E. De Mott Place, Rockville Center, L. I., N. Y Farrow, Inc., 2808 Maplelawn Rd., and (for mail) 1518 Kings Highway, Dallas, Tex. FENSTERMAKER, Sidney E. (M 1909) Pres! (for mail) S. E. Fenstermaker & Co.. 937 Archi FARROW, Hollis L. (J 1937) Air Cond. Engr., Kelly Sales Corp., Arlington, and (for mail) tects & Builders Bldg., Indianapolis, and Carmel Ind. 910 Lynnfield St., Lynn. Mass. FERDERBER, Dr. Murray B. (M 1938) Fellow . FATZ, Joseph L. (2/ 1935) Htg. and Vtg. Engr., of Dept, of Industrial Hygiene, University of Board of Education, Room 536. 228 N. LaSalle ____Pittsburgh Medical-School, and-(farmail)5722 - SL, and-(for mail)-1634 N: Mason Ave., Chicago," Fifth Ave., Pittsburgh, Pa. FAULKNER, Gordon (J 1937; 5 1935) Engr., Standard Oil Development Co., Bayway, and (for mail) 43 BeUewood Place, Elizabeth, N. J. FAUST, Frank H * (2/ 1936; J 1930) Engr. (for mail) General Electric Co., 5 Lawrence St.f Bloomfield, and 239 Vreeiand Ave., Nutley, N. J. FAXON, Harold C. (2/ 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., Rich mond Hill, L. I., N. Y. FAY, Frank C. (2/ 1925) Engr. (for mail) Raisler Heating Co., 129-31 Amsterdam Ave., New York, and 92-17-54th Ave.. Elmhurst. L. I., N. Y. FEAR, S. Lome (2/ 1938) Asst. Mech. Engr. (for mail) H. E. P. C., 620 University Ave., Toronto, 2, and 18 Vesta Drive, Toronto, 10, Ont., Canada. ' FEBREY, Ernest J. (Life Member; M 1903) Pres, (for mail) E. J. Febrey&Co;. Inc., 616 New York Aye.. N. W., and 2331 Cathedral Ave., N. W.. Washington, D. C. FEDDERS, Melvin P. (M 1938) Development Engr., Minneapolis-Honeywell Regulator Co., 2747-4th Ave., S., and (for mail) 5212 W. Nokomis Pkwy., Minneapolis, Minn: FEDER, Nathan (J 1938) Engr., East Side Sheet Metal Co., 1397 Second Ave., and (for mail) c/o Bialek, 909 Beck St., New York, N. Y. FEEHAN, John B. (Life Member; M 1923) Pres.- Treas. (for mail) John B. Feehan, Inc., 58 Spring St., Lynn, and 4 Long View Drive, Marblehead, Mass. FEELY, Frank J. {U 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. FEINBERG, Emanuel (J 1937) General Mgr., Thermalair Engineering Co., 439 Penobscot Bldg., and (for mail) 3246 Cortland Ave., Detroit, Mich. FEIRN, William H. (M 1937) Engr.. C. A. Hooper Co., 453 W. Gilman, and (for mail) Shorewood Hills, Madison, Wis. FELDERMANN. William (A 1937) Pres., Walton Laboratories, Inc., 1186 Grove St., Iivington, N. J. FELDMAN, A. M * (Life Member; M 1903) Con sulting Engr., 40 West 77th St., New York, N. Y. FELDSTEIN, Harold (J 1938) Consulting & Design Engr., Federal Supply Co., 120 E. Main St., and (for mail) 1015 E. Park, Oklahoma City, Okla. FELLOWS, Julian R. (M 1938) Associate in Mech. Engrg. (for mail) University of Illinois, 105 M. E. Laboratory, and 703 W. California, Urbana, 111. FELS, Arthur B. (M 1919) Pres, (for mail) The Fels Co., Portland, and Yarmouth, Me. FELTWELL, Robert H. (Life Member; M 1905) Heating Engr., United States Radiator Corp., 2321-4th St., N. E.. and (for mail) 1370 Oak St., N. W., Washington,-D. C. FERGESTAD, Marvin L. (Af 1938; J 1935) Sales Engr., Bark Prod. Div. (for mail) The Pacific Lumber Co. of Illinois, 59 East Van Buren St. and 2704 Arthur Ave., Chicago. IU. ' FERGUSON, John H. (A 1938) Engr. in Charge, John Ferguson Plumbing & Heating Co., 2700 Euclid Ave.. and (for mail) 4169 West 50th SL. Cleveland, O. FERGUSON, Ralph R. (M 1934; A 1927; J 1925) , Mgr. Air Cond. Dept., American Blower Corp.. 50 West 40th SL, New York, N. Y., and (for mail) 160 Prospect St., East Orange, N. J. FERRARINI, Joseph (J 1937) Staff Asst.. Wash ington Gas Light Co., 411-10th St., N. W. Washington, D. C., and (for mail) 1728 Queens Lane, Colonial Village, Apt. No. 180, Arlington, Va. FEYGE, Harold (Af 1937) Mfrs. Repr., 742 Market St., Room 230, and (for mail) 625 Scott Sl, San Francisco, Cal. FIDELIUS, Walter R. (2/ 1936) Sales Engr., Fitzgibbons Boiler Co., Inc., 101 Park Ave., New York, and (for mail) 135 Amersfort Place. Brooklyn, N. Y. FIEDLER, Harry W. (Af 1923) Owner (for mail) Air Conditioning Utilities Co., 8 West 40th St., New York, and 77 Hillside Ave., Mt. Vernon N. Y. FIFE, G. Donald (2f 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 Ironworks, Kent, England. FILLO, Frank B. (A 1934) Dist. Mgr., Minne apolis-Honeywell Regulator Co., 1134 N. Penn sylvania Ave., Indianapolis, Ind. FINAN, J. J. (Life Member; Af 1923) Retired, 7149 Euclid Ave., Chicago, III. FINERAN, Edward V. (J 1935) Spedal Repr. (for mail) Washington Gas Light Co., 411-lOth St:, N. W., Washington, D. C., and 305 Edgewood Ave., Silver Spring, Md. FINNERTY, John A. (J 1937) Sales Mgr., Auto Heat & Air Conditioning Div., The Herman Nelson Corp., Moline, 111., and (for mail) 28 Ainsworth St., Roslindale, Mass. FINNEY, Brandon (2f 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, Lawrence (/ 1937) Engr. in charge of Manufacture' (for mail) Anemostat Corp. of America, 10 East 39th SL, New York, and Crosby St., SayvUle, L. I., N. Y. FISHER, John T. (J 1936) Chief Engr. (for mail) United Equipment & Supply Co., 1812 M St., N. W., and 3228 Rittenhouse St., N. W., Wash ington, D. C. . FITCH, Howard M. (J 1936) Asst. Sales Mgr., Engine & Compressor Dept., American Air Filter Co., Inc., 215 Central Ave., and 269 Clare Ave., Louisville, Ky. FITTS, Charles D. (M 1920) Mgr. (for mail) American Radiator Co., 692 Prior Ave., SL Paul, and 2807 Dean Blvd., Minneapolis, Minn. Heating Ventilating Air Conditioning Guide 1939 FITTS, Joseph C. (if 1930) Secy.. Heating, FORRESTER, Norman J. (A 1936) Mgr. Con Piping & Air Conditioning Contractors National Association, 1250 Sixth Ave., New York, N. Y., tract Div., Garth Co., 316 Westminster Ave N ' Montreal, W., P.Q., Canada. '' * and (for mail) 215 Kenilworth Rd., Ridgewood, FORSBERG, William (Af 1919) Secy. & Sudl N. J. FITZ, Jean Chandler (Af 1924) Mgr., Arco (for mail) The Hopson & Chapin Mfg. Co., 231 State St., New London, and Quaker Hin Conn Thermo System Div. (for mail) American Radi FORSLUND, Oliver A. (Af 1936) Gen. Mgr. and ator Co., 40 West 40th St., New York, N. Y. Partner, Forslund Pump and Machinery Co FITZGERALD, Matthew J. (Af 1934) Secy.- 1717-19 Main St., and (for mail) 108th St. & Treas., Standard Asbestos Mfg. Co., 820 West Lake St.. Chicago, and (for mail) 1117' N. Linden Ave., Oak Park, 111. FITZGERALD, William E. (7 1936; S 1935) State Line, Kansas City, Mo. FOSS, Edwin R. (A 1936) Dist. Mgr. (for main The Powers Regulator Co., 407 Bona Alien Bid* and 257 Bolling Rd., N. E.. Atlanta, Ga. Secy.-Treas. Engr. (for mail) Fitzgerald Plbg. & Htg. Co., Inc., 939-41 Louisiana Ave., and 435H Herndon, Shreveport, La. FITZSIMONS, J. P. (7 1934; 5 1932) Mgr. Air FOSTER, Charles (Af 1923) Consulting Engr . (for mail) 316 Medical Arts Bldg., and 2831 East 1st St., Duluth. Minn. FOSTER, James M. (Af 1930; A 1920) Owner (for Cond. Dept, (for mail) Trane Co. of Canada, Ltd., Mowat & King St., W., and 151 Dowling Ave., Toronto, OnL, Canada. FLARSHEIM, C. A. (7 1933) Pres.. Clarence A. Flarsheim. Inc., 201-207 Pershing Rd., and (for mail) 3720 Holmes St., Kansas City, Mo. FLEAK, William D. (A 1938) Laboratory Engr., Refrigeration & Air Conditioning Institute, Inc., mail) 4526 Olive St., St. Louis, and 7021 Lindell Ave., University City, Mo. FOSTER, John G. (7 1938) Sales Engr. (for mail) Air Conditioning Utilities Co., 8 West 40th St. and 2635 Sedgwick Ave., New York, N. Y. ' . FOSTER, Philip H. (A 1937) Mgr. (for mail) Hudson Bay Plumbing Co., and Flin Flon Hotel, Flin Flon, Man., Canada. -. 2141 Lawrence Ave., and (for mail) 4535 N. FOULDS, P. A. L. (Af 1916) Partner (for mail) Mozart St., Chicago, 111. FLEISHER, Walter L.* (Af 1914) (Council, 1937 1938) Consulting Engr. (for mail) 11 West 42nd St., New York, and New City, N. Y. FLINK, Carl H. (Af 1923) Mech. Engr. (for mail) American Radiator Co., 8007 Joseph Campau Ave., and 5959 Yorkshire Rd., Detroit, Mich. FLINN, George S. (7 1936) Engr., W, F. Slayter Engineering Corp., 664 Union Ave., and (for mail) 190 N. Avalon, Memphis, Tenn. FLINT, Coll T. (Af 1919) Sales Mgr. (for mail) H. B. Smith Co., 640 Main St, Cambridge, and Hubbard, Rickerd & Blakeley, Consulting Engrs., 110 State St., Boston, and 72 Whitiri Ave., Point of Pines, Revere, Mass. FOWLES, Harry H. (J 1934) Htg. Engr. (for mail) Carman-Thompson Co., 12-14 Lincoln St., Lewis ton, and 176 Summer St., Auburn, Me. . FOX, Edward L. (7 1936) Engr., American Foundry & Furnace Co., Bloomington, and (for mail) 715 Sanford St., Peoria, 111. FOX, Ernest (Af 1935) Asst, to Engr. (for mail) C. A. Dunham Co., Ltd., 1523 Davenport Rd., and 409 Glenholme Ave., Toronto, Ont., Canada. 56 Brantwood Rd., Arlington, Mass. FOX, John H. (Af 1935) Sales Engr. (for mail) FLUM, Joseph C. (5 1938) Henry Disston & Minneapolis-Honeywell Regulator Co., Ltd., 117 Sons, Talcony, and (for mail) 4706 Rhawh St., Peter St., and 37 Macdonell Ave., Toronto, Philadelphia, Pa. Ont., Canada. ' FOERSTNER, George C. (A 1938) Mgr., Amana FRANCE, Clarence N. (A 1936) Service Mgr., Society, Amana, la. Colonial Fuel Oil. 1709 De Sales SL. N. W., FOLEY, Daniel F. (A 1937) Asst. Mgr., W. B. Washington, D. C. Young Supply Co. (for mail) 208 Delaware, Kansas City, Mo., and 25 Wint Ave., Fort Leavenworth, Kan. . FOLEY, John J. (A 1938) Pres., Weathermakers (Canada) Ltd., 593 Adelaide St., W.. Toronto, Ont., Canada. FOLEY, J. Lester (Af 1938) Mgr., Wholesale Dept.. Avery Engineering Co., 2341 Carnegie Ave., Cleveland, and (for mail) 3567 Riedham Rd., Shaker Heights, O. FOLLETT. Thomas L. (5 1936) 10900 Euclid Ave., Cleveland, and (for mail) 306 N. Main St, Hudson, O. FOLSOM, Rolfe A. (Af 1938) Vice-Pres. (for mail) W. R. Ames Co., 150 Hooper St., San Francisco, FRANCIS, Paul E. (Af 1937) Asst. Mgr. of Sales, , Northwestern Fuel Co., E-1203 First National Bank Bldg., St. Paul, and (for- mail) 5115 S. Colfax Ave., Minneapolis, Minn. . FRANCK, Peter (7 1938) Secy., Tiltz Air Con ditioning Corp., 230 Park Ave., New York, and (for mail) 478 State St., Brooklyn, N. Y. FRANK, John M. (Af 1918; A 1912) Pres, (for mail) Ilg Electric Ventilating Co., 2850 N. Crawford Ave., Chicago, and 1152 Chatfield Rd., Hubbard Woods. III. - FRANK, Olive E.* (Af 1919) Vice-Pres., Frank Heaters, Inc., 150 Railroad Ave., and (for mail) 288 Graham Ave., Paterson, N. J. and 2411 Easton Drive, Burlingame, Calif. FRANKEL, Gilbert S. (Af 1926) Mgr., Federal FOOTE, A. G. (Af 1937) Dist. Engr. (for mail) Frigidaire Div., General Motors Sales Corp., Oakland Dist., 1250-53rd St., Oakland, and 2466 Virginia St., Berkeley, Calif. FOOTE, Earl E. (Af 1936) Gen. Supt. Consumers Central Heating Co., 108 East 11th St., and (for and Marine Dept, (for mail) Buffalo Forge Co., 820-24 Woodward Bldg., and 3000 Connecticut \ Ave., Washington, D. C. ' FRANKLIN, Ralph S. (Af 1919) Pres.-Treas. . (for mail) Albert B. Franklin, Inc., 38 Chauncy St., Boston, and 320 Grove St.. Melrose. Mass. mail) 3412 North 28th St., Tacoma. Wash. FRANKLIN, Sam H., Jr. (A 1938) Prop, (for FORBES, Homer B., Jr. (S 1938) Student, Purdue University (for mail) 690 Waldron St., W. Lafayette,'Ind., and 5452 N. Christiana Ave., Chicago, 111. FORD, Edward F. (A 1937) Sales Repr. (for mail) American Radiator Co., 8019 Joseph Campau ' mail) S. H. Franklin, Jr., Heating Contractor, 921 Main St., and 204 Colonial Court, Lynch burg, Va. ' -' FRANKLIN, Stephen D. (A 1938) Engr Stand ard Oil Co. of Pennsylvania, and (for mail) 5016 Greene St.. Philadelphia, Pa. Ave., Detroit, and 288 Ann St., Plymouth, Mich. FRASER, James J. (A 1936) Director (for mail) FORDERBRUGGEN, Kevin J. (7 1938) Engr. (for mail) Mankato Natural Gas Co., 222 S. Front St., and Ben Pay Hotel, Mankato, Minn. Honeywell-Brown, Ltd., 70 St. Thomas St., London, S. E. 1, and 60, The Grove, St. Mar garet's, Twickenham, Middlesex, England. FORFAR, Donald M. (Af 1917) Mech. Engr., Grinnell Co., Inc., 240-7th Ave. S., and (for mail) 4817 Emerson Ave., S., Minneapolis, Minn. FRAZIER, J. Earl (A 1936) Vice-Pres. and Treas. (for mail) Frazier-Simplex, Inc., 436 East Beau St., and 417 East Beau St,, Washington, Pa. FORRESTER, Charles M. (A 1937) Air Cond. Sales Mgr. (for mail) Gurney Foundry Co., Ltd., - 4 Junction Rd., and 77 Coliegeview Ave., Toronto, Ont., Canada. FREAS, Royal B. (U 1928) Vice-Pres.. Freas Thermo Electric Co., 1750 N. Springfield Ave., Chicago. 111., and (for mail) Schodack Landing, N. Y. 24 Roll of Membership FREDERICK, Holmes W. (Af 1937) Asst. Htg. Engr., Cornell University, Merrill Hall, and (for mail) 103 Harvard Place, Ithaca, N. Y. FREDERICK, Kendall C. (A 1938) Sales Engr. (for mail) Sidles Co., Airtemp Div., 502 South 19th St., and 1515 Park Ave., Omaha, Nebr. FREDERICK, Walter L. (A 1937) Pres, (for mail) Bryant Air Conditioning Corp., 1340 Connecticut Ave., and 3016 Tilden St., Washington, D. C. FREEMAN, Edwin M. (A 1937) Vice-Pres. & Sales (for mail) Canadian Asbestos Co., 316-322 Youville Sq., and 37 Sunset Ave., Montreal, P. Q., Canada. FREEMAN, J. Albert (7 1938) Partner, Engr., Western Engrg. Co., 1611 S. E. 9th Ave., and (for .mail) 3143 N. E. Wasco St., Portland, Ore. FREEMAN, John C. (7 1936) Associate Mech. Engr. (for mail) Div. of Architecture, and 2214 23rd St., Sacramento, Calif. . FREITAG, Frederic G. (Af 1932) Engr., Sylvester Oil Co., Inc., 703 S. Columbia Ave., and (for mail) 9 Harrison St., Mt. Vernon, N. Y. FREITAS, Leo J. (A 1938J Branch Mgr. (for mail) Fedders Manufacturing Co., Inc., 1036 Beaubieo St., and 15429 Appoline, Detroit, Mich. . FRENCH, Donald (Af 1926) Vice-Pres. (for mail) . Carrier. Corp., 302 S. Geddes St., and 210 Brattle Rd., Syracuse, N. Y. FRENTZEL, Herman C.'(Af 1936) Chief Engr., The Heil Co., 3000 W. Montana St., and (for , mail) 4363 N. Wildwood Ave., Milwaukee, Wis. FRIED, Harold V. (A 1935) Dealer Repr. (for mail) Birmingham Electric Co., 2100 First Ave., N., and 2640 Canterbury Rd., Birmingham, Ala. FRIEDLINE, James M. (7 1937) Engr., General Air Conditioning Corp., Paramount Bldg., and (for mail) 1811-5th Ave., S. E., Cedar Rapids, la. FRIEDMAN, Arthur (A 1936) (for mail) Air Controls, Inc.,-1933 West 114th St., Cleveland, and 15700 S. Moreland Bivd,, Shaker Heights, O. FRIEDMAN, D. Harry, Jr. (Af 1936) Air Cond. & Industrial Engr. (for mail) Peoples Water and Gas Co., 15th & Washington Ave., Miami Beach, and 1309 Brickell Ave., Miami, Fla. FRIEDMAN, Ferdinand J.* (Af 1921) Mech. Engr. (for mail) McDougall & Friedman, 1221 Osborne St., Montreal, P. Q., Canada, and 31 Union Square, New York, N. Y. FRIEDMAN, Milton (7 1935; S 1933) c/o H. F. Klawuhn, Genl. Contractor,. 34-24 82nd St., Jackson Heights, L. I., and (for mail) 470 West End Ave., New York, N. Y. FRIMET, Maurice (7 1936) Engr.. S. I. Hearing & Air Cond. Co., 28 Oxford PL, Tompkinsville, and (for mail) 15 Mundy Ave., West Brighton, S. I., N. Y. FRITZ, Charles V. (7 1936; 5 1933) Designer and Estimator, Charles F. Fritz (for mail) 67 W. Merrick Rd., and 26 Cottage Court, Freeport, N. Y. FUKUI, Kunltaro (Af 1926) Auditor, Oriental Carrier Engineering Co., Ltd., Toyo Menka Bldg., Koraibashi-Sanchome, Osaka, Japan. FULLER, Elbridge W. (Af 1938) Mgr., Com- merical Air Condirioning-Delco Frigidaire, Tay- lar St., and (for mail) 1916 Emerson Ave., Apt. 5, Dayton, O. G GABBARD, Frederic W. (7 1938) Sales Engr. (for mail) York Ice Machinery Corp., 5051 Santa Fe Ave., Los Angeles, and 6327A Middleton SL, Huntington Park, Calif. GABLE, Harold R. (A 1939) Engr., MayfiowerLewis Corp., Duluth Ave. & East 7th SL, SL Paul, and (for mail) 2730 Portland Ave., S., Minneapolis, Minn. GALE, Hamilton A. (7 1936) Engr., Wallace Stebbins & Sons, Inc., 100 S. Charles SL, Balti more, and (for mail) Murray Hill, Annapolis, Md. GALLAGHER, Frank H. (A 1938) Asst. Chief Engr., Board of Public Education. Forbes St. at Bellefield Ave., and (for mail) 2727 Strachan Ave., Pittsburgh, Pa. GALLIGAN, Andrew B. (Af 1921) 716 South 51st St., Philadelphia, Pa. GALLAWAY, James F. (A 1938; 5 1934) General Electric Co., 570 Lexington Ave., New York, and (for mail) 117-01 Park Lane, S., Kew Gardens, L. I.. N. Y. GAMBLE, Cary B. (A 1935) Consulting Engr. (for mail) Leo S. Weil & Walter B. Moses, 427 S. Peters St., and 732 SL Peter SL, New Orleans, La. GAMMILL, Oscar E,, Jr. (A 1937; 7 1930) Sales Engr. (for mail) Carrier Corp., 1413 Hibernia Bank Bldg., and 5515 Magnolia 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), R. D. No. 1, Glen- moore. Pa. ' GARBER, William E., Jr. (7 1938) Field Engr., Farquhar Furnace Co., Wilmington O., and (for mail) 3643 Graceland Ave., Indianapolis, Ind. GARDNER, Clifton R. (A 1937) Vice-Pres. (for mail) Martyn Brothers, Inc., 911 Camp St., Dallas, and 3708 Watonga, Fort Worth, Tex. GARDNER, S. Franklin (Af 1911) Pres, (for mail) Standard Engineering Co., 2129 Eye SL, N. W., and 4901 Hillbrook Lane, Washington, D. C. GARDNER, William, Jr. (A 1921) Vice-Pres. (for mail) Garden City Fan Co., 1842 McCormick Bldg., and 7836 Loomis Blvd., Chicago, 111. GARNEAU, Leo ( Af1938; 7 1930) Sales Engr. (for mail) C. A. Dunham Co., Ltd., 931 Dom. Square Bldg., and 2541 Maplewood Ave. (ApL 2), Montreal. P. Q., Canada. GARNETT, Ralph E. (A 1936) Sales Engr., 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) Pres, (for mail) Age Publications, Ltd., 31 Willcocks SL, and 156 Dewhurst Blvd., Toronto, Ont., Canada. GAULT, George W. (7 1937; 5 1934) Army Officer,2nd Ll, C. C. C. Camp (formail) CCC, Co. 2340, S-118, and 216 W. Market St., Clear field, Pa. GAUSE, H. Chester (Af 1937) Power Sales Engr., Alabama Power Co. (for mail) 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 Pkwy., Minneapolis, Minn. GAUSMAN, Carl E. (Af 1923) Partner, Gausman & Moore, 1026 First Natl. Bank Bldg., and (for mail) 2360 Chilcombe Ave., SL Paul, Minn. GAWTHROP, Fred H. (Af 1919) Pres., Gawthrop & Bro. Co., 705 Orange St., and (for mail) 2211 Shallcross Ave., Wilmington, Del. ' GAYLOR, William S. (Af 1919) 161 Pelham Rd., New Rochelle, N. Y. GAYLORD, Frank H. (Af 1921) Western Sales Mgr. (for mail) Hoffman Specialty Co., Inc., 130 N. Wells SL, Chicago, and 362 N. York St., - Elmhurst, 111. GAYMAN, Paul D. (Af 1938) Branch Mgr. (for mail) Johnson Service Co., 2142 East 19th SL, Cleveland and 20875 Endsley Ave., Rocky River, GAYNER, James (Af 1937) Mech. Engr., G. M. Simonson, Cons. Engr., 74 New Montgomery SL, San Francisco, and (for mail) 239 Park View Ave., Piedmont, Calif. GEE, William W., Jr. (7 1938) Designing Engr. (for mail) Graham and Gee, 133 Geary SL, and 1670 Chestnut St,, San Francisco, Calif. GEIGER, Irvin H. (Af 1919) Registered Prof. Engr. & Mfrs. Repr. (for mail) 319 Telegraph Bldg., and 240 Maday St., Harrisburg, Pa. GELTZ, Ralph W. (7 1936) Air Cond. Engr., York Ice Machinery Corp., 2700 Washington Ave., Cleveland, and (for mail) 14213 Glenside Rd., Cleveland, O. 25 Heating Ventilating Air Conditioning Guide 1939 GENDRON, Henri (A 1937) Chemical Engr., Canadian General Electric Co., Ltd., 1000 Beaver Hall Hill, and (for mail) 2049 Maplewood, Apt. 6, Montreal, P. Q., Canada. GENRE, E. John (A 1938) Wholesale Sales Mgr. (for mail) Tidmarsh Engineering Co., P. O. Box No. 8, Phoenix, Ariz. v GERHARD, David H. (A 1937) Power Sales Engr. (for mail) Consumers Power Co., and 121 S. Higby, Jackson, Mich. GERMAIN, Oscar (Af 1935) Germain & Frere, Ltd., 237 St. Antonie St., and (for mail) 1343 Blvd. SL 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 Standish Rd., Melrose, Mass. GERRISH, Harry E. (Af 1910) (Council, 1919) -Partner' (for mail)' Morgan-Gerrish Co.,"84"S. Tenth St., 307 Essex Bldg., and 4534 Fremont St., Minneapolis, Minn. GERSTENBERGER, Edgar J. (A 1938) Sales Engr., F. R. Dengel Co., 1134 North 4th St., and (for mail) 3824 North 17th St., Milwaukee, Wis. GETSCHOW, Roy M. (Af 1919) Pres. & Treas. (for mail) Phillips-Getschow Co., 32 W. Hubbard St., Chicago, and 122 Woodstock, Kenilworth, 111. GHILARDI, Fernand (Af 1937) Chief Engr., Minneapolis-Honeywell Regulator Co. (French Branch) 34 Rue Godot de Mauroy, Paris, and (for mail) 12 Rue Gabrielle d'Estrees Vanves (Siene) France. GHOSE, Khagendra N. (A 1938) Consulting Engr. (for mail) 17 State SL, New York, and 2714 Amboy Rd., New Dorp. S. I., N. Y. GIANNINI, Mario C. (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, O. GIBBS, Edward W. (Af 1919) Pres, (for mail) The Smith-Gibbs Co.. 201 S. Main St., and 39 President Ave.. Providence, R- I. CIESECKE, Frederick E * (Af 1913) (2nd Vice- Pres., 1938; Council, 1932-1938) Director, Texas Engineering Experiment Station, A.&M. College of Texas, College Station, Tex. GIFFORD, Clarence A. (A 1934) Salesman, American Radiator Co., 1807 Elmwood, and (for mail) 333 North Drive, Buffalo, N. Y. GIFFORD, Edmund W. (Af 1938; 7 1929) Chief Engr. (for mail) Airtemp Construction Corp., 4841 Woodward Ave., and 745 Seyburn Ave., Detroit, Mich. GIFFORD, Robert L. (Life Member; M 1908) Pres., Illinois Engineering Co., Cor. 21st St. & Racine Ave., Chicago, III., and (for mail) 1231 S. El Molino Ave., Pasadena, Cali*. GIFFORD, William R. (Af 1938; 7 1936) Sales Engr., American Radiator Co., 4th & Channing Sts., N. E., Washington, D. C., and (for mail) Box 584, College Park, Md. G1GUERE, George H. (Af 1920) Consulting Engr., 17205 Fairport, Detroit, Mich. ' GILBERT, Leslie S. (Af 1937) Owner (for mail) Gilbert Engineering Co., 1314 Liberty Bank Bldg., and 3713 Southwestern Blvd., Dallas, Tex. GILES. J. C. (7 1938; 5 1935) 546 South Blvd., Norman, Okla. GILFRIN, George F. (Af 1932) Climas Arti- fitiales, S. A. (for mail) Edificio "La Nacional'' 608, and Esplanada No. 715 Lomas de Chapul- tepec, 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 Theorells Ingeniorsbyra, Skoldun- gagatan 4. Stockholm, and Svanhildsvagen 19, Nockeby, Sweden. GILLETT, M. C. (Af 1916) Dist. Sales Engr., ` Hoffman Specialty Co., Inc., and (for mail) 6600 Rising Sun Ave., Philadelphia, Pa. GILLHAM. Walter E. (Af 1917) Consulting En (for mail) 337 Law Bldg., and 3427 Bellfontafc Ave., Kansas City, Mo. n GILMAN. Franklin W. (Af 1935) Plant En Atwater Kent Mfg. Co.. 4700 Wtssahickon Ave*' and (for mail) 514 W. Coulter St., Philadelphia. GILMORE. John L. (A 1938) Owner. John L Gilmore Htg.-Vtg., 1602 Kay Ave.. and (for main* 1604 Union St., Brunswick, Ga. ' GILMORE, Louis A. (7 1935* S 1930) Vice-Pres (for mail) John Gilmore & Co., 115 South Uth St., and 5906 McPherson Ave., St. Louis, Mo GINI, Aldo (Af 1933) via Correggio 18, Milano" Italy. * GINN, Tony M. (Af 1935) General Mgr., Tony M Ginn Co., 214-24 Fifth St., S., Great Falls. Monti GITTERMAN, Henry'(A 1937) Baptist Church Rd.. Yorktown Heights, N. Y. GITTLESON, Harold (A 1936) Sales Mgr. Lariviere, Inc., 3715 St. Lawrence Blvd.. and ' (for mail) 1125 Lajoie Ave., Montreal, P. Q., Canada. '* GIVIN, Albert W. (A 1925) Sales Mgr. (for mail) The Gurney Foundry Co., Ltd., 4 Junction Rd. and 219 St. Clair Ave., W., Toronto. Ont!) Canada. '* GLASS, William (Af 1934) Mgr., Partridg*. Halliday Ltd., 144 Lombard St., Winnipeg, Man., Canada. GLEASON, Gilbert H. (Af 1923) Partner (for mail) Gilbert Howe Gleason & Co., 28 SL Botolph SL, Boston, and 10 Edgehili. Rd., Winchester, Mass. * GODFREY, Joseph E. (7 1938) Engr., DelcoFrigidaire Cond. Div., 306 G. M. Research Bldg., Detroit, Mich, (for mail) 1500 Ridgeway Rd., Dayton, O. GOELZ, Arnold H. (Af 1931) Pres, (for mail) Kroeschell Engineering Co., 215 W. Ontario St., Chicago, and 827 Greenwood Ave., Wilmette. 111. GOENAGA, Roger G. (Af 1931) Tech. Director,' Ateliers Ventil (for mail) 109 Cours-.Gambetta, Lyon, and 33 Avenue Valioud-Ste-FoyTea-Lyon. . Rhone, France. ' `. GOERG, Bernhard (Af 1928) Director of Institute- of Thermal Research (for mail) American Radi ator Co., 675 Bronx River Rd., Yonkers, and 57 Minerva Drive. Tuckahoe, N. Y. GOERGENS, Albert G. (A 1938) Asst. Engr., War Dept. O. Q- M. G., Munitions Bldg., and (for mail) Apt. No. 10, 33 Concord Ave., N.-W., Washington, D. C. GOFF, John A. (Af 1939) Dean (for mail) Towne Scientific School, University of Pennsylvania, Philadelphia, and 511 Cambridge Rd., Cynwyd, Pa. GOLDBERG, Moses (A 1934) Pres., Electric Motors Corp., 168 Centre St., New York, and (for mail) 885 E. 8 SL, Brooklyn, N. Y. GOLDSMITH, F. Willius (Af 1936) Pres, (for mail) The W. Clasmann Co., 324 E. Wisconsin Ave., and 629 E. Day Ave., Milwaukee, Wis. sGOLL, 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 Association, 1250 Sixth Ave., New York, N. Y., and (for mail) 160 Halsted SL, East Orange, N. J. GONZALEZ, Rafael A. (Af 1936) Mgr., Appli cation Engrg. Dept, (for mail) Airtemp Div-. Chrysler Corp., P. O. Box 1037, and 434 Dela ware SL, Dayton, O. GOODRAM, William E. (A 1936) . Partner. Goodram Bros., 88 King St., 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 SL, Dorchester, Mass. GOODWIN, Eugene W. (M 1936) Sr. Mech. Engr., U. S. Treasury Dept.. Procurement Bldg., Washington, D. C-, and (for mail) 7024 Hampden Lane, Bethesda, Md. , 26 Roll of Membership F GOODWIN, Samuel L. (Af 1924) Consulting GRANT, Walter A. (A 1933 ; 7 1928) Dist. Chief r Engr., John Eberson, 1560 Broadway, New York, Engr., Carrier Corp., and (for mail) 236 Shotwell R.- N. Y., and (for mail) 247 Madison Ave., Has- Park, Syracuse, N. Y. brouck Heights, N. J. GRAVES. Willard B. {Life Member; M 1906) GORDON, Colin W. (A 1938) Supt. and Junior Pres, (for mail) W. B. Graves Heating Co., 162 r. Partner, A. G. Baird. Ltd.. 286 Lisgar SL, and North Desplaines St., and 5920 Addison St., . (for mail) 962 Shaw SL, Toronto, Ont., Canada. Chicago. III. GORDON, Edward B.. Jr. (Af 1908) Pres., GRAY, Earle W. (Af 1938; A 1934) In charge of Pillsbury Engineering Co., 1200 Second Ave., S., Air Cond., Commercial Dept, (for mail) Okla and (for mail) 2450 West 24th SL, Minneapolis, homa Gas and Electric Co., Third and Harvey Minn. Sts., and 2125 N. W. 18th SL, Oklahoma City, GORDON, Henry H. W. (7 1938) AssL Resident Okla. Engr. (for mail) Carrier Engineering S. A., 91 GRAY, Everett W. (Af 1936) Mgr. (for mail) The Smith St., Durban Natal, and 71 Pasadena Trane Co., 1900 Euclid Ave., Cleveland, and Court, South Beach, Durban, South Africa. 17545 Madison Ave., Lakewood, O. GORDON, Peter B. (A 1938; 7 1935) Treas. (for GRAY, George A. (Af 1924) Branch Mgr. (for . .mail) Wolff & Munier,-Inc., 222 East-41st St.,~ - - mail) C. Ar Dunham Co., Ltd.; 404 Plaza Bldg., New York, N. Y., and 35 Park Ave., Bloomfield, and 114 Belmont Ave., Ottawa. Ont., Canada. N. J. GRAY, John W. (Af 1938) Member of Firm, The GORDON, William D. (A 1935) Air Cond. and Gray-Henry Co., 614 N. Water SL, Bay City, Sales Engr., Hart & Cooley Mfg. Co. of Canada, Mich. Ltd., Fort Erie, N., and (for mail) 71 Chilton GRAY, William E. (Af 1922) Gray Engineering Rd., Toronto, Ont., Canada. Co., and (for mail) Box 264, High Point, N. C. GORNSTON, Michael H. (A 1923) Custodian- GREEN, Everett W. (7 1938) Junior Sales Engr. Engr. (for mail) Board of Education. Thomas (for mail) Green Furnace and Plumbing Co., Jefferson High School, Brooklyn, and 90-ll-149th 2815 North 48, and 5100 Leighton Ave., Lincoln, SL. Jamaica, N. Y. Nebr. GOSS, Matthew H. (Af 1921) Partner (for mail) GREEN, William C. {Life Member; Af 1906) Dist. M. H. Goss Co., 3536 Baldwin Ave., and 3417 Repr. (for mail) Warren Webster & Co., 704 i Field Ave., Detroit, Mich. Race SL, and 244 Erkenbrecher Ave., Cincinnati, GOSSETT, Arthur L. (A 1938) Gage Bros., 617 O. Red River, Austin, Tex. GREENBERG, Irving (S 1937) Air Cond. Engr., GOSSETT, Earl J. (Af 1923) Pres, (for mail) S. Greenberg, 873 Columbus Ave., New York, Beil & Gossett Co., 3000 Wallace SL, Chicago, and (for mail) 1615 Walton Ave., Bronx, N. Y. ' and 314 Woodland Ave., Winnetka, III. GREENBURG, Dr. Leonard* (Af 1932) Executive . GOTHARD, William W. (A 1936) Editorial Director, Div. of Industrial Hygiene (for mail) . Director (for mail) Domestic Engineering, 1900 N. Y. State .DepL of Labor, 80 Centre St., and Prairie Ave., Chicago, and 1027 Arlington Ave., 173 West 78th St., New York. N. Y. LaGrange, 111. . GREENLAND, Sidney F. (Af 1934) Htg. & Vtg. GOTSCHALL, Harry C. (Af 1935) Chairman, Air Engr., Gee Walker & Slater, 3, Fitzmaurice Cond. Dept., Lane Technical High School, 2501 Place, London, W.I., and (for mail) 9, Aneriey W. Addison St., and (for mail) 2953 Eastwood Court, Aneriey Park, London, S. E. 20, England. Ave., Chicago, 111. GREENWOOD, Orrin J. (Af 1938) Air Cond. GOTTWALD, C. (A 1916) Pres, (for mail) The Ric-wiL Co., 1563 Union Commerce Bldg., Cleveland, and 2225 Stillman Rd., Cleveland Heights, O. GOUEDY, Kenneth E. (A 1935) Member of Firm and Engr. (for mail) Modern Building Insulating Co., 411 Bona Allen Bldg., Atlanta, and 218 - Columbia Drive, Decatur, Ga. GOULD, Henry E. (7 1936) Secy, (for mail) - Nation & Co., 1800 Baltimore, and 6528 Summit, Kansas City, Mo. . GOULDING, William (A 1933) Air Cond. Engr., World Broadcasting System. 711 Fifth Ave., New York, and. (for mail) 782 Westminster Rd.. Brooklyn, N. Y. GOUNDIE, Joseph K. (Af 1938) Sales Engr.. Engr., Walgreen Co., 744 Bowen Ave., and (for mail) 6357 S. Homan Ave., Chicago, ill. GREGG, Scranton H. {A 1936) Pres., Shellen- Berger-Gregg Co., 2203 N. Prospect Ave., and (for mail) 5134 N. Woodburn SL, Milwaukee, Wis. GREGG, Stephen L. (7 1936) Sales Engr. (for mail) Potomac Electric Power Co.. 10th & E Sts., N. W., Washington, D. C., and 4828 Edgemoor Lane, Bethesda, Md. . GREINER, George E., Jr. (7 1938; 5 1935) Engr., Wayne Crouse, Inc., 4647 Centre Ave., and (for mail) 5515 Claybourne SL, Pittsburgh, Pa. GR1ESS, Philip G. (Af 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 Fritch Coal Co., 116 River SL. Bethlehem, and (for mail) 1426 Walnut St., Allentown, Pa. Contractor Dealer, Bryan, Tex. GR1EST, Hermit (7 1936) Sheet Metal Worker GRABENSTEDER, Louls-<A 1937; 7 1935) 3206 and Sales, Frank-Limbach & Co., 1722 E. Ohio Linnet Rd., Louisville, Ky. St., and (for mail) 437 Bausman SL, Pittsburgh, GRABER, Ernst (7 1936) Engr;, MinneapolisHoneywell Regulator Co., 801 Second Ave., New York, and (for mail) 222 Hollywood Ave*, Douglaston, L. I., N. Y. GRABMAN, Henry B. (S 1938) Student, Carnegie Institute of Technology. Pittsburgh, and (for mail) 355 E. Spring SL, Zelienople, Pa. GRAFF, William F. (A 1937) Salesman-Engr., Standard Sanitary Mfg. Co., and (for mail) 940 Jefferson. S. E., Grand Rapids, Mich. 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. Pa. GRIEVES, Thomas R. (A 1930) Branch Mgr. (for mail) U. S. Radiator Corp., 303 Crosby Bldg., Buffalo, N. Y. GRIEW1SCH, Alfred H. (A 1938) Pres, (for mail) Bayiey Heating Supply Co., 2045 W. SL Paul Ave., and 2557 N. 47th SL, Milwaukee, Wis. GRIFFITH, Claude A. (A 1938) Assoc. Member, Heating & Air Conditioning Service, 632 Hill Top Drive, Cumberland, Md. GRIFFITH, Herbert T. (Af 1938) Designing Engr. (for mail) Lincoln Bouillon (Consult. Engr.) 324-141 l-4th Ave. Bldg., and 1909-3rd Ave., W., Seattle, Wash. GRIFFITH, Joseph B. (7 1938) Sales Engr., Drayer and Hanson, 738 E. Pico Blvd., Los Angeles, and (for mail) 415 N. Sierra Vista Ave., Monterey Park, Calif. GRANSTON, Ray O. (7 1935; S 1930) Secy, (for GRIMES, Fenner M. (7 1935) Junior Engr., War mail) University Plbg. & Htg. Co., 3939 Uni Dept., O.Q.M.G. (Constr. Div.), Munitions versity Way, and 4333-9 Ave., N. E,, Seattle, Bldg., and (for mail) 2301 Cathedral Ave., Wash. N. W., Washington, D. C. 27 t Heating Ventilating Air Conditioning Guide 1939 GROHS, Conrad E. (7 1938) -Washington Repr. (for mail) American Gas Products. 4tn & Chan- ning Sts.. N. E.. and 1349 Newton St.. N. E., Washington. D. C. GROOT, Harry W. (Af 1937) Chief Engr.. The Home Comfortable, Inc., 226 West Walnut St., and (for mail) 3728 N. Western Pkwy., Louis ville, Ky. GROSS, Lyman C. (Af 1931) Sales Engr., Minne- apolis-Honeywell Regulator Co., 2727 4th Ave., S., and (for mail) 5324 Oaklawn Ave.. Linden Hills Station, Minneapolis, Minn. GROSSENBACHER, Henry E. (A 1938) Pres, (for mail) Grossenbacher Steel Furnace & Mfg. Co., 2626 Woodson Rd., and 9741 Lackland Rd., ' Overland, St. Louis Co., Mo. GROSSMAN, Franklin A. (7 1938; S 1937) Ex perimental Engrg., Servel, Inc., Engrg. Dept., 119 N. Morton Ave., and (for mail) 1161 E. Illinois St., Evansville, Ind. GROSSMAN, Harry E. (A 1933; 7 1927) Sales Repr., Haynes Selling Co., Inc., Ridge and Spring Garden Sts., Philadelphia, and (for mail) 218 Parham Rd., Springfield, Pa. GROSSMANN, Harry A. (Af 1931) Owner. H. A. Grossmann Co., 3138 Cass Ave., and (for mail) 3122 Geyer Ave., St. Louis, Mo. GROSVOLD, Fred E. (M 1917) Owner (for mail) F. E. Grosvold Co., 417 Wisconsin St., and 711 Grand Ave., E., Eau Claire, Wis. GROVES, Samuel A. (7 1935) Sales Engr., American Radiator Co., 40 West 40th St., New York, and (for mail) 21 Cassilis Ave., Bronxville, N. Y. GULER, George D. (A 1937) Sales Engr. (for mail) Minneapolis-Honeywell Regulator Co., Wayne & Roberts St., and 334 E. Allens Lane, Phila delphia, Pa. GUMAER, P. Wilcox (Af 1937) Consulting Engr., Toxic Vapors & Dusts, 25 Garden St., West . Englewood, N. J. GUNNELL, George T. (Af 1937) Chief Htg. Engr. (for mail) Sunbeam Heating & Air Conditioning . Co.. 346 Peachtree St., N. E., and 595 Ashby, S. W., Atlanta, Ga. GURNEY, E. Holt (Af 1929) (Pres., 1938; 1st Vice-Pres., 1937; 2nd Vice-Pres., 1936; Council, 1931-1938) Pres, (for mail) The Gurney Foundry Co., Ltd., 4 Junction Rd., and 347 Waltner Rd., Toronto, Ont.. Canada. GURNEY, Edward R. (7 1937) Asst, to Plant Supt. (for mail) Gurney Foundry Co., Ltd., 4 Junction Rd., and 50 Eastbourne Ave., Toronto, Ont., Canada. - GUSTAFSON, Carl A. (Af 1938) Sales Engr. (for mail) The Powers Regulator Co., 2720 Green- view Ave., and 5920 Ridge Ave., Chicago, 111. H HAAS, Samuel L. (Af 1923) Pres. & Treas. (for mail) Advance Heating & Air Conditioning Corp., 117-119 North Desplaines St., and 1513 Fargo Ave., Chicago, III. HACKETT, H. Berkeley (Af 1921) Consulting Engr., 901 Architects Bldg., 17th and Sansom Sts., and (for mail) The Lenox, 13th and Spruce Sts.. Philadelphia, Pa. HADDOCK, Isaac T. (A 1926) New England Gas & Electric Association, 719 Massachusetts Ave., Chicago, 111. HADEN, G. Nelson (Af 1934; A 1928; 7 1922) Chairman and Managing Dir. (for mail) G. N. Haden & Sons, Ltd., 60 Kingsway, London, W. C. 2, and 36 Wildwood Rd., London, N. W. 11, England. HADEN, William N. {Life Member; Af 1902) Retired Chairman, G. N. Haden & Sons, Ltd., 60 Kingsway. London, W. C. 2, and (for mail) Arnolds HiU, Trowbridge, England. HADJISKY, Joseph N. (Af 1930) Consulting Engr., 744 Bates St., Birmingham, Mich. HAERLE, Robert A. (A 1938) Mech. Engr.. Bayley Blower Co., 1817 S. 66th St., and (for mail) 1438 N. Humboldt Ave., Milwaukee, Wis. HAGAN, WUUam V. (Af 1938; A 1933; 7 1926") Secy., V. J. Hagan Co., and (for mail) 1811 Ton^l St.. Sioux City, la. HAGEDON, Charles H. (Af 1919) Partner (for mail) S. E. Fenstermaker & Co., 937 Archt. & Bldrs. Bldg., and 4156 Broadway, Indianapolis Ind. * HAHN, Roy F. (7 1936) Air Cond. Engr. (for mail) Advance Refrigeration. Inc., 350 Peachtree St . and 435-lOth St., N. E., Atlanta, Ga. '* HAINES, John J. (Af 1915) Pres, (for mail) The Haines Co., 1931 W. Lake St., Chicago, and 623 17th Ave., Maywood, 111. HAITMANEK, Louis M. (A 1938) Journeyman Sheet Metal Worker, 217 Rose St., Newark. N t HAJEK, William J. (Af 1932) 372 W. Johnson St., Philadelphia, Pa. . HAKES, Leon M. (Af 1932; 7 1929) Dist. Repr. (for mail) Warren Webster & Co., 410 Reynolds Arcade Bldg., and 327 Lone Oak Ave., Rochester N. Y. * HALE, Fred J. (Af 1936) Mgr. (for mail) Empire - Sheet Metal Works, Ltd., 1606 West First Ave., and 3606 Point Grey Rd., Vancouver, B. C.t Canada. .' HALE, John F. {Life Member; Af 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, 111 W. Washington St., Chicago, and 400 S. LaGrange Rd., LaGrange, 111. * HALEY, Harry S.* (Af 1914) Consulting Engr., Partner (for mail) Leland & Haley, 58 Sutter St.,. and 735-21st Ave., San Francisco, Calif. * . HALEY, Robert T. (A 1938) Supervisor of House Heating (for mail) Minneapolis Gas Co., 800 Hennipin Ave., and 5024-12th Ave., S., Minne- apolis, Minn. HALL, George (A 1937) Secy.-Treas. and Mgr. (for mail) Hyland, Hall & Co., 115 E. Doty St., . and4201 Wanetah Trail, Nakoma, Madison, Wis. HALL, John R. (Af 1937; 7 1932) Mech. Engr., 1416 Lakeview Ave., Minneapolis, Minn. . HALL, Mora S. (Af 1934) Development, Engr. (for mail) Anthracite Industries Laboratory. Primos, Del. Co., and 293 N. Maple Ave., . Lansdowne, Pa. ` ` HALL, Wilton L. (Af 1938) Engr., Frank A. Leon Co., 901 Girard St., N. E., and (for mail) 5316 Dorsett P1-. N. W., Washington, D. C. HALLAR, Edgar V. (A 1937) Sales, Lane-White Electric Co., 204 West 4th St., Joplin, and (for mail) 1001 S. Madison, Webb City, Mo. HALLECK, Leon P. (A 1937) Vice-Pres. & Sales Mgr. (for mail) The Allen Corporation. 9751 Erwin Ave., and 12049 Roseiawn Ave., Detroit, Mich. HALLER, Arthur L. (Af 1920) Pres.-Treas. (for mail) Haller Appliance Sales Co., Inc., .3321 Washington, St. Louis, and 124 W. Cedar Ave., Webster Groves, Mo. HALLSTEIN, Harry T. (7 1938) Dist. Engr. (for mail) Swett Bros. Heating & Appliance Co., 559 \ State St., Springfield, Mass. JlAMACHER, K. F. (Af 1938) Partner (for mail) Hamacher & Williams, 2540 W. Wells St., and 4387 S. Austin St., Milwaukee, Wis. HAMAKER, Ambrose C. (A 1937) Sales Engr. (for mail) Mayflower-Lewis Corp., 63 W. Mil waukee Ave., and 18624 Santa Rosa Drive, Detroit, Mich. HAMERSKI, Francis D. (7 1934) Winona Coal Co., Winona, Minn. HAMIG, Louis L. (7 1935) Engr., 3514 Utah St., St. Louis, Mo. HAMILTON, Lloyd L. (7 1938) Branch Office Mgr., Minneapolis-Honeywell Regulator Co., and (for mail) 208 Norwood Ave.. N. E., Atlanta, Ga. HAMJE, Milton C. (7 1936) Engr.. Syska & Hennessy, 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 Shiiter St.. Montreal, P.Q., Canada. 28 Roll of Membership HAMLET, Thomas F. (Af 1938) Sales Engr. (for mail) Taylor Forbes, Ltd., 1197 University St., Montreal, and 34 Burton Ave., Westmount, P.Q., Canada. HAMLIN, James B,, Jr. (A 1937) Htg. Engr., Crane Co., 14 W. Broad St., and (for mail) 1530 East 51st St., Savannah, Ga. HANBURGER, Fred W. (Af 1930) Consulting Engr.. 252 West 76th St., New York, N. Y. HANLEIN, Joseph H. (Af 1937) Secy.-Treas. (for mail) Wilberding C.o., Inc., 808-17th St., N. W., HARSCH, Richard J. (Af 1936) Naval Archt., U. S. Government; Navy Yard, and (for mail) 142 Avenue O, Brooklyn, N. Y. HART, F. Donald (7 1937) Air Cond. Engr. (for mail) E. 1. DuPont de Nemours & Co., and 1301 Van Buren St., Wilmington, Del. HART, Harry M.* (Af 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. Room 13, and 5420 Connecticut Ave., Washing ton, D. C. HANLEY, Edward V. (A 1933) Pres, (for mail) T-. S. V. Hanley Co., 1653 N. Farwell Ave., Milwau kee, and 844 E. Birch Ave., Whitefish Bay, Wis. % HANLEY, Thomas F-, Jr. (Af 1933) Pres, (for U* mail) Hanley & Co., 1503 S. Michigan Ave., and 1640 E. 50th St., Chicago, 111. HANSLER, John E. (Af 1937) Zone Service Repr., Delco-Frigidaire Conditioning Div., 300 Taylor i St., and (for mail) 2621 Hillview Ave., Dayton. O. ;f HANSON, Leslie P. (Af 1937: A 1936; 7 1935; 5 X 1933) Engr., U. S. Air Conditioning Corp., 2101 Kennedy, N. E., and (for mail) 5027 Nokomis Ave., S., Minneapolis, Minn, tev HARBAUGH, Jacob W. (Af 1937) Supt. of Erection, Kupferle-Hicks Heating Co., 3974 Del- HART, Stanley (Af 1938) Vice-Pres. (for mail) Tuttle & Bailey, Inc., and New Britain, Conn. HART, Theodore S. (Af 1938) Engr., Tuttle & Bailey, Inc., New Britain, Conn. HART-BAKER, Henry W. (Af 1918) Hart Engi neering Co., 451 Kiangse Rd., Shanghai, China. HARTIN, William R., Jr. (7 1935) Htg. Engr., Vice-Pres.-Secy. (for mail) W. R. Hartin & Son, Inc., 2123 Green St., and 212 S. Saluda Ave., Columbia, S. C. HARTLINE, W. Raymond (A 1936) Sales Engr., 5216 Kansas Ave., N. W., Washington, D. C. HARTMAN, John M. (Af 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., 601 Francis, mar Blvd., St. Louis, and (for mail) 607 Lilac and (for mail) 730 E. Hyde Park Ave., St. J St., Webster Groves. Mo. Joseph, Mo. $ HARBORDT, Otto E. (A 1936) Sales Mgr. (for HARTWEIN, Charles E. (Af 1933) Supervisor. mail) U. S. Supply Co., 1315 West 12th St., and House Htg. Dept., St. Louis County Gas Co., 231 -V 303 Brush Creek Blvd., Kansas City, Mo. W. Lockwood, Webster Groves, and (for mail) & HARD, Amos L. (A 1938) Chief Engr., Thos. 135 Peeke Ave., Kirkwood, Mo. * .'Cf Emery & Sons Co., Carew Tower, and (for HARTWELL, Joseph C. (Af 1922) Pres, (for mail) ,% mail) 910 Kreis Lane, Cincinnati, O. Hartwell Co., Inc., 87 Weybosset St., and 16 j# HARDEN, J. Clinton (Af 1938) Htg. Engr., , Freeman Parkway, Providence, R. I. Round Oak Co., and (for mail) 106 Courtland HARVEY, Alexander D. (A 1928; 7 1925) Sales i-V St., Dowagiac, Mich. Mgr. (for mail) Nash Engineering Co., Wilson :/ HARDING, Edward R. (Af 1936) N. C. State Rd., South Norwalk, and West St., New Canaan, Sales Engr. (for mail) Kewanee Boiler Corp*. Conn. y.- P. O. Box 536, 704 Jefferson Bldg., Greensboro, and Guildford College, N. C. A-' HARDING, Louis A.* (Af 1911) {Presidential *\ Member) (Pres., 1930; 1st Vice-Pres., 1929 ; 2nd '.ii! Vice-Pres., 1928; Council, 1922-1931) Coinnris- .'A sioner of Public Works, City Hall, and (for mail) HARVEY, Lyle C. (Af 1928) Pres, (for mail) The Bryant Heater Co., 17825 St. Clair Ave., Cleve land, and 2666 Leighton Rd., Shaker Heights, O. HASHAGEN, John B. (Af 1930) Plant Engr., General Seafoods Corp., 1-15 Fish Pier, Boston, Mass. V 85 Cleveland Ave., Buffalo, N. Y. ' HARDY, Frank L. (7 1937) Secy, (for mail) 4 * Gulf-York Co.. 2300-3rd Ave., N.. and 2312 A Highland Ave., Birmingham, Ala. HARMONAY, William L. (A 1935) Mgr. (for V: mail) M. J. Harmonay, Inc., 124 Elm St., and > 34 Alida St., Yonkers, N. Y. HARRIGAN, Edward M. (Af 1915) Gen. Mgr. .'.* (for mail) Harrigan & Reid Co., 1365 Bagley j: Ave., and 7450 LaSalle Blvd., Detroit, Mich. 2> HARRINGTON, Charles (Af 1923) 43 Indian Grove, Toronto, Ont.. Canada. ,v HARRINGTON, Elliott* (Af 1932; A 1930) Mgr., HATEAU, William M. (7 1934) Draftsman & Designer, J. O. Ross Engineering Corp., 350 Madison Ave., and (for mail) 1530-Sheridan Ave., New York. N. Y. HATHAWAY, Carl B. (A 1938) Salesman (for mail) Advance Insulating Co., 714 Magee Bldg., and 5204 Woodlawn Place, Pittsburgh, Pa. 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. *-* Commercial Engrg. Div., Air Cond. Dept, (for HAUGK, EldenL. (7 1936) Mgr. (for mail) Hauck mail) General Electric Co., 5 Lawrence St., Bros., 232 S. Center St., Springfield, and 1010 vV Bloomfield, and 17 Wilson Terrace, West Cald- S. Main St., Dayton, O. " well, N. J. HARRIS, Albert M. (Af 1938) Sales Mgr., Air Cond. (for mail) Baker Ice Machine Co., 509 . E. 3rd St., and 2941 Glen Garden Drive, Fort i\: Worth, Tex. HARRIS, Jesse B. (Af 1918) Co-Partner (for mail) j, . Rose & Harris Engineers, 416 Essex Bldg., and ~ 3620 Colfax Ave., S., Minneapolis, Minn. HARRIS, John G. (Af 1936) Dist. Repr. (for mail) Frigidaire Div., General- Motors Sales Corp., ' Terminal Tower Bldg., Cleveland, and 14432 Delaware Ave., Lakewood, O. HARRISON, George G. (Af 1937) Chief Engr.. S. T. Johnson Co., 940 Arlington Ave., Oakland, HAUER, Fred (4 1937) Pres, (for mail) Fred Hauer & Co., Inc., Ill North Water St., and 315 Hettinger Place, Peoria, III. HAUPT, Howard F. (4 1938) Htg. Salesman, Kohler Co., 751 N. Jefferson St., and (for mail) 614 E. Beaumont Ave., Milwaukee, Wi9. HAUS, Irvin J. (4 1937; J 1935) Engr.. Everett Smith Automatic Temperatures, Inc., 789 N. Water St., and (for mail) Jackson Hotel, 926 N. Jackson St., Milwaukee, Wis. HAUSMAN, Louis M. (Af 1935) Pres., L. M. Hausman & Co., 440 Dasmarinas, and (for mail) P. O. Box 1729, Manila. P. I. . * and (for mail) 1428 Arch St., Berkeley, Calif. . HARRISON, Julius C. (Af 1938) Design Engr. HAUSS, Charles F.* {Life Member) Via Gesu, No. 8, Milan. Italy. (air conditioning) Texas Air Conditioning Co. HAWISHER, Harold H. (4 1938) Mech. Engr., (for mail) 407 Capps Bldg., and 919 W. Cannon Automatic Heating and Engineering Co.; 416 St., Fort Worth, Tex. N. Main St., and (for mail) 411 S. Jameson Ave., : HARROWER, William C. (A 1937) Air Cond. Lima. O. Draftsman, Gar Wood Industries, 409 Connecti- HAWK, Joseph K. (7 1936) Engr. (for mail) L. cut Ave., and (for mail) 12561 Third Ave., General Air Conditioning Co., 3096 Main St., ' Highland Park, Mich. and 150 Byron, Buffalo, N. Y. 29 id i 1 : Heating Ventilating Air Conditioning Guide 1939 HAWKINSON, C. F. (7 1936) Mech. Engr., U. & Air Conditioning Corp., 2101 N. E. Kennedy, and (for mail) 2833-38th Ave.. S.. Minneapolis, Minn. 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.- Engr. (for mail) Hayes Brothers, Inc., 236 West Vermont St., and 2849 N. Capital Ave., Indi anapolis, Ind. . HAYMAN, A. Eugene, Jr. (7 1935: S 1930) Draftsman, Moody & Hutchison, Consulting Engineers. 1701 Architects Bldg., Philadelphia, Pa., and (for mail) 2715 Washington Sl, Wil mington, Del. HAYNES, Charles V, {Life Member', M 1917) '{PresidentialMember)(Presl,1934;Tst Vice-Pres., 1933; 2nd Vice-Pres.. 1932; Council. 1926-1929; 1932-1935) Vice-Pres., Hoffman Specialty Co., Inc., 500 Fifth Ave., New York, N. Y., and Waterbury, Conn., and (for mail) 115 Llanfair Rd , Ardmore, Mont. Co., Pa. HAYS, Charles A. (A 1937) 4868 N. Woodburn St., Milwaukee, Wis. HAZLETT, Dr. T. Lyle {M 1938) Medical Dir. (for mail) Westinghouse Electric & Mfg. Co., E. Pittsburgh, and 6634 Beacon St., Pittsburgh, Pa. HEARD, John A. E. (A 1938: J 1930) Asst. Mgr.. Air Cond. & Refrigeration Dept., Volkart Bros., Graham Rd., Ballard Estate, Bombay, India. HEATH, William R. (M 1931) Asst. Chief Engr.. Buffalo Forge Co., 490 Broadway, and (for mail) 119 Wingate Ave., Buffalo, N. Y. HEBERLING, C. W. (A 1934) Box 115, Wayzata, Minn. HEBLEY, Henry F. J. (M 1934) Advisory Engr., Comraerical Testing & Engineering Co., 307 North Michigan Ave., and (for mail) 636 Wright- wood Ave., Chicago, 111. HECHLER, 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. {M 1930) Sales Engr. (for. mail) B. F. Sturtevant Co., 2635 Koppers Bldg., and 1467 Bamesdale St., Pittsburgh, Pa. HECKEL, Edmund P. (M 1918) Vice-Pres.. Carrier Corp., 222 West North Bank Drive, Chicago, ana (for mail) 314 Cuttriss Place, Park Ridge. 111. HEDDEN, Willard M. (A 1937) Treas., The Hedden Co. (for mail) 17-25 South Warren St., and 7 Reservoir Ave., Dover. N. J. HEDEEN, Laurel E. (7 1938) Sales Engr., The Trane Co. (for mail) 818 Hubbell Bldg., and 1709 9th, Des Moines, la. HEDGES, H. Berkley (M 1919) Mgr., Industrial Sales (for mail) John H. Nesbitt, Inc., Holmesburg, Philadelphia, and 114 Waverly Rd., Wyn- cote. Pa. HEDLEY, Park S. {M 1923) Park S. Hedley Co., 361 Delaware Ave., Buffalo, N. Y. HEDLUND, Richard A. (7 1938; S 1937) Sales Engr. (for mail) The Trane Co., 1513 N. Cam eron, and 900 N. Third, Harrisburg, Pa. HEEBNER, Walter M. (M 1922) Sales Engr.. Warren Webster & Co.. 20 Washington Place, Newark, and (for mail) 282 Highwood Ave., Teaneck, N. J. HEIBEL. Walter E. (M 1917) Dist. Mgr. (for mail) Aero&n 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, 4400 5th Ave., and 2303 Beechwood Blvd., Pittsburgh, Pa. HEINKEL, Charles E. (7 1938) Sales Engr.. Control Equipment Co., 304 Selling Bldg., and (for mail) 1431 S. W. Park Ave., Portland, Ore. HEISTERKAMP. Herbert W. (7 1937) Sales Engr., The Bryant Heater Co., 17825 St. Clair Ave., and (for mail) 10801 St. Mark St., Cleve land, O. HELBURN, I. B., (M 1929 ; 7 1927) Jr. Assoc, ff*, mail) Wyman Engineering, 1306 Chamber CCoinmcminenractei, OB.ldg., and 3815 Windine8 WWaa*, ^ HELLER, Joseph A. (A 1938) Sales (for main Air Conditioning Utilities Co., 8 West 40th St 150 West 82nd St.. New York. N. Y. ' HELLMERS, Charles C., Jr. (7 1937) Gas Ht Engr., Iowa-Nebraska Light & Power Co.. 14ifi O St., 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 423 Lightfoot Rd., Louisville Kv HELMRICH, G. Bernard (M 1936) Detroit Edison Co., 2000 Second Ave., Room 750 Detroit, _and (for mail) 26590 Dundee Rd Huntington Woods, Royal Oak, Mich. ** HELSTROM, Clifford W. (Af 1938) Mgr. Hti? Plbg. & Air Cond. Dept., Globe Machinery and Supply Co., 205-11 Court Ave., and (for mail) 1614 Thompson Ave., Des Moines, la. ' HELSTROM, Herman G. (Af 1928) Fire-box Boilers and Stoker Div. (for mail) Wm. Bros. Boiler and Mfg. Co., Nicollet Island, and 4608 Arden Ave., S., Minneapolis, Minn. HENDERSON, Alexander S. (S 1938) Jr. Engr. Unit Air Conditioners Pty., Ltd., 300 Pitt Sc! Sydney, and (for mail) 500 Blaxland Rd., East wood, N. S. W., Australia. HENDRICKSON, Harold M. (M 1933) Asst. Branch Engr. (for mail) York Ice Machinery Corp., 5051 Santa Fe Ave., Los Angeles, and 3901 Liberty Blvd.. South Gate, Calif. *. HENDRICKSON, Ralph L. (Af 1938) Chief Engr., Utilities Engineering Inst., 404 N. Wells St., and (for mail) 6125 Kenwood Ave., Chicago, 111. HENDRIKSEN, Leonard (A 1938) Prop., Hen- driksen Sheet Metal & Heating Service, 1919 Vernon Ave., Flint. Mich. '. 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) Engr., .Green Foundry & Furnace Works, Des Moinesi Ial, and (for mail) 1826 S. 23rd St., Lincoln, Nebr. - HENRY, Alexander S., Jr. (Af 1930) 300 Central Park West, New York, N. Y. HENRY, Ernest C. {M 1938) Member of Finn, The Gray-Henry Co., 614 N. Water St., Bay City, Mich. HENSZEY, William P. (7 1935) Chief Engr. (for mail) "Carrier-Egypt, S. A. E.". 37, Shareh Kasr El Nil, Cairo, Egypt, and 320 Hamilton Ave., State College, Pa., U. S. A. HERBACEK. Edward E. {M 1938) Chief Engr. & Secy., Spencer Air Conditioning Co., 515 Essex Bldg., and (for mail) 4624 Upton Ave., Minneapolis, Minn. HERBERT, Richard M. (7 1938) Jr. Engr. (for mail) Major Appliance Co., 2558 Farnam St., and 418 North 39th St., Omaha, Nebr. HERING, Alfred (M 1935) Pres., Hering Hearing \ Co.. Inc., 304 East 78th St., New York, N. Y. HERKIMER, Herbert (M 1934) Dir. (for mail) HerkimeT Institute, 1819 Broadway, and 25 Central Park West, New York, N. Y. HERLIHY, Jeremiah J. (Life Member; M 1914) 3751 Eddy St., Chicago. 111. HERMAN, Neil B. (7 1937; 5 1936) Engr. (for mail) Riggs Distler & Co., Inc., 713 Maritime Bldg.. New Orleans, La., and 4217 Garfield Ave.. S., Minneapolis, Minn. HERRING, Edgar (Life Member; M 1919). Chair man and Governing Dir. (for mail) J. Jeffreys & Co.. St. George's House, 195*203, Waterloo Rd., London, S. E. 1., and "Kenia", Keswick Rd., Putney, London, S. W., England. ' HERSH, Franklin C. (A 1933 ; 7 1930) Specialty Engr. (Htg., Vtg. & Air Cond.) Pennsylvania Power & Light Co., 901 Hamilton St., and (for mail) 47 S. St. Cloud Sl, Allentown. Pa. HERSKE, Arthur R. (M 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. 30 Roll of Membership HERTY, Frank B. (M 1933) Industrial Sales Mgr. (for mail) The Brooklyn Union Gas Co., 176 Remsen St., Brooklyn, and 106 Pinehurst Ave., New York, N. Y. HERTZLER, John R.* (M 1936; 7 1928) Gen. Repr.. Refrig. & Air Cond. (for mail) York Ice Machinery Corp., and 863 S. George SL, York, Pa. HESS. Arthur J. (M 1937) Engr., English & Lauer, Inc., 1978 S. Los Angeles SL, and (for mail) 2616 West 70th SL, 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, 4841 Cass Ave., and (for mail) 15722_Kentucky - - Ave., Detroit, Mich. ------ ' -- HESSLER, Lester W. (M 1936) Branch Mgr.. The Trane Co., 1835 N. 3rd SL, and (for mail) 6034 N. Bayridge, Milwaukee, Wis. HESTER, Thomas J. (Af 1919) Vice-Pres.-Treas. (for mail) Hester Bradley Co., 2835 Washington Ave., and 67 Aberdeen Place, St. Louis, Mo. HEWETT, John B. (Af 1937; A 1935) Anemostat Corp. of America, 10 East 39th St., New York, and (for mail) Sussex Hall, Dobbs Ferry, N. Y. HEXAMER, Harry D. (M 1931) 163 E. Delavan Ave., Buffalo, N. Y. HEYDON, Charles G. (A 1923) Mgr. Sales of Western Div., Wright Austin Co., 315 West Woodbridge SL, and (for mail) 2681 Nebraska, DetroiL Mich. HIBBS, Frank C. (M 1917) Htg. Engr., The H. B. Smith Co., Inc., 2209 Chestnut St., and (for mail) 846 North 65th SL, Philadelphia, Pa. HICKEY, Daniel W. (A 1931) Pres., D. W. Hickey & Co., Inc. (for mail) 1631 University Ave., and 1874 Highland Pkwy., St. Paul, Minn. HICKMAN, Herbert V. (A 1938) Sales Engr., Birchfield Boiler, Inc., 1129 Folsom St., San Francisco, Calif. HIERS, Charles R. (M 1929 ; 7 1927) Sales Engr., Minneapolis*Honeywell Regulator Co., 801 Second Ave., New York, and (for mail) 19 Westminster Rd., Great Neck, L. I., N. Y. HIGDON, Harry S. (A 1937) Sales, Andrews Heater Co., 2231 Market, and (for mail) 231 Byxbee, San Francisco. Calif. HIGH, John M. (A 1938) Mgr., The Ruberoid Co., 500 Fifth Ave., New York, N. Y. HILDER, Frederick L. (M 1937) Chief Engr., Electric Furnace-Man, Inc., 780 E. 138th SL, New York, N. Y.. and (for mail) 162 Trenton Ave., Clifton, N. J. HILDRETH, Egbert S. (A 1936) Air Cond. Promotion (for mail) Indianapolis Power & Light Co., 17 N. Meridian St., and 5626 E. Michigan St., Indianapolis, Ind. HILDRETH, Lane W. (Af 1935) Secy, (for mail) Anthracite Institute, 19 Rector St., New York, N. Y., and 243 W. Tulpehocken SL, Philadelphia, Pa. HILL, Charles F. (7 1936) Carrier Air Cond. Dept. Mgr., United Engineers, Ltd., River Valley Rd., Singapore, Straits Settlements. HILL, Dr. E. Vernon* {M 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., ana ' 6826 Newell Ave., Chicago, 111. HILL, Fred M. (Af 1930) 225 East Avenue 39, Los Angeles, Calif. HILL, Harold G. (7 1938) Sales Engr., Gurney Foundry Co.. Ltd., Junction Rd., and (for mail) ApL 5, 29 Jane SL, Toronto, Ont., Canada. HILL, Harold H. (Af 1935) Branch Mgr. (for mail) American Blower Corp., 1211 Commercial Bank Bldg., and 1705 East Blvd., Charlotte. N. C. HILL, Jared A. (Af 1937) Htg. & Air Cond. Engr., Pacific Gas & Electric Co., 245 Market SL, San Francisco, and (for mail) 717 Laurel Ave., Burlingame, Calif. HILL, Vaughn H. (7 1938) Engr., Nash-Kelvi- nator Corp., Automatic Dept.,. Plymouth Rd., Detroit, and (for. mail) 205 LathroptSt., Lansing, Mich. ' HILLIARD, Charles E. (Af 1932; 7 1927) Htg.Vtg. Engr. (for mail) E. C. Hilliard Corp., 27 B SL, South Boston, and No. 6 Arcade, Framingham, and 341 Hunnewell St., Needham Heights, Mass. HILLS, Arthur H. (Af 1924) Mgr. (for mail) Sarco Canada. Ltd., 85 Richmond St., W., and 100 Nealon Ave., Toronto, Ont., Canada. HINCKLEY, Harlan B. (A 1934) Engr.-Custodian, Chicago Board of Education, 8510 S. Green SL, and (for mail) 6933 Princeton Ave.. Chicago. 111. HINES, Guy M. (A 1937) Chief Engr.. Texas Agricultural & Mechanical College Power DepL, College Station, Tex. HINES, John C. (Af 1937) Vice-Pres.-Treas. (for mail) R. BL_ Hayward_Co., 1714 Sheffield Ave., ` Chicago, and 6629 Ramona Ave., Lincolnwood, III. ' HINKLE, Edwin C. (Life Member: M 1911) 170 N. Franklin St., Hempstead, L. I., N. Y- HINNANT, Clarence H., Jr. (7 1938) Chief Engr., Hungerford Coal Co., 717 E. Grace St., and (for mail) R. F. D. No. 9. Box 156, Richmond, va. HINRICHSEN. Arthur F. (Af 1928) Pres. & Treas. (for mail) A. F. Hinrichsen, Inc., 50 Church St.. New York, N. Y., and Mountain Lakes, N. J. HINTON. Robert P. (A 1938) Sales Engr. (for mail) Crane, Ltd., 95 Lombard SL, and 112 Balmoral St., Winnipeg. Man.. Canada. HIRSCH, Martin H. (Af 1938) Sales Engr., Hoffman Specialty Co., Inc., 500 Fifth Ave., and (for mail) 1478 Walton Ave., New York, N. Y. HIRSCHMAN, William F. (Af 1929) Pres, and Chief Engr., W. F. Hirschman Co., Inc-, 220 Delaware Ave., and (for mail) 165 Le Brun Circle, Buffalo, N. Y. HITCHCOCK. Paul C.* (Af 1931) Vice-Pres. (for mail) Burlingame, Hitchcock & Estabrook, Inc., 521 Sexton Bldg., and 5130 Harriet Ave., Minne apolis, Minn. HITT, John C. (A 1936) Branch Mgr. (for mail) Holland Furnace Co., 34-17th St., and 301 Valley View Ave., Wheeling, W. Va. HOBBIE, Edward H. (A 1937) Mgr. Sale3 Pro motion 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) Vice-Pres., Dia mond Alkali Co., Painesville, O. HOBBS. William S. (A 1936) (for mail) Wm. S. Hobbs, P. O. Box 269, and 327 Park Ave., Swarthmore, Pa. HOCHMAN, Eugene (5 1938) 286 Chestnut St., Chelsea. Mass. HOCKENSMITH, Francis E. (Af 1936) Chief Engr. (for mail) Lennox Furnace Co., Inc., 400 N. Midler Ave., and 124 Ludington St., Syracuse, N. Y. HODGE, William B. (Af 1934) Vice-Pres. & Engr. (for mail) Parks-Cramer Co., P. O. Box 1234, and 301 Hawthorne Lane. Charlotte, N. C. HOEHL, Edward R. (7 1935) Sales Engr. (for mail) Long Island Air Conditioning Co., Inc., 544 Franklin Ave., and 821 Franklin Ave., Garden City, L. N. Y. HOEY, James K. (A 1938) Pres.-Mgr. (Regis tered Mech. Engr.) (for mail) Crater Meta) & Engineering, Inc., 142 N. Front St., and 119 Lincoln SL, Medford, Ore. HOFFBERGER, John P. (A 1938) Merchandising, Electrical Corp., 6400 Plymouth, and (for mail) 5838 Enright, St. Louis. Mo. ' HOFFMAN, Angelo (A 1938) Vice-Pres. (for mail) Louis Hoffman Co.. 117 W. Pittsburgh Ave., and 4850 N. Oakland Ave.. Milwaukee, Wis. HOFFMAN, Charles S. (Af 1924) Pres, (for mail) Baker Smith 8c Co., Inc., 576 Greenwich St., and 108 East 38tb St., New York, N. Y. HOGAN, Edward L.* (Af 1911) General Con sulting 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. Heating Ventilating Air Conditioning Guide 1939 HOLLAND, George R. (5 1938) Asst- Chemist, American Sugar Refining Co., 49 S. 2nd St., and (for mail) 19 East 98th St., New York, N. Y. 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; J 1931) Owner (for mail) Hollister's, 31 Ridge St., and 115 Grant Ave.t Glens Falls, N. Y. . HOLLISTER. Norman A.* (Af 1933) 7101 Colo nial 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. SL, N. E., and 4525 Fessendon St., N. w., Washington, D. C. HOLMES, Richard E. (A 1938; J 1934) Air Cond. Design Engr., Westinghouse Elec. & Mfg. Co., . E. Springfield, and (for mail) 258 Redlands St., Springfield, Mass. HOLT, James (Af 1933) Assoc. Prof, of Mech. Engrg. (for mail) Massachusetts Institute of Technology, Cambridge, and 1062 Massachusetts Ave , Lexington. Mass. HOLT, Walter H. (J 1938) Engr. (for mail) Buffalo Forge Co., 490 Broadway, and 149 Highland Ave., Buffalo, N. Y. HOLUBA, Henry J. ([J 1938) Sales Engr. (for mail) A-J Manufacturing Co., 2119 Washington St., and 501 W. 31st., Kansas City, Mo. HOLYFIELD, Earl F. (A 1937) Air Cond. Engr.. Oklahoma Electrical Supply, and (for mail) 121 E. Park Ave., Oklahoma City, Okla. HOMAN, John D. (Af 1938) Chief Elec. Engr., Amalgamated Phosphate Co., P. O. Box 172, Brewster, Fla. . HONERKAMP, Fritz (Af 1937) Chief Engr. (for mail) Anemostat Corp. of America, 10 East 39th St., New York, and 67-12 50th Ave., Wood- side, L. I., N. Y. HOOK, Frank W. (Af 1937) Branch Mgr. (for mail) Johnson Service Co., 814 Rialto Bldg., 2363 Larkin St., San Francisco, Calif. HOPPE, Albert A. (M 1935) Design and Appli cation Engr., Carrier Corp,, 213 West 1st St., and (for mail) 1941 N. W. 17th St., Oklahoma City, Okla. HOPPE, Marcel F. (Af 1938) Consulting Engr. (for`mail) 1621 Connecticut Ave., N. W., Wash ington, D. C., and P. O. B. 531, Falls Church, Va. HOPPER, Garnet H. (Ai 1923) Engr., Taylor- Forbes, Ltd., 1088 King St., W., and (for mail) 19 Brummell Ave., Toronto, Ont., Canada. HOPPER, John S. (Af 1938) Instructor. Texas A. &. M. College, Mech. Engrg. Dept., College Station, Tex. HOPSON, William T. {Life Member; M 1915) The Hopson & Chapin Mfg. Co., New London, Conn. HORNER, Samuel D. (J 1937) c/o Irrawaddy Flotilla Co., Ltd., Sales Dept., 510 Merchant St., Rangoon, Burma, India.' HORNUNG, J. C. (Af 1914) 854 Bluff St., Glencoe, 111. HOSHALL, Robert Houston (M 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., Pacific Steel Boiler Corp., 101 Park Ave., New York, and 208 Madison Rd., Scarsdale, N. Y. HOSTERMAN, Charles O. (Af 1924) Supt., The McMurrer Co., 303 Congress St.. Boston,' and (for mail) 25 Bateswell Rd., Dorchester, Mass. . HOTCHKISS, Charles H. B. (Af 1927) Editor, Heating and Ventilating, 148 Lafayette St., New York, N. Y. HOTOP, Herbert C. (A 1938) Vice-Pres. and Mgr., Fred J. Hotop & Co., 315 N. Church St., Kalamazoo, Mich. HOUGHTEN, Ferry CL* (Af 1921) Dir. (for mail) Research Lab., A.S.H.V.E., 4800 Forbes St., and 1136 Murrayhill Ave., Pittsburgh, Pa. IIOULLS, Louis >. (if 1935) Chief Engr., Master Baker Ovens, and (for mail) 655 Pedretti Rd., West Price Hill, Cincinnati, O. HOULISTON, G. Baillie (A 1928) Secy, (for main The W. C. Green Co., 704 Race St!. Cindanali O., and 33 Tremont Ave., Fort Thomas Ky ^ HOUSKA, Arthur D. (J 1937) Sales EngrVffor mail) Clowe & Cowan, Inc., and 1417 Hani/ St.. Amarillo, Tex. 800 HOWARD, Fenton L. (Af 1937) Chief Engr. (for mail) Refrigeration & Air Conditioning Inst. 2150 Lawrence Ave., and 6619 N. Rockwell R* * Chicago, 111- * HOWATT, John* (Af 1915) (Presidential Member) . (Pres., 1935; 1st Vice-Pres., 1934; 2nd Vice-Pres 1933; Council, 1927-1936) Chief Engr. (for main Board of Education, 228 N. LaSalle St.. aJ 4940 East End Ave., Chicago, 111. HOWE, Willis W. (Af 1936; A 1917) Sales Engr Pacific Gas & Electric Co., and (for mail) 68 Central Ave., Sausaiito, Calif. HOWELL, Lloyd (Af 1915) Engr., Industrial Dept, (for mail) Peoples Gas Light and Coke Co 122 S. Michigan Ave., and 7605 Yates Ave.' Chicago, 111. ' HOWLETT, Ira G. (Af 1935; S 1934) Consulting Engr. (for mail) I. G. Howlett Co., 120 E. Main St., and 2123 N. Fonshill Ave., Oklahoma Citv Okla. ' HOYT, Charles W. (A 1931) Pres.-Treas. (for mail) Wolverine Equipment 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) Consulting Engr. (for mail) 1406 Railway Exchange, Chicago, and 710 Bonnie Brae, River Forest, 111. HUBBARD. Nelson B. (Af 1919) Partner, Hub bard & Wagschal, Engineers, 243 Congress St., W., and (for mail) 2985 Blaine Ave., Detroit, Mich. HUBBUCH, Nicholas J., Jr. (S 1939) Student (for mail) University of Dayton, Dayton, O., and ' 510 Breckenridge Lane, Louisville, Ky. . HUBER, Enrique (Af 1938) Mech. Engr., BucaroU No. 128, P. O. Box 10633, Mexico, D, F- HUCH, A. J. (Af 1919) Secy. & Treas. (formail) . Central Supply Co., 312 S. 3rd St., and 4037 Harriet Ave., Minneapolis, Minn. % HUCKER, Joseph H. (Af 1921) Partner. Hucker- ' Pryibil Co., 1700 Walnut St., Philadelphia, anc( (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, O. HUDSON, Robert A. (Af 1934) Partner (for mail) Hunter & Hudson, Consulting Engrs., 41 Sutter St., Room 710, San Francisco, and Route 2,- Box 51, Cordilleras Rd., Redwood City, Calif. HUFF, James M. (Af 1936) Air Cond. Engr. (for mail) Kribs & Landauer, Inc., 404 Dallas Gas Bldg., and 839 N. Bishop, Apt. 4, Dallas, Tex. HUGHES, Harold R. (A 1938) Mgr., Fuel Oil Div. (for mail) McColl Frontenac Oil Co., Ltd., 1010 St. Catherine St., W., and 4396 Mayfair , Ave., Montreal, P. Q., Canada. HUGHES, L. K. (J 1936) Vice-Pres. in Charge of Sales, Howard Air Conditioning, Ltd., 881 Yonge St., and (for mail) 43 Rivercourt Blvd., Toronto, Ont.. Canada. - HUGHES, William U. (Af 1936) Pres, (for mail)"' ' The Lewis-Brown Co., Ltd., 1411 Crescent St., Room 206, and 1610 Sherbrooke St., West., Apt,. 36, Montreal, P. Q., Canada. HUGHEY, Thomas M. (A 1935) Sales Engr. (for * mail) Westerlin & Campbell Co., 906 North 4th-. St., and 2350 North 58tb St., Milwaukee, Wis. HUGHSON, Harry H. (Af 1927) Sales Engr. (for mail) The Coon-DeVisser Co., 2051 W. Lafayette St., Detroit, and 58 Florence Ave., Highland Park, 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) Research Engr. (for mail) Frigidaire Div. of General Motors Corp., and 1454 Glendale Ave., Dayton, O. Roll of Membership HUMMEL, George W. (Af 1937) Field Engr. (for . mail) The Trane Co., Drawer 679, and 327 E. McDowell Rd., Phoenix, Ariz. HUMPHREY, Dwight E. (Af 1921) Htg. & Vtg. Engr., Goodyear Tire & Rubber Co., Akron, and (for mail) 2499 Six St., Cuyahoga Falls, O. HUMPHREY. Leonard G., Jr. (J 1938) Engr. (for mail) Buffalo Forge Co., 490 Broadway, and 261 Crestwood Ave., Buffalo, N. Y. HUMPHREYS, Clark M. (Af 1931) (Council, 1938) Asst. Prof, of Mech. Engrg. (for mail) Carnegie Instituteof Technology, Schenley Park, and 1934 Remington Dr., Pittsburgh, Pa. HUNGER, Robert F. (Af 1927) Associate Dist. Mgr. (for mail) Davidson & Hunger, 220 South 16th St., Philadelphia, and 100 Avon Rd., Nar- berth, Pa. ." HUNGERFORD, Leo (Af 1930) Sales Mgr., Utility Fan Corp., 2528 Santa Fe Ave., and (for mail) 900 N. Stanley Ave., Los Angeles, Calif. HUNT, MacDonald (A 1936) Mfrs. Agent (for mail) McDonnell Miller Co., 12 W. Madison St., and Windsor Court Apts., Baltimore, Md. HUNT, Noel P. (Af 1934) Managing Director . (for mail) Catyier Australasia, Ltd., 41-49 Forbes St., and 52 Lang Rd., Centennial Park, Sydney, ILLIG, Ernest E. (J 1938) Sales. Engr., Walter R. Illig, 1 Cushing St., and (for mail) 242 Blossom St., Fitchburg, Mass. ILLIG, Walter R. (Af 1935; A 1927) Owner, Heating .Plumbing, Air Conditioning, 1 Cushing St., and (for mail) 242 Blossom SL, Fitchburg, Mass. INGALLS, Frederick D. B. (Af 1906) Consulting Htg. and Air Cond. Engr., 1 Hopkins St., Reading, Mass. INGELS, Margaret* (Af 1923; J 1918) Mech. Engr. (for mail) Carrier Corp., and 412 University Place, Syracuse, N. Y. IRWIN, Robert R. (7 1937) Air Cond. Engr. (for mail) York Ice Machinery Corp., Mayo Building. - and 811 North Rockford St., Tulsa; Okla. ISETT, William M. (A 1936) Pres., (for mail) C. B. lsett & Son, Inc., 3035 N. Rockwell St., and 4236 N. Drake Ave., Chicago, 111. dTSSERTELLE, Henry G.* {Life Member; Af 1913; A 1912) Consulting Engineer, 31 Park Terrace W., Apt. A-8, New York, N. Y. : IVERSON, Henry R. (Af 1936) Co-Mgr. (for mail) The Trane Co., 1772 Columbia Rd., N. W., and 1601 Argonne Place, N. W., Washington, D. C. HUNTER,'Louis N. (Af 1936) Mgr. of Research (for mail) National Radiator Corp., 221 Central Ave.. and 839 Luzerne 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. (/ 1936; 5 1934) Engr., Zenith Gas System, Box 397, Alva, Okla. HUST, Carl E. (Af 1932) Supervisor Heating Engr. (for mail) Cincinnati Gas & Electric Co.. 4th & Main Sts., and 15 Mason St., Cincinnati, O. HUSTOEL, Arnold M. (A 1930) 2414 N. Kedzie Blvd., Chicago, III. ' HUTCHEON, Clifford R. (J 1938) Engr. (for mail) Anemostat Corp. of America, 10 E. 39th St., New York, and 3131-41st St., Astoria, L. I., N. Y. HUTCHINGS, Robert L. (J 1937) Hughes Heating & Air Conditioning Co., 125 N. Jefferson St., Dayton, O. HUTCHINS, William H. (Af 1934) Chief Engr.. Delco Appliance Div., General Motors Corp., , and (for mail) 88 Magee St., Rochester, N. Y. HUTCHINSON, Frank W. (A 1937) 114 Engi neering Bldg,, University of California, Berkeley, Calif. HUTZEL, Hugo F. (Af 1918) Air Cond. Appli cations Dept., Kelvinator Corp., and (for mail) 2635 Woodstock Dr., Detroit, Mich. HUYBERT, Leslie E., Jr. (J 1938) Draftsman, . U. S. Naval Operating Base, and (for mail) 604 Carolina Ave., Norfolk, Va. HVOSLEF, Frederick W. (Af 1931; A 1921) Heating Research Engr. (for mail) Kohler Co., and 523 Audubon Rd.. Kohler, Wis. HYDE, Elmer H. (A 1937) Tech. Repr., Koppers Co., Tar & Chemical Div., 501 Flannery Bldg., and (for mail) 442 Sulgrave Rd., Pittsburgh (11) Pa. . HYDE, Eric F. (Af 1937) Consulting Engr., 512 Free Press Bldg., Detroit, and (for mail) 708 Oakland Ave., Birmingham, Mich. HYMAN, Wallace M. (Af 1920) Pres, (for'mail) Reis & O'Donovan, Inc., 12 W, 2lst St., and 23 W. 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. I IB1SON, James L. (J 1938) Sales Engr., Ralph 8. Johnson & Co., 201 Petroleum Bldg., Houston, Tex. ICKERINCILL, John C. (Af 1923) Sales Engr., Spencer Heater Co., 2020 N. Broad St.; and (for mail) 477 Flamingo, St., Roxborough, Phita-. delphia. Pa. , .. JACKES, Herman D. (Af 1915) Consulting Engr., . 1 Clinton Rd., Glen Ridge, N. J. JACKSON, Charles H. (Af 1923) Vice-Pres. (for mail) Blower Application Co., 918 N. Fourth St., and 2706 N. Farwell Ave., Milwaukee, Wis. JACKSON, Gilbert R. (Af 1938) Mgr., Boiler & Radiator Dept, (for mail) Crane Ltd., 45-51 Leman St., London, E. 1., and 174 Chiltem Court, Baker St., London, N. W. 1, England. JACKSON, MarsballS. (Af 1919) Repr. (formail) Powers Regulator Co., 250 Delaware Ave., and 108 Larchmont Rd., Buffalo, N. Y. JACOBSEN, K. C: S. (A 1939) Sales Repr., Imperial Electric Co., and (for mail) 309 South 22nd St., Philadelphia, Pa. JACOBUS, Dr. David S. {Life Member; Af 1916) Advisory Engr. (for mail) The Babcock & Wilcox Co., 85 Liberty St., New York, N. Y., and 93 Harrison Ave., Montclair, N. J. JAKOBY, Albert C. (A 1938) Estimator & De signer, Sears Roebuck & Co., Dept. 405, 4640 Roosevelt Blvd., and (for mail) 1913 E. Clearfield St., Philadelphia, Pa. JALONACK, Irwin G. (A 1933; 5 1930) Chief Engr. (for mail) Alfred L. Hart, Inc., 315 Vander bilt Ave., Brooklyn, and 62-30 Saunders St., Rego Park, N. Y. JAMES, Hamilton R. (M 1931) Service Equip. Engr., United Engineers & Constructors, Inc., 1401 Arch St., Philadelphia, and (for mail) 55 W. Drexet Ave., Lansdowne, Pa. JAMES, John W * (Af 1937; J 1933) Tech. Secy., American Society of Heating & Ventilating Engineers, 51 Madison Ave., New York, N. Y. JAMES, Richard E. (Af 1936) Mgr., Htg. Dept.. Harry Cooper Supply Co., and (for mail) 597 E. Elm St., Springfield, Mo. JANET, Harry L. (Af 1920) Mech. Engr., Buensod- Stacey Air Cond., 60 East 42nd St., New York, and (for mail) 688 Decatur St., Brooklyn, N. Y. JARCHO, Martin D. (J 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. JARDINE, William H., Jr. (A 1938) Pres, (for mail) Iona Ventilator Co., Inc., 2821-29 W. Dauphin St., and 3552 Shelmire St., Philadelphia, Pa. . * JEHLE, Ferdinand (Af 1938; A 1937) Dir. of Research Labs, (for mail) Hoffman Specialty Co., Inc., 575 Pacific St., Stamford, and New Canaan, Conn. - JELINKK, Frank R. (/ 1937) Sales Engr. (for mail) Johnson Service Co., 2505 Commerce St., Dallas, and 1214 Banks St.. Houston, Tex.' 33 m Heating Ventilating Air Conditioning Guide 1939 JENKINS, Frank H. (S 1938) Student Engr. (for JOHNSTON, Robert McC. (7 1937) Instructor - mail) Buffalo Forge Co., 490 Broadway, and 149 Highland St., Buffalo, N. Y. JENNEY, Hugh B. (A 1933) General Sales Mgr., Dominion Radiator and Boiler Co., Ltd., Cor. Royce and Lansdowne Aves., Toronto, Ont., Dept, of Mech. Engrg., Virginia Polytechnic Institute (for mail) Box 548 and 707 Main St Blacksburg, Va. JOHNSTON, Rodney M. (A 1938) Steam & Gas Htg. Sales (for mail) New York State Elec. & Canada. JENNINGS, Hal K. (Af 1937) Dist. Mgr., Avery Gas Corp., 115-117 Main St., and 274 Geneses St., Lockport, N. Y. Engineering Co., 1023 Chamber of Commerce JOHNSTON, William H. (Af 1924) 306 East 26th Bldg., and (for mail) 3748 Middle Brook Ave., Cincinnati, O. JENNINGS, Irving C. (Af 1924) Pres, (for mail) Nash Engineering Co., and 138 Flax Hill Rd., South Norwalk, Conn. JENNINGS, Richard A. (A 1937) Chief Engr. (for mail) Keith Massachusetts Corp., 539 Washing ton St., and -695 Atlantic Ave., Boston, Mass. JENNINGS. Stanley A. (Af 1935) Chief Drafts- " . St., New York, N. Y. JONES, Alfred (Af 1928) Chief Consulting Engr. (for mail) Armstrong Cork Co., Box 540, and 402 N. President Ave., Lancaster, Pa. JONES, Alfred L. (Af 1926) Plbg. & Htg. Con tractor (for mail) Alfred L. Jones, 431 Greenwich Ave., Greenwich, and Box 121, Riverside, Conn JONES, Allan T. (Af 1937 ; 7 1935) Mech. Engr! (for mail) S. A. Armstrong; Ltd., 720 Bathurst man, Trane Co. of Canada, Ltd., 439 King St., St., and 325 Kingswood Rd., Toronto, Ont., W., and (for mail) 80 Glen Manor Drive, Toronto, Ont., Canada. JENNINGS, W. G. (A 1930) Resident Vice-Pres. (for mail) Minneapolis-HoneywelJ Regulator Co., 797 Beacon St., Boston, and 20 Chapel St., Canada. - 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 Brookline, Mass. JENNINS, Henry H. (Life Member; M 1901) 15 Grange View, Chapeltown Rd., Leeds, England. Co., Siloam Springs, Ark. . JONES, David J. (Af 1936) Control Engr., Vapor Car Heating Co., Inc., Railway Exchange Bldg., JENSON, Jean S. (Af 1912) Consulting Engr. (for Chicago, and (for mail) 391 Poplar Ave., Elm- mail) 431 S. Dearborn St., and 1634 West 106th St., Chicago, 111. JESSUP, Benjamin H. (Af 1937) Pres, (for mail) Richards & Jessup Co., Inc., 615 Main St., hurst. III. JONES, Edwin (Af 1933 ; 7 1924) Engr. and Estimator (for mail) Watt Plumbing, `Heating & Supply Co., 608 S. Cincinnati, and 1436 East 17th Stamford, and 48 Field St., Glenbrook, Conn. JEX, John, Jr. (A 1936) Sales Engr. (for mail) The Mercoid Corp., 1035 Cathedral St., Balti more, and Earleville. Cedi Co., 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., 861 Delaware Ave., Buffalo, and (for mail) 74 Fruehauf Ave., Snyder, N. Y. JOHNS, Harold B * (Af 1928; 7 1927) (for mail) Peoples Gas Light & Coke Co., 122 S. Michigan Place. Tulsa, Okla. JONES, Edwin A. (Af 1919) Chief Engr. (for fcail) L. J. Mueller Furnace Co., 2005 W. Oklahoma Ave., 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, Hubert L. (A 1938). Zone Engr, DelcoFrigidaire Cond. Div., General Motors, Sales Corp., and (for mail) 519 W. Norman Ave., Ave., Chicago, and 543 N. Elmwood Ave., Oak Park. 111. JOHNSON, Allen J.* (Af 1935) Dir. Anthradte Industries Laboratory, Primes, Delaware Co., Pa. JOHNSON, Carl W. (Af 1912) Pres.. C. W. Johnson, Inc., 211 N. Desplaines St,, 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, P.Q., Canada. JOHNSON, Edward B. (Af 1919) Sales Engr., Staten Island Supply Co., Inc., 1390 Richmond Terrace, and (for mail) 154 Wardwell Ave., Port Dayton, O. JONES, John P. (Af 1937) Pres, (for mail) John Paul Jones, Cary and Millar, 448 Terminal ' Tower, Cleveland, and 3161 Scarborough Rd., Cleveland Heights, O. .' JONES, Sprague (Af 1936) Pres, (for mail) Sprague Jones, Inc., 1116 Madison Ave., and 3769 S. Lockwood Ave., Toledo, O. JONES, WilliamT. (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., Newtonville, Mass. ' Richmond, S. I., N. Y. . JORDAN, Richard C-* (7 1935; S 1933) Instruc JOHNSON, Helge S. (A 1933; 7 1927) Dist. Mgr. tor (for mail) University of Minnesota, Engrg. (for mail) Buffalo Forge Co.. 611 Standard Bldg., Experiment Station, Room 209, and 805 Beacon 112 State St., and 20 Fleetwood Ave., Albany, St., S. E., Minneapolis, Minn. N. Y. JOSEPHSON, Simon (7 1936) Supervising Engr.. JOHNSON, Leslie O. (Af 1938; 7 1930) Sales Astor Plumbing & Heating Corp., 1134 Bedford Engr., H. Y. Keeler Co., 910 Hines Bldg., and Ave., Brooklyn, N. Y. (for mail) 2520 First Ave., Huntington, W. Va. JOYCE, Harry B. (Af 1922) Consulting Engr. JOHNSON, Oliver W. (Af 1937) Engrg. Dept., (for mail) Harry B. Joyce, Registered Engineer, Standard Oil Co. of Calif., 225 Bush St., San 616 Commerce Bldg., and 501 Liberty St., Frandsco, and (for mail) 1831 Waverly St., Palo ' Erie, Pa. Alto, Calif. JUNG, John S. (M1930; A 1923) Owner, Heating, JOHNSON, Robert F. (7 1938) Sales Engr. (for Piping & Air Conditioning (for mail) 2409 W. mail) Howard E, Melton, Inc., 207 N. W. 10th St., and 105 N. E. 7th St., Oklahoma City, Okla. JOHNSON. Tracy R. (Af 1924) Branch Mgr. (for mail) The Trane Co., Hubbell Bldg., and 3438 University Ave., Des Moines, la. JOHNSON, Wayne G. (7 1937; 5 1936) Mech. Engr., Herman Nelson Corp., and (for mail) . 810 20th Ave., Moline. III. JOHNSTON, J. Ambler (M 1912) Partner (for. mail) Carneal, Johnston & Wright, Atlantic Life Greenfield Ave., and 1516 S. Layton Blvd., Milwaukee, Wis. ' JUNGBLUTH, Ernest N. (A 1938) Sales and Estimating Engr., Linde Canadian Refrigeration Co., and (for mail) 5891 Sherbrooke St., W., Montreal, P. Q., Canada. * JUNKER, William H. (Af 1936) Plant Engr., Emery Industries, Inc., 4300 Carew Tower, and (for mail) 6068 Drydeo Ave.. Cincinnati. O. * Bldg., and 2616 Hanover Ave., Richmond, Va. JOHNSTON, Robert E, (Af 1929; A 1926) Pres, (for mail) R. E. Johnston Co., Ltd., 1070 Homer St., and 3342 W. 33rd Ave., Vancouver, B. CM Canada. KACZENSKI, Chester (J 1933) 315 N. Spruce St., Winston-Salem, N. C. 34 Roll or Membership KADEL, George B. (7 1938) Engr., E. R. Squibb & Sons, 25 Columbia Hts., and (for mail) 237 Garfield Place, Brooklyn, N. Y. . KAERCHER, C. M. H. (Af 1937) Managing Dir. KELBLE, Frank R. (Af 1928) Vice-Pres. & Mgr. (for mail) Huffman-Wolfe Co. of Philadelphia. 4660 N. lSth St., Philadelphia, and 305 Pleasant Ave., Glenside, Pa. (for mail) Central Bureau for Heating & Air Conditioning, 3030 Euclid Ave., Cleveland, and 2560 Ashurst Rd., University Heights, O. KAIN, Edward M. (J 1937; S 1936) Draftsman, Babcock & Wilcox Co., Stirling Ave., Barberton, and (for mail) 3656 East 146th St., Cleveland, O. KAISER, Charles W. (7 1938) Installation Engr., Powers Regulator Co., 231 E. 46th St., New.York, and (for mail) 37-35-57th St., Woodside, L. I., N. Y. KAISER, Fred (Af 1935) Dist. Mgr., MinneapolisHoneywell Regulator Co., 45. Allen St-,-and-(for - - - mait)~48l Stanri Ave., Buffalo, N. Y. KAJUK, Andrew E. (Af 1936) Engr., 6907 Theota Ave., Parma, O. KALINSKY, Alex G. (7 1936; S 1934) Htg. Engr. (for mail) Fox Furnace Div. of American Radi ator Co., and Y. M. C. A., Elyria, O. 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. KELLER, George A. (A 1938) Asst, to Supt. of Engrg. & Maintenance, Abraham & Straus. 422 Fulton St.. Brooklyn, and (for mail) P. O. Box 481. Wantagh, L. I., N. Y. KELLEY, James J. (A 1924) (for mail) Colonial Beacon Oil Co., 378 Stuart St., Boston, and 142 Governors Ave., Medford, Mass. KELLEY, Robert D. (Af 1937) Pres, (for mail) Sunbeam Heating & Air Conditioning Co., 346 Peachtree Street, N. E., and 668 Elmwood Drive, Atlanta, Ga. __ __ _____ - KELLOGG, Alfred (Life Member; M 1916) (Council, 1920-1921; 1923-1924) Consulting Engr., 6 Hawthorne St.. Belmont, Mass. KELLOGG, Winston T. (A 1938) Engr. and Secy.-Treas. (for mail) Kelbur Air Conditioning Co., P. O. Box 27, and 1920 Beechwood Rd., Little Rock. Ark. KELLY, Charles J. (Af 1931) Agent (for mail) James P. Marsh Corp., 155 East 44th St., New York, N. Y., and 440 Fairmount Ave, Jersey City, N. J. Engr., Airtemp 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.-Treas. (for mail) Camden Heating Co., Wilson Blvd. and Waldorf Ave., Camden, and 347 W. Kings Highway, Haddonfield, N. J, KARAKASH, Theodore J. (7 1936) Head Engr. (for mail) Air Cond. Branch, G. &. A. Baker Co., P. O. Box 468, and Engin Apt., Feruzaga, 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). Mgr., The James Stewart Mfg. Co., Ltd., and (for mail) 37 Perry St., Woodstock, Ont., Canada. KELLY, John G. (A 1919) Pres., John G. Kelly, Inc., 210 East 45th St., New York, and (for mail) 374 Park Ave.. Yonkers, N. Y. KELLY, Wtibur 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) Sales 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) Vtg. Engr., 112 Dixie Highway, South Fort Mitchell. Ky. KENNEY, Thomas W. (M 1937) Pres.. Kelly & Kenney, Inc., 551 Fifth Ave., New York, and (for KARLSON, Alfred F. (Af 1918) Chief Engr. (for mail) 31 W. John St., Hicksville, N- Y. mail) Parks-Cramer Co., 970 Main St., Fitch KENT, Laurence F, (A 1927; 7 1924) Pres, (for burg, and 186 Prospect St., North Leominster, Mass. mail) Moncrief Furnace Co., P. O. Box 1673, and 1515 Momingside Drive, N. E., Atlanta. Ga. KARLSTEEN, Gustav H. (Af 1935) Plant Engr., KENT, Richard L. (M 1936) Dist. Mgr. (for mail) Dunlop Tire & Rubber Corp., Buffalo, and (for Trane Co. of Canada, Ltd., 138 Portage Ave., mail) Box 55, Route 1. Tonawanda, N. Y. East, and 104 Wellington Crescent, Winnipeg, KARTOR1E, V. T. (7 1935; S 1933) Sales Engr. Man, Canada. (for mail) York Ice Machinery Corp., and 1513 KEPLER, Donald A. (7 1936; 5 1934) Vtg. Engr.. Third Ave., York, Pa. New York Stock Exchange Bldg. Co., 20 Broad KAUFMAN, Hiram J. (Af 1937) Htg.-Vtg. Engr., Commonwealth & Southern Corp., Consumers St., New York, N. Y., and (for mail) 30 Maple wood Ave., Maplewood, N. J. Power Bldg., Jackson, and (for mall) 13215 KERN, Joseph F., Jr. (A 1937) Asst. Editor, Roselawn Ave., Detroit, Mich. Heating & Ventilating, 148 Lafayette St., New - KAUP, Edgar O. (Af 1937) Chief Engr.. Air Cond. Div., W. R. Ames Co., 150 Hooper St., San Francisco, and (for mail) 1129 Curtis St., Albany, Calif. KAWASE, Sumlo (Af 1936) Chief Htg. Engr., Eizen Juhin Kyoku-Manchoukuo, and (for mail) 614 Suchikodo, Hsinking, Manchoukoo. York, and (for mail) 88-24-166th St., Jamaica, L. I., N. Y. KERN, Raymond T. (Af 1927) Chief Engr., Jennison Co., 17 Putnam St., Fitchburg, and fror mail) 51 Claflin St., Leominster, Mass. KERR, William E. (Af 1937) Sales Repr.. Barnes & Jones. Inc. (of Boston, Mass.) College Place, Columbia. S. C- KEARNEY, Joseph S. (Af 1939) Vice-Pres.. Northwestern Heating & Plumbing Co., 1465 Sherman Ave., and (for mail) 1202 Main St., Evanston, 111. 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. KEATING. Arthur J. (Af 1937) Sales Engr., KESSLER, Clarence F. (Af 1938) Asst. Prof. Powers Regulator Co., 2720 N. Greenview Ave., Mech. Engrg. (for mail) University of Michigan, and (for mail) 4429 W. Congress St., Chicago, 111. 241 W. Engineering Bldg., and 1756 Broadway, KEELAND, Burdette W. (A 1938) Vice-Pres. (for Ann Arbor, Mich. mail) Rollosson-Keeland Co., 3714 Main, and KESSLER, Jacob (Af 1936) Pres, (for mail) 2723 Kipling, Houston, Tex. . Jacler Heating Co., Inc., 3810 Third Ave., and KEENEY, Frank P. (A 1915) Pres, (for mail) Keeney Publishing Co., 6 N. Michigan Ave., and ,2115 Ryer Ave., New York, N. Y. KESSLER, Maurice E. (Af 1937) Mgr., Pioneer ' 7059 South Shore Drive, Chicago, 111. Heating-Cooling Co., 901 Niagara St., and (for KEHM, Horace S. (Af 1928) Pres, (for mail) Kehm Bros. Co. & Stevens-Root Co., 51 E. Grand Ave., and 3000 Sheridan Rd., Chicago, III. KEITH, James P. (Af 1938) Consulting Engr., Vice-Pres., Canadian Domestic Engineering Co., Ltd., 1440 St. Catherine St., W. and (for mail) 5196 Durocher Ave., Montreal, P. Q., Canada. mail) Falls Station, P. O. Box 664, Niagara Falls, N. Y. KETTER, Jack W. (7 1937) Design Engr., Krenz & Co., 5114 W. Center St., and (for mail) 3042 N. 2nd St., Milwaukee, Wis. KEYES, Robert E. (Af 1913) Chief Engr., Cooling & Air Cond. Div., B. F. Sturtevant Co., Hyde Park, Boston, Mass. Heating Ventilating Air Conditioning Guide 1939 KEYSER, Herman M. (A 1937) Sales Engr.. Murray W. Sales 8c Co.. Detroit, and (for mail) 10703 Hart Huntington Woods, Royal Oak, Mich. KICZALES, 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. KIDD, Charles R. (A 1938) Mgr., Commercial Kelvinator Dept., and (for mail) 611 N. W. 28th St., Oklahoma City, Okla. KIEFER, Carl J. (Af 1922) Vice-Pres. (for mail) Schenley Products Co., 607 Schmidt Bldg., and - 984 Lenox Place, Avondale, Cincinnati, O. KIEFER, E. J., Jr. (A 1932; 7 1928) Mgr., H. C. Archibald Co., 406 Main St., and (for mail) 108 N. 6th St., Stroudsburg. Pa. KIESLING, Justin A. (Af 1930) Pres, (for mail) . Robischung-Kiesling Contracting Corp., 4848 Main St., and 1602 Stuart St., Houston, Tex. KILDAY, John A. (A 1938) Salesman, The Bimel Co., 305 Walnut, and (for mail) 23 Cal houn St., Cincinnati, O. KILLIAN, Thomas J. (A 1937) Htg. Contractor, 118 Belvidere St., Waukegan, 111. KILLIAN, Vic. J. (A 1937) Pres, (for mail) V. J. Killian Co., 907 Linden Ave., and 1348 Edgewood Lane, Winnetka, 111. KILLOUGH, Robert E. (A 1938) Engr., Standard Oil Co. of Pennsylvania, 1618 N. Broad St,, and (for mail) 2108 E. Chelten Ave., Germantown, Philadelphia, Pa. KILNER, John S. (Af 1929) Sales Engr. (for mail) Clarage Fan Co., 7310 Woodward Ave., and 1091 Seminole Ave., Detroit, Mich. KILPATRICK, William S. (Af 1923) Partner, W. & Kilpatrick '& Co., 1100 East 33rd St., Los Angeles, Calif. KIMBALL, Charles W. (M 1915) Treas. (for mail) Richard D. Kimball Co.,.6 Beacon St., Boston,, and 65 Prescott St., West Medford, Mass. 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 York, N. Y. KIMBLE, Carl W. (J 1938) Mgr. Htg. Dept., A. Y. McDonald Mfg. Co.. 929 S. W. 9th St., and (for mail) 3125 S. W. 13th St. Place, Des Moines, la. K1MMEL, Walter G. {J 1937) Sales Engr., York . Ice Machinery Corp., 25 S. George St., York, Pa. KIMMELL, Phillip M. (7 1936) Melchior Arm strong, Dessau & Co., 2709 Penn Ave., and (for mail) 691 Washington Rd., Pittsburgh, Pa. KINCAIDE, Merrill C. (A 1937; J 1936) Air Cond. Engr. (for mail) Timken Silent Automatic Div., 100 Clark Ave., and 1160 Seward Ave., Detroit, Mich. KINDORF, Harry L. {M 1937) Owner, The Kindorf Co., 46 Oakwood St., San Francisco, Calif. . KINDORF, Orlan (A 1938) Vice-Pres. and Mgr. (for mail) General Air Conditioning Co., .1313 J St., and 3433 N St., Sacramento, Calif. KING, Arthur C. (M 1936) .Consulting Engr., 35 S. Dearborn SL, Chicago, 111. KING, Harry K. (A 1937) Dist. Mgr., Tube- Turns, Inc., 224 East Broadway, Louisville, Ky., and (for mail) 10356 Morrow Circle S., Dearborn, Mich. . KING, Lon D. (A 1937) Air Cond. and Htg, (for mail) Sidles Co., ASrtemp Div.; 425 Stuart Bldg., and 2325 R SL, Lincoln, Nebr. KING, Roy L. (7 1936; 5 1933) Air Cond. Engr., Mayflower-Lewis Corp., Duluth & E. 7th St., . St. Paul, and (for mail) 2538 Clinton Ave., S\ . Minneapolis, Minn. KINGSLAND, George D. (M 1935) Vice-Pres. (for mail) Minneapolis-Honeywell Regulator Co., 2747 4th Ave., S., and 2036 Queen Ave., S., Minneapolis, Minn. KINGSWELL, William E. (Af 1935) Pres, (for mail) William E. Kingswell, Inc., 3707 Georgia j-Ave., N. W., and 2739 Macomb St., N. W., Washington, D. C. KINNEY, Aldon M. (M 1936) Pres, (for mail) A. M. Kinney, Inc-, Consulting Engineers. icon Carew Tower, and 3812 Beech St., Mariemont Cincinnati, O. ' KIPE, J. Morgan (M 1919) Dir. of Education Anthracite Merchandising School, Primos, and (for mail) 801 Homestead Ave., Beechwood! Del Co., Pa. *' KIPP, Theodore (Af 1937) Pres., Kipp-Kelly/Ltd 68 Higgins Ave., and (for mail) 1030 Wellington Crescent, Winnipeg, Man., Canada. KIRKBRIDE, J. Owen (Af 1938) Engr. (for mail) Parent & Kirkbride, 1715 Ritteahouse St Philadelphia, Pa., and 1121 Eldridge Ave., W Collingswood, N. J. ` KIRKENDALL, Horton J. (A 1938) Salesman Shamblen Furnace Parts Co., 23l-39-lst Ave ' and (for mail) 291 Catalpa PI., Pittsburgh (16) KIRKPATRICK, Arthur H. (Af 1935; 7 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, Shigeyuki (Af 1918) 191 Gotanda 6 Chome, Shanagawa-ku, Tokyo, Japan. ' KITCHEN, Francis A. (A 1927; 7 1923) Pres, (for mail) American Warming & Ventilating Co., 1514 Prospect Ave., and 2077 Campus Rd.', Cleveland, O. ' . KITCHEN, John H. (Life Member; Af 1906) Ptes. & Mgr. (for mail) John H. Kitchen & Co., 1016 Baltimore Ave., and 5015 Westwood Terrace, Kansas City, Mo. ' KITCHEN, William H. J. (A 1938) Chief Engr., Bermuda-Trading Co., Reid St., and (for mail) P. O. 271, Hamilton, Bermuda. . KLEIN, Albert R. (Af 1920) Managing Dir. (for mail) Lufttechnische Gesellschaft, Konigstrasse 84, and Heidehofstrasse 40, Stuttgart, Germany. KLEIN, Edward W. (Af 1917) Dist. Repr. (for mail) Warren Webster & Co., 152 Nassau^SL, N. W., and 456 Peachtree Battle Ave., Atlanta, Ga. . ' KLEINKAUF, Henry (Af 1938; 7 1937) Branch Mgr. (for mail) Natkin & Co., 18th & Howard Sts., and 6312 Florence Blvd., Omaha, Nebr. *, KLENERT, William (A 1938) Htg. Expert. Davis & Warshow, Inc., 75 Ludlow St.,. New York, and (for mail) 45-50-159th St., Flushing, L. I., N. Y. . KLIE, Walter (Af 1915) Pres, (for mail) The Smith & Oby Co.. 6107 Carnegie Ave., Cleveland, and 18411 S. Woodland Ave., Shaker Heights, O. KLUGE, Burnett M. (7 1938) Sales Engr., Bayley Blower Co.. Milwaukee, and (for mail) 1926 St. Clair St., Racine, Wis. KNAB, Edward A. (Af 1930; A 1927) Prop., E. A. Knab, Htg. Contractor, 4823 N. Bartlett Ave., Milwaukee, Wis. KNAPP, Andrew E. (Af 1937) Engr. (for mail) Nash-Kelvinator, 14250 Plymouth Rd., and 8059 Sorrento, Detroit, Mich. KNAPP, Donald S. (A 1936) Branch Mgr. (for mail) Chamberlin Metal Weather Strip Co., Inc., 2400 Hennepin Ave., and 4607 Wooddale Ave., - Minneapolis, Minn. . KNAPP, Joseph H, (Af 1936) Designing Htg.-Vtg. - Equip., Utica Products Corp., and (for mail) 111 Lowell Ave., Utica, N. Y. . KNEPPER, H. H. (A 1938) Erection' Engr., Minneapolis-Honeywell Regulator Co., 378 Saun- ders-Kennedy Bldg.. Omaha. Nebr., and (for mail) 122 Gold St.. Kendallville, Ind. . KNIBB, Alfred E. (Af 1930) Htg. Engr. (for mail) . L. L. McConachie Co., 1003 Maryland Ave., and 9333 E. Jefferson Ave.. Detroit, Mich. . KNOWLES, Elwln L. (A 1937) Prop: (for mail) Marshall Heating Co., 2921 Stevens Ave., and 36 Oliver Ave., S., Minneapolis. Minn. KNOWLES, Frank R. (A 1937) Dir. Commercial Engrg. Dept., Pennsylvania Etectric Co., 53o Vine St., Johnstown, Pa. 36 Roll of Membership KNOWLES, Mahlon G. (M 1935) Instructor. Wentworth Institute, 550 Huntington Ave., Boston, and (for mail) 255 Burrill St., Swamp- scott, Mass. . KNOX, James R. (Af 1930) Consulting Engr. (for mail) 26 Commercial St., and 9 Union St., Dundee, Angus, Scotland. KNOX, John C. (A 1938) Secy.-Treas., Waterloo Register Co., Waterloo, la. KNUDSEN, William R. (Af 1937) Zone Mgr., Carrier Corp., 408 Chrysler Bldg., New York, and (for mail) 3427 89th St., Jackson Heights, L. L, N. Y. KOCH, Albert H. (Af 1938) Branch Mgr., Minne apolis-Honeywell Regulator Co., 101 Marietta St. Bldg., and (for mail) 2440 Peachtree Rd., Atlanta, Ga. KOCH, Arthur C. (A 1938) Mgr., A. C. Koch & * Co., 704 Anita St., Houston, Tex. KOCH, Richard G. (A 1935) Househeating Engr. (for mail) Milwaukee Gas Light Co., 626 E. Wis consin Ave., and 734 N. 34th St., Milwaukee, Wis. KOEHLER, C. Stewart (A 1936) Salesman. Minneapolis - Honeywell Regulator Co., 801 Second Ave., and (for mail) 4374 Richardson Ave., New York, N. Y. KOFOED, V. Beckwith (A 1937) Owner (for mail) Fox Furnace Co., 6505 Euclid Ave., Cleveland, and Jaskson & Giles Rd., Chagrin Falls, O. KOHLER, Walter J., Jr. (A 1933) Secy, (for mail) Kohler Co., and "Windway," Kohler, Wis. KOLB, Fred W. (M 1938) Dist. Sales Repr. (for mail) American Air Filter Co., 598 Monadnock Bldg., and 82 Macondray St., San Francisco, Calif. KONZO. Seichi* (Af 1937; A 1936; 7 1932) Special Research Asst., Prof. Mech. Engrg., University of Illinois, Engrg. Experiment Station, 102 Mech. Engrg. Laboratory, and (for mail) 1108 West Stoughton St., Ubrana, 111. KOOISTRA. John F. (Af 1933) Sales Engr. (for mail).Carrier Corp., Room701,625 Market St., San Francisco, and 1245 Laguna St., Burlingame, Calif. KORN, Charles B. (Af 1922) 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 S. A., Ltd., Box 2421, and 258 Florida Rd., Durban, Union of South Africa. KOTZEBUE, Robert W. (A 1937) Mgr. Air Cond. Dept, (for mail) Straus-Frank Co., 301 S. Flores, and 118 Carolina, San Antonio, Tex. KOZU, Tamiichiro (Af 1930) Chief Engr. (for mail) Japan Radiator Industrial Association, 506 Marunouchi Bldg., and 1701 Yonchome Shimoochiai, Yodobashiku, Tokyo, Japan. KRAMER, Conrad (7 1938) Air Cond. Engr., . 85 East Ave., and (for mail) 126 Broad St., Pawtucket, R. I. ' KRAMIG. Robert E., Jr. (A 1933) Vice-Pres.- Treas. (for mail) R. E. Kramig & Co., Inc., 222-4 ' E. 14th St., Cincinnati, and 115 Linden Drive, * Wyoming, O. KRAMINSKY, Victor (Af 1936) Managing Dir. (for mail) Air Conditioning & Engineering, Ltd., 123d, Victoria St., Westminster, London S. W. 1, and 18 Gloucester Place, Portman Sq.t London W. 1, England. KRATZ, Alonzo P. *(Af 1925) (Council, 1938) Research Prof, (for mail) Dept, of Mech. Engrg., University of Illinois, and 1003 Douglas St., Urbana, III. . KRAYENHOF, Harold G. (A 1937) 231 Dick- . enson Ave., Swarthmore, Pa. KRENZ, Alfred S. (Af 1937; A 1935) Pres.-Treas. (for mail) Krenz & Co., Inc., 5114 W. Center St., Milwaukee, and 1766 N. 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. (Af 1935) Pres., Kribs & Landauer, 200 Houseman Bldg., and (for mail) 4209 Shenandoah Ave.. Dallas, Tex. KRLEBEL, Arthur E. (Af 1920) Sales Engr. (for mail) Haynes Selling Co., Inc., 1124 Spring Garden St., Philadelphia, and Berwyn, Pa. KRINTZMAN, Harry (7 1938; S 1936) Air Cond. Engr. (for mail) Dubin & Co., 182 Ann St., Hartford, Conn., and 19 S. Lenox St., Worcester, KROEKER, J. Donald (Af 1936) Consulting Engr. (for mail) Columbia Engineering Co., 619 Failing Bldg., and 6831 N. E. Siskiyou St., Portland, Ore. KROEKER, Sanford P. (7 1938) Draftsman (for mail) Oklahoma Gas & Electric Co., 3rd & Harvey St., and 2426 S. W. 22nd, Oklahoma City, Okla. KRUEGER, James I. (Af 1921) Mfrs. Repr.. Illinois Engineering Co., and Whitlock Coil Pipe Co. (for mail) 357 Ninth St., and 1920 Sacra mento St., San Francisco, Calif. .- KRUSE, W. C,, Jr. (Af 1938) Repr. (for mail) American Air Filters Co., 24 Commerce SL, Newark, and 32 University Court, S. Orange, N. J. ' KUBASTA, Robert W. (7 1936) Sales Engr., Carrier Corp., Syracuse, N. Y., and (for mail) 1088 Summit Ave., Lakewood, O. KUCHER, Andrew A. (Af 1938) Mgr. Air Cond. Engrg., Frigidaire Div. (for mail) General Motors Sales Corp., Taylor St., and 210 Greenmount Blvd., Dayton, O. KUECHENBERG, William A. (Af 1937) Pres, (for mail) R. B. Hayward Co.,-1714 Sheffield Ave., Chicago, and 427 Elmore Ave., Park Ridge, III. KUEHN, Walter C. (A 1933) Keuhn Heating & Ventilating Co., 915 Seventh Ave., S., Minne apolis, Minn. KUEMPEL, Leon L. (Af 1936; 7 1929) Hughes Heating & Air Conditioning Co., 125 North Jefferson St., and (for mail) 927 Cumberland Ave., Dayton, O. KUGEL, H. Kenneth (Af 1938) Engr. (for mail) Div. of Smoke Regulation and Boiler Inspection, Government of the District of Columbia, District Bldg., and 3825 Morrison SL, N. W., Washing ton, D. C. KUHLMANN, Rudolf (Af 1928) Ameresco, Inc., 50 Church St., New York, N. Y. KUMMER, Calvin J. (7 1938) Engr. (for mail) Carrier Corp., 7-122 Merchandise Mart Bldg., and 4531 N. Ashland. Chicago, 111. KUNEN, Herbert (7 1938) Mech- Engr. (for mail) Anemostat Corp. of America, 10 East 39th SL, New York, and 1040 Dickens Ave.,.Far Rock- away, L. I., N. Y. KUNTZ, Edward C. (7 1937) Sales Engr., Ham- ' mond Sheet Metal Co., 119 Cass Ave., and (for mail) 4014 Loughborough Ave., St. Louis, Mo. KUNZOG, Theodore W. (Af 1939) Air Cond. Engr., Northern Air Conditioning Co., Newark, and (for mail) 134 Corbin Ave., Jersey City, N. J. KUREK, Ted C. (Af 1938) Mech. Engr., Henrici- Lowry Engineering Co., 114 West 10th St., Kansas City, and (for mail) R. F. D. No. 2, Liberty, Mo. KURTH, Frank J. (Af 1937) Tech. Dir. (for mail) Anemostat Corp. of America, 10 E. 39th St., and . 875 W. 181st St., New York, N. Y. KURTZ, Robert W. (7 1936) Air Cond. & Sales Engr. (for mail) Robischung-Kiesling Contracting Corp., 4848 Main StM and 3709 Montrose, Houston, Tex. KWAN, I. K. (Af 1933) Gen. Mgr., The China Engineering Co., 30 Brenan Rd., Shanghai, China. KYLE, W. J. (A 1935) Power Sales Engr. (for mail) Public Utility Engineering & Service Corp., 231' . S. LaSalle St., and 1239 Jarvis Ave., Chicago, 111. L LADD, David (Af 1938) Mgr., Philadelphia Branch (for mail) The Powers Regulator Co., ' 2240 N. Broad St., and 305 E. Wadsworth SL, Philadelphia, Pa. LAFFOLEY, Laurence H. (Af 1937: A 1936) Asst. Engr. of Bldgs, (for mail) Canadian Pacific Railway Co., Room 401, C. P. R. Windsor Station, and 4754 The Boulevard, Westmount, Montreal, P. Q., Canada. ' , ' 37 Heating Ventilating Air Conditioning Guide 1939 ''LAFONTAINE, Edmund A. (A 1936) Sales Mgr., Kelvinator of Canada, Ltd., 1632 St. Catherine . St., W,, and (for mail) 2382 Park Row West, LaRUE, Perry (Af 1938) Dir. of Bldgs, and Grounds (for mail) Independent School District 629 Third St., and 1321-43rd. Des Moines, la' LaSALVIA, James J. (Af 1930) Mech.- Engr.' Montreal. P. Q.. Canada. . LACODZINSK1, Harry J. (A 1927; J 1920) Sales Engr. (for mail) Ilg Electric Ventilating Co., 182 N. LaSalle St., Chicago, and Crystal Lake, 111. LAMBERT, Robert D. (Af 1936) Design Ea$r. (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 St., St. Lambert, P.Q., Canada. LANCE, Joseph F. (M 1923) Supt. (for mail) Harrigao & Reid Co., 1365 Bagley Ave., and 14816 Ashton; Detroit. Mich. ~................... ' LANDAU, Mltchel (Af 1937) Mgr., Heating & Air . Conditioning Depts., ABC Oil Burner & Engi neering Co., Inc., 2012-14 Chestnut St., and (for mail) 5965 Kemble Ave., Philadelphia, Pa. LANDAUER, Leo L. (Af 1937; J 1932) Member of Firm (for mail) Kribs & Landauer, 404 Dallas Gas Bldg., and 5707 Velasco, Dallas, Tex. LANDERS. John J. (Af 1930; J 1924) Mfrs. Repr, (for mail) 701 Crosby Bldg., Buffalo, and 120 Burroughs Drive, Snyder, N. Y. LANDES. Botes E. (M 1938) Meeb. Engr. (for mail) 915 Hubbell Bldg., and 1603-47th St., Des Moines, la. ' LANDES, Benjamin D. (A 1937) Mgr. Engrg. Service Dept., A. M. Byers Co., Clark Bldg., Pittsburgh, Pa. ' LANDES, Joseph M. (A 1938) Wholesale Mgr. (for mail) Controlled Air Corp., 3319 Olive St., . and 5754 Elward Ave.. St. Louis, Mo. LANDEWIT, Casimir J. (J 1937) 115-95 226th St., St. Albans, L. I., N. Y. LANE, D. Duffy (Af 1934) Secy., Frank O'Hara, Inc., 4Q-10-82nd St., Jackson Heights, and (for mail) 87-65-52nd Ave., Elmhurst, L. I., N. Y. LANG, Jacob (A 1933) Prop., Lang & Lang, 91-48 Lefferts Blvd., Richmond Hill, L. I.. N. Y. LANG,* J. Clifford (J 1937) Sales Engr., York Ice Machinery Corp., 117 S. 11th St.. St. Louis, Mo. LANGE, Fred F. (A 1934) Pres, (for mail) The Mechanical Service Co., 602 Pence Bldg., and 2896 James Ave., S., Minneapolis, Minn. LANGE, Robert T. (M 1936) Engr. (Test Dept.) HartzelJ Propeller Fan Co., Box 902, and (for mail) 1700 N. Broadway St.f Piqua, O. LANGENBERG, Everett B. (Af 1914) Owner (for mail) Langenberg Heating Co., 3800 West Pine Blvd., St. Louis, and 223 E. Adams St., Delco-Frigidaire Conditioning Div., and (for mail) 2250 Emerson Ave., Dayton, O- LASETER, Frank L. (Af 1938) Mgr., Heating Dept., Chief Engr. (for mail) Atlanta Gas Light Co., 243 Peachtree SL, and 1206 Peachtree St. Atlanta, Ga. '' LASKAR1S, Nicholas G. (S 1938) David Ranken Jr. School of Mech. Trades, 4437 Finney Ave., and (for mail) 759 Aubert Ave., St. Louis, Mo* LAUCKNER, Charles G., 3rd (J 1938) Jr. Engr.i General Electric Co., 920 Western Ave., and (for mail) 37 Porter St., Lynn, Mass. LAUER, Harold B. (Af 1930) Vice-Pres. (for mail) English & Lauer, Inc., 1978 S. Los Angeles St., and 1121 S. Hayworth Ave., Los Angeles, Calif. LAUER, Rodney F. (J 1936) Sales Engr., York Ice Machinery Corp., 1238 N. 44th St., Phila delphia. and (for mail) 236 Glentay Rd., Laos, downe. Pa. LAUFKETTER, Fred C. (Af 1936) Supt. & Chief Engr. (for mail) Jefferson Hotel, 12th & Locust Sts., and 7056 West Park Ave., St. Louis, Mo. LAUTERBACH, Henry. Jr. (Af 1935) Mech. Engr., In Charge of Contract Dept, (for mail). Carrier Corp., Merchandise Mart, and 6959 Merrill Ave., Chicago, 111. LAUTZ, Fritz A. (Af 1936) Dist. Engr.*; Nash- Kelvinator Corp., 605 Central Term. Bldg., St. Louis, and (for mail) 4513 Roanoke Pkwy., Kansas City, Mo. * LAWLOR, John J. (Af 1935) Mgr. Heating Div., The James Robertson Co., Ltd., 215 Spadina Ave., and (for mail) 35 Tennis Cres., Toronto, OnL, Canada. LAWRENCE, Floyd Dwight (A 1938) Sales Repr., Clarage Fan Co. (for mail) 500 Filth Ave., New York, and 34-31 8lst St., Jackson Heights, L. I., N. Y. LAWRENCE, Lewis F., Jr. (J 1938) Field Engr. (for mail) Minneapolis-Honeywell Regulator Co., 304-101 Marietta St., and 1208 Virginia' Ave'., N. E., Apt. 6, Atlanta, Ga. - LEACH, Leiand S. (J 1937) Asst. Chief Engr., Sidles Co., Airtemp Div., and (for mail) 502 South 19th St., Omaha, Nebr. ' LEBRUN, Paul (Af 1938) Sales Mgr., Chaudieres & Radiateurs `!Ideal" S.A. (for mail) 120, nie Neuve, and 151 Boulevard Brand Whitlock, Brussels, Belgium. LEDGETT, F. Donald (S 1936) 108 Clinton St., Toronto, Ont., Canada. LEE, James A. (A 1937) Southeastern Com Kirkwood, Mo. LANNING. E. K. (A 1927) Asst. Secy. & Sales Mgr. (for mail) Warren Webster & Co., Camden, and Clayton, N. J. LANOU, J. Ernest (M 1931) Mgr. (for mail) F. S. Lanou 8c Son, 90 St. Paxil St., and 43 Brookes Ave., Burlington, Vt. . LARKIN, Paul (A 1937) Service Mgr., Minne- apoIis-Honeywell Regulator Co., 378 Saunders- Kennedy Bldg., and (for mail) 4667 Pierce, Omaha, Nebr. ^ LaROCQUE, Paul E. (A 1937) Htg. Contractor, 88 D'Abraham Hill, Quebec, t*. Q., Canada. LaROI, George H., II (J 1936) Engrg. Corre spondent and Asst. Adv. Mgr. (for mail) McDon- neil & Miller, Room 1316, Wrigley Bldg., and 4443 N. Monitor Ave., Chicago, 111. LARSON, Carl W. (M 1936) Sales Engr., Barnes & Jones, Inc., Rm. 901, Industrial Trust Bldg., mercial Div. Mgr. Kelvinator Div., Nash-Kelvinator Corp., 1426 N. Charles St., and (for mail) 1208 Argonne Drive, Baltimore, Md. LEE, Robert T. (J 1937; S 1936) Mech. Engr., Eastman Kodak Co., 333 State St., and (for mail) ' 914 S. Goodman St., Rochester, N. Y. LEEK, Charles W. (Af 1938) Managing Director, ' Leek & Co., Ltd., 1111 Homer St., and (for mail) 4682 West 6th Ave., Vancouver, B. C., Canada. LEEK, Walter (Life Member; Af 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, P. Q., Canada. LECLER, Frederick W. (Af 1935; A 1933) Pres, (for mail) The Waterbury Co., 2754 Hennepin Ave., and 2919 Johnson St., N. E., Minneapolis, Providence, R. 1., and (for mail) 641 Hyde Park Ave., Roslindale, Mass. LARSON, Clifford P. (J 1936) (for mail) The Minn. LEHMAN, M. G. (A 1937) Owner (for mail) M. G. Lehman. 720 O St., and 2011 Worthington, Insulite Co., 205 W. Wacker Drive, and 30 W. x Lincoln, Nebr. . Chicago, Ave., Chicago. 111. LEHMANN, Matt (/ 1937) Engr.. Mech. & LARSON, Gustus L.* (Af 1923) (Presidential Elec. Consulting, 603 Architects Bldg*, and (for Member) (Pres., 1936; 1st Vice-Pres., 1935; 2nd mail) 1569 Midvale Ave., Westwood, Los Vice-Pres., 1934; Council, 1929-1937) Prof., Steam and Gas Engrg., and Chairman of Dept, of Mech. Engrg. (for mail) University of Wis Angeles, Calif. LEICHNITZ, Robert W. (J 1936) Asst. Mgr., Leichnizt Johnson Co., 14 E. A St., and (for mail) - consin, Mech. Engrg. Bldg., and 1213 Sweetbriar Rd., Shorewood Hills, Madison, Wis. 2506 W. Chestnut, Yakima, Wash. 38 Roll of Membership LEIGH, Robert L. (A 1938) Engr., Hart & Cooley - Mfg. Co., and (for mail) 78 E. 12th Sl, Holland, Mich. 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. (Af 1908) Pres, and Managing Dir. (for mail) The Arthur S. Leitch Co., Ltd., . -1123.Bay SL; and 421_Russell Hill Rd.7 Toronto, Ont., Canada. LELAND, Warren B. (Af 1929) Sales Engr. (for mail) The H. B. Smith Co., Inc., P. O. Box 1522, and 159 Sumner Ave., Springfield, Mass. LELAND, William E. (Af 1915) Consulting Engr. (for mail) Leiand & Haley, 58 Sutter SL, San Frandsco, 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 SL, Buffalo, N. Y. LENONE, Jose M. (Af 1919) Designing Engr. (for mail) Wilson & Co., Inc., 4100 S. Ashland Ave., and 1358 East 48th SL, Chicago. 111. LEONARD, Lorcan C. G. (J 1937) Deagner- Draftsman. Messrs. J. Jeffreys & Co., Ltd., SL Georges House, Waterloo Rd.,, London, S. E. 1, England, and (for mail) 265 Clontarf Rd., Dollymount, Dublin. Ireland. LEONHARD, Lee W. (Af 1936) Supvr., Eastman Kodak Co., and (for mail) 1075 Winona Blvd., Rochester, N. Y. LEOPOLD, Charles S. (Af 1934) Consulting Engr. (for mail) 213 S. Broad SL, Philadelphia, and and 7600 West Ave., Elkins Park, Pa. LESCH, Raymond T. (5 1938) Student, Mech. Engrg., University of Minnesota, and (for mail) 4107-41st Ave., S., Minneapolis, Minn. LESER, Fred A. (A 1937) Dist. Mgr. (for mail) llg Electric Ventilating Co., 608 Mills Bldg., and 4711 Chesapeake St., N. W., Washington, D. C. LEUPOLD, George L. (A 1937) Sales Engr.. Minneapolis-Honeywell Regulator Co., 561 Read ing Rd.. and (for mail) 1715 Stonybrook Drive, Cincinnati, O. ' LEUTHESSER, Fred W.t Jr. (Af 1937) Secy, (for mail) National Metal Products Corp., 21 N. Loomis SL, Chicago, and 1640 Wesley Ave., Berwyn. 111. LEVENTHAL, Bernard (J 1937; 5 1935) 3913 13th Ave., Brooklyn, N. Y. LEVY, Marion I. (Af 1938; A 1936; J 1931) Pres., Viking Air Cond: Corp., Main & Center Ste., and (for mail) 3156 Ludlow Rd., Cleveland, Q. LEWIS, Carroll E. (Af 1930) Sales Mgr., DelcoFrigidaire Conditioning Div., General Motors Sales Corp.. 300 Taylor St., and (for mail) 2724 Fairmont, Dayton, O. LEWIS, Clyde A. (J 1937) Htg.-Vtg. & Air CondEngr., A. Edward Johnson, Consulting Engr., 132 East 58th St., and (for mail) 23-27-28th St., Astoria, L. I., N. Y. LEWIS, George M. (Af 1937) Chief Engr. Penob scot Bldg.. Simon J. Murphy Co., 1366 Penobscot Bldg., and (for mail) 14414 Grandmont Rd., Detroit, Mich. LEWIS, H. Frederick (A 1937) Vice-Pres. (for mail) Dwight Oil Heat, 147 Dongan Ave., Albany, and Sweet's Crossing, Nassau, N. Y. LEWIS, J. C. (J 1938) Salesman (for mail) York Ice Machinery Corp., 5051 Santa Fe Ave., and 6327-A Middleton St., Los Angeles, Calif. LEWIS, Kenneth C. (A 1938) Engr., Electric Products Corp., 5624 Penn Ave., Pittsburgh, and (for mail) 224 Emerson Ave., AspinwaU, Pa. LEWIS, L. Logan* (Af 1918) Vice-Pres., Chief Engr. (for mail) Carrier Corp., 300 S. Geddes St., and 207 Sedgewick Drive, Syracuse, N. Y. LEWIS, Samuel R* (Af 1905) (Presidential. Member) (Pres., 1914; 2nd Vice-Pres., 1910; Board of Governors, 1909-1910-1912; Council, 1914-1915) Consulting Mech. Engr. (for mail) 407 S. Dearborn St., and 4737 Kimbark Ave., Chicago, 111. LEWIS, Thornton* (M 1919) (Presidential Mem ber) (Pres., 1929; 1st Vice-Pres., 1928; 2nd VicePres., 1927; Council, 1923-1930) Pres., Pulp Products Co., Inc., 60 East 42nd SL, New York, N. Y., and (for mail) Holiday Hill. R. D. No. 2, Newtown, Pa. LIBBY, Ralph S. (J 1933) Air Cond. Engr., Alco Air Conditioning Engineers, Ltd., (for mail) 1123 ' Bay St-, and 548 Huron St., Toronto, OnL, Canada.. __ ____ -- -- ---------- ----- ---- LICANDRO, James P. (J 1938) Air Cond. Engr., Carrier Corp., 300 S. Geddes SL, and (for mail) 464 Cortland Ave., Syracuse, N. Y. LICHTY, Charles P. (Af 1920) Mgr. (for mail) C. P. Lichty Engineering Co., 400H S. 2lst St., and 100 Devon Drive, Birmingham, Ala. LIEBRECHT, Walter J. (J 1936) Sales Engr. (for mail) American Radiator Co., Fourth and Charming Sts., N. E., and 3032 Rodman St., N. W., Washington, D. C. LIFSHITZ, Hymen (5 1939) Student. Carnegie Institute of Technology, and (for mail) 2902 Webster Ave.. Pittsburgh, Pa. LIGHT, John C. (A 1938) Branch Mgr. Clow Gasteam Heating Co., 1901 North West SL, Jackson, Miss. 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; J 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., 575 Pacific St., Stamford, and (for mail) Breakneck Hill, Middlebury, Conn. LINDBERG, Arthur F. (A 1937 \ J 1935; S 1933) Inspector, National Park Service, 300 Keeline Bldg., Omaha, Nebr. LINDSAY, Griffith W., Jr. (Af 1937) Chief Engr., Air Cond. and Automatic Heat DepL, Chicago Dist., Frigidaire Div., General Motors Sales Corp., 2031 S. Calumet Ave., and (for mail) 10440 S. Eberhart Ave., Chicago, 111. LINEBAUGH, John E. (Af 1937) Chief Engr.. Frigidaire, Ltd., Edgeware Rd., The Hyde, Hen don, London, N. W. 9, and (for mail) 93 Hodford Rd., Golders Green, N. W. 11, London, England. LINGEN, Ralph A. (J 1938) Dist. Mgr. (for mail) American Foundry & Furnace Co., 709 N. 11th St., and 600 N. 51st SL, Milwaukee. Wis. LINGO, Charles K. (A 1936; J 1935) Sales Engr.. Florida Power & Light Co., and (for mail) 2814 S. W. Fifth St., Miami, Fla. . LINN, Homer R. (Af 1914) Consulting Engr., 189 W. Madison Ave., Chicago, and (for mail) 321 S. Ashland Ave., LaGrange, 111. LINSENMEYER. Francis J. (Af 1935) Head, DepL Mech. Engrg. (for mail) University of Detroit, McNichoIs & Livernois, and 17375 Prairie Ave., Detroit, Mich. LINTON, John P. (Af 1927) Pres., Engineering Installations, Ltd., 1154 Beaver Hall Sq., and (for mail) 247 Brock Ave., N., Montreal, West, P. Q., Canada. LIPSCOMBE, Harold W. J. (Af 1938) Dir. Lipscombe Air Conditioning Co.. Ltd., Dacre House, Victoria St., London, S. W. 1, and (for mail) Glenmore, Woodland Way, West Wickham, Kent, England. LISKOW, John G. (A 1938) Chief Engr. (for mail) Claude B. Schneible Co., 3951 Lawrence Ave., and 1260 N. Dearborn St., Chicago, 111. LITTLE, David H. (J 1937) Engr., Boston Edison Co., 39 Boylston St., Boston, and (for mail) 27 Rangeley St., Dorchester, Mass. 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. Heating Ventilating Air Conditioning Guide 1939 L1VAR, Allen P. (Af 1935) Chief Engr. (for maU) ..Chrysler Corp., Airtemp Div., and 44 Ivanhoe Ave., Dayton, O. LLOYD, Edmund H. (7 1936) (for mail) Wash ington Refrigeration Co., 1733-14th St., N. W., and 26l4-39th St., N. W., Washington, D. C. LLOYD, Edward C. (Af 1927) Dir. of Tech. Service (for mail) Armstrong Cork Co., and R. D. 5, Lancaster, Pa. LOCKE, Robert A. (Af 1935) Mgr., Steel Heating Boiler Inst., and (for mail) 500 N. Union St., Middletown, Pa. LOCKHART, Charles W, (7* 1938) Student Engr. (for mail) Buffalo Forge Co., 490 Broadway, and 279 Lexington Ave.. Buffalo, N. Y. 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. LOCKWOOD, Glenn E. (A 1938) Sales Engr. (for mail) Howard E. Melton, Inc., 207 N. W. Tenth St., and 56th and Kelly, Oklahoma City, Okla. LOEFFLER, Frank X. (M 1914) Pres, (for mail) Loeffier-Greene Supply Co.. 1604 N. W. Fifth St., and 1811 N. W. Nineteenth St., Oklahoma City, Okla. LOFTE, John A. (,7 1936; 5 1933) Engr., Pflugradt Co., 215 W. Kilbourn Ave., and (for mail) 3117 W. Highland Blvd., Milwaukee, Wis. LOH, Nan-Shee (Af 1933; A 1931; 7 1927) Mgr., New Shanghai Heating & Plumbing Co., Room 330, National Commercial Bank Bldg., 400 - Kiangse Rd., Shanghai, China. LONG, Herbert P. (Af 1938) Sales Engr. (for mail) Buffalo Forge Co., 490 Broadway, Buffalo, and 336 Stillwell Ave., Kenmore, N. Y. LONG, Wayne E. (Af 1935) Assoc. Prof, of Mech. Engrg., Texas Agricultural & Mechanical College, College Station, Tex. LONGCOY, Grant B. (Af 1933) Engr., Joseph . Breslove, Consulting Engr., 1101 Hippodrome Bldg., Cleveland, and (for mail) 1215 Ramona Ave., Lakewood, O. LONGWELL, James Cooper (S 1937) Student (for mail) Massachusetts Institute of Technology, 400 Memorial Drive, Cambridge, Mass., and 330 Second Ave., Westmont, Johnstown. Pa. LOO, Ping Yok (Af 1933) Gen. Mgr. (for mail) China Engineering Co., 30 Brenan Rd., Shanghai, and 271-73 Dumbarton Rd., Tientsin, China. Lo PICCOLO, Anthony A. (7 1938) Engr., 301 Covert St., Brooklyn, N. Y. LORE, Henry E. (7 1938) Sales Engr., Dravo Corp., Carrier Dept., 300 Penn Ave., Pittsburgh, and (for mail) 311 Chestnut St., Sewickley, Pa. LOUCKS, David W. (A 1930) Supvr., Commercial Electric & Steam Sales (for mail) Duquesne Light Co., 435 Sixth Ave., and 535 Shelbourne Ave. (WilkinsDurg) Pittsburgh, Pa. LOUGHRAN, Patrick H., Jr. (71937) Lab. Engr., 'Washington Gas Light Co., 411-10th St., N. W., and (for mail) 4513-49th St., 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, WUUam H. (7 1936) Laboratory Supvr., Washington Gas Light Co., 411-10th St., N. W.. and (for mail) 3901 Fulton St., N. W., Washington, D. C. LOWE, Robert A. (7 1938) Asst. Engr., Diamond Power Specialty Corp., 10340 Oakland Ave., and (for mail) 20436 Briarcliff Rd., Detroit, Mich. LOWE, Walter (S 1938) Service Man, Peoples Natural Gas Co., 545 Wm. Penn Way, and (for mail) 214 Millbridge St., Pittsburgh, Pa. LOWER, Henry C. (A 1937) Sales Engr., Account Executive, J. J. Gibbons, Ltd., 259 Bay St., Toronto 2, and (for mail) 649 Lakeshore Rd., Toronto 14, Ont., Canada. LOWNSBERY, Benjamin F. (M 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 & Woodward St., Reading and Reiffton, Pa. ' LUCRE, Charles E. (M 1924)Stevens Prof, of Mech. Engrg., Columbia University, and Con sulting Engr., Babcock & Wilcox Co., 85 Liberty St., and (for mail) Pupin Laboratories Bldg Columbia University,New York, N. Y. *' LUDERS. Richard H. (7 1937; 5 1936) Research Engr., Quaker Oats Research Laboratory, 345 E - 25tb St., and (for mail) 2410 N. Kilbourn Ave.' Chicago, 111. '' LUND, Clarence E. (M 1936; 7 1935; 5 1933) Research Engr., University of Minnesota Engrg. Exper. Sta., 108 Experimental Bldg., and (for mail) 48l7-12th Ave., S., Minneapolis, Minn LUTY, Donald J. (Af 1933) Asst. Gen. Mgr.' Air Conditioning Div., Gar Wood Industries' Inc., 7924 Riopelle St., and (for mail) 13661 Cloverlawn Ave., Detroit, Mich. LYCAN, Larb K. (A 1937) 4801 Leavenworth St., Omaha, Nebr. . LYKE, Henry W. (Af 1938) Engr. (for mail) Peter Smith Heater Co., 6209 Hamilton Ave., and 7359 Byron Ave., Detroit, Mich. * . 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) 865 Hueston St., Union, N.'J LYNCH, William L. (M 1928) Pres, (for mail) Rome-Turney Radiator Co., and 1413 N. George St., Rome, N. Y. LYNN, Frederick E. (Af 1938) Chief Engr., Electric Products Corp., 5624 Penn Ave., Pitts burgh, and (for mail) 312 Moyhend St., Spring dale, Pa. LYNN, Richard G. (7 1938) Htg. & Air Cond. Engr., Frigidaire Div., General Motors Sales Corp., 2446 University Ave., and (for*- mail) . 2284 Highland Pkwy., St. Paul, Minn. ' ` LYON, P. S. (Af 1929) Pres, and Gen.- Mgr. (for . mail) Cochrane Corp., 17th St. below Allegheny - ' Ave., and 3416 Warden Drive, Philadelphia, Pa. ' LYONS, Cornelius J. (A 1932) Sales Engr. (for . mail) Nash Engineering Co., Wilson Ave., and * 5 Olmstead Pl., South Norwalk, Conn. . M MABLEY, Louis C. (Af 1937) Salesman (for mail) Surface Combustion Corp., 2375 Dorr St., and 2129 Collingwood Ave., Toledo. O. . MACCUBBIN, Howard A. (Af 1934) Buyer, Montgomery Ward & Co., Chicago, and (for mail) 2135 Ridge Ave., Evanston, 111. MACDONALD, Donald B. (Af 1930) Sales Engr., Donald B. Macdonald Co.,| 101 E. Walnut St.f Kingston, Pa. . MacDONALD, Douglas J. (Af 1935) Vice-Pres. (for mail) Dominion Radiator & Boiler Co., Ltd., Royce & Lansdowne Ave., and 96 Hudson Drive, Toronto, Ont., Canada. .' MacEACHIN, Graham C. (Af 1938) Dist. Engr., Frigidaire Div., General Motors Sales Corp., Air Conditioning Dept., 2615 West 7th St., and (for mail) 4613 El Campo Ave., Fort Worth. Tex. MACHEN, James T. (A 1938 : 7 1934) Chicago Branch Mgr. (for mail) The Ric-wiL Co., Ill W. Monroe St., and 420 Diversey Pkwy., Chicago, ^ 111. MACHIN, Donald W. (7 1935) Fuel Engr., The Pittsburgh & Midway Coal Mining Co., 816 Dwight Bldg., Kansas City, Mo., and (for mail) 2112 Vermont St., Lawrence, Kan. .. MACK, Emil H. (A 1938) Asst. Sales Mgr., The VilterMfg. Co., 2217 S. First St., and (for mail) 2225 N. Booth St., Milwaukee, Wis. MACK, Ludwig (Af 1935) Dist. Mgr., Cooling & Air Cond. Div., B. F. Sturtevant Co., Cresmont 6 Haddon Aves., Camden. N. J., and (for mail) ' 246 W. Upsal St., Germantown, Philadelphia, Pa. ' 40 Roll of Membership MacLACHLAN, Victor D. (7 1938) Sales Engr. (for mail) Minneapolis-Honeywell Regulator Co., 637 Craig St., W., and 495 Prince Arthur, Apt. 16, Montreal, P. Q., Canada. . MacMILLAN, Alexander R. (Af 1936) Mgr., Educational Dept., Delco-Frigidaire Conditioning Div., General Motors Sales Corp., and (for mail) 130 Beverly Place, Dayton, O. MACRAE, Robert B. (7 1935) Air Cond. Engr., E. J. Nell Co., Manila, P. I. MACROW, Lawrence (7 1936) Branch Engr., Carrier Corp., 1201 Statler Bldg., Boston, and (for mail) 27 Arborough Rd., Roslindale, Mass. MacWATT, Donald A. (Af 1938) Sales Engr., Powers Regulator Co., 231 East 46th St., New York, and (for mail) 4611-25$th St., Great Neck, L. I., N. Y. MADDEN, John J. (A 1937) Owner (for mail) The Madden Co., 339 Warren St., Roxbury, and 16 Brown Ave., Roslindale, Mass. MADDUX, O. Lloyd (Af 1935; A 1933) Owner, O. Lloyd Maddux, 53 Park Place, New York, N. Y., and (for mail) 95 Washington St., East Orange, N. J. MADELY, Frederick J. (A 1936) Chief Estimator, Eastern Steel Products, Ltd., 1335 Delorimier Ave-. and (for mail) 6370 Louis-Hemon St., Montreal, P. Q., Canada. MADISON, Richard D. (Af 1926) Research Engr. (for mail) Buffalo Forge Co., 490 Broadway, Buffalo, and 218 Brantwood Rd., Snyder, N. Y. MALONE, James S. (A 1936) Dist. Repr. (for mail) Hoffman Specialty Co., 411 N. Tenth St., and 7124 Waterman Ave., St. Louis, Mo. MALVIN, Ray C. (Af 1929) Pres, (for mail) Malvin & May, Inc., 2427 S. Michigan Ave., and 8220 Dante Ave., Chicago, 111. MANDELL, Thomas P. (A 1937) Salesman, Carrier Corp., 1201 Statler Office Bldg., Boston, and (for mail) Walnut Rd., South Hamilton, Mass. ' MANN, Arthur R. (Af 1930) Partner (for mail) Mann & Co., Archts., 902 Wiley Bldg,, and 122 W. 15th St., Hutchinson, Kan. MANNING, Charles E. (7 1937) Sales Engr., Refrig.-and Air Cond., c/o Bond & Bond, Ltd., Auckland, New Zealand. MANNING, Walter M. (Af 1930) Traveling Engr., Baker Mfg. Co., Omaha, and (for mail) P. O. Box 112, Clarks, Nebr. MANNY, J. Harvey (A 1936) Vice-Pres- & Secy, (for mail) Robinson Furnace Co., 213 W. Hub bard St., and 5950 Midway Park, Chicago, 111. MARCHIO, Emilio, Jr. (S 1938) 212 S. Monroe, Kansas City, Mo. MARCONETT, Vernon G. (A 1936) Engr. & Factory Supt., The Farquhar Furnace Co., and (for mail) Wilmington, O. MARIN, Axel* (Af 1935) Assoc. Prof. Mech. Engrg. (for mail) University of Michigan, 241 W. Engineering Bldg., and P. O. Box 175, Ann Arbor, Mich. MAE.HLING. Leon S. (Af 1932) Supt., Equitable MARKLAND, Charles E. (Af 1939) Mech. Engr. Gas Co., 6304 Penn Ave., and (for mail) 414 Sulgrave Rd., Pittsburgh, Pa. MAGEE, Kevin B. (A 1938) Air Cond. Engr,, (for mail) 110 Power Plant, University of Illinois, Urbana, and 408 N. Prairie, Champaign, III. P. R. Moses & Associates, 11 Park Place, and MARKS. Alexander A. (A 1930) Chief Engr., if 'fr ;*/ (for mail) 2308 Newtown Ave., Astoria, L. I., N. Y. MaGIRL, Willis J. (Af 1934; A 1931; 7 1927) Chief Engr. (for mail) P. H. MaGirl Foundry & Furnace Works, 401-13 E. Oakland Ave., and 108 Warner Ave., Bloomington, III. MAGNUSSON, Nicholas (A 1938) EstimatorDesigner, Montgomery Ward & Co., 150-15 Richmond Radiator Co., and (for mail) 818 Fayette Title & Trust Bldg., Uniontown, Pa. MARKUSH, Emery U. (Af 1931) Consulting Engr. (for mail) 225 East 21st St., New York, and 8442-85th Rd., Woodhaven, L. I., N. Y. MAROTTA, John A. (S 1936) 11116 Tuscora Ave., Cleveland, O. X Jamaica Ave., and (for mail) 138-05 Linden Blvd-. Jamaica, L. L, N. Y. MAHER, Thomas F., Jr. (A 1937) Salesman. Kewanee Boiler Corp., 37 West 39th St., New York, and (for mail) 116-48 218th St., St. Albans, L. I.. N. Y. MAHON, B. B. (Af 1935) Principal of School of MARRINER, John M. S. (M 1934) Vice-Pres. (for mail) Taylor Engineering & Construction Co., Ltd., 80 Richmond St., W., and 111M Balsam Ave., Toronto, Ont., Canada. MARSCHALL, Peter J. (Af 1930; 7 1927) Engr., Kroeschell Engineering Co., 215 W. Ontario St., and (for mail) 6434 N. Seeley Ave., Chicago, 111. '$ Air Cond. (for mail) International Correspond ence Schools, Wyoming Ave., and 433 Fig St., Scranton, Pa. MARSHALL, Albert W. (Af 1937) Asst. Supt. & Resident Engr., Soho Public Baths, 2410 Fifth Ave., Pittsburgh, Pa. MAHON, Clarence A. (A 1938) Pres.-Mgr. (for mail) Air Control Equipment Co., 1712 Main St., and 6123 Kenwood Ave.; Kansas City, Mo. MAHON, Frank B. (Af 1937) Air Cond. Pro MARSHALL, Alexander G. (A 1936) Sales Engr. (for mail) Trane Co. of Canada, Ltd., 660 St. Catherine St.. W., and 2353 Wellington St.*, Montreal. P. Q., Canada. I -i motion, Duquesne Light Co., 435 Sixth Ave., and (for main 1241 Illinois Ave., Pittsburgh, Pa. MAHONEY, David.J. (Af 1930; A 1926) Branch MARSHALL. Orville D. (A 1931) Mfrs. Agent (for mail) 514 Anderson Bldg., and 1350 Calvin Ave., Grand Rapids, Mich. Mgr. (for mail) Johnson Service Co., 503 Franklin St., and 140 Linwood Ave., Buffalo, N. Y. MAIER, George M. (Af 1921) Asst, to Vice-Pres. MARSHALL, R. Douglas (A 1938) Partner, Delavan Engineering Co., 414 12th St., and (for mail) 2719 Moyer Ave., Des Moines, la. . and Gen. Mgr. of Mfg. (for mail) American Radiator Co., 8007 Jos Campau, Detroit, Mich. MAIER, Herman F. (Af 1926) Chief Engr.-Secy., The New York Blower Co., 3155 Shields Ave., and (for mail) 7124 S. Morgan St., Chicago, III. MA1LLARD, Albert L. (Af 1934) Consulting Engr., 3740 Washington St., Kansas City. Mo. MAKIN, Henry T., Jr. (Af 1939) Engr., H. B. MARSHALL, Stanley C. (Af 1939) Chief Engr., Mayflower-Lewis Corp., Duluth Ave. & East 7tb St., St. Paul, and (for mail) Oak Grove Hotel, Minneapolis, Minn. - MARSHALL, Thomas A. (7 1937) Sales Engr., York Ice Machinery Corp., 1275 Folsom St., San Francisco, Calif. Smith Co., 2209 Chestnut St., and (for mail) MARSHALL, William D. (Af 1935) Branch Mgr. 48 W. Gowen Ave., Philadelphia, Pa. (for mail) Noland Co., Inc., 1823 N. Arlington MALCOLM, Bernard L. (7 1937) Sales Engr. (for Ridge Rd., and 1307 N. Wakefield St., Arlington, ar- mail) Sidles Co., Alrtemp Div., 502 South 19th, and 4960 Military Ave., Apt. 7, Omaha, Nebr. Va. MARSTON, Anson D.* (A 1937) Industrial Engr., MALLIS, William (Af 1914) Owner (for mail) 330 . In Charge of Air Cond. (for mail) Kansas City Lyon Bldg., and 723 Federal Ave., Seattle, Wash. Power & Light Co., 1330 Baltimore, and 4943 MALLY, Chester F. (A 1938) General Mgr., Central, Kansas City, Mo. Mally & Co., 307 Stormfeltz Loveley. Bldg., Detroit, and (for mail) 2034 Central Ave., Ferndale, Mich. . MARTEL, Charles L., Jr. (7 1937) Pres., Martel Heating Co., 13534 Cedargrove Ave., Detroit, Mich. - MALONE, Daylc C. (Af 1929; A 1925) Vice-Pres. - (for mail) Petroleum Heat and Power Co., . 1725 S. Michigan Ave., and 7337 Merrill Ave.; Chicago, 111. MARTENS, Edward D. (Af 1937) Mech. Engr. (for mail) Thompson Starrett. Co., Inc., 444 Madison Ave., New York, and 89 Eldridge Ave., Hempstead, L. I., N. Y. 41 Heating Ventilating Air Conditioning Guide 1939 MARTIN, Albert B. (Af 1917> Chicago Branch Mgr. (for mail) Kewanee Boiler Corp., 1858 S. Western Ave., Chicago, and 997 Vine St-, Winnetka, 111. MARTIN, George W* (Af 1911) Supervising 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., H. L. Peiler & Co., Ltd., 620 Cathcart St., Montreal, P. Q., Canada. MARTIN, Raymond (A 1937) Sales Engr. (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., The Mexican Light & Power Co., Ltd... Gante 20. and (for mail) Paseo de la Reforma 183, Mexico, D. F., Mexico. MARTINKA, Paul D. (7 1937; S 1934) 13703 Chautauqua Ave., Cleveland, O. MARTOCELLO. Joseph A. (Af 1934) Pres., Jos. A. Martocello & Co., 229 North 13th SL, Phila delphia, Pa. MARTY, Edgar O. (Af 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 Brothers, Inc., 911 Camp St., and 5306 Ridgedale St., Dallas, Tex. MARZOLF, Frank X. (A 1937) Sales Engr.. Minneapolis-Honeyweii RegulatorCo., 415 Brainard St., and (for mail) 15046 Mettetal, Detroit, Mich. MARZORATI, Giuseppe (Af 1938) Consulting Engr., S-i.N.C. (for mail) Giacomo Jucker, 28 Mauro Macchi, and Via Baldissera 9, Milano, Italy. MASON, Gail C. (Af 1939; A 1937) Air Cond. Engr. (for mail) The Williamson Heater Co., 337 W. Fifth St., and Hotel Sinton,. Cincinnati, O. MASTERS, Robert B. (A 1938) Inspector. Pacific Greyhound Lines, 401 Kansas St., San Francisco, and (for mail) General Delivery, Oakland, Calif. MATCHETT, James C. (Af 1923) Vice-Pres. and Gen. Mgr. (for mail) Illinois Engineering Co., Racine Ave. and 21st St., and 9936 South Win chester Ave., Chicago, 111. MATHER. Harry H. (A 1929) Industrial Pro motion (for mail) Philadelphia Electric Co.. 1000 Chestnut SL, Philadelphia, and 373 Lakeview Ave., Drexel Hill, Pa. MATHEWSON, Marvin E. (Af 1937) Secy, (for mail) A. M. Kinney, Inc., 1820 Carew Tower, and 2156 Alpine Place, Cincinnati. O. MATHIS, Eugene* (Af 1922) Vice-Pres. & Treas. (for mail) The New York Blower Co., 32nd Street & Shields Ave., and 9151 S. Hoyne Ave., Chicago, III. MATHIS, Henry (Af 1921) New York Blower Co., 32nd St. and Shields Ave., and (for mail) 10317 Oakley Ave., Chicago, 111. MATHIS, John (A 1938) Engr., Standard Furnace & Supply Co., 407 South 10th SL, and (for mail) 109 South 42nd St., Omaha,'Nebr. MATHIS, Julian W. (A 1921) New York Blower Co., 32nd and Shields Ave., Chicago, 111. MATHISON, Russell S. (A 1938) Asst. Gen. Mgr. (for mail) Weathermakera (Canada) Ltd., 593 Adelaide SL, W., and 44 Strathgowan Ave., "Toronto, OnL, Canada. ` MATOUSEK, A. G. (Af 1937) Air Cond. Engr., York Ice Machinery Corp., 117 S. 11th St., and (for mail) 1528 Locust St., St. Louis, Mo. MATTHEWS, John E. (Af 1934) Dist. Mgr.. B. F. Sturtevant Co., 1106 Commerce Bldg., and (for mail) 5642 Lydia St., Kansas City, Mo. MATTHEWS, Wesley M. (J 1937) Sales Engr., Sidle9 Co., Airtemp Div., 425 Stuart Bldg., Lincoln, and (for mau) P. O. Box 685, Scottsbluff, Nebr. MATZ, George N. (Af 1938) Mech. Engr., A. Ernest D'Ambly, 901 Architects Bldg., Phila delphia, and (for mail) 649 Feme Ave., Drexel Hill, Pa. MAUTSCH, Robert (A 1928) Engr., Managing Dir., Compagnie Beige dea Freins Westinghouse 97 Avenue Louise, Brussels, Belgium. ' MAWBY, Pensyl (Af 1934) Dist. Sales Mgr Lehigh Navigation Coal Co., 1421 Chestnut St*' Philadelphia, and (for mail) 15 Golf Rd., Lans-' downe. Pa. MAXWELL, George W. (Af 1935; S 1932) Engr Kenealy & Maxwell, Main St., and (for mail) Lower County Rd., Harwich Port, Maas. MAXWELL, Robert S. (Af 1937) Gen. Mgr. (for mail) Bennett & Wright, Ltd., 72 Queen SL, E and 560 Briar Hill Ave., Toronto, OnL, Canada* MAY, Arthur O. (A 1938; / 1928) Sales En^r! (for mail) Stannard Power Equipment Co., 53 W. Jackson Blvd., and 5736 N. Bernard SL. Chicago 111.__ .... _________ ___ ______________________ . MAY, Clarence W. (Af 1933) Consulting Engr. (for mail) 1201 Smith Tower, and 6056 4th, N. E. Seattle, Wash. - *' MAY, Edward M. (Af 1931) Branch Mgr., Steel Products Engineering Co.; 1601 S. Michigan Ave., Chicago, and (for mail) 848 N. RidgeJand Ave., Oak Park, 111. MAY, George E. (Af 1933) Utilization Engr. (for mail) New Orleans Public Service, Inc., 317 Baronne St., and 2031 Short St., New Orleans, La. MAY, James W. (Af 1938; J 1935) Assoc. Prof, of * Htg.-Vtg. (for mail) College of Engrg., University of Kentucky, and 261 Lyndhurst Place. Lexing ton, Ky. * MAY, Maxwell F. (Af 1929) Secy.-Treas. (for mail) Malvin & May, Inc, 332 S. Michigan Ave., Chicago, and Palos Park, 111. * MAYER, Robert L. (A 1938) Sales Engr., Smedley & Mehl Co., 200 W. Montgomery Ave., Ardmore, and (for mail) 43 W. Albemarle Ave., Lansdowne. Pa. MAYER, Robert W. (A 1937) Dist. Mgr. (for mail) Minneapolis-Honeywell Regulator Co., 561 Reading Rd., and 3980 Rose Hill Ave., Cin cinnati, O. MAYETTE, Charles E. (Af 1926) Consulting Engr., Room 1417, Graybar Bidg., 420 Lexington . Ave., New York, N. Y. ' ' MAYNARD, J. Earle (Af 1931) Chief Htg. Engr., Fox Furnace Co., Woodford St., and (for mail) 324 Fifth SL. Elyria, O. * MAYNE, Walter L. (Af 1937) Brance Mgr. (for mail) U. S. Radiator Corp., Cor. Wayne and ' C. L. & N. R. R. and 1239 Delta Ave., Cincinnati, O. McCAFFERTY, Joseph E. (A 1937) Dist. Engr., Petroleum Heat and Power Co., 419 Boylstoa St., Boston, and (for mail) 196 Manthome Rd., West Roxbury, Mass. . McCAFFRAY, Charles E. (Af 1938) Engr., Henry Adams. Inc.. Consulting Engineers, 1263 Calvert Bldg., and (for mail) 1 Hamilton Court, Hamil ton St., Baltimore, Md. McCAIN, H. King (A 1938; 7 1937) Sales Engr., Delco-Frigidaire Div., General Motors Sales Corp., Dayton, O.. and (for mail) 406 Emoriland Blvd., Knoxville, Tenn. McCarthy, John J. (A 1937) Chief Engr. (for mail) Providence Public School Dept., 20 Sum mer SL, and 318 Academy Ave., Providence, R. I. McCarthy, Thomas F. (Af 1938) Dist. Mgr. (for mail) Frigidaire Corp., 2031 S. Calumet Ave., and 6948 Calumet Ave., Chicago, 111. McCAULEY, James H. (Af 1921) Pres, (for mail) J. H. McCauley. Inc., 5558 West 65th SL, Chicago, and 707 Wiliam St., River ForesL 111- McCLAIN, Clifford H. (Af 1937) Htg. Engr., Upper Darby Plumbing & Heating Co., Inc., 7127 Marshall Rd., and (for mail) 1600 Darby Rd., Brookline, Upper Darby, Pa. McCLELLAN, James E. (Af 1922). Mgr., Chicago Office (for mail) American Blower Corp., 228 N. LaSalle St., Chicago, and 738 Marion Ave., Highland Park, III. McCLINTOCK, Alexander, Jr. (Af 1928; 7 1920) Htg. Contractor (for mail) A. McClintock's Sons, 1937 Ridge Ave., and Rochelle Ave., Phila delphia, Pa.' 42 Roll of Membership McCLINTOCK, William (Af 1935) Supervising Engr., Engrg. Design Section, Administrative Staff, U. S. W. P. A., 70 Columbus Ave., and (for mail) 643 East 232nd St., New York, N. Y McCONACHIE, Lome L. (A 1928) Htg. and PIbg., 1003 Maryland Ave., and (for mail) 1379 Maryland Ave., Detroit, Mich. McCONNER, Charles R. (A 1925; 7 1922) Gen. Sales Mgr., Clarage Fan Co., Kalamazoo, Mich. McCORMACK, Denis (Af 1933) Mgr., Air Cond. Instruments and Controls Dept, (for mail) Julien P. Friez & Sons, Inc., 4 N. Central Ave., Balti more, and Ruxton Post Office, Baltimore County, Md. McCOY, C. E. (Af 1936) Partner (for mail) TuraerMcCoy, 210 W. Second St., and 3922 S..Lookout- - -Ave..-Little Rock, Airk......... McCOY, Thomas F. (Af 1924) Mgr. (for mail) The Powers Regulator Co., 125 St. Botolph St., Boston, and Glen Rd., Wellesley Farms, Mass. McCRAE, George W. (A 1936) Chief Engr., John McCrae Machine & Foundry Co., 77-85 William St., N., and (for mail) 51 Bond St., Lindsay, OnL, Canada. McCREA, Joseph B. (Af 1937) Owner, Heating & Ventilating, 3039 Coplin Ave.. Detroit, Mich. McCREERY, Hugh J. (Af 1922) Owner (for mail) 335 Burtard St., and 1617-49th Ave.. W., Van couver, B. C. 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. (Af 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 Constitution Ave., N. W., and (for mail) 3035 Rodman St., N. W., Washington, D. C. McDONALD, Ivan (A 1938) Dist. Repr. (for mail) Minneapolis-Honeywell Regulator Co., Ltd., 791 Erin St., and Ste* 16 Bayview Apt., Winnipeg, "Man., Canada. McDONALD, James J. (7 1938) Research Engr., Nash Kelvinator, and (tor mail) 3974 Common wealth Ave., Detroit, Mich. - McDONALD, Thomas .(A 1931) Vice-Pres*. Minneapolis-Honeywell Regulator Co., 2747 Fourth Ave., S., Minneapolis, Minn. MclLVAINE, John H * (Af 1929) Vice-Pres. and Treas., Landwehr Heating Corp., Sixth and Cuyuga Sts., Philadelphia, Pa. McINTIRE, James F. (Af 1915; A 1914) (1st Vice-Pres., 1938; 2nd Vice-Pres., 1937; Council, 1926-1928; 1932-1938) Vice-Pres. (for mail) U. S. Radiator Corp., 1056-44 Cadillac Square, P. O. Box 686, and 3261 Sherbourae Rd., Detroit, Mich. McINTIRE, James L. (J 1938) Sales Engr., (for mail) York Ice Machinery Corp., 117-121 South 11th SL, and 5164 Washington St., St. Louis, Mo. MclNTOSH, Fabian C. (Af 1921; 7 1917) (Coun cil. 1929-1931; 1933-1935) Branch Mgr. (for mail) Johnson Service Co., 1238 Brighton Rd., and 302 --Marshall Ave.y Pittsburgh, Pa. McKEE, James W. (A 1938) Branch Mgr. (for mail) (J* S. Radiator Corp., 532 E. Corcoran Ave., and 6713 W. Bluemound Rd., Milwaukee, Wis. 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. O. McKENZIE, Murdock C., Jr. (Af 1938) Htg. Engr., Southern California Gas Co., 810 S. Flower St., and (for mail) 3806 Boyce Ave., Los Angeles, Calif. McKERLIE, Jardine (M 1938) 15 Glenarden Rd., Toronto, Ont., Canada. McKINLEY, Carroll B. (J 1936; 5 1934) Sales Engr. (Consulting) General Refrigeration Corp., and (for mail) 1123 Harrison, Beloit, Wis. McKINNEY, Carl A. (7 1937) Mr Cond. Engr. (for mail) United Gas Corp., 1018 Rusk Bldg., and 1904 Brun SL, Houston, Tex. McKINNEY, William J. (Af 1938; A 1934) Mgr.. Atlanta Dist. (for mail) American Blower Corp., 716-101 Marietta St. Bldg.* and 3363 Mathieson Drive., Atlanta, Ga. McKITRICK, Walter D. (Af 1936) Htg.-Vtg. Engr. (for mail) Mills, Rhines, Bellman & Nordhoff, Archta. & Engrs., 518 Jefferson Ave., and 3038 Gunckel Blvd., Toledo. O. McKITTRICK, Percy A. (A 1934) Treas.-Gen. Mgr. (for mail) Parks-Cramer Co., 970 Main SL, and 219 Blossom St., Fitchburg, Mass. McLAREN, Fred S. (7 1935) Air Cond. Sales Engr. (for mail) Frigidaire Div., General Motors Sales Corp., 4436 Toulouse, and 905 Fern SL, New Orleans, La. McDONNELL, Everett N. (Af 1923) Pres, (for mail) McDonnell & Miller, 400 N. Michigan Ave., and Drake Hotel, Chicago, 111. McDONNELL, John E. (A 1936) Vice-Pres. (for mail) McDonnell & Miller, 400 N. Michigan A11v1.e., Chicago, and 2421 Central Park, Evanston, McDOWELL, Harry L. (J 1939) Htg. Engr., Syska & Hennessey, Consulting Engrs. (for mail) 111 Corcoran SL, and 310 Holloway SL, Durham, N. C. McELGIN, John W.* (A 1937; 7 1931) Limekiln and Butter Pikes, Ambler, Pa. McELHANEY, Gerald W. (A 1938; 7 1936) Air Cond. Engr. (for mail) Ohio Edison Co., Akron, and 1924 Tenth St., Cuyahoga Falls, O. McEWAN, Eugene E. (Af 1936) N. Y. Mgr. Air Cond. Div. (for mail) Frigidaire Div., General Motors Sales Corp., 224 W. 57th SL, and Salis bury Hotel. 123 W. 57th St., New York, N. Y. McGAUGHEY, Harold M. (Af 1937) Sales Mgr., Commercial Air Conditioning & Automatic Htg., Nash Kelvinator Corp., and (for mail) 300 Whit more Rd., Detroit, Mich. . McGEORGE, Richard H. (Af 1927) Mgr., Htg. & 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) 1913 Fulton Bldg., Pittsburgh, and 6815 Prospect Ave., Ben Avon, Pa. McGRAlL, Thomas E. (Af 1926) Local Repr., ' Canadian Sirocco Co., Ltd., P. O. Box 555 Station B., Ottawa, OnL, Canada. McLAREN, T. H. (A 1938) Gen. Sales Mgr. (for mail) The James Morrison Brass Mfg. Co., Ltd,, 276 King SL. W., and 2084 Girard SL, E., Toronto, Ont., Canada. McLARNEY, Harry W. (Af 1933) Air Cond. Engr. (for mail) -Union Electric Co. of Missouri, 315 N. 12th Blvd., and 5038 Bancroft Ave., SL Louis, Mo. McLAUGHLIN, Joseph D. (A 1930; 7 1928) Htg. Contractor (for mail) Braley & McLaughlin, 166 Abom SL, and 45 Roslyn Ave., Providence, R. I. McLEAN, Dermid (Af 1917) Member of Firm (for mail) Snyder & McLean, 2308 Penobscot Bldg., and 12651 Birwood Ave., Detroit, Mich. McLEAN. James E. (Af 1936) 520 Bigham Rd.. Pittsburgh, Pa. McLEISH, William S. (A 1932; 7 1928) Sales Engr. (for mail) The Ric-wiL Co., Room 1838, 101 Park Ave., New York, and 6446-184th St. Flushing, N. Y. McLENEGAN. David W.* (Af 1933) Asst. Engr., Comm. Engr. Div.. Air Cond. DepL (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., Lansing, and 135 Gunson, East Lansing, Mich. McMAHON, Thomas W. (Af 1928) DisL Mgr. (for mail) American Blower Corp., 1711 Railway Exchange Bldg., and 6173 Waterman Blvd., St. Louis, Mo. McMULLEN, Earle W. (Af 1938) Dir. of Research (for mail) The Eagle-Picher Lead Co., and 626 Jaccard Place, Joplin, Mo. Heating Ventilating Air Conditioning Guide 1939 McNAMARA, William (A 1930) Mgr. (for mail) The Trane Co., 2694 University Ave., and 1355 Como Ave., W., St. Paul, Minn. McNEVIN, Joseph E. (Af 1937) Mgr. (for mail) Colorado Heating Co., 950 Cherokee St., and 225 E. Dakota Ave., Denver, Colo. Mcpherson, wuium a. cm 1929) chief, Htg.- Vtg. Div., Dept, of School Bldgs.. 26 Norman St., Boston, and (for mail) 86 Dwinnel! St., West ' Roxbury, Mass. McQUAID, Daniel J. (M 1934) Owner (for mail) Daniel J. McQuaid, Engineering Service, 614 Cooper Bldg., and 1565 Milwaukee St., Denver, Colo. McREYNOLDS, C. V. (A 1938) Engr., Natkin & Co., 212 Iowa Bldg., and (for mail) 3905-8th St., Des Moines, la. MEAD, Edward A. (M 1926) Asst. Sales Mgr. (for mail) Nash Engineering Co., South Norwalk, and 5 Thames St., Norwalk, Conn. MEAGHER, Arthur T. (M 1938) Dir. and Sales Mgr., Plbg. & Htg. Dept., Wm. Stairs, Son & Morrow, Ltd., 174-190 Lower Water St., and (for mail) 83 Seymour St., Halifax, Nova Scotia, Canada. MEAKIN, John B. (J 1935) Sales Engr. (for mail) Foxboro Co., Neponset Ave., and 12.Baker St., Foxboro, Mass. MEARS, Leon A. (A 1938; J 1935) 721 Alice St.. and (for mail) 975 Sunnyhills Rd., Oakland, ' Calif. . MEDOW, Jules (J 1937) Designing Engr., Ilg Electric Ventilating Co., 2850 N. Crawford Ave., and (for mail) 147 S. Springfield Ave., Chicago, III. MEHL, Oscar H. (J 1935) Engr. (for mail) Carrier Corp., 2022 Bryan St., and 4841 Tremont St., Dallas, Tex. MEHNE, Carl A. (M 1929) Htg.-Vtg. Expert, C. A. Mehne, Room 821, 102 Park Ave., New York, and (for mall) 35 Livingston St., Valhalla, N. Y. MEINHOLTZ, Herbert W. (M 1936) 608 Mayo Bldg., Tulsa, Okla. ' MEINKE, Howard G. (Af 1933) Div. Engr. (for mail) Consolidated Edison Co. of New York, Inc., 4 Irving Place, New York, and 41 Harte St., Baldwin, L. I., N. Y. MELLON, James T. J. (M 1911) Pres, (for mail) Mellon Co., 4419 Ludlow St., and 431 N. 63rd St., Philadelphia, Pa. ' MELONEY, Edward J. (M 1937) Vice-Pres. (for mail) Bowers Bros. Co., 2015 Sansom St., Philadelphia, and 100 E. Stewart Ave., Lans- downe, Pa. . MENDEN, Peter J. (M 1935) Htg. Engr., Advance Heating Co., 910 Herrick Ave., and (for mail) 1509 Arthur Ave., Racine, Wis. MENSING, Frederick D. (M 1920) (Treas., 1931 1932) Consulting Engr., Mensing & Co., 2845 Frankford Ave., Philadelphia, Pa. MERCER, Charles F. (M 1937) Prof. Physics (for mail) University of South Carolina, and 219 S. Waecamaw, Columbia, S. C. . MERENS, Seymour IL (A 1939) Sales Engr. & Estimator, T. H. Litvin Plumbing & Heating Co., 610 W. Randolph, and (for mail) 3355 Eastwood Ave., Chicago, III. MERLE, Andr6 (M 1934) Engr; (Air Cond. & Refrig.), Office of the Q. M. G.f War Dept., U. S. A., and (for mail) 1501 Massachusetts Ave., N. W., Washington, D. C. - MERRILL, Carle J. (M 1919) Treas. (for mail) C. J. Merrill, Inc., 54 St. John St., and 15 Long fellow St., Portland, Me. MERRILL, Frank A. (Af 1934) Consulting Engr. (for mail) Office of Hollis French, Consulting Engrs., 210 South St., Boston, and 19 Auburndale Rd., Marblehead, Mass. - MERTZ, Walter A. (Af 1919) Secy, (for mail) Kehm Bros. Co., 51 E. Grand Ave., and 3753 N. Keeler Ave., Chicago, 111. MERWIN, GUe E. (M 1924; J 1923) Secy.-Treas.. ' Rockford Plumbing Supply Co., 700 S. Main St., and (for mail) 1536 Myott Ave., Rockford, 111. 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) Vice-Pres. and Htg. Supt., Wbeeler-Blaney Co., 249 N. Burdick St.] and (for mail) 706 Locust St., Kalamazoo, Mich' MEYER, Charles L. (Af 1930) Mech. Engr. American Welfare League, 86-97 Palo Alto Ave.' Hollis, L. I., N. Y. * MEYER, Frank L. (Af 1932; J 1928) Vice-Pres., The Meyer Furnace Co., and (for mail) 9 Cole Court, Peoria, 111. MEYER, Henry C., Jr.* (Life Member; M 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, Karl A. (Af 1938) Design Engr. (Fan) L. J. Mueller Furnace Co., 2005 W. Oklahoma Ave., and (for mail) 3171 North 15th St., Mil waukee, Wis. -MEYERS, John (Af 1937) Branch Mgr.,'Tem perature Regulation, Johnson Service Co,, Bond Bldg., 14th & New York Ave., N. E., Washing ton, D. C. ' MICHIE, D. Fraser (Af 1938; A 1930) Engrg. Sales Dept, (for mail) Crane Ltd., 93 Lombard St., and Ste. 26, 75 Kennedy St., Winnipeg, Man, Canada. - MIDDLETON, David K. (J 1936) Salesmafi, Johnson Service Co., 1100 N. W. 38th St., Oklahoma City, Okla. MIDDLETON, Howard A. (A 1935) Engr., 525 E. . Armour, Kansas City, Mo. MIDEK.E, Joseph M. (A 1937) Vice-Pres., Mideke Supply Co., 100 E. Main St., and (for . mail) 2003 N. W., 13th St., Oklahoma City, Okla. MILENER, Eugene D. (Af 1936) Secy., Industrial Gas Section, American Gas Association, .420 Lexington Ave., New York, N. Y. ' " . MILES, Clarence N. (A 1937) Foreman, Assembly Dept., Kohlenberger Engineering Corp., 805 S. Spadra Rd., and (for mail) Rte. 1, Box 174 A, Fullerton, Calif. ' MILLARD, E. L. (A 1938) Chief Engr. (for mail) A. Y. McDonald Mfg. Co., 1201 Dodge St., and 4238 Larimore Ave., Omaha, Nebr. . MILLARD, Junuls W. (Af 1929) Dist. Mgr., Carrier Corp., 1201 Statler Bldg., Boston, and (for mail) 7 Tappan Rd., Wellesley, Mass. MILLEN, Ralph J. (A 1938) Estimating and Layout Engr., Haried Home Appliance, 121 Downer Place, and (for mail) 933 Harriett Ave., Aurora, Hi. . MILLER, Archibald T. (Af 1938) Mgr., Insulation Sales, The Barrett Co., 40 Rector St., New York, N. Y., and (for mail) 125 Godwin Ave., Ridge- wood, N. J. MILLER, Bruce R. (Af 1935; A 1930) Mech. Engr., 1533 Northwest 25th St., Oklahoma City, Okla. MILLER, Chas A. (A 1917) Salesman. The H. B. Smith Co., Inc., 36-46-33rd St., Long Island City, and (for mail) 2870 Marion Ave., New York, N. Y. MILLER. Charles W. (Af 1919; J 1908) Pres, (for mail) The Rado Co.. 759 N. Milwaukee St., Rm. 405, Milwaukee, and R-l, Box 42, Meno monee Falls, Wis. MILLER, Edgar R. (A 1935) Chief Engr. (for mail) Winnipeg Cold Storage, Cor. Jarvis and Salter, and Ste. 0, Bexley Court, Winnipeg, Man., Canada. MILLER, Floyd A. (Af 1911) Inspection Engr. (for mail) U. S. Treasury Dept., 377 U." S. Court House, and 944 Montrose Ave., Chicago, 111. MILLER, George F. (Af 1936) Owner (for mail) Geo. F. Miller Sales Engr.. 1625 K St.. N. W., Washington, D. C., and 209 Connecticut Ave., - Kensington, Md. 44 Roll of Membership MILLER, Glen (A 1937) Htg.-Vtg. Engr. (for mail) Southern Counties Gas Co., 810 S. Flower St., Los Angeles, and 685 Luton Drive, Glendale, Calif. MITCHELL, John G. (J 1937; S 1936) Sales Engr. (for mail) Fairbanks, Morse & Co., 220 E. 5th St., St. Paul, and 704 Delaware, S. E., Minneapolis, Minn. MILLER, Jack E. (J 1938). Engr. (for mail) Fairbanks, Morse & Co., 217 S. 8th St., St. Louis, Mo., and 7325 Phillips Ave., Chicago, 1111 MILLER, Jacob (Af 1936) Pres, (for mail) Uni MITTENDORFF, Edward M. (Af 1932) Asst. Engr. (for mail) Sarco Co., Inc., Merchandise Mart, Chicago, and 956 Greenwood Ave., Wlnnetka, 111. versal Heating Co., Inc., 121 St. Marks Place, New York, and 435 East 92nd St., Brooklyn, N. Y. MILLER, James E. (M 1914; J 1912) Htg. Con tractor, 2210 Colfax St., Evanston, 111. MILLER, John F. G. (Af 1916) Vice-Pres. (for mail) B. F. Sturtevant Co., Hyde Park, Boston, . and 20 Chapel St., Brookline, Mass. MODIANO, Rene (Af 1925) Managing Dir., Carrier Continentale, 4, Rue d'Aguesseau, Paris (8s) and (for mail) 55 Boulevard Beaus6jour, Paris (16s), France MOFFAT, Ormond `G. (A 1937) Application Engr., Canadian Westinghouse Co., Sanford Ave-, and (for mail) 141 George St., Hamilton, Ont.. Canada. MILLER, Leo B. (M 1926) Mgr., Refrigeration and Air Cond. Div. (for mail) MinneapolisHoneywell Regulator Co., 2753 Fourth Ave., S., and 4255 E. Lake Harriet Blvd., Minneapolis, Minn. MILLER, Lorin G.* (Af 1933) Head, Mech. Engrg. Dept, (for mail) Michigan State College, and 525 Albert St.. East Lansing, Mich. MILLER, Merl W. (Af 1932; J 1926) Plant Engr., The 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. (J 1935) Sales Engr. (for mail) American Radiator Co., 1344 Broadway, and 18264 Birchcrest Drive, .Detroit, Mich. MOFFITT. Lloyd C. (J 1937)`Branch Engr. (for mail) Sidles Co., Airtemp Div., 509 S. 19th, and 3109 Mason. Omaha, Nebr. . MOHN, H. Leroy (Af 1937) Development Engr., Fitzgibbons Boiler Co., Inc., E. 10th 8c Mercer St., and (for mail) 136 E. 4th St., Oswego, N. Y. MOHRFELD, Herbert H. (J 1935) Air Cond. Engr. (for mail) C. P. Mohrfeld, Inc., 24 Lees Ave., Collingswood, and 131 Chestnut St., Haddonfield, N. J. MOLER, William H. (Af 1927; J 1923) Vice-Pres. (for mail) Kribs & Landauer, 200 Houseman Bldg., Dallas, and Box 69 A. R. F. D. No. 1, Irving, Tex. MOLFINO, Philip (Af 1938) Mech. Engr. (for . mail) Leland & Haley, 58 Sutter St., and 125 Clayton St., San Francisco, Calif. MOLLENBERG, Harold J- (Af 1936) Vice-Pres., MILLER, Robert T. (A 1927) Chief Engr., Sales Mollenberg-Betz Machinery Co., 22 Henry St., Dept, (for mail) Masonite Corp., Ill W. Wash Buffalo, and (for mail) 172 Westgate Rd., ington St., Chicago, and Flossmoor, 111. Kenmore, N. Y. MILLER, Tolbert G. (A 1929; J 1921) Supt. and MOLONEY, Roger R. (Af 1937) Design Eng., Engr., Herre Bros., Seventh and Emeralds St., Dept, of Interior, Commonwealth Govt, of Aus Harrisburg, and (for mail) 11 N. Second St., Wormleysburg, Pa. tralia, Canberra, A. F. C., and (for mail) 26 Bonner Ave., Manley. Sydney, Australia. MILLER, William T. (Af 1938) Prof. Htg.-Vtg. MONICK, Fred R. (A 1936) Mgr. (for mail) (for mail) Purdue University, and 525 Hayes St.,' West Lafayette, Ind. Cochran-Sargent Co., 605 E. 8th St., and 1114 S. 6th Ave., Sioux Falls, S. D. MILLHAM, Franklyn B. (Af 1937) Installation Mgr., S. S. Fretz, Jr., Inc., 1902 Chestnut St., MONTGOMERY, Edward G. (A 1938) Special Repr., Steel Co. of Canada, Ltd., 525 Dominion and (for mail) 532 Ellet St.f Philadelphia, Pa. MILLIKEN, J. H * (M 1923) Repr. (for mail) American Air Filter Co., Inc., 20 N. Wacker Drive, Chicago, and 1021 Ridge Court, Evanston, lit. . MILL1S, Linn W. (Life Member; M 1918) Secy., Security Stove & Mfg. Co., 1630 Oakland, and (for mail) 3534 Wabash Ave., Kansas City, Mo. MILLS, Clarence A.* (Af 1936) Prof, of Experi mental Medicine (for mail) University of Cin cinnati, Cincinnati. General Hospital, and 5046 Oberlin Blvd.,.Cincinnati, O. MILLS, Hartzell C. (A 1935) Salesman, Minne' apolis Gas Light Co., 800 Hennepin Ave., and (for mail) 4137 Tenth Ave., S., Minneapolis, Minn. St., Montreal, and (for mail) 20 Finchley Rd., Hampstead, P. Q., Canada. MONTGOMERY, John R. (A 1937) Mgr., Standards and Research (for mail) Truscon Steel Co., Albert St., and 296 Granada Ave., Youngs town, O. MONTGOMERY, Ora C. (Af 1933) Asst. Supt. of Power (for mail) New York Central Railroad, Grand Central Terminal, Room 1842, 70 East 45th St., and 255 West 84th St., New York, N. Y. MOODY, Lawrence E. (Af 1919) Partner (for mail) Moody & Hutchison, Consulting Engineers. 1701 Architects Bldg., Philadelphia, Pa., and 237 Jefferson Ave., Haddonfield, N. J. MOON, L. Walter (Af 1915) Pres, (for mail) Bradley Heating Co., 3834 Olive St., and 5006 N. Kings Highway, St. Louis, Mo. MILNE, Arthur H. (Af 1938) Dir. De^t. of Bldgs., MOORE, Bill J., Jr. (J 1937) Pres.. U. S. Air Protestant Board of School Commissioners of the Conditioning Sales Corp., 1701 Grand Ave., and City of Montreal (for mail) 3460 McTavish St., (for mail) 1305 Valentine Rd., Kansas City, Mo. and 4786 Grosvenor Ave., Montreal,' P. Q., MOORE, Don R. (S 1936) 402 W. Penn St., Canada. . Hoopeston, III. MILWARD, Robert K. (A 1920) Mgr. (for mail) MOORE, Frank C. (A 1938) Canadian Mgr. (for U. S. Radiator Corp., 127 Campbell Ave., and 2441 Calvert Ave., Detroit, Mich. mail) Aerofin Corp., 67 Yonge St., and 323 Manor Rd., Toronto, Ont., Canada. MIRABILE, Jasper J. (A 1938) Sales Engr., Htg. Div., Asbestos Insulating Co., Astor & Main Sts., Philadelphia, and (for mail) 714 W. Marshall St., Norristown, Pa. MITCHELL, Charles H. (Af 1924) Engr., The Fels Co., 42 Union St., Portland, and (for mail) 25 Everett Ave., South Portland, Me. MITCHELL, Jack (Af 1938; J 1930) Mgr., Air Cond. Dept, (for mail) Straus-Frank Co., and 2222 Nebraska, Houston, Tex. - MITCHELL, Johu A. (/ 1938) Sales Engr., Air Cond. and Refrigeration Systems (for mail) 202 Waterloo Bldg., and 1301 Jefferson St., Waterloo, la. MOORE, H. Carlton* (Af 1935) Asst. Prof. Mech. Engrg. (for mail) Massachusetts Institute cf Technology, Room 1-202, Cambridge, and 145 Beaumont Ave., Newtonville, Mass. 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. (M 1935) Mgr. Air Cond. Engrg. Dept, (for mail) The Bimel Co., 305 Walnut St., and Cincinnati Club, Cincinnati, O. MOORE, Herbert S. (A 1923) Dist. Repr., Iron Fireman Mfg. Co. of Canada. Ltd., 602 King St and (for mail) 107 Clendenan Ave., Toronto, Ont., Canada. Heating Ventilating Air Conditioning Guide 1939 MOORE, R. Edwin (A 1928) Vice-Pres., Bell & Gossett Co., 3000 Wallace St.. Chicago, and (for mail) 425 Merrill Ave., Park Wdge, 111. MOORE, Wesley R. (Af 1937) Branch Mgr. (for mail) Minneapolis-Honeywell Regulator Co., 4501 Prospect Ave., Cleveland, ana 14211 Ash- wood Rd., Shaker Heights, O. MOREHOUSE, H. Preston (M 1933) Gen. Air Cond. Repr. (for mail) Public Service Electric & Gas Co., 80 Park Place, Newark, and 85 Halsted St., East Orange, N. J. MOREHOUSE, J.. Stanley (Af 1938) Prof. Mech. Engrg., Villanova College, VUlanova, and (for mail) 102 Llandaff Rd., Upper Darby, Pa. MORGAN, Arthur S. (Af 1938) Mgr., Fess Oil Burners of Canada, Ltd., 85 King St., W., and (for mail) 156J31enmanowDrive,Toronto, Ont., Canada. - MORGAN, Glenn C. (Af 1911) Partner (for mail) Morgan-Gerrish Co., 307 Essex Bldg., 84 S. Tenth St., and 4308 Fremont Ave., S., Minne apolis, Minn. MORGAN, Robert C. (Af 1915) Pres., Stewart A. Jellett Co., 1200 Locust St., and (for mail) 314 W. Seymour St., Philadelphia. Pa. MORCAN, Robert W. (M1938) Research Engr.. Air Cond. & Commercial Refrigeration, Nash- Kelvinator Corp., and (for mail) 12739 Hubbell Ave., Detroit, Mich. MORIARTY, John M. (Af 1937) Owner (for mail) Consolidated Heating & Ventilating Co., 1709 West 8th St., and 2525 Burnside Ave., Los Angeles, Calif. MORIN, A. R. (A 1938) Mgr., Refrigeration Dept., Macklanburg Brass & Copper Products, Inc., Ill N. W. 23rd, and (for mail) 925 S. W. 28th, Oklahoma City, Okla. MORRIS, Arnold M. (7 1934) Sheet Metal Worker, Philadelphia Navy Yard, Sheet Metal - Shop Bldg. (Shop No. 17) and (for mail) 3022 Baits SL, Philadelphia, Pa. MORRIS, C. Raymond (Af 1921) Pres., Power & Heating Equipment Sales, Inc., 14 Burnett Place, Nutley, N. J. MORRIS, John A. (7 1936) Htg. Dept., James Robertson Co., Ltd., 946 William SL, and (for mail) 4134 Marlowe Ave., Montreal, P. Q., MOSS, Edward (Af 1920) Htg.-Vtg. Engr. (for mail) New York Rapid Transit Corp., $5 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, Norwood, O. MOULD, Delmar E. (Af 1936) Mgr. (for mail) J. W. Mould & Son, Ltd., 10708 Jasper Ave., and 8619-108 A St., Edmonton, Alta., Canada. MOULDER, Albert W.* (Af 1917) Vice-Pres. (for mail) Grinnell Co., Inc., 260 W. Exchange St., Providence, and Barrington, Providence. R. I. MUELLER, Harold C. (Af 1936; A 1930) Mgr., Contract Div. (for mail) Powers Regulator Co.) 2720 Greenview Ave., Chicago, and 2720 Lawn dale Ave., Evanston, 111. __ MUELLER, Harold"P. (Af 1936) Pres, (for mail) 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, West Penn Power Co., 14 Wood SL, Pittsburgh, Pa. MLTESSIG, James W. (Af 1938) Sales Engr., Clarage Fan Co., Kalamazoo, Mich. (for. mail) 333 N. Michigan Ave., Chicago, and 442 Lodge Lane, Lombard, 111. MUIRHEID, John G. (7 1937) Sales Engr., Baker- Ice Machine Co., 2311 Hopedale Ave., Charlotte. N. C. . MULCEY, Paul A. (7 1938) Asst. Dir., Anthracite Industries Laboratory, Primos, Delaware Co., and (for mail) 300 Springfield Ave., Aldan, Pa. MULLEN, Thomas J., Jr. (7 1935) Sales Engr.. B. F. Sturtevant Co., Hyde Park, Boston. Mass, MUNIER, Leon L. (Af 1919: 7 1915) Pres, ffor mail) Wolff & Munier, Inc., 222 E. 4lst St., New York, and 63 Columbia Ave,, Hartsdale, N. Y. MUNKELT, Frederick H. (Af 1938) Vice-Pres., Consolidated Air Cond. Div. (for mail) W. B. . Connor Engineering Corp., 114 East 32nd SL, New York, and 1388 East 24th St., Brooklyn, - N. Y. .. MUNN, E. Fltz, (Af 1935) Partner (for mail) Over & Munn. 903 McArthur Bldg., and 65 Berrydale Ave., Winnipeg, Man., Canada, MUNRO, George A. (Af 1937) Member of Firm and Gen. Mgr., Hugh F. Munro & Sons, 2404 Canada. N. Mascher L, and (for mail) 173 W. Godfrey MORRISON, Chester B. (Af 1931) Mgr. (for Ave., Philadelphia, Pa. mail) York Shipley, Inc., 81 Jinkee Rd., and 347 MURDOCH, John P. (Af 1937) Pres, (for mail) Route Cohen, Shanghai, China. John P. Murdoch Co., S. W. Cor. 30th & Oakford MORRISON, Wayne L. (A 1938) Owner (for mail) Sts., and 735 Beechwood Drive, Beechwood, Pa. Fair Plumbing & Heating Co., 1908 Broadway St., and 3422 16th St., Great Bend, Kan. MORROW, J. DeWltt (A 1938) Secy.-Treas. and Gen. Mgr. (for mail) The Warren Co., Inc., 614 Walker Ave., and 5503 La Branch, Houston, Tex. MORSE, Clark T. (Af 1913) Pres, (for mail) American Blower Corp., 6000 Russell, and 8120 E. Jefferson, Detroit, Mich. MORSE, Floyd W. (A 1934) Asst. Gen. Sales Mgr. (for mail) Chamberlin Metal Weather Strip Co., 52 Vanderbilt Ave., New York, and 132 Villa St., MURNIN, Edward A., Jr. (A 1937) Supt'. of Development & Assembly, Sarco Mfg. Co., Clewell & Itaska Sts,, and (for mall) 802 Broad way, Bethlehem, Pa.` MURPHREE, Robert L. (7 1936) Promotional, Standard Sanitary Mfg. Co., 503 South 22nd SL, and (for mail) 1509 North 21st Place, Birming ham, Ala. MURPHY, Edward T.* (Af 1915) Vice-Pres. (for mail) Carrier Corp., Merchandise Mart, and 230 E. Delaware Place, Chicago, III. MURPHY, Howard C.* (Af 1923) Vice-Pres. (for Mt. Vernon, N. Y. mail) American Air Filter Co., Inc.. 215 Central MORSE, Louis S., Jr. (A 1938: 7 1936) Air Cond. ' Ave.. and Light/oot Rd.. Louisville, Ky. Sales Engr. (for mail) Westerlin & Campbell Co., MURPHY, Joseph R. (Af 1934; A 1925) Vice- 5924 Second Blvd., and 19480 Canterbury Rd., Pres. (for mail) Taco Heaters, Inc.. 342 Madison Detroit, Mich. Ave., New York, N. Y.f and The Terrace, River- MORSE, Robert D. (Af 1936) Mfrs. Repr. (for ride, Conn. mail) R. D. Morse Agency, 1534-1st Ave., S., and MURPHY, William A. (Af 1926) Gen. Sales Mgr., 4316 E. 43rd St.. Seattle. Wash. Watts Regulator Co., 417 W. Ohio SL, and (for MORTON, Charles H. (A 1931) Sales Repr., mail) 6214 N. Richmond Ave., Chicago, 111. Kewanee Boiler Corp., Warren Webster & Co., MURPHY, WUllam W. (Af 1930) Treas. (for mail) 228 Ottawa Ave., N. W., and (for mail) 1106 W. W. Murphy Co., 424 Worthington. SL, and Sherman St., S. E., Grand Rapids, Mich. MORTON, Harold S. (Af 1931) Sales Engr., Sutherland Air Conditioning Corp., 385 Minne sota St., St. Paul, and (for mail) 4330 WooddaJe Ave., Minneapolis, Minn. MOSES, Walter B., Jr. (S 1936) Student. Tulane University (for mail) 425 S. Peters SL, and 1516 Dufossat St.. New Orleans, La. MOSHER, Clarence H. (A 1929) C. H. Mosher Co.. 423 Ashland Ave.. Buffalo, N. Y. 25 Mansfield St., Springfield, Mass. MURRAY, Hayward G. S. (7 1938) Sales Engr. Refrig. & Air Cond. Div. (for mail) Canadian Comstock Co., Ltd., 1008 New Birks Bldg., and Apt. 6, 3727 de 1`Oratoire, Montreal, P. Q.. Canada. MURRAY, John J. (A 1933). Salesman-Vice-Pres.. Pierce Perry Co., 236 Congress SL, Boston, and (for mail) 60 Commonwealth Park West, Newton Centre. Mass. Roll of Membership MURRAY,Thomas F. (Af 1923) State Archt., and (for mail) 14 S. Lake Ave., Albany, N. Y. MUSCRAVE, Merrill N. (A 1935) Pres., Harrison Sales Co., 3l4-9th Ave., N., Seattle, Wash. MYERS, George W. F. (Af 1930; A 1928; 7 1923) Myers Engineering Equipment Co., 3736 W. Pine Blvd., St. Louis, and (for mail) 476 Pasadena Ave., Webster Groves, Mo. MYLER, WUllam M.t Jr. (Af 1937) Chief Engr., Space Htg. Engrg. Dept, (for mail) Surface Combustion Corp., 400 Dublin Ave., and 1120 Northwest Blvd., Columbus, O. MYTINGER, Kenneth L. (Af 1936) Owner, Kenneth L. Mytinger, 105 Monmouth St., and (for mail) 119 East Bergen Place, Red Bank, vT NESS, William H. C. (Af 1931) Gen. Mgr. (for mail) Master Fan Corp., 1323 Channing SL, and 215 N. Kingsley Drive, Los Angeles, Calif. NESSELL, Clarence W. (Af 1937) Field Appli cation Engr.. Minneapolis-Honeywell Regulator Co., 1024 Third National Bldg.. Dayton, O. NESSI, Andr6 (M 1930) Ingr. des Arts et Mfrs., Expert pres le Tribunal Civil de la Seine (for mail) 1 Avenue du President Wilson, Pans, XVI, France. NEST. Richard E. (Af 1936) Asst. Chief Engr., Anchor Post Fence Co., Fluid Heat Div., and (for mail) 5018 Morello Rd., Baltimore. Md. NEU, Henri J. E. (Af 1933) Pres., Etablissements Neu, 47-49 Rue Fourier, Lille (Nord) France. NEWCOMB.-Lionel B. (A 1936; 7-1933) Junior "N Engr., Philadelphia Electric Co., find (for mail) 6056 Walton Ave., Philadelphia, Pa. NACHMAN, George P. (Af 1938) Secy. & Treas. (for mail) Spohn Heating & Ventilating Co., 1775 E. 45th St., and 2870 Meadowbrook Blvd., Cleveland, O. NAROWETZ. Louis L., Jr. (Af 1929; A 1912) Active Head. Narowetz Heating & Ventilating Co., 1711-1717 Maypole Ave., Chicago, 111. NASS, Arthur F. (M 1927) Pres, (for mail) McGinness Smith & McGinness Co., 527 First Ave., and R. D. No. 8, Crafton P. O., Pittsburgh, Pa. NATHAN, Perclval V. (A 1938) Chief Draftsman, Linde Canadian Ref. Co., Ltd., 355 St. Peter SL, Montreal, P. Q., Canada. NATKIN, Benjamin (Af 1909; 7 1907) Pres, (for mail) Natkin & Co., 1800 Baltimore, and 5211 Rockhill Rd., Kansas City, Mo. NEAR1NGBURG, Arthur (A 1938) Sales Engr. ' (for mail) Sheldons, Ltd., 1221 Bay St., and 130 Floyd Ave., Toronto, Ont., Canada. NEE, Raymond M. (Af 1936) Head, Steam Service Section (for mail) Boston Edison Co., 39 Boytston St., Boston, and 10 Orkney Rd., Brookline. Mass. NEILER, Samuel G. {Life Member: Af 1898) Owner (for mail) Neiler, Rich & Co., 431 S. Dearborn St., Chicago, and 737 N. Oak Park Ave., Oak Park, 111. NELSON, Arthur W. (A 1936) Mgr., Brockton Oil Heat. Inc., 27 Legion Pkwy., Brockton, and (for mail) 12 Sylvan Rd., Sharon, Mass. NELSON, C. L. (A 1937; 7 1929) Chief Air Cond. Engr., Sears and'Piou, 814 S. Vandeventer, St. Louis, and (for mail) 1731 Princeton Place, Richmond Heights, Mo. NELSON, D. W* (Af 1928) Assoc. Prof, of Mech. Engrg. (for mail) University of Wisconsin, Mech. Engrg- Bldg., and 3906 Council Crest, Madison, Wis. NELSON, Edwlrf L. (A 1936) Engrg. Dept, (for NEWMAN, Harold E. (Af 1938) Asst. Mgr. (for mail) B. A. Newman Co., 320 North H St., and 419 Buckingham Way, Fresno, Calif. NEWPORT, Charles F* (Af 1906) Sales Engr., Weil-McLain Co.. Michigan City, Ind., and (for mail) 10001 Longwood Drive, Chicago, III. NEWTON, AJwin B. (Af 1938) Development Engr. (for mail) Minneapolis-Honeywell Regu lator Co.. 2747-4th Ave., S.. and 18 W. Rustic Lodge Ave., Minneapolis, Minn. NICHOLLS, Percy (Af 1920) Supervising Engr., Fuels Section (for mail) Bureau of Mines, 4800 Forbes SL, and 5251 Forbes St., Pittsburgh, Pa. NICKLE, Arthur J. (A 1936) Sales Engr. (for mail) Darling Brothers. Ltd., 140 Prince St., and 4356 Marcil Ave., Montreal, P. Q., Canada. NIESSE. Joe H. (Af 1937) Indiana Dist. Mgr. (for mail) !lg Electric Ventilating Co., 836 Architects & Builders Bldg., and 5837 Winthrop Ave., Indianapolis, Ind. NIGHTINGALE, George F. (A 1931) Sales Mgr. (for mail) Tuttle & Bailey, Inc.. P. O. Box 1313, and 290 Corbin Ave., New Britain. Conn. NIN1NGER, Christian H. (A 1938) Engr. and Dist. Repr. (for mail) H. C. Baker Co., Inc., 29 Franklin Rd., and 638 Northumberland Ave., Roanoke, Va. NOBBS, Walter W. (Af 1919) Consulting Engr., 26 Victoria St., London S. W. 1, and (for mail) 50 Fairhazel Gardens, London N. W. 6, England. NOBIS, H. M. (Af 1914) Chief Engr., DresserNobis, Inc.. 305-306 Caxton Bldg.. Cleveland, and (for mail) 1827 Stanwood Rd., East Cleveland, O. NOBLE, James P. (A 1937) Mgr., The Refriger ation & Htg. Co., 21 N. Limestone SL, and (for mail) 113 E. Cassilly St.. Springfield, O. NOLAN. Ralph E. (A 1938) Owner, Ralph Nolan, Mfrs. Repr. (for mail) 429 Citizens & Southern Natl. Bank Bldg., and 3384 Mathieson Rd., N. E., Atlanta, Ga. mail) Union Ice Co., 1315 E. Seventh SL, and 4313 Victoria Ave., Los Angeles, Calif. NELSON, George C. (Af 1923) Engr., Carstena .Brothers, Ackley, la. 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. (M 1909) Pres. & Gen. Mgr., Herman Nelson Corp., 1824 Third Ave., ` NOLL, William F. (Af 1924) Htg. and Vtg. Contractor (for mail) 629 North 27th St., and 2850 North 47th St., Milwaukee. Wis. NORAIR, Henry (Af 1938) Pres, (for mail) Norair Engineering Corp., H24-22nd St., N. W,, and 5908-32nd SL, N. W., Washington, D. C. NORBY, Karl H. (A 1938) Mgr. Htg. Dept (for mail) Tacoma Plumbing Supply Co., 315 S. 23rd St., and 1316 S. 25th St., Tacoma, Wash. and (for mail) Le Claire Hotel, Apt. 1202, Moline, 111. NELSON, Richard H. (A 1933; 7 1928) Secy.Treas., Herman Nelson Corp., 1824 Third Ave., NORDINE, L. F. (Af 1914) Mgr., Washington Office (for mail) Trane Co., 1772 Columbia Rd., N. W., Washington, D. C.f and 812 Silver Springs Ave., Silver Springs, Md. and (for mail) l303-30th St., Moline, 111. NELSON, Roy O. (Af 1938) Sales Engr. (for mail) Fedders Mfg. Co., 112 N. Green St., and 6419 N. Richmond SL, Chicago, 111. NESBITT, A. J * (Af 1921) Secy, and Treas. (for . mail) John J. Nesbitt, Inc., State Rd. and Rhawn St., Philadelphia, and Rockfield Farm, Ambler, Pa. NESBITT, J. J. (Life Member; Af 1923) Pres, (for mail) John J. Nesbitt, Inc., State Rd. and Rliawn St., Philadelphia, and Rockfield Farm, Ambler, Pa. NESMITH, OUver E. (A 1928) Engr., Williams 0l-0-Matic Heating Corp., Bell 81 Hanna, and (for mail) 107 Warner, Bloomington, 111. NORMAN. Roy A. (Af 1937) Prof, of Mech. Engrg., Iowa State College, Mech. Engrg. Dept., and (for mail) 715 Ridgewood Rd., Ames, la. NORRINGTON, Walter L. (7 1938) Engr., Minneapolis-Honeywell Regulator Co., 4501 Prospect Ave., Cleveland, and (for mail) 1280 Cranford Ave., Lakewood. O. NORRIS, WUllam P. (7 1938) Sales Engr.. Natkin & Co., 3920 Lindell Blvd., and (for mail) 410 N. Newstead Ave., St. Louis, Mo. NORTHON, Louis (Af 1929) Consulting Engr., 132 Park Ave., Mt. Vernon, N. Y. NOTTBERG, Gustav (A 1933) Vice-Pres. (for mail) U. S. Engineering Co., 914 Campbell SL, and 1835 East 68th St. Terrace, Kansas City, Mo. Heating VentiiiAting Air Conditioning Guide 1939 NOTTBERG, Henry (M 1919) Pres, (for mail) U. S. Engineering Co.. 914 Campbell St., and 150 West 54th St., Kansas City, Mo. NOTTBERG, Henry, Jr. (7 1937) Secy, (for mail) U. S. Engineering Co., 914 Campbell St., and 150 West 54th St., Kansas City, Mo. NOVOTNEY, T. A. (Af 1928) Mgr., Convector Div., National Radiator Corp., 22i Central Ave., and (for mail) 839 Luzerne St., Johnstown, Pa. NOWITZKY, Herman S. (A 1931) Supt. Con struction Maintenance and Repairs. Wilmer and Vincent, Theatres, 1776 Broadway, New York, N. Y., and (for mail) 151 Tenth St., Norfolk, Va. NOYES, Richard R. (7 1938) Sales Engr. (for mail) Canadian Sirocco Co., Ltd., 630 Dorchester St., W., and 2010 Mansfield, Apt. 12, Montreal, P. Q., Canada. NUSBAUM, Lee* (Af 1915) Owner (for mail) Pennsylvania Engineering Co., 1119-21 N. Howard SL, and 315 Carpenter Lane, German town, Philadelphia, Pa. NUTTING, H. G. D. (Af 1938) Sales Engr., Air Cond. & Refrigeration, Vilter Mfg. Co., 604 Donovan Bldg., and (for mail) 1461 Calvert Ave., Detroit, Mich. NYE, L. Bert, Jr. (7 1936) Htg. Engr., Washing ton Gas Light Co., 411 Tenth St., N. W., Wash ington, D. C., and (for mail) 309 Piedmont St., Arlington, Va. o OAKLEY, Le Roy W. (Af 1937) Owner-Sales Engr. (for mail) Plumbing & Heating Sales Co., 408 W. Clinch Ave., and 2003 Laurel Ave., Knoxville, Tenn. ^ OAKS, Orion O. (Af 1917) Executive Engr., American Radiator Co.. 40 West 40th St., New York, N. Y., and (for mail) 119 Oakridge Ave., - Summit, N. J. O'Bannon, L. S. (Af 1928) Research Engr., Agr. Exp. Station (for mail) University of Kentucky, and 123 State St., Lexington, Ky. OBERG, H. C. (A 1933) Mgr., Engrg. Dept., Crane Co. of Minnesota, Fifth and Broadway, and (for mail) 1362 W. Minnehaha St., St. Paul, Minn. OBERSCHULTE, Richard H. (7 1938) Sales Engr. (for mail) D. T. Randall Co., 404 Storm- feltz-Loveley Bldg., and 13999 Mark Twain Ave., Detroit, Mich. ' O'CONNELL, PreslyM. (Af 1916) 5749-31st Ave., ' N. E., Seattle, Wash. . O'CONNOR, George P. (A 1937) Pacific Coast Div. Mgr. (for mail) The Ric-wiL Co., 417 Call Bldg., and 642 Mangels Ave., San Francisco, Calif. . O'DOWER, Hugh J. (A 1938) Sales Engr., Vilter Manufacturing Co., Milwaukee, Wis., and (for mail) 114 W. Tenth St., Kansas City, Mo. OELGOETZ, J. F. (Af 1938) Sole Owner (for mail) J. F. Oelgoetz Co., 3365 N. High St., and 279 E. North Broadway, Columbus, O. 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., 1935-1938; Council. 1935-1938) Consulting Engr. (for mail) 139 E. 53rd St., New York, and 160- 15-llth Ave., Beechhurst, L. I., N. Y. O'FLAHERTY, John G. (Af 1937) Chief Engr., Unifin Tube Co., 1109 York St., and (for mail) 290 Central Ave., London, Ont., Canada. OGARD, Norris L. (7 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, J. S. (A 1934) Mgr. Detroit Office (for mail) Johnson Service Co., 427 Brainard St.-, Detroit, and 147 Abbey Rd., Birmingham, Mich. OKE, William C. (Af 1938; 7 1934) Air Cond. Engr.. Weathermakerg (Can.) Ltd., 593 Adelaide St., W., and 460 Merton St.. Toronto, Ont., Canada. . OLCHOFF, Maurice (Af 1933) Pres... States . Engineering Co., 923 Walnut, Des Moines, la. OLD, William H. (Af 1937) Asst. Mgr. (for mail) Glanz & Killian Co., 1761 Forest Ave., W. Detroit, and 18245 Devonshire Rd.p R. R. No. i' Birmingham, Mich. ' OLDES, Willard E. (7 1936) Piping and Incinera tor Designer, Standard Oil Co., Elizabeth, N. J. and (for mail) 610 West 204th St., Apt. D-3* New York, N. Y. * OLSEN, Carlton F. (A 1925; 7 1920) Combustion Engr., Kewanee Boiler Corp., 1858 S. Western Ave., and (for mail) 7314 Stewart Ave., Chicago 111. ' OLSEN, Gustav E. (Af 1930) Vice-Pres., Fitz- gibbons Boilers Co., Inc., 101 Park Ave., New York, and (for mail) 68-09 Amstel Blvd., Arverne L. I., N. Y. OLSON, Bernhard (A 1929) Pres, (for mail) Barney Olson, Inc., 122 S. Michigan Ave., and 5724 N. Natoma Ave., Chicago, 111. OLSON, Gilbert E. (Af 1930) Chief Engr. (for mail) Kelley Manufacturing Co., and 5411 Austin, Houston, Tex. - OLSON, Milton J. (7 1937) Vice-Pres., Olson Bros., 2612 Leavenworth St., and (for mail) 5627 Williams St., Omaha, Nebr. .. OLSON,. Robert G. (Af 1923) Eastern Mgr. (for mail) Hydraulic Coupling Div., American Blower Corp., 50 West 40th St., and 22 East 38th St.;. New York, N. Y. OLVANY, William J. (Af 1912) Pres, (for mail) _ Wm. J. Olvany, Inc., 100 Charles St., New York, and 109-40^71st Rd., Forest Hills, N. Y. . O'NEILL, J. W. (Af 1929; A 1927 ; 7 1925) Chief Engr., Trane Co. of Canada, Ltd., 4 Mowat Ave., and (for mail) 8 Springmount Ave., Toronto, Ont., Canada. `. OONK, William J. (Af 1937) Dist. Mgr., B. F. Sturtevant Co., 915 Olive St., and (for mail) 4548 Redbud Ave., St. Louis, Mo. . OOSTEN, Louis S. (7 1938) Sales Engr., Bell & Gossett Co., 3000 S. Wallace St., and (for mail) 114 E. Kensington Ave., Chicago, 111. OPPERMAN, Everett F. (7 1935; S 1933) Esti mator, Frederick. Opperman, Railroad Ave., and (for mail) 7 West Elm St., 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'REAR, Lawrence R. (Af 1934) Pres, (for mail) Midwest Plumbing & Heating Co., 2450 Blake St., and 3033 West 37th Ave., Denver, Colo. O'ROURKE, Hufch D., Jr. (7 1937; S 1936) 563 . Summit Ave., Jersey City, N. J. ORR, George M. (Af 1936) Pres, (for mail) G. M. Orr & Co., 542 Baker Arcade Bldg., and 2223 Emerson Ave., N., Minneapolis, Minn. ORR, Leighton (Af 1937) Research Engr., Pitts burgh Plate Glass Co., Research Laboratory, Creighton, and (for mail) 1116 Cambridge St., Tarentum, Pa. ORTIZ, Joseph V. (A 1938) Chief Engr. (for mail) Norman Roossin Corp., 62 W. 45th St., New York, and c/o Steele, 2180 Bronx Park, E., Bronx, N. Y. 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 Terminal Bldg., New York, N. Y., and (for mail) 599 Old Post Rd., Fairfield. Conn. OSBORNE, G. H. (Af 1922) Managing Dir., The Ventilating & Blow Pipe Co., Ltd., 714 St. Maurice St., and (for mail) 836 Pratt Ave., Outremont, Montreal, P. Q-, Canada. OSTROM, Eric W. (Af 1937) Chief Engr.. Air Cond. Dept., A/B Svenska Flaktfabriken, Kungs- gatan 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. 48 Roll of Membership OTT, Oran W. (Af 1925) Consulting Mech. Engr. (for mail) 606 Washington Bldg., and 123 S. Virgil Ave., Los Angeles, Calif. OURUSOFF, Leon* (Af 1931) Engr. of Utilization (for mail) Washington Gas Light Co., 4H-10th St., N. W., Washington, D. C., and 21 Cedar Pkwy., Chevy Chase, Md. OUWENEEL, William A. (Af 1937) Chief Engr., Standard Distributing Corp., 406 E. Wells St., PARTLAN, James W. (Life Member; Af 1916) 14290 Goddard Ave., Detroit, Mich. ' PARVIS, Ralph S. (Af 1938) Engr., Diamond Ice & Coal Co., 827 Market St., and (for mail) 602 McLane St., Wilmington, Del. - PASSUR, Norman A. (Af 1938) Air Cond. Engr., Southern Pacific Co. (Railroad) 65 Market St., San Francisco, and (for mail) 2253-39th Ave., Oakland, Calif. 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 D. (Af 1937) 4070 East Blvd., Culver City, Calif. P PASTOR, John C. (Af 1938) Mfrs. Repr. & Designer, 1091 Talbot Ave., Jacksonville, Fla. PATERSON, Frederick C., Jr. (Af 1936; 7 1928) Pres, (for mail) F. C. Paterson & Co., Inc., and 70 Stone Ave., Bradford, Pa. PATORNO, Sullivan A. S. (Af 1923) Owner, Sullivan A. S. Patomo, Consulting Engineers, 101 Park Ave., New York, N. Y. PATRICK, Horace M. (Af 1936; 7 1929) Engr., PABST, Charles S. (Af 1934) Pres., Pabst Air Conditioning Corp., 55 W. 42nd St., New York, and (for mail) 8727-98th St., Woodhaven, N. Y. 411 Pembroke Rd.. Bala-Cynwyd, Pa. PATTERSON, Frank H. (Af 1936) Sales. Hoffman Specialty Co., and (for mail) 9201 Boleyn, Detroit, Mich. PAETZ, H. E. (Af 1922) Div. Sales Mgr., American Blower Corp., 632 Fisher Bldg., and (for mail) 1415 Parker, Detroit, Mich. PAGE, Arvin (Af 1935) Chief Engr. (for mail) The Bahnson Co., 1001 S. Marshall St., and 752 Oaklawn Ave., Winston-Salem, N. C. PAGE, H. 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) Mgr. Heating Div. (for mail) The United Clay Products Corp., 931 Investment Bldg., and 3000-39th St., N- W., Washington, D. C. PAINTER, David H. (Af 1924) Mfrs. Agent, Hoffman Specialty Co., and (for mail) 7331 Brooklyn St., Kansas City, Mo. PAUL, Donald I. (Af 1936; 7 1932) Chief Engr. (for mail) Gurney Foundry Co., Ltd., 4 Junction Rd., ( and 410 Bayview Ave., Toronto, Ont., Canada. PAUL, Lawrence O. (7 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 Theatre, and 17568 Roselawn Ave., Detroit, Mich. PAWKETT, Lawrence S. (A 1938) Mfrs. Repr. (for mail) Insurance Bldg., and 131 North Drive, San Antonio, Tex. PAQUET, Jean-Marie (7 1936) Engr., J. A. Y. PAYNE, Robert E. (Af 1935) Draftsman, E. I. Bouchard, Ltd., 9 Buade St., and (for mail) DuPont de Nemours Co., Wilmington, Del., and 62, De Salaberry, Quebec, P. Q., Canada. PARENT, Harold M. (Af 1938) Partner (for mail) (for mail) 244 Sedgewood Rd., Del. Co., Spring field, Pa. Parent & Kirkbride, 1715 Rittenhouse St., Philadelphia, Pa., and 324 Pitman Ave., Pitman, N. J. . ' PARK, Harold E. (A 1938; 7 1936) Sales Engr. (for mail) Shaw-Perkins Mfg. Co., 1643 Oliver Bldg., Pittsburgh, and 31 Vilsack St., Etna. Pa. PARK, J. Frank (Af 1937; A 1936; 7 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., Phila delphia Saving Fund Society (Real Estate Dept.) 12 South 12th St., Philadelphia, and (for mail) 509 Jericho Rd.. Abington, Pa. PARKER, Loyd L. (A 1938) Partner, Gas Appliance Co., 403-34th St., N. E., Washington, D. C. . . PEACOCK, James K. (Life Member; 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, P. Q., Canada. PECK, Henry E. (A 1938) Chief Engr. (for mail) The Fred D. Pfening Co., 1075 W. Fifth Ave.. and 1446 W. Sixth Ave., Columbus, O. PEEBLES, J. K., Jr. (A 1925; 7 1924) Archi tectural Engr., 1708 Park Ave., Richmond, Va. PEISER, Maurice B. (7 1937) Sales Engr. (for mail) Natkin & Co., 18th & Howard, and 5016 Cass St., Omaha, Nebr. PARKER, Paul E. (A 1938) Sales Engr., The PELLER, Leonard (7 1934) Mech. Engr., 1726 . Trane Co., Plaza Bldg., 635 N. Penn St., Indian Hobart St., N. W., Washington, D. C. apolis. Ind. PELLMOUNTER, Thomas (A 1936) Dist. Sales PARKER, Philip (Af 1915) 8 Middle SL, Woburn. Mgr., Century Electric Co., 903 McGee St., Mass. Room 512, and (for mail) 3308 Euclid Ave., PARKER, Richard A. (A 1938) Secy.-Treas. (for ' Kansas City, Mo. mail) Parker-Carpenter, Inc., 991 Bryant St., and 1464 Francisco St., San Francisco, Calif. PARKS, Charles E. (Af 1937) Dist. Mgr. (for mail) Ilg Electric Ventilating Co., 805 Professional Bldg., . Pittsburgh, and 284 W. Steuben SL, Crafton, Pa. PARRILLI, Roberto (Jlf 1938) Tech. Repr. for Europe, Nash-Kelvinator Corp., via Colonnetta PELLMOUNTER, Thomas V. (7 1938) Student Sales Engr., Worthington Pump & Machinery Corp., Carbondale Div., Harrison, N. J., and (for mail) 3308 Euclid Ave., Kansas City, Mo. PELOUZE, Henry L., II (A .1934) Mgr.-Owner (for mail) Pelouze Sales Co., 311 Grace American Bldg., and 4209 Grove Ave., Richmond, Va. 2, Milan, Italy. PENNEY, Gaylord W. (Af 1938) Mgr. Electro PARROTT, Lyle G. (Af 1922) Consulting Engr. Physics Div. of Research Laboratories (for mail) (for mail) Snyder & McLean, 2308 Penobscot Bldg., and 3788 Gladstone, Detroit, Mich. Westinghouse Electric & Mfg. Co., E. Pittsburgh, and Orchard Rd., Wilkinsburg, Pa. -L PARSONS, Leonard D., Jr. (7 1937; 5 1936) Combustion Engr., Sears Roebuck & Co., PENNOCK, William B. (Af 1927) Sales Engr., . Pennock Engineering, 63 Sparks St., and (for Technical Lab., Dept. 817, Homan & Arthington mail) 326 Waverly St., Ottawa, Ont., Canada. Sts., Chicago, and (for mail) 795 Park Blvd., PERINA, Arthur E. (7 1936; 5 1933) 126 Cortland Glen Ellyn, 111. St., Port Richmond, S. I., N. Y. PARSONS, Roger A. (7 1933) Htg. Engr. (for ' PERKINS, Robert C. (A 1935) Mgr., New Orleans mail) Board of Water & Electric Light Com Office (for mail) Ilg Electric Ventilating Co., missioners, 114-16 W. Ottawa, and 2609 Clifton 203 Natchez Bldg., and 5317 St. Charles Ave., St., Lansing, Mich. New Orleans, La. i -li - Heating Ventilating Air Conditioning Guide 1939 PERRAS* George E. (Af 1936) Mgr. Htg. Div. (for mail) Thomas Robertson & Co., Ltd., 262 Craig St., West, and 6286 Chambord St., Montreal, P. Q., Canada. PERSSON, N. Bert (Af 1937) Design Engr., Frigidaire Div.of General Motors, University Ave. and (formail) 1418SimpsonAve.,SLPaul,Minn. PESTERFIELD, C. H. (Af 1938; 7 1936; S 1932) Instructor (for mail) Michigan State College, Dept, of M. E., and 142 Gunson St., 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 Engr. (for mail) W. A. Ramsay, Ltd., P. O. Box 1721, and 3608 Sierra Drive, Honolulu, Hawaii. PETERSON, Carl M. F.* (Af 1936) Instructor in Mech. Engrg., Asst. Supt. of Bldgs. & Power (for mail) Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, and 40 Fletcher Rd., Woburn, Mass. PETERSON, Clarence L. (Af 1938) Branch Mgr., Minneapolis-Honeywell Regulator Co., 1274 Fol som St., San Francisco, and (for mail) 2 Indian Rock Path, Berkeley, Calif. PETERSON, Nell H. (Af 1937) Mgr. (for mail) The Trane Co., 1129 Folsom St., and 2744 Green St., San Francisco. Calif. PETERSON, S. D. (A 1930) N. W. Mgr. (for mail) Johnson Service Co.. 514 Colmon Bldg., and 5051 Prince St., Seattle, Wash. PETTIT, Ernest N., Jr. (Af 1937) Engr., Erigrg. Dept., Kansas City School Board. 317 Finance Bldg., and (for mail) 107 Ward Pkwy., Kansas City, Mo. PETTY, Charles E. (A 1939) Sales Engr., U. S. Radiator Corp., Detroit, Mich, (for mail) Box 1301. and 1242 Romany Rd., Charlotte, N. C. PEXTON, Frank S. (A 1936) Sales Engr. (for mail) Kansas City Gas Co., 824 Grand, and 43 West 73rd Terrace, Kansas City, Mo. PFEIFFER, Frank F. (Af 1938) Engr., Day & Zimmerman, Inc., Packard Bldg., and (for mail) 7421 Sommers Rd., Philadelphia, Pa. PFRIEM, Peter G. (A 1937) Sales Engr., The Knapp Supply Co., Ohio and Dudley Sts., and (for mail) 211 N. Hackley St., Munde, Ind. PFUHLER, John L. (A 1925; 7 1923) Owner, John L. Pfuhler, Plumbing & Heating, 600 . Manor Rd., W. New Brighton, S. I., N. Y. PHILIP, William (Af 1937) Sales Engr., Dominion Radiator & Boiler Co.*, Royce & Lansdowne Aves., and (for mail) 74 Bastedo Ave., Toronto, Ont., Canada. PHILLIPS, F. W. (Af 1921) Htg. & Vtg. Engr., Queens Borough Gas & Elec. Co., 1610 Far Rock- away Blvd., Far Rockaway, L. I., and (for mail) 825 E. 38th St., Brooklyn, N. Y. PHILLIPS, Ralph E. (Af 1936) Consulting Mech. & Elec. Ehgr. (for mail) Ralph E. Phillips, 816 ' W. Fifth St., Room 603, and 5153 Angeles Vista Blvd., Los Angeles, Calif. PHILLIPS, Robert H. (J 1938) Engr., Carrier Corp. (for mail) 748 E. Washington Blvd., and 2343 London St., Los Angeles, Calif. PHILLIPS, Walter L. (A 1938) Mgr., Airtemp Div. (for mail) Griffith Consumers Co., 1413 New York Ave., N. W., Washington, D. C., and 305 E. Columbia St., Falls Church, Va. PHIPPS, Frederick G. (Af 1930) Vice-Pres.. Preston Phipps, Inc., 955 St. James St., W., and (for mail) 5431 Earoscliffe Ave., Montreal, P. Q-, Canada. PICKETT, Clinton A. (Af 1937; A 1923) Branch Mgr. (for mail) Herman Nelson Corp., 640 N. Michigan Ave., Chicago, and 2000 Beechwood Ave., Wilmette, 111. PICOT, John W. (A 1937) Dir. and Mgr. (for mail) Unit Air Conditioners Pty., Ltd., 300 Pitt St., Sydney, and 19 Marine Parade, Watsons Bay, N. S. W., Australia. PIERCE, Edgar D. (,7 1933) Mgr., Carrier Air Cond. Dept, (for mail) Electrical Products Consolidated, 585 S. Broadway, and 1365 Corona, Denver, Colo. PIETSCH, James A. (Af 1936) Consulting Engr. (for mail) James A. Pietsch, Inc., 155 Prospect Ave., and 101 Cebra Ave., New Brighton. S. I N. Y. PIHLMAN, Arthur A. (Af 1928) Service Engr. (for mail) Consolidated Edison Co. of New York, Inc., 4 Irving Place, New York, N. Y., and 98 Sherman Place, Jersey City, N. J. PIKE, Wallace H. (Af 1935) Design Engr., New comb David Co., 5779-81 Russell St., and (for mail) 4708 Buckingham Rd., Detroit, Mich. P1LLEN, Harry A. (A 1933) Owner, Mfrs. Agent, Htg., Cooling & Power Equipment (for mail) 626 Broadway, and 2124 Crane Ave., Cincinnati, O. PINES, Sidney (Af 1920) Gen. Mgr. (for mail) Pines-Natkin .Co., 209 -Browder-St.,-and-4441 Livingston Ave., Dallas, Tex. PINTO, Chester B. (A 1937) Div. Head, Mont gomery Ward and Co., Plbg. and Htg., 150-18 Jamaica Ave., Jamaica, and (for mail) 11 Buena Vista Ave., Lawrence, L. I., N. Y. PISTLER, Willard C. (Af 1934) Mech. Engr. in Charge of Design, Carl J. Kiefer, Consulting Engr., 918 Schmidt Bldg., and (for mail) Orchard' Lane & Crestview Ave., Pleasant Ridge, Cin cinnati, O. PITCHER. Lester J. (Af 1929; A 1928; 7 1924) ' Electrimatic Corp., 2100 Indiana Ave., and (for mail) 1224 E. 69th St.. Chicago, 111. .. PLAAG, Albert F. (A 1938) Owner (for mail) Frezon Refrigeration Service, 245 N. Warren St., and 550 Miller Ave., Trenton, N. J. * PLACE, Clyde R. (Af 1924) Consulting Engr. (for mail) 420 Lexington Ave., and 333 East 57th St., New York, N. Y. PLANT, Edward B. (Af 1938) Asst. Engr. (for mail) Canadian Pacific Railway Co., Room 401, Windsor St. Station, and 2 Thurlow Rd., Hamp stead, Montreal, P. Q., Canada. PLAYFAIR, George A. (A 1924) Mgr. (for mail) Johnson Temperature Regulating Co., 113 Simcoe St., Toronto, and West Hill, Ont., Canada.. PLEUTHNER, Richard L. (7 1938) Engr., Buffalo Forge Co., and (for mail) 393 Starin Ave., Buffalo, N. Y. . PLEWES, Stanley E. (Af 1917) Branch Mgr. (for mail) Johnson Service Co., 2853 N. 12th St., N. Philadelphia Station 8, Philadelphia, and 309 Evergreen Rd., Jenkintown. Pa. PLUM, L. H. (Af 1935: A 1934) Engr. (for mail). Warren Webster & Co., 17th & Federal Sts., Camden, and 207 Guilford Ave., Collingswood,' N. J. . : PLUMMER, Robert S. (7 1937) Asst, to Supt.* . Franklin Heating Station, and (for mail) Quarry Hill, Rochester, Minn. PODOLSKE, Arthur R. (A 1938) Prop., Arthur R. Podolske Sheet Metal Works, 818 A E. Center St., and (for mail) 820 E. Center St., Milwaukee, Wis. POEHNER, R. E. (Af 1928) Prop, (for mail) Heating Contractor, 846 Massachusetts Ave., and 2308 Coyner Ave., Indianapolis. Ind. POGALIES, Louis H. (Af 1931) Mech. Engr., Wilbur Watson & Associates, 4614 Prospect Ave., and (for mail) 4102 Archwood Ave., Cleveland. O. POHLE, K. F. (A 1930) Vice-Pres. (for mail) W. F. Hirschman Co., Inc., 202 E. 44th St., New York, and 32-39-80th SL, Jackson Heights, N. Y. . POLING, Dudley B. (Af 1936) Mgr., Metal Products Div., Columbus Heating and Venti lating Co., 182 N. Yale Ave., and 797 E. Fulton St., Columbus, O. POLLAK, Rudolf (Af 1937) Chief Engr.. (for mail) Rockefeller Center, Inc., 50 Rockefeller Plaza, New York, and 79 Pinebrook Drive. Larchmont, N. Y. POLLARD, Alfred L. (A 1932) Gen. Supt.. Light & Power (for mail) Puget Sound Power & Light Co., 860 Stuart Bldg., and 3009-28th Ave., W., Seattle, Wash. 50 Roll of Membership POLLOCK, Carl A. (A 1937) Vice-Pres. and Gen. PRINCE, Raymond F. (7 1936) Htg. & Sales Mgr. (for mail) Dominion Electrohome Indus Engr., R. B. Dunning & Co.,. Broad St., and tries, Ltd., 39 Edward St., and 120 Sterling Ave., (for mail) 27 McKinley SL, Bangor, Me. Kitchener, Ont., Canada. PRITCHARD, William J. (7 1937) 3727-79th St., POND, William H. (Af 1938) Sales Engr., Fitz- Apt. 21iIackson Heights, L. I., N. Y. gibbons Boiler Co., 101 Park Ave., New York, PROEBSTLE, Leonard (7 1938) Air Cond. Engr., N. Y., and (for mail) 820 West Front St., Plain Frigidaire Div., General Motors Sales Corp., field. N. J. 2446 University Ave., St. Paul, and (for mail) PONSELL, Francis I. (A 1935) Partner and Sales - 800 S. E. Superior SL, Minneapolis, Minn. Engr. (for mail) James P. Ponsell & Sons, 826 PROIE, John (Af 1936) Gen. Mgr. (for mail) Orange St., and 2708 Madison St., Wilmington, Del. Proie Brothers, 856 W. North Ave., and 101 Dilworth St., Pittsburgh, Pa. POPE, S. Austin (Af 1917) Pres, (for mail) PRUDDEN, O. D. (7 1938; 5 1936) Engr., General William A. Pope Co.; 26 N. Jefferson St., Chicago,. Plastics, Inc., North Tonawanda, and (for mail) and 831 Ashland Ave., River Forest, III. 37 Park Place, Lockport, N. Y. PORTER, Carl W. (7 1936) Engr. (for mail)._ .PRUDEN,- -Bradlee (Af 1936) - Engr.,-Barber-" --Richards'&'Porter, 42 W.~ Concord Ave., and Colraan Co., 150 Loomis SL, and 1509 Grant 915 Bradshaw Terrace, Orlando, Fla. Ave., Rockford, 111. PORTER, Noel E. (7 1938) Engr., General Air Conditioning Co., 1313 J St., and (for mail) 2600 M St., Sacramento, Calif. POSEY, James (Af 1919) Consulting Engr. (for mail) 1755 Baltimore Trust Bldg., and 4005 Liberty Heights Ave., Baltimore, Md. POTTER, J. Robert (7 1938) Design Engr., A. Warren Canney, 15 E. 40th, New York, and (for mail) 2 Grace Court, Brooklyn, N. Y. POUNDS, Carlos A., Jr. (J 1937) Asst. Chief Htg. Engr. (for mail) Sunbeam Heating & Air Conditioning Co.. 346 Peachtree SL, N; E., and 116 North Ave., N. E., Atlanta, Ga. POWELL, George W., Jr. (Af 1938) Consulting Engr. (for mail) 415 Otis Bldg., 16th & Sansom PRYIBIL, Paul L. (A 1932) Partner, HuckerPryibil Co., 1700 Walnut St., and (for mail) 328 E. Philellena St., Philadelphia, Pa. PRYKE, John K. M. (A 1937) Director, Lipscombe Air Conditioning Co., Dacre House, . Dacre St., London, S. W. 1, and (for mail) 216 Clive Court, Maida Vale, London, W. 9, England. PRYOR, Frederick L. (Af 1913) 5 Colt SL, Paterson, N. J. PUGH, Daniel C. (5 1939). Student, Carnegie Institute of Technology, Pittsburgh, and (for mail) 267 Virginia Ave., Rochester, Pa. PULLEN, Royal R. (Af 1935) Chief Mech. Engr., Homestake Mining Co., and (for mail) 109 East Hill SL. Lead. S. D. Sts., Philadelphia, and 458 S. 4th SL, Colwyn, Del. Co., Pa. POWERS, Edgar C. (A 1934; 7 1931) (for mail) 240 Cherry St., Philadelphia, Pa., and 309 PURCELL, Frederick C. (Af 1926) Sales Engr. (for mail) Minneapolis-Honeywell Regulator Co.; 415 Brainard SL, and 4711 Second Blvd., Detroit, Mich. Westmont Ave., Westmont, N. J. POWERS, F. W. (Life Member \ Af 1911) Pres, (for mail) The Powers Regulator Co., 2720 Greenview Ave., and 900 Castlewood Terrace, Chicago, 111. PURINTON, Dexter J. (A 1923) Vice-Pres., Mahoney-Troast Construction Co., 657 Main Ave., Passaic, N. J., and (for mail)-148 E. 53rd St.. New York, N. Y. POWERS, Lowell C. (A 1937; 7 1930) Sales PURSELL, H. E. (Af 1919) Special Repr., Kewanee Engr. (for mail) Carrier Corp., 1501 Carew Boiler Corp., Kewanee, 111. Tower, and 291 Southern Ave., Cincinnati, O. PUTNAM, Norman J. (J 1938) Sales Engr. (for PRATT, Foster J. (Af 1937) Marine Engr., U. S. mail) Robischung-Kieslmg, 4848 Main, Houston, Navy Yard, Puget Sound, Bremerton, and (for Tex., and 902 S. Darlington, Tulsa, Okla. mail) Annapolis Terrace, Port Orchard, Wash. . PRATT, Joseph C. (A 1936) Sales (for mail) Q Fess Oil Burners of Canada, Ltd., 1405 Drum mond St., and 12 Kiilarney Gardens, Pr. Claire, Montreal, P. Q., Canada. PRAWL, Frank E. (7 1936) Dist. Engr., Sidles Co., Airtemp Div., 1228 P SL, and (for mail) 2001 Avenue D, Scottsbluff, Nebr. QUALL, Clarence O.' (A 1937) Owner, Quail Plumbing & Heating Co., 65 Ninth St., and (for mail) 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, PREBENSEN, Harold J. (Af 1938) Vice-Pres., Air State College, Pa. Comfort Corp., 1307 S. Michigan Ave., Chicago, QUICK, Blair A. (A 1938) Sales Mgr., The Inde and (for mail) 1066 Pine St., Winnetlea, 111. pendent Register Co., 3747 E. 93rd SL, and (for PREECE, Leo W. (A 1936) Owner and Engr., L. W. Preece Co., P. O. Box 284, and (for mail) R. F. D. No. 7, Erie. Pa. mail) Fenway Hall, Cleveland, O. QUIRK, C. H. (Af 1916; 7 1915) Eastern Repr. (for mail) The Trane Co., 250 East 43rd St., New PRENTICE, O. J. (A 1927) Dir.* Publicity & York, and 465 Front SL, Hempstead, N. Y. Public Relations (for mail) C. A. Dunham Co., 450 East Ohio St., and 850 Lake Shore Drive, Chicago, 111. R RABE, Albert E. (Af 1938) Pres, (for mail) PRESDEE, Cliff W. (A 1926) S65 Div. Mgr., S. R. Condition-Aire Corp., 39 Sheridan Ave., and 97 Dresser Mfg. Co., Bradford, Pa. Homestead Ave., Albany, N. Y. . 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. and Air Cond. Engr., The Knapp Supply Co., Ohio Ave. and Dudley SL, and (for mail) 1015 W. Washington . SL, Munde, Ind. PRICE, D. O. (Af 1934) Htg. & Air Cond. Engr., General Steel Wares, Ltd., 199 River St., and (for mail) 131 St. Germain Ave., Toronto, OnL, Canada. PRICE, Ernest H. (A 1937; 7 1934; 5 1932) Engr. (Htg.), Wm. Worton, Consulting Engineer, 504 Scott Block, and (for mail) 170 Harbison Ave., Winnipeg, Man., Canada. PRIESTER, Gayle B. (7 1935; S 1934) Air Cond. Engr. (for mail) Carrier Corp., Merchandise Mart, and 5737 N. Kenmore, Chicago, 111. 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, Sidles Co., Airtemp Div., 14th St., and (for mail) 2222-14th St., Columbus, Nebr. RAINE, John J. (Af 1912) Vice-Pres. (for mail) G. S. Blodgett Co., 190 Bank St., Burlington, and Essex Junction, Vl ' RAINGER, Wallace F. (A 1930; 7.1924) Jaros, Baum & Boiles, 415 Lexington Ave., and (for mail) 441 Hawthorne Ave., Yonkers, N. Y. RA1SLER, Robert K. (A 1933; 7 1930) Treas. (for mail) Raisler Corp., 129 Amsterdam Ave., and 38 East 85th St., New York, N. Y. 51 Heating Ventilating Air Conditioning Guide 1939 RALPH, David S. (J 1938) Engr. (for mail) General Roofing & Air Cond. Co., Charleston, W. Va., and 620 Kenilworth Ave., Dayton, O. RAMSAY, James W. (A 1936) Sales Engr. (for mail) King & Shepherd, 60 Church St., New York, and 8415 Fourth Ave., Brooklyn, N. Y. RAND, Fred R. (Af 1938) Htg. Engr. & Sales Mgr., . Enamel & Heating Products, Ltd., and (for mail) P. O. Box 521, Sackville. N. B., Canada. 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 B. Grand Blvd., Detroit, and 770 Shirley Drive, Birmingham, Mich. - RANDOLPH, C. H. (Af 1930; A 1928; J 1926) Air Cond. Engr., Wisconsin Electric Power Co., 231 W. Michigan St., and (for mail) 1614 E. Royall Place, Milwaukee, Wis. ' RANK, Arthur I. (A 1936) Pres, (for mail) Universal Insulation Co., 2429 South St., and 6308 Ross St., Philadelphia, Pa. RASMUSSEN, Robert P. (Af 1931) Pres., Economy Equipment Co;, 223 N. Wolcott Ave., and (for mail) 1243 E. 46th St., Chicago, 111. RATHER, Max F. (Af 1919) Mgr. Eastern Terri tory, Johnson Service Co., 28 East 29th St., New York, N. Y. RATHKE, Arthur C. (J 1937) Architectural Draftsman, Board of Education (Arch. Dept.) Toledo, and (for mail) 1025 Wayne St., Sandusky, O. . RAVEN, Andrew H. (Af 1938) Htg. Engr., Wigman Co., 316 Perry St., and (for mail) 2119 George St., Sioux City, la. RAY, Lewis B. (M 1932) Mech. Engr. (for mail) Ray Engineering Co., Inc., 800 Broad St., Newark, and 151 Augusta St., Irvington, N. J. RAYMER, W. F., Jr. (A 1936; J 1934) Sales Engr. (for mail) American Blower Corp., 249 High St.,. Newark, and 266-4th Ave., East Orange, N. J. RAYMOND, Fred L* (A 1929) Owner (for mail) F. I. Raymond Co., 629 W. Washington Blvd., Chicago, and 547 N. Keystone Ave., River Forest, 111. RAYNIS, Theodore (J 1934) Asst. Naval Archt.. Brooklyn Navy Yard, Design Section Building No. 5. and (for mail) 8528-118th St.f Richmond Hill, N. Y. READER, Joseph T. (A 1938) Partner (for mail) Kerr Machinery Co., 608 Kerr Bldg., and 8120 E. Jefferson Ave., Detroit, Mich. REAMER, William S., Jr. (Af 1937) Vice-Pres., Treas., Reamer Industries, Inc., Seaboard Park, and (for mail) 2400 Blossom St., Columbia, S. C. RECK, William E. (Af 1927) Civil Engr. (for mail) Reck Heating Co., Ltd., Copenhagen N., Esromgade 15, and Sundvej 16, Hellerup, Denmark. REDRUP, Will D. (Af 1936) Pres- (for mail) Majestic Co., and 310 Randolph St., Huntington, Ind. . REDSTONE, Arthur L. (Af 1931) Research Engr., Proctor & Schwartz, 7th & Tabor Rd., and (for mail) 402 Park Towers, Kemble & Ogontz Ave., Philadelphia, Pa. REED, Irving G. (A 1937; J 1934) Asst. Supt. and Chief Engr., Grant Building, Inc., 420 Grant. Bldg., and (for mail) 3227 Middletown Rd.. Sheradan, Pittsburgh, Pa. REED, Van A., Jr. (Af 1930) Mech. Engr. (for mail) Federal Engineering Co., 239-4th Ave., Pittsburgh, and 114 Water St., Elizabeth, Pa. REED, Virgil C. (Af 1938) Estimator and Engr. (for mail) James H. Pinkerton Co., 927 Howard St., and 1234 Second Ave., San Francisco, Calif. REED, William H., Ill (A 1938) Sales Engr. (for mail) Dravo Corp., Carrier Dept., 302 Penn Ave., Pittsburgh, and 7815 Westmoreland, Swissvale, Pa. REGER, Henry P. (Af 1934) Pres.-Treas. (for mail) H. P. Reger & Co., 1501 East 72nd Place, and 6939 Bennett Ave., Chicago, 111. REID, Henry P. (Af 1931; A 1927) Operating Engr. (for mail) Universal Atlas Cement Co., Rm. 1527* 208 S. LaSalle St., Chicago, and 3507 Oak Park Ave., Berwyn, 111. REID, Herbert F. (A 1932) Reid-Graff Plbg. Co., 1417 Peck St., Muskegon Heights, Mich. REIF, Allan F. (Af 1937) Pres, (for mail) Reif- Rexoil, Inc., 37-43 Carroll St., Buffalo, and 10 Livingston Pkwy., Snyder, N. Y. REIF, Charles A. (Af 1937) Vice-Pres., Treas. (for mail) Reif-Rexoil, Inc., 37-41 Carroll St., and 115 Larchmont Rd., Buffalo, N. Y. REIFSCHNEIDER, Jake (A 1938) Supt. of Maintenance (for mail) Eppley Hotels Co., and 4637 Douglas St., Omaha, Nebr. REILLY, Bertram B. {J 1938) Engr., Trilling & Montague, 24th & Walnut St., and (for mail) 3259 Sansom St., Philadelphia, Pa. REILLY, Charles E. (A 1936; J 1928) 4920 City Line Ave., Philadelphia, Pa. REILLY, J. Harry (Af T931; 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., Gus Reinke Machinery & Tool Co., 63 Dickerson St., Newark, and (for mail) 321 Park Place, Irvington, N. J. ` REINKE, Louis F. (A 1937) Owner (for mail) Reinke Sheet Metal Works, 534 S. Fifth St., and , 1535 W. Walker St., Milwaukee, Wis. REINOLDI, Charles (J 1937) Cadet Gas Engr., Washington Gas Light Co., 411 Tenth St., Washington, D. C.,'and (for mail) 3965 Wiisby Ave., Baltimore, Md. * RENOUF, E. Prince (Af 1933) Air Cond. Supvr.*, Westinghouse Elec. & Mfg. Co., 1005 Insurance' Bldg., and (for mail) 3431 Rankin St., Dallas, Tex. RENTE, Harry W. (Af 1931) Owner, Oil Burner Engr. and Contractor, 114 Morris Ave., Buffalo, N. Y. RESS, Otto J. (J 1937) Gas Htg. Engr., Iowa- Nebraska Light & Power Co., 1401 O St., and (for mail) 1900 South 17th, Lincoln, Nebr. RETTEW, Harvey F. (Af 1929) Chief Engr., Board of Education, 21st St: and the Parkway, and (for mail) Chelton Courts, Apt. B*29, 17th .& Chelton Ave., Philadelphia, Pa. '- REYNOLDS, Thurlow W. (Af 1922) Asst. Mech. Engr., New York World's Fair 1939, Inc., Flushing, L. I., and (for mail) 100 Pinecrest Drive, Hastings-on-Hudson, N. Y. / REYNOLDS, W. V. (A 1928) Pres, (for mail) Walter Reynolds, Inc., 861 Third Ave., and 444. East 52nd St., New York, N. Y. ' RHINE, George R. (A 1938) Air Cond. Engr. (for mail) San Antonio Public Service Co., 201 N1 St. Mary's St., and 155 Harrison Al. Hts., San . Antonio, Tex. '* RHOTON, W. R. (Af 1936) Pres., The W. R. Rhoton Co., 1305 East 107th, Cleveland, and (for mail) 1728 Lee Rd., Cleveland Heights. O. RICE, Clarence J. (A 1923) Pres, (for mail) Sterling Engineering Co., 3738 N. Holton St., and Route 6, Box 374, Milwaukee. Wis. RICE, Robert B. (Af 1934) Prof, of Experimental Engrg. (for mail) North Carolina State College, State College Station, and 700 W. Morgan St,, Raleigh. N. C. RICHARD, Edwin J. (Af 1933) Owner, Edwin J. Richard Equipment Co., 528 Chamber of Com merce Bldg., Cincinnati, O. RICHARDSON, Henry G. (Af 1934) Partner, Williams & Richardson, 204 Dooly Bldg., and (for mail) 1433 Harvard Ave., Salt Lake City.Utah. RICHARDSON, Robert D. (/ 1938) Htg. Drafts man. Messrs. Hope's Heating & Lighting. Ltd., Smethwick, and (for mail) 85 Silhill Hall Rd., Solihull, Birmingham, England. . RICHFIELD, Nicholas H. (Af 1937) Tech. Head, Oil Burner Div., American Radiator Co., 40 West 40th St., New York, and (for mail) 173 N. Tyson Ave., Floral Park, L. I., N. Y. RICHTMANN, W. M.* (A 1932; J 1926) Assoc, Prof, of Mech. Engrg. (for mail) Texas College of Arts and Industries, and 600 W. Richards St.,. Kingsville, Tex. . 52 f! II Roll of Membership RIES, Lester S. (Af 1929) Supt. of Bldgs, and ' Grounds (for mail) Oberlin College, 32 E. College St., and 221 Woodland Ave., Oberlin, O. RIESMEYER, Edward H., Jr. (A 1936; J 1930) Engr., Schaffer Heating Co., 231 Water St., and (for mail) 4702 Stanton Ave., Pittsburgh, Pa. RIETZ, Elmer W.* (Af 1923) Mgr. Specialty Div. . (for mail) The Powers Regulator Co., 2720 Greenview Ave., Chicago, and 2250 S. Sheridan Rd.. Highland Park, 111. RIGBY, Robert A. (A 1937) Sales Engr., Air Conditioning, and (for mail) 3325 North 48th Ave., Omaha, Nebr. RIST, Lawrence M. (/ 1937) Sales Engr. (for mail) Sidles Co., Airtemp Div., 502 South 19th St., and 3326 Harney, Omaha, Nebr. RITCHIE. A. G. (Af 1933) Pres, (for mail) John Ritchie, Ltd., 102 Adelaide St., E., and 41 Gar field Ave., Toronto, Ont., Canada. RITCHIE, E. J. (Af 1923) Vice-Pres.. Sales. Sarco Co., Inc., 183 Madison Ave., New York, and (for mail) 2 Grace Court, Brooklyn, N. Y. RITCHIE, William (Af 1909) 17 Van Reipen Ave., Jersey City, N. J. 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 St. Terrace, Kansas City, Mo. . ROBB, Joseph E. (A 1936) Sales Engr., Minneapolis-Honeywell Regulator Co., 2753-4th Ave., S., Minneapolis, Minn., and (for mail) 6020 Maple Ave., Overland Park. Kan. ROBERTS, Henry L. (Af 1916) Htg. Engr. and Contractor, Henry L. Roberts (for mail) 228 North 16th St., Philadelphia, and 1014 Ailston Rd., Brookline, Del. Co. (Upper Darby P. 0-) Pa. ROBERTS, Henry P. (A 1936) Secy, (for mail) Roberts-Hamilton Co., 713 South 3rd St., and 1901 James Ave., S.. Minneapolis. Minn. ROBERTS, James R. (A 1937; J 1934) Engrg. , Mgr. (for mail) Sutherland Air Cond. Corp., 15 N. Eighth St., and 5705-llth Ave., S., Minne apolis, Minn. ROBERTSON. James A. M. (A 1936) Vice-Pres. (for mail) The James Robertson Co., Ltd.. 946 William St., Montreal, and 109 Sunnyside Ave., " Westmount. P. Q., Canada. ROBINSON, Arthur S. (Af 1936) Engrg. Dept., E. I. duPont de Nemours Co., c/o Dye Works, Carney's Point, N. J., 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 St., Hyattsville, Md. ROBINSON, Earl T. (A 1938) Sales Repr., Crane Co., 201 Church St., and (for mail) 138 Wesley ; Ave., Buffalo, N. Y. ROBINSON, Edgar R. (A 1938) Development Engr., May Oil Burner Corp., and (for mail) 5434 Jonquil Ave., Baltimore, Md. ROBINSON, George L. (A 1935) Draftsman and Designer, E. I. duPont de Nemours (for mail) 210 West 28th St., Apt. I, Wilmington, Del. ROBINSON, Jack A. (J 1936) Air Cond. Engr., Australian Gas Light Co., Parker St.. Sydney (for mail) Box 481 AA, G. P. O., Sydney, and 595 New South Head Rd., Rose Bay, N; S. W.. Australia. ROCHE. I. F. (A 1936) Mgr. (for mail) Fess Oil Burners of Canada, Ltd., 1405 Drummond St., and 4709 Cole St. Catherine Rd.; Montreal, P. Q., 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 (for mail) Carnegie Institute of Tech nology,. Schenley Park,, and Glenover Place, Aspinwall, Pittsburgh, Pa. ' RODEE, E. John (Af 1936) Chief Engr. (for mail) John B. Pierce Foundation, 290 Congress Ave., New Haven, and 130 Bellevue Ave., West Haven, Conn. RODENHEISER, George B. (Af 1933) Asst. Dir. (for mail) David Ranken Jr. School of Mechanical Trades, 4431 Finney Ave., and 3639a Dover Place, St. Louis, Mo. RODGERS. F. A. (A 1934) Branch Mgr. (for mail) Minneapolis-Honeywell Regulator Co., 1916 Cedar Springs Rd., and 3421 St. Johns Drive, Highland Park, Dallas, Tex. RODGERS, Joseph S. (A 1937;. J 1934) Engrg. Draftsman, U. S. Government, Edgewood Arse nal, Edgewood, and (for mail) 1 Third Ave., Brooklyn Park, Md. RODMAN, R. W. (Af 1922) Supt. of Plant Opera tion (for mail) 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) 4020 Dickason St., Dallas, Tex. ROHLIN, Karl W. (Af 1930) Engr., Warren Webster & Co., 17th and Federal Sts., Camden, and (for mail) 4453 Terrace Ave., Merchantville, N. J. ROLLAND, Sverre L. (A 1934) Design Engr. (for mail) Oklahoma Gas & Electric Co., 321 N. Harvey. Ave., and 2131 Northwest 20th St., Oklahoma City, Okla. ROLLOSSON, John A. (J 1938) Pres, (for mail) Rollosson-Keeland Co., 3714 Main St., and 1920 McGregor Ave., Houston, Tex. RONSICK, Edward H. (Af 1937) Industrial Engr. (for mail) The St. Louis County Gas Co., 231 W. Lockwood, Webster Groves, and 7615 Marion Court, Maplewood, Mo. ROOS, Erik B. J. (J 1935) 23, Alwiyah, Baghdad, Iraq. . ROOT, Edwin B. (Af 1936) Mgr. Htg. & Air Cond. Dept., Nelson Co., 2604 Fourth Ave., Detroit, and (for mail) 964 Pierce St., Birmingham, Mich. ROSE, Harold J. (Af 1937) Sr. Industrial Fellow (for mail) Mellon Institute, 4400 Fifth Ave., and 219 Lytton Ave., Pittsburgh, Pa. ROSE, Howard J. (Af 1934) Mgr. of Engrg. Sales. Suburban Air Conditioning Corp., 7 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 (for mail) 8831 Fort Hamilton Pkwy., Brooklyn, N. Y. . ROSE, William H,, Jr. (J 1938) Sales Engr. (for mail) B. F. Sturtevant Co., 812 Michigan Theatre Bldg., and 5442 2nd Blvd., Detroit, Mich. ROSEBROUGH, J. Stoddard (A 1937) Sales Engr., L. J. Mueller Furance Co., 4246 Forest Park Blvd., and (for mail) 5917 Washington Ave., St. 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) Engr., A. B. Svenska . Fl&ktfabriken, Kungsgatan 8; Stockholm, and (for mail) Kv. Atlas 3, Lidingo, Sweden. ROSENBERG, Philip (A 1928) Secy.-Treas., Universal Fixture Corp., 137 West 23rd St., and (for mail) 250 West 104th St., New York, N. Y. ROSENBLATT, Arthur M. (Af 1938) Partner (for mail) Rosenblatt & Hunt, P. O. Box 828, 923 Virginia St., E., and 1250 Edgewood Drive, Charleston. W. Va. ` ROSENTHAL, Emanuel (5 1937) Student, New' York University (for mail) 1893 Vyse Ave., New York, N. Y. ROSS, John D. (A 1937) Sales Engr. (for mail) ' Railway & Engineering Specialties, Ltd., 637. Craig St., West, and 4376 : Eamscliff .`Ave., Montreal, P. Q., Canada. . 53 "S Heating Ventilating Air Conditioning Guide 1939 ROSS, J. O.* (Af 1920) Pres-, Rosa Industries Corp., 360 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 St., Elwood, Melbourne, S. 3, Australia. ROTH, Charles F. (A 1930) Pres, (for mail) International Exposition Co., Grand Central Palace, and 141 East 38th St., New York, N. Y. ROTH, Harold R. (Af 1936) Sales Engr. (for mail) Canadian Sirocco Co., Ltd., 67 Bloor St-, W., and 5 Castleview, Toronto, Ont., Canada. ROTHMANN, S. C. (Af 1936) Industrial Hygiene Engr. (for mail) West Virginia Compensation Commission, State Capitol Bldg., and 2008H Kanawha St., Charleston, W. Va. ROTTMAYER, Samuel I. (A 1933; J 1928) . Mech. Engr. (for mail)-Samuel-R.-Lewis, Con-' suiting Engineer, 407 S. Dearborn SL, and 6041 S. St. Lawrence Ave., Chicago. 111. ROWE, Irving E. (A 1936) Engr., Etie Sheet Metal Works, 1704 Houston Ave., and (for mail) 512 Bishop St., Houston, Tex. ROWE, William A.* (Af 1921) (Council, 1929 1931) Mech. Engr. (for mail) The Trane Co., LaCrosse, Wis., and 718 Longfellow Ave., Detroit, Mich. ROWE, William M. (7 1936) Salesman (for mail) American Blower Corp., 1302 Swetland Bldg., Cleveland, and 151 Bradley Ave., Chagrin Fails, O. 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. ROY, Arthur C. (A 1937) Metropolitan Sales Mgr., Hoffman Specialty Co., Inc., 500 Fifth Ave., New York, N. Y.. and (for mail) Box 507, Morristown, N. J. ROY, Leo (A 1937) Power Sales Engr. (for mail) Quebec Power Co., 229 St. Joseph St., and 41 Laurentide Ave., Quebec, P. Q., Canada. ROYER, E. B. (M 1928) Designing Engr., Fosdick 6 Hilmer, Consulting Engrs., 1703 Union Trust Bldg., and (for mail) 6635 Iris Ave., Cincinnati, O. RUDD, Dann J. (Af 1937) Htg. & Vtg. Engrg.. N. Y. City Board of Education, 49 Flatbush Ave. Extension. Brooklyn, and (for mail) 369 Deer Park Ave., Babylon, N. Y. RUDIO, H. M. (Af 1921) Regional Engr., Airterop Sales Corp., 631 Investment Bldg., Washington. D. C., and (for mail) 2704 N. Lexington St., Arlington, Va. RUEMMELE, Albert M. (J 1938) Sales Engr. (for mail) L. L. Siikensen & Co., Inc., 401-23rd SL, and 3628-0H. Galveston, Tex. RUFF. Adolph G. (Af 1935) SupL of Power, U.S. Playing Card Co.. Park Ave., Norwood, and (for mail) 3824 Woodford Rd., Cincinnati, O. RUFF, DeWltt C. (M 1922) Healy-Ruff Co., 765 Hampden Ave.. St. Paul, Minn. RUFF, Herbert A. (A 1938) Pres. & Treas., Herbert A. Ruff, Inc., 39 Olcott Place, Station E., Buffalo, N. Y. RUGART, Karl (A 1924) Owner Repr., Warren Webster & Co., and Kewanee Boiler Corp- (for mail) 26 S. 20th St., Philadelphia, and 612 Bryn Mawr Ave., Narberlh P. O., Penn Valley, Pa. RUGGLES, Robert F. (Af 1936; A 1927; J 1926) Dist. MgT., Autovent Fan & Blower Co., 2 Rector St., New York, and (for mail) 15 Gregg Place, Randall Manor. S. I., N. Y. RUMMEL, Adolph J. (M 1937) Air Cond. Engr. (for mail) San Antonio Public Service Co., 201 N. St. Marys SL, and 319 Thorman Place, San Antonio, Tex. RUNKEL, Charles (M 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., Manhattan Mfg. Co., 210 S. Lexington Ave., and (for mail) 170 Grand SL. White Plains. N. Y. RUSSELL, Edward A. (Af 1936) Chief Engr Vapor Car Heating Co., Inc., 1600 S. Kllbourn Ave., and (for mail) 8103 Dorchester Ave. Chicago, 111. " RUSSELL, J. N. (Life Member; M1899) Managing Dir., Rosser & Russell, Ltd. (for mail) Romney House Marsham SL, Westminster, and Fernacres Fulmer, Buckinghamshire. England. RUSSELL, Trafton W. (A 1938) Sales Engr L. J. Mueller Furnace Co., and (for mail) 3626 Harriet Ave., Minneapolis, Minn. RUSSELL, Wayne B. (A 1936) Engr., Russell Furnace Co., Inc., 601 N. Monroe, and (for mail) 1203 S. Cedar, Spokane, Wash. RUSSELL, William A. (M 1921) (Council. 1934 1938) (for mail) Hoffman Specialty Co., Water- bury, Conn., and 628_West 57th Terracc,-Kansas City, MoV * RYAN, H. J. (M 1922) Sales Engr. (for mail) The Trane Co., La Crosse, Wis., and 47 Harris Ave., Albany, N. Y. RYAN, James D. (M 1935) Supt. and Engr., Whitney National Bank, St. Charles and Gravier St., and (for mall) 215 N. Rendon St., New Orleans, La. RYAN, Joseph B. (M 1938) Chief Engr. & Mgr. (for mail) Engineering Service Co., 113 Railway Exchange Bldg., and 3904 Tracy Aye., Kansas City, Mo. RYAN, William F. (J 1933) Sales Engr., The Salina Supply Co., 302-304 North Santa Fe. and (for mail) 310 West Republic, Salina, Kan. . ' RYBOLT, Arthur L. (A 1938) Gen. Mgr., The Rybolt Heater Co., Miller St., Ashland, O. RYDELL, Carl A. (M 1931; J 1928) Owner. C. A. Rydell Associates.(for mail) 14 Chambria SL, Boston, and 286 Quinobequin Rd., Waban, Mass. RYERSON, Herbert E. (M 1937) Mgr. Air Cond.. Sales (for mail) Bryant Air Cond. Corp., 122 S. Michigan Ave., and 813 S. Clinton Ave., Chicago, 111. ` s. SABIN, Edward R. (Af 1919) Pres., E. R. Sabin & Co., 4710-12 Market SL, Philadelphia, Pa. SADLER, C. Boone. (M 1928) Associate Civil Engr., Uth Naval Dist., and 4828 Orchard Ave., San Diego. Calif. SAHLMANN, Frank L. (A 1937) Member Trans portation Dept., Electrical Mfg. (for mail) General Electric Co.-, and 3926 Beech Ave., Erie, Pa. . SAITO, Shozo (Af 1923) Saito Shozo Shoten, Ltd., .Marunouchi Bldg., Opposite Tokyo Station, Tokyo, Japan. . SALINGER, Robert J. (J 1937) Engr. (for mail) Reginald F. Taylor, Consulting Engineer, 909 Bankers Mortgage Bldg., and 1654 Danville, " Houston, Tex. SALLANDER, H. A. (A 1937) Branch Mgr.. Sidles Co., Airtemp Div., and (for mail) 4514 Fontenelle Blvd., Omaha, Nebr. SALTER, Ernest H. (Af 1936) Engr. (for mail) Electrical Testing Laboratories, 79th SL & East End Ave., New York, and 182 Cleveland Ave., Great Kills. S. I., N. Y. . SALZER. Alfred R., Jr. (5 1936) Box 7255, Oakland Station, Pittsburgh, Pa., and (for mail) 2322 N. Villere SL, New Orleans, La. SAMPSON, Edwin T. (A 1938) Mgr., Acoustical Dept.'(for mail) Atlas Asbestos Co., Ltd., 110 McGill SL, and 5382 Clanrauald Ave., Montreal, P. Q., Canada. SAMUELS, Sidney (A 1928; J 1925) Pres, (for mail) Sidney Samuels, Inc., 146 W. 99th St., and 825 West End Ave., New York, N. Y. SANBERN, E. N.* (Af 1923) Engr., Hoffman Specialty Cp.. Inc., 500 Fifth Ave., and (for mail) 523 West 112th St.. New York, N. Y. SANDERS, Charles M., Jr. (J 1938) Air Cond. Syndicate Repr. (for mail) Westinghouse Electric & Mfg. Co., 20 N. Wacker Drive, and 5830 N. Kenmore, Chicago, 111. 54 Roll of Membership SANDFORT, John F. (J 1938) Mech. Engr., SCHMID, John U. (/ 1938) Sales Engr., Louis Ohio State University, Architects' Office, and (for Allis Co., 427 E. Stewert, and (for mail) Milwau mail) 275 East Dunedin Rd., Columbus, O. kee Athletic Club. Milwaukee, Wis. . SANDS, Clive C. (M 1929) G. P. O. Box 601 F. F., SCHMIDT/E. Georg (Af 1938) Consulting Engr., Sydney, N. S. W., Australia. Berlin-Friedenau, Kirchstrasse 29, Germany. SANFORD, Arthur L. (M 1915) Mech. Engr., SCHMIDT, HarTy (Af 1937) Air Cond. Engr., C. H. Johnston, Archts. and Engrs., 360 Robert Feddera Mfg. Co., Inc., 57 Tonawanda St., and St., and 1129 Portland Ave., St. Paul, Minn. (for mail) 233 Norwalk Ave., Buffalo, N. Y. SANFORD, S. S * (Af 1930) Sales Engr. (for mail) SCHMIDT, Horace I. (J 1937) Branch Mgr. (for The Detroit Edison Co., 2000 Second Ave., and mail) Fedders Mfg. Co., Inc., 209 S. Pearl St., 1503 Seyburn Ave., Detroit, Mich. and 2615 Laclede SL, Dallas, Tex. SAPP, Charles L. (A 1936) Sales Mgr., Farquhar SCHMIDT, Karl, Jr. (J 1937) House Htg. Engr., Furnace Co., and (for mail) 620 North Walnut Michigan Consolidated Gas Co., 415 Clifford, SL, Wilmington, O. and (for mail) 14438 Mayfield Ave., Detroit, SAUNDERSTl. P. (Af 1933) Chief Engr., Research Mich. Div. (for mail) Harrison Radiator Div., General SCHMIELER, Joseph B. .(/..1938) Research . Motors Corp-. and 507 Pine SL.-Lockport; Nr Y. ' ` `Engr., A.S.H.V.E. Research Lab., U. S. Bureau SAUNIER, William C. (A-1938) Sales Engr. (for of Mines, 4800 Forbes SL, and (for mail) 220 mail) Straus-Frank Co., 301 South Flores St., Zara St.. Pittsburgh, 10, Pa. ' and 237 Pershing Ave., San Antonio, Tex. SCHMUTZ, Jean (Af 1933) Administrateur- SAURWEIN, George K. (Af 1938) Supt. Engrg; Delegue (for mail) Sodete P. R. S. M., 8 Passage Dept, (for mail) Harvard University, Lehman de 1'Atlas, and 18, rue Dufrenoy, Paris, XIX-0, Hall, Cambridge, and 247 Slade St., Belmont, France. - Mass. SCHNEIDER. Charles H. (J 1937) Sales Engr. SAWDON, W. M * (Af 1920) Prof, of Experimental (for mail) Ils Electric Ventilating Co., 1031 Engrg. (for mail) Cornell University, College of Commercial Trust Bldg., Philadelphia, Pb., and Engrg., and 1018 E. State SL, Ithaca, N. Y. 222 Second Ave., Haddon Heights, N. J. SAWHILL, R. V. (A 1929) Exec. Vice-Pres. (for SCHNELL, Robert H. (A 1938) Asst. Mech. Engr. mail) Domestic Engineering Co., 110 East 42nd (for mail) B. E. Landes, Mech. Engr., 915 St., New York, and 115 Townsend Ave., Pelham Hubbell Bldg., and 16l7-33rd SL, Des Moines, la. Manor, N. Y. SCHOEFFTER, Hans M. (J 1939) Sales Engr., SAWYER, J. Neal (J 1933) Asst. Mgr. Industrial Aerofin Corp.. 11 West 42nd SL, New York, DepL. Gustin-Bacon Mfg. Co., 1416 West 12th N. Y., and (for mail) 365 Westwood Ave., Old St., and 33 W. 58th SL, Kansas City, Mo. Tappan, N. J. SCALINCI, Clro R. (S 1938) 59 Pochard Ave.. SCHOENHOFEN, Leo H., Jr. (J 1938) Drafts Somerville, Mass. man, Oklahoma Gas & Electric Co., 3rd & Harvey SCANLON, Edward S. (A 1934) Utilization Engr.. (for mail) 605 N. W. 18th SL, Oklahoma City, Equitable Gas Co., 427 Liberty Ave., and (for Okla. mail) 3310 Regan Ave., Brentwood, Pittsburgh, SCHOENIJAHN, Robert P. (Af 1919) Consulting Pa. Engr. (for mail) Industrial Trust Bldg., and ' SCARLETT, William J. (Af 1936) Kooler-Keg - 719 Nottingham Rd., Wilmington, Del. Div., Novadel Agene Corp., Belleville, and (for SCHOEPFLIN. Paul H. (Af 1920) Pres, (for mail) mail) 91 Haddon Place, Montclair, N. J. Niagara Blower Co., 6 E. 45th St., New York, SCHAD, Clifford A. (A 1938; J 1937) Engr., and 91 Valley Rd., LarchmonL N. Y. United States Air Conditioning Corp., 2101 N. E. SCHOLL, Howard O. (J 1938; 5 1937) Engr., Kennedy St., and (for mail) 4425-43rd Ave., S., Colfax, lit. Minneapolis, Minn. SCHRE1BER, Herbert W. (A 1937) Sales (for SCHAFER, Harry C. (Af 1937) Sales Mgr. (for mail) Johnson Service Co., 507 East Michigan mail) Iroquois Gas Corp*. 45 Church SL, Buffalo, St., and 3136 N. Eighth St., Milwaukee, Wis. and 197 Union St., Hamburg, N. Y. SCHROTH, August H. (Af 1937) 167 N. Grove SCHECHTER, Jack E. (J 1937) Sales Engr.. St., P. O. Box 47,'East Orange. N. J. York Ice Machinery Co., and (for mail) 1720 N. SCHUETT, Donald F. (J 1938) Sales Engr., Orange Grove Ave., Los Angeles, Calif. Curtis Refrigerating Machine Co., South Central SCHECHTER, John P. (J 1935) House Htg. Dist. Repr. (for mail) 8038 Bartow, Dallas, Tex. Engr., Michigan Consolidated Gas Co., 415 SCHUETZ, Clyde C. (A 1936) Research Engr. Clifford, and (for mail) 1812 Burns Ave., De troit, Mich. (for mail) United States Gypsum Co., 1253 Diversey Pkwy., and 2728 W. Agatite Ave., SCHEIDECKER, Daniel B. (A 1919) Secy, (for Chicago, 111. . mail) Hunter-Clark Ventilating System Co., 2800 SCHULEIN, Ernst H. (J 1937) Consulting Engr., Cottage Grove'Ave., and 4626 N. Kilbourn Ave., Birch & Krogboe, 31 V. FarimagBgade, Copen Chicago, 111. hagen V., and (for mail) 3 Dalgas Blvd., Copen SCHERMER, Richard (J 1938; S 1938) Sales hagen F., Denmark. Engr., American Radiator Co., 40 West 40th St., SCHULER, William B. (A 1937) Sales. Taco New York, and (for mail) 40-67 Hampton SL. Heaters, Inc., 342 Madison Ave., New York, Elmhurst, L. I., N. Y. SCHERNBECK, Fred H. (A 1930) Salesman (for N. Y., and (for mail) 1536 East 69th St., Chicago, 111. mail) William Bros. Boiler & Mfg. Co., Nicollet island, and .5045 Portland Ave., Minneapolis, Minn. ' SCHERRER, Kenneth C. (J 1936) Engr., Natkin & Co., 114 E. Third, and (for mail) 12 East 12th St., Tulsa, Okla. SCHERRER, Leon B. (J 1936) Sales Engr., Adams Furnace Co., 3346 Watson Rd., and (for mail) 6112 Simpson Terrace, SL Louis, Mo. SCHLEMMER, Byron C. (J 1938; 5 1937) Engr. (for mail) Johnson Service Co., 300 Bond Bldg., Washington, D. C., and 162 Manchester Ave., SCHULTZ, Albert W. (Af 1936) Engr., Grinnell Co., Inc., 240-7th Ave., S,, and (for mail) 5204 France Ave., S., Minneapolis, Minn. SCHULTZ, Stewart F. (A 1938) Sales Engr., . Bruce Wigle Co., 9117 Hamilton Ave., and (for mail) 19312 Yacama, Detroit, Mich. SCHULZ, Edward L. (J 1937) Engr., Carrier Corp., S. Geddes St., and (for mail) 106 Dewitt Rd., Syracuse. N. Y. SCHULZ, Howard I. (A 1915) Crane Co., 1223 W. Broad St.. Richmond, Va. . Wabash, Ind. SCHULZE, Ben H. (Af 1921) Eastern Sales Mgr. SCHLICHTER, Charles F. (Af 1938) Dist. Mgr., (for mail) Kewanee Boiler Corp., 37 W. 39th St., Surface Combustion Corp., 2375 Dorr St:, and 67 Park Ave., New York, N. Y. Toledo, O.. and (for mail) 600 W SL, N. E., SCIIURMAN, John A. (M 1930; J 1935) Mgr., Washington, D. C. Central Region Air Cond. Div. (for mail) York SCHLICHTING, Walter G. CM 1932) Mgr., Air Ice Machinery Corp*. 2700 Washington Ave., Cond. DepL, Clarage Fan Co., and (for mail) N. W., Cleveland, and 14507 Delaware Ave., 1417 W. Lovell SL, Kalamazoo, Mich. Lakewood, O. 55 Heating Ventilating Air Conditioning Guide 1939 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. SCHWARTZ, Maurice (A 1938) Air Cond. Supervisor (for mail) Queens Borough Gas & ' Electric Co., 1610 Far Rockaway Blvd., Far Rocleaway, and 1445 Broadway, Hewlett, N. Y. SCHWARTZ, Norman E. (Af 1938) Gen. Mgr., Sidles Co.. Airtemp Div., 502 S. 19th, and (for mail) 4611 Davenport St., Omaha, Nebr. SCOFIELD, Paul C. (A 1937; 7 1933) Engr. (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., 3207 Chrysler Bldg., New York, and 3 Hawthorne Rd., Bronx* ville, N. Y. SCOTT, G. 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) Engr.. Alfol Insulation Co., Inc., 155 E. 44th St., New York, N. Y., and (for mail) 314 First Ave., Westfield, N. J. SEAL, Alfred T. (Af 1938) Air Cond. Engr. & Asst. Purchasing Agent,.Research Corp., Bound Brook, and (for mail) 60 Jennings Lane, North Plainfield. N. J. . SEARLE, William J., Jr. (Af 1937) Air Cond. Engr.. The Ballinger Co., 105 S. 12th St., Phila- . delphia, and (for mail) 207 Maple Ave., Narberth, Pa. SEARS, Charles B. (7 1938) College Traveler. John Wiley & Sons, Inc., 440-4tb Ave., New York, N. Y. SEEBER, R. R * (Af 1934) Head Mech. Engrg. ' Dept., Michigan College of Mining & Technology, 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., Minneapolis-Honeywell Regulator Co., 45 Allen St., and (for mail) 280 Crescent Ave., Buffalo, N. Y. SEELERT, Edward H. (A 1935) Secy.-Treas.. McQuay Inc., 1600 N. E. Broadway,' Minne apolis, Minn. - SEELEY, L. E.* (Af 1930) Asst. Prof, of Mech. Engrg. (for mail) Mason Laboratory, Yale University, and 130 Everit St., New Haven, Conn. ` SEELIG, A. E. (Af 1926) Pres. & Gen. Mgr., L. J. Wing Mfg. Co., 154 W. 14th St., and (for mail) 640 Riverside Drive, New York, N. Y. SEELIG, Lester (Af 1925) Head Engrg. Dept., Museum of Science & industry, Jackson Park, and (for mail) 725 Irving Park Rd., Chicago, 111. SEIDEL, Glenn E. (7 1937; S 1936) Tulane Uni versity, and (for mail) 1437 Audubon St., New Orleans, La. SETTER, J. Earl* (Af 1928) Asst. Mgr. in Charge of Dist. Steam Sales, Consolidated Gas, Electric Light & Power Co., Lexington Bldg., Baltimore, Md. SEK1DO, Kunisuke (Life Member, Af 1903) Consulting Engr., 685 Marunouchi Bldg;, and (for mail) 19 Momozono, Nakano, Tokyo, Japan. SELIG, Ernest T., Jr, (Af 1936) Registered Professional Engr. and Industrial Fellow (for mail) Mellon Institute of Industrial Research, 4400 Fifth Ave., and 6609 Woodwell St.. Squirrel Hill, Pittsburgh, Pa. SELLMAN, Nils T. (Af 1922) Asst. Vice-Pres., Consolidated Edison Co. of New York, Inc., 4 Irving Place, New York, N. Y. SELTZER, Paul A. (7 1938) Engr. (for mail) Bryant Air Conditioning Corp., 830 N. Broad St., Philadelphia, and 154 E. Marshall Rd.. Lansdowne, Pa. SENIOR, R. L. (Af 1925) Pres, (for mail) R. L. Senior, Inc., 103 Park Ave., New York, and 10 Cherry Ave., New Rochelle, N. Y. . SESSLER, Robert E. (5 1938) 52 Fountain Rd:, Arlington. Mass. `* SETTELMEYER, James T. (7 1937) Engr., Blocker Air Conditioning Corp., 825 Frelingl huysen Ave., Newark, and (for mail) 293 North Oraton Pkwy., East Orange, N. J. SEVERNS, W. H.* (Af 1933) Prof. Mech. Engrg. (for mail) University of Illinois, and 609 Indiana Urbana. 111. SEYMOUR, James E. (A 1937) Owner, Lee & Seymour Warm Air Htg. & Sheet Metal Works, 346 Russell St., and (for mail) 208 Lakewood Blvd., Madison, Wis. SHAER, I. Ernest (A 1934) Treas., Capitol En gineering Co., 71 Rogers St.. Cambridge, and (for mail) 43 Ormond St., Dorchester, Mass. SHAFFER, Chester E. (Af 1937) Research Engr., Koppers Co., Kearny, N. J. SHANKLIN, Arthur P. (Af 1929) Divisional Sales Mgr. (for mail) Carrier Corp., and 618 Rugby Rd., Syracuse, N. Y. SHANKLIN, John A. (Af 1928) Vice-Pres. & Treas. (for mail) West Virginia Heating & Plumbing Co., 233 Hale St., and 1507 Quarrier St., Charleston, W. Va. . SHAPIRO, Charles A. (7 1938) Sales Engr., Johnson Service Co., 2853 N. 12th St., and (for mail) 2041 N. Wanamaker St., Philadelphia, Pa. SHAPIRO, Maurice M. (7 1937) Brandi Engr., Sidles Co., Airtemp Div., 1228 "P" St., and (for mail) 2145 "N" St., Lincoln, Nebr. * SHARP, Henry C. (Af 1935) Dist. Repr. (for mail) Herman Nelson Corp., and 1204 24th Ave.. Moline, 111. -. SHARP, John R. (A 1937) Supervisor, Htg. and ' Air Cond. Reprs., Bergen Div., Public Service . Electric & Gas Co., 235 Main St., Hackensack, and (for mail) Maple St., Haworth, N. J. SHAW, Burton E.* (A 1936; 7 1934) Research Chief (for mail) Penn Electric Switch Co., Goshen, and The Maples, Bristol, Ind. SHAW, Charles G. (A 1936) Engr. and Prop., Shaw Engineering Co., Port Arthur, Tex. SHAW, Norman J. H. (Af 1927; 7 1925) Barnes & Jones, Inc., 128 Brookside Ave., Jamaica Plain, and (for mail) 37. Benjamin Rd., Arlington, Mass. SHAW, John A. (Af 1938) General Elec. Engr. (for mail) Canadian Patific Railway Co., Windsor Sta., Montreal, and 448 Lansdowne Ave., Westmount, P. Q., Canada. ' SHAWLIN, Walter C. (A 1931) Mgr., industrial Air Cond., Northwestern Ventilation Co., 2540 West Wells St., Milwaukee, Wis. SHEA, Michael B. (Af 1921) Sales Dept, (for mail): American Radiator Co., 8019 Jos. Campau, and 4080 Blaine, Detroit, Mich. SHEARS, Matthew W. (Af 1922) Engr. (for mail) C. A. Dunham Go., Ltd., 1523 Davenport Rd.,-- . and 39 Sylvan Ave., Toronto, Ont., Canada. SHEFFIELD, Raymond A. (Af 1937) Prop., Air Conditioning Engineering Co., Cambridge, and (for mail) 84 Governor Winthrop Ave., Somer ville. Mass. SHEFFLER, Morris (Af 1921) Pres, (for mail) Sheffler-Gross Co., 1000 Drexel Bldg., Phila delphia, and 419 Chapel Rd., Melrose Park, Montgomery Co., Pa. * SHELDON, Nelson E. (Af 1927) Dist. Mgr. (for mail) Carrier Corp., 302 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, Earle D. (Af 1937) Pres, (for mail) Glanz & Killian Co., 1761 W. Forest Ave., Detroit, and Box 243, Birmingham. Mich. SHELNEY, Thomas (Af 1931) Pres., Pierce Blower Corp., 105 Brayton St.. Buffalo, N. Y. SHENK, Donald H. (Af 1934) Assoc. Prof. Mech. Engrg: (for mail) Clemson Agriculture College,- Riggs Hall, Clemson, S. C. ' ,. SHEPARD, John deB. (Af 1937; 7 1929) Air Cond. Repr. (for mail) Consolidated Gas Electric Light & Power Co., Lexington Bldg., Room 406, and Tudor Arms Apts., W. University Pkwy., Baltimore, Md. r 56 Roll or. Membership SHEPHERD, Clark B. (Af 1937) Chemical Engr. : SIMISON, Allen L. (Af 1937) Research Engr.,. (for mail) E. I. duPont de-Nemours & Co., Owens-Coming Fiberglas Corp.^Owens-Illinois .duPont Experimental Station, and - Gordon Lab., and (for mail) 166 North 21st SL, Newark, Heights, Wilmington, Del.. O. SHEPPARD, F. A. (Af 1918) Salesman (for-mail) SIMKIN, Milton (7 1936; S 1933) Engr., Buensod- Johnson Service Co., 1031 .Wyandotte St., and Stacey Air Cond, Inc., 60-E. .42nd St.,. New 27 East 70th St., Kansas City, Mo. York, N. Y., and (for mail) 103 Brighton Ave.,. SHEPPERD, Parker D. (7 1938) Sales Engr. (for! Perth Amboy, N. J.. mail) Johnson Service Co., 814 Rialto Bldg., San SIMONS, Byron C. (Af 1938) St. Louis Branch Francisco, and 1126 Capuchino Ave., Burlin Mgr. (for mail) Minneapolis-Honeywell Regu game, Calif. . lator Co., 3033 Locust Blvd., St; Louis, and 442 SHERBROOKE, Walter A. (Af 1938) Mgr.,: Woodlawn, Webster Groves, Mo. Tech. Div. (for mail) Utica Radiator Corp., and SIMONS, Edward W. (Af 1938) Engr., Redwood 15 Melrose Ave., Utica, N. Y. Manufacturers Co., 1600 Hobart Bldg., and (for SHERET, Andrew (Af 1929; A 1925) Pres, (for mail) 2418-30th Ave., San Francisco, Calif. - mail) Andrew Sheret, Ltd., 1114 Blanshard St., SIMONSON, George M. (Af 1937) Consulting and 1030 St. Charles St., Victoria, B. C., Canada. Engr. (for mail) 74 New Montgomery St., San SHERMAN, Ralph A.* (Af 1933) Supvr., Fuels Francisco, and 20 Loreta Ave., Piedmont, Calif. Div. (for mail) Battelle Memorial Institute, 505- SIMPSON, Arthur M* (A 1935) Chief Engr., King Ave., and 1893 Coventry Rd., Columbus, O. and Sales Mgr. (for mail) Van Kannel Revolving SHERMAN, Victor L. (Af 1935) Acting Head,_ Door Co., 101 Park Ave., New York, and 37-34 Dept. Mech Engrg., Lewis Institute, 1951 W." 85th St., Jackson Heights, N. Y.. Madison St., Chicago, and (for mail) 643 Hillside SIMPSON, W. K. (Af 1919) Vice-Pres. (for mail) Ave., Glen Ellyn, 111. Hoffman Specialty Co., and 9 Sands St., Water- SHERMAN, W. P. (Af 1937) Commercial Branch bury, Conn. `' ' Engr., York Ice Machinery Corp., 412 Houston SINGLETON, John H. (A 1937) Gen. Mgr. (for St., N. E., and (for mail) P. O. Box 2210, Atlanta, mail) Annas Heat & Cold, Inc., 13 N. Perry, and Ga. 66 Franklin Blvd.. Pontiac, Mich. SHERWOOD, Laurence T. (Af 1937) Glass SKELLEY, Jerome H. (A 1938) Educational' Technologist, Pennsylvania Wire Glass Co., Instructor, Delco-Frigidaire Cond. Div., and (for Dunbar, Fayette Co., Pa. mail) 306 General Motors Research Bldg., SHIELDS, Carl D. (7 1937; 5 1936) 213 Crescent Detroit, Mich. - ' Dr., Akron, O. - SKIDMORE, John G. (A 1937; 7 1930)' Sales. SHILLING, Howard C. (A 1936) Salesman (for Engr., Carrier Corp., 405 Lexington Ave., New mail) Barber-Colman^Co., 221 N. La Salle St., York, and (for mail) 5101-39th Ave., Long and 7068 N. Paulina St., Chicago, 111. ' Island City, N. Y. SHIPLEY, Sylvanus C. (Af 1938) Cost Engr., SKINNER, Henry W. (Af 1920> Consulting Engr., (for mail) Minneapolis-Honeywell Regulator Co., 4816 Dexter St., Fort Worth,:;Tex. ' 2753 4th Ave., S. and 1550 East River Terrace, SKLAREVSKI, Rimma (7 1936) Instrument Minneapolis, Minn. Engr., Russian. Div., Brown Instrument' Co.-, SHIRLEY, William B. (Af 1937) Sales Mgr. (for Wayne and Roberts Aves., Philadelphia, Pa., and mail) Lennox Furnace Co., Inc., Marshalltown, (for mail) 226 East University Pkwy., Baltimore, la., and Mayfair Hotel, Charlotte, N. C. Md. SHIVERS, Paul F. (Af 1930) Chief Engr., Re SKLENARIK, Louis (A 1937; 7 1928) 305 East search Div. (for mail) Minneapolis-Honeywell 72nd St., New York, N. Y. Regulator Co., W. Canal St., and 75 W. Maple SLAWSON, Lloyd E. (A 1938) Mgr., Temperature St., Wabash, Ind. Control Dept, (for mail) Barber-Colman Co.,. SHODRON, John G. (Af 1921) Prof., Marquette University Engrg. School, and (for mail) 1810 3030 Euclid Ave., and 16711 West Park Blvd., Cleveland, O. West Wisconsin Ave., Milwaukee, Wis. SLAYTER, Games (Af-1931) Vice-Pres..(for mail) SHOEMAKER, Forrest F. (A 1936) Pres, and Owens-Coming Fiberglas Corp., and 1181 Evans- Mgr. (for mail) Air Conditioning Co., Inc., 222 dale St., Newark, O. Central Bank Bldg., and 2412 East 22nd St., SLEMMONS, John D. (Af 1937) Branch Mgr., Tulsa, Okla. American Blower Corp., Columbus, and (for mail) SHORB, Will A. (Af 1909) Dist. Mgr., Decatur Rte. 2, Wilson Rd., Worthington, O. Pump Co., Decatur, 111., and (for mail) 47 N. SLUSS, Alfred H. (Af 1935) Prof. Mech. and Lime St., Apt. 6, Lancaster, Pa. SHORE, David (7 1938) Research Engr. (for mail)- Industrial Engrg., University of Kansas, and (for ' mail) 827 Mississippi Ave., Lawrence, Kan.. A.S.H.V.E. Research Laboratory, 4800 Forbes SMAK, Julius R. (A 1934) Supt. of Service Dept., St., and 969 Flemington St., Pittsburgh, Pa. Crane Co., South Ave., and (for mail) 3135 Park SHROCK, John H. (Af 1924) Vice-Pres. (for mail) Ave., Bridgeport, Conn. . New York Blower Co., and 1002 Indiana Ave.,1 SMALL, Bartlett R. (Af 1938; A 1937; 7 1932) LaPorte, Ind. Senior Engr., Carrrier Dept, (for mail) Dravo SHULTZ, Earle (A 1919) Commercial National ' Corp., 300 Penn Ave., and 2924 Belrose Ave., Safe Deposit Co., 72 West Adams St., Chicago, III. (16), Pittsburgh, Pa. SIDELL, Philip A. (7 1938; 5 1937) Gale Prod. Div. (for mail) Outboard Marine & Mfg. Co., and 456 N. Cherry St., Galesburg, III. - SIEBS, Claude T. (A 1927) Service Systems Engr. -. (for mail) Western Electric Co., Inc., 195 Broad way, New York, N. Y., and 185 Kent Place Blvd., Summit, N. J. SIEGEL, Daniel E. (5 1938) Student. Washington University (Evening School) St. Louis, and (for mail) 7716 Wise Ave., Richmond Heights, Mo. SIEGEL. William A. (Af 1937) Field Supt., York Ice Machinery Corp., 117 South 11th SL, St. Louis, and (for mail) 3333 Cambridge; Maple wood, Mo. SMITH, Elmer G> (Af 1929) Assoc. Prof, of Physics (for mail) Agricultural & Mechanical College of Texas, Department of Physics, College Station, Tex. SMITH, Card W. (Af 1927) Sales Engr., Premier Furnace Co., Dowagiac, Mich., and (for mail) 1131 Guilford St., Huntington, Ind. - . SMITH, Gerald E. (7-1938) Sales Engr. (for mail) Canadian Sirocco Co., Ltd., 57 BloorSL, W., and 52 Parkway Ave., Toronto, Ont., Canada. SMITH, Jared A. (A 1933) (for mail) Jared A. . Smith & Co.. 481 S. High St., and 102 N. Park- . view Ave., Bexley, Columbus, O. SIGMUND, R. W. (Af 1932) Dist. Mgr. (for mail) SMITH, J. Darrell (Af 1933) Mech. Engrg. Dept. B. F. Sturtevant Go., 913 Provident Bank Bldg., Philadelphia & Reading Coal & Iron Co., and and 304 Oak St., Cincinnati, O. 317 North 19th St., Pottsville, Pa. ' SILBERSTEIN, Bernard G. (Af 1937) Dist. Mgr... SMITH, Milton S. (Af 1919) Treas. (for mail) (for mail) Ilg Electric Ventilating Co., 622 Broadway, Rm. 713, and 814 East Mitchell Ave., Buensod-Stacey Air Conditioning, Inc., 60; East 42nd St., New York, N. Y., and 13 N. Terrace, Cincinnati, O. Maplewood, N. J. 57 Heating Ventilating Air Conditioning Guide 1939 SMITH, Nelson J. (M 1938) Air Cond. Design SOULE, Lawrence C-* (Af 1908) Secy, and Con Engr., Frigidaire Div., 300 N. Taylor St., Dayton, O. sulting Engr., Aerofin Corp., Syracuse, N. Y., and (for mail) Essex Fells, N. J. SMITH, Randall A. (A 1938) Partner (for mail) Delavan Engineering Co., 414-12th St., and 664 26th St.. Des Moines, la. SOUTHMAYD, Richard T. (J 1936) Salesman (for mail) American Blower Corp., 1302 Swetiand Bldg., Cleveland, and 65 Church St., Chagrin SMITH. Reginald J. (Af 1936) Mgr., Smith & Elston. 71 Third Ave., and (for mail) 112 S. Maple St., Timmins, Ont., Canada. SMITH, Stuart (A 1936) Mgr., Cincinnati Branch, Falls. O. SPARK, William (Af 1938) Mgr.. Insulation . Dept, (for mail) Atlas Asbestos Co., Ltd., 110 McGill St., and 6171 Sherbrooke St., W., American Radiator Co., 808 Times Star Bldg., and (for mail) 1188 Hersche! Ave., Cincinnati, O. SMITH, Wilbur F. (Af 1920) Consulting Engr., Montreal, P. Q., Canada. SPARKS, James D.(A 1937) Northwest Repr., Jig Electric Ventilating Co., Chicago. 111., and W. M. Anderson Co., 600 Schuylkill Ave., and (for mail) 709 Braebum Lane, Penn Valley, Narberth P. O.. Pa. SMITH, William D. (Af 1937; A 1935) Pres, (for (for mail) 7331 W. Green Lake Way, Seattle, Wash. `- ' SPECKMAN, Charles H. (Af, 1918) Consulting Htg. and Vtg. Engr., Room 375, Philadelphia mail)-Bryant-Smith,-Inc.,-2153- Prospect -Ave., Cleveland, and 3265 Enderby Rd., Shaker Heights, O. SMITH, William O. (A 1937) Pres, (for mail) Smith Automatic Heat Service Co., 19250 John R St., Detroit, and 343 E. Mapiehurst, Ferndale, Mich. SMOOT, T. H. (Af 1935) Mgr. & Chief Engr.. Fluid Heat Div., Anchor Post Fence Co., 6500 Eastern Ave., and (for mail) 2512 Talbot Rd., Baltimore, Md. SMYERS, .Edward C. (A 1933) Sales Engr.. - Bourse, Philadelphia, Pa. - ------- ~ " SPELLER, F. N. (Af 1908) Advisory Engr. (for mail) National Tube Co., P. O. Box 266, and 6411 Darlington Rd., Pittsburgh, Pa. SPENCE, Morton R. (J 1934).Asst. Purch. Agt. (for mail) Runelle & Spence Mfg. Co., 445 N. Fourth St., and 709 E. Lexington Blvd., Milwau kee, Wis. ' SPENCE, Robert A. (J 1937) Mecb. Engr., Boston Edison Co., 39 Boylston St., Boston, and (for mail) 37 Davis Rd., Belmont. Mass. SPENCE. Robert T. (A 1935) 1556 South 60th Barber-Colman Controls. 1013 Penn Ave., Wilkinsburg, and (for mail) 148 Jamaica Ave., West View, Pittsburgh, Pa. SNAVELY, A. Bowman (M 1937) Chief Engr., St.. West Allis. Wis. . SPENCER, Dean (A 1937) Commercial Mgr,- (for mail) Brown Electric Division-, Brown Supply , Co., 120 E. Grand, and 3110 Northwest'23rd,* , Hershey Chocolate Corp., Hershey. Pa. SNAVELY, Earl R. (Af 1937) Prof, of Air Cond. and Dir. of the School of Refrigeration, New York Technical Inst., 108 Fifth Ave., New York, N. Y., and (for mail) 222 Victory St., Rosetle, N, J. - 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) 0 KnowUon Ave., Ken- more. N. Y. ' SODEMANN. Paul (Af 1926; J 1920) Sales Engr., Oklahoma City, Okla. SPENCER, J. Boyd (Af 1935) Pres. & Treas. (for mail) Spencer Air Conditioning Co., 515 Essex Bldg., and 2215 Newton Ave., S., Minneapolis, Minn. .' SPENCER. Roland M. (/ 1034) Branch Mgr. (for mail) The Powers Regulator Co., 329 M-& M Bldg., and 2715 Rosedale, Houston, Tex. SPENCER, Warner E. (A 1938) Mgr., Buffalo Branch (for mail) National Radiator Corp., P. O. Box 136 No. Tonawanda, and 212 Bidwell Pkwy.', Buffalo, N. Y. SPIELMANN, Gordon P. (A 1931; J 1923) Vice- Pres. (for mail) Harrison-Spielmann Co., 480 Milwaukee Ave., Chicago, and 730 N. Prospect Sodemann Heat & Power Co., 2306 Delmar Blvd., and (for mail) 4136 Farlin Ave., St. Louis, Mo. Ave., Park Ridge, 111. SPIELMANN. Harold J. (Af 1933) Air Cond. SODEMANN. William C. B. (Af 1919) Pres, (for Engr., Vilter Mfg. Co.. 53 W. Jackson Blvd., mail) Sodemann Heat & Power Co., 2306;Delmar Chicago, and (for mail) 507 Elmore Ave., Park Blvd., St. Louis, and 7542 Teasdale Ave., Ridge. 111. University City, Mo. SPITZLEY, Joseph H. (J 1939) Junior Member SOETERS, Matthew (M 1937) Consulting Engr., (for mail) R. L. Spitzley Heating Co., 1200 W. 5392 Seebaldt Ave., Detroit, Mich. Fort St., Detroit, and 26 Renaud Rd., Grosse SOGG, Allen (A 1937) Sales . Engr., Strong, Carlisle & Hammond Co., 1392 W. Third St., Cleveland, and (for mail) 3084 E. Derbyshire Rd., Cleveland Heights, O. SOLSTAD, Lester L. (J 1936) Development Engr., American Radiator Co., Air Filter Div., 1330 W. Congress, and (for mail) 5128 Black- stone. Chicago, 111. - SOLZMAN, Isel I. (A 1937) Owner (for mail) Pasol Engineering Co., 532 World Herald Bldg., and 2714 North 55th St., Omaha, Nebr. SOMERS. William S. (Af 1938; A 1928; J 1926) Chief Engr., Lamneck Products, Inc., 416 Dublin Ave., and (for mail) 2229 Coventry Rd., Colum bus, O. SOMMERFIELD, Sumner S. (J 1936) Instructor, Refrigeration St Air Conditioning Inst.. 2130 Lawrence Ave., and (for mail) 5705 School St., Chicago, 111. SOMMERS, William J. (Af 1937) Sales Repr., Hg Electric Ventilating Co., 505 Delaware Ave., Buffalo, and (for mail) 150 Stillwell Ave., Kenmore, N. Y. SONNEBORN, Charles (Af 1930) R. D. No. 3. New Castle, Pa. ' SOPER, H. A. (Af 1916) Vice-Pres. (for mail) American Foundry & Furnace Co.,'Washington at McClun St., and 1122 E. Monroe St., Bloom ington, 111. . Pointe, Mich. . SPITZI EY. Ray L. (Af 1920) Pres. & Gen. Mgr. (for mail) R. L. Spitzley Heating Co.. 1200 W. Port St., Detroit, and 26 Renaud- Rd., Grosse Pointe Shores, Mich. SPOERR, Frank F. (J 1937) Carrier Engr., Air Cond. Div., Hearnens, So. Warren & E. Front St., Trenton, N. J., and (for mail) 140-19 Queens Blvd., Jamaica. N. Y. ' SPOFFORTH, Walter (Af 1930) Chief of Mech. Services. (J. S. Penitentiary, McNeil Island, and (for mail) 615 N. Ainsworth Ave., Tacoma, Wash. SPREKELMEYER, J. M. (Af 1938) Mgr. (for mail) General Engineering Corp., 1014 Jehnings Ave.. and 1912 Beuhall Court, Fort Worth', Tex. SPRING. Claude L. (A 1938) Htg. Engr., Des. Moines Stove Repair Co., 107 S. W. 2nd Ave., and (for mail) 3840 Columbia Ave., Des Moines, la. . SPROULL, Howard E. (Af 1920) Div. Sales Mgr. (for mail) American Blower Co., 1005-6 American Bldg., arid 3588 Raymar Drive, Cincinnati, O. SPURGEON, Joseph H. (Af 1924) Salesman (for mail) Spurgeon Co., 5203 General Motors Bldg., and 17215 Pennington Drive. Detroit. Mich. SPURNEY, Felix E. (A 1938) Bldg. Mgr., Federal Reserve Bldg., 20th St Constitution Avea., N. W., Washington. D. C., and (for mail) 10 Calvert Place, Kensington, Md. 58 Roll of Membership STACEY. Alfred E., Jr.* (Af 1914) Vice-Pres;, Buensod-Stacey Air Conditioning, Inc., 60 East ` 42nd St., New York, N. Y,, and (for mail) 35 Wotton Rd., Essex Fells, N. J. STACK, Arthur E. (A 1935) Asst. Mgr. of Utilization Dept., Washington Gas Light Co. of D. C., 411 10th St., N. W.. Washington, D. C.. and (for mail) 911 Gist Ave., Silver Spring, Md. STACY, Loyd D. (A 1936) Sales Engr., Ug Electric Ventilating Co.. 182 N. La Salle St., and (for mail) 7434 N. Oakley Ave., Chicago, 111. STACY, Stanley C. (Af 1931) Mech. Engr. (for mail) Board of Education, 13 S. Fitzhugh St., STEENKAMP, Willem (S 1938) Graduate Stu dent (for mail) Senior House, Massachusetts Institute of Technology, Cambridge. Mass., and Box 12, Sheepmoor, Ermelo, Transvaal, Union of South Africa. -. STEFFNER, Edward F. (A 1937; J 1934) Htg. and Air Cond. Engr., Henry Furnace & Foundry Co., 3471 East 49th St., Cleveland, and (for mail) 1427 East 133rd St., East Cleveland. O. . STEGGALL, Howard B. (A 1934) Branch Mgr. (for mail) United States Radiator Corp., 941 Behan St., and 1166 Murray Hill Ave., Pitts burgh, Pa. ' and 531 Wellington Ave., Rochester, N. Y. STAFFORD, J. Fuller (A 1938) Owner, J. Fuller Stafford, Steam Specialties, 519 N. Snelling Ave., St. Paul, and_2925-33 Ave.,-S., Minneapolisr Mirin. ' STAFFORD, Thomas D. (A 1937) Secy.-Mgr., Alexander-Stafford Corp., 313-19 Alien St., N. W., and (for mail) 954 Ogden Ave., Grand Rapids, Mich. STAHL, Walter A. (Af 1938) Operating Engr., Real Estate Div., Marshall Field & Co., 222 Bank Dr., Chicago, and (for mail) 2504 Harrison St., Evanston, 111. STALB, Joseph G. (A 1934) Mgr., Air Cond. Div., Reynolds Corp., 19 Rector St., New York, and (for mail) 149 Columbia Heights. Brooklyn, N. Y. STAMMER, Edward L. (Af 1919) Supt. Htg. and Vtg., Board - of Education, Ninth and Locust STEHL, Howard V. (A 1936) Sales Engr. (for mail) Campbell Metal Window Corp., P. O. Box 148, and 10 Gwynnlake .Drive, Woodlawn,- ' Baltimore, Mdl ' STEINER, Theodore J. (A 1938) Engr., Pomona Sheet Metal Works, and (for mail) 14807 Condon Ave., Lawndale, Calif. STEINHORST, T. F. (Af 1919) Pres., Emil Steinhorst & Sons, Inc., 612-616 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. STEINMETZ, C. W. A. (Af 1934) Mgr. of Newark Office (for mail) American Blower Corp., 249 High St., Newark, and 50 Oakwood Ave., Bogota, N. J. Sts., and (for mail) 4430 Tennessee Ave., St. Louis, Mo. .STANDRING, Ronald A. (J 1938) Htg. Designer, Gurney Foundry Co., Ltd., 100 Principal St., STELLWAGEN, Frank G. (A 1937) Salesman, Fitzgibbons Boiler Co., Inc., 101 Park Ave., New York, and (for mail) 8637-77th, Woodhaven. N. Y. St. Laurent (near Montreal) and (for mail) 4838 Lafontaine St., Viauville, Montreal, P. 0., Canada. . STE-MARIE, Gaston P. (M 1930) Examiner Technician (for mail) Department of Labour, Provincial Government, 97 Notre-Dame St., STANFIELD, Richard E. (J 1938) Industrial East, and 4251 Marril Ave., Apt. 26, N. D. G., Engr. (for mail)' Nebraska Power Co., 723 Montreal, P. Q,, Canada. Electric Bldg., and 5013 Cuming St., Omaha, STENCEL, R. Arthur (Af 1938) Chief Engr., Nebr. Canadian Ice Machine Co., Ltd;, 65 Villiers St., STANGER, R. B. (Af 1920) Prop, (for mail) Robinson & Stanger'. Empire Bldg., Pittsburgh, and 45 Willowbank Blvd., Toronto, Ont., Canada. and Middle Rd., Glenshaw, Pa. STENGEL, Frank J. (A 1935) Secy, (for mail) STANGLAND, B. F. (Charter Member) (2nd VicePres., 1908; Board of Governors, 1905-1906-1909; Board of Mgrs.. 1895-1899; Council, 1896-1897) Retired Htg. & Vtg. Cons. & Constr. Engr., Howard & Morse, New York, and (for mail) . Kendall. N. Y. STANLEY, Robert L. (Af 1938) Engr., Payne Furnace & Supply Co., 338 N. Foothill Rd., Beverly Hills, and (for mail) 2518 Dearborn Drive, Hollywood, Calif. STANNARD, J. M.* (Life Member; Af 1906) Pres, and Treas. (for mail) Stannard Power Equipment' Co-, 53 W. Jackson Blvd., Chicago, ana 1402 . Elinor Place, Evanston, 111. STANTON, Harold W.. (Af 1937) Commercial Engr. (for mail) Iowa-Nebraska Light & Power R. F. Stengel & Son, 76-80 Rosehill PI., and 321 Myrtle Ave., Irvington, N. J. STEPHENSON, L. A. (Af 1917) Mgr. (for mail) The Powers Regulator Co., 409 East 13th St., and 801 West 57th Terrace, Kansas City, Mo. STERLING, James G., Jr. (S 1936) 1841 Wilton Rd., Cleveland Heights, O. 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., Anno Cooling & Ventilating Co.,. 30 West 15th St., and (for mail) 58 East 92nd St., New York, N. Y. STERNE, Cecil M. (A 1934) Chief Engr., Metro politan Refining Co.. Inc., 23-28-50th Ave., Long Island City, N. Y. Co., and 2807 Washington St., Lincoln, Nebr. STERNER. Douglas S.(J 1938; A 1936) Electrical STARK. W. E.* (Af 1920) Regional Mgr., The Div., Barber-Colman Co., Rockford, 111. Bryant Heater Co., 17825 St. Clair Ave.. Cleve land, and (for mail) 1875 Rosemont Rd.. East Cleveland, O. STETSON, L. R. (Af 1913) Engr., McMurrer Co., 303 Congress St., Boston, and (for mail) 35 Bradfield Ave., Roslindale, Mass. STARR. Lyndon (A 1938) Field Repr., Refrigera tion & Air Cond. Inst., and (for mail 1340 Midland Dr., University City, Mo. STEVENS, Alfred L. (J 1938) Refrigerating Engr;, Mollenberg-Betz Machine Co., 20 Henry St., Buffalo, and (for mail) 45 Pasadena Place, STASZESKY, Francis M. (S 1938) Student (for Williamsville, N. Y. mail) Massachusetts Institute of Technology Dormitories, Cambridge, Mass., and 10 Roselawn. Wilmington, Del. STEVENS, Harry L. (Af 1934; A 1927; J 1924) Secy.-Treas. (for mail) M. M. Stevens Co., 108 W. Sherman St., and 7 West 22nd St., Hutchin- STEEL, R. Justin (A 1938) Engr. (for mail) . son, Kan. Wilmington Auto Sales Co., 221 West Tenth St., Wilmington, and 19 Amstel Ave., Newark, Dei. STEVENS, Kenneth M. (/ 1936) Sales Engr. (for mail) The Powers Regulator Co., 409 East 13th, STEELE, John B. (Af 1932) Chief. Operating and 900 East Armour, Kansas City, Mo. Engr., Winnipeg School Board, Ellen and William Ave., and (for mail) 184 Waterloo St., Riverheights, Winnipeg. Man., Canada.. STEELE, Maurice G. (Af 1929) Tech.. Advisor (for mail) Revere Copper & Brass, Inc., 1301 Wicomico St., Baltimore, and Hokeland, Havre de Grace, Md. STEVENS, WUUam R. (A 1934) Partner. L. E. Stevens Co., 626 Broadway, Cincinnati, O., and (for mail) 30 Chalfonte Court, Fort Thomas, Ky. STEVENSON, Melvin J. (Af 1935) Dir. of Sales Air Comfort Corp., 1307 S. Michigan Ave., and (for. mail) 5801 Dorchester Ave., Apt. 2A,Chicago, 1U. IT' Heating VentiIjAting Air Conditioning Guide 1939 STEVENSON, W. W. (M 1928) Steam Htg. Engr. (for mall) Allegheny Co. Steam Htg. Co., 435 .STROMGREN, Sven G. (Af 1938) Consulting Engr., Asea Electric, Ltd., 4 Lyon Range, Cal Sixth Ave., and 1125 Lancaster Ave., Pitts . burgh. Pa. STEWART, Charles W. (M 1919; A 1918) Asst. . Secy, (for mail) Hoffman Specialty Co., Water- bury National Bank Bldg., and 21 Yates Ave., . Waterbury, Conn. STEWART, Duncan J.* (Af 1936; A 1930) Mgr., Electrical Div. (for mail) Barber-Colman Co., ' Drawer 99, and R. R. No. 4, Rockford, III. -STEWART, James P. (J 1937) Engr., Air Con cutta, India. STROUSE, Sherman W. (A 1934) Sales Mgr., Cooney Refrigeration Co., and (for mail) 198 . - Livering Ave., Buffalo, N. Y. -- STROUSE, Sidney B. (Af 1921) Consulting Engr. (for mail) 500-529 Guarantee Trust Bldg., and 22 S. Illinois Ave., Atlantic City, N. J. STRUNIN, Jay (/ 1933) Engr. & Contractor, Strunin Plbg. & Htg. Co., Inc. (for mail) 408 Second Ave., and 54 West 89th St., New York, ditioning, 517 Brooks Bldg., and (for mail) 40 West Northampton St., Wilkes-Barre, Pa. STEWART, Wesley O. (A 1938) Branch Mgr. - (for mail) Johnson Service Co.. 153 West Ave. 34, Los Angeles, and 726 Central, Glendale. Calif. STIEGLER, Alvin J. (A 1938) Owner (for mail) Valley Sheet Metal Works, 315 Main St., and 319 Monroe St., Neenah, Wts. STILES, Gordon S. (J 1936) Sales Engr. (for mail) Airtemp Div., Sidles Co., 118 Tenth St., and 206-11th St., Des Moines, la. - STILL, Fred R.* (Af 1904) {Presidential Member) (Pres., 1918: 2nd Vice-Pres., 1917; Council, 1916 1919) Vice-Pres. in charge of Export (for mail) American Blower Corp., 50 West 40th St., New 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. (M 1934) Associate Naval Archt., U. S. Government (for mail) Norfolk Navy Yard, and 37 Channirig Ave., Ports . - mouth, Va. .` STURDY, Oswald C. (Af 1938) Sales Engr. (for . mail) Foster Wheeler, Ltd., 159 Bay St., and 24. ' Dorval Rd., Toronto, Ont., Canada. :STURM, William {J 1937; S 1936) Engr., Spencer Cooling & Air Cond. Co., 413 S. Sixth = St., and- (for mail) 315-16th Ave., S. E., Minne - York, and 3457-82nd St., Jackson Heights, L. I., N. Y. STILLER, F. W. (J 1933) Estimator (for mail) F. C. Stiller & Co., 129 South Tenth St., and 138 West 49th St..-Minneapolis, Minn. .STINARD, R, L. (J 1934) Sales Engr., American Radiator Co., 40 West 40th St., New York, N. Y., and (for mail) 1377 Boulevard East, West New York. N. J. STITES, Richard, Jr. (J 1937) Sales Engr., Buffalo Forge Co., 2051 W. Lafayette, and 2170 ' E. Jefferson. Detroit, Mich. STOCK, Charles S. (Af 1936) Dist. Repr., The Herman Nelson Corp., Rm. 404-ll08-16th St., N. W., Washington, D. C., and (for mail) 6752 . Fairfax Rd., Bethesda, Md. STOCKWELL, William R. (M 1903; J 1901) Gen. Mgr., Mfg. Div., Weil-McLain Co., Michigan City, Ind. STOKES, Alvin D. (M 1936) Engr., York Ice Machinery Corp., 1238 N. 44th St., Philadelphia, and (for mail) 4010 Eilendale Rd.. Drexel Hill, Pa. STOKES, Arledge (J 1936) Air Cond. Engr. (for mail) Mehring and Hanson Co., Room 1006, Santa Fe Bldg., and 5211 Worth St., Dallas, Tex. STOLTZ, Guy C. (A 1938) Chief Engr., Air apolis. Minn. . . SUDDERTH, Leo (J 1936) Branch Mgr. (for mail) Johnson Service Co., 311 Bona Allen Bldg., and 1115 Los Angeles Ave., N. E., Atlanta, Ga. SULLIVAN, Charles J. (A 1938) Owner & Mgr.., C. J. Sullivan, 5458 Baltimore Ave., and (for mail) 5470 Baltimore Ave., Philadelphia, Pa. SUMMERS, Clarence G. (A 1938) Dist. Mgr., Ilg Electric Ventilating Co., 2144 Madison Ave., . Toledo, O. .. . 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. (/ 1935; S 1933) Engr., Larx Co., Inc., 607 S. Fifth Ave., and (for mail) 3040 Longfellow Ave., Minneapolis. Minn. SUNDERLAND, Richard- P, (A 1938) Pres, (for mail) General Meters & Controls Co.. 25 W. Wacker Drive, Chicago, and 936 Judson Ave., . Evanston, 111. SUPPLE, Graeme B- {M 1934) Dist. Sales Engr. (for mail) American Blower Corp., 625-Architects & Builders Bldg., and 6224 " Park Ave., India napolis. Ind. ' " ' SUTCLIFFE, A. G. {M 1922; A 1918) Chief Engr., Ilg Electric Ventilating1 Co., 2850 N. Crawford Ave., and (for mail) 4146 N. St. Louis Ave., Conditioning Dept, (for mail)'Straus-Frank Co., - and 315 Burr Rd., San Antonio, Tex. STORCH, Clemens A. (M 1930) Sales Engr., . . Johnson Service Co., 1355 Washington Blvd., Chicago, and (for mail) 331 Cumnor Rd., Kenil- worth. 111. .STORMS, Robert M. {M 1936) Mech. Engr., Consulting, Htg. and Vtg. (for mail) 816 West . 5th St., Los Angeles, and 354 W. Wilson, Glen dale, Calif. . STOTT, F. W. (Af 1937) Sales Engr. (for mail) Chicago, III. SUTFIN, George Vl (A 1937) Sales Engr. (for mail) American Blower Corp., 1005-6 American Bldg., and 3270 Hildreth Ave., Cincinnati, O. SUTHERLAND, David L. (A 1934) Pres, and Treas., Sutherland-Air Conditioning Corp., 15 N. Eighth St., and (for mail) 1815 S. Colfax Ave., Minneapolis, Minn. SUTHERLAND, Floyd A. (M 1938) Design Engr., Electric Products Corp., 5624 Penn Ave., Pitts . burgh, and (for mail) 403 Crest Ave., Charleroi, C. A. Dunham Co., Ltd., 1139 Bay St., Toronto, and Palmer Ave., Oakville, Ont., Canada. STOTZ, Robert B. (J 1938) Sales Engr. (for mail) Frigidaire Div., General Motors Sales Corp., 675 Greenwood Ave., and 1702 Harvard Rd., Atlanta, Ga. STRAUCH, Paul C. (A 1934) Sales Engr., The . Pa. . SUTTER, Edgar E. (A 1936) Sales Engr., Mueller . Brass Co., Port Huron, Mich, and (for mail). 6705 Sixth St., N. W., Washington, D. C. SWANEY, Carroll R. {M 1929; J 1921) Co Partner, (for mail) Gilbert Howe Gleason & Co., . 28 St. Botolph St., Boston, and 43 Clyde St., Henry Furnace & Foundry Co., S. 18th & Merreman Sts., and (for mail) Cambridge Court Apts., 131 Edgewood Ave., Edgewood, Pitts burgh, Pa. STREVELL, R. P. (M 1934) Pres. & Treas. (for mail) The Wo. R. Hogg Co., Inc., 900 Fourth Ave.,- Asbury Park, and Cor. Victor Place & State Highway, Neptune, N. J. STRICKLAND, Albert W. (A 1929) Htg. & Vtg. Engr., Big Timber," Mont. STROCK, Clifford (Af 1937; A 1929) Associate Editor (for mail) Heating & Ventilating, 148 . Lafayette St., New York, and 82-15 Britton Ave., Elmhurst. N. Y. .. Newtonville, Mass. . SWANSON, Donald F.. (J 1938) Test Engr., Seeger Refrigerator Co., 850 Arcade St., St. Paul, and (for mail) 4316 Bloom Ave., Minne apolis, Minn. . . SWANSON, Earl C. (A 1935) Vice-Pres., Andersen Corp., Bayport, Minn. SWANSON, Nils W. (A 1936) Salesman, `Mc Donnell & Miller, 400 N. Michigan Ave;, and (for mail) 2746 Morse Ave., Chicago, III. SWENSON, J. E. (A 1930) Mgr., House Htg. Dept, (for mail) Minneapolis .Gas-Light Co.; . 800 Hennepin Ave., and 4853-14th. Ave., S., Minneapolis. Minn. ' . 60 Roll of. Membership SWINGLE, Wayne T. (A 1938) Chief Engr., F. Jaden Mfg. Co., Inc., and (for mail) Y. M. C. A., Hastings, Nebr. SWISHER. Stephen G., Jr. (Af 1936; A 1934) Branch Mgr. (for mail) The Trane Co., 1835 N. TECEMYER, Fred C., Jr, (S 1936) 1515 Wood ward Ave., Lakewood, O. TEELING, Geo. A. (if 1930) Consulting Engr. (for mail) 1 Columbia Place, Albany, and Box 81, Clarksville, N. Y. 3rd St., and 1711 E. Dean Rd., Milwaukee, Wis. SYDOW, Louis J. (Af 1936) Htg. Engr., Federal Heating Co., 2735 N. Union, and (for mail) 9456 TEMPLE, W. J. (Af 1931) Engr., J. A. Temple Co., 108 Parkway, and (for mail) 1215 Reed St., Kalamazoo, Mich. Midland Ave., St. Louis, Mo. TEMPLIN, Charles L. (Af 1921) Pres, (for mail) SYMONDS, Edward S. (Af 1939) Mgr., Abain 1 Engineering, Ltd., 1 Devonshire Square, London, E. C. 2, and (for mail) 84 The Ridgeway, Chingford, Essex, England. 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 S. 66th Carrier Atlanta Corp., 348 Peachtree St., and (for mail) 781 Sherwood Rd.. N. E., Atlanta, Ga. TENKONOHY, Rudolph J. (Af 1923) Vice-Pres.. Airtherm 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., 2237 Oliver Bldg., and 1215 Mississippi Ave.. Pitts burgh, Pa. - St., Milwaukee, and 6026 W. Washington Blvd., Wauwatosa, Wis. SZOMBATHY, L. R. (A 1930) Pres, (for mail) Ferguson Sheet Metal Works, 34 N. Florissant Blvd., Ferguson, and 3125 Hawthorne Blvd., St. Louis, Mo. ' TENNEY, Dwight (Af 1932) Pres. & Chief Engr. (for mail) Tenney Engineering, Inc., 46 Farrand St., Bloomfield, and 33 Summit Rd., Verona, N. J. TERHUNE, Ralph D. (A 1936) Repr., American Gas Products Corp., 4th & Channing Sts., N. E., Washington, D. C., and (for mail) 4516 Highland Ave., Bethesda, Md. ' T . TERRILL, Mark (A 1938) Sales Engr., The TAGGART, Ralph C.* (Af 1912) 14 Lyon Ave., Menands, Albany, N. Y. TALIAFERRO, Robert R.* (Af 1919) Service Engr., Carrier Corp., 300 S. Geddes St., and (for mail) 714 Ostrom Ave., Syracuse, N. Y. TALLIANOS, Peter C. (A 1938) Mgr.. The Egyptian Wireless Co., 36 Nebi Daniel St., Alexandria, Egypt. TALLMADGE, Webster (Af 1924) Pres, (for mail) Webster Tallmadge & Co., Inc., 255 North 18th . St., East Orange, and 7 Claremont Place, , Montclair, N. J. TANGER, Othon C. F. (A 1937) Dir.. N. V. Technische Handelsmaatschappij "Renova" Rem- brandtlaan 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 O TAPLEY, Mark S. (Af 1937) Htg., Vtg. and Air Cond. Engr., 3280 Holdrege St., Lincoln, Nebr. TARR, Harold M. (Af 1931) Htg. & Vtg. Engr., 21 Montague St., Arlington Heights, Mass. TASKER, Cyril* (Af 1935) Research Fellow (for ' mail) Ontario Research Foundation, 43 Queens Park, and 737 Avenue Rd., Toronto, .Ont., Canada. * Philip Carey Co., and (for mail) 656 Fuller, S. E., Grand Rapids, Mich. TERRY, Matson C. (Af 1936) Mgr., Production & Engrg. (for mail) Standard Air Conditioning, Inc., 2nd & Beechwood, New Rochelle, and Apt. 7K, Hawthorne Gardens Apts., Mamaroneck, N. Y. " ter WEEME, Albert {A 1938) Sales Engr., N. V. Radiatoren, Singel 206-208, Amsterdam, Holland. TEVES, Hendrik L. {A 1938) General Mgr., N. V. v. h. Becht & Dyserinck, Amsterdam- Noord, Corn. Douwesweg 1 (for mail) Hiiize "Vechtvliet", Breukelen, Netherlands. THEOBALD, Art (A 1937) Research Engr. (for mail) Payne Furnace & Supply Co.. Inc., 336 N. Foothill Rd., Beverly Hills, and 116M S. Kings Rd., Los Angeles, Calif. THEORELL, Axel T. (Af 1939) Consulting Engr., Theorells Ingeniorsbyra, and (for mail) Lokattsvagen 41, Appelviken, Stockholm, Sweden. . THEORELL, Hugo G. T.* (Life Member; Af 1902) Consulting Engr., Hugo Theorells Ingeniorsbyra, Skoldungagatan 4, Stockholm, Sweden. TH1NN, C. A.* (Af 1921) C. A Dunham Co., 450 East Ohio St., Chicago, IU. THOM, George B. (Af 1937) Asst. Prof. Mech. Engrg., Swarthmore College, Swarthmore, Pa. TAVERNA, F. F, (Af 1928; A 1927; J 1924) Engr., THOMAN, Estell O. (A 1938) Mgr. of Air Cond., Raisler Corp., 129 Amsterdam Ave., New York, Detroit Branch, Burge Ice Machine Co., 3208 N. Y., and (for mail) 406-12th St., Union City, N. J. _ TAYLOR, Edward M. (A 1934) Tech. Mgr. (for mail) Taylors, Ltd., 643 Colombo St., and 51 Totara Rd., Christchurch, New Zealand. TAYLOR, Fielding (J 1938) Sales Engr., Fair Gratiot Ave., Detroit, Mich. THOMAS, Arthur E. (J 1938) Contracts Mgr., Young, Austin & Young, Ltd., H35/36 Exchange Bldgs., Liverpool, 2, and (for mail) "Arlen" 56, Thingwall Rd., Wavertree, Liverpool, 15, Eng land. banks, Morse & Co., 178 Atlantic Ave., Boston, and (for mail) 3 St. James Ave., Haverhill, Mass. TAYLOR, Harold J. (Af 1937) Owner, Harold J. Taylor, Htg. & Vtg., 17514 Greenlawn Ave., Detroit, Mich. TAYLOR, Robert B. (J 1938) Sales Engr. (for mail) Buffalo Forge Co., 702 Tower Petroleum Bldg., and 3000 Yale Blvd., Dallas, Tex. TAYLOR, R. F. (Af 1915) Consulting Engr. (for mail) 911 Bankers Mortgage Bldg., and 1734 W. Alabama, Houston, Tex. TAYLOR, Thomas E. {J 1937) Consulting Mech. Engr. (for mail) 307 Postal Bldg., and 8424 S. E. 13th Ave., Portland, Ore. THOMAS, Bernard A. (A 1927; J 1923) Mgr., Htg. & Engrg. Dept. Crane Co., 1405 Twiggs St., and (for mail) 405 E. Idlewild Ave., Tampa, Fla. THOMAS, Glegge (Af 1923) Mgr., Wash; Office (for mail) Clarage Fan Co., 723 Albee Bldg.. Washington, D. C., and 7 W. Leland St., Chevy Chase, Md. THOMAS, L. G. Lee (Af 1934) Vice-Pres. (for mail) Economy Pump9, Inc., Weller & Zimmer ' man Aves., and Anthony Wayne Hotel, Hamil ton, O. THOMAS, Melvern F. (Af 1909) Consulting Engr. (for mail) Thomas & Wardell, 24 Bloor St., W., TAZE, D. L. (Af 1931) Mgr. (for mail) American and 74 Rivercrest Rd., Toronto, Ont., Canada. Blower Corp., 1302 Swetland Bldg., Cleveland, THOMAS, Norman A. (Af 1928) Pres., Thomas and 19412 Winslow Rd., Shaker Heights, O. Heating Co., 142 South 14th St., La Crosse, Wis. TAZE, Edwin H. (Af 1937) Branch Mgr. (for mail) American Blower Corp., 620 Court Square Bldg., ' Baltimore, and Towson, Md. TEASDALE, Lawrence A. (Af 1926) Engr., . University Service Bureaus (for mail) Yale . University, 20 Ashmun St., and 262 West Rock Ave., New Haven. Conn. . THOMAS, Ralph C. (A 1938) Vice-Pres. & Mgr., Bonair Conditioning & Refrigerating Co.. Inc., . West Norfolk, and (for mail) 819 Westover Ave., Norfolk, Va. ` THOMAS, Richard H. (Life Member; M 1920) ..'Pres., Economy Pumping Machinery Co.. 3431 W. 48th PI... Chicago,. 111. , 61 ss 3 'E L n Heating Ventilating Air Conditioning Guide 1939 THOMMEN, Adolph A. (A 1929) Air Cond. Fitting Mfr., John W. Thomson Co., 1437 W. 103rd St., and (for mail) 3400 W. 61st Place, Chicago, IU. THOMPSON, Edward B. (A 1938) Htg. Engr., Cincinnati Gas & Elec. Co., 4th & Main Sts., and (for mail) 1198 Coronado Ave.. Cincinnati, O. THOMPSON, Frank (Af 1935) Chief Engr., Vulcan Iron Works, Ltd., Pt. Douglas Ave., and TONRY, Robert C. (Af 1936) Mgr. (for mail) Wiedbusch Plumbing & Heating Co., 511 First St., and 217. Fairmont Ave., Fairmont, W. Va. TOONDER, C. L. (Af 1933) Air Cond. Sales Engr., Norge Div., Borg-Waraer Corp., 670 E. Woodbridge, and (for mail) 13391 Marlowe, Detroit, Mich. TORNQUIST, Earl L. (A 1934) Supv. Distri bution Operation (for mail) Public Service Co. (for mail) 543 Newman St., Winnipeg, Man., Canada. THOMPSON. Nelson S.* {Life Member; M 1917; of Northern Illinois, 72 West Adams St., Chicago, and 465 Parkside Ave., Elmhurst, 111. TOROK, Elmer (Af 1936) Supt. of Power (for J 1897) 1615 Hobart SL, N. W., Washington, mail) North American Rayon Corp., and 203 D. C. THOMSEN, Nia B. (Af 1938) Consulting Engr. (for mail) Bayxnond Corp., Victory Bldg., 2lst Floor, Toronto, Ont., Canada. THOMSON, Thomas N.* (Life Member; Af 1899) Consulting Engr., Plbg. and Htg., 37 Irwin Place, Huntington, L..L, N. Y. THORNBURG, Harold A. (Af 1932; J 1929) c/o N. V. Industrieele, Mi j Gebr., Van Swaay, Sodeteitstraat 16, Soerabaja Java, Dutch East Indies. ' THORNTON, Thaddeus L. (M 1937) Main tenance Engr., Prudential Insurance, 96 Barclay St., Newark, and (for mail) 37 Perry St., Belle ville, N. J." THORNTON. W. B.* (M 1931) Engr., Carrier 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 2933) Chairman, Carbon- dale 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 5516 Woodmont SL, Pittsburgh, Pa. TOWLE, Philip H. (J 1938) Air Cond. Engr. (for Corp., Merchandise Mart, and 8314 Indiana Ave., mail) General Air Conditioning Co., 1313 Jay Chicago, 111, St., and 514 23rd St., Sacramento, Calif. THRUSH, Homer A. (M 1918) Pres.. H. A. TOWNE, Charles O. (J 1938) Air Cond. Engr.;' * Thrush & Co., 21 East Riverside Drive, Peru, Apartment 306, Kingston Courts, LaCrosse, Ind. THULMAN, Robert K. (M 1938) Mech. Engr., Federal Housing Administration, Vermont and K Sts., N. W.t Washington, D. C., and (for mail) 6505 Ridgewood Ave., Chevy Chase, Md. ' THUNEY, F. M. (/ 1936) Application Engr. (for mail) Wm. E. Kingswell. Inc., 3707 Georgia Ave., N. W., and 4474 Conduit Rd., N. W., Washington, D. C. TIDMARSH. Patrick M. (Af 1938) Vice-Pres. & ' Gen. Mgr.. Tidmarsh Engr. Co., P. O. Box 2425, Tucson, Ariz. TILLER, Louln (A 1935; S 1933) Air Cond. Engr., Oklahoma Gas & Electric Co., 321 N. Harvey., and (for mail) 2712 Northwest 15th St., Okla homa City, Okla. TILTZ, Bernard E. (Af 1930) Pres, (for mail) Wis. TRACY, William E. (J 1937) Dist. Mgr. (for mail) B. F. Sturtevant Co., 237 Grand 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) 77 Deoon St., North Arlington, N. J. TRANE, Reuben N.* (Af 1915) Pres, (for mail) ' The Trane Co., and 126 South 15th St., La Crosse, Wis. TRAUGOTT, Mortimer (A 1930) Gen. Mgr. (for mail) Bryant Air Conditioning Corp., 830 N. Broad St., Philadelphia, and 721 Meeting House Rd., Elkins Park, Pa. TRAW1CK, Jack G. (Af 1937) Dist. Repr. (for Tiltz Air Conditioning Corp., 230 Park Ave., mail) Minneapolis-Honeywell Regulator Co., New York, and 24 Barnum Rd.. Larchmont, 1316 Comer Bldg., and 315 Altamoht Apts., N. Y. Birmingham, Ala. - TIMMINS, W. W. (Af 1937) Dist. Mgr. (for mail) TRAYNOR, Harry S. (J 1937) Engr., Carrier Canadian Powers Regulator Co., Ltd., 344 Corp., S. Geddes St., and (for mail) 442 Salt University Tower Bldg., Montreal, and 351 Springs Rd., Syracuse, N. Y. . Brock Ave., North., Montreal West, P. Q., TREADWAY, Quentin (A 1936; J 1932) Dist. Canada. TIMM1S, Pierce (Af 1920) Service Equip. Engr. (for mail) United Engineers & Constructors, Inc., 1401 Arch St., Philadelphia, and 202 Midland Ave., Wayne, Pa. ' T1MMIS, W. W. (Af 1933; A 1925) Mgr., Air Conditioning Systems and Control Div., Ameri can Radiator Co., 40 West 40th St., New York, and Pleasantville, 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. La Salle St., and Sales Mgr. (for mail) Clarage Fan Co., 410 Reynolds Arcade, and 826 Winona Blvd., Rochester, N. Y. TRELEAVEN, Herbert M. (J 1938) Junior Engr., Weathermakers (Canada) Ltd., 593 Adelaide St., . W., apd (for mail) 21 Glenfern Ave.; Toronto, Ont., Canada. TRENNER, Kelvin (A .1938) Mgr.. Engrg.. Dept., Staats Coal Co., Malvern 724 W. Marshall St., Norristown* and (for mail) 4819 N. Mascher St., Philadelphia, Pa. . TRIGCS, Fred E. (Af 1938) Sales Engr. & Mfrs. Agent (for mail) P. O. Box 1, H. P. Sta., and 3901-2nd St.. Des Moines, la. TROSTEL, Otto A. (Af 1935) Engr. (for mail) 11256 S. Artesian. Ave., Chicago, III. Kern Engineering Co., Inc., 161 W. Wisconsin TODD, Meryl L. (J 1936) Meryl L. Todd. Mech. Ave., and 3155 N. 7th St., Milwaukee, Wis. Engr. (for mail) 901 Waterloo Bldg., and 1119 TROUP, John D. (Af 19.38) Managing. Dir. (for Vine St.. Waterloo, la. mail) John D. Troup; Ltd., 90 High Holbom. TODD, Stanton W. (J 1935) Sales Repr., Ameri London, W. C. 1, and 48 Plough Lane, Purley, can Radiator Co., 8019 Jos. Campau St.. Detroit, Surrey, England. . and (for mail) 309 Paris. S. E., Grand Rapids, TRUITT, G. Scott (J 1937; 5 1936) Production Mich. . TOLIIURST, George C. (Af 1936) in Charge of Engr. Dept., Gurney Massey Co., Ltd., 36 Principal St., and (for mail) 142 Blvd. St. Germain, St. Laurent (near Montreal) P. Q., Canada. ' Dept., Bastian-Morley Co.. Inc., and (for mail) 907 Indiana Ave., LaPorte, Ind. * TRUMBO, Silas M. (A 1926) Sales (for mail) Buffalo Forge Co., 20 N. Wacker Dr., Chicago, and 921 Franklin St., Downers Grove, III. 62 Roll of Membership TRUMP, Charles C. (Af 1934) Pres, (for mail) James Spear Stove & Heating Co., 1823 Market u St., Philadelphia, and 503 Baird Rd., Merion Station, Pa. UHL, Edwin J. (Af 1925) Partner (for mail) Uhl Co., 132 S. Tenth St., and 4830 Pleasant Ave., TRZOS, Otto A. (J 1938) Industrial Gas Engr., S., Minneapolis, Minn. Consumers Power Co.. 26 W. Lawrence St., UHL, Willard F. (Af 1918) Partner (for mail) Uhl Pontiac, and (for mail) Box 103. Keego Harbor, Mich. ' Co., 132 S. Tenth St., and 4716 Lyndale Ave., S., Minneapolis, Minn. TUCKER, Frank N. (Af 1926) Field Engr., Ilg UHLHORN, W. J. (Af 1920) 733 S. Highland Ave.. Electric Ventilating Co., 15 Park Row, New Oak Park, III. York, and (for mail) 239 Whaley St., Freeport, L. I., N. Y. ULLMAN, Herbert G. (A 1928) Heating Engr., 107 White Rd. Scarsdale, N. Y. TUCKER, Leonard A. (Af 1935) Service Mgr., ULLRICH, Anton B., Jr. (J 1937) Sales Engr., J. J. Pocock, Inc., 31st & Jefferson Sts., Phila Gilbert Engrg. Co.. 1314 Liberty Bank Bldg., and delphia, and (for mail) 518 Monroe Ave.; Ardsley, Pa. (for mail) 1330 Hollywood, Dallas, Tex. UPSON, Walter L. (Af 1938)_Dir._oL Research TUCKER, .Thomas T.- (Af 1938; A~1936)Chief ` (for mail)' Torrington Manufacturing Co., Tor- ' Engr-, Armor Insulating Co.. 260 Peachtree St., rington, and Litchfield, Conn. and (for mail) 3619 Old ivy Rd., N. E., Atlanta, Ga. URDAHL, Thomas H. (Af 1930) Consulting Engr. (for mail) 726 Jackson Place, N. W., and 1505 TUCKERMAN, George E. (Af 1932) Mgr. (for 44th St., N. W., Washington, D. C. mail) Anderson-York Co., 600 Schuylkill Ave., Philadelphia, and 502 Rodman Ave., Jenkin- V town. Pa. TUPPER, George B. (A 1930) Sales Mgr., General Regulator Corp., 2608 Arthington St., and (for mail) 5921 Kenmore Ave., Chicago, 111. TURK, Leonard G. (5 1938) Student (for mall) Carnegie Institute of Technology, 4903 Forbes St.. Pittsburgh, Pa., and 346 Avenue B.. Roches ter, N. Y. TURLAND, Charles H. (Af L934; A 1930) Sales Engr. (for mail) R. E. Johnston Co., Ltd., 1070 Homer St., and 4579 W. 1st Ave., Vancouver, B. C.. Canada. ' TURNER, George G. (A 1934) Western Repr. (for mail) Heating & Ventilating, 228 N. LaSalle St., Chicago, and 827 Hinman Ave., Evanston, III. TURNER, Harry S., Jr. (J 1937; 5 1936) Asst. Engr., Dallas Power & Light Co., 1001 Dallas Power & Light Bldg., and (for mail) 4950 Gaston, Dallas. Tex. TURNER, John (Af 1930) Engr. (for mail) Capitol Engineering . Co.. Potter and Binney Sts., Cambridge. Mass., and Contoocook, N. H. TURNER, Prescott K. (A 1937; J 1935) Engr., 10 Windemere Rd., Worchester, Mass. VALE, Henry A. L. (Af 1929) Managing Director (for mail) Vale & Co., Ltd., 141-43 Armagh St., and 203 11am Rd., Fendalton, Christchurch, New Zealand. VAN ALSBURG, J. H* (Af 1931) Sales Engr., 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 mall) 4402 Maine Ave,, Forest Park, Baltimore, Md. VANDERHOOF, A. L. (A 1933) Dist. Repr. (for mail) Warren Webster & Co., 2341 Carnegie Ave., Cleveland, and 2762 Landon Rd., Shaker Heights, O. VANDERLIP, P. J. (A 1935) Consulting Engr. (for mail) Howland Engrg. Co., 206 S. Grand Ave., and 911 W. Ottawa St., Lansing, Mich. VAN NOUHUYS, Herbert C. (J 1937) Engr., Air Cond. Div., Nash-Kelvinator Corp., 14250 Ply mouth Rd., and (for mail) 2007 Seward Ave., Detroit, Mich. VAN NUYS, Jay C. (/ 1938; 5 1930) 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 Com TURNO, W. G. W. (Af 1917; A 1912) Secy.. H. W. mercial Engr., Jacksonville Refrigeration, Inc., Porter & Co., Inc., Newark, and (for mail) 35 W. Monroe St., and (for mail) 26 W. 6th St.. 71 Lafayette Ave., East Orange. N. J. Jacksonville, Fla. TUSCH, Walter (Af 1917) Secy., Teriney & Ohmes, VARNEY, Frank H., Jr. (/ 1938) Product Engr., Inc., 101 Park Ave., New York, and (for mail) Pacific Dist., Air Cond. Dept, (for mail) General 881 Sterling Place, Brooklyn, N. Y. Electric Co., 116 New Montgomery St., and TUTHILL, Arthur F. (S 1938) Student (for mail) . University of Wisconsin, 1709 Regent St., Madi son, Wis., and Cutchoque, L. L, N. Y. TUTTLE, Geoie H. (Af 1937;. A 1930; J 1934) Htg. Engr. (for mail) The Detroit Edison Co., 2000 Second Ave., and 16714 Kentfield, Detroit, Mich. ' TUTTLE, J. Frank (Af 1913) Sales Agent (for mail) Warren Webster & Co.. 127 Federal St., Boston, arid 9 Lewis Rd., Winchester, Mass. TUVE, G. L.* (Af 1932) Prof, of Heat-Power Engrg. (for mail) Case School of Applied Science, and 1294 Cleveland Heights Blvd., Cleveland, O. TUXHORN, David B. (Af 1936) Engr., L. P. 10 Russian Hill Place, San Francisco, Calif. VAUGHAN, John G., Jr. (J 1935) Norair Engineering Corp., 1114-18th St., N. W., Wash ington, D. C., and (for mail) 8405-I6th St., Silver Spring, Md. VAUGHAN, Lillian Lee (Af 1938) Prof, of Mech. Engrg. (for mail) North Carolina State College, State College Station, and 11 Enterprise St., Raleigh, N. C. VAUGHN, Frank R. (M 1937; A 1936) Vice-Pres. (for mail) Green Foundry & Furnace Wks., and 532 Polk Blvd., Des Moines, la. VEALE, Tinkham (J 1938) Sales Engr., Avery Engineering Co., 2341 Carnegie Ave., Cleveland, and (for mail) 18519 Kinsman Rd., Shaker Steuart and Bro., Inc., 138-12th St., N. E.. and Heights, O. (for mail) 4853 Sedgwick St., N. W., Washing , ton. D. C. VELTMAN, B. M. (Af 1936) Dept. Mgr.. Engrg. Dept.. Sears Roebuck & Co., and (for mail) 5531 TWIST, Charles F. (Af 1921) Pres, (for mail) Seward Park Ave., Seattle, Wash. AshweU-Twist Co., 967 Thomas St., and 2310 VERNON, J. Rexford (Af 1928; A 1928) Ad Tenth Ave., N., Seattle, Wash. vertising Mgr. (for mail) Johnson Service Co., TWIZELL, Edwin W. (Af 1937) Partner (for mail) Connolly & Twizell Regd., 1405 Bishop St., and 5176 Westbury Ave., Montreal, P. Q., Canada. TYLER, Roy D. (Af 1928) Mgr. (for mail) Modine Mfg. Co., 101 Park Ave., Room 1734, New Ynrk, 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. Wolverhampton, England. 1355 Washington Blvd.,. Chicago, and 733 Brummel St., Evanston, III. . VERVOORT, Edward L. (/ 1937; 5 1936) Sales Engr., Brooklyn Union Gas Co., 180 Remsen St., Brooklyn, and (for mail) 31 Yale Place, . Rockville Centre, N. Y. VETLESEN, G. Unger (Af 1930) 1 Beekman Place, New York, N. Y. VIDALE, Richard (Af 1935) Air Cond. Engr. (for mail) Ftesch &, Schmidt, Inc., 60 Brown St., and572 Flower City Park, Rochester, N. Y. Heating Ventilating Air Conditioning Guide 1939 VINCENT, Paul J. (Af 1931) Engr., Paul J. Vincent Co., 2133 Maryland Ave., Baltimore, Md. . VINSON, Neal L. (J 1936; 5 1932) Engr. and Estimator, L. W. Vinson & Son, Bisbee and Douglas, and (for mail) Box 3007, Lowell, Ariz. VISSAC, Gustave A. (Af 1937) Consulting Mining Engr., Coal Preparation, 1325 Frontenac Ave., Calgary, Alta., Canada. . VIVARTTAS, E. Arnold (Life Member; M 1910) Engr., 222 Utter Ave., West Brighton, S. I., N. Y. VOIS1NET, Walter E. (M 1930) 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 Ave., Birmingham, Mich. VOLK, Joseph H. (Af 1923) Pres, and Treas. (for mail) Tbos. E. Hoye Heating Co., 1906 W. St. Paul Ave., and 2965 South 43rd.St., Milwaukee, Wis. VOLKHARDT, Aquila N. (M 1938) Dist. Mgr.. Alfred L. Hart, Inc. (Distributor Gen. Electric Air Conditioning) 1243 Castleton Ave., West New Brighton, and (for mail) 104 Townsend Ave., Stapleton, S. I., N. Y. VOLLMANN, Carl W. (Af 1938) Pres, (for mail) Linde Canadian Refrigeration Co., Ltd., 355 St. Petre St.. Montreal, and 517 Roslyn Ave., Westmount, P. Q., Canada. vonCHRISTIERSON, Carl A. {J 1937) Field Engr., Carbondale Dept., J. H. Vivian & Co., P. O. Box 301. and (for mail) P. O. Box 3249 Johannesburg, South Africa. ' VOORHEES,. G. A. (Af 1922) Mgr. (for mail) Furblo Co., and P, O. Box 63, Hennansville, Mich. ' VOSS, Walter W. (A 1938) Instruction Engr., Utilities Engineering Institute, 404 N. Wells St., and 1347 N. Dearborn St.. Chicago, 111. VROOME, Albert E. (M 1932) Air Cond. Engr., Phoenix Engineering Corp., 2 Rector St., New York, N. Y., and (for mail) 6218 Amboy Rd., Prince Bay, S. I., N. Y.. ` WAID, Glen H. (A 1930) Dist. Sales Mgr.. Scott Valve Mfg. Co., 3963 McKinley Ave., and (for mail) 2928 Northwestern Ave.. Detroit, Mich. WALDON, Charles D. (A 1932) Consulting Engr.. Spencer Foundry Co., Penetang, and (for mail) * 32 Ferndale Ave., Toronto, Ont., Canada. WALFORD, Leslie C. A. (Af 1938) Chief Designer. G. Lome Wiggs, Consulting Engineer, 727 Uni versity Tower, and (for mail) 4264 Royal Ave.. Montreal, P. Q., Canada. . WALKER, Edmund R. (Af 1934) Sales Mgr. (for mail) Fedders Mfg. Co., Inc., 57 Tonawanda.St., Buffalo, and 365 McKinley Ave., Kenmore, N. Y. WALKER, James E. (J 1937; S 1936) 214 Rock- wood Ave., Dayton, and (for mail) 2139 Abington . Rd., Cleveland, O. - WALKER, J. Herbert* (Af 1916) (Council. 1938) Engr. Asst, to the Gen. Mgr. (for mail) The . Detroit Edison Co.; 2000 Second Ave., Detroit, and 432 Arlington Rd., Birmingham, Mich. WALKER, Kirby (Af 1935) Sales Engr.,. American Radiator Co., 40 West 40th St., New York, N. Y. WALLACE, David R. (A 1937) Htg. Engr. (for mail) Young & Bortic Coal Co., 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) Branch Mgr.. Sales Promotion (for mail) Crane Co., 400 Third Ave., N., and 4909-34th Ave., S., Minneapolis. Minn. .. WALLACE, William M., II (Af 1929) Resident Partner (for mail) Syska & Hennessy, Consulting Engrs., Ill N. Corcoran St., and 1011 Mom mouth Ave., Durham, N. C. 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; J 1929) Sales Mgr. (for mail) Air Conditioning Co., Main at Rich . . w mond St., and 803 Hawthorne St./Houston, Tex. WALTERS, Arthur L. (Af 1926; A 1925; / 1924) WACHS, Louis J. (A 1936; J 1930) Salesman, Carrier Corp., Chrysler Bldg., and (for mail) 1820 Cortelyou Rd., Brooklyn, N. Y. WADDINGTON, B. C. (Af 1922) Chief Engr., Major Appliance Co., and (for mail) 4523 Wirt St., Omaha, Nebr. WADE, Richard H. - (A/ 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. (J 1937) Sales Engr. (for mail) Clarage Fan Co., 500 Fifth Ave., New York, N. Y., and 112 Summit St., East Orange, N. J. WAECHTER, Herman P. (A 1930; J 1927) Air Cond. Engr., W. T. Grant Co., 1441 Broadway, New York, and (for mail) 89 Sherman Ave., Tompkinsville, S. I., N. Y. WAGGONER, Jack H. (Af 1937) Test Engr., Owens-Corning Fiberglas Corp.. Newark, O. WAGNER, Earle K. (Af 1938) Sales Engr. (for mail) The Powers Regulator Co., 2240 N. Broad St., Philadelphia, and 312 Myrtle Ave., Chelten ham. Pa. WAGNER, Edward A. (Af 1937; A 1936) Pres.. Wagner Engineering Corp., 22 Dunham St., and (for mail) 28 Waveriy St., Pittsfield, Mass. WAGNER, Frederick H., Jr. (Af 1934) Pres, (for mail) Jenkins Mfg. Co., 2 West 45th St., New York, and 1126 Post Rd.. Scarsdale, N. Y. WAGNER, John G. (A 1937) Employment Inter viewer (for mail) N. J. Employment Service, 283 Market St.. Paterson, and 254 Williams Ave., Hasbrouck Heights, N. J. ' WAHRENBROCK, Orin K. (J 1936) Engr., Automatic Appliance Corp., 36 Richmond Hill Ave., Stamford, and (for mail) 366 West Ave., Box 117, Glenbrook, Conn. Chief Engr. (for mail) Green Foundry & Furnace Works, 322 S. W. 3rd St., and 900-29th St., Des Moines, la. -. WALTERS, William T. (Af 1917) Engr., Illinois Engineering Co., Cor. 21st St. and Racine Ave., and (for mail) 12747 Wallace Ave., Chicago. Ill; WALTERTHUM, John J. (A 1922) Htg.-Vtg. Contractor, 212 E. 58th St., New York, N. Y., - and (for mail) 42-a Van Reipen Ave., Jersey City, N. J. WALTHER, Frederick G. (J 1938) Draftsman and Engr., York Ice Machinery Corp., 2nd Ave. and 42nd St., Brooklyn, and (for mail) 219 Bronx River Rd., Yonkers, N. Y. WALTON, Charles W., Jr. (Af 1934) Mech. Engr. (for mail) Rockefeller Center, Inc., 50 Rockefeller Plaza, New York, N. Y., and 120 Monte Vista Ave., Ridgewood, N. J. \ WALZ, George R. (J 1937) Sales Engr. (for mail) Minneapolis-Honeywell Regulator Co-, 1101 Vermont Ave., N. W.. Washington, D. C,, and 1808 Queens Lane, Apt. 209, Arlington, Va. WARD, Edward B. (Af 1937) Pres, (for mail) Edward B. Ward & Co.. 270 Tremont St., and 235 Lansdale Ave., San Francisco, Calif. WARD, Frank J. (Af 1935) Owner (for mail) Frank J. Ward Co., 237 W. Court St., Cincinnati,. O., and Cold Spring, Ky. .. WARD, Harry H. (A 1937) Dist. Engr., Delco- Frigidaire Cond. Div. (for mail) General Motors Sales Corp., 230 N. E. 14th St., and 724 N- W, 12th St., Miami, Fla. ' WARD, Jerry J. (A 1921) Pres, (for mail) Wenzler & Ward, Inc., 1703 Textile Tower, and 1107- 3lst Ave., Seattle. Wash. ' WARD, Oscar G. (Af 1919) Dist. Mgr., Johnson Service Co.. 1355 Washington Blvd.. Chicago. III. 64 Roll of Membership WARDELL, Arthur (Af 1935) Asst. Prof, of Engrg. Drawing, University of Toronto, and (for mail) 124 Melrose Ave., Toronto, Ont., Canada. WARE, John H., Ill (Af 1937) Vice-Pres., Citizens Gas & Fuel Co., Pres., Oxford Co.; Vice-Pres., Gas Oil Products, Inc., 45 S. Third SL, Oxford, Pa. WARING, James M. S. (M 1932) Consulting Engr., 277 Park Ave., New York, N. Y. 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. John S., Jr. (J 1937) Sales Engr. (for mail) York Ice Machinery Corp., 115-121 South WEBER, Erwin L. (Af 1921) Consulting Engr., 534 Medical Arts Bldg., Seattle, Wash. WEBER, Eugene F. (J 1937) Sales Engr.. York Ice Machinery Corp., 117 S. 11th St., and (for mail) 4515 Maryland-Ave., St. Louis. Mo. WEBSTER, E. Kessler (Af 1915) Warren Webster & Co.. 17th and Federal Sts., Camden. N. J. WEBSTER, Warren, Jr. (Af 1932; J 1927) VicePres. and Treas. (for mail) Warren Webster & Co., 17th and Federal Sts., Camden, and 200 Colonial Ridge Drive, Haddonfield, N. J. WEBSTER, William H., Jr. (A 1935) Vice-Pres. (for mail) Hurst Heating Engineers. Inc., 400 York St., and 200 N. Shore Rd. (Academy Terrace) Norfolk, Va. 11th St., and 2017 Maury Ave., St. Louis, Mo. WARREN, Robert M., Jr. (J 1938) Air Cond. Engr. (for mail) Sam E. Beck, Inc., 400 Brooks- town Ave., and 1126 Walker Ave., Winston- Salem, N. C. " WASHBURN, Marcus J. (A 1934) William Powell Company. Cleveland, O. .' WASHINGTON, George (M 1934) Engr., Hoff man Specialty Co., Waterbury, Conn., and (for mail) 4327 Johnson Ave., Western Springs, 111. WASHINGTON, Laurence W. (Af 1929) (for mail) The Powers Regulator Co., 702 American Bldg., and 1627 Northwood Drive. Cincinnati, O. WASSER, Munny (Af 1938) Elec. Mech. Engr., Igeme S. A. R., Str. Aureliu 25, and (for mail) Bd. Carol 62, Bucharest, Roumania. WECHSBERG, Otto (Af 1932) Pres.-Gen. Mgr., Coppus Engineering Corp., 344 Park Ave., and (for mail)-1006 Main St., Worcester, Mass. WEDDELL, George O. (Af 1936) Branch Mgr.. York Ice Machinery Corp., 2400 Carson St.; and (for mail) 3114 Wainbell Ave., Dormont, Pitts burgh, Pa. " WEGMANN, Albert (Af 1918) 6206 North 17th St., Philadelphia, Pa. ' .' WE1D, Harry L. (5 1938) Test Engr.. Hynes Electric Heating Co., 240 Cherry St., and (for mail). 2967 N. Mutter 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. WASSON, Robert A. (Af 1938) Eastern Dist. Mgr. (for mail) Clarage Fan Co.., 500 Fifth Ave., New York, and 15 Willow St., Brooklyn, N. Y. WATERMAN, John H. (Af 1931) Engr., Chas. T. Main, Inc., 201 Devonshire St., Boston, Mass. WATERS, Frank A. (A 1936) Htg.-Vtg. Engr., Westinghouse Elec. 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, Pittsburgh ` (16) Pa. '' WATKINS, George B. (A 1936) Dir. of Research (for mail) Libbey-Owens-Ford Glass Co., 1701 ' E. Broadway, and 3004 Berdan Ave., Toledo, O. 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. (for mail) 184 College St.,-and 121 Welland Ave., Toronto, Ont., Canada. WATT, Robert D. (J 1937) Engr., H. W. Beecher Consulting Engr., 502 Securities Bldg., and (for 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., Montreal, P. Q., Canada.' WAUDBY, Walter. (Af 1938) Engr.. (for mail) American Radiator Co., 149 Blvd. Haussmann, ' Paris, and 26 Rue de la Tourelle,,, Boulogne sur . Seine. France. ' WAUNG, Tsing FI (Af 1935; J 1933) Htg. Engr.. . (for mail) Andersen Meyer & Co., Ltd., Yuen Ming Yuen Rd., and Apt. A-5, 1562 Ave. Joffre, 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.f Jr. (J 1936; 5 1935) ' Product Engr., Air Conditioning Dept., General Electric Co., 4966 Woodland Ave., Cleveland, . WELL, F. H. Eugene (A 1938) Asst. Chief Engr., Standard Distributing Corp- 406 E. Wells St., and (for mail) 831 West Wisconsin Ave., Mil waukee, Wis. ; WEIL, Martin (A 1925) Vice-Pres. (for mail) Weit-McLain Co., 641 W. Lake St., and 4259 Hazel St., Chicago, III. . WEIL, M. I. (A 1928). Pres, (for mail) Chicago Pump Co., 2336 Wolfram St., and 1409 W. Elmdale Ave., Chicago, 111. . WEIMER, Fred G. (A 1919) Mgr.. Milwaukee Office. Kewanee Boiler Corp., 312 E. Wisconsin Ave., Room 412, and (for mail) 3958 N. Stowell Ave., Milwaukee, -Wis. WE1NERT, Fred C. (A 1937) Asst. Sales Mgr.. Sales Engr. (for mail) Chamberlin Metal Weather Strip Co., Inc., 1254 Labrosse St., Detroit, and Route No. 2; Plymouth, Mich. . ! WEINSHANK, Theodore* (Life Member; Af 1906) (Board of Governors, 1913) Consulting Engr., 3307 Belden Ave., Chicago, 111. . WEISS, Arthur P. (Af 1928) Burnham' Boiler Corp., Irvington, and (for mail) 134 Farrington Ave., North Tarrytown/N. Y. > WEISS, Carl A. (Af 1936; A 1924) Gen. Mgr. (for mail) Kombrodt. Komice Co., 1811-15 Tfoost ` Ave.. and 29 East 68th St., Kansas City/Mo. WEISSBLATT, Norman (5 1938) Student, -N. Y. Technical Inst'., 108 Fifth Ave., New York, and (for mail) 1435 53rd St., Brooklyn, N. Y. WEITZEL, Cameron B. (Af 1936) Owner and Operator, 122 E. High St., Manheim, Pa. : . WEITZEL, Paul H. (/ 1930; 5 1934) Jr. Engr., ' Cameron B. Weitzel, 122 East High St., Man heim, Pa. . . WELCH, Louis A., Jr. (A 1929) Owner (for mail) Welch Bros.,. 443-2nd St., and 2001 Campbell Ave., Schenectady, N. Y. WELDY, Lloyd O. (Af 1930) Branch Mgr. .(for - mail) The Powers Regulator Co., 2341 Carnegie Ave., Cleveland, and 19623 Laurel Ave., Rocky River, O. - " and (for mail) 1243 Warren Rd., Lakewood, O. 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, O. 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 Dir. (for' . mail) Webb Dust Removing & Drying Co., Ltd., WELLS, Earl P. (Af 1938) Air Cond. Engr., Gay Engineering Corp., 2730 E. llth St., Los Angeles, and (for mail) 206'W. Shorb St., Alhambra, Calif. WELSH, Harvey A. (A 1936) Engr., A. P. Wood . son Co., 1313 H St., N. W., Washington^.D. C.. and (for,mail) 4118 Lee Highway, Arlington, Va. WELTER, Michael A. (A 1925) Engr. and Htg. Contractor (for mail) Welter Furnace Mfg; Co., . 2023 S. Lyndale St., and 4200 S. Aldrich Ave., Minneapolis, Minn. '. . ,t Vinery Works, Town Lane, ^Denton Nr. Man s' Chester, and "Ebor", Brinriington, Stockport, England. . WENDT, Edgar F. (Af 1918) Pres.. (for' inail) . Buffalo Forge Co^ 490 Broadway, and 120 . ! Lincoln Parkway. Buffalo, N. Y; . Heating Ventilating Air Conditioning Guide 1939 WENDT, Edwin H. (J 1936) Engr. (for mail) Wendt & Crone Co., 2124 N. Southport Ave.. and 3809 N. Troy St.. Chicago, 111. WERNER, John G. (AT 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, Tex. 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) Prof, of Steam & Power Engrg., Head of Dept. Mech. Engrg. (for mail) _ jCollege of Engineering, University of Kentucky. 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) Engr., C. A. Dunham Co., and (for mail) Long Beach, . Michigan City, Ind. WETHERED, Woodworth (M 1937) Engr., Johnson & Wethered, Hotel Sir Francis Drake, San Francisco. Calif. WETZELL, Horace E. (Af 1934) Chief Engr. (for mail) The Smith & Oby Co., 6107 Carnegie Ave., Cleveland, and 21144 Aberdeen Rd., Rocky River, O. WHEELER, Joe, Jr. (Af 1937) Salesman (for mail) ' Johnson Service Co., 28 E. 29th St.,' New York, and 261 Dogwood Lane, Manhasset, L. I., N. Y. WHITESELL, Roy H. (A 1938) Sales Repr., Bryant Heater Air Cond. Corp., Chicago, III., and (for mail) 4617 Zenith Ave., S., Minneapolis, Minn. WHITMER, Robert P. (Af 1935) Secy, (for mail) American Foundry & Furnace Co., McClun & Washington Sts-. 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. WHITT, Sidney A. (A 1938; J 1937) Sales Appli cation Engr. (for mail) Nash-Kelvinator Corp., 14250 Plymouth Rd., and 12043 Cioverlawn, Detroit, Mich. _ _ . . _. WHITTAKER, Wayne K. (A 1935) Building Maintenance Mechanic, Irving Trust Co. Bldg., I Wall St., New York, and (for mail) 119-23 226th St., St. Albans. N. Y. 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. (if 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. (J 1937) Sales Engr., The Mercoid Corp., 4201 Belmont Ave., and 6109 N. Campbell Ave., Chicago, HI. WIEGNER, Henry B. (Af 1919) Branch Mgr., Johnson Service Co., 20 Winchester St.! Boston, and (for mail) 143 Standish Rd., Watertown, WHELAN, WUllam J. (Af 1923) Purchasing and Estimating (for mail) Harrigan & Reid Co., 1365 Bagley, and 3790 Seminole Ave., Detroit, Mich. WHELLER, Harry S. (Af 1916) Vice-Pres., L. J. Wing Mfg. Co., 154 W. 14th St., New York, N. Y. and (for mail) 725 Union Ave., Elizabeth, N. J. Mass. WIGGS. G. Lome (Af 1936; A 1932; J 1924) (Council, 1938) Consulting Engr. (for mail) 727 University Tower, and 4797 Grosvenor Ave., Montreal, P. Q., Canada. . WIGLE, Bruce (A 1926) Pres., Bruce Wigle Plumbing and Heating Co., 9117 Hamilton Ave., WHITE, Elmer D. (J 1937) Engr. (for mail) Ranco, Inc., 601 W. Fifth Ave., and 211 W. Weis- heimer Rd., Columbus. O. WHITE. Elwood S. (Af 1921) Pres, (for mail) U- S. Radiator Corp., 1056 National Bank Bldg., Detroit, Mich, and Meadowbank Rd., Old ' Greenwich, Conn. WHITE, Eugene B. (Af 1934) Arch. & Engr. (for mail) Architectural & Engineering Bureau, 19 S. LaSalle Street, Chicago, and 309 N. Taylor Ave., Oak Park, 111. WHITE, Everett A. (Af 1921) Engr. Dept., Crane Co., 30 South 16th St., and (for mail) 5244 Nottingham Ave., St. Louis, Mo. WHITE, Everett G. (A 1938) Asst. Custodian Engr., Bronx Central Post Office, Bronx, and (for mail) 425 Rochelle Terrace, Pelham Manor, N. Y. ' WHITE, Harry S. (A 1936) Mgr; (for mail) Acme Sheet Metal Co., 2201 Broadway, and 20 West Dartmouth Rd., Kansas City, Mo. WHITE. John C. (Af 1932) State Power Plant Engr. (for mail) Wisconsin Bureau of Engineer ing, Power Plant Div., 624 E. Main St., and 622 . E. Main St., Madison, Wis. ' WHITE, Robert C. (A 1938) Sales (for mail) Carrier Corp., Merchandise Mart, and 2016 W. Berwyn, Chicago, III. WHITE, Taylor C.. Jr. (A 1937) Sales Engr.. U. S. Radiator Corp., and (for mail) 615 State St., Louisville, Ky. WHITE, Thomas J. (J 1938) Sales Engr. (for mail) American Blower Corp., 625 Market St., and 1850 Sacramento St., San Francisco, Calif. WHITE, William R. (Af 1938; A 1936) Engr., Air Cond. Dept, (for mail) Nebraska Power Co., 723 Electric Bldg., 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 Rings End Rd., Noroton, Conn. WHITELEY, Stockett M. (Af 1933) Consulting Engr. .(for mail) Baltimore Life Bldg., and 3931 ' Canterbury Rd., Baltimore, Md. Detroit, Mich. WILDE, Ray S. M. (Af 1916) Consulting Mech. Engr., 3500 Union Guardian Bldg., and (for mail) 194 Connecticut Ave., Highland Park, Mich. WILDER, Edward L. (Af 1915) Engr., Industrial Dept, (for mail) Rochester Gas & Eleetric Corp., 89 East Ave., and 2 Buffard Drive, Rochester, N. Y. . WILDER, Herbert P: (Af 1938) Engr., Patterson- Kelley Co., 101 Park Ave., New York, and Ardsley Rd.. Scarsdale, N. Y. WILEY, Donald C. (J 1936) Engr. (for mail) John J. Nesbitt, Inc., State Road & Rhawn St., and 3338 St. Vincent St., Philadelphia, Pa. WILHELM, Joseph E. (J 1936: 5 1934) Office Engr. and Purch. Agent., Avery Engineering Co., 2341 Carnegie Ave., and (for mail) 1804 East 100th St., Cleveland, O. . WILKES, Gordon B. (Af 1937) Prof, of Heat Engrg. (for mail) Massachusetts Institute of Technology, Cambridge, 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, P. Q-. Canada. '. WILKINSON, F. J. (Af 1933) Mgr.. Cent. Engrg. Service. Montgomery Ward & Co., Chicago Ave. & Larabee St., Chicago, and (for mail) 18257 Martin Ave., Homewood. 111. - WILLARD, Arthur C.* (Af 1914) (.PreMenliel Member) (Pres.. 1928; lst Vice-Pres., 1927 ; 2nd Vice-Pres.. 1926; Council. 1925-1929) (for mall) President. University of Illinois, and 711 Florida Ave.. Urbana, 111. WILLER, Murray D. (J 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, Ore. WILLIAMS, Allan E. (Af 1938) Branch Mgr. (for mail) Buffalo Forge Co., 428 Dwight Bldg., and 3535 Wabash Ave., Kansas City, Mo. 66 Roll of Membership WILLIAMS, Allen W. (Lift Member; A 1915) Managing Dir., National Warm Air Heating & Air Conditioning Association, 50 West Broad WINSTEL, Frank E. (A 1938) Delco Sales Mgr., The Bimel Co., 305 Walnut St., and (for mail) 1126 Regent Ave., Cincinnati, O. St., and 51 Meadow Park Ave., Columbus, O. WILLIAMS. Chester D. (Af 1938) Mgr., General Air Conditioning & Heating Co. (for mail) 4001 Piedmont Ave., Oakland, and 2709 College Ave., Berkeley, Calif. WILLIAMS, Donald D. (J 1937) Gas Htg. Engr. . (for mail) Iowa-Nebraska Light & Power Co., 14th and O Sts., and 2236 A St., Lincoln, Nebr. WILLIAMS, Douglas C. (A 1938) Engr. (for mail) General Motors Sales Corp.. 2031 Calumet Ave., WINTERBOTTOM, Ralph F. (Af 1923) Engr., Winterbottom Supply Co., and (for mail) 400 Campbell Ave., Waterloo, la. WINTERER, Frank C. (Af 1920) Sales Mgr. (for mail) Cochran-Sargent Co., 300 Broadway, and 836 Juno St., St. Paul, Minn. WINTHER. Anker (Af 1937; A 1936; J 1932) Air Conditioning Engr. (for mail) York Ice Machin ery Corp., 659 E. 6th St-, and 3526 Pape Ave., Cincinnati, O. .. Chicago, and 595 Illinois Rd., Lake Forest, 111. WILLIAMS. Frank H. (J 1934) Tech. Engr., . Delco-Frigidaire-Div:."General Motors'Sales WISSING. Clement B. (A 1936) Secy, and Sales _ _Mgr.. Ebner Ice & Cold-Storage Cor, Locust & ~ " Chestnut, Vindnnes, Ind. Corp., Taylor St., Dayton, O., and (for mail) 68 Amherst Rd., Pleasant Ridge, Mich. WILLIAMS. Gordon S. (/ 1937; S 1936) Branch W1THERIDGE, David E. (J 1936) Sales Engr., W. A. Witheridge Co., 746 S. Fourth Ave., Saginaw, Mich. Mgr. & Engr. (for mail) The Trane Co., 207 Orange St., and 35 Dewitt 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. (J 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) Wiltner Heating Co., Inc., 415 Lexington Ave., New York, and 3875 Waldo Ave., Riverdale, N. Y. WILLS, Fred W. (J 1938) Western Sales Mgr. (for mail) Tuttle & Bailey, Inc, 61 W. Kinzie St., and 2511 Leland Ave., Chicago, ID. WILMOT, Charles S- (Af 1919) (for mail) Building Insulation Co., Lancaster Ave. at WITMER, Charles N. (A 1937; J 1930) Sales Engr. (for mail) Straus-Frank Co.. 1618 Fannin St., and 2301 Southgate Blvd., Houston, Tex. WITMER, Howard S. (A 1937) Sales Engr., Dail Steel Products Co., Hosmer & Main. Lansing, and (for mail) R. F. D. 1, East 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, Mas9. 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) 1752 E. 73rd St., Chicago, III. Jefferson St., Philadelphia, and 406 Essex Ave., Narberth, Pa. WILSON. Alexander (Af 1936) Consulting Engr. (for mail) 1537 St. Matthew St., Montreal. P. Q., 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) General Mgr. in India, (for mail) Carrier Corp., c/o Volkart Bros., WOLIN, Milton W. (J 1938; S 1937) Engr.. Typhoon Air Cond. Co., Inc., 1393 Lexington Ave., New York, N. Y., and (for mail) R. F. D. No. 2, Box 73-D, New Brunswick, N. J. WOLL, WlUard M. (Af 1938) Engr. (for mail) Commonwealth Edison Co., Room 1000 Edison Bldg., and 9320 S. Throop St., Chicago, 111. WOLLENBERGER, Louis (Af 1938) Industrial Gas Engr. (for mail) Coast Counties Gas & Electric Co., 22 Pacific Ave., and 424 King St., Santa Cruz, Calif. Ballard Estate, Bombay, India, and Gorof House, Ystradgynlais, Swansea. England. WILSON, Frederick J. (A 1938) Pres, (for mail) Wilson Air Conditioning Corp., 1726 Sansom St., Philadelphia, and 527 Baird Rd., Merion, Pa. WILSON, George T. (Af 1925) Sales Engr., Gurney Foundry Co., Ltd., 4 Junction Rd.. Toronto, and (for mail) Tyre Ave., Islington. Ont., Canada. WILSON, Raymond W- (Af 1934) Member of Firm (for mail) Wilson-Bnnker Co., 412 Pythian Bldg., and 429 Creston Ave., Kalamazoo, Mich. WILSON, Robert A. (Af. 1936) Sales. Engr.. WONG, W. S. B. (Af 1938) Dir. (for mail) Ameri can Engineering Corp. (China) 989 Bubbling Well Rd., and 669 Hart Rd., Shanghai. China. WONSON, Arthur S., Jr. (5 1938) Student, Beverly Trade School, Beverly, and (for mail) Walnut Park Ave., Essex, Mass. WOOD. Alfred W. (J 1938) Sales Engr., Clare Bros. & Corp., Ltd., and (for mail) 63L William St., Preston, Ont., Canada. WOOD, Charles F. (Af 1937) Chief Engr. or Mgr. Engrg. Dept., Delco-Frigidaire Div., Taylor St. Plant, and (for mail) 359 Aberdeen Ave., Dayton, O. Minneapolis-Honeywell Regulator Co., 4501 Prospect Ave., Cleveland, and (for mail) 1520 Grace Ave., Lakewood, O. , WILSON, Victor H. (A 1938) Engr., John WOOD, Roderick A. (J 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. Bouchard & Sons Co., 1024 Harrison St., and WOODBURY, Clyde D. (Af 1938) Mech. Engr., (for mail) 2613 Acklen Ave., Nashville, Tenn. Leland & Haley, Consulting Engrs., 58 Sutter St., WILSON, W. H. (A 1932) Chief Power Plant and(formail) 1321 37th Ave., San Francisco, Calif. Engr., Pullman-Standard Car Mfg. Co.. 11001 WOODHOUSE. Graham D. (A 1938) General Cottage Grove Ave., and (for mail) 22 West 110th Place. Chicago, 111. Supt., Dowagiac Steel Furnace Co., and (for mail) 412 W. High St., Dowagiac, Mich. WILTBERGER. Constant F. (Af 1935) Partner, WOODMAN, Lawrence E. (Af 1934) Pres., Pennell & Wiltberger, Consulting Engrs., Land Woodman Engineering Corp., Air Cond. Engrs., Title Bldg., and (for mail) 2650 North 9th St., 203 E. Capitol. Jefferson City. Mo. Philadelphia, Pa. WOODS, Bladwin M. (Af 1937) Prof, of Mech. WINANS, Glen D. (Af 1929) Engr. of Steam Distribution (for mail) The Detroit Edison Co., 2000 Second Ave., and 16183 Wisconsin, Detroit, Mich. - Engrg. (for mail) University of California, and 249 The Uplands. Berkeley. Calif. WOODS, Edward H. (Af 1934) Engr., Higgins Zabriskie, 314 E. State St., Ithaca, N. Y. WINKLER, Ralph A. (J 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 School of Medicine, 310 Cedar St., and 314 Prospect St., New Haven, Conn. WOODWARD, Rothwell (Af 1938) Supvr. of Tech. Data., Delco-Frigidaire Conditioning Div., 300 Taylor St., and (for mail) 910 Cumberland Ave., Dayton, O. WOODWORTH, Corlls Z. (Af 1938) Consultant &' Resident, Kribs & Landauer, Inc.. 303 Trades mens Bank, and (for mail) 2736 N. W. 17th St., Oklahoma City, Okla. 67 Heating Ventii*ating Air Conditioning Guide 1939 WOOLCOCK, Edwin (A 1938) Mgr. (for mail) YARBOROUGH, Thomas R. (Af 1938) Dist. C. J. Woolcock Plumbing & Heating. 2217-15th Sales Engr., Frigidaire Div. of General Motors St., and Red Coacti Inn., Niagara Falls, N. Y. Sales Corp., and (for mail) 788 Greenwood Ave., WOOLLARD, Mason S. (M 1934) Htg. Engr., Apt. 4, Atlanta, Ga. H. H. Angus, Consulting Engr., 1221 Bay St., YATES, James E. (M 1934) Mgr. (for mail) and (for mail) 31 Hillcrest Park Ave., Toronto, Yates, Neale & Co., 23l-10th St., and 43i-16th 5, Ont., Canada. '. St., Brandon, Man., Canada. . WOOLLEY, J. Herbert (A 1936) Vice-Pres. (for YATES, James E., Jr. (J 1936) Sales Engr. (for mail) Woolley Coal Co., Inc., 12 Burnett Ave., mail) Yates, Neale & Co., 231-10th St., and Maplewood, and Oakview Terrace, Short Hills, 431-16th St., Brandon, Man., Canada. . N. J. . . YATES, Walter (Life Member; M 1902) Governing WOOLSTON, A. H. (M 1919) Chief Engr. (for mail) Woolston-Woods Co., 2132 Cherry St., and 4815 N. 12th St., Philadelphia. Pa. WOOTAN, Charles (A 1937) 11118 Clifton Blvd., Cleveland, O. WORLD, Harry P. (M 1936) Engr. (for mail) Mackenzie Waters, Archt., 96 Bloor St., West, and 30 Rosewell Ave., Toronto, Ont., Canada. WORMLEY, Robert F. (A 1938) Branch Mgr. (for mail) Grinnell Co. of Canada, Ltd., 700 Beaumont St., and 6092 Terrebonne Ave., Montreal, P. Q., Canada. ' Dir. (for mail) Matthews & Yates, Ltd., Cylcone Works, and Parksend, Swinton, Manchester, England. YEAZEL, Gordon A. (J 1938) Air Cond. Engr.. Sampson Electric Co., 3201 S. Michigan Ave., and (for mail) 8130 Eberhart, Chicago, III. YERKES, William L. (A 1937) Engr. (for mail) Carrier Corp., 12 S. 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, O. YOUNG, Forest H., Jr. (A 1936) Mgr.. Secy.- WORSHAM, Herman (M 1925; J 1918) National Treas,, Young Heat Engineering Co., 116 N. 26th Business Dept, (for mail) DelcoFrigidaire Cond. St., Billings, Mont. Div., 300 Taylor St., and 519 W. Norman Ave., YOUNG, Harold J. (M 1937) Sales Engr., Young Dayton, O. Radiator Co., Occidental Hotel Bldg., and (for WORTHING, Stanley L. (M 1936) Consulting mail) 1364 Lakeshore Drive, Muskegon, Mich. Engr. (for mail) 433 Kelsey Bldg:. Grand Rapids, YOUNG, J. T., Jr. (A 1936) Mgr., Htg. Dept, and Spring Lake, Mich. (for mail) Crane Co., Box 1410, and 1364 Ken WORTHINGTON, Thomas H. (M 1937) Mgr. (for mail) Dominion Radiator & Boiler Co., Ltd., . sington Ave., Salt Lake City, Utah. YUSKA, Leonard J. (5 1938) Student, State 405 Beaubien St., W., and 5145 Cote St. Luc Rd., University of Iowa, and (for mail) 41-C Quad 'Montreal, P. Q., Canada. rangle, Iowa City, la. ' WORTON, William (M 1937) Branch Mgr. (for mail) C. A. Dunham Co., Ltd., 504 Scott Bldg., z and 292 Landowne Ave., Winnipeg, Man., Canada'. . WRIGHT, Clarence E. (J 1935: S 1933) Mgr., Htg. & Vtg. Dept., Fairmont Wall Plaster Co., , Tenth St., and (for mail) 908 Gaston Ave., : Fairmont, W. Va. WRIGHT, Daniel K., Jr. (J 1938) Instructor in Mech. Engrg., Case School of Applied Science, Cleveland, and (for mail) 1676 Lee Rd., Cleveland ZACK, Hans J. (M 1928) Pres-. Zack Co., 2311 Van Buren St., Chicago, 111. ZANGRILLI, Albert J. (/ 1937; 5 1035) Htg. Engr., Chandler Boyd Co., 51 Terminal Way; and (for mail) 537 Turrett St..-Pittsburgh. Pa. ZIBOLD, Carl E. (M 1929) Mech. Engr., Htg. and Vtg., 13 Chadwick Rd., Westminster Ridge, White Plains, N. Y. . ZIEBER, W. E. (M 1935) Asst. Chief Engr. (for Heights, O. mail) York Ice Machinery Corp., Roosevelt Ave., WRIGHT, Harris H. (M 1917) Mfrs. Repr. (for and 112 S. Penn St., York, Pa. mail) 320 E. 10th St., and 808 Greenway Terrace ZIESSE, Karl L. (A 1931) Secy.-Treas. (for mail) Kansas City. Mo. .. ' Phoenix Sprinkler & Heating Co., .115 Carhpau WRIGHT, K. A. (M 1921) Branch Mgr. (for mail) . Ave., N. W., and 315 Hampton Ave., S. E., Johnson Service Col, 1113 Race St., Cincinnati, Grand Rapids, Mich. O. , and 113 Orchard-Rd., Fort Mitchell, Ky; ZIMMERMAN. Alexander H. (M 1939; A 1930) WRIGHT, M. Bimey (A 1932; J 1929) Mech. Ventilation Engr., Chicago Board of Health, 707 Engr. (for mall) E. I. duPont de Nemours & Co.,' City Hall, and (for mail) 5449 N. St. Louis Ave., . P. O. Box 1537, and Cedar Ave., South Hills; Charleston, W. Va. WRIGHTSON, Wilbor T. \M 1937) Eastern Mgr. (for mail) Garden City Fan Co., 55 West 42nd St., New York, and 22 Sagamore Rd.,'Br6nxviile, N. Y. . ' WUNDERLICH, Milton S.* (M 1925) Chairman Research and Test Committee,. Insiilite Co., 1100 . Chicago, 111. ." ZINK, David D. (M 1931) Consulting Engr. (for mail) 300 W. 47th St., Kansas City, and Hickman Mills, Mo. ZITZMAN, Francis T. (5 1938) Asst. Master ' Mechanic, South Mills, Jones & Laughlin Steel Corp., .Aliquippa, and (for mail), 411 Pine St., Beaver''Falls, Pa. ZOKELT, C. G. (Af 1921) Consulting Engr., Builders Exchange, - Minneapolis, and (for mail) 545 Mt. Curve Blvd., St. Paul, Minn. -, 3810-24th Ave., S.. Seattle, Wash. ZOLITSCH, Harry G. (A 1938) Partner (for mail) WYATT, DeWitt H. (M 1936) Consulting Engr., - George J. Zolitsch & Son, 123 Grape St., and Cooling St Heating Systems, 226 Northridge Rd., 392 Sanders Rd., Buffalo, N. Y. . Columbus. O. ZUBER, Otto (A 1938) Chief- Engr. (for mail) WYLD, Reginald G. (M 1937) Vice-Pres., Charge Amana Society, Refrig. Dept., Amana, and of Engineering, Chrysler Corp., Airtemp Div., South Amana, la. - 1119 Leo St., Dayton. 01 . ZUHLKE. W. R. (M 1928) Executive Engr., WYLIE, Howard M. (M 1925; J 1917) Vice-Pres. in Charge of Sales (for mail) The Nash Engi neering Co., and 51 Elmwood Ave., South Norwalk, Conn. ' American Radiator Co.. 40 West 40th St., New York, and (for mail) 54 Midland Ave., Ypnkers, N. Y. ' '- .. ZUMWALT, Ross (J 1938) Partner (for mail) Zumwalt & Vinther, 507 Thomas Bldg., and Y 4115 Travis St., Dallas, Tex. ' ZUROW, William (J 1937) Sales Engr. (for mail) YAGER, John J, (M 1921) 425 Woodbridge Ave., Buffalo. N. Y. .. St. Joseph Railway, Light, Heat & Power Co.. 520 Francis St., and 728 South 10th St.. St. YAGLOU, C. P.* (M 1923) Assoc. Prof., Industrial Hygiene (for mail) Harvard School of Public Health, 55 Shattuck St., Boston, and 10 Vernon Rd., Belmont. Mass. Joseph, Mo. ZWALLY, August V. (A 1937) Chief Air Cond. Engr., Interstate Electric Co.,' and (for .111311). 908 Elmwood, Shreveport, La. ' 68 SUMMARY OF MEMBERSHIP Honorary Members........................................... 2 Presidential Members......................................... 21 Life Members..---....:............................................. 55 Members........ ...................... ................ --............... 1644 Associate Members.................................. ........... 800 Junior Members ..................... ........... 486 Student Members........ .............................. . 59 Total___ _____.-J______ ___ _____ _'.............-3067 _ ------ -- ------`--- ' LIST OF MEMBERS (Geographically Arranged) UNITED STATES and ISLAND TERRITORIES 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-- . , Vinsori, N. L. Phoenix-- Genre, E. J. . Hummel, G. W.- Tucson-- Tidmarsh, P. M. ARKANSAS Little Rock-- Cumnock, H. Kellogg, W.T. McCoy, C. E. ; ? ; Siloam Springs--`7^ Jones, C, R. CALIFORNIA Albany-- ' Kaup, E. O. Alhambra-- . . Wells, E. P. . Altadena-- . Berringer, S. H. Bakersfield-- Baker, H. S. Berkeley-- Bentley, C. -E. Brokaw, G. K. . Cherry. V. H. Harrison, G. G. . Hutchinson, F. W. Peterson, C: L. Raber; B. F. Woods, B. M. Beverly Hills-- . Ekings, R. M., Jr. - . Burlingame-- Hill, j: A. Culver City-- Owen, J. D. f ; Fresno-- Newman, H. E. Fullerton-- Miles, C. N. Glendale-- ;- Eggleston, H. L. Orear, A. G. ' : Hollywood-- Stanley, R. L. - Lawndale-- Steiner, T. J. Los Angeles-- . Anderson, C. S. . ,- Beck, D. ' Blumenthal, M. 1. - Bullock, H. H. Burr, K. Cawby, E. L. Cline, E. A. Cranston, W. E., Jr. - Douglas, H. H. Downes, A. H. Ellingwood, E. L. English, H. Fabling, W. D. ' Gabbard, F. W. Hendrickson, H. M. * Hess, A. J. . Hill. F- M. Hogue, W. M. Hungerford, L. Kendall, E. H. Kennedy, M. '- Kilpatrick, W. S. .. Lauer,.-H. B. .. . Lehmann, M. . ..Lewis, J: C. . McKenzie. M;'C.; Jr. Miller, G. ' .Moriarty, J. M. ' Nelson, E, L.. . Ness, W. H. C. > Ott, o. w. Park, J. F. . Phillips, R. E. . . Phillips, R. H. . Schechter, J. E. Scofield, P.` C. Stewart, W. O. Storms. R. M. - Theobald, A. Weidele. E. J. Monterey Park-- Griffith, J. B. Oakland-- = ~ Cummings; G. JV Foote. A. G. Masters, R. B. ' Mears. L. A. . Passur, N. A.Williams. C. D. Pacific Palisades-- Finney, B.",;, Palo Alto-- Johnson, O. W. Pasadena-- Gifford, R. L. Piedmont-- Gayner, J. Sacramento-- Ames. C. S; ' Freeman, J. C. Kindorf. 0. " Porter, N. E. Towle, P. H.- ' San Diego-- '. Sadler, C: B; ; ' San Francisco-- Bouey, A. J. : . Cochran, L. H. Cockins, W. W. Cooley, E. C. . Corrad, J. Feyge,- H. Folsom. R. A. 1 Gee, W. W., Jr. . Haley, H. S. Hickman, H. V. ' Higdon. HJ S. Holland, R. B:Hook, F- W: . ... Hudson,.R.A.J Kindorf, H; L) Kolb, F. W. ' Kooistra, J. F. - .Krueger, J. I. Leland, W. E. Marshall, T; A. ! Molfino. P. O'Connor, G. P. Parker* R. A. . Peterson. N: H. Reed,.V. C. . 69 Shepperd, P. D. : Simons, E. W. ' Simonson, G. M. Varney, F. H., Jr. Ward, E. B. ' . .. Wayland. C. E: . Wethered, W. White, T. J. ' Woodbury, C. D./ Santa Cruz-- . Carpenter, R. D. Wollenberger, L. - Santa Monica--: - Coghlan, S. F. . Sausallto-- Howe, W. W. 1. West Los Angeles-- Leilich. R. K. COLORADO Colorado Springs-- Jardine, D. C. Denver--- Brierly. K. Conrad, R. Cooper, A. W, Davis, A. F. McNevin, J. E. McQuaid, D. J. O'Rear, L. R. Pierce, E. D. . . . La Junta-- Curtice, J. M. CONNECTICUT Bridgeport-- Earle, F. E. Smak, J. R. . Fairfield-- Osborn, ,W. J:: . Glenbrook--_. Jessupu-B. H. }\ Wahrenbrock, O: K. Greenwich-- Jones, A". L. . Opperman, E. F. Hartford-- ' . Krintrman, H. : Heatino Ventilating Air Conditioning Guide 1939 Meriden-- Colby. C. W. Middlebury-- . Lincoln, R. L. New Britain-- Hart, S. Hart. T. S. Nightingale, G. F. 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. Jennings, I. C. Lyons, C. J. Mead, E. A. Wylie, H. M. Stamford-- Bowles, P. Hoyt, L. W. Jehle, F. ' Torrlngton-- Doster, A. Upson, W. L. Wallingford-- Burns, J. R. Waterbury-- Russell, W. A. Simpson, W. K. DELAWARE Milford-- Downing, C. B.. Wilmington-- Anderson. P. R. Belt, N. O. Gawthrop, F. H. Hart, F. D. . Hayman, A. E., Jr, Kershaw. M. G. Lownsbery, B. F. Parvis. R. S.- Ponsell, F. I. Robinson, G. L.. Schoenijahn, R. P. Shepherd, C. B. Staszesky, F. M. Steel. R. J. DISTRICT OF COLUMBIA Washington-- Baldwin, K. F., Jr. Beitzell, A. E. Bennett, C. A. Bensinger, M. Borkat, P. Bornstein, W. Cover, R. R. Crawford, A. C. Culleh/A. G. Day, I. M. Devore,.A. B. DeWitt, E. S. , Downes, H. H. Eagleton, S. P. Erisman, P. H., Jr. . Febrey. E. J. Feltwell, R. H. Fife, G. D. Fineran, E. V. Fisher, J. T. France, C. N. Frankel. G. S. Frederick, W. L. Gardner, S. F. Goergens. A. G. `Gregg; S; L.~ Grimes, F. M. Grohs, C. E. Hall. W. L. Hanlein, J. H. Hartline, W. R. Holmes, P. B. Hoppe, M. F. Iverson. H. R. Kiczales. M. D. Kingswell, W. E. Kugel. H. K. Leser, F. A. * Liebrecht, W. J. Littleford, W. H. Lloyd. E, H. Lockhart, W. R. Loughran, P. H., Jr. Loving, W. H. McDonald, A. K. Merle. A. Meyers, J. Miller, G. F. Nelson. H. M. Norair, H. Nordine, L. F. Ourusoff, L. Page, V. C. Parker, L. L. Peller, L. Phillips, W. L. Reinoldi, C. Robinson, D. M. Schlemmer, B. C. Schlichter, C. F. Sutter, E. E. ' Thomas, G. Thompson, N. S. Thuney, F. M. Tuxhorn, D. B. Urdahl. T. H. FLORIDA Brewster-- Homan. J. D. Jacksonville- Alien. W.'W. Edge, A. J. ' Pastor, J. C. Varner, J. L. Miami-- Lingo, C. K. Rock, G. A. Ward, H. H. Miami Beach-- Friedman, D. H., Jr. Orlando-- Lyle, E. T. Porter, C. W. Tampa-- Thomas, B. A. GEORGIA Atlanta-- Baker, C. T. Barnes, L. L. . Boyd, S. W. Brockinton, C. E. Brodnax, G. H., Jr. Clare, F. W. Cole. C. B. Crout, M. M. Driscoll, M. G. Foss, E. R. . Gouedy, K. E. Gunnell, G. T. Hahn. R. F. Hamilton, L: L. ' " Kelley. R. D. Kent. L. F. Klein, E.W. Koch. A. H. Laseter, F. L. Lawrence, L. F.. Jr. McKinney, W. J. Nolan, R. E. Pounds, C. A., Jr. Sherman, W. P. Stotz, R. B. Sudderth, L. Templin, C. L. Tucker, T. T, Yarborough, T. R. Augusta-- Akerman, J. R. Arndt, H. W. Brunswick-- Gilmore, J. L. Savannah-- Hamlin, J. B., Jr. HAWAII Honolulu-- Edwards, H. B. Petersen, S. E. ILLINOIS Alton-- Carlock, M. F. Aurora-- Millen, R. J. Bloomington-- MaGirl, W. J. Nesmith, O. E. Soper, H. A. Whitmer, R.P. Chicago-- , Adams, B. P. Aeberly, J. J. . Aikman, J. M. ' Ammerman, A. S., Jr. Arenberg, M. K. Bamond, M. J. Baumgardner, C. M. Beery, C. E. - Benson, B. C. . . Bemstrom, B. Bevington, C. H;-- . Bishop, M. W. Black, F. C. . Borling. J. R. Bowles, E. N.. ` . ' Boyle, J. R. 70 Bracken, J. H. Bradley, J. M. Braun, L. T. ' Brocha, J, F. Brooke, I. E. Broom, B. A. Brown, A. P. Brown, J. S. . Brown, T. Buckley, M. L. 4 Bumam, C. M., Jr. Casey, B. L. Chapin, H. G. ' Christman, W. F. Christopherson, A. E. Close, P. D. Crone, C. E., Jr. Crump-, A."L. - - Cunningham, T. M. Dasing, E. DeLand, C. W. Dolson, C. N. . Dunham, C. A. . Ernmert, L. D. Ericsson, E. B. . Fatz, J. L. Fergestad. M. L. Finan, J. J. Fleak, W. D. Frank, J. M. Gardner, W,, Jr. Gaylord, F. H. Getschow, R. M. Goelz, A. H. Gossett, E. J. Gothard, W.W. Gotschall, H. C. Graves, W. B. Greenwood, O. J. Gustafson, C. A. Haddock, I. T. Haines. J. J.. Hale. J. F. Hanley. T. F., Jr. Hart. H. M. Hattis, R. E. Hayes, J/J. Hebley, H. F. J. Hendrickson, R. L. Herlihy, J. J. Hess. D. K. Hill. E. V. . Hinckley, H. B. Hines, J. C. 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. Krez, L. Kummer, C. J. Kyle. W. J. Lagodzinski, H. J. La Roi, G: H.t Jr. Larson, C. P. Lauterbach, H., Jr. Lenone. J. M. Leuthesser, F. W., Jr. Lewis, S. R. Lindsay, G. W., Jr. Liskow, J. G. . Lockhart, H. A, *. Luders. R. H. ' Machen, J. T.' Maier, H. F;. Malone, D. G* . * Malvin, R. C. Roll of Membership Manny, J. H. Marschall, P. J. Martin, A. B.- Matchett, J. C. Mathis, E. Mathis, H. Mathis, J. W. May. A. O. May, M. F. McCarthy, T. F. McCauley, J. H. McClellan, J. E. McDonnell, E. N. McDonnell, J. E. Medow, J. Merens, S. H. Mertz, W. A. Miller, F. A. Mittendorff, E. M. Mueller, H. C. Muessig, J. W. Murphy, E. T. Murphy, W. A. Narowetz, L. L., Jr. Neiler, S. G. Nelson, R. O. Newport, C. F. Offen, B. Olsen, C. F. Olson, B. Oosten. L. S. Paul, L. O. 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. Reger, H..P. Reid. H. P. Rietz, E. W. Rottmayer, S. I. Runkel, C. Russell, E. A. Ryerson, H. E. Sanders; C. M., Jr. Scheidecker, D. B. Schuetz. C. C. Schuler, W. B. Seelig, L. Shilling, H. C. Shultz, E. Solstad,. L. L. Sommerfield, S. S. Spielmann, G. P. , Stacy, L. D. Stannard.J.'M. Stermer, C. J. Stevenson, M. J. Sunderland, R. P. Sutcliffe, A. G. Swanson, N. W. Thinn, C. A. Thomas, R. H. Thommeif, A. A. Thornton, W. B. Tobin, J. F. Tornquist, E. L. Trumbo, S. M. Topper, G. B. Turner, G. G. Van Alsburg, J. H. Vernon, J. R. Voss, W. W. Walters. W. T. Ward. O. G. Weil, M. Weil. M. I. VVeinshank, T. Wendt, E. H. White. E. B. White. R. C. Whittington, J. A. Widdowfield, A. S.Williams, D. C. Wills. F. W. Wilson. W. H. Wolff, P. P. Woll, W. M. Yeazel, G. A. Zack, H. J. Zimmerman, A. H. Chicago Heights-- Boyar, S. L. Colfax-- . Scholl. H. O. East St. Louis-- Cover, E. B. Elmhurst-- Jones, D. J. Evanston-- Kearney, J. S. Maccubbin, H. A. Miller, J. E. Miliiken, J. H. Stahl, W. A. Flossmoor-- . Miller. R. T. Galesburg-- Side!!, P. A. . Glencoe-- Hornung. J. C. Glen Ellyn-- Parsons, L. D., Jr. Sherman, V. L. Homewood-- Wilkinson, F. J. Hoopeston-- Moore, D. R. Kenilworth-- Storch, C. A. Kewanee-- Bronson. C. E. Dickson, R. B. Hartman, J. M. Pursell, H. E. La Grange-- Eaton, B. K. Linn, H. R. Maywood-- Doerr, C. F. Moline-- Beling, 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-- Fitzgerald, M. J. May, E. M. Uhlhorn, W. J. Park Ridge-- Cochran, C. C. Heckel, E. P. Kuechenberg, W. A. Moore, R. E. Spielmann, H. J. Peoria-- Baird, S. A. Fox, E. L. Hauer, F. Meyer, F. L. . Rochelle-- ' Caron, H. Rockford-- Allen, C. V. Braatz, C. J. Dewey. R. P. Merwin, G. E. Pruden, B. Sterner, D. S. Stewart, D. J. St. Louis-- Blackmore, J. J. Edwards, D. F. Urbana-- Broderick, E. L. Compton, W. E. Engdahl, R. B. Fahnestock, M. K. Fellows, J. R. Konzo, S. Kratz, A. P. Marldand, C. E. Severns, W. H. Willard, A. C. Villa Park-- Armspach, O. W. Waukegan-- Killian. T. J. Western Springs-- Washington, G. Wlnnetka-- Brigham, C. M. Dauber, O. W. Killian. V. J. Prebensen, H. J. Zion-- Baughman, L. R. INDIANA Evansville-- Becker, R. K. Bulleit, C. R. Grossman, F. A. Fort Wayne--7 Abramson, R. Goshen-- SIiaw, B. E. . Huntington-- Redrup, W. D. Smith, G. W. . 71 Indianapolis-- Ammerman, C. R. Clark. L. W. Fenstermaker, S. E. Fillo, F. B. Garber, W. E., Jr. Hagedon, C. H. Hayes, J. G. Hildreth, E. S. Niesse, J. H. Parker, P. E. Poehner, R. E. Supple, G. B. Kendallville-- Knepper. H. H. ~ La Porte-- Shrock, J. H. Truitt, G. S. Lawrenceburg-- Bechtol, J. J. Michigan City-- Stockwell, W. R. Westphal, N. E. . Muncie-- Pfriem, P. G. Price, C. F. Peru-- Thrush, H. A. . Vincennes-- Wissing, C. B. Wabash-- Shivers, P. F. West Lafayette-- Forbes, H. B., Jr: Miller. W. T. - IOWA Ackley-- Nelson, G. O. Amana-- Foerstner, G. C. . Zuber, O. Ames-- Norman, R. A. Cedar Rapids-- Friedline, J. M. Des Moines-- Borg, E. H. Campbell, B. Danielson, E. H. Daubert, L. L. Deiavan, N. B. Elbert, B. F. Hedeen, L. E. ` Helstrom, C. W. Johnson, T. R. Kimble. C. W. Landes, B. E. La Rue. P. Marshall, R. D. McReynolds, C. V, Olchoff, M. Schnell, R. H. Smith, R. A. Spring, C. L. Stiles, G. S. ' Triggs, F. E. Vaughn, F. R. Walters, A. L. Heating Ventiuotng Air Conditioning Guide 1939 Dubuque-- Brashaw, C/-J. Iowa City-- Yuska, L. J.. Marshalltown;--7 Shirley, W. B:; Sioux City-- Hagan, W. V. Raven, A. H. Waterloo-- Knox, J. C. 1 Mitchell, J. A. Todd, M. L. Winterbottom,.R. F KANSAS, Great Bend-- Morrison, W. L. - Hutchinson-- Mann, A. R. Stevens, H. L. Kansas City-- Angus. F. M. Lawrence-- Machin, D. W. Sluss, A. h: Neodesha-- ,, Berzelius, C. E*. Overland Park--; Robb. J, E. , Russell-- Danielson. E. B. PanielspnL L. C. ' Satina-- '' ' Bacbofer, Hv'A.. Jr. Ryan, W. _F. . s,. Wichita-- Droppers, C.'J; KENTUCKY Fort Knox-- Danielson, W. A. : Fort Thomas--. Stevens, W.- R- Lexington-- .. Cabot} M? A.. . May. J. W. O'Bannon, L. S. West, P. Louisville--" Brown, J/S.1, Jr! Fitch, H. M. Grabensteder, L. Graham, J/M. Groot. H. W. HellStrom, J. '. Murphy, H. C. ,' White. T. G:. Jr. Vine Grove-7Cropper, R^ -b;. LOUISIANA New Orleans-- ' Gamble, C..B. . Gaminill, O.'E.i Jr. Herman, N.'B. 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. MAINE5' Bangor-- . Prince, R. F. Lewiston-- Fowles, H. H. Portland--. , .. Demarest. R. T.- Fels, A. B. Merrill, C, J.,. .... South Portland-- Mitchell. C. H.. MARYLAND Annapolis-- ;; Gale, H. Baltimore-- Crosby; Ei~-L.-- Dressell. R.. E.;, Dull. E. J. . Hunt, M.C.L- : . . ' ' Jex, J., Jr. . .; Lee, J; A: ' ' Leilich. R. L. .. MeCaffray, C. E. McCormack, D. Nest, R. E. - Posey, J;- Robinson, E. R. ' Seiter. J. E... Shepard, J. deB. Sklarevski^R.. Smoot, T.`rl. Steele. M. G-. Stehl, H. V. Vance, L: G. Vincent, P. J. Whiteley, S. M. Bethesda-- Goodwin, E. W. Stock, C. S. . Terhune, R. D.:- Brooklyn Park-- Rodgers, J. S. Chevy. Chase--^ Thulman, R. K. College Park-- > : Gifford, W. R. Cumberland-- . Griffith, C. A.. .. ElHcott City-- Collier. W. I.;1;' Kensington-- Spurney, F. E. Rockville-- .Brunett, A..L. Roland Park-- Dorsey, F. C. Silver Spring--r Black, F. M. . Stack, A. E. Vaughan, J. G., Jr. Takoma.Park-- ` Croney, P. A.. Towson-- '' Taze, E; -H.j> MASSACHUSETTS Arlington1-- Bullock, T. A. Sessler, R. E.i . Shaw, N. J. H. . Arlington Heights-- Tarr, H. M. ; ' Belmont-- ' Spence, R.A. ' Boston-- ^ ' ' Archer,' Dl M..,.. Brinton,- J.'W." Brissetta, L, A, Bryani, A. G. . Cummings?`C; -H. Dickson, G. P. Donohoe, J. B: Drinker, P-.c , Edwards, D. J. Foulds,-P. A. L. Franklin, R..S. Gleason; G.'H. * Hashagen, J. B. Jennings,' R.A. Jennings, W. G. Kelley, J. J. . Kellogg, A- ... McCoy. T. F.. . Merrill, F. A. Miller,-J. F; G. Mullen, T. J-. Jr. Nee, R. M.,' ` Rydeli; c: a: Swaney,-C. R.Tuttles J. F. . Waterman, J. H. Yaglou, C:. P. . .. Bridgewater-- Beaulieu,'AT. A-- Cambridge-- . ; Armstrong, E. T. Flint, C. T. Gerrish, G. B. .' Holt. J. . Hoyt, C- W- Longwell, S- C. Moore, H. C. Peterson,'C. M.'-F; Saurweyi, G.- K. . Steenkampi W. Turner, J, r Chelsea-- Hochman, E. Cochltuate-- Ahearn, W. J. Dalton-- Dakin, H. W. Dorchester-- Goodrich, C. F. Hosterman. C. O. Little, D. H. Shaer, 1. E: 'Wonson, A. S:,.Jr. FaU River-- -Fenner, E. M. ' Fitchburg-- " Illig.E.E. .. . Iliig, W. R. Karlson, A. F.. McKittrick, P..A. Forboro-- ' ` Meakin, J. B. ; Harwich Port'-- Maxwell, ` Haverhill-- . Taylor, F. ' ; Hyde Park--. a1 Bartlett, A. C. ^ Ellis, F. R. : *" Keyes,' R. E. v.Woif,j: c:- Lawrence--T ... ,' * Bride^ W. T. Leominster-- Kern, Jt. T, Lynn-- `. Farrow,-HaL. " ' Feehan; J.*?B. Lauckner, C- G-, 3rd Milton-- * Austin, W.H. Corey, G. R- ' Needham--: , ' Webb. J- S. Newton Centre*-- Murray, Jv'J." `1 WUkes, G. B: . Newtonvllle-- . .Emerson, R. Ri. Jones, W. T* Pittsfield-- ,3 Wagner; E. A'.i. Reading-- ' Ingalls', F. D.'.B. Revere-- Brayman, A. 4.- "72 Roslindalc-- Finnerty, J. A. Larson,' C; W. - Macrow, L. Stetson, L. R. Roxbury-- Madden, J. J. Sharon-- ; Nelson. A. W. Shirley-- V Boyden. D. S. Somerville-- . Scaling!, C. R. ' Sheffield, R. 'A. Whitten. H. E. South-Boston-- Hilliard, C. E. South Braintree-- Chenoweth, South Hamilton'-- Mandell, T. P. Springfield-- Cross, R. E. . Hallstein, H:T.S ' Holmes, R. E. Leiand,:.W.B. Murphyi W.. W. Swampscott-- Knowles,.M. G. Wakefield-- ' Bennitt, G. E. ; Watertown-- Wiegnerj H..BV Wellesley-- . Millard, J..W. Wellesley Hills-- Bames, W; E. West Medford-- Kimball. C; W;r West Roxbury-r^ McCafferty; J. ,E. McPherson, W. A. Woburn-- Parker, P. Worcester--. . , Delaney, J.'' V. * ' Turner, P.,K. v Wechsberg, O.. . MICHIGAN , .Ann Arbor-- ' ' Backus, T. H. L. Bichowsky, F. R. Emswiler, J. E. . Kessler, C. F.. . Marin, A. " " Battle Creek-- Christenson; H; Dempsey,. SaJ^< Roii or Membership; r-y- Bay City-- Gray, J. W. Henry, E. C. Birmingham-- Akers, G. W. Hadjisky. J. N. Hyde, E. F. Root. E. B. Dearborn-- King, H. K. Detroit-- Adam. R: W. Annas, H. C. Arnoldy, W. F. Baldwin, W. H. Barth, H. E. ' Barton, J.. Bassett, J; W. Bay, C. H. Bishop, F; R. Blackmore, F. H. Boales, W.' G. Bottum, E..W. Busse, H. - <_mrK, C/. n. - Connell, R. F: Cook, H. D. Coon, T. E. Cummins, G. H. Darlington, A. P. Dauch, E. O; ' Davis, G. L., Jr. Deppmann, R. L. Dickenson, F. R. Doyle, B. J. Dubry, E. E. Estep, L. G'. Falk, D. S. . Feinberg, E. / Flink, C. H. Ford, E. -F. : . Freitas, L.iJ.- Gifford, E. W. ! Giguere, G. H. Goss, M.'H. ' Halleck, L. P. Hamaker, A. C. Harrigan, E. M. Hesselschwerdt, -A. L., Jr. Heydon, C. G. Hogan, E. L\ - Hubbard, N.tB. Hughson. H. H. Hutzel, H. F. Kaufman, H. J: Kilner, J.,S. Kincaide, M. C. . Kirkpatrick, A. H. Knapp, A. E, Knibb, A. E.'!' ' Lance, J. F. Lewis, G. M. ' ' ' . Linsenmeyer, F.` J. Lowe, R. A. Luty, D. J.I-: . . Lyke, H. W., Maier, G. M.. Martel. C. LVjr. Marzolf, F. X. . - McConachie, L.' L. McCrea, J. B. McDonald; J. J. McGaughey, H. M., McGeorge, R. H.' Mclntire, J^F.- McLean, Di*^V- Metcaife, C.; . . Miller, R. E/ ' Milward, R. K:l Morgan,-R.-Wi' Morse, C. T. . Morse, L., S., Jr. Nutting, H..G..D. Oberschulte, R. H. O'Gorman, J. S. Old. W. H. Phetz, H. E. Parrott, L. G. Partlan, J. W. Patterson, F. H. Pavey, C. A. Pike, W. H. Purcell, F. C. Randall, R. D. Randall, W. C. Reader, J. T. - Rose. W. H.f Jr. Sanford, S. S.- Schechter, J. P. < Schmidt, K., Jr. < Schultz, S. F. Shea, M. B. , Sheley, E. D.' Skelley, J. H. Smith. W. O. Snyder, J. W. Soeters, M. Spitzley, J. H. Spitzley, R. L. Spurgeon, J. H. Stites. R., Jr. Taylor, H. J. Thoman, E. O. Toonder, C. L. TutUe, G. H. Van Nouhuys, H. C. Volberding, L. A. * Waid, G. H. Walker, J..H. Weinert, F. C. Whelan,-W;'J. White, E. S. Whitt, S. A. . Wigle, B. Winans. G. D, Dowagiac-- , .. Cunningham, J. S. Harden, J. C. Torr, T. W.` Woodhouse, G. D. East Lansing-- Miller, L.`G. Pesterfield, C. H. Witmer, H. S. - Ferndale-- Mally, C. F. Flint-- Hendriksen, L. Grand Rapids-- . Boot, A. Bradfield, W. W. Bratt, H. D. Dykman, J. 'G. Epple, A. B. Graff, W. F. Marshall, O. D. Morton, C. H,, Osberger,' T. L'. Stafford, T. D. Terrill, Ml Todd, S. W. Warren,' F. C. Ziesse. K. L. Grouse' Pointte-- Buckcridge, y, L. Grosse Pointe Park-- Feely, F.-J. i 73 Hermansville:-- Voorhees, G. A. Highland Park-- Champlin, R. C. Harrower, W. C. Wilde, R. S. M.. Holland-- . Leigh, Ri L. - Houghton-- Seeber, R. R. ' Iron Mountain-- Eisele, L. G. Jackson-- Gerhard, D. H. Kalamazoo1-- Brinker, H. A. Downs, S. -H. Hotop, H. C. McConner, C. R. Metzger, H. J. Schlichting, W. G. Temple, W. J. WUson, R. W. Keego Harbor^-- Trzos, O. A. Lansing-- . Distel, R. E. Hill. V. H. McD5Uth, B. F. Parsons, R. A. : Vanderlip, P. J. Mt. Clemen*-- - Bailey, E. P; Muskegon-- ' Young, H. J. Muskegon Heights-- Reid, H. F. Pleasant Ridge-- Williams', F. H. Pontiac^- . Singleton, J. H'. Royal Oak-- . Burch, L. A. Helmrich,-G: B. Keyser, H. M. ' Saginaw-- * Witheridge. D. E. Spring LakerT-(. Worthing, S.*L; MINNESOTA Bayport-- Swanson, E. C. Duluth-- . Foster, C. -. , Mankato--. ... . Forderbruggen/*K. J. Heating. Ventilating Air Conditioning Guide 1939 Minneapolis-- Albrecht, H. P. Algren, A. B. Armstrong, R. W. Bell, E. F. Bensen, C. L. Benson, M. L. ` Betts, H. M. Bjerken, M. H. Bredesen, B. P. Burns. E. J. Burritt, C. G. Campbell, R. L.. Caple, I. Carlson, C. O. Chalmers, C. H. Comb, F- R., Jr. -Cooper,-T. E. *- - - Coppemd, E. R. Cumming, F. J. Dahlstrom, G. A. Davidson, J. C. Dovolis, N. J. Doxey, H. E. Edelman, B. P. Fedders, M. P.. Forfar, D. M. Francis, P. E. Gable, H. R. Gausewitz, W. H. Gerrish, H. E. Gordon, E. B., Jr. Gross, L. C. Haley. R. T. Hall. J. R: Hanson. L. P. Harris, J. B. Hawkinson, C. F. Helstrom, H. G. Herbacek, E. E. Hitchcock, P. C. Hucb, A. J. Jordan, R. C. King. R. L. . Kingsland, G. D. Knapp, D. S. Knowles, E. L. Kuehn. W. C. Lange, F. F. Legler, F. W. Lilja, O. L. . Lesch, R. T. Lund. C. E. Marshall, S. C. McDonald, T. Miller, L. B. Mills, H. C. Morgan, G. C. Morton, H. S. . Newton, A. B. Ogard, N. L; Orr, G. M. Petersen, C. P. Proebstle, L. Roberts, H. P. . Roberts, J. R. Rowley, F. B. Russell. T.W. " Schad, C. A; Schernbeck, F. H. Schultz, A..W. Seelert, E. H. Shipley, S. C. Spencer, J. B. Stafford, J. F. Stiller, F. W. Sturm, W. Sundell, S. S. Sutherland, D. L. Swanson, D. F. Swenson, J. E. ' Uhl, E. J. Uhl, W. F. Wallace, H. P., Jr. Welter, M. A. Whitesell, R. H. Willis, L. L. Owatonna-- . Anderson, G. A. M. Rochester-- Adams, N. D. Plummer, R. S. St. Paul-- Anderson, D. B. Backstrom, R. E. 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. Jones, E. F. Lynn, R. G. McNamara, W. Mitchell, J. G. Oberg, H. C. Persson, N. B. Ruff, D. C. Sanford, A. L. Winterer, F. C. Wunderlich, M. S, Wayzata-- Heberling, C. W. Winona-- Hamerski, F. D. MISSISSIPPI Jackson-- Light, J. C. Dawson, T. L. Dean, F. J., Jr. Dean. M. H. : Disney, M. A. Dodds. F. F. Downes, N. W. Ellis. L. W. Farber, L. M. Fehlig, J. B. Flarsheim, C. A. Foley, D. F. Forslund. O. A. Garnett. R. E. Gillham, W. E. Gould. H. E. Harbordt, O. E. Holuba, H. j. - --Kitchen,-J--H: ----- - Lautz, F. A. Mahon, C. A. Maillard. A. L. Marchio, E., Jr. 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. O'Dower, H. J. Painter, D. H. Pellmounter, T. Pellmounter, T. V. Pettit. E. N.. Jr. Pexton, F. S. Rivard. M. M. Ryan, J. B. Sawyer, J. N. Sheppard, F. A. Stephenson. L. A. Stevens, K. M. Weiss, C. A. White. H. S. Williams. A. E. Wright, H. H. Zink, D. D. MISSOURI Clayton-- Du Bois, L. J. . Drexel-- . Baender, F. G. -Ferguson-- Szombathy, L. R. Independence-- Cook, B. F. Jefferson City-- Woodman, L. E. Joplin-- , McMullen, E. W. Kansas City-- Allen. D. M. Arthur, J. M.. Jr. Ball, W. Barnes, A. R. Barnes. H. P. Betz. H. D. Caleb. D. Cameron, W. R. Campbell, E. K. Case. D. V. Cassell. W. L. Chase, L. R. Clegg, C. Kirkwood-- Hartwein, C. E. Liberty-- Kurek, T. C. Maplewood-- Curry, R. F. Siegel, W. A. . Mexico-- Badaracco, J. A. Normandy-- Dulle, W. L. Overland-- Grossenbacher, H. E. Richmond Heights-- Nelson, C. L. Siegel, D. E. Springfield-- James, R. E. Karchmer, J. H. St: Joseph-- Harton, A. J. -Zurow, W. St. Louis-- Barry, J. G., Jr. Bayse, H. V. ( 74 Boester, C. F., Jr. Bradley, E. P. Carlson. E. E. Carter, J. H. ` Clarkson, J. R, * Cooper, J. W. Corrigan, J. A.. Davis, C. R. Dreher, L. F. Driemeyer, R. C. Evans, B. L. Fagin, D. J. Foster, J. M. Gilmore, L. A. - Grossmann, H. A. Haller. A. L. Haroig, L. L. . -Hester, Trj: ~ ' ` Hoffberger, Ji P. Hugoniot. V. E. ' Kuntz, E. C. Landes,.J. M. Lang. J. C. Langenberg. E. B. Laskaris. N. G. Laufketter, F. C. Malone, J. S. Matousek, A. G. Mclntire, J. L. McLamey, H. W. McMahon, T. W. Miller. J. E. Moon, L. W. Norris. W. P. Oonk, W. J. Rodenheiser, G. B. Rosebrough, J. S. Rosebrough, R. M. Scherrer, L. B. Simons, B. C. Sodemann, P. Sodemann, W. C. B. Stammer, E. L. Sydow, L. J. Tenkonohy, R. J. Warren. J; S., Jr. Weber, E. F. White, E. A. . University City-- Falvey, J.,,D. Starr, L. . Webb City-- Hallar, E. V. . 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. Roll of Membership Hastings-- Swingle, W. T. Lincoln-- Carlson, C. V. Green, E. W. Hellmers, C. C., Jr. Hennessy, W. J. King, L. D. Lehman, M. G. Ress, O. J. Shapiro, M. M. Stanton, H. W. Tapley, M. S. Williams, D. D. OmahaBanner, F. L. D. Frederick, K. C. Goll. W. A. Herbert, R. M. Kleinkauf, H. Larkin, P. Leach, L. S. Lindberg. A. F. Lycan, L. K. Malcolm, B. L. Mathis, J. Millard, E. L. Moffitt, L. C. Olson, M. J. Peiser, M. B. Reifschneider, J. Rigby, R: A. Rist, L. M. Sallander, H. A. Schwartz, N. E.' Solzman, I. I. Stanfield, R. E. Tracy, W. E. Waddington, B. C. White. W. R. Scottsbluff-- Davis, O. E. . Matthews, W. M. Prawl, F. E. NEW HAMPSHIRE Elkins-- , Baker, R. H. . NEW JERSEY Arlington-- Bock, B. A. Asbury Park-- Strevell, R. P. J Atlantic City-- - Strouse, S. B. Bayonne-- Schwartz, J. Belleville-- Thornton, T. L. Bloomfield-- 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., Jr. Cliffslde Park-- Butler, P. D. Clifton-- Hilder, F. L. Colllngswood-- Bolsinger, R. C. Mohrfeld, H. H. Dover-- Hedden, W. M. East Orange-- Ferguson, R. R. Gombers, H. B. Maddux, O- L. Raymer, W. F,, Jr. Reilly, J. H: Schroth, A. H. Settelmeyer, J. T. Tallmadge, W. Turno, W. G. W. Merchantville-- Binder, C. G. Rohlin, K. W. Montclair-- Broome. J. H. Scarlett, w. J. Morristown-- Roy, A. C. Newark-- Albright, C. B. Bryant, P. J. ------ Carey; PfC.~~ ' Haitmanek, L. M. Kruse, W. C.P Jr. Leinroth, J. P. Morehouse, H. P. Ray, L. B. Steinmetz. C. W. A, New Brunswick-- Auchmoody, F. W. Wolin, M. W. North Arlington-- Bermel, A. H. Trambauer. C. W. North Bergen-- Constance. J. D. Elizabeth--' Anderson, J. W. Bentz, H. Cornwall, G. I. Faulkner, G< Wheller, H. S. Essex Fells-- Soule, L. C. Stacey, A. E,, Jr. Freehold-- Buck, D. T. . Glen Ridge-- Jackes, H. D. Hasbrouck Heights-- Goodwin, S. L. North Plainfield-- Seal, A. T. Nutley-- Atkins, T. J. Morris, C. R. . Old Tappan-- Schoeffter, H. M. Orange-- Crawford^ J. H., Jr. Paterson-- Bannon, L. E. Cox, H. F. Frank, O. E. Pryor, F. L. . Wagner, J. G. HaworthSharp, J. R. Perth Amboy-- Simkin, M. Irvington-- Feldermann, W. Reinke, A. G. Stengel, F. J. Jersey City-- Jones, H. L. Kunzog, T. W. O'Rourke, H. D., Jr. Ritchie, W. Walterthum, J. J. Kearny-- Shaffer, C. E. Leonia-- Close, R. Lyndhurst-- Ehrlich, M. W. Maplewood-- Kepler, D. A. Woolley, J. H. Plainfield-- Pond, W. H. Tobin, G. J. Red Bank-- Mytinger, K. L. Ridgefield Park-- Davis, A. C- Ridgewood--- . Fitts. J. C. Miller, A. T. Wallace, D. R. Roselle-- Snavely, E. R. Roselle Park-- Kampish, N. S. Somerville-- Van Nuys,'J. C. 75 South Orange-- Browne, A. L. Summit--' Oaks, O. O. Teaneck-- Heebner, W. M. Westfield-- Scribner, E. D. West Englewood-- . - -Gumaer,--P._W. Steinke, B. J. Trenton-- Plaag, A. F. Union-- Edwards. L. V. Lyman, S. E.. Union City-- , Tavema, F. F. West New York-- Stinard, R. L. West Orange-- Adlam, T. N. NEW YORK Albany-- Bond, H. A. Dick, A. V. Johnson, H. S. Lewis, H. F. ' Murray, T- F. Rabe, A. E. Taggart, R. C. Teeling, G. A. Westover, W. Bedford Hills Waters, F. A. Bronxville--- Bishop, C. R. Groves, S. A. Brooklyn-- Addington, H. B. Balsam, C. P. Bernhard, G. Blackshaw, J. L. Campbell, R. E. Charles, T. J. Daitsh, A. De Somma, A. E. Dutcher, H. S. Dwyer, T. F. Fidelius, W. R. Franck, P. Gates, R. A. . Goldberg, M. Gomston, M. H. Goulding, W. Hamje, M. C. Harsch, R. J. Herty, F. B. . Hollister, N. A. Jalonack, I. G. Janet, H. L. Josephson, S. Kadel, G. B. v Leventhal, B. Lo Piccolo, A. A. Moss, E. Heating Ventilating. Air;Conditioning Guide 1939 Phillips, F. W. Potter, J. R. Ritchie, E. J. Rose, J. C. Stalb. J. G. Tusch, W. Wachs, L. J. Weissblatt, N. Wilson, A. . Buffalo-- Beman, M. C. Booth, C. A. Cherry, L. A. Cheyney, C. C. Conaty, B. M. Currier, C. H. Curtis, W. A. Davis, J. Day. H. C. Drake, G. M. Eisele, W. S. Eutsler, E. E., Jr. . Farnham, R. Farrar, C. W. Gifford, C. A., Grieves, T. R. Harding, L. A. Hawk. J. K. . Heath. W. R. Hedley, P. S. Hexamer, H. D. Hirschman, W. F. Holt. W. H. . Humphrey, L. G., Jr. Jackson, M. S. Jenkins, F. H. Kaiser. F. Kamman, A. R. Landers, J. J. . Lenihan, W. O. ' Lighthart, C. H. . Lockhart, C. W.,, Long, H. P. ' Love. C. H. Mahoney, D. J. Messenger, T. I. Mosher, C. H. Pleuthner, R. L. Reif, A. F. . Reif. C. A. Rente. H. W. Robinson, E. T. Roebuck, W., Jr. . Ruff, H. A. Schafer, H. C. Schmidt, H.^ Seelbach, H. . Seelbach,'H., Jr.. Shelney, T. i. Strouse, S. W. v Voisinet, W. E. Walker, E. R. .. Wendt, E. F. Yager, J. J. Zolitsch, H. G. Croton-- Elliott, I. Derby-- ` Ensign, W. A. ; . Dobbs Ferry--. Hewett, j. B. Elmira-- ' ' Davis, B. C. Glens Falls-- Hollister, E. W. Hastinjjs-on-Hudson - Reynolds, T. W. Hyde Park-- Burr. G. C. Irvington-- Bastedo, A. E. ' Ithaca-- Elwood. W. H. Fairbanks. F. L. Frederick, H. W. Sawdon, W. M.. Williams, J. W. Woods, E. H. . Kendall-- Stangland. B.'F. Kenmore-- Candee, B. C. Criqui. A. A. Cross, R. A. . Mollenberg, H. J. Snyder, J. S. Sommers, W. J. Larchmont-- . Downe, E. R. Lockport-- Johnston, R. M. Prudden. O. D. Saunders, L. P. Long Island-- Adler. J. C. (Forest Hills) Alt, H. L. (St. Albans) Apt, S. R. (Flushing) Ballman, W. H. (Long Island City) Bastedo, G. R. (Richmond Hill) Belsky, G. A. (Valley Stream) Blackburn, E. C., Jr. (Garden City) . Bloom, L. (Freeport) Cameron, R.-T. (Southampton)' Carbone, J. H. (St. Albans) Dailey, J. A. (Astoria) Eastwood, H. F. .. (Merrick) Eskell. J. E. (Astoria) Fay, D. P. (Richmond Hill) Fritz, C. V. (Freeport) Gallaway. J. F. \ (Kew Gardens) Graber, E. (Douglaston) , Hiers, C. R. . (Great Neck) ' . Hinkle, E. C. . . (Hempstead) Hoehl, E. R. . (Garden City) Kaiser, C. W. (Woodside) Keller, G. A. : (Wantagh) Kenney, T. W. (Hicksville) Kern, J. F,, Jr. : (Jamaica) Klenert, VV. (Flushing) , Knudsen, W. R. (Jackson Heights) Landewit. C. J.' (St. Albans) Lane, D. D. . (Elmhurst) Lang, J. . (Richmond Hill). Lewis, C. A. (Astoria) MacWatt, D. A. (Great Neck) Magee, K. B. (Astoria) Magnusson, N. - (Jamaica) Maher, T. F. . (St. Albans) Meyer, C. L. (Hollis) . Olsen. G. E. (Arverne) Pabst, C. S. (Woodhaven) Pinto, C. B. (Lawrence) . . Pritchard, W. J. (Jackson Heights) Raynis. T. . (Richmond Hill) Richfield, N. H. (Floral Park) . Rudd. D. J. (Babylon) Schermer.R. . ' (Elmhuist) ' Schwartz, M. (Far Rockaway) Skidmore, J. G. (Long Island City) Spoerr, F. F. (Jamaica) ' Stellwagen, F. G. - (Woodhaven) Sterne, C. M. (Long Island City) Thomson, T. N. (Huntington) Tucker. F. N. (Freeport) . Vervoort, E. L. (Rockville Centre) Wade. R. H. (Laurelton) . Wallace, G. J. (East Elmhurst) Whittaker, W. K. (St. Albans) Mt. Vernon-- Cribari,\H. E. Freitag, F: G. ' Northon, L. New Rochelle--... -Abrams, A. . ' Farley, W. F. -Gaylor, W. S. Giannini, M. C. Lambert, R. D. Rose, H. J. Terry, M. C. New York City-- Adams. E. E. Addams, H. . Adler, H. Ashley, E. E. Baker, H. L.,"Jr. - Baker. W. H.. Jr. Barbieri, P. J. 76 Baum, A. L.- ; Bearman, A. A. . Beebe, F. E. W. Bennett, E. A. . Berman, L. K. ' Bianculli, V.'A. Blackman, A. O.' Blackmore, J. J. Bodinger, J. H. Bolton, R. P. Bond, H. H. Bonthron, R. C- : Borak, E. Brown, D. Buensod. A. C. Carpenter, R. H. Charlet, L. W. Chase. C. L. Citron, D. J. Clay. W. Cowell. R. J. Cued, V. J. Cullin. W. W. : Daly, R. E. Darts, J. A. Dauman, A. ' Davis, C. Davison, R. L. ' Denny, H. R. Deterling, W. C. Dodge. H. A. Donnelly, R'- Dornheim, G. A. Downs, C. R. Duncan, J. R. Eadie, J. G. Elliott, L. B. Engle, A. Erickson, E. V. Etlinger. M. J. Everetts. J., Jr. Faile, E. H. Fay, F. C. Feder, N. Feldman, A. M. Fenner, N. P. . Fiedler, H. W. Fischer, L. ' Fitz. J. C. Fleisher. W. L. Foster, J. G. . Friedman, M. Gordon, P. B. Greenburg, I. Greenburg, L. Hanburger, F. W. Hateau, W. M. Hechler, S. . Heibel, W. E. Heller, J. A. Henry, A. S., Jr. Hering, A. Herkimer, H. Herske. A. R: High, J. M. . Hildreth, L'. W. Hinrichsen, A. F. Hirsch, M. H. - Hobbie, E. H. Hoffman,' C. S. Holland, G. R. . Honerkamp, F. Hosking, H. L. Hotchkiss, C. H. B. Hutcheon, C. R. . Hyman, W. M. ' d'Issertelle. H. G. Jacobus, D. S. James, J. W. . Jarcho, M. D.- .. Johnston, W. H. Kelly. C. J. Kessler, J. Kimball, D. D. . Koehler, C. S. Kuhlmann, R. 'i Roll of Membership K' l Kunen, H. North Tarrytown-- Suffem-- High Point-- . Kurth, F. J. Lawrence, F. D. Weiss, A. P. J3arnum, M. C. Gray, W. E. Lucke. G. E. Markush, E. U. Martens, E. D. Martin, G. W. North Tonawanda-- Spencer, W. E.: Syracuse-- Acheson, A: R. Ashley, C. M. Raleigh-- Rice, R. B. Vaughan. L. L. Mayette, C. E. Oswego-- Cady, E. F. Winston-Salem-- ' Ij McClintock, W. McEwan, E, E. McLeish, W. S. Meinke, H. G. Meyer, H. C., Jr. Milener, E. D. Miller, C. A. Miller. J. Montgomery, O. G. Morse, F. W. Mohn, H. L. Pelham Manor-- Peacock, J. K. White. E. G. Port Chester-- Scott, G. M. Carrier, E. G. Carrier, W. H. , Cherne. R. E. Day, V. S. Dee, L. H. Des Reis, J. F. Driscoll, W. H. Dunne, R. V. D. Evans, E. C. French, D. Bahnson, F. F. Brown, M. D. ' . Cornwall, C. C. - Kaczenski, C. Page, A. Warren, R. M., Jr. OHIO If Munier, L. L. Munkelt, F. H. Murphy, J. R. ' ' Offner, A. J.' Oldes, W. E. Olson, R. G. Olvany, W. J. Ortiz, J. V. . Patorno, S. A. S. Pihlman, A. A. Place, C. R. Pohle, K. F. Poliak, R. Purinton, D. J. Quirk, C. H. . Raisler, R. K. Ramsay, J. W. Rather, M. F. Reynolds, W-. V. ' . Ritter, A. Rodman, R. W. Rosenberg, P. . . Rosenthal, E. Ross, J. O. ; Roth, C. F. . Salter, E. H. Samuels, S. ' Sanbern, E. N. Sawhill, R. V. Schoepflin, P. H. Schulze, B. H. Scott, A. F. H. Sears, C. B. Seelig, A. E. . Sellman, N. T.. Senior, R. L. Siebs, C. T. Simpson, A. M. ' Rochester-- Andresen, G. C. Betlem, H. T. Cook, R. P. Dickason, G. D. Eschenbach, S. P.' Hakes. L. M. Hutchins. W. H. Lee. R. T. Leonhard, L. W. Stacy, S. C. Treadway, Q. Vidale, R. Wilder, E. L. ; Rome-- - Lynch, W. L. .. Rye-- Crone, T. E. Scarsdale-- . Cumraing, R. W. Ullman, H. G. Schenectady-- Welch, L. A.. Jr. . Schodack Landing-- Freas, R. B. Scotia-- Hunziker, C. E. Snyder-- John, V. P. Madison, R. D. Graham. W. D. Grant, W. A- Hockensmith, F. E. Ingels, M. Lewis, L. L. Licandro, J. P. Lyle, J. I. Schulz, E. L. Shanklin, A. P. Sheldon, N. E. Taliaferro, R. R. . Traynor, H. S. ` Woese, C. F. Tonawanda-- Karlsteen, G. H. Tuckahoe-- ; Brabble, C. W. Utica-- Knapp, J. H. Sherbrooke,'W. A. Steinhorst, T. F. ' Valhalla-- Mehne, C. A. . White Plains-- Baker, T. - Ruple, P. E. . Zibold, C. E. Williamsvilie--1 Stevens, A. L. Akron--. ... Shields. C. D. , Ashland-- Rybolt, A. L. . Chagrin Falls-- Southmayd,.R. T. Cincinnati-- ' Bird, C. Boyd, T. D. Coombe, J. Cramer, VV. G. Donelson, W. N. Du Chateau, M. F. Edwards, A. W. Fenker, C. M. Green, W. C. Hard, A. L. . Helburn, I. B. Houlis, L. D. Houliston, G. B. Hudepohl, L. F. Hust. C. E. Jennings, H. K. Junker, W. H. Kiefer. C. J. Kilday. J. A. Kinney, A. M. Kramig, R. E., Jr. Leupold, G. L. . Mason, G. C. ' Mathewson, M. E. Mayer, R. W. ' Mayne, W. L. 2. ' Sklenarik, L. Smith, M. S. Sternberg, Ev Still, F. R. - Strock, C. . Strunin, J. Syska, A. G. Tiltz, B. E. Timmis, W. W. Torrance, H. Tyler, R. D. Vetlesen, G. U. Wagner, F.'H., Jr. Wadsworth, R. H. Walker, K. '-'Wallace, GjN/. Walton, C. W.; Jr. Waring, J. M. S. Wasson, R. A. . . Staten Island-- Callahan, P. J. (Great Kills) Connell, H. ' (Mariners Harbor) Frimet, M. (West Brighton) Ghose. K. N. (New Dorp) Johnson, E. B. (Port Richmond) Perina, A. E. . (Port Richmond) Pfuhler, J. L. (W. New.Brighton) Pietsch, j: A. . (New Brighton) Ruggles, R. F. Yonkers-- Dean, D. Goerg, B. Harmonay, W. L. Kelly, J. G. Rainger, W. F. Walther. F. G. Zuhlke, W. R. Yorktown Heights-- Gitterman, H. NORTH CAROLINA Charlotte-- . Brandt, E. H., Jr. Hill. H. H. Mills, C. A. Moore, H. W. 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, S. Sproull, H. E. Sutfin, G. V. Thompson, E. B. Ward, F. J. Washington, L. W. Winstel, F. E. . Winther, A. Wright, K. A. Wheeler, J., Jr. Whitelaw, H. L. (Randall Manor) Vivarttas, E. A. Hodge, W. B. Muirheid, J. G... Cleveland-- '.Wilder, H; P. (West Brighton) Petty, C. E. Baggaley, W. ~ Willner, I. ;woir; P. , Volkhardt, A. N. (Stapleton) Durham-- Beach, W. R.Cary, E. B. . - Wrightson, W. T. Vroome, A. E. Cooke, T. C. Cheeseman, E. W. (Prince Bay) McDowell, H. L. . Cohen. H. Niagara Falls--7 ' Kessler, M. E. Waechter, H. P. . (Tompkinsville) Wood, R. A. ' Wallace, W. M.. II Greensboro-- ` Cohen, P. Conner, R. M. . Curtis, H. F. Woolcock, E.- (W. New Brighton) Harding, E. R. Cushing, C. F. 77 i; Heating Ventilating Air Conditioning Guide 1939 Eveleth, C. F. Ferguson, J, H, Friedman, A. Cayman, P. D. Gottwald, C. Gray, E. W. Harris, J. G. Harvey, L. C. Hdsterkamp, H. W. Jones, J. P. Kaercher, C. M. H. Kain, E. M. Kitchen, F. A. KUe, W. Kofoed, V. B. Levy, M. I. Marotta, J. A. -Martinka. P. D. McKeeman, C, A. Moore, W. R. Nachman, G. P. Pogalies, L. H. Quick, B. A. Rowe, W. M. Schurman. J. A. Slawson, L. E. Smith, W. D. Taze, D. L. Tuve, G. L. Vanderhoof, A. L. Walker, J. E. Washburn, M. J. Webb, E. C. Weldy. L. O. Wetzell, H. E, Wilhelm. J. E. Wootan, C. Young, E. O. Cleveland Heights-- Davis, R. G. Rhoton. W. R. Sogg, A. Sterling, J. G., Jr. Wright, D. K.; Jr. Columbus-- Allonier, H. R. Breneman, R. B. Brown, A. I. ' Cross, R. C. Denise, J. R. Myler, W. M., Jr. recK, xi. c, Poling, D. B. Sandfort, J. Fi Sherman, R. A. Smith, J. A. Somers, W. S. White, E. D. Williams, A. W. Wyatt, D. H. ' . Cuyahoga Falls-- Humphrey, D. E. McElhaney, G. W. Dayton-- Baker. I. C. Buenger, A. Chapman, W. A., Jr. Fuller, E. W. . Gibbons, M. J. Godfrey, J. E. Gonzalez, R. A. Hansler, J. E. Hauck, E. L. Hubbuch, N. J. Hull. H. B. Hutchings, R. L. Jones, H. L. Kucher, A. A. Kuempel, L. L. La Salvia, J. J. Lewis, C. E. Livar, A. P. MacMillan, A. R. NesseU, C. W. Smith, N. J. Wood. C. F. Woodward. R. Worsham, H. Wyld, R. G. East Cleveland-- Geltt, R. W. Nobis, H. M. Stark, W. E. Steffner, E. F. Elyria-- Kalinsky, A. G. Maynard, J. E. Goshen-- Doyle, W. J. Hamilton-- Thomas, L. G. L. Hudson-- Follett, T. L. Lakewood-- Kubasta. R. W. Longcoy, G. B. Norrington, W. L. Tanker, G. E. Teckmyer, F. C., Jr. Weatherby, E. P., Jr. Wilson, R. A. Lima-- Hawisher, H. H. Middletown-- ByTd. T. Newark-- - Simison, A. L. Slayter, G. Waggoner, J. H. Norwood-- Braun, J. J. Motz, O. W. Oberlin-- Ries, L. S. Painesville-- Hobbs. J. C. Parma--' Kajuk, A. E. Plqua-- Lange, R. T. . Sandusky-- Rathke, A. C. Shaker Heights-- Avery, L. T. ' Foley, J. L. Vehle, T. . South Park-- Barney, W. E. Springfield-- Noble; J. P. Toledo-- Baker, H. C. Bergan, J. R. . Jones, S. Mabley, L. C. McKitrick. W. D. Summers, C. G. Watkins, G. B. Waveriy-- Armbruster, F. T. W. Wilmington-- Marconett, V. G. Sapp, C. L. Worthington-- ~ Slemmons. J. D. Youngstown-- Montgomery, J. R. OKLAHOMA Alva Husky. S. T. Houston-- . Putnam, N. J. Norman-- Dawson, E. F. Giles. J. C. Oklahoma City-- Campbell, A. O. Carnahan, J. H. Carroll, W. M. DeVilbiss, P. T. Dolan, R. G. Feldstein, H. Gray, E. W. Holyfield, E. F. Hoppe, A. A. Howlett, I. G. Johnson, R. F. Kidd, C. R. . Kroeker, S. P. - Lockwood, G. E. Loeffler, F. X. Middleton. D. K. Mideke, J. M. Miller, B. R. Morin, A. R. Rolland, S. L. Schoenhofen,L.H.,Jr. Spencer, D. Tiller. L> Woodworth, C. Z. Tulsa-- Dean, C. H. Holmes, A. D. Irwin, R. R. Jones, E. Meinholtz, H. W. Pauling, R. E. Scherrer, K. C. Shoemaker, F. F. OREGON Corvallis-- Willey, E. C. Medford-- Hoey, J.-K. 78 Portland-- Enders, C. E. Fames, B. W. Freeman, J. A. Heinkel, C. E. Kroeker, J. D. Taylor, T. E. PENNSYLVANIA Abington-- Bigelow, E. S. Park, N. W. Aldan--"* ' Mulcey, P, A. Allentown--. Goundie, J. K. Hersh, F. C. Kom, C. B. Ambler-- McElgin, J. W. Ardmore-- Haynes, C. V. Ardsley-- Tucker, L. A. Asplnwall-- Lewis, K. C. Bala-Cynwyd-- Patrick, H. M. Whitney, C. W. Beaver Falls-- Zitzman, F. T. Beechwood-- Kipe, J. M. Murdoch. J. P. Bellevue-- Allen, W. A. Bethlehem-- Mumin, E. A., Jr. Stuart, M. C. Bradford-- Cleveland. C. C. Paterson, F. C., Jr. Presdee. C. W. Brookline-- Donnelly, M. A. Charleroi-- Sutherland, F. A. Clearfield--* Gault. G. W. Drexel Hill-- Matz, G. N. Stokes, A. D. . Dunbar-- Sherwood, L. T. East Pittsburgh-- Hazlett, T. L. Penney, G. W. Elizabeth-- Reed. V. A., Jr. Elizabethtown-- Dibble,. S. E. Erie-- Joyce, H. B. Preece, L. W. Sahlmann, F. L. Glenmoore-- Gant, H. P. Greensburg-- Burkhart. E. M. Harrisburg-- Eichler, H. C. Geiger, I. H. Hedlund, R. A. Haverford-- Black. E. N., 3rd Hershey-- Snavely, A. B. Johnstown-- Hunter, L. N. Knowles, F. R. Novotney, T. Ai Kingston-- Macdonald, D. B. Lancaster-- Jones, A. Lloyd, E. C. Shorb, W. A. Lansdowne-- Hall. M. S. James, H. R. Lauer, R. F. Mawby, P. Mayer, R. L. Manhelm -- Weitzel. C. B. Weitzel, P. H. McKeesport-- . Dugan, T. M. Middletown-- Locke, R. A. Midland-- Crichton, H. C. Narberth-- Dever, H. F. Searle, W. J., Jr. New Castle-- ` . Andrews, G. H. Sonnebom, C. New. Kensington-- Edwards, J. D. Newtown-- Lewis, T. Norristown-- Hucker, J. H. Mirabile, J. J. Roll of Membership Oxford-- Ware. J. H., Ill Penn Valley-- Smith, W. F. Philadelphia-- 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. Bozeman, R. Bulkeley, C. A. Caldwell, A. C. Call, J. . Cassell, J. D. Childs, L. A. Cody, H. C. Culbert, W. P. Dafter, E. H. Dambly, A. E. Davidson, L. C. Davidson, P. L. Dietz. C. F. Dome, A. G. Donovan, W. J. Eastman, C. B. Eckart, J. H. Elliott, E. Erickson, H. H. Faltenbacher, H. J. Familetti, A. R. Flum, J. C. Franklin, S. D. Galligan, A. B. Gillett, M. C. Gilman, F. W. Goff. J. A. Guler, G. D. Hackett, H. B. Hajek, W. J. Hedges. H. B. Hibbs. F. C. Hunger, R. F. Hynes, L. P. Ickeringill, J. C. Jacobsen, K. C. S. Jakoby, A. C. jardine, W. H., Jr. Kelbie. F. R. Killough, R. E. Kirkbride, J. O. Kriebel, A. E. . Ladd, D. Landau, M. Leopold, C. S. Lyon. P. S. Mack, L. Makin, H. T.p Jr. Martocello, J. A. Mather. H. H. McClintock, A., Jr. McCullough, H. G. Mcilvaine, 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. Nesbitt, A. J. Nesbitt, J. J. Newcomb, L. B. Nusbaum, L. Parent, H. M. Pfeiffer, F. F. Plewes, S. E. Powell, G. W., Jr. Powers, E. C. Pryibil. P. L. Rank, A. I. Redstone, A. L. Reilly. B. B. Reilly. C. E. Rettew, H. F. Roberts, H. L. Rugart, K. Sabin, E. R. Schneider, C. H. Seltzer, P. A. Shapiro, C. A. . Sherner, M. Speckman, C. H. Sullivan, C..J... Timmis, P. Touton, R. D. Traugott, M. Trenner, K. Trump, C. C. Tuckerman, G. E. Wagner, E. K. Wegmann, A. Weid. H. L. Werner, J. G. Wiley, D. C. Wilmot, C. S. Wilson, F. J. Wiltberger, C. F. Woolston, A. H. Yerkes. W. L. - Pittsburgh-- Allensworth, J. E. Beighel, H. A. Blackmore, G. C. Brauer, R. Bushnell. C. D. Canon, H. A. Carr, M. L. Caskey, L. H., Jr. Collins. J. F. S., Jr. Comstock, G. M. Cost. G. W. Dickinson, R. P., Jr. Dickson, R. W., Jr. Dorian, M. I. Eckstein, J. E. Edwards. P. A. Eils, L. C. Ellis. G. P. FerderbeT, M. B. Gallagher, F. H. Greiner, G. E., Jr. Griest, K. Hathaway, C. B. Hecht; F. H. Heilman, R. H. Houghten, F. C. Humphreys, C. M. Hyde. E..H. Kennedy, O. A. Kimmell, P. M. Kirkendall, H. J. Landes, B. D. Lifshitz, H. Loucks, D. W. Lowe, W. M&ehUng, L. S. Mahon, F. B. Marshall, A. W. McGonagle, A. McIntosh, F. C. McLean, J. E. Miller, R. A. Moore, H. L. . Mueller, J. E. Nass, A. F. Nicbolls, P. Park, H. E. Parks, C. E. Proie, J. Reed, I. G. Reed, W. H., Ill Riesmeyer, E. H-, Jr. 79 Rockwell, T. F. Rose, H. J. . Scanlon, E. S. Schmieler, J. B. Selig, E. T.. Jr. Shore, D. . Small. B. R. Smyers, E. C. SpeUer, F. N. Stanger, R. B. Steggall, H. B. Stevenson, W. W. Strauch, P. C. Tennant, R. J. J. Tower, E. S. Turk, L. G. Waters, G. G. Weddell, G. O. Zangrilli, A. J. Pottsville-- ; Marty, E. O. Smith, J. D. Primos-- Johnson, A. J. Reading-- Luck, A. W. Rochester-- Pugh, D. C. Scranton-- Mahon, B. B. Sewlckley-- Lore, H. E. Springdale-- Lynn, F. E. Springfield-- Grossman, H. E. Payne, R. E. State College-- Queer, E. R. Stroudsburg-- Kiefer. E. J., Jr. Swarthmore-- Hobbs, W. Si ' Krayenhof, H. G. Robinson, A. S. Thom, G. B. Tarentum-- Orr, L. . Unlontown-- Marks, A. A. Upper Darby-- Blackmore, J. S. Conroy, M. J. McClain. C. H. Morehouse, J. S. Villa Nova-- Barr, G. W. Carey, J. A. Washington-- Frazier, J. E. . Wilkes-Barre-- Stewart, J. P. Heating Ventilating Air Conditioning Guide 1939 Wilkinsburg:-- Biber, H. A. - Campbell, T. F. Williamsport-- Axeman, j. E. Wormleysborg-- Miller, T. G.' Wyncote-- ' Buck, L. York-- Aughenbaugh, H. E. Bamum, W. E., Jr. Hertzler, J. R. Kartorie, V. T. Kimmel, W. G. Walsh, E. R. Zieber, W. E. Zelienople-- . Grabman, H. B. PHILLIPINE ISLANDS Manila-- Hausman, L. M. Macrae, R. B. . RHODE ISLAND Pawtucket-- Arden, I..L. . Kramer. C. Providence-r-. . Blanding, R. L. Coleman, Ji-B. Gibbs. E. W. Hartwell, J. C. McCarthy, J.J.. - McLaughlin, J. D. Moulder,' A.' W. ' Warren-- ' Bowen, H. C. . SOUTH CAROLINA Clemson-r- . , 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* . S, Elizabethton-- Torok, E. Knoxville-- Cross; F. G. McCain, H. K. Oakley, L. W. Memphis-- Campbell, A. Q., Jr. D'lmor, E.J. Flinn, G. S; Hoshall, R. H. Nashville-- Armistead, W. CBaker. W. C. Brown, F. Crane, R. S. Wilson. V. H. TEXAS Amarillo-- Burnett, E. S. Houska, A. D.. Austin-- ` .. Degler, H. E. Gossett, A..L. ' Bryan-- Griesser, C. E. College Station-- Badgett, W. H. Cook, A. L. . Giesecke, F. E. Hines, G. M. Hopper; J. S.. . Long, W.' E. , . Smith, E. G. `' Dallas--^ . Anspacher} -Tr H. Blum, H., Jr.; Bock, I. I. Brown, M; W. . Campbell, E. K., Jr. Cheatwood, W. H. Durkee, M. E. Farrow, E. E. Gilbert, L. S. Huff, J. M. , Jelinek, F. R. -Kribs, C. L., Jr. Landauer, L. L. Martyn, H. J. Mehl, O. H. Moler, W. H. Pines, S. Renouf, E. P. Rodgers, F. A. Rogers, R. C. ' Schmidt, H. I. Schuett, D.-F. . Stokes, A.: Taylor, R. B. Turner, H. S., Jr. Ullrich, A. B., Jr. Zumwalt, R. - - Galveston-- Ruemmele, A. M. Houston-- Banowsky, A. B. Barnes, A. F. Chase, A. M.p Jr. Chrone, R. E. Closner, J. J; ' Cochran, W. B. Constant, E. S. Cooper, D. S. Earl, W. Drescher, F; E. Ibison, J. L. Keeland, B. W.Kiesling, J. A. Koch, A. C. Kurtz, R. W. McKinney, C. A. Mitchell, J. Morrow, J. 'D. Olson, G. E. ' Rollosson, J. A. . Rowe, I. E. ` Salinger, R. J. Spencer, R.` M. Taylor, R. F. Walsh, J. A. Witmer, C. N. Kingsville-- Richtmann, W. M. Port Arthur-- Shaw, C. G. San Antonio-- Billingsley, O. F. Diver, M. L. Ebert. W. A. Kotzebue, R. W. ` Pawkett. L. S. Rhine; G. R: Rummel, A. J. Saunier, W. C. ' Stoltz. G. C. Waco-- : Benham, F. C;, Jr. Salt Lake City-- Richardson/ H. G. Young, J. T., Jr. VERMONT Burlington-- Lanou, J. E. Raine, J. J. North Ferrlsburg-- Breckenridge, L. P. VIRGINIA ; ; Fort Worth-- Gardner, C. R. Harris. A.' M. . Harrison, J/C:. MacEachin, G. C. Skinner, H.' W. Sprekelmeyer, J. M. . Werner,;R...K,';-: Arlington-- - ' * Ferraririi, J.` . Marshall, W. D. Nyct L. B., Jr. Rudio, H. M. waiz, g. r; ; Welsh, H. A. 80. Blacksburg--- Johnston. R. McC. Lynchburg-- Doering, F. L. Franklin, S. H., Jr. Norfolk^-- Capps, E. L. Huybert, L. E., Jr. Nowitzky, H. S. Thomas, R. C. Webster, W. H.. Jr. Portsmouth-- Stubbs, W. C. Richmond-- ' ' Belding, H. H. Campbell, F. B. Carle, W. Hinnant, C. H., Jr. Johnston, J. A. Peebles. J. K.,,Jr. Pelouze, H. L., II Schulz, H. I. Roanoke-- Bailey, A. E., Jr. Nininger, C. H. WASHINGTON Bremerton--1 ` . Bysom, L. L. . Kent-- Boyker, R. O. Port Orchard-- Pratt, F. J. Seattle-- . Beggs, W. E. -.< Bouillon, ,L. v Case, R. H. Cox, W. W. Eastwood, E. O. , Granston, R. O. Griffith, H. T. Hauan, M. J. 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. Veltman, B. M/ Ward, J. J. Watt, R. D; . Weber, E. L. Wesley, R. O. Zokelt, C. G. Spokane:-- : . 4 Russell, W. B. . Tacoma-- ; Foote, E. E. Norby, K. H. 1 ' Spofforth, W. Yakima-- . . Leichnitz, R. W. McCune. B. V. Roll of Membership WEST VIRGINIA Charleston-- Ralph, D. S. Rosenblatt, A. M. 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 Appleton-- Eisele, D. E. Beloit-- McKinley, C. B. Eau Claire-- Grosvold, F. E. Clintonville-- . Quail, C. O. Kohler-- Hvoslef. F. W. Kohler, W. J., Jr. La Crosse-- Anderegg, R. H. Bowen, J. C. ' Miller, M. W. Rowe, W. A. iiiuuias, ]>. rt. Towne, C. O. Trane, R. N. , Madison-- Bledsoe, R. P. Dean, C. L. Feirn. W. H. Hall. G. Larson, G. L. Nelson, D. W. Seymour, J. E. Tuthill, A. F. White, J. C. Milwaukee-- Alfery, H. F. * Allan, W. Banks, J. B. Bernert, L. A. Boden, W. F. - Bowers, A. F. Brown, W. H, Buller, C. R. Carroll, A. F. Cooper, W. B. Cutler, J. A. Davis, K. T. Elliot, N. B. Ellis, H. W. Errath, E. O. Frentzel, H. C. Gerstenberger, E. J. Goldsmith,- F. W. Gregg, S. H. Griewisch, A. H. . Haerle, R. A. Hamacher, K. F. Hanley, E. V. , Haupt, H. F. Haus, I. J. . Hays, C. A. Hessler, L. W. Hoffmann, A. Hughey, T. M. Jackson, C. H. Jones, E. A. Jung, J. S. Ketter, J. W. Knab, E. A. Koch, R. G. Krenz, A. S. Lingen, R. A. ' Lofte, J. A. Mack, E. H. McKee, J. W. Meyer, K. A. Miller, C. W. Mueller, H. P. Noll. W. F. Page. H. W. Podolske, A. R. Randolph, C. H. Reinke, L. F. Rice, C. J. Schmid, J. U. SchrSber. H. W. Shawlin, W. C. Shodron, J. G. Spence, M. R. Swisher, S. G., Jr. Szekely, E. Trostel, O. A. ` Volk, J. H. Weil, F. H. E. Weimer, F. G. ' Winkler, R. A. Neenah-- <'- Angermeyer, A. H. Eiss, R. M. . Stiegler. A. J. Oconomowoc-- Becker, W. A. Racine-- Dixon, A. G. Kluge, B. M. Menden, P.- J. South Milwaukee-- Ouweneel, W. A. West Allis-- Erickson, M. E. Spence, R. T. CANADA Brandon, Man.-- Yates, J. E. Yates, J. E.. Jr. Calgary, Alta.-- Vissac, G. A. Edmonton, Alta.-- Mould, D. E. Flin Flon, Man.-- Foster, P. H. Freeman, Ont.-- Goodram, W. E. - Galt, Ont.-- . . Sheldon, W. D., Jr.' Halifax, Nova Scotia Meagher, A. T. Hamilton, Ont.-- Barnes, H. Charters, W. A. Dickenson, M. E. = Moffat. O. G. Hampstead, P. Q.-- Montgomery, E. G. Islington, Ont.-- Wilson, G. T. Kirkland Lake, Ont. Calver, R. W. Kitchener, Ont.-- Beavers, G. R. Pollock. C. A. Lindsay, Ont.-- McCrae. G. W. London, Ont.-- O'Flaherty, J. G. . Montreal, P. Q*-- Allaire, L. Armstrong, W. J. Ballantyne, G. L. Barnsley, F. R. Baxter, W. E. Berridge, W. W. Bews, J. Boland, R. O. Chenevert, J. G. Colle, S. S. Darling, A. B. Dixon. M. F. Dufault. F. H. Dupuis, J. R. Dykes, J. B. Elliot, G. B. Emerson, J. J. Forrester, N. J. Freeman, E. M. Friedman, F. J. Gameau, L. Gendron, H. . Gittleson, H. Hamlet, F. A. Hamlet, T. F. Hughes, H. R. . Hughes, W. U. . Johnson, C. W. Jungbluth, E. N.' Keith. J. P. Laffoley, L. H. Lafontaine, E. A. LaMontagne, A. F. Linton, J. P. MacLachlan, V. D. Madely, F. J. Marshall, A. G. Martin, L. . Martin, R. Milne, A. H. Morris, J. A. Murray, H. G. S. Nathan, P. V. Nickle, A. J. Noyes, R. R. Osborne, G. H. Peart, A. M. Perras. G. E. ' Phipps, F. G. Plant, E. B. Pratt, J. C. Robertson, J. A. M. Roche, I. F. Ross, J- D. Sampson, E. T. Shaw, J- A. Spark, W. ' Standring, R. A. Ste-Marie, G. P. Timmins, W. W. Tolhurst, G. C. Twizell. E. W. Vollmann, C. W. Walford, L. C. A. Watts, A. E. Wiggs, G. L. Wilkinson, A. Wilanr*. A. ' Ottawa, Ont.-- Allen, A. W. Colclough, O. T. Gray, G A. McGrail. T. E. Pennock, W. B. Preston; Ont.-- ' Everest. R- H. Wood, A. W. . ' Quebec, P. Q.-- LaRocque, P. E. Paquet, J. M. Roy, L. Sackville, N. B.-- Rand, F- R. St. Lambert, P. Q--- Lefebvre, E. J. Three Rivers, P. Q.-- Germain. O. Timmins, Ont.-- Smith, R. J. roronto, Ont.-- Abbott, T. J. Alexander, S. W. Allcut, E. A. Allsop, R. P. Angus, H. H. Anthes, L. L. Arrowsiuith, J. O. Baker, G. R. Baker, L. P. Bishop, J. W. Blackball. W. R. Bowerman, E. L. Brittain, A.. Jr. Church, H. J. Clifton, J. A. Cole. G. E. Davis, E. J. Daynes, J. H. . Dickey, A. J. Dion, A. M. Dowler, E. A. Duncan, W. A. Eaton, W. G. M. Ellis, F. E. Ewens, F. G. Fear, S. L. Fitzsimons, J. P. Heating Ventilating Air Conditioning Guide 1939 Foley, J. J. Forrester, C. M. Fox, E. Fox, J, H. Gauley, E. R. Givin, A. W. Gordon, C. W. Gordon, W. D. Gurney, E. H. Gurney, E. R. Harrington, G. Henion, H. D. Hill, H. G. Hills, A. H. Hopper, G, H. Hughes, L. K. Jenney, H. B. ennings, S. A. onesrA. 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. Mathison, R. S. Maxwell, R. S. McKerlie, J. McLaren, T. H. Moore, F. C. Moore, H. S. Morgan, A. S. Nearingburg, A. 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. Smith, G. E. Stencel, R. A. Stott, F. W. Sturdy, O. C. Tasker, C. Thomas, M. F. Thomsen, N. B. Treleaven, H. M Waldon, C. D. Wardell, A. Watson, M. B. Wilier, M. D. Woollard, M. S. World, H. P. Vancouver, B. C.- Hale, F. J. Johnston, R. E. Leek, C. W. Leek, W. McCreery, H. J. Turland, C. H. Victoria, B. C.-- Sheret, A. Westmount, P. Q. Colford, J. Winnipeg, Man.-- Argue, E. J. Avery, L. Charles, P. L. Davis, G. C. Eade, H. R. Glass, W. Hinton, R. P. Jones, B. G. Kent. R. L. Kipp, T. McDonald, I. Michie, D. F. Miller, E. R. Muon, E. F. Price,'E. H. 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. Henderson, A. S. Hunt, N. P. Moloney, R. R. Picot, J. W. . Robinson, J. A. Sands, C, C,. BELGIUM Brussels-- Lebrun. P. Mautsch, R. . BERMUDA Hamilton-- Kitchen, W. H.J. BRAZIL Rio de Janeiro-- Botelho, N. J. . Darby, M. H. BRITISH WEST INDIES Trinidad-- Cox, T. M., Jr. CHINA Hong Kong--1 Bradford, G. G. Shanghai-- Chen, S. T. Doughty, C. J. Gange. F. B. Hart-Baker, H. W. Kwan, I. K. Loh. N. S. Morrison. C. B. Rachal, J. M. Waurig, T. F. , Wong, W. S. B. Tientsin-- Loo. P. Y. CUBA Havana-- Colmenares. G. V. DENMARK Copenhagen-- Reck. W. E. Schulein, E. H. EGYPT Alexandria-- Tallianos, P. C. Cairo-- Ezz El Din, K. Henszey, W. P. ENGLAND Birmingham-- Richardson, R. D. Cheshire-- Adshead, B. Essex-- Symonds, E. S. Kent-- Figgis, T. G. Lipscombe, H.*W. J. Lancaster-- Bartley, H. E. Leeds-- Jennins, H. H. Liverpool-- Thomas, A. E. London-- Bailey, W. M. Benham, C. S. K. Bird, G. L. H. Butt, R. E. W. Chester. T. Faber, O. Fraser, J. J. Greenland, S. F. Haden, G. N. Herring, E. ' Jackson, G. R. Kraminsky, V. Linebaugh, J. E. Nobbs, W. W. Pryke, J. K. M. Troup,,J; D. Manchester-- Webb. J. W. Yates, W. Middlesex-- Case, W. G. Gill. E. F. St. Albans-- Carter, D. Surrey-- Casperd, H. W. H. Trowbridge-- Haden, W. N. Westminster-- Russell, J. N. Wolverhampton-- Tyson, W. H. FRANCE Dijon-- Bur, J. R. C. Lille-- Neu, H. J. E. Lyon-- Goenaga, R. C. Paris-- Beaurrienne, A, Bodmer, E. Modiano, R. Nessi. A. Schmutz, J. Waudby, W. Vanves-- Ghilardi, F. FRENCH INDO CHINA Tonkin-- Cox. P. E. GERMANY Berlin-- Brust, O. Schmidt, E. G. Hamburg-- * , Brandi, O. H. Stuttgart-- Klein, A. R. HOLLAND Amsterdam-- ter Weeme, A, The Hague-- DeWilde, M. P. INDIA Bombay-- Heard, J. A. E. Wilson, E. D. Burma-- ' Homer, S. D. Calcutta-- Stromgren, S. G. IRAQ Alwiyah-- Roos, E. B. J. IRELAND Cork-- Barry, P. I. Dublin-- Leonard, L. C. G. ITALY Milan-- Dell'Orto, L. ' Gini, A. Hauss, C. F.' Marzorati, G. Parrilli, R. Roll of Membership Torino-- Baldi, G. JAPAN Osaka-- Fukui, K. Tokyo-- Kitaura, S. Kozu, T. Saito, S. Sekido, K. JAVA (D. E. I.) Soeradaja-- Thornburg, H. A. MANCHOUKUO Hslnklng-- Kawase, S. MEXICO Mexico, D. F.-- Gilfrin, G. F. Huber. E. Martinez, J.. J. NETHERLANDS Arnhem-- Tanger, O. C. F. Breukelen-- Teves, H. L. NEW ZEALAND Auckland-- Manning, C. E. Christchurch-- Taylor, E. M. Vale, H. A. L. Macandrew Bay-- Davies, G. W. ; NORWAY Oslo-- Tjersland, A. Stabekk-- Alfsen, N. ROUMANIA Bucharest-- Wasser, M. SCOTLAND Angus-- Knox, J. R. SOUTH AFRICA Durban-- Gordon, H. H. W. Kothe, F. H. Johannesburg-- Boxall, F. Ehiers, J. Overton, S. H. vonChristierson, C.A. SOUTH AMERICA Venezuela-- Bias. R. J. SPAIN Madrid-- Alfageme, B. Jimenez, J. G. STRAITS SETTLEMENTS Singapore-- Faxon, H. C. Hill, C. F. SWEDEN Lidingo-- Roseli, A. F. Stockholm-- ' Eklund, K. G. Gille, H. B. Ostrom, E. W. TheoreU, A. T. Theorell, H. G. T. TURKEY Istanbul-- Karakash, T. J. 8Alabama.............. 4Arizona................ 4Arkansas....;;.. 117California............ 10Colorado............ yjConnecticut........ 15Delaware............. 66Dis. of Columbia Florida................. 83Georgia................ 2Hawaii.................. 275Illinois................. 12 UNITED STATES AND ISLAND TERRITORIES 32In<flpnn................ 36Iowa...................... 13kflWMH................. 15Kentucky............ 12Louisiana............ 6Maine................... 38Maryland............ 109Massachusetts.. 186Michigan........... 115Minnesota........... 1Mississippi........ 136Missouri.............. 4Montana.............. 42Nebraska............. 1New Hampshire. 107New Jersey.......... 455New York............ 18North Carolina.. 188Ohio...................... 36Oklahoma........... 8Oregon................. 288Pennsylvania___ 2Phllllpine Is........ 10Rhode Island.... DOMINION OF CANADA............................... South Carolina. South Dakota... Tennessee.......... Texas.................. Utah..................... Vermont.............. Virginia............... Washington........ West Virginia.. Wisconsin.......... 3289112522354504 --27 13 220 Australia............. Belgium'............... Bermuda_______ Brazil................. .. British W. Indies Cuba..................... Denmark............. Egypt.................... FOREIGN COUNTRIES 9 England............... 2 * France................. 1 Fr. Indo China.. 2 Germany............ | 121 Iraq....'............... 2 Ireland................. 3 Italy.................... 31442301 62I Japan.................... Java (D. E. I,)... Manchoukuo..___ Mexico................ Norwav................ Roumania........... Scotland.............. 5 South Africa... 1 South America. 1 Spain.................. 3422 Str't, Segments I1 Total Membership .. . -662112 134 --3067 PAST OFFICERS American Society of Heating and Ventilating Engineers 1894 President_________________________ Edward P. Bates 1st Vice-President______________ .Wo. M. Mackay Snd Vice-President _Wiltsie F. Wolfe Srd Vice-President.............. ......... Chas. S. Onderdonk Treasurer........................................ Judson A. Goodrich Secretary_................ ...................................... L. H. Hart 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. 1897 President_____________ ;___________Wm. M. Mackay 1st Vice-president____ ___:___ _________ H. D. Crane Snd Vice-President_____ ,,____________Henry Adams Srd Vice-President________ ________ __A. E. Kenrick Treasurer;.____ ________________ Judson A. Goodrich Secretary________ __ ___ ___________ H. M. Swetland 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-President,Wm. M. Mackay Snd Vice-President____________ Chas. S. Onderdonk Srd Vice-Presidents_______________ ____D. M. Quay Treasurer__:_________ judson A. Goodrich Secretary______ ___ __ __________________ L. H. Hart Board of Managers * Chairman, James A. Harding Geo. B. Cobb Ulysses G. Scollay Wm. McMannis B. F. Stangland StewarCA'r-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-President...... ................. ............J. H. Kinealy Snd Vice-President................... ............. .A. E. Kenrick Srd Vice-Presidents..... ............ _...........John A. Fish Treasurer............ ......_............... judson A. Goodrich Secretary................. ............. ......... ,,.Stewart A. Jellett Board of Managers ' Chairman, Wm. M. Mackay Thomas Barwick 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 Presidents............... ............................. R. C. Carpenter 1st Vice-President ______________ ______ D. M. Quay Snd Vice-PresidentEdward P. Bates Srd Vice-PresidentIF. W. Foster . Treasurer.....-............... .......... -- Judson A. Goodrich Secretary_______ ______ ___ _....L. H. Hart . Board of Managers Chairman, Wm. 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, 5y. \ 1899 President................ ........:______ ________Henry Adams 1st Vice-President..D. M. Quay Snd Vice-President!A. E. Kenrick Srd Vice-President_____________ Francis A. Williams Treasurer............ ..... _________ Judson A. Goodrich Secretary ______ _______________Wm. 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. 84 > Roul of Membership 1900 President........... .......... .......... ...................... D. M. Quay 1st Vice-President___ __:__ ___ ________A. E.' Kenrick Snd Vice-President_____________Francis A. Williams Treasurer_____judson A. Goodrich 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. 1905 President_______ _________ _Wm. Kent 1st Vice-President_____ _____ _________R. P. Bolton Snd Vice-President_________________ C. B. J. Snyder Treasurer.:________________ ______Ulysses G. Scollay Secretary_______ __ --_______ ___ Wm. M. Mackay 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-Presidents.;______________ ___ A. E. Kenrick Snd Vice-PresidentAndrew Harvey Treasurer;........ ........ ....... .............. Judson A.-Goodrich Secretary. ______________________ Wm. 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. Sf. Mackay, Secy. 1906 President_______________________ ____John Gormly 1st Vice-President,,.,,C. B. J. Snyder Snd Vice-President.............. ......... .....J___ T. J. Waters Treasurer_____________ ___ ______ Ulysses G. 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..^___ J.......... ....... ^Andrew'Harvey Snd Vice-President_____________ Robert C. Clarkson Treasurer.:'.................... ................Judson A. Goodrich Secretary___ ______________ ._______ Wm. 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 ' .President............. ___________________ C. B. J. Snyder 1st Vice-President...... .......... ......... ,,james Mackay Snd. Vice-Presidents__ _________ ____ Wm. G.,Snow Treasurer___ _________________ Ulysses 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 Win. M. Mackay. Secy. . 1903 President_____ ________________ ______ '....H. Crane Jst Vice-President__ ____________ ________Wm. Kent Snd Vice-President____ _______________ R. P. Bolton Treasurer,,.J.___ _______________ 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. l; ' 1908 . President!___________ ___ ____________James Mackay 1st Vice-President____________ ____Jas. D. Hoffman Snd Vice-President___ _______ _____ B. F. Stangland Treasurer_______........ ...... ......... _.Ulysses G. Scollay Secretary__J_____.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:..s..-j.____ _______________ Andrew. Harvey 1st -Vice-President_____:_____________ ^John Gormly Snd Vice-President_____ :_______Robert C. Clarkson Treasurer-------------- --------------------- Ulysses G. Scollay Secretary................... ......................... .Wm, M. Mackay . Board of Governors - Chairman, Andrew Harvey * John Gormly H. D. Crane - Robert C. Clarkson . A. E. Kenrick . J. J. Blackmore ` C. B. J. Snyder . R. C- Carpenter- .Wm. M, Mackay, Secy. 1909 President........ _______________ ___ .___.Wm. G. Snow 1st Vice-President_________________ __ August Kehm Snd-Vice-President^B. S. Harrison Treasurer_______________________ Ulysses G. Scollay Secretary________ ___Wm. M. Mackay Board of Governors Chairman, Wm. G. Snow August Kehm, Vice-Chm. Samuel R. Lewis John R1 Alien . James^Mackay R. C. Carpenter ' B. F. Stangland B. S. Harrison Wm.' M. Mackay. Secy !85 Heating Ventilating Air Conditioning Guide 1939 1910 President_______ _______ .Jas. D. Hoffman 1st Vice-President___ - '__R* P. Bolton end Vice-PresidentSamuel R. Lewis Treasurer:_________ ___________ ;__Ulysses G. Scollay Secretary.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. 1915 President.Dwight D. Kimball 1st Vice-PresidentHarry M. Hart 2nd Vice-President.;____________ Frank T. Chapman Treasurer'Homer Addams SecretaryJ. 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. 1911 President......... .................. --...............---R. P. Bolton 1st Vice-President..... ............................ John R. Allen 2nd Vice-PresidentA. B. Franklin Treasurer__ '.___________ Ulysses G. Scollay Secretary., - . --- ____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. 1912 President.................. ........-----____ John R. Allen 1st Vice-President~TM_John F. Hale 2nd Vice-President ____________ Edmund F. Capron Treasurer.James A. Donnelly Secretary---------- ------- -------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. 1913 President_______________________John F. Hale 1st Vice-PresidentA. B. Franklin 2nd Vice-Presidents____ _______ Edmund F. Capron TreasurerJames A. Donnelly Secretary___________ ________________Edwin A. Scott Board of Governors Chairman, John F. Hale A. B. Franklin. Vice-Chm. James A. Donnelly John R. Allen Dw*ig'ht D. .K...i.m...b...a..l.l Edmund F. Capron Wm. W. Macon R. P. Bolton James M. Stannard Frank T. Chapman Theodore Weinshank Ralph CoUamore ' Edwin A. Scott, Secy. -- - 1916 - " President;_______________________ ___Harry M. Hart 1st Vice-PresidentFrank T. Chapman 2nd Vice-President:_______________ Arthur. K. Ohmes TreasurerLHomer Addams SecretaryCasin 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. 1917 President-----------------------------1st ` Vice-President______ _____ 2nd Vice-President__________ Treasurer___________________ Secretary____________________ ____ J. Irvine Lyle Arthur K. Ohmes _____ Fred R. Still __Homer Addams __Casio 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 rred R. Still Milton W. Franklin Walter S. Timmis .Charles A. Fuller Casin W. Obert, Secy. 1918 President___________________ 1st Vice-President___________ 2nd Vice-Presidents_________ Treasurer_____ !_____________ Secretary____________________ _____ Fred R. Still .Walter S. Timmis ___ E. Vernon Hill ^..Horner Addams __ 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. 1914 President___________Samuel R. Lewis 1st Vice-Presidents-..................... Edmund F. Capron 2nd Vice-Presidents--------- --------Dwight D. Kimball TreasurerJames A. Donnelly Secretary__________ .J. J. Blackmore Council Chairman, Samuel R. Lewis E. F. Capron, Vice-Chm. John F. Hale Dwight D. Kimball "H"arry `M`. "Hart John R. Alien Frank G. McCann . Frank T. Chapman Wm. W. Macon Frank I. Cooper James M. Stannard James A. Donnelly J. J. Blackmore. Secy. 1919 President______ _________.Walter S. Timmis 1st Vice-PresidentE. Vernon Hill 2nd Vice-President______--_____ Milton W. Franklin Treasurer_______ Homer Addams SecretaryCasin 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. Sepy. Roll of Membership President__________ 1st Vice-President__ 2nd Vice-Presidents Treasurers________ Seerdory________ __ ,,E. Vernon Hill 'Champlain L. Rite, __Jay R. McCott l.iiHoo:mer Addams ..Casin W. Obert 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 President__________ 1st Vice-President__ 2nd. Vice-President.. Treasurer Secretary..-.________ ..Champlain L. Riley ______Jay R. McCoU __________ 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. 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. ....--H. P. Gant 1st Vice-President-- ,,Homer Addams 2nd Vice-President__'____ _...E. E. McNair Treasure. r.--.. ...... ........................ ........Wm. H. Driscoll Secretary_____ ______ :________C. W. Obert . - 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, Secy. President__________ 1st Vice-President__ 2nd Vice-PresidentTreasurer.__________ Secretary..-______ __ 1924 _Homer Addams _S. E. Dibble ..William H. Driscoll _________ Perry West _____F. C. Houghten Council Chairman, Homer Addams S. E. Dibble, Vice-Chm. W, E. Gillham F. Paul Anderson L. A. Harding W. H. Carrftr Alfred Kellogg' J. A. Cutler . Thornton Lewis William H. Driscoll Perry West H. P. Gant F. C. Houghten. Secy. 2nd Vice-presidentTreasurer__________ Secretary___________ 1925 ______ S. E. Dibble TM..Wo. H. Driscoll _F. Paul Anderson Perry West ___F. C. Houghten 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.__________ .1926 ____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. Laugenlterg S. E. Dibble Thornton Lewis W. E. Gillham . J. F. Mclntire A. C. Willard President____ 1st Vice-President__ 2nd Vice-President... Treasurer__________ Secretary___________ 1927 _F. Paul Anderson ____...A. C. Willard __ Thornton Lewis ____W. E. Gillbain ..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. Langenberu Roswell Farnham Thornton Lewis H. H. Fielding J. F. Mclntire W. E. Gillham H. Lee Moore C. V. Haynes F. B. Rowley 1923 President_____________ 1st Vice-President---- 2nd Vice-President--. Treasurer_____________ ; Secretary______________ _____ A. C. Willard __ Thornton Lewis ____ L. A. Harding ____W. E. Gillham ^A. V. Hutchinson Council Chairman, A. C. Willard . Thornton Lewis. Vice-Chm. 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 . ' 1929 President.-:________ 1st Vice-President__ 2nd Vice-PresidentTreasurer_;________ 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. Tl Jones W. H. Carrier E. B. Langenberg N. W. Downes G. L. Larson Roswell Farnham F. C. McIntosh W. E. Gillham W. A. Rowe . . C. V. Haynes F. B. Rowley A. C. Willard 87 Heating Ventilating Air-Conditioning Guide 1939 1st. Vice-President__ 2nd Vice-Presidents. ' Treasurer__________ Secretary.~ Technical Secretary__ : A. Harding,____W. H. Carrier ___ __F. B.. Rowley _____ C. W. Farrar ..A. V. Hutchinson _______ P. D. Close Chairman, L. A. Harding W. H. Carrier, Vice-Chm. John Howatt H. H. Angus -W-. T. J-ones D. S. Boyden E. B. Langenberg R. H. Carpenter G. L. Larson J. D. Cassell Thornton Lewis N. W. Downes ' F. C. McIntosh Roswell Farnham W. A; Rowe ' C. W. Farrar F. B. Rowley President 1st Vice-President..__ 2nd Vice-President... Treasurer___________ Secretary Technical Secretary___ .1____W. H. Carrier _____ F. B. Rowley ______ .W. T. Jones F- D. Mensing -A. V. Hutchinson _______ P. D. Close Council Chairman, W. H. Carrier F. B. Rowley, Vice-Chm. L. A. Harding . D. & Boyden John Howatt- E.K. Campbell W. T. Jones . R. H. Carpenter E. B. Langenberg* J. D. Cassell G. L. Larson E. O. Eastwood F. C. McIntosh Roswell Farnham - F. D. Mensing E. H. Gurney W. A. Rowe 1932 President------------------------------------ --------F. B. Rowley 1st Vice-President-W. T. Jones 2nd Vice-President------- ------ ----- --------- C- V. Haynes Treasurer.' --F. D. Mensing Secretary.___ ,,______ ;i___________ A. V. Hutchinson Technical Secretary........... ............ .......--:.P. 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 Farnham W. E. Stark President.-.. Isi Vice-President. -.C. V. Haynes .John Howatt- 2nd Vice-Prestdent.. . Treasurer.________ ... Secretary_ ...G. L. Larson .JD. S. Boyden -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, R. H. Carpenter L. Walter Moon J. D. Cassell - O. W. Ott F. E. Giesecke W. A. Russell E. H. Gurney W. E. Stark ' President.._________ 1st Vice-President__ 2nd Vice-President.s Treasurer:.__ ______ Secretary______ :____ 1935v -John Howatt. -G. L. Larson ..D.'S. Boyden ' ` . J. Offner _A. V. Hutchinson Council Chairman, John'Howatt G. L. Larson, Vice-Chm. M. C. Beman D. S. Boyden . Albert Buenger R. H. Carpenter C. V. Haynes J. F. Mclntire F. C. McIntosh' L. Walter Moon - A. J. Offner J. D. Cassell . F. E. Giesecke E. H. Gurney O. W. Ott . W. A. Russell W. E. Stark _G. L. Larson - ' Ist'Vice-President__ 2nd Vice-President_ Treasurer_______ ;__ Secretary. _D. S. Boyden' _E. H: Gurney - ,.iA. J. Offner _A. V. Hutchinson Council Chairman, G. L. Larson D. S. Boyden, Vice-Chm. John Howatt M. C. Beman C. Mi Humphreys - 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 1937 President.____ 1st Vice-President_____ 2nd Vice-President____ Treasurer..... ................... Secretary____ ,,D. S. Boyden ___:E. Holt Gurney-. ____ J. F. Mclntire _A. J. Offner ,,A. V. Hutchinson Council. . Chairman, D. S. Boyden E. H. Gurney, Vice-Chm. J.....J.....A...e...b..e..r.ly M. C. Beman R. C.'Bolsinger E. O. Eastwood W. L. Fleisher F. E. Giesecke C. M. Humphreys ' Albert Buenger S. H. Downs - G. L. Larson W A. Russell W. E. Stark 1938 --W. fcr/ President......... ................ .... ___ E. Holt Gurney 1st Vice-President__ 2nd Vice-President_ ---JGo. hy,,/n1.^H&oyrwn-a-&^ttfF^^2-sn.d.i.V^..yi.U!c*ec--PP-rreessiiddeenntt..... ....... _____J. F. Mclntire ___ -..F. E. Giesecke Treasurer^..__ ___ -- Secretary.__-.________ Secretary.,,.D/'S)/B/:B<oydenAD Treasithr. A. V. iHuntfc/.hhiinnosbAnn i _________- -A. J. Offner _____ A. V. Hutchinson 15 Technical Secretary.. --.John James . C. D. E. R. V. S. K. H. Council Chairman, W. T. Haynes, Vice-Chm. Boyden Campbell Carpenter \ - t&ay Jones Council Chairman, E. Holt E. H. Gurnej^->*^-*F./McIntire, Vice-Chm. John Howatt NI D. Adams G. L. Lar5n~M Aeberly J. F. Mclntire M. C. Beman Gurney W. L. FleisherF. E. Giesecke C. M. Humphreys A. P. Kratz J. D. Cassell ' E. O. Eastwood F. C. McIntosh R. C. Bolsinger L. W. Moon D. S. Boyden A. J. Offner ^ W. A. Russell , R. Farnham F. B. Rowley S. H. Downs J; H. Walker F. E. Giesecke W. E. Stark E. O. Eastwood . G. L. Wiggs-. .... 88 American Society of Heating and Ventilating Engineers 51 Madison Ave. New York, N. Y. MEMBERSHIP APPLICATION Check for Admission Fee must Accompany ALL INFORMATION SHOULD BE PRINTED OR TYPEWRITTEN j }I desire advancement*^ which the Council specifies. American Society of Heating and Ventilating Engineers in the grade Residence ............ (Street) 1. Mail Address.... (Street) Business .... (Position) Present Duties (State in Detail) (Print or Type Name in Full) / (City) / ' (City) (State) (State) (Name and Address of Concern) 1 1 " e . j' . | Born at................................................ ................on........................................................................ ......... . (City) (State) (Date) (Age) Member of other Societies.....:..................... .............. ..............---------- -------------------------------------- ...... ' Have "you Previously Applied'*for oft Yield Membership in this Society?::.TM Education. . (State in chronological order the name and location of each high or preparatory school, college, university, or technical school attended, the time spent at each, and if graduate, the year of graduation.) '!. : 2. Name and Location op Institution . . Years From--To Date Graduated Technical Course . Decree . Received Engineering Registration. State Board of Registration.TM ., ------------------- <--.............................----------------------------- 3. Date of Certificate;:Number of Certificate. 4. Grade Minimum Age Requirements, Entrance Fees and Dues. For Full Detail--See Extracts from Constitution and By-Laws on Last Page. Years Responsible Charge Important Engineering Work . Years op Active Practice t ' General Qualifications See Art: C-II References Required Entrance Fee . 1939 Member 30 . ' -5 5 . See Sect. 4 4 $10.00 4 Associate . 25 -- -- See Sect. 6 4 10.00 ' Junior 20 -- 3. See Sect. 5 4 5.00 Student . 18 -- -- See Sect. 7 * Local Chapter dues NOT included. ** $3.50 additional if The Guide is desired. t Graduation from a recognized School of Engineering is equivalent to two years active practice. 4 . -- Annual Dubs* 1939 $18.00 18.00 10.00 3.00**' kiss 5. PROFESSIONAL EXPERIENCE: I have specialized in: HEATING Q VENTILATING AIR CONDITIONING Q Consulting Contracting Research Q Sales Service Q Manufacturing Q IMPORTANT--BEAD BEFORE FILLING OFT FORM '\ 1.. Eaeb of tbe five columns under "Time" should ba filled out for each engagement. Use cerdt where necessary, but do not leave blank spaces, and do not use the word "yes.'* 2. The time "In Sab-Professional Work" plus the time "In Professional Work" most 'equal the time entered under "Total Time." ` }. If any of the time given as "In Professional Work" has been in "Responsible Charge," or `.'In Design," enter the portion of tbe time thas spent in the proper columns. - 4. If the seme period of time is spent in "Responsible Charge" and also in "Design," it should he entered in both columns (4) snd (5). . APPLICANTS MUST FILL OUT ALL COLUMNS . DATE *1 1 From To (Please n eon Engs meat) TITLE OF POSITION, NAME OF EMPLOYER, AND CHARACTER OF EACH ENGAGEMENT (Moke statement brief and concise; say necessary amplification may be made by letter.) 0) Total Time (Actual) . TIME (Years in Decimals to Tenths.) In'Sub- SI1 E? (5) Pro- feastooal Work (Actual) Pro fessional Work (Actual) Re sponsible Choree' (Actual) In Design (Actual) (6) In Sales NAME AND ADDRESS of someone familiar with each engagement, preferably tbe person to whom applicant reported. .) .! - '' , 3 %. ; . ' i " i". ` ... ' . ' ' l . ' . ' ' j:' : ^ - .' . - Summary (Actual Tims)" ' FLEA6E. DO NOT FILL IN ' . Summary (Rated years of Active Practice),1' '';. Sub-professional Work is to cover the time spent as Estimator, Computer or Draftsman; and also the time spent as inspector when working under direct supervision or on work where . ' the personal responsibility and technical knowledge required are small; that is, minor positions in which the responsibility is slight and the individual performance of a task, set and supervised by a superior, is all that is required. It shall'also include time during which he has been occupied in engineering .work before he is 21 years old, except as modified by the statement in ' . regard to education in the definition of Professional Work. No account is to be. taken of work done before the applicant is 16 years old, or of work performed during vacations. In figuring ' , " the years of "active practice in engineering work" each year-of Sub-professional Work. shall be rated as equivilent to one-half year of Professional Work. ; '' Professional Work shall include the time after the applicant is 21 years old, during which; he has been occupied in engineering work of a higher grade and responsibility than that above ' defined as Sub-professional. Work. Time spent in engineering teaching subsequent to graduation shall be listed as professional work. . .. ; . Education shall be considered as Professional Work. The time value given for graduation in engineering from a school of recognized standing shall be considered as equivalent to '. ' 2 years of active practice in ail'cases. Each academic year successfully completed, in an engineering college without graduation shall be rated as % year of active practice. Graduation in .. : a course other than engineering from a college or university of recognized standing shall be considered as equivalent to one year of active practice. Each year of full time post-graduate work in engineering subjects shall be indicated as a year of active practice but not more than a total of four year's of active practice shall be credited because of educational qualifications. ' > Responsible Charge of Work means: , ;.v ' .1. In the field, the applicant tpust have had the direction of work, the successful accomplishment of which rested upon him, where he had to decide questions of methods of execution , ' and suitability of materials, without relying upon advice or instructions from his superior, and'of supplying deficiencies in, plans or correcting errors in design without first referring them to : higher authority for approval, except in'cases where such approval is a matter of-form. ' ' ' / . 2. In the office,' the applicant must have had to undertake investigations, or carry out important assignments, 'demanding resourcefulness and originality, or to make plans, write specifi- - cations and direct the drafting and computations for'designs of engineering work, with only rough sketches,, general information and field measurements for reference and guidance. , - 3. In engineering teaching, the applicant must have taught in an engineering school of recognized reputation, and must have had, at least, a grade of assistant professor; of its equivalent. Design means all that is given above as responsible charge of work in'the office, and more. One qualified to designmust be able, in the case of any desired piece of engineering, to meet "the exigencies of the case, to fulfill the requirements of local-circumstances and conditions, and yet not violate any of the canons of engineering. His plan, when executed, must successfully ' --answer the purpose for which It was designed. . ' ' ' . Membership Grade in A.S.H.V.E. or Nat's. Soc. in Which Sponsor Type Of Print Holds Membership Proposers ` 1.________________________________________________ _________________________________________________________________ _!i First Name Surname Address . 2. Seconders 1. --------- _ 2. _________ PERSONAL SIGNATURES of Proposers and Seconders Required 1,,_____________________________________________ 1_ 2. _ 1_ ' 2.. * * The undersigned certifies that the foregoing statements are correct; and agrees, if elected by the Society, that. he will be governed by its Constitution, By-Laws and Rules as long as his connection with it shall continue; will sub scribe to its Code of Ethics and he further agrees to promote the objects of the. Society as far as shall be in his power, and in case of his severing his connection therewith, that he will return his certificate for cancellation, and all other membership credentials in his possession. If offered membership he agrees to accept the grade which is voted to him by the Council. - ' Signature of Date------ ,----- ---------- --------------------- .------------- Candidate ______ __:............................:...................... _.. EXTRACTS FROM CONSTITUTION AND BY-LAWS .ARTICLE C-II--Membership . ' elected, conform to the Constitution, By-Laws and Rules of the ~\ \ Section 1. Persons connected with the arts and sciences related to heating, ventilating or air conditioning are eligible for admission into the Society. ' Section 4. A Member shall be thirty (30) years of qge or over and shall be a person of experience in the science of heat transfer in. its application to the art of heating, ventilating or air condi tioning, and shall have been in active practice Of his profession and in responsible charge of important work for five (S) years and' shall be qualified to design as well as to direct such engineering work. Fulfilling the duties of a professor in one of die allied sciences in a college or technical school of accepted standing shall be taken as an equivalent to an equal number of years of active practice. Graduation from a school of engineering of recognized . standing shall be considered as equivalent to two (2) years of active practice. (Also see Section 9.) Section 5. A Junior Member shall be a person over twenty (20) years and under thirty (30) years of age, who has been actively' engaged in the work of heating, ventilating or air conditioning for Society. Section 2. A candidate for any grade of .membership in the Society, except Honorary Membership, must be proposed by two (2) members to whom he must be personally known, except as provided in Section 3, and such application must be seconded by two (2) other members. Section 3. In case applicants for membership are not acquainted with' members of the Society, endorsements from ,the faculty of educational institutions, or the recommendations of the members of other professional societies, or by the officers of responsible cor porations, who are well acquainted with the applicant, may be con sidered, if sufficient evidence has been submitted to satisfy the Admission and Advancement Committee that the applicant is worthy of admission to membership. Section 11. Any member of the Society is entitled to member ship in the local Chapter nearest to his residence or place of business, provided he pays his Chapter dues in accordance with the Constitution and By-Laws of that" Chapter. three (3) years, or is a graduate of a school of engineering of recognized standing. ARTICLE B-IV--Admission Fees and Dues Section 6. An Associate Member shall be twenty-five (25) years Section 1. The admission fee of Members, Associate Members, of age or- over. He need not be an engineer, but must have been Junior Members and Student Members shall be as determined by so connected with some branch of engineering or the art of heating, the Council until l940 and thereafter the admission fee of Members ventilating, air conditioning or the industries relating thereto, that and Associate Members shall be fifteen dollars ($15.00) ; of Junior . he may be considered as qualified to co-operate with heating and Members five dollars ($5.00); and of Student Members two ventilating engineers in the advancement of professional knowledge. dollars ($2.00). Admission fee must accompany application. Section 7. A Student Member shall be a person between the ages Section 2. The annual dues of Members, Associate Members, of eighteen (18) and twenty-five (25) years, who is regularly Junior Members and Student Members shall be as determined by attending courses, in an engineering college o.r technical school at the Council until 1940 and thereafter the dues of Members and the time of applying for membership. Associate Members shall be twenty-five dollars ($25!00); of Junior Section 9. Mining, civil, electrical, mechanical, naval or govern Members twelve ($12.00) ; and of Student Members five dollars ment engineers, chemists, physicians, scientists, or architects, who ($5.00). are qualified by reason of their experience in designing, improving, Section 3. Honorary Members shall be exempt from payment of inspecting, investigating or developing the arts or sciences of heat admission fee and dues. ing, ventilating or air conditioning, are also eligible to membership. Section 4. Of the annual dues paid by members of each grade, a sum equal to its current subscription price shall be considered ARTICLE B-III--Admission and Advancement . as a subscription for the Journal of the Society. Section 1. A candidate for admission to any grade of member ship in the Society, except Honorary Membership, must make application on a form approved by the Council, upon which he shall write a statement giving a complete account of his qualifications . Section 5. Of the annual dues paid by Members and Associate Members forty per cent (40%) shall be considered as a direct contribution to the Research Fund and shall be immediately depos ited in said fund and shall not be used for any other purpose. and engineering experience, and an agreement that he will, if (The Procedure for Election Requires from 60 to 90 Days) I % r I $ i ii >:: i \ fc fe k A I i I i I E ft