Document DGQ6kOyEw2agLO75zmxjrv9Ka

.American Society of Heating and Ventilating Engineers Heating ventilating air conditioning guide. VOL 12 19 St 628.8 AMERICAN 21718 76706 : I V a,' X529909 No. Compton Library v . M V . ^ : v. ..-V"3. . " American Society of Heating and Ventilating Engineers Guide, 1934 An Instrument of Service prepared for the Profession-- and Containing reference data on the design and SPECIFICATION OF HEATING AND VENTILATING SYSTEMS---Based on the Transactions--the Investigations of the Research Laboratory and Cooperating Institutions-- and the Practice of the Members and Friends of the Society TOGETHER WITH A Manufacturers' Cataloc Data Section Containing Essential and Reliable Information Concerning Modern Equipment also The Roll of Membership of the Society i l ' ': / , with . j. .. Complete Indexes to Technical and Catalog Data . :Vpl. 12 $5.00 Per Copy X529909 Published Annually by , , American Society of Heating and Ventilating Engineers 51 Madison Avenue New York I. I I I I, | | ' ' h ' Copyright, 1934 BY American Society of Heating and Ventilating Engineers AND BY IT Dedicated To the Advancement of The Profession AND Its Allied Industries T^XT-,AND'.ILL*S7iiATIONS ART. FULLY PROTECTlED "BY COPYRIGHT 'and NOTHING THAT APPEARS MAY.be REPRINTED EITHER WHOLLY or in part 'Without 'special permission! * Printed and Bound by The Horn-Shayer Company BALTIMORE MARYLAND f <4 tie , .'i 1 A ft^ ' Vr ^ A 0 '` Contents Page Title Page..... ........................................... Contents................ .................................... Preface...................................................... Editorial Acknowledgment....... Code of Ethics for Engineers. 1 iii iv v vi Chapter 1. Thermodynamics of Air Conditioning ............................................ ......... 1 Chapter 2. Ventilation and Air Conditioning Standards................................................ 19 Chapter *3. Industrial Air Conditioning....... ,...... .............. ........ -........ ..............:........ 47 Chapter 4. Natural Ventilation.............................--............................................................. 57 Chapter 5. Heat Transmission................................................. ......................... -................... 71 Chapter 6. Air Filtration.......... ................................................................................................. 93 Chapter 7. The Heating Load..................................................... ........................................... 103 Chapter 8. The Cooling Load................................................... ............... -............-.............-- H5 Chapter 9. Central Fan Air Conditioning Systems..................................-....................... 123 Chapter 10. Cooling Methods.................................................................................................... 133 Chap.ter 11. Humidifying and Dehumidifying Equipment.'.............................. .......... --- 147 Chapter 12. Unit Air Conditioners and Coolers......................... ................................ ...... 159 Chapter 13. Unit Heaters and Ventilators............................................................................. 171 Chapter 14. Temperature and Humidity Control.................. :.......................... ;.............. - 185 Chapter 15. Air Pollution............................................................................. ............ ---..... ......... 207 Chapter 16. Air Cleaning Equipment.... ......... ..............................-................................---- 217 Chapter 17. Fans.......................... ........ .................................. :................................................... 225 Chapter 18. Sound Control........................................................... ............... ..................... ...... 241 Chapter 19. Air Duct Design........................................... ......................................................... 255 Chapter 20. Air Distribution...................................................................................................... 273 Chapter 21. Industrial Exhaust Systems........................... ...... ............... ...... ...................... 279 Chapter 22. Central Fan Heating Systems............................................................................ 291 Chapter 23. Mechanical Warm Air and Fan Furnace Systems...................................... 305 Chapter 24. Gravity Warm Air Systems............................................... ........................ ........ 317 Chapter 25. Heating Boilers....... ............................................................................................... 331 Chapter 26. Chimneys.--........... ........ ............................................ ;......................................... 347 Chapter 27. Fuels and Combustion......................................................................................... 365 Chapter 28. Automatic Fuel Burning Equipment.;.........................................................- 377 Chapter 29. Fuel Consumption.................................................................................................. 397 Chapter 30. Radiators and Gravity Convectors................... ........ ...................... ....... ....... 4,07 Chapter 31. Steam Heating Systems............................. .........;.............................................. 419 Chapter 32. Steam System Piping.............................................................. !.......................... 441 Chapter 33. Hot Water Heating Systems....................... ........................ ....................... ...... 471 Chapter 34. Pipe, Fittings, Welding...................... ,.......... ......... ................................ ,.!....... 489 Chapter 35. Heat Losses from Bare and Insulated Pipes............ ...................... ............. 503 Chapter 36. District Heating.............................. ........................... ........................................... 519 Chapter 37. Radiant Heating ............... .:............................:............................... :................... 533 Chapter 38. Electrical Heating.................................................................................... -......... -! 541 Chapter 39. Water Supply Piping............................................................................................. 547 Chapter 40. Test Methods and Instruments.. ....,................... ........................... 1.......... 569 Chapter 41. Properties of Air, Water and Steam............................................................... 577 Chapter 42. Heating and Ventilating Standard Terms......-- .............. ...... : . 587 Index to Technical Data.................... ......... '........................................................ ,!............. 607 Catalog Data Section........... ........................................................................--........ ................. 615 Index to Modern Equipment........ .............................. ........................................... ,.............:. 780 Index to Advertisers......................................................................................... ........ ................ 788 Roll of Membership................... .................................................................................. ...... -- 1~56 111 PREFACE TO THE 12th EDITION HE Technical Data Section of this, the 12th Edition of the A.S.H.V.E. Guide, Thas been enlarged to include newly developed data that are vitally important in meeting the present day demands of engineers who devote their time to heating, ventilating and air conditioning practice. From the practical experience of members as well as from available research sources useful facts have been gathered and incorporated in the 42 chapters which have been arranged for convenient reference. Since its first appearance in 1922 The Guide has maintained its leadership in the development of the heating and ventilating art so that today it is the recognized authority of the profession and industry. It influences thousands of engineers, architects, con tractors and students who are designing, operating, specifying, installing and studying systems and apparatus, the functions of which are to create comfort and to improve the efficiency of processing. All of the data in the previous edition have been reviewed, many chapters have been revised and amplified while others have been completely replaced. The new chapters include the Cooling Load and Cooling Methods, Unit Conditioners, Radiant and Electric Heating, Humidifying and Dehumidifying Equipment, Steam Heating Systems and Piping. Extensive changes will be noted in the chapters on Industrial Air Conditioning, Natural Ventilation, Central Fan Systems, Air Cleaning Equipment, Sound Control, Mechanical Furnace Systems, Radiators and Gravity Convectors, Heating Boilers, Pipe Insulation, Pipe, Fittings and Welding, Definitions and Terms. The remaining chapters were revised in order to bring them up-to-date. Slight modifications were made in the chapters on Heat Transmission and Air Filtra tion. The transmission and air leakage values introduced in the 1933 edition have been retained although considerable comment came from users because some of the factors were greater than those used in The Guide 1932. However, a careful check of the experimental work which produced the basic figures for The Guide 1933 indicated that the values determined by the research groups responsible for these factors were reliable and that the values should be used. However, the method of application in practice has been slightly modified in this 1934 edition of The Guide. With 42 chapters and a comprehensive index totaling 620 pages, The Guide 1934 presents the largest technical data section ever compiled and published by the American Society of Heating and Ventilating Engineers. Supplemented by the engineering data of leading manufacturers in the Catalog Section, the user will find essential facts that are invaluable in laying out a plant or selecting equipment. This unique method effectively covering both practice and equipment makes The Guide outstanding in its service to the user. Leading manufacturers of equipment recognize this fact and find that catalog adver tising is most effective in extending the use of Modern Equipment in tfiis highly specia lized and progressive field. By means of this cooperation, the American Society of Heating and Ventilating Engineers can produce and distribute The Guide econo mically and thereby contribute effectively toward the general- advancement of the profession and its allied industries. The Guide 1934 is released for service and it is the desire of The Guide Publication Committee that it will perform its intended mission for its thousands of friends in the profession. . . W. L. Fleisher, Chairman GUIDE PUBLICATION COMMITTEE ' t i EDITORIAL ACKNOWLEDGMENT FOR the important work of creating The Guide 1934 the assistance of engineers of specialized training and knowledge was enlisted. The careful reviewing, compiling and editing of data selected from authorita tive sources was accomplished through the cooperative efforts of the following men who have unselfishly given of their time and knowledge: T. Napier Adlam J. C. Albright H. L. Alt C. F. Ames C. M. Ashley A. L. Baum J. L. Blackshaw C. A. Bulkeley R. E. Cherne L. A. Cherry P. D. Close ' R. F. Connell J. M. DallaValle Philip Drinker M. William Ehrlich John Everetts, Jr. F. H. Faust W. G. Frank R. S. Franklin F. E. Giesecke W. C. Goodwin L. A. Harding H. M. Hart F. C. Houghten i L..P. Hynes R. E. Keyes V. O. Knudsen A. P. Kratz J. W. Kreitner G. L. Larson R. D. Madison J. F. McIntire H. B. Meller J. G. Mingle H. C. Murphy D. W. Nelson A. J. Nesbitt M. E. O'Connell A. J. Offner E. C. Rack F. G. Sedgwick G. L. Tuve C. P. Yaglou John Zink The Guide Publication Committee is glad to acknowledge the splendid cooperation of these engineers who have served so willingly for the benefit of their associates in the profession. GUIDE PUBLICATION COMMITTEE iij \ Chairman rV i CODE of ETHICS for ENGINEERS NGINEERING work has become an increasingly important factor E in the progress of civilization and in the welfare of the community. The engineering profession is held responsible for the planning, construc tion and operation of such work and is entitled to the position and authority which will enable it to discharge this responsibility and to render effective service to humanity. That the dignity of their chosen profession may be maintained, it is the duty of all engineers to conduct themselves according to the principles of the following Code of Ethics: 1-- The engineer will carry on his professional work in a spirit of fairness to employees and contractors, fidelity to clients and employers, loyalty to his country and devotion to high ideals of courtesy and personal honor. 2-- He will refrain from associating himself with or allowing the use of his name by an enterprise of questionable character. 3-- He will advertise only in a dignified manner, being careful to avoid misleading statements. . 4-- He will regard as confidential any information obtained by him as to the business affairs and technical methods or processes of a client or employer. 5-- He will inform a client or employer of any business connections, interests or affiliations which might influence his judgment or impair the disinterested quality of his services. b--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 and students of engineering and also by contributing to work of engineering societies, schools of applied science and the technical press. 10--He will interest himself in the public welfare in behalf of which he will be ready to apply his sp>ecial knowledge, skill and training for the.use and benefit of mankind. . l i Chapter 1 THERMODYNAMICS OF AIR CONDITIONING Dalton's Laic, Dry- and Wet-Bulb Temperatures, Partial Pressures, Dew-Point Temperature, Humidity9 Relation of Dew-Point to Rela tive Humidity, Adiabatic Saturation of Air, Total Heat and Heat Content, Energy Equation for Air Conditioning Processes, Psychro- metric Chart, Examples in Use of Chart, Rate of Evaporation THE subject of air conditioning involves a study of the desirable or necessary atmospheric conditions for human comfort or for manu facturing processes, as the case may be, and of the various physical or thermodynamic relationships of water vapor and the gases with which it is mixed. This chapter deals with the latter. DALTON'S LAW Air is a mixture of a number of dry gases and water vapor. The per centage of the gases contained in air remains relatively constant, and is usually given no consideration by the air-conditioning engineer. The weight of vapor mixed with dry air varies over wide limits, and this per centage affects the health and feeling of warmth of man, and the behavior of many materials in the process of manufacture. . 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, p3, etc. = the pressure of the gases or vapors corresponding to the observed temperature, then P = pi + Pi + P>> etc. (1) DRY- AND WET BULB TEMPERATURES, PARTIAL PRESSURES Air is sai'd 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 equiv alent, when the space occupied-by the mixture holds the maximum pos sible weight of water vapor at a given temperature. If the water vapor mixed with the dry air- is superheated, i.e., if its temperature is above the temperature of saturation for the actual water vapor partial pressure, the air is not saturated. The starting point of most applications of thermodynamic principles to air-conditioning problems is the experimental determination of the drybulb and wet-bulb temperatures, and sometimes, the barometric pressure. 1 American Society of Heating and Ventilating Engineers Guide, 1934 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. 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 evapor ating moisture from the bulb. The rate at which heat is transferred from the air to the water is substantially proportional to the wet-bulb depres sion (t -- t'), while the rate of heat utilization in evaporation is propor tional to the difference between the saturation pressure of the water at the wet-bulb temperature and the actual partial pressure of the water vapor in the air (e1 -- e). Carrier's equation for this dynamic equilibrium is e< - e t - t' B -- e' 2800 - 1.3/* (2a) In the form commonly used, _ (g ~ ') ~ <') 2800 1.3f where e = actual partial pressure of water vapor in the air, in inches of mercury. e' = saturation pressure at wet-bulb temperature, in inches of mercury. 3 = barometric pressure, in inches of mercury. t = dry-bulb temperature, in degrees Fahrenheit. ' <' = wet-bulb temperature, in degrees Fahrenheit. (2b) 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. 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 Keenan's Steam. Tables1 indicates that water vapor, either saturated or super-heated, at partial pressures lower than 4 in. of mercury may be treated as a gas with 1Published by American Society of Mechanical Engineers, see abstract Chapter 41. 2 Chapter 1--Thermodynamics of Air Conditioning a.gas constant R of 1.21 in the characteristic equation of the gas pV = wR (t + 460). Within such limits, the density (8) of water vapor is s= w V 1.21 (l + 460) (pounds per cubic foot) (3a) where 5785 e t + 460 (grains per cubic foot) (3b) e = actual partial pressure of vapor, in inches of mercury. t = dry-bulb temperature, in degrees Fahrenheit. . Another meaning sometimes given to absolute humidity is the weight of water -vapor mixed with a unit weight of dry air. This quantity is the ratio of the density of the vapor to the density of the dry air, and since the gas constant R for dry air is 0.753, the weight of water vapor mixed with 1 lb of dry air is , - ,' W = e 1.21 (/-+ 460) ' B-e 0.753 (l + 460) = 0.622 (pounds) (4a) = 4354 (grains) where e = actual partial pressure of vapor, in inches of mercury. B = total pressure of mixture (barometric pressure), in inches of mercury. (4b) Relative Humidity - Relative humidity (3>) is either the ratio of the actual partial pressure (e) of the water vapor in the air to the saturation pressure (et) at the drybulb temperature, or the ratio of the actual density (8) of the vapor to the density of saturated vapor (8t) at the dry-bulb temperature. That is: 0 =-- = (5) Relative humidity, so defined, is not exactly equal to the ratio of the weight of vapor per pound of dry air (W) to the weight of saturated vapor per pound of dry air (PFt). This quantity is sometimes called per cent humidity, for from Equations 4 and 5, W_ Wt " 0622 0622 (B-et) 4>t (6) * It is not exactly correct, therefore, to find the weight of vapor mixed with each pound of dry air (W) by multiplying the weight of vaporjnixed with each pound of dry air for saturation at the dry-bulb temperature (Wt) by the relative humidity ($), although the error usually is small, particularly if 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 3 American Society of Heating and Ventilating Engineers Guide, 1934 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 is, that for a fixed relative humidity there is substantially a constant difference between the dew-point and the dry-bulb temperature oveiya considerable temperature range. Table 1 giving the dry-bulb and dew point temperatures, and dew-point differentials for 50 per cent relative humidity, illustrates this relationship clearly. Table 1. Dry-Bulb and Dew-Point Temperatures for 50 Per Cent Relative Humidity Dry-bulb temperature............ ............... 1 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: TOO where t, = 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, tobacco factories, etc., where relatively high humidities are carried and where one of the principal problems is to remove the heat generated by the machinery. It also permits the use of a differential thermostat, responsive to both the room temperature and to the dew-point temperature, to control the relative humidity in the room. Table 2 gives, for different temperatures, the density of saturated vapor (St), the weight Of saturated vapor mixed with 1 lb of dry air (Wt), (for a relative humidity of 100 per cent and a barometric pressure (D) of 4 Chapter 1--Thermodynamics of Air Conditioning Since the difference in vapor pressures is substantially proportional to the difference between the wet- and dry-bulb temperatures (i.e., the wetbulb depression) the rate of evaporation is also for case two substantially proportionate to the wet-bulb depression. In case two, the rate of sensible heat transfer from the air to the liquid to produce evaporation is substantially the same as the rate of heat transfer with the same type of surface, without moisture being present, but with the same temperature differences. In other words, the rate of heat transfer depends upon the temperature difference only, whether the surface is wet or not. For example, it has been shown that the rate of heat transfer with air flowing across staggered coils (transverse flow) may be represented by the formula: _____ ^ Ut = 0.0447 + 50.66 V (18) where : Ut = heat transfer expressed in Btu per hour per square foot per degree . ' difference in temperature between steam and air, for transverse flow. At a velocity of 400 fpm, Z7t = 5.8; at a velocity of 800 fpm, Ut = 9.3. Referring to Fig. 4, showing the rate of heat transmission by evapo ration for different air velocities, it will be noted that for transverse flow there are 560 Btu per hour per square foot transferred per inch difference of vapor pressure at a velocity of 400 fpm and 910 Btu per hour per square foot per inch difference in vapor pressure at avelocity of 800 fpm. One inch of vapor pressure difference corresponds approximately to 95 deg difference between the wet- and dry-bulb temperature. Dividing by 95, 17 American Society of Heating and Ventilating Engineers Guide, 1934 the value of 5.9 Btu per square foot per degree difference in temperature is obtained for a velocity of 400 fpm and 9.55 Btu per square foot for a velocity of 800 fpm. It will be noted that for these two cases the heat transfer by evapo ration per degree difference in temperature corresponds almost exactly with the heat transfer by convection coils. The similarity may be noted by comparing the formula for heat transfer in parallel flow, where _____ 1_ tfp- 0.026 + 161 v (19) with the heat transfer by evaporation with parallel flow. The relationship will be seen to be very close in both cases and would indicate that the heat transfer by evaporation is actually brought about by a process of con vection. The difference in form of the two formulae may be. due in part to errors in observation at the higher and lower velocities. In cooling air and condensing out the moisture therefrom the heat transfer is considerably more rapid than when the air is dry and no moisture is condensed. In general the rate of heat transmission on the air side is increased an amount which is proportionate to the latent heat removed as compared with the sensible heat removed. That is, if the latent heat removed was 50 per cent of the sensible heat removed, then the conductivity of the surface in contact with the air would be increased approximately 50 per cent. REFERENCES A Review of Psychrometric Charts, by C. O. Mackey (Healing and Ventilating, June, July, 1931). . A New Psychrometric Chart, by C. A. Bulkeley (A.S.H.V.E. Transactions, Vol. 32, 1926). Air Conditioning Applied to Cold Storage and a New Psychrometric Chart, by C. A. Bulkeley (Refrigerating Engineering, February,1932). Air Conditioning Theory, by John A. Goff {Refrigerating Engineering, January, 1933). Rational Psychrometric Formula, by W. H. Carrier (A.S.Af.E. Transactions, Vol. 33, 1911). Temperature of Evaporation, by W. H. Carrier (A.S.H.V.E. Transactions, Vol. 24, 1918). Principles of Engineering Thermodynamics, by Kiefer and Stuart. Basic Theory of Air Conditioning, by Lawrence Washington (Western Conference on Air Conditioning, San Francisco, Calif., February 9-10, 1933). Mixtures of Air and Water Vapor, by C. A. Bulkeley (Refrigerating Engineering, January, 1933). Temperature of Evaporation of Water into Air, by W. H. Carrier, and D. C. Lindsay (A.S.M.E. Transactions, 1924). Chemical Engineering, by Lewis, Walker and McAdams. The Psychrometric Chart, by E: V. Hill (Aerologist, April, May, June, 1932). Chapter 2 . VENTILATION AND AIR CONDITIONING STANDARDS Vitiation of Air, Heat Regulation in Man, Effects of Heat, Effects of Cold, Temperature Changes, Acclimatization, Warmth and Comfort, Effective Temperature, Comfort Chart, Comfort Line, Comfort Zone, Application of Comfort Chart, A.S.H. V.E. Venti lation Standards, Natural and Mechanical Ventilation, Recircu lation, Ozone, Ultra-Violet Radiation and Ionization, Heat and Moisture Losses 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 42). 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 implies both air quality and quantity. In addition to air change, its scope is to control simultaneously the tempera ture, humidity, air movement and purity. 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 physiological requirements of the human body. VITIATION OF AIR Under the artificial conditions of indoor life, the air undergoes certain chemical changes and a vitiation which are brought about by the occu pants 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 meta bolic processes, and the humidity raised by the moisture emitted from the skin and lungs. Moreover, according to latest researches1, there is a marked decrease in both positive and negative ions in the air of occupied rooms. 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 often used in ventilation work as an index of odors of human origin, but the 1See A.S.H.V.E. research paper entitled. Changes in Ionic Content in Occupied Rooms Ventilated by Natural and Mechanical Methods, by C. P. Yaglou, L. C. Benjamin and S. P. Choate (A.S.H.V.E. Trans actions, Vol. 37, 1931). 19 American Society of Heating and Ventilating Engineers Guide, 1934 information it affords rarely justifies the labor involved in making the observation2. 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 fact that does appear certain is that expired and transpired air is odorous and offensive, and it is capable of producing headache, nausea, loss of appetite and a disinclination for physical activity. These reasons alone, whether aesthetic or physiological, are sufficient to warrant proper air conditions. A certain part of the dissemination of disease which occurs in confined spaces is caused by the continuous emission of pathogenic bacteria from infected persons. Infections, by droplets from coughing and sneezing constitute a limited mode of transmission in the immediate vicinity of the infected person. Experiments have shown that the mouth spray is a coarse rain which settles down quickly. The contamination is local and the problem is considered to be largely one of contact infection rather than air-borne infection. The primary factors in air conditioning work, in the absence of any specific contaminating source, are temperature, humidity, air movement and 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 temperature, humidity and air movement arises from the profound influence which these factors exert upon body tem perature, comfort and health. Body temperature is a resultant of the balancing action between its heat production and its heat loss. The heat resulting from the combustion of food within the body maintains its 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 auto matically by the action of the heat regulating mechanism. According to the general view, special areas in the skin are sensitive to temperature. 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. Indices of Air Change and Air Distribution, by F.. C. Houghten and J. L. BtacJcshavw(A.S.H.V.E. Journal Section, Healing, Piping and Air Conditioning. June. 1933, p. 324). 20 Chapter 2--Ventilation and Air Conditioning Standards Table 1. Physiological Responses to Heat of Men at Rest and at Work3 Effective Temp. Actual Cheek Temp (Deo Fahr) 60 70 80 96.1 85 96.6 90 97.0 95 97.6 100 99.6 105 104.7 110 Men at Rest Men at Work 90,000 ft-lb of Work per Hour Rise in Rectal Temp CD Fabr per Hour) Increase in Pulse Rate (Beats pa1 Min per' Hour) Approximate Loss in Body Weight by Perspiration (lb per Hr) Total Work Accomplished (ft-lb) Rise in Body Temp (Deg Fahi per Hr) Increase in Pulse Rate (Beats per Min per Hr) Approximate Logs in Body Wt. by Per spiration (lb per Hr) 0.0 0.0 0.1 0.3 0.9 2.2 4.0 5.9b 0 0 i 4 15 40 83 137b 6.2 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 aData by A.S.H.V.E. Research Laboratory. bComputed value from exposures lasting less than one hour. In reasonably warm environments (75 F to 80 F), metabolism, or internal heat production, is decreased to some extent, probably by an inhibitory action on heat producing organs, such as the liver. The blood capillaries in the skin become dilated by reflex action of the vasomotor nerves, allowing more blood to flow into the skin, and thus increase its temperature and consequently its heat loss. The increase in peripheral circulation is at the expense of the internal organs. If this method of cooling is not in itself sufficient, the stimulus is extended to the sweat glands which allow water to pass through the surface of the skin, where it is evaporated. This method of cooling is the most effective of all, as long as the humidity of the air is sufficiently low to allow for evaporation. In high humidities, equally good results may be obtained by increasing the air movement, 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 shrink farther below the surface, thus increasing the insulating layer and decreasing heat loss. The blood supply to the skin is curtailed by vaso motor shifts to the internal organs, in order to conserve body heat. 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 heat regulating center fails, for instance, if 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 conditions, the metabolic rate is markedly increased owing to the excessive rise in body. 21 American Society of Heating and Ventilating Engineers Guide, 1934 temperature, 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 most 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 believed that the feeling of lassitude and discomfort experienced is due to the anaemic condition of the brain. The stomach loses some of its power to act upon the food, owing to a 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 tract3. 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, Moss4 recommends the addition of 6 grams of sodium chloride and 4 grams of potassium chloride in 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 arid 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 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. Influence of Effective Temperature upon Bactericidal Action of Gasto-Intestinal Tract, by Arnold and Brody {Proceedings Society Exp. Biol. Med. Vol. 24, 1927, p. 832). . Some Effects of High Air Temperatures upon the Miner, by K. N. Moss {Transactions Institute of Mining Engineers, Vol. 66,1924, p. 284). ' . 22 Chapter 2--Ventilation and Air Conditioning Standards The blood pressure increases, owing to constriction in the peripheral vessels and to thickening of the blood. The skin subcutaneous tissues and muscles form reservoirs for storing the water which leaves the blood. In extremely cold atmospheres compensation becomes inadequate. The body temperature falls and the reflex irritability of the spinal cord is markedly affected. The organism may finally pass into an uncon scious state which ends in death. Cannon showed that excessive loss of heat is associated with increased activity of the adrenal medulla5. The extra output of'adrenin hastens heat production which protects the organism against cooling. Bast6 found a degeneration of thyroid and adrenal glands upon exposure to cold, and some physicians believe that the common use of tonics in spring has something to do with the degeneration of the endocrine glands. . Effects of Temperature Changes 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 and throat, which is accompanied by a fall in the temperature of the tissues. On rewarming, the palate and throat do not always regain their normal temperature and blood supply. This anaemic condition favors bacterial activity and it is believed to play a part in the inception of the 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 England7 found that in workers exposed to high temperatures and to changes in temperature, namely, steel melters, puddlers, and tin-plate millmen, there is an excess of all sickness, the excess among the puddlers being due chiefly to respiratory diseases and rheumatism. The causative factor was not the heat'itself but the sudden changes in temperature to which the workers were exposed. The tin-plate millmen who were not exposed to chills, since they work almost continuously throughout the shift, had no excess of rheumatism . and respiratory diseases. On the other hand, the blast-furriacemen, 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 industries8. According to these data the highest `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). `Iron Foundry Workers Show Highest Percentage of Deaths from Pneumonia {Statistical Bulletin, Metropolitan Life Insurance Company. 1928). 23 American Society of Heating and Ventilating Engineers Guide, 1934 Fig. 1. n^EG^,M^T,R'CTR Effective Temperature Chart Showing Normal Scale o Effective Temperature. . Applicable, to Inhabitants of the ' United States Under Following Conditions: 24 WE.T B U L B TEt1PE.RA.TURI Chapter 2--Ventilation and Air Conditioning Standards pneumonia death rate is associated with dust, extreme heat, exposure to cold, and to sudden changes in temperature. ACCLIMATIZATION . Acclimatization and the factor of psychology are two important in fluences in air conditioning which cannot be ignored. The first is man's ability to adapt himself to changes in air conditions; the second is an intangible matter of habit and suggestion. Some persons regard the unnecessary endurance of cold as a virtue. They believe that the human organism can adapt itself to a wide range of air conditions with no apparent discomfort or injury to health. In the light of the present knowledge of air conditioning these views are not justified. Acclimatization to extreme conditions involves a strain upon the heat regulating system and it interferes with the normal physiologic functions of the human body. Thousands of years in the heat of Africa do not seem to have acclimatized the Negro to a temperature averaging 80 F. The same holds true of northern races with respect to cold, although the effects are mitigated by artificial control. All this seems to indicate that adaptation to a climate averaging between 60 and 80 F is a very primitive trait9. 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. SENSATIONS OF WARMTH AND COMFORT Temperature, humidity and air motion taken together determine the feeling of warmth and influence the elimination of body heat. In other words, the temperature sensations of the human body 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 comfort varies with the air velocity and is about 46 F (dry- bulb) for still air and about 51, 56 and 59 F for air velocities of 100, 300 and 500 fpm, respectively. ` Thermo-Equivalent Conditions Combinations of temperature, humidity and air movement which pro duce the same feeling of warmth are called thermo-equivalent conditions. Elaborate experiments made by the A.S.H.V.E. Research-Laboratory Civilization and Climate, by Ellsworth Huntington. Yale University Press, 1924. 25 American Society of Heating and Ventilating Engineers Guide, 1934 show that this newly-developed scale of thermo-equivalent conditions not only indicates the sensation of warmth, but also determines the physio logical effects on the body induced by heat and cold. For this reason, it is called the Effective Temperature scale or index. . Effective temperature is an index of warmth or cold. It is not in itself an index of comfort, as it is often assumed to be, nor are the effective tem perature lines necessarily lines of equal comfort. This is true because, in - determining this index, the subjects compared not the relative comfort, but rather the relative warmth or cold of various air conditions. Moist air at a comparatively low temperature, and dry air at a higher tempera ture may each feel as warm as air of an intermediate temperature and humidity, but the comfort experienced in the three air conditions would be quite different, although the effective temperature is the same. The intermediate condition may be entirely comfortable, but the other two would not necessarily be so. Under extreme humidity conditions there seems to be a difference be tween sensations of absolute comfort and of the proper degree of warmth. In other words, human beings are not necessarily comfortable when the air is neither too warm nor too cold. Air of proper warmth may, for in stance, 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 mem brane of the nose and to the skin which dries up and becomes chapped' from too rapid loss of moisture. According to the comfort experiments first conducted at the A.S.H.V.E. Laboratory in the U. S. Bureau of Mines, Pittsburgh, and later studies at the Harvard School of Public Health in Boston, effective temperature appears to be a fair index of comfort also, but only within a humidity range of 30 to 60 per cent, ap proximately. Definition of Effective Temperature Briefly, effective temperature may be defined as an arbitrary index of the degree of warmth or cold felt by the human body in response to tempera ture, humidity, and movement of the air. Effective temperature is not a temperature at all; it is a composite index which combines the readings of temperature, humidity and air motion in a single value. The numerical value of the effective temperature index for any given air condition is fixed by the temperature of saturated air which, at a velocity or turbulence of 15 to 25 fpm, induces a sensation of warmth or cold like that of the given condition. Thus, an air condition has an effective temperature of 65 deg when it induces a sensation of warmth like that experienced in practically still air at 65 F saturated with moisture. In all reports of the A.S.H.V.E. Research Laboratory, the term still air signifies the minimum air movement it was possible to obtain in the Laboratory's psychrometric chamber. Actually, the air motion was between 15 and 25 fpm in all experiments, without qualification, as measured by the Kata thermometer. This was not a linear movement of air but it represented the turbulence or eddy `currents produced by the air change. Even in tightly sealed rooms, the natural air movement is not 26 Chapter 2--Ventilation and Air Conditioning Standards likely to fall below 10 fpm so long as there is a temperature or pressure difference between the air inside and outside the room. A series of tests has been carried out in the psychrometric rooms of the A.S.H.V.E. Research Laboratory, Pittsburgh, in order to determine the equivalent conditions met with in general air conditioning work. Reports of these studies for both still and moving air are given in A.S.H.V.E. Transactions, Vols. 27 to 38, inclusive. Fig. 1 shows the results in a single chart, the so-called thermometric chart. The equivalent conditions or effective temperature lines are shown by the short cross-lines. The difference between the effective temperature for still air and for moving air, of any velocity, represents the cooling resulting from that air velocity. The thermometric chart (Fig. 1) applies to average normal and healthy persons adapted to American living and working conditions. It 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 great. The chart does not apply to rooms heated by radiant methods such as the British panel system, open coal fires, and the like. It will probably not apply with adequate accuracy 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 from those of the subjects employed in experiments at the A.S.H.V.E. Research Laboratory at Pittsburgh. The effective temperature index for persons doing medium or heavy muscular work, in still air, has also been determined at the A.S.H.V.E. Research Laboratory10. Example 1. Given dry-bulb and wet-bulb temperatures of 76 F and 62 F, respectively, and an air velocity of 100 fpm, determine: (1) effective temperature of the condition; (2) effective temperature with still air; (3) cooling produced by the movement of the air; (4) velocity necessary to reduce the condition to 66 deg effective temperature. Solution. (1) In Fig. 1 draw line AB through given dry- and wet-bulb temperatures. Its intersection with the 100-ft velocity curve gives 69 deg for the effective temperature of the condition. (2) Follow line A B 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 effective temperature. (4) Follow line AB to the left until it crosses the 66 deg effective tempera ture line. Interpolate velocity value of 340 fpm, to which the movement of the air must be increased for maximum comfort. OPTIMUM AIR CONDITIONS N 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 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- "Effective Temperature' for Persons Lightly Clothed and Working in Still Air, by F. C. Houghten, W. W. Teague and W. E. Miller (A.S.H.V.E. Transactions, Vol. 32. 1928). 27 American Society of Heating and Ventilating Engineers Guide, 1934 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 heat regulating ^mechanism of the body. This belief is strengthened by results of studies on premature infants over a four-year period11. 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. Comfort Chart; Comfort Line; Comfort Zone Fig. 2 shows a comfort chart, developed at the A.S.H.V.E. Laboratory, on which the average and extreme comfort zones have been superimposed. The extreme comfort zone includes air conditions in which one or more of the experimental subjects were comfortable. The average comfort zone includes those air conditions in which the majority of the subjects (50 per cent or more) were comfortable. That particular effective temperature at which the maximum number of subjects was comfortable was called the comfort line. The average winter comfort zone as determined at the A.S.H.V.E. Laboratory ranges from 63 deg to 71 deg ET (effective temperature). While at rest, 97 per cent of the experimental subjects were found to be comfortable at 66 deg ET and this temperature was accepted as the winter comfort line or optimum effective temperature. The comfort line separates the cool air conditions to its left from the warm air conditions to its right. Under the air conditions existing along or defined by the comfort line, the body is able to maintain thermal equilibrium with its environment with the least conscious sensation to the individual, or with the minimum physiologic 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 made in rooms with wall surface temperatures approximately the same as the room dry-bulb temperature. For walls of large area having unusually low surface temperatures, however, a somewhat higher range of effective temperature is required to compensate for the increased loss of heat from the body by radiation12. The average summer comfort zone for exposures of 3 hours or more ranges from about 66 deg to 75 deg ET, based on studies made at the Harvard School of Public Health13. The probable optimum effective temperature (for exposures of 3 hours or more) is 71 deg. 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. "Application of Air Conditioning to Premature Nurseries in Hospitals, by C. P. Yaglou. Philip Drinker and K. D. Blackfan (A.S.H.V.E. Transactions, Vol. 36, 1930). . "Cold Walls and Their Relation to the Feeling of Warmth, by F. C. Houghten and Paul McDermott (A.S.H.V.E. Journal Section, Heating, Piping and Air Conditioning, January, 1933. p. 53). ' "The Summer Comfort Zone; Climate and Clothing,.by C. P. Yaglou and,Philip Drinker (A.S.H.V.E. Transactions, Vol. 35. 1929). ; 28 Chapter 2--Ventilation and Air Conditioning Standards Fig. 2. A.S.H.V.E. Comport Chart for Air Velocities of 15 to 25 fpm (Still Air)14 Note.--Both summer and winter comfort zones apply to inhabitants of the United States only. Applica tion df winter comfort line is further limited to rooms heated by central station systems of the convection type. The line does not apply to rooms heated by radiant methods. Application of summer comfort line is limited to homes, offices and the like, where the occupants become fully adapted to the artificial air con ditions. The line does not apply to theaters, department stores, and the like where the exposure is less than 3 hours. 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 See Report How to Use the Effective Temperature Index and Comfort Charts, (A.S.H.V.E. Trans actions, Vol. 38, 1932). 29 , American Society of Heating and Ventilating Engineers Guide, 1934 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. Young men as a general rule prefer conditions in the cool region of the comfort zone, and women and older people in the warm region of the . comfort zone. Crowding the experimental chamber lowered the optimum 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. Example 2. Given dry-bulb and wet-bulb temperatures of 75 and 68 F, respectively. First, what is the effective temperature? Second, is this condition warmer or cooler than 80 F dry-bulb and 60 F wet-bulb? Solution. The first condition is given by the intersection of the 75 F dry-bulb line and the 68 F wet-bulb line (Fig. 2). The effective temperature of 72.1 deg is given by the numerical value of the effective temperature line passing through this point and indicated by the scale .along the saturation curve. The second condition is given by the intersection of 80 F dry-bulb and 60 F wet-bulb and is 71.8 deg ET. It is therefore 0.3 deg ET cooler than the first condition. . Example S. Given 76 F dry-buib and 61 F wet-bulb, how many degrees difference between this condition and the winter comfort line or 66 deg ET? Solution. The effective temperature for this condition is given by the intersection of the 76-F dry-bulb and 61-F wet-bulb lines and is 70 deg ET, which is 4 deg ET warmer than the comfort line. In the comfort zone experiments of the A.S.H.V.E. Research Labora tory, the relative humidity was varied between the limits of 30 and 70 per cent approximately, but the most comfortable range has not been deter mined. In similar experiments at the Harvard School of Public Health, a relative humidity of 70 per cent was found to be somewhat humid in winter, by about half of the subjects who were stripped to the waist, even when the dry-bulb temperature was 70 F or less. In summer, a relative humi dity of 30 per cent was pronounced as a little too dry by about a third of the subjects wearing warm-weather clothing. So long as the temperature was kept within proper limits, the majority of the subjects were unable to detect sensations of humidity (i.e., too high, too low, or medium) when j the relative humidity was between 30 and 60 per cent. This is in accord | with studies by Howell16, Miura16 and others. i - Dry air produces an excessive loss of moisture from the skin and respira. tory tract. Owing to the cooling effect of evaporation, higher tempera- tures are necessary, and this condition leads 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. 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 moderate humidity, and that it dries up the mucous membranes in such "Humidity and Comfort, by W. H. Howell {The Science Press. April, 1931). "Effect of Variation in Relative Humidity upon Skin Temperature and Sense of Comfort, by U. Miura (American Journal o/ Hygiene. Vol. 13, 1931, p. 432). . 30 ' Chapter 2--Ventilation and Air Conditioning Standards a way as to increase susceptibility to colds and other respiratory dis orders17, ", w. For the premature infant, a high relative humidity of about 65 per cent is demonstrably beneficial to health and growth20, and according to Huntington21, this seems to be the case for adults also. All of these studies indicate that the optimum humidity must always be considered in combination with temperature. Until more exact information is secured, it would be desirable to restrict the comfort zones to the range of relative humidity employed in the comfort zone experiments, namely, 30 to 70 per cent. Relative humidities below 30 per cent may prove satisfactory from the standpoint of comfort, so long as extremely low humidities are avoided. From the standpoint of health, however, the consensus seems to favor a relative humidity between 40 and 60 per cent. In mild weather such comparatively high relative 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 moisture accumulating inside these materials. Unless special precautions are taken to properly insulate the affected surfaces, it will be necessary to reduce the degree of artificial humidification in sub-freezing weather to less than 40 per cent, according to the outdoor temperature. Information on the prevention of condensation on building surfaces is given in Chapter 7. The principles underlying humidity requirements and limitations are discussed more fully elsewhere22. The comfort chart (Fig. 2) 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 cent. 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)23. Satisfactory comfort conditions are found to vary from 40 deg to 70 deg ET, depending upon the rate of work and amount of clothing worn. The "Reactions of the Nasal Cavity and Post-Nasal Space to Chilling of the Body Surface, by Mudd, Stuart, et al (Journal Experimental Medicine, 1921. Vol. 34, p. 11). . "Reactions of the Nasal Cavity and Post-Nasal Space to Chilling of the Body Surfaces, by A. Goldman, et al and Concurrent Study of Bacteriology of Nose and Throat (Journal Infectious Diseases. 1921, Vol. 29, p. 151). . "The Etiology of Acute Inflammations of the Nose, Pharynx and Tonsils, by Mudd, Stuart, et al (Am. Otol.. Rinol., and Laryngol, 1921).- "Application of Air Conditioning to Premature Nurseries in Hospitals, by C. P. Yaglou, Philip Drinker and K. D. BJackfan (A.S.H.V.E. Transactions. Vol. 36, 1930). ''Weather and Health, by Ellsworth Huntington (Bulletin of the National Research Council No. 75. The National Academy of Science, Washington, D. C.f 1930). "Humidification for Residences, by A. P. Kratz (University of Illinois Engineering Experiment Station Bulletin No. 230, July 28. 1931). . "Ventilation, Report of the New York State Commission on Ventilation, 1923. 31 American Society of Heating and Ventilating Engineers Guide, 1934 effective temperatures giving maximum comfort for persons working have been determined by the A.S.H.V.E. Research Laboratory24 for a rate of work which is considered hard labor. For this degree of work, 50 per cent were fairly comfortable for temperatures ranging from 46 to 64 deg ET, while the greatest percentage found maximum comfort at 53 deg ET. 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. . ' APPLICATION OF COMFORT CHART 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, and has not been advocated officially for use in foreign countries where the climate, heating methods, and general living conditions are materially different from those in the United States, although several foreign workers have attempted to show that it cannot be so applied. 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 are necessary than those indicated by the comfort line on account of counter radiation between the bodies of occupants in close proximity. In rooms in which the average wall surface temperature is considerably below the' air temperature, higher air tem peratures are necessary. The reverse holds true in radiant or panel heat ing methods. (See Chapter 37). 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 may be counteracted by suitable clothing. Air conditions lying outside the average comfort zone but within the extreme comfort zone may be comfortable to certain persons. In other words, it is possible for half of the occupants of a room to be comfortable in air conditions outside the average comfort zone, but in the majority of cases, if not in all, these conditions will be well within the extreme comfort zone as determined experimentally. Strictly speaking, the only authoritative comfort zone on which accur ate data are available, is that for 15 to 25 Ipm air movement or turbulance (often referred to as still air). In the past, the winter comfort ^A.S.H.V.E. research paper enfcitJed, Heat and Moisture Losses from Men at Work and Application 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.'37, 1931). 32 <35 Chapter 2--Ventilation and Air Conditioning Standards zone has often been superimposed on the thermometric chart or on effec tive temperature charts for various air velocities, on the assumption that air conditions of equal warmth are approximately equally comfortable. This may hold in hot industries where the workers are adapted to high temperatures and strong air currents, but it does not apply to sedentary conditions. To ascertain approximately whether a given industrial con dition is reasonably comfortable, it would be necessary first to compute the effective temperature from the thermometric chart (Fig. 1) and then to refer this effective temperature to the comfort chart (Fig. 2). The summer comfort line (71 deg ET) is applicable to the same geo graphic area as the winter comfort line. It is further restricted to cases in which the human body has reached thermal equilibrium with its environ ment. As a general rule this takes place after lj/ to 3 hours exposure. When a person from outdoors enters a room cooled to 71 deg ET on a hot day (95 F or over) an intense chill is likely to be experienced which is Table 2. Desirable Indoor Air Conditions in Summer Corresponding to Outdoor Temperatures Applicable to Exposures Less Than S Hours Outdoor Temp (Deo Fahr) Dry-Bulb 95 90 85 80 75 70 Indoor Air Conditions with Dew-Point Constantat57F ' Dbt-Bulb Wet-Bulb Effective Temp 80.0 78.0 76.5 75.0 73.5 72.0 65.0 64.5 64.0 63.5 63.0 62.5 73 72 71 70 69 68 unpleasant. However, after remaining in the room for about 2 hours, this fundamental optimum condition will prove satisfactory to the average person. The summer comfort zone, as well as the comfort line, makes proper allowance for these adaptive changes in the body, and thus applies to homes, offices, schools and other similar places where persons of sedentary occupations spend from 3 to 8 or more hours daily. In artificially cooled theaters, department stores, 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 temperature and humidity to be maintained. The object of cooling such places in the summer is not to reduce the temperature to the optimum degree, but to maintain therein a temperature which is tem porarily comfortable to the patrons who thus avoid sensations of chill and intense heat on entering and leaving the building. The relative humidity should be low enough (about 50 per cent or less) to give a sense of comfort without chill and to induce a rate of evaporation which will keep clothing and skin dry. For exposures less than 3 hours, desirable indoor conditions in summer corresponding to various outdoor temperatures are given in Table 2. ' 33 American Society of Heating and Ventilating Engineers Guide, 1934 A.S.H.V.E. VENTILATION STANDARDS25 It is the intent of the Committee in presenting this report to confine itself to a statement of those requirements which, based on present day knowledge, will provide adequate ventilation for 8paces intended for human occupancy. The following standards shall apply to all spaces occupied by human beings in all buildings for which ventilation regulations are to be established. SECTION I--AIR TEMPERATURE AND HUMIDITY The temperature and humidity of the air in such occupied spaces, and in which the only source of contamination is the occupant, shall be maintained at all times during occu pancy at an Effective Temperature, as hereinafter stated. The relative humidity shall be not less than 30 per cent, nor more than 60 per cent in any case. The Effective Temperature shall range between 64 deg and 69 deg when heating or humidification is required, and between 69 deg and 73 deg when cooling or dehumidification is required. These Effective Temperatures shall be maintained at a level of 36 in. above the floor. (See Appendix, Tables A and B). SECTION II--AIR QUALITY The air in such occupied spaces shall at all times be free from toxic, unhealthful or disagreeable gases and fumes and shall be relatively free from odors and dust. In every space coming within the provisions of these requirements and in which the quality of the air is below the standards prescribed by good medical and engineering practices, due to toxic substances, bacteria, dust, excessive temperature, excessive humidity, objectionable odors, or other similar causes, means for ventilating shall be provided so that the quality of the air shall be raised to these standards. SECTION III--AIR MOTION The air in such occupied spaces shall at all times be in constant motion sufficient to maintain a reasonable uniformity of temperature and humidity, but not such as to cause objectionable drafts in any occupied portion of such spaces. The air motion in such occupied spaces, and in which the only source of contamination is the occupant, shall have a velocity of not more than 50 feet per minute, measured at a height of 36 in. above the floor. SECTION IV--AIR DISTRIBUTION The air in all rooms and enclosed spaces shall, under the provisions of these require ments, be distributed with reasonable uniformity, and the variation in the carbon dioxide content of the air shall be taken as a measure of such distribution. The air in a space ventilated in accordance with these requirements, and-in which the only source of contamination is the occupant, shall be distributed and circulated so that the variation in the concentration of carbon dioxide, when measured at a height of 36 in. above the floor, shall not exceed one part in 10,000. SECTION V--AIR QUANTITY The quantity of air used to ventilate the given space during occupancy shall always be sufficient to maintain the standards of air temperature, air quality, air motion and air distribution as herein required. Not less than 10 cubic feet per minute-per occupant of the total air circulated to meet these requirements shall be taken from ah outdoor source. APPENDIX Definitions For the purposes of these standards the terms used shall be defined as follows:-- 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). ^Report of A.S.H.V.E. Committee on Ventilation Standards consisting of W. H. Driscoll, Chairman. J. J. Aeberly. F. Paul Anderson, L. A. Harding, D.` D. Kimball, J. R. McColl, C. L. Riley, W. A. Rowe, Perry West and A. C. Willard, presented at the Semi-Annual Meeting of the Society, Milwaukee, Wis., June, 1932, and adopted by the Society in August, 1932. 34 ' Chapter 2--Ventilation and Air Conditioning Standards Table A. Effective Temperatures Ranging from 64 Deg to 69 Deg for Various Dry-Bulb Tem peratures and Relative Humidities for Still Air for Persons Normally Clothed and Slightly Acuves . (For use when heating or humidification is required) - Temperatures (Deg FahR) 30 Relative Humidities (Per Cent) 35 40 45 50 . 55 Effective Temperatures (Degrees) 60 . 67 68 ' 69 70 71 72 73 74 75 76 64.1 64.8 65.5 66.2 67.0 67.7 68.4 69.0 . oSee Fig. 2, p. 29. 64.4 65.1 65.8 66.5 67.3 68.0 68.7 64.0 64.8 65.4 66.2 66.9 67.7 68.4 64.2 65.1 65.8 66.6 67.3 68.1 68.8 64.5 65.4 66.2 '67.0 67.7 68.5 64.0 64.8 65.7 66.5 67.3 68.1 68.9 64.3 65.1 66.0 66.8 67.7 68.5 - Table B. Effective Temperatures Ranging from 69 Deg to 73 Deg for Various Dry-Bulb Tem peratures and Relative Humidities for Still Air for Persons Normally Clothed and Slightly Activeq-L (For use when cooling or dehumidification is required) bThis table applies primarily to cases in which the human body has reached equilibrium with the sur rounding air. A higher plane of summer effective temperatures is required in places of public assembly where the period of occupancy is short, than is required for offices and industrial plants where the period of occupancy is of longer duration. When the period of occupancy is two hours or less, the dry-bulb tempera ture shall be 72 F plus one-third of the difference between the outside dry-bulb temperature and 70 F, and the relative humidity shall not exceed 60 per cent. (See also Table 2, p. 29). _ Air Conditioning: The simultaneous control of all or at least the first three of those factors affecting both the physical and chemical conditions of the atmosphere within any structure. These factors include temperature, humidity, motion, distribution, dust, bacteria, odors, toxic gases, and ionization, most of which affect in greater or lesser degree human health or comfort. . ' ' . Dry-Bulb Temperature: The temperature of the air which is indicated by any type of thermometer which is not affected by the water vapor content or relative humidity of the air. ' ' 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, such as are blown on a windy day, the average diameter of which is approximately 0.01 centimeter, may be called dust. Effective Temperature: An arbitrary index of the degree of warmth or cold felt by the human body in response to temperature, humidity, and movement of the air. Effective temperature is a composite index which combines the readings of temperature, humidity, and air motion into a single value. The numerical value of the effective temperature scale has been fixed by. the temperature of saturated air which induces an identical sensation of warmth. - .' Humidity: The water vapor (either saturated or superheated steam) occupying any space, which may or may not contain other vapors and gases at the same time. 35 American Society of Heating and Ventilating Engineers Guide, 1934 Relative Humidity: A ratio, although usually expressed in per cent, used to indicate the degree of saturation existing in any given space resulting from the water vapor present in that space. 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, which depends merely on the temperature and partial pressure of the vapor. Spaces in Which the Only Source of Contamination Is the Occupant: Spaces in which the atmospheric contamination results entirely from the respiratory processes of the occupant, including heat, moisture, and odors given off by the body. No manufacturing or industrial processes or other sources of atmospheric contamination, including heat and moisture, than people are considered under this title. FACTORS INFLUENCING APPLICATIONS The conditions and limitations outlined under the heading Application of Comfort Chart should be noted in applying the temperatures and relative humidities specified in Tables A and B of the preceding A.S.H.V.E. Ventilation Standards. Air Quality In occupied spaces in which the vitiation is entirely of human origin, the chemical composition of the air, the dust, and bacteria content 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.. A further discussion of air quality will be found in Chapters 15 and 16. Air Motion The air in occupied spaces must be in constant gentle motion sufficient to maintain a satisfactory uniformity of temperature and humidity, but not such as to cause objectionable drafts in any occupied portion of such spaces. Stagnant air, no matter how pure, is depressing, and it fails to produce the pleasant and stimulating effect of cool air in gentle motion. Studies by Baetjer28 on the influence of air motion on comfort indicate that in ordinary air conditioning work the velocity of air currents should never be allowed to fall below 5 fpm, nor should it be allowed to exceed 50 fpm, except when the temperature of the air current striking the face is higher than the temperature of the room. The lower limit of 5 fpm may be taken as the minimum during the heating season, and the upper limit of 50 fpm as the maximum during the cooling season. Air Distribution27 . As a rule satisfactory distribution is secured when the air movement or turbulence as measured by the Kata thermometer (see p. 573, Chapter 40) is uniform in all parts of the occupied space and when simultaneous readings of temperature at any two points on the same level within the occupied space do not differ by more than 3 deg. Measurements of CO% are acceptable in lieu of temperature and air motion variations, but the usual method of determining CO2 in air is much more laborious than the "Threshold Air Currents in Ventilation (American Journal of Hygiene, Vol. IV, No. 6. p. 650, 1924). "Indices of Air Change and Air Distribution, by F. C. Houghten and J. L. Blackshaw (A S H V E journal Section. Healing, Piping and Air Conditioning, June. 1933. p. 324). . 36 Chapter 2--Ventilation and Air Conditioning Standards determination of temperature and air movement. When CO2 is used as an index of distribution, the variation in the concentration of the gas at a height of 36 in. above the floor should not exceed one part in 10,000 parts of air. Air Quantity The quantity of air to be circulated through an occupied space, whether by natural or mechanical means, or whether the air is conditioned or not, must in all cases be sufficient to maintain the required standards of air temperature, quality, motion and distribution. The factors which deter mine 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. Actually there are two air quantities to be considered, namely, (1) total air required and (2) outside air required. The difference between these two quantities represents the amount to be recirculated, or Total air = outside air + recirculated air. Sometimes the ratio of the outside air to the total air can be decreased if the air introduced is conditioned, but in the light of present information, a minimum of 10 cfm of outdoor air per person should be provided. If the air is not conditioned as in a ventilating system, the vitiated air is usually exhausted to the atmosphere, in which case all of the air introduced is outside air. Temperature Rise The total quantity of air introduced is governed largely by the allow able temperature rise when cooling is required and the allowable tempera- lure drop when heating is required. As a rule, the introduction and distribution of warm air into an occupied space does not present as many difficulties as does the introduction of cold air. The former is determined from the amount of heat to be given up to the space, and the latter is determined from the amount of heat to be removed from the space, using a temperature rise that will produce uniform distribution without the production of disagreeable drafts. . Two of the most important factors on which the temperature rise depends are (1) the method of distribution and (2) the most economical temperature rise for the conditions involved. Some systems of distri bution produce drafts with but a few degrees temperature rise, while other systems operate successfully with a temperature rise as high as 35 deg. The total air quantity introduced in any particular case is inversely proportional 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. Small quantities of air reduce the size of equipment, ducts, space, and initial cost, but require lower air temperatures. In any specific case, the cost of refrigeration must be balanced against the extra cost in increased size of equipment and running expense. Outside Air. In order to provide uniform temperature conditions, it 37 American Society of Heating and Ventilating Engineers Guide, 1934 is necessary to maintain a pressure of about 0.1 in. of water in the room or space to be ventilated or conditioned. This usually requires the intro duction of a certain amount of outside air which depends on the particular conditions involved, and may vary over a considerable range. In rooms in which the only source of contamination is the occupant the minimum quantity of outside or new air to be circulated appears to be that necessary to remove objectionable body odors. The concentration of body odors in turn depends largely upon the temperature of the air; the higher the temperature, the greater the amount of perspiration (sensible or insensible) given off from the skin, and the greater the concentration of odors. ' Under proper temperature conditions, body odors may be reduced to a concentration that is not objectionable by as little as 10 cfm of outside air per person. This is the minimum amount specified in the Ventilation Standards adopted in 1932 by the Society. The ventilation laws of many states require the introduction of 30 cfm of outside air per occupant, but the present tendency is to supply a smaller amount of conditioned air. The total quantity of air required to maintain the standards of tem perature, distribution, and air motion is usually at least twice as great as that required to keep down body odors, owing largely to difficulties encountered with distribution systems. NATURAL AND MECHANICAL VENTILATION Under favorable conditions natural ventilation methods properly combined with means for heating may be sufficient to provide for the foregoing standards. As a rule, in instances in which the only source of contamination is the occupant, the requirements may be fulfilled when the following conditions prevail: 1. At least 50 sq ft of floor area for each occupant. 2. At least 500 cu ft of air space per. occupant. 3. Effective openings in windows and skylights equal to at least 5 per cent of the floor area. Whenever natural means are not sufficient to maintain the standards, resort must be made to whatever modifications or mechanical apparatus are necessary to secure such standards. 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 38 " Chapter 2--Ventilation and Air Conditioning Standards control of indoor temperature and humidity. Outdoor smoke, dust and noise, constitute other limitations of natural methods. RECIRCULATION The saving in operating costs due to recirculation of the air, while very considerable, must not be obtained at the. expense of air quality. The percentage of recirculated air may be varied to suit the seasonal changes so as to. conserve heat in winter and refrigeration in summer, but at no time during occupancy should there be taken from out of doors less than 10 cfm for each occupant. As a general rule, recirculation impairs the quality of the air by excessive humidity (if not conditioned), excessive odors, or both, and it tends to deprive the air of its ionic content*8, but the influence of this factor on comfort and health is at present a matter of speculation. Toilets and similar rooms and all kitchens in buildings using recircula tion should be separately, mechanically ventilated, with the exhaust in excess of the supply, in order to prevent objectionable odors from dif fusing into other parts of the building. This air removal may in many cases be sufficient to insure an adequate replacement of outside air to the general recirculating system. OZONE The value of ozone in recirculated air has been greatly exaggerated in the past. Numerous researches29, ", 81 have shown that ozone in con centrations permissible in air conditioning work (0.1 to 0.5 parts per million parts of air) exerts practically no effect on pathogenic air-borne . organisms and that it does not destroy the source of odors. Ozone, however, may mask odors by olfactory compensation. It requires at least 13 parts of ozone per million parts of air to influence bacteria32. Human beings are injuriously affected by ozone in concentrations of one part or more per million parts of air32. This amount will not destroy odors nor kill bacteria. ULTRA-VIOLET RADIATION AND IONIZATION In spite of rapid advances in air conditioning during the past few years, the secrets of reproducing indoors the natural climatic elements as they exist in open country under ideal weather conditions have not as yet been , fully ascertained. Extensive studies have failed to discover the stimulat ing quality in open country air which is lost when the air is brought indoors, and particularly when it is treated mechanically. Ultra-violet light and ionization have been suggested but have not yet been identified. It is generally recognized that total solar radiation in open air is the "See A.S.H.V.E. research paper entitled. Changes in Ionic Content in Occupied Rooms Ventilated by Natural and Mechanical Methoos, by C. P. Yaglou, L. C. Benjamin and S. P. Choate (A.S.H.V.E. Trans actions, Vol. 37, 1931). "Proceedings, Royal Society of London, by L. Hill and M. Flack (1911, B, Vol. 84, p. 404). "Jordan and Carlson (Journal American Medical Association, 1913, Vol. 51, p. 1007). "Konrich (Ztschr. f.-Hyg.. 1913, Vol. 73, p. 443). . "Preventive Medicine and Hygiene, by Milton J. Rosenau. ' srr American Society of Heating and Ventilating Engineers Guide, 1934" greatest curative and is a powerful germicidal agent. A critical review of the literature, however, discloses that artificial ultra-violet radiation has little importance in air conditioning, at least for the time being, because it is not known which of the solar rays brings about the cure, and what physiologic processes are involved in their action. With the exception of rickets and certain skin diseases, artificial radiation was found to have no effect on susceptibility, incidence, and resistance to respiratory infections33, no permanent effects on blood and no effect on the general metabolism of human beings. Ionization, on the other hand, seems to offer a fruitful field for research. Fig. 3. Influence of Room Occupancy on Ionic Content** (Cubical Contents of Room, 10,000 Cu Ft; Number of Occupants, 34) Recent experiments3* show that in occupied rooms there is a marked decrease in both positive and negative small ions.- As shown in Fig. 3, soon after the occupants assembled the ionic content fell abruptly to a very low level which was maintained until the occupants left the room. Both positive and negative ions began to rise again as soon as the occu pants departed. The problem now is to determine whether such altera tions in the electrical quality of air have any significant bearing on com- ` fort and health. If this proves to be the case, some artificial source of ionization may be desirable in occupied rooms. "Light--Its Photodynamic Activity and Use as a Therapeutic Agent, by F. W. Schultz. K. W. Stenstrom and E. M. Clausen (Report of the White House Conference on Child Health and Protection, Washington February, 1931). . "A.S.H.V.E. research paper entitled. Changes in Ionic Content in Occupied Rooms, Ventilated by Natural and Mechanical Methods, by C. P. Yaglou, L. C. Benjamin and S. P. Choate (A.S.H.V.E. Trans- . actions, Vol. 37, 1931). Physiologic Changes During Exposure to Ionized Air, by 'C. P. Yaglou A D Brandt and L. C. Benjamin (A.S.H.V.E. Journal Section, Healing, Piping and Air Conditioning, August * 1933). Diurnal and Seasonal Variations in the Small Ion Content of Outdoor and Indoor Air, by C p' Yaglou and L, C. Benjamin. (A.S.H.V.E. Journal Section, Healing, Piping and Air Conditioning, January 40 Chapter 2--Ventilation and Air Conditioning Standards HEAT AND MOISTURE LOSSES In order to solve air conditioning problems involving the human body it is necessary to know the rate at which sensible and latent heat are given up by the body under various conditions of temperature and activity. Research at the A.S.H.V.E. Laboratory35 has resulted in the data given in Figs. 4, 5, 6 arid 7. Table 3 gives the metabolic rates for various degrees of activity. The experimental data from which the curves were drawn indicate that Table 3. Relation Between Metabolic Rate and Activity15 Activity Metabolic Rate Btu feb Houb fob Average Man (19.5 Sq Ft Sur face Area) Seated at rest............ - 384 Standing at rest.--...... 431 Walking 2 mph........... 761 Walking 3 mph........... Walking 4 mph...........- 1049 1388 Walking 5 mph.......... - Slow run....................... Very severe exercise.... Maximum exertion..... Tailor........................... Bookbinder. .............. Shoemaker................... Carpenter..... :.............. Metal Worker.............. Painter (of furniture).. Stonemason.................. Man sawing wood....... 2530 2285 2555 3333 to 4762 + 482 626 661 762 to 963 862 876 1488 1797 Authority Research Laboratory, American Society of Heating and Ventilating Engineers. Research Laboratory, American Society of Heating and Ventilating Engineers. Average values from Douglas; Haldane, Henderson and Schneider; and Henderson and Haggard. Douglas, Haldane, Henderson and Schneider Average values from Douglas, Haldane, Henderson and Schneider; and Henderson and Haggard. Douglas, Haldane, Henderson and Schneider Henderson and Haggard Benedict and Carpenter Henderson and Haggard Becker and Hamalainen Becker and Hamalainen Becker and Hamalainen Becker and Hamalainen Becker and Hamalainen Becker and Hamalainen Becker and Hamalainen Becker and Hamalainen total heat loss does not vary appreciably within the comfort zone range (see Fig. 4). Above or below this range the variation seems to be approxi mately a function of effective temperature. Sensible and latent heat losses (Figs. 5 and 7) on the other hand, vary greatly within the comfort zone range, the variation following more closely the dry-bulb temperature than any other factor. Although total heat loss and sensible and latent heat losses are not exact functions of effective and dry-bulb temperature, respectively, for all conditions of humidity and air motion, they are plotted as such in the curves. This is accomplished by approximations which are sufficiently accurate for application to practical problems. An atmospheric condition resulting in sensible perspiration is to be "See A.S.H.V.E. research paper entitledH eat and Moisture Losses from Men at Work and Application to Air Conditioning Problems, by F. C. Houghten, W. W. Teague, W. E. Miller and W. P. Yant (A.SJH.V.E. Transactions, Vol. 37, 1931). 41 American Society of Heating and Ventilating Engineers Guide, 1934 avoided for obvious reasons. Tables 4 and 5 give the approximate effec tive temperatures at which perspiration is noticeable in different degrees for 95 per cent and 20 per cent relative humidity. In theaters, auditoriums, department stores and other crowded en closures, the amount of heat and moisture given off by the people is so large that normal changes in outside temperature and humidity have relatively little effect on indoor air conditions. The principal object of air . 42 ' Chapter 2--Ventilation and Air Conditioning Standards conditioning in such places is to remove excessive heat and moisture by supplying a sufficient quantity of properly conditioned air. The indoor air conditions, however, must be varied according to the outside tem perature, as already pointed out. .. Although heat and moisture from the human body constitute the major Table 4. Condition of Sensible Perspiration for Persons Seated at Rest Under Various Atmospheric Conditions56 Degree or Perspiration* Atmospheric Condition 95 Per Cent Relative Humidity 20 Per Cent Relative Humidity E. T.. Forehead clammy.............. ............................ : . Body clammy--------- ---------- -----------------------Body damp------------------------------ ----------------- Beads on forehead.. ___ _____ ____________ Body wet.................................... .. ............. ..... Perspiration on forehead runs and .drips.____ Perspiration runs down body_______________ 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. D. B. W. B. 75.0 75.0 81.0 87.0 86.5 94.0 90.0 87.0 87.0 97.5 109.4 108.5 125.2 116.0 60.7 60.7 67.5 75.2 74.6 85.4 79.5 oForty per cent of subjects registered degree of perspiration equal to or greater than indicated. portion of the cooling load, in most cases where air conditioning is pro vided for comfort and health other factors must also be considered. These include heat from lights, machinery, and processes, as well as the trans mission and infiltration of heat through the building structure. The computations for these'" factors may be made in accordance with data given in Chapters 5 and 7. . In many cases, allowance must also be made for sun effect and for heat capacity of the building structure in accordance with studies by the Table 5. Condition of Sensible Perspiration for Persons at Work Under Various Atmospheric Conditions Atmospheric Condition Degree or Perspirations 95 Per Cent Relative Humidity 20 Per Cent Relative Humidity E.T. D. B. W. B. E. T. D. B. W. B. Forehead clammy...... ............ ........ ......... ........ Body clammy___ Body damp___ ____________________________ Beads on forehead...... ......... .................. ... . Body wet.... .......................... . ............. .... Perspiration on forehead runs and 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.. 56.5 44.2 49.5 63.4 53.0 70.2 69.0 oForty per cent of subjects registered degree of perspiration equal to or greater than indicated. "Thermal Exchanges.between the Human Body and its Atmospheric Environment, by F. C. Houghten, W. W. Teague, W. E. Miller. W. P. Yant (American Journal Physiology. Vol. 88, No. 3, April, 1929, pp. 386-406). 43 American Society of Heating and Ventilating Engineers Guide, 1934 A.S.H.V.E. Research Laboratory37. Another item to be considered is the radiant heat received by the body from high temperature wall and ceiling surfaces. Example If. 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. Solution. The sensible heat given up per person per hour under this condition may be obtained from Fig. 5. With an abscissa value of 80 F, Curve D for men seated at rest Chapter 2--Ventilation and Air Conditioning Standards The sensible and latent heat added to the air may also be found as follows: The effective temperature for dry- and wet-bulb temperatures of 75 F and 63.5 F, respec tively, is 70.3 deg. From Curve D, Fig. 4, find 403 Btu as the total heat added to the air by a person for an effective temperature of 70.3 deg. From Fig. 7 find the percentage of sensible and latent heat at a dry-bulb temperature of 75 F to be 66.5 per cent and 33.5 per cent. The sensible heat added to the air in the auditorium is 1,000 X 0.665 X 403. = 267,995 Btu per hour. The latent heat added is 1,000 X 0.335 X 403 = 135,005. Btu per hour. Example 6. If the dry- and wet-bulb temperatures of the auditorium were 85 F and 63 F, respectively, how much heat and moisture would be dissipated to the atmosphere? Fig. 6. Latent Heat and Moisture Loss from the Human Body by Evaporation, in Relation to Dry-Bulb Temperature for Still Air Conditions3 "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 rt-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. --. 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 per hour may be obtained from Fig. 6. 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). Example 5. How much sensible heat, how much latent heat and how much water vapor will be added per hour to the atmosphere of an auditorium by an audience of 1000 adults, when the dry- and wet-bulb temperatures are 75 F and 63.5 F, respectively? Solution. From Curve D, Fig. 5, find the sensible heat loss per person for a dry-bulb temperature of 75 F and still air to be 265 Btu per hour. From Fig. 6 find the latent heat loss per person for a dry-bulb temperature of 75 F to be 134 Btu per hour and the moisture added to be 905 grains per hour. Sensible heat = 1,000 X 265 = 265,000 Btu. Latent heat = 1,000 X 134 = 134,000 Btu. Water vapor added per hour to the air in the auditorium = 1,000 X 905 = 905,000 grains or 129 lb. . "See A.S:H.V.E. research paper entitled. Heat Transmission as Influenced by Heat Capacity and Solar Radiation, by F. C. Houghten, J. I.. Blackshaw, E. M. Pugh and Paul McDermott (A.S.H.V.E. Trans- actions, Vol. 38, 19321. , 44 Fig. 7. Heat Loss from the Human Body by Evaporation, Radiation and Con vection in Relation to Dry-Bulb Temperature for Still Air Conditions3 *Curve A--Men working 66,150 ft-lb per hour. Curve B--Men working 33.075 ft-lb per hour. Curve C--Men working 16.53S 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. Solution. From Figs. 5 and 6, respectively, the sensible and latent heat losses per person for a dry-bulb temperature of 85 F are found to be 164 and 225 Btu per hour. The water vapor added to the atmosphere is 1,520 grains per hour. The audience will then add 164,000 Btu sensible heat, 225,000 Btu latent heat and 1,520,000 grains or 217 lb of water vapor to the air in the auditorium per hour. Examples 5 and 6 demonstrate that while the effective temperature, and hence the feeling of warmth and rate of total heat loss, do not differ greatly in the two cases, the relative proportion of sensible and latent heat loss is reversed. In order to maintain the air conditions stipulated the air conditioning equipment must remove 63.4 per cent more sensible heat in Example 5 than in Example 6; and 67.9 per cent more latent heat or water vapor in Example 6 than in Example 5. In Example 5, 66.3 per cent of the total heat loss is sensible while in Example 6 only 42.2 per cent of the total loss is sensible. Example 7. Neglecting the gain or loss of heat to an auditorium by transmission or infiltration through the walls, windows and doors, how many cubic feet of outside air, 45 American Society of Heating and Ventilating Engineers Guide, 1934 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 shall not exceed 75 F (dry-bulb) and 65 F (wet-bulb), respectively? Solution. Figs. 5 and 6 give 265 Btu sensible heat and 905 grains of moisture as the additions 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 required to raise '- 265 000 the dry-bulb temperature from 65 to 75 F and ---- = 110,400 lb of air or 110,400 X i A7Q non 13.4 = 1,479,000 cfh of air will be required. This is equivalent to-,= 24.7 cfm 1000 X 60 per person. The moisture content of the inside air as taken from a psychrometric chart is 76 grains per pound of dry air and that of the outside condition is 65 grains. The increase in moisture content will therefore be 11 grains per pound of dry air. Hence = 82,300 lb of air at the specified condition will be required. This is equivalent to 82,300 i inn nnn X 13.4 = 1,103,000 cfh of air or gQ : 18.4 cfm of air per person. The higher volume of 24.7 cfm per person will be required to keep the dry-bulb tem perature from rising above the 75 F specified. The wet-bulb temperature will therefore not rise to the maximum of 65 F. Example 8. Assume that a man performs work at a rate equivalent to 50,000 ft-lb per hour, in an atmosphere having a dry-bulb temperature of 70 F. Estimate the sensible and latent heat given off per hour. "'Solution. Since the net mechanical efficiency of the human body is about 20 per cent, the increase in metabolism due to work, over the resting metabolism, will be 50,000-- . 778* X 0.20 = 320 Btu per hour. Assuming a resting metabolism of 400 Btu per hour (see Fig. 4), the total metabolism during work will be 400 + 320 = 720 Btu per hour, and the total heat loss 720 -- = 656 Btu per hour approximately. In Fig. 7, follow a vertical line from a dry-bulb temperature of 70 F to a point midway between Curves A and B. The sensible heat loss is about 46 per cent of the total loss, or 0.46 X 656 = 302 Btu per hour, and the latent heat 54 per cent of the total or 0.54 X 656 = 354 Btu per hour. In cases in which the external work is not appreciable, as for instance in sewing, walking on a level road, and the like, the rate of heat loss will be approximately equal to the total metabolism. Heat equivalent of mechanical work in foot-pounds per Btu. 46 Chapter 3 INDUSTRIAL AIR CONDITIONING Moisture Content and Regain, Hygroscopic Materials, Atmos pheric Conditions Required, Air Conditioning of Libraries, Banana Ripening, Greenhouse Heating, Apparatus for Industrial Con ditioning, Industrial Humidifying Systems, Direct Humidifiers, Combined Direct and Indirect Humidifiers, Dehumidifiers IN many industries, the temperature and relative humidity of the air have a marked influence upon the rate of production and the weight, strength, appearance, and general quality of the product. These results are due to the fact that most materials of animal or vegetable origin, and to a lesser extent minerals in certain forms, either take up or give moisture to the surrounding air. Air conditioning is applicable to industrial or process conditioning for the improvement of products during manu facture, or for making the process independent of climatic conditions. 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 of 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 . 7.0 centage of the bone-dry weight, is or 7.5 per cent. The use of the term regain does not necessarily imply that the material as a whole has been completely dried out and has re-absorbed moisture. In the case 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. In measuring moisture it is necessary to dry out a sample so that the loss in weight may be used as a basis for calculating the regain of the whole lot. HYGROSCOPIC MATERIALS Air conditioning is extensively used in the manufacture or processing of hygroscopic materials such as textiles, paper, wood, leather, tobacco and 47 American Society of Heating and Ventilating Engineers Guide, 1934 Table 1. Regain of Hygroscopic Materials Moisture Content Expressed in Per Cent of Dry Weight of the Substance at Various Relative Humidities--Temperature, 75 F Classi fication Matebial Description Relative Hcwditt--Peb Cent 10 20 30 40 50 60 70 80 90 Aothoeitt Cotton' Sea Island--Roving 2.5 3.7 4.6 5_5 6.6 7.9 9.5 11.5 14.1 Hartshorne Cotton . American--Cloth 2.6 3.7 4.4 5.2 5.9 6.8 8.1 10.0 14.3 Schloesing Cotton Absorbent 4.8 9.0 12.5 15.7 18.5 20.8 22.8 24.3 25.8 Fuwa Natural Textile Fibres Wool Silk Linen Australian Merino--Skein 4.7 7.0 8.9 10.8 12.8 14.9 17.2 19.9 23.4 Hartshorne - Raw Chevennes--Skein 3.2 5.5 6.9 8.0 8.9 10.2 11.9 14.3 18.8 Schloesing Table Cloth 1.9 2.9 3.6 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 13.8 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 10.8 12.4 14.2 16.0 Robertson 0.8 1.1 1.4 1.9 2.4 3.0 3.6 4.3 5.3 Robertson M. F. Newsprint Wood Pulp--24% Ash 2.1 3.2 4.0 4.7 5.3 6.1 7.2 8.7 10.6 U. S. B. of S. H. M. F. Writing Wood Pulp--3% Ash 3.0 4.2 5.2 6.2 7.2 8.3 9.9 11.9 14.2 U. S. B. of S. Paper White Bond Rag--1% Ash 2.4 3.7 4.7 5.5 6.5 7.5 8.8 10.8 13.2 U. S. B. of S. Com. Ledger 75% Rag--1% Ash 3.2 4.2 5.0 5.6 6.2 6.9 8.1 10.3 13.9 U. S. B. of S. Kraft Wrapping Coniferous 3.2 4.6 5.7 6.6 7.6 8.9 10.5 12.6 14.9 U. S. B. of S. Leather Sole Oak--Tanned 5.0 8.5 1U 13.6 16.0 18.3 20.6 24.0 29.2 Phelps Catgut Racquet Strings 4.6 7.2 8.6 10.2 12.0 14.3 17.3 19.8 21.7 Fuwa Glue Misc. Organic Rubber Hide Solid Tire 3.4 4.8 5.8 6.6 7.6 9.0 10.7 11.8 12.5 Fuwa 0.11 0.21 0.32 0.44 0.54 0.66 0.76 0.88 0.99 Fuwa Wood Timber (Av.) 3.0 4.4 5.9 7.6 9.3 11.3 14.0 17.5 22.0 Forest* P. lab. Soap White 1.9 3.8 5.7 7.6 10.0 12.9 16.1 19.8 23.8 Fuwa Tobacco Cigarette 5.4 8.6 11.0. 13.3 16.0 19.5 2S.0 33.5 50.0 Ford White Bread 0.5 1.7 3.1 4.5 6.2 8.5 11.1 14.5 19.0 Atkinson Crackers 2.1 2.8 3.3 3.9 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 22.1 Atkinson 2.6 4.1 5.3 6.5 8.0 9.9 12.4 15.4 19.1 Bailey , Starch 2.2 3.8 5.2 6.4 7.4 8.3 9.2 10.6 12.7 Atkinson aelatin 0.7 1.6 2.8 3.8 4.9 6.1 7.6 9.3 11.4 Atkinson Asbestos Fibre Finely Div. 0.16 0.24 0.26 0.32 0.41 6.51 0.62 0.73 0.84 Fuwa Misc. Silica Gel. Inorganic Domestic Coke Materials Activated Charcoal Steam Activated 5.7 9.8 12.7 15.2 17.2 18.8 20.2 21.5 22.6 Fuwa 0.20 0.40 0.61 0.81 1.03 1.24 1.46 1.67 1.89 Jelvig 7.1 !4.3 22.8 26.2 28.3 29.2 30.0 31.1 32.7 Fuwa Sulphuric Acid HtSOi ' 33.0 41.0 47.5 52.5 57.0 61.5 |67.0 73.5 82.5 Mason 48 Chapter 3--Industrial Air Conditioning foodstuffs. Where the physical properties of the product affect value, the question of moisture is of special importance. With increase in moisture content, hygroscopic materials ordinarily become softer and more pliable. Economy of manufacturing, therefore, requires that the moisture content be maintained at a percentage most favorable to rapid and satisfactory manipulation and to a minimum loss of material through breakage. A constant 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. Air conditioning is important in certain branches of the chemical industry in controlling the temperature of reaction and facilitating or retarding evaporation. The control of moisture content of air supplied to blast furnaces in the manufacture of pig iron also has proved advantageous. 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. Table 1 shows the regain or hygroscopic moisture content of several organic and inorganic materials when in equilibrium at a dry-bulb tem perature of 75 F and various relative humidities. The effect of relative humidity on regain of hygroscopic substances is clearly indicated. The effect of temperature is comparatively unimportant. In the case of cotton, for instance, an increase in temperature of 10 deg has the same effect on regain as a decrease in relative humidity of one per cent. Changes in temperature do, however, affect the rate of absorption or drying. Sudden changes in temperature cause temporary fluctuations in regain even when the relative humidity remains stationary. Conditioning and Drying Exposure of hygroscopic materials to an atmosphere of controlled humidity and temperature for the purpose of establishing a specified moisture condition in. the material is called conditioning. Where the desired final moisture content is relatively low, the term drying is usually / used. In any case, control of relative humidity, temperature, air velocity and length of exposure are all of more or less importance. The conditioning treatment may be undertaken in a special enclosure (conditioning room) or it may be accomplished in the same room and at the same time as some regular manufacturing process. For instance, in the weaving of textiles a high relative humidity is commonly employed to keep the yarn strong and pliable, thus assisting in the weaving process and at the same time leaving the product in a satisfactory condition of regain for commercial reasons. -- As a rule, commercial regain standards are specified percentages which by test have been found equivalent to a so-called standard atmosphere to 49 American Society of Heating and Ventilating Engineers Guide, 1934 which the goods would be in hygroscopic equilibrium after prolonged exposure. Committee D13 oh Textiles of the American Society for Testing Materials has adopted a relative humidity of 64 to 66 per cent and a temperature of 70 to 80 F as the standard atmosphere for textile testing. 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 represents 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. Extremes in either relative humidity or temperature require relatively expensive equipment for maintaining these conditions and controlling them automatically. Also, in departments where people are working, their health, comfort and productive efficiency must be considered. A compromise often 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 2 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. AIR CONDITIONING OF LIBRARIES1 . Temperature has little effect on the preservation of books. A tempera ture over 100 F, combined with low relative humidity, may cause the book materials to become brittle, while a temperature much below freezing may cause permanent deterioration of the glue in the binding. The relative humidity should be maintained between 40 and 70 per cent, although these limits need not hold for short periods of time. If the relative humidity gets much below 40 per cent, first the glue and then the paper will tend to become brittle which will not cause any permanent damage unless the book is used while in this condition, as a subsequent increase in humidity will bring the materials back to their normal condition. If the relative humidity gets above 80 per cent, the growth of mildew may be expected. One of the principal agents of destruction and deterioration of paper and books in libraries is sulphur dioxide gas in the air. If air containing sulphur dioxide is allowed to come in contact with cellulose, the principal constituent of paper, sulphuric acid is formed on the surface. This acid is not volatile at ordinary temperatures and therefore-accumulates t throughout the life of the paper. The destructive effect of the acid on the See U. S. Bureau of Standards Bulletin No. 12S entitled, A Survey of Storage Conditions in Libraries, by Kimberly and Hicks. 1 50 Chapter 3--Industrial Air Conditioning Table 2. Desirable Temperatures and Humidities for Industrial Processing Industry Process Temperature Degrees Fahrenheit Relative Humiditt Per Cent Automobile. Baking.. Dough fermentation room.......................... Loaf cooling.......................... ...................... Mixing room. ....................................... 65 70 75 80 70 75 to 80 75 to 80 80 80 to 90 70 to 80 28 to 40 40 50 65 . 76 to 80 60 to 70 55 to 70 55 to 70 55 80 to 95 60 60 to 75 Biological Products... Brewing. below 32 38 to 42 44 to 50 60 50 30 to 45 Ceramic... Drying of refractory shapes...................... Molding room. _ ........................................ Storage of clay........................................... 180 to 200 110 to 150 80 60 50 to 60 60 35 Chemical________ Confectionery. 60 to 80 75 70 62 to 65 70 to 80 65 75 to 85 60 to 68 35 to 50 50 45 50 to 55 30 to 50 50 50 50 to 65 Distillery.--...... General manufacture.................................. 60 60 45 30 to 45 Drug. Electrical Storage of powders and tablets_____ ___ Manufacture of cotton covered wire........ Manufacture of electrical windings.-------- 70 to 80 104 60 to 80 60 to 80 60 to 80 30 to 35 5 60 to 70 35 to 50 . 35 to 50 Food____ Storage of bananas (See discussion p. 53).. 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 51 American Society of Heating and Ventilating Engineers Guide, 1934 Table 2. Desirable Temperatures and Humidities for Industrial Processing (Continued) Industry P&OCBSS Temperature Degrees Fahrenheit Drying of furs.................................................... 110 Storage of furs................................................... 28 to 40 Hospital............... 75 to 80 Relative Humid ti t Per Cent 25 to 40 50 to 70 Incubators.......... Human babya.................................................... Incubator........................................................ Laboratory......... General analytical and physical.................. Storage of materials......................................... Leather ,........ Library................. Bookstorage (seediscussioninthischapter) Linoleum............ Lumber.................. Munitions Manufacturing................................................... Storage of matches........................................ . Paint...................... Drying'of lacquers.............................. ............. Brush and spray painting............................. 99 to 102 75 to 88 76 to 100 60 to 70 60 to 70 90 65 to 70 80 180 72 to 74 ' 60 70 60 to 80 60 to 90 60 to 80 55 to 75 59 to 65 59 to 65 60 to 70 35 to 50 38 to 50 40 30 50 55 25 to 50 25 to 50 25 to 50 Paper.................... Binding, cutting, drying, folding, gluing.. Storage of paper. .. ........................... ............. Photographic.... Development of film........................................ Drying................................................................. Printing...................... ......................................... Printing............... Binding................................................................. Folding................................................................. Press room (general)........................... :........... Press room (lithographic).............................. Storage of rollers............................................... Manufacturing. .......................................... Rubber..................... Dipping of surgical rubber articles........... Standard laboratory tests. .................. Soap............................ Drying.......................................................... Textile................. Cotton-- carding. .................................. combing........................... ................. ^ roving...................................................... spinning...................................... weaving................ ...................... 60 to 80 60 to 80 70 to 75 75 to 80 70 ' 72 70 77 75 60 to 75 60 to 80 90 75 to 80 80 to 84 110 75 to 80 75 to 80 75 to 80 60 to 80 68 to 75 25 to 50 35 to 45 60 50 70 65 45 65 60 to 78 20 to 60 35 to 45 25 to 30 42 to 48 70 50 60 to 65 50 to 60 60 to 70 70 to 80 ."Application of Air Conditioning to Premature Nurseries .in Hospitals,' by C. P. Yaglou, Philip Drinker, and K. D. Blackfan (A.S.H.V.E. Transactions, Vol. 36, 1930). i 52 Chapter 3--Industrial Air Conditioning Table 2. Desirable Temperatures and Humidities for Industrial Processing (Continued) Industry Textile..................... Process Rayon-- spinning-- ................................. twisting.......................... ............ Silk-- dressing........ ............................... spinning. ................................... throwing..................................... weaving....................................... Wool-- carding... .................................... spinning.................................. 1-- weaving....................................... Temperature Degrees Fahrenheit 70 70 75 to 80 75 to 80 75 to 80 75 to 80 75 to 80 75 to 80 75 to 80 Cigar and cigarette making....................... Stemming or stripping............................... 70 to 75 Oft 75 to 85 Relative Humiditt Per Cent 85 65 60 to 65 65 to 70 65 to 70 60 to 70 65 to 70 55 to 60 50 to 55 55 to 65 85 70 paper is independent of the relative humidity of the surrounding air. Low alkaline concentration spray water may be used in an air washer to neutralize the acid condition. Such an air washer must be especially constructed to resist corrosion. BANANA RIPENING Ripe bananas are very perishable and for this reason men who deal in them must depend mainly upon control of the ripening speed as a means of regulating their daily supply of the fruit. Knowledge and experience are required in regulating the ripening treatment and to control the ' ripening speed. An accurate appraisal must be based upon a careful examination of the fruit when received to determine its condition, and periodically, thereafter, to determine the rate of ripening. Fast ripening may be accomplished in from three to four days after the green fruit is placed in a ripening room by adjusting the temperatures of the room until the pulp temperature reaches about 70 F. In warming up cool fruit, quick heating is recommended, and it is good practice to use sufficient heat to raise the average fruit temperature at the rate of 2 to 3 deg per houn After the first 24 hours, the room should be held at 68 F until the fruit is colored and then reduced to 66 F and held at this tem perature. A high relative humidity of from 90 to 95 per cent should be maintained until the bananas show color when it may be reduced to about 80 per cent. High humidity is important during the warming period. No ventilation should be used until the fruit has colored, after which, ventilation at a rate not to exceed four changes per hour may be used to assist in reducing the humidity and to freshen the air in the room. If the fruit shows slow or uneven ripening characteristics, one or two applica tions of ethylene gas of approximately 1 cu ft per 1000 cu ft of room.space may be used. Medium speed ripening of bananas in from five to seven days may be accomplished by holding the fruit at 64 F. -The humidity and ventilation control should be the same as for fast ripening. A treatment with ethy lene gas will seldom be necessary. For slow ripening in from nine to ten 53 American Society of Heating and Ventilating Engineers Guide, 1934 days, the fruit should be held at from 60 to 62 F. Temperatures below 62 F are not advisable for very thin fruit. The humidity should be the same as for fast ripening, and ventilation (up to 3 or 4 air changes per hour) should be used provided the humidity can be maintained. Ethylene gas treatment will not be required. For holding ripened bananas, temperatures between 56 and 60 F are recommended. A reduction in humidity is beneficial in toughening the peel and reducing the mould, but too low a humidity will cause shrinkage. Although exact humidity control is not essential, the desirable range is between 75 and 80 per cent. GREENHOUSES Table 3 lists customary dry-bulb temperature ranges, for different types of plants and flowers raised in greenhouses. . Table 3. Customary Temperatures for Different Types of Greenhouses Type of House Carnation.............. Conservatory (general collection, winter garden, etc.). .... ..... .... ........ Cool.. . Cucumber...................................... Fern.................. ForcingGeneral purpose-- .................................. Lettuce.......................................... Orchid, warm.......................................... Temperature Range Deg Fahr 45 to 55 ' 60 to 65 45 to 50 65 to 70 60 to 65 60 to 65 55 to 60 40 to 45 65 to 70 Type of House Palm, warm_______ Palm, cool. ______ Tomato............... .... Tropical. ________ Temperature Range Deo Fahs 50 to 55 60 to 65 50 to 55 55 to 60 55 to 60 45 to 50 65 to 70 65 to 70 40 to 45 APPARATUS FOR INDUSTRIAL CONDITIONING Apparatus for industrial air conditioning may be divided into two distinct groups, namely, (1) humidifiers for increasing the moisture con tent of the air and for producing cooling by evaporation and (2) dehu midifiers for removing moisture from the air and for producing cooling by contact with water or surfaces at a lower temperature than the air. Strictly speaking, humidity control alone, whether it involves humidi-1 fication or dehumidification, is not air conditioning. To be entitled to this classification according to the definition in Chapter 42, the process should include the simultaneous control of temperature, humidity and air motion. Industrial 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. 3. Combined direct and indirect. Spray Generation Spray generation is obtained by (1) atomization, (2) impact, (3) hydraulic separation, and (4) mechanical separation. 54 Chapter 3--Industrial Air Conditioning Atomization involves the use of a compressed air jet to reduce the water particles to a fine spray. With the impact method, a jet of water under pressure impinges directly on the end of a small round wire. Where hydraulic separation is employed, a jet of water enters a cylindrical chamber and escapes through an axial port with a rapid rotation which causes it immediately to separate in a fine cone-shaped spray. In the mechanical separation process, water is thrown by centrifugal force from the surface of a rapidly revolving disc and separates into particles suf ficiently small to be utilized in certain types of mechanical humidifiers. Spray Distribution Spray distribution is obtained by (1) air jet, (2) induction, and (3) fan propulsion. The air jet which generates the spray in atomizers also carries the spray through a space sufficient for its distribution and evaporation, and this method of distribution is termed air jet. Where distribution is obtained by induction, the aspirating effect of an impact or centrifugal spray jet is utilized to induce a current of air to flow through a duct or casing and this air current distributes the spray. Fan propulsion obviously consists of the utilization of fans to entrain and distribute the spray. Industrial type direct humidifiers are commonly classified as (1) atomizing, (2) high-duty, (3) spray and (4) self-contained or centrifugal. Atomizing Humidifiers There are several types of atomizing humidifiers, all of which rely upon compressed air as the atomizing and distributing agency, similar to the familiar method used in ordinary nasal atomizers. Compressed air (ordinarily about 30 lb per square inch) is supplied from a centrallylocated air compressor through pipe lines to the atomizing units. The air lines are usually horizontal and parallel to water lines which supply water by gravity from a float tank. The water in the tank is maintained at a constant level slightly lower than the outlets of the atomizers 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 pumping unit. The spray-generating "nozzle which is of the impact type is located in a cylindrical casing. A drainage pan provides for the collec tion and return of unevaporated water which flows through a return pipe to a filter tank, from which it is recirculated. A powerful air curr.ent 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 55 American Society of Heating and Ventilating Engineers Guide, 1934 and thoroughly diffused. This effective distribution of fine spray over the maximum possible area insures complete and extremely rapid vapori zation even at the highest humidities. . Ut; 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 i Chapter 4 - spray nozzle induces a moderate air current through the casing which distributes the entrained spray. The general method of circulating and NATURAL VENTILATION 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, f. Wind Forces, Stack Effect, Openings, Windows, Doors, Skylights, Roof Ventilators, Stacks, Principles of Control, General Rules, Measurements, Dairy Barn Ventilation, Garage Ventilation is often considered better adapted for producing high humidities. Self-Contained Humidifiers . The self-contained or centrifugal humidifier has the ability to generate VENTILATION by natural forces, supplemented in certain cases with mechanicai forces, finds extensive application in industrial plants, public buildings, schools, dwellings, garages, and in farm buildings. and distribute spray without the use of air compressors, pumps, or other auxiliaries and is therefore convenient for small installations where few NATURAL VENTILATION FORCES heads are required. These humidifiers are generally of two types, one of which operates under low water pressure and evaporates about 20 per cent of the water fed to it, while the other maintains a constant level in the bottom of the humidifier and may be arranged to evaporate all the water supplied to it. The natural forces available for the displacement of air in buildings are the wind and the difference in temperature of the air inside and outside the building. The arrangement and control of ventilating openings should be such that the two forces act cooperatively and not in opposition. Humidifiers and air washers are also described in Chapter 11. Wind Forces Where large quantities of power are generated in a limited space and where a comparatively high relative humidity is required, it is often feasible and economical to use a combination of direct and indirect humidification. The indirect humidification provides the desired quantity of ventilation and cooling, and the additional direct humidification pro vides for increase in humidity without interfering with the ventilation or the cooling effected by the indirect system. In general, it may be stated that direct humidification is most satis factory where high humidities are desired but where little cooling, ven tilation or air motion is required. Therefore, the indirect system is most applicable where either low or high relative humidities are desired with maximum cooling and ventilation effect. For conditions that require an unusually large amount of heat to be absorbed by ventilation, together with the maintenance of high. humidities, it is often preferable to make use of the combination system of indirect and direct humidification. If the indirect system alone were used it would mean an unusually large volume of air to be handled, which might interfere, due to air motion, with production, even though it would result in greater cooling effect. If direct humidification alone were used, no ventilation would be obtained, with consequently higher room temperatures. Dehumidifiers, which are similar in design and appearance to indirect humidifiers and air washers, are described in Chapter 11. The main differences are found in the internal construction of the dehumidifier, in the use of refrigeration or of heat as required for controlling the water temperature, and in differences in the general methods of control. ; In considering the use of natural wind forces for the operation of a ventilating system, account must be taken of (1) average and minimum wind velocities, (2) wind direction, (3) seasonal, daily and hourly varia tions in wind velocity and direction, and (4) local wind interference by buildings and trees. Table 1, Chapter 8, gives values for the average summer wind velocities and the prevailing wind directions in various localities throughout the United States, while Table 2, Chapter 7, lists similar values for the winter. ' In almost all localities the summer wind velocities are lower than those in the winter, and in about two-thirds of the localities the prevailing direc tion is different during the summer and winter. While average wind velocities are seldom below 5 mph, there are many hours in each month during which the wind velocity is from 3 to 5 mph, even in localities where the seasonal average is considerably above 5 mph. There are relatively few places where the hourly wind velocity falls much below 3 mph for more than 10 daylight hours per month. Usually a natural ventilating system should be designed to operate satisfactorily with a wind velocity of 3 to 6 mph, depending on locality. The following formula may be used for calculating the quantity of air forced through ventilation openings by the wind, or for determining the proper size of such openings: Q = EAV (1) where Q = air flow in cubic feet per minute. 57 American Society of Heating and Ventilating Engineers Guide, 1934 A = free area of inlet (or outlet) openings in square feet. V = wind velocity in feet per minute. = miles per hour X 88. E = effectiveness of openings. (E should be taken at from 50 to 60 per cent if the inlet openings face the wind and from 25 to 35 per cent if the inlet openings receive the wind at an angle). 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 wjnd (see Fig. 1)3. In a monitor on the side opposite from the wind. 4. In roof ventilators or stacks exposed to the full force of the wind1. Forces due to Stack Effect2 The stack effect produced within a building is due to the difference in weight of the warm column of air within the building and the cooler air outside. The flow due to stack effect is proportional to the square root of the draft head, or approximately: c where Q = 9.4 A V~H (t, - ct) (2) Q = air flow in cubic feet per minute. A free area of inlets or outlets (assumed equal) in square feet. H = height from inlets to outlets, in feet. it = average temperature of indoor air in height H, in degrees Fahrenheit. h -- temperature of outdoor air, in 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. . In some cases the necessary air flow will be known from the require ments of the building occupancy, and the area necessary for certain assumed temperature differences may be calculated. Or the areas may be fixed by the building construction, and the maximum air flow for various differences between indoor and outdoor temperatures may be* *See Airation of Industrial Buildings, by W. C. Randall (A.S.H.V.E. Transactions. Vol. 34, 1928). See Neutral Zone in Ventilation, by J. E. Emswiler (A.S.H.V.E. Transactions, Vol. 32,1926), and Predetermining Airation of Industrial Buildings, by W. C. Randall and E. W. Conover (A.S.H. V.E. Trans actions. Vol. 37. 1931). 58 Chapter 4--Natural Ventilation calculated. In any case, the conditions which give the minimum air flow are those which control the design, as the system must have ample capacity even under the most unfavorable conditions which are those of mild or warm weather. ' OPENINGS FOR NATURAL VENTILATION The engineering problems of a natural ventilation system consist in the 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) ' design, location, and control of ventilating openings to best, utilize the natural ventilation forces, in accordance with the requirements of build ing occupancy. The types of openings may be classified as: . 1. Windows, doors, monitor openings, and skylights. 2. Roof ventilators. 3. Stacks connecting to registers. 4. Specially designed inlet or outlet openings. .-. . , ..... . Windows, Doors and Skylights -- Windows have the advantage of transmitting light, as well as proyidipg ventilating area when open. Their movable parts are arranged to open in .59 American Society of Heating and Ventilating Engineers Guide, 1934' various ways; they may open by sliding as in the ordinary double-hung windows, by tilting on horizontal pivots at or near the center, or by swinging on pivots at the top or bottom. Whatever the form and type of window used, the amount of clear area that can be made available is the factor of greatest importance in ventilation. All types of sash (double-hung, top, center or bottom horizontal pivoted, or vertical pivoted) have about the same air flow capacity for the same clear area. Air leakage through closed windows is important during high winds (Chapter 6). The proper distribution of air in occupied spaces is an element almost as important as that of sufficient air quantity. Advantageous pivoting of sash is very useful for securing good air distribution. Deflectors are some times used for the same purpose, and these devices should be considered a part of the ventilation system. Door openings are seldom included in the ventilation calculations, though they may be of great value for extreme summer conditions, and should be considered in this connection. Skylight and monitor openings are of importance as these and the roof ventilators are outlets, while the lower windows are usually inlets on the windward side and outlets on the leeward side. In general the areas of inlets and of outlets should be about equal. It is important to make a check on this ratio in any installation,, as any great excess of area of one set of openings over another means waste opening area. The operating devices used for sash, monitors, skylights and roof ventilators shoul4 be well selected as poor operating devices may defeat the entire design. Roof Ventilators . The function of a roof ventilator is to provide a storm and weather proof air outlet, which is sensitive to wind action for producing additional flow capacity, and at the same time is subject to manual or automatic control by suitable dampers. The capacity of a ventilator at a constant wind velocity and temperature difference, depends upon four things: (1) its location on the roof, (2) the resistance it offers to air flow, (3) the area and location of openings provided for air inflow at a lower level, and (4) the ability of the ventilator head to utilize the kinetic energy of the wind for inducing flow by centrifugal or ejector action. Frequently one or more of these capacity factors is overlooked in a ventilator installation. For maximum flow induction, a ventilator should be located on that part of the roof which receives the full wind without interference. (See Fig. 1). This does not mean that no ventilators are to be installed within the suction region created by the wind jumping over the building, or in a light court, or on a low building between two high buildings. Ventilators are highly effective in such low-pressure areas, but their ejector action, caused by wind velocity, is of little importance in these locations, and hence their size should be increased proportionally. Ventilator resistance depends on (1) type of inlet, (2) area of openings and passages and (3) number of turns or changes pf direction,of the air. flow. The inlet grille, if any, should have ample free area, and the venti lator should always be provided with a taper-cone inlet in order to produce the effect of a bell-mouth nozzle (flow coefficient 0.97) rather than that of 60 .A._. Chapter 4--Natural Ventilation Types of Stationary Ventilators' Types of Oscillating Ventilators 61 American Society of Heating and Ventilating Engineers Guide, 1934 a square-entrance orifice (flow coefficient 0.60). In other words, the grille should be oversize as compared with the ventilator, and they should be connected by a tapering collar. If the ventilator head construction produces changes in the direction of air flow, the area of the flow passages should be increased accordingly. Air inlet openings at lower levels in the building are of course necessary for the economical use of ventilator capacity. The inlet openings should be at least equal to, and preferably twice as great as the combined throat areas of all roof ventilators. The air discharged by a roof ventilator depends on wind velocity and temperature difference, but due to the four capacity factors already mentioned, no simple formula can be devised for expressing ventilator capacity. Several types of roof ventilators are shown in Figs. 2 to 11. These may be classified as stationary, Figs. 2 to 6, pivoted or oscillating, Figs. 7 to 9, or rotating. Figs. 10 and 11. When selecting unit ventilators, some attention should be paid to ruggedness of construction, storm-proofing features, dampers and damper operating mechanisms, possibilities of noise from dampers or other moving parts, and possible maintenance costs. It should be kept in mind that a suitable combination of roof venti lators with mechanical ventilation frequently offers the best solution of a ventilating problem. The natural ventilation units may be used to sup plement power driven supply fans, and under favorable weatherconditions it may be possible to shut down the power driven units. Where low operating costs are very important, such a combination has great advantages. Roof ventilators with built-in electric fans are attracting increased attention because they combine the advantages of low instal lation and operating cost with those of continuous service. Controls In connection with any combination between natural and fan venti lation, the controls are of importance. Both the fans and the ventilator dampers may be controlled by some combination of three methods: (1) hand operation, (2) thermostat operation, and (3) control by wind velocity. The thermostat station may be located anywhere in the building, or it may be located within the Ventilator itself. The purpose of wind velocity control is to obtain a definite volume of exhaust regardless of the natural forces, the fan motor being energized when the natural exhaust capacity falls below a certain minimum, and again shut off when the wind velocity rises to the point where this minirfium volume can be supplied by natural forces. ;. Stacks ' Stacks are really chimneys and utilize both the inductive effect of the wind and the force of temperature difference (the so-called.gravity action). While their openings projecting above the roof are not provided with any special construction for developing suction by the action of the wind, the plain vertical opening is also effective in this respect. Like the roof ventilator, the stack outlet should be. located so that tl\e wind may act upon it from any direction. . .. 62 Chapter 4--Natural Ventilation Stacks are applicable particularly in the case of schools, apartments, residences and small office buildings. Partitions interfere with general air circulation, and some type of outlet from each room is necessary- If the building is not too tall, and the requirements of occupancy are moder ate a system of stacks with registers in each room may be more eco-, nomical then a system of mechanical ventilation employing fans. In making the comparison, however, the building space occupied by the stacks should be considered. With little or no wind, chimney effect or temperature difference will oroduce outflow through the stacks and an equal inflow through windows in all sides of the building. With wind, the inductive force at the top of ventilating shafts is more powerful than that on the leeward side of the Fig. 10. Rotating Ventilator building, so that air is drawn in through leeward openings by a combina tion of the forces of wind and temperature difference. On the windward side, the direct forcing pressure of the wind is of course added to the temperature difference effect. Thus forces are available for. causing in flow at practically every window of such a building. Adequacy of stack size must, of course, be provided. Principles of air flow control The air flow through a .Vehtils tio'n opening'depends on the two factors already discussed, namely, (1) the natural forces available, (2) the open ings available, and the resistance !ta flow offered by these openings. The design problem includes, of course, "a determination of the desired air quantity and distribution in order that the openings may be properly placed. 1 The purpose of ventilation is to carry off either excess heat or air impurities, and the desired air quantities depend upon the amount of heat or of impurities present. The amount of heat can be determined, in the case of forge shops for example, from the amount of fuel burned, which in turn is based upon the production capacity- for which the building is being designed. In the case of foundries, the heat given off by the metal in cooling from the molten state can be used. In some instances, not all 63 American Society of Heating and Ventilating Engineers Guide, 1934 of the heat may be dissipated to the air, but a fair estimate of the amount to be removed by the air can usually be made. The next step is to select the temperature difference to be maintained. Knowing the amount of heat to be removed and having selected a desirable temperature difference, the amount of air to be passed through the building per minute to maintain this temperature difference can be determined by means of the following equation: where c = 0.24 = specific heat of air. V = specific volume of the air, cubic feet per pound, about 13.5. (See Chapter 41). H = heat to be carried off, in Btu per minute. Q = air flow in cubic feet per minute. D = inlet-outlet temperature difference in degrees Fahrenheit. Fig. 11. Rotating Roof Ventilator For disposing of air impurities, the required air flow must be such that the outside air will' dilute the-;impurities! to. a :degree that they are no longer objectionable. - For human.occupancy,: suchas-in auditoriums and classrooms, 10 cfm per person is usually taken as the minimum of outside air necessary for ventilation (see; Chapter 2). .'For garage ventilation, sufficient air must be admitted to dililte the carbon monoxide content of the indoor air to 1 in 10,000 (see Garage Ventilation in this Chapter). Air quantity and quality are not the only requirements. For human occupancy, air distribution is important. In ventilation the air distribu tion is almost entirely a matter of the number, the design, and the location of inlets and outlets. In locating openings, special precautions should be taken against the formation of dead air spaces or pockets within the zone of occupancy. - 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 64 r ' Chapter 4--Natural Ventilation estimated quantities. The same openings have been assumed in both cases, and since the resistance to flow through the openings varies ap proximately with the square of the velocity3, this resistance becomes a limiting factor as the flow through the openings is increased. Recent investigations1 2 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 predicated with certainty, and great refinement in calculations is therefore not justified. When designing for winter conditions, an added variable is. the heat lost by direct flow through walls and windows and by infiltration. Example 1. Assume a drop forge shop, 200 ft long, 100 ft wide, and 30 ft high. The cubical content is 600,000 cu ft, and the height of the air outlet over that of the inlet is 30 ft. Oil fuel of 18,000 Btu per lb is used in this shop at the rate of 15 gal per hour (7.75 lb per gal). Temperature differences are 10 deg Fahr 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 minute is: H = 60 X 7.75 X 18,000 = 34,875 Btu per minute. By Equation 3, the air flow required to remove this heat with a temperature difference of 10 deg is: Q VR cD 13.5 X 34,875 196,172 cfm. 0.24 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 196,172 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 VH (ti - h) 196,172 9.4 V 30 X 10 ,,, , ^ ; If this area of openings were provided, a wind velocity of 5 mph, acting alone, would produce a flow according to Equation 1, of: . Q = EAV = 0.50 X 1,205 X 5 X 88 = 265,100 cfm. - If the inlet openings do not face the wind, but are at an angle with it, about half this amount may be considered to flow. A factor of judgment must now be exercised in making the selection of the area of openings to be specified. Apparently 1205 sq ft are a very *This is true for turbulent flow only. It would be more correct to state that the resistance varies approxi mately with V2 for high to moderate velocities, with V1 * for moderate to low velocities, and with the first power of the velocity for very low velocities through small openings. 65 American Society of Heating and Ventilating Engineers Guide, 1934 generous allowance because either a direct wind of 5 mph or an average temperature difference of 10 deg acting alone will more than suffice to carry away the heat, and when the two forces are acting together, the system may have an excess capacity of 25 per cent to 50 per cent, especially if the outlets are made up partially of roof ventilators which employ the force of the wind for producing a suction effect. On the other hand, the wind may at times come from an unfavorable direction, or its velocity may fall below 5 mph or the building construction may not permit a full 2400 sq ft of inlet window area and an equal amount of monitor or roof ventilator outlet area. In case the two sets of openings are not equal, their effectiveness is reduced. From this example it must be apparent that while formulas may furnish a reliable guide, the final solution of a problem of natural venti lation requires a common sense analysis of local conditions to supplement and to modify the dictates of the formulas. ' GENERAL RULES A few of the important requirements in addition to those already outlined are: 1. Inlet openings should be well distributed, and should be located on the windward side near the bottom, while outlet openings are located on the leeward side near the top.' Outside air will then be supplied to the zone of occupancy. ' ' 2. Direct short circuits between openings on two sides at a high level may clear the an- 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 a,n 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 66 Chapter 4--Natural Ventilation , OToiroing of ventilation openings can be readily arranged to take full advantage of fhe force of the wind. On the other hand, where the direction of the wind is quite * riable it may be stated as a general principle that windows should be arranged in bewails 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 xnosed to the pressure force of the wind, and others opposed to a suction force, and Elective movement through the building will be assured. 11 The intensity of suction or the vacuum produced by the jump of the wind is test 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 thespossibility of sidewall or monitor windows being closed on account of weather conditions. Such possibilities favor roof ventilators and specially designed storm-proof inlets. MEASUREMENT OF NATURAL VENTILATION The determination of the performance of any ventilating system involves measurements which are not easy to make. The difficulties are increased in the case of natural ventilation, since the motive forces and the air velocities are very small. The measurements necessary for giving the capacity of a system are (1) velocity of the wind, (2) velocity of the air through inlet and outlet openings, (3) outdoor air temperature, and (4) average indoor air temperature. Measuring Wind Velocity. The cup-type of anemometer as used for Weather Bureau observations is sufficiently accurate for this measure ment. Some more accurate instruments as well as direct-reading types have been developed for airport service, but for ventilation work it is the average wind velocity over a long period which determines the capacity of the system. Hence-the use of the Weather Bureau instrument, with an observation period of one hour or. more, is satisfactory. If observations of wind direction are required, these should be taken by observing a sensitive weather vane at frequent intervals (about every 5 minutes) during the same period. Velocity of Air Through Openings. The vane type anemometer is the most practical instrument for this measurement. Use a small (4 in.) low-speed anemometer, and correct all readings according to a recent calibration. Mount the anemometer in a strap iron clamp with a long handle for convenience. Divide each opening into 5 in. squares (by string or wire) and hold the anemometer in the center of each square for a definite period of from 15 to 30 seconds. Record the result of the traverse as soon as completed and start another one im mediately. A series of traverses over a period of one hour, or the full period covered by the wind velocity observations with a fairly steady wind, may be considered a satisfactory test for that wind velocity: It is preferable to Have an anemometer observer at each opening. If the opening is covered by a grille or register, usejhe proper correction factors (see Chapter 40). - Outdoor Temperature. It is easy to make an error of T to 5 deg in 67 American Society of Heating and Ventilating Engineers Guide, 1934 observing the outdoor air temperature. An accurate thermometer, calibrated in 1 deg divisions should be used. The thermometer should be mounted in the shade at about mid-height of the building and not too near the building wall or adjacent to an air outlet. The heat from a wall or roof which has been exposed to the sun is easily transmitted to a thermometer, with resulting high readings. Average Indoor Temperature. It is important to note that the capacity of an opening (such as roof ventilator) does not depend on the difference in the temperatures measured adjacent to the opening. It depends rather on the difference between the average temperature of the column of air inside the building and that outside. Indoor temperatures should therefore be observed at various heights to secure a good average. DAIRY BARN VENTILATION4 A successful barn ventilating system is one which continuously supplies the proper amount of air required by the stock, with proper distribution and without drafts, and one which removes the excessive heat, moisture, and odors, and maintains the air at a proper temperature, relative humidity, and degree of cleanliness. . 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 barns 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 barns is difficult. For 45 F an average relative humidity of 80 percent 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 barn 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, arid if a barn for the cow has 600 cu ft of air space with 130 sq ft of building exposure, one cow will require 2600 to 3550 cfh of ventilation, depending'on the temperature zone in which the barn is located. The permissible heat losses through the structure, based on one cow and depending on the temperature zone, vary between 0.043 and 0.066 Btu per hour per cu ft of barn space, and 0.197 to 0.305 Btu per hour, per sq ft of barn exposure. ' For additional information oh this subject refer to Technical Bulletin, U. S.`Department of Agriculture (1930). by M. A. R. Kelley. Dairy. Barn Ventilation, by F. L. Fairbanks (A.S.H.V.E. Transactions. Vol. 34. 1923). Cow Barn Ventilation, by Alfred J. Offner (A.S.H.V.E: Journal Section. Heating, Piping and Air Conditioning, January, 1933). . 68 Chapter 4--Natural Ventilation GARAGE VENTILATION On account of the hazards resulting from carbon monoxide and other hvsiologically harmful or combustible gases or vapors in garages, the importance of proper ventilation of these buildings cannot be over emphasized. During the warm months of the year, garages are usually ventilated adequately because the doors and windows are kept open. As cold weather sets in, more and more of the ventilation openings are closed and consequently on extremely cold days the carbon monoxide concentra tion runs high. Many garages can be satisfactorily ventilated by natural means6 par ticularly during the mild weather when doors and windows can be kept open. However, the A.S.H.V.E. Code for Heating and Ventilating Garages, adopted in 1929, states that natural ventilation may be em ployed 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 possible in at least two outside walls, and that the total area of such openings shall be equivalent to at least 5 per cent of the floor area. The code further states that where it is impractical to operate such a system of natural ventilation, a mechanical system shall be used which shall provide for either the supply of 1 cu ft of air per minute from out of doors for each square foot of floor area or for removing the same amount and discharging it to the outside as a means of flushing the garage. Research Research on garage ventilation undertaken by the A.S.H.V.E. Com mittee on Research at Washington University, St. Louis, Mo., and at the 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 papers6 on the subject. Some of the conclusions from work at the Laboratory are listed below: 1. Upward ventilation results in a lower concentration of carbon monoxide at the breathing line and a lower temperature above the breathing line than does downward ventilation, for the same rate of carbon monoxide production, air change and the same temperature at the 30-in. level. 2. A lower rate of air change and a smaller heating load are required with upward than with downward ventilation. . 3. In the average case upward ventilation results in a lower concentration of carbon `Code for Heating and VentUating Garages (A.S.H.V.E. Transactions, Vol. 35, 1929). Airation Study of Garages, by W. C. Randall and L. W. Leonhard (A.S.H.V.E. Transactions, Vol. 36. 1930). Carbon Monoxide Concentration in Garages, by A. S. Langsdorf and R. R. Tucker (A.S.H.V.E. Trans actions, Vol. 36, 1930). . , 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). . --- 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). 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. Journal Section, Healing, Piping and Air Conditioning, July. 1933). Carbon Monoxide Surveys of Two Garages, by A. H. Sluss. E. K. Campbell and Louis M. Farber (A.S.H.V.E. Journal Section, Heating, Piping and Air Conditioning, December; 1933). 69 . American Society of Heating and. Ventilating Engineers Guide, 1934 monoxide in the occupied portion of a garage than is had with complete mixing of the exhaust gases and the air supplied. However, the variations in concentration from point to point, together with the possible failure of the advantages of upward ventilation to accrue, suggest the basing of garage ventilation on complete mixing and an air change sufficient to dilute the exhaust gases to the allowable concentration of carbon monoxide. 4. The rate of carbon monoxide production by an idling car is shown to vary from 25 to 50 cfh, with an average rate of.,35 cfh. 0 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. Chapter 5 HEAT TRANSMISSION Heat Transfer Through Walls, Areas Where Transmission Losses Occur, Calculations for Transmission Losses, Coefficients of Trans mission and Tables, Temperatures and Coefficients, Air Spaces, Surface Conductances, Conductivities of Materials THIS chapter concerns the transmission losses of a building which, in conjunction with the infiltration losses, must always be considered in arriving at the size of the heating (or cooling) plant required for the main tenance of certain specified inside temperature conditions. HEAT TRANSFER Whenever a difference in temperature exists between the two sides of any structural material, such as a wall or roof of a building, a transfer of heat takes place through that material. When the inside temperature is the higher, heat reaches or enters the inside surface of the wall by radia tion and convection, because the air and objects within the building are always warmer than the inside surface of the wall when the inside air temperature t is greater than the outside air temperature tQ. This heat must then pass through the material of the wall from the inside to the outside surface by conduction, and is finally given off from the outside surface by radiation and convection, provided, of course, that equilibrium has been established and all four temperatures are constant. If the out side temperature is the higher, the reverse process takes place. CALCULATIONS FOR TRANSMISSION LOSSES The calculations for heat transmission losses are made by multiplying the area A in square feet of wall, glass, roof, floor, or material through which the loss takes place, by the proper coefficient U for such construc tion or material and by the temperature difference between.the inside air temperature t at the proper level (in many cases not the breathing-line) and the outside air temperature t0. Therefore, where flt = A U {t - to) (1) Hi = Btu per hour transmitted through the material pi..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). I -- 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 many cases. 71 American Society of Heating and Ventilating Engineers Guide, 1934 AREAS WHERE TRANSMISSION LOSSES OCCUR Heat is lost from a building by transmission through all of those sur faces which separate heated spaces from the outside air or from unheated colder spaces within the building. In general, five kinds of surfaces are involved: (1) outside walls; (2) outside glass; (3) inside walls or parti tions next to unheated spaces; (4) ceilings of upper floors, either below a cold attic space or as the underside of a roof slab; and (5) floors of heated rooms above an unheated space. - The net outside wall surface is usually determined by reference to the scale plans and elevations of the building concerned. In some cases, of course, the actual building may have to be measured. The total area of all outside openings which are occupied by windows and doors is accurately measured and listed as glass. The glass area is then deducted from the total outside wall area for each room and the difference is the net wall area. The outside wall areas for any floor should be based on the vertical floor-to-floor heights and the horizontal distance from center to center of partitions separating different rooms. If there are no partitions, measure from inside face of one wall to inside face of next wall. The areas of walls, ceilings and floors next to cold or unheated spaces are found, of course, by taking the inside dimensions of such areas, measured on the heated side. COEFFICIENTS OF TRANSMISSION The coefficients of transmission may be determined by means of the guarded hot box or the Nicholls Heat Meter described in Chapter 40, or they may be calculated from fundamental constants. On account of the unlimited number of combinations of building materials, it would be impractical to attempt to determine by test the heat transmission co efficients of every type of construction in use; consequently, in most cases it is advisable to calculate these coefficients. Symbols The following symbols are used in the heat transmission formulae in this chapter: .' U = Thermal transmittance or over-all coefficient of heat transmission and is 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 F between the air on the inside and outside of the wall, floor, roof or ceiling. k = Thermal conductivity and is 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 tem perature of 1 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 and is 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 X 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 and is the amount of heat expressed in Btu trans mitted 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 72 . Chapter 5--Heat Transmission r 1 Hpv between the surface and the surrounding air. To differentiate between inside ` a "mride wall (or floor, roof or ceiling) surfaces, fi is used to designate the inside film or surface conductance and /,, the outside film or surface conductance. ,, = Thermal conductance of an air space and is the amount of heat expressed in. ,, transmitted by radiation, conduction and convection in one hour through an area BflV ,, ft 0f an air space for a temperature difference of 1 F. The conductance of airspace depends on the mean absolute temperature, the width, the position and the character of the materials enclosing it. .. ^ Resistance or resistivity which is the reciprocal of transmission, conductance, or conductivity, i.e.: ~ = over-all or air-to-air resistance. -i- = internal resistivity. k -i- -- internal resistance. . , ~ film or surface resistance. -J-- = air-space resistance. n. .' Fundamental Formulae The formula of the over-all coefficient for a simple wall x inches thick is: 1 V= i T+ /< + T (2) and for a compound wall of several materials having thicknesses in inches of x,, x,, x,, etc., the coefficient is: V= fi + /o + k\ + k, + k, + etc' (3) In the case of air-space construction, an air-space coefficient for each air space must be inserted in either Equation 2 or 3. Thus for a simple wall with one air space, . 1 V= 1 1 J1 _+JrL T+ T+ a + k (4) and for a simple wall of several air spaces having conductances of a,, a,, a., etc., the coefficient is: U= -L+_L+ * +I+_L+_L+e,c. ' fi fo k al a2 . 3 With certain special forms of materials which have irregular air spaces (such as hollow tile) or are otherwise non-homogeneous, it is necessary to use the conductance (C) for the unit construction, in which case is replaced by -^r. . 73 S American Society of Heating and Ventilating Engineers Guide, 1934 As in the case of the simple wall, /i and fQ are always the inside and outside surface coefficients for the two materials in contact with air. If the air is still (no wind), then for the same material f\ and/0 are the same, and/j = f0\ but, if the outside air is in motion, then /0 is always greater than fi and will increase as the wind velocity increases. Values for fi in still and moving air have been determined for various building materials at the University of Minnesota under a cooperative research agreement with the Society1. The range of values for ordinary building materials is comparatively small and for practical purposes may be assumed constant for either still air or any given wind velocity, particularly in view of the fact that the surface resistances usually comprise only a small part of the total resistance of the construction, except in the. case of thin, highly conductive walls. Table 1. Conductances of Air Spaces a at Various Mean Temperatures Mean Temp Deo Fahb 0.128 CoNDUCTA NCE8 OP Alft 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 1.670 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 1.519 150 3.425 2.090 1.852 1.728 1.592 1.569 1.559 Thermal Resistance of Air Spaces, by F. B. Rowley and A. B. Algren (A.S.H.V.E. Transactions. Vol. 35. 1929). . The conductances of air spaces at various mean temperatures and widths, for ordinary building materials, are given in Table 1. These results were likewise obtained at the University of Minnesota under a co operative research agreement with the Society. Values for k and C, the conductivity and conductance of building ma terials and insulations, are given in Tables 2, 3, 4, 5 and 6, and are taken from the published values of various investigators. It should be noted that values of k and C.as well as U are dependent on the temperature range, and it is therefore desirable that the investigator determine heattransmission values under conditions approximating those existing under actual conditions. Recommended values for calculating the coefficients of transmission of various types of construction are given in Table 7. Surface Conductances as Affected by Air Velocity. Temperature and Character of Surface, by F. B. Rowley. A. B. Algren and J. L. Blackshaw (A.S.H.V.E. Transactions, Vol. 38,1930). See also references at end of chapter. iitaraaiat: I0MA0N*0*Ui **'**' pooo Chapter 5--Heat Transmission While most building materials have surfaces which show similar characteristics as far as the transmission of heat is concerned, it is a well- known fact that certain surfaces such as aluminum bronze, gold bronze, aluminum foil, or in fact any metallic, highly polished surface presents a greater resistance to heat transmission than the surface of the average building material. . The greater heat resistance of such metallic surfaces is due primarily to their higher reflectivity and consequent lower emissivity of radiant heat. The use of multiple layers of metallic surfaces, combined with air spaces of low resistance, provides a definite insulating effect. Factors for single air spaces of various thicknesses bounded by aluminum foil are given in o^rnmnanvin? tabulation: Conductances of. Air Spaces Bounded by,Aluminum Foil Under Various Conditions and. for;^Various Widths Character Width^op'Aib Space--Inches or Surfaces 0.25 0.28 0.33 0.35 0.375 0.4 0.5 0.62 0.675 0.7- 0.75 1.00 1.50 0.696 0.64* 0.65d 0.59* 0.620 0.576 0.54* 0.S4d 0.43* 0.554 0.480 0.56& 0.41* 0.4& 0.42* Plain Foil To Plain Foil 0.82* 0.74* 0.88 0.81* 0 94* 0.83 0.61 P 0.659 0.70* 0.55* 0.60m 0.63** 0.88* 1.00 0.75// ,0.61* 0.502/ 0.4800 0.5290 0.52AA 0.37* 0.440 0.476 0.4766 0.4900 0.48** 0.48<W 0.49// 0.46// 0.64** 0.72U 1.40 1.11 0.74 Crumbled Foil Surfaces 0.80 0.88 0.41 Authority 3H E. R. Queer,* Pennsylvania State College Ralph B. Mason f J. L. Gregg** Prof. G. B1 Wilkes, Mass. Inst, of Tech. J. L-Gregg^ Prof. G. B. Wilkes, Mass. Inst, of Teeh. a--Mean Temp. 95 F; 9 in. horizontal air space. .....................95 F; 9 in. vertical air space. 65 F; 65 F; 9 in. horizontal air space. 65 F; 11% in. vertical air space. /- 97.2 'P; high side. 123.5 F low side, 70.9 F. 9-- 129.7 F; ``.174.2 F " " . 70.7 F. A-- 152 F; ", 232.1 F " " , 72.0 F. t-- 94.7 F ", 122.3 F " ` ,67.1F. t 129.7 F 190.4 F ",191.8 F " ' ,67.6F. ", 258.8 F `, 68.4 F. 92.5 F ", 121.7 F `, 63.3 F. 127.1 F ", 190.8 F ' ,63.5 F. 162.9 F ", 262.3 F \63.6F. 106.0 F ". 136.4 F ` , 75.5 F. 145.0 F 214.2 F " , 75.7 F. 182.6 F 290.0 F ", 75.3 F. 105.6 F 135.4 F , 75.8 F. 1-- u-- GO-- 66-- ec-- dd-- ee-- //- 141.5 F ", 207.0 F " .76.0F. 177.0 F ", 278.3 F " , 75.8 F. 99.0 F ", 129.7 F " , 68.2 F. 137.6 F ", 205.8 F " ,69.4F. 174.7 F \ 279.6 F " , 69.8 F. 105 F; wooden separators occupying 6% ofspace 107 F 106 F 100 F '99 F 92 F 93 F 92 F 98 F 97 F fiber insulation separators occupiyng 8% of space. . 115 F; From data in paper entitled. Importance of Radiation in Heat Transfer Through Air Spaces (Heating, Piping and Air Conditioning, Hovwnber, 1931). ^ ..... tComputed from data in article entitled. Thermal Insulation with Aluminum Foil (Industrial and Engineering Chemistry, March, 1933). Computed from data in paper entitled, Properties of Metal Foil as an Insulation (Refrigerating Engineering, May,*1932). Coefficients of transmission of various types .of, wall, ceiling, floor and roof construction with aluminum insulation can be_ readily calculated. The present installation practice indicates that air spaces of in. to 1 Y<i in. are preferred but manufacturers' recommendations should be closely followed in the application of aluminum foil insulation. 75 p American Society of Heating and Ventilating Engineers Guide, 1934 Table 2. Conductivities (k) and Conductances (C) of Building Materials and Insulations Tests Conducted at the U. S. Bureau of Standards.P Insulation Tests Based on Samples Submitted by Manufacturers Note.--The coefficients in Tables 2-7, inclusive, are expressed in Btu per hour per square FOOT. PER 1 DEC F, PER 1 IN. THICKNESS UNLESS OTHERWISE INDICATED. Description Density (Lb per Cu Ft) Mean Temp (Deg Fahr) ' CONDUC- TIVITY (*) OR Conduc tance (O Asbestos WoodAsbestos Mill BoardBalsam Wool*............ Cabots Cabots Quilt*.. Celotexl._______ Asbestos and cement compressed-------- Pressed asbestos__________ ------- -------Chemically treated wood fiber be tween layers of paper. Eel grass between Kraft paper Eel grass between Kraft paper........ ..... Rigid insulation made from sugar Corkboard .... Pnrkhnard . Corkboard (Eureka)......... Dry Zero*................................. Eagle Insulating Wool ___ Fibrofelt* .............-........... Flaxlinum* Hairinstil* Hairinsut* Hair Felt* Hair Felt* Instilex or Pvrorell Insulex or Pyrocell............... Insulex or Pyrocell..-......... Insulex or Pyrocell Linofelt* Lith Pure; no added binder__ --...................... Pure; no added binder_________ _______ Kapok between burlap or paper______ Gypsum between layers of heavy paper (H in. thick)_________________ 50% hair; 50% jute .............. ....... ......... Cellular gypsum--dry.................... Rigid insulation made from wood pulp.. Rock wool, flax and* straw pulp with Magnesia (Rigid).. ............ Plaster. ................................. Regranulated cork__________ Rock wool Rock wont Sawdust Shavines Thermofelt* Thermofill* Thermofill* Thermofill* ' 85% magnesia, 15% asbestos......... ....... About in. particles..... ..... .................... Rock wool block with binders.________ Fibrous material, made from rock____ Fibrous material, made from rock____ Fibrous material, made from rock____ Gypsum mixed with sawdust between layers of heavy paper (0.39 in. thick) Jute and asbestos fibers, felted________ Hair and asbestos fibers, felted... ....... Peat moss compressed into sheet form 123.0 60.5 2.2 4.6. 3.4 13.2 14.0 10.6 7.0 14.5 1.0 9.4 13.6 13.0 53.5 6.3 6.1 13.0 11.0 30.0 24.0 18.0 12.0 16.9 4.9 14.3 19.3 46.2 8.1 14.5 10.0 14.0 18.0 .2.1..0 60.7 10.0 7.8 34.0 26.0 19.8 10.2 s 86 2.70 86 0.84 . 90 0.27 90 ' . 0.26 90 0.25. 90 90 90 90 90 . 90 103 90 90 0.34 0.34 0.30 0.27 0.32 0.24 0.27 0.32 0.31 90 2.60* 90 0.27 90 0.26 90 0.26 90 0.26 90 1.00 90 0.77 90 0.59 90 0.44 90 0.34 90 0.28 90 0.40 86 0.51 86 2.32* 90 0.31 77 0.33 90 0.27 90 0.28 90 0.29 90 0.30 86 1.04 86 0.71 ; 90 90 90 90 90 90 91.5 . 3.60* 0.37 0.28 0.60 0.52 0.35 0.29 Woods: Balsa wood........................... Balsa wood. ..................... . Balsa wood Manle. Mahogany ,, Vireinia pine White pine.._...................... Across grain.......................-..............______ 20.0 8.8 7.3 28.7 44.3 34.3 34.3 31.2 90 0.58 90 0.38 90 0.33 86 , 0.67' 86 1.10 . 86 0.90 86 0.96 86 0.78 In addition to the conductivity values for the authorities listed, considerable work of importance per taining to the heat transmission of various types of construction and materials has been done by, the late Prof. John R. Allen and the late Prof. A. J. Wood`of the Engineering Experiment Station of Pennsylvania State College. * ' *For thickness stated or used in construction, not per 1 in. thickness. . *Not compressed. . . The conductivity of plaster varies with the composition. Note range of values, from 2.32 to 8.0. On account of the comparatively high conductivity of plaster and the fact that it is seldom applied more than X in. thick, this material does not appreciably affect the over-all transmission of a construction, excepting in the case of thin uninsulated walls. *See Chapter LX. by Chas. H. Herter of the Report of the Insulation Committee, A.$,R.E., Annual .Meeting 1922, Revised to 1924, entitled Heat Transmission of Insulating Materials fora more compre hensive collection of heat transmission data relating to building and insulating materials. - - i " 76 . ' L' Chapter 5--Heat Transmission The majority of the conductivities and conductances of the building materials and insulations given in Tables 2, 3, 4, 5 and 6 were determined by the hot-plate method of testing2. Attention is called to the fact that conductivities per inch of thickness of materials or insulations do not afford a true basis for comparison, although they are frequently used for that purpose. Correct comparisons should take into consideration many different factors, including conductivities or conductances, thicknesses installed and manner of installation, while the selection of an insulation should also give consideration to structural qualities, as well as material and application costs. Fire, vermin, and rot resistance are other im portant factors to be considered when comparing materials. At present there is no universally recognized method of rating insulations. Con ductivities and conductances of building materials and insulations are useful to the heating engineer in determining over-all coefficients of heat transmission of walls, floors, roofs .and ceilings. (C)Table 3. Conductivities (k) and Conductances of Building : Materials and Insulations Based on Tests Conducted at the University of Illinois, By A. C. Willard, L. C. Lichty and L. A. Harding P Material Description Density (Lb per Cu Ft) Mean Temp (Deg Fahr) CONDUC- TIVITY (k) OR CONDUC- : TANCB (O Mortar bond and dry conditions______ 48.3 20.4 132.0 Cement mortar-------------------- 2 in. hollow clay tile, H in. 4 in. hollow clay tile, in. 6 in. hollow clay tile, H in. Cement__________________ ____________ Built-up bitumen and felt, gravel or slag surfaced__ . .................... - Built-up bitumen and felt, gravel or slag surfaced . .. 140.0 9.7 120.0 127.0 124.3 13.5 ........ .. Wood (Fir. onesurface finished)-- ......... Across grain-................................................ 33.4 110 110 100 110 - 110 100 105 110 -- _ -- 0.29 0.48 4.00 5.00/ 8.00/ 8.30 0.32 1.00* 0.60* 0.47* 0.51 8.00* 1.325* 5.30--* 8.00/ 1.00 tin addition to the conductivity values for the authorities listed, considerable work of importance per taining to the heat transmission of various types of construction and materials has been done by the late Prof. John R. Allen and the late Prof. A. J. Wood of the Engineering Experiment Station of Pennsylvania State College. *For thickness stated or used in construction, not per 1 in. thickness. ^Calculated from 2 in. tile tests. /Cement mortar and stucco assumed same as cement plaster. _' *Roofing, 0.15 in. thick (1.34 lb per sq ft), covered with gravel (0.83 lb per sq ft), combined thickness assumed 0.25. .- `The conductivity of plaster varies with the composition. Note range of values from 2.32 to 8.0. On account of the comparatively high conductivity of plaster and the fact that it is seldom applied more than X in. thick, this material does not appreciably affect the over-all transmission of a construction, excepting in the case of thin uninsulated walls. , /Recommended value. See Heating, Ventilating and Air Conditioning, by Harding and Willard, revised edition. 1932. # ?See Chapter LX, by Chas. H. Herter of the Report of the Insulation Committee. A.S.R.E., Annual Meeting, 1922. Revised to 1924, entitled, Heat Transmission-of.Insulating Materials for a more compre hensive collection of heat transmission data relating to building and insulating materials. . *See Standard Test Code for Heat Transmission through Walls (A.S.H.V.E. Transactions, Vol. 34, 1928). See also Chapter 40. ~ 77 American Society of Heating and Ventilating Engineers Guide, 1934 Table 4. Conductivities (k) and Conductances (C) of Building Materials and Insulations Tests Conducted at Armour Institute of Technology, by J. C. Pecbles.P Insulation Tests R/ir/t /< fvM*a it*A __ Material Description Density (Lb. peb Cu. Ft.) Mean Temp. (Deo. Fahr.) Conoco' TIVlTt (i) Conoco tancb (C, AerocreteAerocrete-- Aerocrete^. Acrocrete. Arborite____________ Asbestos shingles___ Asphalt shinglpfi____ Balsam Wool4__ Cellular concrete__ Cellular concrete-.. Cellular concrete.-. Cellular concrete--. Rigid insulation made from wood pulp Chemically treated wood fibre between 40.0 50.0 60.0 70.0 15.2 65.0 70.0 75 75 75 75 75 . 75 1.06 1.44 2.80 2.18 0.33 6.00* 6.50* plain paper___ Beaver Insulating Board__ .. Cane fibre commercial thickness H in. Calicel_______ ______ ____ Granular fill insulation made from 3.62 13.8 70 75 0.25 0.33 combined silicate of lime and Celotex___ alumina........... 4.2 72 0.24 Rigid insulation made from sugarcane Cincrete Block, 8 imHoUow Concrete. Concrete________________ Donnacona Board-.......... ..... Dry Zero Blanket*_________ fibre_____ ________________ _.... Treated cinder aggregate concrete.. Stone.. Cinder.. ........... ....... .................................. Rigid insulation made from wood fiber Pliable slab form of insulation made 13.5 . 145.0 110.0 15.9 70 75 75 72 0.33 0.33* - 6.30 5.20 0.33 Dry Zero Blanker- from ceiba fibres........ --____ _______ Pliable slab form of insulation made 1.9 . 75 0.23 Dry Zero Blanket*.. from ceiba fibres-.......... -............ ........ Pliable slab form of insulation made 1.6 75 0.24 Flax-Ii-num*______ Glass Wool- from ceiba fibres.. 1.5 75 0.24 Flax fibre. 12.1 70 0.30 Fibrous material 25 to 30 microns in diameter made from virgin bottle Glass Wool................. Haydite--ConcreteTM glass...... .......................................... Ditto. 2 to 3 microns in diameter. Heat-treated clay aggregate standard 1.5 0.85 75 75 0.27-- 0.25 Homasote- blocks 8x8x16 in. Made from wood and other vegetable 73.0 __ 1.62 Inso Board........ ................ Insulating Plaster.______ fibres chemically treated Rigid insulation made from wheat straw) Insulating plaster. 9/10 in. thick, ap 25.0 17.0 75 68 0.375 0.33 Insulite___ Keystone Hair*____ plied to H in- plaster board base....... Rigid insulation made from wood pulp. Hair felt between layers of paper; 54.0 16.5 75 70 1.07* 0.34* Lith yi in. thick.--..................... .................. . Rock wool, flax andstraw pulp with 11.0 75 0.25 UnoboardTM Maftex.____ binder............... -................ -.................... Slab form of insulation made from rock wool and vegetable fibres| Rigid insulation made from licorice 14.5 9.9 11.5 75 72 72 0.38 0.296 0.311 Maizewood_____ Maple Flooring- Masonite_______ roots................. --..................... .............. . Rigid insulation madefrom cornstalks Across grain...................................... ........... Rigid insulation made from exploded 16.1 15.0 40.0 * 81 70.5 75 0.34 0.325 1.20 wood fibre- 19.8 75 0.33 Plaster Board.. Gypsum between layers of heavy paper 62.8 70 1.41 Pyrocell or Insulex_______ Pyroceil or Insulex_______ Cellular gypsum--<lry............. ..... .......... Cellular gypsum--dry.. 30.0 12.0 75 75 0.92' 0.40 0 Red Top Insulating Wool- Fibrous material made from dolomite Roofing__ Temlok.. Therm-A-Pad*..,, Thermatex_____ _ Thermax.. Thermofil_____ Thermofil___ Thermasote "A'* and silica................................................... Composition or prepared----------------- -- Rigid insulation made from wood fiber Flexible insulation made from jute....... Rigid insulation made from wood fiber Made from shredded wood and cement Dry. fluffy, flaked gypsum. Dry. fluffy, flaked gypsum..................... Made from wood fibre, chemically 1.5 15.0 6.7 6.5 24.2 24.0 18.0 75 0.27' 75 6.50*' 70 .0.33 75 0.25 72 0.294 72 0*.46 75 0.48 75 . 0.34 Insulating Board-Torfoleum___ ._______ Weatherwood________ treated_________________ ____________ Peat moss compressed into sheet form Rigid insulation made from hard wood 20.0 11.0 70 . 70 0.355 0.28 Wood Lath and Plaster* Yellow Pine___ __________ fibres.... Lime plaster.. Across grain____ 15.2 ,, . 70 . 75 0.32 2.0* 1.00 In addition to the conductivity values for the authorities listed^considerable work .. --_____ transmission of various types of construction and materials has been done by the late Prof. John R, A. J. Wood of the Engineering Experiment Station of Pennsylvania State College. tothehea^ in and tne lafcePr > *For thickness stated or used in construction, not per 1 in. thickness. *Not compressed. Thickness of lime plaster and wood lath from back of lath to face of plaster, about % in. , . ' rSee Chapter LX. by Chas. H. Herter of the Report of the Insulation Committee, AJS.R.E., Annual Meeting, 1922 Revised to 1924, entitled, Heat Transmission of Insulating Materials for a more comprehensive collection of heat transmission data relating to building and inflating materials. - ', 78 Chapter 5--Heat Transmission Table 5, k (C)Conductivities ( ) and Conductances of Building Materials and Insulations Based on Tests Conducted at the University of Minnesota, By F. B. Rowley P Material Description Density (Lb per Cu Ft) Mean Temp (Deg Fahr) Conduc-TIVITY (k) OR ` Conduc tance (C) Concrete-----Dry Zero- Pliable slab form of insulation made Fir sheathing and building FifshStbdng. building paper and pine lap siding------ Fir sheathing, building paper and stucco. --- Gypsum Tile- Goyyppssuumui Tile--- -----*---- Gypsum Fibre Concrete-- 87H% gypsum and 12H% wood chips Lath and H 1* plaster-----Masonite--.------------- -- Rigid insulation made from exploded Pine lap siding and building paper------------------------------- PTlastterasvci--v-- Sheet Rock Pyrofill Roofing, 2>4 in- thick------ -------------- Thickness X in----------------------------------Plaster board, gypsum fibre concrete and 3-ply roof covering_____________ 143.0 51.8 75.6 51.2 17.9 52.4 68.8 30.0 20.0 20.0 69.9 75.9 74.4 70.0 77.6 15.5 73.0 76.0 9.46 0.23 0.71* 0.50* 0.82* 1.66 2.96 1.66 2.50* 0.32 0.85* 8.8* 0.58* In addition to the conductivity values for the authorities listed/considerable work of importance per taining to the heat transmission of various types of construction and materials has been done by the late Prof. John R. Allen and the late Prof. A. J. Wood of the Engineering Experiment Station of Pennsylvania State College. ' `For thickness stated or used in construction, not per 1 in. thickness. rSee Chapter LX, by Chas. H. Herter of the Report of the Insulation Committee. A.S.R.E., Annual Meeting, 1922. Revised to 1924, entitled Heat Transmission of Insulating Materials for a more compre hensive collection of heat transmission data relating to building and insulating materials. . The coefficients in these tables were determined by calculations similar to those shown in Example 1, using Equations 2, 3, 4 and 5 and the values of k (or C),fi,f0 and a indicated in Table 7. In computing heat trans mission coefficients of floors laid directly on the ground (Table 15), only one surface coefficient (/i) is used. For example, the value of U for a 1-in. Table 6. Miscellaneous Conductivities (k) of Materials* Expressed in Bin per hour per square foot per degree Fahrenheit per inch thickness Material Description Mean Temp. (Deg Fahr) Conductivity (k)t Authority Alfol Concrete Concrete Concrete Ten Test Stone 1-2-5 mix Cinder 1-2-4 mix Various ages and mixes Rigid insulation made from wood fiber 115 95* 122 201 52 0.24 to 0.27 6.27 2.35 11.35 to 16-36 10.37 0.33 G. B. Wilkes. Mass. Inst, of Technology C. L. Norton. Boston, Mass. C. L. Norton, Boston. Mass. A.S.H.V.E. Research -Laboratory Lees and Chorlton E. A. AUcut. Uni- versity of Toronto In addition to the conductivity values for the authorities listed, considerable work of importance per taining to the heat transmission of various types of construction and.materials has been done by.tbe late Prof. John R. Allen and the late Prof. A. J. Wood of the Engineering Experiment Station of Pennsylvania State College. *Hot side of plate. , . . . See A.S.H.V.E. Research paper entitled Conductivity of Concrete, by F. C. Houghten and Carl Gut- beriet (A.S.H.V.E. Transactions. Vol. 37, 1931). ~ *See Chapter LX. by Chas. H. Herter of the Report of the Insulation Committee. A-S.R.E., Annual Meeting, 1922, Revised to 1924. entitled, Heat Transmission of Insulating Materials for a more compre hensive collection of heat transmission data relating to building and insulating materials. American Society of Heating and Ventilating Engineers Guide, 1934 yellow pine floor (actual thickness, 25/32 in.) placed directly on 6 in. concrete on the ground, is determined as follows: 1_________ . U= 1 0.781 6.0 = 0.48 Btu per hour per square foot per degree difference 1.65 + 0.80 + 12.0 in temperature between the ground and the air immediately above the floor. The thicknesses upon which the coefficients in Tables 8 to 18, inclusive, are based are as follows: ' .' Brick veneer........ ...................................................................................... 4 in. Plaster and metal lath........................................................................... % in. Plaster (on wood lath, plasterboard, rigid insulation, board form, or corkboard)........ ...................... ...................................... K in. Slate (roofing)........................................................................................ 14 in. Stucco on wire mesh reinforcing...... .............................................. 1 in. Tar and gravel or slag-surfaced built-up roofing. 1- in. Lumber (S-2-S).. 1........................................ .............................. % in. lJ'S-in. Lumber (S-2-S)............. ................ ........................................... ljf6 m. 2- in. Lumber (S-2-S)......... ........................................................ ;...... 1% in. 2J-in. Lumber (S-2-S).......................................................................... 2ys in. 3- in. Lumber (S-2-S)............................................. .................... ........ 2% in. 4- in. Lumber (S-2-S)....................................................................... . 3% in. Finish flooring (maple or oak).__........ .............................................. 1Hb in. Solid brick walls are based on 4-in. face brick and the remainder common brick. Stucco is assumed to be 1 in. thick on masonry walls. Where metal lath and plaster is specified, the metal lath is neglected. Rigid insulation refers to the so-called board form which may be used structurally, such as for sheathing. Flexible insulation refers to the blankets, quilts or semi-rigid types of insulation. . Actual thicknesses of lumber are used in the computations rather than nominal thicknesses. The computations for wood shingle roofs applied oyer wood stripping are based on 1 by 4 in. wood strips, spaced 2 in. apart. Since no reliable figures are available concerning the conductivity of Spanish and French clay roofing tile, of which there are many varieties, the figures for such types of roofs were taken the same as for slate roofs, as it is probable that the values of U for these two types of roofs will compare favorably. The coefficients of transmission of the pitched roofs in Table 17 apply ) where the roof is over a heated attic or top floor, such that the heat passes directly through the roof structure including whatever finish, if any, 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 flodr 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 roof area, is as follows: ' ,p,xg,, n X Ut -|- Uce (6) 80 Chapter 5--Heat Transmission tuhere Ur = coefficient of transmission of the roof. Uce = coefficient of transmission of the ceiling. n = the ratio of the area of the roof to the area of the ceiling. Example 1. Calculate the coefficient of transmission (U) of an 8-in. brick wall with V 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 face brick having a conductivity of 9 20, and that the inside course is of common 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 (face brick) = 9.20; x = 4.0 in.; k (common brick) = 5.0; x = 4.0 in.; k (plaster) = 3.3; x = J4in.;/i = 1.65;/0 = 6.0. Therefore, 1 U = _L 4- _M_ -L 4. M. 4--J-- 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. . Computed Transmission Coefficients Computed heat transmission coefficients of many common types of building construction are given in Tables 8 to 18, inclusive, each con struction being identified by a serial number. For example, the coefficient of transmission ( U) of an 8-in. brick wall and Yp, in. of plaster is 0.46, and the number assigned to a wall of this construction is 1-B, Table 8. In using this formula, a correction factor must be applied. As the amount of heat transferred through an air space is proportional to the difference of the fourth powers of the absolute temperatures of the surfaces enclosing the air space, a greater amount of heat is absorbed or emitted by radiation by the surfaces enclosing an unheated attic than by the surfaces of a wall or ceiling in a room under still-air conditions, where the surrounding objects are only slightly higher in temperature than the interior surfaces of the walls and ceiling. For example, the average coefficient of a surface in still air is 1.65 Btu per hour per square foot per degree Fahrenheit, whereas the average coefficient of an air space in an outside wall is about 1.10 Btu per hour per square foot per degree Fahren. heit difference between the two surfaces, at a mean temperature of 40 F. An air space coefficient of 1.10 is equivalent to a surface coefficient of 2.20 for each of the two surfaces enclosing the air space, where the over-all transmission is computed by using the coefficients of .the two surfaces enclosing the air space instead of the coefficient of the air space itself. Hence, in determining the values of Ut and Ucc to be used in the formula, the coefficients for the surfaces of the roof and ceiling enclosing the attic should be increased to allow for the additional amount ofTieat transferred by radiation, and a coefficient of 2.20 may be used with sufficient accuracy for each of these surfaces, although in very precise work a correction should be made to allow for the fact that the area of a pitched roof over an unheated attic is greater than the area of the ceiling, 81 American Society of Heating and Ventilating Engineers Guide, 1934 . Table 7. Recommended Conductivities and Conductances for ' Computing Heat Transmission Coefficients Conductivities are expressed in Btu Per hour Per square foot Per degree Fahrenheit per inch thickness: Conductances are indicated by asterisks (*) and are for the thickness or condition stated, not per inch. Material Conductivity | OR u Conductance H Material ^Brick. Common. Brick. Face___ _ - Cefhent Mortar--. Cinqer Concrete.. Cinder Blocks- (8 in.)------- ..... Cinder Blocks- (12 in.) Concrete Blocks* (8 in.)------Concrete Blocks* (12 in.).------Concrete. Gypsum Fiber Concrete....Hollow Clay Tile (4 in.)----Hollow Clay Tile (6 in.)* -- Hollow Clay Tile (8 in;)*.__ Hollow Clay Tile (10 in.)*____ , Hollow Clay Tile (12 in.)*____ | Hollow Clay Tile (16 in.)*_. Hollow Gypsum Tile (4 in.) Insulations. Corkboard_ Flexible.,. Flaked Gypsum (24 lb)I Rigid Insulation____________ Rock Wool Plaster (Gypsum)!_ Plaster Board (H in.). 6.00 9.2 12.00 5.20 0.62* 0.51* 1.0* 0.80* 12.00 1.66 1.00* 0.64* 0.60* 0.58* 0.40* 0.31* 0.46* 0.30 0.27 0.48 0.33 0.30 3.3 3.73* Plaster Board (H in.)_ Roofing.____ Asbestos Shingles....... ;__ _______ . Asphalt or Composition Roofing.----- Built-up, H in. thick.-- Slate Shingles.. Wood Shingles (see woods). Stone_________ _________ _ I Stucco. *` j. Tile or Terrazzo___ Wood Lath and Plaster-- I Woods.. 1-in. Fir sheathing, building paper and yellow pine lap siding--------------- 1-in. Fir sheathing and building paper Yellow pine lap sidingYellow pine or fir._____ Maple or oak._ Shingles, wood-----:------------------------1 Air spaces-.....................-........ ...... ......... Surfaces, still air (fi)-----------------------I Surfaces, 15 mpb (Jo)--____________ ___ Conductivity or . Conductance 2.82* 6.00* 6.50* 3.53* 10.37 12.50 12.00 12.00 2.50* 0.50* 0.82* 1.28* 0.80 1.15 .28* 1.10* 1.65* .00* . *For thickness or condition stated, not per 1 in. One air cell in the direction of heat flow. ; - *The 6-ln.. 8-in. and 10-in hollow tile figures are based on two cells in the direction of heatifiow. The 12-in. hollow tile is based on three cells in the direction of heat flow. The 16-in. hollow tile consists of one 10-in. and one 6-in. tile, each having two cells in the direction of heat flow. . and hence, the amount of heat absorbed by radiation by each square foot of roof surface is less than is given off by radiation by each square foot of ceiling surface. Example 2. Determine the combined coefficient of transmission of a roof constructed of asbestos shingles applied over wood sheathing on rafters,' anunheated attic, and a wood lath and plaster ceiling, based on a roof having a'one-third pitch, for which the value of n is 1.2. Ur = = 0.567 U,, = Substituting these values in Equation 6: ' U = i 2 X5<)7567 f^685 = 0 28 Btu per hour per square Pl P r00f&Tea . degree difference in temperature between the air near the under side of the ceiling and the outside air. If the uriheated attic space between the roof and ceiling has no dormers, windows or vertical wall surfaces, the combined coefficients may be used for determining the Heat loss through the roof construction between the attic and top-floor ceiling, but it should be noted that these coefficients Chapter 5--Heat Transmission American Society of Heating and Ventilating Engineers Guide, 1934 11 Chapter 5--Heat Transmission illlt CO 2 E3wa wO 3 z .* Q (C \0 zxr~~:7 .2 S r SSgg --* t) "" "* n rt 5 S *3 to'O'O^jd c -5 G aCt <j v c Og 15 5H<U ** K V) i* lOx, SoS S*81 w0>4 > gX S 8* feaa *ft1'* *c $c c 51 x i XX- ja^ j"aTs?3S_^. K * *C- 3V^N SS.-B'Z ^>53J gB g s oO$ 2 tHz] C 5 co >Cv si* 3.5 2 lx's X b) 3 $3 in Tf Nf *J> 00 9- > 84 85 .o - American Society of Heating and Ventilating Engineers Guide, 1934 should be multiplied by the roof area and not by the ceiling area. If the unheated attic contains windows, ventilators or vertical wall surfaces, which would tend to reduce temperature in the attic to a temperature approaching or equaling the outside temperature, the roof should be neglected and only the top-floor ceiling construction and the correspond ing ceiling area taken into consideration, using the coefficients given in Tables 13 or 14. Tests made in Pittsburgh by Professor Humphreys in dicated that for this type of attic, an attic temperature should be. taken which is an average between the inside and the outside temperature. Table 11. Coefficients of Transmission (Z7) of Frame Interior Walls and Partitions" Coefficients ore expressed in Btu per hour per square foot Per degree Fahrenheit difference in temperature between the air on the tipo sides, and art based on stilt air (no wind) conditions on both sides. Wall No. TYPE OF WALL _ Single DOUBLE PARTITION (Finished on Both Sides of Studding) (Finish on'One Side of Studding) Air Space Between Studding Flaked . Gypsum Fill* Between Studding Rock Wool Fill* Between Studding. M In. Flex ible Insula . tion Between Studding (One Air Space) AB 53 Wood Lath and Plaster On Studding 0.62 0.34 54 Metal Lath and Plaster* On Studding ` 0.69 0.39 55 Plaster Board in.) and 0.61 Plaster* On Studding 0.34 56 H In. Rigid Insulation and 0.35 Plaster* On Studding 0.18 57 1 In. Rigid Insulation and Piaster* On Studding - 0.23 0.12 58 1H In. Corkboard and Plaster* On Studding , 0.16 0.081 59 2 In. Corkboard and Plaster* On Studding 0.12 , a. 063 c 0.11 0.11 0.10 0.083 0.066 0.052 0.045 D 0.071 0.072 ' 0.071 O.OGO 0.051 0.042 0.038 .E Q;21 0.23 0.21 0.14 0.097 0.070 0.057 . Computed from factors given in Table 7. ^Thickness assumed 3H in. Plaster on meta! lath assumed % in. thick. *Plaster assumed M in. thick. ( )Table 12. Coefficients of Transmission U of Masonry Partitions" ' Coefficients ore expressed in Btu Per hour Per square foot per degree Fahrenheit difference in temperature . between the air on the two sides, and are based on still air (no wind) conditions on both sides. No. TYPE OF WALL 60 4-ln. Hollow Clay Tile 61 4-In. Common Brick 62 4-In. Hollow Gypsum Tile Computed from factors given in Table 7. Plain Walls (No Plaster) Walls Plastered on One Side Walls ^ .Plastered on Both Sides A 0.45 0.50 0.30 B 0.42 0.46 0.28 C 0.40 0.43 0.27 86 V v. Chapter 5--Heat Transmission tO c c in 3 z dbi 5 Oa I Z5 <v> *3 ugOJ- Z I I$ . 2 S. S3 S13" .*o .2 3CO'8*C *>5 o- C . M to; So I* c *cCOoc * S o <tad d HI i uojuojuoj ooj td -o-t: a s'? t U. fit. " O ft. 3 y--n O ts, z H* in ^ ^ 2 1* 2*3 Z*1 o** S*> . Z w h z22 oo DCO Z o z wc Ob. >H 87 JS 3 a * 5 5 ft 5c5 bO-Ei- *2 3 -- ^C_C JiSI-s sss s=g 4o) *to) OO. U. S . 8 3s 3 ca 5 ft *33 3 s S S-g I "515 O .C Id cl <3 O H fvc* -g T a b l e 14. C o e f f ic ie n t s o f r a n s m is s io n U ) o f C o n c r e t e C o n s t r u c t io n F l o o r s a n d C e il in g s T ( Coefficients ore expressed in B tu per h o u r per square fo o t Per degree F a h re n h e it difference in tem perature between the a ir on the tw o sides, C o l u m n A . N o flo o rin g (c o n c re te b a re )b. C o l u m n B . Y e llo w p in e flooring on w o o d sleepers em bedded in co n cre te *. C o l u m n C . M a p le o r o a k flo o rin g * o n y e llo w p in e s u b -flo o rin g * o n w o o d sleepers em bedded in concrete. C o lu m n D , T ile o r te rra z z o / flo o rin g on concrete. . American Society of Heating and Ventilating Engineers Guide, 1934 0 .3 6 0 .3 4 0 .3 2 0.31 ' mcOrtN ONNif a coiom^< *0*0 nf n# oooo OOOO *<M9 CO CO COM OOOO ^eociH MMMM OOOO Tf Tj< r}< T#< OOOO T Y P E O F F LO O R IN G .^aoi- ooot-co CO M NhhO o CO COMM COM M M MMMM MMMM oooo OOOO OOOO OOOO OOOO 0 .1 2 0 .1 2 00 ..11 11 g % ! i 1 t-*eo 00*0 COM 00 to tC rf co*o^eo .009 00 CO CO CO MM. *eooeo CO CO CO CO MMMM MMMM (N --* -h ^ OOOO OOOO OOOO OOOO OOOO OOOO . < i(A0O10)*e0o*o0< OOOO NLOWN CO CO CO CO OOOO *m COCO CO CO OOOO ^WNN MMMM OOOO *o >* ^ <* OOOO 0 .5 9 H in . P la s te r A p p lie d D ire c tly to U n d e r S id e 0 .5 4 o f C o n cre te 0.50 0 .4 5 S u sp e n d e d o r F u rre d M e ta l L a th a n d P la s te r (H in .) C e llin g S u sp e n d e d o r F u rre d C e llin g o f P la s te r B o a rd (% in .) a n d P la s te r (H in .) : S uspended o r F u rre d C e llin g o f R ig id In s u la tio n (H in .) a n d P la s te r (H in .) and are based on s till a ir (no w in d ) conditions on both sides. T Y P E O F C E IL IN G V) w|l S H a sz H - ct c *3 o z . (DOOO o' Z .I c g is si e s a o tfl Cfl C eW .5-cC\tsffv-) |i^ 3 3S si rS dU fiu ^tosoo -^co TtKOCOO flMOQOO .. 5s5-g . TS'Sb-S oti wbft.v0 e 53 if I g *g*1e His$3 3ogo3 "as,, O-SOSrS . =^c=" 0mOO' K360 g8 sS 260 Sg a SV c , .2 -- M tv0C9>O -*M 88 / o z 2oo liJ* Sfl t/J o 2 55 < .\> s' SI Ri tt II IS O On **" s v Si *e 3 T Y P E O F F IN IS H F LO O R IN G Chapter 5--Heat Transmission c c *o va S B 0U9 a> a V *35 28 o G? SJ -- t* Vc.Su ~o o If n Sg ' v.5 a4J S, 09 5 #1= $8 sfs o 8 g VjtiM S %"Is lOou*' St 4J o * --*3i V 09 o*5 o55 <du Z ZI !j j j a I s! ooo o uuu a Q cc Tf o 39aor*o cOOO cOM0*0 CcSJNOHNHN 6 o c5000 ! . 0 .3 1 0 .2 8 0 .1 8 0 .1 5 0 .1 0 0 .1 0 U OcoOcoOco^M oooo 1 0 .1 8 0 .1 7 0 .1 1 0 .1 1 M 00 * ** 0T}<*C0O CQ oooo 0*0 s N0090 oostHo'oo 00 ..65 64 M*HMM (N M "< -i OOOO .*116 So-Hu Q> o> V- z> o .3 eo ve >.2 a& J a c T Y P E A N D T H IC K N E S S O F IN S U L A T IO N A. 3o Co *< .C309 O JS =1 CC ' ec c wJS ^ 33W ` a h * McMeSOSO None* SSuu e iiii z0 mmMM h ic k n e s sT OF C(oI n c r e t e nches) 5 jo jo 2 .2 wS -c ^ 2 2 1u Tftocoo Tf* 00 oo *}< oo Ii . -- MfOtF *0 < t>oo. a *Oo *vo aS E oS o< < No, 89 American Society of Heating and Ventilating Engineers Guide, 1934 - to 'fit*, oo 90 (T a b l e 16. C o e f f ic ie n t s o f T r a n s m is s io n U ) o f V a r io u s T y p e s o f F l a t R o o fs C o v e r e d w it h B u il t - U p R o o f in g 1* Coefficients are expressed in B tu per h o u r per square fo o t Per degree F a h re n h e it difference in tem perature between a ir a t the tw o sides. and are based on an outside w in d exposure of. 15 m ph. ' . W ITHOUT CEILINGS--UNDERSIDE OF ROOF EXPOSED W ITH METAL LATH AND PLASTER CEILINGS* 6 'No. TYPE OF ROOF DECK Precast Cem ent T ile C o n c re te ' i Concrete Concrete . Wood Wood Wood Wood G ypsum F ib e r Concrete* (2 in.) on P la ste r Board ($- in.) G ypsum F ib e r Concrete* (3 in.) on P laster Board (% in.) F la t M etal Roofs* "Computed from factors given in Table 7. T h ic k n e s s op R oof ( I D n eck ches ) 1 Column A. No insulation. Column B. Rigid insulation (H in.). Column C. Rigid insulation (1 in.). Column D. Rigid insulation (1H in.). Column E. Rigid insulation (2 in.). Column F. Corkboard (1 in.). Column G. Corkboard ( IH in.). Column H . Corkboard (2 in.). Column I. N o insulation. Column J. Rigid insulation (M in.). Column K . Rigid insulation (1 in.). Column L . Rigid insulation (1H in.). Column M . Rigid insulation (2 in.). Column N . Cprkboard (1 in.). Column 0 . Corkboard (1>$ in.). Column P. Corkboard (2 in.). fa 0 00 z 2 coo**-* 04 --t t-i odd oddd o d n CN"4O-hIN-h-CwH dodo X NHhOhOO dodo o dodo fa fa 04 oo a dodo u c*** o n Nco- *J<CoO odd dodo < oor-co ONCO CCD C0O4 odd dodo cs * <-*C4 O* x04 sCO: 0.85 [0.37 0.24 0.23 0.22 0.18 | 0.14 10.22 | 91*0 | 10.13 10.43 0.26 0.19 0.15 0.17 0.14 0.22 1 0.16 1 10.13 ,0.42 10.26 1 0.19 1 1 0.17 0.13 0.21 | 0.16 0.12 0.40 0.25 , , 0.18 0.16 j 0.13 0.21 0.15 j 0.12 0.37 0.24 0.18 ; 0.12 | 0.12 0.18 0.12 0.17 0.11 0.17 0.14 0.14 0.13 0.13 0.11 0.11 0.11 0.11 9i6nr0oo0 sro 9tn6r0oo0 sro U5 *}< CO --< dodo 5DU5^fC4 dodo C04OCDN^NQh0 dodo ONOCO dodo 00050** dodo 0.11 0.10 0.097 0.087 0.10 0.095 0.092 0.082 00 CD od | 0.13 0.40 0.25 0.14 0.17 0.27 0.19 0.15 0.10 0.14 [ 0.12 0.097 0.32 0.22 0.13 0.16 0.12 0.23 0.17 0.14 0.097 0.13 0.11 0.091 0.39 0.25 0.18 0.14 o OCOl 0.17 0.13 CD* o 0.27 0.19 0.15 0.12 00 o 0.14 " n o 96*0 oro ,, - . i 01 ^Nominal thicknesses specified--actual thicknesses used In calculations. eGypsura fiber concrete-- 87H per cent gypsum, 12H per cent wood fiber. bawd ?i?M ty ibofre 5 0mphated `r n (" roofins) ia 150 Btu per hour per 8Quare foot of Projected area per degree Fahrenheit difference in temperature, the *i^e a id u fcff the*roo^dtti^anrTthe uppe^side^M ^ceH ing!0^ p*a8ter> or p*aater hoar<Jand plaster ceiting9. I t is assumed that there is aa a ir space between !e h. *5 0 fcp 2 2ttoo -eS- tses a S*i H to TYPE OF CEILING (A p p lie d D ir e c tly to R oof R afters) Chapter 5--Heat Transmission 0 o !S^'CW--aoaSB3 S-o L ----- <-r "5 S53 g g'S'E SoU|Sso'Sis~s5s,SgSg. Z2o.?o<e!!aou <pauQu'bt3x z|||||||l uOuOuOuOuOuOuOoOuO ztMd >(Si (hczaulUuj.' zi 'fa ;e Q <g OX ZX 8" fab, Oo wfafoa > H $ a E co 3 c 91 O U<cn O lf^ <og -o cc; 3,,v si o<g 52 Sol e&cm u Sis J= cS a &* : d ;3e -p 'j' ft? * & " X> --c O c <0 V M 55 O a& a _^ a HS'Sy --a . ^ s 2 rB- . Co EaJ .~5 i8: ~,, tsj j-v"S 0 M M CP a-o s a E 1 oE /Sheathing assumed % in., thick. I -T-V . American Society 0/Heating and Ventilating Engineers Guide, 1934 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. ) STable 18- Coefficients of Transmission (U of Doors, Windows and kylights Coefficients are based on a wind exposure of 16 mph, and are expressed in Blu per hour, per square foot. Per degree Fahrenheit difference in temperature between the air inside and outside ofthe door, wirtdor or skylight. A. Windows and Skylights Single......................... Double................ Triple................ u 0.281 Nominal Thickness Inches i IK IK IK 2 2K 3 B. Solid Wood Doorsb-c Thickness Inches % We We W W 2K 2K 0.69 0.59 0.52 0.51 0.46 0.38 0.33 . ______ umt au i^onatitontng. oy Harding and Willard, revised edition, 1932. ^Computed using C = 1.15 for wood; /i = 1.65 and/o 6.0. . It is sufficiently accurate to use the same coefficient of transmission for doors containing thin wood panels, as that of single panes of glass, namely. 113 Btu per hour per square foot per degree difference between inside and outside air temperature. REFERENCES A.S.H.V.E. research paper entitled, Wind Velocity Gradients Near a Surface and Their Effect on Film Conductance, by F. C. Houghtenand Paul McDermott (A.S.H.V.E. Transactions, Vol. 37, 1931). A.S.H.V.E. research paper entitled, Surface Conductances as Affected by Air Velocity, Temperature and VCohla.ra36c,te1r9o3f0)S. urface, by F. B. Rowley, A. B. Algren and J. L. Blackshaw (A.S.H.V.E. Transactions, A.S.H.V.E. research paper entitled. Effects of Air Velocities on Surface Coefficients, by F. B. Rowley. A. B. Algren and J. L. Blackshaw (A.S.H.V.E. Transactions, Vol. 36, 1930). : A.S.H.V.E. research paper entitled. Conductivity of Concrete, by F. C. Houghten and Carl Gutberlet (A.S.H.V.E. Transactions, Vol. 37, 1931). A.S.H.V.E. research paper entitled, Surface Coefficients as Affected by Direction of Wind, by F. B. Rowley and W. A. Eckley (A.S.H.V.E. Transactions, Vol. 37, 1931). A.S.H.V.E. research paper entitled. Thermal Resistance of Air Spaces, by F. B. Rowley and A. B. Algren (A.S.H.V.E. Transactions, Vol. 35, 1929). 5 A.S.H.V.E. research paper entitled. The Heat Conductivity of Wood at Climatic Temperature Dif ferences. by F. B. Rowley (A.S.H.V.E. journal Sectiot^Heating. Piping and Air Conditioning. June, 1933). Heat Transmission through Building Materials, by F. B. Rowley and A. B. Algren. University of Min nesota Engineering Experiment Station Bulletin No. 8. ' Insulating Effect of Successive Air Spaces Bounded by Bright Metallic Surfaces, by L. W. Schad (A.S.H. V.E. Transactions. Vol. 37, 1931). Importance of Radiation actions, VoL 38. 1932). in Heat Transfer through Air Spaces, by E. R. Queer (A.S.H.V.E. Trans Properties of Metal Foil as an Insulating Material, by J. L. Gregg {RefrigeratingEngineering. May, 1932). Thermal Insulation with Aluminum Foil, by R. B. Mason (Industrial and Engineering Chemistry. March, 1933). .. . Heating, Ventilating and-Air Conditioning, by Harding and Willard, Revised Edition, 1932. 92 / Chapter 6 AIR FILTRATION Causes of Air Leakage, Air Leakage Through Walls, Window Leakage, Wind Velocity to be Selected, Crack used for Computa tions, Multi-Story Buildings, Beat Equivalent of Air Entering by Infiltration INFILTRATION (or exfiltration) losses are those resulting from the displacement of heated air in a building by unheated outside air, the interchange taking place through various apertures in the building, such as cracks around doors and windows, fireplaces and chimneys. This leakage of air must be considered in heating and cooling calculations. (See Chapters 7 and 8). CAUSES OF AIR LEAKAGE A building is a shell in which the internal pressure in general is not in equilibrium with the external pressure. At some places, the latter is greater than the former, and inflow will occur in such regions through any openings in the wall whether large or small. At other places the reverse is true. The internal pressure automatically assumes a value to correspond to the requirement that outflow must equal inflow. The agencies that cause leakage are the natural forces of wind and temperature difference, and those produced by fans if any are used. A consideration of all factors involved in causing pressure difference at various places about a building would present an exceedingly complex problem. . \ In tall single story buildings, the chimney effect caused by the insideoutside temperature difference becomes a factor of importance. Even in multi-story buildings it usually is not possible to isolate the several floors completely, and chimney effect is operative to a considerable degree, tending to force air in at the lower levels and out at the upper. ; Since the full force of the wind usually is not the effective pressure differential, owing to back pressure built up within the building, the actual amount of infiltration (cubic feet) is assumed to be 80 per cent of that determined in laboratory experiments. AIR LEAKAGE THROUGH WALLS _ Table l1 gives data on infiltration through brick and frame walls. The brick walls listed in this table are walls which show poor workmanship I'Vj Infiltration through Various Types of Brick Wall Construction, by Larson, Nelson and.Braatz (A.S.H.V.E. Transactions, Vol. 36, 1930), 93 American Society of Heating and Ventilating Engineers Guide, 1934 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 pf good workmanship in proper Table 1.. Infiltration through Walls Expressed in cubit feet Per square foot Per hour* Ttpb op Wall Wind Velocitt, Miles peb Houb 5 10 15 20 25 30 in. Brick Wall {plastered];" 1.75 4.20 7.85 - 12.2 18.6 22.9 0.017 0.037 0.066 0.107 0.161 0.236 13 in. Brick WalL__..... 1.44 0.005 3.92 0.013 7.48 11.6 16.3 21.2 0.025 0.043 0.067 0.097 Frame Wall, with lath and plasterb 0.03 0.07 0.13 0.18 0.23 0.26 Frame Wall, with lath and plaster4 0.02 0.05 0.10 0.15 0.20 0.25 oThe values in thi9 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 A.S.H.V.E. research papers entitled. Air infiltration Through Various Types of Brick Wall Construction, and Air Infiltration Through Various Types of Wood Frame Con struction. (See References on p. 102). . ' bWall construction: Bevel siding painted. No. 1 common butt-edged sheathing, building paper, wood lath and 3 coats gypsum plaster. eWall construction: Cedar shingle, shiplap sheathing, building paper, wood lath and 3 coats gypsum plaster. 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. I, 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 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 simple walls used in farm and other shelter buildings, is shown in Fig. 2. The infil- 94 Chapter 6--Air Filtration Fig. 1. Infiltration through Various Type's.of Shingle Construction tration there indicated is that determined in the laboratory and should be multiplied by the factor 0.80 to give proper working values. WINDOW LEAKAGE The amount of infiltration in cubic feet per hour per foot of crack .for various types of windows is given in Table 2. The distinction between crack and clearance of a wood sash is shown by Fig. 3. For window and Fig. 2. Infiltration through Single Surface Walls Used in Farm and Other Shelter Buildings 95 American Society of Heating and Ventilating Engineers Guide, 1934 Table 2. Infiltration Through Windows . Expressed in Cubic Feel per Foot of Crack per Hour Ttpe or Window Remarks Wind Velocitt, Miles per Hour 5 10 15 20 25 30 Around frame in masonry wall-- not calkedb................. 3.3 8.2 14.0 20.2 27.2 34.6 Around frame in masonry wall-- calkedb~. _.................. 0.5 1.5 2.6 3.8 4.8 5.8 Around frame in wood frame construction15....... 2.2 6.2 10.8 Double-Hung Total for average window, non- Wood Sash weatherstripped, H6-in. crack Windows and in. clearance0. In- (Unlocked) eludes wood frame leakage*1___ 6.6 21.4 39.3 16.6 59.3 23.0 30.3 80.0 103.7 Ditto, weatherstripped*1 Total for poorly fitted window, non-weatherstripped, iKp-in. crack and %2-in. clearance6. Includes wood frame leakage^. 4.3 15.5 23.6 26.9 69.0 110.5 35.5 153.9 48.6 199.2 63.4 , 249.4 Ditto, weatherstripped*1 5.9 18.9 34.1 Double-Hung Non-weatherstripped, locked 20 Metal Non-weatherstripped, unlocked. 20 Windows* Weatherstripped, unlocked__ 6 45 47 19 70 74 32 51.4 96 104 46 70.5 125 137 60 91.5 154 170 76 Industrial pivoted, H6-in.crack 52 108 176 244 304 372 Rolled Architectural projected,11 %4-in. Section crack. ................... 20 52 88 116 152 208 Steel Sash Residential casement,1 M2-in. Windows1* crack _____ 14 32 52 76 100 128 Heavy casement section, pro- iected.i ^n-in. crack 8 24 38 54 72 96. Hollow Metal, vertically pivoted window* 30 88 145 186 221 242 iue values given in itns taoie are zu 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 dtiemteer,mitinisecwdoubnaysidutheaereecudaalkduevdisaanbodlientuoo>tt-c-cchnaao!lokkfseedthntepestms*.asonry fIramme leakage values for calked frames as the average . The fit ofthe average double-hung wood window was determined as )-in. crack and 56-in. clearance bv measurements on approximately 600 windows under heating season conditions. dTbe 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 36-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 center or slightly above, lower part swinging out. . hArchitectural projected made of same sections as industrial pivoted except that outside framing member teavier. and refinements in weathering and hardware. Used in Rpmi-mnnnm^Hi *. -''U-'-i- . tuuuuuLu Bwiug in or our. ana are oai&nced on side arms. iOf same design and section shapes as so-called heavy section casement but of lighter weight. iMade of heavy sections. Ventilators swing in or out and stay set at any degree of opening. 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. - - 96 Chapter 6--Air Filtration sash leakage, the length of crack in double-hung windows is equal to the perimeter of sash plus length of meeting rail. For steel sash the length of crack is the aggregate perimeter of the movable or ventilating sections plus the linear feet of sash section in contact with steel work (at a different leakage rate) at mullions. The crack length for frame windows (when frame is not calked) is the perimeter of the frame. Steel sash frame properly grouted with cement mortar into brickwork or concrete is not to be counted as crack. The value of storm sash is shown by the curves of Figs. 4 and 5. A study of the curves leads to the conclusion that a storm sash is of little value in reducing infiltration when applied to a well fitted window, but that a reduction of 50 percent might be expected when storm sash is applied to a poorly fitted or loose window. Infiltration through ---------- 1 th/at- of window cracks. WIND VELOCITY TO BE CHOSEN 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 Fig. 3. Diagram Illustrating Crack and Clearance 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 gre given in Table 2, Chapter 7. In eonsidering 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 neces sitate a laborious cut-and-try process in every case in order to determine the worst combination of conditions for the building under consideration. It would also be necessary to consider heat lag due to heat capacity in the /case of heavy masonry walls, and other factors, to arrive at the most accurate solution of the problem. Although heat capacity should be con sidered wherever possible, it is seldom possible to accurately determine the 97 American Society of Heating and Ventilating Engineers Guide, 1934 IZ ft u L it t c j 1 t a , ai 1 3n 77 : (r A 03 5 (IA fc /7 1f 1t t 42 8 Q7 1iT t t A.\ *06 j l 105 7 11 t Lu 4t rASTtJiuj wrm rouff iurnButtons ft 04 S 1 7ft V > Sane As C With Wool Q 03 L J it *4 az 1 hT J. >1 L 20/ J jt ov 0 50 too ISO zoo Z50 300 Infiltration CF.H Per Foot OrCrack 5003 45.69 SX 4069 $ 3540 < Z&90 9 ?f)A? | 0 Fig. 4. Infiltration through Sash Perimeter of Window with and without Storm Sash--%4-in. Crack and Mz-in. Clearance worst combination of outside temperature and wind velocity for a given -building and locality. The usual procedure, as already explained, is to select an outside temperature based on the lowest on record 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 t.z aA/ /.> Q7 06 |Q5 jL<34 <3 03 %02 L, 0 s/ yj c >j A r /r 7 J 1 rj r/ y t 1 r/ / / jf 1i t 1 L // y / i t / / y f. / j. y A-Without Storm Sash B- Storm Sash Suspended C-Storm Sash Fastened With Four Turn Buttons 1 ra~n mmnr VO nx> 200 250 500 350 4O0 . ./NFILTRATKN CF H PER FOOT OF CRACK 5003 4569 | 4QB9 to 3, 3540 tj 20.30 | 2042 | n Fig. 5. Infiltration through Sash Perimeter of Window with and without' Storm Sash--H-in. Crack and J^-in. Clearance ; 98 .Y Chapter 6--Air Filtration d non-prevailing winds will ordinarily each occupy about one-half the an imeterof the structure, the proportion varying to a considerable extent wth the plan of the structure. (See discussion of wind movement in Chapter 4). , CRACK USED FOR COMPUTATIONS In no case should the amount of crack used for computation be less than half of the total crack in the outside walls of the room. Thus, in a' room with one exposed wall, take all the crack; with two exposed walls, take the wall having the most crack; and with three or four exposed walls, take the wall having the most crack; but in no case take less than half the total crack. For a building having no partitions, whatever wind enters through the cracks on the windward side must leave through the cracks on the leeward side. Therefore, take one-half the total crack for com puting each side and end of the building. The amount of air leakage is sometimes roughly estimated by assuming a certain number of air changes per hour for each room, the number of changes assumed being dependent upon the type, use and location of the room, as indicated in Table 3. Table 3. Air Changes Taking Place under Average Conditions Exclusive of Air Provided for Ventilation Kind or Room ob Building Nuubzb or Ant Chawobs . Taking Placb per Hour Living Rooms.--....... _......................................................................... - i m 2 2 HtoH 2 to 3 2 1 to 2 1 to 2 2 1 Hto3 MULTI-STORY BUILDINGS In tall buildings, infiltration may be considerably influenced by tem perature difference or chimney effect which will operate to produce a head that will add to the effect of the wind at lower'levels and subtract from it at higher levels. On the other hand, the wind velocity at lower levels may be somewhat abated by surrounding obstructions. Further more, the chimney effect is reduced in multi-story buildings by the partial isolation of floors preventing free upward movement, so that wind and 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 99 American Society of Heating and Ventilating Engineers Guide, 1934 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: Me = VAP - 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. Example t. If M = 15, the equivalent wind velocity at a height of 150 ft from the ground for a building 180 ft high would be * .- Me = VW - 1.75 X 60 = 11 mph ' For a window on the ground floor: Me = V15* + 1.75 X 90 = 19.6 mph For buildings of unusual height, Equation 1 would indicate negative infiltration at the highest stories, which condition may, at times, actually exist, although probably greater wind velocities should be figured at such extremely high levels. Sealing of Vertical Openings2 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 high altitudes makes it advisable to install additional heating surface on the upper floors above the level of neighboring buildings, this additional surface being increased as the height is increased. One arbitrary rule is to increase the heating surface on floors above neighboring buildings by an amount ranging from 5 per cent to 20 per cent. This extra heating surface is required only on the windward side and on windy days,. and hence automatic temperature control is especially desirable with such installations. Heating Surface for Stair-Wells2 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- See Flue Action in Tall Buildings, by H. L. Alt (.Beating, Piping and Air Conditioning, May, i932). 100 Chapter 6--Air Filtration 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 ENTERINC BY INFILTRATION The heat required to warm cold, outside air, which enters a room by infiltration, to the temperature of the room is given by the following equation: Hi = 0.24 Q d (t -- t0) (3) where Hi = Btu per hour required for heating air leaking into building from outside temperature t0 to inside temperature t. Q = cubic feet of air entering per hour at inside temperature t. d = density (pounds per cubic foot) of air at inside temperature /. t = inside temperature at the proper level. to = outside air temperature for which heating system is designed. 0.24 = specific heat of air. It is sufficiently accurate to take d = 0.075 lb, in which case the equa tion reduces to Hi = 0.018 Q (t - to) . (4) While a heating reserve must be provided to warm inleaking air on the windward side of a building, this does not necessarily mean that the heating plant must be provided with a reserve capacity, since the inleaking air, warmed at once by adequate heating surface in exposed rooms, will move transversely and upwardly through the building, thus relieving other radiators of a part of their load. The actual loss of heat of a building caused by infiltration is not to be confused with the necessity for pro viding additional heating capacity for a given space. Infiltration is a disturbing factor in the heating of a building, and its maximum effect (maximum in the sense of an average of wind velocity peaks during the heating season above some reasonably chosen minimum) must be met by a properly distributed reserve of heating capacity, which reserve, how . ever, is not in use at all places at the same time, nor in any one place at all times. Example 2. A 12 ft by 18 ft room with a ceiling height of 10 ft contains three 2 ft-8 in. by 5 ft-6 in. plain double-hung wood windows with Jis-in. crack and %4-in. clearance. Assume a wind velocity of 20 mph and a temperature difference of 75 F. Neglecting chimney effect, what is the maximum heat loss due to infiltration? Solution. From Table 2, the leakage per foot of crack is 59.3 cfh. Length of crack for the three windows is 57 ft. The infiltration (Q) is equal to 59.3 X 57 or 3380 cfh, and the additional heat loss (maximum) due to infiltration is equal to 0.018 X 3380 X 75 or f 4560 Btu per hour. (Since the room has a volume of 2160 cu ft, the air changes would be 3380 , , or 1.57 per hour). , 101 American Society 0/-Heating and Ventilating Engineers Guide, 1934 . . Example 8. What is the probable inleakage of air for a room with three windows on the first floor, if the wind velocity is 15 mph? The building is 90 ft high and is equipped with architectural projected steel windows with two ventilators each with a total peri ' meter of 24 ft of ^U-in. crack. Further, find the probable inleakage in similar rooms on the top floor and on the third floor 30 ft from the ground. . Solution. On the first floor the equivalent wind velocity is Me = V151 -|- 1.75" X *45 or 17.5 mph. Leakage for this type of window is given in Table 2 (interpolating) as 102 cu ft per foot of crack per hour. The total leakage rate (Q) is equal to 3 X 24 X 102 or 7344 cu ft per hour. For a similar room on the top floor, with the same exposure, the equivalent wind velocity is Me = -a/15* -- 1.75 X 45 or 12 mph for which the leakage is 66.4 cu ft per ft of crack per hour. The total, inleakage of air into the room (0) is equal to 3 X 24 X 66-4 or 4780 cu ft per hour. For a similar room 30 ft above the ground, Me = V^15* + 1.75 X 15 or 16 mph for which the unit crack leakage will be 93.6 cu ft per hour, and the total leakage for the room will be 6740 cu ft per hour. REFERENCES Air Leakage, by Houghten and Schrader (A.S.H.V.E. Transactions. Vol. 30. 1924). Air Infiltration through Various Types of Brick Wall Construction, by Larson, Nelson and Braatz (A.S.H.V.E. Transactions. Vol. 35. 1929). . Infiltration through Plastered and Unplastered Brick Walls, by F. C. Houghten and Margaret Ingels (A.S.H.V.E. Transactions. Vol. 33. 1927). - - Air Leakage around Window Openings, by C. C. Schrader (A.S.H.V.E. Transactions, Vol. 30, 1924). Effect of Frame Calking and Storm Sash on Infiltration around and through Windows, by Richtmann and Braatz (A.S.H.V.E. Transactions. Vol. 34, 1928). Air Leakage on Metal Windows in a Modern Office Building, by Houghten and O'Connell (A.S.H.V.E. Transactions, Vol. 34. 1928). The Weathertightness of Rolled Section Steel Windows, by Emswiler and Randall (A.S.H.V.E. Trans actions. Vol. 34. 1928). `" '. Air Leakage through a Pivoted Metal Window, by Houghten and O'Connell (A.S.H.V.E. Transactions, .Vol. 34. 1928). Pressure Difference across Windows in Relation to Wind Velocity, by Emswiler and Randall (A.S.H.V.E. Transactions. Vol. 35, 1929). Air Infiltration Through Various Types of Wood Frame Construction, by Larson, Nelson and Braatz (A.S.H.V.E. Transactions, Vol. 36. 1930). `. Neutral Zone in Ventilating, by J, E-. Emswiler (A.S.H.V.E. Transactions. Vol. 32.1926). Air, Infiltration Through Double-Hung Wood Windows, by Larson. Nelson and Kubasta (A'S.H.V.E.- Transactions, Vol. 37, 1931). . . '' 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. Boetter (Healing, Piping and Air Conditioning, October,. 1932). _ ; ' i'102 A Chapter 7 THE HEATING LOAD Factors Governing Heat Demand, Procedure, Temperatures, Wind Movement, Heat Sources Other Than Heating Plant, Example, Condensation IN the design of any type of heating system, the maximum probable heat demand must be accurately estimated in order that the apparatus installed shall be of sufficient capacity to maintain the desired temperature at all times. The factors which govern this maximum heat demand-- most of which are seldom, if ever, in equilibrium--include the following: 1. Outside temperature. 2. Rain or snow. 3. Sunshine or cloudiness. 4. Wind velocity. . 5. Heat transmission of exposed parts of building. 6. Infiltration of air through cracks, crevices arid open doors and windows. 7. Heat capacity of materials. 8. Rate of absorption of solar radiation by exposed materials. 9. Inside temperatures. 10. Stratification of air. 11. Type of heating system. 12. Ventilation requirements. 13. Period and nature of occupancy. 14. Temperature regulation. Outside Conditions (The Weather) Building , Construction 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 com jectural. Because of the nature of the problem, extreme precision in estimating heat.losses at any time.is,very unlikely. . ... .. . ... . The procedure to be followed in, determining the ;heat loss: from, any building can be divided into seven.consecutive stepsj 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. 'Determineoq an outside air temperature fordesign purposes; baseddnthe minimum temperatures recorded in the locality; in questionj which, will provide, for all but the most severe weather conditions. Such conditions as may exist;for,pnly.a few. consecu tive hours, are readily taken care of by the heat " capacity' of the. building, itself. (See Table-2). . 1 . ... ' '. y;..:.': .'-v..i: i 3. Select or compute the heat transmission coefficients for outside walls and'glasS; 103 American Society of Heating and Ventilating Engineers Guide, 1934 also for inside walls, floors, or top-floor ceilings, if these are next to unheated space; include roof if next to heated space. (See Chapter 5). ' 4. Measure up net outside wall, glass and roof next to heated spaces, as welt as any cold walls, floors or ceilings next to unheated space. Such measurements are made from building plans, or from the actual building. 5. Compute the heat transmission losses for each kind of wall, glass, floor, ceiling and roof in the building by multiplying the heat transmission coefficient in each case by the area of the surface in square feet and the temperature difference between the inside and outside air. (See items I 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 empresses the heat required to warm up the cold air leaking into the building per hour. (See Chapter 6). 7. The sum of the heat losses by transmission (item 5) through the outside wall and glass, as well as through any cold floors, ceilings or roof, plus the heat equivalent (item 6) of the cold air entering by infiltration represents the total heat loss equivalent for any building. Table 1. Winter Inside Dry-Bulb Temperatures Usually Specified* Ttpk or Buildinq Deo Fahh I Ttpk op Building Schools [Theaters-- Class Rooms.............................. Assembly Rooms.--.................. Gymnasiums.............................. Toilets and Baths......................... 70-72 J 68-72 1 55-65 | 70 Seatine Space Loungfe Rooms .. '1 oilets....... Wardrobe and Locker Rooms--| 65-68 Kitchens--......... '.................... --. 66 Dining and Lunch Rooms...... Playrooms......................... ........ 65-7U 60-65 Natatoriums.--.................-........ 75 'Hotels-- Bedrooms and Baths Oininz Rooms ... Kitchens and Laundries Ball Rooms......... Hospitals-- I oilets and Service Rooms Private Rooms.......... ............. Private Rooms (surgical)--.. Operating Rooms................... Wards............................ ...... -- Kitchens and Laundries-----Toilets--................... ................ Bathrooms................ ;............... 70-72 70-80 70-95 68 66 68 70-80 Homes............... Stores . Public Buildings Warm Air Baths ... Steam Baths...... Factories and Machine Shops Foundries and Boiler Shops Paint Shops-- Dbg Fas* 68-72 68-72 70 70 66 65-68 68 70-72 65-68 68-72 120 110 . 60-65 50-60 80 Item 7 represents the heat losses after the building is heated and Under stable operating conditions in coldest weather. Additional heat is required for raising the temperature of the air, the building materials and the material contents of the building to specified standard inside temperature. The rate at which this additional heat is required depends upon the heat capacity of the structure and its material contents and upon the time in which these are to be heated. . This additional heat may be figured and allowed for as conditions r6quire, but inasmuch as the heating system proportioned for taking care 104 . Chapter 7--The Heating Load f 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 more time be allowed for heating-up during the few minimum temperature days, no allowance is made except in the size of boilers or furnaces. INSIDE TEMPERATURES The inside air temperature which must be maintained within a building and which should always be stated in the heating specifications is under stood to be the dry-bulb temperature at the breathing line, 5 ft above the floor or the 30-in. line, and not less than 3 it 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 2. 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. 2, Chapter 2, 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 given 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 on p. 91). . 'See Chapter 2. p. 27. 105 American Society of Heating and Ventilating Engineers Guide, 1934 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. It is the common practice of engineers to allow a change in temperature of 2 per cent per foot of height above the breathing line in determining the probable air temperature at any given level for a direct radiation system, and this value is, no doubt, sufficiently accurate in most cases, although it is not probable that this rule applies to heights above 20 ft. 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 to 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 temperatureo somewhat higher than the lowest on record may be properly assumed in' making the heat-loss computations. The outside temperature to be assumed in the design of any heating system must not be more than 15 deg above the lowest recorded tem perature as reported by the Weather Bureau during the preceding 10 years for the locality in which the heating system is to be installed. In the case of massive and well-insulated buildings in localities where the minimum does not prevail for more than a few hours, it is possible that more than 15 deg above the minimum may be allowed, due primarily to' the fly-wheel effect of the heat capacity of the structure. The outisde ' 106 Chapter 7--The Heating Load temperature assumed and used in the design should always be stated in the heating specifications. Table 2 lists the coldest dry-bulb tempera tures ever recorded by the Weather Bureau. 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 MOVEMENT The effect of wind on the heating requirements of any building should be given consideration under two heads: X Wind movement increases the heat transmission of wails, 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. It is entirely possible that a building may require more heat on a windy day with a moderately low outside temperature than on a quiet day with a much lower outside temperature. It will, therefore, be evident that the wind movement in any locality must be given careful consideration in computing the probable heating requirements of a building, and for the purposes of calculation, not less than the average wind movement in any locality during December, January and February should always be pro vided for in computing (1) the heat transmission of a building, and (2) the heat required to take care of the infiltration of outside air. The first condition is readily taken care of, as explained in Chapter 5, by using a surface coefficientf0 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 transmission coefficient tables in Chapter 5 are based. In a similar manner, the heat allowance for infiltration through cracks and walls (Tables 1 and 2, Chapter 6) must be based on the proper wind velocity for a given locality, as.explained in Chapter 6. In the case of tall buildings, special attention must be given to infiltration factors, as also explained in Chapter 6. HEAT FROM SOURCES OTHER THAN HEATING PLANT 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, Jhese 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 107 American Society of Heating and Ventilating Engineers Guide, 1934 Table 2. Climatic Conditions Compiled from Weather Bureau Records Col. A Col. B Col. C Col. D Col. E Col. F State City Average Temp., Oct. 1st-- May 1st Lowest Tempera ture Ever Reported Average Wind Vel ocity Dec. Jan., Feb. Miles per Hr Direction of Prevail, ing Wind, Dec., Jan., Feb. Ala__________ Mobile Birmingham. Ariz. Phoenix .. Ark. Flagstaff___ . . . ._ Little Rock___ Cal_____ ;____ San Francisco _ Colo Los Angeles ........... Denver ... Grand Junction...... ... Conn.. D. C_________ Washington Fla. ____ . Ga___________ Atlanta__ Savannah Idaho________ Lewiston .. . Pocatello. .. 111____________ Chicago. . .. ___ . Springfield. .. Ind__________ Indianapolis Evansville .......... . .. Iowa_________ Dubuque.............................. Sioux City Kan. _ ....... Dodge City Ky.._ .. . ,, Louisville .... .. .. La. .............. New Orleans___________ _______ Shreveport Me. . Portland..... ......... Md__________ Baltimore ____ ... Mass. ______ Boston . v ....... Mich................ Alpena ........ Detroit . . Marquette___ ___ ... Minn__ ____ Minneapolis______________________ ..... ...... Vicksburg ..... Mo........ 7 . St. Joseph Mont. Neb St. Louis........................ Springfield. __ Billing's .... Havre Lincoln I............... .. Nev__________ N. H................ North Platte . Tonopah___________ ______________ Winnemucca..... Concord ..... N. J.......... ..... Atlantic City....... ....... ....... .......... N. Y.,,...... ...... Albany ... Buffalo .. ...... New York.. N. M............... Santa Fe ........ 57.7 53.9 34.9 51.6 54.3 58.6 BP.3 39.2 aa.n 43.2 fil ,Q 51.4 58.4 42.5 36.4 36.4 39.9 40.2 44.1 33.9 32.1 as.9 40.2 45.2 61.5 56.2 31 1 33.6 43.6 37.6 29.1 35.4 27.61 29.6 56.0 40.3 43.3 43.0 34.7 27.7 37 0 34.6 39.6 37.9 33.4 41.6 35.1 34.7 40.3 38.0 -i 8.3 -10 16 -25 15 8.6 39 e`7 Q -12 29 9.9 28 29 7 4 -16 14 5.6 93 -15 10 7.3 g% -8 1C8 8 -13 -20 -23 -24 8.3 4.7 9.3 17.0 10.2 -25 -15 -32 11.8 8.4 6,1 -35 9JS? 12.2 73 -i6 v wlO.4 --20 3 7 Tw -5 7.7 23 13 g- -17 -7 -- 13 --27 -24 -27 41 -33 10.1 7.2 11 7 11.3 13.1 11.4 11 1 lllS -1 --24 -22 -29 --49 7.6 91 11.8 11.3 -57 --29 8.7 10 9 -35 -7 -28 --35 -7 9.0 .9.9 9fi.n5 10.6 -24 -14 -6 -13 7.9 17.7 13.3 7.3 N 'N F SW F NW N NE s SE N NW NE NW NW E SE SW NW S S NW NW NW N SE W NW NW w w SW NW SW NW SE NW NW SE , w ^ SW N w SE NE NW NW S w NW NE 108 Chapter 7--The Heating Load Conditions Compiled from Weather Bureau Records-- Table 2. Climatic c. (Continued) Col. A State or Province Col. B City Col. C Average Temp.. Oct. 1stMay 1st Col. D Col. E Col. F Lowest Tempera ture Ever Reported Average Wind Vel ocity Dec., Jan., Feb., Miles per Hr Direction of Prevail ing Wind, Dec., Jan., Feb. _ ------------ N. c--:-------- N. D------ ------ Ohio.------------- Columbus--............................ ........... Okla..........-- Ore---- ----------- Pa---------------- R. I..---------- s. C-------------- S. D............. - Tenn------------- Texas----------- Utah----------- - Vt Va___________ MnrfnlX- ...................... Wash________ Wyo_________ Alta.......... ...... rr . Man................ NR NS PFT Pt. Arthur....... .................................. 49.7 53.1 24.5 18.9 36.9 39.9 48.0 34.1 45.9 41.9 40.8 37.6 56.9 53.7 28.1 32.3 47.0 50.9 53.0 54.7 60.7 38.1 40.0 29.3 49.1 45.2 47.4 45.3 37.5 38.8 41.9 28.6 31.2 33.0 31.0 28.9 23.3 43.8 41.7 17.2 27:1 35.5 32.5 26.9 21.6 32.0 30.1 27.4 24.4 14.7 1.6 -2 5 -45 -44 -17 -20 -17 -20 -2 -6 -20 -9 7 -2 -43 -34 -16 -9 -2 -8 4 -24 -20 -27 2 -7 -3 3 -30 -21 -27 -36 -43 -25 -45 -36 -57 -2 2 -46 -35' -12 -26 -33 . -51 -26 -23 -27 -34 -70 -68 1 7.3 8.9 ____ 11.4 14.5 9.3 12.0 6.0 6.5 11.0 13.7 14.6 11.0 8.0 11.5 7.5 6.5 9.6 10.5 11.0 8.2 8.9 4.9 12.9 9.0 5.2 7.4 9.1 4.8 6.6 12.8 5.6 11.7 5.3 3.0 4.5 8.9 4.2 12.4 8.7 13.0 7.5 13.5 8.7 15.4 15.0 3.2 ........ 1 SW SW NW W SW SW N SE s NW NW NW N NE NW W SW NW NW NW N W SE S N NW S SE SW W S SW NW W NW NE W N E SW NW NW __ W SW NW "SW SW SW 1 109 American Society of Heating and Ventilating Engineers Guide, 1934 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 le^st 40 F in the building. Motors and Machinery Motors and the machinery which they drive, if both are located in the room, convert all of the electrical energy supplied into heat, which is retained in the room if the product being manufactured is not removed until its temperature is the same as the room temperature. If power is transmitted to the machinery from the outside, then only the heat equivalent of the brake horsepower supplied is used. In the first case the Btu supplied per hour = Pr ^or.^Power y 2,546, and Efficiency of motor in the second case Btu per hour = bhp X 2,546, in which 2,546 is the Btu equivalent of 1 hp-hour. In high-powered mills this is the chief source of heating and is frequently sufficient to overheat the building even in zero weather, thus requiring cooling by ventilation the year round. . The heat (in Btu pier hour) from electric lamps is obtained by multi plying the watts per. lamp by the number of lamps and by 3.415. One cubic foot of producer gas gives off about 150 Btu per hour; one cubic' foot of illuminating gas gives off about 535 Btu per hour, and one cubic foot of natural gas gives off about 1000 Btu per hour. A Welsbach burner averages 3 cu ft of gas pier hour and a fish tail burner, 5 cu ft per hour. For information concerning the heat supplied by persons, see Chapter 2. For intermittent heating allow 10 per cent additional for rooms heated in the day time only, and for unheated intervals of several days or more, add 25 pier cent in determining minimum heating requirements and size of plant. EXAMPLE OF HEAT LOSS COMPUTATIONS (See Fig. 1.) Fig. 1.. Elevation of Factory Building ; 1. Location..:;.............................. ......................... ....................... ........................ Philadelphia, Pa. 2. Lowest outside temperature. (Table2)...... ......................................................... j.--6F 110 . . Chapter 7--The Heating Load ,, B sE temperature: In this example a design temperature 10 deg F above " lowest on record instead of 15 F is used. Hence the base temperature = (- 6 -F 10) = + 4 F. 4. Direction of prevailing wind (during Dec., Jan., Feb.)................ ..........Northwest 5. Breathing-line temperature (5 ft from floor)...................................... gg F 6. Inside air temperature at roof: The air temperature just below roo.f..i.s...h...i.g..her th' an at the 'b--r-e--a-eth:--ing 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 tteemmppeerraattuurree ouf tuhiec glass will be found t--o -b-e 6--4--.-2- F and that of the doors 61.2 F. 8. Average wind velocity (Table 2)....................................................................... 11.0 mph 9. Over-all dimensions (See Fig. 1)............................................ ................... 120 x 50 x 16 ft 10. Construction: Walls--12-in. brick, with J--in. plaster applied directly to inside surface. Roof--3-in. stone concrete and built-up roofing. 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 8, Chapter 5, Wall 2B) ......... ..................................... U = 0.34 Roof--(Table 16, Chapter 5, Roofs 2A and 3A).............................. U = 0.77 Floor--(Table 15, Chapter 5, Floors 5A and 6A)............................U => 0.63 Doors--(Table 18B, Chapter 5).............................................................U = 0.46 Windows--(Table 18A, Chapter 5),,..................................................... U = 1.13 12. Infiltration Coefficients:- Windows--Average windows, non-weatherstripped, )^6-in. crack and SHU-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 from Chapter 6. , 25.0 X 0.018 = 0.45 Btu per deg Fahr per foot of crack. Doors--Assume infiltration loss through door crack twice that of windows- or 2 Xy0.45 = 0.90 Btu per deg Fahr per foot of crack. ,..., Walls--As shown by-Table 1, Ghapter'6; a plastered wall allows so little infiltration that in this problem it may be neglected. 13. Calculations: See calculation sheet, Table 3. Ill American Society of Heating and Ventilating Engineers Guide, 1934 Fig. 2. Chart for Determining Thickness of Insulation Required to Prevent Condensation 112 Chapter 7--The Heating Load _ Table 3o. Ca1lccuullaation ShBeemtLDShmoGwiSnhgowMnetihnodFiogf. Estimating x Heat Losses of Part of Building Width in Feet Height IN Feet Met Sur face Area or Crack: Length Coeffi cient Temp. Tuff. Total Btv NTortb Wall: in. plasty----------------- Doors (2 in. Wood)------------V in. Crack------------------------ -- West Wall: Brick, M in. plaster......... .. Glass (Single)............................ U in. Crack,--...................... South WalL...... .......................... East Wall--------------------------------------Roof 3 in. Concrete and Slag surfaced built-up roofing------ Kloo7 5 in. Stone Concrete on 3 in. Cinder Concrete:---------- 50 16 . 12 12 I pair doors 656 144 60 120 16 15x4 9 Double Hung Window/s (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 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 side must leave through the cracks on the leeward side. Therefore, only one-half of the total crack will be used in computing infiltration for each side and each end of building. h.4 5 F temperature differential is commonly assumed to exist between the air on one side of a large floor laid on the ground and the ground. CONDENSATION ON BUILDINC SURFACES2 . Condensation on the interior surfaces of buildings is often a serious problem. Water dripping from a ceiling may cause irreparable damage to manufactured articles and machinery. It often results in short-cir. cuiting of electric power and lighting systems, necessitating shut-downs and incurring costly repairs. It also causes rotting of wood roof struc tures, corrosion of metal roofs, and spalling and disintegration of gypsum and other types of roof decks not properly protected. Condensation is caused by the contact of the warm humid air in a building with surfaces below the dew-point temperature, and can be remedied in two ways, (1) by increasing the tempeipture of such surfaces above the dew-point temperature, or (2) by lowering the humidity. Dehumidification, of course, is not permissible where a high relative humidity is necessary for manufacturing processes. Hence, the only alter native is to increase the surface temperature by decreasing the inside surface resistance. This can be accomplished by increasing the velocity of air passing over the surface, or by increasing the over-all resistance of the wall or roof by installing a sufficient thickness of insulation. The latter method is generally used, and the thickness of insulation is determined by ascertaining the amount of resistance to be added to increase the temperature of the interior surface above the dew-point temperature for the maximum conditions involved. This in turn is based* *For additional information on this subject see Preventing Condensation on Interior Building Surfaces, by Paul D. Close (A.S.H.V.E. Transactions, Vol. 36. 1930). 113 American Society of Heating and Ventilating Engineers Guide, 1934 on the fundamental principle that the drop in temperature is proportional to the resistance. The chart (Fig. 2)' can be used for approximating the thickness of insulation required to prevent condensation on the interior wall or roof surfaces of a building. Although this chart is intended primarily for roofs, it can be used-for walls by taking the dry-bulb temperature and the cor responding relative humidity near the walls at the point which will neces sitate the maximum heat resistance to prevent condensation, instead of using the temperature and humidity near the ceiling. Example 2. Determine the thickness of insulation required to prevent ceiling con densation for the following conditions: Dry-bulb temperature near ceiling, 85 F; Relative humidity, 70 per cent; Lowest outside temperature, -- 10 F; Construction of uninsulated roof, 1 in. yellow pine sheathing and built-up roofing; Coefficient of trans mission of roof, 0.49; Conductivity of insulation to be used, 0.30. Solution. The solution of this problem is indicated on the chart (Fig. 2) by the dotted line: . 1. Locate the inside dry-bulb temperature of 85 F on scale A, and draw a line hori zontally to the 70 per cent relative humidity curve, indicated on scale B. 2. Draw line 8 vertically downward from the intersection located in item 1. 3. Locate on scale D the temperature difference of 95 F between the ceiling tem perature of 85 F and the lowest outside temperature of -- 10 F, and draw a line hori zontally until it intersects with line 2. 4. From the point of intersection of lines 8 and S, draw a line to the point P. 5. From the intersection of lines 4 and AB, draw a line horizontally until it intersects with the diagonal line corresponding to a coefficient of transmission of the roof of 0,49, located on scale F. 6. From the intersection found by paragraph 5, draw line 6 vertically downward. 7. Locate the conductivity of 0.30 Btu per hour per square foot per degree Fahren heit of the insulation on scale G and draw a line to. point Q. . 8. From the intersection of lines 6 and 7, draw a line horizontally to scale H. on which the thickness of insulation of this conductivity is indicated, which is 1.3 in. The nearest . commercial thickness above 1.3 in. would, of course, be selected. . 114 Chapter 8 THE COOLINC LOAD Conditions to be Maintained, Cooling Load, Transmission with No Sun Effect, Temperatures, Sun Effect, Transmission Through Glass, Heat and Moisture Leakage, Heat and Moisture Sources THE cooling load may be calculated in a manner similar to that used in calculating the heating load as the conditions are much the same. The direction of the flow of heat is reversed, however, and in most cases additional factors must be considered, such as the sun effect and the heat from occupants, lights, motors, and other sources. The character of the load depends on the type of building to be cooled as, for example, in auditoriums and other places, of assemblage where the maximum load usually is that due to the heat and moisture given off by the occupants, or in office buildings and residences where sun effect and the transmission and infiltration of heat, through the building shell are most important. While cooling is generally identified with the summer season, it is often necessary to cool in winter as well as in summer. In a crowded place of assemblage the heat given off by the occupants, together with that given off by the lighting and power equipment, may be more than the normal heat loss through the structure even in winter under cold climatic con ditions. A typical case for winter might show about 300 Btu of body heat, plus 100 Btu per person from lights, etc., being given up to the building, compared with about 200 Btu heat loss from the building, per person per hour. This would mean that 200 Btu per person must be absorbed by the air conditioning system. Much of the basic information for the design of comfort conditioning installations has resulted from research conducted at the A.S.H.V.E. Research Laboratory and at institutions with which cooperative research investigations have been carried on. These data include the effective temperature index, and heat and moisture loss data, given in Chapter 2. CONDITIONS TO BE MAINTAINED The conditions to be maintained in an enclosure are variable and depend on many factors, especially the season of the year and (during the summer) the outside dry-bulb temperature and the duration of the period of occupancy. Information concerning the proper effective temperatures to be maintained fop various seasons is given in Chapter 2, where are also tabulated the most desirable indoor air conditions to be maintained in summer for exposures less than three hours. (See Table 2, Chapter 2). In installations for auditoriums and theaters the requirements are 115 3SSB8& American Society of Heating and Ventilating Engineers Guide, 1934 different from those in factories, since there must be a considerable volume of air circulated in order to provide ventilation and cooling. COOLINC LOAD The cooling load may be divided into the following parts: 1. Transmission of heat through walls, roof, glass, etc., with allowances for sunexposed surfaces and heat capacity. 2. Transmission of solar radiation through glass and absorption by interior furnishings. 3. Heat and moisture from infiltration and from outside air introduced. 4. Heat and moisture from occupants and heat from lights, machinery and other sources. Transmission With No Sun Effect The transmission load for surfaces not exposed to the sun is calculated in a manner similar to that described in Chapter 7, by means of the following formula: where Bt = AU (to - t) . (I) Ht = heat transmitted through the material of the wall, glass, roof, or floor in Btu per hour. . A = net inside area of wall, glass, roof, or floor in square feet, i = inside temperature, degrees Fahrenheit. to = outside temperature, degrees Fahrenheit. U = coefficient of transmission of wall, floor, roof, or glass in Btu per hour per square foot per degree Fahrenheit difference in temperature. (Tables 8 to 18, Chapter 5). . Temperatures The maximum cooling load in summer may be calculated for an outside dry-bulb temperature not to exceed 95 F and a wet-bulb temperature not to exceed 80 F. . While higher outside dry-bulb temperatures are frequently observed they are either of short duration or accompanied by low relative humidities. Weather Bureau reports are frequently mis- . leading in this respect as they report the maximum temperature for the day with the relative humidity which occurs during a different period and which usually is much higher than the relative humidity occurring at the maximum temperature. Any statement of weather condition which gives , a wet-bulb temperature higher than 80 F in the United States is question able. f Summer dry-bulb and wet-bulb temperatures for various cities are given in Table 1. It will be noted that the wet-bulb temperatures are not the maximums but the design temperatures which should be used in air conditioning calculations. The maximum outside wet-bulb temperatures as given in Weather Bureau reports usually occur only from 1 per centto 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. ' Sun Effect Solar radiation is an important factor in the mechanism of heat flow into buildings. Research conducted at the A.S.H.V.E. Research Labora- 116 ' Chapter 8--The Cooling Load Average Maximum Design Dry-Bulb Temperatures, Design Wet-Bulb Table 1. Temperatures, Wind Velocities, and Wind Directions for June, July, August, and September Ala-- Birmingham.-- Mobile---------------- Phoenix--------- 93 94 110 Artz...... Ark...... Little Rock.------Los Angeles_____ 95 88 Calif--- San Francisco.... 85 Colo......... Conn....... Denver................. New Haven........ Washington-....... 90 88 93 D. Fla......... - Jacksonville....... Tampa............... - 94 94 Ga- Atlanta................ Savannah.... ....... 91 95 Idaho....... Ill........ -- Boise.................... Chicago------------Peoria.. 95 88 91 Ind....... ....... Iowa---------- Ky............... I-a............... Maine.--.... Md----------Mass--....... Mich.......... Minn.......... Miss.--..... Mo--....... Indianapolis......... Des Moines_____ Louisville.............. New Orleans.------ Portland................ Baltimore.............. Boston......... -....... Detroit.................. Minneapolis------Vicksburg............. Kansas City........ St. Louis-.............. 90 92 94 94 85 93 88 88 84 95 92 93 Mont--...... Nebr........ Nev.......... N. J-....... N. Y.......... Helena....... ............ Lincoln......... ........ Reno---------- -------Trenton----Albany...... .................... ............ Buffalo-.......................... -........ 87 93 93 93 90 83 New York.................................. 91 N. M........... N. C--...... N. D........... Ohio.--........ Santa Fe ............................. -- Asheville. Wilmington.......-..................... Bismarck. Cleveland.................................. Cincinnati.... ............................ 87 87 93 88 87 93 Okla__ Ore-----Pa------- Oklahoma City...................... Portland.................................... Philadelphia------------ ------ ------ Pittsburgh-............................. 96 83 93 91 R. I.. S. C.. Providence_____________ ____ Charleston............................... Greenville................................. 85 94 93 Tenn.. Chattanooga............. .............. 94 Memphis.... .............................. 93 77 78 77 77 70 68 64 74 76 78 79 75 79 65 73 75 73 74 75 79 71 76 73 72 72 78 75 76 63 74 64 75 74 72 75 63 72 79 69 72 75 76 65 76 73 73 80 76 76 -- 77 5.2 8.6 6.0 7.0 6.0 11.0 6.8 7.3 6.2 8.7 7.0 7.3 7.8 5.8 10.2 8.2 9.0 6.6 8.0 7.0 7.3 6.9 9.2 10.3 8.4 6.2 9.5 9.4 7.3 9.3 7.4 10.0 7.1 12.2 12.9 6.5 5.6 7.8 8.8 9.9 6.6 10.1 6.6 9.7 9.0 10.0 9.9 6.8 6.5 7.5 S SW W NE SW SW S S S SW E NW SW NW NE S SW SW SW SW s SW SW SW SE SW s SW SW s w SW s SW SW SE ' SE SW NW S SW s NW SW NW NW SW NE SW SW 117 American Society of njiAiinv, ana VENTILATING ENGINEERS Table 1. Average Maximum Design Dry-Bulb Temperatures, Design Wet-Bulb Temperatures, Wind Velocities,-and Wind .Directions for June, July, August, and September (Continued) . State Crir Average Maximum Design `Dar-Bma Design Wet-Bulb Souusb WtND PoBnaora Vblocitt Sujoieh Wind MPH Direction Texas.. Utah..... Vt.___ _ Va..... . Wash.. W. Va.. Wis...... Wyo____ Dallas.............. Galveston____ San Antonio... Houston.......... El Paso.. Salt Lake City.,.. Burlington............ Norfolk Richmond.... ......... Seattle.___________ Spokane.................. Parkersburg.......... Madison.................. Milwaukee...... . Cheyenne............... 99 93 100 93 98 95 85. 91 . 95 83 89 90 89 87 85 76 79 78 79 69 67 71 76 76 61 63 74 73 72 62 9.4 9.7 7.4 7.7 6.9 8.2 8.9 10:9 6.2. 7.9 . 6.5 5.3 8.1 10.4 9.2 s s SE S E SE S S SW s SW SE SW s s tory1 has shown that a large error may be introduced into the calculations by failure to consider the periodical character of heat flow resulting from the diurnal movement of the sun and the heat capacity of the structure, which determine the timing and magnitude of the heat wave flowing through the wall into a building on a hot, sunny day. Unfortunately, despite intensive study, all data on solar radiation Table 2. Heat Equivalents of Various Devices, Btu Lights and electric appliances 'Motors___ . Restaurant coffee urns, 10-gal capacity. Dish warmers per 10 sq ft of shelf..... ..... Restaurant range--4 burners and oven.. Residence gas range Giant burner...... ......................................... Medium burner.......................................... Oven............................................................... Pilot.................. Electric Range Small burner Medium burner.............. Large burner................... Oven............ ...................... Appliance connection.... Warming compartment 3415 per kilowatt 2546 per horsepower hour 16000 per hour 6000 per hour 100,000 per hour 12000 per hour 9000 per hour 1000 per cu ft of space 250 per hour 3412 per hour 4100 per hour 7700 per hour 10236 per hour 2250 per hour 1023 per hour lFor further information on this subject see folio-wing A.S.H.V.E. research papers: Coefficients of Heat Transfer as Measured under Natural Weather Conditions, by F. C. Houghten and C- G. F. Zobel (A.S.H. V.E. Transactions. Vol. 34, 1928)Absorption of Solar Radiation in Its Relation to the Temperature, Color. Angle and Other Characteristics of the Absorbing Surface, by F. C. Houghten and Carl Gutberiet (A.S.H.V.E. Transactions, Vol. 36,1930);- Heat Transmission as Influenced by Heat Capacity and Solar Radiation, by F. C. Houghten, J. L. Blackshaw, E. M. Pugh and Paul McDermott (A.S.H.V.E.'.Trans actions, Vol. 38, 1932). 118 Chapter 8--The Cooling. Load through buildingwalls are too theoretical and mathematically complicated to be of much practical value to the heating and ventilating engineer Accordingly, the customary rule-of-thumb method of adding an arbitrary 25 F to the dry-bulb temperature difference in calculating the heat transmission through a wall or roof which may be exposed to the sun for any appreciable length of time is given as a workable solution to an ex ceedingly complex problem. Solar Radiation Fig 1 shows the total amount of solar energy in Btu per square foot per hour received during the day by a surface normal to the rays of the sun, by a horizontal surface, and by east, west, and south walls. The curves are drawn from A.S.H.V.E. Laboratory data obtained by pyrheliometer, are based on sun time, and are for a perfectly clear day on August 1 at a north latitude of 40 deg. Data from these curves may be used with little error for most United States latitudes and for all of the hotter months of the year. The absorption of solar radiation by an interior surface depends upon the character of the surface, the angle of the surface with respect to the direction of the radiation, and the angle and type of glass through which the radiant rays pass. The heat absorption by a black oilcloth surface perpendicular to the sun's rays was found to be as high as 273 Btu per square foot per hour, based on tests conducted by the A.S.H.V.E. Re search Laboratory in Pittsburgh8. Lamp black, red brick dust, and aluminum bronze painted surfaces perpendicular to the sun's rays showed respectively 94.0, 63.4, and 28.2 per cent as high a rate of absorp tion as the black oilcloth. Transmission Through Class In considering the effect of glass on heat absorption, several factors must be considered. As the sun's rays impinge against and pass through an intervening sheet of glass, some radiation is reflected directly from each of the two glass surfaces, and some is absorbed by the glass depending upon its character and thickness. All of the heat reflected by the glass surfaces and most of that absorbed- within the glass is stopped from passing through the glass into a room. The A.S.H.V.E. tests indicated that a single pane of double strength glass absorbs from 8.9 to 16.5 per cent of the solar radiation passing through it when the impingement is normal. For smaller angles of impingement, the glass retards percentages of the total radiant energy approximately in proportion to the sine of the angle. Experiments' indicate a glass absorption of 16.7 per cent for one pane of glass and 37.5 per cent for two J^-in. panes separated by a 1%-in. air space. In a recent paper by the A.S.H.V.E. Research Laboratory* it was shown 'Absorption of Solar Radiation in Relation to the Temperature, Color, Angle, and Other Characteristics of the Absorbing Surface, by F. C. Houghten and Carl Gutberiet (A.SJi.V.E. Transactions, Vol. 36,1930). 'Field Studies of Office Building Cooling (A.S.H.V.E. Research Paper), by J. H. Walker. S. S. Sanford, and E. P. WeUs'(A.S.H.V.E. Transactions, Vol. 38, 1932). Radiation of Energy Through Glass by J. L, Blackshaw and F. C. Houghten (A.S.H.V.E. Journal Section, Healing; Piping and Air Conditioning. October, 1933). 119 American Society of Heating and Ventilating Engineers Guide, 1934 ; " ''4 2 SUN TIME AUG ! A.M .I Rm ! 10 6 . 120 I/ iF g . 1. C u r v e s G i v i n g So l a r I n t e n s it y N o r m a l t o S u n , o n H o r iz o n t a l Surface and on W alls for A ugust I " Chapter 8--The Cooling Load h t ordinary double strength window glass transmits no measurable 1mount of energy radiated from a source at 500 F or lower; that it trans- 3 its only 6.0 and 12.3 per cent of the total radiation from surfaces at 700 F and 1000 F, respectively; and that it transmits 65.7 per cent of the diation from an arc lamp, 76.3 per cent of the radiation from an in candescent 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. ' Some recent tests' 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 require ments of different sides of the building. Where the glass area is not great, the rule-of-thumb method of adding an arbitrary 25 F to the design dry-bulb temperature difference may be applied. The heat flow may then be figured as if there were no sun effect. Heat and Moisture Leakage An allowance must be made for the heat and moisture in the outside-air introduced for ventilating purposes or entering the building through cracks, crevices, doors, and other places where infiltration might occur. The volume of air entering due to infiltration may be estimated from data given in Chapter 6, and information on the amount of outside air required for ventilation will be found in Chapter 2. The heat gain resulting from the outside air introduced may be esti mated from the following formula: where * Hi = Qdo (Bo -B) . (2) - Hi = heat to be removed from outside air entering the building, Btu per hour. Q = volume of outside air entering the building, cubic feet. d0 -- density of outside air, pounds per cubic foot, at the temperature to- B0 = heat content of mixture of outside dry air (at temperature to) and water vapor, Btu per pound of dry air. .; : 6 = heat content of mixture of inside dry air (at temperature t) and water vapor,*-;: . Btu per pound of dry air. /-i 1 Heat and Moisture Sources Figs. 4 to 7, Chapter 2, show the heat and moisture given off by human beings under various conditions of activity. For average conditions where 'Footnote p,,J 19. 121 American Society o/'Heating and Ventilating Engineers VjUIDE, aiperson is normally at rest, as in a theater, or doing very light work, as in a; restaurant or residence, the heat given off will vary from 700 to' 1200 .grains of moisture per hour. Examples illustrating heat and moisture loss calculations for human beings are given in Chapter 2. All sources of heat must of course be considered in designing the conTable*^ system. The heat equivalents of various devices are given in An example of the calculation of the cooling load, is given in Chapter 9. 122 Chapter 9 CENTRAL FAN AIR CONDITIONING SYSTEMS Types of Systems, Dehumidifier, By-Pass, Local Recirculation, Surface Cooling Unit Method CENTRAL fan systems, equipped for cooling.and dehumidifying, are used principally in the air conditioning of theaters, restaurants, office buildings, or other places where many people gather, and in manu facturing establishments where air conditions have an important influence on the quality of the product. The design of such systems is considered in this chapter, while in Chapter 22 central fan systems for heating and humidifying are described. TYPES OF SYSTEMS The four most common types of central fan cooling and dehumidifying systems are as follows: 1. All air through dehumidiiier or air washer. 2. By-pass method, by which part of the air is put through the dehumidifier and mixed with air from other sources. ' 3. Local recirculation. * 4. Surface cooling. There are, of course, many other methods which may be employed such as dehumidifying air by passing it through or over a dehydrating agent, or passing air directly over ice, or by evaporative cooling. (See Chapters 10 and 11). DEHUMIDIFIER METHOD The dehumidifier system is simple, comprising a dehumidifier, fan, reheaters and necessary accessories, such as pumps, motors, piping and controls. The return air from the conditioned enclosure is mixed with the . outside air and carried through-thg dehumidifier and cooled. It may then be reheated by various methods to the predetermined delivery conditions. Information concerning dehumidifiers will be found in Chapter 11. Example 1. Dehumidifier Method. (See Figs. 1 and 2). The restaurant shown in Fig. 1 has a seating capacity of 300 people and there are 20 employees. The lightingjoad is 4200 watts and the lights are used continuously during the day. The service counter is equipped with an exhaust system with a capacity of 1500 cfm which is used to remove all the heat and moisture produced by coffee urns, steam tables, plate warmers, toasters, and grilles. ' The windows along the north and west streets are colored glass and used only for decorative purposes. Each window is 5 ft wide by 2 ft deep. The show windows on the 123  American Society of Heating ond Ventilating Engineers Guide, 1934 south street and the entrance windows and the first windows on the west street are 9 ft high. ._ The overall heat transmission factors, V, for the different walls of the restaurant are determined by the methods outlined in Chapter 5 and are found to be the following: Exterior walls, 0.221; interior wall, 0.296; floor, 0.433; and ceiling, 0.299. Determine the dehumidification, cooling and reheating loads, considering the outside dry-bulb temperature to be 95 F and the outside design wet-bulb temperature to be 75 F. Solution. According to Table 2, Chapter 2, the inside dry-bulb temperature should be 80 F and the wet-bulb temperature should be 65 F. The heat gain to be considered may be calculated as follows; South Wall BUILDING - Total area = 27 X 15 = 405 sq ft Glass (including entrance windows) 2 (9 X 9) + 2 (5 X 9) + (door) (6 X 9)= 306 sq ft . Net wall area = 405 -- 306 = 99 sq ft Transmission factor for wall = 0.221 . Transmission factor for glass = 1.13 . Temperature difference = 15 + 25 (for sun effect) = 40 deg . 99 X 0.221 X 40 = 875 Btu per hour 306 X 1.13 X 40 = 13831 Btu per hour West Wall Total area = 100 X 15 = 1500 sq ft Glass 15 X (2 X 5) + (9 X 5) = 195 sq ft Net wall area = 1500 -- 195 1305 sq ft 1305 X 0.221 X 40 = 11536 Btu per hour 195 X 1.13 X 40 = 8814 Btu per hour Heat Gain, Blu per Hour 14706 , 20350 North Wall (no sun effect) Total wall area = 27 X 15 = 405 sq ft Glass 2 X (2 X 5) = 20 sq ft Net wall area = 385 sq ft 385 X 0.221 X 15 = 1276 Btu per hour 20 X 1.13 X 15 = 339 Btu per hour 1615 East Wall (interior, no sun effect) Total wall = 100 X 15 = 1500 sq ft 1500 X 0.296 X 15 = 6660 - Fig. 1. Floor Plan of Restaurant Chapter 9--Central Fan Air Conditioning Systems Fig. 2. Diagram of Dehumidifier Method floor 100 X 27 = 2700 sq ft 2700 X 0.433 X 15 = 17537 Ceiling 100 X 27 = 2700 sq ft 2700 X 0.299 X 15 = 12110 INFILTRATION The windows are sealed in metal frames set in concrete and the infiltration may be considered negligible, particularly as the prevailing wind is at a minimum when the temperature is high. The revolving entrance door, however, does present an infiltration proTbhleemd.oor is 8 ft high and 6 ft wide and during rush hours can be assumed to revolve approximately one turn per person entering. This figure is purely an assumption but the percentage error would not be more than 2 or 3 per cent of the total heat load. % The volume of the door = --- ' X 8 = 226 cu ft 226 X 300 W__i_t_h 300 .persons per hour entering this would be equivalent to 60 1130 cfm. A volume of 1130 cfm of air cooled from a wet-bulb temperature of 75 F to a wet-bulb temperature of 65 F would be equivalent to the removal of heat as follows; Total heat at 75 F wet-bulb = 37.81 Btu per hour. (See Table 2, Chapter 1). Total heat at 65 F wet-bulb = 29.62 Btu per hour 8.19 Btu per hour-to be removed dm x 8.19 X 60 = 38,831 Btu pethaur 14.3 " Half of this, however, would be provided for by the outside air taken into the cooling unit so the heat gain to be considered under infiltration would be 19,415 Btu per,hour. Lights - PEOPLE Fig. 4, Chapter 2, shows the heat loss from the human body at different effective temperatures. For an effective temperature of 73.4 deg for persons at rest the heat loss is 400 Btu per hour per person of which 225 Btu per hour is sensible and 175 Btu per hour is latent heat. As there are 300 occupants and 20 employees the heat gain would-be (300 + 20) X 225 = 72,000 Btu per hour of sensible heat (300 + 20) X 175 = 56,000 Btu per hour of latent heat Fig. 6, Chapter 2, shows the moisture loss from human bodies and at 80 F to be about 1200 grains per hour per person at rest. The total moisture gain would then be (300 + 20) X 1200 = 384,000 grains per hour. 125 American Society of Heating and Ventilating Engineers Guide, 1934 FOOD The heat given off by food is somewhat difficult to estimate. In the summer, men as a rule usually eat more hot food than women, who prefer salads or light sandwiches. A fair average for a mixed group restaurant may be taken at 35 Btu per person. The turn over per hour must likewise be taken into consideration. In sandwich shops and quick service cafeterias the turnover may be as high as three persons per seat per Hour. Other types of restaurants vary according to price and service class. For the restaurant in Fig. 1 a turnover of two persons per seat per hour will be taken as an average figure. The heat gain from the food will then be v 300 X 35 X 2 = 21,000 Btu per hour The total Btu per hour gain would be-- ' South wall and glass West wall andglass North wall and glass East wall Floor Ceiling Infiltration Lights People Food 14706 20350 1615 6660 17537 12110 19415 14343 72000 21000 199736 Btu per hour sensible heat With a spray type dehumidifying system an entering air temperature of 12 deg less than the maintained condition may be used because of the high ceiling. With main- ^ Wb), 65 F (wb), 56F (dp), and entering conditions of 68 F (db), 60 F (wb) and 56J^ F (dp), neglecting for the moment the moisture gain in the enclosure, the dew-point temperature in the dehumidifier would be 56f F, assuming a saturation-type denumidifier. With a sensible heat load of 199736 Btu per hour and a 12-deg difference between the entering and maintained conditions, the volume of air required would be: 199736 X 55.2 12 X 60 = 15313 cfm 15313 13.35 = 1146 lb per minute With 384,000 grains of moisture per hour to be picked up, the entering dew-point- temperature should be low enough so that after the pick-up the dew-point temperature will be 56}4 F. 384000 1146 X 60 5.6 grains per pound to be picked up Grains per pound at 56K F = 68.10 (dp) - 5.60 0 - 62.50 grains per pound in entering air which corresponds to a dew-point temperature of 54.17 F. With an entering dry-bulb. temperature of. 68 F and a dew-point temperature of 54.17 F, the entering wet-bulb temperature will be 59.56 F. A check of the air quantity may be made on the basis of total heats. The total heat to be picked up is as follows: ' 199736 Btu per hour sensible heat 56000 Btu per hour latent heat 255736 Btu per hour total heat 126 -- -': ------ - - - . , . . Chapter 9--Central Fan Air .CoNpmQin^p-.Systems;; >..,* i- The total heat per pound of air available is the total' heat at the maintained wet-bulb temperature minus the total heat at the entering wet-bulb temperature. . Total heat at 65 F (wb) = 29.65 Total heat at 59.56 F (wb) = 25.89 .. 3.76 Btu per pound 255736 . 3.76~X~60 ~ 1135 lb per mmute . This is within 1 per cent of the quantity previously calculated. - The exhaust system over the service counter has been designed to handle 1500 cfm nd the exhaust system for the washrooms handles 100 cfm for each washroom or a total a? 200 cfm. Exfiltration through the revolving door has been calculated to be 565 cfm. The total quantity of fresh air to be handled would then be . Exhaust hood Washroom exhaust Exfiltration 1500 200 565 ' 2265 cfm or 169 lb per minute The 1146 lb per minute of air includes the quantity, lost by exhausting and exfiltration of 2265 cfm or 169 lb per minute. This air must be'taken from the outside. The refrigeration required to cooi the air would be that necessary to cool 977 lb per minute of recirculated air from 65 F (wb) to 54.17 F (dp) plus 169 lb per minute of fresh air from 75 F (wb) to 54.17 F (dp), . . .. Total heat at 65 F (dp) = 29.65 Total beat at 54.17 F (dp) = 23.13 ' 6.52 Btu per pound 977 X 6.52 = 6370 Btu per minute Total heat at 75 F = 37.72 . Total heat at 54.17 F = 23.13 ... 14.59 Btu per pound 169 X 14.59 = 2466 Btu,per minute or a total of 8836 Btu per minute. . As a tpn of refrigeration is equal to 200 Btu per minute, this system would require = 44.18 tons of refrigeration. : : ' Reheating. Heating 1146 lb per minute from 54.17 F to 68 F would require . ' 1146 X (68 - 54.17) X 13.35 X 60 = Btu per hou, , 55.2 As the total heat of the steam may be assumed as 1000 Btu, it would require 230 lb of steam per hour. . BY-PASS METHOD The by-pass method comprises a dehumidifier, a fan, a system of dampers operated either automatically or manually, reheaters, pump, motor, piping and accessories similar to a dehumidifier system. In the by-pass system the outside air and sometimes' part of the return air is carried through the dehumidifier and the remainder of the return air is by-passed around the dehumidifier to the fan inlet and mixed with the 127: American Society of Heating and Ventilating Engineers Guide, 1934 cool air to give the proper delivery temperature. By cooling a portion of the total amount of the air, the dehumidifier, pump, motors and water piping are smaller than in the system using all the air through the washer. As the major portion of the reheating is done by the by-passed air, smaller size reheaters are used. This type of system provides a constant supply of air regardless of load, and a decrease in the total refrigeration required for the season. Fresh Air 95* F. (db) 75 F. (wb) 169 lb. per min. Return Air80 F. (db.). 65* F. (wb) 301 lb.per min. < -o-SE 977 lb. pe. r min. -------------- 1 Dehumidifier 51.2* F (dp) 3 oOc. 68*F. (db)in 54.17* F. (dp)l' *"l \ 68" F. (db) conditioned 54.17" F. (dp) Enclosure 1146 lb. per min. Fig. 3. Diagram of By-pass Method Examples. By-pass Method. (Fig. 3). Same data as Example 1. Instead of passing all the air through the dehumidifier to be cooled, a portion of it is passed through and the balance is mixed with the conditioned air at the leaving end of the dehumidifier, the mixture being so proportioned that the resultant conditions will be those required to give proper maintained conditions in the enclosure. . Setting forth the conditions as shown in Fig. 3, it is now necessary to calculate the quantity of air to be passed through the dehumidifier, the quantity by-passed, and the dew-point temperature it is necessary to carry in the dehumidifier to give the con ditions sought. ' There are three unknown quantities to be determined and these may be solved in two successive steps. Let x = the percentage of air to be by-passed. y = the percentage of total air through the dehumidifier. t = the dew-point temperature to be maintained in the dehumidifier. The quantity * of 80 F air must mix with y quantity of dehumidified air to give a resultant of 65 F. Also, x quantity of air at 56J F (dp) must be mixed with y quantity erf dehumidified air to give a resultant of 54.17 F (dp). It is assumed, of course, that the air passing through the dehumidifier is saturated, that is, the dry-bulb, wet-bulb and dew-point temperatures are the same. Therefore, 80* + yl = 68 56.5* + yt = 54.17 23.5* + 0 = 13.83 (la) (lb) (lc) 13.83 *= = 59 per cent of air by-passed. y = (1 -- *) = 41 per cent of total air through washer. The second step is to determine the dew-point temperature in the dehumidifier. Substituting in either Equation la or lb and solving will give the desired results as follows: . (80 X 0.59) + / X 0.41 = 68 (2a)1 1 = 68(j^j4~ = 512 F (dp) (2b) 128 Chapter 9--Central Fan Air Conditioning Systems As the total weight of air is 1146 lb per minute and 41 per cent is required through the dehumidifier, the work done would be 1146 X 0.41 = 470 lb through dehumidifier -- 169 lb fresh air 301 lb recirculated air Refrigeration required would be Total heat at 65 F = 29.85 Total heat at 51.2 F = 20.85 ' 9.00 Btu per pound 301 X 9.0 = 2709 Btu per minute Total heat at 75 F !" = 37.72.Btu per pound Total heat at 51.2 F = 20.8fTBtu per pound 16.87 Btu per pound 169 X 16.87 = 2851 Btu per minute 2709 + 2851 = 5560 Btu per minute, total . 5560 = 27.80 tons of refrigeration required. This is 63 per cent of that required 200 when all the air passed through the washer. LOCAL RECIRCULATION METHOD The local recirculation system cools and dehumidifies a small portion of air and by means of nozzles which are usually specially designed, the air is introduced into the conditioned enclosure at a high velocity (1200 to 1500 fpm) in'such a way as to induce the air in the enclosure to circulate and mix with it to give the proper predetermined conditions. Fresh Air ` 95*f.;(db) 75* F (wb) 169 lb. per min.. ' Return Air 80" f. (db) 65 F. (wb) 301lb.per min. --------- 1 Dehumidifier 51-2* F (dp) 470 lb. per min.f7 | rni 54.17* F (db) Conditioned "" 54.17" F (dp) Enclosure Fig. 4. Diagram of Local Recirculation Method Example S. Local Recirculation Method. (Fig. 4). Same data as Example 1. With this method a small quantity of air is used and discharged into the enclosure at a relatively high velocity to give the air in the room an induced circulation. This is done by omitting the reheaters and discharging the air into the enclosure at the dew-point temperature. With the cut-and-try method it is.found that a dew-point temperature of 51.2 F is necessary to pick up the heat and moisture in the enclosure, that is, the dry-bulb and dew-point temperatures are the same. 199736 X 55.2 , = 470 lb per minute (80 - 51.2) X 60 X 13.35 The 470 lb per minute is the same as that required through the dehumidifier in the by-pass system and as the temperature is the same, the refrigeration load will be the same, the only difference'between the two methods being the additional fan horsepower in the by-pass method, which is negligible, and the larger sized duct work. 129 . American Society of Heating and Ventilating Engineers Guide, 1934 SURFACE COOLING UNIT METHOD The fourth type of system employing a surface cooling unit of the extended-surface type will cool and dehumidify. A refrigerant is cir culated or expanded within the unit and air is blown over it. This system has the advantages of lower initial cost and low operating cost, and it does not require as much attention as a spray-type system'. For comfort cooling, water is usually used as the refrigerant. If a refrigerant with a temperature lower than 32 F is used, care must be exercised in the design to prevent frosting. Low temperature refrigerants often reduce the moisture content of the air lower than is usually required. Water at 45 to 50 F is quite practical, using a 10 to 15 deg rise in water temperature depending on the quantity of water used and the velocity of the water required through the tubes.' ' . Although surface cooling units have advantages over the conventional spray-type systems, they are usually adaptable for both cooling and heat ing, and they can be used to control humidity in summer. The effective cooling accomplished by the unit is dependent upon many variable factors. The air. velocity through the unit, air temperature, moisture content, water temperature, and velocity of the water through the tubes, must all be considered in designing the unit. If any of these factors vary without a corresponding variation of the other factors, the effective cooling obtained by the unit will drop off. F-r-e-s-h-A-i-r-9-5-"-f-.-<-db->--7-5-"-F-. (whl .82 2 F <dt" 169 lb. per min. \S66~|_Fc_ <wb> Return Air 80 F (db.) 65s F <wb> 977 lb. per min. (dp) Water Out 60* F pi 68* F (db) 58% F. twttt 52* F. (dp) 11461b. per min. Water In 50* F Fig. 5. Diagram of Surface Cooling Method Example 4- Surface Cooling Method. (Fig. 5). Assuming the same required condi tions and load as in Example 1, a surface cooling unit of proper size and capacity may be determined by the following calculations: .d Outside air.......................... 169 lb per minute at 95 F (db), 75 F (wb) Recirculated air................ 977 lb per minute at 80 F (db), 65 F (wb) Air leaving unit................ 1146 lb per minute at 68 F (db), 59.56 F (wb), 54.17 F (dp) Water, in.... ....................... 50 F ' Water, out......................... 60 F .. Water flowing counter to air flow. It will be noticed from Fig. 5 that the dew-point temperature of the entering mixture is lower than the leaving water temperature but higher than the entering water tempera ture. Condensation of the moisture in the entering air will therefore occur some place in the unit where the temperature of the pipe or surface is lower than 57 A F. Condensation will continue to the leaving end of the unit and will result in a dew-point temperature of the leaving air between 50 F and 54.17 F, or approximately 52 F. With this dew-point temperature and the dry-bulb temperature of the air leaving of 68 F, which has been set by pre-determined calculations, the new wet-bulb temperature will be 58M F*. '. *It can. readily be shown that if the entering water temperature were 54.17 F and the other conditions were such that-the leaving dew-point temperature were 54.17 F as desired, the refrigeration load would be the same as for the by-pass and local recirculation systems.' These^conditions, however, have not been approached in practice to date. :- 130 Chapter 9--Central Fan Air Conditioning (Systems The total heat to be removed by the water will be Total heat at 66)4 F (wb) = 30.77 Total heat at 58J4 F (wb) = 25.20 5.57 Btu per pound of air 1146 X 5.57 = 6383 Btu per minute Refrigeration = ~ 31.90 tons _' , . 6380 Btu per minute Quantity of water required = ------io deg X 8 33 c 76.6 gpm As the cooling efficiency is dependent partly on the velocity of water through the tubes, this must be determined from a manufacturer's catalog. For instance, one manu facturer gives the formula , y _ (gallons per minute) X 1.235 36 ^ where V velocity in feet per second. 36 = number of tubes per unit. 1.235 = a constant for the particular sized pipe used. Using Formula 3, the velocity would be, . . 76.6 X 1.235 = 2.63 fps 36 To determine, the amount of cooling, surface required it is necessary to ascertain the mean temperature difference between the air and water, and'the coefficient of trans mission. The formula for the mean temperature difference is: (T, - T,) - (F, - T.) 7d (4) where . 7d = mean temperature difference. Ti = entering dry-bulb temperature of air. Ti = leaving water temperature. T, = leaving dry-bulb temperature of air. T, -- entering water temperature. . ` (82)4 - 60) - (68 - 50) Ti = , /82H-60\ Ugel 68 -- 50 / = 22)4 - 18 ***(/2-*2)4)\ -- 20.2 F The coefficient of transmission is usually taken from the manufacturers data, knowing the water velocity through the unit and the air velocity over the tubes. The velocity of the water.through the tubes has been determined, and assuming a velocity of 600 fpm for the air the coefficient of transmission is (from manufacturer's curves): K = 9.7 Btu per square foot surface per mean temperature difference. " The cooling surface required is usually based upon the sensible heat load. The latent heat due to condensation is taken out at the same time the sensible heat is extracted, and no extra surface is required unless the latent heat exceeds approximately 40 per cent of the total heat. This is due to the higher coefficient of transmission factor because of the wetted surface. This factor holds fairly consistent up to a point where the latent heat 131 American Society of Heating and Ventilating Engineers Guide, 1934 approaches 40 per cent of the total heat load to be removed. If this amount is exceeded, approximately 10 per cent surface should be added. Surface required (5) = . (5) where 5 = surface area, square feet. Hs = sensible heat load, Btu. K = coefficient of transmission. - The sensible heat load may be determined by subtracting the latent heat from the total heat. Total heat removed = 6383 X 60 = 382,980 Btu per hour. Latent heat at 573^ F (dp) = 10.70 (From Table 2, Chapter 1). Latent heat at 52 F (dp) = 8.75 (From Table 2, Chapter 1). 1.95 Btu per pound " 1.95 X 1146 X 60 = 134,082 Subtracting this from the total heat = 382,980 - 134,082 Sensible heat ' 248,898 Btu per hour ,, 248,898 , J = 97 x 20 2 ~ 1270 ^ ft of surface As the latent heat load is 35 per cent of the total heat load, it is not necessary to add 10 per cent to this surface. For information on the control of air conditioning systems, see Chapter 14` ' ' ' .0 / 132 Chapter 10 COOLING METHODS Methods of Cooling Air, Evaporative Cooling, Dehumidification by Adsorption and Absorption, Silica Gel Systems, Alumina Systems, Refrigeration, Air Conditioning Applications, Refrigeration Machines, Evaporators, Compressors, Condensers, Amount of Cooling Water, Refrigerants, Methods of Cooling, Air Coolers, Water Coolers, Indirect Coolers, Steam Jet System, Ice for Air Cooling FROM a study of the data in Chapter 2 and in Chapter 8 it is ap parent that a reduction of effective temperature may be produced by any one of the following methods or combinations thereof: a. Lowering of the dry-bulb temperature by the removal of sensible heat without change of the dew-point temperature (sensible cooling). b. Lowering the dew-point temperature by the removal of moisture without change of the dry-bulb temperature (dehumidifying). c. Lowering of the dry-bulb temperature through the evaporation of moisture without the addition or the subtraction of heat (evaporative cooling). d. Increasing the air motion over the body with the consequenting higher rate of evaporation from the skin (air motion). As an example let the condition be considered of 92 F dry-bulb, with a 40 per cent relative humidity, corresponding to a wet-bulb temperature of 72.8 F, and an effective temperature for still air of 81.1 F. This effective temperature may be reduced 3.1 F by any of the four basic methods mentioned as follows: First, by lowering the dry-bulb temperature to 85.5 F without changing the dew-point of 64.2 which gives an effective temperature of 78 F. Second, by reducing the moisture content of the air to 46 grains per pound of dry air without changing the dry-bulb temperature which gives an effective temperature of 78 F. Third, by reducing the dry-bulb temperature to 83.8 F without changing the total heat of the air, requiring the evaporation of 14 grains of moisture per pound of dry air, when the effective temperature again will be 78 F. . Fourth, by increasing the air movement from still air to 460 fpm, velocity which will reduce the effective temperature 3.1 F from 81.1 F to 78 F. Best Method to Employ The best method of reducing the effective temperature in any specific case will always depend on the accompanying circumstances and..only can be determined by the thorough analysis of a competent engineer. Generally speaking, the removal from the air of the sensible heat, or moisture, or both, by sensible cooling or dehumidifying is the most satisfactory method.. Adequate results by the utilization of air motion, or by evaporative cooling, are difficult to obtain because of the dependence 133 American Society of Heating and Ventilating Engineers Guide, 1934 of both methods upon climatic conditions beyond the engineers control although these methods are much less expensive than the first two mentioned. Cooling by evaporation is satisfactory only when the air to be cooled is very dry; air motion as a means of producing cooling effect is never entirely adequate in the range of high temperatures. Of the two, evaporative cooling, or adiabatic saturation of the air, is a much more dependable method and will reduce the effective temperature much more ` than will an increasing air motion within permissible limits. ' As an example of this, consider an outdoor condition of 96 F dry-bulb and 80 F wet-bulb. The effective temperature under this condition is 85.7 F and, if the still air is moved with a velocity of 300 fpm, the effective temperature will be reduced only 2.0 F while saturation at the wet-bulb temperature reduces the effective temperature 5.7 F. At 300 fpm velocity this saturated air will reduce the effective temperature to 75.6 F, or a total improvement of 10.1 F. Evaporative Cooling Evaporative coojing is accomplished by passing air through a water spray, the water being continually re-circulated. 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. A system1 of ducts and a propelling fan are used to distribute the air in a proper manner. It will be seen that the reduction in dry-bulb temperature is a direct function of the wet-bulb depression of the air entering the dehumidifjer and that the resulting air temperature is governed entirely by the entering wet-bulb temperature of the outside air. Often it is possible to reduce the dry-bulb temperature by as much as 18 to 20 F and just as often impos sible to reduce the temperature more than 2 to 3 F. Dehumidification by Adsorption and Absorption Dehumidification may be accomplished in three ways, 1. By cooling the air below the dew-point and causing a part of the moisture con tained to precipitate. - 2. By extracting the moisture entirely, or in part, by absorption. 3. By extracting the moisture entirely, or in part, by adsorption. As used in this discussion, the term adsorption pertains to the action of a substance in condensing a gas or vapor and holding the condensate on its surfaces without any change in the chemical or physical structure of the substance and with the release of sensible heat. The term, absorption, implies a change in the chemical or physical structure in' the process of dehydration. Adsorbers include silica gel, lamisilite, etc.; absorbers include sulphuric acid. . . Silica Gel System of Adsorption .' . . Silica gel is a chemical composition made from sodium'silicate .and acid, 1See Air Washer Performance in Chapter-11; also Theory of-Atmospheric Cooling in same chapter. 134 Chapter 10--Cooling Methods the chemical formula being Si 02 and has an appearance greatly resembling that of clear quartz sand but differing in structure in that the crystals are highly porous the voids constituting 41 per cent by volume although the pores are microscopic in size. This material possesses the property of being able to adsorb a substantial portion (about 25 per cent) of its own weight of moisture drawn from the air without any increase in the silica gel volume. After the silica gel has become "saturated" or has adsorbed moisture to the limit of its capacity, the moisture may be driven off by the application of heat, again without change in the structure, volume or chemical composition of the adsorbing medium. Thus the cycle may be repeated indefinitely and when applied to air conditioning the medium is exposed to the air which results in reducing the moisture content in the Fig. 1. Silica Gel Air-Conditioning System--Single Stage Adsorption air and releasing sensible heat which may be readily removed, thus reducing the wet-bulb or total heat of the air. A typical diagram is shown in Fig. 1. . Practical Application of Silica Cel Silica gel has been used to replace refrigeration in one of two applica tions. In the one principally used, the air, from which moisture is to be extracted, is taken through silica gel beds by means of suction or pressure fans and by means of this process, the moisture becomes adsorbed by the silica gel and the air leaves at a lower dew-point and a higher sensible temperature. If this air is passed over surface coolers in which tap water or another cooling medium is flowing through the tubes, a certain amount of sensible heat will be removed. The air leaves the surface cooler or interchanger with the same dew-point with which it emerged from the silica gel beds, but with a lower dry-bulb temperature, altho the dry-bulb 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 previously are duplicated and in addition, the air.is carried through a spray type washer. 135 !: J American Society of Heating and Ventilating Engineers Guide, 1934 As the air enters the washer with a low wet-bulb, and as adiabatic satura tion will take place at a temperature close to the entering wet-bulb, considerable cooling of the air can be accomplished but with a consequent increase of the dew-point. It is necessary to reactivate the silica gel after it has absorbed 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. Alumina System of Adsorption Activated alumina contains a trifle over 91 per cent of aluminum oxide, Al2 Oj and this material will absorb nearly 100 per cent of the vapor in air up to about 8 to 10 per cent of the weight of the adsorbing material after which the adsorption falls off gradually as the saturation point is approached. 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 fol lowed 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: a. In series with the preceding unit. b. Alone. c. In series with the following unit. This plan allows for adsorption, reactivation and cooling the same as with silica gel. Taking a single unit, when it is in the a step and operating with the preceding unit, the alumina absorbs 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 absorbed is brought up to about 6.7 per cent; in the third step when the unit is operating with the following 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 the weight of the adsorber or a trifle over. The time allowable for reactivating is equal to the time occupied by the following (or second) unit adsorbing alone, plus the time when the second and third units are. adsorbing in series, plus the time when the third unit is adsorbing alone, at the expira tion of which time the original (or first) unit again will be 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 136 Chapter 10--Cooling Methods pound of alumina, require about 6 hours for reactivation. In the three unit system, after reactivation, the cooling of the activated alumina may be carried out with considerable rapidity by using dry air from the adsorp tion unit for circulation through the unit which has just completed reacti vation and the final temperature of the unit before it goes back into service should be not over 200 F. As a basis for the amount of cooling air required each cubic foot of cooling air has been found capable of removing 2.2 Btu when heated from 85 to 200 F and still provide a sufficient margin of safety in operation. REFRIGERATION Air conditioning.imposes requirements on refrigeration equipment not usually found in general cooling work, so that specially designed apparatus is often needed to replace that normally used for industrial cooling. Standard equipment can be adapted to meet air conditioning require ments but extreme care must be taken to determine the limits of its applicability. In industrial or process cooling systems the load is fairly constant, noise in operation is not of paramount importance, space is available or relatively cheap, condenser water is not a source of worry, and the cooling system is to a great extent separate and independent of other mechanical equip ment. By contrast air conditioning, especially as used for space cooling and comfort work in office buildings, theatres, and places of great density of population requires special consideration of all these factors. Space in public buildings is limited and condenser water is expensive. Noise interferes with the occupants and the cooling equipment must dovetail with the other air handling apparatus. Most important, the load fluctu ates tremendously and is seasonal. . A complete discussion of the thermodynamic problems of refrigeration is given in the Refrigerating Data Book2, 1932, so only a brief description of the cycle will be given here before the problems peculiar to air con ditioning are considered. The refrigeration system consists of three main parts, the evaporator, the condenser, and the compressor. Fig. 2 shows a diagram of the cycle. Heat is absorbed in the evaporator and released in the condenser. The compressor changes the level of the heat by taking it from a lower to higher plane. There are also many valves, accessories and special devices necessary for proper operation which vary somewhat with different types of cooling systems and different refrigerants. Heat absorption is accomplished in the evaporator, or cooler, by main taining a pressure sufficiently low to cause the refrigerant to boil at the temperature necessary to cool. The heat of ebullition is taken from the substance cooled, and the vaporized refrigerant is withdrawn by the com pressor which raises the pressure to a point that permits the gas to liquify in the condenser when some readily available medium (usually water), is used to absorb the latent and super-heat. The liquid then returns to the evaporator through a pressure reducing valve and the cycle repeated. The temperature, and the corresponding pressure main tained in the evaporator is fixed by the temperature to which it is desired 'Published by American Society of Refrigerating Engineers. 137 American Society of Heating and Ventilating Engineers Guide, 1934 to cool the air. The temperature and pressure in the condenser are determined by the temperature and quantity of the condensing medium. The two pressures govern the size of the compressor and the amount of power required to drive it. The heat released in the condenser is equal to the sum of the heat absorbed in the evaporator and the heat equivalent of the power required to drive the compressor, with small corrections for direct losses or gains from the surfaces exposed to the atmosphere. . When designing air conditioning systems, the capacity of equipment is fixed by selecting apparatus of sufficient size to maintain predetermined temperatures and humidities in treated spaces when arbitrarily estab lished maximum atmospheric temperatures occur coincident with given population, lighting, power consumption, etc. These factors determine the maximum duty of the cooling system. The duty does not necessarily Heal of Compression Added to Gas determine the size or capacity of the refrigeration apparatus. The capacity is expressed in "tons ice melting effect" or in units equal to the absorption of the heat given up by one ton of ice at 32 F melting to water at 32 F in 24 hours. This is equivalent to heat absorption at a rate of approximately 200 Btu/minute. After the maximum duty is determined, the other factors surrounding the installation must be investigated. The total heat to be removed by the cooling system has many sources, some substantially constant and others extremely variable. These sources can be roughly classified as follows, the first column indicating the order in size and second the order of variability: . 1. Outside air supplied. 2. Population. 3. Transmission through walls. 4. Light and power consumed. 1. Fresh air supplied. 2. Transmission through walls. 3. Light and power consumed. 4. Population By combining these two columns, a third grouping is obtained as follows: 138 Chapter 10--Cooling Methods X. Fresh air supplied. 3. Population. 2. Transmission through walls. 4. Light and power consumed. In this last arrangement, the first two items are governed by atmos pheric temperatures and therefore subject to tremendous fluctuations in size. As they generally form 40 per cent to 60 per cent of the entire maximum load, it is obvious that the duty of the cooling system will be much less than maximum most of the time. A survey of Weather Bureau records indicates that maximum tempera tures occur less than .5 per cent of the cooling period and also that the duration of peak conditions is never more than three or four hours. Design of System As previously mentioned, two factors control.the size of the refrigera tion system, the evaporator or suction, and the condenser or head, tem peratures. With the knowledge, that the system will operate most of the time with a load of not over 60 per cent of maximum, and that maximum demands will occur infrequently and only for short periods, some provision must be made to insure economical operation under average conditions. This can be done by overloading the machine under extreme demands and basing the design on normal or average.loads. Flexibility in arrangement can be provided in several ways. Variations in load change the efficiency of any machine and a refrigera ting system can be costly and inefficient if improperly designed oroperated. Fortunately, the trouble can be concentrated in the compressor and the problem relieved of many complications. It is comparatively easy to furnish condensers and evaporators to carry maximum load and so arranged that they will function properly at small demands. They affect the compressor performance to some extent but most of the compressor problems are in the machine itself. Variations in load are usually effected by lowering the suction tem perature and pumping a larger volume of gas per ton through a greater pressure range. This is possible because the latent heat of the refrigerant remains nearly constant throughout the small range used and the specific volume varies rapidly with change in pressure. As the compressor must remove the gas evaporated, the evaporator temperature fixes the displace ment required. The objection to such a method is that the total power consumed remains nearly constant and the power per unit of cooling increases rapidly. Such operation is satisfactory as long as the load is kept within 10 per cent of the rating of the compressor but this condition does not commonly occur in air conditioning applications. Operating Methods It is possible to divide the entire refrigeration system into a number of small units, which will allow cutting in and out of compressors, condensers, etc., as the load fluctuates. This, however, is an expensive method as a number of small units are more expensive than one large unit. There is a certain amount of duplication of equipment necessary, which tends to increase the initial cost of the system and makes the fixed charges. ap plicable to the operation of the air conditioning and cooling, system, greater than necessary.. . . 139 American Society of Heating and Ventilating Engineers Guide, 1934 A second method of providing for economy of operation, is to have storage capacity which can be utilized during the peak period. A further reference to the Weather Bureau records, indicates that maximum con ditions occur during the day for not more than three hours duration, and consequently, the refrigerating system can be run for a longer period at maximum efficiency, with tanks to store cold water or brine for supple menting the actual output of the refrigerating equipment when the load is - more than the machine will carry. This situation brings complications. Storage tanks require space and extra apparatus, which increases the cost of the entire system, and further, it is difficult to determine what the size of the compressor should be, because of the other variables which enter the problem. Depending upon the availability of storage space, the com pressor could be designed for any capacity above 50 per cent of the maximum load, so the smaller the compressor, the larger the storage space, and vice versa. A third method, is to provide in the compressor itself, some means of reducing the capacity. This can be done by varying the speed (and con sequently the displacement of the compressor), or by varying the dis placement, either by a partial by-pass of the cylinder, or a clearance pocket in the head of the cylinder when reciprocating compressors are used. It might be assumed that the efficiency would remain practically constant. This is not correct, inasmuch as the machine friction remains constant with the by-pass or clearance pocket method, which raises the power required per ton of refrigeration developed. Also, the volumetric efficiency of the machine falls off rather rapidly when the clearance pocket or partial by-pass is used. By varying the speed of the compressor, the efficiency of the motor falls oft as the speed is changed, the power output of the motor varies below maximum, and again, the compressor friction remains constant. Of the two methods, the clearance pocket, or partial by-pass of the cylinder is probably the more efficient, for general use. Another method of operation is automatic starting and stopping of the refrigerating machine, with the automatic control designed to function as the load varies. This, however, is not considered good practice as mechanical troubles develop and the life of the system is impaired. While the equipment is kept in good condition, however, the machine will operate at maximum efficiency so long as it runs. The constant starting and stopping of large compressors is liable to cause the power factor to decrease if adequate allowance is not made. All of the methods described are used from time to time. The methods of varying the output of a refrigeration system which have been outlined, apply to the reciprocating type of compressor, although variations in the speed of the compressor to change the refrigera ting output is common to all types of mechanical refrigeration. 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 demand load. Because of the characteristics of the centri fugal 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 falls off. While this reduces the total power input to the 140 ' Chapter 10--Cooling Methods machine, it does not necessarily reduce the power input per ton of re frigeration developed, as the power input does not drop with a rising discharge pressure as fast as the refrigerating effect produced. It is a method, however, which shows marked economies over the method generally used by the operating engineer, which is to lower the suction pressure in order to reduce the refrigerating output of the system. Steam Jet System So far the discussion has been confined to reciprocating, centrifugal, and rotary compressors. There is another type of compressor which, under certain circumstances, is desirable for use with air conditioning. Reference is made to the steam jet compressor. Fig. 3 shows a complete flow diagram of the system. The power used for compressing the refrigerant z 5 is steam, taken directly from the boiler, thus eliminating the mechanical losses of manufacturing electric current. As the compression 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 con densing water requirements are considerably greater, as both the refriger ant 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. Fig. 2 shows a typical water cooling application. 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 an extremely small percentage of the total water circulated through the 141 - ,American Society of Heating and Ventilating Engineers Guide, 1934 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 into the evaporator, plus any entrained air taken out of the water circulated, to a somewhat higher absolute pressure, and this mixes with the impelling steam on the discharge side of the jet. The total mixture of entrained air, evaporated water and impelling steam is discharged into a surface con denser at a pressure which permits the available condensing medium to condense it. The resulting condensate is removed from the condenser by a small pump, where it can be discharged to the sewer or returned to | the system in the form of makeup water, or part of it may be returned to the boiler feed pump. As the normal temperature of water required for air conditioifing purposes is between 40 F and 50 F, with an average temperature of approximately 45 F, this type of water cooling is particularly desirable, as the efficiencies and operating costs compare very favorably with other types of refrigerating equipment, especially in view of the fact that the cooling apparatus is, as a general rule, Jess expensive to install. Approximately three times as much condenser water is required for the steam jet cooling system as would be necessary with other types of mechanical refrigeration, but as the system can be designed with a large number of jets, each of which can be cut off as the load falls below maxi mum, constant refrigerating efficiency is maintained and frictional losses, volumetric inefficiencies, etc., are kept at a minimum. 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. Steam jet refrigeration has an advantage, where cooling towers are used for supplying the condensing liquid, as there is a great saving in the amount of steam used per ton of refrigeration. As the outdoor weather conditions vary, and of course the load on the cooling system with it, the compression ratio between the condenser and evaporator can be reduced and less propelling steam used per ton of refrigeration developed. Roughly, in air conditioning work, mechanical compressors show a falling off of 30 to 40 per cent in the power input when using the most economical arrangement of compressors, as the load varies from 100 per cent to 25 per cent of the rated capacity; whereas with steam jet cooling equip ment, the amount of steam required for producing the necessary re frigerating effect falls off in direct proportion to the load on the system or with cooling towers, the amount required falls off even more rapidly. Compressors and Refrigerants There are many different types of compressors, a number of refriger ants, different types of evaporators, condensers and arrangements of the cycle; each of.which has itsparti'ctilar place and usage. There are four (4) different types of compressors,. and in general, six (6), different refriger- 142 Chapter 10--Cooling Methods ants normally used for air conditioning purposes. compressors are of the following types: 1. Reciprocating compressors. 2. Centrifugal compressors. 3. Rotary compressors. 4. Steam Jet compressors. The generally used The refrigerants in most general use are: 1. Ammonia. 2. Carbon Dioxide. 3. Dichlorodifluoromethane. 4. Dichloromethane. 5. Methyl-chloride. 6. Water Vapor. The following is a brief discussion of the various types, of compressors and their relationship to the refrigerants: . Reciprocating compressors can be used for any of the refrigerants listed, except water vapor and dichloromethane. ' Centrifugal compressors can be used for dichloromethane or water vapor, and theo retically, for any of the other refrigerants, but the resulting loss in efficiency, with the higher pressure gases, limits the centrifugal compressor to the two refrigerants named. The rotary compressors are generally used for methyl-chloride and dichlorodifluoro methane, because of their relatively low pressure and compression ratios. The steam jet compressor is used only when water vapor is the refrigerant. Reciprocating compressors are a thoroughly familiar piece of equipment and have been developed to a point where their efficiency is high and their operation very satis factory They generally operate at low speeds, and in large installations this fact makes them desirable for general use. They are of two types, the vertical and the horizontal type either single or double acting. Reciprocating compressors are widely used in ordinary refrigeration work and they can be used with more refrigerants than other types of compression units. For instance, when carbon dioxide is used as the refrig erant, the reciprocating compressor is used because of the extremely high pressures and relatively high ratio of compression. Centrifugal compressors 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 general service pumps and fans. Rotary compressors may be used for medium or low pressure refrigerants, with small compression ratios. Steam jet compressors which have recently entered the field, cannot be used econo mically for water temperatures much below 40 F. They are simple and compact, have no moving parts and produce practically no vibration. Further, water is a^ cheap and inexhaustible refrigerant and does not need to be used in an enclosed system in the same way as other gases. The source of condensing water to some extent governs the type of refrigerant used. If condensing water is available at temperatures of not more than 70 to 75 F any of the refrigerants mentioned can be used economically, but if the available condensing water temperature is above 80 deg, carbon dioxide becomes uneconomical as its critical tem perature is approximately 88 F. A condensing.water temperature over 80 deg makes the power required for compression high. All refrigerants have critical temperatures and pressures sufficiently high so that their efficiency is not materially affected by the con densing water temperatures, except in so far as this temperature affects the compression ratio. Steam jet cooling systems can use water up to 85 F, or^even slightly higher. . The applicability of the various refrigerants is interesting. Carbon dioxide is limited by the condensing water temperature, the power consumption is slightly higher than other refrigerants, and the pressures are three to four times that-of ammonia. ; ;- X4Z American Society of Heating and Ventilating Engineers Guide, 1934 Ammonia, probably the best known refrigerant, has the disadvantage of being toxic and under certain circumstances, explosive, corrosive, and irritating, even in smali quantities in the atmosphere. Dichloromethane operates at pressures below that of the atmosphere, and it is to some extent toxic. ' Dichlorodifluoromethane under normal circumstances is non-toxic, non-irritating, and non-explosive, -but under high temperatures breaks down into several obnoxious, poisnous components. Methyl-chloride, under certain conditions, is explosive and slightly toxic. The steam ejector water vapor system has none of the disadvantages of toxicity, explosiveness and corrosiveness encountered in the other refrigerants, but the system operates at less than atmospheric pressure. This, however, is not an important factor as there are no moving parts in the compressor and the possibility of inleakage of air is remote as all of the equipment can be welded air and watertight. The supply of water is inexhaustible, and as a refrigerant, the makeup cost is negligible. The same boiler equipment for heating in winter and for cooling in summer can be used. Motors The motors used for driving compressors can be roughly classified in three groups; synchronous, multi-speed, or variable speed. Further information on motors may be found in Chapter 17. 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. In the order named, the cooling of water sprayed in the dehumidifier is the type most generally in use and can be accomplished in several ways. One method is to install direct expansion coils in the spray chamber so that the water sprayed in the air comes in direct contact with the cooling coils. Another common and rather efficient method of cooling spray water, is to use a baudelot type of heat absorber where the water flows over direct expansion coils at a. rate sufficiently high to give efficient heat transfer from water to refrigerant, and used in connection with a storage tank or collecting pan insures good operation of the refrigeration equipment if proper attention is given to the load on the system. Another type of spray water cooler is the shell and tube heat exchangers; the refrigerant being 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, completely surrounding the tubes at all times, good contact and a high rate of heat transfer is insured. The disadvantage of such a system is that with the falling off of load on the compressor, the suction temperature or the temperature in the evaporator drops and there is a possibility of freezing the water in the tubes, which, of course, would split the tubes and allow the refrigerant to escape into the water passage. This danger can be eliminated by complete 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 any other type of cooler. However, with large storage tanks, this type of cooling can be utilized to advantage. 144 Chapter 10--Cooling Methods In the second group of coolers mentioned, that of direct cooling of air, there is only one type to be considered; the coil type with the refrigerant in the coil and the air passing over it. Cooling depends upon convection and conduction for removing the heat from the air. The type of coil used for cooling can be either smooth or finned; the finned coil being more economical in space requirement than the smooth coils. The third group of coolers, which are sometimes called indirect coolers, where brine is cooled by the refrigerant and the resulting cold brine used to cool either air or water, introduces several other considerations. It is not the most economical from a power consumption 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 the substance being cooled. This requires that the temperature of the refrigerant must be still lower, and consequently the amount of power required to produce a given amount of refrigerant 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 the brine then circulated through the air conditioning equipment in perfect safety; the brine being used to cool the water or air, without any possibility of direct contact between the air and refrigerant. When an indirect system of cooling is used, it will be found that the heat transfer rate of the water cooler is considerably higher as a general rule than a direct exapansion cooler for the same requirements. With direct expansion interchangers, it is almost inpossible to keep the entire system flooded with liquid, whereas with brine interchangers, the cooling medium completely fills the space of the interchanger and perfect contact is insured. . There is one other type of water cooling which might be mentioned, and that is the use of ice. Its application is limited because of the cost of ice, although the efficiency of cooling is higher than any other water cooling system. The word "water cooling" is used advisedly in that the direct cooling of air by ice is, while not impossible, rather impractical. It might be said that ice coolers are economical for systems requiring a maximum rate of 20 tons ice melting effect per 24 hours where the load fluctuates considerably, and it is possible to introduce ice only, as it is required to cool water. The most general method of cooling water with ice is to spray the water over the'surface of the ice, insuring as much contact as possible and approximating the same performance as the baudelot type of cooler. Because of the large fluctuations in load in the air conditioning system, . the higher cost of refrigerating effect when ice is used, is offset by the fact that there are no motor and condenser inefficiencies under partial load, and the cost of the mechanical refrigeration equipment for the small system being so much higher per unit of effect, the fixed charges are small enough to overbalance the extra cost of the ice. ' Condensers Condensers are usually either double pipe or shell and tube type. Shell and tube condensers, are almost identical with coolers. Double pipe con densers are arranged so that water passes through the inner of two con- 145 American Society of Heating and Ventilating Engineers Guide, 1934 centric pipes and refrigeration through the annular space in the outer$>ipe. Where possible, the flow of refrigerant and condensing water should be counter flow to maintain maximum temperature differences. The amount and temperature of the condensing water determines the condensing temperature and pressure, and indirectly the power required for compression. It is, therefore, necessary to strike a balance so that the quantity of water insures economical compressor operation. As part of the condenser, or attached to it, there must be storage space for liquid refrigerant. The installation of all equipment should be made accessible for inspec tion, repair, and cleaning. Both the coolers and condensers should have space for pulling tubes. In connection with air conditioning equipment and the refrigeration 1 system used there is a decided tendency to conserve the water in the city mains and most large cities are restricting the use of this water. In order to use air conditioning systems and refrigeration equipment, it is often necessary to install cooling towers. The cooling towers, unfortunately, produce the highest temperature 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 the maximum load at abnormal condensing water temperatures. If properly designed with the flexibilities mentioned before, this makes little difference in the efficiency of operation throughout the year, except at those times when the condensing water temperature is highest. As this only occurs for 5 per cent of the entire cooling period it can be disregarded as a factor in establishing yearly operating costs. The cooling tower has a certain advantage over the use of water from the city mains, in that the temperature of the condensing water varies directly with the outdoor temperature and as pointed-out, the refrigera tion load also varies with this temperature. Certain economies are pos sible when a cooling tower is used, which cannot be achieved by the use of condensing water from city mains, even where the city water temperature is extremely low. Normally, the lowest city water temperature met during the summer months is from 65 to 70 F. This temperature range takes place for the entire cooling period, regardless of what the outdoor temperatures are. With the cooling tower, the temperature of the con densing water may rise to 80 to 85 F under maximum conditions, but under less than maximum conditions, the temperature of {he water off 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 JO F and the cooling tower water therefore, for the same periods, varies from 65 to 75 F. When the outdoor wet-bulb temperature drops below 60, which occurs approximately 30 per cent of the time, the con densing water temperature is still lower. The cost of water used for condensing is negligible as the only water required is that used for makeup due to the loss by evaporation in the cooling tower itself. See also Chapter 11. 146 Chapter 11 HUMIDIFYING AND DEHUMIDIFYING EQUIPMENT Air 'Washers, Selection, Scrubber and Eliminator Surface, Dis tributing Plates, Materials of Construction, Performance, Heating Spray. Water, One and Turn Bank Humidifiers, Power Require ments, Nozzles and Wash Water Used, Humidifier Efficiency, Flooding Surface Type Humidifiers, Dehumidifiers, Cooling Medium, Atmospheric Water Cooling Equipment, Theory of Atmospheric Cooling, Atmospheric Cooling Reverse of Humidi fying, Factors Affecting Atmospheric Water Cooling, Co-ordinating of Equipment, Wet-Bulb Temperature of Design, Quantity, of Cooling Water, Cooling Ponds, Spray Ponds, Spray Retention, Growths in Spray Ponds, Spray Cooling Towers, Natural Draft Deck Cooling Towers, Wind Velocitiesfor Towers, Mechanical Draft ' for Towers, Indoor Cooling Towers, Make-Up Water, Winter Freezing AN air washer is essentially a chamber in which air is brought in in timate contact with water, the object being (a) to wash the air or (b) to regulate the moisture content of the air and at the same time wash it. The air comes in contact with the water by passing it through water sprays or by passing it over surfaces wetted by a continuous flow of water; hence the classification: spray, scrubber, and combination spray and scrubber type washers. A washer chamber may be constructed of wood, or stone, but it is most often .constructed of sheet metal. The lower portion of it is specially designed as a tank to receive the water dropping through the chamber and to serve as a reservoir from which the water may be recirculated. It is desirable that air leaving a washer contains no water in suspension. For this reason eliminators are provided at the washer outlet. These may be in the form of plates or baffles upon which the free moisture is deposited as the air is deflected through several changes from its original direction of flow. In some washer units steel wool filter sections serve as eliminators. However, specially designed plates are used more gener ally than other devices because they offer the least resistance to the flow of air, while still performing effectively the function of free moisture elimination. They also have the advantage of acting as scrubber surfaces when flooded. . It is essential to uniform performance in a washer, that air enter evenly distributed over the washer inlet. To insure this, a perforated plate or eliminator plates are installed at the inlet. Eliminator plates are now more generally used. They serve a second purpose in preventing the escape of spray through the washer inlet. -- ' Water is supplied to scrubber type units through flooding nozzles. The capacity of these nozzles varies with the manufacturer although a fair 147 American Society of Heating and Ventilating Engineers Guide, 1934 value of 5 gpm may be Used. The nozzles are spaced on one foot centers across the top of the washer over the scrubber plates. Water is supplied to spray type units through atomizing nozzles gener ally arranged in banks across the washer. The nozzles spray either in the direction of the air flow, that is, downstream, or against the air flow, or upstream. Nozzle capacities varies with the manufacturer, from 1-J^ to 2 gpm at a water pressure of about 25 lbs per square inch which pressure is required for effective atomization. The spacing of spray nozzles is determined by the water requirements of the particular installation. A spray type washer may contain one, two or three banks of nozzles depend ing upon its application. When an air washer is used for cleaning air it removes impurities and dusts. In general it does not function as efficiently in this service as a filter. For non-microscopic soluble dust its efficiency averages about 50 per cent, unless the concentration of dust is high. Its effectiveness in removing greasy microscopic dust is practically negligible as is also its deodorizing ability. When a washer is used to regulate the moisture content of air it adds moisture to (humidifiers) or removes moisture from (dehumidifiers) the air to achieve the desired moisture content. (See also Chapter 3). When air passes through a washer wherein water is circulated without the addition or removal of heat, the air tends to become saturated at its entering wet-bulb temperature. What occurs here is.partial or complete adiabatic saturation. The total heat content of the air is unchanged, inasmuch as the dry-bulb temperature of the air drops in proportion to the amount of additional water evaporated. This action is also known as evaporative cooling. A measure of the washer's effectiveness under these conditions is its saturating efficiency which is equal to the drop in drybulb temperature in per cent of the entering wet-bulb depression. Other things being equal, the saturating efficiency of a spray type washer is a function of the number of spray banks and the direction in which they spray. The following table gives a general comparison: 3 banks--2 upstream--X downstream......... _...100% saturation efficiency 2 banks--2 upstream............................................ . 95% saturation efficiency 2 banks--1 upstream--X downstream................ 85% saturation efficiency 1 bank --upstream .............................................. 80% saturation efficiency 1 bank --downstream............................................... 65% saturation efficiency When air passes through a washer wherein the circulated water is either cooled or heated before being returned to the spray chamber, a heat interchange between the air and water occurs, and the air tends to become saturated at the temperature of the leaving water. The extent to which the leaving air and leaving water temperatures approach each other is an index to the effectiveness of the washer under the operating conditions. The total heat absorbed by the water in the process equals the total heat given up by the air or the heat given up by the water equals the heat absorbed by the air. Depending on whether the moisture con tent of the air is increased or decreased during the operation, humidifi cation or dehumidification occurs. Heat will be added to or removed from the air as the water supplied is of a higher or a lower temperature than the wet-bulb temperature of the entering air. 148 Chapter 11--Humidifying and' Dehumidifying Equipment For dehumidifiers the ratio of the difference between the leaving wetbulb and the leaving water to the difference between the entering wetbulb and the entering water may be figured as follows: 3 banks--1 downstream--2 upstream_____ ............................... 0% ............................... 5% . .15% 1 bank --upstream................................................. ............................... 20% --.......................... 1 bank --downstream............................................. ......... .....................35% Humidifiers may be figured on the same basis as dehumidifiers; the leaving water temperature, of course, will be higher than the wet-bulb temperature of the leaving air. Fig. 1. Typical Single Bank Air Washer Fig. 2. Typical Two Bank Air Washer The problem of cooling or heating the circulated water before returning it to the washer chamber is external to the unit. It will suffice here to note that heating is generally accomplished by passing the water through closed hot water heaters or by injecting steam into the water circuit; cooling, by passing the water through closed coolers or over refrigerating coils in a baudelot chamber. Often in a cooling and dehumidifiying application, the refrigerating coils are located within the washer chamber. Washers are sometimes arranged in two or more stages to cool through long ranges or to increase the overall efficiency of heat transfer between air and the cooling or heating medium (water, brine, etc.) A multi-stage washer is equivalent to a number of washers in series arrangement. Each stage is in effect a separate washer. Usually the catalog capacity of a washer is expressed in cubic feet of air per minute and is based upon an air velocity of 500 feet per minute through the gross cross sectional area of the unit above the water level in ' its tank. At this rating spray type washers handle about 2-J/ gpm of 149 American Society of Heating and Ventilating Engineers Guide, X34 water per bank per square foot.of area, that is, about 5 gpm per bank per 1000 cfm. These proportions 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. Two of the more important items are: a. Choose a washer for air velocities above approximately 300 fpm and below approximately 600 fpm. Velocities outside this range are likely to result in faulty elimination of entrained moisture. b. When a high saturating efficiency is required, select a two or three bank spray type unit, having a total water capacity of not iess than 15 gpm per 100-cfm. The area of a washer may be dictated by space limitations outside the washer, such as headroom, or by space requirements inside washer, 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. Fig. 3. Air Washer with Spray Water Heating Arrangement 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 eliminators, number of banks of sprays, direction of spray, type' of scrub ber plates, and, if cooling coils are located in unit, by their size and type. Washers should be selected to limit static resistances below 0.50 in. Power Requirements .. The approximate power requirement for passing 10,000 cfm of air through a humidifier of the spray type by a fan of 78 per cent mechanical efficiency is given in Table 1, this being the fan brake horsepower for various velocities and static pressure losses. Allowance should be made for variations in static pressure due to the use of different diffuser plates or inlet louvres and for variations in fan efficiencies. ATMOSPHERIC WATER COOLING EQUIPMENT To successfully operate a'refrigerating plant or a condensing turbine, the heat from the compressed refrigerant or the discharged steam must be removed and dissipated. This is accomplished ordinarily by first trans ferring the heat of the gas to water in a. heat exchanger. If the plant is 150 . Charter II^Humidifying and Dehumidifying Equipment situated on the banks of a river or lake, an intake may be had 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 water is a city supply or well water, the discharge water may be run into the nearest sewer or open water way. Lacking an unlimited water supply, or in cases where city water is too expensive or where the water available contains dissolved salts which would quickly form scales 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 atmos pheric water cooling apparatus. - As 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 thie govern- Table 1. Approximate Fan Brake Horsepower Requirements for passing 10.000 cfm of air through humidifiers at various velocities and static pressures. Mechanical efficiency of fan--78 per cent. . Velocity ITU 30 Deg Eliminators Spaced on 1-H in. Centebs Static Pressure In. Water BHP 45 Deo Eliminators Spaced on 2-K In. Centers Static Pressure In. Water BHP 500 550 600 650 0.20 0.24 0.29 0.34 0.40 0.48 0.58 0.68 0.40 0.480.58 0.68 0.80 0.97 1.15 1.35 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 with water for a long enough time to permit the wet-bulb temperature of the air and the temperature of the water to reach equilibrium, atmos pheric water cooling equipment aims to circulate only enough air to cool the water to the desired temperature with the least possible expenditure of power. '' Cooling Towers 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. In water cooling equipment the tem perature of the water is reduced by air, and the cooled water is carried to its point of usage. In the air washer, an-.excess of water is used to con dition a fixed quantity of air, while in water- cooling equipment, an excess quantity of air is used to cool a fixed quantity of-water. Both types of equipment have a common basis of design, however, in . that the size of the equipment is determined by the quantity of air that 151 American Society of Heating and Ventilating Engineers Guide, 1934 must be handled. With the air washer, the size of the equipment is fixed by the quantity of air to be conditioned, and the amount of conditioning is controlled by the quantity and temperature of the water supplied and its method of application. With water cooling apparatus, its size and the quantity of air required bear no direct relation to the quantity of water being cooled, but vary through a wide range for different services and conditions. Sizes of Equipment Assuming a definite quantity of water to be cooled, the size and design of atmospheric cooling equipment is 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. Table 2. Condenser Design Data Gas Maximum Pressure Desired in Condenser Gas Temperature m Condenser Leaving Hot Water Temperature F Best Design Average Design Steam................... Steam Steam... .............J Ammonia............ Carbon dioxide.. Methyl chloride........... Dichlorodifluoromethane 185 lb gage head pressure...... 1030 lb gage head pressure...... 102 lb gage 117 lb gage head pressure...... 99.7 114.3 126.0 96.0 86.0 100.0 100.0 97 110 120 92 83 96 96 93 105 114 88 81 92 93 ' Items 1, 2, and 3 are established by the type of service and geographical location, while items 4, 5, and 6 depend upon the design of the equipment. , The establishment of a proper cooling range depends upon : 1. Type of service, (refrigerating, internal combustion engine and steam condensing). 2. Wet-bulb temperature at which the equipment must operate satisfactorily. 3. Type of condenser or heat-exchanger used. Because the design of an entire plant is usually affected by the quantity and temperature of the cooling water supply, plants should be designed for cooling water conditions which can be most efficiently attained.; The first consideration is usually the limiting temperature of the plant. For example, if an ammonia compressor refrigerating plant is to be designed for 185 lb head pressure as a normal maximum, the limiting temperature of the ammonia in the condenser is 96 F. Should the ammonia temperature go above this figure the head' pressure will exceed 185 lb and power.con-' 152 Chapter 11--Humidifying and Dehumidifying Equipment sumption increases. To obtain this head pressure, the temperature of the circulating water leaving the condenser must always be less than 96 F by an amount depending upon the size and design of the condenser, the quantity of water being circulated, and the refrigerating tonnage being produced. A condenser having a large surface per ton of refrigeration may be designed to operate satisfactorily with the leaving hot water temperature within 3 deg or 4 deg of the ammonia temperature cor responding to the head pressure, while a small condenser might require a 10 deg difference. Table 2 lists several gases with data as to the temperature and pressures for which commercial condensers are designed. Internal combustion engines have limiting hot water temperatures of 125 F to 140 F. The cooling of such fluids as milk or wort has. variable requirements and is usually done in counter-flow heat-exchangers in which the leaving circu lating water is at a much higher temperature than is the leaving fluid. 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 1931, inclusive, there were but 6 hrs 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 975 hours represent a third of the summer period, cooling equipment based upon the noon average July wet-bulb of 68 F would be inadequate. Commercial practice is to choose a wet-bulb temperature for refrigeration design purposes which is not exceeded during more than 5 to 8 per cent of the summer hours (75 F for New York City), with somewhat lower requirements for steam turbines and internal combustion engines. This difference is made because the heaviest load on a refrigerating plant is coincident with high wet-bulb temperatures, whereas the heaviest electric power demand occurs either in the winter or after nightfall in summer, when the wet-bulb temperature is low. Table 1, Chapter 8, shows safe . design wet-bulb temperature which will not be exceeded more than 8 per cent of the time in an average summer. Knowing the hot water temperature and the wet-bulb temperature for which the equipment must be designed, the cold water temperature must be chosen to place the requirement within the efficiency range of the type of atmospheric water cooling apparatus to be used. Efficiency of atmos- 153 c American Society of Heating and Ventilating Engineers Guide, 1934. pheric water cooling apparatus is expressed as the percentage ratio of the actual cooling range to the possible cooling range. Since the wet-bulb temperature of the entering air is the lowest temperature to which the water could possibly be cooled this is: Percentage cooling efficiency of atmospheric water cooling equipment = (hot water temperature -- cold water temperature ) X 100 hot water temperature -- wet-bulb temperature of entering air Efficiencies of various types of atmospheric water cooling apparatus vary through wide limits, depending upon air velocity, concentration of water per square foot of area, and the type of equipment. The commercial range of efficiencies is given in Table 3 although unusual designs may operate outside these ranges. ' Table 3. Efficiency of Atmospheric Water Cooling Equipment Equipment Natural Draft Deck or Atmospheric Mechanical Draft..................................... Cooling Efficiency--Peb Cent Minimum Usual Maximum 30 60 40 60 35 50 to 70 90 35 55 to 75 90 From consideration of the factors which include the cooling range and design wet-bulb temperature, the quantity of water required can be calculated from the amount of heat to be dissipated. The normal amounts of heat to be removed from various parts 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 appartus................... 1030 to 1150 Btu per pound of steam Diesel engine...................................................... ..2800 to 4500 Btu per horsepower Cooling Ponds . A natural pond is often used as a source of condensing water. The' hot water should be discharged close to the surface at the shore line, as natural air movement over the surface of the water will cause evaporation and carry away heat. Because increased density due to the loss of heat causes the cooled water to sink to the bottom of the pond, the suction connection for intake water should be placed as far below the surface as possible, and at as great a distance from the discharge as practicable. Spray Cooling Ponds The spray pond consists of a basin, above which nozzles are located to spray water up into the air. Properly designed spray nozzles break up the water into small drops, but not into a mist because the individual drops must be heavy enough to fall back into the basin and not drift off. The water surface exposed to the air for cooling is the combined area of all the small drops. Since the rate of heat removal by atmospheric water cooling is a function of the area of water exposed to the air, the difference in 154 Chapter 11--Humidifying and Dehumidifying Equipment 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 ajr 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 ft to 6 ft above the edge of the basin, to supply from 5 lb 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 per minute in a small pond to 0.8 gpm per square foot per minute 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 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 of air, particularly at the higher wind velocities, and thus further reduce the possibility of water being carried off. The height of an effective fence should be equal to the height of the spray cloud. Louver boards are preferably of red gulf cypress or California redwood supported on castiron, steel or wood posts. Where building ordinances forbid the use of combustible materials, sheet metal is customarily used. Algae formations may be a considerable nuisance in a spray pond. Such growths are killed by the periodic addition of potassium permanga nate to the pond water. Addition of the dissolved chemical should be made until the water holds a faint pink color' for at least 15 min. _ Spray Cooling Towers Where not more than 30,000 Btu per minute are to be dissipated, the spray cooling tower-is a satisfactory apparatus. The word tower in this connection is somewhat of a misnomer as the apparatus is essentially a 155 American Society of Heating and Ventilating Engineers Guide, 1934 narrow spray pond with a high louver fence. As usually built, the nozzles spray down from the top of the structure and the distance from the center of the nozzle system to the fence on either side is not more than half the distance that the nozzles are elevated above the water basin. Heights range from 6 ft to 15 ft and the total width of a structure is not usually greater than its height. Spray cooling towers occupy less space on small jobs than spray ponds of equivalent capacities because the towers have a capacity of from 0.6 gpm to 1.5 gpm per square foot of tower area. The louvers are continually wet, and so add to the surface of water exposed to the cooling air. Natural Draft Deck Type Towers In past years most of the atmospheric water cooling on refrigeration work has been done with natural draft deck type towers, which are also referred to as wind or atmospheric towers. These towers consist of heavy wooden or steel framework from 15 ft to 80 ft high and from 6 ft to 30 ft wide, having open horizontal lattice-work platforms or decks at regular intervals from top to bottom, and a catch basin at the foot. The hot water is distributed over the upper part of the structure by means of troughs, splash heads, or nozzles, and it drips from deck to deck down to the basin. The object of the decks is to arrest the fall of the water so as to present efficient cooling surfaces to the air, which passes through the tower parallel to the decks. The decks also add to the area of water surface exposed to the air, but since they furnish a resistance to air flow, too many decks are a detriment. To prevent the loss of water on the leeward side of the tower, wide splash boards are attached at regular intervals from top to bottom. These boards or louvers extend outward and upward, and in most designs the top edge of each louver extends above the bottom edge of the one above it. Efficiency of a deck tower is improved, within limits, by increased height, increased length, or increased width. The first two increases the area of water exposed to the wind, and the latter increases the time of contact of the air with the water. Wind Velocities on Natural Draft Equipment Since natural air movement is the prime requirement for a deck type tower, spray cooling tower, or spray pond, the apparatus 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 should it need 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 obstructions. 156 Chapter 11--Humidifying and Dehumidifying Equipment : Mechanical Draff 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 louvered 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 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 fpm to 600 fpm over the gross area of the structure. Inside Mechanical Draft Water Cooling Equipment Mechanical draft water cooling equipment may be set up inside build ings, where it usually draws its air supply from the general space in which it is installed, and discharges its exhaust air through a duct to the outside. Indoor cooling towers may be either of the wood-filled or the spray-filled type. In many cases where little height but considerable area is available, water is cooled in a spray-filled structure similar to an air washer, with the air passing horizontally through the apparatus and being discharged through a duct to the outside. Such apparatus does not have the counter flow advantage of the vertical mechanical draft water cooling equipment, and therefore requires a much larger excess of air for proper operation. Air velocities and operating powers are considerably above those required by vertical mechanical draft water cooling equipment. Make-up Water Since the atmospheric water cooling equipment performs its functions chiefly by evaporating, a portion of the water in order to cool the re mainder, there is a continual drain on the quantity of water in the system, 157 American Society of Heating and Ventilating Engineers Guide, 1934 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 deg 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. . Winter Freezing If atmospheric water cooling equipment is operated in freezing weather, the water may be cooled below freezing temperature so ice forms and collects until its weight causes damage. To obviate freezing during con tinued operation, the efficiency of the apparatus may be lowered. This is done on the spray pond and the spray cooling tower by reducing the quantity of water fed to the apparatus, thereby lowering the pressure at the nozzles and increasing the size of the drops produced. On the deck Table 4. Comparison of Various Types of Atmospheric Water Cooling Equipment Figures indicate order of desirability Cooling Sprat Pond Pond Sprat Tower Deck Tower Mechanical Indoor Draft Tower X2i3 4 5 5432 1 1 2 3 4-5 4-5 X X XX 13 4 2 6345 1-2 1-2 1 6 54 2-3 2-3 1 6 54 2-3 2-3 1 2 3 4-5 4-5 6 2 1 34 5 6 X 543 1 2 Water Quantity Required for Definite 6 5 4 1-2 1-2 3 xNot comparable. tower the upper system may be shut off and a secondary distribution^ system put in service midway down the height of the tower. The water will be kept above freezing because it will have shorter contact with the air. The mechanical draft tower can be protected by reducing the air flow through the tower, by stopping or reducing the speed of the fans, or by partially closing dampers. . If the system is operated intermittently in freezing weather, water ino 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. .. 158 Chapter 12 UNIT AIR CONDITIONERS AND COOLERS Classification of Conditioner Units, Evaporative Cooling, Dehu- midifying and Cooling, Make-Up Water Required, Cooling for Summer, Calculation of Cooling Load, Air Temperatures and Volumes, Ratings and Capacities of Units, Location of Units, Commercial Types of Ceiling Units, Floor Units, Ice Units, Portable Units and Accessory Units AIR conditioning with unit equipment has gained in popularity during the past few years and the types and styles of unit air conditioners ' vary widely. In selecting or specifying the unit types the results desired should be carefully determined. The essential feature is that such ap paratus must simultaneously control the temperature, humidity, air motion and distribution within an enclosure. If complete air conditioning functions are not required the simpler and less expensive unit heaters or unit coolers can be used. . Unit air conditioners are devices of small capacity iocated in the space "to be conditioned and may be classified according to design or service. They are not necessarily self-contained but the air treated is not removed, from the room being conditioned. Strictly defined, however, the unit air conditioner is self-contained and includes the compressor and condenser. The unit air conditioner was originally designed to supply proper atmospheric conditions in some room or section of a manufacturing plant where structural conditions or service requirements made installation of a central system un-economic. These units can be readily located in existing buildings or departments and if shifts to meet changing require ments are desirable, they can be moved or the number can be increased to meet growing demands. Because of the flexibility and mobility of the units, tenants of either old or new buildings may have air conditioning even if the building owner does not desire to furnish it. Industrial process conditioning with unit apparatus has had a wide field of application in printing plants, textile mills, candy and tobacco factories, bakeries, drug manufacturing plants, laboratories, meat packing, vegetable and fruit storage rooms. The application of unit air conditioners for comfort in offices, stores, restaurants, shops, hospitals, hotels and homes developed rapidly and many new designs in which quietness of operation and attention to appearance were emphasized. The unit air conditioner has a distinct field of application and through its use brings-the desired temperature, humidity, air circulation and cleanliness to places where a central type plant could not be used. 159 American Society of Heating and Ventilating Engineers Guide, 1934 TYPE OF SERVICE Because of the variety of arrangements with corresponding variation in the service rendered, unit air conditioners may be classified in three divisions: A. All-Year, when supplying (1) Air circulation. (2) Air cleaning. (3) Air heating in winter. (4) Humidification in winter. (5) Air cooling in summer. (6)' Dehumidification in summer. B. Winter, when supplying Items (1), (2), (3) and (4), C. Summer, when supplying Items (1), (2), (5) and (6). The All-Year unit generally takes its air supply from the room and outof-doors, the cleaning being done by filters or air washers and the circu lation being provided by motor-driven blowers or fans. Humidity is obtained usually by evaporation of water or entrained moisture from water sprays or wet surfaces. Dehumidification is accomplished by lowering the temperature below the dew-point and condensing the mois ture either by passing the air through water sprays or over cooled sur faces. Heat is supplied to the air by bringing it in contact with steam or water-heated surfaces and in some instances, by the reverse cycle re frigeration method. Surface cooling may be provided by direct expansion in the surface unit and by circulation of cold water or brine from a central refrigerating plant. The water may be cooled by melting ice or it may be taken from city mains or wells where a low temperature is available. A drip pan or con tainer should discharge to drainage lines in order to remove the con densed moisture or that not taken up by the air. MAKE-UP WATER REQUIRED In the ordinary practice of humidifying, the water is constantly re circulated and the only water loss is that which is evaporated into the air and serves to humidify the air. Where air conditioning units recirculate 100 per cent room air and have no outside air connection, the amount of humidifying required for each passage of the air actually is small, as the air in rotating will gradually increase its moisture content'to any point desired. If, however, the air is taken from outside, the treatment must increase the humidity to the desired degree (since the air only passes once through the device) and more water will be needed because of the larger requirement for humidifying. It is obvious that the tank must be drained and flushed periodically to dispose of the dirt and dust removed from the air by the water. r The air conditioning units for winter service omit the air cooling and dehumidification functions. The units for summer use only usually consist of a cooling coil and a fan or fans electrically operated, erected within an enclosure so as to form a single piece of equipment and are intended solely for cooling purposes. A float valve, surge drum, valves and other auxiliary fittings may or may not constitute part of the complete device depending on the type. The 160 Chapter 12--Unit Air Conditioners and Coolers fan draws or forces the air across the cooling surface and discharges the air in selected directions. As a rule the outlets are specially designed so as to deliver the air without the use of ducts and the units are most frequently placed directly in the room to be cooled. Cooling units are designed to: 1. Circulate the air of the room at a rapid rate. 2. Promote uniformity of temperature throughout the room. 3. Direct the cooled air positively and rapidly to points where it will be most effective. 4. Reduce the amount of space occupied by the cooling equipment. 5. Provide a system readily responding to thermostatic or manual control. 6. Increase the capacity of the cooling surface by passing the air over it at high velocity. 7. Provide, under favorable means, a method of either manual or automatic defrosting of the cooling surface. 8. Provide a neat appearing and sanitary apparatus for obtaining the temperatures and humidities desired. Cooling units are suitable for operating on gas and liquid refrigerants such as ammonia, methyl chloride, sulphur dioxide, carbon dioxide or on brine or cold water. The choice of refrigerant is governed by the design, material and construction of the unit cooling coil. CALCULATION OF THE COOLING LOAD In estimating on the load that the unit air conditioning apparatus must meet a survey should be made of surrounding conditions and the heat losses calculated. The same factors of heat gains and losses are used for all types of comfort cooling. The sensible heat gains may be summarized as follows: o. Sunlight load. b. Radiation load. . c. Infiltration load, depending on air changes. d. People. e. Lights. /.. Electrical motors and appliances. g. Steam and gas appliances. h. Miscellaneous heat sources. . The latent heat load must be determined separately. This latent heat comes from moisture loss from the drying of air, from people and ma terials. The heat losses occur through walls, windows, roofs, by infiltra tion of cold air and humidification. After this total heat has been calcu lated (see Chapter 8), units are selected from the manufacturers' lists in accordance with their rated capacity. Most units for comfort air con ditioning have a cooling capacity ranging from 0.75 tons to 1.25 tons, approximately the amount required for one room of good size or an office, 'though machines up to 10 ton capacity can be obtained. Example 1. A fur storage room is to be maintained normally at a temperature of 32 F, but at intervals, the room is to be lowered to 20 F, which temperature will be maintained for several days, after which 32 F will again be held. It is assumed that there is one air change every eight hours.- What is the cooling load? Data: The room is located in the basement of a building that has no outside exposure. 161 American Society of Heating and Ventilating Engineers Guide, 1934 Maximum temperature of rooms surrounding walls and ceilings, 90 F. Floor is on ground. Room has a vestibule entrance. Four lights of 100 watts each will be burning part of the time. No occupants in room except at infrequent intervals. Brine available at a minimum temperature of 10 F. Size of Room: 25 ft long by 20 ft wide by 9 ft high. Walls: 6-in. concrete, 4-in. cork and J^-in. plaster finish. Ceiling: 4-in. concrete, 4-in. cork and J4-in. plaster finish. Floor: Cinder fill, 6-in. concrete, 4-in. cork, 2-in. concrete. Solution. The cooling load will be the sum of the following items: Sun effect.................. ...... ................... ........................................................... none Lights: 4 X 100 X ^ (25 per cent use assumed)..................... . 340 . Cooling unit motor, Yi hp........ ................................................................. 1260 Transmission Walls: 90 X 9 X (90 - 20) X 0.066.__............................................. 3742 Ceiling: 20 X 25 X (90 - 20) X 0.067............................................. 2345 Floor: 20 X 25 X (70 - 20) X 0.065................................................. 1625 Infiltration 4500 X (90 - 20) 8 hr X 55.2 ....................................................................................... 7,1 Product Load None ' Total..................... ............ ;.............1..............................................................10025 Safety factor (10 per cent)....................................................................... 1002 Total sensible heat load...................... ...................................................... 11027 Btu per hour Dehumidification Load Air at 90 F and 50 per cent rel. hum. 217.6 grs X 50 per cent.. 108:8 Air at 20 F and 50 per cent rel. hum. 15.01 grs X 50 per cent 7.50 Grains per lb to be removed...... ......................................................... ....101.3 Pounds of air per 8 hr: 4500/14 or 321 lb Pounds of air per hr: 321/8 or 40}^ lb Grains per hr: 101.3 X 40H or 4064.6 grs Pounds of moisture: 4064.6/7000 or 0.580 lb, 0.58 X 1057 Btu.-- 613 Grand Total................................................................................................ 11,640 Tonnage, 11,640/12,000............................................................................. 0.96 tons Air Temperature and Volume The drop, in temperature of the air through a cooling unit is com paratively small, while the volume handled is large. This feature permits of greater heat transfer per unit of.surface and a minimum moisture pre cipitation. Consequently, the temperature difference between the room and the delivered air is small, making it of little consequence whether the intake of the unit is located at the floor or at the ceiling. . - RATINGS AND CAPACITIES It is standard practice to rate unit air conditioners for heating in Btu per hour and to rate cooling units in Btu per hour at a given dry-, and wet- 162 , 12--Chapter Unit Air Conditioners and Coolers- - bulb temperature of air entering the unit with a given refrigerant tem perature, maintained within the cooling coil, a certain relationship between sensible and latent heat being designated. In any event the refrigeration unit must have sufficient capacity to care for all of the sensible heat to be absorbed plus the latent heat due to dehumidifying which in some cases may amount to a very substantial part of the load. At.present there is no uniform standard for rating air conditioning units but manufacturers generally have a definite rating for each unit with respect to its air volume or different air volumes, but judgment'must be exercised in the selection of equipment so that the component parts are in proper ratio: to each other. LOCATION OF UNITS The following considerations govern the location of units in a room to be conditioned: 1. Arrangement of product within a space. 2. Location of people within a room. 3. Number and location of units. . 4. Air distribution. 5. Convenience of piping and wiring connections. 6. Location of outside air cooling and heating sources. . Most important of these is air distribution and units should be so located as to secure equal distribution to all parts of the room, whether the application is for comfort conditioning or processing.' The discharge pf cooled air in general should be from a high point and the air traveling back to the inlet of the unit should be at low velocities. - Cold Storage Air conditioning with unit equipment plays an important role in the cold storage of food. Temperature and humidity control is of prime importance in order to retard bacterial development and retain as much as possible of the original moisture in meats, fish, fruits, vegetables and eggs. Spoilage and shrinkage during long storage periods result in costly losses and may be prevented with proper application and control of air conditions within specified limits. To' maintain the high relative humidities generally required, units embodying the features' of central plants are considered most, suitable. The units are placed to discharge the moist cool air horizontally just below the ceiling so that distribution over the stored product will be uniform and rapid. For economic service 80 per cent relative- humidity is the practical upper limit that, can be carried. The higher the relative humidity requirement 'the larger the unit capacity needed. w ' The control methods and devices used for unit conditioners are dis cussed in Chapter 14. TYPES OF EQUIPMENT Ceiling Units: The types and designs of air conditioning units in production are legion and but a few typical arrangements are shown. New 163 American Society of Heating and Ventilating Engineers Guide, 1934 Vertical Diffusing Fig. 4. Industrial Floor Type I t t t I <?nlle ~p Fig. 2. Elevation Through Line AA Fig. 5. Cabinet Type Cooling Unit 164 Chapter 12--Unit Air Conditioners and Coolers designs are constantly appearing arid the general tendency is toward better mechanical construction and more versatile application. Fig. 1 shows one of the simplest units, where modification of a ceiling unit heater has been made so it can serve as an air conditioner. The assembly shows a motor, propeller fan, extended fin heating and cooling element, drip pan and a double louver arrangement, the vertical louvers being formed by condensate eliminators as illustrated in Fig. 2 which is an elevation of this unit on Line A-A. The whole is enclosed in a metal cabinet and is supported by a ceiling hanger. The horizontal louvers are adjustable so that the air may be directed downward, horizontally, or upward as may be desired. During the winter the unit may be used exactly the same as a unit heater when properly supplied with steam and return connections, while in the summer it may be used as a cooler and dehumidifier if correctly attached to a refrigeration plant or supplied with cooled water of sufficiently low degree. This ceiling type unit is par ticularly suited for industrial and business applications. Fig. 3 illustrates a ceiling unit for summer use without any heating provision. This unit, in conjunction with the regular heating system will do a certain amount of humidifying in the winter. It consists of an air washer with the usual water sprays, eliminator plates and air circulating fan. It is hung on the ceiling of the room and takes its air supply from the room through the intake louvers indicated, passes the air through the water spray and eliminators, and then delivers the air back into the room through the discharge outlet provided with louvers of adjustable type. The refrigeration machine may be located at any convenient point and the cooled water circulated to and from the conditioner across the ceiling so that no floor space is lost. This style of unit is for industrial and large 'office installations and, where the appearance on the ceiling is found to be objectionable, the unit may be placed at some other location (possibly with the refrigeration machine) and the conditioned air may be piped from the unit to the room and back again to the unit through a short system of ducts. Floor Units: The floor unit for industrial service shown in Fig.. 4 has a galvanized iron casing enclosing the heating and cooling element with the fans mounted above and the air discharging from the top through galvanized 90 deg elbows which deliver the air in a horizontal or slightly upward direction. The operating motor for the fan is carried on a ` bracket at the side and at the bottom a drip pan is provided to catch any condensation that may form, while the space between the pan and the motor bracket may be utilized for the installation of traps and valves. This unit does not attempt to wash or filter the air but when supplied with steam it will heat the air and when supplied with cold water will cool and dehumidify. . . A similar arrangement housed in an ornamental type cabinet is shown in Fig. 5. The cooling element, fans and motor, together with the drip pan and piping connections are all housed within a steel casing finished in wood grain. The element is suitable in this case for circulating eithefTiot or refrigerated water but not a refrigerant. This, however, does not apply to all units of this type. Another floor unit of ornamental type, Fig. 6, has fans below the elements and separate heating and cooling elements. The fan delivers 165 American Society of Heating and Ventilating Engineers Guide, 1934 the air against deflector baffles which spread the air over the element face, and the usual drip pan for precipitation is provided. When this unit is installed for cooling only, the heating element is simply omitted and this arrangement of two elements--one for heating and one for cooling-- possesses the advantage of allowing the heating element to be connected to the source of heat with piping entirely separate from the lines used for carrying the refrigerant to the cooling element and without any cross con necting. Thus the unit may be used for warming in the morning and cooling at noon if desired and without the manipulation of special valves. The refrigerant is used direct in the cooling element and units of this type are for service in the home, office or other location where appearances are highly important. The refrigeration machine may be placed at any point where water, drain and electric connections are available. Fig. 7. Unit for Cooling Service Fig. 6. Floor Unit for Heating and Cooling Fig. 7 is a unit for cooling only and consists of two fans operated by a motor, a cooling element and a drip pan all enclosed in a specially in sulated cabinet. The element is of copper and may be supplied with cooled water or with any refrigerant which does not attack copper or its derivatives. When occasion demands, a heating element can be added and cross connected to the cooling surface. A winter and summer conditioning unit, Fig, 8, employs propeller type fans to draw the air in from a horizontal direction, a deflector changes the direction to vertical and the air passes through cooling and heating elements successively before being discharged vertically from, the top of the unit. The separate heating and cooling elements make' it possible to use this unit for either heating or cooling as desired without alteration of the valving. The refrigerant is in the cooling element, and to prevent waste of cooling water, a solenoid valve closes the flow to the condenser and compressor whenever the fans are stopped. . The unit in Fig. 9 differs from that illustrated in Fig, 5 in that the re frigerant is supplied direct to the cooling element, isobutane being used as the refrigerant in the smaller sizes and methol chloride in the larger units. This unit for the ordinary size office or room requires small space, and operates with the automatic control arrangement indicated. This unit is intended exclusively for cooling. 166 American Society of Heating and Ventilating Engineers Guide, 1934 rftr to Rooms Warm flir Furnace From Rooms Fig. 13. (top) Cross Section of Furnace Unit Fig. 15. (center) Heating and Cooling Unit with Cloth Filter Fig. 17. (bottom) Gas Fired Furnace Unit Fig. 14. (top) Furnace Accessory Unit Fic. 16. (center) Unit with Hot Water Boiler Fig. 18. (bottom) Oil Fired Unit Chapter 12--Unit Air Conditioners and Coolers A radical departure in arrangement is shown in Fig. 10 where both the air inlet and exit are at the top of the unit. The fan is located in the top portion at one side and discharges the air toward the bottom where it turns and passes horizontally through an air washer equipped with atomizing sprays and then turns so as to pass vertically upward through eliminators, cooling surface and heating surface before leaving the unit. With steam or hot water connected to the heating surface, tempered water to the sprays and refrigerated water to the cooling element this unit gives controlled temperature, humidity, air cleaning and air move ment in the summer and winter. Air washing is continued in the summer to remove room odors. Acoustical treatment of the housing and the out let baffles permits installations where the noise requirements are exacting. Ice Units: In commercial type units using ice there is little difference between the outward appearance and that of the mechanical units. The ice using units are enclosed in the same metal housings, are operated by similar fan arrangements and employ an ice container as cooling surface. Fig. 1} illustrates one type of portable machine. The capacity is limited and, ordinarily, it must not be expected that a single ice-cooled unit will give the same cooling effect as a single room unit of mechanical design. In hotels or hospitals where the unit may be desired in different rooms from day to day and where elevator service is available so that the units may be taken into the utility rooms for emptying and re-charging there seems to be a real field of application. Portable Units: A portable type of mechanical unit is now available which is suitable for cooling and dehumidifying only, this unit being equipped with rubber tired wheels, so that it may be shifted with ease from room to room and with a rubber hose 15 ft long for connecting to a nearby water faucet and with an electric extension cord and plug. Accessory Units: Under this classification may be included every type of unit which has been developed as an accessory to an existing or pro posed system of warm air distribution primarily designed for heating service. Some of these accessory units for warm air furnace systems simply provide a fan and air filter, while others include humidifying and cooling apparatus. The performance of this equipment is influenced by the following factors and conservative manufacturers claim only a moderate degree of added comfort: 1. The outside temperature and humidity conditions. 2. The heating system to'which the device is attached. 3. The location of the outlets on the heating system. 4. The conditions surrounding the house or apartment such as construction, exposure to sun. . The introduction of cooler night air into sleeping quarters or living rooms will give greater comfort on summer nights and for some time during the following day. -The added humidity during the winter will do much to improve indoor conditions but where specified conditions must be obtained and held, a special type of installation must be used. -(-See Chapter 2). Fig. 1'2 illustrates an accessory unit for a warm air furnace installation this unit consisting of a large semi-cylindrical screen on the top of fine copper mesh through which the air is drawn by a fan blowing down into a 169 American Society of Heating and Ventilating Engineers Guide, 1934 .. I . spray chamber where the air is washed and humidified and then passes through eliminators into the lower portion Of the furnace casing. (See cross section Fig. 13). If desired a cooling element and mechanical refrigeration may be added for cooling in summer. In Fig. 14 return air from the rooms is drawn by a fan through a dry mat type air filter and is then delivered into the bottom of the furnace casing. While this unit makes no attempt to utilize cooling water or refrigeration, humidification during the winter is obtained from humidi fiers located in the furnace. A more elaborate unit, Fig. 15, for heating and cooling employs a cloth filter of bag design and a double element for heating and cooling. In summer, water is run through both elements either direct from the street maun or from some mechanical cooling equipment, while in the winter hot water is supplied from a hot water boiler using the same surface. These units are provided with a single element in order to reduce first cost and, when so equipped, will do everything that the double element unit will accomplish except that less cooling is available in the summer. Humidity is provided by spraying water between the two elements. Noise is reduced by the use of rubber pads under the bedplate supporting the fans and by the connecting of the fans to the metal work of the dis charge through canvas connections. Fig. 15 shows the outer casing removed: Another design using hot water heating boilers is given in Fig. 16 where the unit takes air from both inside and outside, utilizing hot water from the boiler for winter heating and water, either iced or mechanically cooled, for summer cooling. The boiler may be coal, oil or gas fired and the air is humidified or dehumidified as the'conditions require; the same element is utilized for heating and cooling, the piping being cross con nected. ' Where gas can be used, Fig. 17 shows a unit consisting of an air filter, motor-driven fan, air washer and gas-fired steel furnace which warms the ` air during the winter season. No refrigeration is used with this equip ment, the idea being that the air washer during the summer will lower the air temperature sufficiently when the humidity is low while at night, the apparatus is run without the washer when the. air is cooler but of rela tively higher humidity. ./ For oil fuel the unit shown in Fig. 18 can be installed to obtain filtered, warmed and humidified air. An oil burner and a heat exchanger provide the heat. A cooling section may be inserted between the fan and the heat exchanger, cold water being circulated through the cooling element.' This equipment is completely automatic and is' thermostatically con trolled. A room thermostat starts the oil burner whenever the tempera ture falls and the rising temperature in the heat exchanger causes a second thermostat to start the fan. As soon as the temperature in the house rises to normal the room thermostat shuts down the oil burner which in turn operates the thermostat controlling the fan. 170 . Chapter . 13 UNIT HEATERS AND VENTILATORS Types of Unit Heaters, Heating Media, Entering and'Delivery Temperature, Output of Unit Heaters, Direction of Discharge, Boiler Capacity, Direct-Fired Units, Unit Ventilators, Split and Combined Systems, Location of Unit Ventilators, Capacities AUN IT heater consists of a combination of a heating unit and a fan or blower having a common enclosure, and placed within or adjacent to the space to be heated. Generally, no ducts are attached to the inlets or outlets. A unit ventilator is similar in principle of operation to a unit heater, but is designed to use all or part out-door air with or without alternate provision for handling recirculated air. Unit heaters are designed mainly for factory and industrial use, whereas unit ventilators are intended largely for school and office ventilation and heating. Unit heaters are designed to: 1.. Circulate the air in the building at a rapid rate. 2. Promote uniformity of temperature and quick heating-up. 3. Direct the heated air so as to accomplish the positive and rapid placing of the heat where it is effective. 4. Reduce the temperature differential between floor and ceiling. 5. Reduce the number of heat emitting units and simplify piping and installation. . 6. Increase the capacity of the heating surface by passing the air over it at high velocity. , ;< : 7. Provide a system by which room temperatures are readily controlled manually or by thermostats. TYPES OF UNIT HEATERS There are many types of unit heaters available. Most of them employ heating coils to be supplied with steam or hot water. Some are mounted on the floor, whereas others are designed for suspension overhead. Heat ing surfaces in the form' of pipe coils, non-ferrous tubes or shapes with extended surfaces, cast-iron, and pressed ahd built-up sections of the cartridge or automotive type are all used in unit heater construction. Among the unit heaters available are types having from one to four outlets per heater which may be arranged to discharge in selected direc tions and which will project their heating effect over distances of from 30 to 200 ft from the heater, depending upon the capacity of the Heater and upon the design of the fans and'outlets. These heaters have been successful when placed as far as 400 ft from each other. This makes it possible to select the heater location best suited to the production layout in factories. There are available propeller fan type heaters of smaller 171 American Society of Heating and Ventilating Engineers Guide, 1934 N ote.-- To determine capacity a t any steam pressure and entering temperature, m ultiply constant from table by rated capacity a t 00 F entering and 2 lb pressure. Chapter 13--Unit Heaters and Ventilators capacity with outlet velocities of from 300 to 800 fpm, and these may be placed from 30 to 100 ft apart. HEATINC MEDIA Unit heaters are made to operate with hot water, or with steam at high or low pressure. When high pressure steam is used, the heater must be especially designed for that purpose. The present day tendency is to use steam at low pressure when the boiler supplies steam for heating purposes only, and when the trans mission lines are short. Many industrial plants, however, generate steam at high pressure either for long distance transmission or for process uses. When such high pressure steam is available in sufficient quantity for the peak load, it is economical usually to use high pressure unit heaters. Thus the line pressure may be turned into the units directly without reducing valves and the condensation may be trapped to overhead returns when desired. Smaller coils may be used in high pressure heaters to lessen their cost and to produce a final temperature which will not be too high. - ESTIMATING HEAT LOSSES The heat losses of a building to be equipped with unit heaters are determined in the same manner as for any other heating system, excepting so far as the unit heaters may change the air temperature at the ceiling or at the mean height of the walls. (See Chapter 7). Unit heaters may be arranged to recirculate the air or to supply warmed air from the outside for ventilation or to make up air exhausted. If all or a part of the air is to be taken in from out-of-doors, the heat necessary to warm this air from the outside temperature to the inside temperature must be added to the transmission or other losses. Unit heaters of the number and size needed to furnish the total heat required are then selected; from the manufacturers' rating tables, using these ratings at the steam pressure to be used and at the temperature at which the air will enter the heater. . ENTERING AND DELIVERY TEMPERATURES For recirculating heaters with intakes at the floor level, the temperature to be maintained in the room should be used as the temperature of the air entering the heater. Where suspended heaters are used without any intake boxes extending down to the floor level, a higher entering air temperature should be used than that at which the room is to be main tained. With suspended heaters taking in air at some distance above the floor, the temperature variation from floor to ceiling may reach as much as 1J4 deg for each foot of elevation during periods when the maximum capacity of the heaters is required. Unit heaters taking in recirculated air at the floor level should maintain temperature differentials of less than 1 deg per foot of elevation when the maximum capacity of the heaters is required. These temperature differences per foot of elevation are less than the corresponding variations per foot of elevation for spaces heated by direct radiation. 173 N ote .-- To determine capacity at any steam pressure and entering temperature, m ultiply constant from table by rated capacity a t 00 F entering and 2 lb pressure. Chapter 13--Unit Heaters and Ventilators A rapid recirculation or turnover of the air in the room will give fuel economy. This requires the selection of heaters having a liberal air capacity for the required heat output, which in turn means a relatively low final temperature. Extremely low final temperatures can be had only at the expense of larger heaters and increased power, so that an eco nomic limit is imposed. Contributing conditions vary too widely to permit of a suggested standard, but in general for heating purposes it is advisable to use a delivery temperature not more than 70 deg above the average room temperature desired. OUTPUT OF UNIT 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 maintained in the coil. Steam at 2 lb pressure and air entering at 60 F are used as the standard basis of rating1. The capacity of a heater increases as the steam pressure increases, and decreases as the entering air temperature increases. The heat'capacity for any condition of steam pressure and entering air . temperature may be calculated approximately from any given rating by the use of factors in Tables 1 and 2. Table 1 is for blow-through and Table 2 is for draw-through unit heaters. These tables are accurate within 5 per cent. The ratings customarily published for unit heaters apply only for recirculation and free discharge, unless otherwise noted in the rating tables. If outside air intakes, filters or ducts on the discharge side are used with the heater, proper consideration should be given to the reduc tion in air and heat capacity that will result because of this added resistance. The percentage of this reduction in capacity will depend upon the characteristics of the heater and on the type, design, and speed of the fans employed, so that no specific percentage of reduction can be assigned for all heaters for a given added resistance. In general, however, disc or propeller fan units will have a larger reduction in capacity than housed fan units for a given added resistance, and a given heater will have a larger reduction in capacity as the fan speed is lowered. When confronted with this problem the ratings under the conditions expected should be secured from the manufacturer. When steam supplied to the heaters contains superheat, the capacity of the heater will be but slightly less than with saturated steam at the same pressure. Recent tests indicate that the reduction of capacity from this cause is negligible for superheat up to 50 deg and will not exceed 3J4 per cent for any degree of superheat. Heaters may be distributed through the central portions of a room discharging toward exposed surfaces, or may be spaced around the walls, discharging along the walls and inward as well, when there are con siderable 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 `See A.S.H.V.E. Standard Code for Testing and Rating Steam Unit Heaters. (A.S.H.V.E. Trans actions. Vol. 36. 1930). 175 American Society of Heating and Ventilating Engineers Guide, 1934 set up by the system rather than to have the heaters discharge at random and in counter directions. DIRECTION OF DISCHARGE , Various types and makes of unit heaters are illustrated in the Catalog Section of The Guide. Usually hot blasts of air in working zones are objectionable, so heaters mounted on the floor should have their discharge Fig. 1. Unit Heater Connections Where Condensation Is Returned to Vacuum Pump Fig. 2. Unit Heater Connections Where Condensation Is Returned to Boiler Through Wet Return Fig. 3. Unit Heater Connections Where Condensation Is Returned to Condensation Pump or Hot Well 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. 176 Chapter 13--Unit Heaters and Ventilators 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 heaters taking air from outdoors the lowest entering temperature will be the extreme outdoor temperature expected in the district. No greater allowance in boiler capacity beyond the calculated heat demand need be added in order to supply unit heaters than for any other type of system. It is unwise to install a single unit heater as the sole load on any boiler, particularly if the unit heater motor is started and stopped by thermostatic control. The wide and sudden fluctuations of load that occur under such conditions would require closer attendance to the boiler than is usually possible in a small installation. Where oil or gas is used to fire the boiler, it is possible by means of a pressurestat to control the boiler, in response to this rapid fluctuation. In most cases, however, and particularly where the boiler is coal-fired, it is advisable to use two or more smaller heating units instead of one large unit. Steam pressures belpw 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 heaters are to take in air that may be at a temperature below freezing, however, a steam pressure of not less than 5 lb should be maintained on the heater coils. QUIETNESS OF OPERATION In- selecting unit heaters, attention should be given to the degree of quietness required for the installation. No given fan speed may be applied as a measure of relative quietness to fans of different designs and proportions. Quietness is a function of type, diameter, blade form and other variables besides speed, and all these must be taken into account. In general small fans may be run at higher motor speeds than large fans with equal quietness. UNIT HEATER CONNECTIONS Piping connections for unit heaters aje similar to those for other types of fan-blast heaters. Typical connections are shown in Figs. 1, 2 and 3. One-pipe gravity and vapor systems are not recommended for unit heater work. For two-pipe gravity, or pump and receiver systems the return from each unit should be fitted with a heavy-duty or blast trap and an air valve should be connected into the return header of each unit. Pressuredrop must be compensated for by elevation of the heater above the water line of the boiler or of the receiver. On vacuum systems the return from each unit should be fitted with a large capacity trap, to discharge the water of condensation and with a thermostatic air valve for eliminating the air, or with a heavy-duty trap 177 American Society of Heating and Ventilating Engineers Guide, 1934 for handling both the condensation and the; air, provided the air finally can be eliminated at some other point in the return system. For high pressure systems the same kind of traps may be used as with vacuum systems,' except that they must be constructed for the pressure used. If the air is to be eliminated at the return header of the unit, a high pressure air valve can be used; otherwise the air may be passed with the condensate through the high-pressure return trap. The connections for steam and return piping to unit heaters must always be calculated on the basis of the high heat emission or condensation rate of such devices, usually by reducing the heat to be supplied to square feet of equivalent radiation by dividing by 240, and then using the pipe- size tables given in Chapter 32. : ALL-ELECTRIC UNIT HEATERS The foregoing discussion relates generally to units in which steam, vapor, or hot water are used as the heating medium. On rare occasions electrical resistances are used as the heating element. These are applied only where electric power is abundant and cheap and where other forms of fuel are scarce and expensive'. (See Chapter 38). DIRECT-FIRED UNITS ; A recent development in gas burning equipment is the direct-fired indus trial unit heater. These heaters are of the warm air type and are equipped either with fans or with blowers 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 in such a way as to give a positive distribution of. the heated air. As is the case with the steam fed unit heaters, the gas fired appliances may be used for heating stores, shops, warehouses, etc. They usually are suspended in the space to be heated and in most in stances -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. "' TURBINE-DRIVEN HEATERS Where high pressure steam is available it is sometimes used to drive a steam turbine direct-connected to the unit heater. The exhaust from this turbine, reduced in pressure, is then passed into the heating coil where it is condensed and returned to the boiler. INDUSTRIAL USES - In addition to their prime function of heating buildings, unit heaters may be adapted to a number of industrial processes, such as drying and curing, with which the use of heated air in rapid circulation with uniform distribution is of particular advantage. They may be used for moisture absorption, such as fog removal in dye-houses, or for the pre vention of condensation on ceilings or other cold surfaces of buildings in 178 .; * Chapter 13--Unit Heaters and Ventilators which process moisture is given off. When such conditions are severe, it is necessary that the heaters draw air from outside in enough volume to provide a rapid air change and that they operate in conjunction with ventilators or fans for exhausting the moisture-laden air: (See. discussion 0f condensation in Chapter 7). Information on the control of unit heaters will be found iri Chapter 14. UNIT VENTILATORS2 A unit ventilator must be pleasing in design because it is generally used where it must harmonize with the furniture or with the decorative scheme. It consists usually of a rectangular steel cabinet finished with an enameled surface and containing the following necessary or optional parts: " 1. Outside air inlet. 2. Inlet damper for closing the opening to the outside air inlet when the unit is not in use. 3. Adhesive or dry type filters for cleaning the air (optional). ; ' 4. A heating element usually of special design and intended for low pressure steam. ' 5. Motor and fan assembly. 6. Mixing chamber where warm and cold air streams are brought together. (No mixing chamber is normally provided where sectional type heating units are used). 7. Outdoor air inlet and recirculating air mixing damper (optional). 8. Humidifying arrangement* (optional). 9. Device for ozonizing air (optional). 10. Discharge grille or diffuser. 11. Temperature control arrangement. . .. The primary functions of a unit ventilator are: 1. To supply a given quantity of outdoor air for ventilation or to mix indoor and outdoor air. , . . 2. To warm the air to approximately the room temperature if the unit is intended for ventilation only, or to a higher temperature if it is intended to take care of all or a part of the heat transmission losses from the room. 3. To control the temperature of the air delivered so as to prevent both cold drafts and overheating. . . 4. To deliver air to the room in such a manner that proper distribution is obtained without drafts. . 5. To recirculate room air for the purpose of heating when ventilation is unnecessary, or to partly recirculate it. mixing inside and outside air. 6. To perform all its functions without objectionable noise. In addition to these functions, unit ventilators frequently are arranged so that the air supplied may be cleaned by means of filters of either the dry or. viscous type. If filters are used, the proper allowance must be made for the increased resistance offered to the air flow. Humidifiers in unit ventilators are optional. 1. Air Supply for Ventilation. The outdoor air supply for ventilation is brought about by motor-driven fan or fans operated at comparatively ^ *A roof ventilator is sometimes termed a unit ventilator.' For information on roof ventilators, see Chapter 4. :' '. Mf the unit includes provision for control of humidity, it is usually called a unit conditioner. See Chapter 12. 179 American Society of Heating and Ventilating Engineers Guide, 1934 low speeds and located in the lower part of the cabinet, the back of the cabinet being connected to the outside through rust-proof louvers and screens. Air quantities may be estimated on the basis of data given in Chapter 2. (See A.S.H.V.E. Ventilation Standards). 2. Warming Incoming Air. The air is heated by blowing it through specially designed extended heating surfaces. The amount of heating surface to be provided in the unit is of course determined by the volume of air to be heated and the temperature range. If the unit is to be used for supplying air for ventilation only, the heating surface must be sufficient to maintain a final air temperature of about 70 F. If the unit is to be used for heating as well as for ventilation, the heating surface must be sufficient to maintain the necessary final air temperature for the con ditions involved. 3. Control of Temperature. This is accomplished by controlling the temperature of the air discharged from the unit in one of two ways: first, by the automatic operation of a mixing damper which controls the relative quantities of air being blown through the heating unit or by passed around it; and second, by dividing the heating unit into two or more sections and controlling (i.e., throttling) the steam so that the proper amount of steam will be supplied to as many sections as required. The outside air inlet damper and recirculating damper (where one is provided) should be so connected that there will be an uninterrupted supply of air to the fans at all times the unit is in operation. These dampers may be operated by hand or by pneumatic or electric motors controlled from some central point such as the engineer's office, or auto matically at the unit itself. Provision should be made for the inlet damper to close automatically whenever the fans are shut down. The temperature of the air from the machine should be regulated auto matically by thermostats in the room which control the position of the by-pass dampers below the heating elements, or the number of sections to which steam is supplied. In addition to the room thermostat, a thermo stat is frequently provided in the air stream from the unit to maintain a minimum air stream temperature. Thermostats for controlling by-pass dampers must be of the intermediate type to hold the dampers in in termediate positions to prevent objectionable drafts. When direct radiators are used in conjunction with unit ventilators, the control is usually arranged so as automatically to open the valves to the direct radiators when the room temperature falls about 2 deg below the setting of the thermostat for the unit ventilator. Another arrangement opens the radiator valve whenever the unit ventilator control reaches the full heating position. Further information on this subject is contained in Chapter 14. ' 4. Distribution. This function is governed by the proper selection and location of the unit. Diffusion and distribution are dependent upon a relatively high velocity air stream discharged in a generally vertical direction, and in order to insure satisfactory diffusion in the room the final temperature of the air discharged from the unit must be kept as low as possible. With a final temperature above 110 F, excessive stratification of the air may be experienced. Troublesome drafts may be eliminated to a large extent if a static pressure is built up in the room, which can be done only if the vent from the room is small. 180 Chapter 13--Unit Heaters and Ventilators 5. Recirculation reduces fuel consumption and aids in heating up rooms. Certain units are designed to recirculate all air at all times, except when the admission of outside air is needed to regulate room temperatures. Under this arrangement, the outside air for ventilating purposes is obtained solely from the infiltration, but the amount thus obtained is ordinarily insufficient to meet legal ventilating requirements. Recircula tion is therefore prohibited by ordinance in some communities. 6. Quiet Operation. The unit ventilator is generally set close to the occupants of the room where activities are being carried on which preclude the use of noisy equipment. Quiet operation is therefore imperative. SPLIT AND COMBINED SYSTEMS In the split system the unit is used primarily for ventilation, delivering the air to the room at very near the room temperature, sufficient separate direct heaters being placed in the room to heat it to the desired tem perature, independently of the unit. With the split system the separate direct heaters tend to improve.the air circulation and diffusion within the room, since they constantly pull the cold air from the floor, warm it and . use it to counteract the window chill. Where the unit ventilator selected may have a capacity more than sufficient to warm the air needed to meet the ventilating requirements, a corresponding reduction may be made in the amount of direct heating surface installed. The greater the amount of excess capacity of the unit, the more efficient will be the temperature regulation of the room. The split system permits the heating of the room during failure of electric ' current, 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 and this also gives assurance of ventilation. . The cost of installation of a combined system is usually less than that of a split system and there is less danger of overheating. . Central fan systems (Chapters 9 and 22) as well as unit ventilator systems may be designed for split or combined operation. LOCATION OF UNIT VENTILATOR The location of the unit ventilator ip a room is important. Wherever possible it should be placed centrally on 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; all units, however,, should be arranged to operate with free air inlet and free discharge. 181 American Society of Heating and Ventilating Engineers Guide, 1934 SIZE AND LOCATION OF VENT The size and location of the vent outlet is important. In many cases the sizes for public buildings are regulated by law, but the location of the vents generally is left to the discretion of the engineer. Best results have been obtained with a velocity through the vent openings nearly equal to that at which the air is introduced into the room, thus maintaining a slight pressure in the room. Calculated velocities at the vent openings of from 600 to 800 fpm produce the best diffusion results from this system. The cross-sectional area of the vent flue itself may be figured on the basis of 15 sq in. of flue for each 100 cfm. Thus the vent flue area of a flue for a room equipped with one 1200 cfm uriit 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 buildings provided with wardrobes or cloakrooms the vents may be so located that the air shall pass through these spaces, heating and venti lating 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. The individual vent flue and the corridor or central vent flue are the types generally used with unit ventilators. The individual vent flue system provides for separate vent flues from each room. The corridor vent or central vent outlet system provides for outlets centrally located to take care of a group of classrooms, the air passing from the classrooms,' wardrobe or cloakroom to the corridor, and from the corridor to the central outlets. The grilles between the wardrobes and corridors may be near the ceiling, provided the air leaves the classroom to enter the ward robes near the .floor in the classrooms. A velocity of 800 to 900 fpnrmay ' be used for the central outlet from the corridor. Where the law and the type of building construction will permit, the escaping spent air from the building may circulate throughout the attic on its way out. . 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 125 to 600 sq ft of equivalent direct heating surface. Some manufacturers furnish a unit with several heating capacities for each air capacity, thus enabling the engineer to select the unit best adapted to the heating and ventilating load. Capaci ties should be determined in'accordance with the A.S.H.V.E. Standard Code for Testing and Rating Steam Unit Ventilators4. Typical capacities are given in Table 3. . The amount of heat to be supplied by the unit ventilator will depend on the amount of air passed through the unit and the temperature range through which the air is heated. The weight of air (W) to be circulated per hour is fixed by the ventilating requirements. `Adopted 1932. See A.S.H.V.E. Transactions, Vol. 3S, 1932. 182 Chapter 13--Unit Heaters and Ventilators 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: V Ht = 0.24 W (ty--to) . (D W = dQ (2) h 0.24 W + t (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 introduced for the ventilating requirements, cubic feet per hour. t -- 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 dQ (l--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 taken from the outside is 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 x 60 = 60,000 cfh; / = 70 F; to = 0. Substituting in Equation 4; Ht = 24,000 + 0.24 x 0.075 x 60,000 (70 -0) = 99,600 Btu ty 0.24 x 24,000 0.075 x 60,000 + 70 = 92.2 F Table 3. Typical Capacities of Unit Ventilators for an Entering Air Temperature of Zero. Cubic Feet op Am per Minute 600 750 1000 1200 1500 Total Capacitt in Square Feet op Equivalent Direct Heatinq Surface (Radiation) - Capacitt Available fob Heat ing the Rook in Square Feet op Equivalent Direct Heating Surface (Radiation) Final Am Tempera ture (Deo Farr) 285 350 455 565 _ 705 95 115 150 -490 235- ' 105" 105 105 105 105 183 IMfr American Society of Heating and Ventilating Engineers Guide, 1934 If all of the air is recirculated, the total heat required is of course the same as the heat loss of the room, or . //,=# = o.24 W (ly--i) (5) . 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: Hy -- 0.24 W (ty -- /(,) (6) 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 of the volume of air that will be delivered at a certain temperature U, for an initial temperature of t0. Therefore a certain amount of heat (Hb) 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. Example S. Assume the same data as in Example 1, for a split system, and select the unit and direct heating surface, making allowance for any excess capacity of the Unit above that required to warm the air introduced for ventilation purposes. Solution. The amount of equivalent direct heating surface required, disregarding the 24 000 unit ventilator, is equal to = 100 sq ft. A unit having an air capacity of 1050 cfm is selected, the excess heating capacity of this unit for an entering air temperature of zero being 82 sq ft. The theoretical net direct heating surface required with the fan in operation is therefore 18 sq ft. However, it is not likely that this or any other unit contains enough indirect heating surface to heat the average size classroom when the-fan is inoperative. The maximum deduction should not exceed 75 sq ft of equivalent direct heating surface, and as previously stated, the best results are obtained when no deduction is made for the excess capacity of the unit. 184 Chapter 14 TEMPERATURE AND HUMIDITY CONTROL Definitions, Thermostats, Temperature Control Systems, Control of Automatic Fuel Devices, Zone Control, Control of Air Con ditioning Systems, Control of Radiators and Convectors, Unit Heaters, Unit Ventilators, Central Fan Systems CONTROL of a heating or cooling system may be obtained through regulation of only the dry-bulb temperature, while in an air con ditioning system, the dry-bulb temperature, the wet-bulb temperature, and air movement must all be regulated. It is possible, however, that the control of only one of these may affect the other two sufficiently to give desired conditions. This chapter contains information on the principles underlying the regulation of both temperature and humidity as well as data concerning various devices for such regulation. Specific control devices and systems are described in the Catalog Data Section of The Guide. ' Controls are applied for the following reasons: 1. To maintain conditions required for human comfort and efficiency. 2. To maintain conditions required for industrial processes. 3. To obtain economy in operation. 4. To provide necessary safety measures. The proper operation of all control systems depends on the selection of the correct type of control instrument, as well as on its correct application within the complete system. DEFINITIONS For the purposes of this chapter the terms used shall be construed as follows: Normally Open or Normally Closed: Used to indicate position taken by a valve or damper when the power for the control system (compressed air, electricity, etc.) is turned off, or fails. Branch Line: The line between a thermostat, humidistat or switch and the valve or damper it operates. "" Main Line: A line furnishing power to a thermostat, humidistat or switch.... Pilot: A thermostat or humidistat which acts directly oh another thermostat or humidistat. The pilot may either throw the instrument it operates out of action by cutting off or throttling its source of power, or it may actas a remote adjusting device by resetting its point of control. In the former case, the branch line of the pilot becomes the main for the other instrument. In the latter case, it is necessary for each to have direct connection to the main line. .- 185 American Society of Heating and Ventilating Engineers Guide, 1934 Positive Acting: A thermostat, humidistat or relay which maintains its valve or damper either wide open or fully closed, that is, when there is always full force or none in its branch line. Intermediate Acting: A thermostat, humidistat or relay which holds its valve or damper in any position, that is, when its branch line may have full main force, or any part of it. Two-Point Thermostat: A thermostat having two branch lines, each of which is independent of the other, thus being equivalent to two separate instruments. Direct-Acting Thermostat: A thermostat that increases power in its branch line on rising temperature. A direct-acting valve is one that is normally open. Reverse-Acting Thermostat: A thermostat that increases the power in its branch line on falling temperature. A reverse-acting valve is one that is normally closed. Threeway Valve: A valve having three pipe connections and used to regulate the flow of a fluid through either one of two,circuits; it may be operated either positively or intermediately. THERMOSTATS Automatic control of temperature requires the use of an instrument known as a thermostat which responds to a change in temperature. Al though there are many types of thermostats, the basic principles of opera tion of practically all types are included in the following classifications; . 1. The diaphragm type (Fig. 1) which, by means of an expanding liquid or gas within a diaphragm or bellows, furnishes motion; which motion may be mechanically transmitted in proportion to the rise and fall of temperatures surrounding the diaphragm. 2. The direct-expansion type (Fig. 2) which operates' by direct expansion and con traction of a substance which has a high coefficient of expansion such as hard rubber. The slight movement of the thermostatic element usually must be multiplied through a system of levers. 3. The bi-metallic type (Fig. 3 a, b, and c) which is actuated by means of two inr timately attached metals having dissimilar coefficients of expansion. This type is in herently more sensitive to temperature changes than the diaphragm or direct expansion types, but lacks the necessary force to cause motion of the controlled equipment and must be used with compressed air, electric current or other source of power. The sensitive element may take any one of a number of forms, the most common being the straight strip, the circular strip, the spiral and the helix. Fig. 3-a shows the straight strip used in a compressed air thermostat, Fig. 3-b shows the spiral used in a mercury tube type of thermostat, and Fig. 3-c shows the curved strip used in an open contact thermostat. . Direct- and Indirect-Acting Thermostats Thermostats may control directly, or indirectly, the equipment which regulates the supply of heat and are frequently classified on this basis as follows: Direct-Acting or Self-Contained Thermostats. These instruments' have sufficient power in themselves to actuate the controlling devices. They may be subdivided further into two groups; (1) those in which the sensitive element and the controlling device are in one body, the power from the thermostat being transmitted by a system of levers; and (2) those in which the sensitive element and the controlling device are separated, the power from the thermostat being transmitted through a capillary tube. The expansion or volatilization of a fluid actuates a diaphragm which transmits its motion to a valve or damper. The small movement of the diaphragm may, if necessary, be multiplied and transmitted by mechanical means, such as a system of levers, or by liquid pressure in order to produce sufficient movement of the damper or valve. This thermostat is inherently intermediate acting since the expansion or volatilization of the fluid and the movement of the diaphragm are proportional to the change in temperature. There are many types of thermostatic radiator valves which come in the first group. 186 Chapter 14t--Temperature and Humidity Control . In general they maintain some temperature at their location which bears a relation to the room temperature. Since these control devices are inherently intermediate acting,: they should not be used on one-pipe systems because a partially closed valve will not allow the condensation to leave the radiator. ............... . . . Fig. 4 shows the operation of a self-contained thermostat in connection with a hot water storage tank whereby the supply of steam to the tank is controlled directly by the temperature of the water in the tank. Fig. 5 shows the use of a self-contained thermostat on a hot water tank with vacuum return. Volatile Liquid Fig. 1- Diaphragm Type Thermostat Fig. 2. Direct Expansion Type ; Thermostat Fig. 3. Three Types of Bi-Metallic Thermostat Indirect-Acting Thermostats. These instruments do not have sufficient power to operate the controlling devices, but function to control the external source^ of power which in turn operates the valves and dampers. There are two distinct groups of these instruments, the compressed air and the electric. . . , Essentially the compressed air thermostat consists of a hole or leak port which is. opened or closed by means of the thermostatic element. This port communicates with a diaphragm which in turn controls the supply of compressed air reaching the valve or damper operator. The instrument regulates the flow of the compressed air to and from the controlled devices. There are two classes of-these instruments, one of-which allows' theiair pressure to build up or be released instantly and' is called the positive or snapr > acting type; and the other which allows the compressed air to be maintained at any: intermediate pressure, called the: intermediate or gradual-acting type. ` : 187. - American Society of Heating and Ventilating Engineers Guide, 1934 . The electric thermostat makes or breaks one or more electric circuits. In other words it amounts to an automatically operated switch which opens and closes circuits in response to the change in temperature. The controlled devices may be constructed to be positive or gradual acting. : .. There are many models of all of these thermostats which may be generally grouped as follows: 1. Room Thermostats. All thermostats which are designed to be used in a room to control the temperature within that area. 2. Duct Thermostats. These instruments are constructed so that the thermostatic element is in the air duct or chamber and the remainder of the instrument is on the out side of the duct. This type of thermostat is generally used to control the temperature of the air in various parts of ventilating and air conditioning systems. Chapter 14--Temperature and Humidity Control plied from outside the building, the amount of gas or oil fuel consumed, or the operating rate of a coal stoker. . TEMPERATURE CONTROL SYSTEMS The foregoing discussion has concerned the sensitive element of the thermostat and its work. The following pertains to the types of control used for (1) direct radiators, (2) unit heaters, (3) unit ventilators, and (4) central fan systems. Fig. 4. Self-Contained Thermostat in Hot Water Storage Tank Fig. 5. Self-Contained Thermostat on Hot Water Tank with Vacuum Return 3. Two-Temperature Thermostats. These instruments are used when it is desired to control at two distinct temperatures at different periods by means of a single thermostat. For example, a temperature of approximately 70 F may be desired during the day, while some lower temperature is satisfactory during the night. Shifting from the high to the low temperature may be accomplished at some remote point by means of a clock or a manual switch. ' 4. Clock Thermostats. These instruments are arranged with clock mechanisms to maintain predetermined temperatures at predetermined hours, such as a low night temperature which may be automatically increased at a certain hour to the proper day temperature. ' 5. Weather Compensating Thermostats. These instruments control the temperature of a building with respect to the outdoor temperature. Two thermostatic elements, one of which is placed outdoors and the other attached to a radiator, are arranged so as to operate the supply of heat in conjunction with each other. The temperature of the radiator is thus decreased as the weather temperature rises. This system may control the temperature of hot water, the pressure on a steam boiler, the volume of steam sup- 188 Fig. 6. Control of Direct Radiator with Positive Thermostat Control of Radiators or Convectors The control of rooms heated by radiators or convectors may be accom plished in several different ways. The problem is to control the heating units located at one or more points in or adjacent to the room. The circulation of air is not rapid, and the rate of temperature change usually is slow. The types of controls commonly used are: first, the direct-acting radiator valves with the thermostatic element at the valve, or at some adjacent point in the room and connected to the valve by means of a capillary tube; and second, the indirect-acting thermostat controlling either air or electrically operated valves. Fig. 6 shows a radiator con trolled by an indirect-acting thermostat. A discussion of control of steam heating systems is given in Chapter 31. 189 American Society of Heating and Ventilating Engineers Guide, 1934 Control of Unit Heaters : Automatic control of unit heaters may be accomplished with and with out by-pass units. There are two general methods of automatic control that may be applied to the unit without by-pass. One is to.stop and start the unit heater motors individually or in a group' by means of a room thermostat. The other is to control the steam supply either to individual units or to a group of units by means of a gradual-acting valve operated from a room thermostat. Where a steam valve control is used, the return system must be equipped with a vacuum pump, as an appreciable pres sure difference between supply and return connections necessarily exists when the steam is throttled. A combination of these two methods is sometimes used wherein the steam supply to the units is cut off completely before the unit heater motor is stopped and is turned on just before the motor is started again. The purpose of this control is to cool off the heater casing and to prevent possible discomfort to persons close to the unit from the radiant heat if steam is left on the coils when the motor is stopped. . This is accom plished by two thermostats, one for controlling the motor and the other for controlling the steam valve. With this combination control, there is some possibility of draft complaint, for at times the fans may deliver cool air. ... Gradual-acting control of the steam valve should not be applied to heaters with outside air connections unless some protection against freezing is also used. This protection can be accomplished by separating" the heater coil into two parts, one of which acts as a tempering coil and is controlled from an outside air thermostat which will keep steam at full pressure on the coil whenever the entering air is below freezing, and which . will cut off the steam when the entering air goes above freezing. The main coil is controlled from the room thermostat and is depended upon for temperature regulation. Another method of protection is to immerse . in the return condensate a thermostat which controls a positive-acting by-pass valve and which will admit additional steam if the temperature of the condensate falls to the freezing point. This is purely a safety device and assumes that no condition of normal regulation will require enough throttling to make freezing possible. If this were not the case, such a method would not be suitable, as it prevents regulation beyond the point where the by-pass valve opens. As a precaution against allowing the unit heater motors to continue to run if the steam supply fails or is for some reason shut off, either a pres- surestat or thermostat in the supply line, or a thermostat on the . return line may be installed to stop the motor when the pressure or temperature in the supply line, or the temperature in the return line, drops below a predetermined point. . The by-pass-type units are equipped with a by-pass opening and two interconnected dampers, so arranged that all or any portion of the air may be passed through or around the coil without being heated. It is possible to obtain a fair degree of temperature regulation by manually operating the dampers, but with the application of automatic controls, unusually good temperature control is obtained. ' , There are two types of control applicable to the by-pass units. The 190 Chapter 14--Temperature and Humidity Control older method is the pneumatic while the newer method is the electric. For the former, an air motor is installed on the unit to actuate the dampers. A pneumatic room thermostat is connected by means of small air lines to this air motor as well as to a source of compressed air supply. Should the room temperature tend to rise above the thermostat setting, the position of the dampers will shift to allow more air to be by-passed and less air to be heated through the coil. This produces a lower discharge temperature, which restores the desired temperature condition in the room. Conversely, should the room temperature tend to fall, the damper positions shift, so that less air is by-passed and more air is heated in going through the coil and a greater quantity of heat is supplied to the room. ., The electric controls are similar to the pneumatic controls. In place of the air motor, a smali reversible electric motor is used, and this is actuated by a room thermostat. When more heat is required, the thermostat makes a contact which causes the motor to shift the damper positions so that less air is by-passed and more air is drawn through the coil. When less heat is required, the thermostat makes another contact which causes the motor to operate in the reverse direction. Where conditions require, an additional thermostat may be used to stop the fan motor when the by-pass damper is wide open and the coil damper tightly closed. Also, a thermostat may be applied to the return line which will stop the fan motor should the steam supply fail. Fig. 7 shows a control for a unit heater which takes into consideration the factors which may arise. The room thermostat No. 1 calls for heat and passes electric current to motor valve No. 2, which operates, admit ting steam to the heater. The same impulse from thermostat No.l also seeks to operate switch No. 3 and so to cause operation of the fan motor, but is prevented by contact thermostat No. 4 coiled around the return pipe of the heater. Thus unless the heater is warm its fan cannot operate and the ensuing cold drafts are avoided. As soon as the contact thermo stat No. 4 becomes warm it permits operation of switch No. 3, starting the fan motor, and where desired also permits the motor damper operator No. 5 to open the intake damper from outside. The fan always stops and the damper always closes when the heater is cold. 191 American Society of Heating and Ventilating Engineers Guide, 1934 Control of Unit Ventilators The unit ventilator presents a different control problem than the unit heater. Generally this type of unit draws its supply of air from the out side, heats it, and introduces this air into the room under control. There are many types of unit ventilators on the market. Some have a mixing damper by which the temperature of the air entering the room may be varied, others have valves for this purpose, and still others use a com bination of the two. Regardless of the construction of the machine, the essential requirement is that the temperature of the air delivered to the room should change slowly and remain as near room temperature as possible. Frequently direct radiators are used in conjunction with the unit ventilators to supply additional heat in extremely cold weather or for quickly heating up the room. The four general types of control for unit ventilators are as follows: 1. A damper operator, the supply of power to which is controlled by a room thermo stat, is attached to the mixing damper. When the thermostat calls for heat, the damper is moved to a position which forces more air through the heating unit and thus increases the amount of heat supplied to the room. This action must be gradual so that the air temperature may be changed slowly to prevent the drafty condition caused by supplying first hot and then cold air. 2. In mild weather the heating unit frequently supplies sufficient heat to cause over heating of the room, even though all of the air is by-passed around the heating unit. To avoid this fault a valve is placed on the heating unit to close the steam supply when the damper is by-passing all of the air. This valve is used in addition to the damper operator explained in the foregoing paragraph. 3. In some unit ventilators one or more heating units and no mixing damper are used. A gradual-acting valve on each heating unit controls the supply of steam to the unit to give the proper amount of heat required to maintain the desire! room temperature. A thermostat to govern each valve may be installed in the room, or one thermostat may be used for all valves. 4. Another type of unit ventilator is arranged so that all recirculated air passes through the heating unit, and the outside air is introduced into the room for cooling purposes only. The outside air damper and the recirculated air damper are interlocked so that one damper operator will control them. In addition a valve operator is placed on the heating unit. Both of the operators should be gradual to avoid drafty conditions. When the thermostat calls for heat, the damper operator slowly closes the outside air damper and opens the recirculating damper simultaneously; if this does not meet the demand, the valve on the heating unit opens until the room temperature reaches thedesired point. Fig. 8 shows a unit ventilator which may or may not be used in con junction with a direct radiator. It is generally considered advisable to shut off the steam to the direct heating surface, if any, first, so that the control system will allow the unit ventilator to supply the full heating requirement where possible. For additional information on the control of unit ventilators, refer to Chapter 13. Central Fan Heating and Ventilating Systems . The numerous types of central fan systems present many control problems. In general they all have one point in common, namely, that the temperature change may be very fast due to rapid circulation. System for Ventilating Only (Split System). Fig. 9 shows an accepted control for ventilating systems. Thermostat A located in the outside air 192 Chapter 14--Temperature and Humidity Control duct set just above freezing, controls a valve C on the first heating coil. This valve is either completely open or completely closed. The by-pass damper B and the other two valves D and E are controlled by a duct thermostat F located in the discharge duct from the fan. If the tempera ture of the air surrounding the thermostat F increases, the damper is moved to admit more cold air. Should this not reduce the temperature sufficiently, the valves on the heating coil will be closed gradually and in sequence until the correct temperature is reached. . The opening or closing of the damper B and the valves D and E must be gradual or there will be a wide fluctuation in air temperature. In ventilating systems it is customary to supply air tothe 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. Hence, in order to maintain controlled room temperatures it is further necessary to use room thermo stats governing control valves placed on the radiators. With this type of central fan system it is possible to ventilate a large number of rooms by means of one fan. In some installations, such as in theaters or auditoriums, it is difficult to install sufficient direct heating surface to offset the heat losses from the room. Also there are installations where a short heat-up period is allowed before occupancy of the room, and it is advisable to use the 193 American Society of Heating and Ventilating Engineers Guide, 1934 entire heating capacity of the ventilating system for this purpose. Systems of this type have, in addition to the control described in Fig. 9, a pilot thermostat located in the room to be heated or in the path of air with- Chapter 14--Temperature and Humidity Control When the room temperature reaches the setting of the pilot thermostat, the control.of the air temperature is returned to the thermostat F in the fan discharge. The fan discharge thermostat, therefore, serves as a minimum temperature control and prevents introduction of air at tem peratures which would produce drafts or faulty air distribution. Accurate control of room temperature is accomplished in this manner, but the system can not well be used where more than one room is supplied with air from a single fan. 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. Fig. 10 shows such an arrangement with control of the second tempering Fig. 9. Control of a Split System of Ventilation Fig. 10. Use of Pilot Thermostat on Ventilating System with Air Washer drawn from that room. This thermostat is set for the temperature required in the ventilated space and controls the supply of power to the thermostat F located in the fan discharge controlling the damper B arid the heating units D and E. . When the temperature of the air in the room is below the setting of the pilot thermostat, the control is such that the by-pass damper B is closed and the valves on the heating coils are open. Thus the maximum heating capacity is available to bring the room temperature to the desired point. 194 Fig. 11. Control of Mixing Dampers with Intermediate Acting Thermostat heating unit from the air washer temperature and with the usual control of the first tempering heating unit from the outside temperature. This permits the air to be kept cool while passing through the washer so that too much moisture will not be absorbed. Fig. 10 also shows control of the re-heating units from a duct thermostat in the fan discharge and the application of a pilot thermostat to a system of this sort. ` Combined Systems. There are various central fan systems which are used for both heating and ventilating. They are usually arranged with tempering heating units, automatically controlled to provide a minimum temperature for ventilating only, and additional heating units to supply the heating requirements. Fig. 11 shows a type of system which has the reheating units located in the fan room. Tempered" air at about 70 F is supplied to the fan and may be further-heated by the reheating units, or it may pass into the tempered air chamber. A room thermostat controls a 195 American Society of Heating and Ventilating Engineers Guide, 1934 gradual-acting damper operator on the double mixing damper in the warm and tempered air chambers. When the thermostat calls for heat, the damper operator moves the dampers so that more air is taken from the warm air chamber. It is essential that the double mixing damper be moved slowly to prevent alternate blasts of hot and cold air from being supplied to the room. Outside Air, Recirculating and Vent Dampers. In all types of plenum systems, the outside air damper is usually opened and closed by a damper operator. This operator may be controlled from a switch in the engi neer's room or it may be operated by a relay in the fan motor circuit. When the ventilating fan is started, the relay causes the damper operator to open the outside air damper. Recirculating dampers and vent dampers may also be opened and closed by means of damper operators controlled from remote locations. Generally these damper operators are positive acting and are either completely opened or closed. However, in some cases where part out side air and part recirculated air is used, it is advantageous to use damper operators which have a certain number of definite positions. With this type of operator it would be possible to use 75 per cent outside air and 25 per cent recirculated air, or any other proportions which might be predetermined. These damper operators are controlled from switches generally mechanically interlocked so that the total opening of the two dampers is 100 per cent. Hand-Fired Coal Systems In small buildings the heating plant may be controlled by a single thermostat located in a key room in the building, instead of each room having its own control. ...... The most common control for a hand fired furnace or boiler consists of a room thermostat and a furnace regulator of some type. The thermostat should be located in a representative room; never, of course, near the chimney or heat flue, too close to a radiator, or in a drafty hallway, and preferably on an inside wall. The regulator is attached to the draft and check dampers of the furnace. When the temperature of the air sur rounding the thermostat drops, the thermostat causes the furnace regu lator to open the draft and close the check damper. As soon as the room comes up to temperature, the draft is closed and the check damper ` opened. With this arrangement on hot water heating systems it is advisable to install an immersion thermostat in the boiler. This thermo stat should be connected with the room thermostat so that both must call for heat before the draft is opened, but either one may cause the draft to be closed. On warm air systems it is advisable to use a bonnet thermostat and on steam heating systems a pressure limiting device, in series, in each case, with the room thermostat. If the temperature of the heating medium becomes too high, the drafts will be closed even though the room thermostat continues to call for heat. ' CONTROL OF AUTOMATIC FUEL APPLIANCES It is essential that automatic temperature control, be used with oil burners, gas burners, and stokers to aid economical operation. I There are 196 . Chapter 14--Temperature and Humidity Control many types of burners and many types of control, but there are some points common to all. First, a room thermostat is located in a key position in the building to maintain a given temperature at that point. Fig. 12. Electric Thermostat Applied to Oil Fired Heating System Fig. 13. Typical Arrangement of Steam or Vapor System with Two Thermostats Controlling Automatic Fuel Burner Used for House Heating and Water Heating Safety devices are: installed in connection with this thermostat so that a failure of the ignition, power, or fuel supply will shut the system down. The same limit controls as recommended for coal burning should be used. ... 197 American Society of Heating and Ventilating Engineers Guide, 1934 Oil Burners '. Fig. 12 illustrates diagrammatically the essentials of an oil burner con trol circuit. Three thermostats are employed as shown in the illustration. Thermostat No. 1 will stop the burner when the room temperature is too high and No. 2 will stop the burner when the temperature of the heating medium exceeds the setting of thermostat No. 2. Both temperatures must be below their respective thermostat settings to start the burner. Thermostat No. 3 responds to the flame temperatures and in conjunction with the control switch acts as a safety to stop the burner if the latter fails to ignite or burn properly as demanded by thermostats Nos. 1 and 2. Steam and hot water heating plants are often used to provide heat for the domestic hot water supply as well as for heating the building. Fig. 13 illustrates one such system. The burner control is similar to that shown in Fig. 12 except that either the room thermostat or the tank thermostat may cause the opening of the valves in the mains which supply them and start the fuel burner, but the burner will not stop unless both thermostats have closed their valves or the steam pressure shall have reached that allowed by the pressurestat. Much the same control is applied to gas burners and automatic coal stokers. Gas Heating Appliances On account of the ease and effectiveness with which the fuel can be controlled, gas-burning appliances are particularly adaptable to full automatic control. Standard equipment on a steam boiler generally ineludes provision for control through a room temperature thermostat, a steam pressure regulator and a device which shuts off the gas in the event that the water level becomes too low. Practically all gas boilers are or may be equipped with automatic safety pilots which shut off the gas if the pilot flame is too low. Water boilers are adapted to operation under thermostatic room tem perature control and are also provided with water temperature control equipment. Warm air furnaces can be under the control of thermostats in the spaces being heated, as well as thermostats located in the heat ducts for the purpose of preventing unpleasantly hot air reaching the heated spaces. Variations in the pressure under which the gas is supplied to the ' appliance are controlled by means of a gas-pressure regulator. This is an essential part of practically all makes- of gas-burning heating appliances, in fact, a gas-pressure regulator is required by the American Gas Associa tion on all approved gas boilers, warm air furnaces (except floor furnaces) and unit heaters. ZONE CONTROL Zone control is a step between a single thermostat and individual room temperature control. The building is first divided into sections or zones which may have quite different heat requirements.' With this method of control: First: The zoning should be done with reference to the compass, since the north and west quarters in most localities require considerably more heat during the heating season than do the south and east quarters. 198 Chapter 14--Temperature and Humidity Control Second: Most large office buildings have more or less space occupied; by merchants, and some by clubs, restaurants, etc., which' have short hours of occupancy. Much can be accomplished in zoning with, reference to the, kind of occupancy of space. . For additional infor mation on this subject, refer to Chapter 31. / ... ., COOLING UNITS Cooling units are readily adaptable to thermostatic control. Several arrangements are as follows: ' . 1. Room thermostat, in conjunction with a magnetic or motor-operated valve to regulate the flow of refrigerant to coil. Usually the fans operate continuously. 2. Room thermostat to control operation of compressor. Fans operate continuously.. 3. Room thermostat to control the operation,of. the fan motors. 4. Room thermostat to. control the operation of fan motor and compressor motor simultaneously. . . 5. Room thermostat to control operation of the compressor with back pressure control to regulate the fans. -' For further information on unit coolers, see Chapter 12. 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 is often:specially designed for .each particular process.' Each installation,'or the installation for each' process, is likely to be a problem peculiar to that process. AIR CONDITIONING SYSTEMS The following' fundamental principles should be borne in mind in the solution of problems involving the control of air conditioning systems: 1. Dew-point temperatures vary only with the amount of moisture. That is, no matter how much a given mixture of air and water vapor is heated or cooled, the dew-; point temperature remains the same, as long as there is-no addition or subtraction of water.. Cooling below the dew-point temperature will, of course, cause subtraction. Also, at the same temperature, there is always the same proportion.of water vapor in the saturated mixture, provided sufficient water and time are furnished for saturation, r Table 2, Chapter. 1, shows the amount of moisture required to saturate a space at various temperatures. When 'the proper, amount of moisture is determined, it is only necessary to set the air washer (dew-point) thermostat for the corresponding.temperature of saturation: then if the air entering the washer has more humidity than desired, the excess will be condensed; and if it has less, the deficiency will be absorbed from the sprays.. For example, the dew-point temperature at 70 F arid 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 ait-tem perature 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 through the walls, roof, etc., the space temperature being maintained at 70 F, the relative humidity will be 40 per cent. ': '" : . '. 2. Within ordinary operating ranges, saturated air will have a relative humidity of approximately 50 per cent when its temperature is raised 20` deg. For example, satu 199 American Society of Heating and Ventilating Engineers Guide, 1934 . rated air at 40 F raised to 60 F has a relative humdity of 49 per cent; 60 F saturated air raised to 80 F has a relative humidity of 50 per cent. (See Table 1, Chapter 1). Thus a differential thermostat can be used to maintain a nearly constant relative humidity of 50 per cent by holding the dew-point temperature 20 deg below the dry-bulb temperature. 3. The total heat of the air and water vapor mixed with it varies directly with the wetbulb temperature. For example, the occupants of an auditorium give off sensible heat which tends to raise both the dry-bulb and wet-bulb temperatures of the space; but they also give off moisture which increases the absolute humidity and tends to further raise the wet-bulb temperature an amount which is a direct indication of the heat expended by the body in evaporating this water. This relationship is useful in regulating the total heat, as wet-bulb temperatures can be controlled directly by means of a thermostat having a sensitive element covered with water-fed wicking, similar to a wet-bulb ther mometer. For example, the total heat of air at 80 F and 60 per cent relative humidity is the same as for air saturated at 70 F, i.e., 33.5 Btu per pound, both having a wet-bulb temperature of 70 F. Air at 80 F and 60 per cent relative humidity (70 F wet-bulb = 33.5 Btu per pound) reduced to 70 F and 50 per cent relative humidity (= 58)4 F wet-bulb = 25.2 Btu per pound, total heat) must give up 8.3 Btu per pound. If the sensible heat and moisture pick-up in an auditorium is 8.3 Btu per pound of air handled in the conditioning system, the wet-bulb temperature of the air entering the space must be maintained at 58)4 F to secure a final condition of 80 F and 60 per cent relative humidity. Control of Relative Humidity Relative humidity is controlled by means of instruments called humidistats or hygrostats, or by the proper combination of two or more thermostats. The following are the most commonly used piethods: 1. A thermostat is located in or at the outlet of a spray-type air conditioner which maintains a constant saturation temperature of the air leaving the conditioner by varying the temperature of water entering the suction of the pump supplying the spray nozzles, or by varying the temperature of the air entering the conditioner, or both. The tempera ture of the air entering the conditioner may be varied by use of tempering heaters, or by the proper proportioning of supply and return air entering the conditioner. This thermo stat is known as a dew-point thermostat, as it determines the dew-point temperature of the air introduced into the conditioned spaces. A second thermostat in the room, or in the path of the air leaving the room,' maintains a constant dry-bulb temperature by varying the amount of sensible heat added to the air leaving the conditioner, or by varying the volume of air introduced into the conditioned spaces. These two ther mostats, in combination, control the dry-bulb and dew-point temperatures, which accordingly fix the relative humidity. 2. A wet-bulb thermostat is located in the room, or in the path of the air leaving the room, to maintain a constant wet-bulb temperature .by varying the saturation tempera ture at the air conditioner outlet. A dry-bulb thermostat is located in the room to maintain a constant dry-bulb temperature, which in combination with a constant wetbulb temperature fixes the relative humidity. 3. A differential thermostat may be used to control relative humidity. This instru ment consists of two thermostatic elements, one of which is in the path of the air leaving the conditioner, and the other under the influence of the dry-bulb temperature in the room. Instruments of this kind maintain a constant relative humidity by maintaining a constant difference between the dew-point temperature and dry-bulb temperature in the room. (See Item 2 under Air Conditioning Systems). One thermostatic element may be equipped with a moistening device to permit it to operate on wet-bulb tem peratures. Such an instrument can be used to control the wet-bulb depression and thus the relative humidity.4 4. A humidistat which responds directly to changes in humidity may be used to maintain a predetermined relative humidity with constant or with varying temperature. It may do this; by varying the dew-point temperature of air leaving a conditioner; by varying, with dampers, the proportion of moist and dry air; by varying the amount of moisture otherwise added to the air; or by varying the dry-bulb temperature. . 200 Chapter 14--Temperature and HuMiDify Control Humidification for Residences ' The principles underlying humidity requirements and limitations for residences are summarized in University of Illinois Bulletin No. 481, as follows: 1. Optimum comfort is the most tangible criterion for determining the air conditions within a residence. 2. An effective temperature of 65 deg! represents the optimum comfort for the majority of people. Under the conditions in the average residence a dry-bulb tempera ture of 69.5 F with relative humidity of 40 per cent is the most practical for the attain ment of 65-deg effective temperature. 3. Evaporation requirements to maintain a relative humidity of 40 per cent in zero weather depend on the amount of air inleakage to the average residence, and vary from practically nothing to 24 gal of water per 24 hours. 4. Relative humidity of 40 per cent indoors cannot be maintained in rigorous climates without excessive condensation on the windows unless tight fitting storm sash or the equivalent are 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 types of 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 radiator shields tested did not prove adequate to maintain 40 per cent relative humidity in a residence similar to the Research Residence when ' the outdoor temperature approximated zero degrees Fahrenheit. Central Fan Air Conditioning Systems In central fan air conditioning systems as described in Chapters 9 and 22, varying amounts of outside and recirculated air are used, except where contamination prevents re-use, and in general, heat is supplied after the air washer, for obtaining humidity control under winter conditions. There are many control variations in use, and Fig. 14 shows a composite diagram, rather than a system of control for a single installation. The control valves for a dehumidifying air washer are shown in Fig. 15. The functions of the control devices shown in Figs. 14 and 15 are as follows: Winter Operation (with steam) 1. Direct-acting thermostat A opens direct-acting valve in steam supply to a lowcapacity tempering coil P; in sub-freezing weather it is set at 35 F. 2. Direct-acting thermostat B in the path of air leaving the second tempering coil Q controls direct-acting valve in steam supply to the coil Q at 45 F. 3. Direct-acting thermostat C controls normally-closed intake M and normally-open return air N dampers at 50 F. This location of thermostat C is primarily lor operation with steam heating and at such times as by-pass damper O is closed. See discussion under heading Spring and Fall Operation. .* * 1See Humidification for Residences, by A. P. Kratz {University of Illinois, Bulletin No. 48). *66 deg is the optimum winter effective temperature recommended by the A.S.H.V.E. Committee on Ventilation Standards. See Chapter 2. 201 American Society of Heating and Ventilating Engineers Guide, 1934 4. Humidistat or wet-bulb thermostat D in return air, acting through relay, causes C to take outside air when the relative humidity rises above 55 per cent (or the wet-bulb temperature rises above 60 F); also, if necessary, shuts off the water supply to the spray heads in the air washer and opens, the supply to the flooding nozzles at the eliminator plates, by operating threeway valve U (Fig. 15). The relative humidity must, of course, be changed to suit the requirements. It must be maintained low enough to avoid con densation on walls or windows'. . . 5. Reverse-acting thermostat E in discharge end of air washer operates a threeway valve ( V, Fig. 15) in water circulating line, so as to cause water to pass through or around a heating unit in order to produce the correct dew-point temperature by adding any necessary heat to the water. It may also operate reverse valve W (Fig. 15) in the steam supply to the heating unit. The heat added may be only that sufficient to make up the temperature drop through the washer, due to evaporation. This thermostat is reverse acting to prevent over-humidification in case of failure of motive power. a Fig. 14. Diagrammatic Arrangement of Various Phases of Control for a Central Fan Air Conditioning System 6. Direct-acting thermostat F in fan discharge operates a direct-acting valve in steam supply to heater R to produce the lowest temperature at which air can be introduced into the conditioned space, without complaints of draft. This varies from 60 to 70 F, depend ing on the velocity through, and location of, the supply grilles. 7. Direct-acting room thermostat C in a representative location controls direct-acting valve in steam supply to coil or coils 5 which supply the heat to replace the loss from the conditioned space. Summer Operation (with refrigeration) _ Thermostats A,.B, F and G all hold their valves closed during summer temperatures which are above the thermostat settings, although this is unimportant while no steam is being supplied. ' . 1. Thermostat C, having been set for 50 F, supplies power to open wide the intake damper and close the return air damper under the higher summer temperatures and this *See discussion of condensation in Chapter 7. Also see paper entitled. Frost and Condensation on Windows, by L. W. Leonhard and J. A. Grant (A.S.H.V.E. Transactions, Vol. 35, 1929). 202 . Chapter 14--Temperature and Humidity Control . power can be passed through a graduating switch to permit manual operation, of the dampers. As the wet-bulb temperature (or total heat) of the outdoor air is now normally greater than that of the return air, it. is desirable, in order to keep down cooling costs, to recirculate the maximum amount of air. 2. Humidistat D is by-passed so that main power is applied direct to threeway valve V (Fig. 15) to prevent shutting off sprays. This by-pass can be arranged for cutting in manually, or automatically, with the starting of the refrigerating machineiy. 3. Thermostat E, operating threeway valve V (Fig. 15), now determines whether the spray water is passed through refrigerated coils or is recirculated without treatment, and thus regulates the dew-point temperature. It is assumed that steam and refrigeration are not both turned on at the same time. 4. Direct-acting thermostat H operates a normally open damper O in the by-pass space around the air washer so as to mix the warmer return air with the cold air leaving the dehumidifier in such proportions as to give the minimum temperature at which air can be introduced into the conditioned space. This might be 70 F for a room temperature of 85 F. A switch should be installed in the branch line from H, and so connected to a main line as to permit keeping normally-open damper 0 closed during winter operation. .-To Sprays Three-way Valve Three-way Valve V-*qX To Flooding Nozzles 1 Reverse Valve Mr Flow Cooling Tank > Heater X . 3 ?'-------------------------------------- ----------------- Pump ^ ' Fig. 15. Control Valves for a Dehumidifying Air Washer 5. Thermostat G,.in addition to operating valve on heating unit 5, acts as a pilot for thermostat H so as to retard the action of the latter in closing the by-pass damper, when the,space temperature is below the desired point. Spring and Fall Operation . During a considerable part of the year, conditioning can be accom plished merely by using all outside air or by mixing it with returned air. For example, when the total sensible heat gain in an auditorium is 2.4 Btu per pound of air being treated, outside.air will be raised from 60 F to 70 F by the heat gain. During this period when dry-bulb temperatures are to be maintained at, or not much above, 70 F, the gain in sensible heat is the only factor that need be considered, because it is large in comparison with the gain in latent heat, except in restaurants and some classes of industrial work. The intake and recirculating dampers can then be operated by thermostat F set at 60 F. (It is assumed that such an outlet temperature can be used; if not, the volume of.air should be increased). Thermostat H, being set higher for hot weather, holds by-pass damper 0 open to provide a maximum volume of air. In order to minimize over humidification,.the air washer and by-pass are arranged so that the return air stream tends to use the by-pass. . However, since dehumidification is not required, as previously stated, the humidity control is obtained by shutting off the spray water by humidistat D. 203 x American Society of Heating and Ventilating Engineers Guide, 1934 Except for heating-up periods or other times when the heat gain is not greater than the heat loss, a system of this type can be operated without artificial heat, with outdoor temperatures as low as 40 F, For this reason it is economical to place a thermostat in the return air near D set to shut off a diaphragm valve in the main steam supply to the system at a tem perature about 3 deg below that desired in the conditioned space. A pilot thermostat exposed to the outdoor temperature prevents the shut-off on days colder than 40 F. As previously stated, there can be many variations from these descrip tions, some of which are: 1. Tempering coils may consist of only one bank, P or Q, controlled by either A or B thermostat. In any case the capacity of the heating unit controlled by the outdoor temperature must be as low as feasible, otherwise if steam is supplied to it when the out door temperature is 30 F, the temperature of air entering the washer is likely to be too high to permit maintaining the proper dew-point temperature. 2. Both tempering coils may be omitted and return air mixed with outside air by G Fig. 16. Diagrammatic Arrangement of Control for a Fan-Furnace Air Conditioning System thermostat C so as to provide a proper temperature at the washer inlet. In this case, humidistat D should not act as a pilot. 3. The heating unit for the air washer water may be omitted, and the proper dew-point temperature maintained by placing thermostat C in-the location of E. This requires additional heat from the tempering coils, or more return air to make up the loss due to evaporation in the washer. 4. Heating unit 5 may be combined with R in one or two banks and controlled by a one- or two-point thermostat at F, set for the minimum temperature at which air can be admitted into the conditioned space. For heating purposes, thermostat G then becomes a pilot for F so that these heating units are operating at full capacity when the space is cold, and are throttled by F when no heat is required. 5. A better arrangement than that described in the preceding paragraph is the use of an automatically readjustable thermostat at F, which can operate at any temperature between a proper minimum and a necessary maximum, depending on the temperature of the space. Thus for winter operation when the room temperature is 68 F, the blower delivers air sufficiently warm to supply the heat required under extreme conditions, and when it is 74 F, the delivery will be as cool as possible without complaint of drafts. A similar instrument can be used to replace H, and set to operate between 60 and 80 F for summer conditions. ' 6. For summer use, a remote readjustable thermostat can be located at II, and can be reset by a pilot exposed to the outdoor temperature. Thus as the outdoor temperature increases, the space temperature is maintained at a higher point. 204 Chapter 14--Temperature and Humidity Control . 7. A constant portion of the return air may be brought to a point between the air washer and the blower, and the temperature of the air leaving the washer regulated to give the proper result at H. The regulation is accomplished by shutting off one or more groups of, sprays, or by changing the temperature of the spray water until the proper degree of cooling is secured. 8. Where an air washer is Selected large enough to pass all the air handled by the fan, the by-pass and its damper O are not used. The washer sprays must then be divided into two side-by-side sections so that one section can be turned on or off by H to provide the proper temperature. 9. Where an ejector type heating unit is used for the spray water, a reverse-acting valve similar to W (Fig. 15) must be placed in the steam supply to be operated by ther mostat E. In this case it is usual to install in this steam line another reverse-acting diaphragm valve to be operated directly by the water pressure in the pump discharge line. This automatically shuts off the steam when the water circulating pump is not in opera tion. 10. Based on the fact that the spray water in the air washer pan has practically the same temperature as the air leaving the washer, dew-point control can be accomplished by installing thermostat E in the water pan. 11. Where cold well-water is used for dehumidification, it is admitted to the sprays through a threeway valve similar to V, operated by thermostat E. 12. Control of steam heat is shown entirely by valves, although it is usual to install a by-pass damper around each heating unit and operate it, either with or without a damper over the face of the heating unit, in conjunction with the valve. Capacities to be Selected In designing apparatus to be automatically controlled, it is advisable to select minimum capacities for desired results. This not only assists the control system, but tends to produce desirable economies in initial costs. For example, in Fig. 14 the heating unit R selected should be one having a capacity that will just raise the temperature from the lowest desired dew point (about 40 F) to the highest dry-bulb temperature required at F (about 70 F). Similarly, heating unit S should be of sufficient capacity to raise the temperature only enough to provide the heat necessary for the space to be conditioned. Dampers should be sized so that extreme conditions will require the full open and closed position. For example, if it is desired that some minimum amount of outside air be supplied constantly during operation of the plant, damper M should be divided into two parts, one of which is oper ated by the thermostat and the other, large enough to supply the constant minimum, is operated by a separate positive-acting switch.' FAN-FURNACE AIR CONDITIONING SYSTEMS The theory of control of mechanical warm air or fan furnace -systems described in Chapter 23 is the same as for other types of central fan systems, but the methods are somewhat different. Fig. 16 shows the arrangement for winter operation. __ Winter Operation 1. Thermqstat E is a two-point instrument with one direct- and one reverse-acting relay. The former operates the normally-closed damper M and normally-open damper N, thus mixing return air to obtain the proper temperature (40 to 50 F) at the discharge 205 American Society of Heating and .Ventilating Engineers Guide, 1934 end of the washer. When this source of heat is insufficient, the reverse-acting, relay opens normally-closed damper P (Fig. 16) to admit air from the .warm-air chamber. . 2. Direct-acting thermostat G operates double damper R (Fig. 16) to mix heated air with that coming direct from the'washer through' passage X, to obtain the proper tem perature for delivery into the conditioned space. The dew-point temperature produced at is not affected by passing, some of the. air through the furnaces; and the proper relative humidity is thus secured. . . Summer Operation . 3. Thermostat E, through its reverse-acting relay, operates a threeway valve (such as E,Fig. 15) to regulate the cooling effect on the spray water; or, through its direct-acting relay, it operates another threeway valve (such as U, Fig. 15) to shut off the sprays when the temperature is too low. . 4. Thermostat H moves a dehumidifier bypass damper (not shown) in conjunction with G. as a pilot, as described for a steam system. . Additional information on the control of fan-furnace systems will be found in Chapter 23. 206 Chapter 15 AIR POLLUTION Sources of Air Pollution, Effects of Air Pollution on Health, Pul monary Effects, Occlusion of Solar Radiation, Industrial Air Pollution, Abatement of Atmospheric Pollution, Smoke Abate ment, Dust and Cinder Abatement THIS chapter considers the hygienic aspects of atmospheric pollution and the methods by which this pollution may be lessened. Infor mation concerning the cleaning of, air brought into buildings for ventilat ing purposes will be found in Chapter 16, and a discussion of the exhaust ing of dusts and toxic gases from factories and industrial plants is con sidered in Chapter 21. SOURCES OF AIR POLLUTION The 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 silk, bits of animal and vegetable matter, and pollen. Microscopic examination of the impurities in city air show? .that a large percentage of the particles are carbon. (See Fig. 1, Chapter 16, for size of impurities in air). Dust, Fumes, Smoke The most conspicuous sources of atmospheric pollution may be arbitrarily classified according to the size of. the particles as dusts, fumes, and smoke. Dusts are particles of solid matter varying from 1.0 to 150 microns in size. Fumes include particles resulting from chemical pro cessing combustion, explosion, and distillation, ranging from 0.1 to 1.0 micron in size. Smoke is composed of fine soot or carbon particles, 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, sulphuric acid, 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 appreciable agglomeration, fumes tend to aggregate, smoke to diffuse. Particles larger than one micron will eventually settle out by gravitation; particles smaller will remain, in suspension as permanent impurities unless they agglomerate to sizes larger than one micron. 207 . American Society of Heating and Ventilating Engineers Guide, 1934 Fly-Ash, Cinders The term fly-ash is usually applied to the extremely small particles of ash, and the term cinder to the larger particles of coke and ash which are discharged with the gases of combustion from burning coal. EFFECTS OF AIR POLLUTION ON HEALTH Many kinds of dusts and gases are capable of producing pathological changes which may cause ill health. The harmful effects depend largely upon the chemical and physical nature of the impurities, and the con centration, length of time, and conditions under which they are breathed. Dust particles must be minute in size to be inhaled at all, although fairly large particles may gain access to the upper air passages. The human body possesses remarkable filtering media for protecting the lungs. Small hairs which line the nasal passages, and a multitude of microscopic hairs, called cilia, in the epithelium lining in the bronchial tubes intercept many of the dust particles before they reach the lungs. PULMONARY EFFECTS The constant inhalation of dusts in city air irritates the mucous mem branes of the nose, throat, and lungs, and eventually may produce dis comfort and a series of minor respiratory disorders. The pigmented lung of the city dweller is an example of the pathological change produced over a period of years. This condition may be of no clinical importance, but an exaggeration of it in the coal miner results in anthracosis or dark spots on the lung due to the presence of phagocyted pigment in the lymph channels which impairs the functioning of the lung cells under stress. Effects of Solids Bronchitis is the chief condition associated with exposure to thick dust, and follows upon inhalation of practically any kind of insoluble and noricolloidal dust. Atmospheric dust in itself cannot be blamed for causing tuberculosis, but it appears to have a marked influence in aggravating the disease once it has started. There is', however, quite reliable evidence that carbon pigment, one of the atmospheric dusts, tends to wall off local tuberculosis rather than to further its spread. The sulphurous fumes and tarry matter in smoke are probably 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, hose, 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. Released in a rare combination of atmospheric calm and dense fogr 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. Physical examination showed difficult breathing, rapid pulse, cyanosis, cardiac dilation, and a redness and inflammation of the mucosa of the nose, mouth, throat, trachea, and bronchi. Carbon monoxide from automobiles and from chimney gases con-. 208 Chapter 15--Air Pollution stitutes another important source of aerial pollution in busy cities. During heavy traffic hours and under atmospheric conditions favorable to concentration, the air of congested streets is found to contain enough CO to menace the health of those exposed over a period of several hours, particularly if their activities call for deep and rapid breathing. In open air under ordinary conditions the concentration of CO in city air is believed to be 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 Baltimore1 by actinic methods show that the ultra-violet light in the country was 50 per cent greater than in the city. In New York City2 a loss as great as 50 per cent in visible light was found by the photo-electric cell method. The effect of air pollution on the health of city dwellers is difficult to determine, owing to the slowness of its manifestations. 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 prevention or elimination of this pollution have seemed justifiable to the public. INDUSTRIAL AIR POLLUTION In many industrial processes, sufficient amounts of dusts, fumes, and vapors are liberated to be injurious to the health of workers. Some dusts are poisonous (lead, mercury, arsenic, manganese, and cadmium) and some act as irritants (silica, steel, iron, and granite). _ Certain dusts may produce catarrhal conditions and increase susceptibility to such diseases as bronchitis; pneumonia, and tuberculosis. Silicious dust is especially harmful because it has a direct damaging action upon the tissue of the lungs, but organic dusts, both animal and vegetable (hair, pollen, textile, and fiber), do not seem to affect the lungs at all, although they may cause considerable discomfort in the upper respiratory passages to persons sensitive to them. Industrial gases and fumes act specifically upon the mucous mem branes, the lungs, blood, skin, and eyes. Some extremely poisonous gases act after very short exposures. Among these are carbon monoxide, hydrogen sulphide, ammonia, chlorine, bromine, arsine, and cyanogen. The industrial processes which liberate harmful substances are too manifold and the effects too diverse to be considered here, where dis cussion is limited to the commonest and most serious with which the ventilating engineer may be confronted: namely, carbon monoxide, lead, and silica. For a more thorough treatise on the subject reference should be made to books by Hamilton', Rosenau4, and Henderson and Haggard5. Effects of Atmospheric Pollution upon Incidence of Solar Ultra-Violet Light; by J. H. Shrader, M. H. Coblentz and F. A. Korff {American Journal of Public Health, p. 7, Vol. 19, 1929). Studies in Illumination, by J. E. Ives (U. S. Public Health Service Bulletin No. 197, 1930). Industrial Poisions in the United States, by Alice Hamilton. . Preventive Medicine and Hygiene, by Milton J. Rosenau. . .. Noxious Gases, by Y. Henderson and H. Haggard. . ........... . 209 American Society of Heating and Ventilating Engineers Guide, 1934 Carbon Monoxide Poisoning Carbon monoxide is a common form pf poisonous industrial gas, met with in mines, foundries, coke-oven sheds, garages, and houses. Its action is due to the fact that the combining power of carbon monoxide with the haerpoglobin of the red blood corpuscles is about 300 times greater than that of oxygen. Since the resulting stable combination destroys the power of the haemoglobin to unite with oxygen in the lungs and to supply it to the tissues, the effects are due to lack of oxygen, and the symptoms are those of anoxemia: namely, dizziness, headaches, sleepiness, fatigue, and, in extreme cases, paralysis and death. The dangerous saturation level of the blood with carbon monoxide is about 50 per cent. Even, as little as 0.07 per cent in the air will render, in half an hour, one quarter of the red corpuscles incapable of uniting with oxygen. One to two parts per 10,000 parts of air is set as a safe limit of pollution which may be breathed for a long time without producing perceptible symptoms. Silicosis Silicosis is a chronic disease of the lungs which results from the local physio-chemical action of hydrated silica upon the pulmonary tissue, causing progressive lymphatic fibrosis, and rendering the tissue suscep tible to tuberculosis. The disease is slow in evolution, requiring usually a number of years of exposure. It occurs principally among granite workers, sand blasters, metal miners, metal polishers, potters, and mill stone workers. Lead Poisoning Lead posioning is the most insidious and most common of all industrial diseases. It occurs principally among lpad workers and smelters, lead miners, potters, painters, typesetters, stereotypers, plumbers, and workers with glass, gold and silver. Lead, in practically all forms, is a cumulative poison which is absorbed by way of the blood stream, chiefly from the respiratory tract, but also from the digestive tract and from the skin. The effect may be either an acute or chronic poisoning. The principal symptoms are colic, constipation, anemia, headache, anorexia, a bluish line along the edges of the gums, rheumantic pains, and, in extreme conditions, paralysis, blindness, insanity, and death. It has been found6 that 2 mg per day is the smallest dose, by inhalation, which in the course of years may result in lead poisoning. Regular inhalation during the usual working hours, of air containing less than 0.2 mg of lead per cubic meter does not seem to produce serious lead poisoning in individuals of representative industrial groups7. Prevention The prevention of industrial hazards from dusts arid poisonous gases is largely a ventilation problem consisting of keeping the impurities in air down to a safe concentration. As yet there are no generally accepted standards on which to base the design of the ventilation equipment. `Lead Poisoning, by Thomas Morrison Legge (,Journal Royal Society Arts, 1929, Vol. 77, p. 1023). What is a Dangerous Quantity of Lead Dust in Air, by C. M. Sails (Industrial Hygiene Bulletin New York State Department of Labor, 1925). . ;' 210 Chapter 15--Air Pollution Approximate data on the toxicity of various gases and fumes met with in industrial establishments are given in Table 1. Column 5, giving the. maximum allowable .concentrations for prolonged exposures, was com piled from experiments in which most exposures lasted not more than a week, and it is reasonable to assume that over more prolonged exposures such concentrations would cause pernicious effects. ' Much is known concerning the physiological and pathological effects induced by various types and conceritrations of atmospheric pollutants. In the absence of an accepted standard for safe breathing, and because of the slow, cumulative effects of certain kinds of air contaminants, the best procedure is the periodic medical examination of individuals, and the routine measurement and study of the concentration and the physical and chemical characteristics of the dusts to which those individuals are exposed. ABATEMENT OF ATMOSPHERIC POLLUTION Successful abatement of atmospheric pollution requires the combined efforts of the combustion engineer, the public health officer, and the public itself. The complete electrification of industry and railroads, and the separation of industrial and residential communities would aid materially in the effective solution of the problem. In the large cities where the nuisance from smoke, dust and cinders is the most seriouSi limited areas obtain soine 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 a much higher level than is possible in the case of buildings that operate their own boiler plants. . SMOKE ABATEMENT 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 27). 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. Thesejets 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 . 211. American Society of Heating and Ventilating Engineers Guide, 1934 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 Table 1. Toxicity of Gases and Fumes in Parts per 10,000 Parts of Airs Vapor ob Gas Rapidlt Fatal Maximum Concentration por prom H to 1 Hour Maximum Concentration pob 1 Hour Maximum Allowable pob Prolonged Exposure Carbon monoxide Carbon dioxide.................... Hydrocyanic acid............... Ammonia............................ Hydrochloric acid gas.___ Chlorine................................. Hydrofluoric acid gas........ Sulphur dioxide................... Hydrogen sulphide............. Carbon bisulphide._______ Phosphene Arsine_ ................................ Phosgene.- ........................ Nitrous fumes________ ___ Benzene Toluene and xylene.______ Aniline Nitrobenzene_______ ___ _ Petrol . . Carbon tetrachloride......... Chloroform............................ Tetrachlorethane,, ......... Trichlorethylene............. -- Methyl chloride. Methyl bromide.......... ....... Lead vapor. ....................... 40 800-1000 30 50-100 10-20 10 2 4-5 10-30 20 2 34 Over 34 234-734 190 190 243 480 250 73 370 1500-3000 200-400 15-20 1/^ 25 34 34 Ko 34-1 5-7 ll 4--6 34 ' 34 l-l 34 100-220 240 140 200-400 20-40 10 34 3 2-3 5 1-2 34 SI -47 31-47 1 "SIA Moo 40 50 70 10 1 34 1 Mo Mo l 34 Moo 34 . 134-3 IV- v5 0 0 16 2 134 5-10 2 5-6 v data compiled bY Y. Henderson and H. Haggard. (See Noxious Coses, 1927). Data revised by r. M. Legge. (See Lessons Learned from Industrial Cases and Fumes, Institute of Chemistry of Great Britain and Ireland, London, 1930). 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 212 Chapter 15--Air Pollution 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 40), 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 the 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 noxious 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 CINDER ABATEMENT 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 the . following paragraphs. The cinder particles are usually larger in size than the dust particles; they are gray or black in color, and are abrasive. Being of a larger size, the range within which they may annoy is limited. The dust particles are usually extremely fine; they are light gray or yellow in color, and are not as abrasive as cinder particles. Being ex tremely fine, they are readily distributed over a large area by air currents. The nuisance created by the solid particles in the air is dependent on the size and physical characteristics of the individual particles. The difficulty of catching the dust and cinder particles is principally a function of the size and specific gravity of the particles. Lower rates of combustion per square foot of grate area will reduce the quantity of solid matter discharged from the chimney with the gases of combustion. The burning of coke, coking coal, and sized coal from which the extremely fine coal has been removed will not as a general rule produce as much dust and cinders as will result from the burning of noh-cokirtg coals and slack coal 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. . . 213 American Society of Heating and Ventilating Engineers Guide, 1934 Dust and Cinder Catchers8 The various types of dust and cinder catchers available today can be divided into six general classes: . 1. Settling.chambers. . 2. Dust and cinder traps. 3. Centrifugal separators. 4. Electrostatic precipitators. 5. Gas scrubbers. 6. Fabric filters. - The selection of the proper type of catcher calls for a careful study of the material to be caught and the draft and space available. After installation, constant vigilance is necessary to keep.the catchers in proper working condition if satisfactory operation is to be obtained. If possible, the dust or cinder catcher should be installed on the inlet side of the induced draft fans because the dust and cinders in the gases seriously erode the wheels of the fans, the inlet connections and the scrolls. Where the induced draft fans operate at high tip speeds and no catchers are installed, it is not uncommon for the fans to require major repairs within one year and complete replacement within five years. Settling Chambers . Probably the oldest form of dust catcher is the settling chamber, which generally consists of a large-sized, gas-tight space into which the dust-laden gases are discharged before being delivered to the chimney. The velocity of the gas should be reduced to a point where the larger and heavier particles will be precipitated by gravity. For good operation, the velocity of the gas should be reduced to a maximum of 2 fps. The bottoms of the chambers should be provided with dump plates through which the collected dust can be removed. Because these chambers are not effective in removing the finer dust particles they have been practically superseded by smaller and less costly devices. . Traps, Catchers, Precipitators Various types of traps have been devised. In general they all depend upon breaking the gas up into thin strata and subjecting those thin strata to several abrupt changes in direction. The dust is thrown out of the gas stream into specially shaped pockets, or impinged against a roughened surface. The trapping pockets are drained into a hopper below with a small quantity of gas and the dust settles out by gravity due to the low velocity in the hopper. In the roughened surface type, various sections of the trap are closed off at intervals by means of dampers and the dust is shaken off the roughened surface into a hopper below. These devices work very well in catching large size dust and cinders and trap much of the fine dust. They have been used most extensively on stoker-fired installations. They have the advantage of low pressure drop, relatively small space requirements, and low first cost. See Smoke and Dust Abatement, by M. D. Engle (A.S.H.V.E. Transactions. VoI. 37, 1931). 2X4 ii..- Chapter .15--Air Pollution Centrifugal catchers obtain separation by projecting the particles tangentially out of the gas stream. The effectiveness of this type of catcher varies directly as the specific weight of the dust and as the square of the tangential velocity, and inversely as the radius of rotation. Electrostatic precipitators are used for catching fine dust. These precipitators consist of dust-tight chambers in which are suspended rein forced concrete slabs on about 10-in. centers. Between the slabs are suspended bare metal rods. High-voltage unidirectional current is applied to the. reinforcing rods in the .concrete slabs acting as positive electrodes, the bare rods acting as. negative electrodes. The dust-laden gas Hows horizontally through the precipitator and the dust particles migrate toward the concrete slabs to which they adhere and then fall or are scraped off into the dust hoppers below. . Gas Scrubbers Wet scrubbers have been used for many years for removing dust from gases. A number of different types of scrubbers are now being built for removing dust from boiler flue gases: One type depends upon saturating the gas and washing the dust out of suspension by a spray of water. For best results with this type, the water should be atomized into as fine a spray as possible. . Another type depends upon splitting the gas into thin strata and subjecting these strata to a number of abrupt changes in direction, throwing the dust against the wet surfaces. The main problem in develop ing a satisfactory wet dust catcher is to find suitable materials of con struction that will resist the corrosive action of the wash water for a .reasonable length of time. Fabric Filters Filters of many kinds have been used with variable success. The filter bags are made of cotton, wool or asbestos fabric. The fabrics used in these filters do not withstand the temperatures at which gases are usually discharged from the boilers, and hence the gases must be cooled by some means. Surface coolers or water sprays can be used for reducing the gas temperatures. One of the serious objections to all of these dust catchers is the relatively high cost of installation and maintenance, and the space required for installation. Disposal of Dust and Cinders Even after the dust and cinders have been caught, the disposal of the material caught presents a serious problem. The cinders discharged with the gases from stoker-fired boilers are usually very high in carbon and contain from 50 to 80 per cent as much heat per pound as the coal which is being' burned. It is possible, and usually economical, to burn these cinders. They cannot be satisfactorily mixed with the coal in the stoker hopper but they can be blown into the furnace over the stoker fuel bed and burned satisfactorily. If a sufficient quantity of cinders is caught, a small unit pulverizer can be installed to prepare them for burning over the stoker fuel bed. ~ The same pulverizer can be used for coal at times of 215 American Society of Heating and Ventilating Engineers Guide, 1934 peak load and will materially increase the capacity of the fuel-burning equipment for the boiler to which it is connected. No satisfactory market has been developed for the dust caught from pulverized coal installations, but the possibilities are being investigated and it seems likely that in the future this material will have a market value that will gp a long way toward paying the fixed charges on the cost of catching it. The distribution of dust in the gas entering and leaving the dust and cinder catchers is not uniform and is different in practically every in stallation, and varies widely with changes in furnace conditions. In order to obtain a representative sample it is necessary to traverse the inlet and outlet of the catcher with a sampling tube which faces into the gas flow. The velocity of the gas into the sampling tube must be the same as the velocity of the gas in the duct at the instant the sample is taken. The swirls and eddy currents in the ducts make it difficult to obtain consistent readings, but if the test is conducted by some one of experience, an indication of the approximate efficiency can be obtained. 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. ,. 216 Chapter 16 AIR CLEANING EQUIPMENT Requirements of an Air Cleaner, Types, Air Washers and Scrubbers, Viscous Type Filters, Dry Air Filters, Air Filter Installations AIR cleaning devices are intended to remove impurities in air brought into a building for ventilating or air conditioning purposes. These impurities include carbon (soot) from the incomplete combustion of fuels burned in furnaces and automobile engines, particles of earth, sand, ash, automobile tires, leather, animal excretion, stone, wood, rust and paper, threads of cotton, wool and silk, bits of animal and vegetable matter, bacteria and pollen. Microscopic examination shows that the character of the impurities varies with the locality, but as a rule carbon forms the greater part of them while the total is somewhat proportional to the state of industrial activity and the wind intensity. Additional information on sources of air pollution will be found in Chapter 15. Observations have shown that practically all atmospheric impurities are less than 5 microns in size. (One micron equals 0.001 millimeter or , approximately 0.00004 in.). The size and composition of each individual particle determines its buoyancy and consequently the length of time it will remain in suspension. The chart, Fig. 1, shows graphically the sizes of impurities found in the air, and other related data. To estimate the probable dust load for air filter installations, the following approximate averages of atmospheric dust concentration may be used (7000 grains equal 1 lb): Rural and suburban districts........................__.............. ............0.2 to 0.4 grains per 1000 cu ft Metropolitan districts.............................................................. ...0.4 to 0.8 grains per 1000 cu ft Industrial districts--...................................................................... 0.8 to 1.5 grains per 1000 cu ft REQUIREMENTS OF AN AIR CLEANER 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, measured in inches of water, 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, or clean itself automatically. . 6. Leave the air passing through thie cleaner free from entrained moisture or charging liquids used in the cleaner. 217 American Society of Heating and Ventilating Engineers Guide, 1934 The A.S.H.V:E. Standard Code for Testing and Rating Air Cleaning Devices Used in General Ventilating Work1 explains how such devices are rated by (1) capaci ty in cubic feet of air handled per minute, (2) resistance Compiled by W. G. Frank and Copyrighted. Fig. 1. Sizes and Characteristics of Air-Borne Solids in inches of water at rated capacity, (3) dust arrestance, the percentage relationship expressing dust removal efficiency at rated capacity, (4) reconditioning power, the energy necessary to operate the mechanism of Submitted at the Semi-Annual Meeting of the A.S.H.V.E., June, 1933. '218. Chapter 16--Air Cleaning Equipment . an automatic air cleaning device, and (5) dust holding capacity, the amount by weight of standard dust which a non-automatic air cleaning device will retain before reconditioning is necessary. TYPES OF AIR CLEANERS According to the Code, the following four classifications are given the devices: Class A. Automatic Type: In general all air cleaning devices which use power to automatically recondition the filter medium and maintain a non-varying resistance to air flow. Class B. Low Resistance Non-Automatic Type: Air cleaning devices for warm air furnaces, unit ventilating machines and similar apparatus and installations in which a maximum of not more than 0.18 in. water gage is available to move air through the air cleaning device. Class C. Medium Resistance Non-Automatic Type: Air cleaning devices for systems in which a maximum of not more than 0.5 in. water gage is available to move air through the air cleaning device. Class D. High Resistance Non-Automatic Type: Air cleaning devices for the air intake of compressors, internal combustion engines, and the like, where a pressure of 1.0 in. or more water gage is available to move air through the air cleaning device. Air cleaners may be also classified as follows: 1. According to principle of air cleaning. a. Air washers. b. Viscous air filters. (1) Unit type. (2) Automatic type. ' c. Dry air filters. . . 2. According to application. ` . a. For central fan systems of ventilation and air conditioning. Filters of the automatic or semi-automatic type are usually recommended and are installed , in a central plenum chamber. 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 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 type viscous or dry filters, installed at air intake of compressors and diesel engines. f. For compressed air lines. Unit type viscous or dry filters. 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 the viscous and dry type air filters which are part of many ventilating and air conditioning systems. _ AIR WASHERS AND SCRUBBERS Information on air. washers will be found in Chapter 11. Scrubbers have not been used very extensively in the past for cleaning 219 American Society of Heating and Ventilating. Engineers Guide, 1934 air for ventilating purposes. However, new types have been developed which appear to have possibilities for cases where the air to be cleaned is extremely dirty or where a higher degree of cleanliness is desired than can be obtained with an air washer. VISCOUS TYPE FILTERS _ The principle of air cleaning used in viscous filters is that of adhesive impingement. Dust and dirt in the air, especially soot and carbons, are trapped and retained by successive impingements on coated surfaces. While the arrangement of filtering media and the kind of materials used are almost unlimited, there are certain rather definite requirements for a practical commercial filter. . Investigations in this country and abroad demonstrate that the first impingement of dust laden air on a viscous coated surface removes about 60 per cent of the dust, the next impingement takes 60 per cent of what then remains--that is, 24 per cent--and the next impingement removes 9-6 per cent. To secure maximum efficiency, it is necessary to divide the air into innumerable fine streams, as the more intimately and freely the air is brought into contact with the viscous-coated media the better will be the cleaning. The binding liquid used with viscous filters should have the following properties: 1. Its surface tension should be such as to produce a homogeneous film-like coating on the filter medium. 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 flow freely at low temperatures. 5. Evaporation should not exceed 1 per cent. 6. It should be fireproof. 7. It should be odorless. Viscous Unit Filters In the unit type viscous filter, the filtering media are arranged in units of convenient size to facilitate installation, maintenance, and cleaning. Each unit consists of an interchangeable cell or replaceable filter pad and a substantial frame which may be bolted to the frames of other like units to form a partition between the source of dusty air and the fan inlet. The necessary washing, draining, and recharging equipment should be installed near each group of unit filters, with hot water and sewer con nections 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 progressive 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. The resistance of a well-designed unit filter of the adhesive impinge- Chapter 16--Air. Cleaning Equipment ent 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 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 Fig. 3. Resistance to Air-Flow of a Typical Unit Air Filter of air being cleaned, and on the amount of dirt which can be accumulated in the filter medium without causing excessive resistance. Filters consisting of inexpensive frames of cardboard or similar material filled with viscous-coated glass wool or steel wool are available. 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 installations where 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 jof air cleaning used in the viscous automatic filters is the same as in the' unit filters. The removal of the accumulated dust, 221 American Society of Heating and Ventilating Engineers Guide, 1934 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 where it may be removed by different methods, depending on the design of the filter. There are three general types of automatic filters. They are differentiated from each other according to the process of self-cleaning and renewing of the viscous coating used by each type, as follows: 1. The filter medium has the form of an endless curtain suspended vertically, with its lower portion submerged in a viscous fluid reservoir. The curtain rotates slowly through this bath, thus performing the cleaning and recoating of the filter medium. 2. The filter screen is arranged in the form of shelves or cylinders, and the viscous fluid is flushed through all parts of the medium in a direction opposite to the air flow. 3. The filter medium is arranged vertically and is stationary. The viscous fluid is flushed from above over the medium, while the air flow is stopped. Fig. 4. Maintenance Chart for Unit Type Viscous Filters 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 jHs-in. water gage at an air velocity of 500 fpm, measured at the filter entrance. Automatic viscous filters are made up in units which are delivered either fully assembled or in parts to be assem bled at the point of installation. > DRY AIR FILTERS 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 222 Chapter 16--Air Cleaning Equipment . 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 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 withstanding 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 FILTER INSTALLATIONS 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 size for the amount of air it is expected to handle. An overload of 10 to 15 per cent is regarded as the maximum allowable. When air volume is subject to increase, a larger filter should be installed. 2. The filter must be suited for the operating conditions, such as degree of air clean liness required, amount of dust in the entering air, type of duty, allowable pressure drop, operating temperatures, and maintenance facilities. . 3. The filter type should be the most economical for the specific application. The first cost of the installation should be balanced against depreciation as well as expense and convenience of maintenance. ' The following recommendations apply to filters and washers installed with central fan systems: 1. Duct connections to and from the filter should change size or shape gradually to insure even air distribution over the entire filter area. 2. Sufficient space should be provided in front as well as behind the filter to make it accessible for inspection and service. A distance of two feet may be regarded as the minimum. - 3. Access doors of convenient size should be provided in the sheet metal connections leading to and from the filters. 4. All doors on the clean air side should be lined with felt to prevent infiltration of unclean air. All connections and seams of the sheet metal ducts on the clean air side should be as air-tight as possible. 223 American Society of Heating and Ventilating Engineers Guide, 1934 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. REFERENCES Testing and Rating of Air Cleaning Devices Used for General Ventilation Work, by Samuel R. Lewis (A.S.H.V.E. Journal Section, Heating, Piping and Air Conditioning May, 1933). 6' 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). Operation and Maintenance of Air Filters, by W. G. Frank (Heating, Piping and Air Condtttomng, May, 1931). Size and Characteristics of Air-Borne Impurities, by W. G. Frank (Heating, Piping and Air Conditioning, January, 1932). s 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). ' A Study of Dust Determinators, by F. B. Rowley and John Beal (A.S.H.V.E. Trans actions, Vol. 34, 1928). Design and Application of Oil-Coated Air Filters, by H. C. Murphy (A S H V E Transactions, Vol. 33, 1927). y ' '' Determining the Efficiency of Air Cleaners, by A. M. Goodloe (A.S.H.V.E Trans actions, Vol. 30, 1924). Chapter 17 FANS Performance, Fan Efficiency, Characteristic Curves, Selection, of Fans, Controls, Designation of Fans, Motive Power, Electric Power FANS are used for producing air flow except where positive displace ment is required, in which case compressors 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 flow 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 a propeller fan is intended for operation at comparatively high pressures the hub is sometimes enlarged in the form of a disc and the fan is known as a disc fan. Radialflow or centrifugalfans include steel plate fans, pressure blowers, cone fans, and the so-called multiblade fans. All the foregoing types have variations which may be obtained by modification of the proportions or ihange in the curvature and angularity of the blades. The angularity of , the blades determines the speed, characteristic, the forward curve cor responding to slow speed and the backward curve to 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 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 requiring a static pressure of less than 1 in. of water, whereas centrifugal fans are more commonly employed for operation at comparatively high pressures. PERFORMANCE OF FANS Fans of all types follow certain laws of performance which are useful in determining the effect of changes in the conditions of operation. These laws apply to installations comprising any type of fan, any given piping system and constant air density, and are as follows: , 1. The air capacity varies directly as the fan speed. 2. The pressure (static,-velocity, and total) varies as the square of the fan speed. 3. The horsepower varies as the cube of the fan speed. 225 American Society of Heating and Ventilating Engineers Guide, 1934 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 horse power? Speed = 400 X ^ QOO = rPm Static pressure = 1 X = 1-56 in. Horsepower = 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 horsepower vary directly as the density. Example 2. A certain fan delivers 12,000 cfm at 70 F and normal barometric pressure (density 0.07495 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 0.06018 lb) and the speed of the fan remains the same, what will be the static pressure and horsepower? Static pressure = 1 X qq^q| = 0.80 in. Horsepower = 4 X = 3.20 hp 5. At constant pressure the speed, capacity and horsepower 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 horsepower? ' Speed = 400 X ^-5^= 446 rpm V-Capacity = 12,000 X 0.07495 = 13,392 cfm (measured at 200 F) 0.06018 Horsepower =4X^-0TM-= 4.46 hp 6. For a constant weight of air: () the speed, capacity, and pressure vary inversely as the density. () 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, staticjpressure, and horsepower? . Sipeed - 400 X gjgff = 498 rpm . 0 07495 Capacity = 12,000 X q QgQ^g = 14,945 cfm (measured at 200 F) Static pressure = 1 X nnlmo = 1.25 in. O.ObUlS Horsepower = 4 X (Sggf)2 = 6.20 hp 226 Chapter 17--Fans FAN EFFICIENCY The efficiency of a fan may be defined as the ratio of the work done in moving the air (air horsepower) to the horsepower input to the fan. The work done in moving the air may be computed on the basis of either the static or the total pressure. When the static pressure is used in the com putation it is assumed that this represents the useful pressure and that the velocity pressure is lost in the piping system and in the air which leaves the system. Since in most installations a higher velocity exists at the fan outlet than at the point of delivery into the atmosphere, some of the velocity pressure at the fan outlet may be utilized by conversion to static pressure within the system, but owing to the uncertainty of friction losses which occur at the places where changes in velocity take place, the amount of velocity pressure which is actually utilized is seldom known, and the static pressure alone may best represent the useful pressure. The efficiency based upon static pressure is known as the static efficiency and may be expressed as follows: . . , cfm X static pressure in inches of water Static efficiency = -------------6369 X horsepoweTffi^Tt 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: _ , _. cfm X total pressure in inches of water Total efficiency = ------------- 6369 X horsepower input------------- 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 centages of their wide-open capacity. Variations in efficiency accompany variations in pressures and power consumption which are characteristic of the individual designs and which are influenced particularly by the shape and angularity of the blades. Such variations in pressure, power, and efficiency are shown by characteristic curves. . .... Characteristic curves of fans are determined by -tests performed in accordance with the Standard Test Code for Disc and Propeller Fans,l lSee Standard Test Code for Disc and Propeller Fans. Centrifugal Fans and Blowers, Edition of 1932. 227 V American Society of Heating and Ventilating Engineers Guide, 1934 Centrifugal Fans and Blowers2 as adopted by the American Society of Heating and Ventilating Engineers and the National Association of Fan Manufacturers. The results of tests are plotted in different ways; the abscissae may be the ratio of delivery, assuming full open discharge as lOOper cent, and the ordinates may be static pressure, dynamic pressure horsepower and efficiency. Pressures may be expressed in per cent of the maximum pressure in the manner shown in the illustrations in this chapter, but in engineering calculations they are sometimes expressed in proportion to the pressures due to the peripheral velocity. It should be noted that characteristic curves of fan performance are plotted for a constant speed. Some variation in values of efficiency may Chapter 17--Fans more particularly to show the manner in which variations occur with changes in fan capacity. Propeller 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 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. The proportions of the housing also affect the performance. As a rule a narrow fan of large diameter shows a higher efficiency than one of greater width and smaller diameter. For a number of designs using blades of certain shapes the proportion of the width to the diameter is so definitely established by the service for which the fan is intended that little variation in efficiency occurs, but in other designs, particularly that which uses straight radial blades, the efficiency may vary over a wide range depending on whether the dimensions are suitable for a fan intended for ordinary ventilating purposes or for a pressure blower. 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 reasonable values and A.S.H.V.E. Transactions, Vol. 29. 1923. Amended June, 1931. 228 power as the resistance increases. The low efficiency when overcoming 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 pressure 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. The straight blade (paddle-wheel) or partial backward curved blade type 229 .... American Society of Heating and Ventilating Engineers Guide, 1934 of fan is practically obsolete for ventilation. Its use is largely confined to such applications as conveyors for material, or for.gases containing foreign material, fumes and vapors. The open construction and the few large flat blades of these wheels render them resistant to corrosion and prevent material from collecting on the blades. This type of fan has a good efficiency, but the horsepower steadily increases as the static pressure falls off, which requires that the motor be selected with a moderate reserve in horsepower to take care of possible error in calculation of duct resistance. 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 Chapter 17--Fans adaptable for direct connected electric motor drives. The high speed necessitates heavier construction, and more operating attention and service is required than for the other type multiblade fans. The dimen sional bulk for a given duty often is 150 to 200 per cent that of a forward curve multiblade type fan. Between the extremes of the forward and the full backward curve blade type 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 fan with a forward angle at the heel and a slight backward angle at the tip of the blade. Characteristic curves of these types show varying degrees of Fig. 3. Operating Characteristics of a Fan with Blades Curved Forward pressure drops consistently from the point of maximum efficiency to full open operation. Fig. 3 shows that this type of fan will have a high and low delivery for a given static pressure at constant speed. 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 con tinue to fall rapidly to full outlet opening. The steep pressure curves tend to produce constant capacity under changing pressures. Where wide fluctuations occur, the use of this type of fan is desirable to prevent over loading 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 makes it 230 Fig. 4. Operating Characteristics of a Fan with Blades Curved Backward resemblance to the forward and the backward curve blade characteristics according to the degree of similarity to one or the other of these two designs. 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. Knowing the requirements of the system, the main points to be con sidered for fan selection are (1) efficiency, (2) reliability of operation, (3) size and weight, (4) speed, (5) noise, and (6) 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: 231 American Society of Heating and Ventilating Engineers Guide, 1934 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 horsepower. 5. Tip or peripheral speed. 6. Static pressure. The most efficient operating point of the fan is usually shown By either bold or italicized figures in the capacity tables. Fans for Ventilation Two important factors in selecting fans for ventilating systems are efficiency (which affects the cost of operation) and noise. First cost and space available are secondary. The fans should be selected to operate at maidmum efficiency without noise. 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, unsatisfac tory 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 required for a specified capacity and pressure varies with the type of blade, and a tip speed that is 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 be 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 for each static pressure corresponding outlet velocities and tip speeds which will give satisfactory results. The proper tip speed for a given static pressure varies with design of wheel and number of blades or vanes in wheel. Lower outlet velocities than listed in Table 1 may be used, but care must be exercised when fans of the forward curved type are used to avoid selecting a fan for operation below its useful range. In exhaust ventilating systems where the air column moves toward the fan, noise due to the higher tip speeds and outlet velocities will not be so readily transmitted back through the air column to the building. Therefore higher outlet velocities may be used, but this will be at the expense of increased horsepower. Amply large fans should always be used for both exhaust and supply systems, as there may be and usually is leakage despite the most careful workmanship, necessitating the delivery of more air at the fans than is exhausted from or supplied through the openings in the various rooms. Long runs of distributing ducts, heaters, and air washers usually are parts of any ventilating system where high static pressures are needed. 232 Chapter 17--Fans Table 1. Good Operating Velocities and Tip Speeds for Forward Curved Multiblade Ventilating Fans Static Pressure In Inches or Water 'K y% y% Vs A % i m IK IK 2 2K 2K 3 Outlet Velocity Feet per Minute 1000-1100 1000-1100 1000-1200 1100-1300 1200-1400 1300-1600 1500-1800 1600-1900 1800-2100 1900-2200 2000-2400 2200-2600 2300-2600 2500-2800 Tip Speed Feet per Minute 1520-1700 1760-1900 1970-2150 2225-2450 2480-2700 2660-2910 2820-3120 3162-3450 3480-3810 3760-4205 4000-4500 4250-4740 4475-4970 4900-5365 Under such conditions it is practicable to select fans with higher outlet velocities and peripheral speeds since the duct system itself will tend to muffle objectionable air sounds. 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 fans are connected to concrete ducts such as are used in the ventilation of vehicular tunnels, the connection is made direct. Fans for Drying Both propeller and centrifugal types of fans are used for drying work. Propeller fans are well adapted to'the removal of moisture-laden air when operating against low resistance and when handling air at low tempera tures. Motors on these fans usually are of the fully-enclosed moistureproof types so that saturated air or air containing foreign material will not injure the motors. Unit heaters employing disc or propeller type fans are widely used in the drying field. In drying, disc or propeller fans may be used where not too much duct work is required and where air is to be delivered against pressure, since the noise developed from the high peripheral speed of these fans is not ordinarily objectionable in process work of this nature. Centrifugal fans or blowers of the multiblade type generally are selected to supply air for drying, as they are capable of delivering large volumes against all pressures. Belt driven fans usually are to be preferred to direct-connected fans as they make a more flexible and economical unit. Wherever drying is done throughout the year and where air requirements 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. _ Due to the low .speeds of forward curved multiblade or yaddle-wheel type fans, these can be direct-connected to reciprocating steam engines. 233 American Society of Heating and Ventilating Engineers Guide, 1934 and the exhaust steam 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 battery operation is required, the full backward curved fan is preferred. This type is well adapted for direct-connected motors of the higher speeds. Fans for Dust Collecting and Conveying The application of fans or exhausters for handling refuse, dust, and fumes generated by machine equipment is covered in Chapter 21. Infor mation is given regarding the methods for determining air quantities, the velocity required for carrying various materials and the method of deter mining maintained resistance or total static pressure at which the fan is to operate. The selection of a proper size fan or exhauster is at times governed by the future requirements 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 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, except in the control of disc fans where an increase in resistance produces an increase in the power required. In many installations adjustments of volume are desirable during varying hours of the day. In others an increased supply of air in summer over that needed for winter is demanded. Experience is required in deciding whether speed-control or damper-control shall be used for " specific cases. Where noise is a factor, it may be exceedingly desirable to reduce the speed at times, while on the other hand, any fan which has its normal speed reduced as much as 50 per cent without change in resistance will move only 50 per cent of the air. DESIGNATION OF FANS Facing the driving side of the fan, blower or blast wheel, if the proper direction of rotation is clockwise, the fan, blower or blast wheel will be designated as clockwise. If the proper direction of rotation is counter-clockwise, the designation will be counterclockwtse. (The driving side of a single inlet- fan is considered to be the side opposite the inlet regardless of tne actual location of the drive)*. This method of designation will apply to all centrifugal fans, single or double width, and single or double inlet. Do not use the word "hand," but specify "clockwise" or counter-clockwise." Recommendations adopted by the National Association of Fan Manufacturers. 234 Chapter 17--Fans The discharge of a fan will be determined by the direction of the line of air discharge and its relation to the fan shaft, as follows: Bottom Horizontal: If the line of air discharge is horizontal and below the shaft. Top Horizontal: If the line of air discharge is horizontal and above the shaft. Up Blast: If the line of air discharge is vertically up. Down Blast: If the line of air discharge is vertically down. AH intermediate discharges will be indicated a 3 angular discharge as follows: Either top or bottom angular up discharge or top or bottom angular down discharge, the smallest angle made by the line of air discharge with the horizontal being specified. In order to prevent misunderstandings, which cause delays and losses, the arrangements of fan drives adopted by the National Association of Fan Manufacturers and indicated in Fig. 5 are suggested. Single inlet, single width fans should be selected wherever possible. 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 forward curved blade type of 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 type 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 horse power can be employed. Justification for liberal power provision exists also in the possibility of varying demand due to changes in ventilation requirements, intensity of occupation, and weather conditions. The motive power of fans should be determined in accordance with the Standard Test Code for Disc and Propeller Fans, Centrifugal Fans and Blowers, as adopted by the American Society of Heating and Venti lating Engineers and the National Association of Fan Manufacturers. Fans may be driven by electric motors, steam engines (either horizontal or vertical), gasoline or oil engines and turbines, but as previously stated the drive most commonly used is the electric motor. ELECTRIC POWER Electric power is almost the universal solution .for fan operation, as electric motor speeds are flexible for adaptation to direct-connected fans. Electric motors are readily suited to various types of drives, such as belts, chains or gears. 235 erican Society of Heating and Ventilating Engineers Guide, 1934 V a to c o to a ts "S3 k (* SI 236 . .C3O-QJnJ Joc -- CO *J ca 4* OJ ^ : JTS-S SIS ww I 3o C g|8g ll'll F ig . 6. A r r a n g e m e n t of F a n D r iv e s Chapter 17--Fans Each type of electric motor and kind of electric current has its advan tages and disadvantages as applied to a fan. Direct-connected electric motors usually are very efficient for fan driving because there is no slippage due to belts, and no wear or noise due to chains or gears. There is less maintenance and upkeep to a directconnected unit, and with an overhung fan wheel on the motor shaft, the usual fan bearings are eliminated. The disadvantage of a slow-speed direct-connected motor is that it may be unduly large and heavy as well as costly, but this may be offset by the compactness of the unit as a whole due to limited space for fan equipment. Should anything go wrong with a slow-speed direct-connected motor there may be a considerable delay in securing replacements, as these motors are not usually carried in stock, as is the case with moderately high-speed motors. If a change of speed is found necessary with a direct-connected motor, it will mean a change of motor, which may necessitate a change in the motor foundation usually built with the fan in such cases. On the other hand, non-direct-connected motors have transmissions subject to wear and slippage, and chains or gears may be noisy with this latter type. However, should a change in speed be necessary where the motor is not direct-connected, changes in speed ratio can easily be accomplished by changing pulleys, sprockets or gears on either the fan or the motor. In the case of a motor breakdown a standard stock motor may easily be substituted. A type of drive using wedge-shaped rope-like belts, often in multiple, has become very popular recently as it enables the use of high speed motors with slow speed fans. These motors are less expensive and more efficient, and they allow very short belt centers, thus saving floor space and making the fan unit and the motor much more compact than the usual belt drive. The compactness secured by this equipment compares favorably with a direct connected layout. This type of drive is also very quiet in operation, being similar to a conventional belt drive in this respect. Alternating current motor designs are such that improved operating characteristics are obtained with the higher motor speeds. Efficiencies and power factors are improved over those in effect with slower speed motors, thus showing a considerable saving in power consumption, where some effective speed reducing transmission device to the fan is installed. Quietness of operation is more readily obtained with moderately high speed induction motors than with low speed motors, as any slight magnetic unbalance is not as easily heard. Magnetic unbalancing at times causes noises whose repetition and wave length is such as to cause vibrations and harmonics. Amplifications of the noises in other parts of a building remote from the motor equipment are sometimes found, due to such noises being carried by the steel work, ducts, or piping ip the building. There is considerable evidence that these sounds are more easily con trolled with higher motor speeds than with lower motor speeds. Motors which are practically quiet in operation and free from magnetic disturbing noises can be obtained and should always be specified for 237 American Society of Heating and Ventilating Engineers Guide, 1934 Table 2. Classification of Motors Gaotrp TM Type Cub _ . Speed ACTEBISTICS Starting Torque Current Applications A 1 Shunt Wound d-c Constant Medium High Fans 2 Squirrel Cage a-c Constant 3 Synchronous a-c Constant Medium Medium High -- About six times full load Starts as Squirrel Cage Motor Fans, Centrifugal Pumps Motor Generator Sets, Air Compressors, 4 Slip Ring or a-c Constant Wound Rotor Heavy Low Fans . Vacuum Pumps, Air Compres- S Double Squir a-c Constant rel Cage Heavy Medium sors Frequent and Heavy Starting Loads, Pumps. 6 Low-Torque a-c Constant Capacitor 7 Hj^h-Torque a-c Constant Capacitor 8 High-Torque a-c Constant Capacitor Light Medium High Low Low Medium Compressors Direct-Con- nected Fans Belt Drive of Fans For H ea v y Starting Load Such as Larger Fans, Pumps. 9 Repulsion a-c Constant Induction High Medium Compressors Fans, Pumps. Compressors B 1 Brush Shifting a-c Adjustable Medium 2 Cumulative d-c Adjustable Heavy Comp'd with Shunt Predominance 3 Squirrel Cage a-c Poles can be Regrouped Multi Speed Medium Low High Stokers, Boiler Fans Pumps High Fans, Ice Ma chines C 1 Series d-c Variable 2 Cumulative d-c Variable Comp'd with Series Predominance 3 Slip Ring-- a-c .Variable fsing External Resistance in Secondary ' Heavy Heavy Heavy Low Low Low Fans Single Acting Reciprocating Pumps 7ans 238 Chapter 17--Fans quietness of operation when used for fan installations in buildings where quietness is a factor. In the construction of fan and motor foundations where the machinery is mounted on the floor or upon a concrete platform, it is a usual practice to install a layer of cork on top of which is laid or floated the base which carries the apparatus. It is essential that the bolts or lag screws which fasten the machines to this foundation shall not extend through to the floor. It is wise to fasten curbs to the floor, these presenting insulated surfaces to the machinery foundation and so preventing it from traveling. The general classification of motors used for heating, ventilation and air conditioning is shown in Table 2. Control for Electric Motors Very small direct current motors may be started by throwing them directly on the line through a suitable starting switch. The larger sizes require some type of starting rheostat. When speed adjustment is desired, the controller for adjusting the speeds of the motor usually functions also as a starting device. Alternating current motors of 5 hp and under usually may be thrown directly on the line. It is good practice to use a starting switch equipped with a thermal overload or inverse time limit overload device. This type of switch provides protection to the motor beyond the power of fuses to supply. Fuses when used necessarily must be large enough to take care of the inrush current which makes them inadequate for protecting the motor under operating conditions. The thermal overload device allows for this inrush and does not function until an overload has become persistent, the time element depending upon the percentage of overload over the rating of the element. This type of switch is available for manual operation and also is furnished in the magnetic type for remote operation by push button, or for operation by other types of pilots, such as pressure switches and thermostats. On the standard squirrel cage motors above 5 hp a starting compen sator usually is employed to keep the inrush current to within the limits specified by the local power companies. Compensators may be obtained in transformer types and primary resistor types, and usually are furnished for manual operation. They can be secured for remote control also, but are necessarily expensive. However, the new type of high reactance, self-starting motors, may usually be thrown across the line up to 30 hp in size, and still have their inrush current within the limits of the rules of the National Electric Light A ssociation. With this type of motor a magnetic contactor usually is used. This device may be operated from a remote point by push button, if desired. These magnetic contactors are furnished usually with thermal overload and no-voltage protection. For remote operation of motors through magnetic starters, the operat ing buttons may be located in the engineer's or manager's office, and tell-tale indicating lamps may be wired up with the circuit to indicate whether or not the unit is in operation. This type of control is very desirable in large buildings where the engineeris to have complete charge of the ventilating system. Remote or automatic control of the units may be affected also by 239 American Society of Heating and Ventilating Engineers Guide, 1934 pneumatic or hydraulic apparatus, or by thermostats or by pressure devices which are provided with electric contacts for starting or stopping the units upon reaching certain conditions. Variable speed slip ring motors and direct current motors may also be arranged for remote speed control by means of pre-set automatic regulators, where the operating speed of the motor is set by a dial-switch . or regulator (which may be near the fan or at a remote point) and the motor is then automatically controlled at this speed merely by operating the remote control push button for starting or stopping the equipment. . Arrangements may be made for remote control of fan motors, or for automatic control by influence of temperature. Remote control may be by pneumatic or by hydraulic manipulation as well as by electrical means. In many large ventilating systems which have heating plants in con nection, steam engines are used to operate fans. A medium speed steam engine, exhausting at low pressure into the radiators which heat the building or which warm the air, is a very economical source of power, is quiet in operation, and has a wide range of speed variation. The steam economy of such an engine usually is of little importance, since the engine serves as an auxiliary to the pressure-reducing valve interposed in such cases between the boiler and the radiators. Internal combustion engines and line shafting are often used for fan I driving, requiring, clutches or shift-belts with loose pulleys in order to secure proper starting and control. It is seldom necessary to reduce the speed of ventilating fans more than 50 per cent from the maximum fan speed, but for economical operation on large systems there should be a number of operating speeds between maximum speed and 50 per cent below maximum speed. REFERENCES Heating, Ventilating and Air Conditioning, by Harding and Willard, Revised Edition, 1332. Fan Engineering. Theories and Practices of Centrifugal Ventilating Machines, by D. Murgue, translated by A. L. Stevenson. Mechanical Engineer's Handbook, by Kent. Mechanical Engineer's Handbook, by Lionel S. Marks. Constructive Mechanism and the Centrifugal Fan, by George D; Beals. Coal Miners Pocket Book. The Fan, by Charles H. Innes. Mine Ventilation, by J. J. Walsh (A.S.H.V.E. Transactions, Vol. 23, 1917). Fan Blower Design, by H. F. Hagen (A.S.H.V.E, Transactions, Vol. 28, 1922). The Centrifugal Fan, by Frank L. Busey. ' Section X, A.S.H.V.E. Code of Minimum Requirements for the Heating and Ventilation of Buildings (Edition of 1929). , 240 Chapter 18 SOUND CONTROL Measurement of Noise, Noise in Buildings, Absorption of Sound, Coefficients of Absorption, Insulation of Air-Borne Sound, loca tion and Insulation of Equipment Room, Insulation of Machinery and Solid-Borne Vibration, Control of Noise Transmission Through Ducts, Air Currents, Effect of Humidity upon Acoustics THE part which ventilating and air conditioning plays in the acoustics of buildings becomes apparent from a consideration of the require ments for good hearing in any architectural interior. These requirements are: 1. The room should be free from noise, whether of inside or outside origin. 2. The useful sound, whether speech or music, should be sufficiently loud (with reference to any residual noise) to be heard easily and distinctly. 3. The useful sound should be distributed uniformly in all parts of the room, and the sound reaching the listeners should be free from long-delayed reflections which produce interference or echoes. 4. The room should be free from pronounced resonant tones which may result from either volume or panel resonance. 5. The room should contain sound-absorptive materials in such amounts, and of such qualities, as will provide a proper balance between the persistence and cessation of the articulated components of sound, that is, the reverberation in the room should be long enough to sustain harmony and impart tonal blending to music, and at the same time it must be short enough to prevent the overlapping and confusing of the separate sounds of, speech. Obviously, the first of these requirements is the one which imposes restrictions on the installation of ventilating equipment--the equipment noises must be unobjectionable in occupied rooms--although the fifth requirement is not entirely independent of the humidity and temperature of the air. LOUDNESS Loudness is the sensation of sound intensity. When we say one sound is louder than another we imply a difference in intensity level. Two identical whistles when sounded together do not make a sound twice as loud as one. It may take ten to make a sound 20 per cent louder than one. It has been found that loudness bears a logarithmic relationship to intensity of sound. On this basis a scale of loudness has been built and a unit, the decibel (db), has been established. This scale is illustrated in Fig. 1 which shows the loudness of some typical noises. The formula for relating loudness and intensity is: ......... where . '- L -- Loudness in db. Li -- Li (db) = 10 logi0 It I = Intensity. 241 (1) ^i American Society of Heating and Ventilating Engineers Guide, 1934 Thus the two whistles made a noise 10 logio 2 = 3 db louder than one whistle and the ten whistles 10 logio 10 = 10 db louder than one. It would take a hundred whistles to make a noise 20 db louder than one and a thousand to make a noise 30 db louder. MEASUREMENT OF NOISE Since the chief acoustical problem in the ventilating or air conditioning of a building consists of reducing equipment noise, it is necessary to describe methods for measuring noise. The measurement of noise is a relatively new problem, and although there are several reliable methods, there are as yet no standardized units, scales, or instruments for measuring noise1. However, the decibel (db) described above is widely used in this country and England as the standard unit for noise or sound intensity--a unit of the same size, but called a phon, is used in Germany--and the zero level of the scale is a barely audible sound. Since the relation between subjective loudness and sound intensity is dependent upon pitch, it is customary to refer loudness to a single frequency. A 1000-cycle tone is generally accepted as the reference frequency, that is, the loudness of any sound is rated in terms of an equally loud 1000-cycle tone. Thus, a noise of 50 db means that the noise would be judged to be of the same loudness as a 1000-cycle tone which is 50 db above the normal threshold of audi bility for the 1000-cycle tone. As the frequencies decrease below 1000 cycles, the ear becomes less sensitive, until at about 30-cycles sounds are no longer audible regardless of their intensity. Similarly, for higher frequencies, the limit of audi bility is reached around 7000 cycles. Thus, at frequencies below 1000 cycles, sounds of the same loudness must have a greater intensity than at 1000 cycles. This is particularly fortunate, as otherwise the low fre quency sounds would mask all others. Noise measurements are usually made by one of three methods. The first is the electrical instrument method, which uses a noise meter usually consisting of a microphone, an amplifier, and a galvanometer. Where such a meter is to measure the loudness of a noise without regard to the frequency distribution, it must contain a weighted network -frhich elec trically simulates the varying sensitivity of response of the ear to different frequencies. Where it is desired to analyze the character of the sound, filters which shut out all but certain bands of frequencies are used with the meter. A number of manufacturers make such meters. The second method consists essentially of varying the intensity of an artificially generated sound until the noise generated is masked by the noise being.measured. Obviously, this method is subject to human errors in observation to which the instrumental method is not, but in the hands of a careful observer quite satisfactory results may be obtained. One instrument used is the audiometer, which consists of a buzzer, an ear phone, and a rheostat. The phone is held a fixed distance from the ear while the resistance of the rheostat is varied until the sound of the buzzer, `A Committee of the American Standards Association is working on this project and it is probable that at least tentative standards will soon be available. For further information on this subject see. How Sound is Controlled, by V. O. Knudsen (Heating, Piping and Air Conditioning, October, 1931) and Acoustical Problems in the Heating and Ventilating of Buildings, by V. O. Knudsen (A.S.H.V.E. Transactions, Vol. 37, 1931). 242 Chapter IS^Sound Control as transmitted electrically to the phone, can no longer be heard. Audio meters are available either for covering all frequencies, as in the noise meter, or for covering certain frequency bands only. A third method of measuring noise, simple, yet sufficiently accurate for most field measurements, employs only three tuning forks and a stop watch. Forks having frequencies of 128, 512 and 2048 are recommended. The forks must be calibrated. That is, it is necessary to know for each fork (1) the initial intensity, in number of decibels above its threshold, immediately after it has received a standard hit or excitation, and (2) the damping rate, in decibels per second. These calibrations can be made in any well-equipped acoustical laboratory. A standard hit or excitation can be imparted to the fork by a felt-covered spring hammer, or simply by letting the fork fall from a vertical position through an arc of 90 deg, hitting a suitable pad (such as soft rubber or felt for the 128 and 512 forks and hard rubber for the 2048 fork). The average 512 steel fork will have an initial intensity, when held 34 in. from the ear with the broad side of the prong facing the ear canal, of about 80 db, and will decay at a rate of about 1.0 db per second. Such a fork will remain audible about 80 sec in a perfectly quiet place, provided the listener has normal hearing. In the presence of a noise, it will remain audible until its tone is just masked by the noise. Thus, if a 512 fork, having an initial intensity of 80 db and a damping rate of 1.0 db per second, should be found to remain audible 35 sec in the presence of a certain noise, the masking effect of the noise is 80 -- 35, or 45 db. Procedure . The method of measuring any noise is as follows: The observer, in the presence of the noise, strikes the 128 fork a standard blow. At the same - instant he starts a stop watch. The fork is then held in front of the ear canal, and moved back and forth slightly, until the tone of the fork is just completely masked by the noise, at which instant the watch is stopped. This measurement is repeated at least two times. The average time is subtracted from the time the 128 fork remains audible in a quiet place. This difference multiplied by the damping rate of the fork gives the mask ing effect of the noise at 128 cycles. Similar measurements are made with the 512 and 2048 forks. Measurements of this type give a satisfactory description of both the' intensity and the frequency distribution of the noise. The average masking effect of the noise at 128, 512 and 2048 , cycles will usually be about 5 to 10 db less than the reading given by a noise meter. NOISE IN BUILDINGS Measurements of the intensity of speech, music and noise in many buildings, with special consideration of the noise produced by ventilating equipment, have given the results indicated by Fig. 1. The equivalent loudness of sounds in buildings varies from less than 10 db near the outlet of an air duct in a very quiet sound studio to nearly 100 db- in a noisy boiler factory. It will be noted that the noise from the ventilating fan in a certain high school auditorium was nearly as loud as average speech in a large auditorium. Such an amount of noise is devastating to good acoustics; iri'fact, it is impossible to hear speech in the presence of . such a noise. 243 American Society of Heating and Ventilating Engineers Guide, 1934 db. 100 Boiler Factory 90 "-Electric Power Substation 80 *- Ventilating Room for targe Hotel (Very Noisy) Average Loudness of Music in Room-*- 70 Conversation in a Small Room-*- "-Inside of Duct, near Large Low Speed Fan Equipment Room (Average Condition J 60 Fan Room for School Building (Rather Quiet) Speech tn a Smalt Auditorium -*> "-Guest Room, Large Hotel on Noisy Street (Windows Open > SO Speech in a Large Auditorium-* Near Outlet of Ventilating Duct in High School Auditorium (Very Noisy. no"Filters" in Duct) 40 Fan Noise in Theater ( Poor Control of Noise) 30 20 *- Fan Noise in Theater < Proper Control of Noise) 10 ^_Near Outlet 6f Ventilating Duct in M. G. M. Sound Studio < Planned Control of Noise) Fig. 1. Chart Showing the Equivalent Loudness (in Decibels) of Speech, Music, and a Number of Noises Incident to the Ventilating of Buildings'1 "Acoustical Problems in the Heating and Ventilating of Buildings, by V. O. Knudsen (A.S.H.V.E. Transactions, Vol. 37, 1931). In every problem of noise reduction in buildings it is necessary to know how much noise can be tolerated. The noise levels given in Table 1 may be regarded as completely inoffensive. They represent what might be termed ideal conditions, not often realized in existing buildings. How ever, they represent conditions which can be attained by proper control Table 1. Acceptable Noise Levels Talking Picture Studios....................:............. ..................................................... Radio Broadcasting Studios............... ....................... ........ .......................... -- Hospitals................................ ................. ..................................................... .......... Music Studios__________________________________________________________ Apartments, Hotels, Homes, Small Private Offices.--............................... Theaters, Churches, Auditoriums, Classrooms, Libraries.... ................... Talking Picture Theaters, Small Clothing Stores....................................... General Offices______ ___________ ________________________________________ Large Public Offices, Banking Rooms, Upper Stories of Department Stores, Restaurants, Barber Shops....................................................... Grocery Stores, Drug Stores--_______________________________ _ Accounting and Typewriting Offices............... ......................... ....................... Main Floor of Department Stores..........................1.................................... .. 6 to 8 db 8 to 10 db 8 to 12 db 10 to 15 db 10 to 20 db 12 to 24 db 15 to 25 db 20 to 30 db 25 to 35 db 30 to 50 db 35 to 45 dD 40 to 50 db 244 Chapter 18--Sound Control of noise, and the heating and ventilating engineer should aim to provide the degree of quiet specified in the table. In considering the tolerable room noise level due to heating, ventilating, or air conditioning apparatus, not only must the absolute value of the noise be considered but also its relation to the room noise level without the apparatus running. This is necessary since a large increase of noise subjects the apparatus to serious criticism even though the level may be low. It must also be borne in mind that the noise produced by the ap paratus is additive to that of the room without apparatus. Thus if the two are equal, when combined the noise level will be 3 db higher. For these reasons the room noise caused by the apparatus should not exceed the other room noise. Noise Control Essential to the design of a satisfactory system are: first, a knowl edge of the nature and intensity of the noise generated by the various parts of the equipment; second, a knowledge of how to vary the noise level between the apparatus and the conditioned room if need be; third, a knowledge of the acceptable level of apparatus noise in the con ditioned room. Besides these, the engineer must be able to deal with other noises which might enter the room when openings are made, into it, such as cross talk between rooms connected with common ducts, and noise transmitted to portions of duct systems outside the conditioned room and thence to its interior. The problem of apparatus noise is receiving the study of equipment manufacturers who are aiming at both noise reduction and standardiza tion. Some manufacturers now have noise ratings available for their equipment, while some pass each unit of equipment of certain types through sound tests during the course of manufacture. The problem of noise reduction from apparatus to room must take into consideration and treat separately the three modes of travel of noise to the . room: first, from the apparatus through the air to the walls of the room and thence to its interior; second, through the building structure to the room; third, through ducts or openings to the room. Because the noise entering by each of these three channels is susceptible to quantitative analysis, solutions are available. Along with the transmission of sound through the building structure, the engineer must also consider the transmission of vibration, which may also be objectionable. The solution is not complete, however, until the effect of the noise entering the room on the room noise level is determined. ROOM NOISE LEVEL, COEFFICIENTS OF ABSORPTION One of the most effective means of reducing noises in ventilating equip ment is accomplished by the proper covering of the interior walls and ceiling of the equipment room, or the inner walls of the ducts, with soundabsorptive materials. The intensity / of a continuous sound in a room is (2) where E = the rate of emission of the noise source = V 5'. (The intensities of noises entering the room times the areas through which they enter). American Society of Heating and Ventilating Engineers Guide, 1934 a = the total amount of absorption supplied by the boundaries and contents of the room. = oi5i + a tSi + atS, +........... , where Si, St, St...............are the areas of the boundary materials for the room. "i. "i,........... are the corresponding coefficients of absorption. Hence, by in creasing tenfold the absorptivity of the boundaries of a room it is possible to reduce tenfold the average intensity of sound in the room; that is, the intensity level would be reduced 10 db. Thus it is possible to compute the noise level in the room if the intensity of noises entering the room or generated in it are known. It will be seen that the noise intensity reduction is dependent upon the amount of sound absorption in the room, and that the first units of absorp tion are more effective than succeeding units. In general, the room noise level will be from 10 to 20 db lower than the air inlet or outlet noise intensity, the 10 db being in the case of bare rooms having large venti lating or air conditioning openings in relation to their size, and the 20 db in the case of rooms having large amounts of absorptive material with small openings. In some cases, the noise level reduction may run up to as much as 30 db, but then the higher sound intensity adjacent to the openings tends to nullify the effects of the extra reduction. Where these openings are large, the local effect on the noise intensity extends some distance from the opening; for instance; a four square foot opening might Table 2. Coefficients of Sound Absorption3 Material Thickness (Inches) Coefficients or Sound Absorption 12S - Cycles 512 Cycles 2048 Cycles Acoustex 60, spray painted.... ............... ................ Acousti-CeJotex, Single B........................................ Acousti-Celotex, Triple B....................................... Acoustic Flexfelt.__................................................... Acoustone..... ............................................................... Akoustolith piaster.... ............................................... Akoustolith A, Tile................................................... Brick wall, unpainted............................................... Calicel................................. ............................ .............. Corkoustic, Type C._......................................... ....... Glass..... ......................................................................... Insulite Acoustile, Type 44....... ............................. Kalite, with three coats lacquer........................... Macoustic Plaster, stippled to depth of in.... Masonite..................................... .................................. Plaster, gypsum on hollow tile...... .................. ...... Plaster, gypsum, scratch and brown coats on , metal lath on wood studs................................... Plaster, lime, sand finish, on metal lath............... Poured concrete, unpainted.................................... Rockoustile______________________ ______________ Sabinite................... ............... ...................................... Sanacoustic Tile......................................................... Stuccoustic Plaster, Type XB._............................ Transite Tile...... ......................................................... Trutone Tile................................................................ Wood sheathing, pine.............................................. Wood, varnished......................................................... i H m i i 18 1 1H IK % K Ke -- ___K_ l K 114 K l H -- 0.16 0.11 0.20 0.27 0.21 0.14 0.024 0.23 0.08 0.035 0.26 0.35 0.13 0.18 0.013 0.020 0.038 0.010 0.18 . 0.19 0.29 0.19 0.31 0.098 0.05 0.51 0.45 0.75 0.56 0.66 0.29 0.48 0.031 0.72 0.61 0.027 0.50 0.43 0.31 0.32 0.020 0.040 0.060 0.016 0.57 0.34 0.79 0.59 0.81 0.57 0.10 0.03 0.72 0.68 0.67. 0.68 0.69 0.37 0.83 0.049 0.71 0.64 0.020 0.61 0.45 0.58 0.33 0.040 0.058 0.043 0.023 0.72 0.49 0.74 0.72 0.72 0.64 0.082 0.03 Architectural Acoustics, by V. O. Knudsen, pp. 219, 220, 240-251. 246 Chapter 18--Sound Control have a local effect within ten feet, while a one-half square foot opening would have a local effect within only five feet. The coefficients of sound-absorption for a number of standard absorp tive materials used, or suitable for use, in equipment rooms are given in Table 2. Coefficients are given for frequencies of 128, 512 and 2048 cycles. Where the frequency of the noise is not known, the values for 512 or 128 cycles are usually used. INSULATION OF AIR-BORNE SOUND The transmission of air-borne sounds through rigid partitions is accom plished primarily by the diaphragm-like vibrations of the partition. The weight per square foot of the wall is the determining factor, and the insulation value of a wall, in terms of the transmission loss in decibels, is proportional to the logarithm of the weight per square foot. Other factors, such as size, stiffness, composition, manner of mounting, and the use of multiple structures separated by air spaces of flexible connectors, contribute to the effective insulation. If the coefficients of sound trans mission of different types of structures and the noise intensity in the space adjoining a room are known, it is possible to calculate the noise intensity in a room by the use of formula (1) and the following formulas: where P = V'x . (3) r> = Noise intensity in space adjacent to room. t = Coefficient of sound transmission. Coefficients of sound transmission for some common walls are shown in Table 3. Example 1. Suppose the brick wall between an equipment room and an adjacent auditorium has an area of 200 sq ft and a coefficient of sound of 0.00001 (see Table 3); that the auditorium contains 2000 sabines' of absorption; and that the noise level in the equipment room is 70 db above zero level. pi 70 -- 0 = 10 logio (from Formula 1) lo = 10' X 0.00001 = 100 (from Formula 3) -J- = 100 X = 10 (from Formula 2) Room loudness = 10 logio 10 = 10 db If the sound absorption in the auditorium had been as small as 200 sabines, the sound intensity in the auditorium would have been 10 times as great and the noise level in the auditorium would have been 20 db. If the rest of the auditorium has an area' of 20,000 sq ft with a surrounding noise intensity of 50 db (/" = 10s) the noise level due to all of the noise entering through the wall would be found as follows -- = 10s X 0.00001 = 1 io --- * *A sabine is 1 sq ft of totally absorptive surface. 247 American Society of Heating and Ventilating Engineers Guide, 1934 -j- = 10 (Through equipment wall) + 1 X 22nohr 1q 20 Room loudness X 10 logio 20 = 13 db Now suppose that there is also a duct having 20 sq ft outlet connecting the room with apparatus having a noise level of 70 db (/" = 107) and suppose that there is an assumed attenuation in the duct equivalent to a transmission factor of 0.0002. Then ~*o = 107 X 0.0002 = 2 X 10' / 20 -ifo-- = 20 (from above) + 2 X 10* X ZoUrU^AU- = 40 Room loudness = 10 logio 40 = 16 db It may be seen how the energies of noises entering a room are added to obtain the final room noise intensity. The average coefficients of sound transmission (128 to 4096 cycles) for a number of wall and of floor and ceiling partitions are listed in Table 3. Table 3. Average Coefficients of Sound Transmission for Building Partitions* Description op Partition Averagb Coesticirnt Brick panel, Mississippi, 8 in.; plastered both sides gypsum brown coat, smooth white finish; good workmanship. Brick wall, 2)4 in. plaster both sides________ Brick wall, in., 2 in. furring strips, in. rigid insulation lath plastered both sides.. ___________ Brick wall, 4 in., 2 in. furring strips arid 3^ in. rigid insulation lath, plaster, on One side; other side plastered directly on brick Concrete flat slab floor construction, re-enforced; floating floor consisting of nailing strips, rough and finish flooring; 34 in. rigid insulation furred out and applied as ceiling.... Glass, plate 34 in.......... .... . Glass, plate 34 in. double glazed, 1 in. separation Metal lath, double, on in. channels, % in. gypsum plaster; without cross bracing clips: 4 in.r connected at. edges only Tile, hollow clay partition, three cells, 4 in. x 12 in', x 12 in., wood furring strips, 34 in. rigid insulation, gypsum brown coat, smooth white finish Wood joists, lower side plastered on wood lath; floating floor consisting of nailing strips, rough and finish flooring...................... ....... ................ ;________ Wood studs, four-paper plaster board, three-coat smooth finish gypsum plaster .... ...... Wood studs, two 34-in. sheets rigid insulation both sides, joints filled, gypsum scratch and brown coats, smooth white finish____ ____________ Wood studs, 2 in. x 4 in., staggered, metal lath, 34 in. gypsum plaster; 7 34 in.: connected at edges only. 0 000010 0 000032 0.0000016 0.0000040 0.0000020 0.0010 0.0001 0.000016 0.0000050 0.0000050 0 000010 0.000013 0.000040 aArchitectural Acoustics, by V. O. Knudsen, pp. 308-322. LOCATION AND INSULATION OF EQUIPMENT ROOM The equipment room, if possible, should be located at a considerable distance from all rooms in which quiet is required. If this is not possible, it is necessary to provide a high degree of insulation against the noise which may be transmitted through the walls of the equipment room, and also against the noise which almost certainly will be communicated through the short ducts. (See discussion of Control of Noise Trans mission through Ducts, p. 253). Three wall sections and two floor and 248 Chapter 18--Sound Control ceiling sections which are satisfactory for the wall insulation of the equipment room are shown in Fig. 2. Other partitions, with their sound insulating values, are listed in Table 3. The addition of absorptive materials (such as are described in Table 2) to the inner walls and ceiling of the equipment room will not only increase the insulation through the walls, but will also reduce the intensity of the noise in the room. The equipment room noise intensity may be figured in the same way as that of the conditioned space, taking the equipment as the source of noise. In case the equipment is subject to considerable vibration it is advisable to provide a separate or floated floor. m ^ '"4 Bnck | *'!' Plaster Insulation Value = 47 db. v 4` Hollow Clay Tile M'* 2* Furring Strips ''Paper and Metai Lath 'T Plaster Insulation Value = 52 db. Absorptive Blanket \ Fibre Board Staggered Wood 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 Resilient Hangers - Plaster on Lath Insulation Value " 60 db., or more Fig. 2. Three Wall Sections and Two Floor and Ceiling Sections which are Suitable for the Insulation of Equipment RooMSa ^Acoustical Problems in the Heating and Ventilating of Buildings, by V. O. Knudsen (A.S.H.V.E. Transactions, Vol. 37, 1931). . INSULATION OF MACHINERY AND SOLID-BORNE VIBRATION Since mechanical vibrations are readily transmitted through the solid structure of a building, it is extremely important in air conditioning that all mechanical equipment in which vibrations are generated be thoroughly insulated from the solid structure of the building. An almost universal notion prevails that the vibrations generated by machinery can be in sulated from a building simply by placing a slab of cork or a layer of hairfelt between the machinery and thefloorof theroom. If themachinery is sufficiently heavy, and the cork or felt sufficiently resilient, this ex pedient may suffice. On the other hand, if the machinery is not suf ficiently heavy to load the cork or felt support to the extent that the natural frequency of the machinery on the cork or felt is low in com parison with the frequency generated by the equipment, the cork or felt may be of little avail. Th'e insulation of vibration can be accomplished by means of suitable elastic supports or suspensions, but the design of these elastic supports should be based upon calculation rather than guess-work. ... . The theory of the insulation of vibration was first worked out by 249 American Society of Heating and Ventilating Engineers Guide, 1934 Soderbergh. 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 bythe elastic and viscous properties of the pad. The ratio of the vibratory force communicated 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: ** + 4x!,* (4) where r1 = the so-called transmissibility of the support. i = the compliance (that is, the reciprocal of the force constant). r -- the mechanical resistance owing to the viscous forces within the support. = the frequency of vibration generated by the machine which is to be insulated, such as the commutation frequency of a motor or the blade frequency of a fan. m =' the mass of the machine to be insulated. It should be noted that hot 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 objectional 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. If the pad is to be of any value in the prevention of solid-borne vibra tions; the value of t' must be considerably smaller than unity. If the fundamental frequency of vibration generated by the machine happens to coincide with the natural frequency of the mass of the machine resting on the elastic pad, a condition of resonance will be established, and the machine will exert a greater force upon the foundation than it would if the pad were completely removed. It is necessary, therefore, that the elastic support be sufficiently compliant, and the mass of the machine sufficiently heavy, that the natural frequency of the mass m upon its elastic support will be low in comparison with the frequencies which are generated by the machine. Thus, if the principal vibrations in the machine be of the order of 100 vibrations per second, the natural frequency ' of the machine mounted on its elastic support should not exceed about 20 vibrations per second. If a slab of insulating material be placed under the entire foundation of a machine, as is often done in practice, it may happen that the natural frequency of the machine on its elastic support will be nearly the same as the frequencies which are to be insulated, in which case the elastic support will be worse than nothing. In general, as Equation 4 shows, both m and c should be as large as possible if the vibrations of the machine are to be effectively insulated from the solid structure of the building. Further more, the machine should rest upon a rigid floor so that the elastic yielding of the floor is prevented from communicating the machinery vibrations to the solid structure of the building. The elastic support under the machine acts as a low-pass filter which passes all frequencies below about two times the natural frequency of the machine mounted on its elastic support, but prevents all frequencies C. R. Soderberg, The Electric Journal (January, 1924), and succeeding articles. See also V. O. Knudsen, Physical Review, VoT 32, 1928, p. 324, and A. L. Kimball. Journal Acoustical Society of America, Vol 2, 1030. p. 297. 250 Chapter 18--Sound Control above about -J ---- from reaching the solid structure of the building. The . .principal influ'encxe of the internal mechanical resistance r is to limit the vibration at the resonant frequency. It is generally advisable, therefore, to use materials which have an appreciable internal resistance. The values of c and r can be determined for any specimen of flexible material and, when known, can be used to determine the insulation value of any particular set-up. The value of c can be obtained by making static measurements of the amount of displacement of the compressed support for each additional unit of the compressing force. If this be done for a specimen of the flexible material of a certain thickness and area of cross section, the compliance can be determined for any other thickness or area from the relation that c will be directly proportional to the thickness and inversely proportional to the area of the flexible support. When the internal resistance r is not too large, it can be determined by observing the successive amplitudes of the free vibrations of a mass m which rests upon a specimen of the flexible material, and solving for r by the usual log- decrement method. Or, if the damping be so great that the free motion of m is non-oscillatory, r can be obtained from measurements on the experi mentally-determined resonance curve of the forced vibrations of m, or from measurements of the rate of return of m when it is given an initial displacement. If the resistance of a certain specimen of material, as cork, felt, or rubber, has been determined by any of these methods, the resistance for any other thickness or area of the material can be determined approxi mately because the resistance will be inversely proportional to the thickness 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 4, the amount of insulation that will be obtained from the use of this material as a flexible support for a piece of equipment having a mass tn. For the routine calculations in practice, r may be neglected with only a slight sacrifice of accuracy. Table 4 gives the values of c and r for a number of commonly used flexible materials. In general, there are two principal points to observe in the design of a flexible support for any piece of equipment, namely, the material should have a relatively large compliance and it should be loaded to nearly the upper safe limit of loading. Several flexible metallic supports have recently been developed. Example 2. A machine weighing 1000 lb has a base area of 20 sq ft. Assume that the principal vibration of the machine has a frequency of 100 cycles per second (most machinery vibrations are less than 150 vibrations per second, and the assumed frequency of 100 is quite representative of typical machines). Suppose that a 1-in. slab-of corkboard weighing 1.10 lb per board foot be placed between the machine and the floor. The loading on the cork will then be only 50 lb per square foot, or slightly more than 14 lb per square inch. (It is assumed that the compliance c in centimeters per dyne for a specimen 1 in. thick and 1 sq cm in cross-section is 0.25 X 10"* and the resistance-r in mechanical ohms is 0.15 X 10s). - . The transmissibilily 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 104. 251 American Society of Heating and Ventilating Engineers Guide, 1934 Chapter 18--Sound Control Therefore, the compliance of the entire support, 1 in. thick and 20 sq ft in cross section, is 0.25 X 10" X ^ ^ = 0.134 X 10~" cm per dyne, and the resistance oi the entire support is 0.15 X 10s X 1.86 X 10* = 0.28 X 10s mechanical ohms (or absolute units). Therefore V: (0.28 X 109)9 + ---- 10" _____ 4x* X 100 X 0.134 (0.28 -f 10s)1 + ^2x X 100 X 4.54 X 10* -- 10" : 0.93 Iransmissibility is reduced to 0.037, or the amplitude of vibration trans mitted to the floor will be only about 1/27 of what it would be if the machine were mounted directly upon the floor. These two numerical examples will serve to show not only the manner of making the calcu lations, but also the importance of selecting the proper type and design of flexible supports for insulating the vibrations of a machine from the rigid structure of a building. 2x X 100 X 0.134 Consequently, it is seen that the transmissibilily 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 = 0.39 X 10-9 cm per dyne, and the resistance will be 0.15 X 10s X 645 = 0.97 X 107 mechanical ohms (or absolute Units). Therefore CONTROL OF NOISE TRANSMISSION THROUGH DUCTS The most troublesome sources of noise from ventilating and air con ditioning equipment are fan and motor noises which are transmitted through the ducts. The reduction, in decibels, of noise transmitted through a duct, neglecting reflection from ends and bends, is proportional (1) directly to the length of the duct, (2) directly to the perimeter of the duct, (3) inversely to the area of cross section of the duct, and (4) directly 'V (0.97 X 10')5 + 10" 4x` X 100 X 0.39 (0.97 X 107)5 + ^ 2x X 100 X 4.54 X 10* - 109 omY 2x X 100 X = 0.037 (or at least approximately so) to the coefficient of sound absorption of the material which comprises the interior surface of the duct. It is apparent therefore that long narrow ducts, lined with highly absorptive material, will provide a high degree of insulation against the transmission of noise through ducts. In fact, small ducts (4 in. x 6 in.), made of material 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 having a coefficient of sound-absorption of 0.50, will provide a noise reduction of slightly more than 1 db per linear foot. As can be seen from an inspection of Table 2, noises of low frequency Table 4. Compliance and Resistance Data for Typical Specimens of are difficult to absorb; on the other hand, these frequencies are easily Flexible Materials3 reflected by elbows, branches, and duct ends whereas higher frequencies The compliances and resistances given in the table are for specimens 1 in. thick and 1 sq cm in cross section are little affected. Furthermore, the reflection effects are more pro nounced in small ducts than in large ducts.. Hence, by introducing into a duct a sufficient length of small, absorptive channels together with a Material Description op Material Approximate Upper Safe Loadin'} in Pounds per Square Inch Compliance e or Centimeters per Dtnb Resistance r in , Absolute Units number of elbows or other reflecting elements it is possible to reduce the transmitted noise to any required degree. This applies not only to ducts between the equipment room and other rooms in a building, but also to ducts connecting adjacent or nearly adjacent rooms. By the proper use Corkboard 1.10 lb per board foot 12 0.25 x 10"* 0.15 x 10* ' of such filters it is possible to eliminate all of the difficulties which arise in connection with the transmission of sound through ventilating ducts. The Corkboard b lax-li-num 0.70.lb per board foot 1.35 lb per board foot 8 4 to 6 0.50 x 10"* 0.60 x 10"*: - 0.25 x 10* 0.50 x 10* problem is an engineering one which can be worked out prior to the in stalling of the equipment, and it can be calculated in such a way as to meet the most rigorous demands for silent operation. There is a need for Celotex Celotex Insulite Carpet linine Insulating board Insulating board 10 12 15 0.40 x 10"* 0.18 x 10" 0.16 x 10"* quantitative data regarding the attenuation or noise-reduction provided by different types of ducts, but even with the meager data available it is possible to design filters which will suppress the ordinary noises incident to the ventilating or air conditioning of buildings4. i! Masonite Insulating 15 0.12x10"* i board Anti-Vibro-Block Sponge Rubber 25 lb per 5 1 to 3 0.60 x 10"* 3.0 x 10"* 1.5 x 10* In general, the motion of air resulting from the ventilating of rooms is not sufficient to introduce any appreciable difficulty in auditoriums, except where noise may originate from the issuing of high-speed air from nozzles. Soft India Rubber cubic foot 55 lb per cubic foot 3 to 6 1.2 xlO"* However, by proper stream-lining of the nozzles, it is possible to work with speeds which are adequate for all practical purposes without pro Hairfeft 10 lb per 1 to 2 1.5 x 10"* ducing any disturbing noises. Since sound is propagated with a velocity cubic foot of more than 1100 fps, the velocity of the air would have to attain speeds Architectural Acoustics, by V. O. Knudsen, p. 278. 252 , 4How Sound is Controlled, by V. O- Knudsen (A.S.H.V.E. Transactions, VoI. 37, 1931)253 American Society of Heating and Ventilating Engineers Guide, 1934 of at least 20 to 30 fps before these wind velocities would have any appreciable influence upon the propagation of sound. If there is to be any. appreciable motion of air in an auditorium, it is advantageous to have the upper layers of air moving in a direction from the stage toward the audience, as this will tend to refract the sound waves down toward the audience. However, unless the speed of the air is as great as 20 or 30 fps, the amount of refraction will not be noticeable. Therefore, as a rule the motion of air in an auditorium does not have an appreciable effect upon the acoustical properties of the room. EFFECT OF HUMIDITY UPON ACOUSTICS Recent experiments6 have shown that both the humidity and the tem perature of air have a marked influence upon the rate of absorption of high-pitched sounds. Perfectly dry air is less absorptive than air con taining any amount of water vapor. At relative humidities of 5 to 25 per cent, the air is highly absorptive but becomes less and less absorptive as the humidity is increased. High-frequency sounds are propagated better in cold humid air than in hot dry air, and since high-frequency sounds are particularly important for the preservation of good quality in speech and music it is advantageous to maintain the air in a room at a relatively high humidity, not less than about 55 to 60 per cent. On the other hand, where it is desirable to absorb all frequency components of sound, as for the reduction of noise in offices, it is advantageous to main tain relatively dry air. The time of reverberation in a room is given by the following equation: where 0.049 V -- 5 loge (1 -- a) + im V (5) V = volume of room in cubic feet. 5 = interior surface of room. a = average coefficient of sound-absorption of the interior surface of the room. m = the absorption coefficient of the air in the room. The coefficient m depends upon the frequency of the sound and the humidity (and probably the temperature) of the air. At a temperature of 70 F, and for sound waves having a frequency of 4096 vibrations per second, m = 0.0027 at 25 per cent relative humidity, 0.0018 at 54 per cent, and 0.0013 at 82 per cent. It will be seen, therefore, that the absorp tion of sound in the air is twice as great at a relative humidity of 25 per cent as it is at a relative humidity of 82 per cent. (This explains why sounds in the open travel so much better on humid days than they do on dry days). Although this dependence of absorption upon humidity is characteristic of low-frequency as well as high-frequency sound, the actual amount of absorption in the air is negligible for frequencies below about 1024 vibrations per second. However, the absorption of the higher frequencies in the air is a significant factor, and its dependence upon humidity calls for careful consideration in planning the air-conditioning equipment for buildings. Effect of Humidity upon the Absorption of Sound in a Room, by V. O. Knudsen {Journal Acoustical Society of America,`July, 1931). Also see report presented at the May, 1933, meeting of A. S. of A. 254 Chapter 19 AIR DUCT DESIGN Pressure Losses, Friction Losses, Friction Loss Chart, Proportioning the Losses, Sizes of Ducts, General Rules, Procedure for Duct Design, Air Velocities, Proportioning the Size for Friction, Mam Trunk Ducts with Branches for Public Buildings, Equal Friction Method, Details of Duct Construction 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 formula for the flow of liquids: ' V = 1096.5 (1) where . V -- velocity in feet per minute. p = velocity head or pressure in. inches of water. W = weight of air in pounds per cubic foot. . For standard air (70 F and 29.92 barometer) W = 0.07495 lb per cubic foot. Sub stituting this value in Equation 1: V- 1096-5 ^0^95 = 4005 ^ . . (2) PRESSURE LOSSES 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. Dynamic 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 255 III:. American Society of Heating and Ventilating Engineers Guide, 1934 0 S3 (00 ISO too ISO CiNm. Lwc Radius m Phjuht or Pm DtAucreg. Fig. 1. Curve Showing Loss of Pressure in Round Elbows 300 0.5 times the velocity head. The pressure loss in elbows must also be allowed for in the design. It is customary to express dynamic losses in terms of the percentage of the velocity head; in other words, the per centage of that pressure corresponding to the average velocity in the duct which is expressed in terms of inches of water gage. Figs. 1 and 2 show the effect of changing the radius of elbows of square and rectangular section. 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 Fig. 2. Curve Showing Loss of Pressure in Square Elbows 256 Chapter 19--Air Duct Design 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 134 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 diameters. 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 29.9$ in. barometer) .L , L ( V \2 hL f Dhv CD; 1l, 4005 / (3) For rectangular ducts *-*(*#)>.-*(**)(*)* (4) 'where hh = loss of head, inches of water. ftv = (4002 1 = velocity head, inches of water. V = velocity of air, feet per minute. L -- length of pipe. D = diameter of pipe. a, b = sides of rectangular duct. . / = coefficient of friction. 1 f all in feet J C =y- -- 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 pipe as used in planning mill exhaust systems; = 50 for heating and ventilating ducts; = 45 for smooth and 40 for rough conduits of tile, brick or concrete. However, Fritzche states (and numerous tests check very closely) that / varies inversely as the 2/7 power of the pipe diameter, and inversely as the 1/7 power of the velocity, or inversely as the 1/7 power of capacity, which is the same thing. Thus Formula 3 may be revised as follows, based upon a loss of one velocity head (at 2000 fpm) in a length equal to 50 diameters of 24 in. galvanized swedged pipe: . he = 1.1 L CD*" / V \ 13/7 \4005 ) (5) 257 American Society of Heating and Ventilating Engineers Guide, 1934 n ri v in' co 800000 600000 500 000 4n ia (p oo * Friction in Inches of Waterper 100 Ft. n Fig. 3. Friction of Air in Pipes 258 ri e w <s. Chapter 19--Air Duct Design The proceding formulae are based on standard air, and for other con ditions the friction varies directly as the air density and inversely (ap proximately) as the absolute temperature. The increase of friction due to increase of air viscosity with increased temperature is small and is generally neglected. Friction Loss Chart Fig. 3 is a convenient chart for determining the friction lo?s 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 are at the entrance to the duct, through the heating units, air washer, etc. In ordinary practice in ventilation work it is usual to keep the sum of the duct losses to and the loss through the heating units at less than Yi 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 veloci ties 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 ,pf air are usually based on the losses due. to. friction, and these losses must be kept within the available pressure difference. This pressure difference in mechanical ventilation is that derived from the fan, while in gravity ventilation the aspirating effect due to the temperature and height of the column of heated air causes the pressure difference. General Rules /. ,- The general rules to be followed in the design of a duct system are: 1. The air should be conveyed as directly as possible at reasonable velocities to obtain the results desired with greatest economy of power, material and space. 2. Sharp elbows and bends should be avoided. 259 Chapter 19--Air Duct Design D iam eter o f B ranch Pipe ' (1 t o 20 P e r C e n t C a p a c it y ) 3. The sides of all ducts or flues should be as nearly equal as possible. (In no case should the ratio between long and short sides be greater than 10 to 1). Procedure for Duct Design The general procedure for designing a duct system is as follows: 1. Study the plan of the building and draw in roughly the most convenient system of ducts, taking cognizance of the building construction, avoiding all obstructions in steel work, equipment, etc., and at the same time maintaining a simple design. 2. Arrange the positions of duct outlets to insure the proper distribution of heat. 3. Divide the building into zones and proportion the volume of air necessary to supply the heat for each zone. . 4. Determine the size of each outlet, based on the volume as obtained in the preceding paragraph, for the proper outlet velocity. 5. Calculate the sizes of all main and branch ducts by either of the following two methods: a. Velocity Method. Arbitrarily fix the velocity in the various sections, reducing the velocity from the point of leaving the fan to the point of discharge to the room. In this case the pressure loss of each section of the duct is calculated separately and the total loss found by adding together the losses of the various sections. b. Friction Pressure Loss Method. Proportion the duct for equal friction pressure loss per foot of length. 6. Calculate the friction for the duct offering the greatest resistance to the flow of air, which resistance represents the static pressure which must be maintained in the fan outlet or in the plenum space to insure distribution of air in the duct system. The duct having the greatest resistance will usually be that having the longest run, although not necessarily so. Air Velocities The following velocities of air are considered standard for public buildings: 1. Through the outside air intakes, 1000 fpm. 2. Through connections to and from heating unit, 1000 to 1200 fpm. - 3. Through the main discharge duct, from 1200 to 1600 fpm. 4. In branch ducts, 600 to 1000 and in vertical flues 400 to 800 fpm. 5. In registers or grilles, 200 to 400 fpm depending upon the size and location. diffusers of proper design are used, 25 per cent higher air velocities are permissible. If, , These duct velocities may safely be increased 20 per cent if first-class construction is used to prevent any breathing, .buckling, or vibration. High velocities at one point in the system neutralize the effect of proper design at all other points; hence the importance of splitters in elbows and similar precautions. For industrial buildings noise is seldom considered, and main duct velocities as high as 2800 or 3000 fpm may be used where conditions will permit. For department stores and similar buildings, maximum velocities with good construction and design may be as high as 2000 or 2200 fpm in main ducts, with suitable reduction in branches and outlets. With these velocities first-class duct construction is essential. Proportioning the Size for Friction By means of Figs. 4 and 5 the diameter of branch pipes necessary to carry a given percentage of the total air in the main pipe with the same friction per foot of the length 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. 261 Chapter 19--Air Duct Design . (20 t o 100 P e r C e n t C a p a c it y ) Example 2. Suppose a 60-in. main pipe is to be used, and it is desired to know the size of branch pipe required to carry 50 per cent of the total air in the main. Find 50 per cent at the left of the chart, move right to the 60-in. diagonal line and note directly above at the top of the chart that the. branch pipe will be 46.5 in. in diameter. Where rectangular ducts are used it is frequently desirable to know the equivalent diameter of round pipe to carry the same capacity and have the same friction per foot of length. Table 1 gives directly the circular equivalent of rectangular ducts for equal friction and capacity. 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 17j-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 just twice that of a 40 x 12 in. duct, or 2 X 23.3 = 46.6 in. ,, DUCTS FOR PUBLIC BUILDINGS 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. Example of Equal Friction Method Example 3. Fig. 6 shows a typical layout of an air distribution system which is applicable for ventilation of hotel dining rooms, offices, etc. The volume of air in cubic feet per minute for the room is determined on the basis of the number of air changes per hour required. In the example shown, the room ventilated is a hotel dining room 135 ft x 85 ft x 15 ft. A 7 J^-minute air change (8 air changes per hour) is assumed for proper ventilation, giving 22,935 cfm as the air required. The clear area of the fresh air inlet is based on a velocity of 1000 fpm or -- 22.94 sq ft. If the air washer is provided with automatic humidity control, the tempering coil should raise the temperature of the entering air to 32 F. The washer with its auto matic control will then raise the temperature from 32 F to 42 F. If the washer is not provided with automatic humidity control. the tempering coil must raise the temperature of the entering air to at least 55 F to allow for some temperature drop in the washer due to evaporation. The reheating coil is selected to raise the temperature of the air from that leaving the air washer to 70 F. The air washer should have a maximum velocity of 500 fpm through the clear area, which, in this case, is 46 sq ft. For more detailed infor mation on tempering coil and air washer control, see Chapters 23 and 14. - 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 16H sq ft. 263 American Society of Heating and Ventilating Engineers Guide, 1934 264 T a b l e 1. C ir c u l a r E q u iv a l e n t s o f R e c t a n g u la r D u c ts fo r E q u a l F r ic t io n * T a b l e 1. C ir c u la r E q u iv a le n t s of R e c ta n g u la r D ucts fo r E q u a l F r ic t io n (C o n tin u e d ) Chapter 19--Air Duct Design 265 American Society of Heating and. Ventilating Engineers Guide, 1934 F ig . 6. T y p ic a l L a y o u t op A ir D is t r ib u t io n System Chapter 19--Air' Duct Design Table 2. Pipe Sizes for Example 3 Volume or Ais (era) 22,935 12,510 10,425 8,340 6,255 4,170 2,085 Per Cent or Total Volume 100.0 54.6 45.4 36.3 27.2 18.2 9.1 Diameter or Pipe (Inches) 56 45 42 39 35 29^ 23 . [Velocity through diffusers (not shown) to be approximately 300 fpm]. Equivalent Size or Rectangular Duct (Inches) 60x44 58x30 50x30 42x30 42x24 30 x 24 30 x 15 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 volume handled by each section as a percentage of the total volume and using the charts, Figs. 4 and 5, the pipe sizes are as shown in Table 2. The pressure at the outlets nearest the fan will be greater than at the pipes farther along the run so that the former will tend to deliver more than the calculated amount of air. To remedy this condition, volume regulating dampers should be located at the base of each riser and adjusted for proper distribution. At points where branches leave the main it may be advisable, depending upon the nature of the installation, to install adjustable splitters similar to that shown in Fig. 6 where the main duct divides into the 58 in.-by-30 in. and 50 in.-by-30 in. branches. The rectangular equivalents are selected from Table 1; the width to depth proportion will be determined by construction requirements and ease of fabrication. The calcu lation of the friction is as follows: The longest run from the fan outlet to diffuser is 150 ft, 0 in.; 150 ft of 56'-in. pipe is equivalent to ---- ^ oo ..................................................... .......................................... ...........32.2 dia. Two 45-in., 90-deg elbows (2 X yrf X 10)---------------- -------- -............................... ....... 16.1 dia. Uu , Two 23-in., 90-deg elbows (2 X gg X 10)................. .................................. .................. 8.2 dia. Two 23-in., 90-deg elbows in riser (2 X jgX 30)........ ....... (Two bad elbows in riser, each equivalent to 30 diameters of duct). 24.7 dia. Total diameter of 56-in. pipe.,--.........--.......... ......................... :....................... 81.2 (134q\2 1005/ = . *n- 81 2 Taking 50 diameters as one head loss, then X 0.112 = 0.182 in. static loss in duct. 50. :' 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 0.033 in. The fan outlet velocity is 1400 fpm with a corresponding velocity pressure of 0.122 in. The regain equals two-thirds (0.122 -- 0.033) = 0.059 in. ............. ' 267 American Society of Heating and Ventilating Engineers Guide, 1934 The net static pressure loss in the duct only is then: 0.182 in. -- 0.059 in.............................................................................................................0.123 in. Other friction losses are as follows: (1) Fresh air intake 1000-fpm velocity (1)4 heads X 0.0625).......... ....................... 0.094 in. (2) Tempering coil loss (from manufacturers tables)................................................... 0.100 in. (3) Air washer loss (from manufacturers tables)--........................................................ 0.250 in. (4) Reheating coil loss (from manufacturers tables)--........................;........................ 0.100 in. (5) Allowance for regulating dampers and diffusers.--.......... :................................--.0.100 in. Static pressure loss of system......................................................................... .............0.767 in. The fan should be selected from the manufacturers ratings which, according to the Standard Test Code for Disc and Propeller Fans, Centrifugal Fans and Blowers', will deliver 22,935 cfm at a static pressure of 0.767 in. and which has an outlet area of 16J^ sq ft. The method of design used iri Example 3 is the equal friction method described under the heading Procedure for Duct Design. This involves the arbitrary reduction of velocity from the fan outlet to the point of discharge to the room, and the friction is calculated by adding the pressure losses of each section of duct. This method requires dampering in the risers. 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. All risers will require dampering as in Example 3. The calculation of the friction is as follows: The longest run from the intake grille to fan inlet is 100 ft. (1) Duct friction 100 ft of 47-in. pipe .................................................. 25.6 dia. Two 28J4-in., 90-deg elbows in riser ^ ^ ^ ^........................................ 36.4 dia. (Two bad elbows in riser each equivalent to 30 diameters of duct). Table 3. Pipe Sizes for Example 4 Volume or Aia (cm) 16,800 11,550 9,450 5,250 4,200 3,150 2,100 Per Cent or Total Volume 100.0 68.8 56.2 31.3 25.0 18.8 12.5 Diameter or Pipe (Inches) 47 41 38 31 28.5 25.3 21.6 Equivalent Size op Rectangular Duct (Inches) 38 x 48 30x46 30x40 24 x 34 24x28 16x34 16x24 [Velocity through intake grilles (not shown) to be approximately 400 fpm]. >See Chapters 17 and 42.. 268 Chapter 19--Air Duct Design Fig. 7. Exhaust System Layout , .t . , /28.5 X 12\ One 28H-in., 90-deg elbow in horizontal run I------ ^----- 1.............................. 6.0 dia. Total diameter of 47-in. pipe.............. .....................-........................ -........--- 68.0 dia. /1400 \2 . Velocity head corresponding to 1400 fpm is f 1 = 122 in. V.4005 / 68 X 0.122 Taking 50 diameters as one head loss, then 50 ' 0.166 in. (2) Intake loss from grille (l)- heads at a 400 fpm velocity 1M X 0.01)............... 0.015 in. (3) Static pressure required to produce one velocity head at 1400 fpm--.............. 0.122 in. (4) Loss occasioned by step-up of velocity (0.20 X 0.122)............... ..................-- 0.024 in. (This loss varies from 0.05 to 0.40 velocity heads depending upon the nature of the change. For average systems 0.20 velocity heads is a close approximation). ____________ Static pressure loss on inlet side.. 0.327 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): _ ` ie y 'lO ----- ---- = 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 0145 X 4 = 0:012 in. The total static pressure loss of the system is then: 50 0.012 + 0.327 = 0.339 in. The fan will be selected to handle 16,800 cfm at a static pressure of 0.339 in. and to.have an outlet velocity of 1525 fpm. Outlet area 11 sq ft. 269 American Society of Heating and Ventilating Engineers Guide, 1934 SECTION I TOP SHEETj SIDE SHEET Bottom sheet elevation reinforceo CROSS SEAMS SEAMS BETWEEN ADJACENT PANELS OR PLAIN CROSS SEAMS Fig. 9. Details of Seams Fig. 10. Method of Installing Heating Unit < ' Fig. 11. Installation of Easement in Duct Around Obstruction Chapter 19--Air Duct Design 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 carrying one-half the total capacity of a 30-in. main with the same friction loss per foot would be 23.4 in. in diameter. By this method of equalizing friction it is unnecessary to consider the resistance of each section of pipe independently, but only to know the distance from the fan outlet to the end of the longest run of pipe, the number and size of elbows, and the diameter and velocity in the largest pipe. Example 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 one-fifth of a velocity head or ten diameters of 20-in. pipe. 20 . This in turn is X 10 = 7.7 diameters of 26 in. pipe. The total equivalent length of the system will then be 60 + 7.7, or 67.7 diameters. Since 50 diameters is equivalent to one velocity head, the loss is--gj- = 1.35 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 1.35 X 0.3 = 0.405 in. Frequently the prevention of sound in a heating or ventilating system imposes more severe restrictions than the prevention of excessive pressure drop. This question is highly involved and requires consideration of many factors. The air velocities to be used will vary with the standard of construction used in the ducts themselves as well as with the nature of the occupancy and the construction of the building. In general, architects and engineers who leave the details of duct construction to the contractor must, of necessity, design for lower velocities than might be required for quiet operation if proper construction details were always followed. The contractor may be. expected to-build the ducts by the least' expensive methods, and the engineer must anticipate this. For further information on noise reduction, see Chapter 18. Details of Duct Construction 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. 271 American Society of Heating and Ventilating Engineers Guide, 1934 Figs. 8 to 15 show acceptable construction details for rectangular ducts, elbows, transformation pieces or connections, and air splitters. 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 If, va tf. VANES Fig. 13. Air Splitters Installed in Elbow Fig. 14. Air Splitters Installed in Elbow at Fan Discharge Fig. 15. - Air Splitters in Branch Ducts and Elbows 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. Air splitters should be installed in elbows as shown in Figs. 13 and 14. The recommended gages for rectangular sheet metal duct construction are given in Table 4. . '' Table 4. Sheet Metal Gages for Rectangular Duct Construction* Gags Width of Duct Sbah 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. m in- x 1% in. 20 61 in. to 90 in. m K in. x 1% in. "If panels are not cross-broken two gages heavier material should be used. 272 Chapter 20 AIR DISTRIBUTION Warm Air Systems, Combined Systems, Split Systems, School Buildings, Theaters, Upward System, Downward System, Vanes TO produce proper air distribution in a room to be ventilated, heated, or cooled by air, the design and location of the air supply inlets and exhaust outlets must be carefully considered. Systems fail though they handle the proper amount of air, because important design principles are ignored. WARM AIR SYSTEMS With gravity warm air systems, it has been the practice to place the supply registers in or near the floor of each room and to place the return grille in the floor of the first story. When there is mechanical air circu lation, the supply ducts are extended to the outside walls and the air is discharged into the rooms near their cold exposures; on the return side a grille is placed in or near the floor at a central location, or individual return grilles are provided, usually at the side of the room opposite the supply register. These arrangements are usually satisfactory for heating (Fig. 1) but not for cooling (Fig. 2). If cool air is introduced at one side of the room at the floor, and if the escape opening for the heated air to be displaced by the cool air is at the floor at the other side, the cool air will travel across the floor and will escape through the vent or return air opening, and thus not appreciably affect the over-heated air in the upper part of the room. The air supply opening will serve satisfactorily if located high on an interior wall opposite the exposed wall, and this location answers well also for gravity indirect heating. The corresponding return air arrangements, however, apparently are not subject to exact rules, but must be adapted to circumstances. For example, where the building is compact, with a first story having rooms open to each other, a single, centrally-located return at the floor functions satisfactorily for heating, and if the second story bedrooms are also compactly arranged no individual return from each will be necessary. On the other hand, any room which is unusually exposed, which is especially remote with reference to the other rooms, or which is apt to be tightly closed most of the time, should have a controlled return grille and duct. With a mechanical warm air system, this return may be close to the floor below the supply-grille, and with a gravity system may be close to the floor at the opposite side of the room from the supply grille. 273 American Society of Heating and. Ventilating Engineers Guide, 1934 COMBINED SYSTEMS For a combined mechanical heating and cooling system using refrigera tion for cooling, no particular change in the ducts usually is necessary. It is desirable from an economic standpoint to take advantage of the natural tendency of the cooler air to remain below the warmer air overhead, and anything which will bring about such stratification will effect an economy in refrigeration. Fig. 1. Air Circulation when Heating with Low-Supply and Return Openings Fig. 2. Air Circulation when Cooling with Low-Supply and Return Openings Fig. 3. Air Circulation when Cooling with High-Supply Opening and Low-Return Openings Fig. 4. Section Through an Elemental Mechanical Warm Air Heating Cooling System, The Attic Fan is Alternative If the return ducts of a mechanically operated warm air system are adequate, appreciable cooling can be accomplished with natural means, as follows: The fan outlet usually has a by-pass duct leading to a basement window or to a chimney provided for the purpose. The return duct has an alternative shaft opening into the highest part of the house. At night, in summer, the fan may be operated to exhaust the hot air from the top of the house by the return air duct just described and the fan will blow this heated air out of doors through the window, or preferably, of course, through the chimney. The cooler night air must then, enter the house through the windows, and by its motion and temperature will extract the heat from the walls and furniture. 274 Chapter 20--Air Distribution Fig. 3 shows the air circulation when Cooling with a high supply opening and a low return opening. The air circulation, when heating, will be substantially the same as when cooling. Fig. 4 shows a section through an elemental mechanical warm air heating-cooling system. The attic plan is alternative. Summer night cooling may, of course, be accomplished by placing an exhaust fan in the attic. : SPLIT SYSTEMS Many buildings which are heated by radiators or convectors and which have rooms requiring ventilation or cooling have air supply and exhaust systems independent of the radiators or convectors. Such installations are termed split systems. When the air enters a room through conventional side wall inlets an occupant may feel comfortable if the air is about the temperature of the room, but the introduction of too cool air may cause a feeling of draft. To correct this draft condition, glass chutes and elabor ate diffusers are sometimes provided. The arrangement shown in Fig. 5 for supplying cool air to a room supplies satisfactory air circulation in spaces up to 400 sq ft in area -with ceilings as low as 8 ft. There is no maximum ceiling limitation as to height. When the room in question is provided with a unit ventilator which obtains its air supply directly through the wall from out of doors, the problem of distribution is by no means easy, although with a high velocity air jet passing in an upward direction, satisfactory air distribution will be had. The use of unit air conditioners for summer cooling introduces no new features or difficulties which have not already been encountered in winter heating. Conditioners must be provided with positive control by means of valves or dampers, or both, which will prohibit any sudden and wide tem perature variation, and keep the entering air not more than approxi mately 7 deg cooler than the air already in the space. This temperature margin is dependent on various factors including the ceiling height of the room and the velocity of the air at the.discharge grille. SCHOOL BUILDINGS The air distribution conditions in school building classrooms are not unlike those illustrated in Fig. 1 for mechanical warm air systems and those in Fig. 6 for unit ventilator-equipped plants. The thermostat (Fig. 6) which controls the mixing damper and the heating unit in the unit ventilator should be in the air stream from the machine. School rooms which have center-ceiling inlets along the lines of Fig. 5 have given excellent results. It is important that the temperature of the entering air, whether this air be supplied by a local unit ventilator or by a distant central fan, be controlled so that the air cannot enter the room from a side-wall inlet or from a unit ventilator at a temperature more than a very few degrees cooler than that of the air already near the ceiling of the room. Fig. 7 shows a section through a room equipped with a unit air con ditioner or unit cooler. This is typical of the condition in effect when any recirculating room-cooling unit is installed. 275 American Society of Heating and Ventilating Engineers Guide, 1934 Fig. 5. Section Through a Radiator-Heated Room Fig. 6. Section Through a Unit Venti lator-Equipped Room when Heating Chapter 20--Air Distribution volume of air to be introduced with the upward system is about 25 cfm of air per person at a low velocity, say at 150 fpm (linear), and at a tem perature not more than 6 deg below the room temperature. For partial occupancy, higher entering air temperatures can be used, with corre spondingly less danger from drafts. Downward System Theaters usually are equipped with downward air distribution with horizontal diffusion of the entering cool air so as to combine it, both as to temperature and dilution, with the heated air which inevitably must rise from the bodies of the patrons. The waste or the recirculated air is with drawn from the room at the floor. If the theater is large, and if the Fig. 7. Section Through a Unit Conditioner-Equipped Room when Cooling Fig. 8. Plan of a Classroom in a School Ventilated by a Central Fan In Fig. 8 the cloakroom ceiling is furred down so as to conceal the metal air supply duct, which is close to the ceiling. The air for ventilation usually is controlled by a duct thermostat near the fan, at a temperature slightly higher than the temperature required in the room, to allow foq . heat losses in the duct system. THEATERS Theaters are usually ventilated or cooled by introducing pre-con ditioned air. No ventilating system for a theater should be given con sideration without definite provision for cooling. Theater cooling generally is far more important than theater heating. There are two widely different methods of theater air distribution, the pward and the downward. - Upward System . If no inlet openings are possible in the ceiling, the upward system may be the least objectionable alternative. Fig. 9 shows a section through a theater with the upward system of air distribution. The occupants often suffer from drafts due to the cool air which comes from the unoccupied zones. When the entire seating area is occupied, the upward system gives little trouble when cooling, and since very little heating is required under such conditions, practically no difficulty is encountered. The maximum 276 Fig. 9- Theater with Upward System of Ventilation Fig. 10. Section Through a Theater with Downward Ventilation exhaust openings are placed in the side walls at the floor, drafts may be felt by the people who sit near the openings. There is no objection, how ever, except that of cost, to the use of small exhaust openings under each seat. These may be cleanable floor grilles or may have mushroom covers. In a downward system, if the entering cool air is not deflected hori zontally, it will fall through the surrounding much hotter air, and will reach high velocities by the time it strikes the heads of the occupants. Air at a temperature 10 deg below that of the surrounding air is decidedly objectionable when forced over one's head at a velocity of nearly 400 fpm. Fig. 10 shows a section through a theater with downward ventilation. The deflectors cause the entering cool air to be spread horizontally so that it will mix with the hotter air. The final escape is through well-distributed openings in the floor. There have been cases in which the downward system of air distribution such as that illustrated in Fig. 10 gave trouble due to overheating at the rear, both above and below the balcony, especially when not provided with refrigeration for cooling, and when not adequately controlled. It is especially necessary that adequate removal of the heated air be provided at these low-ceiling points and it is probable that auxiliary exhaust at or through the ceiling after the manner of the arrangements shown in Fig. 5 would be helpful. ' ... VANES In order to cause the supply air to a room to take a fixed or desired direction when leaving the inlet opening of a flue, stationary vanes may 277 American Society of Heating and Ventilating Engineers Guide, 1934 be provided at both the back of the grille and at the grille to direct the air flow. Fig. 11 shows a section through a room inlet opening at the top of a rising flue and indicates the air conditions when no vanes are used. Fig. 12 shows a section through the same room inlet opening when vanes are advantageously placed to direct the flow of air. ' Fig. 11. Air Conditions at Inlet Opening at the Top of a Rising Flue when no Vanes are Used Fig. 12. Air Conditions at Inlet Opening at the Top of a Rising Flue when Directional Vanes are Used In many theater and commercial installations the ejector-like action of high-velocity air emerging from a duct is taken advantage of, and scientifically proportioned nozzles are installed to cause definite recircu lation of the room air. . V 278 Chapter 21 INDUSTRIAL EXHAUST SYSTEMS Types, Design of Systems, Suction and Velocity Requirements, Design of Hoods, Design of Duct Systems, Collectors, Resistance of Systems, Selection of Fans and Motors EXHAUST and collecting systems are found in almost every industry and are a vital adjunct in maintaining safe and hygienic conditions. The present chapter attempts to give general information relating to the design of factory exhaust systems in order that efficient and economical control of dusts and fumes may be achieved. TYPES 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 279 ~ American Society of Heating and Ventilating Engineers Guide, 1934 , all, owing to the rising air current carrying the dust up through the breathing zones. The objective to keep in mind in all cases is to take advantage of the natural tendency of the material to move upward or downward. In another class of operation the main objective is to prevent the escape of dust into the surrounding atmosphere, the removal of some dust from the machine or enclosure being merely incidental. The dust-creating apparatus is enclosed within a housing which is made as tight as prac ticable, and sufficient suction is applied to the enclosure to maintain an inward air leakage, thus preventing escape of the dust. While the exhaust system is only required to handle 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 OF SYSTEMS The first step in the design of an exhaust system is to determine the number and size of the hoods and their connections. No general rules,, however, can be given since hood and duct dimensions are determined by the characteristics of the operations to which they are applied. When a . tentative decision regarding the set-up has been made, it is then necessary to obtain the suction and air velocities required to effect control. At this point the designer must rely upon the prevailing practice and on such physical data relating to hoods, duct systems and collectors as are avail able. Finally, in choosing the fan, the area of the intake should be equal to or greater than the sum of the areas of the branch ducts. The speed, of course, must be sufficient to maintain the estimated suction and air velocities in the system. In general, the most important requirements of an efficient exhaust and collecting system are as follows1: 1. Hoods, ducts, fans and collectors should be of adequate size. 2. The air velocities should be sufficient to control and convey the materials collected. 3. The hoods and ducts should not interfere with the operation of a machine or any working part. , 4. The system should do the required work with a minimum power consumption. 5. When inflammable dusts and fumes are conveyed, the piping should be provided with an automatic damper in passing through a fire-wall. . Sa/ZTM^^~ata Practice Pamphlets Nos. 32 and 37. pushed by the NaNoaoI 280 Chapter 21--Industrial Exhaust Systems 6 Ducts and all metal parts should be grounded to reduce the danger of dust ex plo7s.ionTshebydesstiagtnicoef laencterixchitayu. st system should afford easy access to parts for inspection . and care. SUCTION AND VELOCITY REQUIREMENTS 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 them 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 op 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'Sa-ws, Blade 4-5 in. wide.------------ :...... .............. .............. Band Saws, Blade 5-6 in. wide.------,------------------- ,--------------- Small Mortisers............................................ ..................................... Single End Tenoners.------------------------ --------------------------------Double End Tenoners----- ------ --------------------------------------------Double End, Double Head Tenoners__________________ ____ Planers, Matchers, Moulders, Stickers, Jointers, etc.-- With Knives, 6-10 in........ ...... ............................................... With Knives, 10-20 in.............................................................. With Knives, 20-30 in................ ........................................... - Shapers, Light Work........................ ................................................ Shapers, Heavy Work-----:------ ------- ,--....................... ................ Belt Sander, Belt less than 6 in. wide____--.............................. Belt Sander, Belt 6-10 in. wide.......... ........................................ Belt Sander, Belt 10-14 in. wide______ :............................;------Drum Sander, 24 in....... ...................... ...................... ...................... Drum Sander, 30 in...................... ....................................-............. Drum Sander, 36 in......................... ................................................. Drum Sander, 48 in.__ ___________________ _____ ____ ________ Drum Sander, over 48 in----------- ---- -----------:------ ------------------ Disc Sander, 24 in. diam____ ;--- -------- --------- --------- --------------Disc Sander, 26-36 in. diam......................................................--. Disc Sander, 36-48 in. diam--......................... .......................... Arm Sander-------------- ---------------------------------------------------- ------- 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 smTahlleasstaptoicsssiubclet.ion 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 I and 2 present the duct sizes usually 281 ` American Society of Heating and Ventilating Engineers Guide, 1934 employed for standard wood-working niaehinery 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 term suction is merely a rough Table 2. Size of Connections for Grinding and Buffing Wheels Diameter of Wheels Grinding-- 6 in. or less, not over I in. thick. m 5 t? !"' '"riusive, not over 1 10 in. to 16 in., " "2 17 in. to 19 in., " " "3 20 in. to 24 in., " " "4 25 in. to 30 in., " " "5 in. thick--.. in " in " in " in' " " Buffing-- 6 in. or less, not over 1 in. thick 7 in. to 12 in., inclusive, not over l}i in. 13 in. to 16 in., " " " 2 in 17 in. to 20 in., " " " 3 in 21 in. to 27 in., " " " 4 in 27 in. to 33 in., " " " 5 in thick__ " " -----" " Max, Grinding Surface Sq In 19 43 101 180 302 472 19 57 101 189 338 518 Min. Diam. of Branch Pipes in Inches .3 4 5 6 4 4H 5 6 7 Table 3. Suction Pressures Required at Hoods Static Suction in Inches or Wateb Exhausting from grinding and buffing whenU Exhausting from tumbling barrels Auausung irom wood-working machinery--light duty Exhausting from wood-working onoe machinery exhaust . machinery--heavy J dut y-- ------- -- t-xtiausting Irom rubber manufacturing nrnrpsses ma siiuuing exnaust.. . pxnausting irom pottery processes A^cau uusc ana tume exhaust. Fur and felt machinery exhaust. ' **' ----------- oxiiausung irom textile machinery ............... ............................ oAuausung irom elevating and crushing machinery_____ Conveying bulky and heavy materials -- - 1H~5 '2-4 2-3 2 2-4 2 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 lj/j to 5 ih. water displacement in a U-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- 282 Chapter 21--Industrial Exhaust Systems 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 than 200 fpm at the point of origin. For granite dust generated by pneumatic devices. Hatch2 gives velocities from 150 to 200 fpm, depending on the type of hood used, as sufficient for safe control. Considering 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. DESIGN OF 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 axis: Y 100 - Y O.IA (1) where Y - per cent of velocity at opening. . A = area of opening in square inches (or square feet). x = distance outward from opening in inches (or feet). - It is important to note that the velocity function varies in direct proportion to the area. Hence, under certain conditions, a large opening may function more effectively than a small one for. the same volume of . *Control of the Silicosis Hazard in the Hard Rock Industries. {Journal of Industrial Hyeicne. Vol. XII, No. 3. March, 1930). 283 >. ! `-pfs&y American Society of Heating and Ventilating Engineers Guide, 1934 flow. The formula, of course, presumes that the air velocity distribution across the hood opening is uniform5. Example 1. A small hood 64 sq in. in area handles 400 cfm. What will be the air velocity at a point 5 in. outward along the axis if the flow is unobstructed? Solution. Substitute in Equation 1 and solve for Y, thus Y 100 - y 0.1 X 64 5X5 from which Y = 20.4 per cent of the velocity at the opening of the hood. V,,e.locity a,t open.mg = -4--0--0-- gXj--1-4--4-- = 900 f.pm Hence, the velocity at the point in question is 900 X 0.204 = 184 fpm Air Flow from Static Readings The volume of air flow into any hood may be determined from the following equation: . . where Q = 4005 fa \At (2) Q = volume of air flow in cubic feet per minute. a = area of connecting duct in square feet. ht = static suction at throat of hood in inches of water. / = orifice or restriction coefficient which varies from 6.6 to 0.9 depending on the shape of the hood. An average value of/is 0.71, although for a well-shaped opening a value of 0.8 may be used. If it is assumed that the entrance loss of a hood is proportional to the velocity head, / can be determined by the relation: where Av ~ the velocity head. . ' , - . ...........l3..> - . For duct ends and abrupt openings ht = hv and for flared openings ht -- 0.5hv. 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 function at any point along the axis varies directly as the area of the opening and inversely as the square of the distance. However, this formula coupled with Equation 2 should serve to indicate the velocity conditions to -be expected when operations are conducted external to the hood opening. Large Open Hoods . Large hoods, such as used for electroplating and pickling tanks, should be subdivided so that the area of the connecting duct is not less than one- Vol^ss^v^4^09 f Ho0dS Under Suction- by 1 M- Oallavalte (A.S.H.V.E. Transactions 284 Chapter 21--Industrial Exhaust Systems fifteenth the open area of the hood. Frequently, it will be found necessary to branch the main duct in order to obtain a uniform distribution of flow. Canopy hoods should extend 6 in. laterally from the tank for every I2-in. elevation. 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 approximately 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: Q = 1.4PDV (4) where . Q = total volume of air handled by hood in dm. P -- perimeter of the tank in feet. O = distance between tank and hood opening in feet. V = air velocity desired along edges and surface of tank in fpm. 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 benzene, should be kept below 100 ppm. Spray booth vapors are dangerous to the health of the worker and care should be taken to minimize exposure to them. It is recommended in the design of spray booths that the exhaust duct be located ,in a horizontal position slightly above the object sprayed. Stagnant regions within the booth should be carefully avoided or should be provided with a Vertical exhaust. The air volume should be sufficient to maintain a velocity of 150 to 200 fpm over the open area of the booth and the vapors should be discharged through a. suitable stack to permit dilution4. 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. -- <For a discussion of spray booths, see Special Bulletin No. 16, Spray Painting in Pennsylvania, Depart ment of Labor and Industry, 1926, Harrisburg, Pa. . ' 285 American Society of Heating and Ventilating Engineers Guide, 1934 DESIGN OF DUCT SYSTEMS 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 ticularly those used in buffing and polishing, are connected by short branch pipes to the main duct which renders proportioning impractical. Construction The ducts leading from the hoods to the exhaust fan should be con structed of sheet metal not lighter than is shown in Table 4. The piping should be free from dents, fins and projections on which refuse might catch. Table 4. Gage of Sheet Metal to be Used for Various Duct Diameters Diameter or Duct Gage or Metal 8 in. or less..................................................................................................................................... 26 in. or more.................................................................................................................................... 24 22 20 18 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. AH branch pipes should join the main at an 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 such that the material from one branch tends to enter the branch on the opposite side of the main. Cleanout openings having suitable covers should be placed in the jnain and branch pipes so that every part of the system can be easily reached in case the system clogs. Either a large cleanout door should be placed in the main suction pipe near the fan inlet, or a detachable section of pipe, held in place by lug bands, may be provided. Elbows should be made at least two gages heavier than straight pipe of the same diameter, the better to enable them to withstand the addi tional wear caused by changing the direction of flow. They should pref erably have a throat radius of at least one and one-half times the diameter of the pipe. Every pipe should be kept open and unobstructed throughout its entire 286 Chapter 21---Industrial Exhaust Systems 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. At the point of entrance of a branch pipe with the main duct, there should be an increase in the latter equal to their sum. Some state codes specify that the combined area be increased by 25 per cent. While this is not always necessary and is frequently done at the expense of a reduced air velocity, it is none the less advisable where future expansion of the exhaust system is contemplated. . Table 5. Air Speeds in Ducts Necessary to Convey Various Materials Material ------------- . Grain dust.......... .---........................................................................ Saw dust-------------- ------- -........................................................... ............................................... I"""..................................................... Metal dust Cgrinaings;--...................................................... . Am Velocities (fpm) 2000 3000 2000 2000 2000 1500 2200 5000 4000 4000 Air Velocities in Ducts When the static suction has been fixed for a given hood, the air velocity in the duct may be determined from Equation 2. Air velocities for conveying a material should be moderate. Table 5 gives the velocities generally employed for conveying various substances. Equations 5a and 5b may be used as tests to determine the conveying efficiency of a system. Velocities determined from these formulas should be increased by at least 25 per cent since they represent the minimum at which a stated size and density of material can be transported. ' For vertical ducts: V = 13,300 --f-r do no J -r 1 (5a) For horizontal ducts: V = 6000 f -j- d-* s+i (5b) where V = air velocity in duct, in feet per minute. , s = specific gravity of particles. d = average diameter of largest particles conveyed, in inches. -- Example S. 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. 287 . / .1 American Society of Heating and Ventilating Engineers Guide, 1934 Substitute data in Equation 5a and multiply by 1.25. V = 1.25 X 13,300 X X 0.37- 2-4 Antilog (0.57 X log 0.37) = 0.568; the required velocity is, therefore, 5500 fpm. Hence, the duct velocity must be increased either by speeding up the fan or decreasing the diameter of the duct or both. . Duct Resistance The resistance to flow in any galvanized duct riveted and soldered at the joints maybe obtained from Fig. 3, Chapter 19. 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 134 times the dia meter, the resistance is about the same as 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 collectof. The diameter of the cyclone should be at least 334 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 two- thirds 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 ( uSso)' . (6) where he = the pressure drop through the cyclone in inches of water. V = the air velocity in the fan discharge duct in feet per minute. If a cyclone is used to collect light dusts such as buffing wheel dusts, 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 '. 288 ' Chapter 21--Industrial Exhaust Systems separation. The capacities and characteristics of this type of separator should be obtained from the manufacturers. Cloth Filters Filter bags are used when the material collected by an exhaust system is valuable or cannot be separated 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 con siderable 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 bags are employed, the filtering capacities vary from 34 to 10 cfm per square foot of filtering surface, depending . on the character of the material collected. The rates for cotton and asbestos cloths are slightly 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 permitted to build up on the surface of the filter and can only be determined by experiment. The limits of the increase may be regulated by adjustment of the shaking or cleaning mechanism. These limits may further be regulated according to the capacity of the fan and the effective performance of the hoods and the duct system. RESISTANCE OF SYSTEM The maintained resistance of the exhaust system is composed of three factors: (1) loss through the hoods, (2) collector drop, and (3) friction drop in the pipes. The loss through the hoods is usually assumed to be equal to the suction maintained at the hoods. The collector drop in inches of water is given approximately by Equation 6, but where possible the resistance of the particular collector to be used should be ascertained from the manu facturer. ' Friction drop in the pipes must be computed for each section where there is a change in area or in velocity. Find the velocities in each section of pipe starting with the branch most remote from the fan. The friction drop for these sections can be determined by reference to Table 6. Total friction loss in the piping system is the friction drop in the most remote branch plus the drop in the various sections of the main, plus the drop in the discharge pipe. . ' 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 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 289 . .. American Society of Heating and Ventilating Engineers Guide, 1934 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 Chapter 17. 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 Table 6. Loss Through 90-Deg Elbows Elbow Center Line Radios in Peb Cent or Pipe Diameter 50 100 150 200 to 300 Loss in Per Cent or Veloott Head 75 . 26 17 H . chemical corrosion. A list of the materials which may be used to resist the action of certain fumes is given in Table 7. Hoods and ducts when short, may frequently be constructed of wood and be quite effective. Table 7. Materials to be Used for the Protection of Exhaust Systems Against Corrosion8 orTm Pome Conteted Protective Material to be Used Oilorine. - ................. Rubber lining or chrome-nickle alloys Hydrogen sulphide........ ,, . Aluminum coated iron, aluminum, high chrome-nickle alloys Ammonia. ... . Iron or steel Sulohurous gases High chrome-nickle alloys Hvdror.holrir. arid Rubber lining, chrome-nickle alloys Nitrous gases................ Nickle-chrome alloys Condensed from data given by Chilton and Huey {Industrial and Engineering Chemistry, Vol. 24,1932). Rubberized paints are available and may be applied as protective coatings in handling such gases and fumes as chlorine and hydrochloric acid. 290 Chapter 22 CENTRAL FAN HEATING SYSTEMS Types of Systems, Blow-Through, Draw-Through, Heating Units, Design, Temperatures, Weight of Air to be Circulated, Tempera ture Loss in Ducts, Heat Supplied Heating Units and Washer, Grate Area, Boiier Selection, Weight of Condensate, Static Pres- sure. Fans and Control ACENTRAL fan system is an indirect system of heating, ventilating, or air conditioning in which fans and blowers distribute air through ducts from one centrally located plant. This chapter considers heating and humidifying systems of this type; similar systems arranged for cooling and dehumidifying are discussed in Chapter 9. A special type of central fan system, the mechanical warm air or fan furnace system, which is especially adapted to residences and other small buildings is covered in Chapter 23. TYPES OF SYSTEMS In the indirect type of central fan heating and air conditioning system, steam is usually the medium by which heat is transferred from the boiler, or other source of heat, to the heating units. If the system is intended solely for heating, the air is passed over one or more stacks or batteries of heating units and then conveyed to the spaces for which it is intended through a system of ducts. In some cases, a predetermined amount of outside air is introduced for ventilating purposes, whereas in others the moisture content is controlled by passing the air through a washer or humidifier. If the apparatus is designed to control simultaneously the temperature, humidity, air motion, and distribution, it is known as an air conditioning system. In the split system, the heating is accomplished by means of radiators or convectors, and the ventilating or air conditioning by means of the central fan apparatus. In the combined system, the entire operation of heating, ventilating, and air conditioning is handled by the central fan system. A common arrangement of the central fan system of heating is illus trated by Fig. 1 and consists of a fan, heating unit (heater) enclosed by a sheet metal casing connected with the suction side of the fan, a sheet metal casing connected to the heating unit casing run to the outside of the building and provided with an adjustable opening inside the building for recirculation of the air when desired, and a duct system attached to the fan outlet to convey and distribute the air to various parts of the building to be warmed by the apparatus. The fan is ordinarily motor-driven; there are, however, many cases when a direct-connected steam engine may be used to advantage. In this event the exhaust from the engine can be con- 291 American Society of Heating and Ventilating Engineers Guide, 1934 nected to one or more sections of the heater, depending upon the con densation rate of the engine. The recirculation duct connected with the opening in the suction duct should be extended to a point as near the floor as possible. When ventilation is not a requirement or is considered relatively unim portant, as in shop and factory heating, and the number of persons vitiat ing the air is small compared with the cubical contents of the building, or the process does not generate obnoxious gas or vapors, the air may be recirculated, sufficient outside air for ventilation being supplied by infiltra- Steam Control Valve || __ Control Valve Rotting Shutter- Outside Air Louvres r Outside Wall * Fig. 1. By-pass Damper Arrangement of a Central Fan Heating System. (Draw-Through) Canvas Connection Heater Fig. 2. Arrangement for Heating Unit and By-pass. (Blow-Through) tion. The amount of heat to be supplied the heating unit in this case is the same as would be required for a direct radiation installation. When ventilation is a requirement to be met, an arrangement similar to that shown by Fig. 1 may be employed. Since the amount of air necessary for heating is generally in excess of the amount required for ventilation, considerable fuel economy may be effected by recirculating a portion of the air. In this case only sufficient outside air is drawn into the system to meet the ventilation requirement and the remainder of the air, required for heating, is recirculated. This may be readily effected by an arrange ment of dpcts and dampers on the suction side of the fan as previously mentioned. If the outside air introduced is to be washed or conditioned the washer or humidifier and tempering coil may be added between thfr inlet for the recirculated air and the fresh air intake. 292 Chapter 22--Central Fan Heating Systems Blow-Through, Draw-Through When the heating unit is located on the suction side of the fan, the system is known as draw-through. (See Fig. 1). When the heating unit, is located in the discharge from the fan the system is known as blowthrough. (See Fig. 2). The draw-through combination is used for factory and toilet room installations because a more compact arrangement of the apparatus usually is possible. In addition, air leakage will be inward. The blow-through combination is used principally in schools and public buildings, and for all booster coil arrangements where different tempera tures and independent temperature regulation are required for different heated spaces. In public building installations, the fan frequently blows the heated air into a plenum chamber from which the air ducts radiate to the various rooms of the building; this arrangement is sometimes called the plenum system. HEATING UNITS The heating units for central fan systems using steam as the heating medium may be classified as (1) tempering coils, (2) preheater coils, (3) reheater coils, (4) booster coils, and (5) water heaters, either open or closed. Tempering coils are used with ventilating and air conditioning systems for raising the temperature of the outside cold air to above freez ing, or 32 F. They are not required for heating systems where all of the air is recirculated, since the temperature of the recirculated air will be above freezing. Preheater coils are used with air conditioning systems to raise the temperature of the air from that leaving the tempering coils to such a temperature that in passing through the water sprays of the washer (without water heater) the air will become partially saturated (adia- batically) having a moisture content corresponding to the required dew point temperature. Preheater coils therefore supply heat as necessary to control the dew-point temperature. The reheater coils are used to raise the temperature of the air leaving the tempering coils (in the case of a heating or ventilating system) or the air leaving the washer (in the case of an air conditioning system) to that necessary to maintain the desired tempera ture in the rooms or spaces to be heated or conditioned, except where booster coils are used in which case the reheater coils raise the air tem perature to approximately room temperature, or slightly higher. Booster coils are installed in the duct branches to control the temperature of the air entering the rooms.or spaces for which it is intended. Water heaters are used on an air conditioning system to control the dew-point temperature. They are used mainly for industrial work, seldom for comfort conditioning. They are not used where preheater coils are employed. The open type supplies steam directly to the spray water, while the closed type utilizes a heat interchanger by which the steam ihiparts its heat to the spray water. Where water heaters are required for comfort conditioning, the closed type is used. ^- The heating units for central fan systems in use at the present time con sist either of pipe coils, finned tubes of steel, copper, brass or other metal, cast-iron sections with extended surfaces, or the cellular type. Steam is passed through these heating units and the air to be heated is passed over their exterior surfaces. . : - 293 American Society of Heating and Ventilating Engineers Guide, 1934 In selecting a heating unit for any particular service, the choice should be based on the desired requirements as follows: 1. Final temperature desired. 2. Loss in pressure (or friction) of air passing over the heating unit. 3. Air velocity over the heating unit. 4. Free area or face area of heating unit. . 5. Ratio of heating surface to net free (or face) area. 6. Air volume required. 7. Rows deep of pipe, tubes or sections. 8. Amount of heating surface. 9. Steam pressure drop through the heating unit. 10. Weight of heating unit. Final Temperature Desired. The choice of a heating unit is largely influenced by the final temperature desired, when the entering air tem perature and steam pressure available at the heating unit are specified. These data are obtainable from manufacturers' catalogs. Loss in Air Pressure (or Friction). The allowable friction through the heating unit is one of the first factors to be determined in the selection of the apparatus. The velocities of air through various types of heating units will not necessarily be the same, but for any particular job the velocity through the heating unit should be a secondary consideration and the allowable friction or air pressure loss should be fixed approximately ' before proceeding with the selection of the heating unit. The loss in air pressure (or friction) through the heating unit should not exceed a pre determined maximum allowable amount for economical operation and for moderate size and first cost of installation. In public building work, the maximum allowable friction through both tempering coil and reheater coils should never exceed ^ in. of water and it is advisable that the friction be kept considerably lower than this figure if possible. A tempering coil friction ranging from 0.10 to 0.20 in. of water is considered satisfactory. The air pressure loss for reheaters ordinarily ranges from 0.20 to 0.40 in. of water. In factory work, the maximum friction through the heater should never exceed 0.8 in. or 1 in. of water and it is advisable to figure the heaters at lower frictions if possible. Velocity through Heating Unit. This velocity has generally been given in manufacturers' tables as being measured at 70 F and in most cases refers to the velocity through the net free area of the heating unit, or through the net space between the pipes, tubes or sections. Although most manufacturers give suitable velocities measured at 70 F, certain manufacturers show velocities measured at 65 F and others indicate velocities measured at the average air temperature through the heating unit. Many new heating units, however, specify net face areas with cor responding velocities instead of velocities through net free areas. In either case, manufacturers publish the corresponding friction or air- pressure loss in tables. The velocity through the net free area of the heating unit averages about 1000 fpm and that through the net face area about 500 fpm. .. The volume of air to be heated in any particular case is determined after . consideration of the ventilation requirements, heat losses, and quantity of ' air required for proper circulation, as explained in Chapters 2 and 7. 294 Chapter 22--Central Fan Heating Systems The number of rows of pipe tubes or sections or the amount of heating surface to be used may be selected from manufacturers' catalogs after the quantity of air handled and heat load are known. Savings in operating expense or cost of installation should result from a proper selection of heater and by-pass areas. For example, instead of having the entire air quantity go through a one-row heating unit, it may be advantageous to use a two-row heating unit and a properly sized by-pass. Thus, when no heating is being done, a suitable by-pass damper may be opened to place a lighter load on the fan. The steam pressure drop through the heating unit is also tabulated in manufacturers' data tables. The sizing of steam supply and return piping, allowing for drops through heating units, is explained in Chapter 32. Weight of Heating Unit. In the design of a heating system, the weight limitations of heating units are determined by the location of the units. Obviously, if there is no loading limitation imposed, any type of heating unit may be selected. On the other hand if the heating unit is to be hung from the ceiling, it may be desirable to use the lightest unit which will accomplish the work required.' DESIGNING THE SYSTEM The general procedure for the design of central fan systems is as follows : 1. Calculate the heat loss for each room or space to be heated. 2. Determine volume of outside air to be introduced. 3. Assume or calculate temperature of air leaving registers or supply outlets. 4. Calculate weight of air to be circulated. 5. Estimate temperature loss in duct system. 6; Calculate heat to be supplied the heating, units and washer. . 7. Select heating units and washer from manufacturers' data and performance curves. 8. Calculate total heat to be supplied. 9. Calculate grate area and select boiler. 10. Design duct system. , 11. Calculate total static pressure of system. 12. Select fan, motor,'and drive. The heat losses (H) should, be calculated in accordance with the pro cedure outlined in Chapter 7. If a positive pressure is maintained by the central fan system in the room or space to be ventilated or conditioned, there will ordinarily be very little infiltration of cold outside air through the cracks and crevices of the space. Consequently, the volume of air introduced into the space at the assumed or calculated outlet temperature need only be sufficient to provide for the transmission losses, plus a part of the infiltration losses, about one-third. The exfiltration of heated or con ditioned air through the cracks and crevices of the space should be pro vided for by making the usual allowance for the infiltration losses in arriving at the total heat loss of the space. The air required to make up for this exfiltration of heated or conditioned air will be brought in at the outside air intake and may be included as a part of the outside air hecessary forthe ventilating requirements. The heat required to raise this air to the 295 '. ; tiXSBBSP' 'rT American Society of Heating and Ventilating Engineers Guide, 1934 conditions maintained in the room must be provided by the tempering coils, preheater coils and reheater coils. If a positive pressure is not main tained in the room or space to be conditioned, the normal infiltration of outside cold air will take place in this room, and the outlet temperature, together with the required air volume at this temperature, must be suf ficient to provide for both the infiltration and transmission losses. Volume of Outside Air . The volume of outside air required for ventilation or air conditioning purposes may be determined from data in Chapter 2. In no case shall less than 10 cfm per person be introduced. The heat required to warm the outside air introduced for ventilation purposes (H0) may be determined by means of the following formula: where H0 = 0.24 (l - to) M0 . (1) 0.24 = specific heat of air at constant pressure. t = room temperature, degrees Fahrenheit. to -- outside temperature, degrees Fahrenheit. M0 = weight of outside air to be introduced per hour in pounds = doQo- Qo = volume of outside air to be introduced, cubic feet per hour. do = density of air at to, pounds per cubic foot. I Example 1. A building in which the temperature to be maintained is 70 F requires 10,000 cfm. If the outside temperature is 20 F, how much heat will be required to warm the air introduced for ventilation purposes to the room temperature? Solution. Qo = 10,000 X 60 = 600,000 cfh; dQ = 0.08276 (Table 1, Chapter 41); Mo = 0.08276 X 600,000 = 49,656 lb; t = 70 F; ta = 20 F; Ha = 0.24 X (70 - 20) X 49,656 = 595,872 Btu per hour. . Temperature of Air Leaving Registers If the system is to function only as a heating^ystem, that is, entirely as a recirculating one, the temperature of the air leaving the register outlets must be assumed. For public buildings, these temperatures may range from 100 to 120 F, whereas for factories and industrial buildings the out let or register temperature may be as high as 140 F. In no case should the . outlet temperature exceed these values. For ventilating or conditioning systems, the temperature of the air leaving the supply outlets may be estimated by means of the following formula: . _ 55.2H h-------n----- r * (2) where ty = outlet temperature, degrees Fahrenheit. H. = heat loss of room or space to be conditioned, Btu per hour! Q = total volume of air to be introduced at the temperature, t, cubic feet per hour. . If the outlet temperature (ty) as determined from Equation 2 exceeds 120 F for public buildings, or 140 F for factories or industrial buildings, this temperature should be assumed using the maximum permissible' 296 Chapter 22--Central Fan Heating Systems temperature and the volume of air to be introduced into the room or space determined by means of the following equation: 55.2H Q = (ty - t) (3) Example S. The heat loss of a certain auditorium to be conditioned is 100,000 Btu per hour. The ventilating requirements are 90,000 cu ft per hour and the room temperature 70 F. Determine the outlet temperature. , Solution. Substituting in Formula 2, = 55.2 X 100,000 ^ 90,000 7Q = 131 3 F Inasmuch as this temperature is excessive, it will be necessary to assume the outlet temperature, which will be taken as 120 F, and to calculate the amount of air to be introduced into the room at this temperature to provide for the heat loss. Substituting in Equation 3, Q = 551^- = 110.400 cfh (at temperature t) Weight of Air to be Circulated The total weight of air to be introduced into the room or space to be heated or conditioned (M) is given by the following formulae: M 0.24(Iy -- t) dQ (4) M = Mo + Mr '(5) (6) 0^ II f9- where 'd -- density of air at temperature t, pounds per cubic foot. do = density of air at temperature to, pounds per cubic foot. Q0 = volume of outside air at temperature to. Mo = weight of outside air, pounds. Mr = weight of recirculated air, pounds. Example 3. Using the data of Example 2 and an outside temperature of 20 F, what will be the values of M, Ma and Mil Solution, d = 0.07495, do = 0.08276, Q = 110,400, Qa = 90,000, H = 100,000. 100,000 M = 8,333 lb. 0.24 X (120 - 70) Mo = 0.08276 X 90,000 = 7,448 lb Mr = M - M0 = 8,333 - 7,448 = 885 lb Temperature Loss in Ducts The allowances to be made for loss in transit through the duct system (Q are as follows: 1. When the duct system is located in the enclosure to which the air is being delivered, as in a factory, it may be assumed that there is no loss between the reheater coil and the point or points of discharge into the enclosure. 297. American Society of Heating and Ventilating Engineers Guide, 1934 2. For ducts in outside walls or attics, or other exposed places, allow 0.25 deg per linear foot of uninsulated duct. ', 3. For ducts run underground an allowance shall be made based on the estimated heat loss of the duct, assuming an average temperature of the ground of 55 F. Heat Supplied Heating Units and Washer ' The following cases may arise in practice: A. The heating of the building is done entirely by means of a central fan system, all of the air being drawn from the outside. B. Similar to (A), except that all of the air is recirculated. C. A portion of the air is recirculated, and the remainder is drawn in from the outside. D. Air at the same temperature to be delivered to all the rooms. A constant relative humidity is maintained in the building and all of the air circulated is drawn from outside the building. (Not applicable to the heating of various rooms where individual control of each room is desired). E. A system using outside air, return air, and by-pass air, reheater being located in by-pass air chamber. F. Arrangement of apparatus where individual control of the temperature for each room is required in conjunction with air washer equipment to maintain a constant relative humidity in the rooms. The air washer is provided with a water heater for the spray water, capable of fully saturating the air. A section of preheater may be used for this purpose in place of the water heater. With this arrangement and with a uniform temperature of air entering the rooms, it is impossible to maintain the same room tem perature throughout the building because the weight of air to be delivered to each room is determined and fixed by the ventilating requirements. In analyzing these cases, the following symbols will be used: H -- heat loss of the room or building, Btu per hour. Hi -- beat to be supplied to the reheater coil, Btu per hour. Ht = heat supplied tempering coil, or tempering coil and preheater, Btu per hour. Ht = heat supplied air washer by water heater, Btu per hour. H, = heat to be supplied booster coil, Btu per hour. M = weight of air to be introduced into the room or building, pounds per hour. Mr = weight of recirculated air, pounds per hour. Mb = weight of air by-passing washer, pounds per hour. M0 = weight of air drawn in from outside, pounds per hour. to = mean temperature of outside air, degrees Fahrenheit. t = mean air temperature to be maintained in the room or building, degrees Fahrenheit. h = mean temperature of the air entering the reheater coil. . ti = mean temperature of the air leaving the reheater coil. tz = temperature loss in the duct system. ty = temperature of the air leaving the duct outlets. tx -- average temperature of air entering tempering coil. . tw -- temperature of air.entering washer. 0.24 = specific heat of air at constant pressure. 298 Chapter 22--Central Fan Heating Systems Fig. 3. Heating Unit and Fan Arranged for Outside Air Circulation. (Case A) Case A. (Fig. 3). All of the air circulated to be drawn from outside the building, in which case tx -- to H, = 0.24 (t, - to) M0 (7) Hi = 0.24 (^ - ti) Mo (8) Example 4- The heat loss H [or a certain factory building is 700,000 Btu per hour. The mean inside temperature t to be maintained is 65 F. The assumed outside air tem- fierature to is 0 deg; fe = 0, Jy = l and is assumed to be 140 F. The temperature eaving the tempering coil is assumed to be 35 F. Required, Hi and Hi. From Equation 4, M = 0^/(U0^~65) = 881889 lb Per h0ur Hi = 0.24 X (35 - 0) X 38,889 = 326,667 Btu per hour. Hi = 0.24 X (140 - 35) X 38,889 = 980,003 Btu per hour. H, + Hi = 326,667 + 980,003 = 1,306,670 Btu per hour. ELEVATION Fig. 4. Arrangement for Recirculation. (Case B) Case B. (Fig. 4) All of the air is to be recirculated, in which case = t. Mr = 38,889 lb Mi = 0.24 (tt - U) Mr Hi = 0.24 (140 - 65) X 38,889 = 700,000 Btu per hour. - This example illustrates the saving in fuel consumption by theTecirculation of the air. The heat to be supplied the apparatus is the same as that required for a direct system of heating and is equal to the heat loss of the building {Hi. = H), in the example 700,000 Btu per hour as compared with 1,306,670 for Case A. 299 yf#r American Society of Heating and Ventilating Engineers Guide, 1934 Chapter 22--Central Fan Heating Systems Fig. 5. Combination of Recirculated Air and Outside Air. (Case C) Case C. (Fig. 5) A portion of the air circulated is recirculated air and the remainder, as may be required for ventilating purposes, is drawn in from the outside. According to Equations 4 and 5, M = M0 -f Mr H 0.24 (ly - i) The temperature of the resulting mixture of outside and recirculated air entering the tempering coil is: Mato "F Mxt lx = M (9) Example S. Assuming that a positive supply of outside air (d0 = 0.0864) is required for ventilation at the rate of 90,000 cu ft per hour in the preceding example, then Ma = 0.0864 X 90,000 = 7776 lb per hour are required, measured at 65 F. Mr = M - M0 = 38,889 - 7776 = 31,113 lb. 7776 X 0 + 31,113 X 65 38,889 " 52 F Hi ~ 38,889 X 0.24 (140 - 52) = 821,336 Btu. This amount of work may be accomplished with one or more banks of heating units, that is, either a single reheater or a tempering coil and reheater. The three preceding cases refer to installations in which conditioning the air to maintain certain relative humidity requirements does not enter into the problem, as for example, certain types of industrial installations. In practically all modern public buildings, theaters, schools, and in many industrial installations the ventilating requirements include the provision for air washing and humidifying the air delivered to the various rooms of the structure. In the following cases it is assumed that in addition to maintaining a mean room' temperature f, the heating and ventilating apparatus is required to maintain a constant relative humidity in the rooms. 300 Case D. (Fig. 6) The maximum relative humidity that may be maintained within the building without the precipitation of moisture on single glazed sash when the outside temperature is 30 F is approximately 35 per cent. If the inside temperature t is 70 F, 35 per cent relative humidity corresponds to a dew-point temperature of 41 F. (See psychrometric chart, Chapter 1). The installation shown in Fig. 6 contemplates the use of a tempering coil, air washer provided with a water heater, and a reheater. The tempering coil, one section in depth, warms the incoming air to approximately 35 F to prevent freezing any of the spray, water. The air passing through the spray chamber is saturated and leaves at a tempera ture of t\ -- 41F. '` The heat to be supplied the reheater is: Hi = 0.24 (It -- 41)M Btu per hour. The heat to be supplied the tempering coil is: Hi = 0.24 (35 -- fo)M Btu per hour. The amount of heat, per pound of air circulated, to be supplied the humidifying washer or humidifier is the difference between the beat content of the assumed dry air entering the washer at a temperature of => 35 F and the leaving saturated air at h = 41 F (Chapter 1): 15.7 -- 8.4 = 7.3 Btu per pound of dry air. The amount of heat required for the washer is: H, = 7.3 M Btu per hour. The total amount of heat required by the apparatus is therefore; J, Ht + Ht -f- Hi Btu per hour. If a washer having a humidifying efficiency of 67 percent without water heater is em ployed it will be necessary to heat the outside air drawn into the apparatus by means of the tempering and preheater coils to such a temperature that the air in passing through 301 American Society of Heating and Ventilating Engineers Guide, 1934 the water sprays will become partially saturated (adiabatically) having a moisture con tent per pound of air equal to saturated air at 41 F. If the incoming air is warmed to tw = 88 F (requiring a two-section-depth heating unit) it will be cooled in the washer to 64 F or 88 -- 64 =24 deg. If the humidifying efficiency of the washer were 100 per cent, the air would become adiabatically saturated at 52 F or a temperature drop of 88 -- 52 = 30 F. The efficiency of the washer is, however, only 67 per cent, so that the actual temperature drop will be 0.67 X 36 deg or 24 deg, as used. - The heat to be supplied the reheater is in this case Hi = 0.24 (<j -- 64)M Btu per hour, ' and for the tempering coil and preheater is Hj = 0.24 (88 -- t0)M. The total heat required by the apparatus is Hi + Hi, no heat being supplied to the washer. Fig. 7. Outside Air Circulated; Constant Temperature and Relative Humidity Maintained in Each Room. (Case E). Case E. (Fig. 7). The temperature ty will ordinarily be different for each room With H and M fixed, 0.24 (ly - f)M = H, or ' ty = 0.24 M + ` In order to'provide the proper temperature for each room, a booster coil is generally installed in each supply duct near the outlet to control the out let temperature ty. The amount of steam supplied to these booster,units is usually controlled automatically by individual thermostats. The heat required by the booster coils depends on the temperature range through which the air is heated and the quantity of air, or H< = 0.24 (ty - l, - tz)M (10) Total Heat to be Supplied - The total heat.to be supplied (Hy) is equal to the sum of the heat requirements of the various heating units and the water heater of the washer, if any, plus the allowance for piping tax, etc. (See preceding Cases A to E. ' 302 Chapter 22--Central Fan Heating Systems Grate Area, Boiler Selection The required grate area may be determined by the following formula; G = EXE X C (U) where G = required grate area, square feet. F = calorific value of fuel, Btu per pound. C = combustion rate, pounds per square foot of grate per hour. E = boiler and grate efficiency, per cent. Example 6. Using the data in Example 4, and assuming coal having a calorific value of 12,000 Btu per pound, a combustion rate of 7 lb per square foot, and a performance efficiency of 0.60, and neglecting piping tax, etc., r 1,306,670 _ ,,,, ' C = 12,000 X 0.60 X 7 26 sq n Weight of Condensate The normal weight of condensate to be handled from central fan sys tems may be estimated by means of the following formula: where W 60 X <2 X At w = 55.2 X fcfg (12) W = weight of condensate, pounds per hour. Q = total volume of air, cubic feet per minute. At = temperature rise of air, degrees Fahrenheit. hfg = latent heat of steam in the system, Btu per pound. Ducts and Outlets, Air Filters, Air Washers The design of the duct system should be based on data contained in Chapter 19. Air washers.and humidifiers are described in Chapter 11. For information on air filters, see Chapter 16. 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. Fpr a simple system, the following static pressure drops may be assumed: 1. Outside air inlet, comprised of screen, louver and short duct, may have a loss of 0.2 in. of water. 2. A typical oil filter at rated capacity and velocity has a drop of 0.25 in. of water. 3. The loss of one row of a standard make tempering stack equals 0.09 in. water. 4. The loss of one row of a standard make preheater equals 0.10 in. water. 5. A standard humidifier at rated velocity may have a loss of about 0.35 in. water. ' 6. The loss through one row of a standard make reheater equals 0.12 in. water. 7. A fair assumption for duct losses on a simple system is 0.25 in. water. 8. The static pressure for a nozzle type outlet may be taken as 0.1 in. water. 303 i -/yjppPpf'-' ' - > American Society of Heating and Ventilating Engineers Guide, 1934 The sum of these values equals 0.2 -+- 0.25 + 0.09 + 0.10 + 0.35 + 0.12 -f 0.25 + 0.1 = 1.46 in. which is the static pressure against which the system must operate. Fans and Control The selection of fans and motors may be based on data contained in Chapter 17. Because centrifugal fans reach their maximum efficiency when working against the resistance offered by the average central fan heating system, they are well adapted to such systems and are generally used. Information on temperature control for central fan systems is given in Chapter 14: 304 Chapter 23 MECHANICAL WARM AIR AND FAN FURNACE SYSTEMS Fan Furnaces, Fans and Motors, Elimination ofNoise, Air Washers and Filters, Cooling Methods, Duct Design, Controls, Selecting the Furnace, Selecting the Fan, Provision for Cooling System, Heavy Duty Fan Furnaces MECHANICAL warm air or fan furnace heating systems, 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 24, The advantages of mechanical systems, as compared with gravity systems, are as follows: : 1. Furnace can be installed in a corner of the basement, leaving more basement room available for other purposes. 2. Basement distribution piping can be made smaller and can be so installed as to give full head room in all parts of the average basement, or be completely concealed from view except in the furnace room. "' 3. Circulation of air is positive, and in a properly designed system can be balanced in Such a way as to give a greater uniformity of temperature distribution. 4. Humidity control is more readily attained. 5. The air may be cleaned by air washers or filters, or both. 6. Some cooling effect in summer will result from the installation of a properly designed system. , 7. The fan and duct equipment may be utilized for a complete cooling and dehumidi- fying system for summer, using either ice, mechanical refrigeration, or low temperature water for cooling and dehumidifying, or adsorbers for dehumidifying. 8.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. FAN FURNACES Furnaces for mechanical warm air systems-may be made of cast-iron, steel, or alloy. Cast-iron furnaces are usually majie in sections and must be assembled and cemented or bolted together on the job. Steel furnaces 305 American Society of Heating and Ventilating Engineers Guide, 1934 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 Hue travel. h. Anthracite or coke--Large fire box capacity and liberal secondary heating surfaces. ' 2. Oil Burning: . Liberal combustion space. . Long fire travel and extensive heating surface. . 3. Gas Burning: a. Extensive heating surface. b. Close contact between flame and heating surface. ' A combustion rate of from 5 to 8 lb of coal per square foot of grate per hour is recommended for residential heaters. A higher combustion rate is Chapter 23--Mechanical Warm Air and Fan Furnace Systems but they may also be constructed of brick. Galvanized-iron casings should be lined with black-iron liners, extending from the grate level to the top of the furnace and spaced from 1 in. to V/% in. from the outer casing. It is generally believed that either brick or sheet metal casings should be equipped with baffles to secure impingement of the air to be heated against the heating surfaces. Brick furnace casings should be sup plied with access doors for inspection. Most furnace casings are sized for gravity flow of air, and where a fan is to be used, many manufacturers recommend the use of special baffles to restrict the free area within the casing and to force impingement of the air against the heating surfaces. The method of making these baffles for furnaces with top horse-shoe radiators and for furnaces with back crescent radiators is illustrated in Fig. 1. Either square or round casings may be used. Where square casings are ' 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. Fig. 1. Usual Method of Baffling Round Casings for Fan Furnace Work A. Liner, 1 in. from casing. B. Hole to vent baffle. C. Baffle, closed top and bottom. D. Outer casing. 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, especially where sectional furnaces are used, 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. . Casings are usually constructed of galvanized iron, 26-gage or heavier, 306 I Fig. 2. Method of Baffling Square Furnace Casing for Fan Furnace Work At. Baffle, closed top and bottom. B. Liner, I in. from /casing. C. Outer casing. D. Hole to vent baffle. ` 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 bf a higher bonnet and thus provides a larger plenum chamber. Fig. 3 illustrates a complete fan-furnace installation showing location of fan, furnace, filters, plenum chamber and method of take-off of warm air pipe. ' FANS AND MOTORS Centrifugal type fans are most commonly used, and these may be . equipped with either backward or forward curved blades. Low tip speed is desirable for the elimination of air noise,'especially where forward curved blades are'used. Motors may be mounted on the fan shaft or outside of the fan with belt connection. Multi-speed motors or pulleys 307 v} American Society of Heating and Ventilating Engineers Guide, 1934 are desirable to provide a factor of safety and to allow for more rapid circulation for summer cooling. For additional information on fans and motors, see Chapter 17. ELIMINATION OF NOISE Special attention must be given to the problem of noise elimination. The fan housing must 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 ------ ------^ 1------} Fig. 3. Complete Fan Furnace Installation Showing Location of Fan, Furnace, Filters, Plenum Chamber and Method of Take-off of Warm Air Pipe A. Transition rf-i"tti'n--g. B. Filters. _ C. Capped open/ng. V. Canvas connection. E. Pulley*--3 diara. V-type- F. Eliminator. . C. Solenoid valve, r * Pressure gage. J- Water supply. A. Drain. must be carefully chosen for quiet operation. Electrical conduit and water piping must pot 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 18. AIR WASHERS AND FILTERS Washers may be provided in separate housings to be installed on the inlet or outlet side of the fan, or they may be integral with the fan con struction. They operate at water pressures of from 10 to 30 lb and use two or more spray nozzles for washing and humidification. The sprays. should be adjusted to completely cover the air passages, . Washers are usually controlled by solenoid valvesswired in parallel with ' '' - . 308 . ...wife' Chapter 23--Mechanical Warm Air and Fan Furnace Systems 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. Further information on washers will be found in Chapter 11. There are many satisfactory types of filters on the market. These include dry filters, viscous filters, oil filters and other types, some of which must be cleaned, some of which must be cleaned and recharged with oil, and some of which are inexpensive and may be discarded when they become dirty, and replaced with new ones. The resistance of a filter must be considered in the design of the system since the resistance rises rapidly as the filter becomes dirty, thus im pairing the heating efficiency of the furnace, in fact, endangering the life of the furnace itself. Manufacturers' ratings of filters must be carefully regarded, and ample filter area must be provided. Filters must be replaced or cleaned when dirty. See also Chapter 16. COOLING METHODS Some cooling 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 provided. Unless the 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 finnedtubing 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 9 and 10. Study of these problems sponsored by the American Society of Heating and Ventilating Engineers in cooperation with the National Warm Air Heating Association is in progress at the University of Illinois. The following conclusions may be drawn from the studies thus far com pleted, subject to the limitations of the conditions under which the tests were run1: 1. An uninsulated building of ordinary residential type may require the equivalent of three tons of ice in 24 hours 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 lSee A.S.H.V.E. research'paper entitled, 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. Journal Section Heating, Piping and Air Conditioning, February, 1933). . ' 309 American Society of Heating and Ventilating Engineers Guide, X934 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 com putation, 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 results of the tests suggest the use of a fan at night either to provide more comfortable conditions during the following day without provision for cooling, or to reduce the load required for cooling during the following day. DUCT DESIGN The ducts may be either round or rectangular. Rectangular ducts should be as nearly square as possible; the width should not be greater than four times the breadth. The radii of elbows should be not less than Chapter 23--Mechanical. Warm Air and Fan Furnace Systems 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 19. 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. 4).' Splitter dampers are used where a branch is taken off from a main trunk. (See C, Fig. 4). Squeeze dampers are used for adjusting the volume of air flow and resistance through a given duct. (See D, Fig. 4). 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. Supply and Return Air Registers ' Supply registers may be located either in the floor, in a side wall at the baseboard, in a side wall at some point higher than the baseboard, or in the ceiling. Velocities through registers may be reduced by the use of registers C 5pLittc.is. V 5gucstc Fig. 4. Three Types of Dampers Commonly Used for Trunk and Individual Duct Systems one and one-half times the pipe diameter for round pipes, or the equiva lent round pipe size in the case of rectangular ducts. The ducts or piping may be designed either as a trunk line system or as a system of individual ducts from the furnace to each register. The engi neering problems incident to the design of a trunk line system are some what more difficult than for the individual duct system. The trunk line system is generally a tailor-made job, whereas the individual duct system with which either round or square ducts may be used may frequently be assembled from stock materials and thus installed at a considerable saving. Individual ducts may frequently be grouped to simulate a trunk duct system in appearance. The design of ducts for air flow is described in Chapter 19. ' 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 310 Fig. 5. Diffusers in Transition Fittings to Equalize Velocities Through Register Faces larger than the connecting pipes. Some suggestions for equalizing veloci ties over the face area of the register by means of diffusers are illustrated in Fig. 5. Merely to use a larger register may not result in materially reduced velocities unless such diffusers are used. Care should be exercised in making the connection between the supply register and its box to prevent streaking of the wall. All warm air registers should be equipped with dampers, or better, with diffuser dampers, which may be used to direct air currents in such a way that they will not be objectionable. (See Chapter 20). . CONTROLS Air stratification, high bonnet temperatures, excessive flue gas tem peratures, and heat overrun or lag in the system can be largely^eliminated through proper care in the planning and installation of the control system. The essential requirements of the control are: 1. To keep the fife burning regardless of the weather. 2. To avoid excessive bonnet temperatures with resultant radiant heat losses into the basement. 311 i American Society of Heating and Ventilating Engineers Guide, 1934 3. To avoid the overheating of certain rooms through gravity action during off periods. 4. To have a sufficient supply of heat available at all times to avoid lag when the room thermostat calls for heat. ' 5. To avoid heat loss through the chimney by keeping stack temperatures low. 6. To provide quick response to the thermostat, with protection against overrun. 7. To provide for humidity control. 8. To provide a means of summer control of cooling. 9. 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 would be near an outside wall, in a sun room, or in a room with some unusual exposure. The thermostat, of course, should not be located where it will be affected by direct radiant heat from the sun or from a fireplace, or by direct heat from any warm air duct or register. 2. A furnacesiat to open and close the drafts according to bonnet temperature. The operating range of a furnacestat is approximately between 125 and 175 F, depending to a large extent upon outside weather conditions. In operation it may be necessary to adjust the setting for particular installations and readjust it for extremes of weather. The furnacestat should be installed either in the bonnet or in a main duct just outside the bonnet. , 3. A stack limit control to shut down the system independently of the thermostat if the stack temperature exceeds 1000 F and thus prevent overheating of the furnace, and fuel waste. . 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 humidistal to regulate the moisture supplied to the rooms. 6. A device to open drafts, regardless of thermostat settings, whenever the bonnet temperature indicates that the fire is dying. SELECTING THE FURNACE 1 The following formula may be used to compute the grate area of the furnace, assuming a ratio of heating surface to grate area of 20 to 1: where r= H FX CXE - G = required grate area, square feet. H = total heat loss from building, Btu per hour. . F = calorific value of coal, Btu per pound. C -- combustion rate in pounds of fuel per square foot of grate per hour. E = furnace efficiency based on heat available at register faces. nv V; In practice it is customary to use the following constants: F = 13,000 (For specific values, see Fig. 1, Chapter 27). C -- 5 to 10 lb (Use 8 lb as maximum in residence work). = 55 per cent to 65 per cent depending on fuel burned. be used with highly volatile solid fuel. Lower efficiency must Where ratio of heating surface to grate area is less or greater than 20 to 1, deduct or add 2 per cent from or to rating of furnace for each unit. decrease or increase in ratio, as the case may be. The foregoing procedure 312 Chapter 23--Mechanical Warm Air and Fan Furnace Systems Hga HrW* c<a at o< w o S3 ^ < t/i 2 | <gogsg* app g|Q[d _ oo <oi O O O aW H< te atd! HWoS Pi fr Sz, es. wH wC6 WD S < 0i (OjWw Oai Xh oi W < Sg a*i.<n wg < *Q J Sgg xW Ip55 CO pi 313 N/ 'C 0- M ,SH d2Q< S< oi b %l gS o< *q** OWbSoh 2h g3 Sg sS3 .< Oc/i fcW S^g3 k-2|(5 C> Q American Society of Heating ond Ventilating Engineers Guide, 1934 for determining the size of furnace to be used applies to continuously heated buildings. For intermittently heated buildings, it is advisable to increase the size by an amount ranging from 75 per cent to 200 per cent depending on the heat capacity of the construction materials, the higher percentage applying to materials of high heat capacity, such as concrete and brick. .. Follow the same methods for an oil furnace as for coal where a con version unit is to be used, making sure that the ratio of heating surface to grate area exceeds 20 to 1. If it does not, a size larger furnace should be selected. Use the manufacturers' Btu rating of furnaces designed for exclusive use with oil, and select a burner with liberal excess capacity. Gas furnaces approved by the American Gas Association, which'grants a Certificate of Approval to manufacturers, must carry the rated Btu per hour and official output in addition to an approval seal. Manu facturers' catalogs are also required to carry the output data. . The selection of the proper size gas furnace for a given installation can be easily made by using the following A.G.A. formula: where H = total heat loss from building in Btu per hour. R = official A .G.A. output rating of the furnace in Btu per hour. In the case of converted warm air furnaces a slightly different procedure is necessary, as the Btu input to the conversion burner must be selected rather than the furnace output. The proper sizing may be done by means of the following formula: where I = 1.5617 . , (3) .' I = Btu per hour input. The factor 1.56 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 con version burner. - SELECTING THE FAN Choose a fan which, according to its manufacturer's rating, is capable of delivering a volume of air, expressed in cubic feet per minute, against, a frictional resistance, expressed in. inches of water, computed by adding together the following items: 1. The frictional resistance of a warm air trunk or leader. 2. The frictional resistance of a return air trunk or duct. 3. The resistance to the flow of total volume of air through the furnace casing or hood, which is usually considered from 0.10 to 0.15 inches of water. 4. The frictional resistance through any other accessories, such as washers or filters. 5. A factor of safety of 10 per cent of the resistance calculated above. 314 Chapter 23-Mechanical Warm Air and Fan Furnace Systems .,, F ig 1 2 H e a t e r A r r a n g e d f o r O u t s id e A i rI w it h W a r m A ir C o n n e c tio n to F a n n l e t F ig 13. H e a t e r A r r a n g e d f o r R e c ir c u l a t io n w it h T r u n k ' l in e D is t r ib u t in g System Sh o w in g T e m p e r a tu r e C o ntro l b y A ir V o lu m e a t O u t le t , or D ir e c t o n H e a te r . to T emp W arm er A A ir ir , A and lTs oM emp ix in g ered Da A ir mpe Ch r a s m f b r e o r m 1 American Society of Heating and Ventilating Engineers Guide, 1934 PROVISION FOR COOLING SYSTEM If the system is to be used for cooling, the following provisions should be made: 1. Where cooling is to be secured through air circulation only: a. Provide for an increase of 25 to 50 per cent in fan capacity through multi-speed pulleys or other means. b. If basement air or outside night air is to be used, provide suitable basement opening in duct system, or outdoor air intake. 2. Where water below 55 F or artificial refrigeration or ice is to be used: a. Provide outside air duct for circulation of cool night air for economy. b. Make provision in return duct system for cooling unit. ' c. Make provision for reduction of fan speed. HEAVY DUTY FAN FURNACES , Fan furnaces for large commercial and industrial buildings are available in sizes ranging from 400,000 to 1,800,000 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 13, in clusive. . Control of temperature is secured through (1) controlling the quantity of heated air entering room, (2) using mixing dampers, or (3) regulating 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 22. Ducts are designed by the method outlined in Chapter 19. Chapter 24 GRAVITY WARM AIR SYSTEMS Procedure for Design, Estimating Heating Requirements, Sizes of Leader Pipes, Proportioning Wall Stacks, Register Sizes, Recircu lating Ducts and Grilles, Return Connection to Furnace, 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 23. 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 Galled stacks. The hetked 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. PROCEDURE FOR DESIGN 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. `All figures ana much of the engineering data which follow are from B,Mains Nos. HI. 188_"d 18|- Warm Air Furnaces and Heating Systems, Part II, by Professor A. C. Willard, A. P. Kratz, and V. S. Day, Engineering Experiment Station, University of Illinois* . 317 Chapter 24--Gravity Warm Air Systems 7. Size of furnace necessary to supply the warm air required to overcome the heat [oss from the building. This size should include square inches of leader pipe area which furnace must supply. It is also desirable to call for a minimum bottom fire-pot diameter in inches, which is the nominal grate diameter. 8. Area and dimensions.in inches of chimney and smoke pipe. If an unlined chimney is to be used, that fact should be made .clear. .. The heat loss calculations should be made in accordance with the procedure outlined in Chapter 7, taking into consideration the trans mission losses as well as the infiltration losses. SIZES OF LEADER PIPES 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 Association has approved an air temperature of 175 F at the registers as satisfactory for design purposes. At this tem perature, the heat-carrying capacity (heat available above 70 F) per square inch of leader pipe per hour for first, second or third floors is shown by Fig. 1 at 175 F to be 105, 170 and 208 Btu respectively. For average calculations, the values 111, 166 and 200 will simplify the work and may be satisfactorily substituted for these heat-carrying capacities. If H \represents the total heat to be supplied any room, the resulting equations are' H Leader areas for first floor, sqqare inches = = approximately 0.00977 (1) \ H Leader areas for second floor, square inches = j-gg = approximately 0.00677 (2) Leader areas for third floor, square inches = 2U0 -- approximately 0.00577 (3) In designing for a lower warm-air register temperature, say 160 F, the factors 111, 166 and 200 become 80, 140 and 166 (Fig. 1 at 160 F), and the resulting equations are: H Leader areas for first floor, square inches = = approximately 0.01277 (4) H Leader areas for second floor, square inches = ygj = approximately 0.007/7 (5) H Leader areas for third floor, square inches = jgg = approximately 0.00677 (6) , These equations are applicable to straight leaders from 6 to 8 ft in length. . Longer leaders must be very thoroughly covered or else the ' vertical stacks must be increased in area as discussed under wall stacks. If some provision is not made for these longer leaders, the air tempera ture may be much lower than anticipated and the room will not be properly heated. --. , While Fig. 1 takes care of the drop in temperature in straight leaders up to 8 ft in length connected to stacks having about 75 per cent the 319 American Society of Heating and Ventilating Engineers Guide, 1934 area of the leader, the designer must make allowances for all other conditions. The temperature drop in leaders of various lengths at three different register temperatures is shown in Fig. 2, and should be used to obtain new register temperatures, lower than 175 F, on which to base selections from the curves of Fig. 1, and thereby new constants for Equations 1, 2 and 3. Leader sizes should in general be hot less than obtained by Equations 1 to 3 nor should leaders less than 8 in. in diameter be used. It is not considered good commercial practice to specify diameters except rrrTTTinrrrr With constant heat input- ] p""j [ t.OO --_Jp At_ofCith--settaia--ctekIi--sr, ]I/Oo-f*I62"'I/^0b10o04ot. t34t.of_i_e^ j/.lpe` r ^br\ register^ Z eaderS/^ 8-0" to < of boot --i--<-- I i. I--I--I-- /Ovn ieorder. S/ng/e Wat/ Stacf \Doub/e Ufa//Stacks --1---- 1---- 1----1---- 1---- 1----1 _r__8-//7... /ea-der. -- ( sS/np/e Ufa// Stack i ''//onb/e Wet// StcrcM --i--1--i--i-- o.eo\ Fig. 3. i i i i ~i--i--i--i--1~ ftstacks compared^ w/f/r. jt/re best s/ng/e leaf/ stack- j__ | //? boffy /O-irr. and <S-in. Z eader\ ` Tests. T1 1 I 1"~TT o-e. <Z3 o.4 os as a7 as fatio Stack Area to Z eac/er Area Relative Heating Effect of Stacks at Constant Heat Input to Furnace . Note.--Pipe bate, bright tin except asbestos strips for joints. in whole inches. The tops of 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 are to be avoided or should receive very special attention. PROP_O__R_TwIOnNwINLG3 IWALL STACKS The wall stack for a--n u----p----p---e-- r f-loor s-hould be made not less than 70 per cent of the area of the . leader which has been selected from Fig. 1. So long as 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 ' 320 -' ' L Chapter 24--Gravity Warm Air Systems- occasioned by the smaller stack is not very 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 order to offset the greater temperature losses (Fig. 2) in the longer leader. In gravity circulating systems, this stack to leader area ratio is a very important consideration. Specific data for a great variety of cases are presented in Figs. 4 and 5 and the designer should check the stack to leader com binations with the nearest comparable case as shown in these figures. Any second-floor stack supplying heat to a room whose heat loss is 9,000 Btu or more (see Figs. 4 and 5 which show that high temperatures are necessary if rooms of more than 9,000 Btu requirement are heated by one stack each in 4-in. studding), should be run within 6-in, studded walls or should have multiple stacks. Stack sections, wherever possible, should be changed from the thin rectangular to the more nearly square shape. REGISTER SIZES The registers used for discharging warm air. into the rooms should have free or net area not less than the area of the leader in the same run of piping. The free area should be at least 70 per cent of the gross area of the register. No upper-floor register should be wider horizontally than the wall stack, and it should be placed either in the baseboard or side wall, if this can be done without the use of offsets. First-floor registers may be of the baseboard or floor type, with the former location preferred. RECIRCULATING DUCTS AND CRILLES .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 _ the air stream must change direction or shape, streamline fittings should be employed. Horizontal ducts should pitch at least 3^2 in. per foot upward from the furnace. The recirculating grilles (or registers) should have a free area at least equal to the ducts to which they connect, and their free area should never be`less than 50 per cent of their gross area. ' The location and number of return grilles will depend on the size, details and exposure of the house. Small compactly built houses may frequently be adequately served by a single return effectively placed in a central hall. More often it is desirable to provide two or more returns, provided, however, that in two-story residences one return must be placed to effectively receive the cold air returning by way of the stairs. 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 321 > 7 American Society of Heating and Ventilating Engineers Guide, 1934 oversize and favored in every way. This precaution is particularly important when long ducts and short ducts are used in the same system. - Return ducts from upstairs rooms may be necessary in apartments or other spaces closed off or badly exposed. Metal linings are advisable in such ducts. It is important that these ducts be free from'unnecessary 322 i , American Society of Heating and Ventilating Engineers Guide, 1934 the casing above the level of the grate in the furnace. To accomplish this the shoe must be wide. Tests of six different systems of cold air returns, Fig, 6, made at the University of Illinois4, resulted in the following conclusions: 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. ' a*/- atea-e* S.5& j- ^__ .. Fig. 6. Arrangement of Cold Air Returns for the Six Installations 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 easily obtained by finding the sum of the leader pipe areas as already-designated. The grate area will depend on several factors of which four are very important. First of all, the air temperature at the register for which the plant has been designed must be determined. Usually, this tempera ture is taken as 175 F. Second in importance is the combustion rate, which must always correspond with the register air temperature, as is shown by reference to a set of typical furnace performance curves (Fig. 7) for a cast-iron circular radiator furnace with a 23-in. diameter grate and 50-in. diameter casing. The conditions shown on these curves which seem to v. . 324 a. p. and Chapter 24--Gravity Warm Air Systems . approximate nearest to the 175 F register warm-air temperature are-- combustion rate, 7 lb; warm-air register temperature, 173 F; efficiency of the furnace, 58.5 per cent. The third factor is efficiency, which, in turn, is a function of the combustion rate varying with it as shown by the effi ciency curve of Fig. 7. The fourth factor is the heat value per pound of fuel burned, which was 12,790 Btu, but is not shown on the curves since it was constant for all combustion rates. 0151 Draff in inches'Wafer- . ZZ0D00 aw------ 1 0o5. ~ X 's/e.r --Temperafc/ire- % 160 0007---- X. ?-- a~~Capa cify J-'Zi t i-- ZL h ---- / r> -- / >1 t 0-- <T 0 -- 80000o -- If De t ?e/erZ>7/?_ c asmg D 'fee 50 /n fficfernf/ I *1--. ft to !2 Fig. 7, Typical Performance Curves for a Warm Air Furnace and Installation in a Three-Story Ten Leader Plant, Operating on Recirculated Air From the relation existing between these factors it is found (Fig. 7) that the capacity of the furnace under test is 147,750 Btu per hour for the total grate, which gives the capacity at the furnace bonnet per square foot of grate'as 51,200 Btu and per square inch of grate as 356 Btu per hour. Suppose it is desired to select a furnace to deliver air to the rooms at a register temperature approximating 160 F rather than 175 F. Referring to the curves, the relation is--combustion rate, 5.5 lb; register warm-air temperature, 160 F; and efficiency of the furnace, 62 per cent. Under this condition the capacity of the furnace at the furnace bonnet per square foot of grate area is 43,200 Btu per hour, and per square inch of grate it is 300 Btu per hour. From these performance values, the grate area for any American Society of Heating and Ventilating Engineers Guide, 1934 Chapter 24--Gravity Warm Air Systems plant requirement will be (allowing 20 per cent heat loss between furnace and registers): 1 2 jj Crate area (175 F register temperature), square inches = - = 0.003477* (7) Grate area (160 F), square inches = = 0.004077* (8) It is not always possible to obtain performance curves, and the fol lowing method is suggested as being a close check. An addition of 2 per cent of the furnace capacity is proposed for each unit that the heating surface to grate area ratio of the furnace exceeds 20. This addition is based on tests of four types of furnaces having various ratios of heating surface to grate area, at the University of Illinois. Let E = efficiency of the furnace. / = fuel value of the coal, Btu per pound. p = pounds of coal burned per square foot grate per hour. R = ratio of heating surface to grate area. E = total heat requirements of the house. Grate area, square inches >= ^ j ho20)1 ^or al*insicle ^ (9) For coal having a heat value of 12,000 Btu, and a furnace having 60 per cent efficiency, with 6 lb of coal burned per square foot of grate per hour, and 20 sq ft of heating surface for 1 sq ft of grate, this becomes: Grate area, square inches = q~^ ^*T a" `nslde air (10) and for another furnace having 24 sq ft of heating surface for 1 sq ft of grate the expression is ,,, .. , _ 1.2 X 144 g Grate area, square inches 0.60X 12,000X6(1+0.02(24-20)] M1, (U) The air temperatures at the registers corresponding to the conditions of Equation 11 would be approximately 165 F; and for 175 F and 12,000 Btu the combustion rate would be about 7.5 lb with an efficiency of 57 per cent, using the curves of Fig. 7 as a guide. EXAMPLES 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 the'Warm Air Research Residence of the National Warm Air Heating Association erected at the University of Illinois8. 'Flans used with permission. Bathroom on third floor not heated. Let B = Btu heat loss from the entire house per hour summation of all room tossesffi +' Ht + etc. *f` the Btu necessary to heat the fresh air, if any. at intake. This fresh air loss in Btu per hour will be approximately 1.27 times the cubic feet of air admitted through .the intake per hour on a zero day. For systems which recirculate all the air this value will be zero. For systems which have a fresh air intake, controlled by damper, this value might well be approximated, 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 20 per cent loss between furnace and registers. , 327 American Society of Heating and Ventilating Engineers Guide, 1934 ' Fig. 11. Third-floor Plan, Research Residence 328 oT d o ! Chapter 24--Gravity Warm Air Systems Leaders, Stacks and Registers. (Direct Method) Living Room, 1st floor: 17,250 4- 111 = 155 sq in. leader area. See summary, Table 1; also example under Standard Code4, Art. 3, Basis of Working Rules for Pipes. Leader diameter = 14 in. Register size = 155 sq in. net area. Gross area = net area 4- 0.7 = 14 X 16 in. Owner's Room, 2nd floor: 15,030 4- 167 = 90 sq in. leader area. See Summary Table; also example under Standard Code4, 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 X 12 in. ' Register area = 90 sq in. net area. Gross area = net area -f- 0.7 = 12 X 12 or 12 X 14 in. In like manner the leaders, stacks and registers are calculated for each room in the house. Leaders, Stacks and Registers. (Code 4 Method. See Art. 3, Sec. 1, 2,3.) . Living Room (Glass = 90, Net wall = 405, Cubic contents 2405) --Lead.er = (^9_0 +, 4_05 +, 2w405 j9 = 155 sq m. . Register, same as Direct Method. Owner's Room (Glass = 68, Net wall = 394, Cubic contents = 2275) ., / 68 . 394 , 2275 \ ,, Qn . Leader- = 90 sqm. Stack and Register, same as Direct Method. Assuming all air recirculated, the minimum furnace for the plant will be: Grate Area = 0.0034 X 132,370 = 450 sq in. = 24 in. diam. at 175 F. register temperature. (Equation 7) Grate Area = 0.0040 X 132,370 = 530 sq in. = 26 in. diam. at 160 F. register temperature. (Equation 8) If provision shall be made for certain outside air circulation, then increase the building heat loss by, say 25 per cent and obtain by Equation 7 a 27-in. grate and by Equations 8 and 10 a 29-in. grate. . . Experiments at the University of Illinois5 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. ' Standard Code Regulating the Installation of Gravity Warm Air Heating Systems in Residences. This code baa been sponsored by the National Worm Air Heating Association, the National Association of Sheet Metal. Contractors, and the American Society op Heating and Ventilating Engineers. It is recommended that the installation of all gravity warm air heating systems in residences be governed by the provisions of thi9 code, the eighth edition of which may be obtained from the National Warm Air Heating Association, 3440 A-I.LfrBuilding, Columbus, Ohio. aSee University of Illinois Eng. Exp. Sta. Bulletin No. 120, p. 129. . 329 ' ') American Society of Heating and Ventilating Engineers Guide, 1934 Table 1. Summary or Data Applied to' Warm Air Research Residence i;1 kAlVUlg. Dining.------Breakfast-- Kitchen____ Sun_______ Hall and stair) Second Floor Owners..___ S. W. Bed-- Bath_______ N. Bed_____ Third Floor E. Bed______ W. Bed____ BOOSTER FANS . Booster fans often may be arranged to operate when the gas and oi! burners operate 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 temperatures, but at high operating temperatures gravity and booster efficiencies are almost identical. See University of Illinois Eng. Exp. Sta. Bulletin No, 141, p. 79. ' 330 Chapter 25 HEATING BOILERS Cast-Iron Boilers, Steel Boilers, Special Heating Boilers, Hot Water Supply Boilers, Furnace Design, Heating Surface, Testing and Rating Codes, Output, Efficiency, Selection of Boilers, Con nections and Fittings, Erection, Operation and Maintenance, Boiler Insulation STEAM and hot water boilers for low pressure heating work are built in a wide variety of types, many of which are illustrated in the Catalog Data Section, and are classified as (1) cast-iron sectional, (2) steel fire tube, (3) steel water tube, and (4) special. 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 in 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 and sufficient side clearance should be provided for this contingency. . 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 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 331 American Society of Heating and Ventilating Engineers Guide, 1934 tube or water tube; second, with regard to arrangement of furnace and 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 wafer available to produce steam is contained in comparatively large bodies.distributed outside of the boiler tubes, the hot gases passing within the tubes. cIn water tube boilers, the water is circulated within the boiler tubes, hedt 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 Y in. Water* Kind of Coal No. 1 Buckwheat Anthracite Anthracite Pea 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 Lb of Coal per Sq Ft Grate pea Hour 3 3K 4 4H 5 Anthracite Nut and Larger Bituminous Up to 4 5 to 9 10 to 14 15 to 19 20 to 25 Up to 4 5 to 14 15 and above 8 9 10 11 13 9.5 12 15.5 ttaktatJUerS USUaUy have mEller combust'on rates for grate areas exceeding 15 sq ft than those indicated combustion chamber. All heating surfaces and the interior of the boiler are accessible for both cleaning and inspection. Horizontal return tubular boilers should be suspended from structural columns and beams indepen dent of the brick setting, especially the larger sizes. 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 all brickwork. They are shipped in one piece . from the factory and come to the j'ob ready for immediate hook-up to piping. They may be of welded or riveted construction and have either water or fire tubes. Manufacturers' catalogs usually list heating surface as well as grate area. The elimination of brickwork also makes this type the. most compact of steel boilers as well as the lowest in first cost. Water tube boilers. For large heating loads water tube boilers are quite frequently- used. They usually require more head room than other types of boilers but require considerably less floor space and make possible a: . 332 Chapter 25--Heating Boilers much higher rate of evaporation per square foot of heating surface, with proper setting, baffling and draft. Water tube boilers used for heating purposes are brick set, supported on structural steel columns and have the brick setting encased in an insulated steel housing to prevent air infiltra tion and to minimize heat losses. For large heating loads at a high rate of evaporation, such boilers should be operated at pressures above 15 lb per square inch with a pressure-reducing valve on the connection to the heating main. SPECIAL HEATING BOILERS A special type of boiler, known as the magazine feed boiler, has been developed for the burning of small sizes of anthracite. These are built of both cast-iron and steel, and have a large fuel carrying capacity which results in longer firing periods them would be the case with the standard types using buckwheat sizes of coal. Special attention must be given to insure adequate draft and proper chimney sizes and connections. Oil-burner boiler units, in which a special boiler has been designed with a furnace shaped to suit the particular burner used, have been developed by a number of manufacturers. These usually are compact units with the burner and all controls enclosed within an insulated steel jacket. Ample furnace volume is provided for efficient combustion, and the heating surfaces are proportioned for effective heat transfer. Consequently, higher efficiencies are obtainable than with the ordinary coal fired boiler converted to oil firing. . . GAS-FIRED BOILERS Gas boilers have.assumed a well-defined individuality. The usual boiler is sectional in construction with a number of independent burners placed beneath the sections. In most boilers each section has its own burner. In all cases the sections are placed quite closely together, much closer than would be possible when burning a soot-forming fuel. The effort of the designer is always to break the hot gas up into thin streams, so that all particles of the heat-carrying gases can come as closely as possible to the heat-absorbing surfaces. Because there is no fuel bed resistance and because the gas company supplies the motive power, to draw in the air necessary for combustion (in the form of the initial gas pressure), draft losses through gas boilers are low. 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. 333 American Society of Heating and Ventilating Engineers Guide, 1934 Indirect heaters generally consist of steam boilers in connection with heat exchangers of the coil or tube types which transmit the heat from the steam to the water. This type of installation has the following advantages: 1. The boiler operates at low pressure. 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 scale is attached can be cleaned or replaced. The accumulation of scale does not affect efficiency although it will affect the capacity of the heat exchanger.' 4. Discoloration of water may be prevented if the water supply comes in contact with only non-ferrous metal. . Where a steam heating system is installed, the domestic hot water usually is obtained from an indirect heater placed below the water line of the boiler. ' FURNACE DESIGN . 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 purpose. The furnace temperature must be maintained sufficiently high to produce complete combustion, thus resulting in a higher COt content and the absence of CO. Hydrocarbon gases ignite at temperatures varying from 1000 to 1500 F. The question of furnace proportions, particularly in regard to mechani cal stoker installations, has been given some consideration by various manufacturers' associations. Arbitrary Values have been recommended for minimum dimensions. A customary rule-of-thumb method of figuring furnace volumes is to allow 1 cu ft of space for a maximum heat release of 50,000 Btu per hour. This value is equivalent to allowing approxi mately 1 cu ft for each developed horsepower, and it is approved by most smoke prevention organizations. ' The setting height will vary with the type of stoker. In an overfeed stoker, for instance, all the volatiles must be burned in the combustion chamber and, therefore, a greater distance should be allowed than for an underfeed stoker where a considerable portion of the gas is burned while passing through the incandescent fuel bed. The design of boiler also may affect the setting height, since in certain types the gas enters the tubes immediately after leaving the combustion chamber while in .others it passes over a bridge wall and toward the rear, thus giving a better oppor tunity for combustion by obtaining a longer travel before entering the tubes. . To secure suitable furnace volume, especially for mechanical stokers or oil burning, it often is necessary either to pit the stoker or oil burner, or 334 Chapter 25--Heating Boilers where water line conditions and headroom permit, to raise the boiler on a brick foundation setting. ,' Smokeless combustion of the more volatile bituminous coals is furthered by the use of mechanical stokers. (See Chapter 28). Smokeless com bustion in hand-fired boilers burning high volatile solid fuel is aided (I) by the use of double grates with down-draft through the upper grate, (2) by the use of a curtain section through which preheated auxiliary air is introduced over the fire toward the rear of the boiler, and (3) by the intro duction of preheated air through passages at the front of the boiler. All three methods depend largely on mixing secondary air with the partially burned volatiles and causing this mixture to pass over an incandescent fuel bed, thus tending to secure more complete combustion than is pos sible in boilers without such provision. BOILER 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. (See definition in Chapter 42), 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 tem peratures 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 radiant heating surface may be as high as 6 to 8 times that of indirect surface. This is one of the reasons why the water legs of some boilers have been extended, especially in the case of st.oker 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 incr&ses. 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 lSee U. S. Bureau of Mines Bulletin No. 18, The Transmission of Heat into Steam Boilers. 335  American Society of Heating and Ventilating Engineers Guide, 1934 3300 Btu per sq ft per hour for hand-fired boilers and 4000 Btu per sq ft per hour for mechanically fired boilers when operating at designed load2. When operating at maximum load2 these values will run between 5000 and 6000 Btu per sq ft per hour. Boilers operating under favorable conditions at the above heat transfer rates will give exit gas temperatures that are considered consistent with good practice. TESTING AND RATING CODES , The Society has adopted three solid fuel testing cqdes, a solid fuel rating code and one oil fuel testing code. A.S.H.V.E. Standard and Short Form Heat Balance Codes for Testing Low-Pressure Steam Heating Solid Fuel Boilers---Codes 1 and 2--^Revision of June 1929)3, are intended to provide a method for conducting and reporting tests to determine heat efficiency and performance characteristics. A.S.H.V.E. Performance Test Code for Steam Heating Solid Fuel Boilers--Code No. 3--(Edition of 1929)3 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 Fuel6 is intended to provide a standard method for cbnducting and reporting tests to determine the heating efficiency and per formance characteristics when oil fuel is used with steam heating boilers. The Steel Heating Boiler Institute suggests a single number dimensional, rating in the S.H.B.I. Code for the Rating of Low-Pressure Heating Boilers by Their Physical Characteristics6. BOILER OUTPUT Boiler output as defined in A.S.H.V.E. Performance Test Code for Steam Heating Solid Fuel Boilers (Code No. 3) is the quantity of heat available at the boiler nozzle with the boiler normally insulated. It should be based on actual tests conducted in accordance with this code. . This output is usually stated in Btu and in square feet of equivalent heat ing surface (radiation). According to the A.S.H.V.E. Standard Code for Rating Steam Heating Solid Fuel Hand-Fired Boilers, the performance data should be given in tabular or curve form on the following items for at least five outputs ranging from maximum down to 35 per cent of maxi mum: (1) fuel available, (2) combustion rate, (3) efficiency, (4) draft tension, (5) flue gas temperature. The only definite restriction placed on setting the maximum output is that priming shall not exceed 2 per cent. These curves provide complete data regarding the performance of the boiler under test conditions. Certain other pertinent information, such as grate area, heating surface and chimney dimensions is desirable also in forming an opinion of how the boiler will perform in actual service.* For definition of design load and maximum load see pages 337 and 338- *See A.S.H.V.E. Transactions. Vol. 35, 1929. Also Chapter 42. See A.S.H.V.E. Transactions, Vol. 36, 1930. Also Chapter 42. . `See A.S.H.V.E. Transactions, Vol. 37, 1931. Also Chapter 42. See Rating of Heating Boilers by Their Physical Characteristics, by C. E. Bronson (A.S.H.V.E. Trans actions, Vol. 36, 1930). 336 Chapter 25--Heating Boilers The output of large heating boilers is frequently stated in terms of boiler horsepower instead of in Btu per hour or square feet of equivalent radiation. Boiler Horsepowers The evaporation of 34.5 lb of water per hour from and at 212 F which is equivalent to a heat output of 970.2 X 34.5 = 33,471.9 Btu per hour. Equivalent Evaporation: The amount of water a boiler would evaporate, in pounds per hour, if it received feed water at 212 F and vaporized it at this same temperature and at atmospheric pressure. It is usually considered that 10 sq ft of boiler heating surface will pro duce a rated boiler Horsepower. A rated boiler horsepower in turn can carry a design load of from 100 to 140 sq ft of equivalent radiation. It is apparent, therefore, that 1 sq ft of boiler heating surface can carry a design load of from 10 to 14 sq ft of equivalent radiation, or somewhat more if the boiler is forced above rating. The application of these values is discussed under the heading Selection of Boilers. BOILER EFFICIENCY The term efficiency as used for guarantees of boiler performance is , usually construed as follows: 1. Solid Fuels. The efficiency of the boiler alone is the ratio of the heat absorbed by the water and steam in the boiler per pound of combustible burned on the grate to the calorific value of I lb of combustible as fired. The combined efficiency of boiler, furnace and grate is the ratio of the heat absorbed by the water and steam in the boiler per pound of 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 Association1. For general information on heating efficiencies see Chapter 29 SELECTION OF BOILERS Estimated Design Load: The load, stated in Btu per hour or equiv alent direct radiation, as estimated by the purchaser for the conditions of inside and outside temperature for which the amount of installed radiation was determined 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 items8: 1. The estimated heat emission in Btu per hour of the connected radiation (direct, indirect or central fan) to be installed. *See A.S.H.V.E, research capers entitled Study of the Characteristics of Oil Burners and Heating Boilers, by L. E. Seeley and E. J. Tavanlar (A.S.H.V.E. Transactions, Vol. 37, 1931), and 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). . . 337 American Society of Heating and Ventilating Engineers Guide, 1934 2. The estimated maximum heat in Btu per hour required to supply water heaters or other apparatus to be connected to the boiler. 3. The estimated heat emission in Btu per hour of the piping connecting the radiation and other apparatus to the boiler. Estimated Maximum Load: Construed to mean the load stated in Btu per hour or 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). The estimated maximum load is given by8: 4. The estimated increase in the normal load in Btu per hour due to starting up cold radiation. This percentage of increase is to be based on the sum of Items 1, 2 and 3 and the heating-up factors given in Table 2. Table 2. Warming-up Allowances for Low Pressure Steam and ___________ __________________ Hot Water Heating Boilers3-1*-0 Design Load (Representing Summation op Items 1. 2, and 3,d Btu per Hour Equivalent Square Feet of Radiations Up to 100,000 100.000 to 200,000 200.000 to 600,000 600,000 to 1,200,000 1,200,000 to 1,800,000 Above 1,800,000 _ Up to 420 420 to 840 840 to 2500 2500 to 5000 5000 to 7500 Above 7500 _______ I Percentage CapAcrrr to Add for Warming Up _____________ 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. ' l>See also Time Analysis in Starting Heating Apparatus, by Ralph C. Taggert (A.S.H.V.E. Transac tions. Vol. 19, 1913): 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); Selecting the Right Size Heating Boiler, by Sabin Crocker (Heating, Piping and Air Conditioning, March. 1932). . cThis table refers to hand fired solid fuel boilers. A factor of 25 per cent over design load is adequate when oil or gas are used as fuels. - > , <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, 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 30. 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 30). 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 See A.S.H.V.E. Code of Minimum Requirements for the Heating and Ventilation of Buildings (Edition of 1929). 338 Chapter 25--Heating Boilers Usually represents a reserve in heating capacity to provide for infiltration in the various spaces of the building to be heated, which reserve, however, is not in use at all places at the same time, or in any one place at all times. For a further discussion of this subject see p. 101, Chapter 6. Hot Water Supply Load . When the hot water supply (Item 2) is heated by the building heating boiler, this load must be taken into consideration in sizing the boiler. The Fig. 1. Typical Performance Curves for a 36-in. Cast-Iron Sectional Steam Heating Boiler, Based on the A.S.H.V.E. Code for Rating Steam Heating Solid Fuel Hand-Fired Boilers allowance to be made will depend on the amount of water heated and its temperature rise. A good approximation is to add 4 sq ft of equivalent radiation for each gallon of water heated per hour through a temperature range of 100 F. For more specific information, see Chapter 39. . Piping Tax (Item 3) ~ It is common practice to add a flat' percentage allowance to the equivalent connected radiation to provide for the heat loss from bare and covered pipe in the supply and return lines. The use of a flat allowance of .25 per cent for steam systems and 35 per cent for hot water-systems is 339 American Society of Heating and Ventilating Engineers Guide, 1934 preferable to ignoring entirely the load due to heat loss from the supply and return lines, but better practice, especially when there is much bare pipe, is to compute the emission from both bare and covered pipe surface in accordance with data in Chapter 35. With direct radiation served by bare supply and return piping the percentages may be higher than those stated, while in the case of unit heaters where the output is concentrated in a few locations, the piping tax may be 10 per cent or less. Warming-up Allowance The warming-up allowance represents the load due to heating the boiler and contents to operating temperature and heating up cold radiation and piping. (See Item 4). The factors to be used for determining the allowance to be made should be selected from Table 2 and should be applied to the estimated design load as determined by Items 1, 2 and 3. 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. 1. 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. , Selection Based on Heating Surface and Grate Area Where performance curves are not available, a good general rule for conventionally-designed boilers is to provide 1 sq ft of boiler heating surface for each 14 sq ft of equivalent radiation (240 Btu per square foot) represented by the design load consisting of connected radiation, piping tax and domestic water heating load. As stated in the section on Boiler Output, this is equivalent to allowing 10 sq ft of boiler heating surface per boiler horsepower. In this case it is assumed that the maximum load including the warming-up allowance will be provided for by operating the boiler in excess of the design load, that is, in excess of the 100 per cent rating on a boiler-horsepower basis. Due to the wide variation encountered in manufacturers' ratings for boilers of approximately the same capacity, it is advisable to check the grate area required for heating boilers burning solid fuel by means of the following formula: where gU C x H F X E m K' C -- grate area, square feet. ' H = required total heat output of the boiler, Btu per hour (see Selection of Boilers, p. 337). , 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. 340 Chapter 25--Heating Boilers Example 1. Determine the grate area for a required heat output of the boiler of 500,000 Btu per hour, a combustion rate of 6 lb per hour, a calorific value of 13,000 Btu per pound, and an efficiency of 60 per cent. 500,000 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 1. 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 Gas-Fired Boilers Gas-heating appliances should be selected in accordance with factors given in Table 1, Chapter 28, which include an allowance for heating-up cold radiation, and for the piping tax. 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 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 underestimated or more is added in the future. Conversions In the case of a solid fuel boiler converted to gas burning, the heat units supplied in the gas should be approximately twice the connected heating load. A combustion efficiency of 75 per cent for a conversion installation would provide a boiler output of 2 X 0.75 = 1.5 times the connected load, which allows 50 per cent for piping tax and pick-up. The presumption for a conversion job is that the boiler already is installed and probably will not be made larger; therefore, it is a matter of setting a gas-burning rate to obtain best results with the available surface. The conversion of a coal or oil boiler to gas burning is accomplished much iinore rapidly than the reverse since but little furnace volume need be provided for the proper combustion of gas. Other Considerations in Selection of Boilers 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 heatrequirements. . Boiler rooms should, if possible, be situated at a central point with 341 American Society of Heating and Ventilating Engineers Guide, 1934 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 of 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 dampers, cleanouts and trimmings. The space at the rear of the boiler should be ample for the chimney connection and for cleanouts and 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 ceiling height for small steam boilers should be at least 3 ft above the normal boiler water line. With vapor heating especially, the height above the boiler water line is of vital importance. When steel boilers are used, space should be provided for the removal and replacement of tubes. BOILER CONNECTIONS AND FITTINGS s 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 32, 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. J.P.S.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. ' Code, Identification of Piping Systems.. 342 Chapter 25--Heating Boilers' . . . 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. Where a return header is used on a cast-iron sectional boiler to distribute the returns to both rear tappings, it is advisable to provide full size plugged tees instead of elbows where the branch connections enter the return tappings. This facilitates cleaning sludge from the bottom of the boiler sections through the large plugged openings. An equivalent clean out plug should be provided in the case of a single return connection. Blow-off or drain connections should be made near the boiler arid so arranged that the entire system may be drained of water by opening the drain cock. In the case of two or more boilers separate blow-off connec tions must be provided for each boiler on the boiler side of the stop valve on the main return connection. Water service connections must be provided for both steam and water boilers, for refilling and for the addition of make-up water to boilers. This connection is usually of galvanized steel pipe, and is made to the return main near the boiler or boilers. For further data on pipe connections for steam and hot-water heating systems, see Chapters 32 and 33 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 up 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. BOILER ERECTION, OPERATION, AND MAINTENANCE The 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 physical precautions should be taken in all installations to prevent damage to the boiler: 1. There should be provided proper and convenient drainage connections for use if the boiler is not in operation during freezing weather. -- 2. Strains on the boiler due to movement of piping during expansion should be prevented by suitable anchoring of piping and by proper provision for pipe expansion Rnd contraction. ' 343 American Society of Heating and Ventilating Engineers Guide, 1934 3. Direct impingement of too intense local heat upon any part of the boiler surface, as with oil burners, should be avoided by protecting the surface with firebrick or other refractory material. 4. Condensation must flow back to the boiler as rapidly and uniformly as possible. Return connections should prevent the water from backing out of the boiler. 5. Automatic boiler feeders and low water cut-off devices which shut off the source of heat if the water in the boiler falls below a safe level are recommended for boilers mechanically fired. Boiler Troubles A complaint regarding boiler operation generally will be found to be due to one of the following: 1. The boiler fails to deliver enough heal. The cause of this condition may be: (a) poor draft; (b) poor fuel; (c) inferior attention or firing; (d) boiler too small; (h) improper piping; (/) improper arrangement of sections; (g) heating surfaces covered with soot; and (h) insufficient radiation installed. 2. The looter 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; (c) boiler operating at excessive output. 3. Water disappears from gage glass. This may be caused by: (o) priming due to grease and dirt in boiler; (b) too great pressure difference between supply and return piping preventing return of condensation; (e) valve closed in return line; id) connection of bottom of water column into a very active section or thin waterway; (e) improper connections between boilers in battery permitting boiler with excess pressure to push returning condensation into boiler with lower pressure. _in ib.oilWera;te(br)isincsaurrfifeicdieonvterstineatomstdeoammemoarinto. oTshmisalml sateyabme cliabuesreadtinbgy:ar(eoa);g(rce)aoseutalentdcdoinrt nections of too small area; -(d) excessive rate of output; () water level carried higher than specified. 5. Boiler is slow in response to operation of dampers. This may be due to: (a) poor draft due to air leaks into chimney or breeching; (6) inferior fuel; (c) inferior attention; (<f) accumulation of clinker on grate; (e) boiler too small for the load. Boiler requires too frequent cleaning of flues. This may be due to: (a) poor draft; (b) smoky combustion; (c) too low a rate of combustion; (d) too much excess air in firebox causing chilling of gases. 7. Boiler smokes throughfire door. This may be due to: (a) defective draft in chimney or incorrect setting of dampers; (b) air leaks into boiler or breeching; (c) gas outlet from firebox plugged with fuel; (d) dirty or clogged flues; (e) improper reduction in breeching size. Cleaning Steam Boilers All boilers are provided with flue clean-out openings through which the heating surface can be reached by means of brushes or scrapers. Flues of solid fuel boilers should be cleaned often to keep the surfaces free of soot or ash. Gas boiler flues and burners should be cleaned at least once a year. Oil burning boiler flues should be examined periodically to deter mine when cleaning is necessary. The grease used to lubricate the cutting tools during erection of new piping systems serves as a carrier for sand and dirt, with the result that a scum of fine particles' and grease accumulates on the surface of the water in all new boilers, while heavier particles may settle to the bottom of the boiler and form sludge. These impurities have a tendency to cause foaming, preventing the generation of steam and causing an unsteady water line. . This unavoidable accumulation of oil and grease should be removed by blowing off the boiler as follows: If not already provided, install a 344 Chapter 25--Heating Boilers surface blow connection of at least 1J4 in. nominal pipe size with outlet extended to within 18 in. of the floor or to sewer, inserting a valve in line close to boiler. Bring the water line to center of outlet, raise steam pres sure and while fire is burning briskly open valve in blow-off line. When pressure recedes close valve and repeat process adding water at intervals to maintain proper level. As affinal operation bring the pressure in the boiler to about 10 lb close blow-off, draw the fire or stop burner and open drain valve. After boiler has cooled partly fill and flush out several times before filling it to proper water level for normal service. The use of acids, alkalis and salts for cleaning is not favored by boiler manu facturers because of difficulty of complete removal and the possibility of subsequent injury. Insoluable compounds have been developed which are effective, but special instructions on the proper cleaning compound and directions for its use in a boiler, as given by the boiler manufacturer, should be carefully followed. When soda ash solution is to be used the procedure is to add about 5 lb of soda ash for each 1000 sq ft of connected radiation. Fill the boiler with water until it just overflows from the surface blow outlet pipe and then fire sufficiently to raise the water temperature to the boiling point without getting up steam pressure. Crack the boiler feed valve so that a steady trickle will run out of the overflow pipe. Allow the boiler to simmer from 2 to 4 hours. At the end of this time the grease and sediment should have passed off through the overflow pipe or loosened sufficiently to drain off through the bottom blow. Extinguish the fire--preferably by letting it burn out and then dumping any Jive coals into the ashpit where water can be applied with a hose--and open the bottom blow wide. Rinse with fresh water and refill to the normal water level. If the water in the gage glass then does not show dear, repeat the process using a stronger soda ash solution and boiling for a longer time. It sometimes is necessary to repeat this process several times to completely rid the boiler of grease. Failure to thoroughly eliminate greaseCusually results in an unsteady water line and danger of damaging the boiler through having the crown- sheet uncovered. . 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 valye 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. All heating surfaces should be cleaned thoroughly of soot, ash and residue, and the heating surfaces of steel boilers should be given a coating of lubricating oil on the fire side. --- 2. All machined surfaces should be coated with oil or grease. 345 V American Society of Heating and Ventilating Engineers Guide, 1934 3. Connections to the chimney should be cleaned and in case of small boilers the pipe should be placed in a dry place after cleaning. 4.; If there is much moisture in the boiler room, it is desirable to drain the boiler to prevent atmospheric condensation on the heating surfaces of the boiler when they are below the dew-point temperature. Due to the hazard of some one inadvertently building a fire in'a dry boiler, however, it is safer to keep the boiler filled with water, A hot water system usually is left filled to the expansion, tank. , ^ 5. The grates and ashpit should be cleaned. . 6. Clean and repack the gage glass if necessary. ' 7. Remove any rust or other deposit from exposed surfaces by scraping with a wire brush or sandpaper. After boiler is thoroughly cleaned, apply a coat of preservative paint where required to external parts normally painted. 8. Inspect all 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 material or blocks wired on, cemented and covered with canvas or duck; and (2) blocks, sheets or plastic material covered with a metal jacket furnished by the boiler manufacturer. Self-contained steel firebox boilers usually are insulated with blocks, cement and canvas, or rock wool blankets; HRT boilers are brick set and do not require insulation beyond that provided in the setting. It is essential that the insulation on a boiler 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. REFERENCES A.S.H.V.E. Code of Minimum Requirements for the Heating and Ventilation of Buildings. A.S.H.V.E. Standard and Short Form Heat Balance Codes for Testing Low-Pressure Steam Heating Solid Fuel Boilers (Codes 1 and 2). A.S.H.V.E. Performance Test Code for Steam Heating Solid Fuel Boilers (Code No. 3). A.S.H.V.E. Standard Code for Rating Steam Heating Solid Fuel Hand-Fired Boilers. Heating, Ventilating and Air Conditioning, by Harding and Willard, Revised Edition, 1932. A.S.M.E. Boiler Construction Code for Low Pressure Heating Boilers. ' Heating and Piping Contractors National Association Standards (boiler selection tables). House-Heating, published by American Gas Association. Handbook of Oil.Burning, published by American Oil Burner Association. Heating and Ventilation, by Allen and Walker (3rd Edition). Selecting the Right Size Boiler, by Sabin Crocker (Heating, Piping and Air Con ditioning, February, March, April, 1932), . .. 346 Chapter 26 CHIMNEYS Natural Draft, Mechanical Draft, Characteristics of Natural Draft Chimneys, Determining Chimney Sizes, General Equation, Chimney Construction, Chimneys for Gas Heating 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 then 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) artificial 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 therelatively hot gases which have passed through the boilers and accessories and from which all of the heat has not been extracted. Hot gases are an essential element in the operation of a natural draft system. 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 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 their normal rating, some form of mechanical 347 S 'American Society of Heating and Ventilating Engineers Guide, 1934 348 Chapter 26--Chimneys 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 parts, (4) low cost of maintenance, (5) relatively long life, (6) relatively low depreciation, and (7) no power required to operate. The principal disadvantages are: (1) lack of flexibility, (2) irregularity, (3) affected by surroundings, and (4) affected by temperature changes. Mechanical Draft ' Artificial draft, or mechanical draft, as it is more commonly called, is a difference in pressure produced either directly or indirectly by a forced draft fan, an induced draft fan or a Venturi chimney as the pressure transformer. The intensity of mechanical draft is dependent for the most part upon the size of the fan and the speed at which it is operated. The element of temperature does not enter into the creation of mechanical draft and therefore its intensity, unlike natural draft, is independent of the temperature of the gases and the atmosphere. Mechanical draft includes the induced and Venturi types of draft systems in which the pressure difference is the result of a suction and also the forced draft system in which the pressure difference is the result of a blowing. Mechanical draft systems tend to produce a vacuum or a plenum, according as the system used in its production creates a pressure difference below, or above, atmospheric pressure, respectively. A mechanical draft system may be used either in conjunction with, or as an adjunct to, a natural draft system. CHARACTERISTICS OF NATURAL DRAFT CHIMNEYS In order to analyze the performance of a natural draft chimney, it is advantageous to compare its general operating characteristics with those of a centrifugal pump and also a centrifugally-induced draft fan, there being a close similarity among the three. Figs. 1, 2 and 3 show the general operating characteristics of a typical centrifugally-induced draft fan, a typical centrifugal pump, and a typical natural draft chimney, respectively. The draft-capacity curve of the chimney corresponds to the head-capacity curve of the pump and also to the dynamic-head capacity of the fan; the efficiency curve of the chimney to the efficiency curves of the pump and fan; and the gas horsepower curve of the chimney to the brake horsepower curves of the pump and 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 available draft. The general equation for the available draft intensity of a natural draft chimney with a circular section is as follows: ~ D, 2MHBo f) 0.00126W*TcfL D*BQ Wc (1) 349 American Society of Heating and Ventilating Engineers Guide, 1934 where . S' Z>a .= available draft, inches of water. , FT = height of chimney above grate bars, feet. Bo = barometric pressure corresponding to altitude, inches of mercury. Wo = unit weight of a cubic foot of air at 0 deg Fahrenheit and sea level atmospheric pressure, pounds per cubic foot. Wc = unit weight of a cubic foot of chimney gases at 0 deg Fahrenheit and sea level atmospheric pressure, pounds per cubic foot. ' To = absolute temperature of atmosphere, degrees Fahrenheit. 7c = 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. ' X = length of friction duct of the chimney, feet. D = minimum diameter of chimney, feet. ' 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 l. Determine the available draft of a natural draft chimney 200 ft in height and 10 ft in diameter operating under the following conditions: atmospheric temperature, 62 F; chimney gas temperature, 500 F; sea level atmospheric pressure, B0 = 29.92 in. of mercury; atmospheric and chimney gas density, 0.0863 and 0.09, respectively; coefficient of friction, 0.016; length of friction duct, 200 ft; and discharging 100.1b of gases per second. Substituting these values in Equation 1 and reducing: Da = 2.96 X 200 X 29.92 X 0.09\ 960/ 0.00126 X 1001 X 960 X 0.016 X 200 10s X 29.92 X 0.09 = 1-27 - 0.14 = 1.13 in. Fig. 4 shows the variation, in the available draft of a typical 200 ft by 10 ft chimney operating under the general conditions noted in Example 1. When the chimney is under static conditions and no gases are flowing, the available draft is equal to 1.27 in. of water, the theoretical intensity. As the amount, of gases flowing increases, the available intensity decreases until it becomes zero at a gas flow of 297 lb per second at which point the draft loss due to friction is equal to the theoretical intensity.- The draft- capacity curve corresponds to the head-capacity curve of" centrifugal 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. 4. . The efficiency .of a natural draft chimney is the thermodynamical ratio of the energy output to the energy input. The energy output is the total 350 Chapter 26--Chimneys work done by the chimney in moving the gases and corresponds to the water horsepower of a centrifugal pump, or the total work done by a fan in moving the gases. The energy input is equal to the theoretical amount of power generated by the chimney and corresponds to the power input of the driving unit of a centrifugal pump or a fan. The thermodynamical efficiency is given by the equation: ' ,, KqWDq Et ~ AVH (2) where FTa = a constant depending upon the temperature of the gases, the atmospheric temperature, the elevation of the plant, and the density and specific heat of the , gases. For average operating conditions, Ka = 0.0065. Fig. 4. Typical Set of Operating Characteristics of a Natural Draft Chimney Fig. 4 shows the variation in the efficiency of the chimney under con sideration for the operating conditions noted. This curve rises from zero at shut-off draft to a maximum for a certain draft and its corresponding capacity and then drops again to zero at the wide open point. The point of maximum efficiency is located by the point on the draft-capacity curve equal to two-thirds of the theoretical draft intensity. In Example 1 the maximum efficiency is at an available draft intensity of 34 X 1.27 = 0.85 in. of water and the corresponding capacity of 175 lb per second. The efficiency curve of a natural draft chimney corresponds to the efficiency curves of a centrifugal pump and a fan and serves the same general use in that it locates the region of most economical operation. 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: 351 American Society of Heating and Ventilating Engineers Guide, >1934 1. The barometric pressure varies inversely as the altitude of the plant above sea level. Fig. 5 gives the barometric pressure corresponding to various elevations as computed from the equation: . where OQ QO , = 62,737 log ^1- l>o ' (3) ' Ei = altitude of plant above sea level, feet. In general, the barometric pressure decreases approximately 0.1 in. of mercury per 100 ft increase in elevation. 2. The unit weight of a cubic fool of chimney gases at 0 deg Fahrenheit and sea level barometric pressure is given by the equation: Wc = O.I31CO, + 0.095.0, + 0.083 Nt (4) Chapter 26^--Chimneys 7. 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 may be computed from the equation: where W = GgGWtp 3600 (5) Cg = pounds of fuel burned per square foot of grate surface per hour. G = total grate surface of boilers, square feet. jytp = total weight of products of combustion per pound of fuel. Fig. 5. Relation Between Barometric Pressure and Altitude in which CO,, 0, and JV, represent the percentages of the parts by weight of the carbon' dioxide, oxygen and nitrogen, content, respectively, of the gas analysis. For ordinary operating conditions; the value of He may be assumed at 0.09. 3. The atmospheric temperature is the actual observed temperature of the outside air at the time the analysis of the operating chimney is made. The mean atmospheric temperature in the temperate zone is approximately 62 F. 4. The chimney gas temperature does not vary appreciably from the gas temperature as it leaves the breeching and enters the chimney. For average operating conditions, the chimney gas temperature will vary between 500 F and 650 F except in the case when economizers and recuperators are used, when the temperature will vary between 300 F and 450 F. If a chimney has been properly constructed, properly lined and has no air infiltration due to open joints, the temperature of the gases throughout the chimney will not differ appreciably from the foregoing figures. In most up-to-date heating plants, the temperature may be read from instruments or ascertained from a pyrometer. 5. The coefficient of friction between the chimney gases and a sooted surface has been found to be approximately 0.016. This factor, of course, will be much less for a new unlined steel stack than fora brick or brick-lined chimney, but in time the inside surface of all chimneys regardless of the material of which they are constructed becomes covered with a layer of soot and the coefficient of friction should be the same for all types of chimneys. . 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. 352 Fig. 6. Chimney Performance Ghart Fig. 6 is a typical chimney performance chart giving the available draft intensities for various amounts of gases flowing and sizes of chiihney. This chart is based on an atmospheric temperature of 62 F, a chimney gas temperature of 500 F, a unit chimney gas weight of 0.09 lb per cubic foot, sea level atmospheric pressure, a coefficient of friction of 0.016, and a friction duct length equal to the height of the chimney above_ the grate level. These curves may be used for general operating conditions. For specific operating conditions, a new chart should be constructed from Equation 1. -- ft 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 353 X American Society of Heating and Ventilating Engineers Guide, 1934 - 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: _________ Dr ' . * = 2.%Bo(ft |c). 0.184JW^V* : (6) where D = 0 288 J WTc " B0WCV ' .W H'= required height of chimney above grate bar level, feet. D = required minimum diameter of chimney, feet. V = chimney gas velocity, feet per second. Dr = total required draft demanded by the entire installation outside of the chimney, inches of water. Equations 6 and 7 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 chimney 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 cost least. Since the cost of a chimney structure, regardless 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: where Q = tIHD (8) Q = volume of material, cubic feet. t = average wall thickness, feet. . For all practical purposes, the value of r.t 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 - 354 Chapter 26--Chimneys 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 whose cost will be least and, as a result, will be the most economical to use. 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 3 and 4 to HD, differentiating this product with respect to V and equating the resulting expression to zero. This pro cedure results in the following expression: where Ve = economical chimney gas velocity, feet per second. Equation 9 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 Conditions. After the value of the economical velocity has been determined, -the 355 152" \ American Society of Heating and Ventilating Engineers Guide, 1934 corresponding height and diameter can then be determined from Equa tions 6 and 7, respectively, and the economical size will then be attained. Equations 6, 7 and 9 may be simplified considerably for average operating conditions in an average size steam plant by assuming the following conditions: Average chimney gas temperature, 500 F..... ....................... Tc = 960 Mean atmospheric temperature, 62 F.... ................................ T0 = 522 Average coefficient of friction, 0.016.........................................../ = 0.016 Average chimney gas density, 0.09........ Wc = 0.09 Sea level elevation with barometer of 29.92........ Ba = 29.92 ' ' Substituting these values in Equations 9, 7 and 6, respectively, and reducing: Ve = 13.71F1/5 (10) . D = 1.5W2/5 (11) H = 190Ur , (12) Fig. 7 gives the economical chimney sizes for various amounts of gases flowing and for required draft intensities as computed from Equations 10, 11 and 12. They are based on the operating factors used in reducing Equations 6, 7 and 9 to their simpler form. The sizes shown by the curves in the chart should be used for general operating conditions only, or for installations where the required data necessary for an exact deter 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 6; 7 and 9. 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: where Dt -- h{ = hF + Ab + *Bd + he + hBt + hv + ho + He + Hr . (13) Dt -- theoretical draft intensity created by pressure transformer, inches of water. hi = draft loss due to friction in pressure transformer, inches of water. ke = draft loss through the fuel bed, inches of water. . . Ab = draft loss through the boiler and setting, inches of water. . hBt = draft loss through the breeching, inches of water: . hv = draft loss due to velocity, inches of water. ABd = draft loss due to bends, inches of water. he -- draft loss due to contraction of opening, inches of water. ho = draft loss due to enlargement of opening, inches of water. Ae = draft loss through the economizer, inches of water. Ar = draft loss through recuperators, regenerators or air heaters, inches of water. The left hand member of Equation 13 represents the total amount of available.draft created by the pressure transformer, that is, the natural 356 Chapter 26--Chimneys Table 1. Recommended Minimum Chimney Sizes for Heating Boilers and Furnaces f Warm Air Furnace Capacity in Sq In. op Leader Pipe Steam Boiler Capacitt Sq Ft op Radi ation 790 1000 590 690 900 900 1,100 1,700 1,940 2,130 2,480 3,150 4,300 4,600 5,000 5,570 5,580 6,980 7,270 8,700 9,380 10,150 10,470 Hot Water Heater Capacitt 8q Ft op Radi ation Nominal Dimen sions op Fire Clat Lining in Inches ` Rectangular Flub Actual Inside Dimensions of Fire Clay ' Lining in Indies Actual Area Sq In. Round Flue Inside Diam eter of Lining in Inches Actual Area Sq In. 973 1,140 1,490 1,490 1,820 2,800 3,200 3,520 4,090 5,200 7,100 7,590 8,250 9,190 9,200 11,500 12,000 14,400 15,500 16,750 17,250 8^x13 7 xll M 81 13x13 llKxllK 127 8)4x18 6% x 16)4 110 13x18 ll)4xl6M 183 18x18 15^x15% 248 20x20 17Mx 17)4 298 20x24 24x24 17x21 21x21 24x24* 357 441 576 24x28* 28x28* 30 x 30* 28x32* 672 784 900 896 10 12 15 18 20 - 22 24 27 79 113 177 254 314 380 452 573 Height in Ft Above Grate 35 40 45 50 55 60 65 Dimensions are for unlined rectangular flues. tThis 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). draft chimney, Venturi chimney, or fan, and is equal to the theoretical intensity less the internal lossesrincidental to operation. The right hand member represents the sum of all of the various losses of draft throughout the entire boiler plant installation outside of the pressure transformer itself. The left hand member expresses the available intensity and is analogous to the head developed by a centrifugal pump in a water works system, while the right hand member expresses the required draft in tensity and is analogous to the total dynamic head in a water works system. For a general circulation of gases then where >a = Dt ZJa = available draft intensity, inches of water. Dz = required draft, inches of water (14) .. The draft loss through thefuel bed (htr), or the amount of draft required to effect a given or required rate of combustion, varies between wide limits and represents the greater portion of the required draft. In coal-fired installations, the draft loss through the fuel bed is dependent upon the following factors:^ (1) character and condition of the fuel, clean or dirty; (2) percentage of ash in the fuel; (3) volume of Interstices in the fuel bed, 357 American Society of Heating and Ventilating Engineers Guide, 1934 coarseness of fuel; (4) thickness of the fuel bed, rate of combustion; (5) type of grate or stoker used; (6) efficiency of combustion. There is a certain intensity of draft with which the best results will be obtained for every kind of coal and rate of combustion. Fig. 8 gives the intensity of draft, or the vacuum in the combustion chamber required to bum various kinds of coal at various rates of combustion. Expressed in other words, these curves represent the amount of draft required to force the necessary amount of air through the fuel bed in order to effect various rates of combustion. It will be noted that the amount of draft increases as the percentage of volatile matter diminishes, being comparatively low for the lower grades of bituminous coals and highest for the high grades and small sizes of anthracites. Also, when the interstices of the coal are large and the particles are not well broken up, as with bituminous coals, Fig. 8. Draft Required at Different Rates of Combustion for Various Kinds of Coal much less draft is required than when the particles are small and are well broken up, as with bituminous slack and the small sizes of anthracites. In general, the draft loss through the fuel bed increases as: (1) the per centage of volatile matter diminishes; (2) the percentage of fixed carbon increases; (3) the thickness of the bed increases; (4) the percentage of ash increases; (5) the volume of the interstices diminishes. In making the preliminary assumptions for the draft loss through the fuel bed, due allowances should be made for a possible future change in the grade of fuel to be burned and also in the rate of combustion. A value 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 358 Chapter 26--^Chimneys 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. The draft loss through the boiler and setting (hs) also varies between wide limits and, in general, depends upon the following factors: 1. Type of boiler. 2. Size of boiler. . 5. Arrangement of baffles. 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 boiler which may even be used generally: It is therefore necessary to secure this information from the manufacturer of the particular type of boiler and baffle arrangement under consideration. When a boiler is installed and in operation, the draft loss depends upon the amount of gases flowing through it. This, in turn, depends upon the proportion of excess air admitted for combustion. The amount of excess air is measured by the COt content; the less-the amount of COt, 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 greater than the loss through one of three or four passes. A poor design and a rough condition, of the brickwork will increase the loss greatly, whereas a proper design and a smooth condition will keep the loss at a 'minimum. The loss through the boiler will be less when the breeching entrance is located at or near the top of the boiler than when it is located at or near the bottom since the gases have a shorter distance to travel in the former instance. The draft loss through the breeching {hsi) is given by the general equation: 0.000194 W*TC}L A'BaWcChr (15) 359 American Society of Heating and Ventilating Engineers Guide, 1934 where W = the amount of gases flowing, pounds per second. Xc = absolute temperature of breeching gases, degrees Fahrenheit. f = coefficient of friction. L = length of breeching, feet. A -- area of breeching, square feet. B0 -- atmospheric pressure corresponding to altitude, inches of mercury. Wc = weight of a cubic foot of breeching gases at 0 F and sea level atmospheric pressure, pounds per cubic foot. Cbr = hydraulic radius of breeching section. It has been the general custom to lump off the intensity of the breeching loss at 0.10 in. of water per 100 ft of breeching length regardless of its size or shape or the amount and temperature of the gases flowing through it. This practice is hazardous and has no more foundation in fact than that of determining the friction head in a water works system without taking into consideration the size of the pipe or the amount of water flowing through it. When the ldfigth 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 (hf) is given by the equation hv 0.000194JF*XC A SB0 Wc (16) 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 (hsb) is equivalent to the loss due to the velocity head for a 90-deg bend. In changing direction of flow, the gas velocity decreases to zero with a loss of velocity head and then increases to its proper value at the expense of a loss in pressure head, the net result being a loss in pressure head equal to the velocity head at the bend. This loss is given by the equation: 0.000194W*TC &Bd A*B0WC (17) 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: 360 Chapter 26--Chimneys 0.000194KcW^Xc he = A\B0Wo (18) where Kr = coefficient of sudden contraction based on Ai smaller to the larger section. At, -- area of the smaller section. the ratio of the areas of the - 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: . 0.000194iCo W*Tc ho a\b0wc (19) where K0 = coefficient of sudden enlarg. ement based on smaller to the larger section. 2 the ratio. of the area- s of the 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 (h&) should be obtained from the manufacturer but for general purposes it may be computed from the following general equation: ta 6.6W^NTc 70s (20) where ' Wo = pounds of gases flowing per hour per linear foot of pipe in each economizer section. N = number of economizer sections. An economizer in a steam plant affects the draft in two ways, (1) it offers a resistance to the flow of gases, and (2) it lowers the average chimney gas temperature, thereby decreasing the available intensity. In the case of a natural`draft installation, both of these factors result in a relative increase in the height of the chimney and, in the case of a large 361 . . American Society of Heating and Ventilating Engineers Guide, 1934 s plant, they may add as much as 20 or 30 ft to the height. The decrease in the temperature of the gases after they have passed through the economizer has an extremely important effect on the performance of a natural draft chimney and also upon the performance of a fan. CHIMNEY CONSTRUCTION For general data on the construction of chimneys reference should be made to the Standard Ordinance for Chimney Construction of the National Board of Fire Underwriters. Briefly summarized, these provisions are as follows for heating boilers and furnaces: ' The construction, location, height and area of the chimney to which a heating boiler or warm-air furnace is connected affect the operation of the entire heating system. Most residence chimneys are built of brick and may be either lined or unlined, but in either case the walls must be air-tight and there should be only one smoke opening into the chimney. Cleanout, if provided, must be absolutely air-tight when closed. The walls of brick chimneys shall be not less than 3% in. thick (width of a standard size brick) and shall be lined with fire-clay flue lining. 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 t^p to allow for a 2 in. projection of lining. The wash or splay shall be formed of a rich cement mortar. To improve the draft the wash surface should be concave wherever practical. Flue lining may be omitted in brick chimneys,-provided the walls of the chimneys are not less than 8 in. thick, and that the inner course shall be a refractory clay brick. All brickwork shall be laid in spread mortar, with all joints push-filled. Exposed joints both inside and outside shall be struck smooth. No plaster lining shall be permitted. Chimneys shall extend at least 3 ft above flat roofs and 2 ft above the ridges of peak roofs when such flat roofs or peaks are within 30 ft of the chimney. The chimney shall be high enough so that the wind from any direction shall not strike the top of the chimney from an angle above the horizontal. The chimney shall be properly capped with stone, terra cotta, concrete, cast-iron, or other approved material; but no such cap or coping' shall decrease the flue area. There shall be but one connection to the flue to which the boiler or furnace smokepipe is attached. The boiler or furnace smoke-pipe shall be thoroughly grouted into the . chimney and shall not project beyond the inner surface of the flue lining. The size or area of flue lining or of brick flue for warm-air furnaces depends on height of chimney and capacity of heating system. For chimneys not less than 35 ft in height above grate line, the net internal dimensions of lining should be at least 7 x 1114 in. for a total leader pipe area up to 790 sq in. Above 790 and up to 1,000 sq in. of leader pipe area the lining should be at least 11J4 x 11J4 in. inside. In case of brick flues not less than' 35 ft in height with no linings, the internal dimensions should be at least 8 x 12 in. up to 790 sq in. of leader area, and at least 12 x 12 in. for leader capacities up to 1,000 sq in. Chimneys under 35 ft in height are unsatisfactory in operation and hence should be avoided. CHIMNEYS FOR CAS HEATING The burning of gas differs from the burning, of coal in that the force which supplies the air for combustion of the gas comes largely from the pressure of the gas in the supply pipe, whereas air is supplied to a bed of 362 Chapter 26--Chimneys burning coal by the force of the chimney draft. If, with a coal-burning boiler, the draft is poor, or if the chimney is stopped, the fire is smothered and the combustion rate reduced. In a gas boiler or furnace such a condition would interfere with the combustion of the gas, but the gas would continue to pass to the burners and the resulting incomplete com bustion would produce a dangerous condition. In order to prevent incom plete combustion from insufficient draft, all gas-fired boilers and furnaces should have a back-draft diverter in the flue connection to the chimney. A study of a typical back-draft diverter (Fig. 9) shows that partial or complete chimney stoppage will merely cause some of the products of combustion to be vented out into the boiler room, but will not interfere with combustion. In fact, gas-designed appliances must perform safely Fig. 9. Typical Back-Draft Diverter under such a condition to be approved by the American Gas Association Laboratory. Other functions of the'back-draft diverter are to protect the burner and pilot from the effects of down-drafts, and to neutralize the effects of variable chimney drafts, thus maintaining the appliance ef ficiency at a substantially constant value. Converted boilers or furnaces, as well as gas-designed appliances, should be provided with back-draft diverters. As is the case with the complete combustion of almost all fuels, the products of combustion for gas are carbon dioxide (COt) and water vapor with just a trace of sulphur trioxide (SOs). Sulphur usually burns to the trioxide in the presence of an iron oxide catalyst. The volume of water vapor in the flue products is about twice the volume of the carbon dioxide when coke oven or natural gas is burned. Because of the large quantity of water vapor which is formed by the burning of gas, it is quite important that all gas-fired central heating plants be connected to a chimney having a good draft. Lack of chimney draft causes stagnation of the products of combustion in the chimney and results in the condensation of a large amount of the water vapor. A good chimney draft draws air into the. chimney through the openings in the back-draft diverter, lowers the dew point of the mixture, and reduces the tendency of the water vapor to condense. 363 \  American Society of Heating and Ventilating Engineers Guide, 1934 s A chimney for a gas-fired boiler or furnace should be constructed in accordance with the principles applicable to other boilers. Where the wall forming a smoke flue is made up of less than an 8 in. thickness of brick, concrete or stone, a burnt fire clay flue tile lining should be used. Care should be used that the lengths of flue tile meet properly with no openings at the joints. Cement mortar should be used for the entire chimney. '- Table 2. Minimum Round Chimney Diameters for Gas Appliances (Inches) Height op Feet 100 or BruGas Consumption in Thousands feb Hour 200 300 400 500 750 1000 1500 2000 20 40 60 81) 100 4.50 4.25 4.10 4.00 3.90 5.70 5.50 5.35 5.20 5.00 6.60 6.40 6.20 6.00 5.90 7.30 7.10 6.90 6.70 6.50 8.00 7.80 7.60 7.35 7.20 9.40 9.15 8.90 8.65 8.40 10.50 10.25 10.00 9.75 9.40 12.35 12.10 11.85 11.50 11.00 13.85 13.55 13.25 12.85 12.40 Table 2 gives the minimum cross-sectional diameters of round chim neys (in inches) for various amounts of heat supplied to the appliance, and for various chimney heights. This is in accordance with American Gas Association recommendations. 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 gas requires the use of highly efficient appliances, the material used for the flue connection not only should be resistant to the corrosion of water, but should resist the corrosion of dilute solutions of sulphur trioxide in water. Sheet aluminum, as well as some other materials, seems to serve this purpose very well. 364 Chapter 27 FUELS AND COMBUSTION Classification of Coal, Air for Combustion, Draft Required, Com bustion of Anthracite Coal, Firing Bituminous Coal, Burning Coke, Pulverized Coal, Hand Firing, Classification and Use of Oil, Classification and Use of Gas COAL, oil, and gas are the principal fuels used for heating. The choice of the fuel to be burned is a question of economy, cleanliness, fuel availability, operation requirements, and control. Information con cerning fuel burning devices will be found in Chapter 28. COAL , The complex composition of coal makes it 'difficult to classify it into clear-cut types. Its chemical composition is some indication but coals having the same chemical analysis may have distinctly different burning characteristics. Users are mainly interested in the available heat per pound of coal, in the handling and storing properties, and in the burning characteristics. A description of the relationship between the qualities of coals and these characteristics requires considerable space; a treatment applicable to heating boilers is given in U. S. Bureau of Mines Bulletin 276. Fig. 1 illustrates the distribution of the kinds of coal by states and shows the average calorific values and the ash and moisture contents of a limited number purchased on the open market. Five hundred tests in a small domestic boiler were made with these coals by the U. S. Bureau of Mines and the lower curves show the averages of the pounds of water evaporated per pound of coal under similar and normally good operating conditions. A brief description of the kinds of fuels is given in the following para graphs, but it should be recognized that there are no distinct lines of demarcation between the kinds, and that they graduate into each other: Anthracite is a clean, dense, hard coal which creates very little dust in handling.. It is comparatively hard to ignite but bums freely when well started. It is non-caking, bums with a short flame, creates very little smoke, burns uniformly, and requires little attention to the fuel beds between firings. It is capable of giving a high efficiency in the common types of hand-fired furnaces. Semi-anthracite has a higher volatile content than anthracite, is not as hard and ignites somewhat more easily; otherwise its properties are similar to those of anthracite.- Semi-bituminous coal is soft and friable, and fines and dust are created by handling. It ignites somewhat slowly and bums with a medium length of flame. Its caking prop erties increase as the volatile matter increases, but the coke formed is relatively weak. Having only half the volatile matter content of the more abundant bituminous coals it can be burned with less production of smoke, and is sometimes called smokeless coal. 365 American Society of Heating and Ventilating Engineers Guide, 1934 s The term bituminous coal covers a large range of coals, and includes many types having distinctly different composition, properties and burning characteristics. The coals ranee from the high-grade bituminous coals of the East to the poorer coals of the West. Their caking properties range from coals -which completely melt, to those from which the volatiles and tars are distilled without change of form, so that they are classed as non caking or free-burning. Most bituminous coals are strong and non-friable enough to permit of the screened sizes being delivered free from fines. In general, they ignite easily, burn freely; the length of flame varies with different coals, but it is long. Much smoke and soot are possible and are difficult to reduce to reasonable amounts at low rates of burning. Sub-bituminous coals occur in the western states; they are high in moisture when 366 Chapter 27--Fuels and Combustion mined and tend to break up as they dry or when exposed to the weather; they are liable to ignite spontaneously when piled or stored. They ignite easily and quickly and have a medium length flame, are non-caking and free-burning; the lumps tend to break into small pieces if poked; very little smoke and soot are formed. Lignite is of woody structure, very high in moisture as mined, and of low heating value; it is clean to handle. It has a greater tendency than the sub-bituminous coals to disintegrate as it dries, and also is more liable to spontaneous ignition. Freshly mined lignite, because of its high moisture, ignites slowly. It is non-caking. The, char left after the moisture and volatile matter are driven off burns very easily, like charcoal. The lumps tend to break up in the fuel bed and pieces of char falling into the ash pit continue to bum. Very little smoke or soot is formed. Coke is produced by the distillation of the volatile matter from coal. The type of coke depends on the coal, or mixture of coals used, the temperatures and time of distil lation and, to some extent, on the type of retort or oven; coke is also produced as a residue from the destructive distillation of oil. High-temperature cokes. Coke as usually available is of the high-temperature type, and contains between 1 and 2 per cent volatile matter. High-temperature cokes are sub divided into beehive coke of which comparatively little is now sold for domestic use, by product coke, which covers the greater part of the coke sold, and gas-house coke. The differences among these three cokes are relatively small; their denseness and hardness decrease and friability increases in the order named. In general, the lighter and more friable cokes ignite and burn the more easily. Low-temperature cokes are produced at lower coking temperatures, and only a portion of the volatile matter is distilled off. Cokes as made by various processes under develop ment have contained from 10 to 15 per cent volatile matter. In general, these cokes ignite and burn more readily than high-temperature cokes. The properties of various low-temperature cokes may differ more than various high-temperature cokes because of the differences in the quantities of volatile matter and because some may be light and others are briquetted. The sale of petroleum coke for domestic furnaces has been small and is generally confined to the Middle West. They vary in the amount of volatile matter they contain,' but all have the common property of a very low ash content, which necessitates the use of refractory pieces to protect the grates from being burned. In order to obtain perfect combustion a definite amount of air is re quired for each pound of fuel fired. A deficiency of air supply will result in combustible products passing to the stack unburned. An excess of air absorbs heat from the products of combustion and results in a greater loss of sensible heat to the stack. ' Total Air Required. The theoretical amount of air required per pound of fuel for perfect combustion is dependent upon the analysis of the fuel; Table 1. Pounds of Air per Pound of Fuel as Fired Anthracite Coke Sna-BrnnoNOUs Bituminous Idatcm 9.6 11.2 11.2 10.3 6.2 however, for estimating purposes the theoretical air required for different grades of fuel may roughly be taken from Table 1. An excess of about 50 per cent over the theoretical amount is considered good practice under usual operating conditions. The amount of excess air, based upon the laws of combustion, can be determined by its relation to the percentage of COt (carbon dioxide) in the products of combustion. This relationship is shown by the curves (Fig. 2), for high and low volatile coals and for coke. _ In hand-fired fur naces with long-periods between firings the combustion goes through a cycle in each period and the quantity of excess air present varies. 367 , American Society of Heating and Ventilating Engineers Guide, 1934 s Secondary Air. The division of the total into primary and secondary air necessary to produce the same rate of burning and the Same excess air depends on a number of factors which include size of fuel, depth of fuel bed and diameter of fire pot. The ratio of the secondary to the primary air increases with decrease in the size of the fuel pieces, with increase in the depth of the fuel bed, and with increase in the area of the fire pot; the ratio also increases with increase in rate of burning. Size of the fuel is a very important factor in fixing the quantity of secondary air required for non-caking coals. With caking coals it is not so important because small pieces fuse together and form large lumps. Fortunately a smaller size fuel gives more resistance to air flow through the fuel bed and thus automatically causes a larger draft above the fuel Chapter 27--Fuels and Combustion Bituminous coals require a large amount of secondary air during the period subsequent to a firing, to consume the gases and to reduce the smoke. The smoke produced is a good indicator, and that opening is best which reduces the smoke to a minimum. Too'much secondary air will cool the gases below the ignition point, and prove harmful instead of beneficial. The following suggestions will be helpful; 1. In cold weather, with high combustion rates, the secondary air damper should be ha2lf.oIpnenvearlyl thmeildtimwee.ather, with a very low combustion rate, the secondary air damper should be closed all the time. Fig. 2. Relation Between CO, and Excess Air in Gases of Combustion bed, which draws in more secondary air for the same slot openings. In spite of this, a small size fuel requires a larger opening of the door slots; for a certain size for each fuel no slot opening is required, and for larger sizes too much excess air gets through the fuel bed. It is impossible to establish a single rule for the correct slot opening for all types and sizes of fuels and for all rates of burning. Furthermore, the size of slot opening is dependent on whether the ashpit damper is open or closed. It is better to have too much than too little secondary air; the opening is too small if there is a puff of flame when the firing door is opened. Fig. 3 taken from the U. S. Bureau of Mines Report of Investigations No. 2980 shows the relationship of the slot opening, for a domestic fur nace, to the size of coke and the rate of burning; these openings are with the ashpit damper wide open, and would be less if the available draft permits of its being partly closed. The same openings are satisfactory for anthracite. 368 '. - ' . From U. S. Bureau of Mines. 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 3. For temperatures between very mild and very cold, the secondary air damper should be in an intermediate position. 4. For ordinary house operation, secondary air is needed after each firing for about one hour. Draft Required 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 369 American Society of Heating and Ventilating Engineers Guide, 1934 s: bed and more frequent cleanings to keep its resistance down. Insufficient draft also restricts the control by adjustment of the dampers. The quantity of excess air present has a marked effect on the draft required to produce a given rate of burning, and it is often possible to produce a higher rate by increasing the thickness of the fuel bed. Combustion of Anthracite Coal An anthracite coal fire should never be poked, as this serves to bring ash to the surface of the fuel bed where it melts into clinker. Grate size anthracite coal is suitable for large grates and for a fuel depth of 20 in. or more. The air spaces are large; the amount of surface in contact with the air is small, and consequently combustion is slow. Lumps of rock or slate, being large, may cause trouble in shaking the grate. On grates 25 in. and under, the fire is likely to go out easily with this fuel, unless mixed with small size coal for reducing the air spaces. . Egg size is suitable for large firepots (grates 25 in. and over) if the fuel can be fired at least 20 in. deep. The air spaces between the pieces of coal are large and normal combustion is slower than with the next smaller size coal. Pieces of rock and slate sometimes may be large enough to cause some trouble in shaking the grate. For best results this coal should be fired deep. . Stove size coal is the popular size of anthracite fuel for most boilers and furnaces used for heating buildings. It is small enough to burn well on 17 in. grates, but large enough so that the draft loss through the fuel bed is not too great. The only instructions needed for burning this type of fuel are that the grate should be shaken before each firing, the fire should never be poked from the top, and the fuel should be fired deeply and uniformly. Chestnut size coal is in demand for firepots up to 20 in. in diameter, especially those in which the fuel cannot be fired over 15 in. deep. The percentage of ash is usually higher than in stove coal, but the pieces of rock and slate are small and do not interfere with the shaking of the grates. Pea size coal is often an economical fuel to burn. It is relatively low in price. When fired carefully, pea coal can be burned on standard grates. It is well to have a small amount of a larger fuel on hand when building new fires, or when filling holes in the fuel bed. Care should be taken to shake the grates only until the first bright coals begin to fall through the grates. The fuel bed, after a new fire has been built, should be increased in thickness by the addition of small charges until it is at least level with the sill of the fire door. This keeps a bed of ignited coal in readiness against the time when a sudden demand for heat shall be made on the heater. When firing, the bright fuel should either be pulled forward or pushed to the back of the firepot, leaving a hollow in which to throw the fresh fuel and leaving a portion of the glowing coal exposed to ignite the gases rising from the fuel; otherwise a gas explosion may occur. Pea size coal requires a strong draft and therefore the best results generally will be obtained by keeping the choke damper open, the coldair check closed, and by controlling the fire with the air-inlet damper only. Pea size can also be fired in layers with stove or egg size anthracite and its use in this manner will reduce the fuel costs and attention required. 370 Chapter 27---Fuels and Combustion Buckwheat size coal requires much the same attention as pea size coal, except that the smaller size of the fuel makes it more difficult to burn on ordinary grates. Even 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. A good draft is required and consequently the fire is best controlled by the air-inlet damper only. Where frequent attention can be given and where there is not a big heat demand, this fuel is frequently burned without the aid of any special equipment. In general it will be found more satisfactory with buckwheat coal to maintain a uniform heat output and consequently to keep the system warm all the time, rather than to allow the system to cool off at times and then to attempt to burn the fuel at a high rate while warming up. A uniform low fire will minimize the clinker formation and keep the clinker in an easily broken up condition so that it readily can be shaken through the grate. Forced draft and special grates or retorts frequently are used with this fuel for best results. No. 2 buckwheat anthracite, or rice size, is used only with forced draft equipment on mechanical stokers. No. 3 buckwheat anthracite, or barley, has no application in domestic heating. Firing Bituminous Coal Bituminous coal should never be fired over the entire fuel bed at one time. A portion of the glowing fuel should always be left exposed to ignite the gases leaving the fresh charge.' Air should be admitted over the fire through a special secondary air device, or through a slide in the fire door or by opening the fire door slightly. If the quantity of air admitted is too great the gases will be cooled below the ignition temperature and will fail to bum. The fireman can judge the quantity of air to admit by noting when the air supplied is just sufficient to make the gases burn rapidly and smokelessly above the fuel bed. The red fuel in the firebox, before firing, excepting only a shallow layer of coke on the grate, should be pushed to one side or forward or back ward to form a hollow in which to throw the fresh fuel. (Some manu facturers recommend that all red fuel be pushed to the rear of the firebox and that the fresh fuel be fired directly on the grate and allowed to. ignite from the top. The object of this is to reduce the early rapid distillation of gases and to reduce the quantity of secondary air required for smoke less combustion). It is well to have the bright fuel in the firebox so placed that the gases from the freshly fired fuel, mixed with the air over the fuel bed, pass over the bed of bright fuel on the way to the flues. The bed of bright fuel then supplies the heat to raise the mixture of air and gas to the ignition temperature, thereby causing the gaseous matter to burn and preventing the formation of smoke. - The fuel bed should be carried as deep as the size of fuel and the available draft permit, in order to have as much coked fuel as possible for pushing to the .rear of the firebox at the time of firing. A deep fuel bed obtains the longest firing intervals. 371 %i ' /s American Society of Heating' and Ventilating Engineers Guide, 1934 If the coal is of the caking kind the fresh charge will fuse into one solid mass which can be broken up with the stoking bar and leveled from 20 min to one hour after firing, depending on the temperature of the firebox. Care should be exercised when stoking not to bring the bar up to the surface of the fuel as this will tend to bring ash into-the high temperature zone at the top of the fire, where it will melt and form clinker. The stoking bar should be kept as near the grate as possible and should be raised only enough to break up the fuel. With fuels requir ing stoking it may not be necessary to shake the grates, as the ash is usually dislodged during stoking. . The output obtained from any heater with bituminous coal will usually exceed that obtainable with anthracite, since soft coal burns more rapidly than hard coal and with less draft. Soft coal, however, will require frequent attention to the fuel bed, because it burns unevenly, even though the fuel bed may be level, forming holes in the fire which admit too much air, chilling the gases over the fuel bed and reducing the available draft. Semi-bituminous coal is fired like bituminous coal, and because of its caking characteristics requires practically the same attention. The Pocahontas Operators Association recommends the central cone method of firing, in which the coal is heaped on to the center of the bed forming a cone the top of which should be level with the middle of the firing door. This allows the larger lumps to fall to the sides, and the fines to remain in the center and be coked. Thepoking should be limited to 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. Burning Coke Coke is a very desirable fuel and usually will give satisfaction as soon as the user learns how to control the fire. Coke ignites and burns very rapidly with less draft than anthracite coal. In order to control the air admitted to the fuel it is very important that all openings or leaks into the ashpit be closed tightly. A coke fire responds more rapidly, than an anthracite fire to the opening of the dampers. This is an advantage in warming up the system, but it also makes it necessary to watch the dampers more closely in order to prevent the fire from burning too rapidly. A deep fuel bed always should be maintained when burning coke. The grates should be shaken only slightly in mild weather and should only be shaken until the first red particles drop from the grates in cold weather. Since coke weighs only about half as much as anthracite coal per cubic foot, and therefore only about half as much can be put in the firepot, it will be necessary to fire oftener; but during the greater part of the heating season this will not be an item of importance. 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 134 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 uniform size of coke is always more satisfactory. Large sizes of coke should be either mixed with fine sizes or should be broken up before using. 372 Chapter 27--Fuels and Combustion The practice of treating the more friable coals to allay the dust they create is increasing. The coal is sprayed with a solution of calcium chloride or a mixture of calcium and magnesium chlorides. Both these salts are very hygroscopic and their moisture under normal atmospheric conditions keeps the surface of the coal damp, thus reducing the dust during delivery and in the cellar, and obviating the necessity of sprinkling the coal in the bin. The coal is sometimes treated at the mine, but more usually by the local distributor just before delivery. The solution is 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. Installations of pulverized coal burning plants in heating boilers are of the unit type, in which the pulverized coal is delivered into the furnace immediately after grinding, together with the proper amount of preheated air. With this apparatus, where the necessary furnace volume is ob tainable, high efficiencies can be obtained. A 150-hp boiler has generally been considered the smallest size for which pulverized fuel is feasible. Complications are introduced if an installation with a single boiler has to take care of very light loads. Hand Firing Hand firing is the oldest and the most widely used method of burning coal for heating purposes. To keep the fuel bed in proper condition where hand firing is used, the following general rules should be observed: 1. Remove ash from fuel bed by shaking-the grates whenever fresh fuel is fired. This removes ash from the fire, enables the air to reach the fuel and does away with the for mation of clinker (which is melted ash). 2. Supply the boiler with a deep bed of fuel. Nothing is gained by attempting to fire a small amount of fuel. A deep bed of fuel secures the most economical results. 3. Remove ash from ashpit at least once daily. Never allow ash to accumulate up to the grates. If the ash prevents the air from passing through, the grate bars will burn out and much clinker trouble will be experienced. The principal requirements for a hand-firedfurnace are that it shall have enough grate area and combustion space. The amount of grate area required is dependent upon the desired combustion rate. . The furnace volume is influenced by the kind of coal used. Bituminous coals, on account of their long-flaming characteristic, require more space in which to burn the gases of combustion completely than do the coals low in volatile matter. For burning high volatile coals provision should be made for mixing the combustible gases thoroughly so that com bustion is complete befoie 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. OIL Uniform oil specifications were prepared in 1929 by the American Oil. Burner Association, in cooperation with the American Petroleum Institute, the U. S. Bureau of Standards, the American Society for Testing Materials and other interested organizations. Oil fuels were classified into six groups, as indicated by Table 2. When these specifications were prepared, it was generally accepted that the first three grades were adapted to domestic American Society of Heating and Ventilating Engineers Guide, 1934 Table 2. Commercial Standard Fuel Oil Specifications A. Detailed Requirements for Domestic Fuel Oils Grade of Oil No. 1 Light Domestic Fuel Oil A light distillate oil for use in burners requir ing a high grade fuel. Approx. Btu per Gal. Flash Point Min. [ Max. Water and Sediment. Maximum * Pour Point. Maximum Distillation Test Viscosity Maximum 139.000 110 F i 165 F , 0.05% lor legal lor legal 15 F 10%point,| End point, maximum maximum 420 F 600 F No. 2 Medium Domestic Fuel Oil A medium distil late oil for use in burners re quiring a high grade fuel. 141.000 125 F 190 F for legal!lor legal] 0.05% 10%point,| 90% point, maximum 1 maximum 440 F 620 F No. 3 Heavy Domestic Fuel Oil A distillate fuel oil for use in burners where a low viscosity oil is required. 143.400 150 F 200 F or legal) or legall 0.1% 15 F 10% point, 90% point, Saybolt . maximum maximum Universal 460 F 675 F at 100 F 55 seconds Ho:erthcLhs!^ifiSSon?rhSiTMr and " _B. Detailed Requirements for Industrial Fuel Oils Grade of Oil No. 4. Light Industrial Fuel Oil An oil known to the trade as a light fuel oil for use In burners where a low vis cosity industrial fuel oil is required. Approx., Btu per Gal. Flash Min, Point. Max. Water and Sediment. Maximum Pour Point, Maximum Viscosity, Maximum 144,500 150 F. See Noteb L0% See Note c Saybolt Universal at 100 F 125 seconds No. 6 ' Medium Industrial Fuel Oil Same as Federal Specifications Board specification for bunker oil "B" for burners adapted to the use of indus trial fuel oil of medium viscosity. 146.000 150 F 1.0% Saybolt Furol at 122 F 100 seconds No. 6 Heavy Industrial Fuel Oil Water sediment Saybolt . Furol Same as Federal Specifications Board specification for bunker oil "C" for 150,000 burners adapted to oil of high viscosity. 150 F 1.759 0.259 at 122 F 300 seconds 5.\l| ^Whenever required, as for example in burners with automatic ignition, a maximum flash poinfmay be specified. However, these specifications shall not require a flash point less than 250 F under any conditions. cpour point may be specified whenever required by conditions of storage and use. However, these specifications shall not require a pour point less than 15 F under any conditions. use, while the last three were suitable only for commercial and industrial burners. This differentiation has not proved stable, and today domestic installations arousing Nos. 4 and 5 of the so-called heavy-oil group. Several burners adapted to domestic use have recently been listed for automatic operation with No. 5, or even No.. 6, oil. Usually oils Nos, 5 or 6 require 374 Chapter 27--Fuels and Combustion preheating for proper operation, but where conditions are favorable, No. 5 can be used without the equipment that this entails. There are two reasons for the trend to lower grades of oil. While the lighter oils contain slightly more heat units per pound, the weight per gallon increases more rapidly than the decrease in heat units per pound, and oil is bought by the gallon. As a consequence, while a No. 1 oil may contain 139,000 Btu per gallon, oil No. 5 may test 146,000 Btu per gallon, or 6 per cent more. Usually there is a differential of 3ff to 4ff between the No. 1 and No. 5 oils, so that the economy of buying the heavier fuels is apparent; there remains the economic utilization of the heat content of the heavier oils. The cost of oil fuel is dependent also upon the amount that can be delivered at one time, and the method of delivery. Common practice has split the tank of the truck delivering oils for domestic use into compart ments of 400 to 500-gal capacity, and these unit dumps are made the basis of price. Where a truck can be connected to a storage-tank fill and quickly discharge its oil by pump, the price obviously can be less than where a smaller quantity must be drawn off in 5-gal cans and poured. For similar reasons an installation that can be supplied from a tank car on a siding provides for a lower unit fuel cost than one where the oil must be trucked, even in the large trucks holding 2,000 gal or more that are used for distributing the heavier oils. CAS 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. When gas is burned a large amount of water vapor is produced as one of the products of combustion. This ordinarily escapes up the chimney, carrying away with it a certain amount of beat. However, when the heat value of gas is determined in an ordinary calorimeter, this water vapor is condensed and the latent heat of vaporization that is given up during the condensation is reported as a portion of the heat value of the gas. The heat value so determined is termed the gross or higher heat value and this is what is ordinarily meant when the heat value of gas is specified. The heat that is reclaimed by the condensation of the water vapor amounts to about 10 per cent of the total heat value. It is impractical to utilize the entire higher heat value of the gas in any house-heating appliance, because to do so it would be necessary to cool the products of combustion down below their dew-point, which is ordinarily in the neighborhood of 130 F. Natural gas is the richest of the gases and contains from 80 to 95 per cent methane, with small percentages of the other combustible hydrocarbons. In addition, it contains from 0.5 to 5.0 per cent of COj, and from 1 to 12 or 14 per cent of nitrogen. The heat value varies from 700 to 1,500 Btu per cubic foot, the majority of natural gases averaging about 1,000 Btu per cubic foot. Table 3 shows typical values for the three main oil fields, although values from any one field vary materially. Table 3 also gives the calorific values of the more common types of 375 American Society of Heating and Ventilating Engineers Guide, 1934 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. There are limits to the variation allowable, because the specific gravity of the gas depends on its Table 3. Representative Properties of Gaseous Fuels Based, on Gas at 60 F and 30 in. Hg.. Gab Natural gas-- Mid-Conti nental Natural gas-- Ohio Natural gas--. Pennsylvania Retort coal gas Coke oven gas Carburetted water gas Blue water gas Anthracite pro ducer gas Bituminous producer gas Oilgas Btu psb Co Ft High Low (Gross) (Net) Ghatitt Ant = 1.00 Ant Required roe Combus tion, (Cu Ft) Products or Combustion Cubic Feet Total COt BiO with Ni Ulti mate COtDry Bsuna 967 873 0.57 9.17 1130 1025 0.65 10.70 1232 575 588 1120 510 521 0.71 0.42 0.42 11.70 5.00 5.19 536 496 0.65 4.37 308 281 0.53 . 2.26 134 124 0.85 1.05 150 140 0.86 1.24 575 510 0.35 .4.91 0.97 1.92 10.2 11,7 1.17 2.16 11.8 12.1 1.30 0.50 0.51 2.29 1.21 1.25 12.9 5.7 5.9 12.3 7 11.2 11.0 0.74 0.75 .5.0 17-2 0.46 0.51 2.8 22.3 0.33 0.19 1.9 19.0 0.35 0.19 0,47 1.21 2.0 19.0 5.6 10.7 ' -- Theoretical Flame Tem perature. (deg Fahr) 3580 3600 3620 3665 3660 3815 3800 3000 3160 3725 composition, and too great a change in the specific gravity necessitates a change in the adjustment of the burners of small appliances. . i Table 3 shows that a large proportion of the products of combustion when gas is burned, may consist of water vapor, and that the greater the proportion of water vapor, the lower the maximum attainable COi by gas analysis. The table also shows that a low calorific value'does not neces sarily mean a low flame temperature since, for example, natural gas has a theoretical flame temperature of 3600 F and blue water gas of 3800 F, although it has a calorific value less than one-third that of natural gas. The quantity of air given in Table 3 is that required for theoretical combustion, but with a properly designed and installed burner, the excess air can be kept low. The division of the air into primary and secondary is a matter of burner design and the pressure of gas available, and also of the type of flame desired. 376 Chapter 28 AUTOMATIC FUEL BURNING EQUIPMENT Stokers, Residential Stokers, Apartment House Stokers, Com mercial Stokers, Domestic Oil Burners, Air and Oil Supply, Atomi zation, Type of Flame, Ignition, Boilersfor Domestic Oil Burners, Commercial Oil Burners, Gas-Fired Appliances, Gas Boilers, Warm Air Furnaces, Space Heaters, Conversion Burners, Gas Appliances, Installation Features ABOR saving, automatic, mechanical equipment for the efficient L combustion of coal, oil, and gas is considered in this chapter. MECHANICAL STOKERS Assuming the same intelligence in handling the fire, coal can be burned more efficiently on a mechanical stoker than on any kind of hand-fired grate. This does not necessarily mean that a stoker installation may be more economical, because the amount of coal burned may be so small or the cost of the installation so high that the savings with stokers may not be sufficient to pay for the investment. The operation of burning coal in volves uniformity in stoking, proper distribution over the fuel bed, admission oT air as required to all parts of the fuel bed, and disposal of the ash. The handling of the volatile gas is largely a matter of furnace design but since this gas forms a considerable portion of the heating value of the coal, it may also be said that the proper handling of this gas is a function of firing. All mechanical stokers must provide means of taking care of these several functions in order fully to serve their purpose. Classifications of Stokers Stokers may be divided into four types according to their construction and operation, namely, (1) overfeed flat grate, (2) overfeed inclined grate, (3) underfeed side cleaning type, and (4) underfeed rear cleaning type. They may also be classified according to their uses. The following classification has been adopted by the U. S. Department of Commerce: Class X. Residential (Capacity less than 100 lb coal per hour). Class 2. Apartment houses and small commercial heating jobs (Capacity 100 to 200 lb coal per hour). Class 3. General commerical heating and small high pressure steam plants (Capacity 200 to 300 lb coal per hour). Class 4: Large commercial and high pressure steam plants (Capacity over 300 lb per hour). Overfeed Flat Crate Stokers This type, is represented by the various chain grate stokers. These 377 American Society of Heating and Ventilating Engineers Guide, 1934 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 com plete 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 clinker forming characteristics of which make it desirable to burn the fuel without disturbing it. This type of stoker invariably requires the use of an arch over the front of the stoker to maintain ignition of the incoming fuel and to maintain the volatile gas at a temperature suitable for combustion. Frequently, a rear combustion arch is required to maintain ignition until the fuel is fully consumed. Overfeed Inclined Crate Stokers In general the combustion principle is similar to the flat grate stoker, but this stoker 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 periodically. 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 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 gas. . Underfeed Side Cleaning Stokers In this type, the fuel is fed in 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 the volatile gas is released, is mixed with air, and passes through the fire where'it is burned. The ash may be continuously discharged as in the small stoker or may be accumulated on a dump plate and periodically discharged. This stoker requires no arch as it automatically provides for the combustion of the volatile gas. ' Underfeed Rear Cleaning Stokers This type carries on 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 sa'me as the side cleaning underfeed. Class 1 Stokers, Residential A common type of stoker in this class consists of a round retort having tuyeres at the top where all of the air for combustion is admitted. Coal is fed from a storage hopper outside of the boiler by means of a worm into the bottom of this retort and beneath the fire. The equipment includes a blower which is driven by the same motor-that drives the stoker. Some domestic stokers are .provided with automatic grate shaking 378 Chapter 28--Automatic Fuel Burning Equipment mechanism together with screw conveyers for removing the ash from the ashpit and depositing it in an ash receptacle outside the boiler. Certain types can also be provided with a coal conveyer which takes coal from the storage bin and maintains a full hopper at the stoker. They may feed coal to the furnace either intermittently or with a continuous flow regu lated automatically to suit conditions. Where the boiler is provided with indirect coils for heating the domestic hot water, the stoker may be so arranged that it can be used the entire year to maintain a continuous hot water supply. . Class 2 Stokers, Apartment House This class is used extensively for heating plants in apartments, hotels, etc., and also for small industrial plants such as laundries, bakeries, creameries, etc. The various stokers in this class differ materially in their design, although the majority 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 combustion to an ash plate at the rear. All of the stokers are provided with a coal hopper outside of the boiler. In the underfeed types, the coal feed from this hopper to the furnace may be accomplished by a continuously revolving worm or by an intermittent plunger. The drive for the coal feed may be an electric motor, or a steam or hydraulic cylinder. With an electric motor, the connection between the driver and the coal feed may be through a variable speed gear train which provides two or more speeds for the coal feed; or it may be through a simple gear train and a variable speed driver for the change in speed of the coal feed; or a simple gear train with a coal feed having an adjustment for varying the travel of the feeding device. With a steam or hydraulic cylinder, the power piston is connected directly to the coal feeding plunger. The stokers in this class vary also in their retort design. It is customary in the worm-feed type to use a short retort in order that the unsupported length of worm within the retort may not be too weak for continuous service. In this type the retort is placed approximately in the middle of the furnace and is provided with tuyere openings at the top on all sides. In the plunger-feed type the retort extends from the inside of the front wall entirely to the rear wall or to within a short distance of the rear wall. This type of retort has tuyeres on the sides and at the rear. This class of stokers also differs in the grate surface surrounding the retort. In many of the worm-feed stokers this grate is entirely a dead plate on which the fuel rests while combustion is completed. In the deadplate type, all of the air for combustion is furnished by the tuyeres at the retort. Because of this, combustion is well advanced over the retort so that it may easily be completed by the air which percolates through the fuel bed. With the dead-plate type of grate the ash is removed through the fire doors and it is therefore desirable that the fuel used shall be one in which the ash is readily reduced to a clinker at the furnace temperature, in order that it may.be removed with the least disturbance of the fuel bed. In other stokers in this class, the grates outside of the retort are air- 379 American Society of Heating and Ventilating Engineers Guide, 1934 admitting and shaking grates. These grates permit a large part of the ash to be shaken into the ash pit beneath, while the clinkers 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 ash pit. . 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 ash pit 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, they can also be used to burn the small sizes of anthracite but at a somewhat lower rate. It is often customary to have the janitor or some other attendant care for the boiler as one of his duties. Under these conditions the heating plant does not receive the same careful attention as it would if a man devoted his entire attention to the fire. With periodic hand-firing, the boiler is operated inefficiently much of the time. With a stoker, the boiler is operated at the rate that the conditions require so long as there is coal in the hopper. With hand firing, it is customary to use the more expensive sizes of fuel, while with a stoker the smaller sizes are used at a considerable saving in the cost per ton. Because the stoker responds promptly to automatic regulation, it is possible to maintain a reasonably constant standard. Also because of the fact that the stoker feeds the fuel' regularly and in small quantities without losses due to opening doors, etc., it must of necessity be more efficient than hand firing. This increase in efficiency depends entirely on conditions, with a minimum of about 10 per cent and a maximum of about 25 per cent. Class 3 Stokers, General Commercial ' - These stokers are suitable for the heating plants of large schools, hotels, hospitals, or other large institutions as well as industrial plants. This class is served both by overfeed stokers and by underfeed stokers^ The overfeed stokers are in general of three types, (1) the chain grate, (2) the rear cleaning inclined grate, and (3) the center cleaning inclined grate or V type. .. Stokers of this type are usually operated by natural draft, although in some cases conditions permit the operation of forced draft under the grates. With most fuels, it is not advisable to operate 'overfeed grates at 380 Chapter 28--Automatic Fuel Burning Equipment too high a combustion rate because of the greater difficulty of cleaning and the higher maintenance, but where the fuel is free burning and has a high ash fusion temperature, the combustion rate is not so restricted. The operation of the chain grates and the rear cleaning type of inclined grates has already been described. The V-type stoker is practically obsolete although many are still in operation. In this stoker, the grates fcre inclined downward from both sides of the furnace to a low point at the middle where there is either a dump plate for periodic disposal of the ash or a rotary ash grate for com tinuous discharge of ash. In this stoker, the fuel is fed into a hopper at the top of the grate on each side of the furnace and advanced down the grates to the center where the refuse is accumulated. This stoker is always provided with a combustion arch over the entire furnace for the purpose of assuring thorough combustion of the solid fuel and providing a furnace temperature sufficiently high to burn the volatile gases. Because of this high furnace temperature and because so little of the boiler surface is exposed to the fire to assist in carrying off the heat by radiation, this stoker is characterized by severe clinkering in the ash area. With all types of overfeed stokers, the most desirable installations are in boilers which are operated with comparatively uniform loads and moderate rates of combustion, since, even with good combustion arches, fluctuating loads or high combustion rates result in free volatile gas and this in turn means smoke. The underfeed stokers in this class were the first of the type to be developed as at the time of their development very few large boilers were in use. The stokers are not so varied in design as those in the'smaller class although in principle they are much the same. Practically all of them are of the plunger coal feed type with retorts extending the entire . length of the furnace, with air supplying grates adjacent to the retorts, and with manually-operated dump plates at the sides of . the furnace. The coal feeding plunger is operated by a steam or electric driver through a reduction gearing, or by a steam or hydraulic piston connected directly to the coal feeding plunger. 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 gas 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. Another difference in these stokers is that some makes use a single air chamber under the whole grate area thus having the same air pressure under the ignition area as under the rest of the grate, while others have a divided air chamber using the full air pressure under the ignition area and 381 American Society of Heating and Ventilating Engineers. Guide, 1934 a reduced air pressure under the remainder of the grate. These stokers vary in size from approximately 5 ft square to a maximum of 834 ft square. Class 4 Stokers, Large Commercial These stokers are usually of the underfeed type with multiple retorts and either side cleaning or rear cleaning. In the side cleaning type there may be as many as three retorts tn the furnace, and the stoker functions in the same manner as has been described for the single retort. These stokers are usually limited in length to approximately 834 ft while the width may be as great as 1034 ft. In the rear cleaning stokers the number of retorts and the dimensions of the furnace are practically unlimited. DOMESTIC OIL BURNERS The number of combinations of the characteristic elements of domestic oil burners is rather large and accounts for the variety of burners found in actual practice. Domestic oil burners may be classified as follows: 1. AIR SUPPLY FOR COMBUSTION a. Atmospheric--by natural chimney draft. b. Mechanical--electric-motor-driven fan or blower. c. Combination of (a) and (b)--primary air supply by fan or blower and secondary air supply by natural chimney draft. 2. METHOD OF OIL PREPARATION a. Vaporizing--oil distills on hot surface or in hot cracking chamber. b. Atomizing--oil broken up into minute globules. ' (1) Centrifugal--by means of rotating cup or disc. . (2) Pressure--by means of forcing oil under pressure through a small nozzle or orifice. ; ' (3) Air or steam--by high velocity air or steam jet in a special type of nozzle. (4) Combination air and pressure--by air entrained with oil under pressure and forced through a nozzle. c. Combination of (o) and (b). 3. TYPE OF FLAME , a. Luminous--a relatively bright flame. An orange-colored flame is usually best if no smoke is present. b. Non-luminous--Bunsen-type flame (i.e. blue flame). 4. METHODS OF IGNITION a. 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. b. Gas. (1) Continuous--pilot light of constant size. (2) Expanding--size of pilot light expanded temporarily at the beginning of burner operation. c. Combination--electric sparks light the gas and the gas flame ignites the oil. d. Manual--by manually-operated gas torch for continuously operating burners. 382 Chapter 28--Automatic. Fuel Burning Equipment 5. MANNER OF OPERATION o. 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 & low flame. . c. Graduated--burner operates continuously but flame is graduated according to needs by regulating both air and oil supply. ; Air and Oil Supply The object of regulating the air and oil supplies is to obtain a complete mixture of the proper quantities of oil and air so the fire will be clean and efficient. Proper and dependable ignition also depends upon the ability of the burner to produce consistent fuel-air mixtures. The type and shape of flame depend largely upon the methods of air and oil supply employed. It should be pointed out that this mixture burns in a space called the furnace, which is lined with refractory bricks or other heat-resistant substances for the purpose of maintaining that space at a high tempera ture so that the oil and air may completely unite and burn. Excessive cooling before combustion is completed stops the combustion process and causes soot. The furnace is in some instances a valuable auxiliary in assisting in the actual mixture of oil and air and in modifying the flame shape, besides its primary function of maintaining high temperatures. The size and shape of furnace required are important, especially where the dimensions of the space into which the burner is to be placed are already fixed. Atomization The purpose of atomization is greatly to increase the surface area of a given quantity of oil in order to accelerate the change from the liquid state (in which oil cannot burn) to the gaseous or vaporous state, in which state it is one of the elementary fuels, gaseous hydrocarbon. This con version is largely accomplished through the action of radiant heat energy upon the flying globules of oil, and the tremendously increased surface provided aids gasification. Air for Combustion Air for combustion usually is supplied by a motor-driven fan, several types being in common use. Electric motors varying from Ho hp to H hp are used and are started and stopped by the control mechanism. In most cases, they are direct-coupled to the fan as well as to a gear or lobe pump for drawing the oil from the storage tank, and in some cases, to a pump for forcing the oil through the nozzle. All of the air required for combustion can be supplied by the blower, or else only the primary air can be supplied under pressure and provision made so that the remainder will be drawn into the combustion chamber by the natural draft developed by the chimney or by an injector-like action of the primary air. In any event there should be definite control of the quantity of air as well as of the rate of oil supply. Some method of draft regulation is advisable in order to secure proper air regulation. It is necessary to supply-more air than is actually required for complete com bustion of the oil, but the amount of excess air should be reduced to the 383 s American Society of Heating and Ventilating Engineers Guile, 1934 lowest workable minimum. Laboratory tests frequently show 25 pier cent to 50 per cent more air than is required for combustion, yet field tests indicate that the average burner operates with; from 50 per cent to 125 per cent excess air, with a corresponding reduction in the efficiency of the burner. Many domestic burners are extremes of simplicity, the only mov ing parts being the motor armature with a shaft and direct-connected fan and pump set. .. Type of Flame, Ignition If the vaporizing of the atomized oil and the combustion are concurrent events, a luminous flame will usually result. If vaporization and mixing are accomplished before combustion, a non-luminous flame will result. Some burners may produce either type of flame according to the adjust ment made. . A limited comparison of these two types of flame shows no inherent superiority of one over the other so far as thermal efficiencies are concerned. This is definitely true when the burners are placed in boilers having ample indirect surface, and is probably true in general. The moot question of radiation has not been conclusively settled. There are' indications that the radiation of luminous and non-luminous flames in boiler furnaces are practically the same. More information is needed upon this subject. It is true, however, that a non-luminous flame may show low excess air and the presence of carbon monoxide, but no smoke. Low excess air with a luminous flame will usually show little or no carbon monoxide, but will be unmistakably smoky. Visual indications, especially with a blue flame, may therefore be quite unreliable. . . ." . When, a burner is operating, intermittently under the control of a thermostat, some positive, form of ignition is required to function every time there is a call for heat... ^ The necessity for certain ignition under adverse .conditions, when the lineyoltage is low or the oil is cold is paramount, and this phase of burner design and operation has been given the closest attention, as faulty igni tion is more to be feared than improper operation once the flame is established. . The effect of the air and oil setting is important, since it may be neces sary.in some instances to adjust for greater excess air than is otherwise required in order to get a mixture suitable for certainty of ignition. Recent research1 at Yale University, conducted in cooperation with the A.S.H.V.E. Research Laboratory and the American Oil Burner Associa tion, reveals that the various methods of operation (i.e., on and off, high and low, and graduated) all have potential advantages and disadvantages and that a chbice in any case requires a consideration of the heat-absorbing characteristics of the boiler in which the burner is to operate. From the standpoint of efficiency of Operation it seems that there is little choice if at the maximum setting of all burners the boiler efficiency were at its maximum value. If, on the other hand, the boiler were operating beyond its point of maximum efficiency, then it appears that the graduated type intermittent Operation of Oil Burners, by L. E. Seeley and J. H. Powers (A.S.H.V.E. Transactions, Voi. 38, 1932). 384 Chapter 28--Automatic Fuel Burning Equipment might show better results. The following additional factors should be considered: 1. The intermittent type by having only one setting might be set for efficient com bustion at that point. 2. An intermittent burner should be set for a higher total heat output: than either of the other two types in order to get the acceleration necessary when heat is required. This may in some cases give less economical performance due to the increased boiler load. 3. An interruption in electric current might in some instances be troublesome with continuously operating burners, where manual ignition is employed. 4. The continuously operating burners must have a minimum fuel setting low enough to prevent overheating in mild weather or during the summer if the boiler is used for domestic hot water. ` 5. Electrical operating costs must be considered, but must be based upon known power requirements. The power requirements of some burners will be several times as high as others so any generalization on operating costs is futile. 6. Evenness of heat supply will have some influence on uniformity of temperature. 7. Number and cost of controls which reflect in the manufacturing costs. This entire subject, therefore, is likely to be somewhat perplexing because of the necessity of knowing, and the difficulty in determining, the efficiency characteristics of many heating boilers. Selections of oil burners on the basis of their manner of operation will probably be largely a matter of preference. The advent of special boilers for oil burning will provide the engineer with the opportunity for greater discrimination. Temperature Control, Protective Devices Domestic oil burners are controlled directly from the change in tem perature of a designated control room (usually the living room, dining room or hall), and by temperature or pressure variations in the boiler. Oil-burner installations put in only a few years ago were simplified to the extent of having a single control element--the room thermostat-- that started and stopped the burner. The modern installation provides, in addition, electrical devices inter-wired with the control system to in sure against poor operation and to guard against troubles brought.on by the characteristics of the heating plant. One control system provides an instrument actuated by two tempera ture bulbs, one placed in the outdoor air and the other in a designated part of the heating system. The control is actuated by both bulbs and is designed to maintain the heating medium at a temperature to suit the variations in outdoor temperature, the lower the outdoor temperature the higher the temperature of the heating medium. Other devices have.been developed to maintain a certain minimum temperature that will effectively .prevent the downward window currents of cold air from reaching and traveling across the floor, regardless of the room thermostat. : Owing to the comparative intensity of heat production with a burner, a boiler with limited water storage above the crown sheet might pass steam to the radiator system so rapidly, at starting, that the sheet would be uncovered, with probable damage to the boiler structure. A low-water safety can be so wired into the system that the burner will be stopped before the water level is reduced to the danger point, or a boiler feed can 385 American Society of Heating and Ventilating Engineers Guide, 1934 be installed to add water to the boiler to maintain a safe level, instead of stopping the burner. Either or both should form part of a first-class installation. Again, with either steam or water systems, the burner control can be inter-wired with a thermostatic device having its temperature element introduced into the boiler near the top, its function being to limit the maximum temperature of water or pressure of steam so the burner will, be shut off before dangerous temperatures or pressures are reached. Win dows of the room in which the thermostat is located are sometimes opened to air out the house in the morning, and if they are not closed promptly, the burner will operate continuously and possibly develop temperature and pressure conditions that might be detrimental to the boiler. This is where the safety device can be used to offset the carelessness of the human being. Safety controls have been developed for intermittent burners to guard against failure of ignition and in some instances against momentary flame failures. In general regulatory devices are well developed and depend able. Otherwise the domestic oil burner probably would not have been possible. . For further information on temperature control with oil burners, see Chapter 14. . Boilers for Domestic Oil Burners2 Boilers used with domestic installations may be those designed for solid fuel or those designed for liquid fuel. The latter are coming to the fore with great rapidity as they usually have greqtly increased secondary sur face. Many are of copper or steel tube design. Increased efficiencies of 5 per cent to 15 per cent are often obtainable with boilers designed espe cially for liquid fuel. It is possible to go to extremes in providing secondary surfaces sufficient to reduce flue temperatures to the order of 250 F to 300 F, with the result that the added resistance through the flues may necessitate the use of a booster fan to insure sufficient draft. It is difficult to obtain satisfactory efficiencies with boilers having little or no secondary surfaces, where the hot products of combustion pass almost immediately from the combustion chamber to the flue; in fact a high efficiency is unlikely with any fuel under such conditions, and the intermittent burner is especially at a disadvantage because of its characteristic development of heat at a high rate while.it is operating. It is essential that the-flame produced by an oil burner, especially where it is strongly luminous, be kept from contact with the water:backed sur faces of the combustion chamber, and to this end bricking or its equivalent must be provided in most cases. Where a burner fires through the ash pit, doorframe bricking must protect the unbacked surfaces of the ash pit. The same fire bricking constitutes the actual combustion chamber for the burner flame, and materially increases the combustion volume for a given boiler. For additional information on this subject, refer to 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). 386 Chapter 28--Automatic Fuel Burning Equipment Installation The intelligence and care with which a burner is installed largely deter mines the satisfaction that will result from its operation. Two plans for the installation of burners are in general use. In the first, the dealer makes all installations. In the other, sales agencies function only to make sales, and the installation for as many as twenty such sales offices is done by a centrally located installation force, usually factory Controlled. Some burners are adjusted for oil rate by means of a blind needle valve that can only be operated with a special wrench; others, by changing the size of the orifice; others, by a combination of orifice size and pressure. In any event, changes in the firing rate, involving careful air and draft adjustment to match the oil rate, should be made by only a trained man, Fig. 1. Full Load Rate of Oil Consumption for Heating Boilers preferably with the aid of an Orsat test set so that the degree of combus tion efficiency can be determined. It is practically impossible to set a burner flame by eye, although that has been general practice in the past. The industry is turning to the Orsat and, as a result, more domestic burners are operating at from 9 per cent to 12 per cent C02, representing a higher efficiency combustion than at 5 per cent to 8 per cent, as frequently is the case where the burner is adjusted by eye. Air for Combustion . It is essential that the basement, or at least that portion used as a boiler room, be open to the outside air, in order that sufficient air be available for combustion. Frequently a case of poor operation will be found where a test with a draft gage made by inserting the tube through the keyhole of the outer door will show that there is a partial vacuum in the basement when the burner is running, allofithe combustion air coming through the keyhole and minute cracks. A simple remedy is to cut an inch from the bottom of the outer door. , 387 American Society of Heating and Ventilating Engineers Guide, 1934 In order to achieve satisfactory heating at the lowest cost, careful con sideration should be given to oil, air and draft adjustment. The oil adjustment should be determined from the total heat requirements to be met. The heat loss of the building plus an allowance for piping plus 20 to 25 per cent for pick-up establishes the maximum output required from the boiler. Fig. .1 indicates the oil required in gallons. Piping allowances will usually vary between 25 and 10 per cent, decreasing with an increase in the size of the building. With the oil rate thus fixed, the air and draft should be set to give efficient combustion (that is, 10 to 12 per cent COi). The furnace draft should be set. reasonably low and should be maintained constant by means of an automatic draft regulator. Without this the air supply will fluctuate, causing uneven performance. A check should be made to insure that ignition will be satisfactory under all conditions. An oil burner of the continuous type might dispense with all or part of the pick-up allowance due to the nature of its operation. Careful adjustment will provide ample heat output under all conditions, will minimize the load on the boiler, and will establish the most favorable conditions for intermit tent operation. .. An essential element in the satisfactory operation of domestic oil burners is the provision for maintenance and service for the burners. What might be called emergency service for mechanical or electrical failure of the burner has rapidly diminished during the last few years until a level has-been reached where groups of 100 to 1000 burners in a community consistently will require an average of not more than one call per burner per heating season. Maintenance service is coming into general practice where, for a fixed annual payment, regular inspection is made of the burner, and faulty operation corrected before the burner becomes inoperative. This service may contemplate entire overhauling of the burner during the summer, and may include annual cleaning of the boiler flues with a specially de signed vacuum cleaner. ........... Domestic Hot Water Supply Provision may be made for heating domestic water through exchange heaters attached to the boiler, in which water is maintained at a fixed temperature or steam at a set pressure during the entire year. The flow of water or steam to the radiators is controlled by electrically-operated valves, which remain closed during warm weather and open (through the functioning of the room thermostat) when heat is required in the house. The room thermostat either causes heat to be produced by starting the burner when the room temperature drops to a predetermined point, or closes the circuit of the motor by operating a valve in the flow line of the heating system, the motor opening the water or steam valve and per mitting water or steam immediately to flow to the radiators. When the flow in a water heating system is sluggish, the room thermostat also can start the motor of a circulation pump, thereby decreasing the time re quired to bring the room temperature up to.the desired point. It is usual in small steam heating systems to dispense with the motor-. operated valve and by means of. an aquastat maintain the boiler water at a constant temperature but well below the steaming temperature, {i.e., 388 Chapter 28--Automatic Fuel Burning Equipment . 140 to 180 F). The lowest temperature setting that will produce suf ficiently hot water will be the most economicah The aquastat will always function in such a way as to maintain this temperature except when the room thermostat calls for heat, which means that a call for steam can be more quickly obtained. Another type of control valve available for hot water systems is thermostatically operated so as to prevent a flow of water to the heating system until the call of the room thermostat for heat raises the water temperature above that normally required for domestic hot water. It should be noted that, except in the case of the graduated burner, the water temperature in the heating system will nearly always reach its maximum, thereby depriving this system to some degree of its natural advantage of modulation. 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. 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. As much as 350 gal of oil per hour can be burned in these units, and frequently they are arranged in multiple on the boiler face, from two to five burners to each boiler. The larger installations are nearly always started with a hand torch, and are manually controlled, but the 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. , 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 389 American Society of Heating and Ventilating Engineers Guide, 1934 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 ash-pit volume; in new installations the boiler should be raised to make added volume available. Approximately 1 cu ft of combustioij volume should be provided for every developed boiler horsepower, and in this volume from 1.5 to 2 lb of oil can properly be combusted. This corre sponds to a maximum liberation of about 38,000 Btu per cubic foot per hour. There are indications that at times much higher fuel rates-may be satisfactory. This in turn suggests that the value of 38,000 Btu per cubic foot per hour should be used with reasonable judgment. For best results, care should be taken to keep the gas velocity below 40 ft per second. Where checkerwork of brick is used to provide secondary air, good practice calls for about 1 sq in. of opening for each pound of oil fired per hour. Such checkerwork is best adapted to flat flames, or to conical flames that can be spread over the floor of the combustion chamber. The proper bricking of a large or even medium sized boiler for oil firing is important and frequently it is advisable to. consult an authority on this subject. The essential in combustion chamber design is to provide against flame im pingement upon either metallic or. fire-brick surfaces. Manufacturers of oil burners usually have available detailed plans for adapting their burners to various types of boilers, and such information should be utilized. CAS-FIRED APPLIANCES ' The increased use of gas for house heating purposes has resulted in the production of such a large number of different types of gas-heating systems and appliances that today there is probably a greater variety of them than there is for any other kind of fuel. Gas-fired heating systems may be classified as follows: I. Gas-Designed Heating Systems. . A. Central Heating Plants. 1. Steam,.hot water, and vapor boilers. 2. Warm air furnaces. . - B. Unit Heating Systems. . 1. Warm air floor furnaces. ,' 2. Industrial unit heaters. 3. Space heaters. : 4. Garage heaters. .. II. Conversion Heating Systems. ' AL Central Heating Plants. ... , l; : I. Steam, hot water and vapor boilers. ; 2. Warm air basement furnaces. ' ' ' .. 390 Chapter 28--Automatic Fuel Burning Equipment The majority of 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. Although no exact rules can be prescribed as to the field best covered by each of the foregoing systems, each installation will have problems point ing more or less directly to some particular type of heating equipment. Gas-Fired Boilers Information on gas-fired boilers will be found in Chapter 25. Either snap action or throttling control is available for gas boiler opera tion. 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. Warm Air Furnaces There are two general classes of gas-fired warm air furnaces, the gravity furnace which depends upon the natural tendency of heated air to rise, providing the proper circulation of heated air into the room, and the mechanical circulation furnace by which the air to be heated is forced through or drawn through the furnace by means of a fan. 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 cor rosive effect of the products of combustion. With some varieties of manufactured gases, this effect is quite pronounced. Warm air furnaces are. obtainable in sizes from those sufficient to heat the largest residence down to sizes applicable to a single room. The practice of installing a number of separate furnaces to heat individual rooms is peculiar to mild climates, such as that of southern California. Small furnaces, frequently controlled by electrical valves actuated by push-buttons in the room above, are often installed to heat rooms where heat may be desired for an hour or so each day. These furnaces are used also for heating groups of rooms in larger residences. In a system of this type each furnace should supply a group of rooms in which the heating requirements for each room in the group are. similar as far as the period of heating and temperature to be maintained are concerned. Bedrooms, living rooms, and dining rooms, often present excellent possibilities for this type of furnace. The same fundamental principle of design that is followed in the con struction of boilers, that is, breaking the hot gas up into fine streams so that all particles are brought as close as possible to the heating surface, is equally applicable to the design of warm air furnaces. The desirability of using an appliance designed for gas, when gas is to be the fuel, applies even more strongly to furnaces than to boilers. Codes for proportioning warm air heating plants, such as that formu lated by the National Warm Air Heating Association (see note p. 329), 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 connection with warm air furnaces for residence heating, it is well to 391 '. . 'I - American Society of Heating and Ventilating Engineers. Guide, 1934 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 are generally used for auxiliary heating, but may be, and are in many cases, installed for furnishing heat to entire buildings. Space heaters are quite extensively used for house heating in milder climates such as exist in the South and Southwest. 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. ' Space Heaters Parlor furnaces or circulators are usually constructed to resemble a cabinet radio. They heat the room entirely by convection, i.e. tlje cold air of the room is drawn in near the base and passes up inside the jacket around a drum or heating section, and out of the heater at or near the top. These heaters cause a continuous circulation of the air in the room during the time they are 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 392 Chapter 28--Automatic Fuel Burning Equipment 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 an economical 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 connected to a basement boiler. A separate com bustion 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, especially in natural gas territories. 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 with luminous flames, operating without refractories. In each case an attempt is made to transfer the majority of the heat from the gas to the medium to be heated within the fire pot itself because of the low heat transfer that takes place in the flue passages. Many conversion units are equipped with sheet metal secondary air ducts which are inserted through the ash-pit 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, therefore 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. ' American Society of Heating and Ventilating Engineers Guide, 1934 Sizing Gas-Fired Healing 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 equivalent 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 possibleto use much Table 1. Selection Factors for Gas Boilers Equivalent Cast Iron Steam Radiation (Squabs Feet of 240 Btu Each) Selection Factor (Peb Cent) 500 800 1,200 1,600 2,000 3,000 4,000 and over 56.0 54.0 51.0 48.0 45.0 42.5 40.0 lower selection or safety factors. A gas-fired boiler under thermostatic control is so sensitive to variations in room temperatures that in most cases a factor of 25 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. Table 1 gives selection factors to be added to the installed steam radiation under thermostatic control. They have been established by experience and are recommended by the American Gas Association. The same factors may be used in determining the gas demand for which conversion burners installed in steam or hot water boilers should be set Multiplying the equivalent direct heating surface (radiation) by 240 and adding the appropriate percentage from Table 1, and then dividing by the heat value of the gas and by the heating efficiency (see discussion of heating efficiencies in Chapter 29), gives the proper hourly rate of gas consumption. However, inadequate boiler heating surface for gas burning, often encountered in coal-designed boilers converted to gas, may necessitate operation at a lesser demand, resulting in much slower pick-up and less margin of safety for piping loss. 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 publica tions of that association. Ratings for Gas Appliances Since a gas appliance has a heat-generating capacity that can be pre 394 Chapter 28--Automatic Fuel Burning Equipment dieted 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 1505 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. The rating given by the American Gas Association Laboratory is not only a conservative rating when considered from the standpoint of capacity and efficiency, but is also a safe rating when considered from the standpoint of physical safety to the owner or caretaker. The rating that is placed upon an appliance is limited by the amount of gas that can be burned without the production of harmful amounts of carbon monoxide. This same limitation applies to all classes of gas-cOnsuming heating appliances that are tested and approved by the Laboratory. Gas boilers are available with ratings up to 14,000 sq ft of steam, while furnaces with ratings up to about 500,000 Btu per hour are available. (See Chapter 23). Installation Features One feature of the piping installation that adds to the satisfactory service rendered by gas boilers is provision for adequate and rapid venting of the air from steam heating systems. If air leaks into the steam dis tribution system during the period that the gas is turned off, and then vents out slowly when the thermostat calls for heat, the result will be a further cooling of the premises between the time that the thermostat calls for heat and the time that steam reaches the radiators. A freely venting steam or vapor system gives maximum economy and minimum temperature variation. When gas boilers are attached to existing heating plants, it is good practice to check the effectiveness of the venting devices and if necessary to replace them with more effective ones that will prevent the return of air into the heating system, and also to check the tightness of the piping. Frequently when a coal boiler is already installed in a home, it is expedient to leave the coal boiler in place, and to cross-connect the gas boiler with it. Where gas heating is new to the community, it pro- >A value of 160 for the heat emission of hot water radiators is used by many engineers. The actual heat emission, however, depends on the temperature of the water and of the surrounding air. See Chapters 30 and 33. 395 '. t American Society of Heating and Ventilating. Engineers Guide, 1934 . _ duces a more secure feeling in the customer's niind when putting in gasfired house-heating equipment, if he knows that he can burn coal at any time he may desire. For steam or vapor installations, it is desirable to have the water line in both boilers at the same level. 396 Chapter 29 FUEL CONSUMPTION Heat Ixfss, Calorific Values, Heating Efficiencies, Non-Heating Periods, Heat Capacity of Buildings, Miscellaneous Factors, Degree- Day Method, Rough Approximations, Relative Heating Costs TO predict the amount of fuel likely to be consumed in heating a building during a normal heating season, it is necessary to know the total heat requirements of the building and the utilization factor of the fuel. The accuracy of the estimate will depend on the ability to select these values and on the care taken in making allowances for other variable factors. . Fuel requirements1 are given by the following general' equation: where AT X (< -- G) X A F= (l-lo)XCX ' (1) _ F = quantity of fuel required for a heating season. N = number of hours of heating season corresponding to average temperature, t = inside temperature, degrees Fahrenheit. . la = average outside temperature, degrees Fahrenheit. .. to = outside design temperature, degrees Fahrenheit. H = calculated heat loss of building based on outside temperature of to, Btu per hour. C = calorific value of one unit of fuel, the unit being the same as that on which F is based. E = efficiency of utilization of fuel, per cent. - HEAT LOSS The hourly heat loss (H) is equal to the sum of the transmission losses (Hi) and the infiltration losses (Hi) of the rooms or spaces to be heated, and the total equivalent heating surface required is equal to H Sq ft' In estimating the fuel consumption of a building of more than one room divided by walls or partitions, it is not correct to use the calculated heat loss of the building without making the proper allowance for the fact that the heating load at any time does not involve the sum of the infiltration losses of all of the heated spaces of the building but only part of the infiltration losses. This is explained in Chapter 6. It is sufficiently accurate in most cases to consider only half of the total infiltration losses of a building having interior walls and partitions, and the value of H in Equation 1 would, under these conditions, be equal to `For further information on this subject see Estimating Fuel Consumption, by Paul D. Close. (Heating, Piping and Air Conditioning, May, 1931). 1 ., . . : . . .... 397 American Society of Heating and Ventilating Engineers Guide, 1934 H 4-Hi Ht + T If a building has no interior walls or partitions, whatever air enters through the cracks on the windward side must leave through the cracks on the leeward side, and only half of the total crack should be used in computing the infiltration for each side and end of the building. Under these conditions it is sufficiently accurate to use the total calculated heat loss (H) for the building. If the average wind velocity during the heating season differs from that upon which H, was derived, the value of H should be corrected accordingly. Of .course, where the required heating surface is estimated by empirical or rule-of-thumb methods, refinements in approximating fuel consump tion are not warranted, but rule-of-thumb methods often lead to unsatis factory results and should be avoided in heating work where more accurate methods are available. It should be emphasized that the value of H in Equation 1 is the total heat loss of the building after making the proper allowance for infiltration. CALORIFIC VALUES AND HEATINC EFFICIENCIES The calorific values of fuel oils and gas can be ascertained with reason able accuracy. The values for various grades of oil are given in Table 2, Chapter 27. The calorific value of gas can always be obtained from the local utility company. Values for natural gas are given in Table 3, Chapter 27; manufactured gas usually has a cajorific value of about 535. Coals have a larger range and may vary for the same type of coal, depend ing on its ash content. For general purposes where specific data are lacking, values can be taken from the top curve of Fig. 1, Chapter 27. To decide on the correct efficiency to use is a more difficult matter, par ticularly if the estimate is being made without a full knowledge of the equipment for burning the fuel and the care the furnace will receive. Efficiencies usually are given in the catalogs of manufacturers of furnaces and boilers, but these values are obtained under test conditions and do not allow for poor attendance, defects in installation, or poor draft. On the other hand, such efficiencies assume that all the heat radiated from the outside of the heaters or casings as sensible heat of the flue gases is lost, whereas, if the heater is installed in the building being heated, a con siderable portion of these losses may help to heat the building2; how much of this it is legitimate to use in increasing the value of E will depend on whether H included the heat losses in the cellar, and on the construction of the chimney. Except for an interior chimney, the heat transferred through the chimney wall to the building will be very small. Chimney allowances should be greater for lower test efficiencies. Thus, an insulated furnace will give a high efficiency on test but will not heat the cellar. A modern gas furnace will have a high efficiency with a correspondingly low flue gas temperature and hence there will be very little heat from the flue pipe. For great exactitude the value for E should take care of inefficiency in the heat distribution in the! building because of such losses as excessive heating of the walls behind the radiators and excessive stratification., It *Analysis of the Over-AH Efficiency of a Residence Heated by Warm Air, by A. P. Kratz and J. F. Quereau (A.S.H.V.E. Transactions, Vol. 35, 1929). . 398 Chapter 29--Fuel Consumption Table 1. Degree-Days for Cities in the United States and Canada* Col. a State Col. B City Col C Degree-Days Col. A State ColB City Col. C Degree-Days Ala.............. Birmingham............... 2,408 Mobile...... .................. 1,471 Ariz--....... Flagstaff...................... 7.145 Tucson.......... .............. 1,845 Ark.............. Hot Springs........ ..... 2,665 Little Rock.............. 2,811 Calif............ Los Angeles___ : 1,504 San Francisco........... 3,264 Colo............ Colorado Springs.... . 6,553 Denver.... ................... 5,873 Conn--------- New Haven............... 5,895 D. C............ Washington............... 4,626 Fla------------ Jacksonville............... 890 Ga----- 1....... Atlanta........................ 2,891 Savannah.................... 1,490 Idaho-------- Boise....... ................... 4,558 Lewiston..................... . 4,924 111........... Chicago....................... 6,315 Springfield.................. 5,370 Ind.............. Evansville...... ............ 4,164 Indianapolis:............ 5,297 Iowa......... Des Moines.............. 6.373 Sioux City................. 7.023 Kan.......... _. Dodge City...... ........ 5,034 Topeka...... ................. 5,301 Ky------------ Lexington.................. 4,616 Louisville.................... 4,180 La........... .... New Orleans............. 1.023 Me... ...... ... Eastport..................... 8,531 Portland..... ................ 7,012 Md._______ Baltimore................... 4,333 Mass........ Springfield.................. 6,464 Boston......................... 6.145 Mich........ -- Detroit........ _______ 6,494 Marquette............. : 8,692 ' Minn._____ Duluth........................ 9,480 Minneapolis............... 7,851 Miss............ Vicksburg.................. 1,822 Mo...______ Kansas City.... ......... 5,202 St. Louis.... ................ 4,585 Mont______ Billings........................ 7,115 Havre.......................... 8,699 Neb..... .. Lincoln........................ 6,231 Omaha........................ 6,128 N. H.......... Concord.................... N. J..... Trenton........ .............. N. M_____ Santa Fe. N. Y.......... Buffalo________ New York. .......... N. C.......... Wilmington...... ......... N. D.......... Ohio........... Cleveland................... Columbus. Okla....... Oklahoma City........ Pa............. R. I..... S. C______ S. D______ Salem......................... Pittsburgh............. .... Charleston................ Spartanburg.. ......... Sioux Falls......... ....... Nashville...... ............. Dallas...... ................... Houston............. ........ San Antonio.. ......... Utah Safi Lake City_____ Vt............... Va.............. Fredericksburg.____ Norfolk;...................... Richmond.. ............ Wash____ _ Seattle.. W. Va____ Parkersburg............... Wis............ Green Bay................. La Crosse................... Milwaukee............... Wyo______ Cheyenne.................... 5,891 6,852 5,175 4,934 6,063 6,889 6,821 5.348 3.234 2,302 8,498 4,702 6,154 5,323 3,613 4,468 4,629 4,855 5.235 6,014 1.769 3,257 7,683 2,950 3.578 1.578 2,455 1,157 1,202 . 6,735 5,553 7,620 4,243 3.349 3,725 4,868 6,353 5,016 4,884 7,612 7,823' 6,690 7,372 7,462 Province City Degree-DayB Province City - Degree-Days B. C_____ Victoria Vancouver.................. Kamloops......... .......... Alb____ ___ Medicine Hat.______ Sask._____ Qu'Appelle................. Man______ Winnipeg........... ........ Ont............ Port Arthur............... 5,777 5,976 6,724 8,152 11,261 11,166 10,803 Que............ MontreaL ......-...... Quebec.................. .... N. B.......... Fredericton_________ N. S......... Yarmouth...... ............ P. E. I____ Charlottetown.......... 7,732 8,705 8,628 9,099 7,694 8,485 aFrom Industrial Gas Series, House Healing (third edition) published by the American Gas Association. These degree-days are.based on daily mean temperatures. Base,.65 F. ' 399 i American Society of Heating and Ventilating Engineers Guide, 1934 is preferable, however, to include these losses in the value of H, and to limit E to the fuel burning equipment. Automatic fuel burning equipment, whether for coal, oil or gas, will tend to save fuel and will therefore produce a higher efficiency if thermostati cally controlled, but on the other hand automatic equipment tends to make the householder prolong his heating season and to maintain a higher temperature in the house in the early fall and late spring. , NON-HEATING PERIODS Obviously, the theoretical fuel consumption will be reduced con siderably by not operating the heating plant at night. Allowance for this may be made in either of two ways: (1) by estimating the average inside temperature (/), or (2) by arbitrarily assuming a certain reduction in the fuel consumption. The first procedure is, of course, the more accurate. If, for example, the daytime temperature is to be 70 F, and the temperature from 12 midnight to 6 a.m. is to be maintained by thermostatic control at 50 F, then the average daily inside temperature (t) will be 18 X 70 + 6 X 50 24 or 65 F. Strictly speaking, this average inside temperature would only apply when the outside night temperature averages below 50 F, but this fact usually is not of sufficient importance to warrant consideration. If the average outside temperature during the heating season is 30 F, the fuel saving 70_65 ' would be approximately 100 X ^ ....,, or 12.5 per cent. In this case, the -# 7U oU additional saving in fuel due to the cooling of the air and structural materials to 50 F would be offset by the heating-up load in the morning. As to the second procedure, it may be arbitrarily assumed that a saving in the fuel consumption of from 10 to 30 per cent (depending on conditions) will result if the heat is shut off after working hours, and the building heated to the required temperature during the period of occu pancy each day. This, of course, is a general statement and wherever possible the average temperature should be estimated from the propor tionate lengths of the occupancy and non-occupancy periods and the cor responding temperatures for these periods. Any deviation from the assumed inside temperature will result in a variation in the estimated fuel con sumption. HEAT CAPACITY OF BUILDINGS The heat required to warm the cold building and contents is a factor to be considered. Under certain conditions, the cooling of the structure and contents will, to some extent, compensate for the heat required to rewarm the building. For example, if the building is under thermostatic control and the day and night temperatures are say 70 F and 50 F, respectively, there will be a period during which no heat will be called for while the building is cooling to 50 F, and.the saving resulting therefrom will correspond to the additional heat required to bring the building and con tents back to the daytime temperature. If in estimating the fuel con sumption the average daily inside temperature is based on the proper day and night temperatures and periods, the heat required to warm the structure may be neglected. ... 400 Chapter 29--Fuel Consumption Where irregular conditions are involved it may be desirable to actuallycalculate the fuel required to warm the building structure and contents for the number of times during the heating season the heating plant would not be in operation and to add this quantity to the fuel required for the number of hours during which the building is heated. The greater the: heat capacity of the structure the greater will be the relative importance of this item. For structures of low heat capacity, such as frame buildings, this factor usually may be neglected. Example 1. A small factory building located in Philadelphia is to be heated to 60 F between the hours of 7 a.m. and 7 p.m.,and to 50 F during the remaining hours. The calculated hourly heat loss, based on a design temperature of -- 6 F, is 500,000 Btu. If coal having a calorific value of 12,500 Btu per pound is fired, and the over-all heating efficiency is assumed to be 60 per cent, how many tons of coal will be required for a normal heating season, neglecting other heat sources and any loss of heat through open windows? .. 1 Solution. Since there are no partitions in this building, the entire heat loss is con . sidered. The average outside temperature during the heating season (/a) is 41.9 F (see Table 2, Chapter 7); i = 60 F; N = 5040; H = 500,000; (t -- to) = 66 F; C = 12,500; E = 0.60. Substituting these values in Equation 1 and dividing by 2000 to change to tons: 500,000 X 18.1 X 5040 66 X 12,500 X 0.60 X 2000 -- 46 tons of coal Inasmuch as the building will be heated to 50 F at night, the average inside tempera- ' - 60_55 ture (at the breathing line) will be 55 F, and the percentage saving will be ^ _"4i 9 = 0.276 or 27.6 per cent. The net fuel consumption will therefore be 46 -- 0.276 X 46 or 33.3 tons. MISCELLANEOUS FACTORS There are many factors which would be likely to affect the theoretical fuel requirements of a building, such as the opening of windows, abnormal inside temperatures, other heat sources, sun effect, wind, and rain. In many cases it is difficult to evaluate these factors accurately, particularly in the case of open windows, and the results are correspondingly less accurate. The degree of refinement of the calculations should, of course," be consistent with the conditions involved. If the heat loss from the boiler and piping does not warm the building or is not included in H, the proper allowance should be made. In selecting a boiler, this allowance is frequently assumed to be 25 per cent of the total heat loss of the build ing, but in estimating fuel requirements, the more accurate procedure of computing the pipe and boiler losses should be used, unless this item is likely to be outweighed by other less tangible factors. Where temperature control is installed the fuel consumption can obviously be predetermined with greater accuracy than where .no such control has been provided. In fact the calculated requirements agree to a remarkable extent in many cases with the actual fuel consumption. This has been particularly true of gas-fired installations, with which effective temperature regulation usually is possible. ^ OTHER HEAT SOURCES Where other-heat sources are available it is quite often possible to make accurate allowance for the reduction in the fuel consumption resulting 401 American Society of Heating and Ventilating Engineers Guide, 1934 therefrom. These sources include the heat supplied by persons, lights, motors and machinery, and should also be ascertained in the case of theaters, assembly halls and industrial plants. (See Chapter 7). In many cases these heat sources should not be allowed to affect the size of the in stallation of heating equipment, although they may have a marked effect upon the fuel consumption. In residences this factor usually may be neglected. DECREE-DAY METHOD A very useful unit for estimating fuel consumption, particularly for residences, is the degree-day. (See definition in Chapter 42). Degree-days for various cities in the United States and Canada are given in Table 1. The term degree-day originated in the gas industry and was later stand ardized by the American Gas Association*. The base of 65 F is used for an inside temperature of 70 F. This base was chosen because it was demonstrated, by means of data collected from numerous installations, that heat is seldom supplied to a residence when the outdoor temperature is greater than 65 F4. It was also found that the fuel consumed varied almost directly with the difference between 65 F and the outside temperature. If the inside temperature were maintained at 70 F throughout the 24 hours of the day, then the base of 65 F would probably be in error. It must be borne in mind, however, that although the temperature head is the difference between the inside temperature of say 70 F, and the outside temperature, a lower temperature than 70 F will usually be maintained at night and the base of 65 F will therefore allow for this condition. As already indicated, a temperature of 50 F from midnight to 6 a.m. will reduce the 24-hour average from 70 to 65 F. It is important to note that the degree-day applies specifically to an inside temperature of 70 F,. which is the usual temperature for residences, and it should also be noted that allowance is automatically made for the lower night-time tempera ture, although this allowance is constant for any given locality. In Equation 1, the quantity (t -- 4) X N is equivalent to the number of degree-days (D) in a heating season multiplied by 24, when the average daily value of t is 65 F. Therefore . (I - <a) X N = 24 D (2) Substituting the value of (/ -- ,) X N from Equation 2 in Equation 1, the following general formula for an average daily inside temperature of 65 F, which is,approximately equivalent to an inside daytime temperature of 70 F for residences, is obtained: . Fi (t - t,,) X C X E (3) Example 8: The calculated hourly heat loss of a residence located in Chicago is 127,000 Btu, which includes 28,000 Btu for infiltration. The design temperatures are -- 8 F and 70 F. The normal heating season is assumed to be 210 days (5,040 hours) and the average temperature during this period is 36.4 F (see Table 2, Chapter 7). The See Industrial Gas Series. House Healing {third edition) published by the American Gas Association. See also Iso-degree-day map and charts developed by P. E. Fansler for coal, oil and gas. 402 Chapter 29--Fuel Consumption building is to be heated with oil fuel having a calorific value of 141,000 Btu per gallon. Xhe heating efficiency is assumed to be 70 per cent. Thermostatic control is to be used and a temperature of 55 F is to be maintained from 11 p.m. to 7 a.m. How many gallons of oil will be required during a normal heating season if the loss of heat through open windows is neglected? OQ QQO Solution. The maximum hourly heat loss will be 127,000 -------- ^-- = 113,000 Btu = H. Substituting the proper values in Equation 1: 113.000 X (70 - 36.4) X 5040 141.000 X 0.70 X [70 - (- 8)1 2486 gal of oil. The average inside temperature will be 70 X 16 + 24 55 X 8 = 65 F 70 - 65 and the fuel saving due to this fact will be 70 - 36.4 0.149 or 14.9 per cent. Hence, the net fuel consumption will be 2486 -- 0.149 X 2486 = 2116 gal. The normal number of degree-days for Chicago is 6315. Substituting in Equation 3 and solving by the degree-day method: 113,000 X 6315 X 24 78 X 141,000 X 0.70 2225 gal of oil No allowance need be made for the average temperature of 65 F since this is taken care of by the selection of a base of .65 F for the degree-day, as already explained. It will be noted that the two methods check within 5 per cent in this case. If the average daily inside temperature in the first solution had been 66.4 F instead of 65 F, the two methods would have checked exactly. INDUSTRIAL DEGREE-DAY Since the standard degree-day is intended for an inside temperature of 70 F, it is particularly convenient for solving residence problems. Where the design temperature differs greatly from 70 F, the standard degree-day cannot be accurately applied. Consequently, the industrial degree-day5 has been developed and values have been derived for two bases, namely 55 F and 45 F, intended for inside temperatures of 60 F and 50 F, re spectively. There is a considerable spread, however, among these three bases, and consequently there would be an appreciable error if the actual basis to be used in a certain case would be approximately midway between any two of the three bases for which degree-day values are at present available. Since the correction cannot be made on a proportionate basis, it would be more accurate in the majority of cases involving inside temperatures other than 70 F, 60 F or 50 F, to apply Equation 1. APPROXIMATING FUEL REQUIREMENTS It is sometimes desirable to obtain a rough approximation of the annual fuel consumption. Such'approximations may be obtained by using unit factors based on the fuel requirements per square foot (or per 100 sq ft) of radiation or per 1000 cu ft of space. Fig. 1 may be used for rough approximations of coal and oil require- 'See Heating and Ventilating Degree-Day Handbook. 403 American Society of Heating and Ventilating Engineers Guide, 1934 ments. It should be noted that this figure is given in terms of the fuel consumption per 1000 degree-days per 100 sq ft of equivalent heating surface (steam) based on an emission of 240 Btu per square foot. Unless the radiation is calculated with reasonable accuracy, unit-factors will be of little value even for rough approximations, since it is obvious that such radiation requirements must bear some relationship to the actual heating requirements of the building. Example 3. Estimate the approximate coal consumption for a building located in New York City in which the calculated heating surface requirements (steam) are 1000 sq ft based on design temperatures of zero and 70 F. Chapter 29--Fuel Consumption radiation (240 Btu) based on the theoretical requirements. A correction for warmer climates is necessary and it is customary to gradually increase the relative fuel consumption below 3,000 degree-days to about 20 per cent more at 1,000 degree-days. . For hot water or warm air heat the fuel consumption is about 0.19 cu ft per degree-day per square foot of equivalent steam radiation, that is, per 240 Btu per hour. The actual requirements likewise relatively increase with hot water or warm-air systems as the number of degree-days de creases below 3,000. For larger installations, that is, 1,000 sq ft of Fig.,1. Curve for Obtaining Rough Approximation.of Annual Fuel Consumption in Tons of Coal or Gallons of Oil per 1000 Degree-Days per 100 sq ft of Equivalent Steam Heating Surface3 ' , "This curve is based on heating efficiencies of 60 and 70 per cent for coal and oil, respectively, a calorific value of coal of 13,000 Btu per pound, a calorific value of oil of 14,000 Btu per gallon, an inside tempera ture of 70 F, and an emission of 240 Btu per equivalent square foot of heating surface (steam), and does not allow for unusual factors which would affect the fuel consumption, such as open windows, week-end shut downs, etc. For hot water, divide the result obtained by means of this chart by 1.6. .; Solution. From Fig. 1, the fuel consumption for a design temperature of zero is 0.53 tons per 1000 degree-days per 100 sq ft of heating surface. Since there are 5348 degreedays in New York City in a normal heating season, the fuel consumption will be approxi mately 0.53 X 5.348 X 10 = 28.34 tons. Fig. 2 is taken from the 3rd edition of Industrial Gas Series on House Heating, published by the American Gas Association, and indicates the average gas consumption per degree-day for various heat contents. While the fuel consumption in individual cases may vary, somewhat from the curve values, these average values are sufficiently accurate for esti mating; purposes and give very satisfactory results. .. The value generally used in the manufactured gas industry for resi dences is 0.21 cu ft per degree-day per square foot of equivalent steam 404 Fie. 2. Chart Giving Gas Requirements per Degree-Day for Various Calorific Values of Gas and for Different Heating Systems3 aThis chart is based on an inside temperature of 70 F and an outside temperature of zero- If the radia tion is installed on the basis of any other temperature difference, multiply,the result obtained from this chart by 70. and divide by the actual temperature difference. . theoretical radiation and above, there is an increase in efficiency, and a consequent decrease in the fuel consumption per degree-day per square foot of heating surface. The approximate quantities of steam required in New York City per square foot of heating surface, for various classes of buildings are given in Chapter 36. The preceding discussion on fuel consumption has dealt with the heating requirements of the building irrespective of any air that may be intro duced for.ventilation purposes other than the norma) infiltration of out side air. The heat-required for warming air brought into the building for .ventilation may be estimated from data given in Chapters 2 and 22. 405 American Society of Heating and Ventilating Engineers Guide, 1934 RELATIVE HEATING COSTS A comparison of the relative cost of heating with different fuels can be made with even a fair degree of accuracy only when there is a full knowledge of the equipment which will be used with each fuel, and the efficiency with which each will be operated. When proposing to sub stitute one fuel for another, the yearly cost with the fuel being used can be obtained. The accuracy of the comparison will depend upon the care taken in estimating the cost of the new fuel with the equipment which will be used. , A convenient basis for comparison of various fuels is the cost per million Btu. The formula used in estimating costs for coal is: 500 X c where Cc X c X = cost of heating with coal in dollars per million Btu. c = cost of coal in dollars per ton. Cc = calorific value of coal, Btu per pound. Eq = over-all or house efficiency for coal, expressed as a decimal. (4) Example 4- If coal having a calorific value of 13,000 Btu per pound costs $10.00 per ton, the cost per million Btu, assuming an efficiency of 60 per cent, will be: 500 X 10 $0.64 13,000 X 0.60 The formula used in estimating costs for oil is: 1,000,000 X p . where Co X W X Eo Y = cost of heating with oil in dollars per million Btu. p = cost of oil in dollars per gallon. C0 = calorific value of oil, Btu per pound. W -- weight of oil per gallon, pounds. Eg = over-all or house efficiency for oil, expressed as a decimal. Example 6. If oil having a calorific value of 141,000 Btu per gallon (C0 X W) costs 10>f per gallon, the cost per million Btu, assuming an efficiency of 70 per cent, will be: 1,000,000 X 0.10 = $1.01 141,000 X 0.70 The formula used in estimating costs for gas is: where . = lOOOg Cg X g (6) Z = cost of heating with gas in dollars per million Btu. g = average cost of gas, including demand and commodity charges, dollars per thousand cubic feet. . Cg = calorific value of gas, Btu per cubic foot. Eg = over-all or house efficiency for gas, expressed as a decimal. Example 6. If manufactured gas, having a calorific value of 535 Btu per cubic foot, costs 60f per thousand cubic feet, the cost per million Btu, assuming an efficiency of 80 per cent, will be: ' , 1000 X 0.60 2 = 635'X 0.80~ = 8140 ^, 406 Chapter 30 RADIATORS AND GRAVITY CONVECTORS Heat Emission of Radiators and Convectors, Types of Radiators, Output of Radiators, Heating Effect, Heating Up the Radiator, Enclosed Radiators, Convectors, Code Tests, Gravity-Indirect . Heating Systems COMMERCIAL heating units are termed (1) radiator, for direct sur faces, either exposed, enclosed, or shielded; and (2) convector, or concealed heater, for extended surfaces that are built in as part of an enclosure or cabinet. Some heating units are also available that are a combination of radiator and convector. HEAT EMISSION OF RADIATORS AND CONVECTORS All heating units emit heat by radiation and conduction. 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 built-in heating unit in a convector emits practically all of its heat by conduction to the air surrounding it and this heated air is in turn trans mitted by convection to the rooms or spaces to be warmed, the heat emitted by radiation being negligible. The small amount of heat trans mitted by radiation to the inside surface of the enclosure diminishes as the surface temperature of the enclosure approaches the surface temperature of the heating unit. TYPES OF RADIATORS Present day radiators may be classified as tubular, wall, or.window types, and are generally made of cast iron. Catalogs showing the many designs and patterns available now include a junior size which is more compact than the standard unit. Pipe Coil Radiators . Pipe coils are assemblies of standard pipe or tubing (1 in. to 2 in.) which are used as radiators. In older practice these coils were commonly used . in factory buildings, but now wall type radiators are most frequently used 407 American Society of Heating and Ventilating Engineers Guide; 1934 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 a true index of output. (The engineering unit of output is now the Mb or 1000 Btu). However, during the period of transition from the old to the new, radiators may be referred to in terms of equivalent square feet. For steam service this is based on an emission of 240 Btu per hour per square foot. Table 1. Variation in Dimensions and Catalog Rating of 10-Section Tubular . Radiators Made by Several Manufacturers No. of Tubes------ Width of Radiator Length per Section________ ____ Inches __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 11.4-12.8 2.5-3.0 Height with Legs---Inchbs ' Heat Emission-- Equivalent Square Feet 13--14 20 25.0-32.5 16-18 28.5 30.0-38.3 20-21 15.0-17.5 20.0-22.5 25.0-31.2 30 36.7-45.0 . 22-23 20.0-21.3 25 30.0-33.9 35 40.0-45.2 25-26 20.0-26.7 25.0-27.5 32.5-39.8 37.5-40.0 50.0-53.5 30-32 " 25.0-30.9 33.3-35.0 40.0-48.6 50 63.3-62.5 36-38 30.0-36.7 40.0-42.5 50.0-56,5 60 70.0-75.4 Output of Tubular Radiators ' Table 1 illustrates the difficulty in tabulating tubular radiator outputs since there is so much variation 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. 408 . Chapter 30--Radiators and Gravity Convectors Output of Pipe Coils The heat emission of pipe coils placed vertically on a wall with the pipes horizontal is given in Table 2. This has been developed from avail able data and does not represent definite results of tests. For such coils the heat emission varies as the height of the coil. It is customary to use an average emission of 100 Btu per linear foot of l)4-in. pipe, 10 ft high. The heat emission of each pipe of ceiling coils, placed horizontally, is about 126 Btu, 156 Btu, and 175 Btu per linear foot of pipe, respectively, for 1-in., lJ4-in., and lj^-in. coils. . Table 2. Heat Emission of Pipe Coils Placed Vertically on a Wall (Pipes Horizontal) Containing Steam at 215 F and Surrounded with Air at 70 F ' Btu per linear foot of coil per hour (not linear feet of pipe) Sms or Pipe Single Row.................................. .............. Two........... .................................................... Four........... ................................................... Six... ............ ...... .......................................... Eight................... ...................................... . Ten________ _________ ______ _______ ____ Twelve:............ ...... .......... ................. .......... l In. 132 252 440 567 651 732 812 . lKlx. 162 312 545 702 796 907 1005 : : IM In 185 348 . 616 793 907 1020 . 1135 Effect of Paint The prime coat of paint on a radiator has little effect on the heat output, but the finishing coat of paint does influence the radiation emission. Since this is a surface effect, there is no noticeable change in the convection loss. Thus, the larger the proportion of direct radiating surface, the greater will be the effect of painting on the radiation. Available tests are on oldstyle column typie radiators which gave results shown in Table 3. >/ Table 3. Effect of Painting 32-in. Three Column, Six-Section Cast-Iron Radiator* Radiator No. i 2 3 4 /. Finish ' Bare iron, foundry finish___ _______ One coat of aluminum bronze Gray paint dipped. ___ __________ One coat dull black Pecora paint__ Area Sq Ft 27 27 27 27 Coefficient or Heat Trans. Btu Relative Heating Value Per Cent 1.77 1.60 1.78 1.76 100.5 90.8 101.1 100.0 ^Comparative Tests of Radiator Finishes, by W. H. Severns (A.S.H.V.E. Transactions, Vol.'33,1927). 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 radiator2. : P 33)Heating Effect of Radiators, by Dr. Charles Brabble (A.S.H.V.E. Transactions, Vol.-33, .1927, 409 American Society of Heating and Ventilating Engineers Guide, 1934 The results of tests conducted at the University of Illinois are shown in Figs. 1 and 2s. For the four types of radiators shown, the following con clusions are given: . y- Co/d Room 7emp in deg-F -22 : 352/b Test F-F2. 5-Tvbe Fbd- -22 2 5*2/b 7est R*-*7,3-TcsbefFod. --2211 3 542 /b Testf?-fO, /-TObe-Fbne/ Rbd. 350 lb- Testf?-2c. fcts/ 225) ftto//Rbd- 2 3 4- - 7 e. A/e/- '/b. cfj/eorr? Condensed/per- fin 0/ 2343*781/0 t/eigtrt Abort? Floor Jn Foot Fig. 1. Room Temperature Gradients and Steam Condensing Rates for Four Types of C. I. Radiators with a Common 60-in. Level Temperature Note that the steam condensations are practically the same for all four radiators v/hen the same air temperature of 69 F is maintained at the 60-in. level. Cok/ Room Temp- in deg-F -20rb **8/b Test R-3*,5-Ti/be Rbd- 22 *48/b lesf R-C20. J-Tc/bC Rbd- --229! i *22lb 7isst R-38>-/-TubeFbne/Rbd330Mx 7estR-2c.-0ut223j.t\b//Fbd 0/2345*78 wet Mx of5beom Condensedper nr / 2.3 4 5 * 7 8 1 /O tie/ght Above Floor in Feeet Fig. 2. Room Temperature Gradients and Steam Condensing Rates for Four Types of C. I. Radiators with a Common 30-in. Level Temperature Note that the steam condensations are different for all four radiators when the same rtir temperature ol 68 F is maintained at the SO-in. level. 1. The heating effect of a radiator cannot be judged solely by the amount of steam condensed within the radiator. 2. Smaller floor to ceiling temperature differentials can be maintained with long, low, this, direct radiators, than is possible with high, direct radiators. ' *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). 410 Chapter 30--Radiators and Gravity Convectors 3. The larger portion of the floor to ceiling temperature, differential in a room of average ceiling height heated with direct radiators occurs between the floor and the breathing level. , . 4. The comfort level (approximately 2 ft-6 in. above floor) is below the breathing line level (approximately 5 ft-0 in. above floor), and temperatures taken at the breathing line may riot be indicative of the actual heating effect of a radiator in the room. The comfort indicating temperature should be taken below the breathing line level. 5. High column radiators placed at the sides Of window openings do not produce as comfortable heating effects as long, low, direct radiators placed beneath window openings4. HEATING UP THE RADIATOR The maximum condensation occurs in a heating unit when the steam is first turned on. 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. 3100 ~ 30 ..80 .7 /V --{ S 60 50 :t: -v .9 .40 | JO f-- ,,O .20 L .10 .o Time elapsing after Steam is turned into Radiator (m Minutes) Fig. 3. Chart Showing the Steam Demand Rate for Heating Up a Cast-Iron . Radiator with Free Air Venting and Ample Steam Supply In practice the rate of 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. ENCLOSED RADIATORS The general effect of an enclosure placed about a direct radiator is to restrict the air flow, diminish the radiation and, when properly designed, improve the heating effect. Recent investigations5 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. t *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). `University of Illinois Engineering Experiment Station Bulletins Nos. 192 and 223, and Investigation of 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). 411 American Society of Heating and Ventilating Engineers Guide, 1934 2. The lessened steam consumption may not materially change the radiator heating performance. 3. The enclosed radiator may inadequately heat the space. A comparison between a bare or exposed radiator (A) and the same radiator with a well-designed enclosure (B), with a poorly-designed enclosure (C), and with a cloth cover (D) will illustrate the relative heating effects. In Fig. 4 the curve (B) reveals that the enclosed radiator used less steam than the exposed radiator, but gave a satisfactory heating performance. A well-designed shield placed over a radiator gives about the same heating effect. Curve (C) shows the unsatisfactory effects produced by improperly designed enclosures. Curve (Z?) 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. Chapter 30--Radiators and Gravity Convectors Fig. 4. Difference in Steam Pressure on Water in Boiler and at End of Steam Main A practical interpretation of allowances to be made for radiator per formance with various styles and forms of enclosures is shown by the diagrams and values listed in Fig. 5. Practically all commercial enclosures and shields for use on direct radiators are equipped with water pans for the purpose of adding nioisture to the air in the room. Tests6 show that an average evaporative rate of about 0.235 lb per square foot of water surface per hour may be obtained from such pans, when the radiator is steam hot and the relative humidity in the room is between 25 and 40 per cent. This source of supply of moisture alone is not adequate to maintain a relative humidity above 25 per cent on a zero day. "University of Illinois Engineering Experiment Station Bulletin No. 230, p. 20. Ttpb Arr. 1 Arr. 2 Arr. 3 Arr. 4 Arr. 5 Arr. 6 Installation Conditions When dimension A is as shown in Arr. 1 and dimen sion B is equal to 80 per cent of A___________ ..... When dimension A is as shown and dimension B is equal to 80 per cent of A__ ____ _________ When dimension B is equal to 80 per cent of A (as in Arr. 1), dimension C is equal to 150 per cent of A and dimension D is equal to A ___ _ ____ When dimension E is equal to 50 per cent of A_____ When dimension E is equal to A___ When dimension E is equal to 150 per cent of A____ When dimension E is equal to A.................................. When as shown_______________ ________________ _____ Heat Emission Shall be Altered bt Pehcentaqb Indicated 10% increase 5% increase . No change ' 10% reduction 20% reduction 35% reduction 30% reduction 5% reduction Fig. 5. Types of Enclosures and Heat Emission of Enclosed Radiators8 ' "From A.S.H.V.E. Code of Minimum Requirements for the Heating and Ventilation of Buildings (edl- tion of 1929). . 413 American Society of Heating and Ventilating Engineers Guide, 1934 CONVECTORS OR CONCEALED HEATERS Although any standard heating unit (i.e., radiator) may be concealed in a cabinet or other enclosure so that the greatest percentage of heat is conveyed to the room by convection, the best results are usually obtained where units of special design are used. Commercially, these specially designed units are built in as part of the enclosing cabinets which are necessary for the proper functioning of these heaters. As distin guished from radiators, these gravity convectors have come to be known as concealed heaters. Fig. 6 shows a typical built-in cabinet convector. . Chapter 30--Radiators and Gravity Convectors . directed flow of warm air into the living zone and but little radiant heat to exposed surfaces. In listing the capacities of convectors, manufacturers allow from 10 to 40 per cent for this heating effect. (See A.S.H.V.E. Standard Code for Testing and Rating Concealed Gravity Type Radia tion, A.S.H.V.E. Transactions, Vol. 37, 1931). 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 hanging 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, although the front outlet Fig. 6. Typical Concealed Convector Using Specially Designed Heating Unit The elements or heating units usually consist of a relatively large a'mount of extended surface which may be integral with the core or assembled over it, making thermal contact by pressure, through solder, or by both pres sure and metallic contact. Heating elements may be of cast-iron, cast aluminum, sheet steel, copper, or commercial alloys. The cross-sections of a number of non-ferrous heating elements are shown in Fig. 7. In these the ratio between the extended surface and the prime surface may be as high as 25 to 1. Concealed heaters or convectors maintain room temperatures with low steam.consumption due, probably, to their performance characteristics which give reduced air temperatures in the upper level of a room with a 414 Fig. 7. Sections Through Typical Heating Units of Extended Surface Type is practically standard. In cases where enclosures are to be used but are not furnished by the heater manufacturer, it is important that the pro portions of the cabinet and the grilles be so designed that they will not impair the performance of the assembled convector. The output of a concealed heater, for any given length and depth, is a variable of the height. Published ratings are generally given in terms of equivalent 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. CODE TESTS 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. 415 / American Society of Heating and Ventilating Engineers Guide, 1934 has adopted the following standards: Code for Testing Radiators (1927); Codes for Testing and Rating Concealed Gravity Type Radiation (Steam, 1932, and Hot Water, 1933). For steam services the actual condensation weight is taken without any allowance for heating effect; for hot water services the weight of circulated water is used without allowance for heating effect. In all cases the total heat transmission varies as the 1.3 power 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 (215 F), or hot water at 170 F and a room temperature of 70 F for radi ators, or an inlet air temperature of 65 F for convectors. The heating capacity of a steam radiator or steam convector is determined as follows: where Ht = WJhg ' (1) Ht = Btu per hour under test conditions. TFS = condensation in lb per hour. Afg = latent heat in Btu per lb. Ht may be converted to standard conditions of code ratings by using the proper correction factor from the following formulae: For radiators: For convectors: The output under standard conditions will be: ' where Hs = Cs Ht (4) " Cs = correction factor. rs = steam temperature during test in degrees Fahrenheit. Tr = room temperature during test in degrees Fahrenheit. Ti = inlet air temperature during test in degrees Fahrenheit. Hs -- heat emission rating under standard conditions in Btu per hour. Similarly, for hot water convectors, the output under test conditions may be determined as follows: H = W (6, -- 0,) ~ where . H = Btu per hour under test conditions. W = pounds of water handled during test. 0i = average temperature ol inlet water in degrees Fahrenheit. 0i = average temperature of outlet water in degrees Fahrenheit. t = duration, of test in seconds. 416 (5) . - Chapter 30--Radiators and Gravity Convectors To convert test results to standard conditions, the following correction factor is used: (C = 170 - 65 \i / 105 0i - 0i V2 - Ti (6) It has been shown for the exponent 1.3 that the range of error when it is used is less than 5 per cent7. aSee Mechanical Equipment of Buildings, by Harding and Willard, Vol. I. second edition, 1929. GRAVITY-INDIRECT HEATING SYSTEMS8 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. 8. 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. In cases where ventilation is a requirement, the air volume needed may become so large that the entering T'ests of Convectors in a Warm Wall Testing Booth, by A. P. Kratz, M. K. Fahnestock, and E. L. hrodenck (Heating, Piping and Air Conditioning, August, 1933). - . *For further information on this subject see A.S.H.V.E. Code of Minimum Reauirements for the Heating ^Ventilation of Buildings (edition of 1929) and Mechanical Equipment of Buildings,, by Harding and Willard, Vol. I, second edition, 1929. 417 'American Society of HEATiNG- and VentE-ating Engineers Guide, 1934 air' temperature will be but' slightly above the room, temperature. To establish and maintain a constant heat flow, provision must be: made for removing the air in the room, after it has cooled to the desired room tem perature, by a system of vent flues or ducts. As the air flow is maintained by natural draft and this gravity head is very slight, it is necessary to make all ducts as short as possible, especially the runs from the heating units to- the base of-the vertical' warm air flues. 418 \ Chapter 31 STEAM HEATING SYSTEMS Gravity and Mechanical Return, Gravity' One-Pipe Air-Vent System, Gravity Two-Pipe Air-Vent System, One-Pipe Vapor System, Two-Pipe Vapor System, Atmospheric System, Vacuum System, Sub-Atmospheric System, Orifice System, Zone Control, Condensation Return Pumps, Vacuum Pumps, Traps STEAM heating systems may be classified according to the piping arrangement, the accessories used, the method of returning the con densate to the boiler, the method of expelling air from the system, or the type of control employed. The essential features of the common types are described in this chapter.' Information concerning the design and layout of steam heating systems is given in Chapter 32. GRAVITY AND MECHANICAL RETURN In gravity systems the condensate is returned to the boiler by gravity due to the static head of water in the return mains. The elevation of the boiler water line must consequently be sufficiently below the lowest heating units and steam main and dry return mains to permit the return of condensate by gravity. The water line difference* must be sufficient to overcome the maximum pressure drop in the system and, when radiator and drip traps are used as in two-pipe vapor systems, the operating pressure of the boiler. This applies only to closed circuit systems, where the condensation is returned to the boiler. If the condensation is wasted; no water line difference is required. In mechanical systems the condensate flows to a receiver and is then forced into the boiler against the boiler pressure. The lowest parts of the supply side of the system must be kept sufficiently above the water line of the receiver to insure adequate drainage of water from the system, but the relative elevation of the boiler water line is unimportant in such cases except that the head on the pump or trap discharge becomes greater as the height of the boiler water line above the trap or pump increases. There are three general types of mechanical returns in common use, namely, (1) the mechanical return trap, (2) the condensation return pump, and (3) the vacuum return pump. Further information on pumps and traps will be presented later in this chapter. GRAVITY ONE-PIPE AIR-VENT SYSTEM In the gravity one-pipe air-vent system each radiator has but a single connection through which steam must enter- and condensation must *The water line difference is the distance between the water line of the boiler and the low point of the water in the dry return main. ' 419 American Society of Heating and Ventilating Engineers Guide, .1934 return in the opposite direction. Each radiator has an individual air valve. Up-Feed Gravity One-Pipe Air-Vent System ^ This system is the most common of all methods of steam heating, due largely to its low cost of installation and its simplicity. As will be seen from Fig. 1, the steam piping rises to a point as high as possible at the boiler and pitches downward from this location until the far end of the main or mains is reached. At the far ends drips are taken off at the low points of the steam mains, are water-sealed below the boiler water line, and then brought back to the boiler in a wet return. Single pipe risers Chapter SI1'--Steam Heating Systems overhead for any distance before dropping, the return should slope down ward with the flow. The radiator valves may be of the angle-globe or gate type. They should not be of the straight-globe type because the damming effect of the raised valve seat interferes with the flow of condensation through the valve. Graduated valves cannot be used, as the steam valves on this system must be fully open or closed to prevent the radiators' filling with water. Air valves may be manual or automatic, with or without a check to prevent the re-entrance of expelled air. Usually the automatic type is installed. The greatest source of difficulty with one-pipe steam systems is that the heat is all on or all off, with no intermediate position possible. However, intelligent use of. the on-attd-off method of manual control gives reasonably satisfactory results. It is important that the lowest points of the steam mains and heating units be kept sufficiently above the water line of the boiler to prevent Fig. 1. Typical Up-Feed Gravity One-Pipe Air-Vent System are branched off the main or mains to feed the radiators, the steam passing up the riser and the condensatfon flowing down it. The steam and con densation flow in opposite directions in the riser but after the condensa tion enters the steam main it flows in the same direction as the steam and is disposed of through the drip connection at the end of the main. In buildings of several stories, it is customary to drip the heel of each riser separately, whereas in one- or two-story buildings this is not necessary. Both types of branches and risers are shown in Fig. 1. Horizontal branches to radiators and risers should be pitched at least i^-in. in 10 ft downward toward the riser or vertical pipe, and the hori zontal branches from the steam main should be graded at least this amount toward the main, except where the heel of the riser is dripped, in which case the branch should pitch down toward the riser drip (Figs. 2 and 3). The return line, if wet, may be run without pitch or may be pitched in either direction, but if it is necessary to carry the return main 420 . Fig. 2. Typical Steam Runout where . Risers are not Dripped Fig. 3. Typical Steam Runout where Risers are Dripped flooding, although proper design will eliminate this danger. Usually 18 in. is sufficient but construction limitations frequently make shorter dis tances necessary. The distance may be checked in the following manner: Referring to Fig. 4 it will be seen that the water in the wet return is really in an in ' verted siphon, or U-shaped container, with the boiler steam 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. 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 % lb, and utilizes an Underwriters Loop1 instead of a check valve on the return, the rise in the water level at the far end of the return due to the difference in steam pressure would be y% 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 12in. as the distance the bottom of the lowest part of the steam main and all heating units must be above the boiler water line. The same system, however, installed and sized for a total pressure drop of M lb, and with a check in the return, would require y of 28 in., or 14 in., for the difference in steam pressure,-? in. for the flow through the return, 4 in. to operate the check, and 6 in. for a factor of safety, making a total of 27 in. as the required distance. Higher pressure drops would increase the distance accordingly. -- 1See discussion of piping details in Chapter 32. 421 i -\ American Society of Heating and Ventilating Engineers Guide, 1934 Down-Feed Gravity One-Pipe Air-Vent System ; In the overhead down-feed gravity one-pipe air-vent system there is no change over the up-feed system in the radiators, the radiator valves, the air valves, or the radiator runouts as far back as the risers. Beyond tjhis point there are basic differences. The steam is taken from the boiler and carried to the top of the building as near the boiler as possible (Fig. 5). If the run to the main riser is long, or if the riser extends several stories in order to reach the top, the bottom of the riser should be dripped into the wet return.' The horizontal main is taken off the top of the riser and, grades down from the riser toward all of the drops, each drop taking its share of the main condensation (Fig. 6),-or all of the drops except the last may be taken from the top of the main (Fig. 7), the last drop being from the bottom and serving as a drain for the entire main. As the overhead Steam pressure at . Boiler steam pressure end of main ' ' , Return .water HrH-t Water line of boiler - + line ^-U-^Rtse Fig. 6. Steam Runouts Dripping Main 777777777777TT: 7 /777T77777777777T Fig. 4. Difference in Steam Pressure on Water in Boiler and at End ' `' of Steam Main Runout Steam drop to radiators-" Fig. 7. Steam Runouts with Main Dripped at End Only Fig. 5. Typical Down-Feed Gravity One-Pipe Air-Vent System 422 Chapter 31--Steam Heating Systems main does not carry any condensation from the radiators it is immaterial which method is used. The air vent shown on the main just before the last drop (Fig. 5) may be placed at this point or it may be located at the bottom of the drop under the last radiator connection and sufficiently above the water line of the boiler to prevent flooding. GRAVITY TWO-PIPE AIR-VENT SYSTEM The gravity two-pipe system is now considered obsolete although many of these systems are still in use in older buildings. Separate supply and Fig. 8. Typical Up-Feed Gravity Two-Pipe Air-Vent System return mains and connections are required for each heating unit; Lir valves are installed on the heating units and mains; hand valves are installed on the returns. . Up-Feed Gravity Two-Pipe System ' This system (Fig. 8) has a steam and a return connection to each radiator. The radiator valves for steam, return, and air are the same as those described for the gravity one-pipe air-vent system. The steam main is run and pitched in the same manner as in the one-pipe system, but the returns from each radiator are connected'into a-separate return line system which has its risers carried down and joined to a Wet-return line under the boiler water line level. Where the return has to be kept high to function as a dry return, it is advisable- to connect the. return risers to the dry return main through water seals about 36-in.-deep,-:as . shown in Fig. 9, to .prevent steam from one riser entering another.-and .closing the air valves on the nearest radiators. . 423 J American Society of Heating and VENTiLAfiNG Engineers Guide, 1934 Down-Feed Gravity Two-Pipe System , The steam main in the down-feed system is carried to the top of the building, and the piping of the steam side is arranged practically as,in the down-feed one-pipe gravity system. The drips at the bottoms Sof the steam drops and the runouts to the radiators are similar to those shown in Fig. 8 for the up-feed gravity two-pipe system. On the return side of the system, the piping is arranged in exactly the same manner as the up-feed gravity two-pipe system. ONE-PIPE VAPOR SYSTEM A vapor system is one which operates under pressures at or near atmospheric and which returns the condensation to the boiler by gravity. The piping arrangement of a one-pipe vapor system is similar to that of Chapter 31--Steam Heating Systems Under the first classification the essentials are packless graduated valves on the radiators, thermostatic return traps on the returns, and traps on all drips unless they are water sealed. Such a system, illustrated in Fig. 10, should be equipped with an automatic return trap to prevent the water from backing out of the boiler. In this up-feed arrangement the supply piping is carried to a high point directly at the boiler and is graded down toward the end or ends of the supply main, each supply main being dripped at the end into the wet return or carried back to a point near the boiler where it drops down below, the boiler water line and becomes a wet return. From this main, runouts are branched off to feed risers or radiators above, these being graded back toward the steam main Fig. 9. Method of Connecting Two-Pipe Gravity Returns to Dry Return Main the gravity one-pipe steam system; in fact, one-pipe gravity installations may readily be changed to one-pipe vapor systems by making a few simple alterations., The steam radiator valve is a plug cock which when opened gives a free and unobstructed passageway for water. The auto matic air valve is of special design to permit the ready release of air from the radiator and to prevent the return of the air after it is expelled. The air valves on the, main are a quick relief type, and the whole system is designed to operate on a few ounces of pressure. '! .' TWO-PI PE VAPOR SYSTEM ' Two-pipe Vapor systems may be classified as (1) closed systems con sisting of those which have a device to prevent the return of air after it is once expelled from the system, and which can operate at sub-atmospheric pressures for a period of four to eight hours depending upon the tightness of the system, and (2) open systems consisting of those which have the return line constantly open to the atmosphere without a check or other device to prevent the return of air, and which operate at a few ounces above atmospheric pressure. ' 424 Fig. 10. Typical Up-Feed Vapor System with Automatic Return Trap* Proper piping connections are essential with special appliances for pressure equalizing and air elimination. if they are not dripped at the bottom of the riser, or toward the riser if the riser heel is dripped. Both conditions are illustrated in Figs. 2 and 3. Return risers are connected to each radiator on its return end through thermostatic traps. Their bottoms are connected to the return main through runouts which slope toward the main. The return main itself is sloped back toward the boiler if it is carried overhead; if run wet, the slope may be neglected. An air vent is installed at the point at which the return main drops below the water line. In the simplest cases this vent consists of a %-in. pipe with a check valve opening outward, but in certain patented systems special forms of vent valves, designed to allow the air readily to pass out of the system and to prevent its return, are used. A check valve is inserted in the return main at a point near the boiler and a vertical pipe is run up into, the bottom of the return trap, which usually is located with the bottom about 18 in. above the boiler . water line. Some traps are constructed to permit the bottom's: being 425 / American Society of Heating and Ventilating Engineers Guide, 1934 Fig. 11. Typical Connections for Automatic Return Trap \ placed as close as 8 in. above the boiler water line. On the other side of this connection a second check valve is installed in the main return just before it enters the boiler. (Fig. 11). Down-Feed Two-Pipe Vapor System In the down-feed two-pipe vapor system the steam is carried to the top of the building, the top of the vertical riser constituting the high point of the system, and the horizontal supply main is sloped down from this location to the far ends of each branch. The branches are taken off the' main from the bottom or at.a 45 deg angle downward, with the runouts Bottom of steam drop' Graduated valve Drip trap Dirt pocket- a^Floor r -Connected to dry return (where connected to wet return, drip trap may be omitted) Fig. 12. Detail of Drip Connections at Bottom of Down-Feed Steam Drop 426 Chapter 31--Steam Heating Systems 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 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 weir 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 above which a drip trap connection is located, as shown in Fig. 12. The returns on a down-feed vapor system are the same as on an up-feed system except that every steam drop must have a drip at the bottom connected either into the return through a trap or into a separate water-sealed drip line below the boiler water line, as illustrated in Fig. 10, in which case the thermostatic traps may be omitted. The runouts to the radiators and the radiator connections of the down-feed system are the same as those of the up-feed system already described. ATMOSPHERIC SYSTEM The distinguishing features of the atmospheric system are gravity return to the boiler or to waste, graduated or ordinary radiator valves, no automatic air valves on the radiators, thermostatic traps on the radiator returns, and the venting of all air from the system by means of pipes open to the atmosphere. The returns are open to the atmosphere at all times, usually by extending the return risers to the. top of the building where they are either connected together in groups and carried through the roof or extended through the roof individually. Atmospheric systems, either up-feed or down-feed, are often used where the condensation is not returned to the boiler, as in heating systems supplied by high pressure steam through pressure-reducing valves at locations far from the boilers. The returns may be delivered back to the boiler, if desired, by condensa tion return pumps which are vented to the atmosphere. The return lines in such systems are simply gravity waste lines in which the condensation flows entirely by gravity and is not aided by any pressure difference. The steam side may be run as that for either up-feed or down-feed two-pipe vapor systems, as the conditions require, and the radiator con nections are the same as for vapor systems in that they have graduated valves on the radiator supply ends and thermostatic traps on the radiator return ends. All drips from the supply main and the steam side of the system must pass through thermostatic drip traps before entering the return system where only atmospheric pressure exists. Fig. 13 illustrates a typical scheme of piping used on atmospheric systems. 427 American Society of Heating and Ventilating Engineers Guide, 1934 428 Chapter 31--Steam Heating Systems VACUUM SYSTEM In the vacuum system, a vacuum is maintained in the return line practically at all times but no vacuum is carried on the steam side, and the usual accessories include graduated valves on the radiator supply and thermostatic traps on the radiator return. The air is expelled from the system by a vacuum pump and all drips must pass through thermostatic traps before connecting to the return side of the system. These systems are often fed from high pressure steam mains through pressure-reducing valves but they may be fed direct from a low-pressure steam heating boiler as shown in Fig. 14, in which a typical up-feed vacuum system is illustrated. The supply main slopes down in the direction of flow; the runouts pitch down toward the riser if the riser is dripped (Fig. 3) or up toward the riser if the riser is not dripped (Fig. 2); both conditions are indicated in Fig. 14. The matter of dripping the risers depends largely on the height of the riser and the judgment of the designer. Ordinarily risers less than three stories high are not dripped and those more than four stories high are dripped, but there is no set rule for this. When risers are dripped the runouts from the steam main may be taken from the bottom if desired and each runout then serves as a drip for the main. '' The risers are carried up to the highest radiator connection and are connected to the radiator through runouts sloping back toward the riser. The radiators usually have graduated valves on the supply end, although this is not absolutely necessary. Angle-globe valves and gate valves may be used where graduated manual control is not desirable. The return valves must be of the thermostatic type which will pass air and water but which will close against the passage of steam. The return risers are carried down to the basement and are connected into a common return line, care being taken that no air pockets exist in the runouts or in the horizontal return main which slopes downward toward the vacuum pump to which it is connected. The air and water are taken by the vacuum pump, which discharges the air from the system and pumps the water back to the boiler, or other receiver, which may be a feed-water tank or a hot well. It is essential on these systems that no connection from the supply side to the return side be made at any point except through a trap. . While the best practice demands a return flowing to the vacuum pump in an interrupted downward slope, in some cases limitations make it necessary to drop the return below the level of the vacuum pump inlet before the pump can be reached. In such event one of the advantages of the vacuum system is that the return can be raised by the suction of the vacuum pump for a. considerable height, depending on the amount of vacuum maintained, by means of a lift fitting inserted in the return. When the lift is considerable, several lift fittings are used in steps (Fig. 15), more successful operation being obtained by this method than when the lift is made in one step. If the lift occurs close to the vacuum pump, a special arrangement is used as shown in Fig. 16. Down-Feed Vacuum System -- The piping arrangement for the down-feed vacuum system is similar on the supply side to the down-feed vapor system in that it has similar 429 American Society of Heating and Ventilating Engineers Guide, 1934 runouts, radiator valves, drips on the bottom of the steam drops, and enlargement of the drops for the lower radiator connections. The return side of the system is exactly the same as the up-feed system except that the steam riser drips at the bottom are connected into the return line through thermostatic traps. It is preferable to take the runouts for the risers from the bottom or at a 45 deg angle down from the steam main (Fig. 6) so that they may serve as steam main drips. When this is done it is practical to run the steam main level if a runout is located at every change in pipe size, or if eccentric fittings are used (Fig. 17). A slight pitch in the steam main, however, should be used when possible. An overhead vacuum down-feed system is shown diagrammatically in Fig. 18. Chapter 31--Steam Heating Systems radiators only during the most severe weather, while under - average winter temperatures the steam is under a partial vacuum which in mild weather may reach as high as 25 in. This vacuum is largely self-induced by the; condensation of the steam in the system when an inadequate supply of steam is being furnished through the control valve which admits jt. In the sub-atmospheric system, a control valve is inserted on the steam main of an ordinary vacuum system near the boiler, a high-vacuum pump is substituted for the ordinary type and is supplied with a pressuredifference control, and traps are placed on the radiators and drips which will operate satisfactorily at any pressure from 5 lb gage to 26 in, of vacuum. Fig. 15. Method of Making Lifts on Vacuum Systems when Distance is Over 5 ft Fig. 16. Detail of Main Return Lift at Vacuum Pump -o, eeOccCeEnNtToQcIC'BEDUOMS fi I--e---- fcoucum 2 Fig. 17. Method of Changing Size .of Steam Main when Runouts are Taken from Top SUB-ATMOSPHERIC SYSTEMS The sub-atmospheric systems are similar to the vacuum system except that a pump capable of operating up to 25 in. of vacuum is used, and a control is placed on the pump so that the vacuum or absolute pressure carried in the return can be maintained a certain amount below that existing in the steam line to cause a constant circulation. The.traps are designed to operate in high vacuum. It is apparent that this system differs from the ordinary vacuum system by having a vacuum on both sides of the system, instead of only on the return side, in order to secure controlof the heat emission from the radiators and thus to-control the temperature in the building. The system can be operated in the same . manner as the ordinary vacuum system when desired. In the vacuum system, steam pressure above that of the atmosphere exists in the supply mains and radiators practically at all times. In the sub-atmospheric system, steam pressure exists in the steam main and 430 Fig. 18. Typical Down-Feed Vacuum System The control valve is a special pressure reducing valve which may be controlled manually or thermostatically from points selected in the building. The vacuum pump regulator is simply a diaphragm , so ar ranged that, when the vacuum in the return line is insufficient to hold the desired difference in pressure between the steam and return sides of the system, the vacuum pump is automatically started and the vacuum increased to the necessary amount. The actual pressure difference main tained between the two sides of the system is only , enough to secure adequate circulation and is often about 2 in. of mercury. This fixed pressure difference between the supply and return sides of the system results in practically constant circulation under all pressure conditions. In order to distribute the steam equally when the system is being warmed up and also to reduce the amount of-steam delivered to the radiators on mild days, orifice plates are used in the graduated radiator control valves. The heat emitted from the radiators in mild weather and 431 American Society of Heating and Ventilating Engineers Guide, 1934 under conditions of high vacuum is not only reduced in proportion to the difference in the steam temperature between that for 2 lb gage and for 25 in. of vacuum but it is reduced still further by a reduction in the amount of steam which can pass through the orifice when the steam is expanded due to the vacuum. This renders possible the control of heat emission from the radiators to a point not indicated entirely by the difference in steam temperatures. The high-vacuum pumps on this system are equipped with receivers having float control so that the pump can be placed on a receiver-returnpump basis at night if desired so no high vacuum will be carried. One radical difference between this system and the ordinary vacuum system is that no lifts can be made in the return line. The returns must grade downward constantly and uninterruptedly from the radiator return outlet to the inlet on the high-vacuum pump receiver. No attempt should be made to heat service water on this system unless the steam line for water heating is taken off the boiler header back of the heating system control valve, and then only when 2 lb or more will be carried on the boiler at all times. ORIFICE SYSTEM Orifice systems of steam heating may have piping arrangements identical with vacuum systems but some of these systems omit both the radiator thermostatic traps and the vacuum pump in cases where the returns are wasted to a sewer or delivered to some type of receiver in which no back pressure exists. The principle on which they operate is embodied in the well-known fact that an orifice will deliver varying velocities when the ratio of the absolute pressures on the two sides of the orifice exceeds 58 per cent. If the absolute pressure on the outlet side is less than 58 per cent of the absolute pressure on the inlet side no further increase in velocity will be obtained. v As a result, if an orifice is so designed in size as to exactly fill a radiator with steam at 2 lb gage on one side and 34 lb gage on the other, the abso lute pressure relation is 14.7 + 0.25 14.7 + 2.0 90 per cent Should the steam pressure be dropped to 34 lb gage, the pressure on each side of the orifice would be balanced and no steam flow would take place. From this it will be seen that if an orifice of a given diameter will fill a given radiator with steam when there is a given pressure on the main, it is simply a question of dropping this main pressure so as to fill any desired portion of the radiator down to the point where the main pressure equals the back pressure in the radiator, at which time no steam will be supplied at all. If orifices throughout a job are designed on a similar basis, all radiators will heat proportionately to the steam pressure within the limits for which the orifices are designed. Some systems use orifices not only in radiator inlets but also at different points on the main; thus balancing the system to a greater extent. For example, the system may be designed for a particularly long run involving an initial pressure of 3 lb gage on the main and 2 lb at the end of the main, 432 Chapter 31--Steam Heating Systems. but each branch from the main may have an orifice for reducing the pressure at it to 2 lb gage. This is particularly useful for branches near the boiler where the drop in the main has not yet been produced. Orifice systems using a vacuum pump operate successfully with the ordinary low vacuum type of pump producing 8 to 10 in. of vacuum. They are controlled by various means to regulate the steam pressure.One method is by a thermostat located on the roof to govern the steam pressure by a combination of outside and inside temperatures; another, useful on systems without traps and vacuum pumps, controls the steam pressure manually from temperature indication stations in the building, or automatically by a thermostatically-controlled pressure reduction valve or draft regulator on the boiler; with oil or gas firing, the on-and-off control or a boiler pressure control may be used. ZONE CONTROL Certain portions of a building may require more heat at times than others but if the whole building is on one general control, such as would occur with a single piping system with an on-and-off control or with the sub-atmospheric or the orifice systems, it would be necessary to supply sufficient heat to accommodate the coldest portion of the building even though some sections would be overheated. By zoning, each section of a building may be controlled separately. The sides of the building with different exposures should be considered first, because of the varying effects of the wind and sun. With the pre vailing winter winds from the northwest, a simple zoning would place the north and west sides of the building on one system.and the south and east sides on another. If the building is large enough to justify the expendi ture, a better arrangement would be to place all north walls on one zone, all west walls on a second, all east walls on a third, and all south walls on a fourth. . In case of high buildings, the lower 8 or 10 stories may be well protected from wind by surrounding buildings, the next 10 stories may have moderate exposure, and above this there may be an unobstructed exposure to gales. On still days the heat demands vertically will vary little, but on windy days there will be a marked difference in the heat requirements for the different horizontal sections. In addition, the chimney effect caused by the difference in density between the warm air on the inside of a building and the colder air on the outside will give an air movement which will require zoning to correct. Where such conditions are encountered, the building should be divided horizontally as well as vertically. An arrangement of this character would give 12 zones, namely: north, east, south, and west lower zones; similar middle zones; and similar top zones. Each zone should constitute an individual and separate system of piping with its own supply steam valve (controlled by thermostats in its respec tive zone) and with its own return or vacuum pump, if one is used. Certain interior areas, such as basements, light well walls and other locations where sun and wind do not affect the conditions, should be placed in still another zone if the most economical results are to be secured. .. Zoning has advantages even where individual thermostatic radiator 433 American Society of Heating and Ventilating Engineers Guide, 1934 control is installed whether this be of pneumatic, electric, or the selfcontained radiator valve type. By operating the different zones to parallel outside temperature requirements, a large part of the load is taken off the thermostatic controls, they make fewer operations and the radiator follows a more even temperature instead of fluctuating from extreme hot to extreme cold. CONDENSATION RETURN PUMPS Condensation return pumps are generally required when the elevation of the boiler with respect to the heating units is such that the condensate will not return by gravity, or.when the boiler pressure is greater than that Fig. 19. Typical Installation Using Condensation Pump , supplied the heating units, as in a high-pressure boiler installation sup plying steam through a reducing valve, to the heating units. The con densate is commonly returned by gravity to a receiver, vented to the atmosphere, from which it flows to the pump. Condensation return pumps are assembled with tank or receiver arid arranged for either continuous operation or for automatic starting and stopping by float control. Any style of water pump may be employed for this service, the power available determining whether the mode of drive shall be steam or electric. The motor-driven, automatic, centrifugal pump and receiver has found wide acceptance in practice for low pressure heating systems. Fig. 19 shows a typical installation using an automatic condensation return pump and vented receiver. A float control operates the pump whenever sufficient water accumulates. Condensation return pumps are 434 Chapter 31--Steam Heating Systems suitable for use on systems in which the returns are under atmospheric pressure. These include atmospheric systems, orifice systems with open returns, and certain types of vapor systems which operate within a few ounces of atmospheric pressure, but ordinarily do not carry any subatmospheric pressure. They may also be used on one-pipe and two-pipe gravity steam systems with a proper arrangement for venting the receiver. In discharging to waste, there is no object in using a condensation pump unless the discharge must be elevated. VACUUM PUMPS A vacuum heating pump is employed to create a vacuum on the return end of a system to remove air and water and to return the condensate to the boiler or to some other intercepting device that may be employed in plants having mixed systems of heating and other services. Pumps of this classification may be driven by steam or electricity; they may be continuous in operation, or automatic with float or vacuum control in one or more combinations. . Return line vacuum pumps are classified as follows: 0. 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 will handle vacuum steam system condensation coming back by gravity at any temperature up to 205 F without either the sealing or the hurling water flashing into steam. These pumps, to operate under a combined water level and vacuum con trol, must be equipped with a float-control receiver between the vacuum pump and the system, but where they are intended for continuous opera tion, they do not require a receiver. Such pumps employ a single vacuum producer which removes the condensate and air from the system and delivers it into a separating chamber under atmospheric pressure from which the condensate is delivered to the boiler or feed water heater. They . are constructed on one of the following evacuating and discharge principles: 1. Hydraulic vacuum producer with one pump impeller. 2. Hydraulic vacuum producer with two pump impellers. 3. Water displacement vacuum producer with two pump impellers. 4. Piston displacement vacuum producer with one pump piston. The second classification of pumps will handle vacuum steam system condensation coming back by gravity at any temperature not exceeding 190 F without the flashing into steam of either the sealing or the hurling water. In order to operate under a combined water-level and vacuum control, these pumps must be equipped with a float-control receiver between the vacuum pump and the system; where intended for con tinuous operation they do not require a receiver. Such pumps empjoy a vacuum producing impeller which removes air from the receiver or heating system under a partial vacuum and delivers it through an air separator against atmospheric pressure. The condensate is removed from the receiver-under a partial vacuum by a separate impeller and is delivered to the boiler or feed water heater. For evacuating and dis 435 American Society of Heating and Ventilating Engineers Guide, 1934 charge, a water displacement vacuum producer with two pump impellers is used. Receiver Capacities for Vacuum Pumps Where receivers are used in connection with vacuum pumps there is a definite relation between the capacity of the receiver and the capacity of the pump. The receiver should have a capacity of not less than times the volumetric quantity of condensation per minute and should not have such a capacity that the pump will empty the receiver in less than half a minute. Receivers of larger capacities will result in less frequent periods of operation. Duplex Vacuum Pumps Duplex vacuum pumps consist of two pumps mounted on a common or separate bedplate and having a common receiver. Duplex pumps now on the market include a motor-drive on one pump and a low-pressure steam-turbine-drive on the other, the exhaust from the turbine being used in the heating system as long as the system has the capacity to condense all of it. When the system capacity has fallen to a point where it no longer can completely condense the turbine exhaust, the equipment auto matically goes over onto electric operation but as soon as the steam demand in the system rises again the turbine is thrown into operation and the motor is cut out. Piston Displacement Vacuum Pumps Piston displacement return-line 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. While the volumetric displacement for such pumps was formerly figured at 8 to 10 times the volumetric flow of condensation to be handled, the more efficient thermostatic traps used today in connection with vacuum heating systems make it possible to change this proportion so that the volumetric displacement of these pumps may not be less than 6 times the volume of condensation. Vacuum Pump Controls In the ordinary vacuum system the vacuum pump is controlled by a vacuum regulator which cuts in when the vacuum drops to the lowest point desired and which cuts out when the vacuum has been increased to the highest point. This is done largely to eliminate the constant starting and stopping of the vacuum pump which- would occur if the vacuum were maintained constant. In addition to this control, a float control is in cluded which will automatically start the pump whenever sufficient con densation accumulates in the receiver, regardless of the vacuum in the system. This arrangement makes the vacuum pump primarily a con densation pump and secondarily an air pump. On the sub-atmospheric systems the high vacuum pump is controlled by a differential regulator which keeps the vacuum in the return line always a few inches higher than that in the steam line and in the radiators. 436 Chapter 31--Steam Heating Systems TRAPS Traps are used for draining the condensate from radiators, steam piping systems, kitchen equipment, laundry equipment, hospital equip ment, drying equipment and many other kinds of apparatus. The usual functions of a trap are to allow the passage of condensate and to prevent the passage of steam. In addition to these functions, traps are frequently required to allow the passage of air as well as condensate. Traps are also required to allow the passage of air and to prevent the passage of either water or steam, or both. In addition, traps are used for returning condensate either by gravity, by steam pressure, or by both, to a boiler or other point of disposal, and for lifting condensate from a lower to a higher elevation, or for handling condensate from a lower to a higher pressure. The fundamental principle upon which the operation of practically all traps depends is that the pressure within the trap at the time of discharge shall be equal to, or slightly in excess of, the pressure against which the trap must discharge, including the friction head, velocity head and static head on the discharge side of the trap. If the static head is in favor of the trap discharge it is a minus quantity and may be deducted from the other factors of the discharge head. Traps may be classified according to the principle of operation as (1) float, (2) bucket, (3) thermostatic, or (4) 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 tinuous 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 the valve against its seat, the valve and its stem usually being fastened to the bucket. When the water rises above the edges of the bucket it flows into it and causes it to sink, thereby withdrawing the valve from its seat. This permits the steam pressure acting on the surface of the water in the bucket to force the water to a discharge opening.-When the bucket is emptied it rises and closes the valve and another cycle begins. The discharge from this type of trap is intermittent. In the inverted bucket trap, steam floats the inverted submerged bucket and closes the valve. Water entering the trap fills the bucket which sinks and through compound leverage opens the valve, and the trap discharges. It is impossible to install a water gage glass on an inverted bucket trap, but if visual inspection is necessary, a gage glass can be placed on the line leading to the trap. No air relief cocks can be used, but this is unnecessary, as the elimination of air is automatically taken care of by air passing through the vent in the top of the inverted bucket regardless of temperature. Thermostatic Traps. Thermostatic traps are of two types, those in which the discharge valve is operated by the relative expansion of metals, and those in which the action of a volatile liquid is utilized for this purpose. Thermostatic traps of large capacity for draining blast coils or very large radiators, are called blast traps. Tilting Traps. With this type of trap, water enters a bowl and rises until its weight over-balances 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 437 American Society of Heating and Ventilating Engineers Guide, 1934 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. Thermostatic traps are generally used for draining radiators and heaters, except for very large capacities where bucket, float or blast-type thermostatic traps are used. Thermostatic traps for this service usually pass both condensate and air and in the case of float and upright bucket traps the air is usually relieved through an auxiliary thermostatic trap in a by-pass around the main trap. Sometimes this auxiliary air trap is an integral part of the trap. Blast-type thermostatic traps are sometimes used on vacuum heating Chapter 31--Steam Heating Systems pressure on the inlet side is sufficient, and should not be used, therefore, with such pressures unless the vent is properly piped back into the return to a feed water heater, a condenser or a perforated pipe in the bottom of the receiver to which the trap discharges in such a way as to prevent the escape of the steam that comes in with the condensate and passes Swing Fig. 20. Method of Discharging High-Pressure Apparatus into Low-Pressure Heating Mains and Vacuum Return Mains through a Low-Pressure Trap systems for connecting old one- or two-pipe gravity systems in parallel with vacuum return line systems, in which case the blast-type thermo static traps should not be provided with auxiliary air by-pass, as the action of this will allow the vacuum to draw air into the old system through its air valves, especially when the steam is wholly or partially cut off. The air from the returns of such old systems should.be relieved just ahead of the traps by means of quick-venting automatic air valves, preferably of the non-return type, especially if the other air valves on the old system are non-return valves. Tilting traps used for discharging to a higher or a lower pressure are provided with two or three valves operated by the action of the trap. In the case of the two-valve tilting traps, one valve closes a steam inlet and the other valve opens a vent outlet while the trap is filling, and as soon as the trap dumps the first valve opens the steam inlet and the second valve closes the vent outlet, while the trap discharges. In this type of trap there must be a swinging check-valve on each side of the trap, in addition to the usual by-pass, to prevent the pressure in the trap, while discharging, from backing up through the inlet and the pressure in the discharge line from backing up into the trap while it is filling. This type of trap will blow steam out through the vent while filling, if the . 438 Fig. 21. Return Trap and Receiver for Automatic Boiler Feed through the vent. In the three-valve traps of this type there is an extra valve for closing the discharge while the trap is filling. ' High pressure traps should not discharge directly into a vacuum return because, of the vapor formed by the re-evaporation of a part of the hot condensation. Fig. 20 shows a method which may be used for disposing of the greater part of the vapor of re-evaporation. 439 American Society of Heating and Ventilating Engineers Guide, 1934 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 the operation of the plant under varying conditions. Automatic return traps, sometimes called alternating receivers, may be of the counterbalanced, tilting type, or spring actuated. These consist of a small receiver with an internal float, and when the condensate will not flow into the boiler under pressure, it will feed into the receiver of the trap, and in so doing, raise or tilt the float or mechanism which actuates a steam valve automatically. This admits steam to the receiver, at boiler pressure, and the equalizing of the pressures which follows allows the water to flow into the boiler. Fig. 21 shows a direct return tilting trap and receiver properly connected for automatically feeding a boiler from a system of returns delivering the condensate to the receiver. 440 Chapter 32 STEAM SYSTEM PIPING Flow of Steam in Pipes, Pipe Sizes, Initial Pressure, Pressure Drop, Maximum Velocity, Reaming, Equivalent Length of Run9 Tables far Pipe Sizing, Sizing One-Pipe Gravity Air Vent Systems, TwoPipe Gravity Air. Vent Systems, Two-Pipe Vapor Systems, Atmospheric Systems, Vacuum Systems, Sub-Atmospheric Systems, Orifice Systems, Pressure-Reducing Valves, Expansion in Steam and Return Lines, Piping Connections and Details, Boiler Con nections, Hartford Return Connection . . THE design of a steam heating system may be divided into four parts, namely, (1) the details of the heating units, (2) the arrangement of the general piping scheme, (3) the details of connections, and (4) the sizing of the lines. Items 1 and 2 are covered in Chapters 30 and 31, respectively, while this chapter considers the two latter items. . The functions of piping are to supply the heating units with steam and to remove the condensation. In some systems both the air and con densation are removed from the heating units by the return piping. To accomplish this effectively, the distribution of the steam should be efficient and equitable, without noise, and the returns should be as short as possible. When air is handled its escape should be facilitated to the utmost since an air-bound system will not heat properly. Condensation takes place in a steam- system not only in the heating units, but through out the piping system as well, and the returns also condense any steam or . vapor that may be contained. At the same time part of the condensation may flash back into steam when the vacuum or pressure in the return is considerably below the steam pressure. It is essential that steam piping systems not only distribute steam at full load but also at partial loads, as the average winter demand is less than half of the demand in most severe outside temperatures. Further more, in heating up rapidly the load on the steam main may exceed the maximum operating load even in extreme weather, due to the necessity of raising the temperature of the metal in the system to the steam tem perature. This may require more heat than would be emitted from the system itself after it once is thoroughly heated.. ' STEAM FLOW IN PIPES 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 following formula: . . 441 American Society of Heating and Ventilating Engineers Guide, 1934 / ,, 3.6 \ W*L P = 0.0000000367 ( 1 + (1) where P = loss in pressure, pounds per square inch. d = inside diameter of pipe, inches. L -- length of pipe, feet. D = weight of 1 cu ft of steam. W -- weight of steam flowing per hour, pounds. Example 1. How much steam will flow per hour through 100 ft of 2-in. pipe if the initial pressure is 1.3 lb per square inch and the pressure drop is 1 oz? Solution. P = = 0.0625 lb; d = 2.067 in. (Table 1, Chapter 34); L = 100 ft16 _ D = 0.04038 lb (Table 5, Chapter 41). Substituting these values in Formula 2; VW = 5220 0.0625 X 0.04038 X 2.067s = 97.2 lb per hour. (' + w)TM Formula 2 does not allow for entrained water in low-pressure steam, condensation in pipe, and roughness in commercial pipe as found in practice. The latent heat of steam (hfg) at atmospheric pressure (Table 5, Chapter 41) is 970.2 Btu per pound. Inasmuch as the heat emission of an equivalent square foot of heating surface (radiation) is 240 Btu, 1 lb of steam at this pressure w.ill supply 970 2 or 4.04 sq ft of equ.ivalent heati.ng surface. This figure is usually taken as 4 even. In Example 1, the weight of steam flowing per hour would therefore supply 4 X 97.2 or 388.8 sq ft of equivalent heating surface. PIPE SIZES The determination of pipe sizes for steam heating depends on the following principal factors: 1. The initial pressure and the total pressure drop which may be allowed between the source of supply and the end of the return system. 2. The maximum velocity of steam allowable for quiet and dependable operation of the system. 3. The equivalent length of the run from the boiler or source of steam supply to the farthest heating unit. 4.' Unusual conditions in the building to be heated. Initial Pressure and Pressure Drop Theoretically there are several factors to be considered, such as initial pressure and pressure required at the end of the line, but it is most im portant that (1) the total pressure drop does not exceed the initial pressure of the system; (2) the pressure drop is not so great as to cause excessive velocities; (3) there is a constant initial pressure, except on systems 442 Chapter 32--Steam System Piping Table 1. Maximum Allowable Capacities op .Up-Feed Risers eOr One-Pipe Low Pressure Steam Based on A. S. H. V. E. Research Laboratory Tests pips Size Inches Velocitt Feet Per Second Pressure Drop Ounces per 100 Ft A `i IX m 2 2 54 3 3K 4 B 14.1 17.6 20.0 23.0 ___ 26.0 29.0 31.0 32.0 C 0.68 0.66 0.66 0.57 0.54 0.48 0.44 0.39 Sq Ft Radiation D 45 98 152 288 464 799 1144 1520 , Capacitt Btu per Hour E 10,961 23,765 36,860 69,840 112,520 193,600 277,000 368,000 Lb Steam per Hour F 11.3 24.5 38.0 72.0 116.0 199.8 286.0 380.0 INSTRUCTIONS FOR USING TABLE 1 1. Capacities given in Table 1 should never be exceeded on one-pipe risers. 2. Capacities are based on lb condensation per square foot equivalent radiation and actual diameter of standard pipe. 3. All pipe should be well reamed and free from constrictions. Fittings should be up to size. (See Tables 4 and 5). specially designed for varying initial pressures, such as the sub-atmos pheric, the orifice, and the vapor systems which normally operate under partial vacuums; (4) there is sufficient difference in level, for gravity return systems, between the lowest point on the steam main, the heating Units, and the dry return, when considered in relation to the boiler water line. All systems should be designed for a low initial pressure and a reason ably small pressure drop for two reasons: first, the present tendency in steam heating unmistakably points toward a constant lowering of pres sures even to those below atmospheric; second, a system designed in this manner will operate under higher pressures without difficulty. When a system designed for a relatively high initial pressure and a relatively high pressure drop is operated at a lower pressure, it is likely to be noisy and have poor circulation. The total pressure drop should never exceed one-half of the initial pressure when condensate is flowing in the same direction as the steam. Where the condensate must flow counter to the steam, the governing factor is the velocity permissible without interfering with the condensate flow. Laboratory experiments limit this to the capacities given in Tables 1 and 2 for vertical risers and in Table 3 for horizontal pipes at varying grades. Maximum Velocity and Reaming The capacity of a steam pipe in any part of-a steam system depends upon the quantity,qf_ condensation present, the direction in which the condensate is flowing, and the pressure drop in the pipe. Where the 443 American Society of Heating and Ventilating Engineers Guide, 1934 Table 2: Maximum Allowable Capacities of Up-Feed Risers for Two-Pipb Low Pressure Steam Based on A. S. H. V. E. Research Laboratory Tests Pipe Size Inches Velocity Feet pee Second Pressure Drop Ounces per 100 Ft A Vi. i m 2 m 3 3K 4 BC 20 -- 23 1.78 27 1.57 30 1.48 35 1.33 38 1.16 41 . 0.95 42 0.81 43 0.71 SqFt Radiation D 40 74 151 228 438 678 1129 1548 2042 Capacity Btu per Hour E 9550 17,900 36,500 55,200 106, ioo: 164,100 273,500 375,500 495,000 Lb Steam per Hour F . ~~ 10.0 18.45 37.65 57.0 109.5 169.4 282.2 387.0 510.5 INSTRUCTIONS FOR USING TABLE 2 ' 1. The capacities given in this table should never be exceeded on two-pipe risers. 2. Capacities are based on M lb condensation per square foot equivalent radiation and actual diameter of standard pipe. 3. All pipe should be well reamed and free from constrictions. Fittings should be up to size. (See Tables 4 and 5). 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 afpove which the disturbance between the steam and the counter-flowing water, may produce object ionable soiinds, such as water hammer, or may result in the retention of water in certain parts of the system until the steam flpw is reduced sufficiently to permit the water to pass. The velocity at which such disturbances take place is a function of (1) the pipe size, whether the pipe runs horizontally or vertically, (2) the pitch of the pipe if' it is run hori zontally, and (3) the quantity of condensate flowing against the steam. Two factors of uncertainty always exist in determining the capacity of any Steam pipe. The first is variation in manufacture, which apparently cannot be avoided and which caused an actual difference of 20 per cent in the capacity of a 1 in. pipe in experiments carried on at the A.S.H.V.E. Research Laboratory (Table 4). The second is the reaming of the ends of the pipe after cutting, which, experiments indicate, might reduce the capacity of a 1 in. pipe as much as 28.7 per cent (Table 5). All of the capacity tables given in this chapter include a factor of safety. However, the pipe on which Table 4 is based showed no particular defects or con strictions 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. . . 444 Chapter 32---Steam System Piping Table 3. Comparative Capacity of Steam Lines at Various Pitches Pitch of Pipe in Inches per 10 Ft Pitch or Pipe X IE- M m. 1 IN. 1M DI. Pipe Size Inches SqFt SqFt SqFt SqFt Rad. Based od 240 Btu >9 S Radi RtutoH on 240 Btu *3 > 3 Rad. on 240 Btu *> MC8 S Rad. Baaed on240 Btu 2 IN. SqFt Rad. Based on 240 Btu Max.Vel. Max.Vel. 3 EN. : 4 IN. 5 at.. SqFt SqFt SqFt Rad. Baaed on 240 Btu 3 a Rad. Baaed on 240 Btu i. s Rad. Based on 240 Btu "3 .> 2 X 25.0 12 30.3 14 37.3 18 40.4 19 42.5 20 46.1 21 47.5 22 49.3 23 1 45.8 12 52.6 15 63.0 17 70.0 20 75.2 22 83.0 23 87.9 25 90.2 26 tx 104.9 18 117.2 20 133.0 23 144.5 25 154.0 27 165.0 28 172.6 29 178.2 31 1H 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 A.S.H.V.E. Research Laboratory. Equivalent Length of Run All tables for the flow of steam in pipes, based on pressure drop, must allow for the friction offered by the pipe as well as for the additional resistance of the' fittings and valves." These resistances generally are stated in terms of straight pipe; in other words, a certain fitting will produce a drop in pressure equivalent to so many feet of straight run of the same size of pipe. Table 6 gives the number of feet of straight pipe usually allowed for the more common types of fittings and valves. In all pipe sizing tables in this chapter the length of run refers to the equivalent length of run as distinguished from the actual length of pipe in feet. The length of run is not usually known at the outset; hence it is necessary to assume some pipe size at the start. Such an assumption frequently is considerably in error and a more common and practical method is to assume the length of run and to check this assumption after the pipes are sized. For this purpose the length of run usually is taken as double the actual length of pipe. .. Table 4. Per Cent Difference in Capacity Due to Variation of Pipe Size and Smoothness Maximum Condensation, Lb per Hour ' Size of Pipe Minimum.. Maximum. Per Cent Variation.......................... ;______ Vi 14.00 15.20 8.6 . 1" 24.89 30.08 20.8 IK' 45.42 52.08 14.7 IK' 70.50 82.00 16.3 Data from American Society of Heating and Ventilating Engineer's Research Laboratory. Table 5. Effect of Reaming Entrance to One-Inch One-Pipe Risers Reamed entrances............................... Rounded entrances Squared entrances Three wheel rutte.r Single wheel rutfer Maximum Capacity or Riser 24.7 lb per hour 23.9 lb per hour 22.2 lb per hour 19.2 lb per hour 17.6 lb per hour Per Cent . . Decrease 0.0 3.2 10.1 22.2 28.7 ... . . "Data from American Society of Heating and Ventilating Engineers Research Laboratory. 445 / American Society of Heating and Ventilating Engineers Guide, 1934 Table 6. Length in Feet of Pipe to be Added to Actual Length of Run-. Owing to Fittings--to Obtain Equivalent Length Size op Pipe Inches St*d. Elbow Side Outlet Tee Gate Valve Gloss Valve Ancle Valve Length in Feet to be Added in Run 2 3 4 5 6 7 8 9 10 12 14 5 16 7 20 10 26 12 31 14 35 18 44 22 50 26 55 31 63 35 69 39 76 47 90 53 105 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. MEASURED LEHSTH. - Bl.-O. . 132-0'-- 4'5ATE VALUE. 4-4 " ELBOYfS. - S-O. - SB-0 ---- EQUNALEHT LENSTH - 193-0' TABLES FOR PIPE SIZING1 Factors determining the size of a steam pipe and its allowable limit of capacity are as follows: 1. Pipe condensate flowing with steam. 2. Pipe condensate flowing against steam. 3. Pipe and radiator condensate flowing with steam. 4. Pipe and radiator condensate flowing against steam. . It is apparent that (3) and (4) are practically limited to one-pipe systems while (1) and (2) cover all other systems. Tables 7 and 8, worked out for determining pipe sizes, have their'col umns lettered continuously, Columns A through L being in Table 7, and M through EE in Table 8. In the following text, reference made to columns will be by letter.' The tables are based on the actual inside diameters of the pipe and the condensation of 34 lb of steam per square foot of equiva lent direct radiation2 (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 noticeable defects. ipipe size tables in this chapter have been compiled in simplified and condensed form for the convenience of the user; at the same time all of the information contained in previous editions of The Guide has been retained. Values of pressure drops, formerly expressed in ounces, are now expressed in fractions of a pound. As steam system design has materially changed in recent years so that 240 Btu no longer expresses the heat of condensation from a square foot of radiator surface per hour, and as present day heating units have different characteristics from older forms of radiation, it is the purpose of The Guide to gradually eliminate the empirical expression square foot of equivalent direct radiation. EDR, and to substitute a logical unit based on the Btu. The Committee on Nomenclature is recommending new terms to express the equivalent of 1000 Btu. and 1000 Btu per hour, for approval by the A.S.H.V.E. In this edition of The Guide, the equivalent square foot has been retained in the tables for the sizing of steam heating systems, . 446 Chapter 32--Steam System Piping Table 7. Steam Pipe Capacities Capacity Expressed in Square Feet of Equivalent 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 OP STEAM MAINS AND RISERS Direction op Condensation Flow in Pipe Line Special Capacities pob One-Pipe Systems Onlt Pip* Size With the Steam in One-Pipe and Two-Pipe Against the Steam Two-Pioe Only Supply Radiator Valves and Radiator and In. lb 1/24 lb Vie lb Drop Drop Drop X lb Drop K lb Drop H lb Drop . Vertical Hori zontal UpFeed Con nections Run outs AB C D E F G ffa /c Jb K La "% 30 30 1 39 46 56 79 in 157 56 \% 87 100 122 173 245 346 122 IX 134 155 190 269 380 538 190 2 273 315 386 546 771 1,091 386 M 449 518 635 898 1,270 1,797 635 3 822] 948 1,163 1,645 3x 1,228 1,419 1,737 2,457 2,326 3,474 3,289 1,129 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 6,929 9,092 12,858 6 5,276 6,094 7,642 10,553 14,924 21,105 8 10,983 12,682 15,533 21,967 31,066 43,934 10 20,043 23,144 28,345 40,085 56,689 80,171 12 32,168 37,145 45,492 64,336 90,985 128,672 .....16 60,506 69,671 84,849 121,012 169,879 240,245 26 58 95 195 395 700 1,150 1,700 3,150 __ __ -- 25 45 98 152 288 464 799 1,144 1,520 20 55 81 165 20 55 81 165 260 475 745 1,110 2,180 ---- All Horizontal Mains and Down-Feed Risers UpFeed Risers Mains and Un dripped Run outs UpFeed Risers Radiator Con- sections Run outs Not Dripped Note.--All drops shown are in pounds per 100 ft of equivalent run--based on pipe properly reamed. Do not use Column H for drops of 1/24 or 1/32 lb; substitute Column C or Column B as required. bDo not use Column J for drop of 1/32 lb except on sizes 3 in and over; below 3 in. substitute Column B. On radiator runouts over 8 ft long increase one pipe size over that shown in Table 7. Coovriuht I American Society of Heating and Venttlatinq Engineers ) Not to be Reprinted Withpyng ( Heating, Piping and Air Conditioning Contractor* National Association J out Special Permission Table 7 may be used for sizing piping for- steam heating systems by determining the allowable or desired pressure drop per 100 equivalent feet of run and reading from the column for that particular pressure drop. This applies to all steam mains on both one-pipe and two-pipe systems, vapor systems, and vacuum systems. Columns B to G inclusive are used where the steam and condensation flow in the same direction, while Columns H and 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 8 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 7. It is customary to use the same pressure drop on both the steam and return sides of a system. ' 447 American Society of Heating and Ventilating Engineers Guide, 1934 448 C o p y r ig h t jjw lin s, Piping and A ir CW ifioninil Contactor* National Auociatum ) , . |[ A m e r ic a n So c ie t t o r H e a t in g a n d V e n t il a t in g E n g in e e r s ) N o t to be R e p rin te d W ith o u t Special P erm ission Chapter 32--Steam System Piping Example 2. What pressure drop should be used for the steam piping of a system if the measured length of the longest run is 500 ft and the initial pressure is not to be over 2 lb gage? ........................... Solution. It will be assumed, if the measured length of the longest run is 500 ft, that when the allowance for fittings is added the equivalent length of run will not exceed 1,000 ft. Then, with the pressure drop not over one-half of the initial pressure, the drop could be 1 lb or less. With a pressure drop of 1 lb and a length of fun of 1,000 ft, the drop per 100 ft would be Ho lb, while if the total drop were H lb, the drop per 100 ft would be Ho lb. In the first instance the pipe could be sized according to Column D for y{$ lb per 100 ft, and in the second case, the pipe could be sized according to Column C for H4 lb. On completion of the sizing, the drop could be checked by taking the longest line and actually calculating the equivalent length of run from the pipe sizes determined. If the calculated drop is less than that assumed, the pipe size is all right; if it is more, it is probable that there are an unusual number of fittings involved, and either the lines must be straightened or the column for the next lower drop must be used and the lines resized. Ordinarily resizing will be unnecessary. ! : SIZING ONE-PIPE GRAVITY AIR VENT SYSTEMS One-pipe gravity air vent systems in which the equivalent length of run does not exceed 200 ft should be sized as follows: 1. For the steam main and dripped runouts to risers where the steam and condensate flow in the same direction, use Hu lb drop (Column D). 2. Where the riser runouts are not dripped and the steam and condensation flow in opposite directions, and also in the radiator runouts where the same condition occurs, use Column L. 3. For up-feed steam risers carrying condensation back from the radiators, use Column J. 4. For down-feed systems the main risers of which do not carry any radiator con densation, use Column H. 5. For the radiator valve size and the stub connection, use Column K. 6. For the dry return main, use Column U. 7. For the wet return main use Column T. On systems exceeding an equivalent length of 200 ft; it is suggested that the total drop be not over ^ lb. The return piping sizes should correspond with the drop used on the steam side of the system. Thus, where H4 lb drop is being used, the steam main and dripped runouts would be sized from Column C; radiator runouts and undripped riser runouts from Column L; up-feed risers from Column J; the main riser on a down-feed system from Column C (it will be noted that if Column H is used the drop would exceed the limit of Ha lb); the dry return from Column R; and the wet return from Column Q. ;, With a drop the sizing would be the same as for H4 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 S. Size the one-pipe gravity steam system shown in Fig. 1-assuming that this is all there is to the system or that the riser and fun shown involves (the longest run on the system. ............... :- : Solution. The total length of run actually shown, is 215 ft.' If the equivalent length of run is taken at double this, it will amount to 430 ft, and with a total drop of H lb the drop per 100 ft will be slightly less than H6 lb. It would be well in this case to use . Yi\ lb, and this would-result in the theoretical sizes indicated in. Table 9. These, theo- 449 . I WAI American Society of Heating and Ventilating Engineers Guide, 1934 Table 9. Pipe Sizes for One-Pipe Up-feed System Shown in Fig. 1 ' Past or Stbtem ' Section or Pipe Branches to Radiators Branches to Radiators Riser......................................... Riser..:.................................... Riser...... ................................. Riser............ _......................... Riser......................................... Branch to Riser............... Supply Main...................... Branch to Supply Main Dry Return Main.......... Wet Return Main...... . Wet Return Main....... Wet Return Main.......... a to b b to c ctod d toe e to / / tog 2 to h h to j f to k i to m m to n n to p Radiation Theoretical Practical Supplied Pipe size Pipe size (So Ft) (Inches) (Inches) 100 50 200 300 400 500 600 600 600 600 600 600 . 600 600 2 IH 2 2X . 2'A 3. 3 m 3 2% 1M 1 1 1 2 lH 2 2K 2X 3 3 3 'A 3 3 2 2 2 2 Fig. 1. Riser, Supply Main and Return Main of One-Pipe System retical sizes, however, should be modified by not using a wet return less than 2 in. while the main supply, g-h, if from the uptake of a boiler, should be made the full size of the main, or 3 in. Also the portion of the main krm should be made 2 in. if the wet return is made 2 in. ' Notes on Gravity One-Pipe Air Vent Systems . 1. Radiator runouts over 8 ft long should be increased one pipe size. 2. Pitch of mains should be not less than y% in. in 10 ft. 3. Pitch of horizontal runouts to risers and radiators should not be less than Yi in. in 10. ft. ,, 4. 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 be not less than half its diameter at its largest part. 5. Supply mains, branches to risers, or risers, should be dripped where necessary. SIZING 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 34 lb the drop per 100 ft would be ~ or 34. lb; therefore, Column D would be used for all O' - . steam mains where the condensation and steam flow in the same direc tion. If a total drop of 34 lb is desired, the drop per 100 ft would be lb 450 Chapter 32--Steam System Piping and Column B would be used. If the total drop were to be 1 lb, the drop per 100 ft would be 34 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 J-fU lb or \^i 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 0, R, U, X, or AA according to the drop used for the steam main; and the risers are sized by reading the lower part of Table 8 under the column used for the mains. The hori zontal runouts from the riser to the radiator are not usually increased on the return lines although there is nothing incorrect in this practice. The same notes apply that are given for one-pipe gravity systems. . SIZING TWO-PIPE VAPOR SYSTEMS While many manufacturers of patented vapor heating accessories have their own schedules for pipe sizing, an inspection of these sizing tables indicates that in general as small a drop as possible is recommended. The reasons for this are: (1) to have the condensation return to the boiler by gravity, (2) to obtain a more uniform distribution of steam throughout the system, (3) because with large variation in pressure the value of graduated valves on radiators is destroyed. For small vapor systems where the equivalent lertgth 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 34 lb to J4 lb. if possible. Thus, for a 400 ft equivalent run the drop per 100 ft should be not over 34 lb divided by 4, or 3*s 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, 451 American Society of. Heating and Ventilating Engineers Guide, 1934 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 O 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. Radiator runouts-over 8 ft long should be increased one pipe size. 2. Pitch of mains should be not less than Y in. in 10 ft. . . 3. Pitch of horizontal runouts to risers and radiators should be not less than in.Y in 10 ft. 4. 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 be not less than 2Y in. at the far end. 5. 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. SIZING VACUUM SYSTEMS Vacuum systems are usually employed in large installations and have total drops varying from Y to Y lb. Systems where the maximum equivalent length does not exceed 200 ft preferably employ the smaller pressure drop while systems over 200 ft equivalent length of run more frequently go to the higher drop, owing to the relatively greater saving in pipe sizes. For example, a.system with 1200 ft longest equivalent length of run would employ a drop per 100 ft of Y. lb divided by 12, or Yc lb. In this case the steam main would be sized from Column C, and . the risers also from Column C (Column II could be used as far as critical velocity is concerned but the drop would exceed the limit of Y* lb). Riser runouts, if dripped, would use Column C but if undripped would use Column I; radiator runouts, Column I; return risers, lower part of Column S; return runouts to radiators, one pipe size larger than the radiator trap connections. . Notes on Vacuum Systems . 1. It is not generally considered good practice to exceed Y lb drop per 100 ft of equivalent run nor to exceed 1 lb total pressure drop in any system. 2. Radiator runouts over 8 ft long should be increased one pipe size. . : . 3. Pitch of mains should be not less than Y in. in 10 ft. . .. 4. Pitch of horizontal runouts to risers and radiators should be not less than Y in in 10 ft. . 5. In general it is not considered desirable to have a supply main smaller than 2 in. When the supply main is 3 in. or over, at the boiler or pressure reducing valve, it should be not less than 2Y in- at the far end. 6. When necessary, the supply main, supply riser, or branch to a supply riser should be dripped separately through a thermostatic trap into the vacuum return. A connec tion should not be made between the steam and return sides of a vacuum system without interposing a thermostatic trap to prevent the steam from entering the return line. 7. Lifts should be avoided if possible, but when they cannot be eliminated. they should be made in the mariner described in Chapter 31 under Up-Feed Vacuum Systems. 452 Chapter 32--Steam System Piping ' SIZING ATMOSPHERIC SYSTEMS The sizing of the supply and return piping on atmospheric systems is practically identical with the sizing used for vacuum systems and the same notes apply, except that no lift can be made in the return line. SUB-ATMOSPHERIC SYSTEM SIZING Any properly pitched, correctly sized vacuum system without a lift may be used as a sub-atmospheric system when the proper equipment is substituted for the ordinary vacuum pump, traps, and controls. On new systems manufacturers usually recommend a drop on the steam line of between Y and % lb for the total run, and suggest adding 25 ft to the total equivalent length of run to insure that the steam gets through to the last radiator. The same notes apply to these systems as for vacuum systems, except that no lifts can be made in the returns. SIZING ORIFICE SYSTEMS The orifice systems can be operated with any piping system suitable for vacuum operation according to experienced designers. Because these systems vary considerably in detail, it is advisable to consult the manu facturer of the particular system contemplated for recommendations. The same notes apply to these systems as to vacuum systems, except that lifts cannot be made in the returns of orifice systems if a vacuum pump is used. ' .. : HIGH PRESSURE STEAM When steam heating systems are supplied with steam from a high pressure plant, one or more pressure-reducing valves are used to bring the pressure down to that required by the heating system. It has been con sidered good practice to make the pressure reductions in steps not to exceed 50 lb in each case. For example, in reducing from 100 lb gage to 2 lb gage, two pressure reducing valves would be used, the first reducing the pressure from 100 lb gage to 50 lb and the second reducing the pressure from 50 lb gage to 2 lb gage. Valves are available that will reduce 100 lb in one step, and it is questionable whether two valves are now required for initial pressures of 150 lb or less. The pressure-reducing valve, or pressure-regulator as it is sometimes termed, has ratings which vary 200 to 400 per cent. Some of these ratings are based on arbitrary steam velocities through the valve of 5,000 to 10,000 fpm and it is assumed that the valve when wide open has the same area as the pipe on the inlet opening of 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 ain area equal to that of the inlet-pipe size, 453 American Society of Heating and Ventilating Engineers Guide, 1934 Table 10; Capacities of Pressure Reducing Valves (100 lb Gage Down to any Pressure--52 lb or Less) Inlet Nominal Pipe Diameter (Inches) X X l IX IX 2 2X 3 3X 4 5 6 - Pounds Steam per Hour at 100 Lb Gage . 866 1,576 2,459 4,263 5,808 9,564 13,623 21,041 28,213 36,285 56,971 82,336 Equivalent Direct Radiation Sq Ft at 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 Equivalent Direct Radiation Sq Ft at 1/s Lb 2,598 4,728 7,377 12,689 17,424 28,692 40,869 .63,123 84,039 108,855 170,913 247,008 Formula: where A X V X 3600 X 50 144 X 3.84 pounds per hour passed by orifice. A -- area of inlet pipe in 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. - 3.8 = cubic feet per pound*at 100 lb gage. that the steam is flowing into a pressure less than 58 per cent of the initial pressure, that the orifice efficiency is approximately 70 per cent, and that 20 per cent more is allowed for a factor of safety, then the pressure reducing valves will have the working capacities shown in Table 10. If the valve, when fully open, does not give an orifice area equal to that of the pipe on the inlet side, then the capacities will be proportional to the percentage of opening secured, taking the pipe area as 100 per cent.. Most exact regulation of pressure on steam heating systems is secured from diaphragm-operated valves controlled by a pilot line from the low pressure pipe, taken off the low pressure main at least .15 ft from the reducing valve. The reducing valves operating on the proportionalreduction principle will give a variation of steam pressure on the low pressure side if the initial pressure varies between considerable limits. The so-called dead-end valve is used for reduced pressures where the line has not sufficient condensing capacity at all times to condense the leakage that might occur with the ordinary valve. Single-disc valves do not give as close regulation 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. 2) of a pressure-reducing valve includes a pressure-reducing valve with a gate valve on each side, a by-pass con trolled by a globe valve, a pressure gage on the low pressure side, and a safety yalve'vbn 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; arid in 454 Chapter 32--Steam System Piping 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 corinected in parallel. One valve should be large enough for the maximum load and the other should have a diameter approximately half that of the first. The smaller valve can be used most of the time, for it will give much better regulation than the larger one on light or normal loads. . Less trouble from expansion leaks will occur when the bypass Fig. 2. Typical Pressure Reducing Valve Installation Control yalves 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 use^ for throttling. Angle globe valves and straight globe valves should be used for throttling, as done on by-passes around pressure reducing valves or on by-passes around traps. EXPANSION IN STEAM AND RETURN LINES Because all steam and return lines expand and contract with changes in temperature, provision should be made for such movement. The expansion in steam supply pipes is normally taken at to in. per 100 ft and in return lines at one-half or two-thirds of this amount. It' may be calculated accurately if the temperature rise arid fall can be determined with reasonable certainty (Table 3, Chapter 34). The tem perature at the time of erection often has a greater expansion effect on piping than the temperature in the building after it has been put irito service. Expansion may be taken care of by any, or all, of three different methods, namely, (1) the spring in the pipe including offsets and expan sion bends, (2) the turning of the pipe on its threads and swing joints, rind (3) the use of expansion joints. ' By the first scheme, which is the most popular method where space permits, the pipe is offset, or broken, around rooms or corners, and is hung so that the spring in the pipe at right angles to the expansion movement is sufficient to absorb the expansion. If conditions do not lend themselves to this treatment, regular expansion bends of the~Z7 or offset type may be used. In tight places.such as pipe tunnels the expansion joint is pre ferable. ' 455 '/ .American Society of Heating and Ventilating Engineers Guide, 1934 On riser runouts and radiator runouts the swing joint is used almost without exception. On high vertical risers the pipes may be reversed every five to ten stories; that is, the supply is carried over to the adjacent return riser location and the return riser is run over to the former supply riser location, thus making horizontal offsets in each line. Corrugated copper expansion joints also are used on risers but must be made acces sible in case future replacement becomes necessary. EXPANSION BENDS The calculation of the distance required for offsets and the size of expansion bends necessary to absorb a given amount of expansion leads into complicated formulas and is a subject of controversy. It seems to have been demonstrated, however, that the shape of the bend, the radius used, the relative amounts of straight and curved pipe in a bend, and the r _< A+B+C=L U bend with Fitting offset 4 fittings U bend with 2 fittings Offset bend Fig. 3. Measurement of L on Various Pipe Bends and Offsets for Absorbing Expansion type of bend have little bearing on the amount of expansion for which they will safely provide. The size, weight and material of the pipe and the length of all of the pipe in the bend, or even in the offset, have a bearing on its capacity to absorb expansion without straining the pipe material beyond the safe working stress. In Fig. 3 typical pipe bends and offsets for absorbing expansion are shown. The lengths L are those which are used in determining the stress in the pipe. Fig. 4 shows a set of curves for standard weight steel pipe bends from which the approximate amount of pipe L (Fig. 3) for each pipe size may be determined from the amount of expansion movement that must be absorbed. These curves are such that the maximum fiber stress in any part of the bend will not be over 16,000 lb per square inch. Since 12,000 lb per square inch is considered to be a maximum working fiber stress in wrought iron pipe, an additional 33 per cent must be added to the length of this type of pipe. The amount of expansion can be doubled for a bend if the bend is cold sprung for one-half of the expansion movement. In other words, if the bend is erected with the main pipe cut, short one-half of the expected expansion and the bend is then sprung open to meet the shortened pipe, 456 . Chapter 32--Steam System Piping Fig. 4. Curves Giving Length L of Bend of Offset Necessary to Absorb Expansion (Without Cold Spring) the expansion in the main will first allow the bend to go back to its neutral point and then will compress the bend an equal distance beyond the neutral point, thus securing a doubled capacity. Generally only a portion of the cold spring is considered as being effective owing to the difficulties of erecting the bends with sufficient exactitude in the length of the main line and the difficulty of cold springing. PIPING CONNECTIONS AND DETAILS Piping connections may be classified into two groups: first, those suitable for any system of steam heating; second, those devised for certain systems which cannot be satisfactorily applied to any other type. There are also various details that apply to piping on the steam side which cannot be used on the returns. An installation that is designed and sized correctly and installed with care may be rendered defective by the use of improper connections, such as runouts that do not allow, for expansion, thermostatic traps unprotected from scale, pressure-reducing valves without strainers, and lack of drips at required points. Supply BOILER CONNECTIONS Boiler headers and connections have the largest sizes of pipe used in a system. Cast-iron, horizontal-type, low pressure heating boilers usually have several tapped outlets in the top, the manufacturers recommending their use in order to reduce the velocity of the steam in the vertical up takes from the boiler and to permit entrained water to return to; the boiler instead of being carried over into the steam main where it must; be cared for by dripping. Steel heating boilers usually are equipped with . only one steam outlet but many engineers believe that better results are obtained by specifying that such boilers have two. The second outlet,, usually, located 3 or 4 ft back of the regular one, reduces the velocity 50 per cent in the steam uptake. .: Fig. 5 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 457 American Society of Heating and Ventilating Engineers Guide, 1934 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. 6 shows a type of boiler connection which is regarded as superior to that shown in Fig. 5 and which is the type illustrated in the system diagrams in Chapter 31. This type is similar to that shown in Fig. 5 except that the horizontal branches from the uptakes are connected into the main boiler runout, and the steam is carried toward the rear of the boiler. The branch to the building or boiler header is taken off behind the last horizontal boiler con nection. At the rear end of this main runout, a large size drip, or balance pipe, is dropped down into the boiler return, or into the top of the Hart ford Loop, which is described in a following paragraph. As a result, any water carried over from the boiler follows the direction of steam flow Chapter 32--Steam System Piping 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. 7 shows this connection for both single boiler and two-boiler installations. By balancing the column of water in the loop against the steam pressure, the water cannot be blown out of the loop whatever the relative pressure conditions in the boiler, steam lines, or return lines. This balancing is done by raising the return to approxi mately the normal water line of the boiler, looping it back to the boiler inlet and connecting the top of this loop by means of a balance pipe with the steam runout from the boiler. It is important that this balance pipe be connected into the boiler steam line on the boiler side of all valves. ^THESEOWKniCNS SWJLD BE AS SHOCI AS HUCT1CAL USING AS FEWn \TUDNS AS POSSIBLE. THE. SEES SHOULD PREFERAHY BE NOT SMALLER THAW OVEN N TABLE BELOW. Fig. 5. Old Style Standard Boiler Connections Fig. 6. Approved Method of Boiler Connections toward the rear and is discharged into the rear drip, or balance pipe, without being carried over into the system. Return Cast-iron boilers are generally provided with return tappings on both sides, but steel boilers often are equipped with only one return tapping. A boiler with side return tappings will usually have a more effective cir culation if both tappings are used. Check valves generally should not be used on the return connection to steam heating boilers 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 inches3. However, if check valves are omitted arid the steam pressure is raised with the boiler steam v*alve 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. *See method of calculating height above water line for gravity one-pipe systems in Chapter 31. 458 THESE PIPES MAY BE ANV SIZE (OISOEEED PROPER FOR FEEDING1 BOILERS AND LESS THAN STEAM CONNECTIONS II TABLE ABOVE. Fig. 7. The Hartford Return Connection Theoretically, the top of the loop should be at the normal boiler water line but since this installation often causes trouble from water hammer in the top of the loop, this top is usually made 2 in. below the normal boiler water line to keep the horizontal pipe at the top submerged under all normal conditions. It is important that this top of the loop be made with the shortest possible horizontal pipe, a close nipple being employed. Sizing Boiler Connections Little authentic information is available on the sizing of boiler runouts and steam headers. Although many engineers prefer an enlarged steam header to serve as additional steam storage space, there ordinarily is no sudden demand for steam in a steam heating system except during the heating-up period, at which time a large steam header is a disadvantage rather than an advantage. The boiler header may be sized by first com puting the maximum load that must be carried by any portion of the header under any conceivable method of operation and then applying the same schedule of pipe sizing to the header as is used on the steam mains for the building. The horizontal runouts from the boiler, or boilers, may be sized by calculating the heaviest load that will be placed ,on the boiler at any time,-and sizing the runout on the same basis as the building . mains. The difference in size between the vertical uptakes from the 459 American Society of Heating and Ventilating Engineers Guide, 1934 boiler and the horizontal main or runout is compensated for by the use of reducing ells (Figs. 5 and 6). The following example illustrates the sizing of the boiler connections shown in Fig. 8. Example 4- Determine the size of boiler steam header and connections (Fig. 8) if there are three boilers, two to carry 50 per cent of the load each,- and the third to be used as a spare. The steam mains are based on l/g lb drop per 100 sq ft of equivalent direct radiation (EDR). Solution: Size of Boiler Header . When on Boilebs Nos. 1 and 2 Nos. 2 and 3 Nos. 3 and 1 Max. Load `A 6000 6000 6000 6000 Load on Various Portions op Headeh B 0 6000 0 6000 c 2000 8000 2000 8000 D 4000 2000 2000 4000 E 3000 3000 3000 3000 F 3000 3000 3000 3000 Maximum Load 6000 8000 6000 8000 8000 sq ft @ }/& lb per 100 ft = 6 in. main. (See Table 7). The three runouts Size of Boiler Runouts Gi, Gj, G = - O,, - '= ' 2667 sq ft each @ % lb per 100 ft = 4 in. pip.e. Hi, Hi, H, -- 2667 sq ft each @ }* lb per 100 ft = 4 in. pipe* (See Table 7). Ji, Ji, Ji -- 5333 sq ft each @ lb per 100 ft = 5 in. pipe4 (See Table 7). Ki, Kt, Kt = 8000 sq ft each @ % lb per 100 ft = 6 in. pipe4 (See Table 7). ' The uptakes from the boiler probably would be 6 in. pip$ with a 6 in. X 4 in. reducing ell at top. " - Return connections to boilers in gravity systems are made the same size as the return main itself. Where the return is split and connected to . *Nqte%--As JCi. Kt, Kt all carry-8000 sq ft and are 6 in. pipe, the whole1 runout including//i, /j and /*. would be made 6 in. pipe, also; .. . . ............................. . .. 460 . Chapter 32--Steam System Piping . two tappings on the same boiler, both connections are made the full size of the return line. Where two or more boilers are in use, the return to each may be sized to carry the full amount of return for the maximum load which that boiler will be required to carry. Where two boilers are used, one of them being a spare, the full size of the return main would be carried to each boiler, but if three boilers are installed, with one spare, the return line to each boiler would require only half of the capacity of the entire system, or, if the boiler capacity were more than one-half the entire system load, the return would be sized on the basis of the maximum boiler capacity. As the return piping around the boiler is usually small and short, it should not be sized to the minimum. 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 Friction Losses for Various Rates of Flow of Water, Fig. 3, Chapter 39. The relative boiler loads should be considered, as in the case of gravity return connections. Radiator Connections . Radiator connections are important on account of the number of repetitions which occur in every heating installation. They must be properly pitched and they must be arranged to allow not only for move ment in the riser but, in frame buildings, for the shrinkage of the building. In a three story building this sometimes amounts to 1 in. or more. The simplest connection is that for the one-pipe system where only one radia tor connection is necessary. Where the radiator runouts are located on the ceiling or under the floor, sufficient space usually is available to make a good swing joint with plenty of pitch, but where the runouts must come above the floor the vertical space is small and the runouts can project out into the room only a short distance. Fig. 9 illustrates two satisfactory methods of making runouts on a one-pipe gravity air vent system of either the up-feed or down-feed type, the runout below the floor being indicated in full lines arid the runout above the floor in dotted lines. Sometimes it is necessary to set a radiator on pedestals, or to use high legs, in order to obtain sufficient vertical distance to accommodate abovethe-floor runouts. Particular attention must be given to the riser expan sion as it will raise the runout and thereby reduce the pitch. Similar connections for a two-pipe system of the gravity air vent type are illustrated in Fig. 10 for the old steam type radiator. If the water type is used, the supply tapping is at the top instead of at the bottom, the runouts otherwise remaining as shown in Fig. 10. A satisfactory type of radiator connection for atmospheric, vapor, vacuum, sub-atmos pheric, and orifice systems of both the up-feed and down-feed types is shown in Fig. 11. While short radiators, not exceeding 8 to 10 sections, may be supplied and returned from the same end as indicated in Fig. 12, the top7anbottom-opposite-end method is to be preferred in all cases where it can be used. On down-feed systems of the atmospheric, vapor, vacuum, subatmospheric, and orifice types, the bottom of -the supply riser must be dripped into the return somewhat as illustrated in Fig. 13. On up-feed systems of the vapor arid atmospheric types, where radiators' in the 461 American Society of Heating and Ventilating Engineers Guide, 1934 / joint ' "'"''-Runout below floor PLAN Fig. 12. Top and Bottom Radiator Connections from Up- or Down-Feed Risers. (Not to Exceed 8 to 10 Sections). . Note.--Suitable for up-feed or down-feed at mospheric, vapor, vacuum, sub-atmospheric, and orifice systems. Opposite end connections always preferable. Fig. 9. Typical One-Pipe Radiator Connections (Up-Feed or Down-Feed) Fig. 10. Connections to Steam-Type Radiator for Two-Pipe Gravity System, Up-Feed or Down-Feed Note.--Steam-type radiators should not be used on any except gravity one-pipe and gravity twopipe systems. Fig. 13. Top and Bottom Opposite End Radiator Connections with Heel of Down-Feed Riser Dripped into Dry Return Note.--Suitable for down-feed only. For at mospheric. vapor, vacuum, sub-atmospheric, and orifice systems. . Fig. 11. Top and Bottom Opposite End Radiator Connections from Up or Down-Feed Risers Note.--Suitable for up-feed or down-feed at mospheric, vapor, vacuum, sub-atmospheric and orifice systems. on Wall Note.--For up-feed with radiators below level of steam main. For atmospheric and vapor systems. Not suitable for vacuum, sub-atmospheric, or orifice systems. 462 Chapter 32^-Steam System Piping '\ basement are located below the level of the steam main, the drop to the radiator is dripped into the wet return and an air line is used to vent the return radiator connection into an overhead return line, as illustrated in Fig. 14. When the radiator stands on the floor below the main, the drip on the steam branch down to the radiator may be omitted if an overhead valve, as shown in Fig. 15, is used. This' method is also suitable for vacuum, sub-atmospheric, and orifice systems. Convector Connections Convectors often are installed without control valves, a damper being used to shut off the flow of air to retard the heat transfer from the con vector even though it is still supplied with steam. The piping connect tions for a convector with the inlet and outlet at the same end are shown in 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. Convectors with damper control, installed in cabinets or under window sills, usually are connected as shown in Fig. 19. A convector located in the basement and supplying air to a room on the floor above may be piped as pictured in Fig. 20 for all systems except gravity one-pipe or two-pipe systems. Vapor systems with heating units in the basement where the returns are wet would be treated as in Fig. 21-. Similar heating units where a dry return is available would be connected as shown in Fig. 22. If the dry return were on a vacuum, atmospheric, sub-atmospheric or orifice system, the treatment would bp identical. Pipe Coil Connections Pipe coils, unless coupled in a correct manner, often give trouble from short circuiting and poor circulation. The method of connecting shown in Fig. 23 is suitable for atmospheric, vapor, vacuum, sub-atmospheric, and orifice systems. Indirect Air Heater Connections Heating units for central fan systems have simple connections on the steam side. The steam main is carried into the fan room and has, a single branch tapped off for each row of heating units. Each of- these main branches is split into as many connections as need be made to each row, governed by the number of stacks and the width of the stacks. Each stack must have at least one steam connection, and wide stacks are more evenly heated with two steam connections, one at each end. The piping shown in Fig. 24 is for small stacks and has the steam con nected at only one end. On the return side all of the returns are collected together through check.valves and are passed through blast traps which are connected to the vacuum return or to an atmospheric return. The air 463 CHAINPUU. VALVE f American Society of Heating and Ventilating Engineers Guide, 1934 464 Chapter 32--Steam System Piping from the stacks, in the case illustrated, passes up into a small air line and through a thermostatic trap into a line connecting into the return beyond the blast trap. It is important to use a nipple the full size of the outlet tapping on the stack and to reduce the pipe size to the normal return size required, by the use of a reducing ell, as indicated in Fig. 25. Where the stacks contain some thirteen or more sections, an auxiliary air tapping is made to the lower portion of one of the middle sections, in the manner illustrated in Fig. 26, to prevent air collecting at this point. Thermostatic control as applied to such heating units in modern practice consists of a thermostatic valve located in each main branch from the steam line so that each valve will open or close a complete row of stacks across the entire face of the heating unit. In this case no particular attention need be paid to the method of connecting the returns, that is, they do not need to be connected in parallel with the steam connections but may be hooked together in any convenient manner. The arrange ment shown in Fig. 27 is satisfactory. A-detail of the arrangement where a connection is made with a stack is shown in Fig. 28. It is essential to have a check valve on each individual stack to prevent reverse flow when the thermostatic valve in the steam line closes off and a partial vacuum is produced in the stack. The end of the steam main also should be dripped as indicated1, in Fig. 27. If the separate air line is used as shown in Fig. 24, the blast traps may . be supplied without thermostatic by-passes but if the piping is arranged as shown in Figs. 26 or 27, the blast traps must be supplied with the thermostatic by-passes to permit the passage of the air. PIPE SIZING FOR INDIRECT HEATING UNITS Pipe connections and mains for indirect heating units are sized in a manner similar to radiators, but the equivalent direct radiation must be ascertained for each row of heating unit stacks and then must be divided into the number of stacks constituting that row and into the number of connections to each stack. fdr = <2 X 60 X fa - fa) = Q X (ft - fe) 55.2 X 240 220.8 (3) where - 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. " h =. 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 5. Assume that the heating units shown in Fig. 27 are handling 50,000 cfm of air and that the rise in the first row is from 0 to 40 F, in the second row from 40 to 65 F, and in the third row from 65 to 80 F. What is the load.in EDR on each supply. . and return connection? . . .. ................. 465 American Society of Heating and Ventilating Engineers Guide, 1934 aagECT QAOATQgj ^ Keens iOivc Thermostatic trap Fig. 22. Typical Piping Connections tojIndirect Radiators with Dry Return Note.--Suitable for atmospheric, vapor, vacuum, sub-atmospheric, and orifice systems. m **TEVALVE' Full size of tapping - To return line beyond blast traps To blast trap Reducing eii Check vatve Fig. 25. Heating Unit Return Con nection with Separate Air Line Chapter 32--Steam System Piping Solution. For the C row, ,, 50,000 X (40 - 0) - 220.8 9058 sq ft. For the B row, 50,000 X (65 - 40) . R= 220.8 = .5661 sq ft. For the A row, 50,000 X (80 - 65) K~ 220.8 = 3397 sq ft. TYPKAL CONNECTIONS TO UWffOUD COILS HWIWa MOQE THAN 6 PPES. Fig. 23. Typical Pipe Coil Connections Note.--Suitable for up-feed or down-feed. For atmospheric, vapor, vacuum, sub-atmospheric, and orifice systems. x^valve 8tASI MEATEta, M' SUPRY AND RETURN CONNECTIONS TO LAST COtLS TOR VACUUM SYSTEM USING LAST TRAP ON EACH TIER. . Fig. 24. Connections for Heating Units of Central Fan Systems /JNote.--Suitable for atmospheric and vacuum' systems. Fig. 26. Typical Connections to Central Fan System Heating Units Exceeding 12 Sections Note.--Suitable for vacuum and atmospheric systems. 466 Fig. 27. Typical Piping for Atmospheric and Vacuum Systems with Thermostatic Control (Central Fan System) 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 c B A Total Load (EDR) 9058 5661 3397 Stack Load* (EDR) 2265 1415 849 - Connection LoADb (EDR) 2265 or 1132 ,, 1415 or 708 849 or 425 of total row load. of stack load if two steam connections are made; otherwise, same as stack load. 467 J American Society of Heating and Ventilating Engineers Guide, 1934 Chapter 32--Steam System Piping Fig. 28. Heating Unit Return Connection without Separate Air Line (Central Fan System) TO FWD LDCTHC - MULTIPLY A 61 OOUSIMJT EDO ANGLE B- Fig. 32. Constants for Determining Proper Length of Offset Pipe eccepiable vethco pbefehed methoo Fig. 33. Acceptable and Preferred Methods of Taking Branch from Main * of Dripping Main Where It RisestoHigher Level fNote.--Suitable for vapor and atmospheric systems. Fig. 30. Looping Main Around Beam dot Pocket- Fig. 34. Dirt Pocket Connection . Fig. 31. Looping Dry Return Main Around . Opening Note.---Suitable for any dry return line and any return line carrying air. .. SEDUCING COUPUNGFig. 35. Dripping , End of . Main into Wet Return Note.--Suitable for vapor systepis. 468 W.TEB "line Fig. 36. Dripping End of Main into Dry Return. (A Gate Valve is Recommended at the Inlet Side of the Trap) Fig. 37. Dripping Heel of Riser into Dry Return. (A Gate Valve is Recommended at the Inlet Side of the Trap) The pipe sizes would then be based on the length of the run and the pressure drop desired, as in the case of radiators. It generally is considered desirable to place the in direct heating units on a separate system and not on supply or return lines connected to the general heating system. DRIPPING Any steam main in any type of steam heating system may be dropped to a lower level without dripping if the pitch is downward with the steam flow. Any steam main in any heating system can be elevated if dripped. (Fig. 29). Steam mains also may be run over obstructions without a change in level if a small pipe is carried below the obstruction to care for the condensation (Fig. 30). Return mains may be carried past doorways or other obstructions by using the scheme illustrated in Fig. 31; in vacuum systems it is well to have a gate valve in the air line. 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. 32. Branches from steam mains in one-pipe gravity steam systems should use the preferred, connection shown in Fig. 33, but where radiator condensa tion does not flow back into the main the acceptable method shown in the same figure may be used. This acceptable method has the advantage of giving a perfect swing joint when connected to the vertical riser or radia tor connection, whereas the preferred connection does not give this swing without distorting the angle of the pipe. Runouts from the steam main are usually made about 5 ft long to provide flexibility for movement in the main. 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. 34-. 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. 35. On vacuum systems the ends of the steam mains are dripped and vented into the return through thermostatic drip traps opening into the return line. The same method. may be used in atmos pheric systems. The cooling leg (Fig. 36) is for cooling the condensation 469 . ..American Society of Heating and Ventilating Engineers Guide, 1934 l' sufficiently before it reaches the trap so the trap will not be held shut by too high a temperature. On down-feed systems of atmospheric, vapor, and vacuum types, the bottom of the steam risers are dripped in the manner shown in Fig. 37. 'NJ 470 Chapter 33 HOT WATER HEATING SYSTEMS One- and Two-Pipe Systems, Selecting Pipe Sizes, Forced Circu lation, Effect of Variations in Pipe Sizes, Gravity Circulation, Mechanical Circulation Devices, Expansion Tanks, Installation Details . AHOT water heating system is one in which water is the medium by which heat is carried through pipes from the boiler to the heating units. There are two general types, namely, forced circulation and gravity circulation systems. In the former the pressure head maintaining flow is produced mechanically, whereas in the latter the pressure head is pro duced by the differences in weight of the water in the flow and in the return risers. The.fundamental rule in the design of a hot water system is that the total friction and resistance head in any circuit must equal the pressure head causing the water to flow in the same circuit. 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 25). 3. The location, type, and size of heating units. (See Chapter 30). 4. The method of piping. 5. Suitable pipe sizes. 6. The type and size of circulating pump (if forced circulation). 7. The type and size of expansion tank. The unit, a square foot of equivalent direct radiation, EDR, has been used for many years for rating purposes in both steam and hot water systems, but its use, especially in hot water systems, has always resulted in complications and confusion. It is the plan of The Guide to eventually eliminate this empirical expression and to substitute a logical unit based on the Biu. The Mb, the equivalent of 1000 Btu, and the Mbh, the equivalent of 1000 Biu per hour, which have been approved by the A.S.H.V.E., are used in this chapter on hot water systems to replace the square foot of radiation formerly used. . ONE- AND TWO-PIPE SYSTEMS Pipe systems may be divided into two general types, namely, two-pipe and one-pipe systems. 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 a one-pipe system, the water .flows through more than one radiator during its circuit. In that case, the 471 / American Society of Heating and Ventilating Engineers Guide, 1934 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, consequently, the total heating surface for a one-pipe system must be greater than that for a two-pipe system for the same service. . 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 longest. Iii a reversed return system, the water returns to the heater by an indirect route after it has passed through the radiators, so that the paths leading through the three radiators shown in Fig. 2 are practi cally of equal length. The reversed return system has an advantage over the direct return system in that it is more likely to function satisfactorily even though the f---- --TX-U4--hu----i-.>i--1 m. I 1 H -J ' rtn [ED, 1--4- ---1-- r h -J ji Fig. 1. A Direct Return System Fig. 2. A Reversed Return System 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 pa^hs 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. 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. For example, note the reversed return system of Fig. 3. . SELECTING PIPE SIZES The pressure heads available in forced circulation systems are much larger than those in gravity circulation systems, consequently, higher velocities may be used in designing the system, with the result thatsmaller 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 472 Chapter 33--Hot Water Heating Systems . the velocity of the water increases the cost of operating the circulating pump. There is an optimum velocity of the water in a heating system for which the sum of the cost of the system and the cost of its operation is a minimum. This velocity 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 /z" /a." This system could be divided into two branches. This would permit the use of smaller pipes and would produce only slight changes in the total length of the pipe. It is shown as a single system here simply to Illustrate the method of determining pipe sizes by means of pipe size tables. Note that the numbers on the radiators indicate thousands of Btu per hour (Mbh) and not square feet. is easier to design a satisfactory forced circulation system than a satis factory gravity circulation system. ~ FORCED CIRCULATION The following examples will illustrate the procedure to be followed in designing forced circulation systems: Example 1. Assume that the paths through the five radiators shown in Fig. 3 consist each of 150 ft of mains, 5 ft of radiator connections, 1 boiler, 1 radiator, 1 radiator valve, 10 ells, and 2 tees. Design the piping for this system. _ Solution. The friction heads in the boiler, radiator, valve, and tee may be expressed in terms of the friction head in one elbow according to the values given in Table 1. Having done this, each of the five circuits is taken as 155 ft of pipe and about 24'elbow equivalents. The friction head of one elbow is approximately equivalent to that in a pipe having a length equal to 25 diameters. Assuming that the average pipe size in this case will be about IK in., one elbow equivalent may be placed equal to about 3 ft of pipe and the total length of the circuit equivalent to about 227 ft of pipe. . Having determined the equivalent pipe length, assume the rate at which the water is 473 Friction Head in M iuncheo per Foot op Pipe American Society of Heating and Ventilating Engineers Guide, 1934 Fig. 4. Friction Heads in Pipes for a 20 deg Temperature Difference of the Water in the Flow and Return Lines 474 Chapter 33--Hot. Water Heating Systems .. to be forced through the system. This rate may vary widely. The water may flow through the radiator so that it will cool 10 deg or 20 deg or any other reasonable number of degrees. In this case, assume a 10-deg drop. Since the system is to dissipate 66,000 Btu per hour (66 Mbh), the pump must circulate 6600 lb of water per hour or 13.8 gpm based on the actual density of water of 7.99 lb per gallon at 215 F. One gallon of water per minute at this density will deliver 9600 Btu per hour (9.6 Mbh) with a temperature drop of 20 deg. . Table 1. .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 angle radiator valve........ 1 radiator............................... 1 heater........ ............................ 1 tee.......................................... ........ 1.0 ......... 0.7 ......... 0.5 ____ 1.0 ......... 0.5 ........ 12.0 ____ 2.0 ........ 3.0 ............ 3.0 (Noteb) The loss of head in one elbow can be expressed in terms of the velocity head by the formula: where h i 2g h = the loss of head in feet.-f = the velocity of approach in feet per second, and 2g per second. .. (1) 64.4 ft per second bThe loss of head in tees when water is diverted at right angles through a branch of the tee varies with the per cent diverted. When the water diverted is less than 60 per cent of that approaching the tee. the loss of head, in elbow equivalents, may be expressed as follows: where h. Il1 cJ (2) = the loss of head in elbow equivalents, v = the velocity of approach. v9 = the velocity of water diverted at right angles. ` Values in elbow equivalents for the most common percentages of water diverted in a lxlxl-in. tee are as follows: 25% 16.0 33% 9.0 50% 4.0 100% 1.8 For other percentages the approximate values may be secured by interpolation. When the water is diverted from the tee into a smaller size branch, as in a lxlxj^-in. tee, approximate values may be secured by means of Formula 2. . The next step in the design is to assume the velocity at which the water is to circulate , through the system. This also may vary materially. As the velocity is increased, the 'sizes of the pipes and the cost of the system are decreased, but the cost of operating the circulating pump is increased. The designing engineer should make a careful study to determine the velocity which will produce the most economical installation for the particular case in hand. In this case, assume a velocity of about 1% fps for a lj^-in. pipe. . Reference to Fig. 4 shows that for a pipe and a velocity of 18 in. per second, the'friction head is about 100 milinches per foot, or about 2 ft for a circuit of 227 ft, if the pipe sizes for that circuit are chosen so that the average friction head is about 100 milinches per foot of pipe. The pipe sizes may now be selected from Fig. 4 by making allowance for the fact that Fig. 4 is based on a temperature drop of 20 deg and that the system to be designed is to have a temperature drop of only 10 deg as follows: Sections AB and KA carry 66,000 Btu per hour (6.6 Mbh) with a temperature drop of 10 deg; if the temperature drop were 20 deg these sections would, with the same velocity and the same friction head, carry 132,000 Btu per hour (132 Mbh). Hence, refer to Fig."4 for 132,000 Btu and a unit friction head of 100 milinches, and note that the correct size would be about halfway . between a lj-m. and a 2-in. pipe. Therefore, select a lj^-in. pipe for Section AB and 475 .. i American Society of Heating and Ventilating Engineers Guide, 1934 a 2-in. pipe for Section KA. The pipe sires for the remaining eight sections and for the radiator connections can be selected in the same manner and recorded on the pipe diagram as shown. The circulating pump for the system should be one which has its highest efficiency when it is delivering 13.8 gpm against a head of 2 ft. If a number of heating systems are to be designed for similar conditions, i.e., for a total friction head of 2 ft and a temperature drop through the radiators of 10 deg when the maximum quantity of heat is being delivered to the building, a table such as Table 2 may be prepared from the data of Fig. 4. Having this table, the pipe sizes for the system of Example 1 can be easily selected. For example, for Sections BC and JK, each supplying 54 Mbh, the equivalent pipe length of the system is 227 ft. In the table the length shown nearest to this length is 200 ft. In the 200-ft column, a l]/2-in. pipe is slightly too small and a 2-in. pipe is too large. The lj^-in. pipe will therefore be selected. For Sections CZ) and IJ, supplying 42 Mbh,'a 134'in pipe is too small and a 134-in- P'Pe is too large, so 134 in. will be selected for the flow and 134 in. for the return line. For larger Table 2. Capacities of Pipes in Mbh (1000 Btu per Hour) and Velocities of Water in Pipes in Inches per Second for Forced Circulation Systems with a Total Friction Head of 2 ft and for a'Maximum Temperature Drop of 10 deg* i Pipe - Size (Inches) 2 Equivalent Length op Pipe (Fserb) 3*56 8'1 Equivalent Total Length op Pipe in Feet in Longest Circuit 9 too 150 200 250 500 350 | 400 Unit Friction Head, in Muinches 240 160 ,120 96 80 69 60 Ai 6.2 15 4.8 12 4-1 10 3.4 2.9 98 2.6 2.4 7.5 7 3A 2 13.2 10.3 8.6 7.3 6.2 6.0 5.5 18 14 12 11 10 9 8.5 l . 2.3 25.0 19.2 16.3 14-4 12.5 12.0 u.i 22 17 15 13 12 11 10.5 f'A 3.0 52.8 40.8 34.8 31.2 27.k 26.4 24.0 27 21 18 16 15 14 13 lA 3.5 79.2 60.7 51.2 45.6 40.8 40.0 36.0 30 23 20 18 16 15 14 2 4.0 153.8 120.0 104.0 93.5 86.4 81.5 73.8 36 28 24 22 20 18 17 2A 6.0 250.0 192.0 164-5 149.0 139.2 185.8 122.5 41 32 28 25 22 21 19 3 6.5 444-0 348.0 294.0 270.0 254.0 24O.O 223.0 48 37 32 29 26 24 22 por oiner lempeiamie uiups vuc capaviuca u< pipca **>_ vv ----------------------------------------------- ._ for a temperature drop of 30 deg, the capacities shown in this table are to be multiplied by 3. The velocities remain unchanged. ^Approximate length of pipe in feet equivalent to one elbow in friction head. This value varies with the velocity. 476 Chapter 33--Hot Water Heating Systems systems, it will be economical to operate with higher friction heads, and tables may be prepared similar to Tables 3 and 4, which are based on total friction heads of 6 and 18 ft, respectively. Example 2. Design a direct return two-pipe forced circulation system for the layout shown in Fig. 5. For this system the length of the pipe line from the boiler to the highest radiator on the farthest riser and back to the boiler is about 250 ft. There are about 16 elbow equivalents having an equivalent pipe length of about 50 ft, so the total equivalent pipe length is about 300 ft. Solution. The same pipe size tables may be used as those developed lor the reversed return system of Fig. 3. Since this system is somewhat larger than that shown in Fig. 3, Table 3 which provides for a friction head of 6 ft may be used instead of Table 2 which provides for a friction head of only 2 ft. Referring to the column for an equivalent total length of 300 ft for Sections A B and KA, each supplying 117.6 Mbh, it will be found that a 1 J4-in. pipe is too small and a 2-in. pipe is too large. Consequently, a lJ4-in. pipe is selected for the flow line AB, and a 2-in. pipe for the return line KA. For Sections BC and JK, each supplying 88 Mbh, a lj^-in. pipe is only slightly too small and it is selected. The remaining pipe sizes are selected in a similar manner and recorded in Fig. 5. For a temperature drop of 10 deg, 24.5 gpm of water must be circulated. The pump to select is one which has its highest efficiency when it is delivering 24.5 gpm against a 6-ft head. i able <s. capacities of fipes in Mbh (1000 Btu per Hour) and Velocities Water in Pipes in Inches per Second for Forced Circulation Systems with a Total Friction Head of 6 ft and for a Maximum Temperature Drop of 10 deg* 1|2 Pips Size (Inches) Equivalent Length op Pipe (FEETb) . 3 4 5| 617 8 C 2UITirEquivalent Total Lenqth op Pipe in Feet in Lonqbst 200 | 300 | 400 | 600 | 800 | 1000 360 ' Unit Friction Head, in Muinches 240 . 180 120 90 / 72 A1 7-4 18 6.0 15 5.0 13 3.8 10 3.4 3.1 9 7.5 2 15.8 12.7 10.8 8.4 7.7 6.7 22 18 16 12 11 9 1 2.5 30.0 24.0 20.4 15.8 13.9 12.5 27 22 19 15 13 11 1M 3.3 64.8 52.5 . 44-4 33.6 30.0 26.8 33 26 23 18 16 14 1A 4.0 96.0 37 76.8 31 64.8 26 50.1 20 44-7 40.8 18 15 2- 5.0 192.0 153.0 130.0 100.1 90.0 78.0 44 36 30 24 21 18 "4A 6.0 300.0 244.0 206.0 161.0 144-0 130.0 50 41 35 26 24 21 3 7.5 550.0 436.0 368.0 287.0 249.0 228.0 58 48 42 32 27 24 "For other temperature drops the capacities of pipes are to be changed correspondingly. For example, for a temperature drop of 3Q..deg, the capacities shown in this table are to be multiplied by 3. The velocities remain unchanged. . * ^Approximate length of pipe in feet equivalent to one elbow in friction head. This value varies with the velocity. .. 477 American Society of Heating and Ventilating Engineers Guide, 1934 To secure a correct distribution of hot water among the several risers it is necessary, as previously stated, to introduce special resistances to balance the several risers, as follows: The first riser is 80 ft hearer the boiler than the fifth riser. In order that the two may be balanced, i.e., that they may operate under equal pressure heads, resistance must be added to the first riser equal to the friction head in the 80 ft of flow main from E to F plus that in the 80 ft of return main from G to K. It will be noted from Table 3 that the unit friction head is about 240 milinches per foot. The total friction head in the flow and return mains between the first and fifth risers is therefore 160 X 240 or 38,400 milinches, or a little more than 3 ft, which must be supplied by additional resistance in the first riser to prevent its having an advantage over the fifth riser. This resistance can be supplied by a calibrated and adjusted modulating valve or by an orifice resistor in a union. If the orifice resistor is to be used, its size may be selected from Table 5 as follows: The lower part of the first flow riser supplies 28.8 Mbh. According to Table 3, it should be a 1-in. pipe and would have a velocity of 22 in. per second, if it were supplying 24 Mbh. Since it is supplying 28.8 Mbh, the velocity will be about 26 in. per second. From Table 5 it will be found that for a 1-in. pipe and a velocity of 24 in. per second, an 0.45-in. orifice will produce a loss of head of 37,000 milinches. For a velocity of 26 in. per second, the loss of head will be somewhat more, probably about 43,000 milinches; the Table 4. Capacities of Pipes in Mbh (1000 Btu per Hour) and Velocities of Water in Pipes in Inches per Second for Forced Circulation Systems 18with'a Total Friction Head of ft and for a Maximum Temperature Drop of 10 deg3 1 Pm (Inches) 2 Equivalent Length or Pipe (Feet**) ' 3 1 ! 5 1 6' | 7 Equivalent Total Length or Pipe in Feet in Longest Circuit 200 400 600 | 800 1000 Unit Friction Head, in Milinches . 1080 540 360 270. 216 -M 1:0 12.7 32 8.6 23 7.2 18 6] 15 5.5 13 K 2.0 27.5 40 18.7 28 15.1 22 13.7 19 11.5 17 1 2.5 55.0 48 86.8 34 30.0 27 26.4 23 22.6 ' 20 IK 3.0 122.0 81.5 66.0 58.8 50.5 59 42 33 28 25 m i 2 4.0 5.0 182.0 66 871.0 80 122.0 46 252.0 56 98.2 37 201.0 45 86:2 74-S 31 27 180.0 38 151.0 33 2K 7.0 598.0 91 407.0 65 . 823.0 51 287:0 43 240.0 38 3 9.0 1110.0 790.0 598.0 527.0 443.0 107 76 60 51 44 or or omer temperauiie uiuijs iuc uimuucs v* pipes ---------- ------------------- - -- -- . foT a temperature drop of 30 deg, the capacities shown in this table are to be multiplied by 3. The velocities remain unchanged. ., ^Approximate length of pipe in feet equivalent to one elbow in friction head. This value varies witb the velocity. 478 Chapter 33--Hof Water Heating Systems difference between it and the required resistance will be about 10 per cent which is per missible, and the 0.45-in. orifice is selected. The sizes of the orifice resistors for the second, third, and fourth risers are selected in a similar manner and found to be 0.45 in., 0.50 in., and 0.55 in., respectively. If the design of the system of Fig. 5 is to be extremely refined, the gravity pressure heads produced by the risers should be taken into con sideration. With water at 220 F and 210 F, respectively, in the risers, the gravity head is 50 milinches per foot of water column or 25 milinches per foot of flow and return pipe. The pump pressure head in this case is 240 milinches per foot of pipe, and the gravity head, being only one tenth as large as the pump head, may be neglected without serious error. This is generally done. Temperatures of 220 F and 210 F would be used only during the coldest weather for which the system is designed. At other times the tempera tures would be lower, the temperature drop smaller, and the gravity heads smaller. The pump pressure head remains constant throughout the season if the pump is operated at a constant speed and, consequently, the gravity head is generally less than one-terith of the pump head. Effect of Variations in Pipe Sizes The pipe sizes for the several parts of the system selected from the tables are only approximately correct but the resulting error should be negligible as may be seen from, the following study; Assume, as an extreme case, that the error in pipe size is so large that the water flows twice as fast through one of the radiators as through the others. This would make the friction head through this radiator almost four times as large as those through the other radiators. The result would be that the water, in flowing through the radiator, would cool 5 deg instead of 10 deg. The mean water temperature in the radiator would then be 217 F in stead of 215 F, and the mean temperature difference, water to air, would be 147deg instead of 145 deg: The heat dissipated by the radiator would therefore be about 2 per cent more than Calculated. It is evident, that this difference in heat dissipation is smaller than the difference 479 American Society of Heating and Ventilating Engineers Guide, 1934 Table 5. Friction Heads (in Milinches) of Central Circular Diaphragm Orifices in Unions Diameter or Orifices (Inches) 2 Velocity or Water in Pipe in Inches per Second 3|4 6 |8 | 10 | 12 18 | 24 %-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 57,000 12,000 26,000 6800 13,000 2900 - 6500 1400 3200 700 1600 47.000 24.000 53,000 12,000 27,000 5700 13,000 2800 6400 0.35 0.40 0.45 0.50 0.55 0.60 0.65 900 2000 3500 460 1000 1800 270 570 1000 160 330 580 190 330 200 120 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 0.55 0.60 0.65 0.70 0 75 0 HO 0.85 850 1900 3300 600 1300 2300 400 850 1500 260 600 1100 180 400 760 300 540 200 380 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 1 -in. Pipe- 7800 4000 2300 1400 750 440 260 14,000 7200 4100 2300 1300 800 460 22,000 12,000 6400 3700 2200 1300 720 32,000 17,000 9300 5400 3000 1800 1100 37,000 21,000 12,000 7000 4200 2400 65,000 37,000 22,000 50.000 13,000 28.000 7400 17.000 4300 10.000 l}4-in. Pipe 8900 5800 3800 2500 1700 1150 750 16,000 10,400 6800 4400 3000 2000 1300 25,000 16,400 10,500 6900 4700 3100 2100 36,000 23,000 15,000 10,000 6700 4500 3000 53,000 34,000 22,000 15,000 10,000 6700 7 607000 40,000 27,000 60,000 18,000 40,000 12,000 26,000 1%-in. 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 2-in. Pipe 7400 3900 2200 1320 850 460 275 14,000 7400 4200 2520 1600 950 525 22,300 11,700 6500 4000 2500 1360 980 33.000 17.000 9500 5800 3700 1910 1375 37,000 20,500 12,500 7900 4200 3100 38,000 23,000 49,000 14,000 30,000 8100 16,800 4400 8850 practically true in tne tests to determine me iussc u ucau ... - .....-------- ,, .... _ .. ducted by the Texas Engineering Experiment Station, and also in the tests to determine the losses of head in orifices in 4-in., 6>in.. and'12-in. pipe, conducted by the Engineering Experiment Station of the University of Illinois. (Bulletin 109, Table 6, p. 38, Davis and Jordan). 480 Chapter 33--Hot Water Heating Systems between the calculated heat losses and the actual heat losses, and also smaller than the average difference between the calculated radiator sizes and the nearest stock sizes selected. GRAVITY CIRCULATION For gravity circulation, the one-pipe system shown in Fig. 6 and the two-pipe direct return system shown in Fig. 7 are probably in most common use. The one-pipe system has the disadvantage that the radiator nearest the Fig. 7. A Two-Pipe Direct Return Gravity Circulation System boiler is the only one which receives water at approximately the tem perature at which it leaves the boiler. All other radiators receive cooler water and must be proportionally increased in size, so the total heating surface in the system is considerably larger than that in a corresponding two-pipe system. The pipe sizes in gravity circulation systems may be varied. As the pipe sizes are decreased, the temperature drop through the radiators, which produces circulation, is increased and. it becomes necessary to increase the temperature of the water leaving the boiler so that the mean temperature in the radiator remains constant. For example, Fig. 8 shows 481 American Society of Heating and Ventilating Engineers Guide, 1934 diagrammatically an elementary heating system which'will function with either or 1-in. pipe. The radiator is required to deliver 27 Mbh, and the circuit consists of 30 ft of pipe and 20 elbow equivalents. If 13^-in. pipe is used, the system will operate correctly if the water temperatures in the flow and return risers are 200 F and 180 F, respectively. The mean water temperature in the radiators will then be 190 F and, if the radiator is located in air having a temperature of 70 F, the size of the radiator must be sufficient to deliver 27 Mbh under these conditions. If 1-in. pipe is used, the system will function correctly with water tem peratures in the flow and return risers of 210 F and 170 F, or of 200 F and 160 F. In the first case, the mean water temperature is again 190 F and the same size radiator may be used as with the l^-in. pipe, but the temperature of the water leaving the boiler must be raised from 200 F to 210 F. In the second case, the temperature of the water leaving the boiler is the same as for the lj^-in. pipe, but the mean water temperature Fig. 8. An Elementary System in the radiator is lowered from 190 F to 180 F, and theoretically the size of the radiator should be increased about 12}^ per cent to deliver the required 27 Mbh (See Table 3, Chapter 6, 1933 Guide). This indicates the extent to which pipe sizes and radiator sizes may be . decreased by increasing the temperatures of the water in the boiler, as is possible in closed systems and in open systems in which the open expansion tank is located sufficiently high to secure a pressure in the boiler equal to that existing in the boiler of the closed system. Example 8. Design a one-pipe gravity circulation system for the layout shown in Fig. 6. Assume that the main circuit consists of 150 ft of pipe, 7 elbows, and one boiler. Solution. Replace the boiler by 3 elbow equivalents and assume that the size of the main will be about 2 in. According to Table 6, Column 2, a 2-in. elbow is equivalent to 4 ft of pipe, and the total equivalent length of the main will be about 150 plus 40, or 190 ft. Assuming that the center of the boiler will be about 4 ft lower than the horizontal portion of the main and that the temperature drop in the system is to be 35 deg, Table 6 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 234-im main, 75.4 Mbh. Since the system to be designed is to supply 66 Mbh, a 2-in. pipe is too small and a 23^-in. pipe too large. The solution is to use some 2-in. and some 2y-in. pipe. Since the 234-in. is nearer the correct size than the 2-in., select 2-in. pipe for the first 50 or 60 ft out of the boiler and 2J-in. for the remaining pipe back to the boiler. ' Tables 7 and 8 may be used to design the radiator risers and connections. According to Table 7, for 12 Mbh the flow riser should be J4 in. and the return riser 1 in., and the riser branches should be 1 in. and 1J4 in., respectively. Note that according to Table 8, both radiator tappings should be 1 in. To simplify the construction, select 1-in. flow risers with l-iii. riser branches and 1-in. radiator tappings. Also select 134-in. return risers with 134-in. riser branches, and 134-in- radiator tappings. Similarly, for 18 Mbh; select 134-in. flow and return risers and riser branches, and 134-in. radiator tappings. 482 v.onm m--hot water Heating Systems Table 6. Capacities of MaIns in Mbh, for- One-Pipe and for Two-Pipe Direct Return Gravity Circulation Systems with a Total Friction Head of 0.6 In., a Temperature Drop of 35 Deg, when the Mains ------------- r~ are 4 Ft Above the Center of the Boiler * " - _ PtPE Sob (Inches) Equivalent Length op Pipe (Frbto) EaeiYAumr Total Length Q, Pipe m Feet m 100 150 175 250 Uhit Fbiction Head, m Moinchzs CiaccrT 550 8.0 6.0 4.0 3.4 14 1.7 m 3.0 4S.0\ S7.5\ 33.0, 30.0 27.0, 25.0\ 22.21 20.2 18.7 4.0 83.0, 72.0\ 63.01 67.01 61.0 48.0 42.0i 38.0, 35.0 234 4.5 140.01 7/5.01 100.0\ 90.01 81.61 754 67.2\ 61,0 66.0 5.0 8S4.O 204.0 175.6 160.0\ 143.01 183 j0 110.0 107.5 100.0 3 H 5.5 S47.0\ 300.0 260.0, 236.0 214.0, 200.0 177.0, 160.01 146.0 6.0 490.0, 422.01 370.0, 334.01 297.0\ 278.0 248.0 223.0, 205.0 Approximate length of pipe in feet equivalen t to one elbow in friction h1jeadi. Tjhis_v_a_lu_e__v_ar_ie_s_ wLi_th___ I_____ T_____ the velocity. To develop a rule for determining radiator sizes, assume a system similar to that of Fig. 6, in which the total temperature drop is to be 35 deg 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 deg for each successive radiator. If the mean temperature of the water in the first radiator is 200 F, the mean tem- Table 7. Maximum Capacities of Risers3 in Mbh, and Velocities of Water in Pipes in Inches Per Second for One-Pipe and for Two-Pipe Direct Return Gravity Circulation Systems with a Drop of 35 Deg Through Each Radiator Pipe Size (Inches) Plow Return Equivalent Lekoth op Pipe (Feetc)' 1st FloobI) VeL(FtperSec.)d Mil Flow Return 2nd Flood . Mbh 3bd and 4th Floohs JIM Xx 34 34 X 1* 34 11 l 134 134 134 m 134 1.0 1.5 . 2.0 3.0 3.5 9 2.3 2.3 12 3.2 2.0 18 2.5 2.5 21 3.0 2.0 26 3.0 3.0 34 4.0 2.5 48 3.0 3.0 5 6.4 10.1 12.8 20 26.2 43 6.2 8.0 14.0 17.1 26.0 34 55 j. t -I___________________________________________________________ Jl_______________________ 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. , , .. . t>The riser branches, the piping which connects the risers to the mains, are to be one size larger than the - risers. ` __ cApproximate length of pipes in feet equivalent to one elbow in friction head. This value varies with . the velocity. . ^Velocities apply to the riser branches. 483 American Society of Heating and Ventilating Engineers Guide, 1934 perature of the water in the seventh radiator will be 170 F, and, according to Table 3, Chapter 6, of the 1933 Guide, the heat dissipation of these two radiators will be to each other as 868 is to 617, or as 140 is to TOO, and therefore if the last radiator is to dissipate as much heat as the first, its size must be 40 per cent larger. Example 4. Design a two-pipe, direct return, gravity circulation system for the lay out shown in Fig. 7. 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 deg for the system, the pressure head caused By the difference in weight between the water in the Table 8. 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 Deg Through Each Radiator Pipe Size Flow Return Equivalent Length 09 Pipe (Feet*) 1st Floor Mbh 2nd. 3rd, and 4th Floors , Mbh *v AA AX XX %1 11 1m ix IX 1.0 1.5 2.0 3.0 4-1 5.2 7.0 9.1 12.5 17.5 23.3 5.9 <L 7.5 10.5 13.0 17.8 23.2 33.2 aApproximate length of pipe in feet equivalent to one elbow in friction head. This value varies with the velocity. .. flow and return risers joining the mains to the boiler will be about 0.6 in. of water, or about one-fortieth of the pressure head produced by the circulating pump selected for the system of Fig. 3. . Table 6 may be used to determine the size of the main as follows: Refer to Column 8 and note that for Sections AS and IA, which supply 105.6 Mbh, a 3-in. pipe is too large and a 234-in. pipe is too small; hence, select 2A in. for Section AB and 3 in. for Section IA. For Sections BC and HI, which supply 76.8 Mbh, a 234-in. pipe is almost exactly the correct size and is selected for both sections. For the forced circulation system of Fig. 5, the pressure head produced by the circu lating pump is used to force the water through the mains and also through the risers. Gravity circulation systems have two distinct pressure heads. One is produced by the difference in weight of the water in the flow and return risers adjacent to the boiler, and is the boiler pressure head, which in this case is 0.6 in. The other pressure head is pro duced by the difference in weight of the water in the flow and return risers adjacent to the radiators, and is the radiator pressure head. If the temperature drop through the radiators is about 35 deg, and if the story heights of the building are 9 ft and the distance from the center of the first floor radiator to the average level of the main is 3 ft, the radiator pressure head of the first floor radiator is about 450 milinches and the pressure heads of the radiators on the upper floor are 1350 milinches greater than those on the next lower floors. Tables 6 and 7 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 7 and begin with the set nearest the boiler. The first floor risers must supply 28.8 Mbh. According,to the table, 134-in. flow and return risers will supply 26.0 Mbh; if the return riser is increased to 1A in., the capacity will be increased to 34.0 Mbh. This is considerably larger than necessary, and 134-in. flow and return risers are selected. However, it must be remembered that the riser 484 Chapter 33--Hot Water Heating Systems branches, which are the connections from the flow and return mains to the -flow and return risers, are to be one size larger than the risers. The second floor risers must supply 19.2 Mbh. According to the table, the capacity of 1-in. flow and return risers is 20.0 Mbh, and that size is selected. The third floor risers must supply 9.6 Mbh. If a 34-in. flow and a M-in. return riser are used, the capacity will be 8.0 Mbh; if both risers are X in., the capacity will be 14.0 Mbh. The X-in. pipe is selected for both risers. To design the radiator connections, use Table 8 and note that for the first floor radiator connections the capacity of a 34-in. flow and 1-in. return is 9.1 Mbh, and that of 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. 7 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 6, Column 8), the boiler pressure head available for the first set of risers is 360 milinches in excess of that available for the fourth set. The velocity in the riser branch is 3 in. per second (See Table 7) and, therefore, according to Table 5, an 0.75-in. orifice in. a lj^-in. union should be used. This will provide a resistance of about 400 milinches. In the same manner it is found that for the second set of risers a resistance of 240 milinches is required and that an 0.80-in. orifice in a lj^-in. union will provide a resistance of 300 milinches. For the third set of risers, a resistance of 120 milinches is required and an 0.75-in. orifice in a lj^-in. union will provide sufficient resistance. MECHANICAL CIRCULATION Circulating pumps for hot water systems may be used to provide the motive head'for forced circulation systems as already described, or to improve the operation of gravity-designed systems. Small speciallydesigned centrifugal pumps installed on a by-pass with the necessary gate or check valves near the point where the return main enters the heater may be employed. Specially-designed, electrically-driven, propeller-type circulating pumps or units may also be employed. The latter are usu ally installed directly in the return main and are available for all com mercial pipe sizes used for hot water heating. The motor switch may be under manual control, automatic control using thermostatic elements, or tied in with the oil or gas burner switch which starts and stops the burner. For large capacities these units may be installed in multiple. For exceptionally large installations such as central heating plants, cir culating pumps of the centrifugal single stage type, having an av.erage operating efficiency of 70 per cent against heads up to 125 ft, are some times used. It is generally advisable to install the pumps in duplicate to provide for contingencies and to insure continuous operation. In such cases each pump., may be made equal to two-thirds of the maximum capacity required. . 485 . American Society of Heating and Ventilating Engineers Guide, 1934 EXPANSION TANKS When water at ordinary temperatures is heated or cooled, its volume is increased or decreased. This variation in the volume of the water in a heating system is generally provided for by means of an expansion tank into which the water can flow from the system during the heating-up periods and from which it can flow back into the system during the cooling-down periods. The expansion tank may be open or closed. In an open expansion tank (Fig. 9), the water is subjected to atmospheric pressure and can expand freely without a material increase in pressure. In a closed expansion tank (Fig. 10), the water is subjected to the pressure of the compressed air Fig. 9. An Open Expansion Tank Fig. 10. A Closed Expansion Tank 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 of about 32 lb per scjuare inch must be maintained in the expansion tank if the water in the highest radiator is to be heated to 225 F without danger of boiling. The type of expansion tank used in a heating system, whether open or closed, has no influence on the operation of the system. The only function performed by the axpansion 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 use of an expansion tank may be dispensed with when the heating system is allowed to float on the water system, i.e., when the connection between ' 486 Chapter 33--Hot Water Heating Systems the heating system and the water system is kept open so that the water system replaces the expansion tank. 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 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 should be connected to the return main near the circulating pump. 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 ex pansion tank, except where it is desired to maintain a temperature higher than 212 F, in which case the connection should be in the return main to prevent possible boiling in 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 be heated to cause further expansion, the resulting force will burst the boiler or some other portion of the system. 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. 2. All piping must be arranged so that the entire system can be drained, either to permit alterations or repairs, or to prevent freezing if the system is not to be operated during a cold period. It is well to install a gate valve and union in every riser near the main to permit the draining of individual risers without draining the entire system. It is also well, in large installations, to divide the system into branches and to provide each branch with unions and valves so that any one branch can be drained without disturbing the remaining ones. The dividing of large heating systems into branches or zones and providing each zone with individual valves has the further advantage of permitting a varying temperature control. For example, if a building is equipped with a forced circulating system and if the south rooms are on one branch of the main and the north rooms are on a separate branch, the valves may be set so that the water will circulate through the north branch with a temperature drop of, say, 10 deg, and through the south branch with a tempera: ture drop of, say, 20 deg, 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. 487 \ American Society of Heating ar.d Ventilating Engineers Guide, 1934 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 less than 1 in. in 10 ft. The flow main should always be covered; the return main should be covered except where it is to provide the heating surface for the basement. The connections from mains to branches and to risers should be such that circulation through the risers will start in the right direction. Hence, in a one-pipe system the flow connection must be nearer the heater than the return connection. In a correctlydesigned two-pipe system, the pressure in the flow main is higher than that in the return Fig. 11. Method of Connecting Radiator to Allow for Expansion of Pipe main, and a slight variation in the distances of the flow and return connections from the heater is not material; but it is generally best to have the two connections about equally distant from the heater. ' In some cases it may be advisable to take the flow connection off the top of the main and the return connection from the side, but in most cases both connections should be at an angle of 45 deg. This method shortens the lines and substitutes 45-deg ells for 90-deg ells. Preferably, connection of the flow riser to a radiator should be to the upper tapping, and connection of the return riser to a radiator should be to the lower tapping. When hot water enters at the top of a radiator it will distribute itself along the entire length of the radiator, and as it cools it will settle gradually to the bottom; the cool water may then be taken out of thg radiator at either end. 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 expahsion 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. 488 Chapter 34 PIPE, FITTINGS, WELDING Designation of Pipe, Types of Pipe, Expansion and Contraction, Fittings, Valves, Corrosion, Pipe Welding PIPE used for heating and ventilating installations 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. In the latter case, it is termed seamless tubing or seamless pipe. Welded pipe usually is made by either the forge lap-weld or butt-weld process, depending upon the size. DESIGNATION OF PIPE Wrought pipe up to 12 in. in diameter is usually designated by its nominal internal diameter which is slightly different from its actual in ternal diameter, being considerably less in the smaller sizes than the actual dimension. There are three weights of wrought iron and steel pipe com monly used, known as standard, extra strong, and double-extra strong. Because of the necessity of maintaining the same external diameter 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 the various wall thicknesses listed. In sizes 14 in. and upward pipe is designated by its outside diameter (O.D.) and the wall thickness is specified. The dimensions of standard and extra strong pipe are given in Tables 1 and 2. The use of double-extra strong pipe is limited almost entirely to high pressure hydraulic work. TYPES OF PIPE Wrought-Steel Pipe. Because of its low price, the great bulk of wrought pipe used at the present time is of wrought steel. The material used for steel pipe is a mild steel made either by the Bessemer or basic openhearth process or by the electric furnace. Wrought-iron Pipe. The correct definition of wrought iron as suggested by the International Society for Testing Materials is "malleable iron which is aggregated from pasty particles without subsequent fusion and con tains so little carbon that it does not harden usefully when cooled rapidly." Identification of Wrought-Iron and Steel Pipe. Wrought-iron pipe is marked at the mill-with a spiral line the entire length of each bar, either knurled into the metal or painted in red or other bright color. Otherwise 489 \ American Society of Heating and Ventilating Engineers Guide, 1934 3 "8 II C.-Ho3 IS SS 3a aH w" Ssv<_? S Is II gs NltOJ^iV<N)iOO'OOO'nON^'rHOJ<VO^OOC-OSf^-*<N'Oe'O-C^OOO\''OOONNOOOpO'H0O`0oOO0^QOOOQOOQOQNO^^O5f' T* t#* f'-'OO NTj<lOOO^H,OMt>.'Ot^iGTHr''00\'OiGNCN'tiO t^-io'ooo'oo'foco-^'o--'co rH^NmO'ON(*)0010NOO'N'0^^(OtO()^ tJ' Of''0'^,fONN * 4000000000 rf^4OO(4t'0')`O0v0)^ONWNOO^*'f-0O4OO'0OO0tfCOS0OO*-Oi4iOT'0),'0t0W'0O'O`>O*'0^'NttM^^r`loOOt*O,0)ltO`O<)ONCN' 0\t^w">Tj<roc^c>lCNT 40000000000 8CN'tiiNr>'Ot>-lOtn"0O4$'O<0O''N'1/,O>^M<oOoOt,:^*4 ~o-ow')ooav ofo'*c*sT'OtTyNco> CO >0 c) ro ^ O O' dooodoooHHNNco^ioNooftO' itOn^rOr}H<0r^H'iO^^uffO0)0'O^0'O^0,'CO'00f`OOf0OC-Oc0Of0Oo>O'00N00'OO'0OPHO0--"j-04N0Vu6),)*0'-O0tC'`O0O&NO oooooo- C0*HV'0CJ'NC0cM0o'i'Oo!foI'O0O0'cOO0'O'HrOt0''C00^O0,CcT}Oj,-'-OOi'GC'0OS^''OC'0OOrTO4}N''T0Cj<'0NTftN0'r'^Of0r--'Ocf'-0O. 'nN0o dWooddniNM^'OO'M'O^^HTHjW'OCOOICOIiOOOO'OO'OO'CSr' ^>000',^-^|*0l^Ov"Or0j*'0l0O0''c00si'0rfO00i0O0l<0'i,tNt'i>0'.0cf0^0^'0O',t0O0`0'O0v4)f}O''00Olc>Oo*0^O'^rO0,r0^'t'0'00'' OH'4^4NC0'tO'0N0' ^lC00MOH'f0i/')-O'O*-'0,Cf0S0'O\O'0cl'*0NNr0-4'00'0\C0S'r^(Nf^CNSii00 4'OMp4CS0'^OO'<^,h^00OONn>NO T a b l e 1. St a n d a r d W r o u g h t P ip e Table of Standard Dimensions z9sIIa ^Z6n- *p- .gSfge8-i i CV~4 Q3 6-S 1" iCOOOOOOOOOT-O>*4t'-O0Mif'-HO<f*fOHOO^Vil-,H^>'CO^4'fOP^4^'r0N4C'C^SOrCHiN0OC0OONnOtc^NONMNCONOO'Ct',OO,)fN`O/> OOOOOOOOOOOOOOOOOOOOO OOOOOhhhNNCOcO^iO'OoONOOON >O^0l^OON'lO/^)OO'OOOHO>f0OOO'OONO<C'Cfl'O>O0CQOOOiOO'OOO'cON0'ON'0'niO0>'iO0o'OOO^nNiOoNiOfo* OOOO HNNCO^^'O'OOOCOOOON 'X3XRX^HS^CNRNtoXcOX^'O'OoOoOO_OOW 490 Chapter 34-t-Pipe, Fittings, Welding there is little difference in the appearance of wrought-iron and steel pipe but there are several tests which readily identify the materials. The fracture of wrought-iron pipe is ragged, dull gray, and fibrous. By hammering a piece of pipe flat the fracture can easily be observed. The fracture of steel is even, bright and crystalline. Wrought-iron pipe, when threads are cut on it, gives a crumbled chip, due to the fibrous structure. Steel pipe, when threaded, gives a long spiral chip. A microscopic examination of polished and etched specimens is an infallible test. The presence of slag in the wrought iron is unmistakable, while the steel is almost without slag. Seamless Pipe. Steel pipe or tubing without the lap or butt weld is frequently used for high-pressure work. Its advantages are its somewhat greater strength, permitting the use of a thinner wall, and in the small sizes its freedom from the tendency of welded pipe to split at the weld occasionally when bent. Furthermore, the inherent physical properties of the steel used in its manufacture are somewhat better, and a variety of combinations of carbon content and heat treatment are available. Seamless pipe is made by either of two different processes, depending upon the size. The piercing process is used in the smaller sizes and the cupping process is sometimes used for tubing of 6 to 8 in. diameter. Cast Ferrous Pipe. There are now available several types of cast ferrous metal pipe made of a good grade of cast-iron with additions of nickel, chromium, etc. This pipe is available in sizes from in. to 6 in. and 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 had coupled, bevelled for welding, or with ends plain or grooved for the several types of couplings. It is readily cut, and threaded, as well as welded. The fact that it is readily welded enables the manufacturers to supply the pipe in any lengths practical for handling. Alloy Metal Pipe. Steel pipe bearing a small alloy of copper is some what more resistant to corrosion than plain steel pipe. It is recommended usually for atmospheric corrosive conditions, i.e., for corrosion caused by alternate exposure to air and water. Copper Pipe. Copper and brass pipe are used to some extent in heating work. Special fittings are also available. While the friction loss through copper pipe is slightly greater than for steel (for hot water), this is offset by the smaller loss in the fittings1. Therefore, for practical purposes there is little difference between the two. (See Chapter 33). EXPANSION AND CONTRACTION The proper provision for the expansion and contraction of piping must be made in all cases where water, steam, or gas is to be used at high tem peratures, and is usually accomplished by directional changes, long sweep bends or expansion joints. In instances where it is impracticable to install the piping to obtain the required flexibility by directional changes,'it may be advantageous to insert expansion bends in the line. Such expansion bends may be (1) a complete unit such as the expansion I/-bend, the `See Loss of Head in Copper Pipe and Fittings, by F. E. Giesecke and W. H. Badgett (A.S.H.V.E. Transactions. Vol. 38, 1932). 491 American Society of Heating and Ventilating Engineers Guide, N o m inal W bio bt per F oot Pla in E nds Pounds T a b l e 2. E x t r a Stro ng W r o u g h t P ip e Table of Standard Dimensions E x te rn a l Inches i- SrofOoOr-*r-`'tocS'Otoo0^t'-OOto-2 OOOHiHNN^>ONON^OoOiJ^ L enot o r P ip C o ntain One C ubic Feet o so NOftr'OrO'Ot^'0'0^(N<OiO^,^0'00 OnO'OO--<--<0'`000 r-O \rto^i*tnrOtN'-,OOfO^H>oe'*r--tOtO^-*^*t 0\ fO CN O- * to CN 1-t o |s 0* o o sa 11 eK* ft. 15 PCQ ll -S'E eo '0000b*^'00'00>^,t^'000f000^0 t--CNs'OtocOCN<'sl^-<"'-*^"* tH ^noof't'x}'HOoooo-i'#co'0'Onioo\ T#0'0|b'oStOO^00'CO'0'b'T'f)N OMs>l0^4fOM<NN^i^tr4000 3.2 So? o\io.--tC'4rotooo'Ot-`io--it"-*-"'O^ OO'-'^CS to to ^'OOON'OO* <g OCN^HT+lfOONCOt--r*}OOti'>OOt-",*,t".rOeNTj< a 3.0 O O ^ ^ I'* -- 0'CNOCOTj.wO'0'0'd< &aCQc ^,^ck<^,'oo^ij22^ij^^ U5 sc (M?100't'O00'd|iGOCN-HO^5(N'O^O cscmoi/)'0o'0f0f00>toNO'o' tooo^^oj*'"0 *ti 0*-'CNCN^,'Ovcto^^oot^ 3s WO>O\n^NONN^i00OOOi<O^,t 'OOvtOt^fOOt'>*OM^>0^00''OOi a 3 s*3 H y--t --< fS CO tO g eat> o oi'O^OvON^Htoot^es'0't^r^to'csto r~0\CNf00'<0'-- cnvo-h'Ocs^c, ^'^`ovo^h^*cox^* o 3j< as s a Sg| BM * r-> "eJ_ .a a 8 a <co2v-.-a2*.2g 1 Q is 11 ioN'*^Tj<ot-<oo'oot^-toe^ <C'qT$<LO*''0'*-",f''.0*--<cOt--CO oooo tocstO'Des4r>*oO'to^'to-4to ^0*CCOSTT*tNto^rt'O-t\^C^ttOoCv^fO'O'CtONO^O-tONOtC"*S'tto".rto-- 00-,^^H<s4e^fOtOTftor>*\^H tO/> ^oNto^olO-H*o'OON*ot'tOo OO'OtoNttoStolOlOo ^*t0'000t0'tt000t0t00''0t^t^' QOO-^-H,--,CNCNfO^'Tt,tO'OGOCN 8 ieeI nches ^H^H^-HCSCStOf0^tO'000<N 492 Chapter 34--Pipe, Fittings, Welding double-offset expansion U-bend, or the circle bend (Fig. 1); (2) a built-up bend composed of several of the smaller curved pieces illustrated in Fig. 1; (3) a combination of straight pieces with such curved pieces or cast ells; (4) a so-called square bend made up entirely of straight pieces, cast ells, etc. All risers must be anchored and safeguarded so that the difference in length when hot from the length when cold shall not disarrange the normal and orderly provisions for drainage of the branches. It is especially necessary with light-weight radiators so to anchor and so to give freedom for expansion of the piping that no strain therefrom shall be allowed to distort the radiators. When expansion strains from the pipes are permitted to reach these light metal heaters they usually emit sounds of distress which are exceedingly troublesome. The linear expansion of the pipe can be determined from Table 3. The elongation values in this table were computed from the following formula: where Lt = length at temperature t degrees Fahrenheit, feet. Lo = length at 32 F, feet. t = final temperature, degrees Fahrenheit. a and b are constants as follows: Metal r a Wrought-Iron............................................ 0.005441 0.006212 0.006503 0.009278 6 0.001747 0.001623 0.001622 0.001244 In selecting expansion fittings it is well to allow a margin of 25 per cent between the computed expansion and the actual allowable travel of the expansion fitting to provide for inaccuracies in assembling, etc. Table 4 gives the dimensions of expansion offsets and bends required to take care of different amounts of expansion. FITTINGS Fittings for joining the separate lengths of pipe together are made in a variety of forms, and are either screwed or flanged, the former being generally used for the smaller sizes of pipe up to and including 3J^ in., and the latter for the larger sizes, 4 in. and above. Screwed fittings of large size as well as flanged fittings of small size are also made and are used for certain classes of work at the proper pressure. The material used for fittings is generally cast-iron, but in addition to this malleable iron, steel and steel alloys are also used, as well as various grades of brass or bronze. The material to be used depends on the character of the service and the pressure. As.in the case of pipe, there are several weights of fittings manufac tured, designed'to be used with pipe of corresponding grade. These varia- 493 American Society of Heating and Ventilating Engineers Guide, 1934 QUARTER. BEND i. VJBEMD CR.OSS OVER. SINGLE OFFSET QUAB.TEK.BEUO 45 DEG. BEUD double offset u Beuo Circle Bemo EXPANSION U BEHO Fig. 1. Common Types of Pipe Bends 494 Chapter 34--Pipe, Fittings, Welding tions in weights are known as (1) low-pressure fittings for steam working pressures of 25 lb (cast-iron flanged only, sizes 4 in. and larger), (2) standard fittings for saturated steam working pressures of 125 lb, and (3) extra heavy fittings for saturated steam working pressures of 250 lb. These last fittings are suitable for cold water working pressures of 350 lb and are usually tested to twice the steam working pressure, or 500 lb cold hydrostatic. Screwed fittings include: nipples or short pieces of pipe of varying Table 3. Thermal Expansion of Pipe in Inches per 100 Ft* (For superheated steam and other fluids refer to temperature column) Saturated Stbam Vacuum Pressure Pounds Tem perature Inches of Hg. nSqtu*arre Inch Gage Degrees Fahren heit Elongation in Inches peb 100 FT FROM --20 F UP Saturated Steam CastIron Pipe Steel Pipe Wrought Iron Pipe Copper Pipe Pressure Pounds Tem perature Square Inch Gage Degrees Fahren heit Elongation in Inches peb 100 FT FBOM --20 F UP CastIron Pipe Steel Pipe Wrought Iron Pipe Copper Pipe 29.39 28.89 27.99 26.48 24.04 20.27 14.63 6.45 ___ ______ _____ ____ _________ _______ _____ _____ ______ .... ___ 2.5 10.3 20.7 34.5 52.3 74.9 103.3 138.3 180.9 232.4 293.7 366.1 451.3 550.3 -20 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400 420 440 460 480 0 0 0 0 664.3 0.127 0.145 0.152 0.204 795.3 0.255 0.293 0.306 0.442 945.3 0.390 0.430 0.465 0.655 1115.3 0.518 0.593 0.620 0.888 1308.3 0.649 0.725 0.780 1.100 1525.3 0.787 0.898 0.939 1.338 1768.3 0.926 1.055 1.110 1.570 2041.3 1.051 1.209 1.265 1.794 2346.3 1.200 1.368 1.427 2.008 2705 1.345 1.528 1.597 2.255 3080 1.495 1.691 1.778 2.500 1.634 1.852 1.936 2.720 1.780 2.020 2.110 2.960 1.931 2.183 2.279 3.189 2.085 2.350 2.465 3.422 2.233 2.519 2.630 3.665 2.395 2.690 2.800 3.900 2.543 2.862 2.988 4.145 2.700 3.029 3.175 4.380 2.859 3.211 3.350 4.628 3.008 3.375 3.521 4.870 3.182 3.566 3.720 5.118 3.345 3.740 3.900 5.358 3.511 3.929 4.096 5.612 3.683 4.100 4.280 5.855 500 520 540 560 580 600 620 640 660 680 700 720 740 760 780 800 820 840 860 880 900 920 940 960 980 1000 3.847 4.296 4.477 6.110 4.020 4.487 4.677 6.352 4.190 4.670 4.866 6.614 4.365 4.860 5.057 6.850 4.541 5.051 5.268 7.123 4.725 5.247 5.455 7.388 4.896 5.437 5.660 7.636 5.082 5.627 5.850 7.893 5.260 5.831 6.067 8.153 5.442 6.020 6.260 8.400 5.629 6.229 6.481 8.676 5.808 6.425 6.673 8.912 6.006 6.635 6.899 9.203 6.200 6.833 7.100 9.460 6.389 7.046 7.314 9.736 6.587 7.250 7.508 9.992 6.779 7.464 7.757 10.272 6.970 7.662 7.952 10.512 7.176 7.888 8.195 10.814 7.375 8.098 8.400 11.175 7.579 8.313 8.639 11.360 7.795 8.545 8.867 11.625 7.989 8.755 9.089 11.911 8.200 8.975 9.300 12.180 8.406 9.196 9.547 12.473 8.617 9.421 9.776 12.747 "From Piping Handbook, by Walker and Crocker. This table gives the expansion from -- 20 F to the temperature in question. To obtain the amount of expansion between any two temperatures take the difference between the figures in the table for those temperatures. For example, if a steel pipe is installed at a temperature of GO F and is to operate at 300 F. the expansion would be 2.519 -- 0.593 = 1.926 in. 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, may have the smaller connection tapped eccentrically to permit free drain age of the water-of condensation in steam lines or free escape of air in water lines. 495 American Society of Heating and Ventilating Engineers Guide, 1934 Flanged fittings are generally used in the best practice for connecting all piping above 6 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 breaks the joints in these large sizes. The dimensions of elbows, tees and crosses for 125 lb cast-iron screwed fittings are given in Table 5, whereas the dimensions for 125 lb cast-iron flanged fittings are given in Tables 6 and 7. A special type of joint known as the Sarlun joint consists of a lip which is provided for welding to make the joint fluid tight, while mechanical strength is provided by bolted flanges. Another type of pipe joint, the lap flange, is made by using loose flanges on lengths of pipe whose ends are lapped to give a bearing surface for a gasket or metal joint. Table 4. Length of Expansion Offsets and Bends for Proper Expansion of Pipe Total Expansion in Inches i 2 3 4 5 6 7 8 Feet op Pipe and Offset ob U-Bend fob dippebent Diameters op Pipe 2* 3" 4' 5* 6* 8* 10* 12* 14' 16* ii 13 15 17 19 21 23 25 27 30 15 18 21 23 26 29 32 35 38 42 18 22 26 29 32 36 40 43 48 52 21 26 30 34 37 42 47 50 56 58 24 30 34 38 41 47 53 57 63 65 27 33 37 41 45 52 58 63 69 71 30 36 40 44 48 56 62 68 74 .... 32 39 43 47 52 60 66 72 -- -- aThis column shows the total expansion the offset will take care of without a cold strain. Although some engineers allow an increase of 40 per cent in the allowable expansion if the pipe is given a suitable initial cold strain when made up. it is regarded as better practice not to allow for it. The length of pipe in the expansion piece should be the same whether in the form of a single right-angle * offset or double offset or U-bend. The lengths of arms are figured for 12,000 lb per square inch tension for wrought iron pipe. If steel pipe is used this is good for 16,000 lb per inch so that the arm will take care of M more expansion. 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. Practically all iron or'steel valves intended for steam or water work are bronze-mounted or trimmed, and valves for acids, ammonia and cor rosive gases are of iron throughout. 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. 496 Chapter 34--Pipe, Fittings, Welding A special class of valves is required for controlling the steam and hot water supply to radiators. These valves are of brass, usually of the angle type, modified to suit the service requirements, and are often arranged with graduated heads and lever handles in order to indicate the relative opening of the valve port in any position. Table 5. Tentative American Standard Dimensions of Elbows, 45 Deg Elbows, Tees, and Crosses (Straight Sizes) for 125 Lb Cast-Iron Screwed Fittings Elbow A Nominal Pipe Sm Cbnteb to End, Elbows, Tees and Crosses cB B Center to End, 45 Dbg Elbows Length or Thread Min. Width of Band, Min. F Inside Diameter op Fitting Min. Max. GH Metal Thickness, Min. Outside Diameter op Band, Min. x lA yi X i IX lji 2 m 3 3X 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 0.675 0.840 1.050 1.315 1.660 1.900 2.375 2.875 3.500 4.000 4.500 5.563 6.625 8.625 10.750 12.750 14.000 16.000 0.584 0.719 0.897 1.107 1.385 1.730 1.970 2.445 2.975 3.600 4.100 4.600 5.663 6.725 8.725 10.850 12.850 14.100 16.100 0.110 0.120 0.130 0.155 0.170 0.185 0.200 0.220 0.240 0.260 0.280 0.310 0.380 0.430 0.550 0.690 0.800 0.880 1.000 0.93 1.12 1.34 1.63 1.95 2.39 2.68 3.28 3.86 4.62 5.20 5.79 7.05 8.28 10.63 13.12 15.47 16.94 19.30 All dimensions given in inches. CORROSION Experiments in research laboratories have demonstrated that the amount of corrosion found in piping and closed water systems is almost directly proportional to the amount of oxygen in solution, and varies with the temperature and rate of flow. The composition of the water also has a bearing on the rate of attack. All reliable data on this subject indicate that the composition of the iron or steel as regards carbon, phosphorous, 497 <c American Society of Heating and Ventilating Engineers Guide, 1934 manganese, sulphur, silicon, and copper makes very little difference in the amount or character of corrosion when under water, although under atmospheric exposure the influence of composition is more marked. Corrosion is stimulated by scale adhering to the iron surface, by electric Table 6. American Standard Dimensions of Tees and Crosses (Straight Sizes) for 125 Lb Cast-Iron Flanged Fittings Chapter 34--Pipe, Fittings, Welding (1) by deaerating the water mechanically and (2) by fixing the free oxygen by chemical combination. Corrosive action may be retarded by the use of a metal which is electro-positive to that to be protected, such as zinc Table 7. American Standard Dimensions of Elbows for 125 Lb Cast-Iron Flanged Fittings . TEE 'SIDE OUTLET CROSS Nominal Pips Sizso-b A Center to Face Tees and Crosses *>-o ' AA Face to Face Tees and Crosses Diameter or Flange Thickness or Flange, Min. Metal Thickness or Boot, Min. i lK i\4 2 2K 3 3K 4 5 6 8 10 12 14 O.D. 16 O.D. 18 O.D. 20 O.D. 24 O.D. 30 O.D. 36 O.D. 42 O.D. 48 O.D. 3K 3K 4 4K 5 5K 6 614 714 8 9 11 12 14 15 16H 18 22 25 28 31 34 7 m 8 9 10 11 12 13 15 16 18 22 24 .28 30 33 36 44 50 56 62 . 68 : 4H m 5 6 7 m 814 9 10 11 13J4. 16 19 21 . 23K . 25 1 2714 32 3m 46 53 : 59 K Me Ms He y% 'Ke ZA 'Me 'Me 'Me 1 IK IMe IK m IMe IMe l'Ke IK 2K m 2Vs 2M Me. He He He He He He ' Mi Me K . %A . 'Me . v* i 1M6 1K IK iMe IK l'Me 2 All dimensions given in inches. , aSize 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. SiTA 18 in. and larger, reducing on the outlet, are made in two lengths, depending on the size of the outlet. cTees 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. t currents from external sources, by acids carried in solution or as gases, by solids that break down in water, by strains due to inadequate annealing and by contact between dissimilar materials. . . The' best way to deal with corrosive water Supply is to treat it at its source. In practice, oxygen removal has been accomplished in two ways, 498 Nominal Pipe She A Bc Center to Face Elbow b-c-d Center to Face Long Radius Elbow b-e-d - Center to Face 45 Deo Elbow o Diameter or ' Flange Thickness or Flange, Min. Metal Thickness or Boot, Min. i IK 1% 2 214 3 3K 4 5 6 8 10 12 14 O.D. 16 O.D. 18 O.D. 20 O.D. 24 O.D. 30 O.D. 36 O.D. 42 O.D. 48 O.D. 3K 3K 4 5 5K 6 6K m 8 9 11 12 14 15 1614 18 22 25 28 31 34 5 5K 6 6K 7 7M 8K 9' 10K nK 14 1614 19 21K 24 26 K 29 34 41K 49 56K 64 IK 2 2K 214 3 3 314 4 4K 5 514 6K 714 7K 8. m 914 11 15 18 21 24 4K 4K 5 6 7 714 8K 9 10 11 13K 16 19 ' 21 23 K 25 2714 32 38M 46 53 59K Me K Me K 'Me K 'Me 'Me 'Me 1 IK IMe IK IK IMe IMe l'Me IK 2M 2M . 2K 2K Me Me Me Me Me Me Me. K K Me K K 'Me .K l IMe IK IK IMe IK , l'Me 2 All dimensions given in inches. Size of all fittings listed indicates nominal inside diameter of port. b Reducing elbows and side outlet elbows carry same dimensions center to face as straight size elbows, corresponding to the size of the larger opening. especial degree elbows, ranging from 1 to 45 deg, inclusive, have the same center to face dimensions as given for 45 deg elbows and those over 45 deg and up to 90 deg, inclusive, shall have the same center to face dimensions as given for 90 deg elbows. The angle designation of an elbow is its deflection from straight line flow and is the angle between the flange faces. ' ' <*Side outlet elbows shall have all openings on intersection center-lines. to protect iron; by the effective neutralization of acid or alkaline'contents; by the elimination of ununiform materials; and through the exercise of care in counteracting the effects of stray electric currents. The introductiqn into piping systems of various chemical compounds, usually for forming ~a protective coating of thin deposit, has apparently 499 American Society of Heating and Ventilating Engineers Guide, 1934 had some success. Non-ferrous piping may deteriorate rapidly unless selected with due regard to the service conditions to which it will be sub jected. The composition and micro-structure are items of special impor tance. Electrolysis set up by joining copper alloys to iron must be guarded against. Piping exposed to the elements or buried in the ground is quite success fully protected by coatings of the asphaltic type which are usually applied hot and are often reinforced with fabric wrappings. Galvanizing by the hot-dip process and painting with specially prepared mixtures also afford satisfactory protective safeguards. The problem of corrosion has been summarized2 as follows: 1. Corrosion in steam heating systems is confined mainly to the returns and varies widely in different localities and sometimes in the same locality, due to variations in the water and in operating conditions. ^ 2. There does not seem to be any necessity to use a more costly material for piping than wrought iron or steel, between which long experience indicates no material dif ference in durability when used for this purpose. 3. The amount of dissolved oxygen and carbon dioxide present determines the extent of corrosion. The carbon dioxide should be low, especially when any considerable amount of oxygen is present. ' 4. The carbon dioxide in the condensate comes mostly from the dissociation of bicarbonates or carbonates in the boiler. For this reason sodium carbonate should not be used for internal treatment of water in heating boilers. 5. In high pressure plants the water should be pretreated to remove free and half bound CO, and scale-forming matter without leaving more than a slight excess of sodium carbonate. The water should be thoroughly deaerated before entering the boiler. 6. In low pressure steam boilers (less than 5 lb pressure) where corrosion occurs in the returns, an excess of caustic soda with an equal amount of sodium sulphate should be maintained in the boiling water. The hydroxyl alkalinity should be at least twice the carbonate alkalinity. This may be controlled by testing samples of boiler water and the condensate. 7. All returns should be sealed, and every precaution taken to prevent unnecessary leakage of air into the system. Oiling the steam will afford substantial protection to steam piping. `` A series of investigations, on the factors influencing corrosion in steam systems, including a study of the raw water, the production, the distribu tion, and the utilization of steam, demonstrated the extent and constitu tion of deposits in the heating systems of a large office building and a large hotel in New York City3. These deposits were found to originate from the action of corrosion and were found to contain little material from the boilers. The cause of the excessive corrosion was found to be the in leakage of air into the vacuum return system. The amounts of oxygen and carbon dioxide associated with the steam were shown to be of in significant importance as corrosive agents by the application of the Law of Henry and Dalton. Causes of corrosion trouble in heating systems were reported in the operation and, to a small extent, in the design of the system and not in the quality of steam used if that quality equals that encountered in these studies. .* * *Corrosion in Steam Heating Systems, by F. N. Speller (A.S.H.V.E. Transactions, Vol. 34, 1928). *Some 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). . 500 Chapter 34--Pipe, Fittings, Welding A study of water supply as related to air conditioning equipmentS4 indicated that the characteristics of waters used vary widely. Certain waters are corrosive while others are scale forming5. Waters often bring about high rates of depreciation of apparatus and lower operating effi ciencies. Chemical analysis of waters followed by chemical conditioning may obviate many of the difficulties encountered. a. Typical Short Radius Elbows - r" ^-- b. Tee c. Forged Cap d. Concentric Reducer : ZZZZZ^^ Jb e. End Closure /. Welding Neck Flange g. Lap Joint Flanged Welding Neck Fig. 2. Welding Fittings PIPE WELDING Fusion welding in the heating and ventilating industry is an improved method of fabrication and installation widely used and accepted as com petitive to the screwed and flanged joint in piping, and the rivet and bolt assembly in sheet and plate construction. The process of fusion welding is easily understood. Two pieces of metal are brought substantially together and melted, with the addition of filler Corrosion as related to'Air Conditioning Equipment, by R. M. Palmer. For additional information on corrosion, see 1933 report of National District Healing Association on this subject. - 501 American Society of Heating and Ventilating Engineers Guide, 1934 rod, by the welding flame. The molten metal will flow together with the aid of mechanical manipulation by the workman so that when cooled there is a single continuous unit. Welding application is made by either the oxy-acetylene or electric arc processes, and the two processes are given equal rating when used under proper control standards and intelligent supervision. The welding process is applied with equal efficiency and economy in high and low pressure service, and thru the range of all pipe sizes. A correct understanding of the diversified application of welding will in most cases reflect lower initial costs and. complete elimination of main tenance. Reduction in weight, adaptability to space allowance, saving in supplemental materials such as pipe covering, hangers, and supports, and finished appearance are other distinct advantages in favor of welding which have contributed to its wide and economical use; 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 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 hot accept the employment of mechanics of undetermined ability nor on the basis of past experience. Neither does industry accept the statement that a weld is only as good as the workman who makes it. The control Codes now in process of adoption will be the law governing 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 with plain ends machine beveled for welding and with radii similar to short and long radius flanged fittings. Some typical types of these fittings . are shown in Fig. 2. They are made in pipe sizes M to 24 in., standard and extra heavy, in steel, wrought iron, brass, copper, and special alloys. 502 Chapter 35 HEAT LOSSES FROM BARE AND INSULATED PIPES Heat Losses from. Bare Pipes, Steam and Hot Water Lines, Low Tem perature Pipe Insulation, Pipe Sweating, Heat Losses from Pipe Surfaces, Thickness of Pipe Insulation, Underground Insulation WHEN steam or hot water are conveyed from one part of a building to another, it usually is desirable that the loss of heat from the pipes through which these heating media pass be reduced to an economic minimum by means of the proper types and thicknesses of insulation. Pipe insulation is also used to reduce the absorption of heat by cold pipes as well as to prevent condensation on the outer surfaces: HEAT LOSSES FROM BARE PIPES Heat losses from horizontal bare iron pipes, based on data obtained from tests conducted at the Mellon Institute, are given in Table 1. These losses are expressed in Btu per hour per linear foot of pipe per degree Fahrenheit difference in temperature between the steam or hot water in the pipe and the air surrounding the pipe. The 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 differences 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 indicated 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 handling it, boiler room expense, etc. For additional information on this subject refer to paper entitled Heat Emission from Iron and Copper Pipe1, by F. C. Houghten and Carl Gutberlet. 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 linear foot of pipe. Table 2 gives these areas for various standard pipe sizes while Table 3 gives the area in square feet for flanges and fittings for various standard pipe sizes. Very often, even where pipes are thoroughly insulated, flanges and fitting's are left bare due to the belief that the losses from these parts are not large. However, the fact that a pair of 9-in; standard flanges having an area of 3.00 sq ft would lose, at 100 lb steam pressure, an amount of *A.S.H.V.E. Transactions. Vol. 38. 1932. 503 American Society of Heating and Ventilating Engineers Guide, 1934 Table 1. Heat Losses from Horizontal Bare Iron Pipes Expressed in Btu per linear foot per degree Fahrenheit difference in temperature between the pipe and surrounding still air at 70 F_________________________ Nominal Pipe Size (Inches) 120 F Hot Water 150 F 180 F 210 F 227.1 F (S Lb) Temperature Difference Steam 297.7 F (50 Lb) 337.9 F (100 Lb) A % l m \A 2 1A 3 3A 4 iA 5 6 8 9 12 S0F 0.543 0.660 0.791 0.979 1.09 1.34 1.58 1.88 2.13 2.36 2.60 2.87 3.39 4.32 4.80 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 5.05 6.62 no F 0.605 0.729 0.878 1.087 1.220 1.491 1.778 2.100 2.380 2.650 2.920 3.200 3.775 5.050 5.350 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 5.71 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 5.885 7.670 227.7 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 6.824 8.900 267.9 F 0.796 0.955 1.166 1.450 1.640 2.015 2.388 2.853 3.215 3.582 3.956 4.368 5.153 6.635 7.400 9.670 Table 2. Radiating Surface per Linear Foot of Pipe Nominal Pipe Size (Inches) A H l iA lA Surface Area (Sq Ft) 0.22 0.275 0.344 0.435 0.498 Nominal Pipe Size (Inches) 2 2A 3 3A 4 Surface Area (Sq Ft) 0.622 0.753 0.917 1.047 1.178 Nominal Pipe Size (Inches) 5 6 8 9 12 Surface Area (Sq Ft) 1.456 1.734 2.257 2.519 3.338 Table 3. Areas of Flanged Fittings, Square Feet3 Nominal Pipe Size (Inches) i 1A 1A 2 2A 3 3A 4 4A 5 6 8 9 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 0.383 0.477 0.672 0.841 0.945 1.122 1.344 1.474 1.622 1.82 2.41 3.00 4.41 0.438 0.510 0.727 0.848 1.107 1.484 1.644 1.914 2.04 2.18 2.78 3.77 4.44 6.71 0.795 0.957 1.174 1.65 2.09 2.38 2.98 3.53 3.95 4.44 5.13 6.98 8.71 13.08 1.015 1.098 1.332 2.01 2.57 3.49 3.96 4.64 5.02 5.47 6.99 9.76 11.44 17.73 0.892 1.084 1.337 1.84 2.32 2.68 3.28 3.96 4.43 5.00 5.99 8.56 10.57 16.35 1.083 1.340 1.874 2.16 2.76 3.74 4.28 4.99 5.46 6.02 7.76 11.09 13.17 18.76 1.235 1.481 1.815 2.54 3.21 3.66 4.48 5.41 6.07 6.81 7.84 10.55 13.18 19.67 1.575 1.925 2.68 3.09 4.05 5.33 6.04 7.07 7.72 8.52 10.64 14.74 17.23 26.65 1.622 1.943 2.38 3.32 4.19 4.77 5.83 7.03 7.87 8.82 10.08 13.44 16.78 24.87 2.07 2.53 3.54 4.06 5.17 6.95 7:89 9.24 10.07 10.97 13.75 18.97 22.10 34.11 Including areas of accompanying flanges bolted to the fitting. 504 Chapter 35--Heat Losses from Bare and Insulated Pipes Fig. 1. Chart for Estimating Dollar Value of Heat Loss from Bare Iron Pipes. (See Table l)a This chart is based on 100.linear feet per 1000 hours. For fractions or multiples of these factors, multiply by proper percentage. heat equivalent to more than a ton of coal per year shows the necessity for insulating such surfaces. Table 3 shows the areas of both standard and extra heavy flanged fittings including the accompanying 'flanges bolted to the fittings. STEAM AND HOT WATER LINES - The conductivities of various materials used for insulating steam and hot water pipes are given in Table 4. 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 505 American Society of Heating and Ventilating Engineers Guide, 1934 Table 4. Conductivities (k) of Various Types of Insulating Materials for Medium and High Temperature Pipes Mean Temperature (4 Plies per 1 in. thick) (8 Plies per 1 in. thick) , (30-40 Laminations per 1 in. thick) (20 Laminations per 1 in. thick) (Diatomaceous Earth and Asbestos) (Felted Fibre) 100 F 0.425 0.530 200 F 0.465 0.650 300 F 0.505 0.770 400 F 0.550 0.890 500 F 0.590 0.480 0.555 0.630 0.705 0.360 0.415 0.470 0.525 0.585 0.545 0.605 0,665. 0.725 0.785 0.350 0.410 0.470 0.530 0.590 0.515 0.545 0.575 0.605 0.635 0.600 0.640 0.675 0.715 0.750 ^Mechanical Engineer's Handbook, Marks, 3rd Ed., 1930. conductivities makes it possible readily to calculate the heat loss through single or compound sections. It should be emphasized that the con ductivities given in Table 4 for the various insulations are the average of 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 4 for 1, llA and 2-in.-thick materials, and for temperatures commonly encountered in engineering practice can be obtained from Tables 5 to 10, 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 5 to 10 are based on the conductivities in Table 4 and were computed from data given in Chapter 22, The Guide 1931, as in the following problem: Example 1. Determine the totalheat loss for a period of 30 days through a 1-in. (4 ply) thickness of corrugated asbestos insulation on 100 ft of 3-in. pipe carrying steam at 5 lb pressure, and with, surrounding air at 60 F. Also determine percentage of heat saving over bare pipe loss. Solution. Difference in temperature between pipe and surrounding air - 227.1 -- 60 or 167 1 deg. From Table 6 the coefficients of transmission for 1-in. corrugated asbestos (4 ply) are 0.608 and 0.652 Btu per hour per square foot per degree temperature difference at temperature differences of 157.1 deg and 227.7 deg, respectively. The difference is 0.044 Btu per hour per square foot per degree temperature difference lor a temperature difference of 70.5 deg.' For a temperature difference of 167^1 deg (10 deg higher than 157.1 deg) the coefficient of transmission is then 0.608 + (jqI; X 0.044J, or 0.614 Btu per hour per square foot per degree temperature difference. From Table 2 the area per linear foot of 3-in. pipe is 0.917 sq ft. The total h.t loss is therefore 0.917 X 0.614 X 167.1 X 100 (linear feet) X 720 (hours) = 6,774,000 Btu. From Table 1, and in the same manner it is determined that the loss through an uninsulated 3-in. pipe for the same conditions will be 25,917,000 Btu. The saving due to insulation is 19,143,000 Btu or 74 per cent of the bare pipe loss. 506 Chapter 35--Heat Losses from Bare and Insulated Pipes Table 5. 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 at70F Thickness of Insulation (Inches) i m 2 Nominal Pipe Size ' (Inches) X X l ix 2ix 2X 3 3X 4 4X 5 6 8 9 12 A X l IX IX 2 2A 3 3X 4 4X 5 6 8 9 12 120 F S0F 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 0.380 0.369 Hot Water I Steam 150 F 180 F 210 F 227.1 F 1 (5 Lb) 297.7 F (50 Lb) Temperature Difference 80 F 110 F 140 F I 157.1 F 227.7 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 0.385 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 0.390 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 0.395 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 1 0.398 0.386 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 0.410 0.398 337.9 F (100 Lb) 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 0.417 0.405 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 0.280 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 0.284 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 0.288 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 0.292 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 0.294 0.285 0.665 0.596 0.540 0.490 0.459 0.427 0.401 0.380 0.364 0.353 0.343 0.336 0.328 0.311 0.303 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 0.308 0.299 X 0.543 0.551 0.558 0.565 0.569 0.587 0.597 X 0.484 0.490 0.497 0.503 0.507 0.523 0.532 1 0.433 0.439 0.445 0.451 0.454 .0.467 0.476 ix 0.393 0.398 0.403 0.409 0.412 0.424 0.432 IX 0.365, 0.370 0.376 0.381 0.384 0.397 0.402 2 0.338 0.343 0.347 0.351 0.354 0.364 0.370 2X 0.316 0.320 0.324 0.328 0.331 0.341 0.347 3 0.297 0.301 0.305 0.309 0.312 0.321 0.326 3X 0.284 0.288 0.292 0.295 0.297 0.306 0.311 4 0.275 0.278 0.282 0.285 0.287 0.296 0.301.. 4X 0.266 0.270 0.273 0.276 0.278 0.286 0.290 5 0.258 0.262 0.265 0.268 0.270 0.278 0.283 6 0.250 0.254 0.257 0.260 0.262 0.270 .0.274 .8 0.236 0.239 0.242 0.245- 0.247 0.255 0.258 9 ... 0.228 0.231 0.234 '0.237 0.239 0.246 0.250 12 0.219 0.222 0.225 0.228 0.230 0.237 0.240 American Society of Heating and Ventilating Engineers Guide, 1934 Table 6. Coefficients of Transmission (U) for Pipes Insulated with Corrugated Asbestos Type Insulation (4 Plies Per Inch Thickness) These coefficients are expressed in Btu per hour per square foot of pipe surface per degree Fahrenheit difference in temperature between pipe and surrounding still air at 70 t Thickness op; Inspiration (Inches) 114 ` .2 Pipe ; Size (Inches) 14 ' Va. 1 1U 2 ?14 3 3V6 4 5' 6 g o 12 u y1 1 1% ljS4 2* 2A X 314 4* 454 5 6 g 0 12 . 54 Va. 1 IK \lA 2* 254 3 354 4* 454 5* 6 g o 12 120 F Hot Water 150 F 180 F 210 F Steam 227.1 F 297.7 r (5 Lb) | (50 Lb) 337.9 r (100 Lb) SOF 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 0.453 0.441 80 F 0.919 0.829 0.756 0.693 0.656 0.615 0.586 0.562 0.544 0.530 0.518 0.507 0.496 0.477 0.468 0.456 Temperature Difference no f 140 F 157.1 F 227.7 r 267.9 F 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 0.483 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 0.498 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 0.507 0.493 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 0.544 0.529 1.106 0.997 0.909 0.834 0.788 0.742 0.705 0.677 0.654 0.639 0.624 0.6U 0.599 0.575 0.564 0.550 0.737 0.657 .0.594 0.542 0.507 0.471 0.443 0.421 0.403 0.393 0.383 0.372 0.362 0.343 0.334 0.323 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 0.273 0.263 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 0.345 0.334 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 0.282 0.272 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 0.357 0.346 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 0.291 0.280 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 0.368 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 0.375 0.364 1 0.726 0.713 0.637 | 0.648 0.570 0.580 0.517 0.527 0.481 | 0.490 0.444 1 0.452 0.415 0.422 0.390 1 0.397 0.373 1 0.380 0:360 0.367 0.350 0.340 0.329 0.310 0.357 i 0.346 I 0.335 1 0.315 0.300 J 0.305 0.289 1 0.294 0.884 0.790 0.713 0.649 0.609 0.565 0.533 0.5U6 0.483 0.471 0.460 0.447 0.436 0.413 0.403 0.391 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 .0.325 0.314 0.918 0.820 0.740 0.675 0.652 0.587 0.555 0.525 0.502 0.489 0.476 0.463 0.452 0.429 0.419 0.407 0.810 0.720 0.645 0.587 0.545 0.502 0.466 0.440 0.421 0.406 0.395 U.384 0.371 0.349 0.338 U-325 Chapter 35--Heat Losses from Bare and Insulated Pipes Table 7. Coefficients of Transmission {V) for Pipes Insulated with Corrugated Asbestos Type Insulation (8 Plies Per Inch Thickness) These coefficients are expressed in Btu per hour per square foot of pipe surface per degree Fahrenheit difference in temperature between pipe and surrounding still air at 70 F Thickness op Insulation (Inches) I . 2 Nominal Pipe Size (Inches) A H 1 m 2 2A 3 4 4A 5 6 8 9 12 K 1 iH iA 2 2A 3 3A 4 4A 5 6 8 9 12 . A H 1 iA iA 2 2A 3 $l/2 4 4A 5 6 8 9 12 - 120 F 50 r 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 0.408 0.397 Hot Water I 150 F 180 F I 210 F 1 227.1 F 8 (5 Lb) Temperature Difference 80 F 110 F 140 F 1 157.1 F 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 0.418 0.406 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 0.427 0.415 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 0.437 0.424 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 0.442 0.429 Steam 297.7 F 1 337.9 F (50 Lb) (100 Lb) 227.7 F 267.9 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 0.466 0.452 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 0.480 0.466 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 0.301 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 0.309 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 0.316 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 0.324 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 0.328 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 0.346 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 0.356 0.344 0.585 0.520 0.465 0.422 0.394 0.364 0.339 0.319 0.304 0.295 0.285 0.278 0.269 0.253 0.244 0.236 0.599 0.533 0.476 0.432 0.403 0.372 0.347 0.327 0.311 0.302 0.292 0.284 0.275 0.259 0.250 0.241 0.613 0.545 0.487 0.442 0.412 0.380 0.355 0.334 0.318 0.308 0.299 0.290 0.282 0.265 0.2S6 0.247 0.627 0.558 0.498 0.452 0.422 0.388 0.363 0.342 0.326 0.315 0.306 0.297 0.288 0.270 0.262 0.253 0.635 0.565 0.504 0.458 0.427 0.393 0.367 0.346 0.330 0.319 0.310 0.301 0.292 0.273 0.265 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 0.280 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 0.287 0.277 American Society of Heating and Ventilating Engineers Guide, 1934 Table 8 Coefficientsof Transmission (U) for Pipes Insulated with Laminated Asbestos Type Insulation (30 to 40 Laminations Per Inch Thickness) These coefficients, are expressed in Btu per hour per square foot of pipe surface per degree Fahrenheit difference in temperature between pipe and surrounding still air at /u r Thickness 07 Insulation (Inches) \ IK 2 Pipe Size (Inches) V> 1 2 2H 3 3K 4 4 5- 6 8 9 12 K K 1 2 2K 3 3 K. 4~ 4K 5 6 8 9 12 K K 1 114 IK 2 2K 3 3% 4 4Kt 5' 6 8 9 12 Hot Water f 120 F 1 ISO F 1 180 F | 210 F | 227.1 F (5 Lb) &PEAM 297.7 F (50 Lb) 337.9 F (100 Lb) Teuperaturb Difference sot 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 0.308 0.301 80T 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 0.316 0.308 110 F 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 0.325 0.316 HOF 1 157.1 F I0.650 0.658 0.586 I 0.594 0.534 | 0.541 0.491 1 0.497 0.464 0.470 0.437J 0.442 0.415 1 0.420 0.398 1 0.403 0.385 [ 0.390 0.375 0.380 0.367 0.372 0.359 I 0.364 0.351 1 0.356 0.338 0.343 0.333 0.336 0.324 1 0.328 227.7 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 0.355 0.346 267.9 F 0.716 0.645 0.587 0.540 0.511 0.481 0.457 0.438 0.426 0.414 0.405 0.395 0.387 0.373 0.366 0.356 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 0.227 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 0.233 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 0.239 0.232 0.539 0.546 0.484 | 0.490 0.436 I 0.442 0.396 0.401 0.370 0.375 0.345 0.350 0.324 0.330 0.308 0.313 0.295 0.300 0.287 0.291 0.279 0.283 0.272 0.276 0.266 0.269 0.252 0.255 0.245 0.249 0.238 0.241 0.577 0.517 0.466 0.423 0.397 0.369 0.348 0.330 0.316 0.307 0.299 0.291 0.284 0.270 0.263 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 0.271 0.263 0.442 0.392 0.352 0.319 0.297 0.274 0.256 0.243 0.231 0.223 0.216 0.210 0.203 0.191 0.185 0.178 0.453 0.402 0.360 0.327 0.304 0.280 0.262 0.249 0.236 0.228 0.222 0.215 0.208 0:196 0.190 0.183 0.464 0.412 0.369 0.335 0.311 0.287 0.269 0.254 0.242 0.234 0.227 0.220 0.213 0.201 0.195 0.187 0.475 0.422 0.378 0.343 0.319 0.294 0.275 0.260 0.248 0.240 0.233 0.225 0.218 0.206 0.200 0.192 0.481 0.428 0.383 0.348 0.323 0.298 0.279 0.264 0.251 0.243 0.236 0.228 0.221 0.209 0.203 | 0.195 0.508 0.452 0.405 0.367 0.341 0.314 0.293 0.277 0.265 0.257 0.249 0.241 0.233 0.220 0.214 0.205 0.523 0.465 0.417 0.379 0.352 0.324 0.302 0.285 0.273 0.265 0.256 0.248 0.240 0.227 0.220 0.210 Chapter 35--Heat Losses from Bare and Insulated Pipes Table 9. Coefficients of Transmission (V) for Pipes Insulated with Laminated Asbestos Type Insulation (Approximately 20 Laminations Per Inch Thickness) These coefficients are expressed in Btu per hour per square foot of pipe surface per degree Fahrenheit difference in temperature between pipe and surrounding still air at 70 F TH1CXNE88 OF Insulation (Inches) 1 ` 2 Nominal Pipe Size (Inches) K H 1 IK 1K . 2 3 3K 4 4K 5 6 8 9 12 K K 1 IK 2IK . 2K 3 3K 4 4K 5 6 8 9 12 K K 1 2IK 2K 3 3K 4 4K 5 6 8 9 12"*----. 120 F 50 r 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 0.463 0.452 Hot Water I 150 F 180 F 210 F 1 l 227.1 F (5 Lb) Temperature Difference 80 F 110 F 140 F j 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 0.471 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 0.478 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 0.486 0.475 0.964 0.871 0.792 0.728 0.688 0.647 0.615 0.59.1 0.571 0.556 0.544 0.533 0.522 0.502 0.491 0.478 Steam 297.7 F (50 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 0.510 0.497 337.9 F (100 Lb) 267.9 F 1.022 0.921 0.840 0.771 0.731 0.685 0.651 0.626 0.604 0.589 0.575 0.565 0.553 0.532 0.520 0.507 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 0.342 0.332 0.767 0.68S 0.618 0.562 0.527 0.490 0.460 0.436 0.419 0.407 0.396 0.386 0.375 0.358 0.349 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 0.355 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 0.361 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 0.364 0.353 0.831 0.743 0.670 0.610 0.572 0.535 0.500 0.475 0.456 0.443 0.429 0.418 0.408 0.388 0.378 0.367 0.848 0.759 0.684 0.622 0.584 0.547 0.511 0.485 0.465 0.453 0.437 0.427 0.417 0.397 0.387 0.375 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 0.280 0.269 0.675 0.601 0.538 0.488 0.453 0.420 0.392 0.370 0.352 0.342 0.332 0.322 0.312 0.293 0.284 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 0.289 0.278 0.698 0.(521 0.557 0.505 0.470 0.434 0.405 0.382 0.365 0.354 0.343 0.333 0.323 .0.303 0.294 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 0.297 0.286 0.732 0.652 0.584 0.529 0.494 0.455 0.425' 0.400 0.382 0.371 0.360 0.349 0.338 0.317 0.307 0.296 0.747 0.665 0.597 0.540 0.504 0.464 0.434 0.408 0.390 0.378 0-.-367 0.356 0.345 0.324 0.313 0.302 511 American Society of Heating and Ventilating Engineers Guide, 1934 Table 10. . Coefficients of Transmission (U) for Pipes Insulated with Rock Wool Type Insulation . These coefficients are expressed in Bin 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) lX Nominal Pipe Size (Inches) hi X 1 mix 2 2X 3 3H 4 4H 5 6 8 9 12 xx 1 IX ix 2 2X 3 m 4 4X 5 6 8 9 12 34 X 1 iX m 2 2X 3 3X 4 4J4 5 6 8 9 12 120 F Hot Water 150 F 180 F 210 F 227.1 F (S Lb) Steak 297.7 F (SO Lb) 337.9 F (100 Lb) Tbmfebatube Difference 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. 0.321: 0.313 80 V 9.644 0.581 0.529 0 486 0 460 0 431 0 411 0.394 0 381 6 371 0 363 6.356 0 348 0 335 0 328 0.320 110 K 0.658 6.593 0.541 0.497 0.470 0.441 0.420 0.402 0.389 0.379 0.371 0.364 0.356 0.342 0.335 0.327 140 F | 157.1 F 0.672 1 0.680 0.606 I 0.613 0.552 | 0.559 0.507 1 0.513 0.480 1 0.485 0.450 1 0.456 0.428 1 0.434 0.411 | 0.415 0.398 I 0.402 0.387 S 0.392 0.379 | 0.383 0.371 J 0.376 0.363 0.368 0.349 0.353 0.342 0.347 0.334 0.338 227.7 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 0.365 0.355 267.9 F .730 0.659 .600 0.551 0.522 0.490 0.466 0.446 0.432 0.422 0.413 0.404 0.396 0.381 0.374 0.364 0.523 0.468 0.42L 0.383 0.359 0.333: 0.314 0.296 0.286 0.278 0.270 0.263 0.257 0.244 0.238 0.230 0 534 0 477 0 430. 6 391 0 366 6 340 0 320 0 302 6 291 6 284 6 276 CL 269 6 262 6 249: 6 243 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 0.248 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 0.254 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 0.257 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 0.270 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 0.277 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 0.193 0.185 0 471 6 418 6 374 6 340 6.316 0 292 6 274 6 257 6.246 6 237 0 230 6.223 6.217 6.204 0.197 6.190 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 0.201 0.194 0.491 0.496 0.436 0.441 0.390 0.395 0.355 0.359 0.330 1 0.334 0.304 I 0.308 0.285 I 0.289 0.268 1 0.272 0.257 1 0.260 0.247 1 0.250 0-240 1 0.243 0.233 1 0.236 0.226 0.228 0.213 0.215 0.205 0.207 0.198 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 0.218 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 0.224 0.216 512 Chapter 35--Heat Losses from Bare and Insulated Pipes . LOW TEMPERATURE PIPE INSULATION Surfaces maintained at low temperatures should be insulated so as to retard the flow of heat from the outside into the low temperature area and to prevent the formation of condensation and of frost if the temperatures are low enough, as well as to prevent corrosion induced by the presence of condensed moisture on metal surfaces. Materials commonly used for insulating pipes and surfaces at low temperatures are cork, rock cork, hair felt and other felted or fibrous non-absorbent materials. Thermal conductivities of low temperature insulating materials are given in Chapter 5. Insulating materials are available commercially to meet varying tem perature gradients. For example, the thickness of insulation for ice water is approximately IJ^-in. if the temperature in the line is not lower than 25 F; the thickness of insulation for brine is approximately 2l/i in. where the temperature ranges from 0 deg to 25 F; and the thickness of insulation where the brine temperature ranges from --30 F to zero degrees is ap proximately 4 in. Insulation 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 maintained at a sufficiently high rate, freezing may be prevented. Table 11 may be used for making estimates of the thickness of insula tion necessary to take care of still water in pipes at various water and surrounding air temperature conditions. Because of the damage and service interruptions which may result from frozen water in pipes, it is essential that the most efficient insulation be utilized. This table is based on the use of hair felt or cork, having a conductivity of 0.30. The initial water temperature is assumed to be 10 deg above, and the sur rounding air temperature 50 deg below the freezing point of water (tem perature difference, 60 F). The last column of Table 11 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 exposal 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 advisable to double the rates of flow listed in the table. It must be emphasized 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 513 American Society of Heating and Ventilating Engineers Guide, 1934 Table 11. Data for Estimating Requirements to Prevent Freezing of Water in Pipes (iNCHEB)Ji to Cool Water to Freezing Point Water Required to Flow to Prevent Freezing Pounds per Linear Foot op ' Pipe per Hour *1 i 1H 2 3 4 5 6 8 10 12 0.42 0.83 1..40 1.94 3.25 4.55 5.92 7.35 10.05 13.00 15.80 2. 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 31 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 2 0.45 0.55 0.68 0.75 0.94 1.11 1.29 1.46 1.78 2.12 2.46 3 0.40 0.48 0.58 0.64 0.79 0.93 1.06 1.19 1.44 1.70 1.93 required will be one-half that shown in the last column of Table 11. However, if the water enters the pipe at 34 F it will be cooled to 32 F in one-fifth of the time given in the table. It will then be necessary to in crease 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. 11, the loss of heat stored in the insulation, the effect of a varying temperature dif ference 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. When water must remain stationary longer than the times designated in Table 11, 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 exces sive, and the heating effect is concentrated against the water pipe where it is needed. For this form of protection 2 in. of an efficient insulation may be applied. Pipe Sweating In some cases the prevention of condensation rather than the con servation of heat is the governing factor in determining the thickness of 514 Chapter 35--Heat Losses from Bare and Insulated Pipes insulation required. Fig. 2 may be used for determining the thickness of any material of known conductivity which should be used to prevent con densation on pipes and flat metallic surfaces. The surface resistances used for calculating the family of curves in Fig. 2 are based on the results of 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 Fig. 2. Thickness of Pipe Insulation to Prevent Sweating3 Solve problems by drawing lines as indicated by dotted line, entering chart at lower left hand scale. given may be followed with no alteration on account of the surfaces commonly used. . Moisture will be deposited on a surface whenever its temperature falls to that of the dew-point. The maximum permissible temperature drop is indicated on Fig. 2 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 conditions involved. (See discussion of con densation in Chapter 7). 515 American Society of Heating and Ventilating Engineers Guide, 1934 (L. B. McMillan, Proc. National Dist. Heating Ass'n., Vol. 18, p. 131.) Fig. 3. Chart for Determining Economical Thickness of Insulation i .Chapter 35--Heat Losses from Bare and Insulated Pipes 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 waterproof jacket, and other outdoor insulation should be thoroughly weather-proofed. THICKNESS of pipe insulation Table 12 shows the thicknesses of insulation which ordinarily are used for various temperature conditions. Where a thorough analysis of economic thickness is desired, this may be accomplished through 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 temperature difference; thence vertically to the line representing the conductivity 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. The dotted line on the chart illustrates its use in solving a typical example. Underground Insulation Underground steam distribution lines are carried in protective struc tures of various types, sizes and shapes. (See Chapter 36). Detailed data on commonly used forms of tunnels and conduit systems have been published by the National District Heating Association2. " Pipes in tunnels are covered with sectional insulation to provide maximum thermal efficiency and are also finished with good mechanical protection in the form of metal or 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 *.Handbook of the National District Heating Association, Second Edition, 1932. 517 American Society of Heating and Ventilating Engineers Guide, 1934 Table 12. Thicknesses of Insulation Ordinarily used Indoors3 (Lb Gage) ob Condition 0 to 25 25 to 100 100 to 200 Low Superheat Medium Superheat ' High Superheat Steam Temperatures . Degrees Fahrenheit 212 to 267 267 to 338 338 to 388 388 to 500 500 to 600 600 to 700 Thickness op Insulation ` Pipes Larger loan 4 In. 1 in. 1)4 in. 2 in. 2X in. 3 in. 3X in- Pipes 2 In. to 4 In. 1 in. 1 in. IX in. 2 in. 1)4 in- 3 in. Pipes M In to 1H In- 1 in. 1 in. 1 in. 1)4 in. 2 in. 2 in. All piping located outdoors or exposed to weauier 13 uiu.u.i than shown in this table, and covered with a waterproof jacket. the pipes with high quality, loose insulating material. The insulation must be kept dry at all times, and for this purpose effective waterproofing membranes 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 dif ficult of accurate determination due to the many variables which have to be considered, As a result of theories developed by J, R. Allen3, together with experimental data presented by others, the usual endeavor is to secure not less than 90 per cent efficiency for underground piping. Table 13 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 Xz in. less in thick ness than that determined by the use of Fig. 3. . Use of Fig. 3 involves conditions of insulation exposed to the air, whereas normal ground tem perature is substituted for air temperature in determining the tempera ture difference for use with the chart when applying it for underground pipe line estimates. Table 13. Thickness of Loose Insulation for Use as Fill in Underground Conduit Systems Steam Pressure (Lb Cage) or Condition Steam Temperature Degrees Fahrenheit Minimum Thickness op Insulation in Inches Steam LrNES 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 Minimum Distance Between Steam and Return Hot Water, 1)4 IX IX' or 0 to 25 212 to 267 1)4 2 IX IX ix.25 to 125 267 to 352 2 2)4 3 i Above 125, or superheat 352 to 500 . 1)4 3 3K IX ix IX Theory of Heat Losses from Pipes Buried in the Ground, by J. R. Alien (A.S.H.V.E. Transactions, Vo!. 26, 1920). 518 Chapter 36 DISTRICT HEATING Underground Steam Piping, Selection of Pipe Sizes, Provision for Expansion, Capacity of Returns with Various Grades, Pipe Con duits, Pipe Tunnels, Service Connections, Steam per Square Foot of Heating Suiface, Fluid Meters and Metering THIS chapter deals with those phases of district heating which frequently fall within the province of the heating engineer. Data and information are included for solving incidental problems in connection with institutions and factories and for the design of building heating systems which are to be supplied with purchased steam, A complete district heating installation should not be attempted without a thorough study of the entire problem by men competent and experienced in that industry. The Handbook and other publications of the National District Heating Association and the references at the end of this chapter should be consulted. UNDERGROUND STEAM 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. Any unusual requirements such as those for process steam should be individually calculated. 8 The steam requirements for water heating should be taken into account, but in most types of buildings this load will be relatively small compared 519 American Society of Heating and Ventilating Engineers Guide, 1934 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, in part, upon whether or not it has been passed through electrical generating units. If it has, the pressure will be considerably lower than if live steam, direct from the boilers, is used. The advantages of low pressure distribu tion (2 to 30 lb per square inch) are (1) smaller heat loss from the pipes, (2) less trouble with traps and valves, and (3) simpler problems in pressure reduction at the buildings. With distribution pressures not exceeding 40 lb per square inch there is little danger even if the full distribution pressure should build up in the radiators through the faulty operation of a reducing valve; but with pressures higher than this a second reducing valve or some form of emergency relief is usually desirable to prevent excessive pressures in the radiators. The advantages of high pressure distribution are (1) smaller pipe sizes and (2) greater adaptability of the steam to various operations other than building heating. The different kinds of apparatus which frequently must be served require various minimum pressures. Kitchen equipment requires from 5 to 15 lb per square inch, the higher pressures being necessary for apparatus in which water is boiled, such as stock kettles and coffee urns. An increased amount of heating surface, which is easily obtained in some kinds of apparatus, results in quicker and more satisfactory operation at low pressures. For laundry equipment, particularly the mangle, a pres sure of 75 lb per square inch is usually demanded although 30 lb per square inch is sufficient if the mangle is equipped with a large number of rolls and if a slow rate of operation is permissible. Pressing machines and hospital sterilizers require about 50 lb per square inch. PIPE SIZES The lengths of pipe, steam quantities and initial and terminal pressures having been chosen, the pipe sizes can readily be calculated by. means of the Unwin pressure drop formula. This formula, which gives pressure drops slightly larger than actual test results, is as follows: (+)0.000X306 W*L P= yd5 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. y = average density of steam, pounds per cubic foot. (1) This formula] is similar to the Babcock formula given in Chapter 32. Information on provision for expansion will be found in Chapters 32 and 34. . In general return lines when installed follow the contour of the land, and Table 1 gives sizes of return pipes for various grades. It is evident that at points where the grade is great, smaller pipes can be installed. 520 Chapter 36--District Heating PIPE CONDUITS Conduits for steam pipes buried underground should be reasonably water-proof, 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 installation or conduit. Expansion of the piping must be carefully controlled by means of anchors and expansion joints or bends so that the pipes can never come in contact with the conduit. Anchors can be anchor fittings or U-shaped steel straps which partially encircle the pipes and are firmly bolted to a short length of structural steel set in concrete. Table 1. Capacity of Returns for Underground Distribution Systems in Pounds of Condensate per Hour Size or Pipe In. i IK m 2 3 4 5 6 8 10 12 6' 448 1740 2700 4980 13900 30900 54800 90000 190000 344000 555000 r 998 2490 4190 7380 22500 44800 79800 138000 277000 498000 798000 Pitch or Pipe peb 100 Ft. V 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 Size of pipe should be increased if it carries any steam. 10' 5490 9480 14500 24900 74800 154000 294000 449000 938000 -- 20' 7490 . 13500 20900 36900 105000 229000 418000 ....... --- In laying out conduits of this type the following points should be borne in mind: . 1. An expansion joint offset or bend should be placed between each two anchors. 2. If the distance between buildings is 150 ft'or less and the steam line contains highpressure steam, it may be anchored in the. basement of one building and allowed to ex pand into the basement of the second building. If the steam line contains low-pressure steam (up to 4 lb pressure), this method may be used if buildings are 250 ft or less apart. 3. If the distance between buildings is between 150 ft and 300 ft and the steam line contains high-pressure steam, the lines should be anchored midway between the buildings and allowed to expand into the basements of both buildings. If the steam line contains low-pressure steam this method may be used if buildings are between 250 ft and 600 ft apart. No manhole is required at the anchor, and a blind pit is all that is necessary. 4. For longer lines, manholes must be located according to judgment and depending upon the expansion value of the type of expansion joint or bend that is used. The minimum number of manholes will be required when an expansion bend or an anchor with double expansion joint is placed in each manhole and the pipes are anchored mid way between manholes. . 5. A proper hydrostatic test should be applied to the piping before the top of the con duit is applied and before application of insulation. The pressure used in this test should be grpter than the pressure used in service, and should be not less than 100 lb per square inch in any case. .. The styles and construction of conduits commonly used may be classi fied as follows. Some of the more common forms are illustrated in Fig. 1.: Wood Casing; The pipe.is enclosed in a cylindrical casing usually having a wall 4 in.: thick and built of segments which are bound together by a wire wrapped spirally around 521 American Society of Heating and Ventilating Engineers Guide, 1934 the casing. The casing is lined with bright tin and coated with asphalturri. 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. LUOfrXy FuifBSH mojy ojvsuof'uoj Chapter 36--District Heating ==C) lal F ig . 2. St e a m S e r v ic e a n d M e t e r C o n n e c tio n s w it h C o o lin g R a d ia t o r The pipes are protected by a sectional tile conduit, scored for splitting, or a cast-iron conduit, both being of the bell apd spigot type. . The conduit has a longitudinal side joint for cementing, after the upper half of conduit is in place, so shaped that the cement is keyed in place while locking .the top and bottom half of the conduit together with a water-tight vertical side joint. The cast-iron conduit has special side locking clamps in addition to the vertical side joint. The entire space between the conduit and the pipes is filled with a water-proofed asbestos insulation. The conduit is supported on the base drain foundation, each section resting on two sections of the base drain, thus inter locking. The base drain is so shaped that it provides a cradle for.the conduit, resting solidly on the trench bottom and providing adequate drainage area immediately under the conduit. The underdrain is connected to sewers or some other point of free discharge. For tile conduit the base drain is vitrified salt glazed tile and for cast-iron conduit it is either extra heavy tile or cast-iron. A free internal drainage area is also provided.to carry away any water that may collect on the inside of the conduit from a leaky pipe or joint in the conduit. Broken stone is filled in around the base drain and up to the vertical side joint. The broken stone is covered with an asphalted filter cloth to prevent sand, etc., 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 522 American Society of Heating and Ventilating Engineers Guide, 1934 separate top and bottom halves. Special reinforcing ribs give the cast-iron conduit ample strength with minimum weight. Insulated Tile Type: The insulating material, diatbmaceous 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 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 Conduits. 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 waterproof 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. . PIPE TUNNELS Where steam heating lines are installed in tunnels large enough to provide walking space, the pipes are supported by means of hangers of 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 524 H <HH CL Id ZO (d 22O U Hw Cd S 2Q < s < C(H/d3 O American Society of Heating and Ventilating Engineers Guide, 1934 to accommodate miscellaneous other services, such as for underground passage between buildings. . SERVICE CONNECTIONS * Most district heating companies enforce certain regulations regarding the consumer's installation, partly to safeguard their own interests but principally to insure satisfactory and economical service to the consumer. 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. 1. Provision should be madefor 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 a restaurant 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 condensation should not be wasted. This heat may be salvaged by means of a cooling radiator as illustrated ' in Fig. 2, or, as is more frequently done, by a heat exchanger which pre heats the water used for lavatory purposes, as in Fig. 3. Figs. 2 and 3 show'the practice of a Boston utility as to the service arid meter con nections. Fig. 4 shows a typical installation for service from the system of a New York utility. The condensation from the heating system, after leaving the trap, passes through the preheater on its way to the meter. The supply to the -hot water heater passes through the preheater, absorbing heat from the condensation. If the hot water system in the building is of the recircu lating type, the recirculating connection should be tied in between the preheater and the water heater proper, not at the preheater inlet, because the recirculated hot water is itself at a high temperature. The number of square feet of heating surface in the preheater should be approximately equal to one per cent of the equivalent square feet of heating surface in the building. 526 In s ta ll Service Pressure and Low Pressure Reducing Valves F ig . 4 . T y p ic a l S e r v ic e n s t a l l a t io nI Chapter 36--District Heating 527 American Society of Heating and Ventilating Engineers Guide, 1934 Because of the lack of coincidence between the heating system load and the hot water demand, a greater amount of heat can be extracted from the condensation if storage capacity is provided for the preheated water. Frequently a type of preheater is used in which the coils are submerged in a storage tank. 3. Heat supply should be graduated according to variations in the outside temperature. This may be done in several ways, as by the use of thermostats of various types or by orifice systems. Another method which is very simple is the use of an ordinary vacuum return line system in which the pressure ' in the radiators is varied between a high vacuum and a few pounds pres sure, thus producing some control over the heat output. One form of con trol which appears to be well suited for controlling district steam service to a building is the weather compensating thermostat. It regulates the steam supply automatically according to the outdoor temperature, and gives frequent short intervals of intermittent steam supply, and at the same time insures delivery of steam to all the radiators. Another form of regulation, known as the time-limit control, is sometimes employed for regulating the steam supply from the central station main to the building. Such a control provides an intermittent supply of steam to the radiation either throughout the 24 hrs 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 set tings, 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 intermittent supply called for by the day switch setting, or may be set to interrupt the operation of the day switch and entirely cut off the supply of steam to the radiation at night during certain hours which are selected by the operating engineer. FLUID METERS No one thing has contributed more to the advancement of district heating than that of the perfection of fluid meters, which may be clas sified 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: The fluid does not pass in isolated separately-counted quan tities but in a continuous stream which may flow through the line without actuating the primary device of the meter. In the differential meter, the quantity of flow is not determined by simple counting, as with the positive meter, but is determined from the action of the steam on the primary element. Additional subdivisions of these two general classifications can be made as follows: . 528 Chapter 36--District Heading Fluid Meters Positive - quantity *" Volumetric { TM&P { g*gj Quantity - Current - Turbine Differential Rate of flow Head (Kinetic) Area (Geometric) Venturi Flow nozzle Orifice Pitot tube I 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. (c) Calibration cost. (d) Maintenance cost. 11. Servicing facilities of the manufacturer. 12. Pressure at which fluid is to be metered. 13. Type of record desired as to indicating, recording or totalizing. 14. Stocking of repair parts. 15. Use of open jets where steam is to be metered. 16. Metering to be done by one meter or by a combination of meters. 17. Use as a check meter. 18. Its facilities for determining or recording information other than flow. . Condensation Meters - The majority of the meters used by district heating companies in the sale of steam to their customers are of the condensation or flow types. The condensation meter is a popular type for use on small and medium sized installations, where all of the condensate can be brought to a com mon point for metering purposes. Its simplicity .of design, ease in testing, accuracy at all loads, low cost, and adaptability to low pressure distri bution has made it standard equipment with many heating companies.. 529 American Society of Heating and Ventilating Engineers Guide, 1934 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 pressure. They are made for either gravity or vacuum installation. Continuous flow traps and vented receivers ahead of gravity type meters are desirable. A typical Chapter 36--District Heating 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. 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 mechanical or electrically operated type. The electric flow meter makes it possible to locate the instruments at some Fig. 5. Typical Gravity Installation of Condensation Meter Fig. 6. Gravity Installation for Condensation Meter Using Vented Receivers . gravity installation for a condensation meter is shown in Fig. 5, while Fig. 6 is a gravity installation using a vented receiver ahead of the meter. Fig. 7 shows a vacuum installation without a master trap. The pipe discharge from the meter should be of ample size pitched so as to rapidly remove the condensate from the meter. It is advisable to follow the instructions of the meter manufacturer in installing a meter as the successful operation of any meter depends upon its being properly connected. Steam flow meters are available in many types and combinations, as indicated in the subdivision covering fluid meters on page 528. The orifice and plug meter is one in which the steam flow varies directly 530 Fig. 7. Vacuum Condensation Meter Installation without Master Trap distance from the primary element, which is not always possible with the mechanical flow meter. . 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 as follows: 1. It is desirable to place the differential medium in a horizontal pipe in preference to a vertical one, where either location is available. . 2. Reservoirs should always be on the same level and installed in accordance with the instructions of the meter company. 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. 531 . - / American Society of Heating and Ventilating Engineers Guide, 1934 6.' The meter body and meter piping should be kept from 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 PER SQUARE FOOT OF HEATINC SURFACE The following factors are used in New York City for the different classes of buildings listed. The factors are based on maintaining an inside . temperature of 70 F for certain hours with a minimum outside tempera ture of 0 deg F, and an average of 43 F for the heating season of eight months (October 1 to June 1). In this group are six types of buildings: For manufacturing or commercial loft type where steam is used to heat the premises during the day hours to maintain 65 to 68 F from 9 a.m. to 5 p.m. No Sunday or holiday use and no night use. Factor: 325 lb per square foot of heating surface per season. For office buildings using steam during daylight hours only to maintain 70 F from 9 a.m. to 6 p.m. for approximately 240 days (heating season). No night use. Factor: 400 lb per square foot of heating surface per season. For office buildings using steam during day hours and at night when required to 7, 8 and 9 p.m. (customary where there are stock brokers or banking offices), 240 days. Factor: 500 lb per square foot of heating surface per season. For residences of the block type (not detached) where high-class heating service is required somewhat similar to apartment buildings. Factor: 550 lb per square foot of heating surface per season. For apartment houses where high-class heating service is required. (Steam off at midnight). Factor: 650 lb per square foot of heating surface per season. For hotels (commercial type) where very high-class service is required for 24 hoursFactor: 800 lb per square foot of heating surface per season. By assuming one square foot of equivalent heating surface for each 100 cu ft of space heated, which seems a fair ratio in New York City, it is possible roughly to estimate the steam required per cubic foot of space, information which is often more easily obtained than the square feet of. heating surface. Additional data on the heating requirements of various types of buildings in a number of cities may be found in the Handbook of the National District Heating Association. REFERENCES Pipe Line Design for Central Station Heating, by B. T. Gifford (A.S.H.V.E. Transactions, Vol. 17,1911). Engineering and Cost Data Relative to the Installation of Steam Distributing Systems in a Large City, by F. H. Valentine (A.S.H.V.E. Transactions, Vol. 22, 1916). .' Transmission of Steam in a Central Heating System, by J. H. Walker -(A.S.H.V.E. Transactions, Vol. 23. 1917). , . Efficiency of.Underground Conduit, by G. B. Nichols (A.S.H.V.E. Transactions, Vol. 23, 1917). ' Economical Utilization of Heal from Central Plants, by N. W. Calvert and J. E. Seiter (A.S.H.V.E. Transactions, Vol. 30, 1924). : *. 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. 391-39217" . _ . , , Characteristic Meter Calibration Curves (N.D.H.A. Proceedings, Vol. XX, pp. 444-453). .. 532 Chapter 37 RADIANT HEATING Physical and Physiological Considerations, British Equivalent Temperature, Control of Heat Losses, Methods of Application, Principles of Calculation* Mean Radiant Temperature, Measure- ment of Radiant Heating THE general theory behind heating for comfort is that heat must be supplied to. regulate the rate of heat loss from the human body so that the physiological reactions are conducive to a feeling of comfort in the individual. While in convection heating, as described in Chapter 30, heat is transferred from a heating unit to the air and thence to the occu pant, the primary object of radiant heating is to warm the occupant directly without heating the air to any extent. Thus, the difference between convection heating and radiant heating is partly physical and partly physiological. PHYSICAL AND PHYSIOLOGICAL CONSIDERATIONS Comfort requires that heat be removed from the body at the same rate as it is generated by the oxidation of the foodstuffs in the body tissues. The normal rate of heat production in a sedentary individual is about 400 Btu per hour1, or, since the entire surface area of an average adult is. 19.5 sq ft, about 20.5 Btu per square foot per hour. Conditions should be such as to remove heat at this rate if the surface is to be maintained at the mean normal surface temperature of the human body. Heat is transferred from any warm, dry body to cooler surroundings principally by convection and by radiation, the total rate of heat loss being the sum of the two. Where the body surface is moist 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 that of the surrounding air, and on the rate of air motion over the body. The loss by radiation depends entirely upon the difference between the temperature of the body and the mean surface temperature of the surrounding walls and objects. This latter difference is called.the mean radiant temperature (MRT). Because these two types of heat loss 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 lHeat and Moisture Losses from the Human Body and Their Relation to Air Conditioning Poblems; by F. C. Houghten, W. W. Teague. W. E. Miller, and W. P. Yant (A.S.H.V.E. Transactions, Vol. 35,; 1929). - ... 533 American Society of Heating and Ventilating Engineers Guide, 1934 reduced from a given temperature to a lower temperature, 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 correspond ingly lower MRT. The loss by evaporation depends on the air temperature, air movement,' and humidity; it is increased if the humidity is reduced. For the usual conditions of heating by radiators or convectors, where the air tempera ture ranges from 70 F to 73 F, approximately 75 per cent of the total heat loss of 400 Btu per hour occurs by radiation and convection, and the balance, or 100 Btu per hour, occurs by evaporation. In the case of radiant heating, if the air temperature is reduced to 60 F, 84 per cent of the 400 Btu per hour, or 336 Btu per hour, is lost by radiation and con vection, and 64 Btu per hour are lost by evaporation. The mean normal surface temperature of the human body, taken over the whole area, including not only the exposed skin surface but also sur faces of the clothes and the hair, has been very extensively used as 75 F, particularly in British literature. However, results obtained by Aldrich* in rooms in which the air and wall surface temperatures were approxi mately 72 F gave mean values nearer to 83 F than 75 F. The mean body surface temperature which will maintain the optimum heat loss by radiation and convection, in a uniform environment of 72 F may be calculated from fundamental equations for radiation and natural convection by substituting a comparable cylinder for the body. Heilman' gives the following equations: *-[(&)-(] <> where *--(*)" * ()" * (w)"" . Ht = heat loss by radiation in Btu per square foot per hour. Hc = heat loss by convection in Btu per square foot per hour. TB = absolute temperature of the body surface in degrees Fahrenheit. . fw = absolute temperature of the walls in degrees Fahrenheit. Fa = absolute temperature of the air in degrees Fahrenheit. TM _ Ts-f-7'a D = diameter of cylinder in inches. e = the ratio of actual emission to black body emission. By assuming for a normal adult an average height of 5 ft 8 in. and an average body surface of 19.5 sq ft, an equivalent diameter of 13.15 in. is obtained. The value of e for skin and clothing is practically 0.95. If both jPa and T,, are taken as 72 F, or 532 absolute, and the sum of Hr and Hc is made 15.4 Btu per square foot per hour, solution of these equations gives a value of approximately 83 F for the normal, temperature *A study of Body Radiation, by L. B. Aldrich (Smithsonian Miscellaneous Collections, Vol. 81. No. 6. December. 1928). .. .. 'Surface Heat Transmission, by R. H. Heilman {Trans. A.S.M.E.. Fuels and Steam Power Section. Vol. 51, No. 22. September-December, 1929). . 534 Chapter 37--Radiant Heating of the body surface. This agrees more closely with the values obtained by Aldrich than with the 75 F used by British investigators. British Equivalent Temperature , The British equivalent temperature (BET) is an index number used in radiant heating considerations which indicates the rate of heat loss, by radiation and convection only, from a body in still air maintained at a surface temperature of 83 F. As originally defined, this index was based on a surface temperature of 75 F, but 83 F has been accepted as giving results more nearly conforming with American practice4. When the mean radiant temperature is the same as the air temperature, this value is also that of.the BET, but when there is a difference between the two, the BET is always intermediate. The higher the BET, the less the heat loss from the body, the rate of loss in still air being approximately proportional to the difference between the BET and the mean body surface temperature. If the BET were 83 F, there could be no loss of heat 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. When convected heat is used, the temperatures of the air and walls are nearly the same, and the optimum value of the BET from the physio logical point of view is 72 deg Fahr. Under these conditions the mean surface temperature of a normal body would have the optimum value of 83 F because the rate of heat loss by radiation and convection would be 15.4 Btu per square foot per hour and that by evaporation, 5.1 Btu per square foot per hour, which would just balance the rate of heat production of 20.5 Btu per square foot per hour. This BET of 72 deg Fahr in a uni form environment is exactly equivalent to the effective temperature of 66 deg Fahr as defined by the American Society of Heating and Ventilating Engineers (see Chapter 2), because, in a uniform environ ment, a dry bulb temperature of 72 F in still air with a relative humidity of 30 per cent gives an effective temperature of 66 deg Fahr, which has been determined to be the optimum. In radiant heating, where the air may differ considerably in tempera ture from the surrounding objects, a change occurs in the relations among the heat lost by radiation, convection, and evaporation. It would seem, therefore, that a modification should be made in the optimum BET. If the air temperature drops as low as 60 F the heat loss by evapor ation is reduced to 64 Btu per hour, and that by radiation and convection must be increased to 336 Btu per hour in order to maintain the total loss of 400 Btu per hour needed for optimum comfort. This 336 Btu per hour, or 17.2 Btu per square foot per hour, corresponds to a BET of 71 deg Fahr. Hence, for all practical purposes, the optimum BET of 72 deg Fahr may be regarded as applicable to both convection heating and radiant heating. METHODS OF APPLICATION There are two general methods of application of radiant heating, as follow: Application of the Eupatheoscope for Measuring the Performance of Direct Radiators and Convectors in Terms of Equivalent Temperatures, by A. C. Willard, A. P. Kratz, and M. K. Fahnestock (A.S.H.V.E. Journal, Heating, Piping and Air Conditioning, July, 1933). 535 American Society of Heating and Ventilating Engineers Guide, 1934 1. By warming the interior surfaces of the building. Pipe coils are embedded in the concrete or plaster of the walls, ceiling or floors, the heating medium being hot water or, in some cases, steam. The temperature of the heating medium should not exceed about 120 F on account of the possibility of cracking the plaster. The area of the panel can be sufficient to supply the requisite quantity of heat at this low temperature. This has the effect of warming the entire concrete or plaster surface in which the pipes are embedded. When carefully designed, this method produces comfortable and economical results. 2. By separate heated plates or panels attached to the interior surfaces of the structure. These plates or panels are placed either in an insulated recess and flush with the surface of the walls or ceiling or bolted on its face, and may be decorated as desired. As it is difficult to make an invisible joint between the edge of such a plate and the plaster, it is common to use a frame, either of plaster, wood, metal or composition, around the panel itself. These plates may be placed either on the ceiling or the wall, or in some cases as a margin around the edge of the floor. If floor heating is required the temperature over the whole area should not exceed 70 F. They may be erected conveniently in the form of a dado along the whole length of a long room, as for example, a hospital ward, or they may be designed to form part of the panelling under a window, or in other positions. They are capable of a wide variety of applications. If the entire warm surface is installed at one end of the room there may be a marked difference between the BET on the two sides of a body in the room. It is usually desirable therefore that the heat be distributed at different points in the room so that no uncomfortable effects will be felt from unequal heating. PRINCIPLES OF CALCULATION The calculations for radiant heating are entirely different from those for convective heating. The purpose of the latter is to determine the rate of heat loss from the room by conduction, convection-and radiation when maintained in the desired condition; radiant heating involves the regu lation of the rate of-heat loss per square foot from the human body. The first step in the calculations for radiant heating is to ascertain the necessary mean radiant temperature (MRT); next, the size, temperature and disposition of the heating surfaces required in the room to produce this MRT are estimated; and after this the determination of the convec tive heat is made. Mean Radiant Temperature If the whole of the interior surface of a room were at the same tempera ture, this temperature would represent the MRT. Such a condition 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 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. 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 536 . Chapter 37--Radiant Heating are added together, the gross total amount of radiant heat discharged into the room by the wall surface per hour is obtained. This quantity, divided by the total interior surface, gives the average amount of heat coming into the room from the surface of the walls per square foot of surface per hour. \ According to 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 Table 1. Total Black Body Radiation to Surroundings of Absolute Zero11 Boot OB Mean Radiant Temper ATUBE Deg Fahr Radiation in Btu per square foot per hour emitted to surroundings with a tempera ture. of absolute sero by bodies at various temperatures and with emissivity factor e e 1.00 e 0.95 e 0.90 'e 0.80 Boot OB Mean Radiant Temper ATUBE Deg Fahr Radiation in Btu per square foot per hour emitted to surroundings with a temperature of absolute sero by bodies at various temperatures and with emissivity factor o e 1.00 e 0.95 e 0.90 t 0.80 30 99.3 94.3 89.4 79.4 71 136.5 129.6 122.9 109.3 35 103.5 98.3 93.2 82.8 72 137.4 130.5 123.6 109.9 40 107.6 102.4 96.8 86.1 73 138.4 131.5 124.5 110.6 45 112.1 106.5 100.9 89.7 74 139.6 132.6 125.6 111.7 46 112.9 107.3 101.6 90.4 75 141.0 133.9 126.9 112.8 47 113.9 108.2 102.5 91.1 80 146.6 139.4 132.0 117.4 48 114.8 109.1 . 103.4 91.9 85 152.3 144.6 137.1 121.9 49 115.6 109.9 104.1 92.4 90 157.9 149.9 142.1 126.4 50 116.5 110.6 104.9 93.2 100 169.6 161.1 152.6 135.7 51 117.5 111.6 105.8 94.0 110 181.6 172.5 163.5 145.4 52 118.4 112.5 106.5 94.7 120 194.8 185.0 175.4 155.9 53 119.4 113.4 107.4 95.5 130 210.1 199.6 189.1 168.1 54 120.2 114.2 108.2 96.2 140 223.2 212.1 201.0 178.5 55 121.1 115.1 109.0 96.9 150 237.1 225.2 213.5 . 189.7 56 122.1 116.0 109.9 97.7 160 251.1 238.8 226.0 201.0 57 123.1 117.0 110.9 98.5 170 270.5 257.0 243.5 216.4 58 124.0 117.8 111.6 99.2 180 288.0 273.8 259.1 230.4 59 124.9 118.6 112.4 99.9 190 306.5 291.0 275.8 245.1 60 125.8 119.5 113.4 100.7 200 325.2 309.0 292.8 260.3 61 126.6 120.3 114.0 101.4 210 348.0 330.6 313.1 278.4 62 127.7 121.4 114.9 102.2 220 371.5 353.0 334.4 297.1 63 128.6 122.2 115.8 102.9 250 437.8 415.9 394.0 350.2 64 129.6 123.1 116.7 103.7 300 575.0 546.1 517.5 460.0 65 130.5 124.0 117.5 104.4 350 740.0 703.0 666.0 592.0 66 131.6 125.0 118.4 105.4 400 942.1 895.0 847.5 753.5 67 132.5 125.9 119.3 106.0 450 1176.0 1117.0 1059.0 941.0 68 133.5 126.8 120.1 106.8 500 1464.0 1390.0 1318.0 1171.0 69 134.5 127.8 121.1 107.6 550 1791.0 1701.0 1613.0 1434.0 " 135.5 128.8 121.9 108.4 600 2405.0 2284.0 2165.0 1925.0, "These factors are calculated from the formula: where Q- / 0.1723 XT4\ V 100.000.000 / 0 = total black body radiation, Btu per square foot per hour. e -- emissivity. T = absolute temperature, degrees Fahrenheit. 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 the 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 deter .537 American Society of Heating and Ventilating Engineers Guide, 1934 mined, as can also the required air temperature for the corresponding convective effect. The determination of the amount of radiant heating surface needed in a room requires knowledge of the climate, the type of structure, the type of heating, and the surface temperature of the walls. This problem can be solved only on an empirical basis. After some experience, however, it is possible to estimate these variables with a considerable degree of accuracy for any climate or construction. Assume that a mean radiant temperature of 65 F is desired. Table 1 shows that with all the walls at this temperature, and with an emissivity of 0.95, the gross heat emission is 124 Btu per square foot per hour, The total emission of radiation into the room from that surface would there fore bei 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--a,, a%, as, etc.,--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. The following example will illustrate the principles involved: Table 2. Surface Areas, Temperatures and Emissions for a Room of 5760 Cu Ft Area Sq Ft External Wall...................... Glass........................................ Inner Wall............................. Ceiling.................................... Floor........................................ 297 279 480 480 480 Total....--................ ...... 2016 Assumed Surface Temperature (Deo Fahb) 50 45 . 55 55 55 Heat Emission (Btu Per Sq Ft Per Hr) 110.6 106.5 115.1 115.1 115.1 Total Heai Emission from Area (Btu Per Hr) 32,850 29,710 55,250 55,250 55,250 228,310 Example t. 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. ' ` 22S 310 ' The mean radiant temperature of the room is - on'.fi-- = H.2 Btu per square foot 538 Chapter 37--Radiant Heating 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 of 19.5 sq ft, under conditions of comfort with a body surface temperature of 83 F, the heat given off by radiation may be determined by means of Equation 1 as 217 Btu per hour, or 11.1 Btu per square foot per hour. This corresponds to an environmental emission of 142 -- 11.1 = 130.9 Btu per square foot per hour, and according to Table 1, to an MRT of 72 F. If this body be placed in the room described, it would lose heat at the rate of 19.5 (142 -- 113.2) = 562 Btu per hour. This loss is 345 Btu per hour, or 17.7 Btu per square foot per hour, more than the rate of heat loss for comfort, which is only 19.5 (142 -- 130.9) = 217 Btu per hour. In order to determine the amount of radiating surface necessary to maintain the MRT at 72 F, assume the surface temperature of the hot plates to be installed to be 200 F, which is approximately the temperature they would have if heated by steam. The 2016 sq ft total area of the surfaces of the room multiplied by 130.9, 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 263,890 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 263,890 Btu desired. The additional heat needed is the difference between these figures, or 35,580 Btu. Since, from Table 1, the emission per square foot at 200 F is 309 Btu, the required radiant 35 580 heating surface needed is gqg~ = 115 square feet. 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. It is necessary also to calculate how much heat will be given off by the same surfaces by convection, and thereby to determine whether this amount of convected heat will warm entering ventilating air to the tem perature maintained. If it will not, additional convection surfaces must be introduced to make up the balance. ' In the solution of this particular example, the radiation loss from the human body was selected as 217 Btu per hour, which is that taking place under optimum comfort conditions, with a body surface temperature of 83 F in a uniform environment at 72 F. The mean radiant temperature necessarily was 72 F. If the optimum BET of 72 deg Fahr is desired, an air temperature of 72 F also must be maintained. If it is desired to maintain a lower air temperature than this, a mean radiant temperature greater than 72 F must be selected and the radiation loss from the in dividual must be recalculated from Equation 1. 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 60 F to 70 F. It would, therefore, be necessary only to multiply the respective areas by the appropriate factors, and to add the results, to obtain the required total. MEASUREMENT OF RADIANT HEATING Convection heating, having as its object the raising of the air tempera ture to a specified degree, must be measured by thermometric methods which indicate essentially the air temperature, and not the rate of heat loss from the human body. Radiant heating, having as its object the control of the rate of.heat loss from the human body, can be measured only by methods which basically are calorimetric, that is, which measure 539 American Society of Heating and Ventilating Engineers Guide, 1934 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 83 F (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 BET of 72 deg Fahr 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 rate of 15.4 Btu per square foot per hour, 15.4 which corresponds to 3.415 4.5 watts pier square foot of exposed surface. 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 in the vessel is increased or decreased. A modifi cation 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 about 6 in. to 9 in. in diameter, usually made of thin copper and painted black. The temperature thus recorded is termed the radiation-convection temperature. REFERENCES A.S.H.V.E. paper" entitled Room Warming by Radiation, by A. H. Barker (A.S.H.V.E. Transactions Vol. 38, 1932). . Panel Warming, by L. J. Fowler (A.S.H.V.E. Transactions, Vol. 36, 1930). Calculations for Radiant Heating, by T. Napier Adlam (Heating and Ventilating, October, 1931). . Principles of Calculation of Low Temperature Radiant Heating, by A. H. Barker (paper presented before The Institution of Heating and Ventilating Engineers, London, December, 1931). Application of the Eupatheoscope for Measuring the Performance of Direct Radiators and Convectors in Terms of Equivalent Temperatures, by A. C. Willard, A. P. Kratz and M. K. Fahnestock (A.S.H.V.E. Journal Section, Heating, Piping and Air Con ditioning, July, 1933). 540 Chapter 38 ELECTRICAL HEATING Resistors, Heating Elements, Electric Heaters, Unit Heaters, Central Fan Heating, Electric Steam Heating, Electric Hot Water Heating, Heat Pump, Control, Calculating Capacities, Potcer Problems, Electric Heating Data . WHILE it is improbable that electricity will ever replace fuels as the . main source of heat, this type of heating has a logical and a rapidly growing place in the heating industry due to its advantages, such as flexibility, cleanliness, safety, convenience, and ease of control. Electric heating practice has many basic principles in common with fuel heating, but there are also important differences. The advantages of good building insulation are even more important in electric heating than for fuel heating, because the initial cost per Btu is usually higher. All heat is a form of energy. Fuels hold stored chemical energy which is released into heat by combustion. Electrical power is a form of energy which can be released into heat by passing it through a resisting material. Both fuel and electric heating have two divisions: first, the conversion of energy into heat; second, the distribution and practical use of the heat after it is produced. ' In converting the chemical energy of fuels into heat by combustion, there is necessarily a considerable variation in thermal efficiency. This is not true, however, when converting electric power into heat, because 100 per cent of the energy applied in the resistor is always transformed into heat. In electric heating practice the engineer need not be concerned about efficiencies of heat production, but rather about efficiencies of heat utilization. DEFINITIONS Definitions of terms used in fuel heating are given in Chapter 42. 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 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 and is heated by an alternating current of electricity passing through it. . 541 American Society of Heating and Ventilating Engineers Guide, 1934 HEATING ELEMENTS Commercial electric heating elements are divided into open type elements, enclosed type elements, and cloth fabrics. Open type elements have resistors exposed to view. The resistors may be coils of. wire or metal ribbon, supported by refractory insulation, or they may be nonmetallic rods, mounted on insulators. Open type elements are used extensively for operation at high temperatures when radiant heat is desired. They are also frequently used at low temperatures for convec tion and fan circulation heating, especially in large installations. Enclosed type elements have metallic resistors embedded in a refractory insulating material, and encased in a protective sheath of metal. Fins or extended surfaces may be used to add heat dissipating area. Enclosed elements are made in many forms, such as strips, rings,_ plates, and tubes. Strip elements are used for clamping to surfaces requiring heat by con duction, and in convection and fan circulation air heaters. Ring and plate elements are used in electric ranges, waffle irons, and ip many small air heaters. Tubular elements may be immersed in liquids, cast into metal, and, when formed into coils, used in electric ranges and air heaters. Cloth fabrics woven from flexible resistor wires and asbestos thread, are used for many low temperature purposes. ELECTRIC HEATERS Electric heaters are classified according to the manner in which they deliver heat in practical use, that is, by conduction, by radiation, or by convection. The term radiator should not be used in electric heating, because of confusion between its established usage in fuel heating and the radiant principle of many electric heaters. Among the uses of conduction electric heaters, which deliver most of their heat by actual contact with the object to be heated, are aviators' cloth ing, hot pads, foot warmers, soil heaters, ice melters, and pipe heaters. Conduction heaters are useful in conserving and localizing heat delivery at definite points. They are not suitable for general air -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 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. The location of radiant heaters is important. They should never face a window as some rays pass through glass and are lost. Figs. 1 and 2 show common types of portable and wall-mounted radiant heaters. Convection electric_ heaters, designed to induce thermal air circulation, deliver heat largely by convection, and should be located and used in much the same manner as steam and hot water radiators or convectors. They should have heating elements of large area, with moderate surface temperature, enclosed to give proper stack effect to draw cold air from the floor line (Figs. 3 and 4). The flexibility possible with electric heating 542 . Chapter 38--Electrical Heating elements should discourage the use of secondary mediums for heat transfer. Water and steam add nothing to the efficiency of an electric heater and entail expensive construction. UNIT HEATERS Fan unit electric heaters, having electric heating elements combined in the same enclosure with a fan or blower, are made in many styles and.are excellent for general air heating. They should be located and used much as steam unit heaters. The warm air can be directed toward the floor, if desired, to give a positive circulation which will reduce stratification of Fig. 1. Portable Radiant Electric Heater Fig. 2. Radiant Electric Heater Recessed in Wall Fig. 3. Convection Electric Heater on Wall Surface Fig. 4. Convection Electric Heater Recessed in Wall air. Small units which are free from radio interference are used for homes; there are large units for industrial plants, substations, power houses, and pumping stations; portable units are useful for temporary work, such as drying out damp rooms, or for warming rooms during construction (Figs. 5, 6, 7 and 8). CENTRAL FAN HEATING Central fan electric heating systems have electric heating elements and fans or blowers to circulate the air through ducts, and in addition to the main heaters at the fan location, booster heaters may be located in branch ducts. . Humidification or complete air conditioning can readily be in cluded in the system, in much the same manner as with steam. In coordinating the input of heat energy and the volume of air circu lation, a basic difference between electric heating and steam heating enters into the problem. Steam is approximately a constant-temperature source of heat for any given pressure as a change in air volume flowing over steam coils does not greatly affect the temperature of the delivered 543 American Society of Heating and Ventilating Engineers Guide, 1934 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, being a constant source 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 because the electrical energy input remains constant and the surface temperature of the heating elements will vary as is necessary to force the air to accept all the heat. With electric heat the total heat is constant Fig. 5. Small Portable Fan Unit Electric Heater Fig. 6. Large Industrial Type Port able Fan Unit Electric Heater w tt w t K f Fig. 7. Small Fan Unit Electric Heater Fig. 8. Large Industrial Type Fan Unit Electric Heater unless some compensating action is performed by control. Automatic modulation to vary the electrical heat input and synchronize it properly with the air flow has been successfully applied to Central fan systems: ELECTRIC STEAM HEATING Electric steam heating differs from fuel heating only in the use of electric boilers to generate steam. Small boilers usually have heating elements of the enclosed metal resistor type immersed 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 are made removable for cleaning off deposits of scale which will restrict the heat flow. Boilers of this type 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. Electric boilers are entirely automatic and are well adapted to inter mittent operation. It frequently is economical to shut down the main plant boilers when the heating season ends, and to supply steam for summer needs with small electric boilers located close to the operation, 544 Chapter 38--Electrical Heating 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. In Canada and Europe many successful installations have been made, but in the United States the cost of electric power, in comparison with fuels, does not favor their general use. ELECTRIC HOT WATER HEATING Electric hot water heating occupies much the same position as electric steam heating. It is useful in many moderate-sized installations, but large ones are seldom economical in this country. Electric boilers for supplying domestic needs for hot water are inexpensive, entirely auto matic, and are insulated to. prevent excessive heat losses. Similar boilers in large sizes are useful for industrial needs for hot water. When lower power costs can be secured, by confining the heating to certain fixed hours water may be heated and stored in well-insulated tanks for use when needed. In large industrial plants it is often possible to balance power loads by this means and to avoid running the fuel-fired steam boilers at night or over week ends. In Europe use has been made of this hot water storage principle for heating. Experiments have been made in this country for heating houses, but the cost of serving individual homes with the necessary heavy electric power loads has proved unprofitable at rates comparable to other forms of heating. The problems incident to installing large storage tanks in home basements, and the lack of flexi bility under variable weather conditions, are also unfavorable factors. OIL HEATING Electric hot oil heating is useful in some industrial work as a substitute for superheated steam. Special oil can be electrically heated as high as .600 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. HEAT PUMP The electric heat pump is not strictly an electric heater, as it does not directly convert electrical power into heat. It operates a compressor electrically which 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. This system has been used in evenly-balanced climates where the heating requirements in winter are about the same as the cooling requirements in summer. 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 apply ing local heating, locally controlled. Wherever radiant heaters are used, thermostats are not an effective means of control and manual operation or control by eupatheoscope is necessary. For all convection and fan circulation heaters thermostatic control is useful. For small heaters having ratings up to. about 1500 watts, there are direct-acting thermostats which are satisfactory, but for larger heaters it is advisable to use relays 545 American Society of Heating and Ventilating Engineers Guide, 1934 or contactors, which should break all of the power lines. All heaters having fan circulation should have the heat circuit interlocked with the motor circuit so that the fan will be running when the heat is on. A thermal fuse or trip should be located in the heat chamber to throw off the heat in case any interruption of air flow should' occur; otherwise undue temperature rise would result. In all large heaters the heating elements should.be arranged in groups and control provided to vary the ' heat input to correspond approximately to the heat demand. If this is not done, and all the heat is kept available, the thermostat will continue throwing it on and off at short intervals. Except for central fan systems, the heat stages can be operated by manual switches, but automatic ^modulation of the heat load is usually preferred. 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 POWER PROBLEMS (1) 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. As distribution is a big item in power costs, the best places to use power for heating are large industrial plants which have heavy service lines. Homes are almost universally supplied with lighting current of 115 volts, which cannot be used economically for any but the smallest heaters. Usually the service lines will not permit more than plug-in devices. The underwriters permit- heaters of 1250 watts to be used from approved base board 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 230, 460 or 575 volts. All polyphase heaters should be balanced between phases. ELECTRIC HEATING DATA Electric heater capacity is rated in kilowatts (kw). Electric power is measured in kilowatt-hours (kwh). Cost of operation = kw rating X hours used X cost per kwh. One boiler horsepower (bhp) 33,471.9 Btu per hour One kilowatt-hour (kwh) = 3,415 Btu per hour . One boiler horsepower = = 9.80 kwh 3,415 One boiler horsepower will evaporate 34.5 lb water per hour from and at 212 F. 34 5 One kilowatt-hour = y.o`U = 3.52 lb of water per hour a.t 212 F Additional conversion factors are given in Chapter 42. 546 Chapter 39 WATER SUPPLY PIPING 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 Storage IN the design and layout of domestic water supply systems, the engineer is confronted with the necessity of combining the somewhat empirical rules and formulae in use with the more or less exact hydraulic principles involved. Unlike heating and ventilating layouts, there are practically no definite data for estimating the quantity of water likely to be consumed or the probable rate of water flow at any particular moment. Metered results in one building often show two or three times the metered amount in another building of the same size and with the same type of tenants. In hotels, one riser will often have an almost constant flow that may never be reached by another at peak load. In office buildings, the women's toilets show a far greater daily consumption than those of the men, yet at no time will they approach the hourly consump tion of the men's toilet during the first hour of the day. This condition has led to a multiplicity of rules of practice which vary as much as the data used. All must of necessity be based on an assumed rate of con sumption and on an assumed probability of simultaneous use, and while the formulae employed may have been derived on sound technical bases the assumptions are often in error. To arrive at a safe standard, the approximate rate of flow of each fixture to be supplied must be known and the probable number of fixtures in use at any one time must be assumed. Obviously, the maximum number of fixtures assumed to be in use must be taken at the peak of ,demand and the lines must be made adequate to supply such a peak regardless of the riser or branch on which the demand may occur. This means that all water piping under the usual conditions will be over-sized. In tall buildings it is customary to divide the water supply systems, both hot and cold, into sections of 10 to 20 stories. Such zoning or 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 ft1. __* *It is impractical to attempt to size piping 90 as to produce the proper pressure on fixtures at different levels by employing friction, owing to the fact that this friction will be built up to the amount desired only in times of maximum demand and at all other times the friction will.be only a fraction of the maximum friction so that the fixtures by this method are subjected to a varying pressure on the water supply line. A much more practical method, isjto 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. 647 American Society of Heating and Ventilating Engineers Guide, 1934 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 putlets on all fixtures were opened simultaneously. This condition is seldom, if ever, obtained in actual practice except in cases of gang showers con trolled 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 Number op Fixtures 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. 548 Chapter 39--Water Supply Piping Factor of Usage 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. On the other hand it is probable that outside of flush valve Table 1. Approximate' Flow from Fixtures Under Normal Water Pressures Fixtures Cold Water (Gallons per Minute) Hot Watee (Gallons per Minute) Water-closets, flush valve............ .............. ........... ............. ........... Water-closets, flush tank.................... ............................................ Urinals, flush valve...... .................................................................... Urinals, flush tank............................................................................ Urinals, automatic tank............................................................. . Urinals, perforated pipe per foot........... .................................. .... Lavatories........................ ......... .'........................................................ Showers, 5 to 6J4 in. heads........................................................... Showers, tubular.................... ............ ................................ ............. Needle bath--................... ............................................................... Shampoo spray....... --................................................. ............. . Liver spray.--................................ .................................. ^..... Manicure table....... ..................................................................... 1__ Baths, tub...... --....... ......... .................................... ............... ........ . Kitchen sink...................................................................................... Pantry sink, ordinary...................... -......................... .................... Pantry sink, large bibb...................... .;.___ _________________;... Slop sinks.......................................................................................... Wash trays.......................................... ............................................... 50a 18 40 a 18 1 10 3 3 6 30 1 2. 1H 5 4 *2 6 4 3 0 0 0 0. 0. 0 3 3 6 30; , , 1 .2 1M 5 4 2 6 4 3 Actual tests on water-closet flush valves indicate 40 gpm as the maximum rate of flow with 30 lb pres sure at the valve; this would increase to 60 gpm (about 50 per cent) at 90lb pressure. The50gpm 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 same manner. . fixtures, the factor of usage would never be less than about 25 per cent no matter how many fixtures were installed, provided no fixtures in excess of those required for the actual occupancy were included. This factor, beginning at 100 per cent for two ordinary fixtures, decreases rapidly until 5 fixtures is reached and then becomes almost constant, as shown in the upper curve. Fig. 1. This applies to a normal building and not to institutions where the inmates may all be required, for instance, to bathe on certain days of the week and at certain hours of those days. In such special cases a new factor of usage must be developed based on the maximum probable usage under the conditions involved. For flush valve fixtures the quantity of water is greater, but owing to the short duration of the flush, the simultaneous usage drops more rapidly so as to reach 1 per cent for 1000 fixtures as shown, on lower curve, Fig. I2.* *This can be proved by assuming, for example. 1000 water-closets which would not be used more than six times per hour (or once every 10 minutes) and which require from 5 to 7 gal per flush or an average of about 6 gal. If these closets were all being used at their utmost capacity, the water demand would be 600 gpm. But average use would be about one-third of this and peak-conditions would be in the neigh borhood of twice the average, or about 400 gpm as the maximum that would ever develop. Assuming 50 gpm as the maximum rate of flow.per closet and 1 per cent of the total closets in operation, the rate would be 60 gpm X 1 per cent of 1000 or 500 gpm. This is 100 gpm higher than obtained by the first method indicating an additional factor of safety over the first method. - 549 N! American Society of Heating and Ventilating Engineers Guide, 1934 Example 1. Assume that in a normal building, such as a residential hotel or an apart ment house, there are 50 flush valve water-closets, 50 lavatories, 50 sinks and 50 baths, and that it is desired to determine the maximum probable flow in a line supplying all of these fixtures with both hot and cold water. Fig. 1 shows a maximum probable use for 50 water closets of about 8 per cent and for 150 ordinary fixtures, of about 31 per cent. Therefore: Cold Water 50 W. C. x 50 gpm at 8 per cent......................... 50 Lavs, x 3 gpm...........................................-....... 50 Sinks x 4 gpm........... ......................................... 50 Baths x 5 gpm............................................ ....... 150 Fixtures................. .............................................. Total maximum probable flow of cold water-- ............................................ 200 gpm 150 gpm 200 gpm 250 gpm 600 gpm at 31 per cent 186 gpm .................. .......... ................386 gpm Hot Water 50 W. C._...... ........................................................... 50 Lavs, x 3 gpm.................................................... 50 Sinks x 4 gpm_________ ___ -......................... 50 Baths x 5 gpm.................................................... 150 Fixtures.._____ ____________________________ ... ........ ........ ............................... None 150 gpm 200 gpm 250 gpm 600 gpm at 31 per cent 186 gpm Total for main supplying cold and hot water..................................................... It should be noted that this is a rate offlow or an instantaneous demand. 572 gpm 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, 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 . 550 wuni.ibn UO-- MAICK 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. 150 250 s04 0a4 oO OtcanS 2 oo uWaQ. ooo 2 O> Q too boost WNcoJ c73 oto o9* oco - UnDQ a cto* o04 to o * 5 ta ,,g2 CO 04 04 04 X04 04 X04 X04 X04 S04 04 04 x04 x04 x04 0x4 04 ^04 04 04 XCO X04 X04 04 sO* 304: 04 X04 S04 0s4 X04 0X4 04 0X4 04 0X4 X04 0$4 ^04 034: CO X04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 CO 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 X04 04 04 04 04 09 04 04 04 04 04 04 04 04 04 04 04 Ol 04 04 X04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 X04 04 04 X 5 XH 3 3 3 3 3 3 3 3 3 3 3 3 3 3 35sXX333333333333333 04 5 5 s 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 04 X 5 5 S 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 04 S*-H 5 s 3 3 3 3 3 3 3 3 3335 3 3 3 3 55- s_ - - -H -H ^ ^ ^ ,, _^ . Hn 5 - - - r* ^ W ^ &X SJ it 5; s s s s * x * & 5? S S X s a s & s :s & s; S it **** ^ 'o ^ o o, o i? OS O 82 <2 S - ni/i ij V\ 11 i i i i 1 til e s . s' s 9 O' CO N IO ID M _ .... Z E C..*->! =of**.iSSS2s3 1 11 1 ~> oPS e- eoasoo.Ofcs u * "> - * o t*. q o os x A <N.<N 6 os i! 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 551 American Society of Heating and Ventilating Engineers Guide, 1934 ' pipe friction plus that introduced by the pipe fittings, all of which produce an excessive drop when compared to the conditions existing with a down- feed 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 the pipe fittings. Table 3 gives the additional lengths necessary to allow for the various fittings and valves. The drop allowable in pressure per 100 ft of run may then be obtained by multiplying the surplus pressure (over that required for the gravity head and to supply 15 lb at the fixture) by 100 and by dividing this by the equivalent length of run to the farthest or highest fixture. . 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 pressure which will be available for pressure drop will then be . 60 lb - (15 lb -f 50 ft X 0.43 lb) = . .; . 60 lb - (15 lb + 21.5 lb) =. 23.5 lb To change this into drop per 100 ft: 23.5 lb X 100 200 ft + 100 ft 7.8 lb per 100 ft. The pipe may then be sized from the maximum probable flow by selecting a size that does not give a drop in excess of 7.8 lb per 100 ft. 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 3. Approximate Allowances for Fittings and Valves in Feet of Straight Pipe Sob of Pips . (Inches) J4 H l 1)4 2 VY, 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 Type of Fittinq or Valve Return Bend . Gate Valve 82 10 3 10 3 12 3 14 4 14 4 20 5 24 6 36 9 50 13 60 15 Globe Valve 48 60 60 72 84 84 120 144 216 300 360 Angle Valve. 8 10 10 12 14 14 20 24 36 50 60 Chapter 39--Water Supply Piping 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), flush tank water-closets are sub stituted, or a separate cold and hot water supply is installed with a small pneumatic tank to give the increase in pressure necessary.: The chief objection to the use of a pneumatic tank is that a separate hot water heater is required and this heater must be located either sufficiently below the highest fixtures to obtain a gravity circulation, or it must be provided with a. circulating pump in order to force the hot water to the top floor level. .. The most common solution is to place the house tank as high as the structural and architectural. conditions will permit and then to use liberally-sized lines between the house tank and the upper fixtures, say for the two top stories, below which the riser sizes may be reduced to those indicated in Fig. 2 and Table 2. Where the house tank is only one story above the top fixtures, flush tank water-closets must be used and the drop in the entire run from the house tank down to the farthest fixture should not exceed 1 lb; the less, the better. This means that if the total equivalent run to the farthest top fixtures supplied is 300 ft, the drop per 100 ft should not exceed 1 100 or 0.33 lb per 100 ft. The friction curves shown in Fig. 3 may be used for quickly determining the proper size of pipe to give any desired drop in pounds per 100 ft ofequivalent run. SIZING AN OVERHEAD DISTRIBUTION MAIN Example 3. Suppose an installation has a house tank in which the water line is 20 ft above the level of the top fixtures to be supplied and that the length of run to the farthest fixtures on this level is 400 ft with the pipe fittings adding another 200 ft, making an equivalent length of 600 ft. What would be the size of main coming out of the tank where a maximum flow rate of 400 gpm may be expected, of the horizontal main where a maximum flow rate of 200 gpm may be expected and of the riser down to the fixture level where the maximum flow rate is approximately 100 gpm? Here the level of the water in the house tank is 20 ft above the faucet of the highest fixture and the gravity pressure will be 0.431b X 20 ft = 8.61b '. 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 itr 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 553 American Society of Heating and Ventilating Engineers Guide, 1934 would be. sufficient, and that where the flow is 100 gpm in the riser branch and riser, a 5-in. size would be correct. Of course these are somewhat excessive flows and the head from the tank is small so that large sizes are to be expected. It would be necessary to carry a 5-in. riser down to the branch to the top floor, then reduce to 4 in. for the . branch to the floor below the top, and below this the sizes in Table 2 could be followed. In such a case, flush tank closets should doubtless be substituted. Had the tank been set 10 ft higher, the head available to be used up in friction, but Fig. 3. Chart Giving Friction Losses 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 lb + 4.3 lb or 5.3 lb which, divided by the600 ft'equivalent run gives a drop per 100 ft of 5.3 X 100 or 0.9 lb 600 and, with this drop, the sizes according to the chart (Fig. 3) are 6 in., 4 in., and 4 in., 554 JJ Chapter 39--Water Supply Piping respectively, while if the run is reduced to 200 ft instead of 600 ft, the allowable drop will 5.3 lb X 100 200 or 2.7 lb per 100 ft. This gives 5 in., 4 in., and 3 in., respectively, for the flows of 400, 200, and 100 gpm. Water Line - * House Tank-t'" r* House Supply Fire Reserve i_ 199 199 4 8th. -*. 4W.C.-F.V. 2U.-F.V. 3 Lav. 179 2i 7th. , 165 2 6th. 4W.C.-F.V. 2U.-F.V. 3lav. 4W.C.-F.V. 2 U.-F. V. 3 Lav. 4' 296 202 V 6W.C.-F.V 4 Lav. 5* H-H* 297 si is.s. 189 2>" 2 6W.C.-F.V. 4 Lav. . ` 182 2- 6W.C-F.V. 4 Lav. 136 2 st" 1S.S. 134 134 T 1S.S. 134 2 5th. 4W.C.-F.V. 2 U.-F. V. 3 Lav. 173 2" 6W.C.-F.V. 4 Lav. 133 133 2* 1 S. S. 19 1* 4th. 10 Lav. . 4W.C.-F.V. 164 2 2 U.-F. V. | > 3 lav. 131 2" 3 W.C.-F.V. 1 Lav. las." 10 lias. 3rd. . I-*. . 149 2 4W.C.-F.V. 2 U.-F. V. .. 3 Lav. ' 129 2" 2 Lav. 8 1 iaa 2nd *--k- 98 2W.C.-F.V. 1 U.-F. V. 1 Lav. 127 * 3W.C.-F.V. 1 Lav. 4 3* 4 i a s. 1st 50 l! 1W.C.-F.V. ' 4 3" 4 1S.S. (2) (3) Fig. 4. Typical Layout for Down-Feed System 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 J>. 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 555 American Society of Heating and Ventilating Engineers Guide, 1934 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. . 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 v Table 4. Typical Calculation of Pipe Sizes on Down-Feed Riser with Flush Valve Water-Closets and Urinals Riser No, 1 Floor of Bldg. Fixtures on Floor . GPM PER Fext. Max. Fixt. GPM Probable Use (per cent) Probable Fixt. GPM Probable Allowable Riser GPM Drop Lb per 100 ft Pipe Size In. 1st . IS.S. . . '4. . 4 ZOO ... 4. 2nd 1S.S. 4 4 100 4 3rd 1 s. s. .4 4 3 12 ' 80 4th 10 Lav. 3 30 13 .. .42 . 45 5th 4 W. C. 50 2 U. 40 200 80 6 3 Lav. . 280 . 40 39 16 51 45 10 19 . 112 . 22 6th 4 W.C; 50 2 Xj. 40 12 3 Lav. 3 19 200 80 560 25 9 60 42 140 25 7th 4 W. C. 50 2 U. 40 18 . 3 Lav. .. ........ 3 22 200 80 840 18 9 69 40 151 28 8th . 4 W. C. . 50 2 U. 40 24 3 Lav. -3 25 200 80 1120 9 78 15 168 40 31 . . :--r-- 4 30 8. . .30 ' x A 10 *30- K 19 . 30 1 134 30 2 165 30 2 179 199. 30 . 2M ; 24 tank must be sized on the basis of a drop of 21b per 100 ft. Tables 4; 5, 6 and 7 showthe 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 8 and 9. 556 Chapter 39-^Water Supply Piping tloor when a house .tank is the--so--u--r--c--e----o- -f- wa..tteMr purceisusyurae.ie suDstituted'O' n the uppermost 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 Table 5. Typical Calculation of Pipe Sizes on Down-Feed Riser with Flush Valve Water-Closets and Urinals Riser No. S Floor of Blog. Fixture 5 on Floor GPM . PER Fixt. 1st 2nd 3rd 1 w. c. 2 W. C. 1 u. 4 1 Lav. 4 W. C. 2 U. 10 3 Lav. 4 50 50 40 3 50 40 3 4 W. C. ; 2 u. 16 3 Lav. 7 50 40 3 6 W. C. 22 . 4 Lav. 11 50 3 6 W. C. 28 4 Lav. 15 -___ 7th 6 W. C. 34 4 Lav. 19 8th 6 W. C. 40 4 Lav. 23 50 3 50 3 50 3 Max. Fixt. GPM .- 50 100 40 190 3 200 SO - 470 9 12 200 80 750 9 21 300 1050 12 33 300 1350 12 45 300 1650 12 57 300 1950 12 69 Probabl b Use (per ceni0 Probabl.b Fixt.- GPM Probabl b Allowable Riser Drop . gpm LBPBR 100 Ft Pipe Size Itr. 100 50 50 . 30 IX 50 100 30 70 95 3 . 141 8 98 149 3d. : ix . 30 2 20 150 70 14 164 15 157 ... 48 16 173 12 162 45 20 182 10 . 42 165 . 24 189 9 175 40 27 202 30 2 30 2 30 2 - 30 2X 24 0.43 lb X 80 or 34.4 lb 557 per 100 ft. . American Society of Heating and Ventilating Engineers Guide, 1934 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 Id which may be used up in friction. If the distance from the Table 6. Typical Calculation of Pipe Sizes on Down-Feed Riser with Flush Valve Water-Closets and Urinals Riser No. S Floor of Bloc. Fixtures on Floor GPM PER Fixt. Max. Fixt. GPM Probable Use per cent) Probable Fixt. gpm Probable Riser gpm Allowable Drop Lb per 100 ft Pipe Size In. 1st 2nd 1 S. S. 3 W. C. 1 Lav. 2 4 50 3 4 150 3 7 100 80 100 4 120 7 4 127 30 X 30 2 3rd o w. c. 0 3 2 Lav. 3 4 000 150 6 13 80 70 120 9 129 30 ` 2 4th 5th 6th 7th 8th 3 W. C. 6 1 Lav. 1 S. S. 6 0 w. c. 6 1 S. S. 7 ow.c. 6 1 S. S. 8 ow.c. 6 1 S. S. 9 ow. c. 6 1 s. s. 10 50 43 0 4 0 4 0 4 0 4 150 300 3 4 20 000 300 4 24 000 300 4 28 000 300 4 32 000 300 4 . 36 40 55 40 53 40 51 40 50 40 48 120 11 131 30 2 120 13 133 30 2 120 14 _ 134 30 2 120 16 136 1 30 2H 120 17 137 23 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 even 300 ft. Then the allowable drop per 100 ft will be 25.6 lb X 100 _ . ---300--------or8'51b . and the sizes shown in Fig. 5 are based on this amount of drop. Of course the other 558 J Chapter 39--Water Supply Piping risers will have the same maximum flows at the bottom as they formerly had at the top, namely 202 and 137 gal, respectively, for Risers Nos. 2 and 3. Combining these maxi mum flows in the same manner as pursued in the down-feed system it is seen that the maximum flow between Riser No. 2 and Riser No. 3 is 296 gpm, and between Riser No. 3 and the street main, 297 gpm which at a drop of 8.5 lb gives the main sizes indicated. It will be noted that in determining the maximum flow in an up-feed riser Table 7. Size of Distribution Main for Down-Feed Systems. (See Fig. 4) Riser No. 1 2 3 Fixtures GPM PER Fixture 16 W. C. 8 U. 24 22 Lav. 3 S. S. 25 50 40 3 4 35 W. C. 5 U. 64 23 Lav. 48 50 40 3 6 W. C. 70 4 Lav. 6 S. S. 58 50 3 4 Maximum Fixture GPM 800 320 1120 66 12 78 1750 200 3070 69 147 300 3370 12 24 183 Probable Use (Per Cent) 15 40 8 35 7 33 Probable gpm 168 31 199 245 51 296 236 61 297 Allowable Drop (Lb per 100 Ft) Size of Main (Inches) 24 25 25 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 on account of the many plumbing fixtures having 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 in variably 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 follow: 1. By using the plain up-feed with a return carried back from the top of the riser-and paralleling it. 2. By carrying a supply riser up in one location thus supplying fixtures on up-feed, then crossing over at the top and coming down past another collection of fixtures and supplying these by a down-feed. 3. By carrying all of'the water to the top of the building and dropping risers wherever needed, feeding all hot water on a down-feed system. 559 / American Society of Heating and Ventilating Engineers Guide, 1934 Table 8. Typical Calculation of Pipe Sizes on Down-Feed Risers with Flush Tank Water-Closets and Urinals on Top Floor Only Bldg. Floor GPM Fixt. Max. Fixt. GPM Probable Use (per cent) Probable Use GPM Probable Riser GPM Allowable Drop Lb per 100 ft Pipe . Size In. 7th and below 612 W. C. U. 18 19 Lav. . 3 S. S. 22 8th 0 W. C. 0 U. 18 4 W. C. 2 U. . 3 Lav. 31 50 40 3 4 0000 18 18 3 Riser No. i 600 240 840 - is i 57 12 69 40 | 000 000 840 72 36 9 18 186 37 151 28 151 69 179 220 30 '2H 3.3 4 7th and below 29 W. C. 6 U. OA 19 Lav. 8 th 0 W. C. 0 U. 34 6 W. C. 4 Lav. 29 50 40 3 00 00 18 3 Riser No. 2 1450 200 1650 57 000 000 1650 108 12 177 10 42 10 38 165 24 165 67 189 232 30. 2*4 3.3 4' 7th and below 6 W. C. 5 S. S. 4 Lav. 9 Sth 0 w. c. 6 I S. S. 10 50 4 *3 00 4 Riser No. S 300 40 , 120 20 12 32 50 16 000 300 40 4 120 36 48 17 -- 560 136 137 30 2K 3.3 3 J Chapter 39--Water Supply Piping' The last method is usually the most satisfactory. (See Fig. 6). 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 beless 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. 7. 8th. 7th. 6th. 5th. : 4W.C.-F.V. 2U.-F.V. | 3 Lav. 4W.C.-F.V. 2l 2U.-F.V. JL 3Lav- 1W.C.-F.V. 2j 2U.-F.V. j 3 Lav. 4W.C.-F.V. 2i 2U.-F.V. | 3 Lav. 3" 10 Uv. 4th. 3" 1S.S. 3rd. 3" 1S.S. 2nd 3' IS.S. 1st r 3" Main (1) Fig. 5. Up-Feed System For the second arrangement of hot water risers, circulation lines are run back from the last fixture supplied to the main return circulation line in the same manner as just described, using % in. for the near risers and 1 in. for the far risers. The sizing is much more difficult, as it is necessary to start at the bottom floor of the return riser and work back to the top of this riser and then carry the maximum flow across onto 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 561 American Society of Heating and Ventilating Engineers Guide, 1934 f*- '! t Sf t >t 1 (a) 1\ Supply . Supply \1 . Supply rt t j t t 1 (6) - 1 \ ^Q. <C3/}L 1 1 T1 1 1 / Vent -- 1V | __^ \^ . 1_ \ tt | 1 a s} i I ' i y /> y So? 1\ -^ y >s a. C3L CO --> aa3>*. 00 1 ti 1 T 1 f /W S<F <c) Fig. 6. Methods of Arranging Hot Water Circulation Lines water risers which do not have the combined up- and down-travel which the hot water must make. In the third and most common arrangement all of the water is carried 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 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 botton of each riser should be arranged in the manner already outlined and any riser not going to the basement to Table 9. Summary of Riser Sizes to Give Main Sizes Riser No. 1 Fixtures GPM PER Fixture 12 W. C. 6 U. 18 31 Fixt. 50 40 29 W. C. 5 U. 50 40 52 2 29 Fixt. 60 6 W. C. 50 58 10 Fixt. 3 70 Riser GPM 600 240 840 186 1450 200 2490 177 363 300 2790 . 36 - -- 399 Probable Use (Per Cent) Probable GPM Allowable Drop (Lb per 100 Ft) Size of Main (Inches) 18 151 37 69 220 3.3 4 8 199 33 120 319 3.3 4 7 195 33 131 326 3.3 4 562 IT Chapter 39--Water Supply Piping Table 10. Typical Calculation of Pipe Sizes on Up-Feed Riser with Flush Valve Water-Closets and Urinals Floor of Bldg. Fixtures on Floor Gras PER Fixt. Max. Fixt. gpm Probablit Use (per cent ) Probablii Fixt. GPM Probable Riser gpm Allowable Drop (Lb per 100 ft) Pipe Size In. 8th 4 W. C. 2 U. 6 3 Lav. 7th 4 W. C. 2 U. . 12 3 Lav. 6 6th 4 W. C. 2 U. 18 3 Lav. 9 5th 4 W. C. 2 U. 24 3 Lav. 12 4th 24 W. C.* and U. 10 Lav. 22 3rd 24 W. C.* and U. 1 S. S. 23 2nd 24 W. C. and U. 1 S. S. 24 1st 24 W. C. and U. 1 S. S. 25 rrom floors above. 50 40 3 SO 40 3 50 40 3 50 40 3 3 4 4 4 Riser No. 1 200 80 280 9 200 80 560 9 18 200 80 840 9 27 200 80 1120 9 36 40 80 25 55 18 50 15 47 112 7 119 140 10 150 151 14 165 168 17 185 1120 30 66 15 40 168 27 195 1120 4 70 15 40 168 28 196 1120 4 74 15 40 168 30 198 1120 4 78 15 40 168 31 199 8.5 2H 8.5 "" ' 8.5 2M 8.5 ' 3 8.5 3 8.5 3 8.5 3 8.5 3" -- / Y i American Society 0/ Heating and Ventilating Engineers Guide, 1934 supply fixtures must have these returns carried down to the basement from the termination of the supply riser at whatever level it may end. 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 Fig. 7. Supply and Return Main Connections for Hot Water Supply System some means of heating the water and in this respect it is necessary to pass from the maximum probable flow to the maximum probable hourly demand, which is quite different. If an instantaneous heater were used, it would require adequate capacity to provide for the heating of the water as fast as it is drawn and a heater of this type should be sized on the basis of the maximum probable flow with the accompanying heavy drafts on the heating device and with intervals of no draft at all. To balance these inequalities of flow the storage-type heater is often utilized so that the water demand can be heated during periods of light demand and stored up for use during the periods of heavy demand. The total water con sumption per person usually varies between 100 and 150 gal per day when 564 . 3 Chapter 39--Water Supply Piping 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 provided for by storage in the hot water tank where this water is heated during hours when the demand is below the average. HOT WATER STORAGE 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 and this is an average of 500 X 40 gal or 20,000 gal 20,000 24 galor 833 gph but the peak hour will require Ho of 20,000 or 2,000 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 2,000 - 833 or 1167 gal so that the storage capacity, based on 75. per cent being available from this capacity without cooling the tank excessively, will be 1167 . or 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 2,000 - 1200 or 800 gal as the shortage during the peak hour, and the necessary storage will be 800 gal nc_ . 075 or 1067 gal; or the heating capacity can be increased to 1500 gal, leaving a shortage of 2000 - 1500 or 500 gal 565 American Society of. Heating and Ventilating Engineers Guide, 1934 Table 11. Ordinary Maximum Hourly Demand for Hot Water for Various Fixtures in Gallons and Probable Percentage of Usage Tm or Buildinq Maximum Pbobable Usage GPM Lavatories Private Public SinksSaowsBS Slop [Kitchen Pantkt Sinks Sinks Foot Baths Wish Teats Av. Max. Use* 20 20 Probable Usage in Per Cent of Maximum Ordinary Apt. House Club Gym. Hospital Hotel Industrial Laundries Office Bldg. Baths Residences Schools Y. M. C. A. 25 25 25 25 25 25 25 25 25 25 25 25 50 75 100 .75 100 150 100 75 150 75 100 33 50 100 50 50 100 150 50 100 67 67 100 33 33 100 __ _ 100 33 100 100 67 _6_7 67 100 67 33 50 50 50 67 67 33 67 .... 67 67 67 -- .... __ ' 33 33 67 50 100 -- 100 100 --. 50 100 100 25 25 100 25 25 100 -- -- -- 50 50 100 60 80 "80 80 100 60 "80 35 60 80 45 70 90 100 20 100 50 25 75 aPercentage of fixtures likely to be c Table 12. Hot Water Consumption in Various Types of Buildings for Different Purposes Ttps or Building Conditions Gallons , Hotels Public . Buildings - Industrial Buildings Restaurant 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 dhy) . 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 $0.50 Meals 2 (per day) 5 (per day) , 3 (per 1000 sq ft per day) 0.5 (per customer with hand washing) 1.0 (per customer with machine $1.00 Meals 1.0 (per customer with hand washing) 2.0 (tier customer with^ machine $1.50 Meals 1.5 (per customer with hand washing) 4.0 (per customer with machine washing) 566 Chapter 39--Water Supply Piping and the storage required only 500 or 667 gal. 0.75 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. 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 3)4 sq ft* of equivalent steam heating surface (radiation) must be provided for every gallon of water heated .100 deg 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) 2916 4200 5250 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. 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 11 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 12 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? 20 Baths at 40 gal and 33 per cent................................................................. 270 gal 20 Lavs, at 20 gal and 25 per cent................. ................................................ 100 gal 20 Sinks at 30 gal and 33 per cent..............................-................................... 200 gal 20 Trays at 50 gal and 60 per cent................................................................. 600 gal Total........................................................ ................................... ...........................1170 gal Probable peak use at one time......................................................................... 35 per cent Probable actual peak demand.................................... ....................................... 409 gph 100 X 8.33 Actual requirement for -IOO-deg temperature difference =* 240 water heated. 567 3.33 sq ft per gallon of American Society of Heating and Ventilating Engineers Guide, 1934 If three persons are assumed to an apartment the total daily, use of hot water should approximate 20 X 3 X 40 gal or 2400 gal and if the peak hour is 10 per cent of this amount, the peak hour by this method shows probable demand of one-tenth of 2400 gal which indicates that the values in Table are safe. j 568 Chapter 40 TEST METHODS AND INSTRUMENTS Pressure Measurement, Temperature Measurement, Air Move ment, Humidity Measurement, Carbon Dioxide Determination, Dust Determination, Flue Gas Analysis, Measurement of Smoke Density, Heat Transmission, Eupatheoscope PRESSURE MEASUREMENT ATMOSPHERIC pressure is usually measured by a mercurial barom eter 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 atmosphere, pressing on the exposed top of the mercury 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 latitude 45 deg and sea level, and at a temperature of 32 F, the atmos phere 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. An aneroid barometer con tains no liquid. Atmospheric pressure in bending the thin corrugated top of a partially exhausted metallic box, or in distorting a thin-walled bent tube of metal, is made to move a pointer. It is portable but 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 brass tube of oval cross section, known as a Bourdon tube. When subjected to unequal inside and outside pressures, this tube tends to' straighten out, and a pointer motivated by this straightening indicates the pressure difference on a suitably graduated scale. A gage which indicates pressures slightly above or below atmospheric is known as a draft gage. It is essentially a U tube containing either water, kerosene, alcohol or mercury, with one leg exposed to the air and the other connected to a point where the pressure is to be determined. When the pressure being read is equal to atmospheric,, the level of the liquid in the legs will be the same, indicating a zero gage pressure. When a pres- 569 American Society of Heating and Ventilating Engineers Guide, 1934 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. TEMPERATURE MEASUREMENT In engineering work, mercurial thermometers are largely employed to measure the intensity of heat. These 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 centigrade 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. Thermocouples1 may be used to measure any range of temperatures up to 2,900 F. When two dissimilar metals are joined at two points and a temperature difference exists between these junctions, an electromotive force will be developed. Its magnitude depends on the composition of the wires 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 proportional to the tem perature difference between the hot and cold junctions. Thermocouples connected in series are called thermopiles. Thermocouples for the measure ment of high temperatures are calibrated with the aid of the known melting points of pure metals. t For temperatures above 500 F various types of pyrometers are employed. The mercurial pyrometer is a thermometer with an inert gas, such as nitrogen or carbon dioxide, above the mercury column to prevent the mercury from boiling. The radiation pyrometer consists of a thermopile upon which the radiation from a hot source is focused by a concave mirror. A sensitive galvanometer with a calibrated temperature scale indicates the thermo-electromotive force created by the heat on the thermopile. The optical pyrometer measures radiant energy by comparing the intensity of a narrow spectral band, usually red light emitted by the object, with . that emitted by a standard light source (electric lamp). Thermo-electric pyrometers operate on the same principle as thermocouples. When measuring high temperatures, it is customary to hold the cold junction at room temperature which may cause some error if the room temperature is above or below the calibration point. - In the measuring of room temperatures care must be exercised to pre vent the results from being affected by the body heat of the observer, by drafts from doors, windows and other openings, or by radiant heat from some local source such as a radiator or wall. All thermometers should be mercury thermometers with engraved stems. The total gradua tions of the thermometers should be from 20 to 120 F, in one degree See A.S.H.V.E. research paper entitled Study of the Application of Thermocouples to the Measurement of Wall Surface Temperatures, by A. P. Kratz and E; L. Broderick (A.S.H.V.E. Transactions, Vol. 38. 1932). 570 Chapter 40--Test Methods and Instruments graduations. No ten degrees should occupy a space of less than one-half inch. The accuracy throughout the whole scale must be within one-half degree. The operator should take hold of the top and no part of the body, including the hand, should be nearer than 10 in. to the bulb. The thermometer 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. For measuring duct temperatures an angle-duct thermometer should be used, having a flange to bolt on the side of the duct, with the bulb extending into the duct at least 6 in. Recording thermometers generally have considerable lag and should not be used for the taking of temperatures for testing, but rather for giving continuous records of the operation of the plant, as the charts will indicate any lack of attention on the part of those responsible for the operation of the plant. MEASUREMENT OF AIR MOVEMENT The quantity, velocity and pressure of air discharged by a fan or flowing through a duct or grille may be determined by various methods. Those in common use are by Pitot tube, anemometer and Kata-thermo meter readings, 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. 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 other, which when properly held in the air stream will register the total or impact pressure and the static pressure, respectively. If these tubes are connected to opposite sides of a water column the recorded pressure will be the dif ferential or velocity head. 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 determinations from Pitot tube readings must take into account the barometric pressure, temperature and humidity. These factors determine the weight or density of the air. In general no accurate velocity pressure readings can be taken when the flow of air in ducts is turbulent. 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 atcordingly. For accurate work it is neces sary 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 corresponding to these pressures giving the true velocity in the duct. Anemometer ~ This instrument is delicate, and requires frequent calibration when 571 / American Society of Heating and Ventilating Engineers Guide, 1934 accuracy is desired. In duct measurements the same procedure is followed as for the Pitot tube. The anemometer usually reads directly in linear feet. To obtain the velocity in feet per minute, the reading must be divided by the elapsed time in minutes. 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 Laboratory2. 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: cfm CVA+orCVAi-l + (1) where V -- average of corrected anemometer readings in 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 000 /pm, 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 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 ficient time in each space to minimize the percentage of error. In the case of exhaust grilles it is found that the formula . . cfm = KVA . (2) in which ' V =,average indicated velocity obtained by the anemometer traverse in contact with grille. Measurement of Flow of Air through Registers and Grilles, by L. E. Davies (A.S.H.V.E. Transactions, Vol. 36, 1930, Vol. 37, 1931, and A.S.H.V.E. Journal Section, Heating, Piping and Air CondUtontng, Sep tember. 1933). .. ' * 572 Chapter 40--Test Methods and Instruments A -- gross area of grille, square feet. K -- coefficient determined by experiment.' For average use, with exhaust grilles, K may be taken as 0.8 for all usual velocities. This formula is of advantage, especially with ornamental grilles, in that the free area need not be measured. The flow of air through registers and grilles is of considerable impor tance, being frequently the only convenient method of measuring the volume of supply air to a room. While duct measurements, if available, are more dependable, grille measurements provide a fairly accurate method, if care is taken in the technique of using the anemometer. Kata-Thermometer The Kata-thermometer can be used as an anemometer provided the walls and surrounding objects are at or near the room temperature. Especially at low velocities it constitutes a useful instrument for readily detecting drafts. The instrument is essentially an alcohol thermometer with a bulb approximately % in. in diameter and in. long with a stem 8 in. long reading from 100 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. .' A dry Kata gives the cooling power by radiation and convection. A wet Kata, which has a cotton lisle wick fitted snugly around the bulb, gives the cooling power by radiation, convection and evaporation. For constant velocities the time of cooling of the dry Kata is a function of the dry-bulb temperature alone, while that of the wet Kata is a function of the wet-bulb temperature regardless of the dry-bulb temperature or the relative humidity. Due to the comparatively brief time of fall of the wet Kata-thermometer, the dry Kata-thermometer is far more accurate for measuring air motion since any probable error in recording the time of fall will only amount to a small fraction of the total period. HUMIDITY MEASUREMENT The sling psychrometer is the recognized standard instrument for determining humidities. In order to obtain accurate readings consider able skill is required on the part of the operator. The wicking must be clean, distilled water should be used, 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 two or three observations should be made to see that the wet-bulb temperature has become station ary before the final reading is noted. Standard psychrometric tables should be used. In making wet-buib 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 573 American Society of Heating and Ventilating Engineers Guide, 1934 become thoroughly frozen the wet-bulb temperature will rise .to normal. Care must be taken to read the temperatures in the region below 32 F accurately because the spread between the wet- and dry-bulb is small. In taking humidity readings in ducts it is usually impracticable to use a sling psychrometer. For this work the stationary hygrodeik arranged for bolting on to the side of the duct, with two bulbs extending into the duct, will be found very convenient. Due to the velocity of the air passing over the bulbs within the duct an accurate reading will be secured, corresponding to that given by the sling psychrometer. CARBON DIOXIDE DETERMINATION3 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. A high carbon dioxide concentration in parts of an occupied room may indicate air stagnation which can result in objectionable odors or in failure to remove local surplus heat. 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 Standard Methods for Examination of Air, American Public Health Asso ciation, Vol. 7, No. 1; American Journal of Public Health, Jan., 1917). Where field conditions are such that this apparatus may not be con veniently used, as in street cars, air samples may be collected in prepared bottles having rubber stoppers, and these may be subjected 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 dust counter, using a microscope, the impingerV using chemical changes in water, and the Lewis sampling tube6, involving the analytical weighing of a porous crucible, are accepted. FLUE CAS ANALYSIS The analysis of flue gases by chemical means is made with the Orsat apparatus. A solution of KOH is used to absorb the C02. Free oxygen is See A.S.H.V.E. research paper entitled Indices of Air Change and Air Distribution, by F. C. Houghten and J. L. Blackshaw (A.S.H.V.E. Journal Section, Healing, Piping and Air Conditioning, June, 1933). . Public Health Bulletin, No. 144, 1925. U. 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. Journal Section, Heating, Piping and Air Conditioning, May, 1933). 574 '. Chapter 40--Test Methods and Instruments 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 C02, 02 and CO. MEASUREMENT OF SMOKE DENSITY Smoke density is usually measured by comparison with the Ringel mann 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 as nearly as convenient in .line with the chimney. At this distance, the lines become invisible, and the cards appear to be of different shades of gray, Fig. 1. Ringelmann Smoke Chart 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 the smoke, and makes a record accordingly, noting the time. Observations are made continuously during say one minute, and the estimated average density during that minute recorded, and so on, records being made once every minute. 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 Smoke recorders are available which give a much more accurate in dication of the amount of smoke being produced than the Ringelmann Chart. Although most of these instruments are in the process of develop ment, they constitute a satisfactory tool in the control of smoke emission. They all depend upon projecting a beam of light through the smoke flue or through a separate compartment from which a sample of the flue gas is drawn continuously. The light of the beam which passes through with out being absorbed by the smoke is measured to determine the smoke 575 American Society of Heating and Ventilating Engineers Guide, 1934 density.. Most of these instruments make use of a photo-electric cell or a thermopile to measure the relative amount of light which has not been absorbed. Standard electrical instruments serve for indicating or re cording; MEASUREMENT OF RATE OF HEAT TRANSMISSION The standard methods of testing built-up wall sections are by means of the guarded hot-boxf and the guarded hot-plate6. The Nicholls heat-flow meter1 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 corhpiuted 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 plate's 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 37. ; See Standard Code for Heat Transmission through Walls (A.S.H.V.E. Transactions, .Vol. 34, 1928) and Report of the Committee on Heat Transmission, National Research Council. 'See Measuring Heat Transmission in Building Structures and a Heat Transmission Meter, by P. Nicholls (A.S.H.V.E. Transactions, Vol. 30, 1924). , 576 Chapter 41 PROPERTIES OF AIR, WATER, AND STEAM Composition of Air, Specific Density, Boyle's Late, Charles' Law, Composition of Water, Density, Water Pressures, Boiling Point, Specific Heat, Sensible and Latent Heat, Saturated Steam, Superheated Steam, Quality, Tables AIR is a mechanical mixture made up, by volume, of 20.91 per cent of oxygen and 79.09 per: cent of nitrogen, or by weight, of 23.15 per cent of oxygen and 76.85 per cent of nitrogen. Air as found in nature always contains other constituents in varying amounts, such as carbon dioxide, ozone, water vapor, dust, and bacteria. The specific density or weight per cubic foot of dry air decreases with an increase in temperature; and the specific volume, or volume per pound, increases with such increase. The specific heat\oi air at constant pressure, or the. Btu required to raise the temperature of one pound one degree Fahrenheit, varies from 0.2375 to 0.2430 as determined by various in vestigators. The value 0.24 is recommended for engineering calculations. It has been found that a given volume of air expands when heated under constant pressure, and again that if the temperature of a given volume of air be kept constant and the pressure increased, contraction takes place. These changes follow definite laws, which apply to other gases as well as air, known as the laws of perfect gases. These laws do not generally apply to steam, since it is not a perfect gas, but superheated steam at high temperatures follows the laws approximately. (See Tables 1, 2 and 3). Example 1. To show the use of table on air weights, Table 3: Given air at 83 F dry- bulb and 68 F wet-bulb (or a depression of 15 deg) with a barometric pressure of 29.40 in. of mercury. What wiil be the weight of this air in pounds per cubic foot? Solution.; From Table 3 the weight of saturated air at 80 F and 29.00 in. barometer is found to be 0.07034 lb per cubic foot! There is a decrease of 0.00015 lb per degree dry- bulb temperature above 80 F. There is an increase of 0.00025 lb for each 0.1 in. above 29.00 in. From the last column of Table 3 it is found that there.is an-increase of approxi mately 0.000035 lb per degree wet-bulb depression when the dry-bulb is 83 F. Tabu lating the items: j . :; 0.07034 = weight of saturated'air at 80 F and 29.00 bar. - 0.00045 = decrement for 3 deg; dry-bulb, 3 X 0.00015. + 0.00100 = increment for 0.4 ini bar, 4 X 0.00025. .. + 0.00053 = increment for 15 deg wet-bulb depression, 15 X 0.000035. - * . .. 0.07142 = weight in pounds per cubic foot of air at 83 F dry-bulb, 68 F wet-bulb, 29.40 in. bar. . Boyle's Law refers to the relation between the pressure and voluitie of a gas, and may be stated as follows: With temperature constant, the volume of 577 American Society of Heating and Ventilating Engineers Guide, 1934 Temperatuhb Deo F 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 Table 1. Properties of Dry Air3 Barometric Pressure 29.921 In. Weight pee Ctj Ft Pounds 0.08636 0.08453 0.08276 0.08107 0.07945 0.07788 0.07640 0.07495 0.07356 0.07222 0.07093 0.06968 0.06848 0.06732 0.06620 0.06510 0.06406 0.06205 0.06018 0.05840 0.05673 0.05516 0.05367 0.05225 0.04903 0.04618 0.04368 0.04138 0.03932 0.03746 0.03423 0.03151 0.02920 . . 0.02720 Pee Cent of Volume at 70 F Btu Absorbed bt One Cu Ft Dbt Ara peb Deg F 0.8680 0.02080 . 0.8867 0.02039 0.9057 0.01998 0.9246 0.01957 0.9434 0.01919 0.9624 0.01881 0.9811 0.01846 1.0000 0.01812 1.0190 0.01779 1.0380 0.01747 1.0570 0.01716 1.0756 0.01687 1.0945 0.01659 1.1133 . 0.01631 1.1320 0.01605 1.1512 0.01578 1.1700 0.01554 1.2080 0.01506 1.2455 0.01462 1.2833 0.01419 1.3212 0.01380 1.3590 0.01343 1.3967 0.01308 1.4345 . 0.01274 1.5288 1.6230 1.7177 1.8113 1.9060 2.0010 2.1900 2.3785 2.5670 2.7560 . 0.01197 0.01130 0.01070 0.01018 0.00967 0.00923 0.00847 0.00782 0.00728 0.00680 Cu Ft Dbt Air Warmed One Degbeb peb Btu 48.08 . 49.05 50.05 51.10 52.11 53.17 54.18 55.19 56.21 57.25 58.28 59.28 60.28 61.32 62.31 63.37 64.35 . 66.40 68.41 70.48 72.46 74.46 76.46 78.50 83.55 88.50 93.46 98.24 103.42 108.35 118.07 127.88 137.37 147:07 aFrom Fan Engineering. 578 . Chapter 41--Properties of Air, Water and Steam a given weight of gas varies inversely as its absolute pressure. Hence, if Pi and Pi represent the initial and final absolute pressures, and Vt and Vt represent corresponding volumes of the same mass, say one pound of Vi Pi gas, then 77- = 5-, or Pi Vi = Ps Vi, but since Pi Vi for any given case is Vi Jr1 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 Table 2. Properties of Saturated Air3 Weights of Air, Vapor of Water, and Saturated Mixture of Air and Vapor at 29.921 Inches of Mercury Temp. Deo F Weight in a Cubic Foot op Mixture Bin Absorbed bt Cubic Feet Sat. One Cubic Foot Am Warmed One Weight or Weight op Total Weight op Sat. Aib peb Degree per Dbt Am Vapor the Mixture Deg F Btu Pounds Pounds Pounds Specific Heat Btu peb Pound op Mixture 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 212 0.08625 0.08433 0.08246 0.08062 0.07878 0.07694 0.07506 0.07310 0.07103 0.06879 0.06635 0.06364 0.06060 0.05715 0.05319 0.04864 0.04340 0.03734 0.03035 0.02228 0.01300 0.00230 0.00000 0.000068 0.000110 0.000176 ' 0.000277 0.000409 0.000587 0.000828 0.001151 0.001578 0.002134 0.002850 0.003762 0.004914 0.006351 0.008120 0.010295 . 0.012936 0.016108 0.019896 0.024400 0.029715 0.035938 0,037307 0.08632 0.08444 0.08264 0.08090 0.07919 0.07753 0.07589 0.07425 0.07261 0.070920.06920 0.06740 0.06551 0.06350 0.06131 0.05894 0.05634 0.05345 0.05025 0.04668 0.04272 0.03824 0.03731 0.02083 0.02039 0.01998 0.01958 0.01921 0.01885 0.01851 0.01819 0.01790 0.01762 0.01736 0.01714 0.01695 ` 0.01679 0.01668 0.01662 0.01662 0.01668 0.01684 0.01710 0.01749 0.01802 0.01815 From Fan Engineering. 48.02 49.05 50.07 51.07 52.06 53.05 54.02 54.97 55.87 56.76 57.59 58.35 59.00 59.56 59.96 60.17 60.17 59.96 59.38 58.49 57.18 55.50 55.10 0.2413 0.2415 0.2418 0.2420 0.2426 0.2431 0.2439 0.2450 0:2465 0.2485 0.2509 0.2543 0.2587 0.2644 0.2721 0.2820 0.2950 0.3121 0.3351 0.3663 0.4094 0.4712 0.4865 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 between pressure; volume and tem perature of a gas and may be stated as follows: The volume of a given weight of.gas varies directly as the absolute temperature at constant pressure:, and the pressure -varies directly as the absolute temperature at-constant volume. Hence, when heat is added at constant volume, Fc, the resulting 579 American Society of Heating and Ventilating'Engineers Guide, 1934 Equation is ^- = 7=-, or, for the same temperature range at constant pres- El 4II '' ' .y 'p . ....................! i . ^. sure, Pc, the relation is ,-z = : : . . - ii ii - ; ; In general, for any weight of gas, W, since volume is proportional to weight, the relation between P, V and Pis ' . '' PV = WRT ........................................... (1) where . ...... P = the absolute pressure of the gas in pounds per square foot. V ,,= the volume of the weight W in cubic, feet...... ......................... w = the weight of the gas in pounds. . R = a constant depending on the nature-of the gas. - T = the absolute temperature in 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 1 will apply to most engineering computations. . . I o; Additional information on the properties of air. will be found.in Chapters 1 and 2. . . . ' - ' . .. I rz PROPERTIES OF WATER ! ;" Composition of Water. Water is a chemical compound (H20) 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 is at 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 23l Cu ini of water weighs approximately Sjf lb, and a .cubic foot of water is equal to 7.48 gal. The specific volume of water depends on the temperature arid it is always thereciprocal of its specific jdensity. (See Table 4). ' ' j :; Water,Pressures. Pressures are often stated iri 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/i lb per square foot, or 0.433h lb per square-inch. A column of water 2.309 ft (27.71 in.) high exerts a pressure of one porind per square inch at 62 F. } ;, .; . . . > i i 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. ' ^Specific Heat. The specific heat of water, or the amount of heat (Btu) required to raise the temperature of one pound of water one degree Fahren heit, varies with the temperature, but it is commonly assumed to be unity at all temperatures.; ;Steam tables are ibased :on exact-values, however. The specific heat of ice at 32 K 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. .s v i Sensible and Latent Heat. The heat necessary to raise the temperature of orie pound ofi water from 32 F to the. boiling point is known as the heat . 580 - . Chapter 41 -Properties ok Air, Water and Steam I ; .581 American Society of Heating and Ventilating Engineers Guide, 1934 of the liquid or sensible heat. When more heat is added, the water begins to evaporate and expand at constant temperature until the water is entirely changed into steam. The heat thus added is known as the latent heat of evaporation. Table 4. Thermal Properties of Water Temperature Deo F 32 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180. 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 O'. 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 Cu Ft fee 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 0.0195 0.0205 0.0219 0.0241 0.0394 Weiqbt Lb feb Cb 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 51.3 48.8 45.7 41.5 25.4 * 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 l!0052 1.0055 1.0068 1.0104 1.0148 1.020 1.026 1.044 1.067 1.095 1.130 1.200 1.362 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 5). 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 582 Chapter 41--Properties of Air, Water and Steam Table 5. Properties of Saturated Steam: Pressure Table3 Abe. Press. Temp. Lb./Sq. In. Dec. F. Pt V4" Bg 58.83 3A" Hg 70.44 l"Hg 79.06 lW'Be 91.75 2" He 101.17 iW'Bg 108.73 3"Hg 115.08 Specific Volume Sat. Sat. Liquid Evap. Vapor Vf VC* V 0.01603 1256.9 1256.9 0.01605 856.5 856.5 0.01607 652.7 652.7 0.01610 4453 0.01613 339.5 0.01616 2753 4453 339.5 2753 0.01618 2313 2313 Total Heat Sat. Sat. Liquid Evap. Vepor hi he* h* 2638 10583 1085.7 38.47 10523 1091.0 47.06 10473 1094.9 59.72 10403 1100.6 69.10 1035.7 11043 76.63 10313 1108.1 82.96 1027.9 11103 1.0 101.76 2.0 126.10 3.0 141.49 4.0 152.99 0.01614 0.01623 0.01630 0.01636 3333 173.94 118.84 90.72 333.9 173.96 11836 90.74 69.69 93.97 10933 12033 10353 1021.6 1012.7 1005.9 11053 1115.6 11223 11263 5.0 162.25 6.0 170.07 7.0 176.85 8.0 182.87 9.0 188.28 0.01641 0.0164S 0.01649 0.01652 0.01656 73.59 62.03 53.68 4738 42.42 73.61 62.05 53.70 4739 42.44 130.10 1000.4 137.92 9953 144.71 991.7 150.75- 988.1 156.19 9843 1130.6 1133.7 1136.4 1138.9 11413 10.0 11.0 12.0 13.0 14.0 14.696 193.21 197.75 201.96 205.88 209.56 212.00 0.01658 0.01661 0.01664 0.01666 031669 0.01670 38.44 35.1S 32.40 30.06 28.05 26.80 38.45 35.17 37.42 30.08 28.06 2632 161.13 165.68 169.91 17335 177.55 180.00 9813 1143.0 979.1 11443 9763 1146.4 974.1 1147.9 9713 11493 9703- 11503 16,0 18.0 20.0 22.0 24.0 26.0 28.0 21632 222.40 227.96 233.07 237.82 242.25 246.41 0.01673 0.01678 0.01682 0.01685 0.01689 0.01692 0.01695 24.75 22.16 20.078 18363 16.924 15.701 14.647 24.76 22.18 20.095 18380 16.941 15.718 14.664 18435 190.48 196.09 201.25 206.05 210.54 214.75 967.4 11513 963.5 11S4.0 959.9 11563 956.6 1157.8 953.4 11593 9S0.4- 1161.0 947.7 1162.4 30.0 32.0 34.0 36.0 38.0 2S034 254.05 257.58 260.94 * 264.16 0.01698 0.01701 0.01704 0.01707 0.01710 13.728 12.923 12309 11.570 10.998 13.745 12.940 12326 11.587 11.015 218.73 222.50 226.09 22931 232.79 945.0 9423 9403 937.7 9353 1163.7 116S.0 1166.1 11673 11683 40.0 42.0 44.0 46.0 48.0 26734 27031 273.06 27S.81 278.45 . 0.01712 0.01715 0.017170.01719 0.01722 10.480 10.010 9.582 9.189 8329 10.497 10.027 9.599 9307 8.846 235.93 238.95 34136 244.67 247137 9333 9313 9293 9273 925.4 11693 11703 1171.1 1171.9 1172.7 60.0 62.0 64.0 66.0 68.0 281.01 283.49 285.90 288.23 290.50 0.01724 0.01726 0.01728 0.01730 0.01732 8.496 8.189 7.902 7.636 7388 8.514 8.206 7.919 ` 7.653 7.405 249.98 25232 254.99 25738 259.71 9233 921.7 920.0 9183 916.6 11733 11743 11753 1175.7 1176.4 60.0 292.71 0.0173S 62.0 294.85 . 0.01737 64.0 296.94 0.01739 66.0 . 298.98 0.01741 68.0 300.98 0.01743 7.155 6.937 6.732 6.539 6357 7.172 6.95S 6.749 6.556 6375 261.98 264.18 26633 268.43 270.49 915.0 913.4 911.9 910.4 908.9 11773 1177.6 11783 11783 1179.4 70.0 72.0 74.0 76.0 78.0 302.92 304.82 306.68 308.50 31038 0.01744 0.01746 0.01748 . 0.01750 0.01752 . 6.186 6.024 5370 5.723 5.584 6303 6.041 5.887 5.741 5.602 272.49 274.45 27637 27835 280.09 907.4 906.0 904.6 903.2 901.9 1179.9 11803 11813 11813 1182.0 80.0 82.0 84.0 86.0 88.0 312.03 313.74 315.42 317.06 318.68 0.01754 0.017S6 0.01757 0.01759 0.01761 5.452 5325 5.204 5.089 4.979 5.470 5343 5322 5.107 4.997 281.90 283.67 285.42 287.13 28830 900.5 8993 897.9 896.7 895.4 1182.4 1182.9 1183.4" 11833 11843 90.0 92.0 94.0 96.0 98.0 32037 321.83 32337 32438 32637 0.01763 4374 0.01764 . . 4.773 0.01766 ' 4.676 0.01768 4.584 0.01769 4.494 4392 4.791 4.694 4.602 4.512 290.45 292.07 293.67 39535 196.80 8943 893.0 8913 890.6 889.4 1184.6 11853 1185.4 11853 11863 Entropy Sat. Sat. Abe. Pm. Liquid E..p, Vapor Lb./Sq. In. SC 03533 03754 0.0914 0.1147 8fg 2.0422 1.9856 1.9451 1.8877 2.0955 2.0609 2.0365 2.0024 P W'Bg %"Hg 1"Hg l'A" He 0.1316 1.8468 1.9784 2" He 0.1450 1.8148 1.9598 2<A" Bg 0.1561 1.7885 1.9446 3" He 0.1326 0.1750 03009 0.2198 1.8442 1.7442 1.6847 1.6420 1.9769 1.9192 1.8856 1.8618 1.0 2.0 3.0 4.0 0.2348 03473 03580 03674 03758 1.6088 1.5814 1.5582 1.5379 1.5200 1.843S 1.8287 1.8162 1.8053 1.7958 6.0 6.0 7.0 e.o 9.0 03834 03903 03968 03027 03082 03119 1.5040 1.4894 1.4750 1.4636 1.4S21 1.4446 1.7874 1.7797 1.7727 1.7663 1.7604 1.7564 10.0 11.0 12.0 13.0 14.0 14.696 03184 03274 033S6 03431 03500 03564 03624 1.4312 1.4127 13960 13809 13670 13542 13422 1.7496 1.7402 1.7317 1.7240 1.7170 1.7106 1.7046 16.0 16.0 20.0 22.0 24.0 26.0 28.0 03680 03732 03783 03830 03876 13310 13206 13107 13014 13925 1.6990 1.6938 1.6890 1.6844 1.6800 30.0 32.0 34.0 36.0 38.0 0.3919 03961 0.4000 0.4039 0.4076 13840 13759 13682 1.2608 13537 1.6759 1.6720 1.6683 1.6647 1.6613 40.0 42.0 44.0 46.0 48.0 0.4111 0.4145 0.4178 0.4210 0.4241 1.2469 13404 1.2340 13279 13220 1.6580 1.6549 1.6518 1.6489 1.6461 60.0 62.0 64.0 66.0 68.0 0.4271 0.4300 0.4329 0.4356 0.4384 13162 1.2107 13053 13001 1.1950 1.6434 1.6407 1.6382 1.6357 1.6333 60.0 62.0 64.0 66.0 68.0 0.4410 0.4435 0.4460 0.4485 0.4509 1.1900 1.1852 1.180S 1.1759 1.1714 1.6310 1.6287 1.6265 1.6244 1.6223 . 70.0 72.0 74.0 76.0 78.0 0.4532 0.4555 0.4578 0.4599 0.4621 1.1670 1.1627 1.1586 1.1545 1.150S 1.6202 1.6182 1.6163 2.6144 1.6126 80.0 82.0 84.0 86.0 88.0 0.4642 0.4663 0.4683 0.4703 0.4723 1.1465 1.1427 1.1389 1.13S2 1.1316 1.6107 1.6090 1.6072 1.6055 1.6038 90.0 92.0 94.0 96.0 98.0 "Abstracted from Steam Tables and MoLlier Diagram, by Prof. J. H. Keenan, 1930 edition, by permission of the publisher. The American Society of Mechanical Engineers. 583 American Society of Heating and Ventilating. Engineers Guide, 1934 ' Table 5. Properties of Saturated Steam: Pressure Table--(Continued) Abt. Pnu. Lb./Sq. In. P 100.0 102.0 104.0 106.0 108.0 Temp. Deg. F. t 327.83 329.27 330.68 332.08 333.44 Specific Volume Set. Sat. Liquid Evap. Vapor Vf Vfc 031771 4.408 0.01773 4326 0.01774 4.247 0.01776 4.171 0.01777 4.097 g 4.426 4344 4.265 4.189 4.115 110.0 112.0 114.0 116.0 118.0 334.79 336.12 337.43 338.72 340.01 0.01779 4.026 0.01780 3.958 0.01782 3.892 0.01783 3.828 0.01785 3.766 4.044 3.976 3.910 3.846 3.784 120.0 122.0 124.0 ' 126.0 128.0 341.26 342.50 343.73 344.94 346.14 0.01786 3.707 3.725 .0.01788 3.652 3.670 0.01789 3.597 3.615 0.01791 3.542. 3.560 0.01792 3.487 3.505 130.0 132.0 134.0 136.0 138.0 34731 348.48 349.64 350.78 351.91 0.01794 3.433 0.01795 3383 0.01796 .3335 0.01798 3.288 0.01799 3342 3.451 3.401 3353 3306 3360 140.0 142.0 144.0 146.0 148.0 353.03 354.14 3S532 35631 35737 . 0.01801 3.198 0.01802 3.155 0.01804 3.112 0.01805 3.071 0.01806 3.031 3316 3.173 3.130 3.089 3.049 160.0 162.0 164.0 166.0 168.0 358.43 359.47 360.51 361.53 362.54 0.01808 2.992 0.01809 2.954 0.01810 2.917 0.01812 2.882 0.01813 2.846 3.010 2.972 2.935 2.900 2364 160.0 162.0 164.0 166.0 168.0 363.55 ' 36434 365.52 366.50 367.46 0.01814 2.812 0.01816 2.779 0.01817 2.746 0.01818 2.715 0.01819 2.683 2.830 2.797 2.764 2.733 2.701 170.0 172.0 . 174.0 176.0 178.0 368.42 36937 37031 37134 372.16 0.01821 2.653 0.01822 2.623 0.01823 2.594 0.01825 2.566 0.01826 2.538 2.671 2.641 2.612 2.584 2.556 180.0 182.0 184.0 186.0 138.0 373.08 374.00 374.90 375.78 376.67 0.01827 2.511 0.01828 2.484 0.01829 2.458 0.01831 2.433 0.01832 2.407 2.529 2.502 2.476 2.451 2.425 190.0 192.0 194.0 196.0 198.0 3773S 378.42 37937 380.13 380.97 0.01833 2.383 0.01834 2359 0.01835 2335 0.01837 2312 0.01838 2.289 2.401 2377 2353 2.330 2307 200.0 206.0 210.0 216.0 220.0 38132 .383.89 . 385.93 387.93 389.89 0.01839 2.267 0.01842 2.213 0.01844 2.162 0.01847 2.113 0.01850 2.066 2385 2.231 2.180 2.131 . 2.084 226.0 230.0 236.0 240.0 246.0 391.81 393.70 395.56 397.40 39930 0.01853 2.0208 2.0393 0.01856 1.9778 1.9964 0.01859 1.9367 1.9553 0.01861 13970 1.9156 0.01864 1.8589 1.8775 Total Heat Sat. Sat. Liquid Enp. Vapor - hf hfg hg 29833 888.2 1186.6 299.83 887.1 1186.9 30130 886.0 11873 302.76 884.9 1187.6 304.19 883.8 1188.0 305.61 882.7 11883 307.00 881.6 1188.6 30836 880.6 1188.9 309.71 879.S 11893 311.05 878.5 11893 Entropy Sat. Sat. Liquid Evap. Vapor 8f Sfg Sg 0.4742 1.1280 1.6022 0.4761 1.1245 1.6006 0.4779 1.1211 1.5990 0.4798 1.1177 1.5974 0.4816 1.1144 1.5959 0.4834 0.4851 0.4868 0.488S 0.4901 1.1111 1.1079 1.1048 1.1017 1.0986 1.5944 13930 1.5915 1.5901 13887 Abe. Press. Lb./Sq. In. P 100.0 102.0 104.0 106.0 108.0 lio.o 112.0 114.0 116.0 118.0 31237 877.4 1189.8 v 313.67 876.4 1190.1 314.96 875.4 1190.4 316.23 874.4 1190.6 317.49 873.4 1190.9 0.4918 0.4934 0.4950 0.4965 0.4981 1.0956 1.0926 1.0897 1.0868 1.0840 13874 1.586Q 13847 1.5834 1 13821 120.0 122.0 124.0 126.0 128.0 318.73 872.4 11913 319.95 871.5 1191.4 321.17 870.5 1191.7 32237 869.6 1191.9 323.56 868.6 11923 0.4996 0.5011 0.5026 03041 0.5056 1.0812 1.0784 1.0757 1.0730 1.0703 1.5808 13796 13783 13771 13759 130.0 132.0 134.0 136.0 138.0 324.74 867.7 1192.4 325.91 .866.7 1192.6 327.06 865.8 1192.9 328.20 864.9 1193.1 32932 864.0 11933 0.5070 0.5084 03098 03112 0.5126 1.0677 1.0651 1.0625 1.0600 1.0575 1.5747 13735 13724 13712 13701 140.0 142.0 144.0 146.0 148.0 330.44 863.1 11933 331.54 8623 1193.7 332.64 8613 1193.9 333.72 860.4 1194.1 334.80 859.5 11943 03140 1.0550 1.5690 160.0 0.5153 1.0526 1.5679 162.0 03166 1.0502 13668 164.0 0.5180 1.0478 1.5658 166.0 0.5193 1.0454 13647 . 168.0 335.86 858.7 1194.5 336.91 857.8 1194.7 337.95 857.0 1194.9 338.99 856.1 1195.1 340.01 855.2 11953 0.5205 0.5218 03230 03243 03255 1.0431 1.0408 1.0385 1.0363 1.0340 1.5636 13626 13616 1.5606 13596 160.0 162.0 164.0 166.0 168.0 341.03 854.4 1195.4 342.04 853.6 1195.6 343.04 852.7 11953 344.03 851.9 1196.0 345.01 851.1 1196.1 03268 03280 03292 0.5304 0.5315 1.0318 1.0296 1.0275 1.0253 1.0232 13586 1.5576 13566 13557 13548 170.0 172.0 174.0 176.0 178.0 345.99 8503 11963 346.97 8493 1196.4 347.94 848.6 1196.6 348.89 847.9 1196.8 349.83 847.1 1196.9 0.5327 1.0211 0.5339 1.0190 0.53S0- 1.0169 0.5362 1.0149 0.5373 1.0129 13538 1.5529 1.5520 13511 1.5502 180.0 182.0 184.0 186.0 188.0 350.77 8463 1197.0 351.70 845.5 1197.2 352.61 844.7 11973 353.53 844.0 11973 354.43 8433 1197.6 03384 1.0109 1.5493 190.0 0.5395 1.0089 1.5484 192.0 0.5406 1.0070 1.5475 194.0 0.5417 1.0050 1.5467 196.0 0.5427 1.0031 13458 .. 198.0 35533 842.4 11973 357.56 840.5 1198.1 359.76 838.6 1198.4 361.91 8363 1198.7 364.02 835.0 1199.0 0.5438 0.S46S 03491 03516 03540 1.0012 0.9964 0.9918 0.9873 0.9829 13450 1.5429 13409 13389 13369 200.0 206.0 210.0 216.0 220.0 366.10 8333 11993 368.14 831.4 1199.6 370.15 829.7 11993 372.13 827.9 1200.1 374.09 826.2 12003 : 03565 0.9786 13350 0.5588 0.9743 13332 0.5612 0.9702 13313 0.563S 0.9661 13295 0.5658 0.9620 13278 226.0 230.0 236.0 240.0 : 245.0 584 Chapter 41--Properties of Air, Water and Steam Table 5. Properties of Saturated Steam: Pressure Table--(Continued) Abe. Prase. Lb./Sq. In. P 260.0 260.0 270.0 260.0 290.0 Tamp. Dag. F. t 400.97 404.43 407.79 411.06 414.24 Specific Volume Sat. Sat. , Liquid Evap. Vapor Vf Vf* Vg 0.01867 1.8223 1.8410 0.01872 1.7536 1:7723 0.01877 1.6895 1.7083 0.01882 1.6302 1.6490 0.01887 13745 13934 Total Heat Sat. Sat. Liquid Evap.. Vapor hf hfg hg 376.02 824.S 1200.5 379.78 8213 1201.0 383.44 818.0 1201.4 387.02 814.7 1201.8 390.50 811.6 1202.1 Entropy Sat. Sat* Liquid Evap. Vapor Sf Sfg Sg 0.5680 0.9581 1.5261 0.5723 0.9504 1.5227 0.5765 0.9430 1.5194 . 0.5805 0.9357 1.5163 0.5845 0.9287 1.5132 Abe. Press. Lb./Sq. In. P 260.0 260.0 270.0 280.0 290.0 . 300.0 320.0 . 340.0. 360.0 380.0 41733 . . 0.01892. 1.5225 1.5414 42339 0.01901 1.4279 1.4469 428.96 0.01910 13439 13630 43439 0.01918 13689 13881 43939 0.01927 13015 13208 .393.90 808.5 1202.4 400.47 802.5 1203.0 406.75 796.6 1203.4 412.80 790.9 1203.7 418.61 7853 1203.9 0.5883 0.5957 0.6027 0.6094 03157 0.9220 0.9089 0.8965 0.8846 0.8733 1.5102 1.5046 1.4992 L4940 1.4.891 300.0 320.0 340.0 360.0 380.0 400.0 420.0 440.0 ; r 460.0 480.0 44438 44938 454.01 458.48 462.80 0.0194 0.0194 0.0195 0.0196 0.0197; 1.1407 U601 1.0853 1.1047 1.0345 1.0540 0.9881 1.0077 0.9456 0.9633 424.2 429.6 434.8 439.9 444,9 779.8 1204.1: 774.5 1204.1 7693 1204.1 764.1 1204.0 759.0 1203.9 03218 0.8625 1.4843 0.6277 0.8520 1.4798 0.6334 0.8420 1.4753 ' 0.6388 0.8322 1.4711 0.6441 03228 1.4670 400.0 420.0 440.0 460.0 480.0 . 600.0 620.0 640.0 660.0 : 680.0 46699 471.05 474.99 478.82 482.55 0.0198; 0.9063 0.9261 ; 0.0198 0.8701 0.8899 0.0199 0.8363 0.8562 0.0200 0.8047 0.8247 0.0201 0.7751 0.7952 * 449.7 454.4 459.0 463.6 468.0 754.0 1203.7 749.0 1203.5 744.1 12033 7393 1202.9 734.5. 1202.5 0.6493 03137 1.4630 0.6543 0.8048 1.4591 0.6592 0.7962 1.4SS4 0.6639 0.7878 1.4517 0.6686 0.7796 1.4482 600.0 620.0 640.0 660.0 680.0 600.0 620.0 640.0 660.0 680.0 486.17 - 0.0202 -489.71 .0.0202 493.16 0.0203 496.53 . 0.0204. 499.82 0.020S 0.7475 0.7677 0.7217 0.7419 0.6972 0.717S 0.6744 0.6948 0.6527 0.6732 4723 - 476.6 4803 484.9 488.9 729.8 725.1 720.5 715.9 7113 1202.1 1201.7 12013 12003 12003 03731 0.7716 1.4447 0.6775 0.7638 1.4413 0.6818 0.7562 1.43800.6861 0.7487 - 1.4348 0.6902 0.7414 1.4316 600.0 620.0 640.0 660.0 680.0 700.0 720.0 740.0 760.0 780.0 503.04 506.19 50938 512.30 51S.27 0.9206 0.0206 0.0207 0.0208 0.0209 0.6321 0.6S27 0.6128 0.6334 03944 0.6151 0.5769 0.5977 03602 0.5811 492.9 496.8 500.6 504.4 5083 706.8 702.4 697.9 693.S 6893 1199.7 1199.2 1198.6 1198.0 1197.4 0.6943 0.6983 0.7022 0.7060 0.7098 0.7342 0.7272 0.7203 0.7136 0.7069 1.4285 1.425S 1.4225 1.4196 1.4167 700.0 720.0 740.0 760.0 780.0 800.0 820.0 840.0 860.0 880.0 518.18 521.03 523.83 526.58 529.29 0.0209 0.0210 0.0211 0.0212 0.0213 03444 03653 03293 03503 0.5149 03360 0.5013 03225 0.4881 0.5094 511.8 515.5 519.0 522.6 526.0 684.9 1196.7 680.6 1196.0 676.4 1195.4 672.1 1194.7 667.9 1194.0 0.7135 0.7004 1.4139 0.7171 0.6940 1.4111 0.7207 0.6877 1.4084 0.7242 0.6815 1.40S7 0.7277 0.6754 1.4031 600.0 820.0 840.0 860.0 880.0 900.0 920.0 940.0 960.0 980.0 531.95 S34.56 537.13 539.66 542.14 0.0213 0.0214 0.0215 0.0216 0.0217 0.4756 0.4969 0.463S 0.4849 0.4520 0.4735 0.4409 0.4625 0.4303 0.4520 529.5 532.9 536.2 539.6 542.8 663.8 11933 6S9.7 1192.6 655.6 1191.8 651.5 1191.1 647.5 11903 0.7311 0.6694 1.4005 0.7344 0.6635 13980 0.7377 0.6577 139S4 0.7410 0.6520 13930 0.7442 0.6464 13905 900.0 920.0 940.0 960.0 980.0 1000.0 1060.0 1100.0 1160.0 1200.0 544.58 55033 556.28 561.81 567.14 0.0217 0.0219 0.0222 .. 0.0224 0.0226 0.4202 0.4419 03960 0.4179 03738 03960 03540 03764 03356 03582 546.0 554.0 561.7 5693 576.5 643.5 1189.6 633.6 11873 623.9 1185.6 6143 1183.5 604.9 1181.4 0.7473 0.6408 13881 0.7550 0.6273 13822 0.7624 0.6141 13765 0.7695 0.6014 13709 0.7764 0.5891 13656 1000.0 1060.0 1100.0 1160.0 1200.0 1260.0 1300.0 1350.0 1400.0 1460.0 57230 57732 582.21 586.96 591.58 0.0228 0.0230 0.0232 0.0235 0.0237 03187 03415 03029 03259 0.2884 03116 0.2748 0.2983 03621 03858 583.6 590.6 597.5 6043 611.0 595.6 1179.2 5863 1177.0 5773 1174.7 568.1 1172.4 559.1 1170.0 0.7831 0.5772 13603 0.7897 0.5654 13552 0.7962 0.5540 13501 0.8024 0.5428 1.3452 0.8086 0.5318 13404 1260.0 1300.0 1360.0 1400.0 1460.0 1600.0 1600.0 1700.0 1600.0 1900.0 596.08 604.74 612.98 620.86 62839 0.0239 0.0244 0.0249 0.0254 0.0260 03502 0.2741 0.2284 0.2528 0.2089 0.2338 0.1913 03167 0.1754 03014 617.5 6303 642.5 654.7 666.8 5503 532.6 515.0 4973 478.9 11673 1162.7 1157.5 115L8 1145.7 0.8146 0.5212 13357 0.8262 0.5003 13265 0.8373 0.4801 13174 0.8482 0.4601 13083 0.8589 0.4402 13990 1600.0 1600.0 1700.0 -1800.0 1900.0 2000.0 2200.0 2400.0 2600.0 2800.0 635.6 649.2 661.9 673.8 684.9 0.0265 0.0277 0.0292 0.0310 0.0333 0.1610 0.187S 0.1346 0.1623 0.1112. 0.1404 0.0895 0.1205 0.0688 0.1021 679.0 703.7 72914 756.7 786.7 460.0 1139.0 420.0 1123.8 376.4 1105.8 327.8 1084.5 2723 1058.9 0.8696 0.4200 13896 0.8912 03788 13700 0.9133 03356 13488 0.9364 0.2892 1.22S7 0.9618 03379 1.1996 2000.0 2200.0 2400.0 2600/0 2800.0 3000.0 3200.0 3226.0 6953 704.9 706.1 0.0367 0.0477 0.0844 0.C459 0.0142 0.0601 0.0522 0 0.0522 823.1 887.0 925.0 202.5 1025.6 0.9922 0.1754 1.1676 75.9 962.9-- 1.0461 0.0651 1.1112 0 925.0 1.0785 0 1.0765 3000.0 3200.0 3226.0 585 American Society of Heating and Ventilating Engineers Guide, 1934 be higher than that of saturated steam at the same pressure. The relation between pressure and specific volume for dry saturated steam is given by the experimental equation (Goodenough) as: pti.an = 484.2 . (2) where- p = the pressure in pounds per square inch. p = the specific volume. . . The total heat of a dry saturated vapor for any pressure and temperature is the sum of the heat required to raise the temperature of one pound of the liquid from the freezing point to the given temperature and cor responding pressure plus the heat required to entirely vaporize it at this pressure. . . ' . Steam which is in contact with the water from which it was generated is called wet saturated steam if it contains more or less actual water in the form of mist or priming. The percentage of dry steam in a mixture of steam and water is known as the quality (x) of the steam. The total heat of wet vapor at any pressure and temperature is the sum of the heat required to raise the temperature of one pound of the liquid from the freezing point to the given temperature and corresponding pressure plus the heat required to vaporize the part (x) at this pressure. 586 Chapter 42 HEATINC AND VENTILATING STANDARD TERMS Glossary of Physical and Heating and Ventilating Terms-Used in the Text, Standard Abbreviations, Conversion Equations, Drafting Symbols, A.S.H.V.E. Codes Absolute Humidity: bee Humidity. Absolute Tempe fture: The temperature of a substance measured above absolute zeroi Absolute Zero, he temperature ( -- 459.6 F) at which the molecular motion of a sub: theoretically, ceases. This is the temperature at which the subs| theoretically contains no heat energy. Acceleration The rate of change of .velocity. In the fps system this is express! units of one foot per second per second. ' V t Acceleration Due to Gravity: The rate of gain in velocity of a freely falling body. 1 In the fps system this is 32.174 feet per second per second. Air Cleaner: A.device designed for the purpose pf removing air-borne impurities such as'dusts, fumes and smokes. (Air cleaners include air washers and air filters). Air Conditioning: The simultaneous control of all or at least the first three of those factors affecting both the physical and chemical conditions of the atmosphere within any structure. These factors include tempera ture, humidity, motion, distribution, dust, bacteria, odors, toxic gases, and ionization, most of which affect in greater or lesser degree human health or comfort. '' Air Infiltration: The inleakage of air through cracks and crevices, and through doors, windows and other openings, caused by wind pressure or temperature difference. .. 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 arid 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 587 American Society of Heating and Ventilating Engineers Guide, 1934 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 'Srj^Q of 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. '' ' . 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 consisting of a central plant where the air is heated and conditioned and then circulated by fans or blowers through a system of distributing ducts. . Chimney Effect: The tendency in a duct or other, vertical air passage for air to rise when heated, owing to its decrease in density. Coefficient of Transmission: The amount of heat (Btu) transmitted from air to air in one hour per square foot of the wall, floor, roof or ceiling for a difference in temperature of 1 deg Fahrenheit between the air on the inside and that on the outside of the wall, floor, roof or ceiling, (The velocity Of air passing over the surfaces and the distances from the sur faces at which the temperatures are measured affect the coefficient of transmission). . .. . Column Radiator: A type of direct radiator. (This radiator, has hot been listed by manufacturers since 1926). Comfort Line: The effective temperature at which the largest per centage of adults feel comfortable. . .' . .Comfort Zone (Average): The range of effective temperatures over which the majority (50 per cent or more) of adults feel comfortable. Comfort Zone (Extreme): The range of effective temperatures over which one or more adults feel comfortable. (See Chapter 2). Concealed Radiator: See convector. : 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 deg Fahrenheit 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 deg Fahrenheit between the two surfaces of the material. Conductor (heat): A material capable of readily conducting heat. The opposite of an insulator (or insulation). . . v :; .. 588 Chapter 42--Heating and Ventilating Standard Terms . 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 concealed radiator. A heating unit and an enclosure (or shield) located either within, adjacent to, or exterior to the room or space to be heated, but transferring heat to the room or space mainly by the process of convection. (If the heating unit is located exterior to the room or space to be heated, the heat is transferred through one or more ducts or pipes; see Chapter 30). - - Decibel: The standard unit for noise or sound intensity. One decibel is the power supply to a telephone receiver which will produce approxi mately the smallest change in volume of sound which the normal ear can detect. Degree-Day: A unit representing a difference Of 1 deg Fahrenheit existing for one day between the average indoor and outdoor tempera tures. The standard degree-day is based on an average indoor tempera ture of 65 F. Density: The weight of a unit volume, expressed in pounds per cubic W foot. ? (rho) = -y. . Dew-Point Temperature: The temperature corresponding to satura tion (100 per cent relative humidity) for a given moisture content. Diffuser: A vaned device placed at an air supply opening to direct the air flow. Direct-Indirect Heating Unit: A heating unit located in the room or space to be heated and partially enclosed, the enclosed portion being used to heat air which enters from outside the room. Direct Radiator: Same as radiator. Direct-Return System (Hot water): A hot water system in which the water, after it has passed through a heating unit, is returned to the boiler along a direct path so that the total distance traveled by the water is the shortest feasible, and so that there are considerable differences in the lengths of the several circuits composing the system. Down-Feed One-Pipe Riser (Steam): A pipe which carries steam downward to the heating units and into which the condensation from'the heating units drains. 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 vertical distance of a gravity convector between the bottom of the heating unit and the bottom of the air outlet opening. ' . .. . Draft Head (Top Outlet Enclosure): The vertical distance of a gravity convector between the bottom of the heating unit and the top of the enclosure. 1. Dry Air: Air with which no water vapor is mixed. This term is used comparatively, since in nature there is always some water vapor included in air, and such water vapor, being a gas, is dry". Dry-Bulb Temperature: The temperature of the air.indicated by 589 xI American Society of Heating and Ventilating Engineers Guide, 1934 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. See wet return. Dust: Solid material in a finely divided state, the particles of which are large and heavy enough to fall with increasing velocity, due to gravity in still air. For instance, particles of fine sand or grit, the average diameter of which is approximately 0.01 centimeter, such as are blown on a windy day, may be called dust. * Dynamic Head or Pressure: The total or impact pressure. This is the sum of the radial pressure and the velocity pressure at the point of measurement. Effective Temperature: An arbitrary index of the degree of warmth or cold felt by the human body in response to temperature, humidity, and movement of the air. Effective temperature is a composite index which combines the readings of temperature, humidity, and air motion into a single value. The numerical value of the effective temperature scale has been fixed by the temperature of saturated air which induces an identical sensation of warmth. - Equivalent Evaporation: The amount of water a boiler would evaporate, in pounds per hour, if it received feed water at 212 F and vaporized it at the same temperature and atmospheric pressure. Estimated Design Load: The load, stated in Btu per hour or equiv alent direct radiation, as estimated by the purchaser for the conditions of inside and outside temperature for which the amount of installed radiation was determined. It is the sum of the heat emission of the radiation to be 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). 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- WV dition as to rest or motion. F = . 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. ' . 590 Chapter 42--Heating and Ventilating Standard Terms Furnace: That part of a boiler or warm air heating plant in which combustion takes place. Also, a fire-pot. Furnace Volume (Total): The total furnace volume for horizontal return-tubular boilers and water-tube boilers is the cubical contents of the furnace between, the grate and the first plane of entry into or between tubes. It therefore includes the volume behind the bridge wall as in ordinary horizontal return-tubular boiler settings, unless manifestly in effective (i.e., no gas flow taking place through it), as in the case of wasteheat boilers with auxiliary coal furnaces, where one part of the furnace is out of action when the other is being used. For Scotch or other internally fired boilers it is the cubical contents of the furnace, flues and combustion chamber, up to the plane of first entry into the tubes. (A.S.M.E. Power Test Codes, Series 1929). Grate Area: The area of the grate surface, measured in square feet, to be used in estimating the rate of burning fuel. This area is construed to mean the area measured in the plane of the top surface of the grate, except that with special furnaces, such as those having magazine feed, or special shapes, the grate area shall be the mean area of the active part of the fuel bed taken perpendicular to the path of the gases through it. For furnaces having a secondary grate, such as those in double-grate down-draft boilers, the effective area shall be taken as the area of the upper grate plus one-eighth of the area of the lower grate, both areas being estimated as defined above. (A.S.H.V.E. Standard and Short Form Heat Balance Codes for Testing Low-Pressure Steam Heating Solid Fuel Boilers). Gravity Warm Air Heating System: See warm air heating system. Grille: A perforated covering for an air inlet or outlet usually made of wire screen, pressed steel, cast-iron or plaster. (Grilles may be plain or ornamental). Heat: A form of energy generated by the transformation of some other form of energy, as by combustion, chemical action, or friction. [Accord ing to the molecular theory, heat consists of the kinetic and potential energy of the. molecules of a substance. The addition of heat energy to "a body increases the temperature or the kinetic energy of motion of its' molecules (sensible heat) or increases their potential energy of position but does not increase the temperature, as when melting or boiling occurs (latent heal).] Heat Capacity: The amount of heat (Btu or calories) required to raise the temperature of a body (of any mass and variety of parts) one degree (Fahrenheit or centigrade). This will depend on the masses and specific heats of the various parts of the body. Therefore .' S = m\ ri -|- mi St + mi ri.. . . etc. where ' 5 is the heat capacity and mi, mi, mi, and s, si, rj stand for the masses and cor responding specific heats of the parts, respectively. . Heating Medium: A substance such as water, steam, air, electricity 591 American Society of Heating rand Ventilating, Engineers Guide, 1934 or furnace gas used to convey heat from the boiler, furnace or other source of heat or energy to the heating unit from which the heat is dissipated. Heating Surface: The exterior surface of a heating unit. Extended heating surface (or extended surface): Heating surface having air on both sides and heated by conduction from the prime surface. Prime Surface: Heating surface having the heating medium on one side and air (or extended surface) on the other. (See also boiler heating surface). 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. Humidity: The water.vapor (either saturated or super-heated steam) occupying any space, which may or may not contain other vapors and gases at the same time. Relative Humidity: A ratio, although usually expressed in per cent, used to indicate the degree of saturation existing in any given space resulting from the water vapor present in that space. '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, which depends merely on the temperature and partial pressure of the vapor. Absolute Humidity: The actual weight of water vapor contained in a given volume of a mixture of air and water vapor at the observed temperature. ' Humidistat: A regulatory device, actuated by changes in humidity, used for the control of humidity. Hygrostat: Same as humidistat. , ',, Insulation (heat): A material having a.relatively high heaGresistance per unit of thickness. Latent Heat: See heat. . Mass: The quantity of matter, in pounds, to which the unit of force (one pound) will give an acceleration of one foot per second per second. W m = -------- g . '. . . - - ... Mb, Mbh1: Symbols which represent, respectively, 1000 Btu and 1000 Btu per hour. , . Mechanical Equivalent of Heat: The mechanical energy necessary to produce 1 Btu of heat energy. J -- 777.5 ft-lb. Micron: A unit of length, the thousandth part of one millimeter or the millionth of a meter. .. .. ............. ' Mol: The unit of weight for gases. It is defined as 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 apd the weight of a cubic foot is 0.002788 m lb). . Neutral Zone: The level within a room or building at which the pressure is exactly equal to the outside barometric pressure. . ; tThese symbols .were approved by the A-.S.H.V.E., June, 1933. 592 ' Chapter 42:--Heating, and Ventilating Standard Terms . 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. ;; One-Pipe System (Steam): A steam heating system consisting of a main circuit in which the steam and condensate flow in the same pipe and 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 .that the heating process talfes place mainly by radiation from the wall, floor or ceiling surfaces to the objects in the room. .. . Plenum Chamber: An air compartment maintained under pressure and connected to one or more distributing ducts. Prime Surface: See heating surface. : 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. \^ Psychrometer: An instrument for ascertaining the humidity or hygrometric state of the atmosphere. Psychrometric: Pertaining to psychrometry or the state of the atmosphere as to moisture. Psychrometry: The branch of physics that treats of the measurement.of degree of moisture, especially. the moisture mixed with the air. . , Pyrometer: An instrument for measuring high temperatures. Radiation: The.transmission of heat through space by wave motion. Radiator: A heating unit located within the room or space to be heated and exposed to view. (A radjator 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). Concealed Radiator: See convector. - Recessed Radiator : A heating unit set back into a wall recess but not enclosed. .. ' Register: A grille with a built-in damper or shutter. Relative Humidity: See humidity: see also discussion of relative humidity in Chapter 1. : ' __ . Return Mains :-The pipes which return the heating: medium from the heating units to the source of heat supply. . : :. . . 593 %t American Society of Heating and Ventilating Engineers Guide, 1934 Reversed-Return System (Hot Water): A hot water heating system in which the water from several heating units is returned along paths arranged so that all circuits composing the system or composing a major subdivision of the system are practically of equal length. Roof Ventilator: A device placed on the roof of a building to permit egress of air. 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. . 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 deg Fahrenheit. Specific Volume: The volume, expressed in cu-ft, of one pound of a substance, v = -- p 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 foot of heatihg surface may have no direct relation to the actual surface area). Stack Height: The vertical distance 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. ofmercury. (Most engineering tables and formulae involving the weight of air are based on air weighing 0.07495 lb per cubic foot, which is dry air at 70 F dry-bulb with a barometric pressure of 29.92 in. of mercury. The error involved in disregarding the difference between the above two weights is very slight and in most instances-may be neglected). Static Head or Pressure: The radial pressure within an enclosure, tending to burst it. (This is also termed frictional or resistance pressure or maintained resistance). Steam: Steam is water vapor which exists in the vaporous condition because sufficient heat has been added to the water to supply the latent heat of evaporation and change the liquid into vapor.' Steam in contact with the water from which it has been generated may be dry-saturated steam or wet-saturated steam. The latter contains more or less actual water in the form of mist. If steam is heated, and the pressure main tained the same as when it was vaporized, its temperature will increase and it will become superheated. : , 594 Chapter 42--Heating and Ventilating Standard Terms Steam Heating System: A heating system in which heat is trans ferred from the boiler or other source of steam, to the heating units by means of steam at, above, or below atmospheric pressure. ' Steam Trap: A device for allowing the passage of condensate and preventing the passage of steam, or for allowing the passage of air as well as condensate. Superheated Steam: See steam. Supply Mains {Steam): The pipes through which the steam flows from the boiler or source of supply to the run-outs and risers leading to the heating units. Surface Conductance: The amount of heat (Btu) transmitted by radiation, conduction and convection from a surface to the air or liquid surrounding it, or vice versa, in one hour per square foot of the surface for a difference in temperature of 1 deg between the surface and the sur rounding air or liquid. Synthetic Air . Chart: A chart for evaluating the air conditions maintained in a room. Thermostat: An instrument which responds to changes in tempera ture and which directly or indirectly controls the source of heat supply. 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 Air Conditioner: A self-contained air conditioning plant which provides for humidification or dehumidification, air washing, heating or cooling, and includes spray nozzles, air re-heater, fan, pump, automatic control, all within a common enclosure. (As a rule the outlets are designed to accomplish air distribution without ducts). Unit Cooler: A combination of a cooling coil and a fan or blower, erected as a unit and having a common enclosure. (As a rule the outlets are designed to accomplish air distribution without ducts). Unit Heater: Any combination of a heating unit and a fan or blower, having a common enclosure and placed within or adjacent to the space to be heated; generally no ducts are attached to the inlets or outlets. (Unit heaters are designed primarily for industrial use). Unit Ventilator: A unit heater designed to use all or part outdoor air with or without alternate provision for handling recirculated air. (Unit ventilators are intended primarily for school and office ventilation). Up-Feed System {Steam): A steam heating system in which the supply mains are below the level of the heating units which they serve. 595 American Society of Heating and Ventilating Engineers Guide, 1934 - Vacuum Heating System: A two-pipe steam Keating system equip ped with the necessary accessory apparatus which will permit operating the system below atmospheric pressure when desired. . , ' Vapor : Any substance in the gaseous state. Vapor Heating System: A steam heating system which operates under pressures at or near atmospheric and which returns the condensa tion to the boiler or receiver by gravity. (Vapor systems have thermo static traps or other means of resistance on the return ends of the heating units for preventing steam from entering the return mains; they also have a pressure-equalizing and air-eliminating device at the end !of the dry return. Direct Vent Vapor System: A vapor heating system with air valves which do not permit re-entry of air. Velocity: The time rate of motion of a body in'a fixed direction. In . ' - ' . s the fps system it is expressed in units of one foot per second.. V = --. Velocity Head or Pressure:: The head or pressure required to create the velocity of flow, that is, the head or pressure required to accelerate the mass from a state of rest to the velocity at the point measured. Ventilation: The process of supplying or removing air by natural,or mechanical means, to or from any space. Such air may or may riot have been conditioned. (See Air Conditioning). : Warm Air Heating System: A warm air heating plant consists of a heating unit (fuel-burning furnace) enclosed in a Casing, from which the heated air is distributed to the various rooms .of the1 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). ABBREVIATIONS2 Absolute...... .:........... .........:......... :..... ........-......................................... -----......... .......... .... ...:.abs Acceleration, due to gravity.............................. ........................ ........................ ,......................... g Acceleration, linear............ .......... ---.... 1...............--........ !.......... .......................... .......-......... ..a Air horsepower...........'............................ .-............ ......... ............. --..........:..... -a'r hp Alternating-current (as adjective)--................................................................................. -......-a-c Ampere.................... ................................... --.................. ....................................... --............... .amp Ampere-hour.--.....!............................... --....................... -............----..............:...... :........ amp-hr 'From compilations of abbreviations approved by the Americdn-Standards Association...... 596 Chapter 42--Heating and Ventilating Standard Terms Area........................................................... ................ Atmosphere-..... .................................................................. Average............................................................ .................. Avoirdupois........ ............................ .......................;....... Barometer.......................... ............................................... Boiler pressure-.--................. ,................. ,................ .... Boiling point--_,.............................................................. Brake horsepower....... ,......,............. ,......... ............. .... Brake horsepower-hour...................... ............. ,............ British thermal unit.....................,........... ,___ ...... Calorie,-,--......................................... Centigram..-,..,.......... ,,......................... ..........,......... Centimeter.....,..................... ,,,.......... ,____,___ ___ Centimeter-gram-second (system)...,..,.............. Change in specific volume during vaporization........ Cubic.,.............. ...................................,.................... ........ . Cubic foot.............. ,................. ....................................... , Cubic feet per minute.,--.............. ,,............................... Cubic feet per second,..----............................. ........... Decibel........ ........................ ,........,....... .......... ...... Degree3..:____________ ............................................ .,. Degree centigrade...................... ........................... Degree. Fahrenheit--............. .......... --............. ,.............. Degree Kelvin...:...................... .......,.....--................. . Degree Reaumur..___ .1............;.................... ;.............. Density, Weight per unit volume, Specific weight... - ....................... ' ' -1 ........... A ;............. atni ........... --avg .... ........ avdp .............. bar. ........... -.......--hp ___ ____ blip ......... bhp-hr ................Btu ..........,..... cal ...... -.......... eg ................ cm ................ cgs .... fg .................:cu .... ........ cu ft ...............cfm .................cfs ............ db .......deg or " :..................C ......... ,..... F ............... ........K ................ R d or p (rho) Diameter............................ .................................................... .......................................:...D or diam Direct-current (as adjective)............................. ................................................;.......................d-c Distance, linear................ ..................................................... ................................................ ........... s Dry saturated vapor, Dry. saturated gas at saturation pressure and temperature, Vapor in contact with liquid..... :......... ............ ,,................. ..............................Subscript g Entropy (The capital should be used for any weight, and the small letter for unit weight) ............ ;.....:................. :................. ............ 1........................................................5 OT S Feet per minute...............:...... ................. .................................... ....... .............. ............ .......... fpm Feet per second-......................... .................................................!....:......,............................... ...ips Foot...... ..:........... --.............. ............... 1.......................................... ............................... :............. --ft Foot-pound........ ......................................................................... ;....... ........... .......... ............ . .ft-lb Foot-pound-second (system)..... ............................................................. ......................... ......... fps Force, total load.................... L ................................................................ ....................................F Freezing point. ................................... ,.............. :.................................................................. ,....... fp Gallon................................................. .,............................................................................................gal Gallons per minute............................................. .,....................,......................................... ,......gpm Gallons per second--..... --......................... ............ ........... ......... .............................. ............gps Gram................... ............ .................................................... ............ :: -....................................g Gram-calorie:.........--......... ............ ....................................... ................................................ . g-cal Head............................................................................. :............................................................ H or h Heat content, Total heat, Enthalpy. (The capital should be used for any weight and the small letter for unit weight).........................--..................... ................. ...II or h Heat content of saturated liquid, Total heat of saturated liquid, Enthalpy of saturated liquid, sometimes called heat of the liquid-............... ......................:......... h; Heat content of dry saturated vapor, Total heat of dry saturated vapor, Enthalpy of dry saturated vapor......................................... ................................................................. Ag Heat of vaporization at constant pressure ....... ......... .....,........ !_..............................L or Afg Horsepower................................................... ................. .................................................... .......... 'hp Horsepower-hour..._......................................................................................................,........... hp-hr Inch.............................. .........................:................................................ ................................ -..--in. : *It is recommended that the'abbreviation for the temperature scale. F, C, K, etc., be included in expres-, sions for numerical temperatures but, wherever feasible, the abbreviation for degree be omittedas .68 K. 597 American Society of Heating and Ventilating Engineers Guide, 1934 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 Kilogram.......................... kg Kilowatt.............................................................................................................................................kw Kilowatthour.......................................................................................... kwhr Length of path of heat flow, thickness.................... L Load, total..... ....................................................................................................................................W Mass..................................................................................................................................................... Mechanical efficiency.......................................................-........................................--..................m Mechanical equivalent of heat.__............................................................................... J Melting point........ ................................... mp Meter....................................................................................................................................................m Micron.... ...................................................................................................... -........................... V- (mu) Miles per hour..........:....................................................................................;............................. mph Minute...... .............................. -.......................... ....... ................................................ -..................m'n Molecular weight....................-.................................... ..................... --.-...................... .....mol. wt MoL........... .............................................................. mol Ounce.................................................. -----....................................................... .--.......... ................oz Power, Horsepower, Work per unit time..................................................................................-P 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--................................................... Q 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 i Specific gravity............. .............................. ...............................................................................sp gr Specific neat........................ ...............................-................................................ -.......... -~sp ht or c Specific heat at constant pressure................................................................................................ tp Specific heat at constant volume........................................ ......................................................... Specific volume, Volume per unit weight, Volume per unit mass.................................. ,......v Square foot...-.................................. .......................-.............. -......... -............................. -...... vsq ft Squarelnch................................................. _................................................................ ............. in. sq Temperature (ordinary) F or C. (Theta is used preferably only when t is used for Time in the same discussion)............;.............. :...................................-.......t 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 C=-- =-- = ? ' R L ti -- ti Thermal conductance per unit area, unit conductance (heat transferred per unit time per unit area, per degree).........................................................................-......C* A RA A(t,-l,) L Thermal conductivity (heat transferred per unit time per unit area, and per degree per unit length)..........................................................................-------- ---------- g . k = (ti A -- <>) L 4Terms ending ivity designate properties independent of size or shape, sometimes called specific proper ties. Examples are--conductivity and resistivity. Terms ending once designate, quantities depending not only on the material, but also upon size and shape, sometimes called total quantities. Examples are-- conductance and transmittance. Terms ending ton designate rate of heat transfer. Examples are--con duction and transmission. ' -' . 598 Chapter 42^--Heating and Ventilating Standard Terms 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)................................. ......................... ............. ......................................................... ./ /= g A it -- /* (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 U= g A t, - t, . Thermal transmission (heat transferred per unit time)...........................................................q Thermal resistance (degrees, per unit of heat transferred per unit time)...........................R Thermal resistivity...... ...... 1/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.................................. ,................................................................................................................. w Watthour................. ..................................... ;............................................................................... whr Weight of a major item, Total weight...... ................................................................................. W Weight rate. Weight per unit of power, Weight per unit of time.................... :................. w 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. Powers and Work 1 ton refrigeration Latent heat of ice 1 Btu 1 watthour 1 mean calorie 200 Btu per minute 143.33 Btu per pound 777.5 ft-lb 0.293 watthours 252.02 mean calories ( 2,655.2 ft-lb I 3.415 Btu | 3600 joules { 860.648 mean calories f 0T003968 Btu \ 3.085 ft-lb ( 0.0011619 watthours 599 American Society^/ Heating and Ventilating Engineers. Guide, 1934 1 kilowatt (1000 watts) 1 horsepower 1 boiler horsepower - Weight and Volume 1 gal (U. S.)................. ' 1 British or Imperial gallon 1 cu ft 1 cu ft water at 60 F 1 cu ft water at 212 F 1 gal water at 60 F 1 gal water at 212 F ... 1 lb (avdp) 1 bushel 1 short ton 1 long ton . Pressure 1 lb per. square inch 1 oz per square inch 1 atmosphere 1 in. water at 62 F 1 ft water at 62 F 1 in. mercury at 62 F Metric Units ...... 1 cm 1 in. 1m lft 1 sq cm 1 sq in. 1 sq \n 1 sq ft 1 cu cm . :. { 1.3405 horsepower 56.92 Btu per minute . 44,252.7 ft-lb per minute , ( 0.746 kilowatt Z, I 42.44 Btu per minute | 33,000 ft-lb per minute { 550 ft-lb per second = 33,471.9 Btu per-hour. . , . ;; _ / 231 cu in. ~ \ 0.13368 cu ft = 277.274 cu in. _ / 7.4805 gal ~ \ 1728 cu in. . <= 62.37 lb ' = 59.76 lb = 8.34 lb = 7.99 lb / 16 oz \ 7000 grains = 1.244 cu ft = 2000 lb = 2240 lb I 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 f 0.1276 in. mercury at 62 .F \ 1.732 in. water at 62 F. 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 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 sq m = 0.061 cu in. 600 .Charter 42--Heating and .Ventilating Standard Terms 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) 16.39 cu cm = 35.32 cu ft -: = 0.0283 cu m = 1000 cu cm = 0.264 gal .. = 2.20461b = 0.4536 kg = 2205 lb (avdp) .. = 980.59 dynes = 0.002205 lb = 0.6214 mph . . . . ,,, _ / 0.0290 in. mercury, at 0 deg'C \ 0.394 in. water, at 15 C = 14.22 lb per square inch - _ f 0.03614 lb per cubic inch \ 62.43 lb per cubic foot = 0.00007233 poundals _ / 10,000,000 ergs ' \ 0.73767 ft-lb . , .. {75 kg-m per second 0.986 hp (U. S.) ' { 1000 gram-calories ;(small . calorie) 1 kilogram-calorie per kilogram 1 gram-calorie per square centimeter = 1.83.B97tuBptuer pound = 3.687 Btu per square foot 1 mtte^'0"6 Per SqUare Centimeter ^ Centi` = }l-451 Btu per square foot per inch 1 gram-calorie'per second per square centimeter (2903 Btu per hour per square foot for a temperature graduation of 1 deg C per = ( fora temperature graduation of centimeter ( 1 deg F per inch of .thickness. SYMBOLS FOR HEATING AND VENTILATING DRAWINGS5 1. The objects of this standard set of symbols are to ihsure'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 insofar as possible but Hhe list imnnot be expected to match exactly the existing practice of every drafting room. . 2. Simplicity, ease of execution and unmistakable identification were carefully con sidered in .selecting the symbols. Uncommon fittings and appliances such as vacuum pumps, separators, etc., have purposely been omitted in order to produce a list which can be easily remembered. It is assumed that when the scale of the drawing permits, the valves'and fittings will be drawn to scale and a conventional representation is then unnecessary. 3. High pressure steam supply pipe 4. Low pressure steam supply pipe 5. Hot water pipe--flow 6. Return pipe--steam or water 7. Air vent line From A.S.H.V.E. Code of Minimum Requirements for the Heating and Ventilation of Buildings, edition of 1929. 601 . American Society of Heating and Ventilating Engineers Guide, 1934 8. Flanges ' 9. Screwed union 10. Elbow 11. Elbow--looking up ' 12. Elbow--looking down 13. Tee 14. Tee:--looking up 15. Tee--looking down ' ~ft- u c*-- ei-- -lhHf- 16. Gate valve 17. Globe valve 18. Angle valve 19. Angle valve--stem perpendicular m- 20. Lock shield valve 21. Check valve ,, 22. Reducing valve -fy- 23. Diaphragm valve 24. Diaphragm valve--stem perpendicular 25. Thermostat 1 26. Radiator trap--elevation 602 . 'of-. . -9- Chapter 42--Heating1 and Ventilating Standard Terms 27. Radiator trap--plan 28. Expansion joint 29. Column radiator--plan ' 30. Column radiator--elevation 31. Wall radiator--plan 32. Wall radiator--elevation H0 F=l 33! Pipe coil--plan 34. Pipe coil--elevation . 35. Indirect radiator--plan - 36. Indirect radiator--elevation S H 0 GJM 37. Supply duct--section 38. Exhaust duct:--section 39.. Butterfly damper--plant (or elevation) 40. Butterfly damper--elevation (or plan) 41. Deflecting damper--square pipe /~ -k1- 42. Vanes 43. Air supply outlet 44. Exhaust outlet American. Society of Heating and .' Ventilating Engineers Guide, 1934 A.S.H.V.E. CODES ; ^i : Various codes and standards relating to the design, installation, test ing, rating and maintenance of materials and equipment used for the heating and ventilation of buildings, have been adopted by the Society as follows: ' ' 1 Subject Title When Adopted ' " ' Reverence ' ' , Air purity Synthetic Air Chart June, 1917 A.S.li.V.E. Transactions, Vol. 23, p. 607, and The Guide, 1931 Boilers (testing) Standard and Short-Form Heat Balance Codes for Testing Low Pressure Steam Heating Solid Fuel Boilers (Codes 1 and 2) June, 1929 A.S.ILV.K. _ Transactions, " ' Vol. 35, 1929,. , Boilers (testing)... A.S.H.V.E. Performance Test Code for Steam Heating Solid Fuel Boilers (Code 3)a J une, 1929 . A.S.H.V.E. Transactions, Vol. 35, 1929. Boilers--: Oil Fuel (testing) A.S.H.V.E. Standard Code for Testing Steam Heating Boilers Burning Oil Fuel June, 1932 A.S.H.V.E: v Transactions, Vol. 37, 1931 Boilers (rating) A.S.H.V.E. Standard Code for Rating Steam Heating Solid Fuel Hand Fired Boilers January, 1929 Revised April, 1930 A.S.H.V.E. : '< Transactions, Vol. 36, 1930, p. 42 Convectors A.S.H.V.E. Standard Code for Testing and Rating Concealed Gravity Type Radiation . (Steam Code) January, 1931 A.S.H.V.E. Transactions, Vol. 37, 1931, p. 367 Ethics Code of Ethics for Engineers January, 1922 A.S.H.V.E., ,, Transactions, ' Vol. 28, 1922, p. 6 (See frontispiece : The Guide, 1934) Fans Standard Test Code for Disc and Propeller Fans, Centrifugal Fans and Blowers May, 1923. Revised June, 1931 A.S.H.V.E. Transactions, Vol. 29, 1923, "" p. 407b Garages Code for Heating and Ven tilating Garages June, 1929 A.S.H.VE. 'Trans actions, Vol. '35, 1929,' p. 355 ,, , Heat transmission through walls Standard Test Code for Heat Transmission through Walls January, 1927 A.S.H.V.E. Transactions, Vol. 34, 1928,p. 253 Minimum requirements Code of Minimum Require ments for Heating and Ventila tion of Buildings, Edition--1929 June, 1925 A.S.H.V.E.. Codes Originally adopted by the National Boiler and Radiator Manufacturers Association. bAlso, see Heating, Piping and Air Conditioning, August, 1931, p. 743. 604 \. ' Chapter 42--Heating and Ventilating Standard Terms Subject Pitot tube Title Code for Use of Pitot Tube When Adopted January, 1914 Reference A.S.H.V.E. Transactions, Vol. 20, 1914, p. 211 Radiators Code for Testing Radiators January, 1927 A.S:H.V.E. Transactions, Vol. 33, 1927, p. 18 Unit heaters Standard Code for Testing and Rating Steam Unit Heaters0 January, 1930 A.S.H.V.E. Transactions, Vol. 36, 1930, p. 165 Unit Ventilators A.S.H.V.E. Standard Code for Testing and Rating Steam Unit Ventilators June, 1932 A.S.H.V.E. Transactions, Vol. 38, 1932, p. 25 Ventilation Report of Committee on Ventilation Standards August, 1932 a.s.h.v:e. Transactions, Vol. 38,1932, p. 383 The following Codes and Standards have been endorsed or approved by the American Society of Heating and Ventilating Engineers: Subject Chimneys Piping systems Warm air furnaces Title Sponsored bt Reference Standard Ordinance for Chim National Board of Chapter 14, ney Construction Fire Underwriters The Guide, 1931 Identification of Piping Systems'1 American Society Heating, Piping and of Mechanical Air Conditioning, Engineers July, 1929 Standard Code Regulating the National Warm National Warm Air Installation of Gravity Warm Air Heating As Heating Association, Air Furnaces in Residences sociation Columbus, Ohio Adopted jointly by the Industrial'Unit Heater Association, and the A.S.H.V.E. dAdopted November, 1928. Sponsored by (1) American Society of Mechanical Engineers, (2) National Safely Council. 605 I INDEX Technical Data Section (Pages 1-605) CROSS REFERENCE TO SUBJECTS IN CHAPTERS 1-42 ALPHABETICALLY LISTED A Page Air conditioning (continued) Page Abbreviations 596* air washers 54.123,308 Absolute humidity 2, 587 all year 158 7 Absorption of sound 246 application of comfort charts 32 Absorption system of refrigeration 137 A.S.H.V.E. standards 34 Acclimatization 25 by-pass method 127 Acoustics 241 central fan cooling systems 123 effect of humidity , - 254 central fan heating systems 291 Acoustical treatment * . 247, 308 central fan systems, control of 304 Adiabatic saturation of air 5 comfort chart . 28, 32 Adsorption and absorption 134 cooling load 115,161 Air cooling methods 123,133.159 adiabatic saturation of * 5 . Dalton's law 1 amount per persdn 37 dehumidifier method 123 cleaners ., 217, 587 .dew-point temperature 1 for combustion of'gas 376 definition 587 combustion of oil 383,387 dry- and wet-bulb temperatures 1 combustion of solid fuels . 367 drying ` 49 composition and vitiation of . 19 duct design 255 cooling 115,123, 133 effective temperature index' 24 density of 578 enthalpy 11 dry 589 evaporation, rate of 16,45 ducts ' . 255. 261, 310 fan furnace system 305, 590 flow control 63 fan furnace systems, control of 311 . friction in pipes 257 filters 217 leakage 93 ' fundamental principles of control 199 mixtures with saturated water vapor '6 heat and moisture losses 41 motion of 36 heat content 10 properties of 578 heat transmitted by evaporation 16 pollution . 207 humidifiers 54,123,308 quality for ventilation 36 humidity 2 quantity for ventilation 64 ice for air cooling 165 recirculation of 39,123 . industrial 51 saturated. - . 579 ionization ' 39 spaces, conductance of 74 libraries 50 standard 594 local recirculation method 129 thermal properties 582 mixtures of air and water vapor 6 velocities in ducts 261,287 ozone 39 volume of 6, 34. 578- partial pressure .1 weight of . 581 psychrometric chart 13 Airation, predetermining 59 recirculation ' 39,129 Air changes 100 - refrigeration as applied to 137 Air circulation 273 relative humidity 2 Air cleaning devices 217 sound control 241 Air conditioning standards for comfort 27,34 absolute humidity 2,587 steam jet cooling system 141 adiabatic saturation of air 5 summer 160 air cleaning devices 217 sun effect on buildings 116 air cooling, methods of 123 . surface cooling method 130 air distribution . 34, 36,273 ' systems, control of 37 air distribution within enclosures 273 temperature rise - 37 air ducts, design of * * . 255 . thermodynamics of 1 air motion . ' . 34,36 ' total heat 10 air quality 34,36 ultra-violet radiation 39 V air quantity #. air washer characteristics 34, 37 147 unit conditioners and coolers winter 159 160 607 American Society of Heating and Ventilating Engineers Guide, 1934 Page Page Air conditions ' optimum 27 summer 33, 35,148 Air coolers 159 Air cooling methods of 115,159 Air distribution 273 Air ducts, design of 255, 261,310 Air filters 217, 308 Air flow 57 Air leakage through walls ' 94 Air leakage through window and door cracks 96 Air motion, temperature and humidity 25 Air movement, measurement of . 571 Air requirements 34 Air spaces 74 Brass valves ,. Breechings Brine cooling . British effective temperature British thermal units Building materials, conductivity of Buildings multi-story . - Burners automatic . coal gas. oil noise in By-pass method' - 496 343 144 535 588 . 76 99 378,393 377 390 382 243 123,127 Air supply Air vent systems 419,449 Air washers , . 54 123,147,308 Ammonia . Aluminum surfaces A.S.H.V.E. codes A.S.M.E. boiler construction code 75 604 343 Analysis - . '. ' of coal .. flue gas Anemometers . Aneroid barometer Anthracite coal . Apartment house stokers Areas where transmission losses occur Arrangement of drive for fans Asbestos, pipe covering Atmospheric cooling . 365 574 571 569 365 379 72 236 508 150 Atmospheric pollution, abatement of Atmospheric systems Automatic controls Automatic stokers 427 185 378 Cabinet-enclosed heating units. Calculations cooling load heating load calorie . . for transmission losses . Calorific values . estimating fuel consumption : ' gaseous fuels liquid fuels . solid fuels Carbon dioxide ' Cast-iron, fittings Cast-iron pipe .* expansion -a Ceilings, heat loss !' Central fan systems . control of cooling design of. .' . electric 411 115,161 103,110 \ 588 71 403 376 374 366 574 498 491 455,495 87 588 192 123 295 543 B heating residence type . . . 291 305 Babcock's formula Baffling of boiler tubes Banana ripening .. Barometers Bends, pipe Bi-metallic thermostats Bituminous coal Blast heaters . ' 441 temperature control of . 335 types of 53 Central heating . 569 Centrifugal catchers 494 Centrifugal fans 187 test code 366 Centrifugal pumps . 293 Charles' law . 304 291 519 214 225,307 227 434 . ' 579 Blow-off connections - 342 Blow-through arrangement, central fan systems 295 ( unit systems - 172 Boiler 587 care of 345 cast-iron ' 331 central fan system 303 combustion rates 332 connections ' 342,457 corrosion . 345 cleaning - 344 efficiency 337 erection 343 fittings 342 furnace design / 334 gas fired 333,341,391 heating surface 335, 587 heat transfer rates 335 Chimney characteristics of natural draft connections construction draft for combustion economical sizes equations . for gas heating mechanical draft natural draft performance chart table of sizes tops Cinder catchers, testing of Cinders, disposal of - Circulation, air . - steam water . '' 351 , 343 362 358 . 356 354 . 362 349 347 ' 358 357 363 214 215 273 419 . 471 horsepower. ' hot water supply insulation maintenance oil fired , operation . 588 Cleaning 333 boilers . 346 filters . 343 Clearance, window sash 386 * Climatic conditions 343 Clock thermostats . 344 223 97 - 108 188 output rating setting selection of . steel , testing codes Boiler settings . Booster coils Booster fans Bourdon tube ' Boyle's law Branch connections ' 336 4 336,394,604 390 337 336, 604 334,390 293 330 569 ' 577 421 Coal . classification draft required firing relative heating cost Coal-fired furnaces Codes and standards . Coefficients of transmission Coke Cold, adverse effects of . Cold air returns Cold storage units . 365 , 369 370 406 306,317 604 72,80, 507. 588 372 22 324 . 163 608 Alphabetical Index to Technical Data Section . . Page Collectors for exhaust system 288 Combined heating and ventilating system Combustion 171. 291,305 air for . of fuels rates of ` Comfort chart, line, zone Comfort charts, application of Comfort cooling Comfort, sensation of warmth Comfort zone Commercial stokers Compressors, refrigerating Condensate \ ` 367,376,383 382 332 . 28 32 133 25 28 380' 144 methods of returning . 434.437 Condensation meters 529 Condensation on building surfaces 113 Condensation pumps 434 Condensers 147 Conditioning and-drying 49 Conductances of materials 76,82. 588 Conductivities of materials 76,82, 506, 588 insulated pipes - 507 Conduit, pipe . . 518, 521 Connections boiler 457 drip . . 469 Hartford ' 459 header ' 460 heating unit 462, 464,466 meter 530 radiator 461 steam piping . 457,488 Construction code for low pressure heating boilers '' - 343 Control (see also temperature control) air conditioning systems air flow ' cooling units damper electric heating . fan fan furnace 198 63 198 62 545 62 205, 311 gas appliances humidity sound - unit ventilator Convection- _ Convectors . . 198 200 241 180 589 cabinet connections to heat emission of selection of - rating . . temperature control of wall enclosed Conversion burners (gas)- Conversion equations and units . 414 463 407 414 415 189 414 341. 393 599' Coolers, air, water, and indirect 144 Cooling effect ' 4,16,123 evaporative 134 load 115,161 methods . 133,137, 309 problems 123,162 steam jet ., 141 systems 54,123,150,159,309 towers . 144,151 Cooling and dehumidifying 4,16,123,133,150,159 Copper pipe . . 491 expansion ' 495 Corrosion 345,497 Crack, window 97 D Dairy barn ventilation Dalton's law Dampers Decibel Definitions . Degree-day Dehumidifiers ^ 69 .. 1 310 589 587 399,402, 589 54,123 Page Dehumidifying and cooling Density 133 of air 589 of insulating materials. of smoke 76 575 of water Design load 580 337 Design temperature Dew-point temperature 117,153 1, 589 Diaphragm type thermostats Diffusers Direct-acting thermostats Direct boiler heating surface Direct current motors Direct heaters for hot water 187 311 186 335 238 333 Direct return hot water systems Disc fans, test code for District heating /- 472 227 519 conduits for . 521 pipe sizes 520 service connections ' 526. Domestic hot water supply 388 Domestic oil burners Domestic water requirements 382 549 Doors Downfeed piping systems 59,92 . 422,424,426,429,550,589 Downward system of air distribution 277 Draft - chimney ' 347 draft-producing systems 57, 349 equations 356 forced gage head induced .. . 349 569- 589 349 natural required for solid fuels . Drain connections 57,347 . 358 342 Drawings, symbols for . 601 Draw-through arrangement, fan systems . 293 Drives for fans 236 Dry-bulb temperatures . . 1,104,589 Dry filters 219. Dry returns . 590 Drying * '' 49 Ducts, air cold air \ . 255 324 construction of 271,286 design of ; exhaust system noise control 255,261,310 286 . 253 recirculating rectangular round . temperature loss velocities in Duct thermostats Dust Dust and cinders, disposal of Dust and cinder catchers Dust collecting, fans for Dust determinations . Dynamic head Dynamic losses in ducts 297 261,287 188 207, 590 215 214 234, 289 574 .590 255 E Effect of paint on radiators. Effective temperature definition of . chart . ' Efficiency of boilers of fans ' of filters ! . Elbow equivalents, hot water of pipes Elbows . cast-iron dimensions of.. ' friction in welding Electricity, heat'equivalents of Electric heaters . 409 26.590 24 337 227 . 218 475 446 499 497 256 ,501 546,600. . 542 609 American Society of Heating and Ventilating Engineers Guide, 1934 Page Page Electric roof ventilators Electric unit heaters Electrostatic precipitators Enthalpy . 62 Flow, of water 543 friction of 214 in pipes 11 Flow meters . 554 471 528 Equations, conversion Equivalent evaporation . ' . 599 Flue gas 337 analysis . .574 Erection of boilers . Estimating fuel requirements approximations - degree-day method . fuel values in heating efficiencies heating up building structure hourly heat loss - industrial degree-day non-heating periods relative heating costs ' Estimating heating requirements 343 Flues . chimney 357 403 dairy barn . 68 402 Fluid meters ' 528 398 Foodstuffs 48 400 Forced circulation hot.water system 473 397 Friction, head 257 403 loss of ' . 259 400 Friction losses in ducts 257 406 Fuel consumption ' * 397 Fuel values 366, 398 climatic conditions factors goveming heat ,demand floor level ' heat from other sources heat loss computations high ceilings inside temperatures outside temperatures wind movement 108 103 105 107 110 106 104 106 107 Fuels classification . gaseous heating value oil solid Furnace capacity, gravity warm air Furnace design of boilers . Furnace dimensions for stokers 365 376 366 374- ` 365 324 334 390 Estimating hot water demand 567 Furnace size for mechanical warm air system 312 Eu patheoscope Evaporation, rate of Evaporative cooling Evaporators or coolers Exhaust head . Exhaust systems ` Expansion bends joints ' linear of pipe . thermal Expansion tanks, hot water Extended surface radiator . Extra strong pipe F . 540, 676 Furnace - 16,45 - design J 334 134 selection of 312 54.1& standard code 391 60 volume 591 279 warm air, gas fired 306; 390 Fumes * 212, 590 456,494 . , 455,491 G 493,495 Gages - 342, 569 491 Garage ventilation ` 69 495 Gas, analysis 574 486 boilers 328, 391 414 burners 392 492 furnaces 306, 390 unit heaters 391 water heaters , 393 Factors governing heat demand Fan and motor characteristics Fan furnace systems Fans blast heating booster . characteristic curves control of . drives . ' 103 227,238 305, 590 ' 225 . 2o9o3n 227 234, 239 234 Gaseous fuels calorific values combustion characteristics properties of relative heating costs Gas fired heating systems Gas heating appliances . control of > Gas heating, chimneys for 375 376 375 376 406 394 390 198 362 drying . 233 Gas scrubbers 215 forced draft furnace heating - 349 Glass 305 heat transmission 119 noise . 249 Glossary of heating and ventilating terms 587 power consumption rating of - 235 Grate area ' - 252 Gravity circulation, hot water . 324,591 471 selection of stoker 231,289,314 349 Gravity indirect heating systems Gravity steam heating systems 417 419,449 testing code 604 Gravity warm air heating systems 59J ventilating ` 232 booster fans 330 Filters furnace capacity 324 air 217 procedure for design 317 automatic ' 219. proportioning wall stacks - - 320 dry fabric ' furnace 219 215, 289 - 308 recirculating ducts and grilles register sizes . sizes of leader pipes ` `. 321 321 319 viscous Fire tube boilers 219 Green house heating 332 temperatures of _ "54 Fittings areas of flanged screwed . welding Flanges, pipe Floor furnaces,-gas fired 493 Grilles 504 498 H 497 Hand-firing 501 Hard coal 496 Hartford connection . 392 Header 321,591 373 365 343,459 460 Flow, of air in ducts in pipes measurement of Flow, of steam through orifices * through pipes . - 57.255, 273,281. 261. 286 319 571 432 441 Heat capacity 591 measurement of medium sensible and latent 591 591 sources 41,107, 115 Heat and moisture loss from human body 21,41 610 1 Alphabetical Index to Technical Data Section Page Humidity Page Heat content . . 10 Heat emission of radiators and convectors 407 Heat equivalents 101,118 Heat from varying sources . 107 Heat losses ' calculation of ' 110 infiltration . 93 pipes .. 503 Heat pumps 545 Heaters. air blast 293 electric 542 friction thru 294 hot water 388 pipe coil 407 unit 171 Heating . blast 293 costs of 406 district 519 effect . # 407 . electric * 541 fan 171,291,305 gravity 317,419,471 hot water systems ' 471 radiant ' 533 requirements 103 steam 419 surface unit 171 Heating costs 406 Heating efficiencies 337 Heating pumps, steam 435 Heating surface, boiler 335,587 Heating units 171, 331,407 Heating up building structure 400 Heating-up factors ' 338,340 Heating with electrieity 541 Heat loss computations 71 Heat losses for fuel requirements 397 Heat regulation in man 20 Heat transfer rates of boilers 335 Heat transmission . calculation of 71 coefficients 72 measurement of ' 576 through ceilings . 87 through doom . 92 through floors 87 through frame walls 85 through glass " 92 through insulated construction 83-91 . through interior walls 86 through masonry walls 83 through roofs '90 through windows 92 Heat transmitted by evaporation . 16,17* Hill dust counter . 574 Hoods, design of - 283 Horizontal return tubular boilers 332 . Horsepower, boiler 592 Hot box apparatus . 576 absolute definition . effect on acoustics measurement of . relative temperature and air motion Hygroscopic materials ' 2 2,592 254 573 3 25 47 Ice for air cooling . 165 Identification of piping 605 Idle heating boilers, care of' 345 Ignition of oil 374, 383 Indirect-acting thermostats 186 Indirect boiler heating surface ' 335 Indirect return hot water system 472 Individual duct systems 255 Industrial .. air conditioning 47 buildings, ventilation of 57 degree-day 403 humidifying systems 55 processing, temperatures and humidities 51 Infiltration heat losses ' air leakage through walls 93 crack used for computations 99 forces producing infiltration 93 heat equivalent of air entering 101 heating surface for stair-wells 100 multi-story buildings steel sash 99 96 window leakage 95 wind velocity 97 Inside temperatures , 104,105 Installation details, hot water 487 Installation features of gas appliances 395 Installation of ducts 271,286 Installation of oil burners .382 Instruments ' 569 Insulation asbestos ( 508 bare pipe ` 504 building 76,78,79 conduit type 517, 522 conductivity of . 506 density of 76 duct 253 85% magnesia . 507 machinery . 249 pipe . 506 sound 247 thickness of pipe 515 underground. Ionization. 517 39 Iron valves 496 Joints, expansion , ' 455,491 Kata thermometer 573 Hot plate apparatus -- 576 Latent heat Hot water consumption. - 566 Leader pipes, sizes of Hot water demand 566 Libraries, conditioning of Hot water heating Lift, fittings ' booster pumps 485 Linear expansion, table of . expansion tanks 486 Liquid fuels forced circulation 473 calorific values gravity circulation . . 471 relative heating costs with ' . installation details .487 specifications for mechanical circulation 473,485 Load, boiler- . off-peak electric heating system 545 Local recirculating method one-pipe * radiators and convectors 471,481 407 A M- . selecting pipe sizes 472 Machinery, heat from insulation of two-pipe systems 471,481 Mains __ Hot water storage - . 565 hot water Hot water supply 564. return . Human body, heat and moisture, loss'from 21,41 * steam __ water supply ' Humidification for residences 163,201,308 Maintenance of boilers Humidifiers 54,147,159,308 ' Man, heat regulation in . . Humidifying systems, industrial 55 Maximum load, boilers 580, 591 319 50 -430 . 493,495 374 406 - 374 ' 338 129 .-110 476 - 593- 447,595 553 343 20 338 611 American Society of Heating and Ventilating Engineers Guide, 1934 Mean radiant temperature < Mechanical circulation, hot water Mechanical steam heating systems Mechanical stokers Mechanical ventilation Mechanical warm air systems Men working, comfort zone for Metabolic rate Metal ducts 255, 2 Meter condensation steam Metric units . . Micron ` Moisture content Moisture loss from human body . Motive power Motors 145,2 Multiblade fans .- N Natural gas . Natural ventilation . . Nature's dust catcher Neutral zone NichoUs heat-flow meter Noise . elimination, levels Nominal pipe sizes Non-heating periods ' . ' ` Page 533 485 419 377 171, 291 305 32 41 286,310 528 ' 523 . 600 592 47 21,41 235 289.307 225 375 57 216 592 576 . 242 308 244 490 400 Off-peak electric heating system Offset Oil atomization , specifications * Oil burners . air for combustion boilers ' ' boiler settings . commercial domestic . flame - heating water supply - ignition installation of .. - temperature control Oil fired boilers One-pipe hot water systems . One-pipe steam heating systems ' Openings, for ventilation Operation of boilers ' ' Orifices Orsat apparatus Oscillating ventilator Outside temperatures average '* lowest Over-feed stokers . Ozone Oxygen 541 494 383 374 383, 387 386 390 389 382 384 388 384 387 198, 385 336, 386 471 419,424 59 343 432 574 61 106 108 108 378 39 577 Paint, effect of, on radiators 409 Panel heating system . 535 Paper . 48 Partial pressures 1 Performance curves for boiler selection 339 Perspiration . 41,43 Physiological consideration of radiant heating 533 Pipe . bends 494 capacity of 447 conduits ' 321 connections, steam systems. 420,457 copper 491 designation of . 489 diameters . 490 dimensions . 490 district heating 519 expansion and contraction 491 fittings 1 493 Pipe (continued) . . Page friction head . heat loss from insulation - leader radiating surface sizes sweating tables tunnels welding wrought ' 257 503 506 319 504 442, 550 . 514 i 446 524 . 501 492 Pipe coil . . connections . 466 radiators . ' 507 Pipe sizes for domestic water requirements 547 Pipe sizes for hot water systems 472 Pipe sizes for steam heating systems 441,446 Piping expansion return steam symbols water supply -' . -. ' . ^ y) 491 447,448 519 . 601 547 Piping connections . boiler 342,457 radiator , " 462 Pitot tube 571 Pollution, air * 207 abatement of 211 effect on health . 208 industrial . 209 Portable fire box boilers . ' 332 Power . definition of .. . for air washer . - for fan for refrigeration Pre-heater coils . 593 * 150 235 144 293 Pressure- '1 gage ` losses in ducts measurement . .. . partial . . . Properties of air, water and steam Protective devices for oil burners Psychrometer, sling ., Psychrometric ch^rt ,. . Pulverized fuel * 569 255 569 1 577 385 593 13 373 Pumps circulating condensation vacuum Pyrometers . .. . , ' __ 485 434 435 . 570,; 593 R Radiant heaters, electric 542 Radiant heating . methods of application . . ' physical and physiological considerations principles of calculation ; 535 533 536 Radiator^ concealed . . . ' ' 407 connections to 1 ' 462 control of convection .. . 189 414 effect of paint . . , 409 gas-fired steam 409 . heating effect . . 407 heating up . . 411 output of 408 panel . . .. 593 temperature control 189 tests . . 415 types of 407 Radiation, load . . 338 solar Ratings, boiler 11 . 338 Ratings for gas appliances 394 Rayons ' Recirculating ducts and grilles 48 321 Recirculation 39,123 Refrigerants . " *42. Refrigeration for air conditioning 1^1 Registers 311,321,593 612 Alphabetical Index to Technical Data Section Page Page Reheater coils ' 293 Specifications . Relative humidity control of 200 definition of . . . -2 for industrial processing 51 Residences, air distribution in 273 Residences, humidification for 163,201,308 Residential stokers 37s Resistors . 541 Return air ducts " 321 ` Return header . 460 Returns . to boiler to furnace 342,458, 460 . 323 Returns for underground distribution systems 521 Reversed return hot Water systems Ringelmann chart' 472 575 Risers downfeed ` 447 hot water 483 steam supply . 593 water supply 550 Rock wool pipe insulation* 512 ' Roof ventilators : 60,594 Roofs . v ` heat loss from 90 sun effect .116 Room thermostats ' . . ' 188 Rotating ventilators * 63 S Sash, infiltration through ' ' . 395 Saturated air 579 Saturated steam - 583 Scale, formation of .' 345 School buildings, air distribution in 275 Scrubbers . 147,215,219 Seamless pipe * 489,491 Selection factors for gas boilers 324,394 Self-contained thermostats 186 Sensations of warmth and comfort Sensible heat 25 , 594 Service connections, district heating 526 Setting heights for boilers - 390 Settling chambers * . -' 214 Silica gel system 134 Sizing piping systems. atmospheric . '. 453 one-pipe hot water * 471 one-pipe steam 449 orifice 453. return '. . 448 sub-atmospheric 453 two-pipe hot water ' 471 two-pipe steam 450 vapor . 451 vacuum 452 Sizes of pipe " 489 1 . SSSSSSSSSSSSSttttttpptppppeeoppefdddgooeaacaaghptwaclerrorraaoliorlecaniopntnirerithaaaapiepgamicsoatitmmkmwsnewfeddnoyyiyyaeciiihrtmspifnsvcd-raoaemgrnni,tl.pacwyweebgriosiegphfrsrrnffncatifilhsdtidearooecnypfropealzaiheattrotecoesfeotnsieerseahwysteeiyepaoiswnaoedtashemrtteanhaassseinnivtnrcteprnmrnasttiayuaaondeiooiureogcdnnsrstmteefnnrn.ufei,tmdeoctestcseriinstpymioanleticrnaorsud"sclouatntmpeheovp_ncn*sisampierptdtpisrnesoneso.disntcsliialsa(ltt..rri.ioeb' n.tuu.trino. n.422,44-213494. ,,,441252288674697554,,,,,8,5444444414445343455524653529,21414231643151484358202856899645779929914499320113243194410527 * Pumps 421. 426,462, 464, 4.66.468.446394 sub-atmosphenc - 43q traps ." two-pipe system . up-feed vacuum pumps ' vacuum system . vapor system zoned Steam jet cooling system ` . 437 423.424,450 420,423,424 435 429 452 * 424 433 . 141 Steam per square foot of heating surface Steam pipe tables Steam tables ' Steel boilers Steel pipe, expansion of . . Steel sash, infiltration through - 532 443 445 ' 533 33J* 491 495 *96 Stoker-fired boilers, selection of -.Stokers, mechanical Storage for hot water Sun effect on buildings .' . 334 377 565 ng Surface conductance . Surface cooling '. . , ... 595 123 Symbols for heating and ventilating drawings 601 Symbols for transmission formulae 72 Synthetic air chart ' 595 Skylights Sling psychrometer 59 573 T Small heating plants, control of Smoke and dust abatement Smoke breeching connections Smoke clouds . Smoke density, measurement of Smokeless combustion Smoke recorders . Soft coal Solar heat Solid fuels , - air for combustion of calorific values' combustion of draft required .. hand-fired mechanical stokers pulverized . . types of ' Sound absorption, coefficients of Sound insulation * ' Space heaters, gas fired -. Spaces, unheated Specification for liquid fuel 196, 205 211 343 207 575 371 * 575 366 no 367 366 370 369 373 377 373 365 246 247,308 * 392 92 374 Tees, dimensions of . Tempering coils Temperature . attic spaces ' . . basements and unheated rooms control systems dew-point . dry- and wet-bulb inside outside . regulation rise '. . usually specified . Temperature changes, effects of Temperature control air conditioning systems central fan systems, convectors cooling units- heating plants industrial processes oil burners . thermostats 497 293 72 92 189 2 1 68 67 189 37 104 - 23 199 192 189 199 196 199 198 186 613 American Society of Heating and Ventilating Engineers Guide, 1934 Temperature control (continued) unit heaters unit ventilators ' zone , Temperature difference, flow due to Temperature, humidity and air motion ` Temperature measurement Temperatures and wind velocities auto painting brewing confectionery design drug storage drying effective final foodstuffs for banana ripening greenhouse indoor leather lumber . outside .' paint ' printing textiles tobacco winter Test codes, boiler fan a . Textiles . .. Theaters, air distribution in Thermocouples , . ... . . Thermodynamics of air .conditioning Thermo-equivalent conditions Thermometers ' Thermometric chart Thermostats ' Ton, refrigeration Transmission losses area where losses occur basements and unheated rooms . calculations for : coefficients of transmission glass , temperature in attic spaces transfer of heat through walls Traps, dust and cinder Traps for steam heating systems ' Trunk duct systems Tubular radiators . . Tunnels, pipe Two-pipe hot water systems Two-pipe steam heating systems Two-temperature thermostats U Ultra-violet radiation Under-feed stokers Underground insulation steam piping - Unit air conditioners Unit conditioners ' control of location of ' rating of types of Unit coolers Unit heaters - electric output .. piping connections temperature control Unit ventilators ` - capacities location of tempeihture control . Up-feed risers . for cold water ` for steam ' maximum capacities Upward system of air distribution Page V Page 190 192 198 58,63 27 570. 108' 51 51 51 117 51 49 26 249 ^ 51 53 54 104 52 52 106 52 52 52 53 104 336 227 48 276 570 1 25 Vacuum ' condensation meter gage heating pumps 528 569 435 heating systems Valves allowance for control pressure reducing Vanes 429,452, 596 . 496 . 552 455 454 277 Vapor systems Vent flues 4y24,451,59660 Ventilation (see also air conditioning) air quantity dairy barn definition of . ,37,64 68 19, 596 fans for 232 flow due to temperature difference 57 garage ' industrial buildings natural natural and mechanical methods 69 63 57 38 roof stacks for natural ventilation 60 62 wind action 57, 59 Ventilation standards accli matization adverse effects of cold ' adverse effects of heat A.S.H.V.E. composition and vitiation of air 25 22 21 34 19 heat regulation in man 20 temperature changes, effects of 23 Vent outlets Viscous filters 60 220 570 24 186, 595 138 W Wall-enclosed heating units Wall radiators Wall stacks 414 408 320 72 Walls 92 heat transmission thru 71 infiltration 83 94 72 92 92 83 214 437 263,310 408 524 471 423 188 39 378, 595 517 519 157 192,199 161 160 162 159.595 171 543 175 176 190 179.595 182 181 192 551 449 443 276 Warm air furnaces capacity of fan selection of Warm air pipes Warm air research residence Warm air, standard code Warm air systems Warming-up allowance Warmth, sensations of Water make-up properties of rates of flow requirements, domestic * . storage systems thermal properties of Water cooling Water heaters for air washers Water supply systems Water tube boilers Water vapor Weather bureau records Weather compensating thermostats Welding, pipe Wet-bulb temperatures Wind movement Wind velocity average summer " Window leakage ,, Window radiators Window ventilation Winter air conditioners Winter temperatures Wrought pipe expansion of extra strong Z Zero, absolute . Zone control 324 305 '312, 319 326 605 305,317,596 411 . - 25 158 580 554 547 565 582 144,150 147 547 332 6 108,117 . - 188 501 596 57,107,117 . 67 " 108 117 95 407 59 157 104 489 495 492 587 198 614 Catalog Data Section (Pages 615-779) with an INDEX TO MODERN EQUIPMENT (Pages 780-787) and INDEX TO ADVERTISERS (Pages 788-790) Air Conditioning Air-Way Electric Appliance Corporation Air Conditioning Division GENERAL OFFICES AND FACTORY 2101 Auburn Avenue, Toledo, Ohio COMPLETE AIR CONDITIONING SYSTEMS (Unit Type) DOMESTIC AND COMMERCIAL HEATING SYSTEMS (Steam and Hot Water) INDUSTRIAL UNIT HEATERS (Steam and Hot Water) AERIET AIR CONDITIONER--(Ceiling Type) A compact self-contained overhead unit for stores, offices, restaurants, fur vaults, etc., with limited floor space. Combines every facility for complete air con ditioning. Filters, washers, heats, cools, humidifies or dehumidities. Manual or automatic control. Economical to install and operate. An ideal all year air conditioner for commercial use. AERIET AIR CONDITIONER--(Floor Type) Designed for all year air conditioning in homes, offices, etc. Encased in attractive beautifully finished furniture steel cabinet containing complete air conditioning facilities, when connected to steam, refrigeration and electric lines. Cools and dehumidifies in summer, heats and humidifies in winter. Filters, washes and circulates conditioned air through out the year. Units may be operated singly or in multiple according to space and atmospheric require ments. CHASSIS OF AERIET AIR CONDITIONER Constructed throughout of welded aluminum sheets. Light, durable,.strong, non-corrosive, Monel, bronze, stainless steel or copper are used where advisable. Spun glass filters in aluminum frames act as dry air filters and moisture eliminators. Motor fan and pump assembly is compact, strong, silent in operation. All moving parts are readily accessible and inter changeable. Large centrifugal atomizers cannot clog or get out of order. . AERIET HEATING UNITS-- (Steam and Hot Water) A complete line of mechanical convection units for operation on steam and hot water lines, providing accurate, flexible control of heat distribution. Fur nished in cabinets for concealed installation, also in attractive free standing cabinets for radiator replace ments. Furnished in a wide range of capacities and sizes. AIRWAY-UNIVERSAL REFRIGERATING UNITS Capacities from one to ten tons. Designed especially for use with Aeriet Air Conditioners. Compact, completely self-contained assemblies of compressor with full automatic controls, water cooling coils in insulated tank, cold water circulating pump, auto matic condensate elimination. Write for descriptive folders and engineering data. . 617 Air Conditioning American Blower Corporation General Offices: Detroit Works: DETROIT. MICHIGAN ' Canadian Sirocco Company. WINDSOR, ONTARIO Branch Offices in Principal Cities of United States and Canada American Blower Air Conditioning Equipment for the comfort of human beings and efficiency of production in industry .4 typical Sirocco System of Air Conditioning for large buildings, auditoriums or factories Sirocco Systems Sirocco Systems for cooling, heating, humidi fying, dehumidifying and purifying air, in all classes of business and various manufacturing processes, permits control, as desired, of tem perature, humidity and air motion. Component parts: Sirocco or American HS fan and motor, dehumidifier, tempering coils, preheaters, re heaters, spray and circulating water pumps, tem perature and humidity control apparatus and a "Ross" Decalorator, or mechanical refrigeration with accessories. Bulletin No. 2727. Sirocco Dehumidifiers This line of dehumidifiers, air washers, scrubbers and purifiers, commonly referred to as the "Sirocco Washer," is available in standard sizes and designs, constructed of galvanized iron casing and eliminators with welded iron tank. Capacity: 1,000 to 300,000 cu. ft. of air per minute. These washers are built in lengths from 4' 0" to 24' 0" with one to six stages of sprays depending upon the duty to be performed. Also built of special metals when required. Bulletin No. 3523. Sirocco Dehumidifiers and Washers The " Decalorator" for eooling water in connection with Sirocco Air Conditioning Systems 618 Decalorators Decalorators are built and furnished in sizes varying in cooling capacity from 24,000 B.t.u. to 48,000,000 B.t.u. per hour. Chilled or decalorized water is produced by the practical application of a well known physical law, namely: water under high vacuum will vaporize at low temperatures. Decalorators will produce chilled water at a temperature of 38 F. or above. The Decalorator has no moving parts and water is the only refrigerant used. Completely described in Bulletin No. 2927. ! } American Blower Corporation Air Conditioning American Blower Corporation General Offices: Detroit Works: DETROIT, MICHIGAN Canadian Sirocco Company, WINDSOR, ONTARIO Branch Offices in Principal Cities of United States and Canada Manufacturers of Air Conditioning, Heating, Ventilating, Drying, Dust Collecting, Dust Separation, Mechanical Draft, Pneumatic Con veying and all types of air handling equipment for more than 50 years. Sirocco Conditioners Series "O" Series "O'1 Sirocco Conditioners are made in four sizes for comfort cooling of restaurants, shops, hospitals, offices, etc. Units are provided with three-speed switch automatically controlled by means of a thermostat, and can be equipped with wall box for outside air intake. Air filter and humidifier furnished extra. For winter heating, units are connected to hot water boiler. Com plete data in Bulletin No. 2127. Series "0" Conditioner for cooling and heating offices, restaurants and hospitals, etc. Series "R" Conditioner for Homes Sirocco Conditioner Series "R" The Series " R" Conditioner is a complete conditioning .unit for controlling the temperature, humidity, motion and cleanliness of air in the home. For winter heating, is directly connected to hot water boiler (gas, oil or coal fire). For summer cooling, uses tap, ice cooled or refrigerated water. Equipped with a Sirocco electrical control for. regulation of temperature and humidity.' Conditioned air is distributed by means of ducts. For details refer to Bulletin No. 1127. Sirocco Surface Coolers Series "C" Sirocco Surface Coolers can be easily and quickly in stalled to add comfort cooling to many types of venti lating systems which are already installed and in opera tion. A complete Sirocco Surface Cooler consists of casing, tank, eliminators and coils. Detailed informa tion and application data is contained in Bulletin No. 3423. '-- . 619 Surface Coolers for low cost comfort cooling Air Conditioning Carrier Weathermakers to the World ) . 850 Frelinghuysen Avenue - . Newark, New Jersey . NEW YORK DETROIT . District Offices PHILADELPHIA BOSTON CHICAGO DALLAS CLEVELAND LOS ANGELES Foreign and Marine Division--CARRIER-BRUNSWICK-INTERNATIONAL, Inc. NEWARK, N. J. , ' If your problem is air conditioning or any of its related branches--heating, venti lating, humidifying or. de-humidifying, refrigeration or drying--or a combina tion of any of these--Carrier, through its broad engineering service and its complete line of equipment can serve you. Whether you are interested in air con ditioning for large buildings, theatres or department stores, or in providing . summer comfort in a single room or office, ` there's a\ Carrier system exactly fitted to each requirement. The Carrier office nearest you offers a complete service in solving any air conditioning, refrigeration, drying or in dustrial unit heating oroblem. This service is the result of more than 25 years experience in applying the scientific principles of air conditioning, to com mercial structures, industrial plants, laboratories, public buildings, stores, auditoriums, offices, office buildings and ships. .. ucts may be purchased on a merchandise basis for installation by yourself or by contractors. Engineering bulletins and descriptive literature is available to you for the asking. A Carrier representative trained in the analysis of refrigeration, air conditioning or industrial heating problems will call on you without obligation, survey your requirements and recommend the type of system best suited to yo.ur needs. .. An organization of Carrier Dealer-Dis^ tributors has been established in certain cities to provide sales and engineering service for Carrier products. Architects aqd consulting engineers are especially invited to consult with us in laying out air conditioning systems for large projects. The important thing to remember is that from the smallest to the largest requirement, you can secure a Carrier system exactly adapted to the, need at hand. By making use of Carrier service, you are assured of a finely engineered job which, can. be depended on to meet the most rigid specifications plus scientifically de signed equipment which produces results. Or, if you desire, certain Carrier prod We invite you to examine the products illustrated and described on the pages following. If you want full details re garding their design and operation, write Carrier, Newark, N. J., or consult with the district office nearest you. 620 Carrier Air Conditioning Carrier Industrial Weathermaker Unit A complete line of self-contained units for industrial and comfort conditioning, for humidifying or de-humidifying. Each unit is a compact system in itself requiring only heating or refrigeration connections. Equipped for surface or spray type cooling. Capacities range from 1,000 to 10,000 c.f.m. Available in horizontal, vertical, or suspended models. Automatic or manual control. Flexible, easily installed. Per form all the essential functions of a com plete central station system. farrier Central Plant Weathermaker A specially designed standardized assembly to meet the increasingly wide variety of applications in central station air con ditioning systems. These units are offered as a part of a complete air conditioning system, with automatic dew-point control, pre-heater and re-heater sections, spray chamber, damper- control fans and air ducts. Standard for all Carrier air con ditioning systems in theatres, office build ings, large stores and public buildings. In stalled under licenses of Auditorium Con ditioning Corporation. Vertical Type Air Conditioning Unit for control of weather conditions in manufacturing plants. Humidifies, de-humidifies, or heals: washes and circulates the air. .- Complete de-humidifying unit of the kind used in central station air conditioning work, showing air intakes. healing coils, spray heads, fan and control devices. Carrier Store Weathermaker (Type 39F) Especially designed as a suspended unit for stores of all kinds. Air filtering, humidifying and de-humidifying, heating and cooling positive air distribution and automatic control--Lall built into single attractively encased unit, requiring only connections to source of heat or refriger ation. A thoroughly practical all-year- round'system for retail stores, restaurants, small auditoriums, etc. ' View of Store Air Conditioning Unit. Sus pended type. Contains all mechanism for cooling and de-humidifying, circulating and filtering the air. 621 Carrier Air Conditioning Carrier Store Weathermaker (Type 39E) Floor mounted model especially designed for stores of all kinds. Units available in models ranging from 800 to 4800 c.f.m. Air filtering, humidifying and de-humidifying, heating and cooling positive air distribution and automatic control--all built into single attractively encased unit,- requiring only connections to source of heat or refrigeration. A thoroughly practical all-year-round system for retail stores, restaurants, small auditoriums, etc. Carrier Store Weathermaker (Type 39D) For offices and small stores this suspended type comfort cooling unit supplements the larger Carrier store cooling systems. It is made - in one standard size--1 Yi tons refrigerating effect--and its overall dimen sions are 22"x22"x20" malting it flexible, compact and easily installed. It is cleverly designed to harmonize with any style of interior decoration. The fan is of the disc type entirely enclosed in the housing. View of Ulore Air Conditioning Unit complete with casing and ready for refrigerating connections, chamber, heater coils, air filler, cooling coils, re-heater and fan. Carrier . Room Weathermaker . (Cabinet Type) A combination heating, and cooling unit for individual rooms in homes or offices. Encased in attractive jacket, it is hand some in appearance, harmonizes with room surroundings. Heats and humidifies in winter, cools.and de-humidifies in summer. Replaces a radiator in connection with the heating system and connects to source of refrigeration for summer cooling. Con tains air filter, humidifying sprays, fan, heating and cooling coils. One or more cabinets may be installed to meet require ments. Small cooling unit or comfort conditioning unit for offices, stores and shops. s Cabinet model combination cooling and heating unit for rooms and offices, equipped with fans, air filter, spray humidifier, heating and cooling coils. 622 Carrier Air Conditioning Carrier Home Weathermaker (Direct Fired Type) The original complete air conditioning system for homes in winter. A gas-fired centrally operated unit, fully automatic, with electric temperature and humidity control. Positive distribution of clean conditioned air. Available in five sizes from 100,000 to 300,000 B.T.U. output per hour. Manufactured or natural gas. Approved by American Gas Association Testing Laboratories. Automatic gas-fired air conditioning plant for homes. Provides controlled humidity and forced circulation of cleaned air with aoulomatic tern ' perattire control. Carrier Home Weathermaker (Indirect Fired Type) An air conditioning plant for homes, employing steam generated in separate boiler with gas, oil or coal as the heating medium. Contains heating coil, filters, humidifier, fan and automatic controls. Connects to supply and return air ducts. Available in capacities from 100,000 to 300,000 B.T.U. per hour output and in five different sizes. Where it is desired to use both air conditioning ducts and direct radiation in the same installation, the Indirect Fired Home Weathermaker is particularly applicable. Carrier Centrifugal Refrigerating Machine The most outstandingly successful and highly efficient type of large refrigerating machine for central station air .condition ing work--comfort or industrial applica tions. Available in capacities from 25 to 350 tons. Steam turbine or motor driven. Adapts itself automatically to the air con ditioning load. Occupies two-thirds less space for the same capacity than any other system. Operates below atmospheric pressures with Carrene, the harmless, odorless refrigerant assuring absolute safety. This air conditioning unit is sup plied with steam from a separate source and performs the same func tions as the machine illustrated at the lop of the page. Self-contained refrigeration system in ' eluding compressor, evaporator and con denser. The most efficient type of refrigera ting machine yet developed. 623 N/ Carrier Air Conditioning farrier Industrial and Marine Refrigeration Carrier makes a full line of refrigerating machines for every industrial, commercial and marine requirement, using Ammonia, Carbon Dioxide, Freon, Methyl Chloride, Carrene and special refrigerants. Capaci ties range :from 3-2 oth to 120 tons A.S.R.E. rating. For air conditioning service, capacities range from Koth to 350 tons. Whatever your refrigerating problem, whether in a small meat market, a great industrial plant or a merchant vessel, you will find a Carrier machine available for your purpose. The Carrier line is the most complete that the industry offers and is built on over .30 years of practical refrigeration experience. farrier Commercial Refrigeration The Carrier-Brunswick Refrigerating Unit here illustrated, represents one type in a complete line of'small machines available in sizes from to 3 h.p. These units are applicable to comfort air conditioning when connected to Carrier atmospheric cabinets and small store units and for commercial refrigeration purposes in meat markets, delicatessen, groceries, restaur ants, for dairy products, water cooling, etc. farrier Cold Diffuser (Floor Mounted Type) Employs the principle of ductlessly dis tributed air, -positively circulated and automatically controlled as to tempera ture and humidity. These cold diffusion units which are available in sizes from 1200 to 11,000 c.f.m. and capacities from M to 15 tons, are being used in many com mercial air conditioning applications-- meat packing, fur storage, dairy products, etc. Surface cooling or brine spray units are available. 624 Bell driven Ammonia compressor of from 12 to 24 tons capacity. This unit is extremely compact and repre sents the latest refinements in re frigeration machine design. Small refrigerating unit for use with room cooling equipment and for general commercial refrigerating applications. This cold diffuser finds wide applica tion in meat storage plants, for dairy products cooling and meets many other commercial cooling problems. Carrier Air Conditioning Carrier Cold Diffuser (Suspended Type) Similar in principle to the floor mounted type of cold diffuser previously described but made in smaller capacities from l/i to 5 tons. Compact and easy to handle, they take up little space and assure efficient results. Made for single, double and triple fan assemblies--220 to 3800 c.f.m. Where space saving is unusually important, this suspended type cold diffuser meets a long-felt want. Carrier . Heat Diffusing Unit (Floor Mounted Type) The Carrier line of floor mounted .type Industrial Heating Units (formerly known as the York Super-Control Heat Diffusing Unit) embody the most advanced design in unit heater construction and come in a complete range of sizes from 1600 to 16,000 c.f.m. and in two, three and four fan assemblies. Rated from approxi mately 100,000 to 1,000,000 B.T.U. per hour. Carrier Heat Diffusing Unit (Suspended Type) A convenient, flexible system for all kinds of factory and industrial heating, will be found in the Carrier Heat Diffusing Unit, "Kroy" type, here illustrated. These units which range from 400 to 5,000 c.f.m. are of the suspended type and take up little space. They are available in one, two or three fan assemblies. Designed for low outlet temperatures, they concentrate maximum heat in the working zone. Rated from 20,000.to 574,000 B.T.U. per hour. ~ 625 'I The floor mounted model Heal Diffusing Unit shown above is the most advanced type of equipment for industrial use. Unusually efficient type of in dustrial heating unit for con trolled zone healing in manu facturing plants. Air Conditioning Clarage Fan Company MAIN OFFICE AND PLANTS Kalamazoo, Michigan Sales Engineering Offices in All Principal Cities (Consult Telephone Directory) Unitherm Unit Heater Unitherm Unit Cooler AIR HANDLING AND CONDITIONING EQUIPMENT Unitherm Unit Heaters--either floor mounted or suspended units. Standard equipment includes Synchro therm Control (protected by patent coverage) which gives effective heating with low-temperature air and marked savings in fuel cost. Unitherm Unit Coolers--for product or space cooling and refrigeration, producing practically any desired tem perature. Units easily installed, saving labor and materials, eliminating expensive bunkers and wall coils. Air Washer Unit Conditioners--for cooling and dehumidifying, heating and humidifying, maintaining any desired con dition. Offer great flexibility, close control, eliminate duct system--save in both first and operating costs. Air Washers--for air purifying, cooling, etc. Improved spray nozzles make possible very economical operation. Various types and sizes to meet all requirements. Vortex Control--outstanding improvement, with its applications to systems covered by patents granted and pending. Gives any desirable capacity regulation, with the fan operating at constant speed. Does not waste power. Eliminates need for expensive variable speed motor. . Adaptable to any Clarage fan for practically any service. Fans and Blowers-r-complete line for air conditioning, ventilating, mechanical draft, pneumatic conveying, etc. Write for Clarage Catalogs. . Vortex Control--lower opera ting cost than damper con trol; more efficient; no power wastage. Lower first cost than variable speed motor; simple; inexpensive; trouble-free. In stalled in fan inlet as shown above. Automatically con trolled, or manually operated. 626 Boston New York Philadelphia Baltimore Washington Charlotte Atlanta Palatka New Orleans Dallas Los Angeles Air Conditioning Frick Company (Incorporated) Refrigerating and Ice-Making Machinery Waynesboro, Penna. Distributors in 85 Principal Cities Seattle Oklahoma Citt Memphis St. Louis Kansas Citt Chicago Detroit Cleveland Cincinnati Pittsburgh Buffalo Low pressure Refrigeration Ammonia Refrigeration Commercial Units in more than 20 sizes, with motors of ^ hp. and up. Charged with either methyl chloride or freon. Low Pressure Refrigerating Unit Air and water cooled condensers. Finned coils, fan units, ice cube makers, beverage coolers, farm milk cabinets, etc. to suit any need. Bulletin No. 97-A. ` Freon Refrigeration ' Special freon com pressors: vertical en closed machines, in sizes to suit all air conditioning jobs. Pressure lubricated Prick Enclosed Freon Compressor from pump inside crankcase. Ample gas ports and valves: large capacity, compact design, perfection of details. Coils, coolers, condensers and controls for systems using this gas. Condensers of All Types Either vertical or horizontal shell - and - tube designs, double pipe or atmospheric, or fan type, for ammonia, Multipass Shell carbon dioxide, methyl and Tube Condenser chloride or freon. Sepa rators, receivers, etc. Bulletins 228, 230 and 232. Machines in ca pacities from ^ ton refrigeration up. Combined units, vertical enclosed type compressors, horizontal ma chines: for any kind of drive. Full auto matic, semi-auto matic, or hand con Enclosed Ammonia Compressor trol. Widely used in air conditioning. Ask for Bulletins 102, 104, 108, 112 and 138. Carbon Dioxide Refrigeration Compressors of the vertical enclosed de sign, with extra long pistons extending into well lubricated guides in the crankcase: wrist pins are engaged on both sides by forked Enclosed connecting rods. Smooth - running, effi Compressor for Carbon Dioxide cient and reliable machines, in use the country over. 6 sizes, any drive. Bulletins Nos. 118, 124 and 208. Coils and Coolers _ Continuous welded coils, with or without fins, furnished to suit any refrigerant and any requirement. Shell - and - tube, vertiflow, and zig-zag " Instant" coolers for water, brine, air, etc. Also complete line of valves and fittings. Typical Air Conditioning Installations using Frick Refrigeration WU-Low Cafeteria, New York City Valencia Theatre, Chicago 627 Ed. Stem Printing Plant, Philadelphia Air Conditioning Frigidaire Sales Corporation Subsidiary of General Motors Corporation Dayton, Ohio Outlets in All Principal .Cities Air Conditioning Division Frigidaire refrigerating equipment has been applied to air conditioning since 1925. In the ensuing years, thousands of Frigidaire installations have been made, covering practically every type of air conditioning application. Along with this long and varied experience, supple mented by both Frigidaire and General Motors research, a comprehensive line of Frigidaire air conditioning apparatus has been evolved. With equipment to meet the diverse situa tions .arising in the air conditioning field, the Frigidaire organization is prepared and qualified to handle all kinds of air conditioning requirements in residences, stores, offices, hotels, hospitals, railway vehicles, yachts, fac tories, etc. To the problems of air conditioning, Frigid aire is devoting the same inventive and engineering genius which has achieved . leadership in domestic and commercial refrigeration. This is evidenced by the perfection of Frigidaire air conditioning equipment and engineering; also by the de velopment of FREON, the ideal refrigerant, specifically for air conditioning purposes. Frigidaire .4tr Conditioning Cabinet, Vertical Design Sketch Showing Two Cabinete Installed for Selective Operation Frigidaire Air Conditioning Cabinet, Horizontal Design Frigidaire Cabinet Type Air Condi tioners. These are of two classes. One class consists of completely self-contained units for cooling, dehumidifying, cleansing, and circulating the air of a room. The other class consists of units for connection to remote compressors. They may be operated individually or in multiples. In the latter event, any selected number or group of the conditioners may be re frigerated at one time. The cabinets of the second class are attachable to steam or hot water lines, in which event the air of the room is cooled in summer and warmed in winter, as well as properly dehumidified or humidified, cleansed, and circulated. All of these may be installed to use any desired percentage of outside air. . 628 Frigidaire Sales Corporation Air Conditioning Sketch Showing Model SV-3 Installed Over Window Deck of Store Frigidaire Store Type Air Condi* tioners. These comprise cooling coils (or both cooling and heating coils) and fans in housings which have outlets scientifi cally designed for wide-spread air diffusion. Cooling capacity ranges up to 3 tons of refrigeration per 24 hours. Conditioners of this type may be installed on ceilings, Frigidaire Store Type Air Conditioner, Model SU-S on window decks, on platforms, in alcoves, in the bulkheads of railway cars, etc. Refrigeration is supplied by remotely in stalled Frigidaire compressors. Several units may be connected to a single com pressor. Provisions are made for drawing in as large a proportion of outside air as desirable. Frigidaire Central System Cooling Coil Skelch of a Frigidaire Central Cooling System Frigidaire Central System Cooling Coils. Cooling and heating coils of this class are available in numerous shapes and _ sizes. The coils have extensive finned : areas for providing contact with large . volumes of air in relation to the size of the units. These coils are specifically de signed for installation in the cooling and heating chambers of central systems. They can be used with existing warm air systems or with systems providing general ventilation. Frigidaire Compressors. These are made in many sizes from small to large capacity. Each Frigidaire compressor is built like the finest automobile engine, as would be expected of a General Motors product. - Complete, data will be gladly furnished by Air Conditioning Division, Frigidaire 1 riijid'iire h f>ur-(Ajtindrr Compressor, Model FW-7500 Sales Corporation, Dayton, Ohio. 629 Air Conditioning General Electric Company AIR CONDITIONING PRODUCTS Air Conditioning Department, 570 Lexington Ave., New York, N.Y. For Steam, Hot Water, Vapor, or Warm Air Heating Systems, a complete line of Air Condition ing Equipment: The G-E Oil Furnace (2 sizes) Type LA4 and LA5--See Page 666. The G-E Winter Air Conditioner for Warm Air Systems(Type AA3) .--This Air Conditioner, combined with the G-E Oil Furnace, provides all the four functions of winter air conditioning-- heating, humidifying, fil tering and circulation. A fan draws air from the return duct system through dry. steel-wool filters, delivering it over the steam heating surface and humidifying screens, to the delivery duct system. Hu midifying water is heated by an indirect heating coil, flow being controlled by a magnet valve operated from a Humidistat. Cooling coils 'for summer air conditioning optional. Specifications the room. Control of humidification is obtained by means of a magnet valve operated by a humidistat. Specifications Fan--400 c.f.m. Humidifying Capacity -- 1M gallons per hour. Power Input-- 45 watts. The G-E Room Air Conditioner The G-E Room Air Conditioner (2 sizes) provides complete year round conditioning --heating, humidifying, filtering, venti lating and circulating in winter--and cooling, dehumidifying, filtering, venti lating and circulating in summer. The heating surface is used with existing steam system. Automatic control of temperature is by means of a thermostatic inlet valve. Ventilation is controlled by means of a damper in the outdoor air duct, and circus lation is controlled by varying the speed of the blower motor. Humidifying is con trolled by means of a switch. On the small size, the condensing unit for cooling may be mounted either integral or remote, while on the large size, the condensing unit is always mounted remote. Output--130,000 B.t.u. per hour. Power Input--260 watts at full load. Humidifying Capacity --1.5 gal. per hour maximum. Blower--Multi-vane, max imum delivery, 1600c.f.m. Heating Surface--2)^ in. tappings for supply and return, 15 lbs. maximum operating pressure. ' Specifications Type ADI Recirculation............... Heating Capacity-- ' Low Speed................ High Speed............... Cooling Capacity-- Nominal Maximum. Humidifying Capacity 0-200 c J.m. 200-400 c.f.m. 7900 B.t.u. 12200 B.t.u. 16800 B.t.u. 8500 B.t.u. 1.2 lbs. per Hr. AD2 0-200 c-fjn. 400-600 ci.m. 9200 B.t.u. 16000 B.t.u. 22000 B.t.u. 14000 B.Lu. 1J. lbs. per Hr. The G-E Winter Air Conditioner for Radiator Systems (Type AC1) The Type AC1 air conditioner combines means for humidifying, filtering and circu lating. It is mounted in the floor, either operating as an open system, or with return duct. Hot water for humidification is sup plied from an indirect water heater con nected to the heating boiler. Air is ad mitted through filters located on each side, discharging over the humidifying screens and finally through the delivery grille into 630 Air Conditioning Me/er Furnace GbMPANy Peoria. Illinois Manufacturers of Domestic Heating and Air Conditioning Units for Coal, Gas and Oil Burning Branches and Distributors Kansas City. Mo. Omaha, Neb. Green Bay, Wis. Pittsburgh, Pa. New Orleans, La. Detroit, Mich. St. Louis, Mo. San Francisco, Calif. The WEIR Conditioned-Air Unit for coal or oil burning, built around the famous Weir Steel Furnace, is, as its name implies, a complete outfit for conditioning the air in the home during the heating season with respect to temperature, humidity, air-cleans ing and positive circulation. Casing of in sulated asbestos composition with pleasing red finish. Equipment includes automatic humidifier (which may be provided with room control if desired), renewable filters, centrifu gal blower and fully automatic damper and blower controls. (Refer to table below for data on gravity as well as mechanical installations). The WEIR Funutee' Crate No. Surface (Sq Ft.) Ratio ' Htg. to Grate Surface Smoke Outlet Diam. On.) Gravity Circulation Casing Dimen. Round Rect'lar (In.) (In.) Rated Output At Reg. Pipe Area (Btu/Hr.) (Sq. In.) Fan Circulation Casing Dimen. (In.) Air Rated Output Delivery at register (C.F.M.) (Btu/Hr.) 671 1.26 624 1.78 628 2.32 630 3.08 633 3.82 636 4.74 540 544 7.60 41.2 33.9 29.2 26.4 22.7 19.4 19.3 18.5 9 10 10 10 10 10 12 12 48 52 54 58 65 67 47x50 50x52 54x56 56x64 56x66 54,400 73,600 94,100 119.000 138,000 160,000 400 541 692 875 1015 1180 47x90 50x99 54x103 56x110 56x118 64x114 1200 1600 2000 2300 2700 5000 97 non 118 000 177 000 200;000 316.000 The MEYER Gas Fired Air Conditioner automatically provides completely conditioned air for the heating season. It is as attractive in appearance as it is compact and efficient. Heating section of special heavy gauge welded steel, gas- and fume-tight construction; casing of insulated asbestos composition with pleasing red finish. Equipment includes specially designed auto matic humidifier (which may be provided with room control if desired), renewable filters, centrifugal blower and fully automatic controls. Manu factured or natural gas. Data od refrigerating equipment for summer Output at Bonnet (Btu/Hr.) Input at Burner (Btu/Hr.) Vent Diam. (In.) W. (In.) L. K (In.) I (In.) Air Delivery S.P. (C.F.M.) Motor Size (HP.) cooling, to be used in con junction with any of the mechanically - circulating systems described, will be supplied upon request. MEYER Gas-Fired Air Conditioner 1-B I'/z-B 2-B 3-B 4-B 5-B 72,500 108,000 145.000 217,500 290,000 362,500 . 90,000 135.000 180.000 270,000 360,000 450,000 4 20 5 27 7 40 8 60 9 80 10 . 100 53 60 53 53 53 53 1000 1500 2000 3000 4000 5000 1/6 1/4 1/3 1/2 3/4 3/4 MEYER Gravity Gas Furnace C-100 C-120 C-150 80,000 96,000 120,000 100,000 120,000 150.000 5 38 38 60 6 42 42 67 6 42 42 67 The MEYER. Gravity Gas Furnace Designed for high efficiency and resultant fuel economy with gravity circulation. Heat ing section of all-steel, welded construction with unusually large vertical heating surface. Casing same as on Air Conditioner. Complete with automatic controls. Manufactured or natural gas. Priced for the pocketbook of the average home. 631 Air Conditioning L. J. Mueller Furnace Co. Established 1857 2009 W. Oklahoma Avenue, Milwaukee, Wis. CLIMATOR AIR CONDITIONING SYSTEMS In the illustration is shown a Mueller Climator instal lation designed to handle all functions of both winter and summer air condition ing. During winter, the cir culated air is warmed by a heating unit specially de signed for the fuel to be used, coal, oil or gas. Controlled humidity is supplied by the air washer. Climator Year Round System Removal of air-borne im purities is accomplished by the filters. Adequate circulation, uniform temperature and silent air distribution is secured by the fan. ' In summer, temperature reduction and dehumidification is secured by Frigidaire refrigerating equipment, the cooling coils being enclosed within the washer housing. Compressor may be located adjacent to the equipment, or in any desired location. Where cooling and dehumidification is omitted, arrangement may be such that it may be added at a later date without change in equipment. If no provision for refrigeration is desired, a somewhat smaller washer is employed, and a more compact assembly may be secured. The air conditioned in the Climator system is distributed to all rooms through ducts and discharged through small overhead registers. Individual returns from each room secure perfect balance. Catalog and detailed information furnished upon request. Climator 111.Unit Climator III Unit This unit is a fan, filter and washer in a single casing finished in green prismatic lacquer. It may be con nected to any type warm air furnace, new or existing installations. It will pass through an opening 27]/2 in. wide. The return air duct, recirculating air from the rooms, connects directly to the unit, the only method by which an efficient, balanced installation can be secured. Fan is of adequate capacity to secure positive air delivery against resistances encountered through ducts, washer and filters. Made in one size only, with rated c.f.m. to 2,250, and adjustable speed driving pulley for adjustment to requirements. ' 632 Air Conditioning Parks-Cramer Company Fitchburg, Mass. CERTIFIED CLIMATE Charlotte, N. C. Complete Air Conditioning Systems including Heating, Cooling, Humidifying, De-humidifying, Ventilating, Refrigeration, Air Filtering and Air Washing AUTOMATIC REGULATION Industrial Heating by Oil Circulation with Merrill Process Central Station Psychrostat High Duty Humidifier Mistyfier Industrial Air Conditioning 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; Cel luloid; Glassine Paper; Starch and Dextrine; Cement. I nstallations similar in design are effective in Hospitals, Art Galleries, Auditoriums and Restaurants. Automatic Regulation The Psychrostat for accuracy, durability, sensitivity. Hygrostat (not illustrated) where requirements are not so exacting. Psychrostat uses the Principle of the Sling Psychrometer. U. S. Government uses Sling Psychrometer in all Weather Bureau Stations. An Air Con ditioning System is no better than its Regulation. Central Station Air Conditioning A centrally located apparatus supplying maximum moisture needed with positive pre-determined air change. Usually includes indirect radiation for heating --may include refrigeration and cooling. All air is washed. Automatic Regulation essential. While initial and operating costs are high, this absolute and cen tralized control of Certified Climate is often desirable;-- sometimes essential. High Duty Humidifier Water under pressure.generates spray. Excess water returns to filter tank and recirculated. Evaporation per unit high; two sizes of heads each with two sizes of noz zles give flexible capacity for varying conditions. Circu lation increased by individual motor-driven fan. Spray thoroughly diffused and distributed over wide area. Centrifugal Humidifier (Not Illustrated) Water without pressure. Fine spray. The Mistyfier A mechanical humidifier made according to same high standards as Parks Certified Climatedeviceabut refined for home and office use.. Quiet and automatic--not a ' toy. Inexpensive to operate;--wastes no water. Uses little electric current. Permanently, though. flexibly connected to water supply without expensive plumbing. Safeguards health. Increases comfort. Raises effective temperature during heating season, lowers it during dry non-heating season. "" Unit Air Conditioner (Not Illustrated) Principle similar to Mistyfier but for larger spaces, or may be made part of basement installation. 633 . Air Conditioning Niagara Blower Company AIR ENGINEERING EQUIPMENT AND SYSTEMS General Sales Office: 6 East 45th Street, New York City Buffalo Boston Philadelphia Cleveland Pittsburgh Chicago Seattle San Francisco PRODUCTS -- Air Conditioning, "Humidifying, Dehumidifying, Comfort Systems, Niagara Air Conditioners, Niagara Fan Coolers, Niagara Fan Heaters, Niagara Aluminum Cooling Coils, Heating Coils. ----------------:--------- ni/^Ira -- 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 Surface Cooling Method Niagara Pan Cooler Manufactured in 1-, 2-, 3- and 4-fan units and in 7 sixes. Air conditioning lor human efficiency and comfort. A year 'round operating system provid ing winter heating and humidi fying and summer cooling and dehumidifying for offices, stores, restaurants and all places where people gather. An advanced engineering method introducing simplified apparatus and con- VI trols superior in operating re- '1 suits, in economy and longer life. Niagara Air ConAitioner Type A Niagara Air Conditioner ----- _1 ype * A .' Maintainsconstantly, or makes ' lustration f unit. Also manufactured in 2-, 3- and 4-fan units and in 7 sixes. any change required in tem perature and relative humidity; dries or moistens within tolerance of 1 deg. F. ana 2 per cent R. H. in processing hygroscopic materials; cleans air most effectively; secures saturation for dehumidifying. cSeven sizes. | Niagara Fan Cooler^ Recommended for comfort cooling, process cooling, low temperature storage for dairies, fruits, meats, food products, fur storage vaults, etc. . Gives complete circulation of air at desired temperature with even temperature at all points. Manufactured in seven sizes. Niagara Disk Fan Cooler For overhead suspension, saves space and provides the efficiency of moving air cooling for small storage areas, market coolers, etc. Seven sizes. Niagara Humid Heater Niagara Disk Pan Coaler Manufactured in 7 eiaea including 2-fan unit. Recommended for industrial applica tions where heat and humidity are required as in manufacture of textiles, cordage, printing and paper-converting plants. 634 Niagara\Humid Healer Niagara Blower Company Air Conditioning Niagara Spray Cooler For food product applications, especially meat chilling and storage pre-cooling and storage of fruits and vegetables. Prevents drying out, wilting. Niagara Spray Cooler is built with cooling coils in a constant brine or water spray. Maintains constant relative humidity as re quired. ANiagara Fan Healer Illustration of 2-fan unit. Also manufactured in 1-, 3- and 4-fan units and in 7 sixes. Niagara Fan Heaters For the heating and ventilating of large areas, Niagara Fan Heaters put the heat immediately ` Niagara Spray Cooler Illustration of two-fan unit. Also manufactured in 1-, ,v and 4-fan units and in 7 sizes. where needed in the working zone, give quicker heating up to working tem peratures. Definitely built to the highest possible standards; welded aluminum heating coils, welded frames. Niagara Aluminum Cooling Coils Tested cooling coils are used in Niagara Fan Coolers and Niagara Surface-Method air conditioning. Encased, seven standard sizes for blast cooling installations. 20-in. and 30-in. widths. Aluminum coils in aluminum cases. . Niagara Aluminum Healing Coil* Niagara Aluminum Heating Coils For use with fan heating systems giving the advantage of alumi num, light weight and resistance to corrosion. Manufactured in two widths, 20-in. and 30-in., and in two types of three lengths, giving a complete range of sizes. 150 lbs. working steam pressure. Niagara Aluminum Booster Heaters are used for reheaters to control room temperature independently of fan system. Niagara Aluminum Bootter Healer Write for Bulletin No. 20 Niagara Disk Fan Heaters A most effective suspended heater. Oper ates with lower discharge temperature, cuts down roof and wall losses. 635 Niagara AU Aluminum Ditk Pan Healer . Air Conditioning Westinghouse Electric & Manufacturing Co. East Pittsburgh Sales Offices and Service Pennsylvania Shops in over 110 Cities UNIT AIR CONDITIONING EQUIPMENT 1. Westinghouse "EL" low type air conditioning unit for stores, offices, homes, etc. Walnut finish cabinet. Heats and humidifies in winter, cools and dehumidifies in summer, and filters and circu lates air the year 'round. 2. Outer cabinet removed, showing finned type coils for heating, cooling and dehumidifying. Air is drawn in by fans at each end and deflected up ward by baffles. A water spray, atomized in air stream, humidifies winter air. Installed in room, with refrigerating unit in basement, adjoining room or closet. 3. "EH" high type unit, modernistic finish, can be installed in aisles, beside columns or along the wall. Both high and low models are made in both finishes. Rated at 12.000 B.t.u. per hour cooling and 24,000 B.t.u. per hour heating. 4. Self-contained mobile unit with cover removed, showing refrigerating unit in lower half, with evaporator above. Cooling and dehumidifying only, rated at 6,000 B.t.u. per hour. Quiet in operation and easily installed. Can be equipped with wheels and moved from room to room. 636 5. Suspended type air con ditioning unit type ES-62. Can be suspended from ceiling or mounted on the deck over show windows. Used with or with out ducts. Summer and winter operation. Westinghouse Electric & Manufacturing Co. Air Conditioning 6. Small suspended unit; type'ES-10 for`summer operation. Cools, dehumidifies and circulates the air. Adjustable louvres direct air stream as desired. ' .' .. .. 8. Larger size refrigerating unit type RW-6, water cooled. All Westinghouse refrigerating units have multi-cylinder, vertical, single acting' compressor direct-connected to electric motor, are designed speci fically for unit system of air conditioning, and for use with Freon, the new. non-poisonous, non-inflammable, non-irritant refrigerant. ' There are no valve cams or levers, and crankshafts are dynamically balanced. The units are compact, efficient and quiet. ' 7.-Refrigerating unit, , smallest size, rated.at 12,000 B.t.u. per hour.* Many ' sizes available, air-and.- water, cooled for all commercial electrical -circuits: The Westinghouse Steam Jet Refrigeration Unit .(not shown) utilizes steam pressure to provide cooling effect for air conditioning or water cooling. It is highly economical in operation and maintenance because it has few moving parts. . AIR CONDITIONING UNITS A-C. OR I Model Type EL-12 EL-10 EH-12 EH-IO Suspended ES-10 Suspended ES-22 Suspended - ES-20 Suspended ES-42 Suspended ES-40 Suspended ES-62 Suspended ES-60 fOperaation Dimensions, Inches ' With Case Lgth Hgth . Dpth ' Without Case Lgth Hgth Dpth S W 39 27 13/2 34 23 12 S 39 27 IV/2 34 23 12 S W 39 S 39 40 40 1% 34 38 12 l3Vi 34 38 12 S sw 23V, 3l'/2 21 20 13'/, 22 20 12 54 S 31'A 20 38i/4 SW s sw s 54 54 65 65 20 20 22'/? 22'/2 54 .38'/, 59J/, 44 Weight. Lbs. . Com- - Without plete Case Air . Discharge Cu. Ft:;. Min:' ' Motor ' Horse Power 226 180 272 225 136 425 375 850 600 1200 870 195 450 1/60 150 450 1/60 220 - 450 1/60 175 ~ 450 1/60 120 450 1/60 900 ' 1/4 900 1/4 1800 1/2 1800 1/2 2700 3/4 . ts for summer, W for winter. REFRIGERATING UNITS ** Capacity Type Cooling Cooling Electric Power Inches Lgth Wdth Hgth Wt.,Lb. H.P. Refri- (Approx.) gerant. Lb. Oil, Pints RW-I RA-1 RA-I RW-2 RA-2 RA-2 RW-4 RA-4 RA-4 RW-6 Water Air Air Air Air Water Air Air Water RA-6 Air RA-6 Air RW-12 Water RW-18 Water 12000 12000 12000 24000 24000 24000 48000 48000 48000 72000 50 or 60 cy. 50 or 60 cy. DC or 25 cy. 50 or 60 cy. 50 or 60 cy. DC or 25 cy. DC. 60. 50. 25 cy. DC or 60 cy. 50 or 25 cy. ' DC, 50 or 60 cy. 72000 DC or 60 cy. - 72000 50 cy. . 144000 - .25. 50 60 cy. or DC 216000 257 50 60 cv. or DC 19V. 28 46 21% 37 52 191/4 191/4 20V 201/4 24 24'/, 58'/2* 23'/2 23V2 26V, 24Vi 29*/, 32 291/, 38'/2 350 400 450 450 500 575. / AC-1085 \ 1 DC-1225 / i'/2 2 2 3 3 3 5.. 13 4'/2 19 13 4/2 18 5 25 5 18 5 40 . 13 7614 33'/; 761/4 33'A 58>/2* 23'/2 32V, 32'/, 38'/2 / AC-1085 \ \ DC-1225 / 7i/2 6'/2 7i/j 40 13 40 .--13. 40 13 76V, 33'/2 32'/, / AC-1850 \ L DC-1975 J 10 40 13 76V. 33'/, 32'/, 1850 8>/2 40 13 Refer to nearest Westinghouse Air Conditioning Dealer for - * information on these ratings. Add 4-in. for DC motor. **Based on 40 evaporator temperature and with 60 cycle or DC motors. Capacities with 25 or 50 cycles wall be lower. 637 Air Conditioning York Ice Machinery Corporation General Offices: York, Pennsylvania Direct Factory Branches in 71 U. S. Cities Complete Air Conditioning and Refrigerating Systems for maintaining proper atmospheric conditions for industrial pro cesses and human comfort. Available in central and unit sys tems . . . from fractional tonnage up to any capacity required. Coil Type Air Conditioner Floor Type Unit Air Conditioner Freon {V-tt) Refrigerating Unit Vertical Single Acting Freon (F-lf) Compretsor Coil Type Air Conditioner: A self-contained air cooling unit provided with coils for direct expansion of the refrigerant or for circulation of water or brine. Also furnished for ceiling mounting. Coil design insures maximum efficiency. Low speed fans designed for quiet operation. Adapted to thermostatic control with defrosting feature. Spray Type Air Conditioner: Complete self-contained air conditioning unit requiring minimum space and including air washer with refriger ating coil, air heating coils, water heating coils, fan and motor, pump and motor, temperature and humidity con trols, all assembled as a single unit. Floor Type Unit Air Conditioner: " A compact, year 'round, unit air conditioner for office, home, restaurant, store .... wherever capacity or building requirements dictate its use. Provides summer cooling and dehumidifying; winter heating and humidi fying. Attractive lines and finish permit it to harmonize with any type of furniture or decorations. Air Washer: .. Galvanized iron and copper air washers of extra heavy' construction, designed for air conditioning or ventilating duty with water or brine. Washers furnished with or without cooling coils. Adjustable self-cleaning mist nozzles insure maximum humidifying efficiency. Refrigerating Systems for Air Conditioning: Complete refrigerating systems for use with Freon (F-12), Ammonia and Carbon Dioxide. Because refrigeration for air conditioning is essentially a water cooling problem, York has developed properly balanced, standard water cooling systems for this duty. Designed especially for human comfort applications, Freon was selected as the most suitable refrigerant because of its outstanding characteristics.... odorless, non-toxic and non-poisOnous, non-inflammable and non-explosive, non-irritant and non-, corrosive. Freon's thermal properties make it ideally suited for use in vertical single acting reciprocating com- pressors, the standard of sim plicity and efficiency. York Engineering Service: Because of York's vast fund of technical information and operating data in the field of air conditioning and refrigeration, York engineers can offer many helpful suggestions in the solu tion of your problem. Archi tects, Engineers, Contractors and others are invited to avail themselves of this service. Air Wother 638 Air Diffusers and Dampers Knowles Mushroom Ventilator Co. 41 North Moore Street, New York Knowles Air Diffusers for Auditoriums of Theatres, Churches, Schools ORIGINAL----------- RELIABLE----------STANDARD Giving Satisfactory Service in Over 4,000 Installations PRODUCTS:--Cast-Iron and All-Steel Adjustable Mushroom Ventilators; Aisle Hood, Tu-Way Air Deflectors; Round and Oblong Gallery Riser Vents A. ero Valve--The Improved Mushroom Air Diffuser The newest Knowles product. An up-to-date mechanically correct .air unit of fixed height made of HEAVY.steel, with strong supports bearing across 1-in. flange. Easy to regulate and install and low in price. Combines high efficiency with convenient adjustment afford ing finest control of air by simply turning screw on TOP of CAP. Can be positively locked at desired adjustment by side screw--is noiseless and made so that it cannot be taken apart before or after installation--an exclusive feature. Quick Anchorage to Wood or Concrete floors in one piece--Made in 6-in. and 8-in. diameter sizes--Same capacities as Nu-Notch type (see table below). Knowles Jhiffngfch Mushroom Ventilator or Air Diffuser The idea! cast-iron mushroom. Head has three outer bearings and is absolutely rigid. Ten recessed notches give close regulation of air. Locked into positive adjustment by tightening head screw with key--a new feature to prevent tampering . by unauthorized person. Supplied with dome or flat tops. Three screw holes in floor flange for fastening to wood, or three angle L lugs for setting in concrete, or three tapped holes in floor collar for fastening with set-screws to sleeve. _ Size y diam. 6' *' V" 8' " 10* " Cu. Ft. per Min. at 300 ft. Vei. 42 60 81 105 165 Area, Sq. Ft. 0.1364 0.1964 0.2673 0.3491 0.5454 Weight Lbs. 3.50 4.25 5.75 8.00 11.75 Specifications--Furnish and install where in dicated on drawings or as hereinafter specified (5-in.), (6-in.), (7-m.). (8-in.).- (10-in.). (Dome Top), (Flat Top), Nu-Notch Cast-Iron Mushroom Air Diffusers with recessed notches for the per manent adjustment of mushroom caps at any desired opening together with center locking screw feature as manufactured by Knowles Mushroom Ventilator Co., New York, N. Y. Knowles jOisc-Loc Gallery Riser Ventilators are designed to insure better control of air. Round holes in the gallery risers do not weaken the construction but, on the contrary, with the cast-iron rings it is actually strengthened. The cast-iron grille is quickly inserted and locked by a simple twist motion--no bolts, screws or springs. Furnished with or without damper to fit same rings. Made in Four Sizes (See Booklet). . Tu-Way Air Deflectors are designed to deliver maximum area with minimum fixed height. The air is discharged at both sides along the row of seats. Heavy Cast- Iron-- Ornamental design -- Adjustable double-wing curved damper deflects air down ward. Fine, positive adjust ment--Rattleproof, noiseless. A DEVICE THAT DELIVERS THE FULL AREA OF FLOOR OPENING. Floor opening 6)4 patented ' by 8)4 inches--Area )4 Sq. Ft. --100 CFM at 300 Velocity. Standard Aisle Hood (Cast-Iron) Air Deflectors are used to throw the fresh air. out into the aisles in one direction. A curved damper reduces friction loss. Large size: 8 in. long, 6 in. wide, 6 in. high; area J4 sq. ft.; Small size; 8 in. long, 4)4 in. wide, 4)4 in. high; area M sq. ft. Send for New Booklet of Complete Engineering Data or Samples ` 639 . Air Fillers and Cleaners American Ai r_Fi lterCompany Inc. 1st Street and Central Avenue, Louisville, Ky. Representatives in Principal Cities Dust Engineering--Dust Engineering is that branch of applied science which deals with the origin, nature and characteristics of the small solid air-borne particles called "dust," and the development of methods, processes and apparatus for its control or elimination. The American Air Filter Company, Inc., has had an important part in advancing the science of Dust Engineer ing. The efforts of its Re search and Engineering Staff for the past twelve years have been devoted exclusively to the study of dust problems and the development of a complete line of air cleaning equipment for modern air conditioning, building venti- lation and the control of pro cess dust in industry. American Air Filter pro ducts, therefore, not only embody the knowledge ac cumulated from years of con stant research and the ex perience gained from design ing, building and applying thousands of air filters, but are backed by ample technical and financial resources to in sure their outstanding posi tion in the Dust Engineering field. Products--American Air Filters are available for every condition, with operating characteristics and efficiencies to suit specific problems. In Renu~Vml Filler Data Section under "Air Cleaners." Air filters are generally used for the removal of dust, dirt, bacteria and other foreign matter from the air and are applied to general ventilation, modern air conditioning, pro cess dust controWor air com pressors and Diesel Engines; mill motors, turbo-generators and other electrical applica tions; 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 tempera ture, air movement and humidity, but science today emphasizes the prime neces sity of pure air for heqlth and efficiency. ' Throway Air Filter Air cleaners have, of course, always been considered an integral part of large central systems. These are usually of the fully automatic type such as the Multi-Panel filter, illustrated in the accompany ing photograph. There are now available to manufacturers of unit air con ditioners moderate priced unit filters, such as the Re-Nu filter, the Drifilter and the Throway filter, illustrated herewith. The Re-Nu filter is an general, there are two dis tinct types based upon the "viscous film" and "dry mat" principles. Each entirely new departure in air filter construction. It consists of a permanent metal frame provided with type is made in several styles which differ in method of operation, servicing, space required and initial cost to meet the various conditions en countered in air cleaning problems. A discussion of various filter types will be found in the Technical Standard Viscous Unit Filter 640 American Air Filter Co., Inc. Air Fillers and Cleaners a removable cover and renewable filter pad. The cover is easily removed without the use of tools, and filter pad can be lifted out and replaced with a new one at very small expense in less than a minute's time. The Drifilter consists of the Airmat filtering media mounted on a supporting member and arranged in saw-tooth fashion, as illustrated. The filter media is reason able in. price and can be easily replaced when desired. . The throway filter, as the name implies, is an inexpensively constructed unit de signed to be discarded after it has served its maximum period of usefulness and re placed with a new filter unit. The filter pad is enclosed in a perforated cardboard container which makes it possible to dispose of the dirty filter by burning it in a furnace or incinerator. There is probably no single item which costs as little and may mean as much in the design of an air conditioner as air. filtra tion. These units are furnished in any dimensions or shapes desired. They are usually built in units handling 400 c.f.m. 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. Cleaning efficiencies from 90 to 99 per cent can be secured, with a resistance to air flow ranging from }/{ in. to % in. water gauge. Automatic Self-Cleaning Air Filters --The American line of automatic air filters is among the most complete that has ever been offered, the most popular types being Multi-Panel, Horizontal and Phoenix Filters. All types are furnished for either con tinuous or intermittent service and are available in sizes and set-ups suitable to any desired capacity or space condition. Standard Viscous Unit--The Ameri can Unit Air Filter incorporates the time tested unit principle of construction. Each unit consists of a standard steel frame and interchangeable cell equipped with auto matic latches to facilitate removal for cleaning and recharging. Airmat Filter Dry Type--The filter ing media in this type is the Airmat sheet, a dry filter mat composed of thin sheets of gauzy, cellulose tissue. The Airmat sheets are supported in screen pockets mounted in a unit frame of box-like construction. These unit frames can be set up to meet any capacity requirement or space con dition. The Airmat sheets are renewable --their life depending on the dust con dition and hours of daily service. Airmat filters are used both for air con ditioning and industrial air conditioning. In the latter field they are particularly well adapted for the recovery of valuable dusts and for abating the dust nuisance which confronts so many industrial plants. Our standard data books and catalogues are to be found in most engineering files or libraries. We will be glad to furnish full data to engineers or manufacturers interested in this subject. Various Types of Unit Air Filters for Air Conditioning Work 641 Air Fillers and Cleaners Coppus Engineering Corporation 339 Park Avenue, Worcester, Mass. MANUFACTURERS OF AIR FILTERS, STEAM TUR BINES, FORCED DRAFT BLOWERS, COOLING FANS Annis Unit Filter The Annis Unit Filter is of the dry type, using a removable filter glove of special wool felt supported by a rigid welded wire frame and held tautly over the wire frame by a spreader grid the edges of which are extended box-like to give protec tion to the filter element. AH metallic parts are rust-proofed (Bonderized, Cadmium plated), the steel filter box Duco painted. Specifications Normal Rating: 800 c.f.ra: Resistance when clean: \2 in. W.G. Dust Arrestance (cleaning efficiency): for dust particles of 10 micron size (0.0004 in.) and larger 99$% + Dimensions: 20 in. by 20 in. by 6H in. Weight per unit: 25'lbs. Clean Air Side of Stationary Unit Filter 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 Cleaning Filter' Ele ment$ with Portable with highest quality of material and workmanship. Vacuum Cleaner Automatic, Self-Cleaning vacuum cleaner. Built in capacities from 3000 c.f.m. up. Air Filter It uses the same special wool felt as filter medium ar ranged in the shape of an endless belt in zigzag fashion over rolls. Either by means of a time clock at predeter mined intervals, or with the help of a sensitive pressure gauge, when a maximum air resistance is reached, the filter curtain is moved by a small geared motor over the rolls and-passes over the nozzle of a small Coppus Window Air Filter It supplies a continuous Bow of filtered air, is extremely quiet in operation, keeps out street noises, eliminates dirt and dust including more than 90 per cent of invisible particles, and last, but not least, is practi cally 99 per cent plus efficient against rag weed pollen in concentrations commonly found in the hay fever season. Its use is recommended for offices, homes and hospitals. vacuum cleaner. This automatic cleaning, operation takes place while the ventilating system is in operation and is finished with in 15 to 20 minutes. The motion of the filter curtain isthen stopped automatically. The only attention necessary is the oc Air Filters for Compressors and Internal Combustion Engines. , Steam Turbines, Horizontal and Verti cal, 1 to 60 Hp. Forced Draft Blowers. casional removal of the dust bag from the Portable and Cooling Ventilating Fans. 642 Air Filters and Cleaners DUSTOP Owens-Illinois Glass Company Industrial Materials Division MANUFACTURERS OF DUSTOP AIR FILTERS Toledo, Ohio . the Glass Wool Air Filter of Highest Efficiency and Lowest Cost The Dustop filter--standard size 20'x20'x2'. Rating--Capacity per unit. 800 c.f.m.--Maximum velocity recommended 300 f.p.m. --Resistance at rated capacity: Clean. .25* w.g. (Two filters in tandem within unit frame)-- Dirty. .36'-.40' w.g. With the side member at right angles to the Base Plate, the first "L" shaped frame member is bolted in the comer to both the side mem ber and the Base Plate. The Dustop frame assembles into a bank of any required number of units. To accom modate any specified volume of air two Dustop filters are- in serted in series, for greatest economy and a cleaning efficiency from 96% to 98%. Dustop frames are not bulky, and are easily assembled--only a screw driver is needed. The frame units can be nested for handling and shipping, which effects considerable saving in freight, and greatly reduces labor necessary in carrying equipment to site and erecting it. First assembly operation-^Comer angle and side member are'bolted to Base Plate. This first row of cells is com pleted by bolting one end of each frame member to the preceding one and the other end to the Base Plate. This' is done so that the bolts through the Base Plate can be inserted easily. - The completed rows of units are raised into approximate position to complete assembly. 643 The replacement operation is simple. Dirty filters are easily lifted from the frame and can be removed from the premises in the shipping carton in which .the new ones arrived. The Dustop glass wool air filter will clean the air in every type of commercial and industrial build ing at lowest cost. Dustop filters cost less for initial in stallation and less for replace ment in maintenance. Dustop filters maintain an efficiency of 96% to 98% in removing not only dust, dirt, lint and soot from air. but also hay fever pollen, bacteria and other harm ful impurities. Hundreds of Dustop installations are now in service efficiently cleaning air. Dustop filter banks are available through leading. heating and ventilating supply houses and fan manufacturers everywhere. Re placement filters are available in all principal cities. Air Filters and Cleaners Staynew Filter Corporation Air Filters for Buildings and Mechanical Equipment 6 Leighton Avenue, Rochester, N. Y. Products-- .. , Protectomotor Dry Type Positive Filters for removing dust, dirt and foreign matter from small or large volumes of air at atmospheric ' or at higher or lower pressures. Made in various types and sizes for buildings, windows, oxygen chamber in hospitals, furnaces, pipe lines, air compressors, diesel engines, blowers, motors, pneumatic systems, air brakes, etc. Operation-- " The efficiency of Protectomotor Air Filters is exceptionally high due to their large filtering surr,. face within a relatively smalt' space. The intake air currents move parallel to the filtering surface at very low velocity, so that the dust and dirt are . not packed on to the felt, but remain in a loose and porous condition, which permits the air to pass through the accumulated dust and dirt quite as . readily as through the felt itself. Dust and dirt do not enter pores of felt, which is of extremely fine texture. Efficiency-- Due to the low air velocity and the fine texture of the felt, practically complete removal of dust is obtained. An exceptionally high efficiency is maintained, even on fine air-floated dust. Efficiency is not greatly affected by continuous service, nor by any change in volume of air passed. Pressure Drop-- Resistance to the flow of air is less than 34 in. water gauge when operated at rated capacity. Less pressure drop, when required, may be obtained by using an oversize filter. Prolectomotor Building Filter 3* it<sM 1 *' * r r% f- '1 v.` vit L* r m AS bn jiTjV-' 3838' m SMJlfSi WSgs latest Ki lit SSI US pi -#fl| JW Mvlti-V-Type Building Filter Cleaning-- Under ordinary conditions filters operate from six months to a year without atten tion. A special cleaning device enables the material collected on the filtering surface to be very quickly and com pletely removed by compressed air or vacuum cleaner. The material may be reclaimed, if valuable, without con tamination, since no sticky or adhesive oils are used. No spare parts or cleaning . tanks are necessary.. Less than two minutes' time, per 1000 cu. ft. per minute of air capacity, required for cleaning. Filters may be cleaned while in operation, without removing filtering units. .. ProledomU Window Ventilator ' One filter cell removed, erposing one of the fane and motors Application-- All filter units or filter assemblies are complete in weatherproof housing, ready to attach to air intake pipe for applica tion to engines, compressors, etc. For building ventilation, equipment is easily adapted to space available. Diagonal view shotcing adjustable ends storm hoods, filter and deflector plate. Note the large, active surface 644 Boiler Cleansers and Leah *5ea/ The Yinco Company, Inc. 305 East 45th Street . New York, N. Y. Vinco Boiler Cleanser A positively harmless in* soluble powder cleanser ` for . new, remodeled and old heating systems. A unique, scientifically pro* cessed compound of in gredients, on a special for mula not to be confused' with other powder boiler cleaners. ADOPTED BY Vinco Boiler Leak Seal A different liquid leak seal. Unique in that it does not Induce priming and foam ing. It has no unpleasant smell. It makes speedy and permanent'repairs of all boiler and heating sys tem leaks. Fine to tighten up new jobs. The direc tions are simple to follow-. American Radiator Corp. . American Gas Products Co. . . Barnes & Jones "' QUANTITIES Steam and Vapor Boynton Furnace Co. ' - *Burnham Boiler Corp. . . ' . Systems Gorton Heating Co. ' . Hart < Crouse Co. : . Heggie-Simplez Boiler Co. * - Hoffman Specialty Co. Ideal Boiler Co. - Use 1 quart Vinco Liq uid Boiler Seal to each 6 Distributed by Boiler Manufacturers and Jobbers. Sold only in our trade-marked cans like above. square feet grate area. International Boiler Works Kewanee Boiler Corp. `National Radiator Corp. Petroleum Heat & Power Co. Sarco Co. `Standard Sanitary Mfg. Co. The Thatcher Co. - VINCO BOILER CLEANSER Packed In iy$, 3, 5 and 10 lb. cans VINCO LEAK SEAL Packed in 1 qt. cans only . Hot Water Systems Use 2 quarts Vinco Liq uid Boiler Seal to each 6 square feet grate area. Thermo Service, Inc.. . The. Vapor Heating Co. TUusviUe Iron Works Co. .' The Vapor Engineering Co. `United States-Radiator-'Corp. . and many others. 'Vinco Distributors. What Vinco Does . . V inco permanently removes all the oil, grease, scale and dirt from the internal surfaces and from the boiler water without the labor ofblowing boilers over the top. Vinco Specifications for Hot Water Systems Cleaning the System--Upon completion of the installation, the contractor shall clean the system by the Vinco method using **..........lb. of Vinco in exact accordance with manufacturer's special di rections for hot water systems, given on their cans. .'`Only one-half quantities in specification table re By this thorough cleansing Vinco stops foaming, priming, quired for hot water systems. . surging, incomplete circulation and poor radiation. 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 blown through the bottom, according to directions on each can.. 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- Vinco Specifications for New and fire attendance. . Remodeled Steam and Vapor Systems Cleaning the System -- Upon completion of the installation, the contractor haH dean the system by the Our Free Laboratory Service Vinco method to remove oil, grease, rust and dirt from the Saves thousands of dollars by analyzing boiler using, t---- lb. of Vinco, in exact accordance with manufacturer's directions. ' '. When Vinco is first introduced, have a low fire--just enough for the water to simmer--for three or four hours. After this, pressure can be raised. This compound must remain in the for 36 actual steaming hours, which corresponds to six or seven days average operation. - At the.end of this period, boiler must be thoroughly- drained and flushed before refilling with clean water. '' fin writing specification, insert in this space number of. 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. Then if the boiler still primes, foams, or surges, look for mechanical flaws. (Write for details.) pounds of Vinco to be used in accordance with the following schedule. For systems having: , Up to 350 sq. ft of tradiation......... .................. 3 lb. 351 * 600 ` " ................. 5 601 * 1100 ` " ... 8 1101 ` 1400 ' ..10 1401 ' 1800 ` 1801 ` 2100 ` " ...13 ...15 2101 ` 2700 ' *' ...18 2701 ` 3100 4 ..20 3101 4 3700 4 * ...23 3701 4 4200 4 ..26 4201 4600 44 ..28 4601 5000 44 " ______ / __ 30 Our Three-fold Guarantee. 1. Vinco contains no potash, lye, soda of any kind, oil, acid, or other harmful ingredients. (See most recent Publications of leading boiler manufacturers advising against use cf acids or alkali in boilers). 2. Vinco meets every performance claim. Purchase price is refunded if results are not entirely satis factory when Vinco has been used according to directions. . 3. Your time, money and comfort are further safe guarded by our free laboratory service. Above 5000 sq. ft. use an additional pound of Vinco for each additional 300 sq. ft. of radiation. Un determining amount of Vinco to be used all radiation may be taken at actual rating. *For old systems use only one-half quantities given in specification table. 645 Boiler Feeders MCDONNELL & MILLER - Manufacturers of McDONNELL Boiler Water Level CONTROL Wrigley Building, Chicago ' "/Jotng S/t/ng well" Automatic Boiler Water-Level Control McDonnell Boiler Water-Level Controls protect low pressure boilers from the costly repairs and shutdowns that result when someone forgets the boiler water line, and end the trips up and down the basement stairs to watch the water glass. In all of the controls illustrated, the feed valve and working parts are removed from the heat of the float chamber--all are packless and have stainless steel valves. These features are behind the acknowl edged dependability of McDonnell Water- Level Controls. . Combined Low-Water Cut-Offs and Pressure Controls No. 36-- Switch -- A combination 1 o w- wat er cut-off and The No. SO-S-81 pressure control (2 to 14 pounds) for use on No. 37 Feeder. No. 33--Switch--Same as No. 36 except has special mounting plate for use on Nos. 30-S or 30-L. McDonnell Safety Feeders for Hand-Fired Boilers No. 37---Safety Feeder--For boilers up to 2,500 sq. ft., maximum steam pressure, 15 lbs. Is installed in gauge-glass tappings --no hack saw needed. Cuts installation time from hours to minutes. No. 30-S--Safety Feeder--For boilers from 2,500 to 5,000 sq. ft., maximum steam pressure, 15 lbs. The ideal feeder for boilers of this size. , No. 30-L--Safety Feeder--For boilers above 5,000 sq. ft., maximum steam pres sure, 25 lbs. No. 30-H--For all boilers where steam pressure is 25 to 50 lbs. Same design and capacity as No. 30-L, but of heavier con struction to stand higher pressure. Low-Water Cut-Offs No. 48--For boilers of any size. Maximum steam pressure, 25 lbs. The lowest priced thoroughly dependable low-water cut off! (110 or 220 volt circuit). No. 38---Es pecially recom mended for round boilers. Maximum steam pressure, 25 lbs. Has quick hook up feature. Combined Feeders and Low-Water Cut-OSs for Automatic Jobs (These combinations give low water pro tection with added convenience of auto matic water supply). No. 37-35--For boilers up to 2,500 sq. ft., maximum steam pressure, 15 lbs. The No. 37 Feeder with No. 35 Low-Water Cut-Off Switch attached. (Switch may also be purchased separately and added to any No. 37). No. 30-S-31--For boilers from 2,500 to 5,000 sq. ft., maximum steam pressure, 15 lbs. The No. 30-S Feeder with switch attached. No. 30-L-31--For boilers above 5,000 sq. ft., maximum steam pressure, 25 lbs. (No. 31 switch may be purchased separately and added to any Nos. 30-S or 30-L Feeder). Low-Water Alarms No. 40--Switch. switch. Can be furnished with mountings for use on Nos. 37, 30-S. 30-L, 30-H, or 38. No. 41---Com bination lowwater cut-off and low voltage alarm switch for use on Nos. 37, 30-S, 30-L, 30-H, or 38. A high voltage alarm Our Engineering Department offers prompt advisory service. Descriptive literature, engineering data, and installation drawings upon request 646 Boilers, Cast-Iron Offices: New York Office: Graybar Building Boston: Philadelphia; Chicago; Queens Village. L. San Francisco; Baltimore; Springfield; Lancaster; Pittsburgh; Zanesville; Elizabeth Plants at Elizabeth.'N. J.; Lancaster, Pa.; Zanesville. Ohio There's a Burnham for every Heating purpose 1--Water Tube Boilers for Steam and Hot Water Heating. 17, 21, 27 and 36 in. Double shaking grates and long fire travel. Rating to 9,050 sq. ft. for steam and 15,085 sq. ft. for water. 2--Water Tube Boilers Jacketed in Color. ' 17, 21 and 27 in. Steel Jacket and 4-ply air cell asbestos insulation. Enameled rich red. Jacket goes on after all other set up work. Rating tc>, 4,225 sq. ft. for steam and 6,800 sq. ft. for water. 3--Big Twin Sectional Boilers. 50 in. Grate, divided for easy shaking. Twin sections, divided down the middle. Ratings to 19,450 sq. ft. for steam, 31,800 sq. ft. for water. 8--Junior Hot Water Supply Boilers. Will keep 175 to 700 gallon tank always full of hot water. Guaranteed to 80 lbs. working pressure. 9--Burnham-Simplex Gas Boiler. With the patented flue ways, tapering section fins, air control and cast-iron draft diverter. Highly efficient. Steam boiler A.G.A. ratings from 290 to 5250 sq. ft. Water boiler A.G.A. ratings from 470 to 8400 sq. ft. 10--Burnham Oil-Burning Boilers. A specific-sized boiler for each specific heat job for use with any standard oil burner. Round Sectional Burnhams in 6 Series and 24 sizes. Square Burnhams in 5 Series and 39 sizes. For steam, vapor or water. 4--Tube Type Smokeless Boilers. For burning soft coal efficiently and without smoke. Meet smoke ordi nances everywhere. Similar to (1) above, with addition of smokeless feature. 5--Welded Steel Boilers--Also ThreePurpose Welded Steel Boilers. For heating, hot water supply and incineration. Coal or oil. Complete ly welded for 15 lbs. working pressure. Multiple shaking grates. Sizes for commercial or domestic uses. Special folder sent on request. " 11--Burnham-Taco Tanks. Combining water heater and storage tank in one unit for summer-winter use. Removable copper heating element. Tanks may be galvanized, everdur or copper. 12--Burnham Cast-Iron Radiators. Occupy about ) less space than ordinary cast-iron radiators of same rating. Shorter. Lower. Narrower. 3-tube type, 3)4 in. wide. 4-tube type 4)4e in. wide. 6--Round Sectional.Boilers. This boiler made the long fire travel famous. Handled easily. Very large steam dome. Ratings up to 1,550 sq. ft. for steam, 2,560 for water. 7--High Pressure Hot Water Supply Boilers. Sectional construction Guaranteed to 80 lbs. working pressure.- Supplies up to 3,800 gallons:---- 13--Fero Tube Radiators. All heights--3, 4, 5, 6 and7.tubes. 14--Burnham Air and Vacuum Valves. - Full line for radiators, risers and mains. -- 15--Complete Line of Heating Ac cessories. ' Including steel tanks of all kinds. Catalogs Sent on Request 647 Boilers, Cast-Iron American Radiator Company 40 West 40th Street, New York, N. Y. Division of AMERICAN RADIATOR & .STANDARD SANITARY CORPORATION AMERICAN RADIATOR PRODUCTS BOILERS IDEAL REDFLASH BOILERS NEW IDEAL ARCO ROUND Completely equip ped, sectional arid en closed in red enamel ed steel jacket, the Ideal Redflash Boiler is made in a range of sizes to fit homes and other buildings, large or small. It combines the latest scientific improvements with economy, cleanliness and attractiveness. Retaining all fundamental features which made its pre decessor the standard round boiler of America, the New Ideal Arco Round now comes completely equipped and enclosed in a stippled red enameled jacket. A new device, the Arco Circulator, sets up positive water circu lation within the boiler. IDEAL OIL BURNING BOILER O .0 With its attractive green enameled steel jacket, trimmings and fittings in glistening chromard finish, the Ideal Oil Burning Boiler No. 12 brings new beauty and ef ficiency to'oil burning. Hot gases must travel four times the length of the boiler. IDEAL HOT-WATER SUPPLY Ideal Hot-Water Supply Boilers are designed for use where large quantities of hot-water must be con stantly available. They are made of cast-iron and are virtually immune to rust and corrosion. They burn all types of fuel. IDEAL MAGAZINE BOILERS Gravity-feeding and automatically regu lated, Ideal Magazine Boilers, Nos. 15 and 25, burn coke, anthra cite or a mixture of either fuel with buck wheat or pea coal. They will run 12 to 24 hours on one fuel charge, depending upon outside tempera'- ture. - IDEAL WATER TUBE . Because of its section al construction, the Ideal Water Tube Boiler can be installed in old buildings with out difficulty. An extensive series of water- backed, verti cal tubes expose an unusually large amount of heating surface. SEE IDEAL FITTER for Complete Information on American Radiator Products 648 American Radiator Company Boilers, Cast-Iron American Radiator Hompany 40 West 40th Street, New York, N. Y. Division of AMERICAN RADIATOR & STANDARD SANITARY CORPORATION AMERICAN RADIATOR PRODUCTS RADIATORS ARCO RADIATORS ARCO CONVECTOR The New Arco Radi ator is equally adapt able for exposed, rer cessed or concealed installations. It oc cupies approximately one-third less space than older models, yet it provides the same heating output. Its slender, graceful lines and compact, sturdy construction contribute another step in modern heating design. CORTO RADIATORS Made of cast-iron, Corto Radiators are durable and time tested. Their threaded nipple construction is known for tightness and perma nence. The scientific in ternal design assures un hampered passage of steam or water. And a severe hydraulic pressure test guar antees every Corto free from defect. FANTOM RADIATORS Blending with the wall, the Fantom is a cast-iron radiator to be hung on brackets under a window... Re cessed, partly reces sed or fully, exposed, it radiates heat from its exposed surface and also sends up ward a curtain of warm air which blankets off window drafts. The Arco Convec tor is a cast-iron radiator for com plete concealment. Ample inner space assures positive air elimination and un hampered flow' of steam or water. Fins are scientifically proportioned and spaced to allow proper air flow. A full line of Arco Enclosures are designed for the Arco Convector. ARCO ENCLOSURES Arco Radiator En closures are designed either entirely to con ceal radiators such as New Murray, Arco and Arco Convector; or to frame such radi ators as the Arco, Corto or Fantom. In each instance Arco Enclosures give a "tailor-made job." All enclosures give easy access for cleaning and regulation. Type "OK" Enclos ures are made in a complete range of sizes to fit Arco, Corto and Peerless. Radia tors of all dimensions. No cutting or fitting required. They heed only: be ordered in proper length, width and height' and ' quickly set in place. . SEE IDEAL FITTER for Complete Information on American Radiator Products 649 Boilers, Cast-Iron CRANE CO Manufacturers of Valves, Fittings, Fabricated Piping, Steam Specialties, Plumbing and Heating Materials 836 S. Michigan Avenue Chicago, III. Branches In All Principal Cities Write for catalogues and full information about any materials in which you are interested Crane Boilers Styles--Crane boilers are made in round and sectional styles .... in capacities to efficiently and economically meet the heat ing requirements of every type of structure. Complete Line--Crane supplies every thing for the entire heating system-- boilers, radiators, valves, fittings, piping, and specialties. Uniformity in quality and efficiency is assured. Economical Firing--Elongated two pass gas flues are arranged for controlled water travel and have 50 per cent more ceiling heating surface. Baffles direct water across top of combustion chamber control . ling as well as lengthening water travel and keeping walls scrubbed free of insulating film. Grate areas, combustion chambers, and heating surfaces are proportioned for longest firing periods. Easy Cleaning--Broad, flat gas flues have less tendency to collect soot and permit easy entrance for scraper. Soot drops into the first pass when scraped and from there it can be pushed into the combustion chamber. Croup of Radiators Crane radiation is made in styles and sizes to meet all building requirements. The Crane radiator has established a reputa tion for high heating efficiency, durability, ease of assembly, and decorative grace. The addition of the Crane Invisible Shield places this radiator in a class by itself. This shield directs the warmed air into the living zone instead of to ceiling and, con sequently, reduces fuel consumption. Concealed Radiator with legs Crane Concealed Radiators are exception ally compact and made in sizes to suit recess requirements. Cast in one piece of cast-iron. Unaffected by expansion or contraction. 650 Crane Co. Boilers, Cast-Iron No. 981 Inverted Open Float Steam Traps Sectional View No. 981 Trap This is a new line of very efficient steam traps of large capacity yet low in price for draining condensation from various steam heated apparatus such as garment presses, coffee urns, jacketed kettles, unit heaters, laundry machinery, heating coils,, etc. Under the most exhaustive service tests, these traps have proven themselves dependable and economical in first cost, installation and maintenance. Operation is as follows: Condensation flows upward into the trap' until the body is full. Then it is auto matically discharged through a valve at the top. When no more condensation enters, steam displaces the water in the float, which then becomes buoyant and rises, thus closing the valve and stopping the discharge until an accumulation of condensation enters the float and causes it to sink. Capacities in Pounds of Water per Hour Prexsure at Inlet Vl In. Size % In. Size . 1 In. Size 5' 10 15 30 50 75 100 125 150 915 3050 880 3500 1080 4300 960 3800 680 2700 350 2250 405 2650 450 ' 460 1850 ~ '-2050 12300 14000 17500 15300 10900 9060 10450 7370 8000 Crane Welding Fittings 90 EU Tee * W ea Crane Co. manufac tures a complete line of welding fittings and flanges in all sizes from . 1 in. to 18 in. inclusive. Elbows and Return Bends are made of seamless steel tubing in standard and extra strong pipe thickness. Tangents are provided at each end for ease of lining up by the use of ordinary jigs and clamps and to bring the weld away from the point of curvature. Tees are forged seam less in sizes 2H in. and smaller. Sizes 3 in: to 10 in. are forged in halves and electrically welded. Forged Sled Witting Welding neck flanges may be had in various weights and with vari ous facings to suit all conditions of service. Forged Sled Slip-on Flange Return Bend. Cranelap Welding Nip ples, which are short lengths of seamless steel pipe provided with a full thickness Cranelap on one end and beveled for welding on the other end, are made of standard and extra strong pipe. Proper weight forged steel ' Cranelap flanges to suit the required service can be furnished with these nipples. * Crandap Welding Nipple and Crandap Flange In addition to tire fit tings listed, welding caps, reducing nipples and reinforcing saddle flanges are available in a wide range of sizes. 651 l Boilers, Cast-Iron National Radiator Corporation MANUFACTURERS OF BOILERS, RADIATORS AND CONVECTORS Johnstown, Pa. National Service through these Branch Offices and Warehouses: Baltimore, Md--------- Boston, Mass.----------Buffalo, N. Y-------Chicago, III............. Cincinnati, Ohio...... Cleveland, Ohio...... _____ 2622 Matthews St. __________250 Stuart St. ,,, 004 Main St. _____ 1U1 East 83rd St .3530 Spring Grove Ave. _______4500 Euclid Ave. Milwaukee, Wis--------New York, N. Y._...... Philadelphia. Pa......... Pittsburgh, Pa_______ Richmond, Va.. Washington, D. C...... ..... .....511 E. Mason St. ............. 55 West 42nd St. __________ 2124 Arch St. ...339 Blvd. of the Allies 3032 Norfolk St ____ 2205 Fifth St. N.E. AERO CAST IRON CONVECTORS The Convector with a Guaranteed Rating Tested and Rated in Accordance with the A.S.H.V.E. Standard Code for Testing and Rating Concealed Gravity Type Radi ation (Steam Code). ' U. S. Patents No. 1,888,545 No. 1,912,556. Other Patents Pending A message to Heating and Ventilating Engineers, Heating Contractors and Architects Aero Convector Ratings Aero Convectors are rated in accordance with the American Society of Heating and Ventilating Engineers' Standard Code for Testing and Rating Concealed Gravity Type Radiation. .... T . .u . These Ratings are based on the Condensation from the convector, the Latent Heat in the steam and the Correction Factor as provided in the Code. The Catalog Ratings of Aero Convectors are Guaranteed when: 1. The Convectors are used with enclosures having dimensions as shown in the current catalog. 2. The.Convectors are placed at a height in the enclosures corresponding to that obtained with "low legs." . 3. The Convectors are completely filled with steam at a temperature of 215F. or water at a temperature of 175F. - ...... Other Methods of Rating Present day methods of rating concealed heating units are not uniform, due to the ;uhiition to actual condensation ratings of an intangible called "Heating Effect on the theory that less Equivalent Direct Radiation is required with a concealed radiator than with an exposed radiator. ,, . ,, The Code makes no provision for.deterrhimng ratings on the basis of Heating r.nect, "Available Heat" or "Effective Heat." ' Results of a State University Investigation of Heating Effect Recent tests conducted at a State University developed these two conclusions which disprove the "Heating Effect" theory: ' 1. The steam condensation obtained when the temperature is maintained at 68F. at the 30 inch level is an approximate measure of the relative effectiveness of different types of heating units in providing human comfort; lower condensation corresponding to greater effectiveness. 2. The heating effect is not materially greater than the total heat output as measured by steam con densation under given standard conditions, and the practice of adding a large proportion to condensation rating in order to provide for heating effect CANNOT BE JUSTIFIED. , For Your Protection When specifying convectors be sure of the basis of rating. Insist that Ratings be according to the A.S.H.V.E. Standard Code. Be safe and choose Aero Convectors with catalog ratings that are guaranteed. " Write or 'phone nearest Branch Office for copy of Aero Convector Catalog No. 2 and Supplement "A" ; - . 652 Boilers, Cast-Iron National Radiator Corporation General Offices, Johnstown, Pa. NATIONAL PREMIER STEEL BOILERS Constructed for 15 lbs. working pressure in accordance with the A. S. M. E. Code SMALL STEEL BOILERS--REAR SMOKE OUTLET--THREE PASS Type "DB" Type "MB" Type "OB'* Solid Fuel--Hand Fired Solid Fuel--Stoker Fired OiJ or Gas Fired "MB/ "OB".. ..Sq. Ft. ' "OB* ..Sq. Ft. Water Rating-- type "L)B" . .Sq. Ft. ' ` OB* ..Sq. Ft. Stack Height...........:................ ......... Ft. 251 485 735 775 1175 12 35 252 .645 890 1030 1425 12 35 253 840 1045 1340 1675 12 35 254 990 1200 1580 1925 12 40 255 1120 1355 1790 2175 12 40 256 1250 1510 2000 2425 12 40 311 1350 1635 2160 2615 16 . 40 312 1525 1850 2440 2960 16 40 313 1700 2065 2720 3305 16 40 314 1875 2280 3000 3650 16 45 315 2050 2495 3280 3995 16 45 316 2225 2710 3560 4340 16 45 REAR SMOKE OUTLET--THREE PASS Type "DB'' (Direct Draft); Type "SB" (Smokeless); Type "OB" (Oil, Gas or Stoker Fired) Stack, . || W id th of B oiler Size of Steam O utlet. Size o f R e tu rn II S-H.B.i. Boiler ' Steam S.H.B.I. No. Ratings Steam Types Type Ratings DB" *DB." "SB" and Br- and "SB" "OB" Heat ing Sur Face Grate Area Types "DB" and "SB" Furnace Volume Above Water Leg Ring Type "OB" Gross Base Volume Floor to Water Leg Ring Type "OB" Height of Water Line Length Length Over Boiler all Sq. Ft. Sq. Ft. Sq.Ft. Sq. Ft. Cu. Ft. Cu. Ft. Ft. In. In. Ft. In. Ft. In. In. f D ia. o f Stack, I Boiler Height Dia. JO inRear enSmoke Out Height Over ' all of Rear Smoke Out o_ let let 2 eo Q.S H 1 In. Ft. In. Pt In. In. In. In. Ft. ro ilh te go eBi 371 2550 3100 183 11.6 28.3 372 3000 3675 216 11.6 31.6 373 3500 4250 250 11.6 36.1 431 4000 4900 287 12.5 45.2 432 450th 5500 323 14.0 49.8 433 5050 6125 360 15.5 54.3. 491 6000 7300 428 16.3 58.7 492 6550 7950 467 18.0 63.4 493 7000 ' 8500 500 19.8 66.4 551 8500 10350 608 20.6 83.5 552 9575 11625 684 22.6 92.0 611 10840 13150 774 25.5 97.8 612 12000 14575 857 25.5 106.6 671 14330 17400 1024 28.3 131.6 672 16350 19850 1168 30.8 145.7 731 18650 22650 1332 33.9 172.0 732 20700 25175 1480 36.6 189.3 791 22650 27500 1618 36.9 218.1 792 25550 31000 1825 39.9 241.4 851 28750 34900 2054 40.1 233.3 852 33000 40050 2357 43.3 258.6 853 34150 41450 2438 46.5 266.0 16.5 19.1 22.0 25.5 28.2 30.9 29.0 31.4 33.5 48.4 53.7 52.5 57.3 68.9 77.1 85.9 94.2 103.3 115.1 107.7 121:1 124.8 5-8'/, 5-8*/, 5-11 5-11 5-11 6-9 6-9 6-9 7-1 7-1 7-11 7-11 8-0 8-0 8-W, R-3'/? 8-5'/2 8-5'/2 S# 9 T/l 37 5-4 6-4 37 6-1 7-1 37 7-0 8-0 43 7-0 8-0 43 7-9 8-9 43 8-6 9-6 49 7-0 8-2 49 7-7 8-9 49 8-1 9-3 55 8-4 9-6 55 9-3 10-5 61 8-2 9-5 61 8-11 10-2 67 9-9 11-1 67 10-11 12-3 73 11-2 12-10 73 12-3 13-11 79 12-5 14-1 79 13-10 15-6 85 12-0 13-8 85 13-6 15-2 85 13-11 15-7 , 64 64 64 64 64 64 85 83 85 83 83 86 86 86 86 86 86 10 6 10 6 10 .6 10 6 10 6 5-4 5-4 5-4 5-7 5-7 5-7 6-5 6-5 6-5 6-10 6-10 7-4 7-4' 7-7 7-7 7-9 7-9 8-0 8-0 9-0 9-0 9-0 6-7 6-7 6-7 7-0 7-0 7-0 8-2 8-2 8-2 8-6 8-6 9-4 9-4 9-6 9-6 9-10 9-10 10-2 10-2 U-5 11-5 11-5 22 22 22 24 24 24 26 26 25 28 32 32 34 34 36 36 40 40 42 42 42 22 20 50 22 20 50 22 20 55 24 22 33 24 22 55 24 22 60 26 24 60 26 24 60 26 26 65 23 26 65 23 28 65 32 30 70 32 30 20 34 32 20 34 32 70 36 34 80 36 34 90 40 38 90 40 38 90 42 40 100 42 40 100 42 40 100 FRONT SMOKE OUTLET--TWO PASS Type "DF" (Direct Draft); Type "SF" (Smokeless); Type "OF" (Oil, Gas or Stoker Fired) Boiler No. S.H.B.I. Steam Ratings S.H.B.I. Steam Bp? Ratings "SF" and "OF' and "SF' BP Heat ing Sur Face Grate Area Bl? and "SF' Furnace Volume Above Water Leg Ring Type "OF* Gross Base Volume Floor to Water Leg Ring Bp Height Water Line Sq. Ft. Sq. Ft. Sq.Ft. Sq. Ft. Cu. Ft. Cu. Ft. Ft. In. u 0 at | Length Length 5 0 ` of Over vS JZ Boiler all *0 t> T5 .8js & coO In. Ft. In. Ft. In. In. 1 Height Size h j c/j Smoke Height Over of Smoke Q O "cn 2 * * Out let all Out let o,,_ "0:3 jwztoo .2 co "CQ *5u Q.S 15 X- Ft. In. Ft. In, In. In. In. Ft |,ST.Size o f R e tu rn 371 3000 372 3500 373 4000 431 4500 432 5000 433 6000 491 7000 492 8500 551 10000 552 12500 611 15000 671 17500 731 20000 791 25000 851 30000 852 35000 3650 4250 4900 5500 6100 7300 8500 10300 12150 15200 18200 21250 24300 30400 36450 42500 214 250 286 322 358 429 500 607 715 893 1072 1250 1429 17862143 2500 11.6 If.6 12.9 14.0 15,5 16.9 18.1 21.3 72 6 26.6 28.0 30.9 33.9 37.0 43:3 46.5 37.9 41.8 45.8 61.1 65.1 73.6 80.1 91.2 114.3 132.8 155.4 181.6 222.4 278.4 295.7 326.6 21.0 5-8 37 5-5 6-9 6 4 5-10 6-7 10x26 20 23.6 5-8 37 6-3 7-7 6 4 5-10 6-7 10x26 20 26.2 5-8 37 7-1 8-5 6 4 5-10 6-7 10x26 20 32.2 5-ld/j 43 7-6 8-11 6 4 6-OlA 7-0 11x30 22 34.6 5-101/2 43 8-2 9-7 . 6 4 6-0/2 7-0 11x30 22 39.7 5-101/7 43 9-7 11-0 6 4 6-O/2 7-0 11x30 24 36.6 6-9 49 7-4 9-0 8 5 6-11 8-2 14x36 26 42.5 6-9 49 8-9 10-5 8 5 6-11 8-2 14x36 2b 61.4 7-1 55 9-0 10-9 8 5 7-3 8-6 15x40 28 73.0 7-1 55 11-0 12-9 8 3 7-3 8-6 15x40 30 77.0 7-11 61 10-3 12-2 8 6 8-1 9-4 17x42 32 91.4 8-1 67 11-2 13-1 8 6 8-3 9-6 17x46 34 101.5 8-4 73 11-5 13-4 8 6 8-6 9-10 17x50 36 121.6 8-6 79 12-10 14-9 10 6 8-8 10-2 17x56 40 124.5 9-7 85 11-10 14-0 10 6 9-9 11-5 20x60 42 140.9 9-7 85 13-8 15-10 10 6:> 9-9 11-3 20x60 42 Ratings comform with the Steel Heating Boiler Institute's Code for Rating Low Pressure Heating Boilers. S. H. B. I. Water Ratings are 60 per cent greater than S. H. B. I. Steam Ratings. 18 50 18 55 18 55 20 60 20 60 22 60 24 65 24 63 26 70 28 73 30 80 32 83 34 90 38 90 40 100 40 100 653 Boilers, C. I. and Steel Tubular New York. N. Y. Buffalo, N. Y. Chicago, III. Spencer Heater Company Division of Cord Corporation Williamsport, Pa. Albany, N. Y. N. Y.Syracuse, Boston, Mass. . Philadelphia, Pa. Bethlehem, Pa. Scranton, Pa. Milwaukee, Wia. Cincinnati, Ohio Birmingham, Ala. . Spencer Magazine Feed Boilers' by-product coke. No. 1 Buckwheat anthracite, for example, costs as much as 84.00 less a ton than the larger sizes. The original magazine feed boiler with slop ing grates, a gravity stoker boiler. The water jacketed magazine holds enough fuel for 12 to 24 hours. Fuel feeds auto matically by L-S Series Spencer Cast-Iron Sectional Boiler Minneapolis No. 40 Thermostat and electric damper motor furn ished asstandard equipment with all Spencer Cast-Iron Boilers. gravity as fast or as slow as the fire requires. Uniform depth of fire bed keeps fire always at most efficient combustion point, giving maximum efficiency at minimum fuel cost. Spencer Boilers are made in sizes to suit every home or building, large or small. The direct cast-iron column radiation load which each size Spencer will carry is guaranteed. Automatic Heat at Lowest Cost Spencer Boilers are designed especially to burn small-size, low-cost fuels, such as No. 1 Buckwheat anthracite or small size Spencer Rotary Ash Receiver affords an ideal method of ash disposal. Ashes are raked directly from the ash pit into cans, contained in a water-tight steel tank sunk in the basement floor. Elimi nates dust and ashes about the cellar. Spencer Combination Boiler designed to burn coal, coke or gas with equal efficiency. Possible to change in stantly from coal or coke to gas; specially designed gas burner is always there, ready for instant use, nothing to at tach or connect. Furnished com plete with burner, Minne apolis No. 77 8day room tem perature ther mostat, pressuretrol, vaporstat or aquastat, throttling valve and automatic pilot control. Spencer Combination Boiler for Coal, Coke or Gas GUARANTEED CAPACITIES AND DIMENSIONS Boiler No. X J-3 Ht, JJ--45 Direct Cast-Iron Column Radiation Tank Loads. Sq. Ft.* Capacity Steam Water Gallons 175 290 240 265 440 390 355 590 540 Grate Area 1.30 1.90 2.50 Outlets 1-3* 1-3' 1-3' Returns 2-3' 2-3' 2-3' Chimney Flue 8'* 8'x35' 8'* 8'x35' 8'* 8'x35' Diame ter . Smoke Pipe 8' 86'' Over-all Dimensions Length 28>/,' 35'/;' Wl' Width 24' 24' 24' Height 45' 45' 45' 1 L-105 H L-106 3 k"107 390 645 600 510 845 810 630 1,045 1,020 2.60 3.33 4.07 1-4' 2-4' 2-4' 2-4' 2-4' 2-4' 8'* 8'x35' -8'x 8'x35' 8'xl2'x35' 10* 10* 10* toy,- 32' 57' 471/5' 32' 57' 54'/$' 32' 57' ,, L-205 L-206 t- L-207 r? L-208 J L-209 550 725 900 1,075 1,250 910 1,200 1,490 1,760 2,070 900 1,170 1,440 1,740 2,040 3.63 4.66 5.68 6.70 7.73 1-4' 2-4' 2-4' 2-4' 2-4' 2-4' 2-4' 2-4' 2-4' 2-4' 6'xl2'x35' 8'x12'x35' 8'xl2'x40' I2'xl2'x40' 12'xl2'x40' 10* 10* 10* 10* 10* 40/;' 40* 60* 47'/;' 40* 60* 54'/' 40* 60' 61'/$' 40* 60* 681/2' 40* 60* L-305 L-306 L-307 H L-308 ^ L-309 J L-310 L-3H 1,150 1,500 1,650 2,200 2,550 2,900 3.250 1,900 2.475 3,050 3,625 4,200 4,775 5.350 7.29 9.33 11.37 13.41 15.45 17.49 19.53 2-4' 2-4' 2-4' 2-4' 2-4' 2-4' 2-4' 2-4' 2-4' 2-4' 2-4' 2-4' 2-4' 2-4' I2'xl2'x40' 12'xl2'x40' I2'x12'x40' I2'x!6'x45' 12'xl6'x45' I6'xl6'x50' 16'x!6'x50' 14' 14' 14' 14' 14' 14' 14' 42' 49* 56' 63' 70* 77' 84' 56' 65' 56' 65' 56' 65' 56' 65' 56' 65' 56' 65' 56' 65' This includes ample provision for beat loss io covered mains, risers and returns, and for peak loads, as covered by guarantee. 654 Spencer Heater Company Boilers, C. I. and Steel Tubular Spencer Heaty Duty Sled Tank Heater Spencer Heavy Duty Tank Heaters Furnished in both cast-iron sectional and steel tubular types. Cast-iron sectional built with extra heavy sec tions, and steel tu bular with copper bearing steel plates and Toncan Iron tubes. For working pressure up to 120 pounds. Spencer Steel Tubular Boilers are combina tion water and fire tube construction, built of heavy steel plates and copper bearing tubes. I mproved and perfected through more than thirtyfive years successful operation; M-7 Series Spencer Steel Tubular Boiler Spencer Oil Burning Boiler Specially designed to meet every re quirement for ef ficient oil burning. Boiler, combination water tube and fire tube; welded steel construction; built in two sections for easier installation and handling. Ca pacities, 2250 to 40,000 sq. ft: Ask K-L Series Oil Burning Boiler for detailed data. Spencer Stoker-Boiler Unit Consists of boiler and stoker, built as a unit, auto matically con trolled. Designed to burn cheap grades of coal, smokelessly, at high efficiency. Requires no brick work or concrete in set ting. Capacities, 2250 to 40,000 sq. ft. Literature and data sent on request. K-R Series Stoker-Boiler Unit . Spencer Low Cost Automatic Heating Equipment for Every Fuel and Every Building. Write for catalog. GUARANTEED CAPACITIES AND DIMENSIONS Boiler No. Direct Cast-Iron Column Radiation Tank Loads. Sq. Ft.* Capacity Gallons Steam Grate Area ^ M4-2 . M4-3 b M4-4 2 M4-5 5 M4-6 ~ M4-7 8 M5-4 | MS-5 & M5-6 S M5-7 g M5-8 ^ M64 E M6-7 c>5 M6-8 M6-9 g M6-I0 "5 M7-6 c M7-7 co M7-8 C: M7-9 g M7-I0 9 M8-6 c M8-7 m MU s M8-9 g M8-I0 250 410 570 730 890 1,050 1,200 1,400 1,600 1.800 2.000 2,300 2,600 2,900 3,200 3,500 4,000 4,700 5,400 6,100 6,800 8,000 9,750 11,500 13,250 15,000 430 710 990 1,270 1,550 1,830 . 2.25 3.17 4.09 5.02 5.94 6.86 2,100 2,450 2,600 3,150 3,500 6. 9.75 11.50 13.25 15. 14.0 15.8 17.6 19.4 21.2 19.0 22.0 25.0 28.0 31.0 32.36 37.02 41.68 46.34 51.00 Outlets Returns Chimney Flue Diameter Smoke Pipe Overall Dimensions Length Width Height 1-3' 1-3' 8'x 8'x3V 10* 32'/;' 27' 55' 1-3' 1-3' 8'x 6'x35' 10* 39$$' 27' 55' 1-3' 1-3' 8'xl2'x35/ 10* 46$$' 27' 55' 2-3' 2-3' 2-3' 2-3' 8'x12'x35' 8'x12'x35' 10* 10* 53'/,' 60'/$' 27' 27' 55* 55' 2-3' 2-3' 8'xl2'x35' 10* 671/,' 27' 55' 1-4' 2-3' I2'xl2'x35' 12' 50* 48' 60* 1-4' 2-3' 12'xl2'x35' 12' 57' 48' 60* 1-4' 2-3' 12'xl2'x40' 12' 64' 48' 60* 1-4' 2-3' I2'xl2'x40' 12' 71' 48' 60* 1-4' 2-3' I2'xl2'x40' 12' 78' 48' 60* 1-6' 1-6' 1-6' 1-6' 1-6' 22--22$'/$2*' 2-2/$' 22--22V'/$>'' 12'xl2'x40' 12'x16'x4y 12'xl6'x45' 16'xl6'x50f U'xU'xSO'- 14' 14' 14' 14' 14' 65'/,' 72'/$' 79$$' 86$$' 93$$' 58' 58' 58' 58' 58' 66' 66' 66' 66' 66' 1-8' 1-8' 1-8' 1-8' 1-8' 2-3' 2-3' 2-3' 2-3' 2-3' 20'x20'x60' 20'x20'x60' 20'x20'x65' 22'x22'x70' 22'x22'x70' 18' 75'/,' 68' 80* 18' 82'/$' 68' - 80* 18' 89'/,' 68' 80* 18' 68' 80* 18' 103'/$' 68' 80* 1-8 1-6' 1-8' 1-8' 1-8' 2-4' 2-4' 2-4' 2-4' 2-4' 24'x24'x65' 24'x24'x65' 30'x30'x7(K 36'x36'x70' 36'x36'x7(T 24' 79'/.' 108' 85' 24' 861/.' 108' 85' 24' 93'/.' 108' 85' 24' I00>/.' 108' 85' 24' 107%' 108' 85' "This includes ample provision for heat loss in covered mains,' risers and returns, and for peak loads, as covered by guarantee. 655 Boilers, Cast-Iron UnitedjStates IfADiATOR (orporation Manufacturers of Capitol Boilers and Radiators THE PACIFIC STEEL BOILER CORPORATION Manufacturers of Pacific Steel Heating Boilers GENERAL OFFICES: DETROIT, MICHIGAN The Capitol Oil Burning Boiler--OB Series Steam boilers include Capitol Low Water Cut-off, manufactured by the McDonnell- Miller Company and built-in Taco Domes tic Hot Water Heater. . Automatic Water Feeder in combination with Low Water Cut-off, extra. Water boilers include built-in Taco Domestic Hot Water Heater. Capitol Oil Burning Boilers, OB Series, when connected to the direct cast-iron radiator load shown in table, have sufficient reserve capacity to provide for heat loss from piping amounting to 25 per cent of the standing radiation, with an additional 25 per cent reserve for, pick-up load, plus the reserve required to raise the tempera ture of the domestic hot water from 50 degrees to. 150 degrees Fahrenheit in three hours. Storage tank capacity has been estimated not to exceed 40 gallons with the OB-20 Boiler and 40 to 85 gallons with the OB-25 Boiler. Where the domestic hot water supply is not heated by the boiler, the OB-20 Boiler may be connected to 530 sq. ft. of steam radiation, or 850 sq. ft. of water radiation, and the OB-25 may be connected to 763 sq. ft. of steam radia tion or 1220 sq.ft, of hot water radiation. Construction Made of cast-iron. Heavy Metal Jacket. Rock Wool Insulation. Heating Surface Large combustion space. Concentrated prime and ribbed heat ing surfaces. Seven direction changes of gases--no stratification. Controlled gas travel--intimate contact of all gases with heating surface. Operation Year 'round hot water with built-in Taco. Low water cut-off. Enclosed steam trimmings. Visual fire inspection. Provision for stack switch and enclosed aquastat. Sound insulated. Capitol Fincast Radiators and Enclosures Made entirely of cast-iron. Made without joints. Cast in one piece. Many lengths and widths. Tappings--top, bottom or ends. Complete choice of enclosures. 656 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 Weil-McLain Distributors in most of the important distributing centers. PRODUCTS--Cast-Iron Heating Boilers and Water Supply Heaters, Cast-Iron Radiators including standard tubular senior and junior types, "RAYDIANT" Concealed Cabinet and Wall Radiators, and Humidifiers. Weil-MPLain BOILERS Weil-McLain Boilers are made in various types and in a wide range of sizes to satisfy every heating need and demand. The conventional line includes the Round, Jacketed, Square, Self-Feed and Smokeless types. A more recent addition is the Jack eted Type Round Boiler built especially for Automatic Heating with Oil, Gas or Stoker. Ttcu/jcUa/vb Iwith Heat Radiatinq'LtVEFront The Weil-McLain Raydiant Radiator is made in both concealed and cabinet en closure types. - It emits a scientific blend of radiant warmth and convected heat. Made entirely of cast-iron, it forms its own live metal front and grille. Has space saving advantages, low roughing-in and setting cost. Vents equally well on all systems. ' CftMEO Weil-McLain Radiators Weil-McLain "Cameo" Radiators are made in a complete range of sizes, heights and widths, for every place and purpose in modern homes and buildings. Besides the regular floor type, Weil-McLain also make other types of "Cameo" such as the Junior floor type radiator, "Cameo" Wall and Bathroom types. 657 Self Feed i3 Oil Burning There is a distinctness in the design of Weil-McLain radi ator tubes. They are in the form of a wide "V" running the full length of the tubes that adds to them longi tudinal strength. Nt Boilers, Gas L. J. Mueller Furnace Co. Established 1857 2009 W. Oklahoma Ave., Milwaukee, Wis. Gas-Era Gas-Fired Boilers Adaptable for steam or hot water heating. Completely automatic operation. Cast iron construction for durability, with asbestoslined metallic jacket. Vertical burner adjustment permits use with any manufactured or natural gas. Have steady water line and will not prime. Interior surfaces may be thoroughly cleaned without disturbing jacket. Multiple unit con struction permits increase in size when desired. Boiler is highly efficient, securing maximum heat utilization with minimum gas consumption. HOT WATER Boiler No. A.G.A. Rating STEAM Boiler No. A.G.A. Rating Floor Space Inches VENTS Number Diameter Inches 13-W 24-W 25-W 36-W 37-W 49-W 5II-W 613-W 715-W 817-W 919-W 102 l-W 1123-W 1225-W 1327-W 1429-W I53I-W 1634-W 1838-W 2042-W 2246-W 2450-W 2654-W 2856-W 3062-W 670 1.005 1.340 1,675 2.010 2.680 3,350 4,020 4,690 5.360 6,030 6.700 7,370 8.040 8.710 9.380 10.050 10.720 12.060 >3.400 14,740 16,080 17,420 18,760 20,100 13-S . 24-S 25-S 36-S 37-S 49-S 511-5 613-S 715-S 817-S 919-5 >021-5 1123-S 1225-5 1327-S 1429-S 1531-5 J634-S 1838-5 2042-S 2246-S 2450-S 2654-S 2858-S 3062-S 420 630 840 1,050 1,260 1.680 2,100 2.520 2,940 3.360 3,780 4.200 4,620 5,040 5.460 5,880 6,300 6,720 7,560 8.400 9,240 10.080 10,920 11.760 12.600 31%, 46% 35%, 46% 39 z 47% 43 x 51% 46y4* 51% 541/2 * 53% 62'/* 54# 70 , 51V. 79% * 53% 87% * 53% 95%, 54% >03 * 54% 110%, 56% I201A* 53% 128%, 54% 136 , 54% 143%, 54% 87% , 107% 95% * 109% 103 , 109% 110%, 112% 120% , 107% 128% * 109% 136 , 109% 143% x 109% ) 1 1 1 1 2 2 2 2 2 2 3 3 3 3 2 2 2 2 3 3 3 3 4 6 7 9 9 10 11 9 10 10 II >> . 12 10 II 11 14 16 16 17 14 16 16 16 Gas-Era Gas-Fired Water Heaters Adaptable for heating of water in considerable volume. May be used as direct or indirect systems. Automatic operation. Boiler No. Gal. Heated per Hour, 25 Rise Gal. Heated per Hour, 40 Rise Gal. Heated per Hour, 100 Rise Gal. Heated per Hour. (40 Rise 13 485 303 121 24 728 455 181 25 970 606 242 36 1,213 758 303 37 . 1,455 909 364 49 1,940 1,212 485 511 2.425 1,515 606 613 2.910 1,818 728 715 3,395 2.121 849 817 3,880 2,424 971 919 4,365 2.727 1,091 1021 4,850 3,030 1,212 1123 5,335 3,333 1,334 1225 5,820 3,636 1,455 1327 6.305 . 3,939 1,576 1429 6,790 4,242 1,697 1531 7.275 4.545 1,819 Complete descriptive and illustrated catalog on request. 658 86 129 172 215 259 345 432 518 605 691 779 665 951 1,038 1,124 1,211 1.298 Size Gas Connection Required 1 I 1% 1<%/, 1 2 % A 2% Wz 2% r 3 3 3 3 4 4 4 4 5 5 Boilers, Steel THE BABCOCK Be. WILCOX COMPANY 85 Liberty Street, New York, N. Y. Water-Tube Boilers Oil Burners Manufacturers of Chain-Grate Stokers , Seamless Steel Tubing and Pipe Branch Offices and Representatives in all Principal Cities Type H Stirling Boiler The Babcock & Wilcox Type H Stirling Boiler is a highly efficient unit built for moderate pressures at moderate prices.. . . and is designed to occupy minimum floor space and head room for the heating sur face required. This boiler is built in four classes and 36 sizes ranging from 714 to 5071 sq. It. 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. The advantages of the Babcock & Wilcox 1 1 Floor to Center of M ud Drum, Ft.. In. Floor to Face of ' Steam O utlet, Ft.. In. Floor to Top of Boiler, F t.. In. Size o f Steam Outlet, In. ' FDt.e.ptIhn .of Setting. 1 Width of Setting <n I Jl O Two Single Boilers Boiler, in "t.. In. 3attery rL, In. 714 15-Z1 6-0 952 \m 7-0 6-0 H-1 1428 1666 1904 2142 9-0 10-0 11-0 12-0 2380 " 13-0 no 130 150 170 190 210 230 250 5-2 * * * 14-5% 14-2% "* *" * * " 900 i7-a| 6-0 171X1 * 7-0 150(1 H-2 180C 2l0f ?40f a a a OO 9-0 10-0. 11-0 771X1 12-0 3000 * 13-0 no 130 150 170 190 210 23-0 250' 4-9% 14-5% 14-2% "" "** "" " *"8 "* 5 8" " " 8 9 " " 8 8* 1086 20-7 144 I8IC 7172 H-3 2534 ?m 325f m $987 4344 * a * a a a a 6*0 7-0 6-0 9-0 10-0 11-0 12-013-0 14-0 15-0 HO 130 150 170 190 210 230 250 270 290 4-5% 14-5% 14-2% * ** ** "* ** * * 5 8 * 8 " " " " 6 6 1268 m 71V. 22a-8 . 2535 H-4 2951 3381 380: a a 4226 464 5071 1 6-0 7-0 6-0 9-0 10-0 11-0 12-0 13-0 140 150 no 4-1% i4-n 130 150 B 170 " 190 * 210 230 *- 250 * 270*~ --,,* * * * * 290 * 14-5% " 5 8 8 * 8 88 6 6 Type H Stirling Boiler with Babcock & Wilcox Chain-Grate Stoker Type H Stirling Boiler may be sum marized as follows: Unusual steaming capacity for the floor space and head-room required. Boilers may be set singly or in battery. Setting heights can be varied to suit any condition of firing. ' The choice of three locations for gas exit reduces cost of flues and breeching. Distribution baffles make effective all of the heating surface. Tube renewal is facilitated by correct tube spacing, and a tube removal door. Soot blowers can be readily installed to simplify thorough cleaning of all tubes. A superheater can be furnished with out any change in the standard design or construction. The boiler is supported by a structural- steel framework entirely independent of the brickwork. Ample provision is made for free movement of parts due to expansion and contraction. ' A complete table of sizes and dimensions, together with pertinent installation data, is contained in a new thirty-two page bulletin which will be sent upon request. Simply ask for Bulletin G-8-A. 659 ! Boilers, Steel The Bigelow Company Established 1860 Main Office and Works New Haven, Connecticut New York Office--Graybar Building Manufacturers of Bigelow-Hornsby Water Tube Boilers Bigelow Low Head Water Tube Boilers Bigelow Three Drum Vertical Water Tube Boilers Bigelow Horizontal Return Tubular Boilers Bigelow Electric Steam Generators Bigelow Two-Pass Boilers Bigelow Manning Boilers Bigelow Upright Boilers Catalogues Gladly Furnished on Request - 7Vo I'O H.P. Bigelow Two-Pass Boilers used for healing the new Home Office Building of The Hartford Steam Boiler Inspection and Insurance Co., Ike largest insurer of steam boilers in the United States Since 1S60 it has been the endeavor of The Bigelow Company to merit a reputation for constructing boilers of a high standard of design, workmanship and material. We are proud of the confidence shown in us by the use of Bigelow boilers in this building. The Bigelow Two-Pass Boiler is designed to meet heating and power requirements, especially where space limitations prevail. It contains the recognized features of the well-known H.R.T. boiler, but due to the small amount of brickwork required it can be in stalled at a lower complete cost. The elimination of special Iwick shapes and staybolts in the furnace reduces I he cost of maintenance to a minimum; Other features of importance are large furnace volume, long gas travel, uniform velocity of gas over heating surface and low exit temperature, all of which assure a maxi mum efficiency. ' Bigelow Two-Pass Boilers are constructed in standard sizes from 25 H. P. to 200 H. P. and for working pressures of 15 pounds and 125 pounds. 660 Boilers, Steel E. Keeler Company Williamsport, Pa. Established 1864 Riveted Steel Boilers For Heating and Power Steel Stacks, Breechings and Plate Fabrications Keeler Double Duty Boiler Keeler Type "J" Watertube The Keeler Double Duty Boiler is designed for heating or power purposes. It may be set singly or in battery and fired by hand, stokers, oil, or gas. # The Keeler Type "J" .Water ; Tube Boiler.is designed especially for installation The construction eliminates curved in boiler rooms where both floor space arid crown sheets requiring radial stays, flat ceiling height are limited. Less space is ( sides with braces between tubes and staybolted side furnace walls, thus internal required for replacement of tubes than any cleaning is simplified and lower main other design of high pressure water tube tenance costs are obtained. boiler. . The use of a refractory lining and the The Keeler Straight Tube Cross Drum large furnace volume results in highest possible efficiencies. The tables below show floor space re Water Tube Boiler is recognized as a lead ing high pressure boiler in school and quired is the minimum. office building heating plants. * Setting Dimensions Keeler Double Duty Boilers Boiler HP. Inside Dia. Grates . Small Large Shell Shell Length Width Setting Width Length Space Required Front Rear Height Top of Steam Nozzle ' Height to Low Water Mark Height to Smoke ' Outlet 35 24" 6(>' 3'-0" 4'-6" 6'-2" H'-2'/z' 7'-0" 2'-6" 6'-83d* 7'-2%* 40 24" ' 60" 3'-6" 4'-6" 6'-2" 12'-6'/i" 8'-6" 2'-6" 8'-5>" 6'-83d* 7'-25/g* 50 27" 66" 3'-6" 5'-0" 6'-8" l3'-6'/2' 9'-0" 2'-9"- 8'-7V,' 6'-l09d' 7'-53d* 60. 27" 66" 4-0" 5'-0" 6'-8* 14'-6>/2" 10'-0" 2'-9" 9--!%' 7'-63d* 7'-11 s/s' 70 27" 66" 4'-0" 5'-0" 6'-8" 15'-%' IO'-9" 2'-9" 9'-!%' T-TW 7'-IP/,' .83 32" 78" 4'-0" 6'-ri" 7'-8" IS'-tf/i' H'-O" 3'-3' <r-9%r T-WA* S'-P/g" 105 32" 78' 5'-0" 6'-0" 7'-8" 16'-6'/2" 12'-0" 3'-3" 9/-9%" 7'-l03d" 8'-4y8* 130 32" 78" 6'-0" t'jy `7'-8" !8'-3>/2" 13'-9" 3'-3" 9'-93d* 8'-03d* S'-V/t' 150 34"' 82" 6'-0" 6'-0" 7'-8" W-bVz* !4'-0" 3'-5" 9'-!!%' 8'-0%" - 8'-6y8* 175 36' 88" 6'-6" 6'-6" 8'-2" l8'-6>/2" 14'-O' 3'-8" I0'-4V4* 8'-6%" S'-ioy,* 200 . 39" 94" 6'-6" 7'-0" 8'-8" l8'-9'/2' , l4'-3" 4'-0" lO'-lOVe" 8'-89d" 9-3!!fe" 225 . 44' ' 104" -6'r6" 250 44" 104" 6'-6" 8'-0" 8'-0" 9'-8" 9'-8" l8'-9i/2" ww !4'-3" 14'-6" 4'-4" 4'-4" ir-ii9d' ir-n%" 9'-6y,' 9'-8%" w-p/t* IO'-23/4' Bulletins of Each Type Sent on Request 661 - Boilers, Heating Wl OO ou* Mr Titzgibbons Boiler Company,Inc. . Established 1886 General Offices: 570 Seventh Avenue, New York, N.Y. . Works: OSWEGO, N.Y. Branches and Representatives in Principal Cities PRODUCTS: The Fitzgibbons line of Steel Heating and Power Boilers, listed on this and the next page, meet the heating requirements of all buildings from the small home to the gigantic modern skyscraper. The line includes types for burn ing anthracite, bituminous (soft) coals or coke, and for Tht Stffn of the BEST in STEEL BOILER HEAT oil, gas or stoker firing, in steam, vapor, vacuum or hot water systems. In other words, there is a Fitzgibbons Steel Boiler for every fuel, and every heating system from the smallest to the largest. RATINGS: All boilers of the line are rated in accordance with the S.H.B.I. Code. FITZGIBBONS OIL-EIGHTY AUTOMATIC Residence Steel Boiler for Oil Burning Ratings, Steam--425 to 1513 sq. ft. Outstanding Features Tanksaver (optional) supplies year 'round clean hot water without a separate storage tank. Tank- heater (optional) a more efficient indirect water heater. Combustrol, automatically maintains balanced draft, diverts back drafts, prevents back firing. Thermalizer, makes every tube do its full share of heat absorbing. Copper-Steel Plate Construction, combines maximum strength with corrosion resistance. Attractively Jacketed. Teams up with any good rotary or gun type burner to form a unit of Highest Efficiency. . Descriptive Bulletin on Request FITZGIBBONS R-Z-U JUNIOR Multi-Service Steel Boiler RATINGS, STEAM Coal Burning Type____ 750 to 3200 sq. ft. Oil Firing Type.-.............1003 to 3893 sq. ft. Stoker Firing Type.... .....1003 to 3803 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"' door way. Low Water Line, eliminates need for a pit. Jacket (optional), on all types. Descriptive Bulletin on Request 662 Fitzgibbons Boiler Co., Inc. Boilers, Healing FITZGIBBONS Z-U Steel Firebox Boilers For All Fuels and All Heating Systems Built for 15 lb. w.s.p.--A.S.M.E. Code RATINGS, STEAM Up-Draft Type............................_.2324 to 37,828 sq. ft. Smokeless Type............................. 2324 to 37,828 sq. ft. Oil, Gas, Stoker Type..................2822 to 45,934 sq. ft. Descriptive Bulletin on Request ' FITZGIBBONS R-Z-U Steel Firebox Boilers The'ZrU Boiler arranged for installations where con ditions make it desirable to place smoke outlet at the rear. For All Fuels and All Heating Systems Built for 15 lb. W.s.p.--A.S.M.E. Code RATINGS, STEAM Up-Draft Type.............................. 2660 to 33,980 sq. ft. Smokeless Type............................. 2660 to 33,980 sq. ft. Oil, Gas, Stoker Type................. 3230 to 41,259 sq. ft. Descriptive Bulletin on Request FITZGIBBONS F SERIES--Portable Riveted Firebox Boilers' For All Fuels and All Heating Systems Built for 100 lb. w.s.p.--A.S.M.E. Code. Ratings. Steam--700 to 20,353 sq. ft. ( Descriptive Bulletin on Request FITZGIBBONS 500 SERIES Portable Firebox Boilers Welded--Return Tubular i For All Fuels and All Heating Systems Built for 15 lb. w.s.p.--A.S.M.E. Code Ratings, Steam--5960 to 36,000 sq. ft. Descriptive Bulletin on Request FITZGIBBONS 700 AND P SERIES Portable Riveted Firebox Boilers For All Fuels and All Heating Systems 700 SERIES built for IS lb. w.s.p.--A.S.M.E. Code Ratings, Steam--5960 to 27,580 sq. ft. P SERIES bujJt for 100 lb. w.s.p.--A.S.M.E. Code Ratings. Horse Power--50 to 225 Descriptive Bulletins on Request FITZGIBBONS 600 AND 800 SERIES Smokeless Down-Draft Riveted Firebox Boilers Built for 15 and 100 lb. w.s.p.--A.S.M.E. Code Ratings, Steam--7126 to 27,426 sq. ft. Descriptive Bulletins on Request 663 KtW AN&t B9ILEK Kewanee, Illinois BRANCHES IN 6 0 PRINCIPAL CITIES Steel H e a tin g and Power B oilers, W ater H e a tin g G arbage B urners, Tabasco Heaters and Tanks. 664 Boilers, Sleel Kewanee Boiler Corporation oo 'O'X- x -- - sCOsO 665 S P E C IF IC A T IO N S -- SM O KELESS D O W N -D R A F T B O ILE R 3s=* ss OT X -- NN o 355-;=# \0 ^ oo S-- fSofN'::8' ^SlsNn 88 --s CR'OS'OICS'O* -- -- > OcosoOC--O '--O o--S^ OO og^COcA o o _J >otN|^eor^ sO'so> kOoOO'tOC'o<Or _r*;!Oooki>. . SSo"o 2S NOO>'OOA^"C* *OT l--* **S .u. t : iN & g K SO o-J*C& " F.S Uu~Cv-s.2r^1j-5T5_^57~IJ-^.c5Cg5o'Q--SgC~3Q <MOTJ U.? (If to ssss SS ONN' N--- 88 iUs<No ss so*iro Sto 3so O'CO 1 B o i l e r N o ........................................... Rated C apacity, Steam, sq. ft.: B u rn in g C o a l. H a n d F ire d ............. O il. G as o r S to k e r F ire d .................. W id th a n d L e n g th .................in . x ft. . . ; . 'O v e r-a ll H e ig h t...................... ... .in . H e ig h t o f W a te r L in e .............in . A pproxim ate W eight: C o a l B u r n in g ................................lbs. O il B u rn in g ................................. .lb s. 407 2550 4730 48x8.6 84 . 71 6900 6400 408 409, 410 411 , 412 fA * 414 415 416 417 418 419 420 421 422 i1 423 424 3340 4170 4300 5130 5270 | 6340 17040 7900 6070 , 7440 8760 1 9600 6760 10640 8700 | 10310 11480 ; 13220 12420 15780 14560 17680 16350 19850 18240 22150 21200 25730 23950 29080 30930 37500 33980 40460 48x9.5 84 48x11.1 1 84 54x10 54x11.1 89 89 54x12.1 60x12.4 89 1 98 60x13.6 60x14.3 60x16.2 66x15.8 98 101 r o i 107 66x17.3 107 72x15.9 72x17.5 113 113 78x17.9 78x19.9 84x20.1 115 115 121 84x22.1 121 71 71 76 76 76 83 83 87 87 90 90 96 96 97 97. 105 105 7400 8300 9000 9800 6800. 7600 8300 9000 10600 13200 14100 15900 17300 20400 22000 24000 25700 28000 31000 37000 40000 9700 12000 12800 14600 15900 18800 20200 22000 23600 25800 28600 3 & 0 0 37100 'B o i l e r N o . ................... 749 1 753 750 751 752 754 755 R td C . o Ca al, p., Ha St., sq. nd F ire df t.. :. . . O il, Gas or S to ke r.... W id th & length, in.x ft. O v e r-a ll H e ig h t............ in. H e ig h t of W ater Line, in. A pproxim ate W eight: C oal B u rn in g ..........lbs. O il B u rn in g ............. lbs. CO S *n ikOk fCANC>-.t exOAlsf'k. O 2690 3250 3630 4060 4550 , ^ W i ^3260 3940 4450 4930 5520 36x6.3 36x7.3 36x8 42x7.9 42x8.5 7 77'A 8 83>/2 69 72 1 4700 1 6000 5200 5500 6500 3800 4200 4600 5000 i 5400 vnctcooi^ SS uO*'ite>xoxocors i*~r. rA fONrA-OX'>c^Cc-4<\fNn. o--O' U1N0 e-.A 756 757 1 6470 7850 48x8.8 86./, 7900 6700 NOoQoiOAOof^AXteO-TOm* N COolAOOoN-- OinO t> 759 760 761 762 763 765 766 769 770 ! 8280 9610 10850 10040 11670 13180 54x9.7 54x10.8 60x10.4 , 99 99 , m v i , 85 85 1 94 OOrjt<\ < --1> -- oOai <o 14300 16380 17420 1 19880 18660 20750 22650 ! 25200 22520 25530 28780 27300 31000 34900 33070 40150 66x11.9 66x13.2 72x12.7 72x13.8 78x13.7 78x15 84x13.8 84x15.3 112 112 (1 8 118 , 122 122 135 ,3 5 1 95 95 101 101 103 103 114 | 114 OO 10600 11700 12900 8800 9600 10600 16300 17900 19800 21300 22600 24700 28400 31300 13700 15100 16600 17800 19200 21100 24300 27000 00 - t'O" ts NO ts 1IM& 5 3 g - . J' till SE ooo.?5w2g2i.22 s SS *> * SS <-^aTc-a 1 co Z o h < u E 5 * a to -- o . Vo 1.5>3 3 -S=wjE:?. eoCQ 3 *i ISeoO.sj:-HUG OS DO^ ' B o i l e r N o . ............... ................... R ated Capacity.. Steam, sq. ft.; B u rn in g C o a l............................. . O il. C as o r.S to k e r F ir e d ........... W id th and Length . '. . . . . in . x in. O v e r-a ll H e ig h t ; ...........................in . H eight o f W a te r L in e ............... im A pproxim ate W eight: . C o a l B u rn in g ........................... lbs. O il B u r n in g . .............................lbs. Ja cke t, C ra te d , A d d . ................. lbs. 742 . 'Sis kA.*.JJJOA1"1 N-- --O' NSri tA ' fA SS5Uo SSr 88r OOIA^ nn f--A^--^JJJrosOA <A 1 746 743 | . 745 oo :--lN_Nw,_cN --5--Uoa5 CA 747 Boilers, Steel rOe--"O.O--rx'^*jfQfs>Tto>.>u.s0Ofn*'' AOeOx'S--S fA . A(oA_? e-.' an 3,0 Oo Boilers, Oil Burning General Electric Company AIR CONDITIONING PRODUCTS Air Conditioning Department, . 570 Lexington Ave., New York, N. Y. For Steam, Hot Water, Vapor, or Warm Air Heating Systems, General Electric Offers a complete line of Air Conditioning Equipment consisting of: The G-E Oil Furnace (2 sizes) Type LA4 and LA5. The G-E Winter Air Conditioner for Warm Air Systems (Type AA.3)--See Page 630. The G-E Winter Air Conditioner for Radiator Systems (Type ACl)--See Page 630. . The G-E Room Air Conditioner (Type ADI and AD2)--See Page 630. The Furnace is ideally suited for the heating of large quantities of water for commercial purposes. It may be used for spaces entirely surrounded by water. 3. Down-draft opera tion, with chimney at the bottom, results in high efficiency. 4. Built-in domestic hot water heating coil. 5. Sub-atmospheric pressure within unit pre vents escape of odors. 6. Large oil orifice, non clogging; non-dripping nozzle tip protected from heat of flame. 7. Oil viscosity com pensation. , 8. Temperature-resist ing metal parts. 9. Electric ignition during starting cycle only. 10. All controls built-in, including four-second de tector with self-checking special applications requiring up to 14 lb. steam pressure. The G-E Oil Furnace uses a new principle of atomization and combustion. Oil, and atomizing air, under low pressure, meet in collision within the nozzle tip and emulsify; expansion of the air, as the mix ture emerges from the nozzle, shatters the oil into an "oil fog." This atomized oil is contacts, water tempera ture or steam pressure limit, low water cut-off (steam), expansion relief door with electric cut-out, domestic hot water temperature switch, synchro nous motor-driven primary control, and electric clock thermal control with separate day and night settings. 11. Burner head, motor compressor, and controls separately and quickly removable and replaceable. 12. Designed, manufactured and guaranteed by a single responsible manufacturer--General Electric. blown from the nozzle toward the bottom of the furnace, where it meets the supply of secondary air introduced at the bottom, resulting in progressive, quiet and com plete combustion of the oil. Design Features 1. All rotating parts on one shaft, automatically oiled, no belts, no packing. 2. Heavy welded-steel boiler, with combustion Specifications TYPE LA4 Output--133,000 B.t.u. per hour (555 sq. ft. equivalent direct steam radiation). Water Capacity--47.5 gal. (full). 31.6 gal. (to water line). ^_ Heating Surface--30.5 sq. ft.--93.3% water backed. ' Piping Connections--3 m. outlet, two 1% in. returns. Electrical Input--195 watts at max. oil rate for steam systems, 285 watts with water circulator for water systems. # Dimensions--5 ft, 3 in. ' high, 35 in. wide, 42 in. deep. Weight--050 pounds com- yk_pletely assembled, without / water. . ^ TYPE LA5 Output -- 275,000 B. t. u. per hour (1145 sq. ft. equiva lent direct steam radiation). Water Capacity--76.7 gal. (full), 64.3 gal. (to water line). Heating Surface--53.5 sq. ft.--95% water backed. Piping Connections--4 in. outlet, two 2M in. returns. Electrical Input--200 watts at max. oil rate for steam system, 290 watts with water circulator for hot water systems. Dimensions--5 ft., 7 high; 37 wide; 51 in. deep. .. Weight--1660 lbs. completely assembled, with out water. 666 Burners, Oil Williams Oil-O-Matic Heating Corporation Manufacturers of Automatic and Manually Controlled Fuel Oil Burners ommc Bloomington, 111. Bloomington, III. Service to Architects and Builders Chicago, 185 North Michigan Avenue 0iic New York, Graybar Building Williams Oil-O-Matic offers a complete line of oil heating equip Model No. SPECIFICATIONS Length, Width. In. In. Height, In. HP. Gals. Fuel Oil per RTJVf. Operating Hr. Min. Max. ment--covering all heating and hot water needs. Also boilerburner units, heavy duty range burners and unit heaters. Latter used with water heaters where both hot water and heat are required. Model K-1.5 Model KB(I200). Model KB (1800) 25 29 29 15 18 18 22 1/8 1750 V2 20 1/6 1150 20 1/4 1750 $V6A 3 5 Model J(I200) 45 20 25 1/4 1150 4 10 Model J (1800) 45 23 25 1/2 1750 8 15 Model J J . 50 33 22 1 1750 12 Model K (1200) 34 28 21 1/6 1150 l`/2 3 ModelK(l800) 34 28 21 1/4 1750 2'A 5 WATER HEATERS WHA* WHBf WHCt * 48 2i 28 IM 1750 6785 23 29 23 1/8 1750 34 1/8 1750 i.(5 m Output: 90 rise, 60 gallons per hour. tOutput: 90 rise, 120 gallons per hour. tOutput: 90 rise. 210 gallons per hour: . In case odd frequency motors are used, the maximum capacity of the burner will be reduced in proportion to the r.p.m. of the motor. The minimum capacity remains the same. Model K must be substituted for KB for odd currents and export How to Decide Size of Burner For low pressure domestic boiler, 1 gal. of fuel oil per hour (L40,000 B.t.u.'s) is re quired for ap proximately: 300 sq. ft. of steam radia tion or its equivalent. 480 sq. ft. of hot water radiation or its equivalent. 70,000 B.t.u.'s when Model K-1.5 OU-O-Maiic using hot air furnace ratings. 24 sq. ft. steam boiler heating surface (or 2.2 hp.). 1 sq. ft. of grate surface with combustion space 3 ft. high or its equivalent. For detail data, see Oil-O-Matic Instal lation and Service Manual. Domestic Hot Water Supply Three water heater models cover the domestic and commercial water heating fields. Entire apparatus-including genuine Oil-O-Matic oil burner, combustion cham ber, water tank, and all automatic controls --now combined in a single neat and compact unit. Refer to specifications for dimensions and output capacities of all models--WHA, WHB, and WHC. ... Wide variety of sizes for steam or hot Water. Write for details. . Underwriters' Listing ' Oi1-OMatic burn ers are listed as standard by National Board of Fire Underwriters to bum oils conforming to A. P. I. standard specifications for Nos. 1, 2, 3, and 4, also . Pacific Coast Disel. Each burner carries Underwriters' label. Also approved by all important codes and governing bodies. Range Burners New type Oil-O-Matic range burner, for heavy duty ranges, brings oil heat econo my to restaurant,, hotel, hospital, steam ship, dining car, resort and club. No priming, no heat generating, no matches, no wicks required; a single lever controls everything. Boiler-Burner Units Engineering Service A complete line of welded steel and also Engineering service is available to cast-iron sectional Boiler-Burner Units. architects--see A. I. A., File No. 30-GL. 667 Burners, Oil Petroleum Heat & Power Company Manufacturers of ' Petro & Nokol Commercial, Industrial, and Domestic Oil Burner Equipment, Arco-Petro Automatic Boilers for Oil or Gas, and Oil Burner Accessories Distributors of Fuel Oil Factory and Main Offices: Stamford, Conn. - Nbw York, N. Y. Boston, Mass. R. I.Providence, Springfield, Mass. Branch Offices In .. Newark, N. J. Philadelphia, Pa. Baltimore, Md. Washington, D. C. Detroit, Mich. Chicago, III. Subsidiary Companies Boston Harbor Oil Co. East Coast Fuel Oil Co. Power Plant Engineering Co. OIL BURNERS THAT FIT THE BOILER A Complete Line of PETRO & NOKOL OIL BURNERS Each Designed for Specific Types of Domestic, Commercial, and Industrial Boilers and Furnaces The Petroleum Heat and Power Company recognized early in its 30 years of experience that no one type of burner meets every oil heating requirement in an equally satisfactory way, or solves every oil burner problem. TYPES OF BURNERS AND RECOMMENDED APPLICATIONS No. Type Oil No. per-Hr. Radiation Sq. Ft. Steam Hot Water Ignition Motor Price Range and H.P. Applications W-IA W-IB W-IC Horizontal Direct Motor Driven Rotary Cup Type Burner ; 3 .5 to 1.0 1.0 to 175 1.75 to Z6 350 560 Gas-Elec. 615 985 Uas-Liec. 910 , 1450 Elec.-Gas i/10 1/10 1/10 New. low cost rotary cup type burner for very small round or sauare boilers. Also for process steam and hot water service. K Wall-wiping Flame Rotary Type Burner P-1 P-V/z P-2 - Atomizing Gun Type Burner 2 (Gas) 2 (Elec.) .<r\> .8 to 2.1 .8 to 2.1 Gas or 285 to 730 460 to 117U EJec. 3 1.3 to 3.0 1050 1680 Continuous 3 2.0 to 5.0 1750 2800 Elec. 3 3.0 to 7.5 2620 4190 1/20 Minimum cost. fully automatic burner for. small round or square boilers and warm air furnaces. 1/6 Low cost, qualitv 1/6 built burner tor 1/4 rectangular fire box, sectional or tubular, boilers or furnaces. Radiation Maximum Sq. Ft. * Boiler Steam H. P. W-2. W-3 W-4 W-5 W-6 W-7 Horizontal 300 secs. 1.5 to 7.0 2450 vr/2 Elec.-Gas '/. Manual, semi- Direct Motor Saybolt 5.0 to 15.0 5250 37 with full Vl automatic, or full Driven Rotary Universal at 10.0 to 25.0 8750 63 automatic Vi automatic heavy Cup Type Burner 100F. max. 20.0 to 33.0 11550 83 l duty burner for viscosity' 25.0 to 45.0 15750 113 Manual V/i average Industrial or No. o Uii 25.0 to 62.0 21700 156 with semi- 2 and Commercial preheated automatic installations Full Full or Manual using heavier Automatic Automatic Control grades of oil. H Air Turbine No. 6 Oil 15.0 to 75.0 Driven Rotary preheated Cup Type Burner Manual 1 to 5 Manual and semiautomatic - equipment for large multiple burner installations up to any capacity. M Mechanical No. 6 Oil Up to 125.0 Atomizing preheated' Type Burner Natural and t* orced Draft Manual Manual equipment for large multiple burner installations up to any capacity. 668 Petroleum Heat & Power Co. Burners, Oil PETRO-NOKOL DOMESTIC OIL BURNERS Models ` W-IA," "W-1B," Horiztonal, Rotary Cup Type Burners Model "W-l" is a development and a refinement of the giant burners now heating some of the world's largest buildings. It embraces every operating principle--every important detail of design--the same precision in manu facture--the same economy and reliability. It is simply smaller--a giant in "junior" size--and of course simplified. In Model "W-l" a long, conical, whirling rotary cup reduces heavy fuel oil to a thin film before it reaches the edge of the cup. Here the high speed of the cup's edge breaks the oil up into a mist. Air from the fan in the burner passes down through the nozzle of the burner--and out over the edge of the cup where it is deflected by angular vanes in a direction opposite to the rotation of the Model " W-IA " Horizontal, Rotary Cup Type Burner cup. Air and oil meet off the end of the rotary cup, moving in opposite directions, and form a highly turbulent com bustible mixture which ignites instantly and burns in suspension into an incandescent hot gas. The exact amount of air for the amount of oil required is governed by an adjustment built in the burner. Model "K" Rotary Type Burner The Model "K" is a fully automatic, forced draft, centrifugal atomizing burner for the small round boiler or furnace. Its design provides for complete control of the air for combustion over the oil consumption range. This assures maximum operating efficiency. The air and oil are delivered through a rotary head assembly revolving at a speed of 1750 r.p.m. Air and oil are thoroughly mixed in their passage across the deck in stalled to cover the grate area. Ignition, either gas or electric takes place slightly above the base of the sections of a refractory ring provided to aid combustion. Model "K" produces the brilliant luminous flame, characteristic of all Petro & Nokol Burners. It provides Model "K": Rotary Burner the radiant heat which most boilers are designed to take advantage of. This flame is concentrated at the grate level.... where the coolest water absorbs the maximum heat. Model "K" burners are built for operation with No. 2 oil or lighter, and have a capacityjip to 2.1 gal. per hour. Control and Safety Devices--All domestic and the smaller industrial burners are fully automatic in operation. All automatic burners are equipped with com plete automatic control devices protect ing both the burner and the boiler or furnace from abnormal operating condi tions. Special controls and protective devices can be supplied to meet unusual operation conditions. Undivided Responsibility--Through out the Atlantic seaboard territory and in many of the more important mid-western centers, this company offers an undivided responsibility embracing the installation, servicing, provision of proper fuel oil, which insures satisfaction with Petro & Nokol equipment. ' A factory field engineering organiza tion is available at all times for survey, and conference in all things related to the use of oil as a fuel. Performance and Acceptance--The parentage of the Petroleum Heat and Power Company extends back to 1903--to the development of the first modern industrial oil burner. In the intervening years more than 100,000 installations have been made from coast to coast. Today, Petro & Nokol oil burners are found in practically every type of building from the 52-story Metropolitan Life Insurance Building and the Ritz-Carlton Hotel in New York, to modern residences in subur ban and rural districts. A Few Prominent Installations Equitable Buildings ...-New York City Riverside Memorial Church_____________ _New York City New York Hospital--Cornell Medical.___ --New York City Mark Hopm kins Hotel. ___ San Francisco Standard Oil Company. 26 Broadway_______ New York City American Central Life Insurance Company___...Indianapolis Pacific Telephone & Telegraph Building________ Los Angeles Sinclair Building:San Antonio University of Toledo- .__..Toledo,1 Ohio Detroit Public Library__ ..Detroit, Mich. All Petro & Nokol burners are approved and listed by the Underwriters Labora tories, as well as by all other Government, State and Municipal authorities. 669 Petroleum Heat & Power Co. Burners, Oil Model "P" Pressure Type Burners A fully automatic, forced draft, pressure at omizing burners. Design provides complete con trol of the air required for efficient combustion over the oil consumption range assuring maxi mum operation efficiencies. The air is delivered to the combustion chamber through vanes arranged tangentially to the flow of air in the tube which impart to the air a centrifugal motion. This swirling stream of air mixes thoroughly with the oil atomized from the nozzle to form a Modd "P": Pressure Atomising Burner lightly combustible compound. The quantity of air is regulated by means of the fan intake shutter. The Model "P" is a very simple mechanical device. The only moving part in the burner is a small motor, fan and oil pump, which combipe as a single rotating unit. It runs on two large oversized bearings. Both static and dynamic balance of this rotor are easily secured. This insures quiet operation. It also eliminates the usual gear or belt drive. .The flow of oil through the burner is controlled by a unique regulator that; governs both minimum and maximum pressures. No oil is admitted to the' combustion chamber unless there is adequate pressure for proper atomization of the fuel. An unusually effective strainer is built into the burner to remove any foreign substances from the oil that could possibly obstruct the flow of oil through the burner. When the Model "P" starts,-a high tension electric spark instantly provides ignition for the atomized fuel. It continues until the burner stops. A.momentary stoppage of oil has no effect because this continuous ignition is unfailing--always there ahead of any oil. ARCO-PETRO AUTOMATIC BOILERS OH or Gas Burning Types Arco-Petro Automatic Boiler Arco-Petro Automatic Boiler--For Oil or Gas In addition to the oil-burners listed in the accompanying table, Petro offers a series of domestic steam and hot water boilers con taining built-in Petro oil burners or gas burners, in 6 sizes for 285 to 800 square feet of steam radiation, with corresponding capacities for hot water radiation. Conversion from oil burner to gas burner or vice versa is easily made by mere substitution of the desired burner assembly. Fuel consumption is exceptionally low because of the perfect co-ordination made possible by building burner and boiler for each other. Units are encased in heavily insulated, attractively finished cabinets of superior appearance. Yet the cost of this fine equipment completely installed is commonly no greater than the cost of other boilers when equipped with an oil burner. . The Facts At a Glance Arco-Petro Automatic Boiler Commonly saves R to H on fuel. Completely automatic--with oil or gas. ` Petro Radiant Rotary Burner--or latest type Gas Burner. Burner concealed inside boiler. Quiet operation. ' - Boiler especially designed for highest operating efficiency with burner. A complete unit, ready to be connected to the piping. . For steam, hot water, or vapor. `. Provides automatic hot water service at lowest cost--summer as well as winter. Beautiful color combinations. Costs no more than an ordinary boiler and oil burner. . Data and Dimensions Boiler Model ' T-11 T-12 T-13 T-14 T-2 Base and Burner for Oil Base and Burner for Gas Max. Cap. Total Tax Sq. Ft. Steam Rad. .................................. 285 390 495 600 800 Max. Cap. Total l ax Sq. Kt. R W. Rad................. .. 456 624 794 960 1280 Water Cap. to Water Line Gal. 15 17 19 21 16 Outlets--Number and Size.-.... 2-y 2-3' 2-3' 2-3' 2-3' Returns--Number and Size.... 2-3' 2-3' 2-3' 2-3' 2-3' Shipping Weight--Pounds.......... 1385 1435 1510 1675 1478 670 Petroleum Heat & Power Co. Burners, Oil PETRO COMMERCIAL AND IN DUSTRIAL OIL BURNING SYSTEMS Model "W" Direct Driven Rotary Cup Type Burner The Model "W" is a complete oil burning unit in itself, combining motor, fan, oil pump and atomizer, completely synchronized and controlled. This type of equipment is designed for medium-sized commercial and industrial plants and large, single boiler installations. Model "H" Air Turbine Driven Cup Type This equipment is adapted to medium and large boiler plants with multiple boiler installations, also for industrial applications. Bums all grades of fuel oil. Low pressure air and oil are supplied from the combination fan and pump set to a series of burners and air registers mounted at the boiler fronts. Operating burners from a central source of motive power eliminates the multiple installation of elec trical equipment. Fan and pump sets can be driven by electric motor, steam, turbine, or gaso line engine power. Additional firing units can be added at any time without increase of motorized equipment. Low pressure air is delivered through an air line buried in the floor. Secondary air is drawn through the controlling air vane registers by natural draft. ( Model "M" Mechanical Type Model " M " is now adaptable for either natural or forced draft in one standard design. Oil is delivered to the burners at high pressure and high Model "H": Air Turbine Driven Rotary Cup Burner temperature (approximately 250 pounds and 250 F.) and atomized through a small orifice at the improved tip. The oil is supplied by steam pumps. Petro Oil Pumps for All Services The Petro Belt Driven Pump motor operates at a full load speed of 1,750 r.p.m. and is of ample capacity to meet load demands. Motors are available for use with alternating or direct current. Pump speed is 220 r.p.m. Bunker "C" oil may be handled as readily as furnace oil. The Petro Domestic Wall Pump is designed for installations where fuel oil is fed to the burner by static pressure created by a column of oil. The reservoir maintains a steady head of oil. Available in two sizes, rated at 10 and 20 gallons of No. 3 oil per hour. The Petro Worm Drive Pump is a heavy duty pump designed for installations where regulations impose the most exacting requirements. Model "M" Mechanical Type Petro Belt Driven Pump Modd " H" Combination Fan and Pump Set ' 671 Coal Burners, Automatic 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. 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 Fireman "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 increases heating plant efficiency in four major ways: (1) Cuts fuel costs; (2) reduces labor costs; (3) provides steady, even heat Typical Iran Fireman InstaUation under Cast Iron Boiler or power; (4) eliminates the smoke nuisance. Installation and Sizes--Iron Fireman is made in a range of sizes for commercial heating and power plants up to 250 h.p. boilers, and also for homes. It can be in stalled quickly in practically any solid fuel boiler or furnace, old or new. If necessary, the installation can be made with practi cally no interruption of the service from the boiler. Machines are shipped complete from the factory. All parts are stand ard and interchangeable. Features of Design and Con struction--Construction and opera tion of the Iron Fireman are charac terized by simplicity throughout. Out- | standing features of design and con-. struction are: (1) Pressed steel construc tion. (2) Special patented transmission-- three speeds and neutral. (3) Continuous feed transmission. Gears run in bath of oil. (4) Electric motor--standard make. (5) V-belt drive. (6) Safety shear pin pro tects mechanism from damage. (7) Quiet ball bearing fan supplying forced draft to fire. (8) Automatic fire banking damper-- conserves fuel and holds fire in proper con dition when stoker is idle. (9) Posi tive pneumatic . fume eliminator-- an auxiliary air supply that in sures positive movement of all gases through the fire. (10) Sec tional retort es liT--m pecially designed Typical Iron Fireman Installa to allow for heat tion under Four Drum Tube Boiler Water expansion. (11) Dead plates of heavy iron and ribbed. (12). Sectional, self-cleaning tuyere blocks. (13) Conveyor screw cast of special Iron Fire man alloy steel from one-piece pattern. (14) Automatic electric controls, designed for and used exclusively on Iron Fireman. Iron Fireman in Operation. Installed under Horizontal Return Tubular Boiler. Low Bridge Wall. Cutaway View, showing details of Typical Iron Fireman Installation 672 Iron Fireman Manufacturing Company Coal Burners, Automatic Transmission and Continuous Feed Principle--The Iron Fireman speed re duction unit and its patented speed-change gears are an exclusive Iron Fireman development. This transmission drives the conveyor screw at a constant speed which in turn feeds the coal to the 'fire in a slow, steady stream at the required rate for proper burn ing. As a result a steady, non-agi- tated fire is ob tained. The Iron Fireman trans mission has three Iron Fireman Transmission speeds and three _ neutrals. The gears can be shifted while the stoker is in operation; in fact more easily than when the stoker is idle, arid it is' impossible to strip gears while shifting. All the gears operate in a bath of lubricating oil and the unit is most quiet. In design, materials and precision of construction, the Iron Fireman transmission is like that of a fine automobile. Automatic Controls--Iron Fireman starts and stops at the command of sensi tive, accurate automatic controls. Direct ing controls govern stoker operation ac cording to demands of time, temperature, or pressure. An example of the superiority of Iron Fireman directing controls is the " Syncro-Stat " which provides automatic stoker motor at the command of the Syncro-Stat or other directing controls. In the case of the larger stokers a magnetic operating switch works in conjunction with the relay switch. Important Factor in Plant Economy --Iron Fireman users report savings of from 15 per cent to 50 per cent on fuel costs alone. In a recent investigation of 342 users, fuel savings alone averaged an earning of 39.44 per cent a year on the total cost of their installations. Iron Fireman for Homes--The Iron Fireman residential model employs "Forced Underfiring" principle the same as larger machines, with simplified opera tion. The enclosed hopper accommodates sufficient small size coal for an ordinary day's consumption. Can be recommended for any steam, hot water, vacuum or warm air furnace. Quickly installed. Models for both bituminous and anthracite coal. All an- Iron Fireman Installed in a Domestic Boiler ENGINEERING SERVICE control of day and night temperature.. It is powered by. a Telechron motor, thus eliminating winding or setting, and making it an accurate all-electric temperature regulator. Other directing controls in clude pressure regulators, hot water and furnace regulators and the "Timetactor" a device which runs the .Iron Fireman during predetermined intervals in order to keep the fire alive during mild weather. The most important.unit of the operating control system is the motor-driven relay switch. This device starts and stops the The Iron Fireman organization is nation-wide. Trained men--backed by one of the largest manufacturing organi zations 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 infor mation requested. . CATALOG AND INFORMATION Catalog No. 33 gives 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. 673 Coal Burners, Aulomalic Detroit Stoker Company Sales Offices and Engineering Department -- General Motors Bldg., Detroit, Mich. Main Office and Works at Monroe, Mich. District Offices in Principal Cities Built in Canada at London, Ont. Since 1898 A Detroit Stoker (or Every Service, and all sizes of boilers, from small heating boilers, to large water tube boilers. Each installation, regardless of size is carefully studied from an engineering standpoint to insure best results. Detroit LoStoker Built in various widths and lengths to fit furnaces of all types of boilers. Com pact, easily installed, responsive and auto matic. Savings, due to increased efficiency, combined with the ability to successfully burn less expensive grades of coal, make Detroit Stokers pay a handsome return on the investment. Write for Bulletin 369. Coal Burners, Automatic 290. MOTOR stOkorHudson Street New York N. Y. CORPORATION A FULLY AUTOMATIC COAL BURNER Series 2AF Motorstokor, the ash removing -- anthracite -- universal type feeder model, conveys "buckwheat" or "rice" coal direct from the bin into an underfeed retort. Ashes are removed into two or seven full size ash barrels. Minneapolis-Honeywell series 10 controls are standard equipment on all Motorstokdrs. Detroit LoSloker, showing Motor Driven Blower and Stoker, One Compact Unit at the Front Detroit LoStoker Advantages include: Agitator in coal hopper for positive coal feed. Cannot stick or jam with wet coal. Adjustable Plunger Feed for the con-. trol of the quantity of coal and its dis tribution within the furnace. Heavy Mechanical Drive of simple design and with Timken Bearings. Little power is required for operation. Side Cleaning with dumping grates. Ash doors are provided. No hand cleaning. Automatically Controlled. Detroit LoStokers are motor or turbine driven, controlled from steam pressure, water temperature or room thermostat.^ Write for Bulletin 369. Detroit LoStoker Rear View shelving Enclosed Air Chamber, Tuyeres and Dumping Grates Side View showing Adjustable Plunger Feed. No Moving Parts in or Near the Fire Front Sectional View. Large Active Fuel Bed, with Provision for Admitting Air under the Dumping Grates at each side to burn out the Combustible Prior to Dumping Ashes 674 Series 5AF Motorstokor, the straight line feeder model offers automatic coal feed from the bin with ash removal by gravity into a sunken pit. Series 3BH Motorstokor is designed for bituminous coal. The remarkable retort design, originated in Motorstokor's re search laboratory, enable 3BH models to burn even high volatile, caking and coking "slack" without creating smoke and with out manual agitation. Other bituminous models provide automatic coal feed from the bin and automatic ash removal. __ Please ask for catalog and specifications. 60 models and sizes from ten lbs. per hour to 200 lbs. per hour feed rates. (300 to 7,000. sq. ft. E.D.R. on single units, up to 140 H P. on multiple installations. 675 Copper Radiation, Concealed Waterbury Chase Brass & Copper Co. INCORPORATED - Heating Products Division Connecticut For data on Chase Copper Tube and Sweat Fittings for Heating Lines see pages 696-697 . ' Over Fifty Years In Business Expansion Joints American District Steam Pompanv NORTH TONAVANOA. NX STEAM DISTRIBUTION EQUIPMENT ADSCO EXPANSION JOINTS Branches and Agents in Principal Cities CONSTRUCTION--Copper, the best commercially, practicable material from a heat transfer standpoint, is used'for both the tube and fins. The tubes are firmly secured to the headers by compression nuts, a universally accepted method of making a permanent bond not affected by strain or stress. The fins when they contact the tubes, have a flange or lip, which acts as a definite spacer for the fins. Part of the lips are lapped over and under each other to prevent slipping and insure a tighter bond on the tube: Fins are corrugated to provide greater area for a given depth of unit and to increase strength and rigidity. . TUBE SIZE--On the Chase copper radiator the supply tubes are 54 in. diameter. This is an important advantage as it assures a more satisfactory operation. For example, when used with hot water it permits freer circulation. On one pipe steam installations there is enough room for condensation return. . ADVANTAGES--Here are four advantages of the Chase Radiator. copper and brass materials with high heat con ductivity and long life. 2. Adequate and per manent bond between fin and tube and between tube and header. 3. Sufficient steam on water way to meet all conditions of service. 4. High heat output with respect to space required and to weight. 1. The use of Complete catalog filed in Sweet's Architectural Catalog The copper to copper bond is accom plished by a patented process of tube expansion. No solder is Used 676 Internally Guided Slip Type ' Packless Variator ADSCO Expansion Joints, whether packless or slip tube type, are available in a complete line of types and sizes; for all pressure to 400 pounds and temperatures to 750F. Slip tube types range from the simple semi-guided joint to the completely guided type with all bearing surfaces of bronze and no possible metal to metal contact between any part of the joint and the sliding surface of the slip, a feature obtainable only in ADSCO Joints, and one of the reasons leading architects and engineers specify them. ADSCO Packless Expansion Joints (Variators) utilize a flexible stainless steel diaphragm to control expansion and contraction. Movement is controlled both ways. There are no strains on the flexible members because all stresses are transmitted to the joint body by backing plates--a most unique and successful method as proved by the hundreds installed more than 25 years ago, with no maintenance since installation. Engineers are constantly giving them their stamp of approval for use where accessibility is practically impossible when the job is completed. ADSCO UNDERGROUND CASING CONDUIT ADSCO ROTARY CONDENSATION METER ADSCO Red Diamond Brand Casing --an ideal underground steam or hot water line conduit since it is both conduit and insulation--is real economy, for a college or institution distribution system. Doing service after 38 years is conclusive evidence. More than 90 per cent efficient. Fur nished in split form for two or more pipes, if desired. Lays quickly because of 5 to S ft. lengths. Trench may be backfilled immediately. Does not expand or con tract longitudinally, assuring permanent water-proof construction. For measuring the steam condensation of a heating system or heating equipment. Commercial distributors of steam use them as a basis of charge for steam sold-- institutional groups for steam cost dis tribution--and industrial firms for steam consumed in process work. Accurate within 1 per cent of absolute. Depen dable. Compact. Reads directly in pounds of condensed steam. Furnished with cast-iron or aluminum body and cover in seven sizes: 250, 500, 750,: V15.Q0, 3000, 6000 and 12,000 pounds capacity per hour. Expansion Joints E. B. Badger & Sons Co. 63-75 Pitts Street, Boston, Mass. Engineers and Manufacturers New York Office. 271 Madison Avenue Offices in Principal Cities PRODUCTS: Corrugated Expansion Joints, Pipe Bends, Chemical Apparatus, Copper and Sheet Metal Work, Copper Boilers and Hot Water Tanks. BADGER SELF-EQUALIZING EXPANSION JOINTS These have been on the market for more than forty years and as sold- today represent the results of a series of distinct improvements. Badger engineers are responsible for such developments in the corrugated type of joint as special analysis copper of which the seam less tubes have been made, the equalizing rings, the monel metal sleeve to protect against superheated steam, the welding end joint. Now, Badger Joints carry another big Flanged Types improvement in a new design corrugation which functions on the principle of Directed Flexing. Before passing to this subject, a word about the importance of using the corru gated type of joint. Not only is it compact and easily installed, but it. requires no main tenance. It u^no packing. Fitted with alignment bars on the 4 and 5 in. sizes. Choice of standard or extra heavy flanges. Directed Flexing The shape of the new Badger Corrugation is entirely curved. There are no straight sides. In action the corrugation undulates, using the equalizing ring as a guide. This is the so-called "Directed Flexing." In stead of being left to chance, the flexing of the metal is guided so as to undulate along an all-curved surface. This is well brought out in the two sections shown. The shaded portions are two halves of adjacent equalizing rings; the heavy, line is the corruga tion. Note how it is wrapped around the curve of the ring. Longer joint life is the direct result of this improvement. A new bulletin, describing this new corruga tion, will be sent on request. Different Types Available Both flanged end and welding end joints are available from 3 in. (welding) and 4 in. (flanged) up. Single or double joints with or without service outlets. All joints can be equipped with telescoping monel metal sleeves to protect against superheated steam. On 6 in. pipe and larger, no alignment bar is used. Standard 125 lb. or extra heavy 250 lb. flanges as required. Welding Types For use with both saturated and super heated steam. Single type from 3 in. up, to take care of 1 in. expansion or more. Pipe nipples welded directly into pipe line. Double units for 2 in. expansion or more. Equipped with service outlets as shown, if desired. Complete units furnished, mounted on base plate, with anchor and guides. . Single and Multiple Corrugated Expansion Joints for Low Pressure For use between turbine or engine exhausts and condenser or on low pressure lines. Excellent for absorbing shock and vibra tion. Flanges in round, oval or rectangu lar shapes. Guaranteed up to 30 lb. pressure. 678 Fans and Ventilating Equipment Bayley Blower Company 1817 S. Sixty-Sixth Street Branches in Principal cities Milwaukee, Wis. Builders of Heating, Ventilating, Cooling, Purifying, Humidifying and Air Washing Equipment; Exhaust and Drying Apparatus, Mechanical Draft and Blast, Fans and Blowers of all Types . Bayley Plexiform Fan: Is a multi-blade fan for supplying air for heating and ventilating systems, manufacturing processes, drying systems, forced and induced draft sys tems. It is suitable for handling high or low temperature gases at medium or low pressure. Will deliver maximum quanti ties requiring minimum space with great economy. This is a distinct Bayley product, high class material and workmanship, properly designed to avoid excessive vibration and overstressing of parts. Inlets and outlets are properly sized for maximum delivery and maximum efficiency. Fans are fur nished in single or double width of any required arrangement and with sleeve or anti-friction bearings. 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 center of a The Bayley Turbo Air Wother Shovy ing Turbo Atomizer and Eliminator rapidly re 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 inc.orporates 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. 679 Fans and Ventilating Equipment Buffalo Forge Company 484 Broadway, Buffalo, N. Y. Branch Offices Albany, X. Y.................. 414 Standard Bldg., H. S. Johnson Atlanta, Ga...... .................. 404 Title Bldg., E. T. Gorbandt Baltimore, Md......................... 303 Morris Bldg., R. W.'Hogan Boston, Mass--......................P. 0. Box 71, E. D. Johnson Charlotte, N C..........................P. 0. Bo* 376, J. W. Fraser Chicago, III.................... 15 N. Jefferson St., L. D. Emmert Cincinnati, Ohio................. 622 Broadway, F. W. Twombly Cleveland, Ohio.......... 418 Rockefeller Bldg., T. A. Weager Dallas, Texas............................2710 Live Oak St., W. J. Allan Denver, Colo., Hendrieand Bolthoff. 1621 17th St., H. V. Waterman Detroit, Mich..._Cooh dc Visscr, 2051 W. Lafayette Blvd. Greenville, S. C..... ............... P. 0. Box 563, G. R. Morgan Hoktington, \V. Va..............1612H Third Ave., J. K. Giffen Indianapolis, Ind.... 725-727 Circle Tower. I. C. DeHaven Kansas Citt, Mo..................217 Dwight Bldg., L. R. Chase Kirchener, Ont., Canada. Canadian Blower &. Forge Co., Ltd., A. S. Capwell Knoxville, Tenn...._...............P. 0. Box 1035, C. F. Sexton .Los Angeles, Calif., . 610 Pershing Square Bldg., P. It. Adrianse Minneapolis, Minn............... 430 Oak Grove St., E. F. Bell Nashville, Tbnn................117 Fifth Ave. N.. P, D. Jarrett New York, N. Y.39 Cortlandt St., W. S. Koithan New Orleans........ ..........................2841 Pine St., A. C. Hays Philadelphia, Pa......... 220 South 16th St.. L. C. Davidson Pittsburgh, Pa....................912 Fulton Bldg.. H. L. Moore San Francisco, Calip., Herberts Moore Machinery Co., 550 Fifth St., J. G. Scott St. Louis, Mo..... ................ 1596 Arcade Bldg., J. W. Cooper Salt Lake Citt, Utah, . Salt Lake City Hdw. Co., W. H. Trasls, Jr. Seattle, Wash...................... 2719 First Ave. S., A. T. Forsyth Toledo, Ohio...................--1817 North 13tb St., C. M. Eyster Washington, D. C., Commercial National Bank Bldg., G. S. Franke! Wilkes-Barre, Pa., Power Eng. Corp., Coal Exchange Bldg., C. Ide 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 " Limit Load'* Conoidal Fans with Silent Floating Base -- The quiet, h igh -ef ficiency *1 Limit Load" Conoidal fan is now available on the silent floating Buffalo Base which is rubber- insulated so that no motor or fan vibra tions are transmitted to structural frame work of the building. This makes an almost noiseless installation, particularly suitable forauditoriums, theatres, churches, hotels, etc. Buffalo Air Washers Developed from the, original de sign, Buffalo Air Washers- h a v e de mountable, one-p'iece eliminators, non-clogging ___ r___ . . ^ AtrWtuKer spray nozzles, fully flooded scrubbing surfaces, and wide suction screen. Gas and Steam Unit Heaters Both types of steam unit have extended surface copper heating coils. Buffalo Gas Unit Heaters are made in eight sizes with capacities from 75,000 B.t.u. Breezo-Pin to 500,000 B.t.u. input per hour. They are suitable for burning any kind of gas, natural or manufactured, and provide unusual heating economy. Breezo Venti lating Fans In sizes from 8 in. to 36 in. diam eter, Breezo fans provide inexpen sive efficient ventilation on any job' where they may be used to exhaust into the open. Popular 8 in. home ventilating model is supplied in metal case for installation in kitchen wall. Unit Coolers Buffalo Unit Coolers are made in floor and suspended types for use with ammonia, brine, methyl chloride or freon refrig erants. They are suitable for installation in chilling rooms, packing plants, fruit storage rooms, etc. Complete information contained in Bulletin 2904. 680 Fans and Ventilating Equipment 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; Unit Heaters and Blast Gates. For Heating, Ventilating, Cooling, Drying or Forced Draft Type "CE" Manivane Fans For Duct Work and Quiet Operation. Type "BC" Backward Curve Fan Sizes--12" to 72" Wheels Type "C" Manivane Blast Wheel Built Strong and Substantial. Free from Vibration and Noise. Very desirable for Oil Burners and General Heating and Ventilating Purposes, especially where noise is an objection. Super Fans for Free Air To Ventilate and Remove Odors or Foul Air from Rooms, Shops, Mills, Factories, Foundries and Steam in Laundries and Steam Rooms. Sizes--12" to 36". 681 Fans and Ventilating Equipment L. J. Wing Mfg. Co. Branch Offices in . Principal Cities 59 Seventh Avenue, New York Phone: CHelsba-3 0027-0030 Factory: NEWARK, N. J. Wing Featherweight Unit Heaters and Process Heating Units; Utility Unit Heaters; Wing Scruplex Safety Ventilating Fans, Fog Eliminators and Exhausters; Wing Forced Draft Blowers, Turbine or Motor-Driven; Steam Turbines; Man-Coolers. LIGHT weight, and vertical downward discharge of the heated air through high velocity multiple discharge outlets are original and unique features of Wing Feather weight Unit Heaters. Thus, downward circulation of large volumes of warmed air to the Detail of Wing Featherfin Heating Element showing Compression Union Tube Connection floor and uniform distribution of it over the entire area is assured, with resultant economy in plant heating. Wing Featherweight Unit Standard Discharge Outlets for Type HC Heaters produce a pleasing sense of warmth at the floor level because the warmed air from each of the several heater dis charges actually reaches the floor. On the other hand, at tempting to accomplish this re sult by the method of with drawing cold air from the floor would create cold drafts and circulate floor dust through the atmosphere. TYPE LC UNIT Cross-Section showing location of motor and fan. Used in buildings having low roofs or ceilings Wing Featherfin Heating Element--(Tested to 1000 lbs. Pressure). Extremely light in weight. By simple variations of the heating surface any desired final air temperature may be ob tained with any given steam pressure. Fin and tube extended surface type.' Hairpin or return bend design. Headers of steel, tubu lar design. Tubes secured to TYPE HC UNIT Comnlete coverage accompluhcd with an, of discharge outlets illustrated at right headers by steam-tight compres- s'01? lini,n- Easi'y removed and replaced in case of damage. Bulletin H-5 Contains Complete Data Wing Utility Unit Heater Wing Featherfin Process Heating Units A general purpose heater. Delivers heated air in one general direction. With vane diffusers and safety guard ,, for fan. Capacity !j ^ data same as Type ' HC. Bulletin US. ! I I I I Wing-Scruplex Fog Eliminators " Supply tempered fresh air to completely de-fog any building or room where steam, fog or fumes are liberated in manufacturing processes--e.g., Dye Houses, Creameries, Galvanizing Plants, etc. , For manufacturing processes such as dry ing, ageing, etc., requiring the recirculation of the heated air. Motor or turbine located outside air current. Bulletin PS. Wing Featherfin Heater Sections for1 general blast heating. Bulletin HS-1. 682 L. J. Wing Mfg. Co. Fans and Ventilating Equipment Wing-Scruplex Safety Ventilating. Fans An integral guard of strong steel rings welded to the frame features every model of the WingScruplex Safety Ventilating Fan. This guard removes the ever-present danger which exists whenever fans are in an exposed location, and does not reduce fan efficiency. The high volumetric efficiency of WingScruplex Safety Fans is due to their true screw propeller design which moves the air forward in straight lines without eddy. Motor is fully enclosed, easily accessible and generously proportioned. Can also be supplied with pulley or turbine drive. Wing-Scruplex Safety Fans are built in the following sizes: 10, 13, 17, 22, 25, 30, 36, 42, 48, 54 and 60 in.--capacities from 950 c.f.m. to 33,000 c.f.m. Up to 25 in. dia. propellers are made of cast-aluminum--large sizes of pressed steel. Bulletin F-5 Contains Complete Data H. 5CUisANhoAoIRde-AdIRcMoxAsNtDuImEDv DwOmCSill COME IH CONTACT WITH MARlNOf I IUirI inVet Wing-Sr.riipier Exhauster with bottom inlet Wing-Scruplex Exhausters In the Wing-Scruplex Exhauster the motor is en tirely outside the exhaust housing, therefore always easy of access, clean and cool. As an elbow in any duct system where resistance is moderate this ex hauster provides efficient, low cost, convenient ventilation. For acid laden air, fan and exposed parts can be supplied in Monel metal. Wing-Scruplex Exhausters are made for either horizontal or vertical operation--top, bottom or side intakes. The drawings below show the flexibility of application of these units. Bulletin E-8 Contains Complete Data Wing Blowers for Forced Draft - The installation of Wing Motor-driven Type EM Blowers on heating boilers of all sizes makes possible the use of Buckwheat coal and other inexpensive fuels with great savings in fuel costs, which usually pay for the blowers in the first year of operation. These blowers are of the ' propeller type fan con struction. They afford large air passages and low air velocities, resulting in quiet operation and even Wing EM Blower fires. Wing Blowers control led by speed regulation, conveniently operated from the front of the boiler. Totally enclosed motors keep out the dust and dirt of the boiler room, insuring many years of service without repair. Automatically controlled, they make the fireman's work easier. Ask for Bulletin NorM-56 describing Wing EM The Wing Blower in foreground suppliedforceddraftto Units. For High-Pressure Boilers.ask for Bulletin " * No. T-97 describing Wing Turbine Blowers. , 683 Fans and Ventilating Equipment ILG Electric Ventilating Company Propeller Fans, Blowers, Unit Heaters, Unit Coolers 2880 North Crawford Avenue, Chicago, 111. Sales Representatives in all Principal Cities Ilg Self-Cooled Motor Propeller Fans Furnished with direct-connected fully enclosed and self-cooled motor. Wheels rotational static balanced. Sizes 12 to 72 inches. Capacities 750 to 40,500 cubic feet per minute. Self-Cooled motor makes fan especially effective in handling gases and extreme heat. Used every where for general exhaust ventilating. Ilg Universal Multiblade Blowers Ilg Type B Universal Blowers are designed so as to combine compact ness, high efficiency, quietness and low power consumption. The motor is recessed in the side of the blower requiring no separate base and insuring quietness of operation, economy of installation. Ilg Blowers are furnished either direct connected to Ilg ballbearing motors or for belt drive. Sizes 25 to 90 single or double width. Ilg Unit Heaters--Steam and Electric Ilg built throughout with copper tube and fin coil and patented fully enclosed, self-cooled motor. For operation on steam or hot water. Tested with 500 pounds hydrostatic pressure. Available in 14 capacity sizes. Ilg electric unit heaters for all electric operation, avail able in 20 sizes for wall or ceiling suspension and for floor mounting.; Ilg-Kold Electric Cooling Systems A new and simpler system of unit cooling for stores, offices, factories, restaurants, homes, etc. Floor cabinet or ceiling suspension .units. Combines air cooling and air dehumidifying to obtain better hot weather air conditions. Installation can be made with a minimum of expense and time. Quiet and extremely effective. OTHER ILG PRODUCTS Kitchen Ventilators, Power Roof Ventilators, Humidi-. fiers. Automatic Shutters, Ilg Columnar Heat Systems, Ilg-Kold Compressors. V E:N 684 Heat-Surface (Fan System) Aerofin Corporation 850 Frelinghuyaen Avenue Newark, N.J. AManufacturers of erofin The Standardized Light-Weight Fan System Heat-Surface II West 42nd Street, NEW YORK Land Title Building PHILADELPHIA United Artists Building DETROIT Burnham Building CHICAGO Aerofin is the modern Standardized Light-Weight Fan System Heat-Surface originated by Fan Engineers to meet the present-day requirements of this highly specialized field, and to afford an adapta bility which permits and fosters the new and advanced applications of tomorrow. Flexitube AEROFIN Flexitube Aerofin: (Fig. 1) supplants the former Low Pressure Aerofin (the original light-weight, non-corrodible, en cased Heat-Surface) and will, we believe, eventually supplant Universal Aerofin, as Architects and Engineers become familiar with its unusually adaptable characteristics. Flexitube Aerofin is distinguished from all other developments by its off-set tubes, Fig. 1 as shown. This ingenious idea imparts to the tube a flexibility which enables it to expand or contract, under temperature changes, without strain upon itself, the header joints, the header or the casing. Hence the name Flexitube Aerofin. The flexibility of the off-set tube per mits a single-pass, header-to-header design which allows the use of rigid headers and so perfectly relieves or absorbs expansion and contraction strains that header and header-joint construction adequate for high pressure service may be employed, and the permanency of the construction assured thruout the practically unlimited life of the surface. Single-pass tube construction is essen tial for low pressure service and is desirable for intermediate pressure service (up to 200 lbs.) since it insures uniform steam or cold water distribution and proper, quiet drainage of condensate, while permitting installation of the Unit in any position, The off-set tube of Flexitube Aerofin is the first definite achievement of the ideal single-pass, header-to-header design. Tests equivalent to a life-time of service show that Flexitube Aerofin will stand up indefinitely against the strains of ex pansion and contraction because the Unit, due to its design, does not resist these strains, but absorbs them in its flexible tubes without rack or injury.. The headers are one-piece brass castings, machined for tube joints and pipe tappings. The joints between the tubes and the headers are of a patented type made by using a brazing material applied at high temperature and have proved stronger than the tube itself under all operating con ditions for which Aerofin is sold. We believe this joint to be the most'practical and dependable yet developed. . Steam tappings are located on the center line of the casing with respect to its width, off-set from center line with respected its depth. Return tappings are eccentric, at opposite end of casing. 685 Aerofin Corporation Heat-Surface (Fan System) This arrangement of Supply and Return connections readily lends itself to every installation requirement and permits in stallation in any position, tubes vertical or horizontal, or Units "laid flat" for vertical air flow. . Uniform steam or cold water distribu tion thru every tube is assured by proper orifice restriction at supply ends of tubes, this being accomplished without use of separate orifice rings, by machine-shaping the tube ends. Complete descriptive and Engineering Data are presented in our new Bulletin GSS, which Architects, Engineers and Contractors are urged to secure at once by request to Newark. Flexitube Aerofin is constructed as briefly described above. In Universal Aerofin and High Pressure Aerofin the seamless tubes, with their extended fin sur face, are continuous. (See Figs. 2 and 3.) Flexitube Aerofin, Universal Aerofin and High Pressure Aerofin are furnished as completely encased Units, ready for pipe and duct connections. The casings are built of pressed steel and are ex ceptionally strong and rigid, protecting the Unit from all the strains of pipe con nections and expansion or contraction in service. The casings are flanged on both faces, top and bottom, and template punched for bolting together adjacent Units, or for duct connection. Design and Construction: The heattransfer surface in Aerofin is a plurality of seamless copper tubes about which is wound a helix of copper ribbon, crimped on its inner edge to permit winding and to afford maximum contact between tube and fin. The extended fin surface is applied and tinned while held in position, by highly developed automatic machines, being accurately crimped and spaced. The tinning of the tube and the extended sur face makes them metallidy integral, affording maximum heat transmission and permanent effectiveness. The thickness and width (height) of the extended surface, the crimping and the pitch of the helix were determined by careful experiment, to afford maximum heat transfer, uniform air flow and minimum resistance thereto. The copper tubes and fins of Aerofin transmit heat eight times as effectively as iron. So scientifically is Aerofin designed that air is heated more in passage through a single row of its tubes, a travel of in., than in passage through an entire section of castiron surface, a travel of 9 in. Standard Casings: The casings of all Aerofin Units (including the new Flexi tube, which is interchangeable with former Fig. S Low Pressure), whether comprising one, two or three rows of tubes, are 29 in. wide (except 6-tube Universal Aerofin which is 21^6 in.) across tubes, from outer edge one flange to outer edge opposite flange, and 10 in. deep in direction of air flow. Length of casing is nominal tube length plus 8H in. Fig. S Aerofin Sizes: Flexitube Aerofin: Made in thirteen standard tube lengths, either one or two staggered rows of tubes per Unit, in 5 series (as explained in Bulle tin). There are thus sixty-five standard Units available, a range which adequately meets all requirements. Tubes are furnished of any length between 2 ft. and 6 ft., in increments of 686 Aerofin Corporation Heat Surface (Fan System) 6 in., and between 6 ft. and 10 ft. in increments of 1 ft. Complete tables of sizes and capacities are shown in Bulletin GSS, mailed gratis upon request. This bulletin also contains 19 proved Piping Diagrams in four colors. Universal Aerofin: (Fig. 2). Available in one-row or two-row Units, 6-tubes or 9-tubes across face, in seventeen standard tube lengths (distance between end baffle plates, or between 180 bends) between 2 and 10 ft., inclusive, in increments of 6 in. Batteries of double width are easily as sembled by setting Units end-to-end, leaving space for pipe connections. Complete information is contained in our Bulletin GSS, mailed gratis upon request. High Pressure Aerofin: (Fig. 3). Made in five standard tube lengths (*.., length of straight section of tubes, between 180 bends) 2 ft.; 2 ft. 6 in.; 3 ft.; 3 ft. 6 in.; 4 ft., either one, two or three stag gered rows of tubes per Unit. There are. thus fifteen standard units now available, meeting practically all requirements. Since the supply and drip connections of High Pressure Aerofin are located on the same end (Figure 3) Units may be placed end-to-end, thus affording battery widths of twice the standard tube-lengths. Com plete tables of sizes and capacities are shown in our Bulletin GSS, mailed gratis upon request. Narrow Width Aerofin: (Fig. 4), is to be used for Cooling only. The con struction of Unit is the same as Flexitube Aerofin except that tubes are straight and depth of casing is "5 instead of 10 in." This saves half the space required, in direction of air flow. Note that brass air-vent connection is installed at top of outlet end, outlet being shown, in illustration, at bottom of Unit, with inlet in center on opposite end. Dimensions other than given above are the same as in Flexitube Aerofin. Aerofin Booster Units: (Fig. 5) for horizontal or vertical air flow. Six sizes 150 to 1624 c.f.m., 200 lbs. working steam pressure. Complete information upon request to Newark. Ask for Bulletin GSS. Steel Supporting Legs: Standard steel supporting legs, 18 or 24 in. high, template punched to same bolt hole centers as standard casing, are furnished when ordered. These legs may be attached quickly and obviate necessity of any other foundation. Advantages: Aerofin weighs but 9 to 16 per cent as much as equivalent castiron and occupies but 35 per cent of the space required by equivalent cast-iron (2-row units). Two men can easily carry any Aerofin Unit. Expensive founda tions are unnecessary, building re-enforce ment is not required and the Units may readily be suspended from beams or roof trusses, or installed snugly in any out-ofthe-way corner. Ask Newark for Bulletin G32 at once. Fig A Pig. 5 Sale: Aerofin is sold only by manu facturers of nationally advertised Fan System Apparatus. List upon request. 687 Heat-Surface (Fan System) The G & O Manufacturing Company 138 Winchester Avenue New Haven, Connecticut <*$0 INDIVIDUAL FIN TUBING for . - Unit Heaters (high and low pressure), Concealed Radiation, Refrigeration Condensers, Evaporators, Intercoolers, After coolers, Cooling Units, and other Heat Transfer Products. Individual G & O Fins--The use of individual fins results -in high efficiency in heat transfer from primary tube surface to secondary fin surface, because all G & O fins have ample collars around the tube opening insuring 'liberal contact with tubing. Any Size or Shape--Fins of any size or shape may be obtained giving any desired proportion of primary and secondary radiating surface. Square Fins--A square fin has about 30% greater surface than a round fin of a diameter equal to a side of the square. 8-Pass Condenser Individual Fins--Individual fins permit of. any fin spacing: also, of using fins in groups at intervals along tubes. Fins placed at practically any angle on tubes. - Various Shapes--G & O individual fin tubing is furnished in straight lengths: in U bends with short radii: in continuous return bend coils, or other shapes. Ends of tubes may be left free of solder for mechanical joints. G & O Individual Fin Tube Data Standard Sizes O.D. of Tube Fin Size . Fin Spacing per Inch Surface linear Foot y." ` '/*. '// 1' q. '/' Wr-d. Wl' r'd. W q. T/l'r'A 6 0.59 sq.ft. 6 0.81 sq, ft. ' 6 0.64 sq.ft. 6 1.61 sq. ft. 6 2.50 sq. ft6 4.00 sq. ft. 5 3.55 sq. ft. 688 Heaters, Unit American Foundry Equipment Company Mishawaka, Indiana, U. S. A. Manufacturers of Industrial and Domestic All-Electric Unit Heaters Experience of hundreds of users and many operation tests by power and public service interests, insurance companies, United States Government and other authorative institutions have proved that the American All-Electric Heaters are practical for hundreds of varied applications. They incorporate the unit heater principle in which forced air circulation provides uniform temperature. They are clean, convenient, instantaneous, efficient, fully automatic and portable. The low initial cost and minimum installation expense enables economical heating for many applications. The heart of the American Heater is the heating unit. This consists of a helicoil, sheathed wire type (Calrqd) of resistance heater element cast integral with an aluminum alloy fin type grid. The heat transformed from electric energy is quickly conducted through the finned area of the heating unit and is carried off by the forced air circulation. The operating tempera ture of the unit is comparatively low and with the special cut-out switch, absolute safety is assured. In addition to the industrial type, the American Heaters are made in domestic models. The built-in type and the por table model are both ideal for home use where occasional heat is required. Write us for complete information on the American Line of heaters INDUSTRIAL HEATER Model No. 83-12 83-15 83-18 84-20 84-24 84-30 84-40 12-6 12-9 12-12 18-135 18-1575 18-18 18-27 24-36 24-42 24-48 24-60 K.W. 1.2 1.5 1.8 2.0 2.4 3.0 4.0 6.0 9.0 12.0 13.5 15.75 18.0 27.0 36.0 42.0 48.0 60.0 C.F.M. 75 95 95 150 150 210 210 375 560 625 1055 1055 1055 1410 2815 2815 3130 3130 B.T.U. 4,098 5,122 6,147 6,830 8,196 10,245 13,660 20,490 30,735 40,980 46,102 53,786 61,470 92,205 122,940 143,430 163,920 204,900 RATINGS ELECTROMODE E.D.R. 17.1 21.3 25.7 28.5 34.2 42.7 57.0 85.4 128.0 170.8 192.1 224.1 256.1 384.2 511.8 597.6 683.0 853.8 Model K.W. C.F.M. B.T.U. E.D.R. A1200 A1600 A2000 B3000 1.2 110 1.6 2.0 no no 4,098 5,464 fir, 830 17.1 22.8 28.5 3.0 180 .10,245 42.7 All models supplied either for 2 in. by .4 in. or 2 in. by 6 in. stud mountings. THERMOFAN Model . Switch ' Current P Plug in Type ' II0V-A.C. f Heat Switch in Base 110V-A.C. 2 Heat and Fan Switches in Base 110V-A.C. All models either 1000--1200--or 1600 Watts. 6N 89/ Heaters, Unit Thermal Units Manufacturing Company Pershing Road and Loomis Street, Chicago, 111. New York Office: 30 Church Street Representatives in Other Principal Cities PRODUCTS--Unit Heaters, Unit Coolers, Air Conditioning Units and Ap paratus, Dehumidifyers. Also Blowers, pressure or volume; Coolers for gas, oil or water; Dryers; Evapo rators; Fans, ventilating or exhaust; Air Heaters for dryers; etc.; Heating and , Ventilating Units combined; Concealed Radiation; Refrigerating' and Ice Making Machinery and Plants. The Thermal. Unit Integrally Cast, One-Piece Aluminum Alloy Element No Joints, Welds, Brazed or Soldered Connections. Freezeproof, Corro sion and Acid Resist ing. Neutral to All Re frigerants. High Heat Transfer. Tested to 450 lbs. Hydrostatic Pressure. Leakproof -- I ndefinite Life Without Servicing. Lowest Air Resis tance. Thermal Unit Heaters Thermal Unit Coolers . Model No. R.p.m. Steam Pressure, Lbs. B.t.u. 60 at C.f.m. Final Tem perature Motor FLP. 5 12 1750 100 5 16 1150 100 5 20 1150 100 5 24 1150 100 5 30 1150 100 47.600 79,100 83.600 140.000 132.000 219.900 188.000 314.800 274,100 459.200 1101 1101 1958 1958 3060 3060 4406 4406 6426 6426 100 127 100 127 100 127 100 127 100 127 1/10 % 1/6 % % Rust resisting construction throughout, and manufactured in five sizes, with capacities of Yt ton to 8 tons per unit depending on refrigerant temperature and final temperature desired. Suitable for cold storage or any process or product requiring cooling or de- humidifying. For use with Ammonia, Methyl Chloride, Sulphur Dioxide, Freon, Brine or cold water. ' Defrosted and controlled automatically. Complete Catalogues, Information and Engineering Data furnished on request 690 Heaters, Unit The Unit Heater and Cooler Co. Wausau, Wisconsin Offices in Principal Cities . MANUFACTURERS OF THE GRID UNIT Model No." GRID UNIT HEATER DATA , Delivers More Warm Air to Floor and Working Zone Dimensions CA B D Face Area Sq. Ft. Motor Hp. R.P.M. Volume at Fan Capacities 5 Lb. Press. 60 Air B.T.U. Final Temp. Approx. Shipping Weight Pipe Sizes Supply Outlet 1/20 1700 711 46000 119 1200 15 12% n% 17% 1.04 1/30 1150 515 34900 122 120 !% l%* n%1500 22 18 20 1.67 1/10 1/20 1750 1150 1450 1015 77500 65500 109 ,, H8 210 I%* I%- n%(520 27 18 20 2.2 1/8 1/20 1750 1150 1700 1288 104000 83500 113 118 250 l%* !% n%2000 27 23% 21% 2.8 1/6 1/10 1150 850 2500 1835 148000 114 113000 . 117 320 2* 1%' n%2025 32 23% 21% 3.6 1/6 1/10 1150 850 2875 2380 177000 158500 .115 ` 120 370 2" 1%' n% 1/2 1150 4200 225000 108 2500 32 28% 28 4.5 1/4 850 3375 197000 113 440 2" 1%' n% 1/2 1150 4650 282000 115 2530 36 28% 28 5.3 1/4 850 3350 226000 121 500 ` 2" 1%' 3000 38 33 13% 29 6.5 Varies with type of motor. 1 1/2 1/2 1150 850 8100 6350 394000 341000 104 109 725 2%' . 1%' Long Life--Efficient Service--Good for 250 lbs. working pressure. Steam Chamber--Cast High Test Iron. Fin Surface--Aluminum alloy cast metal to metal contact with steam chamber. Manifolds or Headers--Cast high test iron. Lower outlet temperatures and greater volume delivers warm air to working zone of room, thus eliminating heat losses at ceiling and avoiding stratification. Grid Unit Heaters--Reduce fuel cost and maintenance expense--no damage possible to Grid due to electrolytic action as it cannot take place in Grid Units. Cooling and Refrigerating--Grid Unit Cooler ideal for cooling, using cold water, sodium or calcium brine or direct expansion ammonia. Write for further information and catalog. . . 691 Heaters, Unit Young Radiator Company Unit Heaters, Convection Heaters, Blast Heaters, Heat Transfer Surfaces, Unit Coolers Representatives in all : 'YcYDT 1 ulfilffv Principal Cities Home Office: Racine, Wis. Sectional view of plastered-in enclosure Young Streamaire copper convectors are furnished with plasteredin type enclosures, metal front recess cabinets, wall-hung cabinets and free-standing cabinets. These present a pleasing appearance, are solidly built, extremely compact and highly efficient in opera tion. The patented construction of Young Streamaire convectors insures positive satisfaction when operating on vapor, vacuum, or one-pipe steam systems or on gravity or forced circulation hot water systems. Recess Cabinets Free-Standing Cabinets Unit Heaters Type "SH" for Steam or Hot Water --to heat garages, Are availabe in various sizes and capaci ties to fill every heating need. They offer a complete compact enclosure for the heating element. stores, industrial, and similar type build ings. Made in 17 dif ferent models, equip ped with constant or multi-speed motors. Recirculating ducts, wall boxes, and heat diffusing nozzles can be furnished with all models; also air filters Unit Coolers when desired. DeLuxe models have chro mium plated housings. Type "VH" Slow fan speed and low power cost as sures quietness and economy in this model. Blower type fans circulate a large volume of heated air. An ideal unit to operate in conjunction with air ducts. Blast Heaters and Commercial Units . Types "XC" and "SC"--Made with two types of coils, one for use with ice water or brine as the cooling medium, and 1 one for direct expan sion use in connec Unit Cooler tion with refrigerating machines using re frigerants such as sulphur dioxide, methyl chloride, F 12, ammonia, etc., where they are to be used to maintain room tempera tures above the freezing point. Blast Heater Made with heavy seam less copper tubes and cop per fins (extended heating surface). Ideal for use with forced air heating and ventilating systems. For use with high and low steam pressures or with hot water. Designed so that all internal strains due to expansion and con traction are eliminated. Write for catalogue giving sizes and capacities. Evaporators and Condensers Selected by prominent raanu- facturers i of refrig- era ti n g and air condi tion ing equip-1 ment for Evaporator--Condenser special, heavy service and exceptional ap plications. A great variety of tool; die and assembly equipment is available to manu facture these units to meet almost any specification. 692 Heaters, Water Bell & Gossett Company 3000 Wallace Street Chicago, 111. Steam and Vapor B & G Indirect Water Heaters for Steam and Vapor Systems Description SINGLE COIL For residences of all sizes. Duplex apartments and small buildings. DOUBLE COIL For larger apartments, garages. medium sized factories and office buildings. TRIPLE COIL For heavier requirements. DOUBLE TRIPLE COILS No. 30 40 52 66 82 100 120 144 Capacity Gallons 30 40 52 66 82 100 120 144 Max. Length Inches ny i% 20% 22% 25v. Max. Width Inches 5* 5XS 7% 7% 7% 7% 7% 7% Shell . Coil Shipping Openings Openings Weights Inches Inches Pounds 1 1 yi 12 % 13 1 % 15 V/2 1 29 Ig 1 1 39 40 IB: - 1 1 42 46 160 160 12 11% 2 I9ji192 192 14% 11% 2 300 300 11% 2 400 400 23% 11% 2 1% 53 1% . 59 1% 78 1% 86 600 800 1000 1200 1600 2000 600 800 1000 1200 1600 2000 21% 25% /. 23% 27% 30% 15% 15% 15% 29 29 29 3 3 3 4 4 4 2% 230 2% 250 2% 290 3% 568 3% 642 3% 716 AIj'.ivc ratings based on 100 degree rise in three hours with boiler water temperature of 180 degrees or more. HOT WATER--B & G Triple Duty Systems for Hot Water Systems These three units comprise the Triple Duty System No. 19 20 2J 22 23 24 Recommended Tank Sizes 30 to 42 Gallons 42 to 52 Gallons 52 to 66 Gallons 66 to 120 Gallons ' 120 to 180 Gallons 180 to 300 Gallons Recommended Number of Baths 2 3 4 5 6 Important--This system will furnish year round domestic hot water supply from any oil, gas, stoker or hand fired hot water heating boiler. B & G BOOSTER--Automatic Electrically Operated Circulator with Positive Centrifugal Pump Action No. Type Flange Size Capacity Motor Style IVr-30 industrial V/z Inches 30 Gallons per Min. 1/8 H.P. Repulsion P/2-30 I1/? Inches 2-50 Industrial 2 Inches 30 Gallons per Min. 1/8 H.P. Capacitor 50 Gallons per Min. 1/6 HP. Repulsion 2-50 7 Inches 50 Gallons per Min. 1/6 H.P. Capacitor. 3-100 Residential 3 Inches 100 Gallons per Min. 1/4 H.P. Capacitor B & G THERMO-CHECK Controls automatically the temperature of hot water storage tanks heated by indirect heaters. A simple device that-requires no attention and. also eliminates lime and sediment formation in the heater coils. Sizes 1^6" and 2". " B & G Motorized Valves--Sizes 2" to 6" in both Straightway and Angle Patterns 693 ; Heaters, Water 101 New York Park Ave. McDermott Water Heaters, Inc. City SOLD BY JOBBERS AND BOILER MANUFACTURERS McDermott Water Heaters, Inc., installed the first submerged water heater in New York City. Today McDermott Heaters are in stalled in buildings supplying hot water to over 48,000 apartments in the New York metropolitan area. These heaters may be used as oil preheaters and converters for any usual adaptation. We manufacture water heaters exclusively. We believe we can show them to be superior in quality and performance. We are prepared to meet price competition anywhere. Complete information on request. Table 2--McDermott In-Boiler Heaters W ith steam a t 1 1-lb. pressure |[Using w ater from steam heating boiler as the heating m edium fU s in g 180 F . w a te r as th e heating m edium Steam I Steam I Table 1--McDermott Exterior Heaters and McDermott In-Tank Heaters (cra te d ), lbs. W e ig h t w ith shell Capacity, Cals. Pipe Con Dimensions nections. In. in Inches ao Coil Shell L D *3 o Zc V =5 h.a V a <J le 0 3 61 & JT || ""/a 1 5? 180 53 28C 54 37(1 55 465 56 56(1 57 65(1 58 740 59 840 510 920 110 165 220 275 330 385 440 495 550 77 2 116 2 154 2 193 2 231 2 270 2 308 2 347 2 385 2 21 2 21 2 2 1% 2 2 l'/4 21/2 2 1/2 2>A 2 IV7 I'/i 22 3 22 3 22 3 30 42 54 66 78 90 102 114 126 8 8 8 8 8 8 8 8 8 3.14 4.71 6.2fi 7.85 9.42 10.99 12.56 14.13 15.70 78 $24.00 98 40.00 117 50.00 136 60.00 155 65.00 1/4 72.00 193 80.00 212 90.00 230 100.00 Cat. Size No. 4?" Cap. Gals.* Tank Con., In. Boiler Opening. In. List Price V4I03 V4I06 V4108 M42I0 M42I2 3 6 8 10 12 150 245 350 550 800" IV4 !'/ l'/ 2 2 I'/4*4V4 174*4!/. 174-4!/, 3y3'/; %*3'A $30.00 50.00 66.67 100.00 116.67 Ratings based on 100 temperature rise in three hours, 180 F. boiler water in summer with supply at 75* F.. and 212 F. boiler water in winter with supply at 45* F. Special lengtht take price of next larger size. 103 1100 104 148(1 105 1840 106 2220 107 2580 108 2950 109 3370 1010 3690 660 880 1100 1320 1540 1760 1980 2200 125 2775 126 3330 177 3885 128 4440 179 4995 1210 5550 1650 1980 2310 2640 2970 3300 462 2 4 2 4 616 7 4 2 4 'A770 2 925 2 42 4 5 2/, 5 <A1078 2 5 i'/l 5 Mm1232 5 5 1386 3 6 3 6 1540 4 6 4 6 m1155 5 2'A 5 1386 3 5 3 5 1617 4 6 4 6 1848 4 6 4 6 2079 5 8 5 8 2310 5 8 5 8 83 1330 792' 555 2 42 4 84 1774 1056 85 2270 1320 740 7 4 2 4 925 l'/z 5 ?/, 5 86 2662 1584 1110 I'/l 5 2/7 5 87 3106 #1848 1295 3 6 3 6 88 3550 1480 1460 4 6 4 6 56 16 68 16 80 16 92 16 104 16 116 16 128 16 140 16 18.64 25.12 31.40 37.68 43.96 50.24 56.52 68.80 405 105.00 459 135.00 513 216.00 567 258.00 621 300.00 675 350.00 729 400.00 783 450.00 84 19 96 19 108 19 120 19 132 19 144 19 47.10 56.52 65.94 75.36 84.78 94.20 628 415.00 697 460.00 766 505.00 835 550.00 904 595.00 973 640.00 54 13'/, 18.90 303 88.00 66 13/2 25.2 357 188.00 78 15/, 31.5 411 238.00 90 I3'/S 37.8 465 288.00 102 13'/, 44.1 519 338.00 Vi114 13 50.4 573 386.00 Gallons raised 130 F. in 3 hra. ||GaUons raised 100s F. in 3 hrs. Based upon 180 F. boiler water in summer with Bupply at 75 F. and 212 F. boiler water in winter with supply.at 45 F. fGalions raised 100* F. in 3 hra. Based on supply at 45 F. Use with circulating pump if heating medium is water. {Write for discounts. Table 3--McDermott Tankless-Instantaneous Water Heaters Using Water or Steam as the Heating Medium--Installed in Boilers or in Self-contained Shells Size No............................................ V3 V4 V5 V6 V7 V8 MI0 M12 In Cals, raised 40 lbs. . Steam 130* F. velocity 650 600 1000 3500 5500 7300 14000 17000 Boiler hourly pressure* In Cals, raised 40 lbs. Water 100 F. velocity 455 560 700 2450 3850 5110 9800 11900 Boiler hourly pressure* Square feet of surface................ Boiler opening, in........................ Shell dimensions, in...................... If self-contained, ft..................... 10.5 13.65 16.80 19.95 23.1 26.25 50.24 I|xl5.5 Ixl5.5 1x)53 Ifr15 11x15.5 I|xl5.5 3.75x12 lOx lOx lOx lOx lOx lOx I4x 3 4 5 6 7 8 10 54.95 3.75x12 14x 12 L--length, ft................................. 3 4 5 6 7 8 10 12 W--width, in..................................... 15.25 Weight with shell, crated.......... 198 15.25 248 15.25 298 15.25 348 15.25 398 15.25 448 11.5 810 11.5 880 Weight without shell, crated. . 45 52 59 66 73 80 170 180 No. of units in 1 able 2 of equal capacity?.................................... 3V4103 3V4104 3V4I05 3V4I06 3V4107 3V4108 3M42I0 3M42I2 List price with shell................... $120.00 $150.00 $165.00 $190.00 $215.00 $240.00 $370.00 $410.00 List price without shell............ $90.00 $110.00 $125.00 $150.00 $175.00 $200.00 $300.00 $350.00 This McDermott Heater wu 'Maximum discharge temperature 30* F. less than boiler water temperature. Smaller boiler open- manufactured by us for Uu/U. S. ings and greater efficiency in maintaining primary heat on transfer surface result from non-groupea Government coils. They are connected in series by piping contractors. 694 . C` om plete w ith h e ll | *r "f u Heaters, Water Parkinson Heater Corporation Parkinson Tankless Submerged Water Heaters, Tempering Valves, etc. 11 West 42nd St., New York City 4105 N. Damen Ave., Chicago, 111. Local Distributors in Principal Cities. Consult phone book or write -ni/mn/SM PRODUCTS--Parkinson Tankless lvrx'i iiovjli Submerged Water Heaters for do W-----A--T---E---R-- -- -- - - mestic water supply, designed to eliminate storage tanks, insulation, separate heater, extra flue, fittings, piping and hook up at a very definite savings in fuel costs. Holby Temper ing Valves (write for details) for use with water heaters to increase gallon capacity and assure uniform tem perature within 5 degrees and permit continuous circulation. Free Service--Without obligation, our Engineering Department will submit recommendations, layouts, or advice on domestic hot water and piping require ments. One of the typical instaUatione Send for list of users, actual case Parkinson tn a fire tube boiler studies and circulars. Officially approved by the Investigatin Committee of Architects and Engineers. Guarantee--Parkinson Heaters are guaranteed to produce under normal con ditions a saving of from 30% to 70% of fuel costs. All parts tested under 250 lbs. pressure. How to Figure Heater Required Tankless water heating cannot be figured by the customary method as used for tanks. Therefore the following method using the "Demand Unit" is used. This unit has been developed from the result of thousands of installations over six years. Calculation of Demand Units Units Installation No. Comparative Kitchen and bathroom. Capacity 10normal....................................... Demand Standard Water Pressure Extra apartment bath, pri Units Estimated Up 40 80 vate............................................ 3 Tank Size, to to to Extra apartment bath, maid. Kitchen......................................... Cupboard kitchen..................... 4 5 2 Gals. 40 80 120 Lbs. Lbs. Lbs. Bathtubs, normal...................... 5 10 50 1 1 3 Separate shower......................... Shower in tub............................. Lavatories........................... ....... 51 2 20 30 . 60 90 120 240 3 3 6 33 36 6 12 Club or institution showers... 25 120 480 12 12 12 Sinks (slop).................................. Restaurant (hand washing).. 31 160 220 600 12 18 20 840 18 >8 20 per seat 280 1080 20 30 30 Wash tubs, apt. laundry......... 5' 360 1400 30 30 50 All other loads: the detail of 420 1680 30 50 50 equipment should be fur 480 1900 50 50 70 nished. 540 2150 50 50 70 Load on Boiler Steelflue type boiler--Due to increased efficiencies set up in the boiler it is safe to install PARKINSONS in boilers without additional radiation provided the boiler is ample for the heating load. For new boilers a factor of safety of 2 sq. ft. per demand unit may be figured. Cast-iron boilers require 4 sq. ft. radi ation for each demand unit.* Water Temperature Line temperatures range from 135 , 600 660 720 840 1000 1500 2000 2500 2400 2700 2900 3100 5400 6400 7000 9000 50 70 70 50 70 224 70 224 224 70 224 224 250 250 270 270 270 270 270 290 290 290 290 290 Note--Put the letter C after installation number if it is a cast-iron boiler. Piping details furnished per request. To estimate the cost of piping same as hooking to tank. to 165. but may be controlled within 15. For hotter water special heater is required. Holby Tempering Regulators are sup plied for more uniform requirements built special for Parkinson Heater. 695 Construction--The Parkinson is protected by Pat. No. 1,834,070 and operates on an ex clusive principle not to be confused with other heating coils. Supply tube and return tubes are sized to produce a rapid and constant flow of hot water. Heater is constructed of virtually pure copper, consisting of heavy wall tubes and cast headers, brazed together, with copper flux at high tempera ture. Installation--Heat ing unit is submerged in boiler water j ust be low water line of prac tically any low pressure boiler. Simple to in stall. Does not multilate the boiler as only one incision is required. Unit takes up no usable space in cellar. Oper ates on any fuel, auto matic or hand fired. Heating Lines Chase Brass & Copper Co. INCORPORATED . Waterbury Connecticut For data on Chase Copper Radiators see page 676 Rustless Heating Lines of Chase Copper Tube and Chase Sweat Fittings Here are a few reasons why copper tube should be used for heating lines: 1. Copper does not rust, the water, vapor, or steam inside the lines is kept clean. 2. Delicately adjusted thermostatic valves and traps are not rust-clogged out of commission. 3. Rustless heating pipes also eliminate the need for dirt pockets in steam mains. 4. Copper is in expensive and as satisfactory for giving service as any material known. , TEMPER--Both hard and soft tubing are available for heating lines. In remodelling work, and in replacing old heating systems the soft copper tubing will be found par ticularly useful. It can be worked down between walls and around corners, long 60 ft. coils eliminate many useless connections. For all soft copper tubing we recommend the extra heavy gage, (known by United States Government specifications as "Type K"). For the average new installation we recommend the light gage copper tube ("Type M "). PRESSURE--Chase copper tube is adaptable for all low pressure heating systems. While we do not recommend the use of copper tubing with any steam system having more than 30 lbs. pressure, the factor of safety over such pressure is very great. The bursting pressure, for example, of % in. Chase copper tubing and sweat fittings when connected together is 3,050 lbs. per square inch. RETURN LINES--While we recommend copper tubing for all heating lines, it is in the return lines that the greatest amount of rusting takes place. Architects and Engineers have learned by experience that these are the lines that are apt to rust and in larger instal lations need replacement, after a very short period of service. 1 This is a typical vapor installation. Notice the neatness of the copper tube and sweat fitting heating lines. Also the absence of union connections. 696 Chase Brass & Copper Co. Heating Lines CHASE COPPER TUBE FOR HEATING LINES Copper tube and sweat fittings are used for the run-outs from main to risers. This minimizes resistance to flow of steam. Steam Carrying Capacities The steam carrying capacity of copper tubing is greater than that of iron pipe of the same nominal-size. For example, in a steam main, 2 in. copper tubing is capable of taking care of a load of 444 sq. ft. of radiation as compared with 386 sq. ft. for 2 in. iron pipe. This is an increase of 15.1 per cent. For equal steam pressure drop the capacity of copper tubing is on the average 10 per cent greater than for the same nominal size of iron pipe. Because of this it is frequently possible to use tubing of smaller size. Pipe Covering Copper Water Tubing uses the same standard pipe coverings as other heating-pipes, but in most cases requires one size smaller covering. This is a saving in the cost of covering. Costs The slight extra cost of Chase copper tubing and sweat fittings is a very small amount in dollars to pay for the advantages of a copper tube installation. SIZES AND WEIGHTS Nominal Size !" V/< " l Vi " 2" l'/i M 3" 3Vl " 4" Outside Diameter 0.625 Inch 0.875 " 1.125 " 1.375 " 1.625 * 2.125 " 2.625 " 3.125 " 3.625 M -.4,125 '* Inside Diameter 0.569 Inch 0.811 " 1.055 " 1.291 " 1.527 " 2.009 " 2.495 " 2.981 " 3.459 " 3.935 -- _ Wall Thickness 0.028 Inch 0.032 0.035 !* . , 0.042 ' 0.049 M 0.058 " 0.065 " 0.072 0.083 " 0.095 " Pound per ' Lineal r oot - 01203 Lbs. 0.328 " 0.464 " , 0.681'"'" ' 0.940 " 1.46 " - 2.03 " 2.68 " 3.58 " 4.66 " ; . 697 Heating and Ventilating Units John J. Nesbitt, Inc. AND Buckeye Blower Company Manufacturers of Heating, Ventilating and Air Conditioning Equipment EXECUTIVE OFFICES State Road and Rhawn Street Holmesburg, Philadelphia, Pa. FACTORIES Holmesburg, Philadelphia, Pa. Columbus, Ohio Buckeye Sales and Service Offices In Principal Cities of U. S. A. Sales and Service on Nesbitt Universal School Room Unit Ventilators through Offices of American Blower Corp. ' 1 Universal Type "D" and Buckeye Series 900 Double Radiator Duo Luxe Heating and Ventilating Units--Tomorrow's Heating and Ventilating Unit Today--insures healthful, comfortable rooms without drafts by syncretizing room temperature with air-stream tem perature. Air capacities from 450 to 1560 c.f.m. As today's most economical unit, this unit delivers a constant amount of outdoor air heated to the proper temperaturp. As fast as State codes are changed this unit can be ad justed to mix indoor and outdoor air in any desired proportion, thus it is also tomorrow's most economical unit. Ask for Universal publication No. 217--Buckeye publication No. 133. Universal Type "O" and Buckeye Series 400 Heating and Ventilating Unit--Always delivers outdoor air to occupied rooms in per centages governed by both indoor and outdoor temperatures. Heat required for ventilation is only that necessary to raise the air-stream tem perature from 60 to 70. The operation of this unit is exceptionally economical--syncretizes air-stream and room temperatures to perfect harmony, thus removing the cause of cold drafts and overheating. Air capacities 450 to 1560 c.f.m. Ask for Nesbitt publication No. 218 or Buckeye publication No. 138. Nesbitt Concealed and Cabinet Radiators --A rugged copper multifin, copper tube radiator supplied with or without metal en closures. Built in a variety of styles and sizes to meet the most exacting conditions. Com plete information in Nesbitt publication No. 224. 698 Nesbitt, Inc. & Buckeye Blower Co. Fans and Ventilating Equipment Nesbitt Type "HC" Air Conditioner heats and humidifies or cools and dehumidifies--Mixes room air and outdoor air in the proportion desired--Filters all air delivered and dis tributes it evenly throughout the room. The Nesbitt Con ditioner can be used in one or in all of the offices in a single building, store, restaurant, hotel or home--in new building or old. Made in a variety of sizes, having a wide range of per formance. Ask for " Personal Weather"--Nesbitt publication No. 221. Buckeye "E" Thermovent and Universal Type "E" Heating and Ventilating Unit for auditoriums, churches, etc., where quiet operation is essential in the delivery of a large quantity of air. Made in a variety of types to handle all outdoor air or all indoor air or a mixture of indoor and outdoor air. Capacities from 2,000 to 6,000 c.f.m. Ask for Buckeye publication No. 137 or Universal publication No. 220. The Buckeye Giant Unit Heater--A blower, draw-through type Unit Heater for the economical heating of large areas in industrial plants, garages, airplane hangars. Made in a variety of types and sizes of capacities from 1,880 c.f.m., 125,500 B.t.u. to 20,000 c.f.m. and over 1,000,000 B.t.u. capacity. Equipped with Thermadjust by-pass feature. Ask for Buckeye publication No. 136. . Buckeye Unit Heater--A rugged, compact, suspended type, disc fan unit heater built in capacities up to 313,500 B.t.u. (2 pounds--60) for steam pressures up to 150 pounds with single or multispeed motors. Ask for Buckeye publication No. 140. .' All Buckeye Unit Heaters are tested and rated in accordance with the Code of the American Society of Heating and Venti lating Engineers and the Industrial Unit Heater Association. Nesbitt and. Buckeye manufacture a transfer surface for blast heating or cooling. This surface is regularly applied for cooling as well as heating in both the Giant and disc fan type unit heaters. Ask for Nesbitt publication No. 222 covering the Nesbitt Coolofan, a disc fan Unit Cooler. 699 -/ 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 Albant, N. Y. Atlanta, Ga. (Plant and Foundry) Auburn. R, I. (Plant and Foundry) Baltimore, Md. Boston, Mass. Buffalo, N. Y. Charlotte, N. C. (Branch) Chicaqo, III. (Branch) Cincinnati, Ohio Cleveland, Ohio (Branch) Columbia, Penna. (Plant) Dallas, Texas Detroit, Mich. Hartford, Conn. Kearny, N. J. (Branch) Milwaukee, Wis. Minneapolis, Minn. (Branch) Newark, N. J. New Orleans, La. New York, N. Y. -. Philadelphia, Penna. (Branch) Pittsburgh, Penna. . Providence, R. I. (Plant and Foundry) Rochester, N. Y. St. Louis, Mo. (Branch) Srr. Paul, Minn. (Branch) Warren, Ohio (Plant and Foundry) Washington D. C. . GRINNELL COMPANY OF THE PACIFIC Los Anoeles, Cal. (Branch) Oakland, Cal (Branch) San Fhancisco, Cal (Branch) Seattle, Wash. (Branch) GRINNELL COMPANY OF CANADA, LTD. Montheal Qoe. (Branch) Vancouteb, B. C. (Branch) Toeonto. Out. (Plant and Foundry) Oshawa, Ont. (Foundry) Winnipec, Man. '' PRODUCTS AND SERVICES-- Complete Service on materials to Specification on Power Plant Piping, Industrial Piping, and Industrial Heating Systems; Fabricated Piping including Pipe Cutting and Thread ing, Pipe Bends, Welded Headers, Welded and Welding Fittings, Lap Joints and the Grinnell Triple XXX 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 Thermoliers (Unit Heaters); Grinnell Unit Coolers (for refrigerating service); Thermoflex Traps and Heating Specialties. Also Humidifying Systems; Con stant Level Size Circulating Systems; Piping for acids and other special materials. Malleable Iron, Brass, Bronze find other Castings; Brass, Cast Iron, Wrought Iron and Steel Pipe; Seam less Steel Tubing in Iron Pipe Sizes., Valves: Check, Globe, Pressure Re ducing and Regulating, Quick Open ing, Safety and Y. Automatic Sprinkler Systems; Stand Pipes; Underground Supply Mains; Hydrants; Fire Pumps; Pressure and Gravity Tanks. Grinnell "Junior" Automatic Sprinkler Systems for Basements and other hazardous areas of Dwellings, Small Apartment Buildings, Schools, Churches, Stores, etc. 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 745 Grinnell Company, Inc. Heating and Piping Systems, Industrial Grinnell Thermolier (Patented) Industrial and Factory Types---125 Lbs. W.S.P. Thermolier, the Grinnell development in "unit heaters," is a ruggedly built unit whose efficiency and dependability have been proved by actual performance in field service. Thousands of them are installed in industrial buildings and com mercial 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. THE THERMOLIER INTERNAL COOLING LEG ACCOMPLISHES A RESULT SUCH AS IS DIAGRAMMATICALLY ILLUSTRATED HERE THERMOSTATIC TRAP 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 location to another at small cost if found desirable on account of changes in building or occupancy. Furnished in sizes as listed. Thermoliers provide maximum distribution of heat without objectionable drafts. Specifications Fan--Grinnell special of rugged construction. Motor--heavy duty, oversize, enclosed, moisture-proof. Housing--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 j^-in. trap on Models 100 and 200, %-in. on Models 300 to 800, 1-in. on Model 1200, 1 J^-in. on Model 1600 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; same sizes as above except a J^-in. trap on Model 300 and 400, 1-in. trap on Model 1600. CAPACITIES 60 F. Entering Air Temperature--5 lbs. Steam Pressure Model Nos. 100 200 - 300 400 600 600 1200 1600 B.t.u. per Hour 24,500 32,900 82,300 110,800 159.500 199,100 311.000 388.000 Model Nos. 100A 200A 300A 400A 600A 800A _ 1200A 1600A B.t.u. per Hour 18,000 24,000 56.900 73,400 105.000 123.000 207.000 246.000 Model Nos. .. B.t.u. per Hour 300B 400B 600B 800B . 72.300 94,000 136.500 166,500 > ^ Data Book cover ing other pressures and temperatures, dimensions and complete installa tion information on application. Address Grinnell Company, Inc., 277 West Exchange Street, Providence, R. I. 701 Grinnell Company, Inc. Heating and Piping Systems, Industrial GRINNELL ADJUSTABLE PIPE HANGERS AND SUPPORTS One of the chief advantages of Grinnell Adjustable Hangers is that they permit adjustment of pipe lines after installation, thus obviating the necessity of turnbuckles or the removal of hangers. Their time and trouble-saving qualities during installation are equally exceptional. Below are shown a few Grinnell Hangers and Supports of par ticular interest to heating engineers. Send for Hanger Catalogue showing complete line. 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 lJdjin. is secured by turning Swivel Shank. Swivel Shank automatically locks, Fig. No. tOt Solid Ring preventing loosening due to vibration in the pipe line. The off-center hinging of Split Ring provides sufficient seating to hold pipe line securely, and permits adjustment either before or after ring is closed. A wedge type pin is loosely but inseparably cast into the hinged section for fastening this section after pipe is in place. Fig. No. 104 Split Ring Adjustable Swivel Pipe Rolls (Patented) These Rolls supply the need for an adjustable type of pipe roll hanger using a single hanger rod. Vertical adjustment is made by use of Swivel Shank which automatically locks, preventing loosening due to vibration in the pipe line. Fig. No. t74 Universal Concrete Inserts (Patented) Made of malleable iron, they have ample vertical and hori zontal adjustment. Made in one body size to take a special removable nut. Nuts furnished tapped for % in., in., % in., or % in. rod as required. Nuts automatically lock laterally by means of serrated teeth on both insert and nut. U. F. S. I-Beam Gamps (Patented) Fif. No. m The U. S. F. I-Beam Clamps are an ' out-standing development in conveni ence, strength and adjustability. While made only in three sizes, they cover the whole range of beam sizes from the . smallest to Bethlehem 24-in. Forged steel construction gives to each size the same strength as the maximum rod strength in volved. Rods carried range from to 1H in., providing for .all pipe sizes up to 24 in. Fig. No. 228 Adjustable Pipe Roll Stands, Anchor Chairs, Brackets The Grinnell Welded Steel Brackets, Fig. No. 199 are designed for use with Grinnell Adjustable Pipe Roll Stands, Fig. No. 274 and Anchor Chairs, Fig. No. 197, here illustrated. These combine the strongest type of brackets and pipe supports. . Vertical adjustment is obtained by adjusting screws on Stand; lateral movement by Stands sliding on ends of adjusting screws. With Anchor Chair, lateral adjust ment is possible if moved before nuts on yoke are tightened. Fig. No. 197. Anchor Chair 702 Grinnell Company, Inc.. Heating and Piping Systems, Industrial GRINNELL WELDING FITTINGS A Recent Major Addition to the Grinnell Line of Piping Supplies The principal types of Grinnell Welding Fittings are illustrated and briefly described herewith. Catalogue giving list prices, dimensions, etc., will be sent upon your request. 00 Elbows, Long Turn Standard weight Extra heavy weight 45 Elbows, Long Turn Standard weight Extra heavy weight 18CP Returns Short Turn Long Turn Standard weight Standard weight Extra heavy weight Extra heavy weight Grinnell Welding Elbows and Returns, have the following distinguishing features: 1. Made from seamless steel tubing. 2. Uniform thickness of inner and outer walls. 3. Wall thickness same as steel pipe. 4. Homogeneous metal structure throughout. 5. No buckling or deformation. ' 6. No flattening of cross section. 7. Conformity to standard and extra strong pipe sizes. Fittings can be cut on the job, straight across the pipe, to any desired angle quickly and accurately, and any simple or compound bend may be made by a combination of two or more fittings. . The process of manufacturing Grinnell Welding Elbows and Returns is not a bending process and is protected by U. S. and Foreign Patents. & Welding Tea Welding Tees (Patents Applied For) Grinnell Welding Tees, being of the same physical character istics as Standard, Extra Strong and O. D. Steel Pipe or Seamless Steel Pipe of comparable pipe size, can be used, under same conditions, pressures, and temperatures as the pipe itself. They have these distinctive features: Made from Seamless pipe; one piece fitting--no seams; outlet presents a smooth rounded surface. Lap Flanged Welding Necks Grinnell Lap Flanged Welding Necks are regularly furnished for working steam pressures of 150, 300, 400 and 600 pounds at total temperatures up to 750 F., and can be furnished on order for higher pressures. Each Welding Neck consists of a forged steel flange and a short piece of steel pipe or tubing with square lap having a thickness of at least 100 per cent of pipe walls. Opposite end of neck is scarfed for welding. Lap Flanged Welding Necks Welding Outlets and Threaded Outlets (Patents Applied For) Welding Oidlete Grinnell Welding Outlets and Threaded Outlets are stock fittings properly designed for pipe welding and provide a simple and economical method of making welded branch con-' nections. They can be used wherever 'it is desired to make tees, side outlet tees, crosses, etc., by welding. 703 Threaded Outlets Instruments Branches Akron, Ohio Birmingham, Ala. Boston, Mass. Chicago, III. Denver, Colo. Detroit, Mich. The Bristol Company Waterbury, Conn. Indicating, Recording and Control Instruments Since 1889 TRADE MARK ----- :------ BRISTOLS ---------- - Branches Los Angeles, Calif. New York, N. Y. Philadelphia. Pa. Pittsburgh, Pa. St. Louis, Mo. San Francisco, Calif. Direct Reading Relative Metameter Recording Telemetering System Humidity Recorders Bristol's Humidigraph, Model 4044, reads per centage of relative hu midity directly. It gives a permanent chart record for future reference, and shows at a glance the trend of Modd4069 _ humidity condition. Simple construction. Novel vapor-sensitive hygroscopic element. Special aging process assures sustained accuracy. Eliminates calculation and use of humidity tables. Eliminates errors from personal element. No water required. No fan used. Accurate below freezing temperature. Light porta ble case of corrosion-resisting materials. Model 4069 is a combination Portable Humidigraph and Temperature Recorder, furnished with two pens for recording both relative humidity and temperature on same chart. Recording Thermometers Model 240M Class I Thermome ters are either liquidtilled with connecting tube and bulb, or bi metallic self-con tained. They are for ranges from -- 40F to 150F. Class II Thermometers are of the vapor tension type, and are used for ranges from 90F to 650F. Class III are gas-filled, for ranges from --60F to 1000F. All three classes are furnished ina hand some moisture-proof, fume-proof, dust- proof rectangular case. One or more pen arms, upright or inverted. 12 in. or 8 in. chart, obtainable in over 800 ranges and graduated for one revolution in 24 hours or 7 days. Electric motor or spring wound clock. For wall or switchboard mounting, or portable. Bristol's Metameter Sys tem transmits instanta neously changes in pres sure, temperature or liquid level occurring at a given locality to another locality as far as 240 miles away, and at this second locality pro duces an accurate un distorted graphic chart record of the quantity measured. The System consists of a transmitter, a recording receiver, a relay and rectifier box at Bristol's Metameter Transmitter, side view the receiver, and a two wire circuit con necting transmitter and receiver. Bristol's Metameter offers many out standing advantages. Distance is limited only by the cost of installing or securing the necessary wires. Simplicity of circuit makes operation possible on only two wires, or on one wire and the ground. Over long distances, the impulse may be sent through arrangement with the A. T. & T. Co., over a standard telephone circuit also carrying conversation. Only 40 milli- amperes at 6 volts D.C. are required for operation. Transmitter and receiver may use separate sources of power, as long as accurate timing is provided at each end.* Variations in capacitance, in resistance, or induced currents do not introduce errors. No fire or explosion hazard. Reliable and durable mechanism. Long Distance Electrical Transmit' ting and Recording System for Telemetering Steam Pressure Bristol's Long Dis tance Electric Transmitting Sys tem operates on the induction balance principle. Widely used by district steam heating com panies, public utili ties, etc., it provides centralized control of steam pressure at distant points throughout the dis tribution system. Long Distance Receiving Recorder, Modd 840 MFR 704 Instruments Consolidated Ashcroft Hancock Co., Inc. Bridgeport, Conn. BLANCHES IN PRINCIPAL CITIES Makers of AMERICAN INDUSTRIAL INSTRUMENTS--Since 1851 Subsidiary of Manning, Maxwell and Moore, Inc. 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; Engine Indicators; Counters; Absolute Pressure Gauges. Also manufacturers of Bronze. Cast Steel and Forged Steel Valves, Locomotive and Engine Room Clocks; Barometers; Mercury Column Gauges; Steam Whistles; Hydraulagraphs; Gauge Boards. Ashcroft American Gauges--Ashcroft American Gauges are made in all sizes from 2M to 12 in., for pressures from 8 oz. to 25,000 lbs. 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. For Mercury Pressure and Vacuum Gauges, "U" Gauges, Draft Gauges and Mercurial Barometers, write for Catalog B-59. American Recording Gauges--Ameri can Recording Gauges are made for all pressures from 15 in. of water to 10,000 lbs. and for vacuum. They are made in one size only to accom modate a 10 in. chart, having an effective scale width of 3% in. The case is Die Cast with a dull black hard-rubber finish and with either bot tom or back connection. The pen-arm is made of non-corrosive Monel Metal and is of the inverted type. Operating instruc tions are lithographed on the chart plate so that they cannot be lost. Especially designed Seth Thomas clocks are used, and all customary time periods can be furnished. American Recording Gauges are equipped with the Time Punch which virtually makes each instrument a time clock, since a hole is punched in the chart whenever a reading is taken. Write for Catalog E-59. American Air Duct Thermometer-Designed especially for both warm and cold air ducts. Fitted with polished brass "V" shaped case, glass front. Furnished 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 only to accommodate 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. Ameri can Indicating Gauges and Dial Thermometers are also furnished in same case. Write for Catalog H-59. American Dial Thermometers--A m e r i c a n Dial (mercury-filled) Indicating Thermometer has theaccuracy of the standard glass tube thermometer and the reading convenience of a dial face. Entire working mechanism is made ofsteel, meaning long life. Standard size of dial 6 and 12 in. Furnished with rigid connection or flexible capillary steel tubing up to 200 ft. long. For temperature ranges from minus 40 to plus 1000 F. Write for Catalog G-59. American Precision Temperature Controllers--Self-operated and simple in construction. For regulating tempera tures from 25 to 385 F. Under fa vorable conditions temperature will be held within 1. Sen sitive, rugged and accurate. For hot water service tanks, water heaters, etc. Standard -ranges carried in stock. Size of valve must be specified. Write for Catalog R-59. .705 Instruments Tailor InMrAimjeivb ComfmnieA Rochester, N. Y., U. S. A. NEW YORK CHICAGO BOSTON IN CANADA--'Tailor Instrument Companies op Canada, Ltd., Toronto PHILADELPHIA PITTSBURGH CLEVELAND LOS ANGELES INDIANAPOLIS SAN FRANCISCO ST. LOUIS CINCINNATI TULSA Manvfaduring Didnbvton in GreatBrilain, Short A Mason, Ltd, London DETROIT ATLANTA MINNEAPOLIS Manufacturers of Taylor Instruments for Indicating, Recording and Controlling Temperature, Pressure and Humidity Taylor Recording Thermometers--Temperature ranges and time requirements vary great ly in heating and venti lating work. Taylor Re corders are made in scale ranges and time periods to meet these needs. In their handsome new cases, these in struments are beautiful and efficient, par- ticularily adapted for heating and air conditioning appli cations. They may be had for surface or flush mounting. When set in panel boards, the polished flanges make an ef fective installation. Write for special information suit able to your needs. Taylor Electric Contact Tempera ture Control--These instruments com bine in the same case an electricallyoperated temperature regulator with an indicating thermometer. One tube system operates both units. Taylor Dial Thermometers can be used for air ducts or any application where it is desirable to have tempera ture readings at some distance from the. thermometer bulb, as in a central control room. Can be read at a glance as . easily and quickly as a clock or steam gage. Taylor Thermo meters for Air Ducts, Etc.--The Taylor line of industrial thermo meters presents many styles and scale ranges with bulbs for every ap plication. Suitable for air ducts, kiln tem peratures and oven temperatures. For de tailed information, write direct, mentioning your requirements. Taylor Self-Acting Tem perature Regulator--Adapted for use on hot-water storage tanks, etc. It is "self-acting" in that it requires no auxiliary motive power, such as compressed air, to open and close the steam valve. As heat is applied to the bulb, the volatile liquid inside sets up a vapor pressure proportional to the temperature. This. pressure is transmitted to a "stack" of metal diaphragms attached to the upper end of the valve stem, thus moving the valve disc toward the valve seat. The valve can be closed at any desired temperature, orathrottling action can be ob tained. . Not practi cable on pipe lines having steam pressure over 125 lbs. Should be installed in a vertical position on top of a horizontal line. Operating ranges 120 deg. to 170 deg. F., 130 deg., to 190 deg. F., or 170 deg. to 240 deg. F. as specified. 706 Taylor Instrument Companies Instruments Taylor Sling Psychrometer--The advantage of this form of Wet-andDry-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 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. mometers mounted on a die- cast frame. , The New Taylor "Fulscope" Re cording Regulator--An air-operated re cording regulator so versatile that `practi cally any character of process control can be obtained, regardless of time lag in apparatus, by a simple screw driver adjustment on a graduated dial --without re quiring a skill ed operator or interruption of service. Vast im provements in entire me chanism. Easily changed from direct to. re verse-acting, or vice versa--no extra parts. Compensates for fluctuations in airpressure supply. Die-cast case; dust-, moisture-, and fume-proof. Available forms: for controlling tem perature, pressure, temperature and pres sure, rate of flow, liquid level. Taylor Type-P Regulator--A compact and very sensitive regulator, ideal for air- ducts, air-washing -- machines, cooling rooms and similar applications. Uses .compressed air as an actuating medium. Where extreme load changes or badJy balanced operating conditions exist, the Taylor."l}ubl-llesponse Control Unit" is the only positive means of maintaining control-point. Write for literature. ' 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 Anemometer--This instrument is ideal for measur ing air velocities with the fan revolutions indicated on the dial. Available in various models for a wide range of air speeds and registration limits. Taylor HamptonModel Humidiguide (Direct - Reading)--A hygrometer giving direct humidity per centages, in a smart modern case suitable for home, office or public building. Finish is satin black with chrome trim. The thermometer has a Permacolor tube, distinct, column. 707 Insulation Alfol Insulation Co. Chrysler Building New York, N. Y. Agents in Principal Cities INSULATION for INSULATION for * Fans Turbines Blowers DehumidiGers Pumps Air Conditioners Ducts Boilers, Pipes, etc. Houses, Buildings, etc. At temperatures up to 1150 F. Patented in 34 Countries Refrigerators Refrigerator Cars Refrigerator Trucks Refrigerator Boxes Refrigerated Rooms etc. Ships Ovens Ranges Tanks Stills DESCRIPTION Alfol Insulation is a flexi ble form of insulating material for use on irrigular, curved or straight surfaces where it is desirable to conserve heat or cold, prevent condensation and block sound transmission. In its simplest form it con Alfol Insulationlayers spaced ap proximately apart Conductivity-- Panel Type SB Crumpled Type j98 sists of successive layers of crumpled special metal foil applied approximately apart. The outside layer of Alfol is covered with a re movable metal jacket. Alfol is a modern, scientifically designed insulation which effectively and econo mically meets all high and low temperature require ments. Some of the many advantages are: 1. Negligible Weight-- only 34 oz. per board foot. 2. Highly Efficient--con ductivity .28 B.t.u. per hour, per sq. ft., per 1 F temp, difference, per inch thick. 3. Non-Inflammable -- being metal it will not burn. 4. Impervious to Mois ture--repels all mois ture attacks thereby retaining its uniform high insulating value. 5. Durable -- unaffected by vibration, will not disintegrate, crumble, warp or settle. 6. Odorless and Clean--Alfol has no odor. No dust, dirt or waste result from its use. 7. Low Heat Stor- age--Alfol pos much more rapidly than with any other insulation. 8. Low Initial Cost--ease, rapidity of application and no dirt or waste make the initial cost of Alfol lower than for most other insulations. APPLICATION Alfol Insulation is applied in never riiore than 3 crumpled layers to one inch thick- ness. The high re- reflecti vity of the foil ( 95% ) and the non-con Alfol Insulation for Heating and Ventilating Duett ducting air spaces between the layers, pro vide Alfol's amazing efficiency. It is never necessary to wad or pack Alfol in place. As a matter of fact, when applied loosely in corners, slots, etc., its efficiency is actually increased. All Alfol joints are lapped in each layer about I" and staggered with respect to joints in adjacent layers. All stiffeners, studs, rivet heads, etc., pro truding into the insulation are lightly covered over with the same number of layers used on sur rounding surfaces. Removable metal jackets with their many obvious ad vantages are ap plied over Alfol Insulation. Alfol Insulation on 9000 KW. Turbine SIZES Alfol is furnished in convenient size rolls of 2000 or 3000 sq. ft. Rolls are approx. 6" diam. x 15 long. . ENGINEERING sesses virtually Trained Alfol en no heat storage capacity --there fore pre-heating gineers are ready to assist in the solu or pre-cooling may be done Texas & Pacific R. R. Alfol Insulated Train tion of your insula ting problems. (See Chapter 5 for information on Aluminum Foil insulation) 708 Insulation 141 Milk Street Incorporated Boston, Mass. 101 Park Avenue, New York 5000 Bloomingdale Avenue, Chicago Philadelphia, Kansas City, Minneapolis. Los Angeles, San Francisco, Seattle, Portland Agents in All Principal Cities Cabot's Heat-, Cold-, and Sound-Insulating Quilt Cabot's Quilt being applied to under side of roof and walls, for heal insulation Thicknesses--Cabot's Quilt is made in Single-Ply (X), about 0" thick. Double-Ply (XX), about %o" thick. Triple-Ply (XXX), 3io" thick; and Inch Quilt, l^o* thick. U. S. Government Bureau of Stand ards Letter Circular No. 227, reporting' tests of numerous Insulating Materials, gives Cabot's Quilt a Thermal Con ductivity rating of 0.25 per inch, which was equalled by only two other insula tors, regardless of cost. Tests conducted by Prof. Gordon B. Wilkes, of the Massachusetts Institute of Technology, show the following savings in heat leakage in different methods of construction, by the use of Cabot's Quilt. Conductivity.Insulated with Cabot's" Doublel PlyQuilt-- H " 1Percentage Heat Saving || J | Uses--For insulating side walls and roofs of buildings against cold in winter and heat in summer, for insulating cold storage buildings and ice houses, refrigerators, etc.; for sound proofing partitions and ventilating ducts. Description--Cabot's Quilt is a felted springy matting of Zostera Marina, a marine plant, stitched between two layers of Kraft (Standard Quilt), non-inflammable Kraft (Anti-Pyre Quilt), asbestos (Asbestos Quilt), water-proof paper (Water-proof Quilt). Cabot's Quilt has an insulation value inch for. inch excelled or equalled by only two other insulators, both greater in cost. Permanent--Because of its natural prop erties, no special chemical treatment is re quired, and Cabot's Quilt will not pack down, rot or harbor insects or vermin. Quilt shows no deterioration after having been in actual use for over forty years. Fire Resistance--Standard Quilt is natu rally fire resistant and when made with the new non-inflammable Kraft paper (Anti-Pyre Quilt) can be used in any fire-proof building. Easy, Low Cost Application--Quilt can be applied at the lowest labor cost. Being flexible it fits into corners or around projec tions without danger of cracking. Requires no special preparation or smoothing of walls or floors in cold storage work. Easily adapts it self to lining or covering of ventilating ducts. Readily cut with ordinary knife or shears. Widths--Quilt is made in 36" and 18" . widths. 18" Quilt is quickly applied between studs and roof rafters. CONSTRUCTION WALL Clapboard, studding.............. . 0.70 Clapboard, studding, lath, plaster . 0.44 Clapboard, sheathing, studding. lath, plaster......................'........ 0.28 8 in. brick...........................'........... 0.40 8 in. brick, furring, lath, plaster... 0.27 4 in. tile, stucco, outside, plaster 0.40 12 in. concrete............................... 0.46 Corrugated iron............................. 1.50 12 in. stone.................................... 0.49 12 in. concrete, furring, lath. plaster........................... 0.40 Stucco, studding, plaster............... 0.45 0.26 63 0.21 52 0.16 43 0.20 50 0.16 41 0.20. 50 0.21 54 0.32 79 0.22 55 0.20 50 0.21 53 ROOF Tar, gravel on 4 in. concrete.......... 0.60 0.24 60 Metal on tongue and groove sheathing.................................... 0.42 0.20 52 Corrugated iron on wood frame... 1.80 0.32 82 Tile or slate on wood sheathing___ 0.82 0.27 61 i ar, gravel, tar paper, 1 in. wood plank......................................... 0.26 0.16 39 Shingles, sheathing, studding, lath. plaster........................................ 0.30 0.17 43 Wood shingles on shingle lath........ 0.64* 0:24 63 'Average, value from Jones' tables. The Heating and Verddating Magazine. The cast of Cabot's Quilt is so low, for material and application, that the resulting smaller Heating Equip ment required usually more than pays for entire in sulation. Thereafter there is a yearly fuel saving. Conductivity Uninsulated " H " 709 / Insulation The Celotex Company 919 N. Michigan Ave., Chicago, 111. Mills:' NEW ORLEANS. LA. Branch Sales Offices Telephone Books for Addresses) Boston, Mass. Minneapolis, Minn Berlin, Germany London, England - Denver, Colo. New York, N. Y Cleveland, Ohio Buenos Aires, Argentina Sydney, Australia Los Angeles, Calif. St. Louis. Mo. Durban, South Africa Tokyo. Japan CezoteX BRAND ' INSULATING CANE BOARD . (Registered U. S. Patent Office) PRODUCTS-- damage to buildings (about five million Building Board. dollars a year in Illinois alone) in the Lath, W, %" and 1". Sheathing, W, 3A" and 1\ Tile Board. ' United States each year. By means of this process--perfected after ten years of research and two years of actual produc Industrial Insulation Board. tion--Celotex provides a powerful protec Roof Insulation Board. C-X WaUboards. tive armor against loss through deteriora tion. Low Temperature Insulation. The Ferox Process is not a surface . Rock-Wool-Batt. Acousti-Celotex Cane Fibre Tile. Acousti-Celotex Mineral Fibre Tile. treatment--it is integral. The chemical complex used is insoluble in water. It is non-volatile -- odorless -- permanent. It does not discolor the product or otherwise Celotex Cane Fibre Insulation Celotex is`a rigid insulation manufac tured by felting strong, tough cane fibres into a continuous board. Several products are then fabricated for various purposes. alter its physical properties. It has been tested out successfully for over two years in the tropics where the termites are so active that entire buildings are sometimes* ruined in the course of a few weeks. The resulting products combine high in- sulating efficiency with unusual structural strength. ' The thermal conductivity of Celotex is 0.33 Btu per hour, per square foot, per 1 degree Fahrenheit, per inch thickness (based on a density of 13.5 lb. per cubic foot and a mean temperature of 70 F.) Tests conducted at Armour Institute of Technology and at recognized laboratories confirm this figure. . The Celotex Company maintains ah Celotex Building Board Two-surface utility. One side smooth for stenciling and other interior finish treatments. The other retains that unique Celotex texture. Sizes--4 feet wide, and 7, 8, 8JS.-9, 9H, 10 and 12 feet long. Jf6" and %" thick--also H" and 1" thick with both sides rough texture. Finish Plank--Jf6' thick; 6", 8", 10', 12' and 16' wide; 8' long. Long edges Beveled and Beaded. engineering and research staff which is available for investigations of all types of Celotex Lath . insulation installations. Engineers are in vited to address their problems to The Celotex Service Bureau at Chicago. A natural bond for plaster--a con tinuous plastering surface providing special resistance to lath cracks--eliminated lath marks--beveled and shiplapped. joints The Ferox Process (see diagram). Size: 18' x 48". j^", $' The Ferox Process (patented) is exclu and 1" thick. sive with Celotex. It makes all Celotex cane fibre products safe from dry rot and . termites--proof against those two age-old enemies of wood and other cel lulose materials which cause unbelievable 710 fhe Celotex Company Insulation Celotex Sheathing Insulation and structural strength. May be used with standard frames. 1" thick; 4' wide; 7', 8', 8)4'. 9', 9J-3', 10' and 12' long. Sheathing Plank--thick; 18" wide; 8' long. Celotex Rock-Wool-Batt Highly effective wall-thick insu lating material made from Molten Rock. Absolutely incombustible, vermin-proof and permanent. Light in weight (about 2]A lbs. per unit). Fits snugly be . tween studs and rafters. Size 115' x 18" x full wallthickness. Celotex Tile Board An'attractive interior finish which in sulates against heat and cold and deadens noise. For installation in new and old buildings alike. Has a smooth surface like Celotex Building Board, which may be left natural, or may be painted or stenciled. Thicknesses, ^6* and ranging in sizes from 6" x 12" to 24" x 32". Celotex Roof Insulation Board Celotex Low Temperature Insulation A moisture-proof, vapor-proof low density insulation. Each block hermeti cally sealed by means of a coating of asphalt and a wrapping of two thicknesses of heavy waterproof paper with asphalt between, all edges being thoroughly sealed with asphalt. For all low temperature re quirements, including Coolers (Beer, Meat, Creamery, etc.), Fruit and Vegetable Storage Rooms, Air-Conditioned Spaces, General Cold Storage Rooms, and Freezers. Conductivity 0.30 Btu per inch--odorless. Ferox-treated. Size 18" x 36". Thickness 1", 1}4", 2", 3", 4" or any-multiple of H". Preferred as insulation over wood, con crete, steel, unit tile and poured gypsum roof decks. Sizes 22" x 46" approximately thick. Also furnished laminated from 2 to 8 plies. Service The Celotex Company has sales dis tributors throughout the world. This world-wide service has a background of trained insulation engineers who are at your service whenever some unusual in sulating problem is before you. Write to the Celotex Service Bureau, 919 North Michigan Avenue, Chicago, III., for infor mation of any kind, without obligation. 711 Insulation Johns-Manville Executive Offices 22 East 40th Street, New York, N, Y. Offices in All Large Cities JOin*-MiirvTut !/3l Johns-Manville Home Insulation J-M Home Insulation involves the ap plication of J-M Rock Wool (actual rock fibre) within the walls and the roof or atlic spaces of residences, stores, apartment buildings and other structures. J-M Home Insulation is thick insula tion, remarkably effective in providing year round comfort and in reducing fuel bills. (On hot summer days homes in sulated with this material are up to 15 cooler; in winter fuel bills are reduced from 25% to 40%). J-M Home Insula tion is non-combustible, sanitary and odor less, and will not support vermin. Furnished in two forms: .Type A for blowing into existing construction; and Type B bats for new homes. Blown Method--Type A In the Type A form, Rock Wool is blown by air into the spaces between studs in outer walls and between rafters or joists .in attic floors. The insulation thickness in the walls corresponds to stud depth, approximately 3% in., and the density does not exceed 10 lbs. per cu. ft. J-M Home Insulation has been installed by this method in thousands of existing homes. This type of material is installed by J-M Approved Home Insulation Contractors, who are equipped with the necessary apparatus. Applying J-M Home Insulation bats in new home Bat Method--Type B Home Insulation Type B is furnished in resilient bats, 15 in. by 18 in., approxi-* mately 3 in. to 4 in. thick. This form is widely used for homes or buildings under construction. The bats can be readily pressed between studs or beams and are easily cut or torn to fit odd-shaped spaces, conforming perfectly to the space occupied and providing a continuous insulation of even density. Data and Specifications For technical data and specifications on both types of J-M Home Insulation, write for brochure HI-17A. J-M Insulating Board and Plaster Lath . J-M Insulating Board is a light weight, efficient material, having high insulating value and moisture resistance and unusual structural strength and rigidity. Furnished 4 ft. wide, in lengths of 4, 5, 6, 7, 8, 9, 10 and i2; ft. Also 6 by 8, 8 by 8, 8 by 10 and 8 by 12 ft. Thicknesses-J4 and 1 in. . J-M Insulating Lath is the same material as Insulating Board, except that it is fur nished 18 in. by 48 in. with long edges shiplapped. Also furnished with long edges ship-lapped and beveled, and short edges beveled. Thicknesses l/2 in. and 1 in. ' 712 Johns-Manoille Insulation Johns-Manville Pipe and Boiler Insulation equally effective and durable on either hot or cold water service piping. . By the use of waterproofed felts shrinkage troubles have been eliminated. Supplied in two finishes, the regular canvas and a smooth, dull-coated alumi num. In either, finish, it is furnished in 3-ft. sections in thicknesses of in. % in., 1 in., Double 3^ in., and Double % in> fr pipe sizes from ^ in. to 5 in. J-M Pre-Shrunk Asbestocel Pipe Insulation with aluminum finish J-M Pre-Shrunk Asbestocel J-M Pre-Shrunk Asbestocel is a. radically improved material in which, by the use of waterproofed asbestos paper, shrinkage troubles have been eliminated. It is used for hot water or low pressure steam piping, including supply and return mains, branches and risers. Supplied in three finishes: The regular canvas finish; and the new high-speed asbestos paper or aluminum finished material which slips easily over the pipe and clinches on tight with quick-fastening staples. . All types are furnished in 3-ft. sections in standard thicknesses of 2, 3, and 4 plies, each ply approximately ]/i in. thick. J-M 85% Magnesia Recommended as the most efficient in sulation of the molded type for tempera tures up to 600 deg. 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 )/2 in. to 4 in. thick. J-M Asbesto-Sponge Felted Recommended on all high pressure steam piping at temperatures up to 700 deg. F. where insulation may be subjected to rough usage or where maximum ef ficiency and durability are desired. Fur nished in 3-ft. sections up to 3 in. thick. J-M Superex Combination Superex Combination Insulation (an inner layer of high temperature Superex and an outer layer of 85% Magnesia) is recommended where temperatures exceed 600 deg. F. Superex and Magnesia are both furnished in sectional and block forms. J-M Asbestocel Sheets Asbestocel Sheets are used for insulating warm-air ducts, flues, heater casings and fan housings in the ventilating system. Temperature limit 300 deg. F. Furnished 6 in. by 36 in. and 36 in. by 36 in., from % in. to 4 in. thick. J-M Rock Cork J-M Rock Cork is made of rock wool and a moisture-proof binding ingredient molded into sheets for insulating refrigerated rooms and air conditioning ducts. It is strong, durable, and will not support vermin. Because of its unusual moisture resistance its high insulating efficiency is maintained indefinitely. Furnished 18 in. by 18 in. and 18 in. by 36 in., in thicknesses from 1 in. to 4 in. J-M Wool Felt Due to its Dual-Service Liner--an asphalt-saturated felt--J-M Wool Felt is . Detailed Specifications . Specifications on the use of any J-M In sulating Material may be had on request. 713 Insulation International Fibre Board Limited Insulating Building Board Non-Inflammable Insulating Building Board * Sales Offices OTTAWA--MONTREAL--TORONTO--WINNIPEG Administrative Offices and Mills: GATINEAU, QUE. r London Office ' THE TENTEST FIBRE BOARD CO. (1929) Ltd. Astor House. Aldwych. London. W. C. 2.. England 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. 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 2 in. thick. Official Tests TEN/TEST Notch Board Plaster Base. Insulating plaster base having Conductivity. TEN/TEST has a con ductivity of 0.33 B.T.U. 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 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 2 in. of Applied Mechanics, University of Toronto. Tests performed by Hot-Plate method. Mean temperature 47.8 deg. Tensile Strength 228 lb. per sq. in. TEN/TEST Roof Board. An effective roof insulation. Manufactured in two sizes: 1 x 4 ft. and 2 x 4 ft. Thicknesses from % in. to 2 in. Tests made on Jfg 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 Ji a in. board, 6 in. wide, 18 in. long, on 12 in. centers, and load being'applied to breaking point. TEN/TEST Ashlar Block (Acousti "A"). For interior decoration and acoustical correction. Absorbs 35 per cent of incident sound at a frequency of 512. Can be supplied in a variety of designs and sizes to harmonize with any decorative treatment, allowing the archi tect much freedom in design and finish of churches, auditoriums, theatres, etc. Ashlar Blocks have bevelled edges, Plaster Bonding Strength 2163 lb. per sq. ft. Brown and scratch plaster coats were applied to standard jf6 in board, and the pull registered in an OlsenTesting Machine. Authority: Columbia University Testing Laboratories, New York. standard or to suit, can be left in the natural color or tinted as desired. TEN/TEST Panel Strip. Provides pleasing trim and finish for joints, corners and openings. Manufactured in widths of from 2 in. to 6 in. and lengths up to 12 ft. Moisture Resisting. TEN/TEST, after complete immersion in water for 24 hours, registered 37.5% increase in weight. Note.--Authority for tensile strength, PYRO/TEST. Non-inflammable, fireresistant, insulating building board with same physical characteristics as TEN/ TEST. transverse and moisture tests; J. T. Donald & Co., Ltd., Chemical Analysts and Engineers, Montreal, Que. HYDRO/TEST. Water proof, insula ting building board, designed particularly for low temperature requirements. 714 Insulation Mundet Cork Corp. 450 Seventh Avenue - New York, 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. * Branches . Atlanta, Ga, Boston. Mass. Buffalo. N. Y. Chicago. III. . Cincinnati, Ohio Cleveland, Ohio Des Moines, Iowa Detroit, Mich. Houston, Texas Kansas Cm. Mo. , Agents Los Angeles. Calif. Memphis, Tenn. New Orleans, La. Philadelphia, Pa. St. Louis, Mo. San Francisco. Calif. Tulsa, Okla. Charlotte, N. C:C. R. Howard Portland, Orb________________________________--.---Pacific Asbestos & Supply Co. Hartford, Conn.The Hartford Cement Co. Salt Lake Citt, Utah-------------------------------------------------------------------L. A. Roser Pittsburgh. Pa.Smith-Doeright Co. Seattle, WashPioneer Sand & Gravel Co. Portland, Orb._______ ____________________ ___ F. J. Leonard Utica, N. Y.George Weisenberger Engineering and Specification Service 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 who has a cold insulation or a vibration isolation problem, and is rendered without obligation. Send for our catalogue now. It is replete with valuable information and should always be within reach of every specification writer whose field touches our products. Contract Service We contract for the erection of our pro ducts in order that we may be certain that our material is installed in accordance with best established practice, and in order to eliminate divided responsibility for a given installation. No contract involving cork is too large or too small. All materials and workmanship are unqualifiedly guaranteed. Jl ' - Mundet "Jointite" iCorkboard 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 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 x/i in., 2 in., 3 in., 4 in. and 6 in. 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 lines. The three thicknesses in which it is manufactured make* it' suitable for pipes carrying sub-zero to 50 temperature. The pipe covering comes in sections 36 in., long. A complete line of standard fitting covers is available in the three thick nesses. Mundet Cork Vibration Isolation Machinery isolation is today a most important part of the design of all struc tures. The transmission of machine vibra tion can be easily and permanently pre vented by the use of proper cork isolation. Mundet Natural Cork Isolation Mats are best adapted to most of the isolation field and Mundet Machinery Isolation Cork to the balance. Mundet Natural Cork Isolation Mats are blocks of pure cork. These blocks are held together within a rigid steel frame, or bound with asphalt paper applied with hot asphalt top and bottom. Mats are con structed to fit under any type of machine foundation. Above it shown a typical Mundet Natural Cork Isolation Mai. Note the natural cork stripe xoithin the steel frame. Mundet Machinery Isolation Cork is manufactured board and comes in the three standard densities. It is composed of granules of pure cork, fabricated and baked under pressure. The standard size board is 12 in x 36 in. but these can readily be cut into any size or shape. Both types of isolation are furnished in 1 in., 1 in., 2 in.,3 in., 4 in.and 6in., thick nesses, depending on the class of service. Insulation The Upson. Company |j^| Lockport, New York S UPSON Insulating BOARD i and 33Z. UPSON Insulating LATH Upson Insulating Board Upson Insulating Board is a structural, rigid board form of-Insulation, made from -wheat straw, for use in walls, floors, ceilings and partitions. It quiets sound, saves fuel and adds comfort in all seasons. Upson Insulating Board may be used as a. sheathing under wood shingles, wood siding, masonry or stucco veneer. ' Tests Upson Insulating Board, in its com mercial thickness, has a Resistance or Insulating Value of 1.36. Conductivity per 1 in. of Thickness-- .324. . Conductance of Commercial Thickness --1.74 B.t.u. per square foot per hour per degree Fahrenheit Temperature Difference. Tension 1 in. wide Commercial Thick ness--163J4 lbs. Tension, pounds per square inch-- 362 lbs. Mullen Test Commercial Thickness-- 433^ lbs. Modulus of Rupture--923 lbs. Application Upson Insulating Board is furnished 48 in. wide for application directly to studs, joists or rafters spaced 12, 16 and 24 in. on centers. Panels to be applied parallel to studs and joists. t Upson Insulating Lath Upson Insulating Lath is a structural insulating plaster base. It is scientiflcally designed to meet the exacting needs and requirements for obtaining better plastered walls and ceilings. - The exclusive nail slot, and enclosed feathered edge spaces at all edges provide room for the expansion of the lath. These permanent expansion spaces protect the plaster from strains arid stresses set up in the framing members, due to shrinkage. The ship-lapped edges exclude infiltra tion of air at the joints, thus preventing unsightly streaks of dust deposits at these points. Application Upson Insulating Lath is furnished in panels 18x48 in. and is applied horizontally to studs and joists so that all vertical joints are staggered or broken. Only gypsum or other quick drying plaster should be used. Sizes . Upson Insulating Board is supplied in panels Yv o in. in thickness--48 in. wide and lengths of 6, 7, 8, 9, 10 and 12 ft; Average weight is approximately 70 lbs. per 100 sq. ft. Sizes Upson Insulating Lath is furnished in Ye >n. thickness, in individual lath 18x48 in; They are packed 15 lath to the bundle, each bundle containing 90 sq. ft. and weighing approximately 59 lbs. per bundle. 716 Insulation MO. U. 8. PAT: Off. The RIC-WIL Company Union Trust Bldg. Cleveland, Ohio CONDUIT SYSTEMS FOR UNDERGROUND STEAM PIPES NEW YORK--CHICAGO--SAN FRANCISCO Agents In Principal Cities Established 1910 Conduit--Standard conduit is vitrified salt glazed tile or cast-iron with Loc-HP Side Joints, bell and spigot type, unlined or lined. Tile in 24 in. sections and cast-iron in 48 in. sections, sizes 4 to 27 in. inside diameter. Fully described in Bulletin No. 32. A special light weight cast-iron con duit with flanges, bolts and gaskets for bad water conditions and a heavy weight castiron conduit for extra heavy duty are also available. Send for A & E Sheets Nos. 14 and 23 for details of these special cast-iron conduits. 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. Special U-Type Base Drain to hold return line and Support Blocks for use with round tile construction also available. Pipe Supports--Standard Pipe Sup ports are of the externally supported type with rollers for single or multiple pipes. Load is carried entirely on side shoulders of Base Drain. Pedestal Pipe Supports are shaped like the Base Drain and set be tween Base Drain sections embedded in a concrete pier. Internal Pipe Supports also available. All Pipe Supports are rustproofed. Details of Ric-wiL Pipe Align ment Guides and Anchors furnished upon request. Insulation--Dry-paC Waterproofed Insulation, non-settling and non-corrosive --packed into the conduit becomes a solid mass'without cracks, joints.br openings-- positively non-capillary and water-repellant. Has low conductivity and insures highest thermal efficiency--non-waterproof kind also furnished. Lined conduit insula tion is a moulded diatomaceous earth mix- Rie-wiL Cast Iron conduit has ample strength tcith minimum weight for use under roadways, railroad tracks, or other places subject to ex-. Irene loads and vibration. It is installed without delays and with out added con struction or engi neering. Cutaway view at pipe support showing how Ric-toiL parts interlock. Note Loc-liP Side Joints and how pipe assembly i independent of the conduit. Cut shows Type DF System, lined conduit, with Dry-paC Waterproofed Insulation. ture. Sectional pipe covering, sponge felt, 85% magnesia, etc., can also be furnished. Accessories--Conduit fittings, with Loc-liP Side Joints for all types up to 15 in. are carried in stock--45 and 90 elbows, tee branches and reducers. Tee branches and reducers made to order for larger sizes. Mitred Base Drain fittings made for all conduit fittings. Shutter sleeves of galvanized iron, with asbestos rope for encircling pipes to provide a form upon which to cement or brick in ends of con duit lines. Filter Cloth to prevent sand, etc., from sifting thru broken stone into drainage area of Base Drain. Special asphalt cements for sealing all joints and waterproofing compounds for cement joints. Manhole covers, with non-rattling double lidded covers, furnished in 22 in. and 30 in. sizes. Engineering Service--Cooperation in preparing preliminary surveys, plans and layouts or complete plans with full con struction details. Also installation super vision. Technical Data--Tabulated Steam Heating Rates, Test Report Bulletins, Service Detail Bulletins, Catalog Bul letins, Central Heating Bulletins and Architects and Engineers Detail Sheets available upon request. 717 Insulation Underground Steam Construction Co. 75 Pitts Street, Boston, Mass. PRODUCTS--Underground Steam Conduits. Engineering and Contracting of Steam Line Installations. 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 feet 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. > t'* --sw- ."*r - V- ' 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. 718 Meiers, Steam Builders Iron Foundry 9 Codding Street Providence, R. I. Representatives In Principal Cities The VENTURI METER for water supply, boiler feed and other main pipe lines. The CHRONOFLO ELECTRIC FLUID METER for long distance transmission of flow rates, quantities, pressures, temperatures, etc. The SHUNT METER for steam, air and gas. THE CHRONOFLO ELECTRIC FLUID METER "From hundreds of feet to hundreds of miles" The Chronoflo has introduced new features to the field of metering. Four common electric units are utilized: the synchronous motor; the mercury switch; the magnetic relay; the magnetic clutch. Electric impulses of variable time intervals proportional to rates or positions are transmitted by the primary unit to the receiver gauge. Regular A.C. current is used and accuracy is not affected by voltage variation. Suitable for in tramural or long distance transmission over regular telephone channels. Shunt Steam Meter, Type KJ5- THE SHUNT METER Distinctly filling the need for a low priced, practical, mechanical, meter easily installed and accurate over a wide range. For measuring steam sold or in checking distribu tion of steam (also air or gas) to buildings, departments dr processes. The illustration shows the complete meter. Installation consists simply of'bolting to flanges in the flow line; no connecting pipe or electric wiring. A portion of the entering steam is deflected by an orifice through nozzles against the blades of a turbine located in the upper or shunt passageway. The speed of the turbine is kept low by a damping fan on the vertical turbine shaft, at the bottom end of which is a magnetic drive to the totalizer dials. The meter ^installed as a unit in 2, 3 and 4-inch lines; for larger capacities the installation is made in a by-pass around an orifice in the main line. Steam Pressure Lbs. per Sq. In. Gauge Rated Capacity of Saturated Steam--Lbs. per Hour (Meters with largest orifice) V Meter Meter 4' Meter 6' Meter 8' Meter 10* Meter 12* Meter Extra Heavy Meters 0 5 15 30 50 50 100. 150 200 250 275 300 600 800 1200 1650 2000 2650 4150 5000 5700 6300 6600 6900 1,400 1,900 2.750 3,400 4,050 6.000 9,500 11.400. 13.000 14,400 15,200 15,700 2,530 3,350 4,750 5,850 7,000 10.600 16.600 20,000 22,700 25,200 26,500 27,500 5.660 6.500 7,860 9,550 11,400 22.200 29,000 34,400 39.000 43,200 45.000 46^800 9,850 11,300 13,700 16.600 19,800 39.000 '51,000 60,500 68,600 76,000 79,400 82,500 15,200 17,500 21,100 25.600 " 30,500 60.500 79,200 94,000 107.000 118.000 123,000 128,000 19;000 .21,800 26,300 31,900 . 38,000 75,500 99,000 M7.000 133,000 148,000 154,000 160,000 , Minimum Capacities equal one-tenth tabulated quantities. Many other intermediate capacities available. Bulletin No. 255 gives complete information. 719 i Century Electric Company 1806 Pine Street, St. Louis, Mo. Offices and Stock Points in Principal Cities . Motors A MOTOR FOR EVERY PURPOSE One Speed--Multispeed--Alternating and Direct Current -2 Horse Power Repulsion Start Single Phase Induction Motor. Sizes 1/8 to 40 horse power. 25 Horse Power Splash Proof-- Squirrel Cage Induction Motor. Sizes 1/2 to 30 horse power. i___ 5 Horse Power Squirrel Cage 3 Phase Induction Motor. Sizes ' 1/6 to 600 horse power. 1/6 Horse Power Capacitor -- Single Phase Induction Motor. Sizes 1/8 to 5 horse power. .1/6 Horse Power Split Phase In duction Motor. Sizes 1/6 to 1/3 horse power. 30 Horse Power Slip Ring 3 Phase Induction Motor. Sizes 1/4 to 250 horse power. OTHER PRODUCTS SINGLE PHASE MOTORS--1/250 to 40 Horse Power. SQUIRREL CAGE MOTORS--1/6 to 600 Horse Power. SLIP RING MOTORS--1/4 to 200 Horse Power. DIRECT CURRENT MOTORS--1/20 to 150 Horse Power. '- ALSO: MultisReed Motors Blower Motors: ' Unit Heater Motors . Capacitor Motors Cushion Mounted Motors Refrigeration Motors Totally Enclosed Fan Cooled Motors Enclosed Motors . ` . 720 Splash Proof Motors Explosion Proof Motors Gasoline Pump Motors Portable Motors Elevator Motors Rotary Converters Vertical Motors Motor Generator Sets 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 Merchandise Department, Bridgeport, Conn. Quiet Operating Motors and Control For Heating, Ventilating and Air Conditioning Systems Modem buildings should be equipped with motors andotherequipment especially designed for quiet operation. The General Electric Type KB and MB"q uiet ' * motors are especially designed, built and tested for quiet operation and furnished with this nameplate: C QUIET MOTOR THIS MOTOR IS SPECIALLY ** DESIGNED AND TESTED FOR Itessos. QUIET OPERATION Furthermore, the apparatus should be so installed that no vibrations are transmitted to the building structure as no matter how skillfully the equipment is designed and built, some vibrations (principally mag netic) must remain and if uncontrolled, they may appear as noise. The Genera! MIS Wound-rotor quiet-operating motor mounted on sound-isolating bate Electric Company's "sound isolating base" is designed for use with General Electric motors to check the transmission to the building structure of vibrations, which otherwise may appear as noise through amplification or resonance. ~ ' Alternating Current Control The General Electric Co. manufactures a complete line of control devices for starting and controlling motors driving ventilating fans. All controllers are of the enclosed type externally operated. Speed regulators are designed to give 50 per cent speed reduction on fan load and arranged to maintain equalized current in all phases of the rotor which is necessary to maintain quiet operating motors. Details may be obtained at the nearest sales office. CR77G1-F1. SOSO Hp. Controller For Use with Wound-rotor Motors This Company will gladly assist in the solution of any electrical problem in relation to heating and ventilation 721 Motors and Controllers The Lincoln Electric Company 13036 Coit Road, Cleveland, Ohio Largest Manufacturers of Arc Welding Equipment in the World Branch Offices and Distributors In AH Principal Cities Manual and Automatic Arc Welding Equipment, Electrodes and Supplies; A.C. Motors in Standard Types 34 to 200 H.P. Shielded Arc Welding Welding Electrodes Welds made by the shielded arc with Lincoln equipment have a tensile strength of 65,000 to 75,000 pounds per square inch, ductility and`density equal to 'mild rolled steel and greater resistance to impact, fatifue and corrosion.-; Shielded'arc welding is used in the fabrication of'pipe systems, steam, water, oil and gas transmission lines, also in the fabrication of ducts and other sheet'metal products, also in the con struction ' of fan and blower housings, boilers, furnaces, tanks and pressure vessels. Shielded arc welding under the proper procedure satisfies all the require-' ments of the A.S.M.E. Boiler Code and insurance regulations. "Fleetweld"--For shielded arc welding of pipe, plate and shapes. Welding speed 150 to 300 per cent faster than ordinary welding. "Lightweld"--For shielded arc weld ing of 16-24 gauge metal. ' "Stainweld A"--For welding 18-8 stainless steel. "Aluminweld"--For welding alumi num. ` "Ferroweld"--The electrode that solves cast-iron welding problems. "Hardweld"--A high carbon rod for hard surfacing. "Manganweld"--For welding high maganese steel. - ``Stable-Arc''--A non-splashing rod for general welding purposes. The Lincoln "Shield-Arc" Welder Lincoln "Shield-Arc" welders have many exclusive patented features which make possible the following 3-way guarantee of welding with "Shield-Arc" welders: 1. More weld metal deposit per K.W.H. 2. Faster welding.per K.W.H. 3. Lower cost per unit of welding--the unit being per lineal foot of weld, or per pound of weld metal, or per hour of welding. . Lincoln welders, A.C. and D.C. motor driven, are built in 100 to 400 ampere sizes; belt and gasoline driven types in 100 to 600 ampere sizes. Lincoln "Line-Weld" Motors Known as the motors which de liver extra horse power without sacrifice of power factor or efficiency. Arc-welded rolled steel" frames pro vide structural. The Motor with the Extra Horse strength without power, Lincoln "Linc-Wdd" bulk. This permits Type D larger openings for greater venti lation, resulting in cooler opera tion of motors. Built in all stand ard types of poly phase induction motors for pump, , ,1 fan and blower Malar Lmc-W.di Type -B, Totally. Bnjdotei, Fan Coded service, also for ' other general and special purposes. Use of the stainless steel motor, the "Line-Weld," Type E (totally enclosed, fan cooled), is recommended wherever there is dust, dirt, moisture or fumes in suf ficient quantities to clog an open type motor or to abrade and corrode windings and bearings. Though completely sealed, the "Line-Weld" Type E stainless steel motor operates continuously at full load well within the N. E. M. A. allowable tem perature rise of 55 degrees Centigrade. 722 Motors and Controllers Westinghouse Electric & Manufacturing Go. East Pittsburgh Pennsylvania Research, Application and Design Engineers will cooperate and solve any electrical problem for heating and ventilating systems. Sales Offices and-Service Shops in all Principal Cities Quiet Operating Motors . The Westinghouse Company has long recognized the need for quiet operating machinery and has devoted a vast amount of research work to the development of special instruments to measure noise ac curately. The human element, which gives variable results, is eliminated in all testing procedure. Westinghouse Quiet Operating Motors are specially designed and individually For fan drives, the new Westinghouse Type O-l Controller offers unusual ad vantages. This unit assembly includes the equipment ordinarily housed in three separate cabinets. Primary Linestarter, A Type CW Variable Speed, Quiet Operating Motor Driving Pan tested under loaded and unloaded con ditions in a sound-proof room. A special nameplate is your assurance of their high standard of quiet operation. Lasting quietness is assured by rigid, unit cast motor frames which contribute to the permanence of bearing alignment and air gap. Rotors are given a special dynamic balance, practically eliminating noises due to vibration. Motor Control speed regulator and Nofuze breaker for circuit disconnect and protection are all mounted and wired in a neat cabinet for wall or floor mounting. Installation .is greatly simplified and its appearance is improved. Arc Welding FlczArc A-c. Welder for Simplified Fabrication Linestarter for A-c. Drives A Close lt-016 Speed Regulating Rheostat for use with Pan Drives Starters, speed regulators, thermostats, switches and Nofuze circuit breakers are available for every requirement. For the fabrication of thin-gauge ma terials such as ducts, Westinghouse'offers the FlexArc A-C. welder. Its operation is extremely simple and it uses less than 15 cents worth of power an hour. One man can wheel it easily from place to place. It operates from the ordinary single-phase power circuit. 723 / Publications American Artisan Published by KEENEY PUBLISHING COMPANY 1900 Prairie Ave., Chicago, 111. merican A ARTISAN, published monthly, serves the warm air heating, sheet metal contracting and air condition in each issue exclu sively to the tech nical and merchan dising problems of air conditioning and automatic heating in homes ing industry. It foresaw in the early stages of air conditioning and auto matic heating development a field and small build ings. Just as this field is an essential part of the warmair heating and sheet metai con of great possibilities for its warm air heating dealer and sheet metal contractor readers, and for a num ber of years has given close editorial attention to the merchandising, in stallation and operation of this type of equipment and its accessories as developed for residential and similar applications. Residential air conditioning and automatic: heating have progressed rapidly and logically along the lines of the warm air heating type of system. To keep pace with the trends of the industry, AM ERICAN ARTISAN devotes a special section tracting industry, so is this section an essential part of AMERICAN ARTISAN. Ventilation and forced air heat ing, together with all phases of sheet metal contracting and gravity warm air heating, make the entire magazine of interest and value to engineers and contractors who wjsh to keep up with this division of the heating, ventilating and air con ditioning field. ' AMERICAN ARTISAN is a member of the A. B. C. and A. B. P. Subscription rates--$2.00 per year. Advertising rates furnished upon request. 724 Publications Heating, Piping and Air Conditioning . Published by KEENEY PUBLISHING COMPANY 1900 Prairie Ave., Chicago, III. eating, Piping Hand Air Con ditioning is edited to give specialized attention to the de sign, installation, operation and maintenance of heating, piping and air conditioning systems in indus trial plants and larger classes of construction. It is a strictly technical journal, published monthly. It carries in each issue, as a separate section, the journal of the American Society of Heating and Ventilating Engineers, and numbers among its subscribers the members of this Society. Besides its regular staff of editors, fifteen consulting and contributing editors on heating, fourteen on piping and twelve on air condition ing insure a high grade, authorita tive, technical and practical cover age of the subjects for which it is named. Heating, Piping and Air Con ditioning by concentrating editori ally on these specialized services has singled out in the leading industrial plants of the coun try the one man whose major or sole concern is with this division of plant operation and maintenance. Similarly, it has attracted the con sulting engineers, the chief engineers of large buildings, and large contrac tors who require this specialized treatment of the services which constitute their in terest and work. Such a coverage means, for the advertiser, consideration at all points in the selling of a heating, piping or air conditioning product--consider ation in the selection of a product during the preparation of plans and specifications; consideration in the actual purchase of a product for in stallation; consideration in the year 'round buying of a product for operating and maintenance require ments. Heating, Piping and Air Con ditioning is a member of the A. R.C. and A.B.P. Subscription rates--$2.00 per year. Advertising rates furnished upon request. 725 Domestic Engineering 1900 Prairie Avenue Chicago Publications section as a sepa T, HE Automatic Heat and Air Conditioning Section of DOMESTIC ENGINEERING has had an unusually interesting career. Starting in 1931 with a few articles, it developed into a department, and, as its importance increased, it grew into a special rate publication went to 1,000 of these special dealers. Later other advertisers, realizing the importance of this separate distribution, which is in addition to the regular distribution as part - of DOMESTIC ENGI NEERING, added their lists of special dealers. section. . At the present time, in addition Later, requests ' came from ad-' to its more than 15,000 circulation vertisers to send reprints of this in DOMESTIC ENGINEERING, section to lists of their special it goes to over 9,000 special dealers dealers, which included exclusive in automatic heating and air con oil burner dealers, coal stoker ditioning equipment every month, dealers', dealers in air conditioning giving advertisers in the section equipment, gas fired boiler dealers, blanket coverage of their market. and to other dealers outside of the This gives advertisers a blanket regular heating trade. coverage of over 24,000 at . the The first distribution of this lowest available cost per thousand. 726 Pumps Ms PUMPS Decatur Pump Company Decatur, 111. Ms PUMPS Oaf oammtrifagpa*t BURKS SUPER TURBINE PUMPS AND WATER SYSTEMS Self Priming High Head Units High Efficiency. Open-Impeller Type. Self Priming Centrifu gal Pumps that are DIFFERENT! Capacities to 400 G.P.M. Built up to an Engineering Ideal. Burks Self Priming Centrifugal Pumps BURKS CONDENSATION RETURN UNITS Will Not Steambind! Ability to pump air alone, or air mixed with water, to the full pressure rating of the pump, means that the Burks pump will not steambind. Pump capacities range from 150 gph to 1,000 gph against boiler pressures up to 100 lbs. per square inch, and will take care of up to 12,000 sq. ft., of radiation per unit. Hydraulically Balanced These pumps are hydraulically balanced and cannot be made to pound or hammer under any condition of operation. Construction Features Only one moving part--the impeller-- and this one part does not contact with metal at any stage of operation. Self-priming and fully automatic. Im peller and raceway bf cast bronze. Shaft of stainless, non-corroding steel, impervious to mild acids, and carried in oversize ball bearings. Tank of copper-bearing steel, %6-in. shell; yi-in. top and bottom, welded con struction. ' Series 4700 Condensation Return Unit A SATISFACTORY CONDENSATION RETURN UNIT TO INSTALL 727 Pumps CHKACO PUMP COMPANY SEWAGE-CONDENSATION-CIRCULATING BILGE- FIRE-HO USE-VACUUM 2330 Wolfram Street - BRUnswick 4110 - Chicago PRODUCTS--Vacuum and Boiler Feed Pumps, Condensation, House, Booster, Fire Pumps, Circulating, Brine, Sewage, Bilge, Sludge, Pneumatic Tankless Water Systems and Automatic Alternator. ' > WE DO OUS MKT Condensation Pump and Receiver for Low, Medium and High Pressures Systems up to 150,000 Sq. Ft. Radiation "Sure-Retum" Condensation Pump for Low and Medium Pressure, and Systems up to 35,000 Sq. Ft. Radiation Fig. 1946 Fig. 1931--F. C Condonation Pump "Chicago" Condensation Pumps are built for systems ranging from 2,000 up to 150,000 sq. ft. of radiation, and for boiler pressures up to 200 lbs. Units are built in either single or duplex--the duplex being alternated in their operation by the Automatic Alternator. For tables and com plete description ask for Bulletin 129. Vertical Condensation Pump for Low and Medium Pressure for Systems up to 100.000 Sq. Ft. Radiation The vertical condensation pump is designed to re ceive returns from lowest radiation. The receiver is placed underground--an ordinary hole sufficing if necessary -- and requires very little floor space. Unit is shipped complete, easy to install, assembled so as to prevent steam leaks. Special bearings will stand up under hot water for several years. A special float mechanism is guaranteed not to leak or stick in stuffing box. Complete data and descrip tion in Bulletin 133. "Sure Return" Condensation Pumps and Receivers are built for systems up to* 35,000 sq. ft. of direct radiation and for low and medium pressures. Built in either single or duplex units. Duplex units are alternated in their operation by the Auto matic Alternator. Complete data in Bulle tin 131. Horizontally Split Pumps for all Services ` Fig. 1831--Single Stage Type ">" Pump For any service (such as boiler feed, water supply, tank filling, circulating, fire protectiqn, etc.). Chicago Pump Co. builds . a line of horizontally split case centrifugal pumps in both single and multistages. Completely bronze fitted (except where special fittings are required) ball bearings, internal water seal, oil is filtered. "Chicago" Horizontal Pumps are built for efficient performance and long. life. 728 Chicago Pump Company "CONDO-VAC" Return Line Vacuum and Boiler Feed Pump Pumps Automatic Alternator is available on Duplex Return Line Vacuum and Boiler Feed Pumps "Sure Return" Engineering Table Maximum square feet 1 direct radiation Pounds pressurepump w ill discharge against Horse power motor furnished Size of discharge in inches Size of return inlet in inches ' Capacity of pump in gallons per minute 1 Capacity of receiver ] in gallons Height of inlet in receiver from floor level in inches 1 Approximate shipping ) weight--Single 6, Z 5 SR602 2,000 10 SR604 - 27 SR606 50 / 1 Vi 1 2 3 16 -" : " - a . aA 2IVl 300 350 400 SR609 4,000 10 SR611 21 SR613 " 50 SR6I6 6,000 10 SR6I8 * 18 SR620 * 50 SR623 SR625 SR627 SR629 SR631 SR633 8,000 * * " 10 17 17 22 29 35 SR636 10,000 SR638 . SR640 SR642 " SR644 5R646 " 10 15 16 21 29 35 y. 1 2 A1 AA 6a A1 A1 29 *a `/a A m 12 A1 * aA IV. " \ t'/i " " 2. " 12 aaa a * %1 A1 2 " A 1% a 1a IV, " B 2* 15 a a a " a16 2l'/2 300 350 400 16 21V? 300 a 350 " 425 19 23 300 a " 350 aa a 3/5 " 400 a a 500 525 19 23 350 a " 400 a a 425 " " . 450 " " 550 5/5 SR651 15,000 10 Zi I'/. 3 21 59 30 450 SR653 SR655 . " 17 % 20 1 a " . " " 510 " " " 550 SR657 28 IV, * * a a 650 SR659 " 34 2 " " 675 SR662 20,000 10 SR664 " 16 y? IV. 3 A 30 59 a" 30 475 " 510 SR666 * . 19 1 a " a 550 SR668 * 26 IA- * " a " 650 SR670 " 33 2 " 675 SR673 25,000 10 a IV, 3 35 59 30 475 SR675 " 15 a "" 510 SR677 18 a" 550 SR679 25 IV? aa 650 SR68I " 30 2 675 SR684 35,000 12 A 1 3 50 59 30 510 aSR666 15 l " " 550 aSR688 22 IV, " " 650 SR689 27 2 675 Units marked with asterisk run at 17S0 R.P.M. All other units listed on thia sheet run at 3500 R.P.M. ' 729 Fig. ilOO--Single "Condo-Vac" _ . No vacuum on stuffing boxes,, ample clearance in rotating member. It costs less to operate a Condo-Vac. CondoVac reduces corrosion in piping and boiler to minimum--because pump does not take in air from atmosphere and entirely eliminates all air coming back from system. Condo-Vac is quiet, has a low inlet, entirely automatic, fool-proof, easy to maintain. Ask forBulletin 137, learn more about the modern vacuum pump with the long life principle of operation. "Condo-Vac" Engineering Table Single Standard Capacity, with Double Automatic Control and Receiver. 20 Pounds Discharge Pressure Simultaneous Water and Saturated Air Capacity at 160 F Square Feet Direct. Radiation Horsepower of Motor Furnished Capacity for Water only, at 160 F. GPM Water GPM AirC FM I at 5 '// ! Pump Discharge in Inches Approxinate Shipping Weight in Pounds A2,500 V-5,000 3.8 i 7.5 10,000 ! 15.0 15,000 IV4 22.5 20.000 2 30.0 25,000 2 37.5 30,000 3 45.0 40,000 5 60.0 65,000 i'/i 97.5 100,000 10 150.0 150,000 15 225.0 1.3 2.5 5.0 7.5 10.0 12.5 15.0 20.0 32.5 50.0 75.0 1.3 2.5 4.0 5.4 6.8 8.3 9.7 12.6 19.8 30.0 50.0 iv. `u " " . 2 - a3 . .500 525 550 1,000 1,200 1,300 1,450 1,700 2,200 3.000 4.000 Vertical Style Condo-Vac (Fig. 2120) operating at 3500 R.P.M. / Pumps Goulds Pumps, Inc. - Seneca Falls, New York New York........ ...... .............16 Murray St. Philadelphia-------- . 111 N. Third SL Boston -----------------------------.8 Albany St. Tulsa 213 E. Archer St. Chicago.-- 5,1 W. Jackson Bl.d. Pittsburgh6.36 H. W. Oliver Bldg, Atlanta22 Marietta St. Bldg. Houston ...................................... P. O. Bok 965 Manufacturers of Pumps for Every Service PRODUCTS--Centrifugal Pumps for all purposes--Single and Double Suction, Sump, Fire, Single and Multistage, Horizontal and Vertical. Triplex Pumps. Single and Double Acting, Deep Well, Power Rotary, Pressure Pumps, etc. Goulds Pumps, manufactured since 1848, comprise a line of hand and power pumps, including types and sizes for practically all pumping services. Every Goulds Pump sold is guaranteed to give reliable, satisfactory service under the conditions for which it isxecommended. The power pumps can be furnished for belt, chain, gear or direct drive from all types of drivers. inlets both tapped for 3 in. pipe, one 8 in. the other 14 in. below top of tank. Tapped for vent connection, and fitted with drain opening. 1-in. discharge from pump to boiler. Motor--1750 r.p.m., 110-220 volt, 60 cycle repulsion induction motor:' . Fig. 3354 has % hp. motor; Fig- 3356 has 1 hp. motor. Capacity--Pumps are suitable for Maximum Direct Radiation, 25,000 sq. ft.; Maximum Discharge Pressure, 28 lb,; Height Over-all, 64% in.; Weight 350 lb. Condensation Return Pump and Receiver For handling returns which come back at or below the floor line of boiler room. 'Will handle returns from 2,000 to 25,000 sq. ft. of radiation; good for pressures up to 28 pounds. Outfits shipped from stock com pletely assembled.. Pump--Ball bearingcentrifugal type, two stage, bronze fitted. Requires no lubrication. Fig. 3364 Pump Shaft and Float Rod--Oper ate through stuffing boxes to prevent leaks. This enables outfit to be used under pressure.. Float Rod cannot bind. ` Tank -- Heavy, galvanized, welded steel, 24,in. in diameter by 40 in. high.' Tank has two Horizontal Condensate Return Receiver The unit consists of a horizontal, gal vanized, corrosion-resistant, welded steel receiver tank, in 20, 40 or 60 gallon ca pacity, with float and automatic switch mounted upon bedplate as illustrated. Pump is the Goulds well known FlexiUnit type with capacities from 5 to 60 g.p.m. Pressures up to 20 lbs. Complete units can be furnished for radiations up. to 40,000 sq. ft. . For higher ratings, special units can be furnished. 730 Goulds Pumps, Inc. Pumps Close Coupled Centrifugal Pumping Units A compact, low cost and efficient cen trifugal pumping unit with a capacity range up to 1000 g.p.m. Heads range from 10 feet up to 290 feet. Pumps are built in sizes % in. to 4 in. For general pumping service in industrial plants, offices and apartment buildings, green-houses, re fineries, cold storage plants--in fact, its application is universal. For any instal lation where an inexpensive yet efficient and dependable unit is required, a Goulds Close-Coupled unit will give years of trouble-free service. Pumps can be furnished in standard .fitted, all iron, bronze fitted or all bronze construction. Standard motors without shaft extensions may be used if they have the proper ball bearings. No special end plates or brackets required. Short bed plate provides positive support for pump independent of motor. Self venting top horizontal discharge gives quiet running pump with no loss in capacity or head due to air binding. . Write for Goulds Bulletin 204 for com plete description and performance chart. Fig. sios Automatic Cellar Drainers Self-Contained Verti cal Type--Fig. 3108. Ca pacities up to 40 gals, per minute. Heads up to 25 feet. For use in an 18-inch diameter tile or ordinary barrel set in a pit 2 feet deep. Shipping weight, 75 lbs. Pump has cast bronze casing, bronze impeller and stainless steel shaft. Lower bearing made of non-scor ing, non-seizing, self-Iubrieating, "Bearium" metal. Upper bearing is combined radial and thrust type ball bearing. Motor is % hp., for 25 or 60 cycle, A.C. or D.C. circuits. Float switch is entirely enclosed in housing which is part of motor support. Float is heavy gauge copper with brass rod and adjustable stops. Complete with 10 feet of rubber covered cord and plug. Horizontal Self i*riming Type--Fig. 3034. Two sizes, capacities 1 in. size up to 30 gal. per minute; 1 % in. size up to 50 gal. per minute. Heads up to 20 ft. Approxi mate weight, 100 and 250 lb. This type is equipped with special priming chamber making it entirely auto matic for pit depths of 3% ft. Minimum diameter drainage pit, 1 in. size, 13% in.; 1% in. size, 16 in.,. ' Pump is bronze fitted. Discharge l. in. or 1% in. Pump shaft is connected to motor shaft by flexible coupling. Motor is repulsion induction type. Double pole type switch. Copper float with brass rod. Centrifugal Sump Pump--Fig. 3047. Electrically driven, directly connected to motor. Single stage, single suction. Used to elevate drainage in buildings to street level, where basement floors, boilers and elevator pits are below sewer level, and for any other service where liquid accumulates in a catch basin, pit or tank. Furnished with non-clogging bronze impeller to prevent corrosion during idle periods. Outfit includes pump, motor and control completely assembled and ship ped from stock. Built in 1%, 2, 3, and 4 inch sizes for capacities up to 650 G. P. M.; heads up to 70 feet. Motors %, %, 1. 1%, 2, 3, 5, and 7% carried in stock with auto matic control. All pumps may be fur nished for pit depths up to 14 ft. Duplex units also available. Centrifugal Sump Pump Fig. 8047 731 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 av 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 lbs. Sup plied standard in capacities up to 300,000 sq. ft. E.D.R. . Complete data in Bulletin No. 85 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 operate 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. L 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 ca pacities up to 30,000 sq. ft. E.D.R. Complete data in Bulletin No. SOS on request. Condensation Pump and Receiver Removes condensation from radiators.-, in return line steam heating systems and pumps condensation back to the boiler. They are sturdy and compact in construc tion, and combine receiving tank, pump and driving motor in a single assembly. Bronze fitted throughout, with Tobin bronze shaft. Impeller is of special design adapted to hand ling hot water with highest efficiency. Jennings Condensation Pumps are fur nished in standard sizes with capacities rang ing from 4 to 200 g.p.m. of water. For serving up to 150,000 sq. ft. of equivalent direct radiation. Complete data in Bulletin No. 165 on request. 732 Pumps The Nash Engineering Company South Norwalk, Conn., U. S. A. Sales and Service Offices in all Principal Cities Centrifugal Pump Made in standard and suction (self-priming) types. For circulating hot and cold water; boosting city water pressure; handling water in air washing and conditioning; handling ash sluicing water, etc. Compact--motor armature and pump im peller are mounted on the same shaft. Simp lified--no bearings in pump casing, one stuf fing box. Accessible--impeller removable without disturbing piping or shaft alignment. Self-priming types will handle air or gas con tinuously with liquid being pumped, and can be operated intermittently without foot valve. Supplied in 1 , 1 2, 3, 4, 6, and 8 in. sizes with capacity up to 2000 g.p.m. Heads up to 300 ft. ' Complete data in Bulletins 155, 159 and 161, on request. Suction Sump and Sewage Pumps Jennings Suction Sump Pumps are self priming centrifugals for ^ handling seepage water and liquids reasonably free from solids. The Suction Sewage Pumps are equipped with a non-clog type impeller for liquids containing . solids. Suction piping only is submerged. Centrifugal impeller and vacuum priming rotor are both mounted on same shaft that carries rotor of the driving motor, forming a single moving element and rotating without metallic contact. 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. Complete data in Bulletins 159 and 161, on request. Sewage Ejector For pumping unscreened sewage or drain age from basements below street sewer level; handling crude sewage from low level dis tricts; pumping effluent, sludge and other heavy liquids. The Jennings Sewage Ejector is of exclusive pneumatic design, no sewage passing through the pump. Air is furnished by the Hytor Compressor at operating pressure, and com pressor operates only when air is required. Reciprocating compressors, air valves, high pressure air storage tanks, and pressure re ducing valves have all, been eliminated. Furnished in standard-sizes for handling from 30 to 1500 g.p.m. Heads up to 50 ft. Complete data in Bulletins 103 and 108, on request. 733. Registers and Grilles Hart & Cooley Manufacturing Co. General Sales Office: 61 W. Kinzie St., Chicago PRODUCTS--Steel, Semi-Steel and All Cast Registers; Steel and Cast Register Faces and Reinforced Cold Air Face Plates; Ceiling and Sidewall Ventilators; Lock Registers; Heat Control; Damper Regulators; Chain; Pulleys; Furnace Accessories. A COMPLETE LINE OF FORCED-AIR REGISTERS With Choice of Three Designs Shown Below No. SO Grille Design No. 40 Grille Design No. 60 Grille Design A TYPE FOR EVERY CONDITION 3-Piece Sidewall Register--Consists of a re movable grille face, plaster frame, and detachable flange. Frame has extension arms which are fastened directly to studs, eliminating all special carpentry work and resulting in a rigid installation. Flange holds stackhead permanently in place and prevents streaking. Face overlaps edge of frame, effectively concealing plaster joint. 1-Piece Sidewall Register--Consists of a grille face and detachable flange. Stackhead is formed Diagram below shows Installation qf S-Pieee Register over flange and face is drawn up to wall by means of screws engaging in flange. Ideal for either old or new house work. 3-Piece Baseboard Register--Similar in con struction to 3-pieCe sidewall register except frame has a depth of y& in. Detachable flange results in a permanently streak-proof installation. 1-Piece'FBaseboard Register--Consists of an integral face and frame to which is welded a flange for engaging stackhead. Easy to install arid especially suitable for old house work. Return Air Intakes--Flanged Intake--Has a depth all around of % in. Suitable for use where intake extends above top of baseboard. Flat Intake--Designed for installations in which the baseboard height is greater than that of the intake. Advantages of Flat Type Grille 1. Easily decorated to match interior, resulting in inconspicuous installation. 2. Does not collect dust. 3. Easily cleaned or redecorated. 4. Strong and rigid--not easily dented. 5. Will not rust. 6. Offers ideal control over velocity of air entering room. 7. Causes air to enter room on a nearly horizontal plane. 8. Does not cause any audible noise. CLASS NUMBERS___________ ___________ STANDARD SIZES Type Register Design No. 30 3-Piece Sidewall...... 1-Piece Sidewall......... 3-Piece Baseboard.... 1-Piece Baseboard----- Flat Intake............. i. 3331 , 3330 fc 3131 3130 3630 3635 Design No. 40 334! 3340 3141 3140 3640 t 3645 Brio .... 51 lllo 3655 Flanged Intakes Flat Intakes 10x4,5,6,8 12x4.5,6,8,9.10 14x4,5,6.8.10 30 a 4.5.6.8 12x4.5.6 14x4.5.6 24x4,5.6 30x4,5.6.8 12x4.5 24x4.5 14x4,5 30x4.5 18x4.5 20x4.5. The above registers are stocked in all leading finishes. Special sizn and finishes furnished promptly. Send for Complete Catalog with Chart Showing Proper Sizes for All Conditions 734 Registers and Grilles Independent Register & Mfg. Co. Established 1898 3753 East 93rd Street, Cleveland, Ohio "Fabrikated" and Wrought Steel Registers and Grilles Two of 25 Designs to Choose From Wall Design No. 311--Single Valve Registers Design`No. 211--Single Valve Nos. 311,300, 211. 201, 175-12SV With Web Wall Frames (Styles WX and BX) ' SIZES AND LIST PRICES -- To Fit Stackhead Size: (Horizontal Dimension First). Inches 10x4 10x5 10x6 10x8 12x4 12 x 5 12x6 12x8 12x9 12 x 10 14x4 14x5 14x6 14x8 14 x 10 16x4 - 16 x 5 16x6 16x8 16 x 10 20x4 20x5 20x6 20x8 20 x 10 24x4 24x5 24x6 24x8 24 x 10 30x4 30x5 30 x 6 30 x 8 30 x 10 "Fabrikated" Daylight Opening Size Inches "Fabrikated" Overall Size * Straight Edge Faces. Bev. Edge Faces Hs* less Black Japanned or Prime Coat 9'/, 9'/, 9'/. 9'/. II'/, II >/4 II'/, II'/, II'/, II'/, 13'/, 13'/, 13'/, 13'/, 13'/, 15'/, 15'/, 15'/, 15'/, 15'/, l9>/4 191/4 19'/4 191/4 l9'/4 23% 23% 23% 23% 23% 29'/, 29% 2?% 29% 29% 2'A 37/e V/, 6% 2% 3'/, V/. 6% 7% va 2% VA VA VA m 2% VA VA VA VA 2'A y/f VA VA 2'A VA VA va VA 2'A VA VA VA VA ny.x 5 11% x 6 11% x 7 IP/,. 9 13% .5 13% x 6 13% . 7 13%. 9 13% x 10 13% x 11 15% x 5 15% x 6 15%. 7 15% . 9 15% x 11 17% . 5 17% 16 17%. 7 17%. 9 17% x 11 21%. 5 21% x 6 21%. 7 21% 1 9 21% x 11 25%. 5 25% x 6 25% . 7 25%. 9 25% x 11 31%. 5 31% x 6 31% . 7 31% . 9 31% x 11 $2.15 2.30 2.40 2.50 2.30 2.40 2.55 2.65 2.90 3.10 2.75 2.80 2.65 3.00 3.15 2.95 3.05 3.10 3.35 3.60 3.40 3.55 3.65 4.00 4.35 3.85 4.00 4.20 4.65 5.10 4.50 4.75 5.00 5:656.30 . White Japanned Oak, or Lacquered Finishes $2.50 2.65 2.80 3.00 2.65 2.80 2.95 3.30 3.45 3.60 3.20 3.25 3.35 3.50 3.70 3.45 3.55 3.65 3.90 4.15 4.00 4.15 4.30 4.70 5.10 4.45 4.65 4.90 5.45 6.00 5.20 5.50 5.80 6.60 7.40 - Electroplated Oxidized Copper Chrom., Nickel, Brass, or Bronze $3.35 3.60 ' 3.80 4.20 3.60 3.80 . 4.05 4.55 4.75 5.00 4.30 4.35 4.45 4.70 4.95 4.65 4.75 4.85 5.25 5.65 5.30 5.50 5.70 6.30 6.90 6.00 6.25 6.60 7.35 8.10 7.00 7.40 7.85 8.95 10.05 $3.90 4.20 4.40 5.00 4.15 4.35 4.65 5.05 5.35 5.55 4.95 5.05 5.15 5.45 ' 5.75 . 5.35 5.50 5.65 : 6.05 6.45 6.10 6.35 6.60 7.30 8.00 6.95 * 7.30 7.65 8.55 9.45 8.10 - 8.60 9.10 10.40 11.70 Multiple Valve Registers--For Wall, Baseboard or Ceiling. Valves swing from their edge, when closed lay flat on back of register. The frame is Jfj" deep, not cutting down duct capacity. Moder ate additional cost over single valve types. . Ask for Complete Forced Air Register Catalogue 735 ' '! . Registers and Grilles Tuttle & Bailey, Inc. HART & COOLEY WM. HIGHTON & SONS New Britain, Conn. Branch Offices: New York, N. Y. Boston, Mass. Philadelphia, Pa. Chicago, III. PRODUCTS--Ornamental Grilles, Ventilating and Air Con-. ditioning Registers, Convection Heaters, Cast Bronze Tablets. IMPORTANT NOTICE On April 1, 1933, the Hart & Cooley interests acquired the goodwill of the Tuttle & Bailey Mfg.Co. Hart & Cooley, Tuttle & Bailey, and Wm. Highton & Sons are all combined into one company, known as "Tuttle & Bailey, Inc." Increased facilities and the centralization of efforts will give greater benefits and better service to the Engineering profession as well as to the trade in general. Mcknight register, no. 1000 McKnight Patent Pending FOR HEATING, VENTILATING, AND AIR CONDITIONING The McKnight Register, No. 1000, was designed by a practical Engineer who had in mind the problems in volved in laying out and operating a ventilatingsystem. This register gives positive volume control, a vital feature in a register used in air conditioning systems. Various tests that have been made on this register prove conclusively that the volume of air may be -con trolled from 100 per cent of normal down to nothing by simply turning a key at the register face, provided a system is designed for equal resistance. # A resistance is set up by this register at the outlet with the result that air delivered to the register face is less subject to changing pressures from the outside. Fur thermore, an even distribution of the air flow over the entire register face is obtained without the necessity of using diffusers; this permits an easy and correct deter mination of the air velocity by means of. an anemo meter, \ Outstanding Advantages of the McKnight Register 1. Positive Control of air volume with minimum adjustment. 2. Ease of balancing system. 3. No need of other dampers or any diffusers. 4. No counter effects in system caused by open windows or doors. 5. Minimum of air leakage through register. . 6. Register has the appearance of a grille; 7. Air flow always uniform and. at right angles to the register face. ' 8. No whistling noises perceptible. 9. Positive operation by key control. 10. Minimum resistance to air flow with register full open. u 11. More accurately balanced system. 12. System costs no more than if ordinary registers are used. A List of McKnight Register Installations will be gladly sent to Engineers on request 736 Registers and Grilles Uni-flo Grille Corporation 4646 Lawton Avenue Detroit, Michigan iimtlo Counselors of Air Distribution PRODUCTS--Directional Air Distribution Outlets for Heating, Ventilating, Cooling and Air Conditioning Systems Literature Upon Request XJni-flo 5-Way AIR DIRECTIONAL-OUTLET Construction-- The construction of UNI-FLO Products--are of the fin and bar design. ' _ .. . Performance-- UNI-FLO-Directional Air Flow Outlets direct the air to almost any desired position by using combinations of different type cores. Air may be controlled to flow right, left, tan shape, or in up or down direction. When air flows through UNI-FLO Outlets, it is separated into ribbon-like thin sheets and by the aid of diffusers formed on the edges of the fins, the air is broken up at the face of the outlet in such a way that a rolling-action to. the air is created causing an asperating effect at the face of the outlet that induces room air to mix with the discharged air thus tempering the air at the face of the outlet before its distribution throughout the room, this is a very desirable feature especially when refrigerated air is distributed as the pre-tempering of the air at the outlet increases the distance of air delivery at lower velocities insuring quiet air discharge. Air-Noise-- UNI-FLO-Discharge Outlets are exceptionally quiet up to 1400 ft. only registering 35 decibels of noise at this velocity. Refrigerated Air-- . Air that is 15 degrees lower than room temperature will travel approximately 45 feet when discharged through UNI-FLO Outlets at a velocity of 1400 ft. per min. Air-Control-- Individual controlled dampers are provided either key operated or spring actuated so that all or part of the air flowing from the outlet can be controlled. A very important feature where control of temperatures have-to-be-maintained-regardless-of-the-number of-people-in-the-room. - __ Sizes-- .. In inches from 4 in. to 96 in. long and 4 in. to 48 in. high. . 737 NI Sheets, Iron Republic Steel Corporation General Offices Youngstown, Ohio Birmingham, Ala. ' Boston, Mass. Buffalo, N. Y. Chicago, III. Cincinnati, Ohio Cleveland, Ohio District Sales Offices Denver, Colo. Detroit, Mich. Grand Rapids, Mich. Houston, Texas Indianapolis, Ind. Los Angeles, Calif. Milwaukee, Wis. New York, N. Y. Philadelphia, Pa. Pittsburgh, Pa. San Francisco, Calif. Seattle, Wash. St. Louis, Mo. St. Paul, Minn. Toledo. Ohio Tulsa, Okla. Youngstown, Ohio TONCAN COPPER MOLYBDENUM IRON What Is Toncan Iron ? >*4^ H3B.INI.Sfr. .Toncan Iron Sheets Toncan Iron is a ferrous <mNCAN> Toncan Iron is available in various sheet forms. alloy of scientifically re fined iron, copper and molybdenum in correct COPPER MO-LYB-DEN-UM IRON Plain sheets, may be had black of" galvanized, in gauges No. 8 to'28, widths proportions--the alloy . from 24 to 50 inches, and which ranks first in rust- lengths from 10 to 13 feet, resistance, among the ferrous metals, after depending upon gauge and width. The the stainless alloys. Toncan Iron trade mark is stencilled in Thousands of rigid tests and the per two or three places on every sheet. formance of uitjtold tons of Toncan Iron in actual service point to the greater economy in the heating and ventilating systems of which the sheet metal and pipe are Toncan Iron. . Toncan Iron Pipe Toncan Iron Pipe is available in standard, extra strong and double extra strong; black or galvanized; in sizes from 14-inch to 16-inch O.D. All Toncan Iron Advantage of Toncan Iron Pipe, 2-inch and larger, is electric resis (I) It resists to a higher degree more ol the many and varied types ol corrosion than any other ferrous material except the stainless alloys. This resistance is not con fined to the surface or " skin " of the metal, but is uniform throughout. . (2) It combines the high rust-resistance of an alloy iron with many of the desirable physical qualities of less resistant ferrous tance welded, and combines the foregoing advantages of Toncan Iron with the ad vantage of Republic's electric weltfing process--100 per cent weld', perfect round ness, uniform diameter and'wall thickness, and freedom'from scale. ,Toncan Iron Pipe, black, is painted blue; galvanized finish is marked with two blue stripes. Couplings are stamped RT. materials. Source of Supply (3) It is one of the most workable of Toncan Iron Sheets and Pipe are materials. Sheets form easily. Pipe may stocked by jobbers in all large cities; lead be handled like any iron. ing contractors everywhere use Toncan (4) Unlike other ferrous materials, cold Iron and are glad to supply it where working--cutting, bending, punching, specified. If, for any reason, you cannot threading, etc.--in no way affects the rust- obtain Toncan Iron, write to Republic's resistance of Toncan Iron. nearest sales office. (5) It welds easily by any of the usually accepted modern methods. The use of Toncan Iron welding rod insures an instal lation of equal rust and corrosion-resis tance throughout. ' ` (6) A uniform and tightly adherent galvanized coating can be applied, thus adding the protection of a heavy coating of Literature . Two 64-page books, "The Path to Permanence" on Toncan Iron Sheets and "Pipe for Permanence" on Toncan Iron Pipe, will bring you the complete story. Write for your copies. Other Republic Products zinc to the already high rust-resistance of Republic Steel Corporation manufac the base metal itself. tures hundreds of iron, steel and alloy pro (7) Through its longer, trouble-free life, ducts, among which of interest to heating it has been found to cost far less per year and ventilating engineers are Enduro of service. Its use is more than an econo Stainless Steel in sheets and other usual my. It is insurance against sheet and pipe forms, steel pipe, and steel or Toncan Iron failures and costly replacements. boiler tubes. 738 Specialties, Heating frames clones NCODOOIATIO^' 129 Brookside Avenue, Jamaica Plain, Boston, Mass. New York Office: 101 Park Avenue Barnes & Jones Vapor and Vacuum Systems of Steam Heating; Radiator Valves; Metering Orifice Supply Valves; Thermostatic Radiator Traps; Thermostatic Traps for medium and high pressure; Condensators (Boiler Return Traps); Blast Traps; Drip Traps; Vent Traps; Strainers; Damper Regulators; Gages; Proportionator Systems with Zone Control.' Barnes & Jones Modulation Valve. Large unobstructed passages prevent trouble. from scale ' and dirt'. Tail piece extra heavy to pre vent breakage, extra long to facili tate connection to radiators. Valve is packless with quick opening, non-rising stem and renewable disc seat. Size..................................... 'h- >/.* i' w Cap. Sq. Ft. Rad............... 30 60 100 180 Condensators For returning water of condensation to boiler from open return line systems in dependently of boiler pressure, without change in operating conditions, air bind ing, or admitting steam to return side. Simple in construction, but positive in operation. Its few moving parts are wholly enclosed. Connections are large to eliminate friction and insure an easy and sensitive working apparatus under all conditions. All working parts are of best bronze metal. New B & J Ther mostatic Trap. The interchangable con trol unit contains the thermostatic element, carries its own seat of special alloy and is a com plete operating unit in itself. Cali brated under actual working pressure at the factory and locked in adjustment. Unit easily and quickly replaced without special tools; lift out the old unit and drop a new one in. Size Valve.......................................... Vi' vs r Pounds Water per Hour................... .30 80 200 Sq. Ft. C. 1. Rad............................... 120 320 800 Sq. Ft. Co3s...................................... 100 240 600 Blast Drip Traps, Type BD--For use on Unit Heaters, also drips from supply mains and risers and on returns from water heaters and in direct stacks. Floatcontrolled valve governs discharge of water; thermostatically-controlled valve allows passage of all air but prevents pas sage of steam. Made with 1 in. tappings. Capacity 500 lbs. per hour at l/z lb. pressure. Blast Traps Vent Traps Equipped with float valve to prevent discharge of water, and ball check valve to allow free discharge of air, but pre vent return into system, enabling B. & J. Vapor Systems to operate under vacuum conditions, saving fuel. ymt fmp Combination float and thermostatic traps with an air and water capacity -large enough to take care of the condensation from the largest vento stacks, dry kiln- coils, hot .water heaters and other units condensing large quantities of steam at low pressures. Made in sizes from 1 to 2J<j in. Capacities to 5,000 lbs. of water per hour. 596 739 / Specialties, Heating Armstrong Machine Works 851 Maple Street Three Rivers, Mich. . District Sales Offices in 42 Cities Exclusive Manufacturers of Armstrong Inverted-Bucket Steam Traps A Specialized Product--For more than twenty years, the Armstrong M achine Works hasconcentrated on the design, manufacture and applica tion of inverted bucket-steam traps. This specialization has resulted in a trap that will adequately meet any operating requirement and a sales and service organization competent to handle any steam trap problem. -Simplicity--The Armstrong Steam Trap has only two moving parts--the valve lever assembly and the inverted bucket. Friction is practically eliminated in .this mechanism. All wearing parts are made from nickel chrome steel except the dis charge valve and seat which are made from binding is impossible because the air passes out. of the bucket ahead of the steam through the vent at the top. When the trap is discharging, the flow .of water under the bottom of the bucket prevents the accu mulation of any dirt or sediment. The "Blast" Type Trap^--For fast handling of large quantities of air, the standard Armstrong trap can easily be furnished-as a "blast" type trap by the use of a thermic bucket. The air handling capacity of this bucket is approximately 100 times as great as with the regular air vent. As long as the trap is cold a large vent in the top of. this bucket remains open, and it is impossible for the bucket to a special chrome steel heat float and close the valve with treated after machining to RCGUL AR AIR VENT obtain maximum hardness this vent open. As soon as the air has been eliminated and toughness. Many, years and steam comes to the trap, of service without main the heat bends the strip of tenance expense is the cus thermic mftal supporting a tomary experience of Arm flat disc which closes fhe strong trap users. - Large Capacity--Dis \BUCKET , large vent. Thereafter, the trap functions in the normal charge orifices used in Arm strong traps are very large in manner. This thermic bucket Thermic Bucket in "Blast" Trap ' can be supplied in any size proportion to the size of the Armstrong/ trap. The table pipe connections. . on the following page gives Armstrong trap capacity the prices for traps so equip ratings are not theoretical ped. . but show actual test capaci Service Organization-- ties when handling condens- ate at steam temperature. The effect of flash steam and pipe friction to and from the trap is thus automatically taken into consideration.-(See chart). Avoid Steam Trap The satisfactory operation of all Armstrong traps is as sured by 42 district repre sentatives in the United States and Canada. Stocks of these traps are carried in nearly 100 leading cities. Troubles--The customary We will gladly put you in troubles with steam traps are leaky valves, air-binding and plugging up with dirt or oil. The intermittent action of this trap and the metal used in the valves stop, scoring and wire-drawing, the common sources of leakage.. Air Cross Section of Trap Showing Regular Air Vent in Top of Bucket touch with your nearest representative. The Armstrong Trap Book gives very complete infor mation on trap selection, installation and maintenance. Write for your copy. 740 Armstrong Machine Works Specialties, Heating Sizes, Capacities and List Prices of Armstrong Traps Trap Size No. 200 and 201 No. 211 No. 212 No. 213 No. 214 No. 215 No. 216 Pipe Connections.............................. List Fnce (Kegular)......................... -List Price (Blast Trap).................... Telegraph Code (Regular)............... Telegraph Code (Blast Trap).......... Height................. .'............................ Diameter............... ........................... Weight.......................... :................... Maximum Pressure........................... Vi' $7.00 $8.50 fAcacia (Acanthus lAcacette 4' w 3'/. Lb. 125 Vi' $9.25 $10.75 Aspen Aspette <%" w 5Vi Lb. 200 . Vf $15.00 $17.00 Birch Birette 8* y IO>/2 Lb. 200 Vi' or >/,' $20.75 $22.75 Walnut 1* $29.00 $31.50 Hemlock Walette loy,- 19 Lb. 250 Hemlette 12Vi' 7Vi' 32 Lb. 250 I" or 1 vs 1 Vj' or 2' $38.00 $'55.00 $40.50 $60.00 Larch Tamarack Larette 14' 8'h" 47 Lb. 250 Tamrette 163/,' I0J6'. 76 Lb. 250 accompanying chart are Actual Continuous Discharge .capacities.. To be efficient, the trap must remove the water as it forms, which may be at a m uch higher rate than . the average. There fore it is good prac tice to. allow a factor of safety of at least two in all steam trap applications. Four conditions may tend to increase the neces sary factor of safety for any particular in stallation, (1) an ex cessive amount of air, (2) wide variations in rate of condensation, (3) variable steam supply pressure, and (4) variable back pres sure in the return line. Many common combinations of these conditions call for the use of a factor of safety as large as six or eight. 0 to 15 19 S 39 40' SO C ro so so loo t IS ISO IDO zso Below--Rate of Con densation in Bare Room Temperature. o s 10 is 29 IS 30 40 SiS CO 70 SO SO 100 IS ISO 200 ISO Gauge Temperature Pressure . Difference Pounds Degrees F. 5 . 153 50 223 100 263 150 291 200 313 ' Pounds of Water per Hour per Linear Foot Pipe Sizes in Inches l 'h 2 3 4 5 6 8 10 12 .16 .21 .25 0.30 0.45 0.54 0.64 0.82 1.01 1.19 -.28 .'38 .45 0.63 0.79 0.97 1.14 1.47 1.80 2.13 .36~ .41 .59 0.84 1.05 1.28 1.51 1.94 2.39 2.82 .43 .59 .71 1.00 1.26 1.54 1.82 2.35 2.89 3.40 .50 .68 .81 1.16 1.45 1.74 2.09 2.69 3.30 3.91 741 Flat Surface or Larger Pipe Per Sq..Foot 0.34 0.62 0.82 . 0.99 1.14 Specialties,' Heating G. A. Dunham Company Administrative and General Offices 450 E. Ohio Street, Chicago, 111. Factories: Marshalltown, Iowa; Michigan City, Ind.; Toronto, Canada SALES OFFICES Akron, Ohio Albany, N. Y. Allentown, Pa. Atlanta, Ga. Baltimore, Md. Bangor, Mb. Birmingham, Ala: Boston, Mass. Buffalo. N. Y. Charlotte, N. C. Chattanooga, Tenn. Cincinnati, Ohio Chicago, 111. Clarksburg, W. Va. Cleveland, Ohio Dallas, Texas Davenport, Iowa Denver, Colo. Des Moines, Iowa Detroit, Mich. Duluth, Minn. El Paso, Texas Grand Rapids, Mich. Greenville, S. C. Harrisburg, Pa. Houston, Texas Huntington, W. Va. Indianapolis, Ind. Johnstown, Pa. Joliet, III. Kalispell, Mont. Kansas Cm, Mo. Kingston, Pa. Little Rock,' Ark. C. A. Dunham Co., Ltd., 1523 Davenport Road. Toronto, Ont., Canada Los Angeles, Calip. Louisville, Kt. Madison, Wis. Memphis, Tenn. Milwaukee, Wis. Minneapolis, Minn. Newark, N. J. New Haven, Conn. New Orleans. La. New York, N. Y. Oklahoma City, Okla. Omaha, Nebr. Philadelphia, Pa. Pittsburgh, Pa. Plattsburgh, N. Y. Portland, Ore. Poughkeepsie, N. Y. Providence, R. I. Pueblo, Colo. Richmond, Va. Rochester, N. Y. St. Louis, Mo. Salt Lake Cm, Utah San Antonio, Texas San Francisco, CalipI Seattle, Wash. Spokane, Wash. Springfield, Mass. Syracuse, N. Y. Tampa. Fla. Toledo, Ohio Trenton, N. J. Washington, D. C. Wichita, Kan. C. A. Dunham Co., Ltd., (of the United Kingdom) 18 St. Thomas St., S.E., London Over eighty sales offices in the United States, Canada and the United Kingdom bring Dunham Heating Service as close to you as your telephone. These representatives are available for engineering counsel in correct selection of Dunham Systems and Appliances for any type of building. The accumulated experience of the entire Dunham organiza tion is put at the disposal of the Heating and Ventilating Engineer. This cooperation is available for Modernization Work, as well as for new construction in industrial, com mercial and other projects. DUNHAM DIFFERENTIAL VACUUM HEATING ' The advantages of the Sub-Atmospheric principle which govern stealm distribution in Dunham Differential Vacuum Heating Systems are utilized in three different applications: 1. The Dunham Differential Vacuum Heating System for High Duty--This is a two-pipe system giving excellent room temperature control and air conditions. The pressure, the temperature and the volume of steam in circulation are varied under a control which is a normal function of system operation. The wide range over which the vacuum and quantity of steam in the radiators is regulated (from atmosphere to twenty-five inches) establishes correct rates of heat emission with radiators either complete or partially filled as required. A continuous valuation of heat requirements under positive temperature control may be secured through nine thermostats in a building, or zone of a building. 2. The Dunham Differential Vacuum Heating System for Low Duty--The design of this system embraces equipment of the same general type as used in the High Duty System. Its fuel economy closely.approaches that system but it does not claim the same preciseness of temperature control as characterizes the High Duty System. However, the principal of control is the same as in that system; the radiator tem peratures are varied and radiators may be either completely or partially filled; the vacuum, however, is limited to fifteen inches. The Low Duty System can be very 742 C. A. Dunham Company Specialties, Heating effectively related to existing buildings in changing over ordinary vacuum return line systems to differential operation. One or more thermostats may be used with a Low Duty System. 3. The Dunham One-Pipe Vacuum Heating System with Sub-Atmospheric Steam in which the range of steam temperatures and pressures is ample to give great flexibility of operation in the lower range of vacuums. This System is designed primarily to enable owners of existing one-pipe systems to obtain the benefits of the Dunham Differential Vacuum principle of operation by rearranging the system to operate on that principle. The change-over can be made without extensive cutting of floors or walls. Systems having air lines will usually require no such cutting. " DV" Series for Dunham Differential Vacuum Heating Sgsteme " VR" Series for Vacuum Return Line Heating Service '"PHIS line of pumps is characterized by an entirely new and improved Vacuum Produ* cing Element of exceptional quietness and high efficiency; by a Discharge Valve which is rugged and reliable and by a new Control Equipment Mounting. These, with other refinements, result in an outstanding piece of equipment. These Pumps are built in eleven sizes, ranging from capacity of 2,500 to 150,000 sq. ft. of radiation inclusive. They meet the requirements of the Vacuum Return Line Heating Pump Manufacturer's Section of the Hydraulic Institute. . Specialties, Healing D. G. C. Trap and Valve Company, Inc. 9 East 46 Street New York Plaza 3-3790 Makers of Cryer Radiator Control Valves, Radiator Traps and Steam Traps Complete Vapor Heating Systems Distributors in All Principal Cities Cryer Radiator Control Valve A Control Valve which gives to steam heating systems the same operating economies, and the same medium temperatures in the radiator afforded by hot water heating systems. The Cryer Control Valve mixes the steam with air already in the radiator, and circulates this humid mixture of air and steam through all sections of the radiator. The temperature of the whole radiator may be varied at will from the low temperatures usual only with hot water, to the full steam effect. % Cryer Radiator Trap , A Thermostatic Radiator. Trap constructed to endure as well as to operate efficiently. The * bellows is made of a special bronze alloy, the seat of stainless steel, the spud, nut and cap are bronze forgings, and the body is a heavy bronze casting. Made to standard dimensions. . Suitable for low pressure, vacuum or vapor . heating. Cryer Condensation Trap A heavy duty Condensation trap for Unit Heaters, Ventilating Stacks, Hot Water Heaters and other large units. Compact design, smalt enough to be used anywhere, but of large ca pacity. Cannot air-bind. The Cryer Condensation Trap is of the unat tached ball float type, with a thermostatic air by-pass. The valve seats are stainless steel, the float seamless copper nickel-plated, the bellows of bronze alloy, and the body of heavy cast-iron. The pressure limit is 10 lbs. Catalogues on Request 744 Specialties, Heating GRINNELL COMPANY. Heating, Industrial and Power Plant Piping, Fittings, Hangers, Valves, Pipe Bending, Welding, Piping Supplies, Etc. Executive Offices:: Providence, R. I. National Distributors of ThermoflerTraps and Heating Specialties For data on other Grinnell Products, see pages 700-703 Thermoflex Specialties Thermoflex High Pressure Traps The heart of all Thermoflex Traps is the Hydron Bellows. The Hydron Bellows is formed under hydraulic pressure. This powerful internal pressure locates any weakness of any nature in the tubing. Such hydraulic pres sure is many times more severe than any pressure the Trap will ever be called upon to control. Every Thermoflex Trap, there fore, is practically indestructible. Thermoflex Traps have an exceptionally large orifice. This large orifice combined with high lift, insures fast action and freedom from clogging. We supply Thermoflex Traps guaran teed for steam pressures up to 25 lb. and to 125 lb. Complete information and details of typical installations will be gladly sent on your request. Ask for Data Book 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. 100 Thermoflex Trap-is guar anteed for steam pressures from 25-125 lb. Must not be used where the steam temperature exceeds 400 deg. FaKr. 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 in com parison to the usual float or bucket trap. 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 the best bellows ever made. Because of the Hydron-forming process every bellows is absolutely perfect. Body is heavy bronze construction throughout. Fully nickel-plated with highly, polished trimmings. The No. 12 is made in angle and in comer patterns, with Y in. inlet and % in. outlet tappings'."The inlet neck is double thick to allow for expansion strains. Guaranteed for steam pressures up to 25 lb. For dripping, mains, risers, coilsaridunit heaters, we offer this type of trap-: Cast iron body, bronze cap and inserted re newable bronze seat, angle pattern only, without unions. Can be used for any general purpose where a finished, nickel- plated trap is not necessary, and at a lower cost. Guaranteed for steam pres sures up to 25 lb. . 745 Specialties, Heating Hoffman Specialty Go., Inc. Main Office and Factory, Waterbury, Conn. General Sales Department, Chrysler Building, New York Sales Representatives in Principal Cities VENTING VALVES FOR ONE-PIPE STEAM SYSTEMS No. 70--Airport--Is an efficient, low cost air valve--made and guaranteed by Hoff man. Radiator con nection in. No. 71--Air port--rSame as the No. 70, except with straight shank H in. connec tion for venting certain types of c o nce a 1e d radiators. No. 1--Hoffman Siphon Air Valve --The "perfect" venting valve, with patented, double shell construction. Angle pattern only. Radiator connection M n. No. 44 No. 44--Quick Vent Valve--For venting mains, risers, coils, etc., where water is not encountered. Vent port--in. Connection 1 in.\ female. Where water \ is liable to be a factor use No. 5 Float Vent. Connection H in. Vent port in. or on order, % in. for pres sures below 3 lbs. ' No. 71 Maximum Guaranteed Operating Pressure--10 Lbs. No. 5 VENTING VALVES FOR ONE-PIPE VACUUM SYSTEMS No. 78 No. 77--Vacu um Air Valve --With double air locks, con sisting of air check and vacu um diaphragm, selling in - the lower price field. Angle pattern, H in. connec tion. No. 18 No. 78--18 the same as the No. 77 except with in. straight shank connec tion for venting certain types of concealed radi ators. No. 2--Hoffman Siphon Air and Vacuum Valve-- Air is freely vented without steam or water loss. The double "airlock"-- air check and power ful vacuum dia phragm--prevents return of air. Angle pattern only. Radi ator connection V6 in. No. 16--Vacuum Vent--For venting risers, coils or mains, that end 18 in. or more above boiler water line. Vent, port, in. Connec tion % in. Where mains end less than 18 in. above water line, use No. 6 Vacu um Float Vent. No. 6 connection $< in. Vent port & in. (standard) or % in. on order for pressures below 3 lbs. Maximum Guaranteed Operating Pressure--10 Lbs. 746 No. 6 Hoffman Specialty Co., Inc. Specialties, Heating MODULATING AND PACKLESS SUPPLY VALVES The No. 7 Hoffman Adjustable Modulating Valve--For use in Vapor, Vapor Vacuum or Forced Hot Water Systems, is made in 54 in. size, angle or swivel pattern, having a range of adjustment up to 200 sq. ft. of direct cast-iron radiation. After installation, whether the system is in operation or cold, the port of each valve is adjusted for size of the radiator to which it is attached. Adjustment is simple; loosen a locknut; turn valve handle until proper graduation is opposite notch on bonnet; then'tighten locknut. The valve handle may then be moved to admit sufficient steam to heat a quarter, half, three-quarter, or entire radiator. The valve steam stuffing box .has a frictionless metallic fibre packing that will last indefinitely and require no attention, giving at the same time, a valve action so free that the pressure of only one finger is required to open the valve. . The No. 7 Hoffman Modulating Valve provides a most convenient and accurate method of obtaining balanced distribution throughout vapor or vacuum systems and control of the output of each heating unit. The visible adjustment aids the designing engineer by enabling heating contractor to make a final accurate adjust ment which compensates for slight irregularities in pipe sizes, failure to ream pipe, installation of extra fittings not foreseen in original layout, etc. The advantages of an adjustable port in forced hot water systems to secure proper balance makes the ' No. 7 Valve especially adaptable for such use. N<i. 7 Swivel Connection No. 37--Bellows Packless Valves are used on one- or twopipe systems. The durable, leak-proof bellows is hydraulically formed and eliminates steam or water leakage and leakage of air into vacuum systems. There is no torsional strain on bellows, as flat-sided stem operates thru key in bonnet. ,An attractive hexagonal Bakelite handle is standard on all sizes, or the l/z, 54 and 1 in. sizes can be equipped with lever handles at no extra charge. Angle pattern (standard) all sizes--)4 in. to 1)4 m. Swivel connections for )4 and 54 in. valves at slight extra cost. Adjustable orifice plates available for 54 in. size only. SPECIAL ATTACHMENTS FOR NOS. 7 AND 37 VALVES Bevel Gear for Noe. 7 and 87 "'-Offtet Extended Noa 7 and 87 Straight Stems Noa. 7 and 87 747 Chain Puli for No. 7 only Lock Shield for Noa. 7 and 87 Hoffman Specialty Co., Inc. Specialties, Healing BELLOWS TYPE THERMOSTATIC TRAPS The No. 17-A Radiator Trap has a hydraulically formed bellows thermostat attached to cap. Hydraulic forming process automatically places severe pressure test on bellows. Valve pin is of special nickel-silver alloy. Capacity, 200 sq. ft. direct radiation. Valve port, % in. Maximum guaranteed operating pressure. 15 lbs. Angle pattern or with swivel connection. Connections in. The No. 18-A Radiator Trap is also equipped with the " tested-in-the-making" hydraulically formed bellows. Thermal members are interchangeable in all No. 18-A bodies without adjustment. Valve port, z/% in. Nominal capacity at pressures below 1 lb.--300 sq. ft. direct radia tion. Angle pattern with % in. connections standard. Also furnished with % in. outlet and with swivel con nection. Maximum guaranteed operating pressure, 25 lbs. A novel feature of the No. 8-A Radiator Trap is the combination of all vital parts--bellows, valve pin and valve seat, into a single unit which threads into the body and the joint is sealed by a soft copper gasket. The valve pin and renewable seat is of a special wearresisting nickel-silver alloy. Valve port, % in. Nominal capacity at pressures below 1 lb.--300 sq. ft. direct radiation. Angle pattern with ' * ` nections standard. Also " furnished with % in. out let and with swivel conMaximum guaranteed operating 25 lbs. or 50 lbs. on special No. 9-A is similar to the No. 8-A in con struction, except with in. inlet and out let connections. Furnished in angle pat tern only, with or without union connec tion. Valve port, in. Nominal capa city at pressures below 1 lb.--700 sq. ft. direct radiation. Maximum guaran teed operating pressure, 25 lbs. or 50 lbs. on special order. The swivel connec tion provides straight way, right or left hand offset or any interme diate angle. The fitting is reversible, giving the option of two roughingin dimensions. "8* iU_A The No. 10-A is a heavy duty thermostatic trap for dripping unit heaters, short steam mains, risers, etc., where a cooling leg (for temperature drop) can be installed. The bellows thermal member is water-filled to enable it to withstand severe service, and is interchangeable in No. 10-A bodies without adjustment. Nominal capacity, 2800 sq. ft. direct radiation. Valve port, in. Iron body--angle pattern--without union. Maximum guaranteed operating pressure, 25 lbs. Connections 1 in. The Nos. 20 and 21 Thermostatic Steam Traps operate on pressures from 0 to 100 lbs. without change or adjustment. Bodies are all bronze with integral strainer. The hydraulically formed bellows is water-filled to better withstand the shocks usually encountered in high pressure' service. Thermal members inter changeable without adjustment. Valve pin and renewable seat is of special nickel-silver alloy. No. 20--Yi in. connections--in valve port. No. 21--% in. connections--% in valve port. . . 748 Nos. 0 and tt Hoffman Specialty Co., Inc. Specialties, Heating No. 4 FLOAT AND THERMOSTATIC TRAPS The No. 24 Drip Trap (float and thermostatic) is used for draining risers, short steam mains, unit heaters, etc. Weighing only 4% lbs., it has a capacity of 780 lbs. of condensate per hour at 1 lb. pressure difference. The combination of large capacity, light weight and compactness is made possible by its balanced, double-seated valve assembly, which permits the use of a direct acting float. Iron body, with % in. or lj^ in. connections. Maximum guaranteed operating pressure, 15 lbs. The principle of the balanced, double-seated valve assembly, with direct acting float, is also used in the Heavy Duty Float and Thermo static Traps Nos. 25 to 28. The smaller trap has a capacity of 2250 lbs. of condensate per hour at 1 lb. pressure difference and is furnished with 1 in. connections (No. 25) or 1 in. connections (No. 26). The No. 27--1J- in. and 28--2 in. traps have a capacity of 3090 lbs. of condensate at 1 lb. pressure difference. These traps are used for draining mains, hot-water generators-and other large capacity units where the operating steam pressure does not exceed 30 lbs. Nos. 5, 6, 7 and 8 HOFFMAN "CONTROLLED HEAT" EQUIPMENT WITH DIFFERENTIAL LOOP Hoffman "Controlled Heat" is a two-pipe vapor-vacuum system of heating, using the No. 7 Adjustable Orifice Modulating Valves for balancing the distribution of steam and controlling the radiator output. Hoffman traps are used at the return end of the radiators. Where hard coal is used as fuel and the installation does not require a normal operating pres sure in excess of eight ounces, the Differential Loop equip ment is recommended. The Loop is a non-mechanical device which insures the .return of condensate to the boiler should the pressure exceed that at which it will return by gravity. ./ Damper Regulator The No. 15 Valve is used only in conjunction with the Differential Loop and functions to relieve the air from the entire system and prevent its return. \. The No. 13 Damper Regulator is extremely sensitive in con trolling the drafts to meet slight changes in the demand for steam. A compensating plate prevents the accumulation of water on the diaphragm when it is depressed, maintaining perfect balance at all times. Connection, 1 in. The No. 14-A Kompo Gage measures pressure up to 30 lbs., vacuum to 30 inches. The pressure side is graduated in ounces up tO 5 lbs. and vacuum is shown in half-inch graduations up to 10 inches. Connection in. 749 Kompo Gage Hofman Specialty Co., Inc. Specialties, Heating HOFFMAN "CONTROLLED HEAT" EQUIPMENT WITH BOILER RETURN TRAP For Hoffman "Controlled Heat" installations fired with oil or gas burners, or soft coal, where pressures are generally built up quickly, or where Unit Heaters or other devices requiring a constant pressure in excess of 8 ounces, are used, we recommend the Hoffman Boiler Return Trap equipment. At low pressures, water returns by gravity to the boiler but when the pressure exceeds this point, the Boiler Return Trap functions to maintain the prompt return of condensate to the Boiler. The balanced, double-seated valve mechanism opens quickly when the high water level of the trap is reached, allowing rapid equalizing of pressures. Air is freely vented thru the Receiver Vent but is not per mitted to return to the system thru the valve. Boiler Return Traps and Receiver Vents are made in four sizes of the following capacities: No. 30--2000 sq. ft. No. 31--2900 sq. ft. No. 32--5300. sq. ft. No. 33--8000 sq. ft. These capacities are based on a condensation rate of lb. per sq. ft. of radiation per hour and one operation of the trap per minute. * The sketch below shows the general piping arrangement where the Boiler Return Trap and Receiver Vent fire installed. ^ The Receiver Vent provides ample Receiver Vent ' storage capacity for the condensate ' which accumulates during the period that the Trap is discharg ing to boiler and prevents temporary flooding of1 the dry re turns. Minimum differential between the boiler water line and low end of dry return is therefore required. Operation of the Return Trap is noiseless as all working parts are enclosed and the balanced valve construction permits- the use of light counter-weights. Interior parts are made of Beiler Return Trap non-corrosive materials. Detailed literature-, supplied on application. TYPICAL LAYOUT USING BOILER RETURN TRAP EQUIPMENT HOFFMAN RADIATORVALVE:- HOFFMAN THERMOSTATIC TRAP. ------- - V DRY RETURN MAIN. HOFFMANBOHIRRETUBNlllAR-. //--HnOuFrFrMnnANjiKRuEC.uEIiVLEnR VENT // HOFFMAN THEJDU35TATIC VWATIR UNE (YAIYES. PRESSURE RETURN. TYPICAL HOFFMAN CONTROLLE D HEAT SYSTEM USING BOILER RETURN TRAP ANQ HAVING PRESSURE RETURN. 750 Size Rating B.R. Sq. Ft. A.* B. D. Trap. Rad. N. 30 . 2000 31 2900 32 5300 33 8000 19* 7' 4' 22' 9* A1/?* 24' 10* 9' 26' M' 9' 'Minimum to Bottom of Pipe. Hofman Specialty Co., Inc. Specialties, Heating HOFFMAN-ECONOMY PUMPS Vacuum.Pumps--The Jet-Type Vacuum Producer enables this pump to deliver full rated capacity in extremely hot-water. There are no moving parts with close clearances. Single pump consists of one vacuum producer, centrifugal pump, cast-iron receiver and accumulator tank, automatic boiler feed control, motor and full automatic starting equipment, mounted complete. Duplex units consist of a single cast-iron tank, with two vacuum producers, two pumps, two motors, each pump and motor furnished with full auto matic control. Standard pumps made in pressure of discharge range of 20--30 and 40 pounds. Capacities 2500 to 300,000 sq. ft. cast-iron radiation. Single Vacuum Pump Type E Condensation Pump is a compact unit shipped ready for installation. It consists of pump, motor, cast-iron tank with all necessary tank trimmings for auto matic controt. Pump is of close coupled type with impeller securely mounted on the motor shaft extension. These pumps give full capacity at 1750 r.p.m. and improved per formance makes possible the use of comparatively small motors with consequent low consumption of electricity. Capacities, 1,000 to 20,000 sq. ft. cast-iron radiation. Type B Pump Discharge pressure for standard pumps 10--20--30 pounds. Discharge pressure up to 60 pounds can be furnished. Type B & C Condensation Units consist of pump, motor, steel tank and tank trimmings assembled on a single cast-iron base. The pump is direct connected to the motor through a flexible coupling. The pumping unit is of the multi-stage type and so constructed that access may be had to impeller and other interior parts without breaking the piping connections. Receiver is of heavy gauge welded steel securely attached to cast- iron feet by anchor bolts welded to the shell. Capaci ties range from 6,000 to 70,000 sq. ft. of cast-iron radiation, with discharge pressure up to 175 lbs. duplex or single units can be furnished. Type B and C Pumps Vertical Type Vertical Underground Pumps and-Receivers are designed for use on heating plants where the returns are locdted below basement floor levels, or otherwise too low for horizontal condensation pumps. The receiver is of heavy cast-iron suitable for underground use without danger of corrosion, making a cement lined pit unnecessary. The pumps are of vertical bronze fitted centrifugal type suspended from the receiver cover and bearings may be renewed without removing impeller from shaft or shaft from pump. A flexible coupling connects motor to pump shaft. Shaft is protected from bearing wear by a re movable sleeve. Receiver is equipped with float switch for automatic control of motor, this control being removable without disturbing pump or pipe connections. Duplex Units with two pumps and motors mounted in a single receiver of larger size can be furnished if desired. Capacities, 3000 to 30,000 sq. ft. of cast-iron radiation with discharge pressures ranging from 16 to 100 lbs. - The Reciprocating Pump and Receiver is recom mended where high pressures of from 50 to 100 lbs. are met and moderately priced equipment is desired. These pumps operate on less power than required for centrifugal pumps, but are not as quiet, due to a slight pulsation at the end of each stroke and slight hum of the chain drive. As the pumps are usually installed in Laundries, Drying Plants or other industrial establishments, the slight noise is not objectionable. Receivers are of welded steel equip ped with automatic float control. Capacities 1,000 to 10,000 sq. ft. Discharge pressures 50 to 150 pounds. 751 Reciprocating Pumps Specialties, Heating William S. Haines & Company 12th and Buttonwood Sts., Philadelphia, Pa. Manufacturers of Equipment for Vapor and Vacuum Heating Systems Haines Radiator Traps. Haines Medium Pressure Thermostatic Traps. Haines High Pressure Thermostatic Traps. Haines Float and Thermostatic Blast Traps. Haines Vent Traps. Haines Modulating Valves. . Haines Boiler Return Trap. All Haines traps, whether:designed for pressures below atmosphere or pressures in excess of 100 lbs. per sq.'in., employ as their operating member a specially constructed bourdon tube--the principle that actuates the steam gauge. , The tube is of tempered steel. It is charged with a vplatile fluid and hermetically sealed. It is the expansion and contraction of the fluid, under varying temperatures, that furnishes the operating power. . The tube is mounted vertically on a horizontal valve motion. The end opposite tffe valve is anchored so that the travel of the tube either opens or closes the valve piece. The thermostatic member is outboard the valve seat and closes the valve against the flow of steam. This arrangement prevents fouling of the trap due to scale or other foreign matter and permits a thorough draining of the unit to which it is attached. Haines thermostatic traps are made in sizes from Yi in. to 1J4 in. All traps are factory tested and'adjusted before shipment. Haines modu lating valves never need re packing. They seat tightly and open on less than a full turn of the lever or wheel handle. Made in sizes from Yi to 2 in. in angle, globe, or corner pattern. HAINES VENTO TRAPS No. of Trap Center to ' Inlet Center to ' Outlet Capacity Sq. Ft. 1 2 2E 3 3E . 2W 31// W 3Ve 3%' I\1Xxwr/ i\wr. 125 200 250 400 500 HAINES MODULATING VALVES Size of Valve Center ' ' to Inlet Center to Outlet 1/2* VS 1' 11// ivy V 1 x/: w IH' \%r 2>' 2>/y 2i/y m* y 3s/y w *%' 752 Specialties, Heating Illinois Engineering Company General Offices and Factory: Chicago Branches and Representatives in Principal Cities Illinois Thermo Radiator Trap The Original Vertical Seat Trap. Self clean ing, non-adjustI able. Positive I and sensitive in operation. Thousands in Series T use for over fifteen years without diaphragm replacements. Fur nished in all sizes and patterns. Illinois Modulating Supply Valve Quick-opening, packless. Steam tight on 50 pounds 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 Blast Traps Series 8G Unsurpassed for draining ventilating units, unit heaters, and for dripping mains and risers-- wherever it is desira ble quickly to vent air from the main as well as handle the water of condensation in quantity, whether hot or cold. 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. Will withstand 75 pounds steam pressure without damage although only low pres sure service are required of them. . . Made in three sizes from 3^-in. to 2-in., in a variety of patterns. Furnished in either plain or nickel plated finish. Illinois Steam Trap Valve and stem are separate from the bucket and operated only by the bucket at the ex treme top and bottom of travel-- result--valve is always oe. ics ou either full op. en or t.igh t. closed. No wire drawing or cutting of valve and seat which are of Monel metal. Steam tight and long lasting. Illinois Thermal-Zone Control Prevents over heating and fuel waste in large buildings or groups of buildings heated from one central power plant. Buildings may be zoned as to occupancy, time, location, exposure and -so on. In many installations this valve has paid for itself in one heating season. Illinois Reducing Valve In general use on vacuum or low pres sure heating systems. Will reduce to 4 oz. pressure from an in itial pressure of 150 lbs. The large diaphragm insures sensitive opera tion. Made in both straightway and ex panded outlet bodies in sizes from % in. to 12 in. 753 Specialties, Heating Kieley & Mueller, Inc. ' Established 1879 Engineering Specialties for Pressure and Level Control 34 West 13th Street, New York, N. Y. . Factory: NEWARK, N. J. Agents in All Principal Cities PRODUCTS--Valves: Altitude, Stop and Check, Pressure Regulating, Float, Pilot Reducing, Back Pressure, Tank Control. Liquid Level Controllers, Pump Governors, Steam Traps, 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 200 lbs. and reduced pressures from 14 lb. to three-quarters of the initial pressure. Single or double seated in sizes %" to 16". Suitable for steam, water, air, oil and gas. Controlled 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 lbs. to 25 lbs. Made horizontal, or verti cal lever and weight or spring operated. Water Feeder Automatically maintains water level in low pressure steam boilers, receiv ing tanks, feed water heaters, etc. Will hold water level with little or no fluc tuation. For working steam pressure up to 50 lbs.; and water pressures up to 100 lbs. 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. 754 Specialties, Heating J. E. Lonergan Co. 207 Florist Street, Philadelphia, Pa. Pop Safety Valves; Relief Valves; Steam Gauges; Hydraulic Gauges; Air Gauges; Water Gauges; Pressure and Temperature Gauges; Test Gauges; Gauge Boards; Oil Gauges; Clocks; Counters; Gauge Cocks; Steam Gauge Syphons; Lubricating Specialties. Model "ORV" Oil Relief Valve. Sizes % to 2 in. Model "HHU" Pop Safety Valve A.S.M.E. ``House Heating Boiler." Standard pres sures, 5. 10 and 15 lb. Model "WRV" Model "VAK" Water Relief Special valve for Valve for tank vacuum breaking. service. Six sizes, 14 to Sizes 14, 14 and 2 in. 14 in. Model "GLP" Low pressure, Iron Body, Brass Mounted. Set to blow off at 10, 15, 20, 25. or 30 lb. Five sizes-2 J4 to 414 in. Model "U" Relief Valve. Snifter, Water or Cylinder-- Bronze. Recommend ed for steam en gines, pumps, pipe lines, etc. Ten sizes, 14 to 4 in. CATALOGUE Write for our new 100-page cata logue, describing and illustratingthe complete ``Lonergan Line" or ask us about specialties in which you are interested. Model "GV" Vacuum Gauge. Gauges graduated to 30 in. vacuum. Ten sizes, 214 to 10 in. dial. Model "GOZ" Vapor Gauge. Graudated to 5 lb. by ounces. Two sizes, 414 and 5 in. dial. Model "BLGB" Tank in basement type of gauge for closed heating systems. Made in two- and three-story calibrations only. One size, 314 in. dial. 755 Gauge for indicat ing height of water in feet. Graduation 70 ft. Three sizes, 314, 4}4 and 5 in dial. Model "BLGW" For 'either pressure or .altitude, or com bination of both. ' Graduation 30 lb., 70 ft. . Two sizes, 314 and 4J4 in. dial. Model "BLGA" Pressed steel case gauge for indicating height of water in feet. Graduation 70 ft. Three sizes, 314, 414 and 5 in. dial. 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 No. 11--For Vacuum, Vapor and Low Pressure Heating Systems. Initial Pressures, up to 200 lb.; Reduced Pressures, 0 to 10 lb. No. 17 and 21--For automatic control of reduced pressures on dead-end service, requiring a tight closing valve, such as tank heaters, kitchen utensils, sterilizing ap paratus, laundry equipment, kettles, cookers, driers, etc. Initial Pressures up to 200 lb. Reduced Pressures 0 to 150 lb. Constructed with full globe bodies. Center guide eliminates the wings on discs, and increases efficiency, assures minimum noise and prolongs the life of the seats and discs. Lever and weight operates on a steel roller bolt, assuring a most sensitive valve. Spring type furnished with special long springs for sensitive operation and wide ranges of reduced pressures. . Automatic Water Feeders With a powerful leverage to control the water line in steam boilers, etc. They supply make up water to compensate for evaporation, leaks, steam utilized in process work and condensation wasted. Where condensation held up in the system eventually returns in large quantities, our Duplex type protects the boiler against flooding. All working parts of non-corrosive metal, are accessible without breaking pipe connections. Provided with an integral strainer. For steam pressures up to 100 lb., water pressures up to 1201b. Steam Traps Simple, Sturdy and Compact Ball Float and Open Bucket Steam Traps for draining water of condensation from steam appa ratus and steam mains. Powerful leverage enables them to take care of large quantities of condensation. Equipped with strainer, water gages, air cocks, blow off and integral by-pass valve, when desired. Atl working parts are ac cessible without disturbing any pipes. Ball Float No. SI9---Up to SO lb. No. 221--Up to 150 lb Valves are sealed with sev eral inches of water, making the escape of steam impossible. No. 229--Up to SO lb. No. 231--UP to 150 lb. No. 233--Up to 260 lb. Sizes from % to 3 inches. Catalogue and Bulletins covering our Complete Line gladly furnished on application. 756 Specialties, Heating New York Air Valve Corporation 476-478 Broome Street New York THE "AIR-OUT" LINE SYPHON THERMOSTATIC NON-ADJUSTABLE ` `Air-Out " valves, for eliminating air from steam radiators, operate by the expansion of a phosphor bronze diaphragm, soldered on the bottom of a brass float, containing a volatile liquid. This float is large in size, allowing ample capacity for the necessary pressure to operate the diaphragm. . The seating pin at the top of float is made from nickel silver, as called for in United States Government specifications for Air Valves. Verdigris will not form on nickel silver--corrosion at the vent port is therefore reduced to a minimum. We are making the "Air-Out" in a special straight Convector Type, for use on copper radiation. Specially adapted and guaran teed to work satisfactorily on one-pipe steam systems. OTHER SPECIALTIES Also made in straight pattern, threaded 14 in., in., and % in. for quick venting of cellar mains and risers.. No. 10 Syphon Non-adjustable Air Valves. No. 476 Syphon, Non-adjustable Air Valves. , Carbon Post Automatic Air Valves. No. 10 Adjustable Floor and Ceiling Plates. -" : Key and Wood Wheel Air .Valves. Steam and Altitude Gauges. i Water Gauges and Pop Safety Valves. "Air-Out " Valves Guaranteed for One Year . 757 y Specialties, Heating Sarco Company, Inc. MANUFACTURERS OF STEAM SPECIALTIES 183 Madison Ave., New York, N. Y. Branches in all Principal Cities SARCO CANADA LIMITED, Federal Bldg., Toronto, Ont. PRODUCTS--Sarco Radiator Traps, Steam Traps, Packless Inlet Valves, Air Eliminators, Alternating Receivers, Float Traps, Temperature Regulators, Self-Cleaning Strainers, Damper Regulators, Pipe Savers, Dial and Recording Thermometers. SARCO RADIATOR TRAPS For vacuum, vapor, and gravity heating systems, pressures up to 25 lbs. Available in angle, right and left offset and straight way patterns. Special features are the flexible bellows, made from a single piece of Type B seamless, helically corrugated bronze tubing of large diameter and heavy wall. Type R Also the self-aligning valve head which assures perfect seating. The valve has a full .J4".li.ft, securin,,g exce.ptionally large capacity. The body is of heavy brass, nickel plated with polished trimmings. ROUGHING-IN DIMENSIONS Type Size Dimensions ABCDE .H E E E wvs . y3yy>////sis'' w 1w\v" s IW 2l''k/,' 2VS r 2VS 2W>/S wws iy' Capacity List Price F G Vacuum Vapor vvvsss w Wws 250. ft. 250 sq. ft. 800 m. ft. 220000 sq.ft. sq.ft. 600 sq.ft. $5.00* 6.00 8.00 1800 m- ft- 1500 sq.ft! 15.00 SARCO BELLOWS-PACKLESS VALVES These valves are of the truly packless, quick-open ing type. The valve stem is sealed to the cap by a flexible bellows made of the same seamless, helically coiled tubing, used in Sarco Traps. No possibility of leak age, binding or sticking--no attention or maintenance. The disc is of high temperature asbestos composition, cone shaped and fully protected. Lever or round handles, or lock shield furnished. Angle, straightway or comer pat terns available. The body is of heavy brass, nickel plated with polished trimmings. 758 Sarco Company, Inc. Specialties, Heating ROUGHING-IN DIMENSIONS Size ABC vvss 2Vt 3 ti i% i%, i% \m 3X Wf iy. twvs VA w* A Dimensions. Inches List Prices D E F H j K L M N Capacities. Feet Direct Radiation Angle Offset or Straightway % % 2V. 2Yf 2<A A vK 2V, 22%* 2K TV- A 2 2 22^'h 2X 22%% 2% y/i 22%% 2% 3K 2Vi 0-25 26-75 75-125 126-200 201-300 *530 6.00 7.50 9.50 12.00 *630 7X0 830 10.50 13.00 Capacities are for use with Vapor Systems. For Vacuum Systems, add 30 per cent. SARCO FT FLOAT AND THERMOSTATIC TRAPS Fordripping ends of mains, risers, stacks, unit heaters, hot water tanks, etc. Have internal thermostatic air by-pass. Made in three sizes, furnished with pipe-connections to 2" as shown below. '\ FT-0, 3A"; FT-0,1"; FT-1,1M"; FT-1,1 W\ FT-2,2' List Prices: $16.00 818.00 $20.00 $22.00 $60.00 SARCO AIR ELIMINATORS For venting air from Vapor Systems at one central point in basement. Has separate check valve to prevent air from entering 7 system when operating below atmospheric pressure. Capacity sufficient to vent air from 15,000 sq. ft. of radiation in 20 minutes. 1' I. P. S. List prices, No. 12 (illustrated) $25,00; No. 5A, for small systems, $9.00. SARCO ALTERNATING RECEIVER For automatically returning condensate to boiler in Vapor Systems.. Insures prompt return of water to boiler under all pressure conditions. SARCO TEMPERATURE REGULATOR A simple, self-contained automatic valve for regulating temperature of water in storage heaters, for room or kiln control.' Made m sizes yi' to 6" for temperatures, 0-300F. Alternating Receiver SARCO STRAINERS Strainers in pipe lines are effective insurance against injury to valves, traps, meters, etc. Suitable for steam,-water and oil lines. Write for Catalog HV-/,5. 759 Specialties, Heating La Crosse* Wis. Sales and Service Offices New York, N. Y................ .............. ........... 122 East 42nd St. Chicago, III........... ............. :............................................. 842 Rush St. Philadelphia, Pa..TM...........................................2006 Chestnut St. Boston Mass.......... Power Equipment Co., 250 Stuart St. San Francisco, Calif....................................... ......1129 Folsom St. Pittsburgh, Pa., . Ventilating Equipment Corp., 1101 Bessemer Bldg. Cleveland, Ohio............. ................................... 2011 Prospect Ave. Detroit, Mich...... .............................. ............8316 Woodward Ave. Milwaukee, Wis............... ........................ .....125 E. Wells St. Los Angeles, Calif................. ....... Room 402; 406 S. Main St. Atlanta, Ga....................................................... 312 Bona Allen Bldg. Minneapolis, Minn......... ........................--722 Plymouth Bldg. Baltimore, Md........... ..10 W. Chase St. New Orleans, La______ 321 Burgundy St. Washington, D. C.......................................... -136 K St. N.E. Portland, Ore........................... ......................... 227 E. Burnside St. St. Louis, Mo., -- 7441 Flora Blvd., Maplewood, St. Louis Co., Mo. Indianapolis, Ind............................................... 208 E. St. Chur St. Also In 45 other cities--please consult your telephone directory Trane Products Unit Heaters The many applications of Trane heat ing, cooling, ventilating, drying, processing and air-conditioning equipment make it impossible to discuss them all here. Because of this we are listing for the con venience of the engineer, the architect, and the contractor a list of available catalogs. Any or all of these catalogs will be sent on request to interested parties: Heating Specialties Trane System of Unit Heating. Unit Heater Data Bulletin. Blast Heating and Special Drying and Processing Applications '\ Bulletin containing complete infor mation on the applications of Trane extended heat transfer surface to (an systems of heating, drying, and process: applications. Complete data. Complete catalog on steam and vacuum heating specialties which includes com plete data on the Trane ; 14-corrugation bellows traps and other specialties. ' Bulletin. on orifice steam heating sys tems for residences and buildings re quiring up to 800 square feet of radiatidn.. Cooling Trane Engineer's Data Book on Codling. How to Figure Trane Cooling Surface Applications. Roughing-in dimensions and data on Trane Cooling. Temperature Control Bulletin describing the Trane Tern- perature Control Valve with remote con trol and balanced pressure for controlling room temperatures. . .. Bulletin describing the Trane Tem perature Control Valve for controlling vat, urn and liquid temperatures on special applications. . Air-Conditioning . The Trane Climate Changer for resi dences--heating and cooling. The- oil and gas burning Climate Changer Data. The Steam Climate Changer Data. Also; air-conditioning data for all types of buildings. . Ventilation Convection Heaters ' Colo/ Bulletin containing complete story of Trane Convection Heaters. - Technical Data on Trane Convection Heaters. . The Trane Air-o-lizer a complete heat ing, ventilating and temperature control unit for schoolroom ventilation. Pumps Trane Small Centrifugal Pumps.- 760 Specialties, Heating WARREN WEBSTER & COMPANY Pioneers of the Vacuum System of Steam Heating Camden, N. J. Branches in over 60 Cities -since ISSS fH Systems of Steam Heating Manufacturers of Improved Webster Systems of Steam Heating, Webster Central Controls, Webster System Radiation, Webster Series "78" Traps for "Process" Steam Pressures. WODERATOF IMPROVED WEBSTER SYSTEMS-- Webster System Radiation--Con Low pressure, two-pipe systems of steam cealed, non-ferrous type for use exclusively circulation employing Webster Supply with Improved Webster Systems. Is Valves and Webster Return Traps ai radi unique in that it combines in a single unit, ators, and Webster Drip and Heavy Duty a light-weight heating element of high Traps at drip points of mains and risers. efficiency with an orificed radiator supply Webster Dirt Strainers, Boiler Prot ectors. valve, a radiator trap, and supply and Lift Fittings, Expansion Joints, etc., are return piping connections. Metal enclosure used where needed. is furnished for installation within the Return line operation may be either wall. Webster System Radiation and en vacuum, gravity or "vapor." Webster closures are so designed that the entire Type "R" equipment consisting of Boiler heating element can be quickly removed Return Trap and Vent Trap is used with without damage to plaster or paint. Space gravity or "vapor" systems. requirement reduced to a minimum and Steam for an Improved Webster System installation greatly simplified. may be supplied from a boiler, street mains, Webster Electric Moderator Con or other source. Either cast-iron or Web trol--A single, centrally-located, gradual- ster System Radiation (concealed, non-ferrous type) may be employed. Balanced Steam Dis tribution--Improved Webster Systems use ac curately-sized metering ori fices in radiator supply connections and, where re quired, at intermediate points in branch mains. The sizes of orifices are determined by the Com pany's representatives in accordance with the Com pany's exclusive methods. These orifices provide balanced or equalized dis tribution of steam to all radiators, a condition which is essential for satis factory control of steam delivery from a central point. Fig. 1, Webster System Radiation 701 Warren Webster & Company AUTOMATIC OUTDOOR THERMOSTATvari** txpth of ittan to ooch radiator with chaapea ia'ootdodr tacapara* (METERING ORIFICES IN WEBSTER. SUPPLY VALVES dbtnkrto stoaao proporlioaitaly aod at tho mbo Uao to oath radi ator. Note radiator parHetty fiOed with toaoi' for i ffliU woathor hoatiop. VARIATOR, touted pririd*i mmi to *ry AtM ttpHf (orqeki Wit> m^-up, r*4c*d oieht load tad saotetl weather conditio**. Specialties, Heating by action of AUTO* MATIC OUTOOOR THERMOSTAT. Ow hoattag aod oodorhoatiog aro rodoeod teaatoioMBB* Window* say bo ppoo Bphtfy for oootilatioo bat (toas Row wiQ not bo in* croatod *withwindow* ! U'-r' OPEN OR CLOSED RETURM^fc^'' Fig. 2. Standard Arrangement of Improved Webster System with Webster Electric Moderator Control. Using a Single Main Steam Control Valve ` acting control. Automatically varies amount of steam supplied to entire beating system in accordance with outside tem. perature. Heat delivery is continuous. Automatic Outdoor or "Roof" Thermo stat operates Main Valve so that at mini mum outdoor temperature (0 F. or --10 F., etc.) all radiators receive full heat. As outdoor temperature rises, steam delivery is proportionately reduced until at 70 F. outdoor temperature radiators are empty. While largely automatic Moderator Control includes a manual Variator which permits operator to modify effect of Roof 762 Warren Webster & Company Specialties, Heating Thermostat. Variator pulsations of varying is used for heating- length. Length of pul up, reduced night load, sation is changed by unusual weather con moving knob on Hylo ditions, etc. Controller according to Webster Moderator changes in outdoor Control is provided temperature.. A rota in (1) a single Con ting cam in cabinet trol Valve arrangement opens and closes Con which adequately trol Valve in steam meets requirements of main. Provides contin average building and uous heating effect (no (2) two or more Valve intermittent heat or arrangement for zoning "cold 70") with low large installations or Fig. 3. Electric Hylo Controller cost central control for for groups of build small and medium sized ings. With the latter, each Valve is buildings. under the control of its own Outdoor Webster Hylo Steam Control--A Thermostat and each Valve is adjustable manual central control of the graduated, by means of an individual Variator. continuous flow type to vary steam supply Application--For all types of Improved to entire system according to changes in Webster Systems of 3,000 sq. ft. or more outdoor temperature. Consists of Hylo equivalent direct cast-iron radiation. Steam Variator (Fig. 4) and Type "E" Particularly desirable for larger buildings. Main Steam Control Valve as used with Webster Pneumatic-Type Moder Moderator Control (see Fig. 1). Position ator Control--Uses compressed air as of weights on beam scales causes motor to medium of operation. Results in comfort proportionately open or close Type "E" and economy same as with the electric type. Valve in steam main. Ordinary variations Applicable to large buildings, particularly in supply and return mains are compensated zoned buildings or groups of buildings using for automatically. Can be furnished with two or more Main Control Valves operated . indoor thermostat for automatic overheat by a single Roof Thermostat and Variator. limit control and clock for automatic Webster Electric Hylo Control--A shut-off. Applicable to two-pipe orificed manual central control especially applicable systems using low pressure steam from to two-pipe orifice sys any source. Suitable in general for tems using "street" medium sized buildings. steam. Steam is supplied Hylo Vacuum Variator . Con to each radiator in short trol--A manual cen tral control of the graduated, continu ous flow type for vacuum systems only. Operating principle similar to Hylo Steam Variator. Fig. 4--The Webster Hylo Steam Variator Note--Adjustable weights. Scale on beam is clearly marked reading from left to-right "Heating Up," "Colo Weather," "Moderate Weather" and "Mild Weather," making ad justment simple and understandable by unskilled operators. 763 Specialties, Heating Wright-Austin Go. 315 West Woodbridge Street Detroit, Michigan PRODUCTS--Steam Traps, Strainers, Air Traps, Steam and Oil Separators, Compressed Air Purifiers, Exhaust Heads, Pump Governors, Boiler Feed Water Regulators, Alarm Water Columns. "Combination" Steam Trap Made with in ternal thermo static air by pass and internal strainer. F or vacuum service, also pressures up to 100 lbs. An excellent trap to take away con densation and air from heating apparatus. "Airxpel" Bucket Type Steam Trap This is a "double duty" trap expelling entrained air and condensate auto matically. Unusually large capacity. Has exception ally long life without re pairs. All parts are acces sible. Horizontal pipe con nection; easy to install; . hangs on the pipe line like a valve. Made in small sizes. Air Trap for Relieving Air from Hot and Cold Water Systems 0 to 150 Ho. Extreme simplicity and reliability char acterizes this air trap. There is nothing to it bjjt a float, a lever and a valve. No over flow needed,. ample valve opening. Seven inches high by 6 - inches diameter. "Tuway" Angle or Straightway Strainer An alternate inlet enables this strainer to be used either as an angle or straight way type in hori zontal or vertical pipe line. The per forated brass screen has 400 holes per square inch but can be made to. suit requirements. 0 to S00 lbs. "Victor" Low Pressure Steam Trap For heavy vol umes of condensa tion at low pres sures. Furnished with thermostatic air by-pass for vacuum return lines. Makes a re liable, non choking oil and grease trap, be 0 to 10 Ibt. cause of the large valve opening. "Emergency" Float Type Steam Trap 0 to 150 Hi. Three valve trap with large capacity at high loads and no wire drawing at low loads. No change of valves or adjustments from 0 to 200 lbs. Strong nickel float. An ex ceptionally reliable trap for use in inac cessible places. Type "S" Horizontal, Self-Cleaning Qil Separator Will remove oil from exhaust steam down to a very small fraction of 1 per cent. Self-clean ing, cast in one piece requiring no mainte nance. Thousands in use throughout the world. 0 to 50 Ibt. 764 Steam Heating Systems F. I. Raymond Company 629 W. Washington Boulevard Chicago, 111 RAYMOND DUO-STAT SYSTEMS OF AUTOMATIC HEAT REGULATION RAYMOND SYNCRO-FLOW HEATING SYSTEMS Raymond Syncro-Vent This is a duplex vent with two air ports. While the element is cold the top port is open and the bottom port is closed. When the element, is hot the top port is closed and the bottom port is open. Syncro-Flow Vapor System The end of the steam main is vented into the top port of the Syncro-vent. The return lines are vented into the lower port. While the system is warming up no air can escape from the return line until jthe steam line is filled. Thus no steam can enter the first radiators until the steam line is filled. Then steam enters the first and last radiators at the same time. No radiator traps are required. Syncro-Flow Vacuum System . The drips from the risers are connected to a . separate return -line which runs direct to the vacuum pump. . , A water seal is inserted in the return from the radiators.' The water seal keeps steam from entering the ' rfr- first radiators until the steam lines are filled. Then steam enters the first and last radiator at the same time. Radiator traps are not required when Duo-Stat control is used. i .! - Complete engineering data will be furnished on request. "... i ' See Also Page 776 .- ; :,,. 765 ' -. ; Steam Heating Control Systems Webster Tallmadge & Go., Inc. New York, N. Y. Factory: East Orange, New Jersey THE TALLMADGE ZONE HEATING SYSTEM With Simplified Orifice Distribution and Compensated Control Remote or Locally Controlled Residence Heating Systems Tallmadge electrically operated Zone Control Valve for admittii the proper amount ol steam to each sone separately. . Tallmadge Simpli fied Orifice scien tifically distributes the steam in a . practical, simple Simplicity Predominates In the Tallmadge System of Zoned Heating The devices Uluetraied above are the only ona need The Tallmadge Zoned Heating System increases building comfort and saves the steam usually wasted in overheating in ordinary system operating without control. In the application of the Tallmadge con trol the. heating system is divided into separate systems or zones, each zone con sisting of the radiators serving the same general ' building exposure or type of occupancy. A control valve and mechanism is placed on the steam supply to each zone and is electrically connected to a central control board. An orifice or restricted opening is placed in the entrance to each radiator. The. continuous (not intermit tent) steam flow to the radiators of a zone is then controlled (automatically or by hand frojn central control board) in accordance with the requirements of weather or oc cupancy . affecting the steam demand of each zone which varies with relation to that of other zones and with every change in weather, thus saving additional steam on zones exposed to the sun or protected from the wind. . Radiator orifices are sized in propor tion to the size of each radiator; fit in any make of radiator valve; no orifices in mains or risers,, hence no unbalancing of steam distribution when radiators are changed or turned off. The valve control mechanism automatical ly increases or decreases the continuous steam supply to the zone as radiators are turned on or off. It opens slowly to pre vent noise usually resulting from too quick starting up and closes slowly to prevent blowing of the boiler safety valve; reduces peak demand on district steam supply; is motor-driven, taking current from the lighting circuit; operates on any initial pressure thus eliminating reducing valves and permitting smaller mains supplying steam to the control valve; prevents more than full steam flow entering any radiator hence radiator traps and vacuum are un necessary regardless of the height or size of the building. Valve can be hand- operated. Operating mechanism can be removed without shutting off stetfm. No by-pass required. . No special pipe sizes required as those used in good standard practice for steam and return are satisfactory. Unnecessary to zone the returns as they may be com mon to all zones. Low initial cost, low installation cost in new or old system due to simplicity of few devices used. Cost often offset by elimina tion of equipment otherwise necessary. Depreciation and maintenance practically nil due to few moving parts, hence ef ficiency does not decrease with age or use. Temperature and Humidity Control Julien P. Friez & Sons, Inc., (Subsidiary of Bendix Aviation Corporation) Baltimore, Maryland, U. S. A. Established 1876 ' MANUFACTURERS OF METEOROLOGICAL, HYDROMETRIC AND AIR CONDITIONING INSTRUMENTS PRODUCTS--Humidistats, Ther mostats, Indicators, Thermometers, Hygro-thermographs, controlling and recording instruments for heating, ventilating and air conditioning--in dustrial, domestic and research fields. Weather instruments, indicating and recording, all types. Special remote indicating and re cording equipment of various kinds. Hu midis tat--Ex tremely sensitive, ac curate and reliable. Uses specially pre pared, multiple human hair element. Setting graduated in percent age relative humidity over range from 10% to 100%. For use on 2 or 3 wire, high or low voltage electric circuits. Highest quality ano dized finish in "bronze" or satin "silver" and suitable for all classesof comfort and industrial applications. The finest instrument of its type at attractive prices.-- Apply for Bulletin "A." Thermostat--First class, accurate and re liable instrument that matches exactly with Humidistat. 2 and 3 wire system types. Very finest finish and appearance.--Apply for Bulletin "E." Effective Temperature Control--The new Friez "Comfortrol," in the one in strument, provides automatic control of-- heating, cooling, humidifying and dehumidifying or any two or three of those four functions. Controls in terms of A.S.H.V.E. Comfort Chart Effective Tem peratures and marks a great advance.-- Apply for Bulletin "C." New Friez Recorder--Specially de signed for air conditioning and refrigera sales and service aid.-- Apply for Bulletin "G." Humidity and Tem perature Indicator-- Very accurate, sensitive, easy to read. Covers range 10% to 90% R.H. Human hair element. First class instrument for comfort, industrial and refrigeration work.--Ap ply for Bulletin "D." Control Assemblies for Air Conditioning-- We specialize in complete equipment, instruments, relays, transformers, switches, solenoid valves, dampers, etc., for auto matic control of motors, fans, pumps, water or compressed air. Furnished assembled and interwired with diagrams, etc.--Apply for Bulletin "B." Weather Instruuments (all types --record ing or in dicating) --For 58 years we have been the lead ing build ers of me teorologi cal equip ment for Govern ment, Re search and In dustrial use. We have many applications of interest to engineers and architects for use in large buildings and homes, and for tion work. Available for--Humidity, Tem perature or Operation records or for any two or all three in the one instrument. Low . in cost, accurate, reliable, compact, por table, rugged and at low prices. Of great value in all tests, surveys, research and as application to heating and ventilating con trol. See our equipment--Daily News or Empire State Building, New York. We solicit your inquiries for all types of indicating, recording or controlling equip ment. 767 Temperature Control Barber-Colman Company Rockford, Illinois BARBER-COLMAN ELECTRIC SYSTEM OF TEMPERATURE AND HUMIDITY CONTROL Atlanta, Ga. Buffalo, N. Y. Chicago, III. Cincinnati, Ohio Cleveland, Ohio Detroit, Mich. Duluth, Minn. Fort Myers, Fla. Framingham, Mass. Branches and Representatives Hibbing, Minn. Indianapolis, Ind. Kansas City, Mo. Lincoln, Nebr. Los Angeles, Calif. Milwaukee, Wis. Minneapolis, Minn. Moline, III. New Orleans; La. New York, N. Y. Omaha, Nebr. Philadelphia, Pa. Phoenix, Ariz. Pittsburgh, Pa. Richmond, Va. Salt Lake City, Utah San Francisco, Calif. Seattle, Wash. St. Louis, Mo. Topeka, Kans. Brooklands, England Montreal, Canada Oslo, Norway Sidney, Australia Tokio, Japan Toronto, Canada Winnipeg, Canada The principal feature of the Barber-Colman Electric System of Temperature and Humidity Control is that it uses electricmotor-operated valves and damper controllers governed by electrically connected ther mostats. Sufficient variety of equipment is available for the accurate and efficient control of any of the various types of heating, ventilating, or air conditioning installa tions. Special equipment and accessories are available to take care of special con ditions. Competent engineering counsel is available without charge. Thermostats and Hygrostat Thermostats (and the Hygrostat) con tain the sensitive elements of the control system--the elements that detect any change from the desired condition, and actuate' the valves or damper controllers accordingly. The thermostats have' bi metal sensitive elements, the Hygrostat a belt of human hairs. Available types in clude the following: Room Thermostat. Two-Temperature Thermostat. Duplex Thermostat. Compound Thermostat. Duct Thermostat. Furnace Thermostat. Air Stream Thermostat. Immersion Thermostat. . Surface Thermostat, Hygrostat. Further information on request. Motor-Operated Valves Motor-Operated Valves are used to con trol the flow of fluids, such as steam, water, gas, oil, etc., in pipes. Positive valves are for shut-off service where the control re quirements call for either full flow or complete shut off, whereas reversing valves provide regulating or throttling control. Both positive and reversing valves are available in stand ard body patterns, a wide range of sizes, and with operators to suit practically all requirements. Data Sheets are avail able describing all types of" valves and giving dimensions, electrical data, ma terials, lift of disc, etc. Principal types available are as follows: ' Packless Valves in. to 2 in. Single Seat Packed Valves M in. to 3 in. Single Seat Packed Valves 2 in. to 6 in. Pilot Piston Valves in. to 8 in. Semi-Balanced Vee-Port Valves Yi in. to 4 in. Full-Balanced Vee-Port Valves 5 in. to 12 in. Three-Way Valves % in. to 4 in., Butterfly Valves 2 in. to 16 in. Damper Controllers Motor-Operated Damper Controllers will open and close single or multi-louvred dampers in the ducts of unit ventilators, indirect warm air heating systems, blast systems, furnaces, ovens, etc. The con troller is connected to the damper and positions it in accordance with indications from a thermostat or other switch. Most" types of Damper Controllers are available with either positive (for open-and-shut operation) or reversing, (for positioning operation) motors. Two standard sizes are made, as well as several specialized types. Complete information is provided in data sheet form. Barber-Colman Company Temperature Control EXAMPLES OF CONTROL SYSTEMS Direct Radiation -- Motor - operated valves on the radiators are connected to and controlled by the thermostat on the wall. For a large room it is sometimes advisable. to have several thermostats, each controlling a group of radiators. With an automatically-controllable heat source--such as an oil or gas-fired boiler, a mechanical stoker, or a valve on a purchased-steam line--a "relay control" can be used. With an oil burner, for instance, the relay control will operate the burner and keep steam in the lines as long as one or more thermostats in any room or rooms is calling for heat. When all thermostats are satisfied, the burner is shut off. In this way, heat is always available when ever and wherever needed. Any system for the control of direct radiation is easily installed on existing heating equipment. Unit Ventilator--A conventionalized unit ventilator is illustrated. There are two damper controllers, one on the intake damper and one on the mixing damper. A room thermostat on the opposite wall actuates the mixing damper controller, positioning it to provide an output of warmer or cooler air, as required. The in take damper controller is governed by a manual switch in a central location (such as the janitor's office) and is positioned in accordance with weather conditions so that fresh outside or recirculated air may be taken in. A motor-operated valve on the steam line may be used. Sometimes an air- stream thermostat in the path of the out put air is used as a pilot to prevent cold blasts. Other types of controls--specialized valves, and the like--are made to suit the requirements of various designs of unit ventilators. These controls may be purchased as original equipment on new unit venti lators or may be installed on existing heat ing systems using such units. ? Blast System--A full blast heating system is diagrammed. Any part of it, if used separately, may be controlled ap proximately as shown. . H :iffflfl* I firilCb [k\ >? % *...... An important element of this type of control system is the motor-operated valve (G) which is governed by the action of the damper controller (H) which, in turn, is controlled by the thermostat (F). The valve (G), which operates slowly, will remain stationary (it may be open, or closed, or in a throttling position) as long as the by-pass damper,, which operates relatively fast, is "floated" by its con troller (H) somewhere between the wide open and completely closed positions. In other words, the by-pass damper controller acts as a limit switch which, when the by pass damper reaches its maximum cooling position, cuts off the steam supply to the reheating coil slowly, and, when the by pass damper reaches the maximum heating position, opens the steam valve to the reheating coil slowly. Variations of the controls shown can be adapted to any heating system of this general type. 769 / Temperature and Humidity Control Johnson Service Company TEMPERATURE AND HUMIDITY CONTROL General Offices and Factory Milwaukee, Wis. Branch Offices in all Large Cities Johnson Temperature Regulating Co. of Canada. Ltd., 97 Jarvis Street, Toronto, Ont. Montreal, Que. Winnipeg, Man. Calgary, Alb. Vancouver, B. C. Products and Services Manufacturers, engineers, and contractors for Automatic Temperature and Humidity Control Systems applied to all types of heating, ventilating, and air conditioning in stallation's. Temperature and Humidity Control for every range required in manufacturing and industrial processes. . Johnson "Duo-Slats" to maintain the proper relationship between outdoor and radi ator temperatures. j 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. . Johnson All-Metal Thermostats Room Thermostat . All Johnson thermostats, both room and insertion types, are all-metal . throughout, having no soft or hard rubber parts to deteriorate and become inoperative. Every thermostat is precise in construction and is thoroughly tested for accuracy, efficiency, and durability. The Johnson intermediate action thermostat gives a true graduated motion 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. Johnson diaphragm valves are simple and rugged. Seamless metal bellows and heavy spring operate the valve stem. No complicated moving parts. Johnson Dual or Two-Temperature Thermostat The Dual, two-temperature, thermostat is 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 are avoided. The shifting from "day" or occupancy tem perature to an economy temperature for "non-occu pancy" conditions, is accomplished by a switch or Johnson program clock at a central point. Push buttons on the thermostat are provided when "oc cupant control" is desired. Dual thermostats are all metal and operate valves and dampers gradually to maintain temperature accurately within one degree. Dual Thermostat Svivhm Vaiw Humidostats and Humidifiers The Johnson humidostat automatically controls the supply of moisture delivered to the air by a humidifier or air washer and maintains a con stant percentage of relative humidity. Available in both room and insertion patterns and with elements as determined by requirements, the most sensitive controlling within 1 per cent at relative humidity of 95 per cent for 100 degrees F. , Johnson humidifiers are furnished in steam "grid" type or pan type with copper evaporating pan, brass heating coil, and float control. Room Humidostat (Cover removed) 770 Johnson Service Company Temperature and Humidity Control Automatic Regulation of Ventilating and Air Conditioning Insertion thermostats in one, two, three, and four-point patterns for operating valves and dampers successively at dif ferent temperatures. Direct or reverse acting and in various ranges of sensitivity from one degree to twenty degrees. Dif ferential thermostats to maintain desired temperature differences between two points such as outdoors and treated space. Pour-point Multiple Thermostat liemote readjustable thermostats, re-set from a distant point by pilot or differential thermostat or by pressure switch. Solenoid air switches, manual switches, static pressure regulators, velocity regulators operating dampers to regulate flow of air in ducts. Pneumatic Switch Process Control Adjustable range and calibrated insertion thermostats for controlling temperature of liquids, air and gases. Mercury extended tube thermostat for use where remote location of sensitive element is necessary. Wet and dry bulb thermostats for close regulation of hu midity. Remote Readjxutable Thermostat Zone Control Johnson "Duo-Stats" to regulate the flow of heat in a group of radiators constituting a "heating zone" by maintaining the proper re lationship between outdoor and radiator .tem peratures. Program Clock ' / Temperature Control Minneapolis-Honeywell Regulator Company Eiecutire offices: 2711 Fourth Avenue, S., Minneapolis ' Factories: Minneapolis, Minn., and Wabash, Ind. . ' Branch and Distributing Offices: N^w York, Chicago, Philadelphia, Boston, Detroit, Indianapolis, Cleveland, Providence, St, Louis, Cincinnati, Milwaukee, Pittsburgh, Balti more, Washington, D. C.; Buffalo, Syracuse, Rochester, N. Y.; Denver, Salt Lake City, Los Angeles, San Francisco, Portland, Seattle, Hartford. In Canada: Montreal, Toronto, Calgary. Agencies in almost every city. THE MODUTROL SYSTEM Provides flexible automatic temperature control adaptable to the requirements of all types of buildings, from the smallest cottage to the tallest sky-scraper. Complete temperature - control engineering service available on request. The.Modutrol System of Temperature and Air Conditioning Control not only eliminates waste, but actually saves fuel as well. Heat is not wasted because over heating is eliminated. Fuel is actually saved because the plant always operates at right efficiency. There is a Minneapolis-Honeywell Modutrol System to fit every heating, ventilating and air conditioning system. Types of Modutrol Systems All Modutrol Equipment (except self contained radiator valves) is Electrically Operated The Modutrol System for Air Conditioning and Ventilating--This system provides automatic modulating control of dampers, louvres, valves, etc., used in connection with air conditioning and venti lation. systems, and Unit Ventilators of ail kinds. Zone Control System--A wide variety of con trols is used to provide any desired degree of auto matic control. A system of this type includes thermostats and motorized valves that control the supply of heat to the various zones of control. The Low Limit Control System--By keeping the radiators or warm air ducts always slightly warmer than room temperatures air stratification due to lack,of air circulation is prevented, and the condition known as Cold 70 is eliminated. This system is adaptable to any type of heat burning any kind of fuel. Summer-Winter Control System--This sys tem; enables.an automatic coal, gas, or oil burner to provide domestic hot water supply economically by means of an indirect heater throughout the entire year. Unit Heater Control System--There are MinneapolisrHoneywelI Controls suitable for the control of single unit heaters or batteries of unit heaters. This system includes, line voltage or low voltage thermostats, single or polyphase, high or low voltage relays, and Unifan Controls that prevent the heaters from operating when the heating coils are cold. ' ' . . 772 Used in Zone System Minneapolis-Honeywell Regulator Company Temperature Control SOME OF THE PRINCIPAL CONTROLS The Modutrol. Motor is a truly modulating electric motor. It is used wherever modulation of valves, louvres, dampers, etc., is used for control of heating, ventilating and air conditioning; unit ventilators or central fan systems. Extraordinary power is developed thruout its entire Modutrol Modulating Motor travel;--"hunting "--overshooting--undershooting are totally eliminated. Controllers are available for its operation from room or duct tem peratures, water temperature, pressure, humidity or manual switches. All thermostats--room and duct--are indicating as well as con trolling. The Modustat--This self-contained modulating radiator valve automatically controls the temperature of individual rooms. It can be used successfully on direct or concealed radiators in two pipe S steam systems. It is often employed as part of a complete Zone Control System. Thermochron controls through the combining of time and tern- perature actuation, to supply exactly the amount of heat to com pensate for heat losses without overheating or underheating. It is not merely another thermostat. It senses the trend of temperature changes before the ordinary thermostat will register such changes and therefore provides fractional degree control of room temperature. Power is supplied thru a transformer from the lighting circuit. The clock movement is a synchronous type which restarts itself when . power is resumed following a power failure. At night it automatically lowers the temperature setting. In the morning it automatically restores the day time setting. Available for 60 cycle operation only. Electric Clock Thermostat has same characteristics as the Thermochron except that it does not combine thermostatic and time functions to maintain the temperature level. Humidity Control--The actuating element in this instrument is human hair, the most satisfactory substance known for accurate, dependable humidity control. This control is made for low or line voltage and in indicating and non-indicating models. Scale, range 20 per cent to 80 per cent relative humidity. Differential 2 per cent under average rate of change. Plain Thermostats (low voltage)--are used where one tem perature is required at all hours or where irregular temperature regulation or group or master clock control is necessary. Available for motor valve or relay operation. The Electric Radiator Valve is for use on all radiation heating systems. It is available in all standard body types and sizes from % in. to . 2 in. Operates silently and against 10 lb. maxi mum pressure. Primary Controls for coal, gas, oil and dis trict steam. .' . Combustion Safety Controls for domestic and industrial use. Motor Valves, 2 position and modulating for pressures up to 900 lbs. temperatures up to 750 F. and for the control of liquids, gases, steam or air. --- ...Complete catalogs fully describing and illustrating Electric Radiator Valve--t Position Ike instruments or systems will be gladly sent upon request. 773 Modutrol Modulat ing Type Room Thermostat The Moduslat Thermochron ilumidity Controller Temperature Control The Powers Regulator Co. Over 40 years of specialization in temperature control General Offices and Factory--2719 GREENVIEW AVENUE, CHICAGO, .ILL. General Eastern Offices--231 EAST 46th STREET. NEW YORK CITY THE CANADIAN POWERS REGULATOR CO., LTD., 106 LOMBARD ST.. TORONTO, ONT. Atlanta, Ga. Baltimore, Md. Birmingham, Ala, Boston, Mass. Buffalo, N. Y. Butte, Mont. Chattanooga, Tenn. Cincinnati, Ohio Cleveland, Ohio Columbus, Ohio Dallas, Texas Davenport, Iowa Denver, Colo. Detroit, Mich. El Paso, Texas High Point, N. C. Houston, Texas Indianapolis, Ind. Kansas City, Mo. Los Angeles, Calif. Memphis, Tenn. Milwaukee, Wis. Minneapolis, Minn. Nashville, Tenn. New Orleans, La. Philadelphia, Pa. Pittsburgh, Pa. Portland, Ore. Reading, Pa. Rochester. N. Y. Salt Lake City, Utah San Antonio, Texas San Francisco; Calif Seattle. Wash. ` St. Louis, Mo. Syracuse, N. Y. Calgary Halifax Montreal Vancouver Winnipeg . Products Systems of Automatic Temperature and Humidity Control for Heating, Ventilating, and Air Conditioning Equip ment. - . . Thermostats--both graduated and positive acting for dry or wet-bulb con trol. Hygrostats--both pneumatic and electric for humidity control. . Self Con tained Regulators--complete line for control of air and liquid temperatures. Brine Control--regulators for control of brine circulating systems. Dampers-- both single and multiple blade, with or without operating diaphragm motors. Diaphragm Valves--All metal construc tion, including three-way valves, brine con.trol valves, etc., etc. Accessories--Auto matic Water Pan for wet-bulb' control, Relays, Pressure Reducing Valves, Pneu matic Switches, Dial Thermometers, etc! Temperature regulators for HotWater Heaters, Industrial Processes, etc. Powers Engineering Service Forty years of specialization in Auto matic Temperature Control serving the leading industrial firms and manufacturers of air conditioning equipment, has. given us a wealth of knowledge and experience from which you can draw in selecting the proper type of control for any purpose. Some firms make only compressed air operated regulators, while other firms' make only self-operated regulators. We make a complete line of both and so are free from the selfish necessity of stressing one type of regulator above the other and can give unbiased advice.. ' Powers Compressed Air Operated Apparatus The Powers Regulator Co. Temperature Control Powers Compressed Air Operated Apparatus No. St Temperature Regulator Pheumatie Relay for Amplifying action of Thermo stat* and Regu lators No. 14 Temperature'Regulator AQ Meta Dampers and Motors Powers Self-Operated Temperature Regulators Style D Thermostat Hygrostat Style K Thermostat with Flexible Tubing and Bulb Dud Thermostat Thermostat and Hygrostat Combination 774 Thermostatic Radiator Valve 775 Heaters, etc. Temperature Control F. I. Raymond Company 629 W. Washington Boulevard Chicago, 111. RAYMOND DUO-STAT SYSTEMS OF AUTOMATIC HEAT REGULATION RAYMOND SYNCRO-FLOW HEATING SYSTEMS Raymond Duo-Stat for Steam Two liquid filled thermometer bulbs control a switch in the Duo-Stat. One is placed outdoors, the other is attached to the last radiator on the longest steam line. The switch controls a coal stoker, oil burner, or steam valve. As the outdoor bulb cools below 70" the radiator temperature is raised proportionately above 70 to supply the amount of heat required. An unexpected advantage of Duo-Stat control for steam heating systems is that it produces low radiator tem peratures in any good one pipe, two pipe, vapor, or vacuum heating system. The performance is similar to hot water heat. . Duo-Stat for Hot Water x The operation is the same as that of the. Duo-Stat for steam. The inside bulb is attached to a hot water main instead of to a radiator. Typical Wiring Diagrams These diagrams show two com mon applica tions of the High-Low DuoStat. One is for stoker control, the other is for district steam service valves. Other wiring diagrams and complete engi neering data will be furnished on request. NIGHT THERMOSTAT HIGH-LOW DUO-STAT E=IKrt LECTRIC Tl ME SWITCH 1 BOTTOM SWITCH xy] CLOSES AT 6AM OPENS AT 6PM TOP SWITCH CLOSES AT 6AM OPENS AT 9AM TIMESCAN BECHANGED See Also Page 765 776 Jenkins Bros. Manufacturers of Valves and Mechanical Rubber Goods . Principal Stores and Offices - 510 Main Street 80 White Street BRIDGEPORT, CONN. NEW YORK, N. Y. 524 Atlantic Ave. BOSTON, MASS. 133 No. 7th St. PHILA., PA. 822 Washington Blvd CHICAGO, ILL. ' Factory: BRIDGEPORT. CONN. JENKINS BROS., LIMITED Canadian Worksand Head Office: Montreal, Que,, 617 St. Remi Street London Office: 6 Great Queen Street, Kingsway, W. C. 2 PRODUCTS Jenkins Globe, Angle, Cross, Check, Hose, Blow-Off, Safety and Gate Valves; Radiator Valves; Rapid Action Valves; Steam Traps; Gage Cocks; Regrinding Valves; Needle Valves; Valve Discs; Jenkins '96 and Jenarco Sheet Packing, Gaskets; Pump Valves; Asbestos Jointing; MoncrieS Scotch Gauge Glasses. . Consult the Jenkins Catalog Full details on over 400 valves with helpful data on layouts Fig. 106-A Bronze Globe, Screwed, Onepiece eerevHtver bound, slip-on. etay-on ditc holder This is more than a catalog. It is a real valve manual. Gives unusually complete de tails on over 400 different valves, meeting practically every need. Has a large section of engineering data and practical information for men concerned with valves and valve layouts. A copy of this Catalog will be mailed on request. Renewable Disc, Bronze and Iron Body Valves Jenkins Bronze and Iron Body Valves of the globe, angle, cross and check types in standard, medium and extra heavy patterns have re newable discs and disc holders. The renewable, resilient disc, first introduced by Jenkins many years ago, assures absolute tightness. For steam use. the discs are made of hard composition, which becomes pliable in service. For water, gas and air, softer compounds are furnished. New advantages for valve users are to be found in Jenkins Standard Bronze Valves with the one-piece screw-over bonnet and the slip-on stay-on disc holder. Fig. 106-A, globe, screwed, is shown at the left. This line also includes angle, cross, horizontal and angle check types, screwed and flanged. Radiator Valves Fig. 186 BronzeOffset Corner, Radiator with Union Fig. 168 Radiator Angle, with Union Fig. 801 Bronze Globe Valve, Screwed, with re newable composi tion ditc and re newable teat ringt, for 850 Ibt. steam toorking pressure. Regularly furnished with two-piece sanitary wheels, or, if desired, with black composition, bronze, wire or iron wheels. Furnished in the new low-bonnet patterns or the regular pattern as supplied for years. - Lock shield valves, to be opefated with key, designed to prevent tampering. Supplied in all patterns. Corner valves are made in two patterns--regular and offset. Regular styles of finish follow: Rough body, finished trimmings. No. 1 screwed. No. 6 with union. Finished and polished all over. No. 2 screwed, No. 7 with union. Rough body, nickel-plated trimmings, No. 3 screwed. No. 8 with union. Rough body, nickel-plated all over. No. 4 screwed. No. 9 with union. Finished and nickel-plated all over, No. 5 screwed, No. 10 with union. . Fig. 170 Bronze Lock Shield Radiator Angle, with Union Fta 8Si Bronze ^ catalog of all the Jenkins valves, giving sizes, styles and list Strinp Check Valve Prices, mailed on request. Fig. 858 Low Bonnet Radiator Angle, Male Union Fig. 859 Low Bonnet Radiator Offset Globe, Male Union Fig. 148 Iron Body Globe, Flanged 777 Fig. 8t5 Iron Body Gate, Screwed Fig. 870 Bronze Gate, Screwed Ventilators, Roof W. F. Hirschman Co., Inc. Main Office: Buffalo, N.Y. Works: Le Roy, N.Y, NEW YORK, N. Y,, 205 East 42nd Sr. CHICAGO, ILL., 2539 Eabt 73rd St. BOSTON, MASS.,! Fedebal St. Manufacturers: Roof Ventilators, Electric Controls and Steel Curbs Bulletin No Product Description E-9 EFFICO ROTARY WIND-DRIVEN VENTILATOR HEADS Exhaust efficiency starts at one mile per hour wind. This gives the Effico a high exhaust capacity during very low prevailing winds. Also the Effico is so designed that during high winds its exhaust capacity remains reasonably constant. Oil flooded''bearings. ELU-10 WE-15 EFFICO LOUVER UNIT VENTILATOR. EFFICO WIND-ELECTRIC FULL AUTOMATIC VENTILATOR Same as Effico head, but is equipped with our pat ented Multiple Louver Damper (Circular) installed by us at factory in the ventilator. This ventilator is very desirable for thermostat controlled buildings and is used on many hundreds of schools and other public and semi-public buildings. A constant exhauster. Electric power co-ordinated with wind power exhausting a uniform volume of air regardless of wind velocity or temperature difference. Electric motor is energized and de-energized auto matically. Adjustment of automatic control, which co ordinates the wind driven, capacity with the electric power capacity. Ventilator is absolutely quiet. 8-A "F" ELECTRIC FAN VENTILATOR NON-AUTOMATIC A positive exhauster for free air or up to Yi in. static pressure. For volume under 25,000 c.f.m. per unit, its efficiency is high and with motor idle the ventilator will function as a syphon ventilator. The "F" head is the only ventilator head specially designed to permit air to be driven through the head. F-662 ISOLATED "F** ELECTRIC FAN VENTILATOR NON-AUTOMATIC Special provisions for protecting motor from air being exhausted. Fumes, heat, greases, etc., do not contact motor at all and motor is well ventilated. The Isolated "F" Electric Ventilator is otherwise identical to the "F"-Ventilator mentioned above. 1-LO FA-202 LORATE CONCEALED VENTILATORS FIRMA VENTILATORS STATIONARY A conventional air exhaust outlet, suitable for any type of architecture, can be fitted into a brick or stone stack. This ventilator is strictly weather-proof and of capaci ties based on quiet operation; supplied in capacities from 400 c.f.m. to 15,000 c.f.m. and up to in. static pressure. A well designed mushroom type ventilator; strictly weather-proof and sold with capacities of recognized testing laboratories guarantee. The Hirschman Steel Curb is suitable fop decks of con crete, wood, steel and gypsum. Light weight, serves as D ELECTRIC CONTROLS re-enforcing frame; reduces cost. Supplies a form for the opening and a solid and nicely finished opening. Also a real anchor for roof ventilator and skylight and supplies a lock for holding roofing felt or flashing. C-650 STEEL VENTILATOR AND SKYLIGHT CURB We are the originators of ventilator damper electric control. Our controls hold damper and louver installed in ventilator firmly, are positive acting, have semi-open position. If desired for electric ventilators our controls co-ordinate fan motor and damper. Suitable controls and design are supplied to handle any louvers and motors. 778 Water Conditioning Ferro-Nil Corporation 500 Fifth Avenue New York City WATER CONDITIONING FOR AIR CONDITIONING Photograph reprinted with permission of National Broadcasting Company All water used for washing air picks up corrosive matter from the air. The corrosive matter may be oxygen, carbon dioxide, sulphur tri-oxide or sulphur di-oxide. In air conditioning systems where water is recirculated, the amount of acidic material contained in the water may reach very high levels. This acid water will corrode metallic surfaces with which it comes in contact. In severe cases equipment has been known to fail after three months operation due to corrosive action of water used. Ferro-Nil Service by maintaining water in a non-corrosive condition, prevents corrosion. Corrosion1 causes high rates of depreciation. Ferro-Nil Service by maintaining metallic surfaces free from rust and scale affords optimum heat transfer efficiencies at all times. We number among our clients, nationally known corporations such as:-- ' Rockefeller Center . National Broadcasting Company . Columbia Broadcasting Company Runkel Chocolate Company Metropolitan Life Insurance Company U. S. Government SUBSTANTIAL DOLLAR SAVINGS GUARANTEED Let us submit estimate of cost of Ferro-Nil Service for your air conditioning equipment. The illustration depicts a typical installation used on dehumidifier by the National Broadcasting Company. Note simplicity of design with consequent simplicity of in stallation and'operation. See discussion of Corrosion Chapter 34. 779 Index to Modern Equipment American Society of Heating and Ventilating Engineers Guide, 1934 AIR CLEANING EQUIPMENT AIR RECEIVERS (See Receivers, BOILER FEED PUMPS (See Air-Way Electric Appliance Corp. Air) Pumps, Boiler Feed) 617 American Air Filter Co., Inc. 640-641 American Blower Corp. 618-619 Bayley Blower Co. 679 AIR VALVES.(See Valves, Air) AIR WASHERS (See Air Cleaning Equipment) BOILER TUBES (See Tubes Boiler) ' BOILERS, Cast-Iron American Radiator Co. 648-649 Buffalo Forge Co. 680 AIR WASHERS, Warm Air Burnham Boiler Corp. 647 . Carrier 620-625 Furnace Crane Co. 650-651 - Clarage Fan Co. 626 Buffalo Forge Co. 680 L. J. Mueller Furnace Co. 632,658 Coppus Engineering Corp. 642 Meyer Furnace Co., The 631 National Radiator Corp. 652-653 Frigidaire Sales Corp. 628-629 L. J. Mueller Furnace Co. 632, Spencer Heater Co. 654-655 W. F. Hirschman Co., Inc. 778 Meyer Furnace Co., The 631 L. J. Mueller Furnace Co. 632, 658 Niagara Blower Co. 734-735 Owens-Illinois Glass Co. 643 Parks-Cramer Co. 633 Staynew Filter Corp. 644 Uni-Flo Grille Corp. 737 L. J. Wing Mfg. Co. 682-683 York Ice Machinery Corp. 638 AIR COMPRESSORS (See Com pressors, Air) 658 AMMONIA COILS (See Coils, Ammonia) ASBESTOS PRODUCTS (See Insulation) AUTOMATIC SHUTTERS (See Shutters, A ulomatic) . BENDS, Pipe Crane Co. 650-651 The G & O Manufacturing Co. 688 Grinnell Co.. Inc. 700-703, 745 United States Radiator Corp. 656 . Weil-McLain Co. 657 . BOILERS, Combination, Gas. Coal or Oil American Radiator Co. 648-649 Fitzgibbons Boiler Co., Inc. 662 663 National Radiator Corp. 652^653 Spencer Heater Co. 654-655 United States Radiator Corp. 656 BOILERS, Down Draft Fitzgibbons Boiler Co., Inc. 662 663 AIR COOLING AND DEHU- Parks-Cramer Co. 633 Kewanee Boiler Corp. 664-665 MIDIFYING APPARATUS Air-Way Electric Appliance Corp. 617 American Blower Corp. 618-619 Bayley Blower Co. 679 BENDS, Return (See Pipe, Return . Bends) .. BLOWERS, Fan (See Fans, Sup ply and Exhaust) BOILERS, Gas Fired American Radiator Co. 648-649 Crane Co. 650-651 ' Kewanee Boiler Corp. 664-665 L. J. Mueller Furnace Co. 632, Buffalo Forge Co. 680 ' Carrier 620-625 Clarage Fan Co. 626 Frick Co. 627 Frigidaire Sales Corp. 628-629 General Electric Co. 630, 666, 721 Grinnell Co., Inc. 700-703, 745 Ilg Electric Ventilating Co: 684 L. J. Mueller Furnace Co. 632, 658 Parks-Cramer Co. 633 Thermal Units Mfg. Co. 690 Trane Co.. The 760 Uni-Flo Grille Corp. 737 Unit Heater & Cooler Co. 691 Westinghouse Electric & Mfg. Co. 636-637, 723 Williams Oil-O-Matic Heating Corp. 667 York Ice Machinery Corp. 638 Young Radiator Co. 692 BLOWERS, Forced Draft Air-Way Electric Appliance Corp. 617 American Blower Corp. 618-619 Bayley Blower Co. 679 Buckeye Blower Co. 698-699 Buffalo Forge Co. 680 Champion Blower & Forge Co. 681 Clarage Fan Co. 626 Coppus Engineering Corp. 642 Motorstokor Corp. 675 Uni-Flo Grille Corp. 737 Unit Heater & Cooler Co. 691 L. J. Wing Mfg. Co. 682-683 BLOWERS, Heating and Venti lating Air-Way Electric Appliance Corp. 617 American Blower Corp. 618-619 658 National Radiator Corp. 652-653 Petroleum Heat & Power. Co. 668-671 Spencer Heater Co. 654-655 United States Radiator Corp. 656 BOILERS, Heating American Radiator Co. 648-649 Bigelow Co., The 660 Crane Co. 650-651 ' Fitzgibbons Boiler Co., Inc. 662 663 E. Keeler Co. 661 Kewanee Boiler Corp. 664-665 L. J. Mueller Furnace Co. 632, 658 ,, National Radiator Corp. 652-653 Spencer Heater Co. 654-655 United States Radiator Corp. 656 Weil-McLain Co. 657 AIR ELIMINATORS Carrier 620-625 C. A. Dunham Co. 742-743 Hoffman Specialty Co., Inc. 746 751 Bayley Blower Co. 679 Buffalo Forge Co. 680 Clarage Fan Co. 626 llg Electric Ventilating Co., 684 Niagara Blower Co. 734-735 BOILERS, Magazine Feed American Radiator Co. 648-649 Spencer Heater Co. 654-655 Weil-McLain Co. 657 BOILERS, Oil Burning Illinois Engineering Co. 753 BLOWERS, Pressure Warren Webster & Co. 761-763 American-Blower Corp. 618-619 American Radiator Co. 648-649 Crane Co. 650-651 AIR FILTERS (See Air Cleaning Equipment) . AIR HEATING SYSTEMS (See Heating Systems, Air) AIR MEASURING AND RE CORDING INSTRUMENTS American Blower Corp. 618-619 Bayley Blower Co. 679 Buffalo Forge Co. 680 Clarage Fan Co. 626 L. J. Wing Mfg. Co. 682-683 BLOWERS, Turbine Coppus Engineering Corp. 642 General Electric Co. 630, 666, 721 L. J. Wing Mfg. Co. 682:683 Fitzgibbons Boiler Go., Inc. 662 663 Kewanee Boiler Corp. 664-665 ' L. J. Mueller Furnace Co. 632, 658 . -. National Radiator Corp. 652-653 Petroleum Heat & Power Co. 668-671 Spencer Heater Co. 654-655 Bristol Co., The .704 Julien P. Friez & Sons, Inc. 767 Parks-Cramer Co. 633 Taylor Instrument Cos. 706-707 BLOWERS, Warm Air Furnace Buffalo Forge Co. 680 Clarage Fan Co. 626 Meyer Furnace Co., The 631- United States Radiator Corp. 656 Weil-McLain Co. 657 Williams Oil-O-Matic Heating Corp. 667 . AIR MOISTENING APPA RATUS (See Humidifiers) BOILER COMPOUNDS (See Com pounds, Boiler) '" BOILERS, Steel Bigelow Co., The 660 . Fitzgibbons Boiler Co., Inc. 662 AIR PURIFYING APPARATUS BOILER COVERING (See Cover Air-Way Electric Appliance Corp. ing, Pipes and Surfaces) 617 663 E. Keeler Co. 661 Kewanee Boiler Corp; 664-665 - American Blower Corp. 618-619 BOILER FEEDERS (See Feeders, National Radiator Corp. 652-653* . Carrier 620-625 ' . Boiler) Spencer Heater Co. 654-655 Numerals following Manufacturers* Names refer to pages in the Catalog Data Section 780 - Index to Modern Equipment BOILERS. Water Tube American Radiator Co. 648-649 Republic Steel Corp. 738 Ric-wiL Co., The 717 Tuttle & Bailey, Inc."736` Warren Webster & Co. 761-763 Babcock & Wilcon Co., The 659 Bigelow Co., The 660 E. Keeler Co. 661 BREECHINGS AND CHIMNEYS Bigelow Co., The 660 BURNERS, Coal, Automatic (See Coal Burners)- BURNERS, Gas (See Gas Burners) Underground Steam Construc tion Co. 718 CONTROLLERS AND CON TROL EQUIPMENT (See also Temperature Control) American Radiator Co. .648-649 Barber-Colman Co. 768-769 Bristol Co., The 704 Builders Iron Foundry 719 Consolidated Ashcroft Hancock Co., Inc. 705 DIFFUSERS (See Ventilators, Floor and Wall) DRAFT APPARATUS, Mechanical American Blower Corp. 618-619 Bayley Blower Co. 679 Buffalo Forge Co. 680 Clarage Fan Co. 626 . Motorstokor Corp. 675 DRYING EQUIPMENT BURNERS, Oil (See Oil Burners) CIRCULATORS, Hot-Water Heating Bell & Gossett Co. 693 Parkinson Heater Co. 695 . Johnson Service Co. 770-771 Lincoln Electric Co., The 722 F. I. Raymond Co..765. 776 Sarco Co., Inc. 758-759 Webster Tallmadge & Co., Inc. 766 Air-Way Electric Appliance Corp. 617 Bayley Blower Co. 679 Buffalo Forge Co. 680" Carrier 620-625 Clarage Fan Co. 626 COAL BURNERS, Automatic Babcock & Wilcox Co., The 659 Detroit Stoker Co. 674 Iron Fireman Manufacturing Co. Thermal Units Mfg. Co. .-Warren Webster & Co. ,/ / Westinghouse Electric Co., 636-637, 723 690 761-763 & Mfg. 672-673 J COOLING EQUIPMENT, Oil Motorstokor Corp. 675 and Water (See also Air Cooling G & O Manufacturing Co., The 688 Thermal Units Mfg. Co. 690 Trane Co., The 760 Uni-Flo Grille Corp. 737 Unit Heater & Cooler Co. 691 Spencer Heater Co. 654-655 Westinghouse Electric & Mfg. and Dehumidifying Apparatus) Aerofin Corp. 685-687 DRY KILNS (See Kilns, Dry) Co. 636-637, 723 . American Blower Corp. 618-619 DUST SEPARATORS (See Air cWilliams Oil-O-Matic Heating Carrier 620-625 Cleaning Equipment) Corp. 667 COILS, Ammonia Frick Co. 627 The G & O Manufacturing Co. 688 ' Parks-Cramer Co. 633 Thermal Units Mfg. Co. 690 Unit Heater & Cooler Co: 691 York Ice Machinery Corp. 638 COILS, Pipe, Copper ' E. B. Badger & Sons Co. 678 Bell & Gossett Co. 693 Frick Co. 627 Frigidaire Sales Corp. 628-629 The G & O Manufacturing Co. 688 Minneapolis-Homeywell Regula tor Co. 772-773 . Westinghouse Electric & Mfg. Co. 636-637, 723 York Ice Machinery Corp. 638 Young Radiator Co. 692 CORROSION, Treatment of Ferro-Nil Corp. 779 EXHAUST HEADS Kieley & Mueller. Inc. 754 Wright-Austin Co. 764 EXPANSION JOINTS American District Steam Co. 677 E. B. Badger & Sons Co. 678 Crane Co. 650-651 Illinois Engineering Co. 753 Warren Webster & Co. 761-763 FANS, Furnace American Blower Corp. 618-619 COILS, Pipe, Iron - E. B. Badger & Sons Co. 678 York Ice Machinery Corp. 638 COILS, Tank American Radiator Co. 648-649 McDermott Water Heaters, Inc. 694 - COVERING, Ammonia Pipe Alfol Insulation Co., Inc. 708 Johns-Manville 712-713 Mundet Cork Corp. 715 Ric-wiL Co., The 717 COVERING, Pipe and Surfaces Alfol Insulation Co., Inc. 708 American Radiator Co. 648-649 Buffalo Forge Co. 680 Champion Blower & Forge Co. 681 Clarage Fan Co. 626 Ilg Electric Ventilating Co. 684 Meyer Furnace Co., The 631 L. J. Mueller Furnace Co. 632, 658 Trane Co., The 760 COMPOUNDS, Boiler Samuel Cabot, Inc. 709 Uni-Flo Grille Corp. 737 Vinco Co., Inc. 645 . Johns-Manville 712-713 ` Westinghouse Electric & Mfg. COMPOUNDS. Boiler arid Radi Mundet Cork Corp. 715 - ator Sealing CUTTING AND WELDING AP Co. 636-637. 723 L. J. Wing Mfg. Co. 682-683 Vinco Co., Inc. 645 ' PARATUS (See Welding and FANS, Portable COMPOUNDS, Underground Conduit Sealing Ric-wiL Co., The 717 . COMPRESSORS, Air Carrier 620-625 General Electric Co. 630, 666, 721 Nash Engineering Co., The 732 733 * Powers Regulator Co. 774-775 Thermal Units Mfg. Co. 690 CONCRETE INSERTS (See In serts. Concrete) CONDENSERS . Frick Co. 627 The G & O Manufacturing Co. 688 Thermal Units Mfg. Co. 690 Westinghouse Electric & Mfg. Co., 636-637, 723 Young Radiator Co. 692 Culling Apparatus) DAMPERS r Hart & Cooley Mfg. Co. 734 Johnson Service Co. 770-771 Powers Regulator Co. 774-775 Tuttle & Bailey, Inc. 736 DAMPER REGULATORS, Boiler and Furnace American Radiator Co. 648-649 Barber-Colman Co. 768-769 C. A. Dunham Co. 742*743 ' William S. Haines & Co. 752 Hart & Cooley Mfg. Co. 734 Hoffman Specialty Co., Inc. 746 751 ... . . Illinois Engineering Co. 753 Johnson Service Co. 770-771 Kieley & Mueller, Inc. 754 Minneapolis-Honeywell Regula tor Co. 772-773 L. J. Mueller Furnace Co. 632, American Blower Corp. 618-619 Bayley Blower Co. 679 Century Electric Co. 720 f General Electric Co. 630, 666, 721 Westinghouse Electric & Mfg. Co. 636-637, 723 L. J. Wing Mfg. Co. 682-683 FANS, Supply and Exhaust American Blower Corp. 618-619 Bayley Blower Co: 679 Champion Blower & Forge Co.- 681 General Electric Co. 60, 666, 721 Ilg Electric Ventilating Co. 684 Unit Heater & Cooler Co. 691 L. J. Wing Mfg. Co. 682-683 FEEDERS. Boiler ` American Radiator Co. 648-649 Builders Iron Foundry 719 Chicago Pump Co. 728-729 Kieley & Mueller, Inc. 754 CONDUITS, Underground Steam Pipe .. American District Steam Co. 677 E. B. Badger & Sons Co. 678 ---, General Electric Co. 630, 666, 721 Johns-Manville 712-713 658 Parkinson Heater Co. 695 *...... Powers Regulator Co. 774-775 F. I. Raymond Co. 765, 776 Sarco Co., Inc. 758-759 Trane Co., The 760 McDonnell .& Miller 646 . . - Mueller Steam Specialty Co. 756 Nash Engineering Co., The 732 733 Warren Webster .& Co. 761-763 Wright-Austin Co. 764 ' Numerals following Manufacturers* Names refer to pages in the Catalog Data Section 781 American Society of Heating and Ventilating Engineers Guide, 1934 FEEDERS, Water Chicago Pump Co. 728-729 . Decatur Pump Co. 727 Kieley & Mueller, Inc. 7S4 McDonnell & Miller 646 . Minneapolis-Honeywell Regula tor Co. 772-773 Mueller Steam Specialty Co. 756 United States Radiator Corp. 656 Warren Webster & Co. 761-763 Wright-Austin Co. 764 FEED WATER HEATERS (See GAUGES, Altitude American Radiator Co. 648-649 Consolidated Ashcroft Hancock Co., Inc. 705 Julien P. Friez & Sons, Inc. 767 J. E. Lonergan Co. 755 New York Air Valve Corp. 757 Taylor Instrument Cos. 706-707 United States Radiator Corp. 656 GAUGES, Ammonia Consolidated Ashcroft Hancock Co., Inc. 705 GRILLES, REGISTERS AND ORNAMENTAL METAL WORK Chase Brass & Copper Co R7A 696-697 *` Hart & Cooley Mfg. Co. 734 Independent Register & Mfg. Co. 735 L.^J^ Mueller Furnace Co. 632, Tuttle & Bailey, Inc. 736 Uni-Flo Grille Corp. 737 Heaters, Feed Water) ' FEED WATER REGULATORS {See Regulators, Feed Water) J. E. Lonergan Co. 755 HANGERS, Pipe New York Air Valve Corp. 757 Chase Brass & Copper Co. 676 GAUGES, Draft ^ 696-697 ' Consolidated Ashcroft Hancock n Crane Co. 650-651 FILTERS, Air {See Air Cleaning Co., Inc. 705 General Electric Co. 630,666 721 Equipment) FITTINGS, Pipe, Flanged GAUGES, Hot-Water Consolidated Ashcroft Hancock Grinnell Co., Inc. 700-703, 745 Unit Heater & Cooler Co. 691 American Radiator Co. 648-649 Co., Inc. 705 HANGERS, Radiator Chase Brass & Copper Co. 676, New York Air Valve Corp. 757 American Radiator Co. 648-649 696-697 United States Radiator Corp. 656 Grinnell Co., Inc. 700-703, 745 Crane Co. 650-651 Frick Co. 627 General Electric Co. 630,666, 721 Grinnell Co., Inc. 700-703, 745 FITTINGS, Pipe, Screwed Crane Co. 650-651 Frick Co. 627 GAUGES, Pressure American Radiator Co. 648-649 Bristol Co., The 704 Consolidated Ashcroft Hancock Co., Inc. 705 C. A. Dunham Co. 742-743 J. E. Lonergan Co. 755 United States Radiator Corp. 656 HEAT CABINETS (See Heaters, Cabinet) HEATERS. Air Aerofin Corp. 685-687 Air-Way Electric Appliance Corp. General Electric Co. 630,666,721 Grinnell Co.. Inc. 700-703. 745 FITTINGS, Pipe, Sweat Chase Brass & Copper Co. 676, 696-697 FITTINGS, Welding Crane Co. 650-651 General Electric Co. 630,666, 721 Grinnell Co., Inc. 700-703, 745 Taylor Instrument Cos. 706-707 Trane Co., The 760 United States Radiator Corp. 656 GAUGES, Steam American Radiator Co. 648-649 Consolidated Ashcroft Hancock Co., Inc. 705 J. E. Lonergan Co. 755 New York Air Valve Corp. 757 Trane Co., The 760 American Blower Corp. 618-619 American Foundry Equipment Co. 689 Bell & Gossett Co. 693 Buffalo Forge Co. 680 . Carrier 620-625 G & O Manufacturing Co., The 688 Grinnell Co., Inc. 700-703, 745 W. F. Hirschman Co., Inc. 778 FURNACE HEATING SYSTEMS {See Heating Systems, Furnace) FURNACES, Electric General Electric Co. 630,666, 721 United States Radiator Corp. 656 Warren Webster & Co. 761-763 GAUGES, Vacuum American Radiator Co. 648-649 Bristol Co., The 704 . Meyer Furnace Co., The 631 . Niagara Blower Co. 734-735 ' Thermal Units Mfg. Co. 690 Uni-Flo Grille Corp. 737 .* * Unit Heater & Cooler Co. 691 L. J. Mueller Furnace Co. 632, 658 Westinghouse Electric & Mfg. Co. 636-637. 723 Consolidated Ashcroft Hancock Co., Inc. 705 C. A. Dunham Co. 742-743 Illinois Engineering Co. 753 Westinghouse Electric & Mfg. Co., 636-637, 723 York Ice Machinery Corp. 638 Young Radiator Co. 692 Williams Oil-O-Matic Heating Corp. 667 FURNACES, Warm Air Carrier 620-625 Meyer Furnace Co., The 631 J. E. Lonergan Co. 755 New York Air Valve Corp. 757 Taylor Instrument Cos. 706-707 Trane Co., The 760 Warren Webster & Co. 761-763 HEATERS, Automatic Hot Water American Radiator Co. 648-649 Chase Brass & Copper Co. 676, 696-697 . L. J. Mueller Furnace Co. 632,658 GAUGES, Vapor Fitzgibbons Boiler Co., Inc. GAS BURNERS American Radiator Co. 648-649 Babcock & Wilcox Co., The 659 Petroleum Heat & Power Co. 668-671 GAS HEATERS (See Heaters, Gas) GASKETS, Asbestos American Radiator Co. 648-649 Consolidated Ashcroft Hancock Co.. Inc. 705 Illinois Engineering Co. 753 New York Air Valve Corp. 757 Trane Co., The 760 United States Radiator Corp. 656 Warren Webster & Co. 761-763 662-663 McDermott Water Heaters, Inc. 694 Williams Oil-O-Matic Heating Corp. 667 HEATERS, Blast Aerofin Corp. 685-687 Bayley Blower Co. 679 Crane Co. 650-651 GAUGES, Water Thermal Units Mfg. Co. 690 Jenkins Bros. 777. American Radiator Co. 648-649 Trane Co., The 760 ' Johns-Manville 712-713 Builders Iron Foundry 719 Unit Heater & Cooler Co. 691 GASKETS, Rubber Crane Co. 650-651 Jenkins Bros. 777 Johns-Manville 712-713 Consolidated Ashcroft Hancock Co., Inc. 705 New York Air Valve Corp. 757 Wright-Austin Co. 764 Young Radiator Co. 692 HEATERS, Cabinet Air-Way Electric Appliance Corp. 617 * GAUCE BOARDS . Consolidated Ashcroft Hancock Co.. Inc. 705 J. E. Lonergan Co. 755 Webster Tallmadge '& Co., Inc. 766 Warren Webster & Co. 761-763 GOVERNORS, Pump C. A. Dunham Co. 742-743 Illinois Engineering Co. 753 Kieley & Mueller, Inc. 754 Mueller Steam Specialty Co. 756 Warren Webster & Co. 761-763 Wright-Austin Co. 764 American Radiator Co. 648-649 Grinnell Co., Inc. 700-703, 745 Thermal Units Mfg. Co. 690 Yound Radiator Co. 692 HEATERS, Electric Air-Way Electric Appliance Corp. 617 GRATES FOR BOILERS AND American Foundry Equipment GAUGE GLASSES FURNACES Co. 689 American Radiator Co. 648-649 American Radiator Co. 648-649 American Radiator Co. 648-649 Jenkins Bros. 777 ' ' L. J. Mueller Furnace Co. 632,658 General Electric Co. 630, 666, 721 Owens-Illinois Glass Co. 643 Unit Heater & Cooler Co. 691 Grinnell Co.. Inc. 700-703. 745 Numerals following Manufacturers' Names refer to pages In the Catalog Data Section 782 Index to Modern Equipment W. F. Hirschman Co., Inc. 778 Ilg Electric Ventilating Co. 684 Thermal Units Mfg. Co. 690 Trane Co., The 760 Westinghouse Electric & Mfg. Co. 636-637, 723 . Young Radiator Co. 692 Clarage Fan Co. 626 C. A. Dunham Co. 742-743 G. & O. Manufacturing Co., The 688 . Grinnell Co., Inc. 700-703, 745 Ilg Electric Ventilating Co. 684 John J. Nesbitt, Inc 698-699 Niagara Blower Co. 734-735 Hoffman Specialty Co., Inc. 746 751 L. J. Mueller Furnace Co. 632, 658 ^ National Radiator Corp. 652-653 F. I. Raymond Co. 765, 776 Sarco Co., Inc. 758-759 Webster Tallmadge & Co., Inc- HEATERS, Feed Water Bell & Gossett Co. 693 McDermott Water Heaters, Inc. 694 Parkinson Heater Co. 695 HEATERS, Gas American Radiator Co. 648-649 Kewanee Boiler Corp. 664-665 United States Radiator Corp. 656 HEATERS, Hot-Water Service Parkinson Heater Co. 695 766 ' Thermal Units Mfg. Co. 690 - ` Thermal Units Mfg. Co. 690 Trane Co., The 760 Trane Co., The 760 Unit Heater & Cooler Co. 691 United States Radiator Corp. 656 United States Radiator Corp. 656 Warren Webster & Co. 761-763 Westinghouse Electric & Mfg. Williams Oil-O-Matic Heating Co. 636-637, 723 Corp. 667 Williams Oil-O-Matic Heating HEATING SYSTEMS. Vacuum Corp. 667 American Radiator Co. 648-649 L. J. Wing Mfg. Co. 682-683 Barnes & Jones, Inc. 739 Young Radiator Co. 692 -Chicago Pump Co. 728-729 American Radiator Co. 648-649 American District Steam Co. 677 Bell & Gossett Co. 693 Burnham Boiler Corp. 647 ` HEATERS, American Unit, Gas Fired Radiator Co. 648-649 Buffalo Forge Co. 680 D. G. C. Trap & Valve Co., Inc. 744 C. A. Dunham Co. 742-743 Grinnell Co., Inc. 700-703, 745 Crane Co. 650-651 HEATING SYSTEMS, Air ` William S. Haines & Co. 752 Fitzgibbons Boiler Co., Inc. 662 Aerofin Corp. 685-687 Hoffman Specialty Co., Inc. 746 663 Air-Way Electric Appliance Corp. 751 General Electric Co. 630,666,721 617 Illinois Engineering Co. 753 Kewanee Boiler Corp. 664-665 American Blower Corp. 618-619 L. J. Mueller Furnace Co. 632, McDermott Water Heaters, Inc. American Foundry Equipment 658 c 694 Co. 689 F. I. Raymond Co. 765, 776 ^ Parkinson Heater Co. 695 Buckeye Blower Co. 698-699 Sarco Co., Inc. 758-759 Petroleum Heat & Power Co. Carrier 620-625 Thermal Units Mfg. Co. 690 668-671 General Electric Co. 630,666,721 Trane Co., The 760 United States Radiator Corp. 656 Meyer Furnace Co., The 631 United States Radiator Corp. 656 Weil-McLain Co. 657 L. J. Mueller Furnace Co. 632, Warren Webster & Co. 761-763 Westinghouse Electric & Mfg. Co. 636-637, 723 HEATERS, Indirect Aerofin Corp. 685-687 American Radiator Co. 648-649 . Bayley Blower Co. 679 Bell & Gossett Co. 693 658 John J. Nesbitt, Inc. 698-699 Niagara Blower Co. 734-735 Thermal Units Mfg. Co. 690 Uni-Flo Grille Corp. 737 Unit Heater & Cooler Co. 691 L. J. Wing Mfg. Co. 682-683 HEATING SYSTEMS, Vapor Air-Way Electric Appliance Corp. 617 _ ^ American Radiator Co. 648-649 American District Steam Co. 677 Barnes & Jones, Inc. 739 D. G. C. Trap & Valve Co., Inc- G & O Manufacturing Co., The HEATING SYSTEMS, Furnace 744 : 688 American Blower Corp. 618-619 C. A. Dunham Co. 742-743 McDermott Water Heaters, Inc. Carrier 620-625 . Grinnell Co.. Inc. 700-703. 745 694 General Electric Co. 630,666,721 William S. Haines & Co. 752 United States Radiator Corp. 656 Meyer Furnace Co., The 631 Hoffman Specialty Co., Inc. 746 Young Radiator Co. 692 L. J. Mueller Furnace Co.> 632 751 HEATERS, Refuse Burning Kewanee Boiler Corp. 664-665 L. J. Mueller Furnace Co. 632, 658 HEATERS, Storage Kewanee Boiler Corp. 664-665 McDermott Water Heaters, Inc. 694 Parkinson Heater Co. 695 United States Radiator Corp. 656 HEATERS, Tank 658 Thermal Units Mfg. Co. 690 Williams Oil-O-Matic Heating Corp. 667 HEATING SYSTEMS, Gas Fired American Radiator Co. 648-649 Carrier 620-625 Crane Co. 650-651 Meyer Furnace Co., The 631 L. J. Mueller Furnace Co. 632, 658 Illinois Engineering Co. 753 L. J. Mueller Furnace Co. 632, 658 National Radiator Corp. 652-653 F. I. Raymond Co. 765, 776 Sarco Co., Inc. 758-759 Webster Tallmadge & Co., Inc. 766 Thermal Units Mfg. Co. 690 Trane Co., The 760 United States Radiator Corp. 656 Warren Webster & Co. 761-763, , American Radiator Co. 648-649 HEATING SYSTEMS, Hot- HEAT SURFACE, Fan System Burnham Boiler Corp. 647 Water Aerofin Corp. 685-687 ' Kewanee Boiler Corp. 664-665 American Radiator Co. 648-649 Air-Way Electric Appliance Corp. McDermott Water Heaters, Inc. 694 Bell & Gossett Co. 693 Burnham Boiler Corp. 647 617 " American Blower Corp. 618-619 L. J. Mueller Furnace Co. 632, 658 Parkinson Heater Co. 695 United States Radiator Corp. 656 . Weil-McLain Co. 657 HEATERS, Unit Aerofin Corp. 685-687 Air-Way ElectricAppliance Corp. Crane Co. 650-651 Grinnell Co.. Inc. 700-703, 745 L. J. Mueller Furnace Co. 632, 658 National Radiator Corp. 652-653 Thermal Units Mfg. Co. 690 United States Radiator Corp. 656 Williams Oil-O-Matic Heating Corp. 667 Bayley Blower Co. 679 . Carrier 620-625 ,,G & O Manufacturing Co., The 688 Thermal Units Mfg. Co. 690 Trane Co., The 760 L. J. Wing Mfg. Co. 682-683 Young Radiator Co. 692 617 American Blower Corp. 618-619 HEATING SYSTEMS, Steam HOT WATER HEATING SYS TEMS (See Heating Systems, American Foundry Equipment Co. 689. Bayley Blower Co. 679 Buckeye Blower Co. 698-699 Buffalo Forge Co. 680 Burnham Boiler Corp. 647 Carrier 620-625 Champion Blower & Forge Co. 681 Air-Way Electric Appliance Corp. Hot Water) 617 _ American Radiator Co. 648-649 HUMIDIFIERS Barnes & Jones, Inc. 739 Air-Way Electric Appliance Corp. Burnham Boiler Corp. 647____ 617 Crane Co. 650-651 American Blower Corp. 618-619 C. A. Dunham Co. 742-743 American Radiator Co. 648-649 Grinnell Co., Inc. 700-703, 745 Buffalo Forge Co. 680 William S. Haines & Co. 752 Burnham Boiler Corp. 647 Numerals following Manufacturers' Names refer to pages In the Catalog Data Section 783 American Society of Heating and Ventilating Engineers Guide, 1934 Carrier 620-625 Grinnell Co., Inc. 700-703, 745 W. F. Hirschman Co.. Inc. 778 Johnson Service Co. 770-771 Minneapolis-Honeywell Regula tor Co. 772-773 L. J. Mueller Furnace Co. 632, 658 Parks-Cramer Co. 633 Powers Regulator Co. 774-775 Thermal Units Mfg. Co. 690 Trane Co., The 760 Unit Heater & Cooler Co. 691 Weil-McLain Co. 657 Westinghouse Electric & Mfg. Co. 636-637, 723 York Ice Machinery Corp. 638 Young Radiator Co. 692 INSULATION, Sound Deadening Alfol Insulation Co., Inc. 708 Samuel Cabot, Inc. 709 Celotex Co., The 710-711 International Fibre Board, Ltd. 714 Johns-Manville 712-713 Mundet Cork Corp. 715 Owens-Illinois Glass Co. 643 Upson Co., The 716 INSULATION, Underground Steam Pipe ~ American District Steam Co. 677 Johns-Manville 712-713 Owens-Illinois Glass Co. 643 Ric-wiL Co., The 717 ORIFICES, Radiator Webster Tallmadge & Co., Inc. 766 PACKING Jenkins Bros- 777 Johns-Manville 712-713 PIPE, Asbestos-Cement Johns-Manville 712-713 PIPE BENDING E. B. Badger & Sons Co. 678 Crane Co. 650-651 Grinnell Co.. Inc. 700-703, 745 PIPE, Brass ` Chase Brass & Copper Co. 676, 696-697 HUMIDIFIERS. Unit Air-Way Electric Appliance Corp. 617 American Radiator Co. 648-649 Buffalo Forge Co. 680 Carrier 620-625 Chase Brass & Copper Co. 676, 696-697 Clarage Fan Co. 626 G & O Manufacturing Co., The INSULATION, Ventilating Ducts Samuel Cabot, Inc. 709 Celotex Co., The 710-711 Johns-Manville 712-713 Mundet Cork Corp. 715 Owens-Illinois Glass Co. 643 LOUVRES Champion Blower & Forge Co. 681 PIPE COILS (See Coils, Pipe) PIPE CONDUITS (See Conduits, Underground Pipe) PIPE, Copper Bearing Steel American Radiator Co. 648-649 Republic Steel Corp. 738 . PIPE, Copper Molybdenum Iron Republic Steel Corp. 738 688 Grinnell Co.. Inc. 700-703, 745 . Parks-Cramer Co. 633 Thermal Units Mfg. Co. 690 Westinghouse Electric & Mfg. Co. 636-637, 723 Young Radiator Co. 692 HUMIDITY CONTROL Air-Way ElectricAppliance Corp. 617 American Radiator Co. 648-649 Barber-Colman Co. 768-769 Bristol Co.. The 704 Carrier 620-625 Frick Co. 627 Julien P. Friez & Sons, Inc. 767 Grinnell Co., Inc. 700-703, 745 Johnson Service Co. 770-771 Parks-Cramer Co. 633 Powers Regulator Co. 774-775 Sarco Co., Inc. 758-759 Taylor Instrument Cos. 706-707 Thermal Units Mfg. Co. 690 W. F. Hirschman Co., Inc. 778 Powers Regulator Co. 774-775 Tuttle & Bailey, Inc. 736 MECHANICAL DRAFT APPA RATUS (See Draft Apparatus, Mechanical) METERS, Air Builders Iron Foundry 719 Taylor Instrument Cos. 706-707 METERS, Condensation American District Steam Co. 677 Builders Iron Foundry 719 METERS, Feed Water Builders Tron Foundry 719 METERS, Flow Builders Iron Foundry 719 . Taylor Instrument Cos. 706-707 METERS, Steam . American District Steam Co. 677 Builders Iron Foundry 719 PIPE COVERING (See Covering, Pipes and Surfaces) PIPE FITTINGS (See Fittings, Pipe) PIPE HANGERS (See Hangers, Pipe) . PIPE, Return Bends . Crane Co. 650-651 G & O Manufacturing Co., The 688 Grinnell Co., Inc. 700-703, 745 . Republic Steel Corp. 738 PIPE, Steel .. Babcock & Wilcox Co., The o59. Crane Co. 650-651 *- Republic Steel Corp. 738 ` PIPE, Wrought Iron . Crane Co. 650-651 PITOT TUBES (See Air Measure ing and Recording Instruments)- INCINERATORS Kewanee Boiler Corp. 664-665 METERS, Water Builders Iron Foundry 719 PLASTER BASE, Insulating Celotex Co., The 710-711 . INSERTS; Concrete MOTORS, Electric Johns-Manville 712-713 . Grinnell Co., Inc. 700-703, 745 Barber-Colman Co. 768-769 PLASTER BASE, Sound Westinghouse Electric & Mfg. Century Electric Co. 720 Deadening . - Co., 636-637, 723 General Electric Co. 630, 666, 721 Johns-Manville 712-713 INSTRUMENTS, Indicating and Recording Bristol Co., The 704 Consolidated Ashcroft Hancock Co., Inc. 705 Julien P. Friez & Sons, fnc. 767 Lincoln Electric Co., The 722 Westinghouse Electric & Mfg. Co. 636-637, 723 Williams Oil-O-Matic Heating Corp. 667 NOZZLES, Spray (See Spray PLASTER BASE, Fire Retarding * Johns-Manville 712-713 PRESSURE REDUCING VALVES (See Regulators, Pres sure) General Electric Co. 630, 666, 721 Powers Regulator Co. 774-775 Sarco Co.. Inc. 758-759 " Taylor Instrument Cos. 706-707 INSTRUMENTS (See Weather Instruments) ' INSULATION, Building Alfol Insulation Co., Inc. 708 Samuel Cabot, Inc. 709 Celotex Co.. The 710-711 International Fibre Board, Ltd. 714 Johns-Manville 712-713 Mundet Cork Corp. 715 Upson Co., The 716 Nozzles) OIL BURNER EQUIPMENT Bell & Gossett Co. 693 Champion Blower & Forge Co. 681 Crane Co. 650*651Minneapolis-Honeywell Regula tor Co. 772-773 Parkinson Heater Co. 695 Thermal Units Mfg. Co. 690 Williams Oil-O-Matic Heating Corp. 667 OIL BURNERS Babcock & Wilcox Co., The 659 Petroleum Heat & Power Co. PSYCHROMETERS (See Air Measuring and Recording In struments) PUBLICATIONS American Artisan 724 Domestic Engineering 726 . Heating, Piping and Air Con ditioning 725 PUMP GOVERNORS C. A. Dunham Co. 742-743 Illinois Engineering Co. 753 Kieley & Mueller, Inc. 754 Mueller Steam Specialty Co. 756 Warren Webster & Co. 761-763 INSULATION, Pipes and Sur faces (See Covering, Pipes and Surfaces) . 668-671 Thermal Units Mfg. Co. 690 Williams Oil-O-Matic Heating Corp. 667 ' - ' PUMPS, Air and Gas Nash Engineering Co., The 732- Thermal Units Mfg. Co. 690 Numerals following Manufacturers* Names refer to pages in the Catalog Data Section 784 Index to Modern Equipment PUMPS, Ammonia Goulds Pumps, Inc. 730-731 Nash Engineering Co., The 732 733 . York Ice Machinery Corp. 638 PUMPS, Boiler Feed . Chicago Pump Co. 728-729 Decatur Pump Co. 727 Goulds Pumps, Inc. 730-731 Nash Engineering Co., The 732 733 Trane Co., The 760 Thermal Units Mfg. Co. 690 Trane Co.. The 760 - Tuttle & Bailey, Inc. 736 ' Unit Heater & Cooler Co. 691 Warren Webster & Co. 761-763 Weil-McLain Co. 657 RADIATION, Cast-Iron American Radiator Co. 648-649 Crane Co. 650-651 National Radiator Corp. 652-653 Unit Heater & Cooler Co. 691 United States Radiator Corp. 656 Julien P. Friez & Sons, Inc. 767 Hart & Cooley Mfg. Co. 734 Illinois Engineering Co. 753 Kieley & Mueller, Inc. 754 Powers Regulator Co. 774-775 F. I. Raymond Co. 765, 776 Sarco Co., Inc. 758-759 Webster Tallmadge & Co., In 766 Trane Co., The 760 Warren Webster & Co. 761-763 REGULATORS, Feed Water Kieley & Mueller, Inc. 754 PUMPS, Brine RADIATOR AIR VALVES (See McDonnell & Miller 646 - . Chicago Pump Co. 728-729 Valves, Air) Mueller Steam Specialty Co. 756 Decatur Pump Co. 727 Taylor Instrument Cos. 706-707 Goulds Pumps, Inc. 730-731 RADIATOR ENCLOSURES AND Wright-Austin Co. 764 Nash Engineering Co., The 732 SHIELDS 733 PUMPS, Centrifugal American Radiator Co. 648-649 REGULATORS, Humidity (See Crane Co. 650-651 Humidity Control) G & O Manufacturing Co., The Chicago Pump Co. 728-729 Decatur Pump Co. 727 C. A. Dunham Co. 742-743 General Electric Co. 630,666, 721 Goulds Pumps, Inc. 730-731 Nash Engineering Co., The 732 688 Thermal Units Mfg. Co. 690 Tuttle ; Bailey, Inc. 736 Uni-Flo Grille Corp. 737 United States Radiator Corp. 656 Warren Webster & Co. 761-763 REGULATORS, Pressure American Radiator Co. 648-649 American District Steam Co. 677 Bristol Co.. The 704 . Crane Co. 650-651 C. A. Dunham Co. 742-743 733 ^ Trane Co., The 760 PUMPS, Circulating Bell & Gossett Co. 693 Chicago Pump Co. 728-729 Decatur Pump Co. 727 RADIATOR HANGERS (See Hangers, Radiator) RADIATORS, Cabinet and Concealed American Radiator Co. 648-649 Illinois Engineering Co. 753 Kieley & Mueller, Inc. 754 Mueller Steam.Specialty Co. 756 Powers Regulator Co. 774-775 F. I. Raymond Co. 765, 776 Webster Tallmadge & Co., Inc. - Goulds Pumps, Inc. 730-731 Nash Engineering Co., The 732 Buckeye Blower Co. 698-699 Burnham Boiler Corp. 647 766 Taylor Instrument Cos. 706-707 733 Chase Brass & Copper Co. 676, Warren Webster & Co. 761-763 Trane Co., The 760 PUMPS, Condensation 696-697 Crane Co. 650-651 C. A. Dunham Co. 742-743 REGULATORS, Temperature (See Temperature Control) Chicago Pump Co. 728-729 G & O Manufacturing Co., The Decatur Pump Co. 727 C. A. Dunham Co. 742-743 688 Grinnell Co.. Inc. 700-703, 745. RELIEF VALVES (See Valves, Relief) . , Goulds Pumps, Inc- 730-731 Hoffman Specialty Co., Inc. 746 Trane Co., The 760 Unit Heater & Cooler Co. 691 SAFETY VALVES (See Valves, 751 United States Radiator Corp. 656 Safely) Nash Engineering Co., The 732 Warren Webster & Co. 761-763 733 SEPARATORS, Dust (5 Air Trane Co., The 760 RECEIVERS, Air Cleaning Equipment)- - ' - PUMPS, Oil Goulds Pumps, Inc. 730-731 Petroleum Heat & Power Co. 668-671 PUMPS, Sump Chicago Pump Co. 728-729 Goulds Pumps, Inc. 730-731 Nash Engineering Co., The 732 733 Parks-Cramer Co. 633 Warren Webster & Co. 761-763 RECEIVERS, Condensation Chicago Pump Co. 728-729 Crane Co. 650-651 Decatur Pump Co. 727 Goulds Pumps, Inc. 730-731 Trane Co., The 760 Warren Webster & Co. 761-763 SEPARATORS, Oil Crane Co. 650-651 Goulds Pumps, Inc. 730-731 Illinois Engineering Co. 753 Kieley & Mueller, Inc. 754 Staynew Filter Corp. 644 Warren Webster & Co. 761-763 Wright-Austin Co. 764 SEPARATORS, Steam PUMPS, Turbine Goulds Pumps, Inc. 730-731 Nash Engineering Co., The 732 733 PUMPS, Vacuum Chicago Pump Co. 728-729 REFRIGERATING EQUIP MENT, Steam Jet American Blower Corp. 618-619 Carrier 620-625 Westinghouse Electric St Mfg. Co. 636-637. 723 Crane Co. 650-651 Illinois Engineering Co. 753 Kieley & Mueller, Inc. .754 Warren Webster & Co. 761-763 Wright-Austin Co. 764' SHEETS, Asbestos, Fiat and C. A. Dunham Co. 742-743 . Hoffman Specialty Co., Inc. 746 REFRIGERATING MACHINERY 751 Nash Engineering Co., The 732 ' Carrier 620-625 Frick Co. 627 733 Fridigaire Sales Corp. 628-629 RADIATION, Aluminum, Brass, Copper, Steel, Etc., Plain and Extended Surface Aerohn Corp. 685-687 Air-Way Electric Appliance Corp. Westinghouse Electric & Mfg. Co. 636-637. 723 Williams Oil-O-Matic Heating Corp. 667 York Ice Machinery Corp. 638 Corrugated _ ' Johns-Manville 712-713 SHEETS, Copper Molybdenum Iron _ Republic Steel Corp. 738 , SHEETS, Black, Corrugated, Galvanized . Republic Steel Corp. 738 617 American Radiator Co. 648-649 Buckeye Blower Co. 698-699 REGISTERS (See Grilles, Registers, Etc.) . SHEETS, Copper Bearing Steel Republic Steel Corp. 738 Burnham Boiler Corp. 647 Chase Brass & Copper Co. 676, REGULATORS^ Damper - --. 696-697' Crane Co. 650-651 .. ` American Radiator Co. 648-649 Barber-Colman Co. 768-769 G & O Manufacturing Co., The Bristol Co.. The 704 688 C. A. Dunham Co. 742-743 SHEETS, Special Finish Republic Steel Corp. 738 SHEETS, Stainless Steel Republic Steel Corp. 738 Numerals following Manufacturers' Names refer to pages In the Catalog Data Section 785 American Society of Heating, and Ventilating Engineers Guide, 1934, SHUTTERS. Automatic Champion Blower & Forge Co. 681 Ilg Electric Ventilating Co. 684 L. J. Wing Mfg. Co. 682-683 F. I. Raymond Co. 765, 776 ` Sarco Co., Inc. 758-759 Webster Tallmadge & Co., Inc. 766 Taylor Instrument Cos. 706-707 Thermal Units Mfg. Co. 690 D.?a C. Trap & Valve Co., Inc. C. A. Dunham Co. 742-743 Grinnell Co., Inc. 700-703, 745 Hoffman Specialty Co., Inc. 746- SOUND DEADENING Alfol Insulation Co., Inc. 708 Samuel Cabot, Inc. 709 Johns-Manville 712-713 Upson Co., The 716 Trane Co.. The 760 Warren Webster & Co. 761-763 } THERMOMETERS, Indicating and Recording Illinois Engineering Co. 753 Sarco Co., Inc. 758-759 Trane Co., The 760 Warren Webster & Co. 761-763 SPRAY NOZZLES E. B. Badger fit Sons Co. 678 Buffalo Forge Co. 680 Clarage Fan Co. 626 - Parks-Cramer Co. 633 York Ice Machinery Corp. 638 STEAM HEATING SYSTEMS {See Heating Systems, Steam) STOKERS, Mechanical {See Coal Burners) American Radiator Co. 648-649 Bristol Co.. The 704 Consolidated Ashcroft Hancock Co., Inc. 705 Julien P. Frier & Sons, Inc. 767 New York Air Valve Corp. 757 Powers Regulator Co. 774-775 Taylor Instrument Cos. 706-707 United States Radiator Corp. 656 THERMOSTATS American Radiator Co. 648-649 Barber-Colman Co. 768-769. TRAPS, Return Barnes & Jones. Inc. 739 D. G. C. Trap & Valve Co., Inc. 744 . . * C. A. Dunham Co. 742-743 Grinnell Co., Inc. 700-703, 745 Hoffman Specialty Co., Inc. 746- Illinois Engineering Co. 753 Kieley & Mueller, Inc. 754 Mueller Steam Specialty Co. 756 Warren Webster & Co. 761-763 STRAINERS, Oil Kieley & Mueller, Inc. 754 Mueller Steam Specialty Co. 756 Petroleum Heat fit Power Co. 668-671 Sarco Co., Inc. 758-759 Wright-Austin Co. 764 Consolidated Ashcroft Hancock Co.. Inc. 705 Julien P. Frier & Sons, Inc. 767 Hart & Cooley Mfg. Co. 734 Illinois Engineering Co. 753 Johnson Service Co. 770-771 Minneapolis-Honeyweli Regula tor Co. 772-773 TRAPS, Steam Armstrong Machine Works 740 741 Barnes & Jones, Inc. 739 Crane Co. 650-651 D. G. C. Trap & Valve Co., Inc. 744 C. A. Dunham Co. 742-743 STRAINERS, Steam Illinois Engineering Co. 753 Kieley & Mueller, Inc. 754 Mueller Steam Specialty Co. 756 Powers Regulator Co. 774-775 Sarco Co., Inc. 758-759 Warren Webster & Co. 761-763 Wright-Austin Co. 764 Powers Regulator Co. 774-775 F. I. Raymond Co. 765, 776 Sarco Co.. Inc. 758-759 Webster Tallmadge & Co., Inc. 766 Warren Webster & Co. 761-763 Williams Oil-O-Matic Heating Corp. 667 Grinnell Co., Inc. 700-703, 745 William S. Haines & Co.-752 Illinois Engineering Co. 753 Kieley & Mueller, Inc. 754 Mueller Steam Specialty Co: 756 Powers Regulator Co, 774-775 Trane Co.. The 760 Warren Webster & Co. 761-763 Wright-Austin Co. 764 STRAINERS, Water Kieley & Mueller, Inc. 754 Mueller Steam Specialty Co. 756 Powers Regulator Co. 774-775 Sarco Co., Inc. 758-759 Warren Webster & Co. 761-763 Wright-Austin Co. 764 TRADE PUBLICATIONS {See Publications) - TRAPS, Bucket Armstrong Machine Works 740 741 Crane Co. 650-651 C. A. Dunham Co. 742-743 TRAPS, Thermostatic. . American District Steam Co. te77 Barnes & Jones, Inc. 739 , D. G. C. Trap & Valve Co., Inc. 744 C. A. Dunham Co. 742-743 Grinnell Co., Inc. 700-703. 745 TANK COILS {See Coils, Tank) Illinois Engineering Co. 753 Mueller Steam Specialty Co. 756 William S. Haines & Co. 752 Hoffman Specialty Co., Inc. 746 TANK COVERING (See Covering. Pipes and Surfaces) TANK HEATERS {See Heaters. Tank) Wright-Austin Co. 764 TRAPS, Float Crane Co. 650-651 D. G. C. Trap & Valve Co., Inc. 744 751 Illinois Engineering Co. 753 Powers Regulator Co. 774-775 F. 1. Raymond Co. 765, 776 Sarco Co., Inc. 758^759 Trane Co., The 760 TANKS, Blow-off Bigelow Co., The 660 Kewanee Boiler Corp. 664-665 Illinois Engineering Co. 753 Warren Webster & Co. 761-763 Mueller Steam Specialty Co. 756 ^Webster Tallmadge & Co., Inc. TRAPS, Vacuum - ' 766 Armstrong Machine Works 740 TANKS, Storage American Radiator Co. 648-649 Bigelow Co., The 660 Frick Co. 627 Kewanee Boiler Corp. 664-665 McDermott Water Heaters. Inc. 694 TEMPERATURE CONTROL American Foundry Equipment Co. 689 American Radiator Co. 648-649 Barber-Colman Co. 768-769 Bristol Co.. The 704 Consolidated Ashcroft Hancock Co., Inc. 705 C. A. Dunham Co. 742-743 Julien P. Frier & Sons, Inc, 767 General Electric Co. 630.666,721 Grinnell Co., Inc. 700-703, 745 Hart & Cooley Mfg. Co. 734 Illinois Engineering Co. 753 Johnson Service Co. 770-771 Powers Regulator Co. 774-775 Trane Co., The 760 Warren Webster & Co. 761-763 Wright-Austin Co. 764 TRAPS, Float and Thermostatic American District Steam Co. 677 Barnes & Jones, Inc. 739 D. G. C. Trap & Valve Co., Inc. 744 C. A. Dunham Co. 742-743 Grinnell Co., Inc. 700-703, 745 WilJiam S. Haines & Co. 752 Hoffman Specialty Co., Inc. 746* 751 Illinois Engineering Co. 753 Mueller Steam Specialty Co. 756 Sarco Co., Inc. 758-759 Trane Co., The 760 Warren Webster & Co. 761-763 Wright-Austin Co. 764 TRAPS, Radiator Armstrong Machine Works 740 741 Barnes & Jones, Inc. 739 741 Barnes & Jones, Inc. 739 D. G. C. Trap & Valve Co., Inc. 744 . C. A. Dunham Co. 742-743 Grinnell Co.. Inc. 700-703. 745 Illinois Engineering Co. 753 F. I. Raymond Co. 765, 776 Sarco Co., Inc. 758-759 Warren Webster & Co. 761-763 Wright-Austin Co. 764 TUBES, Boiler Babcock & Wilcox Co., The 659 Republic Steel Corp. 738 * TUBING, Copper Chase Brass & Copper Co. 676, 696-697 TUBING. Steel ` 'Republic Steel Corp.' 738 TURBINE BLOWERS {See Blowers, Turbine) Numerals following Manufacturers' Names refer to pages In the Catalog Data Section 786 Index to Modern Equipment TURBINES Coppus Engineering Corp. 642 General Electric Co. 630,666, 721 L. J. Wing Mfg. Co. 682-683 VALVES, Balanced Illinois Engineering Co. 753 Jenkins Bros. 777 -- Mueller Steam Specialty Co. 756 Warren Webster 8t Co. 761-763 Crane Co. 650-651 Illinois Engineering Co. 753 J. E. Lonergan Co. 755 Mueller Steam Specialty Co. 756 United States Radiator Corp. 656 UNDERGROUND PIPE CON VALVES, Blow-off DUITS (See Conduits. Under Crane Co. 65(M>51 ground Pipe) Jenkins Bros. 777 . . VALVES, Safety ,,_ American Radiator Co. 648-649 Consolidated Ashcroft Hancock Co., Inc. 705 UNIT HEATERS {See Heaters. Unit) UNIT VENTILATORS {See Ventilators, Unit) VALVES, Check Crane Co. 650-651 Frick Co. 627 Illinois Engineering Co. 753 Jenkins Bros. 777 Crane Co. 650-651 Frick Co. 627 Jenkins Bros. 777 J. E. Lonergan Co. 755 New York Air Valve Corp. 757 UNITS, Air Conditioning Aerofin Corp. 685-687 Air-Way Electric Appliance Corp. 617 American Blower Corp. 618-619 Warren Webster & Co. 761-763 VALVES, Float Illinois Engineering Co. 753 Mueller Steam Specialty Co. 756 Warren Webster & Co. 761-763 VALVES, Stop and Check {See Valves, Non-Return) ` VAPOR HEATING SYSTEMS {See Heating Systems, Vapor) Buckeye Blower Co. 698-699 Buffalo Forge Co. 680 Carrier 620-625 Clarage Fan Co. 626 Frick Co. 627 VALVES, Gate American.Radiator .Co. 648-649 Crane Co. 650-651 Jenkins Bros. 777 Frigidaire Sales Corp. 628-629 G & O Manufacturing Co., The 688 General Electric Co. 630,666,721 VALVES, Hydraulic Crane Co. 650-651 Jenkins Bros. 777 Grinnell Co.. Inc, 700-703, 745 W. F. Hirschman Co., Inc. 778 Ilg Electric Ventilating Co. 684 Meyer Furnace Co., The 631 L. J. Mueller Furnace Co. 632, 658 VALVES, Non-Return Crane Co. 650-651 Illinois Engineering Co. 753 Jenkins Bros. 777 Kieley & Mueller, Inc. 754 John J. Nesbitt, Inc. 698-699 Thermal Units Mfg. Co. 690 Trane Co., The 760 Westinghouse Electric & Mfg. VALVES, Pump * Jenkins Bros. 777 Johns-Manville 712-713 VENTILATORS, Floor and Wall American Blower Corp. 618-619 Independent Register & Mfg. Co. 735 Knowles Mushroom Ventilator Co. 639 . ,, L. J. Mueller Furnace Co. 632, 658 Tuttle fit Bailey, Inc. 736 Uni-Flo Grille Corp. 737 . VENTILATORS, Mushroom American Blower Corp. 618-619 Knowles Mushroom Ventilator Co. 639 L. J. Mueller Furnace Co. 632, 658 ` VENTILATORS, Roof Co. 636-637, 723 Williams Oil-O-Matic Corp. 667 Heating ' VALVES, Pressure Reducing {See Regulators, Pressure) ' W. F. Hirschman Co., Inc. 778 Johns-Manville. 712-713. L. J. Wing Mfg. Co. 682-683 York Ice Machinery Corp. 638 VACUUM HEATING SYSTEMS {See Heating Systems, Vacuum) VALVES, Air American Radiator Co. 648-649 Barber-Colman Co. 768-769 Burnham Boiler Corp. 647 C. A. Dunham Co. 742-743 Hoffman Specialty Co., Inc. 746 751 Illinois Engineering Co. 753 Jenkins Bros. 777 Minneapolis-Honeyweli Regula tor Co. 772-773 New York Air Valve-Corp. 757 Powers Regulator Co. 774-775 United States Radiator Corp. 656 VALVES, Radiator American Radiator Co. 648-649 Barnes & Jones, Inc. 739 Crane Co. 650-651 D. G. C. Trap & Valve Co., Inc. 744 C. A. Dunham Co. 742-743 Grinnell Co., Inc. 700-703, 745 William S. Haines & Co. 752 Hoffman Specialty Co., Inc. 746 751 Illinois Engineering Co. 753 Jenkins Bros. 777 Johnson Service Co. 770-771 Minneapolis-Honeyweli- Regula tor Co., 772-773 . Powers Regulator Co. 774-775 Sarco Co., Inc. 758-759 Webster Tallmadge & Co., Inc- 766 ` VENTILATORS, Unit American Blower Corp. 618-619 Buckeye Blower Co. 698-699 W. F. Hirschman Co., Inc. 778 John J. Nesbitt, Inc. 698-699 Staynew Filter Corp. 644 . Thermal Units Mfg. Co. 690 Trane Co., The 760 WARM AIR FURNACES {See Furnaces, Warm Air) WARM AIR HEATING SYS TEMS {See Heating Systems, Furnace) WATER CONDITIONING Ferro-Nil Corp. 779 WATER FEEDERS (Se Feeders, VALVES, Angle, Globe and Cross t American Radiator Co. 648-649 Trane Co., The 760 Water) . United States Radiator Corp. 656 Warren Webster 8c Co. 761-763 WATER HEATERS {See Healers, Hot Water Service) Crane Co. 650-651 Frick Co. 627 Grinnell Co.. Inc. 700-703, 745 Illinois Engineering Co. 753 VALVES, Radiator, Orifice Webster Tallmadge & Co., Inc. WEATHER INSTRUMENTS, 766 Indicating and Recording Bristol Co.. The 704 Jenkins Bros. 777 VALVES, Anti-Siphon Petroleum Heat St Power Co. 668-671 VALVES, Back Pressure Crane Co. 650-651 Illinois Engineering Co. 753 Jenkins Bros. 777 . Mueller Steam Specialty Co. 756 VALVES, Radiator, Electric Motor Operated Barber-Colman Co. .768-769 Bell & Gossett Co. 693 Illinois Engineering Co. 753 Minneapolis-Honeyweli Regula tor Co. 772-773 VALVES, Relief American Radiator Co. 648-JQ49 Consolidated Ashcroft Hancock Julien P. Friez & Sons, Inc. 767 Taylor Instrument Cos. 706-707 WELDING AND CUTTING APPARATUS General Electric Co. 630^666,721 Lincoln Electric Co., The 722 Westinghouse Electric & Mfg. Co. 636-637, 723 WELDING FITTINGS {See Numerals following Manufacturers' Names refer to pages in the Catalog Data Section 787 N/ INDEX TO ADVERTISERS American Society of Heating and Ventilating Engineers Guide, 1934 Page Aerofin Corporation, 850 Frelinghuysen Ave., Newark, N. J.................. .......-- 685-687 Air-Way Electric Appliance Corp., 2101 Auburn Ave., Toledo, Ohio........................ 617 Alfol Insulation Co., 830 Chrysler Bldg., New York, N. Y..................................... . 708 American Air Filter Co., Inc., First St. and Central Ave., Louisville, Ky......... 640-641 American Artisan (a pub.), 1900 Prairie Ave., Chicago, 111--............................- ........ 724 American Blower Corp., Detroit, Mich.............................. ........ ..... ................ -... 618-619 American District Steam Co., North Tonawanda, N. Y..................... ............. --;-- 677 American Foundry Equipment Co., Mishawaka, Ind....... ........................................... 689 American Radiator Co., 40 West 40th St., New York, N. Y............................... 648-649 Armstrong Machine Works, 851 Maple St., Three Rivers, Mich............ .......... 740-741 Babcock & Wilcox Co., The, 85 Liberty St., New York, N. Y......................... 659 E. B. Badger & Sons Co., 63-75 Pitts St,, Boston, Mass...................................... .678 Barber-Colman Co., Rockford, 111..... ,........... ........................................................ 768-769 Barnes & Jones, Inc., 128 Brookside Ave., Jamaica Plain, Boston, Mass.................. 739 Bayley Blower Co., 1817 S. Sixty-Sixth St., Milwaukee, Wis....................:................ 679 Bell & Gossett Co., 3000 Wallace St., Chicago, 111....................................................... 693 Bigelow Co., The, New Haven, Conn.... ......... ....................................................... ...... 660 Bristol Co., The, Waterbury, Conn...................... ................. I..... .................................. 704 Buckeye Blower Co., State Rd. and Rhawn St., Holmesburg, Philadelphia, Pa. 698-699 Buffalo Forge Co., 484 Broadway, Buffalo, N. Y................................... ................... -- 680 Builders Iron Foundry, 9 Codding St., Providence, R. I............. ......................... 719 Burnham Boiler Corp., Irvington-on-Hudson, N. Y..................................................... 647 Samuel Cabot, Inc., 141 Milk St., Boston, Mass........................... .............................. 709 Carrier, 850 Frelinghuysen Ave., Newark, N. J.._................................................. 620-625 Celotex Co., The, 919 N. Michigan Ave., Chicago, 111. ........,. ........................ 710-711 Century Electric Co., 1806 Pine St., St. Louis, Mo.......................:.................. ............ 720 Champion Blower & Forge Co., Lancaster, Pa.... .... ........................ .......................... 681 Chase Brass & Copper Co., Inc., Waterbury, Conn,.....,............................... 676, 696-697 Chicago Pump Co., 2330 Wolfram St., Chicago, 111........................................... -- 728-729 Clarage Fan Co., Kalamazoo, Mich.............................. .................................... ............. 626 Consolidated Ashcroft Hancock Co., Inc., Bridgeport, Conn........,.....................--'... 705 Coppus Engineering Corp., 339 Park Ave., Worcester, Mass...................................... 642 Crane Company, 836 S. Michigan Ave., Chicago, 111....:....... :.............................. 650-651 D. G. C. Trap & Valve Co., Inc., 9 East 46th St., New York, N. Y--............... . 744 788 '*' . i n ; - ; Index to Advertisers Page Decatur Pump Co., Decatur, ............................................. ................... ............. .. 727 Detroit Stoker Co., General Motors Bldg., Detroit, Mich--....................................... 674 Domestic Engineering (a pub.), 1900 Prairie Ave., Chicago, III................................. 726 C. A. Dunham Co., 450 East Ohio St., Chicago, 111......-...................................... 742-743 Ferro-Nil Corp., 500 Fifth Ave., New York, N. Y........ -.............................................. 779 Fitzgibbons Boiler Co., Inc., 570 Seventh Ave., New York, N. Y...................... 662-663 Frick Company, Waynesboro, Pa--....................... -....................................................... 627 Julien P. Friez & Sons, Inc., Baltimore, Md............................ ......... ........................... 767 Frigidaire Sales Corp., Dayton, Ohio................... ................................... -.............. 628-629 G. & O. Manufacturing Co., The, 138 Winchester Ave., New Haven, Conn.......... - 688 General Electric Co., 570 Lexington Ave., New York, N. Y--..... ...................... 630,666 /General Electric Co., Schenectady, N. Y........................................... ^...... .................... 721 Goulds Pumps, Inc., Seneca Falls, N. Y................................................................ 730-731 Grinhell Co., Inc., Providence, R. I--,................................... ....................... 700-703, 745 William S. Haines 8c Co., 12th and Buttonwood Sts., Philadelphia, Pa..................... 752 Hart & Cooley Manufacturing Co., 61 W. Kinzie St., Chicago, III........... '............ -- 734 Heating, Piping and Air Conditioning (a pub.) 1900 Prairie Ave., Chicago, 111--1- 725 W. F. Hirschman Co.,.220 Delaware Ave., Buffalo, N. Y........................................ - 778 Hoffman Specialty Co., Inc., Waterbury, Conn.... .......... ........................ -........... 746-751 Ilg Electric Ventilating Co., 2880 N. Crawford Ave., Chicago, III............................. 684 Illinois Engineering Co., Chicago, 111............................ --......... *............... -..... .......... 753 i: Independent Register & Mfg. Co., 3753 East 93rd St., Cleveland, Ohio......... .......... 735 International Fibre Board Limited, Ottawa, Ont., Canada........................ -............... 714 Iron Fireman Manufacturing Co., Portland, Oregon................ ............................ 672-673 f.: /v;.. Jenkins Brothers, 80 White St., New York, N. Y....................-...... ............................ 777 , Johns-Manville, 22 East 40th St., New York, N. Y.............................. -....... 712--713 . Johnson Service Co., Milwaukee, Wis...... ............................-................................. 770--771 E. Keeler Co.,, Williamsport, Pa................-..................... ...... ........................... .......... . 661 Kewanee Boiler Corp., Kewanee, 111.................... ....................................................664-665 Kieley & Mueller, Inc., 34 West 13th St., New York, N. Y........................................ 754 Knowles Mushroom Ventilator Co., 41 N. Moore St., New York, N. Y........ .......... 639 Lincoln Electric Co., 13036 Coit Road, Cleveland, Ohio........ ..................................... 722 J. E. Lonergan Co., 207 Florist St., Philadelphia, Pa--............................................... 755 McDecmott Water Heaters, Inc., 101 Park Ave., New York, N. Y....................... . 694 McDonnell & Miller, Wrigley Bldg., Chicago, 111............................ --....... -................. 646 Meyer Furnace Co., The, Peoria, 111....... ,.................. --.............. _................................ 631 Minneapolis-Honeyweli-Regulator Co., 2711 Fourth Ave. S., Minneapolis, Minn.................................................................... . ..... .............................. ........ 772-773 - 789 . . VJ 1 American Society of Heating and Ventilating Engineers Guide, 1934 Page Motorstokor Corp., 290 Hudson St., New York, N. Y......... ........... ........................... 675 L. J. Mueller Furnace Co., 2009 W. Oklahoma Ave., Milwaukee, Wis.............. 632, 658 Mueller Steam Specialty Co., Inc., 349-351 West 26th St., NewYork, N. Y............ 756 Mundet Cork Corp., 450 Seventh Ave., New York, N. Y................ 715 Nash Engineering Co., The, South Norwalk, Conn...... ............................ -........... 732-733 National Radiator Corp., Johnstown, Pa.,.............................................................. 652-653 John J. Nebsitt, Inc., State Rd. and Rhawn St., Holmesburg, Philadelphia, Pa... 698-699 New York Air Valve Corp., 476-478 Broome St., New York, N.Y--..........................757 Niagara Blower Co., 6 East 45th St., New York, N. Y........................................ 634-635 Owens-Illinois Glass Co., Toledo, Ohio........................................................................... 643 Parkinson Heater Corp., 11 West 42nd St., New York, N. Y..................................... 695 Parks-Cramer Co., Fitchburg, Mass................................................................................ 633 Petroleum Heat & Power Co., Stamford, Conn..................................................... 668-671 Powers Regulator Co., 2719 Greenview Ave., Chicago, 111................................... 774-775 F. I. Raymond Co., 929 W. Washington Blvd., Chicago, 111............................. :. 765, 776 Republic Steel Corp., Youngstown, Ohio.,....................'................................................. 738 Ric-wiL Co., The, Union Trust Bldg., Cleveland, Ohio..... .......................................... 717 Sarco Co., Inc., 183 Madison Ave., New York, N. Y........................................... 758-759 Spencer Heater Co., Williamsport, Pa.................................................................... 654-655 Staynew Filter Corp., 6 Leighton Ave., Rochester, N. Y...... ............ ;........... .......... :. 644 Webster Tallmadge & Co., Inc., New York, N. Y........................................................ 766 . Taylor Instrument Companies, Rochester, N. Y................................................... 706-707 Thermal Units Manufacturing'Co., Pershing Rd. and Loomis St., Chicago, HI............ 690 . Trane Company, The, La Crosse, Wis........ ...... ........................................................... 760 Tuttle & Bailey, Inc., New Britain, Conn.............................................................'......... 736.- > Underground Steam Construction Co., 75 Pitts St., Boston,. Mass............................ 718 Uni-Flo Grille Corp., 4646 Lawton Ave., Detroit, Mich.............................................. 737 Unit Heater & Cooler Co., The, Wausau, Wis ........................................................... 691 . United States Radiator Corp., Detroit, Mich .......................:.................................. 656 Upson Company, The, Lockport, N. Y.......................................................................... 716 Vinco Co., Inc., The, 305 East 45th St., New York, N. Y.......................................... 645 Warren Webster & Co., Camden, N. J........................................!............... .......... 761-763 Weil-McLain Co., 641 W. Lake St., Chicago, 111 .................... !................................. 657 Westinghouse Electric & Manufacturing Co., East Pittsburgh, Pa--............ 636-637, 723 Williams Oil-O-Matic Heating Corp., Bloomington, 111................................................ 667 L. J. Wing Mfg. Co., 59 Seventh Ave., New York, N. Y..................................... 682-683, Wright-Austin Co., 315 W. Woodbridge St., Detroit, Mich........................................ 764^0 York Ice Machinery Corp., York, Pa..................................... i........................................638 Young Radiator Co., Racine, Wis......................... ................ ......................................... 692 790 Roll of Membership AMERICAN SOCIETY o/ HEATING and VENTILATING ENGINEERS 1934 Contains . Lists of Members Arranged Alphabetically and Geographically, also. Lists of Officers and Committees, Past Officers and Local Chapter Officers Corrected to January 1, 1934 Published at the Headquarters of the Society 51 Madison Avenue, New York, N. Y. Officers and Council American Society of Heating and Ventilating Engineers 51 Madison Ave., New York, N. Y. 1933-34 President......................................... ,................. ......................................... ..... -.VV. T. Jones First Vice-President.......................................... ................................................ C. V. Haynes Second Vice-President................................................................................................ .............. .....John Howatt Treasurer.................... .... .............................. ..................................................... D. S. Boyden Secretary. :.A. V. Hutchinson Council W. T. Jones, Chairman C. V. Hayne:s, Vice-Chairman One Year E. K. Campbell E. O. Eastwood Roswell Farnham E. Holt Gurney F. B. Rowley Two Years F. E. Giesecke G. L. Larson J. F. McIntire W. E. Stark Committees of the Council Three Years R. H. Carpenter J. D. Cassell F. C. McIntosh L: Walter Moon ;y Executive: C. V. Haynes, Chairman; G. L. Larson, F. B. Rowley. Finance: John Howatt, Chairman; R. H. Carpenter, F. C. McIntosh. Meetings: Roswell Farnham, Chairman; E. O. Eastwood, J. F. McIntire. Membership: E. .K. Campbell, Chairman; E. Holt Gurney, L. Walter Moon. Advisory Council ' F. B. Rowley, Chairman; W. H. Carrier, Homer Addams, F. Paul Anderson, R. P. Bolton, S. E. Dibble, W. H. Driscoll, H. P. Gant, John F. Hale, L. A. Harding, H. M. Hart, E. Vernon Hill, J. D. Hoffman, S, A. Jellett, D. D. Kimball, S. R. Lewis, Thornton Lewis, J. I. Lyle, J. R. McColl, D. M. Quay, C. L. Riley, F. R. Still and A. C. Willard. - Cooperating Committees -- s A.S.H.V.E. representative on National Research Council: Prof. A; C. Willard (3 years). 3 . '' Special Committees ' Committee on Admission and Advancement: J. D. Cassell, Chairman (one year); F. D. Mensing (two years), and A. J. Offner (three years). Publication Committee: W. E. Stark, Chairman (one year); W. M. Sawdon (two years) A. P-. Kratz (three years). Committee on Constitution and By-Laws: Thornton Lewis, Chairman; R. H. Carpenter and W. E. Stark. Committee on Chapter Relations: E. K. Campbell, Chairman. Guide Publication Committee:. W. L. Fleisher, Chairman; D. S. Boyden, F. E. Giesecke, S. R. Lewis and Perry West.. . Committee on Code for Testing and Rating Condensation and, Vacuum Pumps; John Howatt, Chairman; W. H. Driscoll, L. A. Harding and F. J. Linsenmeyer. Committee on Code for Testing and Rating Convectors: R. N. Trane, Chairman; E.'H. . Beling, R. F. Connell, J. H. Holton, Hugo Hutzel, A. P. Kratz, M. G. Steele and O. G. Wendel. Committee on Nomenclature: S. R. Lewis, Chairman; W. H. Carrier, P. D. Close, W. H. Driscoll, L. A. Harding, Thornton Lewis, J. F. Mclntire and A. C. Willard. Committee on Ventilation Standards: W. H. Driscoll, Chairman; J. J. Aeberly, F. Paul Anderson, L. A. Harding, D. D. Kimball, J. R. McColl, C. L. Riley, W. A. Rowe, Perry West and A. C. Willard. . Committees--1933 Nominating Committee for 1933 Chapters Cincinnati Cleveland Illinois Massachusetts Michigan .. Western Michigan Minnesota . ' New York- . : Western New York Pacific Northwest Philadelphia Pittsburgh St. Louis Wisconsin Representative H. E. Sproull C. F. Eveleth J. J. Aeberly . E. Q.Cole - J. H. Walker S. H. Downs C. E. Lewis Russell Donnelly M. C. Beman P'. M. O'Connell W. R. Eichberg R. B. Stanger . C. A. Pickett E. A. Jones Alternate A. A. Blomfeldt F. A. Kitchen J. J. Hayes . W. W. Murphy H. E. Paetz J. H. Van Alsburg A. J. Huch Walter Heibel D. J. Mahoney M. F. Blankin F. C. McIntosh C. R. Davis Ernest S2exely 4 One Year C. A. Booth' F. B. Howell Walter Klie E. N. Sanbern J.'H. Walker Committee on Research G. L, Larson, Chairman J. H. Walker, Vice-Chairman Prof. A. C. Willard, Technical Adviser . F. C. Houghten, Director O. P. Hood, Ex-Officio Member Two Years D. E. French F..E.'Giesecke - L. A. Harding G. L. Larson A. P. Kratz Three Years Albert Buenger S. H. Downs H. N. Kitchell H. R. Linn Perry West Executive Committee G. L. Larson, Chairman C. A. Booth L. A. Harding Finance Committee , J. H. Walker, Chairman E. C. Evans Thornton Lewis C. V. Haynes R. N. Trane Technical Advisory Committees, 1933-1934 -. Air Conditions and Their Relation to Living Comfort: C. P. Yaglou, Chairman; J. J. Aeberly, W. L. Fleisher, D. E. French, Dr. R. R. Sayers and Dr. C.-E. A. Winslow. Air Flow Through Registers and Grilles; John. Howatt, Chairman; J. J. Aeberly, L. E. Davies, D. E. French and J. J. Haines. Atmospheric Dust and Air Cleaning Devices (Including Dust and Smoke): H. C. Murphy, Chairman; J. J. Bloomfield, Albert Buenger, Philip Drinker, Dr. Leonard Greenburg, Dr. E. V. Hill, Samuel R. Lewis, H. B. Meller, Games Slayter and Dr. S. W. Wynne. . Correlating Thermal Research: R. M. Conner, Chairman; D. S. Boyden, J. C. Fitts, H. T. Richardson and Perry West. . Corrosion: J. H. Walker, Chairman; H. F. Bain, E. L. Chappell, W. H. Driscoll and R. R. Seeber. Direct and Indirect Radiation with Gravity Air Circulation: H. F. Hutzel, Chairman; A. P. Kratz, H. R. Linn, J. Fi Mclntire, J. P. Magos, T. A. Novotney, R. N. Trane and G. L- Tuve. Gas Heating Equipment: W. E. Stark, Chairman; Robert Harper, E. A. Jones, Thomson King, J. F. Mclntire and H. L. Whitelaw. Heat Transfer of Finned Tubes with Forced Air Circulation: F. B. Rowley, Chairman; H. F. Bain, H. F. Hutzel, W. G. King, A. P. Kratz, E. J. Lindseth, G. L. Tuve and W. E. Stark. . Heat Transmission (Heat Received by and Emitted by Buildings in Relation to Living Comfort): P. D. Close, Chairman; A: B. Algren, R. E. Backstrom, A. E. Stacey, Jr. and J. H. Walker. . . Infiltration in Buildings: D. W. Neison, Chairman; V. W. Hunter, W. C. Randall, E. N. Sanbern, J. G, Shodron and Ernest Szekely. Oil Burning Devices: H, F. Tapp, Chairman; Elliott Harrington, F. B. Howell, J. H. Mcllvaine and L. E. Seeley. ' . Pipe and Tubing (Sizes) Carrying Low Pressure Steam or Hot Water: S. R. Lewis, Chairman; J. C. Fitts, F. E. Giesecke, H. M. Hart, C. A. Hill, R. R. Seeber and W. K. Simpson. Refrigeration in Relation to Air Treatment: A. P. Kratz, Chairman; E. A. Brandt, E. D. Milener, K. W. Miller, F. G. Sedgwick, J. H. Walker and R. W. WaterhU. Sound in Relation to Heating and Ventilation: Warren Ewald, Chairman; C. A. Andree, Carl Ashley, C. A. Booth, V. O. Knudsen, R. F. Norris, J, P. Reis and G. T. Stanton. Ventilation of Garages and Bus Terminals: E. K. Campbell, Chairman; S. H. Downs, T. M. Dugan, E. C. Evans, F. H. Hecht, H. L. Moore and A. H. Sluss. 5 Officers of Local Chapters 1933-34 Cleveland Headquarters, Cleveland Meets: Second Friday in Month President, F. A. Kitchen 1514 Prospect Avenue Secretary, M. B. Wright Case School of Applied Science Cincinnati Headquarters, Cincinnati, Ohio Meets: Second Tuesday in Month President, H. N. Kitchell 4528 Circle Avenue Secretary, E. B. Royer 6535 Iris Avenue ' Illinois . Headquarters, Chicago Meets: Second Monday in Month President, C. W. DeLand 211 N. Desplaines Street Secretary,' J. J. Hayes 53 W. Jackson Boulevard . ' ' Kansas City - Headquarters, Kansas City, Mo. ' Meets: Second Monday in Month President, David Caleb 1330 Baltimore Avenue Secretary, C. A. Weiss ` 1811 Troost Avenue . Massachusetts Headquarters, Boston - Meets: First Monday in Month President, Leslie Clough Box 34, Weymouth, Mass. Secretary, E. W. Berchtold . 100 Arlington Avenue . . ' New York University Student Chapter . . Headquarters, New York University President, Herbert Maiman . 79-04--78th Avenue, Glendale,- L. I., N. Y. Secretary, Abraham Rafpes . 977 East 178th Street, New York, N. Y. : Western New York Headquarters, Buffalo Meets: Second Monday in Month President, D. J. Mahoney 503 Franklin Street Secretary, W, E- Voisinet 250 Delaware Avenue , . Ontario ' ' ` - Headquarters, Toronto, Canada Meets: First Monday every other Month President, W. P. Boddington . 106 Lombard Street ; - Secretary. H. R. Roth 1104 Bay Street .. Pacific Northwest Headquarters, Seattle, Wash. Meets: Second Thursday in Month ` President. P. M. O'Connbu, 5749-31at Avenue N.E. ; , Secretary, S. D. Peterson ? . 473 Colman Bldg. - . Philadelphia Headquarters, Philadelphia Meets: Second Thursday in Month : President, M. F. Blankin . 1518 Fair-mount Avenue ` Secretary, W. R, BicbbbRg 4210 Sansom Street Michigan . Headquarters, Detroit * Meets: First Monday after the 10th of the Month President, H. E. Paetz . 2539 Woodward Avenue ' . Secretary, Tom Brown 487 W. Alexandrine Avenue . . Pittsburgh . Headquarters, Pittsburgh . Meets: First Monday t'n Month President, P. A. Edwards 608 Wabash Bldg. - . Secretary, J. L. BlacksHAw 3728 Dawson Street . . . Western Michigan - Headquarters, Grand Rapids Meets: Second Monday in Month President, K. L. ZlESSE 115 Campau Avenue . Secretary, P, O. Wierenga 49 CoJdbrook Street, N.E. . St. Louis '. J Headquarters, St. Louis Meets: First Wednesday *n Month . President, Paul SodemaNn 4136 ^ariin Avenue . Secretary, A. L. Walter$ 7284 Richmond Place, Maplewood, Mo. . ' . Minnesota Headquarters, Minneapolis Meets: Second Monday in Month President, A. B. Algren 5109-17th Avenue S. ' Secretary, C. E, GausMan 2360 Chilcornbe . - r . Southern California '/ Headquarters, Los Angeles Meets: First Tuesday after (he 10th of the Month . President, W. H. C. Ness 1323 Charming Street . Secretary, E. Hi Kendall , 1224 S. San Pedro Street New York ' Headquarters, New York Meets: Third Monday in Month ` President, H. L. Alt ' 18-C Kearny Street, Newark; N. J. ; ' Secretary, T. W. Reynolds ' . . 100 Pinecrest Dr., Hastings-on-Hudson, NT. Y. . Wisconsin Headquarters, Milwaukee Meets: Third Monday in Month President, J. S; Jung `' - 2409 W. Greenfield Avenue . Secretary, G. E. Hochstetn 3000 W. Montana Street f -' . ' 6 Roll of Membership American Society o/Heating and Ventilating Engineers 1933-34 HONORARY MEMBERS . BALDWIN, WM. J. (1915), New York, N. Y. (Deceased May 7, 1924.) BILLINGS, DR. J. S. (18%), New York, N. Y. (Deceased March 10, 1913.) 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, DC. . . JEZXETT, STEWART A. (Charter Member), (Presidential Member), Philadelphia, Pa. LIST OF MEMBERS IN GOOD STANDING Arranged Alphabetically--All Grades (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. . A. ` ' ADLER, Alphonse A.* (M 1921), Consulting Engr., 35 Stewart Ave., Arlington, N. J. ABBOUD, Alfred (M1930; A 1930; J1924), Alfred AEBERLY John J.* (M 1928), Chief of Div. of , Abboud & Co., Inc., 334 Shawmut Ave., Boston, and (for mail), 119 LaGrange St., West Roxbury, Mass:. ! Heating Ventilation and Industrial Sanitation,' Chicago Board of Health, 704 City-Hall, and (for mail), 6321 N. Oak Park Ave., Norwood Park . ABEL, D. Morgan (J 1928), Box 21, Rochelle, La. P. O., Chicago, III. ' ABRAHAM, Leonard (5 1932), Student, New AHEARN, William J. (M 1929), Htg. and Vtg. York University, New York, and (for mail), 37 S. Engr., 21 Lake Rd., Cochituate, Mass.. . .Washington St., Tarrytown, N. Y. ABRAMS, Abraham (M 1927; J1924), (for mail), 100 Clove Rd., and Abbey Htg. Co., Inc., New AHLBERG, Henry B. (/ 1933), Engr. (for mail). Chase Brass & Copper Co., Erskine Radiator. Div., and 157- Hillside Ave., Waterbury, Conn.' ' Rochelle, N. Y. ACHESON, Albert R. (M 1919), Consulting Engr. ' 601 Eckle Theatre Blag., Syracuse, N. Y. ADAMS, Benjamin (M. 1919), Dist. Mgr. (for mail), American Blower Corp., 612 Otis Bldg.. ' . and 3006 W. Coulter St., Queen Lane Manor, Philadelphia, Pa. . f ADAMS, Charles W. (M 1920). U. S. Radiator Corp., 1405 West 11th St., Kansas City, Mo. ADAMS, Harold E. (M 1930), Nash Engineering Co., South Norwalk, Conn. ADAMS, Neil D. (M 1929; A 1925; / 1922), Supt. AHLFF, Albert A. (M 1923; A 1918), New York Mgr. (for mail), Spencer Heater Co., 101 Park Ave., New York, and 150 Sickles Ave., New ' Rochelle, N. Y. . AKERS, George W. (M 1929), Secy-Treas. (for mail), George W. Akers Co., 2847 Grand River . Ave., Detroit, and 424 Willitts, Birmingham. . . Mich. ALCOTT, William L. (A 1929), 945 Liberty Ave., Pittsburgh, Pa. . .. ALFSEN, Nikolai (M 1933), Partner, Alfsen S , . (for mail), Franklin Heating Sta., 220 Second . Gunderson Prinsensgt 2C, Oslo, Norway. >. Ave. S.W., and 836 Eighth Ave. S.W., Rochester, ALGREN, Axel B.* (M1930), Instr. Mech. Engrg., , Minn. *> ADAMS, WilUam H. (S 1930), 19 S. Main St., University of Minnesota, Exp, Engrg. Lab., and . (for mail), 5109-17th Ave. S., Minneapolis, Minn- ' Colchester, Conn. .. ` ALLINSON, Orrie H. (M 1915), Plbg. and Htg. . ADDAMS, Homer (Charier Member; Life Member), Contractor, Jobstown, N. J. (Presidential Member), Pres., 1924; 1st Vice-Pres., 1923; Treas., 1915-1922; Council, 1915-1925). Pres. Kewanee Boiler Co., Inc., and Fitzgibbons Boiler Co... Inc., 570 Seventh Ave., New York, n.y. : " . ADLAM, T." Napier (M 1932).Chief Engr.. Sarco Co., lac., 183 Madison Ave., New York, N. Y- and (for mail), 904 Linden St., Bethlehem, Pa. : ALT, Harold L.* (M 1913), Bldg. Equip. Engr., ' Gibbs & Hill, Penn. Sta., New York, N. Y., and. (for mail), 18-C Kearny St., Newark, N. J. . ALVORD, Arthur M. (M 1926), Pres, (for mail). Alvord & Swift, Grand Central Terminal, New York, and 240 Hamilton Ave., New Rochelle, N. Y. - * , ' 7 American Society of Heating and Ventilating Engineers Guide, 1934 AMES, Charles F. (A 1928), Vice-Pres. (for mail), Ames Pump Co., Inc., 30 Church St., New York, and 3175-29th St., Long Island City, N. Y. AMMERMAN, Charles R, (M 1916)> 924 Conti nental Bk. Bldg.. Indianapolis, Ind. AMUNDSON, Leland R. (S 1932), 1227 Fourth St.. S.E., Minneapolis, Minn. AXEMAN, James E. (M 1932; A 1931; 7 1925), Br. Mgr. (for mail), Spencer Heater Co,, 1205 Court Sq. Bldg., and 908 Old Oak Rd.. Stoneleigh, Baltimore, Md. AXTHELM, Fred G- (A 1930), 648 N. Forest Ave., Webster Groves, Mo. ANDEREGG, R. H. (Af 1920), Mgr., Air Cond. Dept., The Trane Co., and (for mail), 324 North B 24th, LaCrosse, Wis. ANDERSON, David B. (S 1933), Pioneer Hall, Minneapolis, Minn. ANDERSON, F. Paul* (Af 1921). (.Presidential Member), Pres., 1927; 1st Vice-Pres., 1926; 2nd * Vice-Pres., 1925; Council, 1924-1928), Dean (for mail). College of Engrg-, University of Kentucky, and 1018 Richmond Rd., Lexington, Ky. ANDERSON, Samuel W., Jr. {J 1930), Alderson, W. Va. ANDERSON, William M., Jr. (7 1929),. 600 Schuylkill Ave., Philadelphia, Pa. ANGUS, Harry H.* (Af 1918). -(Council. 1927 1929), .Consulting Engr., 25 Bloor St., W., and (for mail), 34 Farnham Ave., Toronto, Ont., Canada. ANKER, George W. (5 1933). 27 Jeannette St., Albany, N. Y. ARCHDEACON, Howard K. (S 1933), 28 Niles Pi., Yonkers. N. Y. BABBITT, William D. (5 1930), Assoc, to the Scout Executive (for mail), Boy-Scouts of America, 214 Investment Bldg.. Fourth Ave., and 5546 Pocussett St.. Sq. Hill, Pittsburgh, Pa. BACHLER, Leonard J. (Af 1918). 304 East 41st * St., New York, N. Y. BACHMAN, August (A 1933) t Executive Secy, (for mail). Heating & Piping Contractors Cincin nati Assq.. 909-910 Times Star Bldg., and 610 Terrace Ave., Cincinnati, Ohio. BACKSTROM, Russell E. (A 1931; 7 1928), (for mail). Wood Conversion Co., E-808 First Natl. Bk. Bldg., and 543 S. Snelling Ave., St. Paul, Minn- BACKUS, Theodore H. L. (Af 1916), Schumacher & Backus, 200-208 Hil) St., Ann Arbor, Mich. BADGETT, W. Howard* (,71932). Research Asst.. Texas Engrg. Exp. Sta., Box 208 Faculty Exchange, College Sta., Texas. BAHNSON, Frederick F* (M 1917), V/ce-Pres. ARENBERG, Milton K. (A 1920), Dist. Mgr. (for mail), Ug Electric Vtg. Co., 182 N. LaSalle St.,. and Chief Engr- (for mail). The Bahnson Co., 1001 S. Marshall St., and 28 Cascade Ave., Chicago, and 1033 S. Linden. Ave., Highland Park. 111. Winston Salem, N. C. ' . BAILEY, Edward P., Jr. (M 1925). Vice-Pres. in ARMAGNAC, Arthur S. (M 1914; A 1907), Vice- charge of Operations (for mail). 17825 St. Clair Pres., Frost Research Labi, 30 Church St., New Ave., and 16376 Glynn Rd., Cleveland Heights, York, N. Y., and (for mail), 375 Upper Mountain Ohio. Ave., Upper Montclair, N. J. BAILEY, James L. (A 1931; 7 1930), Engr. (for ARMSPACH, Otto W * (Af 1919), Chief Engr., KroescbeJl Engrg. Co., 2306 N.- Knox Ave.,- mail). Parks Cramer Co., and 2033 Lyndhurst Ave., Charlotte, N. C. Chicago, and (for mail), 205 S. Summit Ave., Villa Park. 111. BAILEY, Joseph H. (M 1928;- A 1027; 7 1923), Sales Engr. (for mail). Carrier Engrg. Corp,, 180 ARMSTRONG, Asher D. (Af 1931). Crane Co:, 400 Third Ave., N., Minneapolis, Minn. . N. Michigan Ave., and 1613 Farweli Ave., Chicago, 111. ARMSTRONG, John A. (A 1930), 208 East End Ave., Beaver, Pa. ' ARNOLD, Edward Y. (A 1931), Mgr. (for mail), Plbg. & Htg. Assns., 2324 Hampden Ave., and 1634 Laurel Ave., St. Paul, Minn. BAILEY, W. Mumford (Af 1930), Managing Director, Mumford, Bailey & Preston, Ltd., and . Joint Managing Director, British Trane Co., Ltd. (for mail), "Newcastle House," Clerkenweli Close, London EC1, and "Oldbury Court," Dainesway, Thorpe Bay, Essex, England. ARNOLD, Robert S. (A 1926; 7 1922), Sales Supervisor (for mail),. Carrier Corp., 12 South BAKER, Howard C. (Af 1921), The H. C. Baker Co.. 128 S. St. Clair St., Toledo, Ohio. ` 12th St., Philadelphia, and Wallingford, Pa. * BAKER, Irving C. (Af 1921), Mgr., Air Cond. Div. ARNOLDY. William F. (A 1930), Br. Mgr. (for . (for mail), York Ice Machinery Corp., and 604 mail). 2847 Grand River Ave., 'Detroit, and 520 Linden Ave., York, Pa. St. Clair Ave., Grosse Pointe Village, Mich... ; BAKER, Roland H. (Af 1928; A 1924), Pres, ARONSON, Henry H. (7 1929), 1015. Chestnut St., Philadelphia, Pa. .. (for mail). Baker Engrg. Corp., 145 Broadway, and 244 Brattle St., Cambridge, Mass, ARTHUR, John M. (M 1923), Supt. Commercial BALDWIN, William Howard (Af 1921), Br. Mgr. Light & Steam Sales (for mall), Kansas City (for mail), C. A- Dunham Co., 2988 E. Grand Powet & Light Co., 1330 Grand Ave., Kansas Blvd., and 1622 Virginia Park, Detroit, Mich. City. Mo., and 3311* State Ave., Kansas City, BALSAM. Charles P. (Af 1932), Sales Director, Kans. . House Htg. Div. (for mail), Peoples Gas Light ASHLEY, Carlyle M.* (M 1931), Research Engr. (for mail). Carrier Research Corp:, 750 Freling- huysen Ave., Newark, and 7 Girard PL, Maple wood. N. J. . ASHLEY, Edward E. (Af 1912), Consulting Engr., 10 East 40th St., New York, N. Y., and (for mail). Noroton Heights, Conn. " ASTON. James (Af 1919). A. M. Byers Co.. 235 Water St., Pittsburgh, Pa. '' ATHERTON,- G. R..(Af 1930), 40 West 40th St., New York, N.Y. ATKINS, Thomas J. (Af 1931). Sales Engr., Air Cond-, 119 Kenilworth Rd., Merion, Pa. Co., and Illinois Athletic Club, Chicago, 111. BAMPTON, C. Morton (Af 1919), Gates Htg. Co., Inc., 915 Gates Ave.. Brooklyn, N. Y. BARBERA, Henry A. (5 1932), Student. New ^ York University, College of Engrg., New York, ' and (for mail), 3I46-102nd St., Corona, L. I., N. Y. . BARBIERI, Patrick J. (S 1933), 2166 Belmont Ave., New York, N. Y. BARKER, Charles M. (Af. 1930), B. F. Sturtevant Co., 706 Hollingsworth Bldg., Los Angeles, Calif. BARNES, Ralph B. (Af 1927), Owner. Ralph B. Barnes Htg. Contractor, 212 S. Marion St., and (for mail), 800 Carpenter-Ave., Oak Park, 111. ATKINSON, Kenneth B. (J 1930), Office and . Personal Mgr. (for mail). Carrier Corp., 850 , Frelinghuysen Ave., Newark, and Elizabeth- Carteret Hotel, Elizabeth, N. J. - BARNES, Walter E. (Af 1933), Pres.. Barnes & - Jones, Inc., 128 Brookside Ave., Jamaica Plain, ' Boston, and (for mail), 7 Woodlawn Ave., Wellesley Hills, Mass. ' AUSTIN, Frank L. (Af 1914), Arch, and Engr. (for BARNETT, Stephen J. (A 1931), Barnett Bros., mail), 240 College St., and Lindenwood Farms, . Shelburne Rd.. Burlington, Vt. ` . 1282 Abbott Rd., and (for mail), 131 Pomona PL, Buffalo, N. Y. . AUSTIN, Herbert F., Jr. (S 1932), 295 Bay Ave., Patchogue, N. Y. ` ' BARNS, Amos A. (Af 1933), Owner (for mail), 440 W. State St., Ithaca, N. Y. s R: ? j I K I i i Roll of Membership BARNUM, Marvin C. (Af 1930; A 1928), R 1622 1133 Broadway, New York, N. Y. BARNUM, Willis E., Jr, (Af 1933; A 1933; 7 1930), Sales Engr., York Ice Machinery Co., 5051 Santa Fe Ave., Los Angeles, and (for mail), 2496 Poplar PL, Huntington Park, Calif. BARR, George W. (Af 1905), (Bd. of Governors 1910), Dist. Mgr., Aerofin Corp., Land Title Bldg., Philadelphia, and (for mail), Villanova, Pa. BARRY, James G. Jr, (Af 1933). Vice-Pres. (for mail), Elliott & Barry Engrg. Co., 4060 W. Pine Blvd., and 5051 Queens Ave., St. Louis, Mo. BARRY, Patrick I. (Af 1920), M. Barry, Ltd., 4 Marlboro St., Cork, Ireland. BARTH, Herbert E. (Af 1920), Sales Mgr., American Blower Corp., 6000 Russell St.. Detroit, Mich. , BARTLETT, Amos C. (Af 1919). Dist. Mgr. (for mail), B. F. Sturtevant Co., 89 Broad St., Boston, and 30 Hollingsworth -Ave., Braintree, BENSON, Maurice A. (7 1929), Sales Engr. (for mail), 1238 Brighton Rd.. Pittsburgh, and 619 ~ Highland PL, Bellevue, Pa. BENTZ, Harry (Af 1915), 18 Holland Ter., Montclair, N. J. BERCHTOLD, Edward W. (Af 1927; A 1925), Rate Engr. (for mail). Boston Consolidated Gas Co., 100 Arlington St., Boston, and 20 Randolph St., S., Weymouth, Mass. BERGHOEFER, Victor A. (7 1926), Vice-Pres., Sterling Engrg. Co., 3738 N. Holton, and (for mail), 4129 North 20th St-, Milwaukee, Wis. BERMAN, Louis K. (Af 1908), Pres, (for mail), . Raisler Htg. & Sprinkler Cos., 129 -Amsterdam Ave., and 101 Central Park. W., New York, N. Y. BERMEL Alfred H. (A 1933; 7 1928), 16 Pershing PI., North Arlington. N. J. BERNHARD, George (A 1929), Pres., Bernhard Engrg. Corp., 101 Park Ave., New York, and (for mail). 18 Lisraore Rd., Lawrence, L. I., N. Y. BERNSTROM, Bert (Af 1930), Engr., Lakeside BAMRaTssL. ETT, C. Edwin (M1922), Pr es, (for mail), Bartlett & Co., Inc., 1938 Market St., and 3111 W. Coulter St., Philadelphia, Pa. BASTEDO, Albert E. (Af 1919), Vice-Pres-TreasMgr. (for mail), Burnham Boiler Corp., Irvington-on-Hudson, and Burnside Dr., Hastings-on- Hudson, N. Y. BAUM, Albert L. (Af 1916), Member of Firm (for mail), Jaros, Baum & Bolles, 1350 Broadway, and 601 West 113th St., New Yoik, N. Y. BAUMGARDNER, Carroll Miles (Af 1928). Br. Mgr. (for mail), U. S. Radiator Corp., 3254 N, Kilboum Ave., Chicago, and 602 Michigan Ave., Evanston, III. BAYSE, Harry V.. (Af 1923), American Furnace Co., 2725 Morgan St., St. Louis, Mo. BEASOM, George R. (Af 1927), Sales. Scully Steel Products Co.. 1319 Wabansia, Chicago, and (for mail), 119-Second Ave., Joliet, 111. BEATY, Guy M., Jr. (5 1930). 224 Grandin Rd., Charlotte, N. C. -BEAURRIENNE, Auguste* (Af 1912), Consulting Engr., 25 Rue des Marguettes, Paris, France. BEAVERS, George R. (M 1929), Chief Engr., / Canadian Blower & Forge Co., Ltd., Woodside Ave., and (for mail), 168 Samuel St., Kitchener, Ont., Canada. BEEBE, Frederick E. W. (A 1915), Johnson Service Co., 28 East 29th St., New York, N. Y. BEGGS, William E. (Af 1927), Pres., W. E. Beggs Co., 907 Lloyd Bldg., and (for mail), 3639 Co., Hermansville, Mich. BEST, Millard W. (A 1933). Pres, (for mail), Kolelectric Underfeed Stoker Co., Ltd., 245 Kenilworth Ave. S. and 1750 King St, E., Hamilton, Ont., Canada. BETTS, Howard M. (Af 1927), Senior Mech. Engr.. Htg. & Vtg. (for mail). Dept, of Bldgs.. City of Minneapolis. 213 City Hall, and 4923 Russell Ave., S., Minneapolis. Minn. BETZ, Harry D. (Af 1928). Pres, (for mail), Betz Unit Air Cooler Co.. 6 W. Ninth St., and 4210 Mercer, Kansas City, Mo. BINDER, Charles G- (Af 1920), Mgr. Htg. Dept.. Warren Webster & Co., 17th and Federal Sts., Camden, and (for mail), 115 Oak Ter., Merchant- ville, N. J. BINFORD, Wilmer M. (7 1930), Mgr. Contract Dept.. So. Div. (for mail), 2120 East 25th St., and 6215 San Vicente Blvd., Los Angeles, Calif. BIRCH, Herbert R. (Af 1922), U- S. Radiator Corp., 370 Lexington Ave., New York, N. Y. BIRKHOLZ, H. E. (A 1925), Novelaire Corp.. 1114 Bardstown Rd.. Louisville. Ky. BfRRELL, Allan L. (A 1925), Consulting Engr. (for mail), 372 Bay St., Toronto 2, and 93 Kings- way. Old Mill P. 0-. Ont.. Canada. BIRUKOFF, Roman R. (S 1933). 2034 Grand Concourse Apt. 4c, New York, N. Y. BISCH, Bernard J. (Af 1931), Engr., St: Mary of The Woods College, St- Mary of the Woods, Ind. BISHOP, Charles R. (Life Member; M 1901), 413 Locust St., Lockport, N. Y. Palatine Ave., Seattle, Wash. BISHOP, Frederick R. (Af 1921), Mfrs. Agt., BEIGHEL, Howard Atlee (A 1927), SalesRepr. 8836 Quincy Ave., Detroit, Mich. (for mail). The Herman Nelson Corp., 503 BJERKEN, Maurice H. (A 1927), DisU Repr. (for Columbia Bk. Bldg., Pittsburgh, and 207 Puritan mail), Hoffman Specialty Co., 533 S. Seventh St., .Rd., Rossiyn Farms, Carnegie, Pa. ' and 4952-17th Ave. S., Minneapolis, Minn. BEIRN, John U. (7 1928), 26 Larchmont Ave., BLACK, Edgar N., 3rd (Af 1922), Philadelphia Larchmont, N. Y. BEITZELL, Albert E. (A ig33; 7 1930), 1339. Mgr., Fitzgibbons Boiler Co., Inc., 814 Land Title Bldg., Philadelphia, and (for mail). 111 Girard St., N.W., Washington, D. C. BELING, Earl H. (A 1930; 71925), 2428~I3th St., ` Woodside Rd., Haverford, Montgomery Co., Pa. BLACK, F. C. (Af 1919), Pres, (for mail), F. C. Black Co., 622 W. Randolph St., and 4535 N. Moline, IU. BELL, E. Floyd (Af 1933), Dist. Repr. (for mail), Buffalo Forge Co., 430 Oak Grove St., and 2605 Fremont Ave., S., Minneapolis, Minn. BELT, Newton O. (Af 1929), BlandvUle, Ky. BEMAN,- Myron C. (Af 1926), Consulting Engr. * (for mail). Beman & Candee, 374 Delaware Ave., and 699 Richmond Ave., Buffalo, N. Y. BENEDICT, Everett R. (Af 1926), United Dist. Htg., 4400 Perkins Ave., Cleveland, Ohio. BENNETT. Edwin A. (7 1929), Sales Engr. (tor Ashland Ave.. Chicago, I1L BLACK, George E. (Af 1915), 709 Broad St.. Sewickley Pa BLACK, Harry G. (Af 1917). Prop, (for mail), P. Gormly Co., 155 N. Tenth St., and 927 North 65th St., Philadelphia, Pa. '. BLACK, William B. (7 1932), Salesman, Bryant HeaterCo.,2341 Carnegie Blvd., Cleveland, Ohio. BLACKBURN, Edwin C., Jr. (Af 1929). Consult ing Engr., 12 Clermont Ave., Hempstead, L. J., mail), American Blower Corp., 401 Broadway,n New York, and 51 Chatfield Rd., Bronxville, N.Y. BENNETT, Ralph E. (A 1928), Gen. Sales Mgr; (for mail), Therraax Corp., 228 N. LaSalle St., Chicago, and 670 Hinman Ave., Evanston, III. BENNITT, George E. (M 1918), Consolidated Gas Co. of New York, 4 Irving PL, New York, N. Y. * BLACKHALL, WUmot R. (Af 1922), 332 Waverley Rd., Toronto, Ont., Canada. BLACKMAN, Alfred O. (Af 1911). Consulting Engr. (for mail), 145 West 45th St., and 149 West 12th St., New York, N. Y. BLACKMORE, F. H. (Af 1923), Mgr. Operating Dept..(for mail). U. S. Radiator Corp., Box 686, Detroit, and 515 Tooting Lane, Birmingham, N.Y. ' - BENSON, John C. (.J1930), Engr., Carrier Corp., 2200-12 South 12th St., and (for mail), 6128' Nassau Rd., Philadelphia, Pa. Mich. BLACKMORE, George C. (Charter Member; Life Member), Edgewood, Pittsburgh, Pa. American Soceity of Heating and Ventilating Engineers Guide, 1934 BLACKMORE, J. J * (iCharter Member; Life Member), 32 West 40th St., New York, N. Y. BOYNTON. Daniel W. (A 1927), International Heater Co.. 77 Franklin St., Boston, Mass. BLACKMORE, James S. (J1931), 301 Brushton Ave.r Pittsburgh, Pa. BLACKSHAW, J.X.* (J 1929), Research Engr.. A.S.H.V.E. Research Lab., 4800 Forbes St.,`and (for mail), 3728 Dawson St., Pittsburgh, Pa. BLAKE, Albert Henry (M 1926), 4 Main St. S., BRAATZ, Chester Johnson* (M 1930), Engr. Temp. Control, Barber-Colman Co., and (for mail), 1931 Douglas St., Rockford, 111. BRABBEE, Charles W* (Af 1925), American Radiator Co., 675 Bronx River Rd., Yonkers N. Y. Weston, Ont., Canada. BLAND1NG, George H. (M 1919), 800 N. Lom bard Ave., Oak Park, 111. BRACKEN, John Henry (Af 1927), Mgr.. In dustrial Uses Dept, (for mail). The Celotex Co., 919 N. Michigan Ave., Chicago, 111. BLANKIN, Merrill F. (M 1927; A 1926; J 1919), Pres, (for mad), Haynes. Selling Co.. Inc., 1618 Fairmount Ave., and 3328 W. Penn St., Phila delphia, Pa. . BLISS, George L. (A 1933), Engr. and Sates, (for mail), Allia-Chalmers Mfg. Co., 1410 Waldheim Bldg., 11th and Main, and 7641 Brooklyn Ave., BRADFIELD, William W. (M 1926), Consulting Engr. (for mail), 901 Michigan Trust Bldg., and . 1352 Franklin St. S.E., Grand Rapids, Mich. . BRADFORD, H. H. (A 1927), Asst. Br. Mgr., Minneapolis-Honeywell Co., 2747 Fourth Ave. S., and (for mail), 4701 Blaisdell Ave., Minneapolis, Minn. Kansas City, Mo. ' BLITZ, Emmanuel (Af 1931), 2158 Crotona Ave., New York, N. Y. BRADLEY, Eugene P. (Af 1906), Pres, (for mail), Hester-Bradley Co., 2835 Washington Ave., and 6935 Pershing Ave., St. Louis, Mo. ' BOALES, William G. (A 1923), (for mail), 6537 Hamilton Ave., Detroit, and 195 McMillan Rd., Grosse Pointe Farms, Mich. BOCK, Bernard (A 1929; J 1927), Engrg. Drafts man, 425 Beech St.. Arlington, N. J. . BODDINGTON, William P. (M 1927), Mgr. (for BRAEMER, William G. R. (Af 1915), (for mail), Wm. G. R. Braemer and Josiah H. Smith Engrs., Room 1265 Commercial Trust Bldg., Phila delphia, Pa., and Haddonfield, N. J. BRAKENRIDGE, Charles E. (A 1930), 3817 Johnson Ave., Western Springs, 111. mail). The Canadian Powers Regulator Co., Ltd., 106 Lombard St., and 280 Clendenan Ave., Toronto, Ont., Canada. BODINGER, Jacob H. (Af 1931), 439 West 38th St., New York, N. Y. ` BOGATY, Hermann S. (Af 1921), 5230 North 15th St., Philadelphia, Pa. BOLSINGER, Raymon C. (M 1916), Pres, (for mail). Automatic Florzone Htg. Co., Con . shohocken, Pa., and 238 E. Madison Ave., Collingswood, N. J. BOLTE, E. Endlcott (A 1929), Salesman, Natl. Radiator Coro., 601, No. 1 N. LaSalle St., and BRANDI, O. H. (Af 1930), Office Mgr.,- Carrier Lufttechnische Gesellschaft, Berlin-Charlottenburg II, Savignyplatz 31 and (for mail), Berlin- Wilmersdorf Hohenzollemdamm 35, Germany. . BRANDT, Ernest Hamilton, Jr. (Af 1928), Pres, (for mail). Reliance Engrg. Co., Inc., 1219 Eye St. N.W., Washington, D. C., and Frederick Apts.. Charlotte, N. C. BRASSINGTON, Arthur F. (A 1918), (for mail). 505-7 West 45th St., New York City, and 337 Richmond Ave., Port Richmond,* N. Y. BRAUER, Roy (M 1926), Pres, (for mail). Venti lating Equipment Corp., 1101 Bessemer Bldg.. (for mail), 6516 Kenwood Ave., Chicago, 111. BOLTON, Reginald Pelham* (Life Member; Pittsburgh, and R. F. D. No. 1, Hillcrest Library, Pa. M 1897), (Presidential Member), (Pres., 1911; 1st Vice-Pres., 1905-1910; 2nd Vice-Pres., 1903; Bd. of Governors, 1901, 1905, 1910, 1911, 1912, 1913), The R. P. Bolton Co., 116 East 19th St., BRAUN, John J. (Af 1932), Factory Mgr., The U. S. Playing Card Co., Norwood Sta., Cincin nati, and (for mail), 4305 Floral Ave., Norwood, Ohio. New York, N, Y. . BOND, Horace A, (Af 1930). 12 Ramsey PL, Albany, N. Y. ' .. BOON, George (Af 1915), Boon & Sample, Inc., 3008 Ludlow St., Philadelphia, Pa. BOOTH, C. A. (Af 1917). Vice-Pres. (for mail). BRAUN, Louis T. (Af 1921), Executive Secy, (for mail), Chicago MasterSteamfittere Assn., 228 N. LaSalle St., and 1548 Pratt Blvd., Chicago, 111. BRAYTON, William M. (Af 1926), Sales Engr. (for mail), Robert Gordon, Inc., 22 W. Austin Ave., Chicago, and Cary, 111. . Buffalo Forge Co., 490 Broadway, and 142 Summit Ave., Buffalo, N. Y. BRECKENRIDGE, L. P * (Life Member; M 1920), The Brackens, N. Ferrisburg, Vt. BOOTH, Harry N. (M 1924; A 1917), Vice-Pres., Sales Dept, (for mail), U. S. Radiator Corp., BREDESEN, Bernhard P. (A 1931), 3119 Knox Ave. N., Minneapolis, Minn. Room 1056, 1st Natl. Bk, Bldg., and 688 Taylor Ave., Detroit, Mich. ,. BREITENBACH, George C. (Af 1933; A 1933; J 1928), Sales Engr. (for mail). The Trane Co., BORNEMANN, Walter A- (M 1924; J 1923).. 2006 Chestnut St., Philadelphia, and 300 Essex Carrier-York Corp., 1541 Sansom St., Phila-.. delphia. Pa. HOSTAIN, James C. (Af 1923), 3469 Evanston . Ave., Cincinnati, Ohio. Ave., Apt. 203A, Narberth, Pa. ' BREMSER, Harry A. (A 1930), 239 W. Los Flores Dr., Altadena, Calif. . . BRENEMAN, Robert B. (A 1931; J 1927), Sales BOUEY, Angus J. (J 1930), 706 Hollirigsworth Bldg., Los Angeles, Calif. Engr. (for mail), Armstrong Cork & Insulation Co., 232 W. Seventh St., and 1557 Addingbam BOUILLON, Lincoln (Af 1933), Consulting Engr., PL, Cincinnati, Ohio. 1411 Fourth Ave., Bldg., and (for mail), 4186 42nd Ave. N.E., Seattle, Wash. BREWER, John G. (5 1933), 5549 Bryant St., Pittsburgh, Pa. BOWERS, Arthur F. (A 1919), Pres., Industrial BRIDE, WilUam T. (Af 1928; A 1928; J 1925). Htg. & Engrg. Co., 828 N. Broadway, Mil waukee, WIs. Supt. Engrg. (for mail), P. O. Box 777, Lawrence, and 50 High St., Methuen, Mass. BOWERS, J. S. (Af 1921), J. Sylvan Bowers Sales ' Co., 3805 Page Blvd., St. Louis, Mo. , BOWERS, Ross C. (A 1932), Br. Mgr. (for mail), Minneapolis-Honeywell Regulator Co., 335 W. North Ave., and 3773 North 52nd St., Pittsburgh, Pa. BOWLES, Potter (A 1928), Pres, (for mail), Hoff man Specialty Co.. 3707 Chrysler Bldg.. New York, and 678 Ely Ave., Pelham Manor, N. Y. BOYDEN, Davis S.* (M 1909), (Council. 1917 1930-1933-; Treas., 1933), Supt. Steam Htg. Service Dept, (for mail), Edison Electric Illumi nating Co. of Boston, 39 Boylston St., Boston, and 1496 Commonwealth Ave., Brighton, Mass. BRIDGES, Frank G. (Af 1919), 13602 McElhat- tan Ave., College Sta., Cleveland, Ohio. BRIGHAM, Frederick H. (Af 1930), Sales Engr., G. H. Gleason & Co., 25 Huntington Ave., Boston, and (for mail), 80 Bedford St., Lexington, Mass. ` BRILL, Joseph W. (Af 1932; A 1932; J 1931), 105 Canisteo St., Homell, N. Y. BRINTON, Joseph Ward (Af 1920), Dist. Mgr. (for mail), American Blower Corp., 1003 Statler Bldg., Boston, and 51 Gleason St., West Medford, Mass. ' BRISSETTE, Leo A. (Af 1930), Treas. (for mail), Trask Htg. Co., 4 Merrimac St., Boston, and 168 , Florence St., Melrose, Mass. 10 Roll of Membership BRODERICK, Edwin L. (M 1933). Research Asst, in M. E. (for mail), University of Illinois, 105 M. E. Laboratory, and 1108 W. Stoughton St., Urbana, 111. BRONSON, Carlos E* (Af 1919), Mech. Engr. (for mail), Kewanee Boiler Corp., and 311 McKinley Ave., Kewanee, III. BROOM, Benjamin A. (Af 1914), Sales Promo tion Engr., Weil-McLain Co., 641 W. Lake St., and (for mail), 1311 Farwell Ave., Chicago, 111. BROWN, Alfred P. (Af 1927). B. F. Reynolds 8t; Co.. 609 N. LaSalle St., Chicago, III. . BROWN, Aubrey I.* (Af 1923), Associate Prof, of Htg. and Vtg. (for mail), Ohio State University, and 169 Richards Rd.. Columbus, Ohio. BROWN, Foskett* (Af 1926), Vice-Pres. (for mail), Gray & Dudley Co., 222 Third Ave. N., , P. O.. Box 722, and 2314 West End Ave., Nash BULLOCK, Howard H. (A 1933), General Elec-. trie Co., 5201 Santa Fe Ave., Los Angeles, Calif. BULLOCK, Thomas A. (Af 1930), Engr. (for . mail), Densmore, LeClear 8c Robbins, 31 St. James Ave., Boston, and 39 Fairmont St., Arlington, Mass. BUNKER, Kenneth S. (A 1930), Sales Engr. (for mail). Union Tank & Pipe Co., 2801 Santa Fe Ave., and 352 N. Stanley Ave., Los Angeles; Calif. BUR, Julien R. C. (/ 1931), Chief Engr. (for mail). Bur & Co., 10 Rue du Chapeau Rouge, and 1 Place Francois Rude, Dijon, France. . BVRBAUM, W. Allen (J 1933), Asst. Br. Mgr., . Rex Cole, Inc., 2392 Grand Concourse, New York, and (for mail), 180 Clinton Ave., Brooklyn, N. Y. BURDOIN, Allen J. (S 1933), 2 Sherman St., Lexington, Mass. BURKE, Fletcher H. (Af 1925), 677 Ellicott Sq.. ville, Tenn. BROWN, Morris (J 1928), 609 W. Park St., Dorchester, Mass. . BROWN, Ronald F. (S 1933), 66 Mitchell Ave., Binghamton, N. Y. BROWN, Tom (Af 1930), Owner Air Cond., Mfgrs. Repr. (for mail), 487 W. Alexandrine Ave., , Buffalo, N. Y. BURKE, James J. (J 1930), Engr., Carrier Engrg. ` Corp., 12 South 12th St., Philadelphia, and (for mail), 720 N. Broad St., Elizabeth, N. J. BURNAP, Charles W. (Af 1922), Herman Nelson Corp., 724 Commercial St., Emporia, Kan. Detroit, and 40 Connecticut Ave., Highland BURNETT, Earle'S. (Af 1920), Mech. Engr., U. S. Park, Mich. ; * BROWN, Thomas (A 1931), 41 Glenholme Ave., Bureau of Mines, Amarillo Helium Plant, and (for mail), 4223 West 11th Ave., Amarillo, Texas. Toronto, Ont., Canada. BROWN, William A. (Af 1930), Consulting Engr. BURNS. Edward J. (Af 1923), Supt., H. Kelly & Co , 948 N. W. Bank Bldg., and (for mail), 4710 (for mail), Cucci & Brown, 347 Madison Ave., ' Aldrich Ave. S., Minneapolis, Minn. New York, and 929 East 28th St., Brooklyn, BURNS, John R. (S 1933), 5035 Forbes St., N. Y. r Pittsburgh, Pa. BROWN, William H. (A 1923), 3015 North 22nd BURRITT, Charles G. (A 1916), Mgr. Minne St., Milwaukee, Wis. BROWN, W. Maynard (A 1930), Warren Webster . apolis Office (for mail), Johnson Service Co., 922 Second Ave. S., and Buckingham Hotel, Minne & Co., 17th and Federal Sts., Camden, N. J. . BROWN, W. Murray (S 1930), Draftsman and Estimator (for maU). William P. Brown, 31 Sanford St., and 78 Randolph St., Springfield, apolis, Minn. BUSHNELL, Carl D. (Av1921), Pres, (for mail). The BushneU Machinery Co., 1501 Grant Bldg., Pittsburgh, and 94 Pilgrim Rd., Rosslyn Farms, Mass. BROWNE, Alfred L. (Af 1923), Illinois Engrg. Co.. 3514 Grand Central Terminal, New York, N. Y. BRUCKMANN, John C, (S 1932), 2290 Sedgwick Ave., New York, N. Y. BRUEGGEMAN, Arthur R. (Af 1920), A. R. Brueggeman Co., 1740 East 12th St., Cleveland, ` Ohio. . BRUNETT, Adrian L. (Af 1923), Assoc. Mech. Engr., U. S. Supervising Architects Office, Treasury Dept., Washington, D. G., and (for mail), P. O. Box 236, Rockville, Md. . BRUNT, T. Bayard (Af 1917), 405 Eighth St.. Carnegie, Pa. BUTLER, Peter D. (Af 1922), Salesman, U. S. Radiator Corp., Davis and Central Ave., Har rison, and (for mail), 127 Edgewater Rd., Grant- wood, N. J. . BUTT, Roderick E. W. (J 1930), 3 Onne Court, London W2, England. . BYNUM, Otis W. (A 1930), Carrier Engrg. Corp., 850 Frelinghuysen Ave., Newark, N. J. c Riverton, N, J. CALDWELL, Arthur C. (Af 1930). 550 South 48th BRUST, Otto (M 1930), Prague II, Revolucni 13, St., Philadelphia, Pa. Czechoslovakia. BRYANT, Dr. Alice G. (Af 1921), 502 Beacon St., CALEB, David T, (Af 1923), Engr. (for mail), Kansas City Power & Light Co., 1330 Baltimore Boston, Mass. Ave., and 141 Spruce St., Kansas City, Mo.' BRYANT, Percy J. (Af 1915), Chief Engr. (for mail), Prudential Insurance Co., 783 Broad St., Newark, and 754 Belvidere Ave., Westfield, N. J. BUCHER, Harry G. (J 1930), Junior Htg. Engr., C. A. Dunham Co., 3002 Grant Bldg.. Pittsburgh, and (for mail), 210 Copeland St., McKees Rocks, CALLAGHAN, Philip F., Jr. (J 1929), Sales Mgr., D. G. C. Trap & Valve Co., 9 East 46th St., New York, and (for mail), 3003 Ave. I., Brooklyn, N. Y. CALVERT, Norman W.* (Af 1921), 20 Lime St., Pa. . . BUCK, Lucien (Af 1928), Pres, (for mail). Buck Dryer Corp., P. O. Box 308, Manchester, Conn. BUCKLEY, Martin B. (A 1930), 910 Grand Ave., Boston, Mass. .CAMPBELL, Alfred Q,, Jr. (J 1933), Salesman, E. K. Campbell Htg. & Vtg. Co., and (for mail), 1083 Meriwether Ave., Memphis, Tenn. - Kansas City, Mo. ' CAMPBELL, Everett K.* (Af 1920), (Council, BUENGER, Albert* (Af 1920; A 1917), Mech. Engr. (for mail), C. H. Johnston Archt., 715 Empire Bk. Bldg., and 1666 Stanford, Ave., St. 1931-1933), Pres, and Treas. (for. mail), E. K. Campbell Htg. Co., 2445 Charlotte St., and 3717 Harrison Blvd., Kansas City, Mo.- Paul, Minn. BUENSOD, Alfred Charles (M1918), Sales Engr.. CAMPBELL, E. K., Jr. (J 1930), Thermidaire Corp., 2445 Charlotte St., Kansas City, Mo. Carrier Engrg. Corp., Chrysler Bldg., and (for. CAMPBELL, F. B. (A 1927), (for mail), American mail), I Fifth Ave., New York, N. Y. Radiator Co., 40 West 40th St., New York, and BUFORD, Jack W. (S 1933), 3 Hammond St., 245 Macon St., Brooklyn, N. Y. - .- Cambridge, Mass. . . CAMPBELL, Thomas F. (Af 1928), Minneapolis- BULKELEY, Claude A.* (Af 1923), Chief Engr. Honeywell Regulator Co., 1013 Penn Ave., (for mail), Niagara Blower Co., 6 East 45th St., Wilkinsburg, Pa. ' and 25 Prospect PL, New York, N. Y. ' CAMPBELL, Walter E. (M 1931), 619 Milan BULL, AIvah Stanley (S1933). 304 West 35th SL, Ave., South Pasadena, Calif. `. Minneapolis, Minn. - BULLE1T, Charles R. (Af 1932; A 1932; J 1930), 1630 S. Grand Ave., Evansville, Ind. CANDEE, Bertram C. (Af 1933), Partner, Beman & Candee, 374 Delaware Ave., Buffalo, and (for mail), 19 Tremont Ave., Kenmore, N. Y. 11 American Society of Heating and Venturing Engineers Guide, 1934 'T CANNON, C. Newton (5 1933), General Electric Co., and (for mail), 13 State St., Schenectady; N. Y. CHASE, Chauncey L. (M 1931), Associate. Kopf & Sears, Consulting Engre- 13 East 37th St., CAREY, James A. (M 1928). Carrier Engrg. Corp., Newark, N. J., and (for mail), Villanova, Pa. New York, and (for mail), 8829 Ft. Hamilton Pkwy., Brooklyn, N. Y. CHASE, Louis R. (J 1931), Br. Mgr. (for mail), CAREY, Paul C. (M 1930), (for mail). Runyon & Carey, 33 Fulton St., Newark, and 31 Claremont Dr., Maplewood, N. J. - CAREY, Thomas M. (M 1931), 622 Jefferson Ave- Defiance, Ohio. CARLE, William E. (Jf 1926), Pres, (for mail). Carle-Boehling, Co,, Inc., 1641 W. Broad St., and 2220 Floyd Ave- Richmond. Va. CARLSON, Everett E. (M 1932, A 1929), Br. Mgr. (for mail). The Powers Regulator Co., 1010 Louderman Bldg., and 6652 Washington Ave., St. Louis, Mo. CARMAN, George G. (A 1931; J 1928), Lewis Institute, Chicago, 111. . CARPENTER, R. H. (M 1021), (Council, 1930 1933), Mgr., New York Office (for mail), Nash Engrg. Co.. Graybar Bldg., 420 Lexington Ave., New York, and 10 Jefferson Ave., White Plains, N. Y. Buffalo Forge Co., 217 Dwight Bldg., and 4822 Wornall Rd., Kansas City, Mo. CHERNE, Realto E, (/1929), Engr. (for mail), 916 Temple Bldg., and 280 Westfield St., Rochester N. Y. CHERRY, Lester A.* (M 1921), Construction Engr. (for mail). Industrial Planning Corp., 43 Court St, Buffalo, and 155 Euclid Ave., Ken. more, Erie Co., N. Y. ' CHERVEN, Victor W. (M 1928; A 1920), Chief Engr. (for mail), Holland Fumace Co., and 326 Maple Ave., Holland, Mich. CHESTER, Thomas* (M1917), Consulting Engr., 949 Chicago BVvd., Detroit, Mich. ' CHEYNEY, Charles C. (A 1913). Buffalo Forge Co., 490 Broadway, Buffalo, N. Y. CHOFFIN, C. C. (M1919), Pres-Treas. (for mail). The W. J. Scholl Co., Mahoning Ave. and Hogue St., and 450 Catalina Ave., Youngstown, Ohio. CARR, Maurice L. (M 1931), Director (for mail). Pittsburgh Testing Lab., P. O. Box 1115, and Webster Hall, Pittsburgh, Pa. CARRASCO, Saturnlno (A 1932; J 1928), Monedo 944, Casilla 2405, Santiago, Chile, S. A. CARRIER, Earl G. (J 1929), Estimating Engr., Carrier Engrg. Corp., 850 Frelinghuysen Ave., ' Newark, and (for mail), Essex Fells, N. J. CARRIER, Willis H.* (M 1913), (Presidential Member), (Pres., 1931; 1st Vice-rres- 1930; 2nd Vice-Pres., 1929; Council. 1923-32), Chair man of the Bd. (for mail). Carrier Corp., 850 Frelinghuysen Ave., Newark, and Rensselaer Rd., Essex Fells, N. J. CARROLL, William J. (A 1925), 1344 Broadway. Detroit, Mich. CARSON. Clifford C. (M 1930), 15722 Detroit Ave., Cleveland, Ohio. CARSTEN, William H. (M 1923), Majestic Fumace & Mfg. Co., 1723 Westlake Ave. N.. Seattle. Wash. CARTIER, C. Ernest, Jr. (M 1930), Associate, Htg. and Vtg. (for mail), Clinton S. Robison and Associates. Room 1812, 208 W. Washington St., and 7416 Rogers Ave., Chicago, 111. CASE, Walter Cl (A 1930), Tech. Mgr., National Radiator Co.. Ltd., Ideal .House Gt., Marl borough St., London Wl, and (for mail), 66 The Ridgeway- Kenton,* Middlesex, England. CASEY, Bryon L. (M1921), Sales Engr. (for mail). Hg Electric Vtg. Co., 182 N. LaSalle St., Chicago, CHRISTENSON, Harry (A 1931), Supt of Htg. (for mail). Hunter Prell Co.,-311 Elm St., and 85 * Wentworth Ave., Battle Creek, Mich. CHRISTIAN, Charles W. (M 1913), Mgr. (for mail), Chas. W, Christian Co., P. .O. Box 292, Charlotte, and 1101 Providence Rd., Myers Park, N. C. CHRISTIE, Alfred Y. (A 1933), Salesman. U. S. Radiator Corp., 233 Vassar St., Cambridge, and (for mail), 715 LaGrange St., West Roxbury, Mass. CHRISTMAN, William F. (A 1932; J 1931), Engr. (for mail), Kroeschell Engrg. Co., 2306 N. Knox Ave., and 3912 N. Hoyne Ave., Chicago, 111. CHURCH, Herbert John (M 1922), Mgr. (for mail). Darling Bros., Ltd., 137 Wellington St, WRoom 902, Toronto, and 358 Main SL N., Weston, Ont., Canada. CLARE, Fulton Warren (M 1927), 141 Spring St. N.W., Atlanta, Ga. CLARKE, Samuel S. (Life Member; M 1909). Pres, and Mgr. (for mail), S. S. Clarke & CoLtd., 605 Second St. W- and 603 Second St. W., Calgary, Alta, Canada.' CLARKSON. Robert C., Jr. (M .1921), 6050 Overbrook Ave., Philadelphia, Pa. CLARKSON, W. B. (M 1919), 251 Broadway. Owatonna. Minn. CLEGG, Carl (M 1922), Dist. Mgr. (for mail), American Blower Corp., 311 Mutual Bldg- ana 3321 Gillham Rd., Kansas City, Mo. . CLEGG, Robert R. (A 1933), Zone Repr- Owens, . and 423 N. Prospect Ave., Park Ridge, 111. Illinois Glass Co- Industrial Materials Div.. CASEY, Huntley F. (M 1931). Mech. Engr.. Construction Div- War Dept., Washington. Landreth Bldg- and (for mail),' 4515 Lindell Blvd- St. Louis, Mo. D. C., and (for mail), P. O. Box 271, E. Falls Church, Va. CLODFELTER, John L, (A 1932), Supt. (for mail), Carolina Sheet Metal Corp- 4210 Sansom CASH, Tidle T. (A 1925), Mgr. (for mail). Grinnell Co., Inc., 240 Seventh Ave. S., and 617 Kenwood Pkwy., Minneapolis, Minn. '. CASPERD, Henry W. H. (J 1930), Carrier EngrgCo., Ltd., 12 Mission Row, Calcutta, India. CASSELL, John D* (.Life Member; M 1913), N(C. oJu.ncil, 1930-33), 740 Garfield Ave., Palmyra, CHALLMAN, Samuel A. (M 1919), Director of School Bldgs, for Minn, (for mail). State Dept, of Education, State Capitol, St. Paul. Minn. St- Philadelphia,andWest Chester Pike and Brief Ave., Elizabeth Manor Apt- Upper Darby, Pa. CLOSE, Paul D.* (M 1928),. Chief Engr- In dustrial Uses Div. (for mail), CeJotex Co- 919 N. Michigan Ave- Chicago, and 4622 Grove " Niles Center, IU. , CLOUGH, Leslie (M 1922), Consulting Engr. (for mail). Box 34, and 203 Pierce Rd- Weymouth, Mass. . COE, Ralph T. (M 1917), Prop, (for mail). The R. T. Coe Cos- 400 Reynolds Arcade, and 235 Chili Ave- Rochester, N. Y. . CHANDLER, Clark W. (5 1930), (for mail). COHAGEN, Chandler C. (M 1919), P. O. Box Chandler Co., and 1815 Ridgewood Ter., Cedar 1305, Billings, Mont. Rapids, Iowa. COHEN, Nathan (S 1933), 2305 Loring Pi- New CHAPIN, C. Graham (M 1933), 231 State St. York, N. Y. . ' New London, Conn. . COHEN, Philip (M 1932), Acting Dist. Mgr. (for CHAPPELL, Henry D. (M 1931). Dist. Mgr., V-Belt Drive Co., 100 Morgan Bldg., Detroit, and (for mail), 68 S. Johnson Ave.. Pontiac, .Mich. CHARLTON, John Felder (A 1932), Engr. 1 Appraiser (for mail). Box 2087, and 1631 N.E., Fifth St., Ft. Lauderdale, Fla. mail), B. F. Sturtevant Co- 407 E. Ohio Gas Bldg- Cleveland, and 18519 Kinsman BlvdShaker Heights. Ohio. COLBY. Clyde W< (M 1915), 2341 Carnegie AveCleveland, Ohio. COLCLOUGH, O, T. (A 1933), Custodian, American Legation, American Government Bldgand (for mail), 407 Elgin St., Ottawa, Canada. 12 f i i I s. I i I -V I t * Roll of Membership COLE. Edwin Q. (M 1931). 382 Lebanon St., CRESSY, Ralph E. (J 1929), Sales Engr., Hoffman Melrose, Mass. * ` Specialty Co., Chrysler Bldg- New York, and COLE, Grant E. (A 1925), 439 King St. W.f " (for mail), 408 St. Lawrence Ave- Buffalo, N. Y. Toronto, Ont- Canada. CRIOUI, Albert A.* (Af 1919), Chief Engr- Htg. COLEMAN, John B. (M 1920), Chief Engr.. (for _ and Vtg. Dept., Buffalo Forge Co- 490 Broad mail). Grinnell Co- Inc., 275 W. Exchange St way, and (for mail), 250 Blaine Ave., Buffalo, and 237 Cole Ave- Providence, R. 1. N. Y. COLLAMORE, Ralph (M 1904), (Bd. of Gover- CROFT, Terrell (M 1924), Apartado 563; Mexico 1 nors, 1913), Secy- Smith, Hinchman & Grylls. City, Mexico. 800 Marquette Bldg- and (for mail), 679 CRONE, Charles E- Jr. (M 1922). Secy-Treas. Pingree Ave- Detroit, Mich. (for mail), Wendt & Crone Co- 2124 Southport COLLIER, William I. (M 1921), W. I. Collier & Ave- and 1320 N. State St- Chicago, LIU Co- 522 Park Ave- Baltimore, Md- CRONE, Thomas E. (Af 1920), 601 West 110th COLLINS, John F. S., Jr. (M 1933), Supervisor St- Apt. 10 M- New York, N. Y. - of Steam Installations (for mail), Allegheny CROSS, Robert E. (A 1931), 95 State St, Spring County Steam Htg. Co- Philadelphia Co. Bldg- field. Mass. 435 Sixth Ave., and 827 N. Euclid Ave-' Pitts *GUGGI, Victor J. (M 1930), Consulting Engr.. burgh. Pa. ' Cucci & Brown, Inc- 347 Madison Ave- New COMSTOCK, Glen Moore (A 1926), Dist. Repr. York, N.Y. (for mail). L. J. Wing Mfg. Co- 154 College Ave., CULBERT, William P. (A 1929). Secy, (for mail),, Beaver, Pa. Culbert-Whitby Co., Inc- 2019 Rittenhouse St- CONNELL, Richard F. (M 1916), Mgr. Capitol Philadelphia, and 929 Alexander Ave- Drexel Testing Lab- U. S. Radiator Corp- 1056 First Hill, Pa. Natl. Bk Bldg., Detroit, Mich. - GUMMING, Robert W. (M 1928). Mech. and CONNER, Raymond M. (Af. 1931), Director, Sales Engr- Sarco Co- Inc., 183 Madison Ave., A. G. A. Lab- Gas Engrg- and (for mail), 271 New York, and (for mail), 81 Alkamont Ave., East 216th St- Cleveland. Ohio. ' Scarsdale, N. Y. COOK, Benjamin F. (Af 1920), Consulting Engr. CUMMINGS, Carl H. (A 1927; J 1926), Mgr. (for (for mail), 114 W. Tenth St-.Bldg- Kansas City, mail), industrial Appliance Co. of New England, and 1720 Overton Ave- Independence, Mo. 250 Stuart St- Boston, and 41 EdgehiU Rd., COOK, Chauncey J. (A 1930), 121 Lyndhurst St, Chestnut Hill. Mass. Syracuse, N. Y. CUMMINGS, Charles A. (M 1929; A 1929; COOK, Howard A. (A 1933), Supt., University J 1926), 38A Moreland St- Winter Hill, Mass. Plbg. & Htg. Co., 3939 University Way, and (for CUMMINGS, C. J. (M 1923), 2001 Hoover Ave., mail), 1433-33rd Ave., Seattle, Wash. Oakland, Calif. COOK, Ralph P, (M 1930), Engr. of Mech. CUMMINS, George H. (M 1919), Dist. Mgr. (for Equip. (for mail), Eastman Kodak Co- Kodak mail), Aerofin Corp., United Artists Bldg- and Park, and 105 Falleson Rd- Rochester,'*!. Y. 17376 Wisconsin Ave., Detroit, Mich. COOMBE, James (A 1932), Vice-Pres. (for mail), CUNNINGHAM, Thomas M. (Af 1931; A 1931; . Th$ Wm. Powell Valve Co- 2525 Spring Grove . J 1930), Vice-Pres. (for mail). Carrier Engrg. Ave- and 2363 Grandeu Rd- Cintinnati, Ohio. Corp. of Texas, 2022 Bryan St, and 5712 Mar- COON, Thurlow E. (Af 1916), Pres, (for mail). quita St- Dallas, Texas. The Coon-De Visser Co., 2051 W. Lafayette, and CURRIER, Charles H. (M 1919), Pres, (for mail). 826 Edison Ave- Detroit, Mich. ` Drying Systems, Inc- 1800 Foster Ave., and 2440 - COOPER, Frederick D. (A 1930), Sales Engr- 905 Lakeview Ave- Chicago, 111. ; Holden Ave- and (for mail), 1746 Longfellow CUSHMAN, Lester D. (M 1930), 89 Traincroft < Ave- Detroit, Mich. ' St- Medford, Mass. COOPER, John R. (M 1931). East. Br. Mgr. (for CUTLER, Joseph A. (Af 1916). (Cound), 1917 mail). Thermal Units Mfg. Co- 30 Church St., - 1926), Vice-Pres. (for mail). Johnson Service Co- and 680 Madison Ave- New York, N. Y. ` 1355 Washington Blvd- Chicago, and 649 COOPER, John W. (M 1932; A 1925; J 1921), Hinman Ave- Evanston, IU. - Buffalo Forge Co- 1596 Arcade Bldg., St. Louis, Mo. D. COPPERUD, Edmund R. (J 1933). Minneapolis Plbg. Co., 1420 Nicollet Ave., Minneapolis, DAHLSTROM, Godfrey A. (A 1927), 372l-47th Minn. ' Ave. S- Minneapolis, Minn. CORBIN, William E. (/ 1929). 158 Laurel St, DAILEY, James A. (A 1920). 31-64-30th St, Buffalo, N. Y. Astoria. L. I- N. Y. CORLETT, Lawrence D. (M 1930), 401 N. DALLA VALLE, J. M.* (J 1933), Asst Sanitary Emerson St- Detroit, Mich. Engr. (for mail), U. S. Public Health Service, CORNELL, J. Clarence (A 1930), Checker 19th and Constitution Ave- Washington, D. C- (Mechanical) 12 South 12tb St, and (for mail), and 6409 Georgia St, Chevy Chase, Md. 2823 W. Allegheny Ave- Philadelphia; Pa. / DALY, John H. (M 1915), Mfrs. Agent, 1544- CORNWALL, George i. (M 1919), Mgr- Boiler Welton St- Denver, Colo. Dept, (for mail), Hitchings & Co., 701 Spring St DALY, Robert E. (Af 1931), Executive Dept (for and 633 Madison Ave- Elizabeth, N. J. mail), American Radiator Co- 40 West 40th St, CORRAO, Joseph (/ 1933), Estimator and Engr., and 12 East 88th St- New York, N. Y. Herman Lawson Co- 465 Tehama St- and (for DAMBLY, A. Ernest (M 1924; J 1921), (for mail), mail), 854-31st Ave- San Francisco, Calif. H. B. Hackett, 901 Architects Bldg- Phila CORRIGAN. James A. (5 1930), 2501 W. St. delphia, Pa- and Harvey Cedars, N. J. Louis Ave., St. Louis, Mo. . DANE, Irving S. (M 1925), 166 George St, COTTER, Leonard F.. (J 1929), 34 Pearl St, Medford. Mass. - Springfield, Mass. COUGHLIN, Robert J. (M 1925), 1526 Oakwood Blvd-- Royal Oak, Mich. COWARD, Herbert (M 1921), Carrier Engrg. Corp., 604 Washington Bldg- Washington, D. C. COX, Harrison F. (A 1930), 243 Canon St- Paterson, N. J. COX, William W. (Af 1923). (for mail). Heating Service Co., 326 Columbia St, and 6232 31st Ave. N.E., Seattle, Wash. CRANSTON, William E,, Jr, (M 1931). Vice- DANFORTH, N. Loring (M 1919), John W. Danforth Co- 72 EUicott St., Buffalo, N. Y. DARLING, Arthur B. (A 1929), Asst. Sales Mgr. (for mail). Darling Bros,, Ltd- 14.0 Prince St, and 1935 St. Luke St, Montreal, P. Q- Capada. DARLINGTON, Allan P. (M 1930). Salesman (for mail), American Blower Corp- 2539 Woodward Ave., and 3605 Devonshire Ra- Detroit, Mich; DARTS, John A. (M 1919). Kewanee Boiler Co lne- 570 Seventh Ave., New York, N. Y. Pres. (for mail), Thermador Electrical Mfg. Co- DAUCH, Emil O. (M 1921), Secy-Treas. (for 116 Llewellyn St, Los Angeles, and 1912 Meri mail), McCormick Plbg. Supply Co- 1675 Bagley dian Ave- South Pasadena, Calif. Ave- and The WiJshire Hotel, Detroit, Mich. 13 American Society of Heating and Ventilating Engineers Guide, 1934 . . DAVENPORT, R. F. (A 1933), 77 James St. E-. BrocfcviHe, Ont., Canada. DAVIDSON, L. Clifford (M 1927), Associate Dist. Mgr. (for mail), Buffalo Forge Co., 220 . South 16th St., and 6312 Sherwood Rd., Phila delphia, Pa. DAVIDSON, Phillip L. (M 1924; J 1921), Carrier Engrg. Corp., 12 South 12th St., Philadelphia, Pa. DAVIES, George William (M 1918), Managing Director (for mail), Htg-, Vtg. and Domestic Engrs., 79 Maclaggan St., Dunedin, and 145 Kenmure Rd., Morniugton, New Zealand. ' DAVIS, Arthur C * (M 1920), Asst. Supt., The Holland Tunnel, Canal and Varick Sts., New York, N. Y., and (for mail), Ridgefield Park, N. J. 73 Preston. St., ' DAVIS, Bert C. (M 1904), (Council. 1917), Pres- Treas. (for mail), American Wanning & Vtg. Co., 317-19 Pennsylvania Ave., and 603 W. Church St., Elmira, N. Y. DAVIS, Calvin R. (M 1927), Br. Mgr. (for mail), . Johnson Service Co., 2328 Locust St., St. Louis, and 7534 Westmoreland PI., Clayton, Mo. DAVIS, Herbert H. (A 1929), Herbert H. Davis . DIVER, M. L. (M 1925), Consulting Engr., P. o. Box 1016, San Ant&nio, Texas. : DIXON, Arthur G. (M 1928), Sales Mgr. (for . mail), Modine Mfg. Co., and*442 Wolff St., Racine, Wis. . DOBBS, C. E. (A 1921), Repr., Burnham Boiler Corp., 31st and Jefferson Sts., Philadelphia, Pa., and (for mail), 72 Berlin Ave., Haddonfield, N. J. DOCK, Chester J. (M 1931), 132 S. Tenth St., Minneapolis, Minn. . '. DOCKERAY, Fayette (A 1931), Mfrs, Agent, Htg. and Vtg. Specialty, Box 135, Kingston, Pa. DODDS, Forrest F. (At 1920), Br. Mgr. (for mail), American Radiator Co., 1021 Grand Ave., and 235 Ward Pkwy., Kansas City, Mo. DOERING, Frank L. (M 1919), Salesman, Ameri can Radiator Co., 219 Denver Ave., Lynchburg, Va. ' : DOHERTY, John J. (M 1921), P. C. Doherty Co., 114 Main St., Poughkeepsie, N. Y. DOHERTY, Russell (A 1929), Asst. Chicago Mgr. (for mail). National Radiator Corp., 1111 East 83rd St., Chicago, and 300 Forest Ave., Oak Park, III. Co., Inc., 4146 S. Western Ave., Chicago, 111. DAVIS, Joseph (M 1927; A 1926), Htg. and Vtg. DOLAN, Hugh P. (At 1930), 14419 Strathmoor Ave., Detroit, Mich. Contractor, 607 Root Bldg., Buffalo, and (for mail), 85 Warren Ave., Kenmore, N. Y. DAVIS, Leo J. (M 1917), 18261 Grayfield Ave., Detroit, Mich. . DOLAN, Raymond G. (M 1926; A 1926;. J 1922), Secy-Treas. (For mail), Tom Dolan Htg. Co., Inc., 614 W. Grand, and 2112 West 20., Oklahoma City, Okla. . DAVIS, Otis E. (M 1929; A 1925), 1501 Fourth Ave., Scotts Bluff. Nebr. DAVIS, Robert J. (A 1933), Supt, Construction (for mail). Metropolitan Bldg. Co., 1201 Fourth Ave., and 6318-r39th Ave. S.W., Seattle, Wash. DAVIS, Rowland G. (A 1921), Sales Engr., Herman Nelson Corp., 400 Ninth Vincent Bldg., , DONNELLY, James A.* (M 1904), (Treas-, 1912 1914), Largent, W. Va. DONNELLY, Russell (M 1923), Sales Engr. (for mail), Nash Engrg. Co., Graybar Bldg., 420 Lexington Ave., New York, N. Y. - . DONOVAN, William J. (A 1930), 2239 North 27th St., Philadelphia, Pa. , , \ Cleveland, and (for mail), 887 Nela View Rd.. Cleveland Heights, Ohio. DAWSON, Thomas L. (M 1930). Pres, (for mail), Thomas L. Dawson Co., 2035 Washington St., Kansas City, Mo., and 56th and Shawnee Mission Rd., Rosedale Sta., Kansas City, Kaos. DAY, V. S.* (M 1924), Engr. (for mail). Carrier Corp., 850 Frelinghuysen Ave., Newark, and 18 Roosevelt Rd., Summit, N. J. DEAN, Charles L. (M 1932), Asst. Prof. Mech. Engrg., University of Wisconsin, and (for. mail), 2603 Stevens St., Madison, Wis. DEELV, James J. (J1933), House Htg. (Resident) Sales Engr., Brooklyn Union Gas Co., 180 Remsen St-. Brooklyn, and (for mail), 61 College Ave., Tarrytown, N. V. ' . DEEX, Charles J. (M 1920), Mouat-Vapor Htg. Co., 1246 W. Fourth St., Cleveland, Ohio. . DeLANCEY, Ralph W. (A 1932; / 1930), 1000 W. Fifth St., Winona, Minn. ' DeLAND, Charles W. (M 1924; J 1923), Secy- Treas. (for mail), C. W. Johnson Co., Inc., 211 N. Desplaines St., and 2021 Estes Ave., Chicago, IU. DEMPSEY, Harry P. (M 1919), 394 Pleasant Ave., Hamburg, N. Y. DEUTCHMAN, Julius (S 1933), 1-3 Wellesley Ave., Yonkers, N. Y. DIBBLE, S. E.* (M 1917), (Presidential Member), . (Pres., 1925; 1st Vice-Pres., 1924; 2nd Vice-Pres., 1922; Council, 1921-1926) Supt., Patton School, Elizabethtown, Pa. ' DONZELLI, Enrico (At 1933), Piazza SS Pietro e ` Lino No. 4, Milan, Italy. . DORFAN, M. I. (M 1929), Mgr. Dust Collecting Div., Blaw-Knox Co., P. O. Box 915, and (for mail). 6436 Nicholson St., Pittsburgh, Pa. DORNHEIM, G. A. (At 1912; J 1906), 15 Hamil ton Ave., Bronxville, N. Y. DORSEY, Francis C. (M 1920), Engr. and Con tractor (for mail), Francis C. Dorsey, Inc., 4520. Schenley Rd., Roland Park, and 212 Gittjngs . Ave., Baltimore, Md. - DOUGHTY, Charles John (M 1925), Pres; and ` .' Managing Director (for mail), C. J. Doughty & Co., Fed., Inc., U. S. A., 30 Brenan Rd., and 1920 Ave Joffre, Shanghai, China. DOWNE, Edward R. (M 1927), American Gas Products Corp., 40 West 40th St., New York, N. Y. -- DOWNE, Henry S. (Life Member; M 1895), Cie Nationale des Radiateurs. 149 Boulevard - Haussman, Paris, France. DOWNS, Nate W. (At 1917), (Council, 1928-1930), Chief Engr. and Supt. of Bldgs, (for mail), School Dist. of Kansas City, Mo., 317 Finance. Bldg., and 2119 East 68th St., Kansas City, Mo. DOWNS, Sewell H. (M 1931), Chief Engr.; , Clarage Fan Co., and- (for mail), 211 Creston , Ave., Kalamazoo, Mich. . DOYLE, William J. (M 1920), Factory Mgr., ' The Williamson Heater Co., 4558 Marburg Ave., . ` and (for mail), 3766 Hyde Park Ave., Cincinnati, Ohio. DICE, Eugene S. (S 1933), 7141 Upland St., . Pittsburgh, Pa. . DRESEN, William D. (M 1929; A 1929; J 1928). 3506~73rd St.. Jackson Heights, L. L, N. Y. DICKEY, Arthur J. (M 1921), yice-Pres.-Gen. DRINKER, Philip* (At 1922). Assoc.. Prof, (for Mgr. (for mail), C. A. Dunham Co., Ltd., 1523 mail). Harvard School of Public Health, 55 Van Davenport Rd., and 9 Mosson Pl,, Toronto, Ont., Canada. Dyke St., Boston, and 11 Lowell Rd., Brookline, Mass. ` DICKSON, Robert B. (At 1919), Pres, (for mail), DRISCOLL, William H.* (M 1904), (Presidential . Kewanee Boiler Corp., Franklin St and Q Tracks, Member), (Pres., 1926; 1st Vice-Pres, 1925; 2nd and 409 E. Prospect St., Kewanee, 111. DIGBY, Homer E. (A 1925; J 1922), 216 Oneida St., Pittsburgh, Pa. DTMOR, Elton J. (M 1933), Mgr. and Engr., The Trane Co., LaCrosse, Wis., and (for mail), 44 S. Tucker, Memphis, Tenn. . DISTEL, Frank (M 1918), P. O. Box 133, Lansing, Mich. ' 'J . Vice-Pres., 1924; Treas.. 1923; Council, 1918 1927), Vice-Pres. (for mail), Thompson-Starrett . Co., Inc., 250 Park Ave., New York, N. Y., and 65 Union St., Montclair, N. J. ' DUBE, Wilbrod (M 1925), 316 Laurier Ave., Quebec, Canada. . ' DuBOIS, Louis J. (M 1931), Air Cond. Engr., York Ice Machinery Corp., 117 South 11th St,, and (for mail), 7337a Lindell Ave., St. Louis. Mo. , 14 $,- S' i ISIf' Roll of Membership DUBRY, Ernest E. IM 1924), Asst. Supt., Central , Htg., The Detroit Edison Co., 2000 Second Ave., and (for mail), 9116 Dexter Blvd., Detroit, Mich. DUDLEY, William Lyle (M 1922). Western Blower Co., 1800 Ninth Ave. S., Seattle, Wash. DUFF, Kennedy (M 1915), Mgr. (for mail), Johnson Service Co., 28 East 29th St., New York, and 9 Park Ave., Maplewood, N. J. DUFFIELD, Thomas J.* (A 1927), 525 West 238th St., Apt. 4-L, New York. N. Y. DUGAN, Thomas M. (M 1920), Sanitary and Htg. Engr., Natl. Tube Co., Fourth Ave. and Locust St., and (for mail), 1308 Freeraont St., EDWARDS, Paul A, (M 1919), Pres, (for mail). The G. F. Higgins Co., 608 Wabash Bldg., and 3074 Pinehurst Ave., Pittsburgh, Pa. EELLS, Henry B. (M 1926), New York Mgr., Barnes & Jones, Inc., 101 Park Ave., New York, and (for mail), 1049 East 27th St., Brooklyn, N. Y. EGGLESTON, Lewis W. (M 1921), American Radiator Co., 5961 Lincoln Ave., Detroit, Mich. EGGLY, Harry J, Jr. (M 1933), Consulting Engr. (for mail), 1805 Walnut St., Philadelphia, and Elkins Park Apts., Elkins Park, Pa. EHRLICH, M. William* (M 1916), Chief Engr., Commodore Heaters Corp., 11 West 42nd St., . , DUNBRACK,' Alvin P. (J 1933), 172 Arlington New York, N. Y., and (for mail), 56 Ridge Rd., Ave., Jersey City, N. J. . DUNCAN, George W., Jr. (M 1923). 2512 Benvenue Ave., Berkeley, Calif. DUNCAN, James. R. (At 1923), Carrier Austra lasia, Ltd., 56 Hunter St., Sydney, Australia. DUNCAN, William A. (A 1930), Dist. Service Engr. (for mail). Dominion Oxygen Co., Ltd., 92 . Adelaide St. W., and 20 Tyrell Ave., Toronto, Lyndhurst, N. J. EICHBERG, W. Roy (M 1929). Pres, (for mail), Carolina. Sheet Metal Corp., 4210 Sansom St., Philadelphia, and 828 Turner Ave., Drexel Hill, - Pa. EICHER, HuBert C. (M 1922), State Director, School Bldgs. Div., Dept, of Public Instruction, State Capitol, and (for mail), 103 South St., Ont., Canada. DUNHAM, Clayton A.* (M 1911), Pres, (for mail), C. A. Dunham Co., 450 E. Ohio St., Chicago, and 150 Maple Hill Rd., Glencoe. 111. DURKEE, Merritt E. (A 1930), Sales Engr. (for mail), C. A. Dunham Co., 101 Park Ave., New York, and 254 Martine Ave., White Plains, N. Y. -DURN1NG, Edward H. (J 1931), Commercial . Sales, Community Natural Gas Co., 1915 Wood St.,and (for mail),4937 Worth St., Dallas, Texas. , DURYEA, Albert A. (S 1933), Belden Point, City Harrisburg, Pa. EISS, Robert M. (M 1933; A 1933; J 1930), (for mail), 72 Brantwood Rd., c/o Buffalo N.Y.P.O., Eggertsville, N. Y. . ELLINGWOOD, Elliott L. (M 1909). Consulting Engr. (for mail), 354 S. Spring St., Los Angeles, Calif. ' ELLIOT, Edwin (M 1929), (for mail), Edwin Elliot & Co.. 560 North 16th St., Philadelphia, and 403 W. Price St., Germantown, Philadelphia, Pa. ' ELLIOTT, Louis (M 1932), Consulting Mech. Island. N. Y. DUSOSSOIT, Edmond A. (M 1920), Treas. (for mail). Lynch & Woodward, Inc., 320 Dover St., Boston, and 16 Hancock Ave., Newton Centre, Mass. DWYER, Thomas F. (M 1923). Mech. Engr. (for mail). Board of Education, 49 Flatbush Ave. Ext., Brooklyn, and 1242 Morris Ave., New York, N.Y. . DYER, Orville K. (M 1919), Mgr. JBlower Div. (for mail), Buffalo Forge Co., 490 Broadway, and 11 Russell Ave., Buffalo, N. Y. Engr., Electric Bond & Share Co., 2 Rector St., Room 1914, New York, N. Y. . ELLIS, Ernest E. (At 1922), Secy-Treas., F. A.. Ellis & Co., Inc., 840 Center St., Winnetka, 111.. ELLIS, Frederick E. (M 1923), Sales Mgr. (for mail). Imperial Iron Corp., Ltd., 30 Jefferson Ave., and 372 Dune St., Toronto, Ont., Canada. ELLIS, Frederic R. (M 1913), Sales Engr., . Buerkel & Co., Inc.. 18-24 Union Park St., Boston, and (for mail), 131 Beacon St., Hyde Park, Mass. . E ELLIS, Harry W. (M 1923; A 1909), Pres.. Johnson Service Co., 507 E. Michigan St., Milwaukee, Wis. EADIE, John G. (At 1909). Eadie, Freund & Campbell Co., 110 West 40th St., New York, N. Y. . EAGAN, Walter H. (M 1926). Walter H. Eagan & Co., 1612 Vine St.. Philadelphia, Pa. EAGAR, R. Frank (M 1922), 89 Hollis St., - Halifax, Nova Scotia. EAKINS. Walter (M 1928). Vice-Pres. (for mail), Louis J. Sommer & Son, Inc., 2436 Brown St., Philadelphia, and 336 E. Phil Ellena St., German town, Philadelphia, Pa. . EASTERBROOKS, Clifton C, (M 1922), Sales Engr., (for mail), Koithan & Pryor, 39 Cortlandt St., New York, N. Y., and 722 Mountain Ave., Westfield, N. J. Eastman, Carl b. (M 1932; a 1932; j 1929), Mgr. Philadelphia, Sales Office., C. A. Dunham Co., 1500 Walnut Si., Philadelphia, and (for mail), 7247 Calvin Rd., Upper Darby, Pa. EASTWOOD, E. O. (M 1921), (Council, 1931 1933), Prof, of Mech. Engrg. (for mail). Uni versity of Washington, ahd 4702 12th Ave. N.E., Seattle Wash. - EATON, Byron K. (At 1920), Regional Sales Mgr., Delco Appliance Corp., and (for mail), 2018 Binney St., Omaha, Nebr. EATON, Vincent (M 1930). Consulting Engr., 3030 Euclid Ave., Cleveland, and (for mail), 15702 Hazel Rd., E. Eleveland, Ohio. EBERT, Wiiliatn A. (At 1920), 1004 Drexel Ave, San Antonio, Texas. EDWARDS, Daniel F. (M 1920), 2340-42 Pine St:, St. Louis, Mo. , EDWARDS, Don C., Jr, (J 1931), London, Ky. EDWARDS, Don J. (A 1933), Vice-Pres. (for mail), General Heat & Appliance Co., 94 Mas sachusetts Ave., Boston, and 40 Rockledge Rd., Newton, Mass, EMERSON, Ralph R. (M 1922), 48 Gay St., Newtonville, Mass. -' EMERY, Hugh (S 1933), 20 Morgan PI.. N. Arlington, N. J. ,. EMMERT, Luther D. (At 1919), Repr. (for mail), Buffalo Forge Co., 15 N. Jefferson St., Chicago, and 1704 Hinman Ave., Evanston, 111. ENGEL, Edward (J 1933), Design Draftsman (for mail), U. S. Navy Yard, Hull. Div., and 2608 . . North 30th St., Philadelphia, Pa. ENGLE, Alfred (A 1923), Sales Mgr; (for mail), Jenkins-Bros., 80 White St., New York, and X Edgewood Rd., Scarsdale, N. Y. ' ERDLE, Gardner F. (A 1933), (for mail), 374 Delaware Ave., Buffalo, and 19 Tremont Ave., Kenmore, N. Y. ERICKSON, Harry H. (A 1929), Sales Engr., . National Radiator Co., and (for mail), 5909 North 21st St., Philadelphia, Pa. ERICKSON, Martin E. (A 1926), Supt., Main tenance, Bd. of Education, and (for mail), 1533 - South 74th St., West Allis, Wis. . ERICSSON, Eric B. (M 1933), Engr.. Custodian, Bd. of Education, and (for mail), 605 West 116th St., Chicago, III. ETHERIDGE, G. Thomas, Jr. (S 1931), 118 Main St., Belle Vernon, Pa. . '' . EVANS, C. A. (M 1919), 218 Lexington Ave., Buffalo, N. Y. EVANS, Edwin C. (M 1919). 2953 Zephyr Ave., Corliss Sta. P. O., Pittsburgh, Pa. EVANS, William A. (At 1918), 24 Woodland Rd., Maplewood, N. J. EVELETH, Charles F.* (At 1911), 2030 East 115th St., Cleveland, Ohio. EVERETTS, John, Jr. (J 1929), Engr. (for mail), W. L. Fleisher, 11 West 42nd St., New York, and 83 Kenilworth PI., Brooklyn,N. Y. 15 AMERIcAN Soc,ETY f He*ting Ventilating Engineers Guide, 1934 EVLETH, Everett B. (A 1927), Br. Mgr. (for mail). Minneapolis-Honeywell Regulator Co., FEST, Leon T. (M 1919), 6646 North 18th St., 2831 Olive St., and 1138 Boland PL, St. Louis, Mo. Philadelphia, Pa. EWALD, Warren* (Af 1930), Engr., John J. Nea* FEYDT, John C. (S 1932), 2374 E. Main St- bitt Co., and (for mail), 2140 E,' Griffith St., Philadelphia, Pa. Bridgeport, Conn. FIEDIXR, Harry William (M 1923), Mgr- Air Conditioning Utilities, 139 Bast 53rd St., New F York, Consulting Engr- and (for mail), 49 Palmer Ave- Scarsdale, N. Y. FaGIN, Daniel J. (Af 1932), Htg. Engr., House FIFE, George Donald (A 1931; J 1929). Carrier Htg. Div., Laclede Gas Light Co., 11th and Olive, Engrg Corp- Chrysler Bldg., and (for mail), and (for mail), 4920 Chippewa Ave., St. Louis, ' Mo. 102 East 22nd St.. New York, N. Y. FILKINS, Harry L. (A 1932), Chief Engr. (for FAHNESTOCK, Maurice K.* (Af 1927). Special mail). City Ice Co. of Kansas City, 2lst and Research Asst., Prof, (for mail). University of Campbell Sts- and 3532 Bellefontaine, Kansas Illinois, 214 M. E. Lab., and 701 W. California City, Mo. St.. Urbana, ill- FINAN, James J. (Af 1923), Supervising Engr- FALTENBACHER, Harry J. (Af 1930), 235 E. Board of Education, City of Chicago, 228 N. Wister St., Philadelphia. Pa. LaSalle St- Builders Bldg.; and (for mail), 7149 FALVEY, John D. (M 1922), Hester-Bradley Co., Euclid Ave., Chicago, 111. 2835 Washington Ave., St. Louis. Mo. FINCH, Stanley B. (A 1931), Industrial Engr., FAMILETTI. a. Robert (J 1930), 2230 Tasker Brooklyn Union Gas Co- 180 Remsen St- St., Philadelphia, Pa. . - Brooklyn, N. V. FANSLER, P. E. (A 1927), Editor, Oil Heat (for FINNEY, Gerald J. (Af 1930), (for mail). Carrier- mail), 167 Madison Ave., New York, N. Y,, and Brunswick Intern'J- Inc- 850 Frelinghuysea Ave- Catonsville, Md. . FARLEY, John W. (A 1921). Mgr.. Farley Sleeve and 930 South St- Newark, N. J. FIRESTONE, James F. (A 1925; J 1914), 203 & Hanger Co., 3748 East 71st, Cleveland, Ohio. ' Orchard St- Dowagiac, Mich. FARLEY, W. F. (M 1930), Salesman' American FITTS, Charles D. (Af 1920), Mgr. (for mail), Radiator Co., 40 West 40th St., New York, and American Radiator Co- 692 Prior Ave- St. Paul, (for mail), 28 Elm St.r New Rochelle, N. Y. FARLEY, WlUoughby S. (J 1933), Partner, and 2807 Dean Blvd- Minneapolis, Minn. FITTS, Joseph C. (Af 1930), Secy- Hearing, Farley & Luther, 211 Montague St., Danville, Va. Piping & Air Conditioning Contractors Natl. FARNHAM, Roswell (Af 1920). Council. 1927: Assn- 1250 Sixth Ave- New York, N. Y- and 1933), Dist. Mgr.. Engrg. Sales (for mail), (for mail), 215 Kenilworth Rd- Ridgewood, N. J. ' Buffalo Forge Co., P. O. Box 985, and 6 Claren FITZSIMONS, J. Patrick (S 1932), Student. don PL, Buffalo, N. Y. Carnegie Institute of Technology, Box 396, and FARNSWORTH, John G. (/ 1931), Gas House (foT mail), 5538 Forbes St- Pittsburgh, Pa. Htg. Engr. (for mail). Central Illinois Light Co., FLANAGAN. Edward T. (A 1929), C. A. Dunham 316 S. Jefferson St., and 313 Crescent St., Peoria; Co., Ltd- 1139 Bay St- Toronto, Ont- Canada. UL FLARSHEIM, Clarence A. (J 1933), 3720 Holines FARRAR, Cecil W. (Af 1920; A 1918). (Treas., St-Kansas City, Mo. 1930; Council, 1930). Pres, (for mail), Exceiso FLEISHER, Walter L.* (Af 1914). ConsulUng Products Corp., 1807 Elmwood Ave., and 29 Engr- 11 West 42nd St- New York, N. Y. Oakland PL, Buffalo, N. Y. FLETT, Henry R. (Af 1915), 170 Indian Rd- FAUST, Frank H.* (J 1930), Engr. (for mail). Toronto, Ont- Canada. Genera! Electric Co., 1 River Rd., and 114 Union FLINK, Carl H. (Af 1923), Director of Research St., Schenectady, N. Y. (for mail). American Gas Products Corp- 408 FAY, Francis C. (Af 1925), Raisler Htg. Co.. 129 East 111th St- New York, N. Y- and 74 Brook- 31 Amsterdam Ave., New York, N. Y. side Ave- Mt. Vernon, N. Y. ' , FEBREY, Ernest J. (Af 1903), Htg. and Air Cond. FLINT, Coll T. (Af 1919), N. E- Sales Mgr. (for (for mail), 616 New York Ave. N.W., and 1610' Riggs PL N.W., Washington. D. C. FEEHAN, John B. (Af 1923). Pres-Treas. (for mail). The H. B. Smith Co- 640 MainSt- Cam bridge, and 56 Brantwood Rd- Arlington. Mass. FLOYD, Morris (Af 1933), Mfcr,, Air Cond. Div., mail), John B. Feehan, lac., 471 Union St., Lynn, The Edwards Mfg. Co- Cincinnati, Ohio. .. and 4 Ocean View Dr.. Marblehead, Mass. FEELY, Frank J. (A 1929), 17215 Greenlawn. Detroit, Mich. FORFAR, Donald M. (M1917h Mech. Engr. (for mail), Grinnell Co- 240 Seventh Ave- S- and 4817 Emerson Ave. S- Minneapolis, Minn. FEGLEY, Donald R. (S 1933). 2274 Loring Pi- FORSBERG, William (Af 1919), Hopson & New York, N. Y. FEHLIG, John B. (Af 1918), Pres, (for mail). Chapin Mfg. Co- 231 State St., New London, Conn. Excelsior Htg. Supply Co- 528 Delaware St., and FORTUNE. J. Robert (Af 1929), Partner , (for 2927 Brooklyn Ave., Kansas City, Mo. mail), J. R. Fortune & Son, 608 Fisher Blg- and FELDMAN. A. M.* (Af 1903), Consulting Engr.. ' 2063 Oakman Blvd- Detroit. Mich. 40 West 77th St., New York, N. Y. FELS, Arthur B. <Af 1919), The Fels Co., 42 FOSTER, Charles (Af 1923), Consulting Engr. .(for mail), 512 Sellwood Bldg-and 2831 E. First Union St- Portland, Maine. ` FELTWELL, Robert H. (Af 1905), Repr., U. S. St- Duluth, Minn. FOSTER, James M. (Af 1930; A 1920), (Pres. St. Radiator Corp., 2321 Fourth St. N.E., and (for . Louis Chapter 1932), Factory Repr. (for mail), mail), 1370 Oak St. N.W., Washington, D. C. ' 4526 Olive St- and 7021 Lindell Ave., St..Louis, FENN, Charles Van O. (/ 1930), Engr.. 7019 Mo. Georgia Ave. N.W., Washington, D. C. FOSTER, Tillman R. (/ 1930), Carrier Engrg. FENNER, N. Paul (A 1928), Hoffman Specialty Co.. Room 3707 Chrysler Bldg., New York, N. Y. FENSTERMAKER, Sidney E. (Af 1909), Pres. (for mail), S. E, Fenstermaker & Co., 937 Archi tects & Builders Bldg., and 3102 Washington Blvd., Indianapolis, Ind. FENTON, Frederick A. (Af 1932), Sales Engr., Thos. Devlin Htg. Co- 30 Church St- and (for mail), 140 East 46th St- New York. N. Y. FERNALD, Henry B., Jr. (S 1933), 145 Lorraine Corp- 180 N. Michigan Ave- Chicago, 111. FOU1LHOUX, J. Andrd (Af 1915), West Rd- Short Hills, N. J. FOULDS, P. A. L. (Af 1916), Mech. Engr. (for . mail). Office of HolUa French, Consulting Engr.. 210 South St- Boston, and 72 Whitin Ave- Point of Pines, Revere, Mass. FOULDS, Samuel T. N. (J 1930). 854 North Shore Rd., Revere. Mass. . FOX Otto (Af 1931), 17825 St. Clair Ave., Cleveland, Ohio. Ave- Upper Montclair, N. J. FRANK, John M. (Af 1918; A 1912), Ilg Elec. FERRERO, Henry J. (S 1933). 1738 Adams St., New York. N. Y. , .' Vtg, Co- 2850 N. Crawford Ave- Chicago, UL FRANK, Olive E * (Af 1919), Frank Engrg. Co ll Park Place, New York, N. Y. 16 Roll of Membership FRANKEL, Gilbert S. (Af 1926), Mgr- Federal & Marine Dept, (for mail), Buffalo Forge Co- 403 Commercial Natl. Bk. Bldg- 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. FRASER, William G- (Af 1916), 370 Delaware Ave- Buffalo, N. Y. ` FREAS, Royal Bruce (M 1928), Pres, (for mail), . Freas Thermo Electric Co- 1206 S. Grove St- Irvington, N. J- and 4 West 43rd St- New York, N. Y. ' FREEMAN, Alton M. (A 1929), Sales Engr- 6088 Plankington Bldg- and (for mail), 4533 N. Bartlett Ave;. Milwaukee, Wis. FREITAG, Frederic G. (Af 1932), Consulting Engr- Sylvestre Oil Co.', 707_S. Columbus Ave- and (for mail), 9 Harrison St-'Mt. Vernon, N. Y. FRENCH, Donald E. (Af 1926), Carrier Research Corp- 750 Frelinghuysen Ave., Newark, N. J. FRIEDMAN, Abraham (Af 1922), Friedman & Kiss, Inc- 207 East 43rd St- New York, N. Y. FRIEDMAN, Ferdinand J. (Af 1921), McDougall & Friedman, 1221 Osborne St- Montreal, Que- Canada. FRIEDMAN, Milton (5 1933), 470 West End Ave- New York, N. Y, .- FRITZ, Charles V. (S 1933), P. O. Box 303, Carnegie Institute of Technology, Pittsburgh, Pa. FRITZBERG, L. HUdlng (J 1931), Engr- B. F. Sturtevant Co., and (for mail), 24 Dell Ave- Hyde Park, Boston, Mass. FROST, Robinson V* (Af 1921), Pres- Frost Research Lab- Inc- 1326 Markley St- Norris town, Pa. FUKUI, Kunltaro (Af 1926), Oriental Carrier Engrg. Co., Ltd- Nomura Bldg- Bingo Machi, Osaka, Japan. G GABELMAN, Harold D. (S 1930). 681 Oakwood Ave., Webster Groves, Mo. GABY, Frederick A. (Af 1926), Chief Engr. (for mail), Hydro-Electric Power Commission of Ontario, 190 University Ave., and 480 Spadina Rd., Toronto, Ont- Canada. GALLARNO. Charles A. (A 1930), Donald Miller Co- 1720 Brush St- Detroit, Mich. GALLIGAN, Andrew B. (Af 1921), 716 South 51st St- Philadelphia, Pa. . GAMMILL, Oscar E., Jr. (J 1930), Sales Engr. (for mail). Carrier Engrg. Corp- 1416 Hibernia Bk- Bldg- and 2133 Calhoun St- New Orleans, La. GANT, H. P.* (Af 1915), .(Presidential Member), (Pres- 1923; 1st Vice-Pres- 1922 ; 2nd VicePres- 1921; Council, 1918--1924), Vice-Pres. (for mail). Carrier Corp- 12 South 12th St- and Penn Athletic Club, Philadelphia, Pa. GARDNER, S. Franklin (Af 1911), Pres, (for mail). Standard Engrg. Co- Inc- 2129 Eye St. 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, IU. GARNEAU, Leo (J 1930), Sales Engr- Room 608 University Tower Bldg- and (for mail), 8454 Brouages St- Montreal, Canada. GAUSMAN, Carl E. (Af 1923), Mech. Engr- 1100 Minnesota Bldg- and (for mail), 2360 Cbilcombe Ave- St. Paul, Minn. GAUTESEN, Alf (S 1933). 1039-79th St- Brook lyn.. N. Y. ' 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), ConsulUng Engr., Flameking Co- Inc., 2159 Madison Ave- New York,' and (for mail), 42 Mayhew AveLarchmont, N. Y. GAYLORD, F. H. (Af 1921), Hoffman Specialty Co- 130 N. Wells St- Chicago, 111. GEIGER, Irvin H. (Af 1919), Reg. Engr. and Mfrs. Repr. (for mail). Room 319 Telegraph Bldg- and 240 Maclay St- Harrisburg, Pa. GfcNCHI, Bernard (S 1933), 880S-15th Ave- Brooklyn, N, Y. GERRISH, Grenville B. (J 1930), N. E. Repr- Fitzgibbons Boiler Co- Inc., 80 Boylston St., Boston, and (for mail), 1 Overlook Rd- Melrose, Mass. GERRISH, Harry E. (Af 1910), (Council. 1919). Vice-Pres. (for mail), Morgan Gerrish Co- 307 Essex Bldg., and 4534- Fremont Ave. S- Minne apolis, Minn. GESMER, Joseph (S 1933), 41 Beacon St ' Quincy, Mass. GETSCHOW, George M. (Af 1906). Pres-Treas. (for mail), Phillips Getschow Co., 32 W. Austin Ave- and 4542 Beacon St., Chicago, UL GETSCHOW, Roy M. (Af 1919). Secy, (for mail). Phillips Getschow Co- 32 W. Austin Ave- and 1336 Arthur Ave- Chicago, 111. G1ANN1NI, Albert A. (S 1933), 64 West 176th St- New York. N. Y. CIBBONS, Michael J., Jr. (Af 1914), 22 Oxford Ave- Dayton, Ohio. GIBBS, Edward W. Of 1919), (for mail), 201 S. Main St., and 234 President Ave- Providence, R. I. ' GIBBS. Frank C. &Af 1921), Gen. Supt. (for mail). Natl. Regulator Co- 2301N. Knox Ave., Chicago, and 150 N. Cuyler Ave- Oak Park, III. G1ESECKE, Frederick E.* (Af 1913), (Council. 1932-33), Director, Texas Engrg. Exp. Sta- Agri cultural and Mech. College of Texas, College Sta- Texas. GIFFEN, J. Kerr (A 1931). Sales Engr.. Stanton Heater Co- and (for mail). Box 331, Martins Ferry. Ohio. GIFFORD, Edmund W. (J 1929). 825 N. St. Johns Ave- Highland Park, 111. GIFFORD, Robert L. (Af 1908), Pres- Illinois Engrg. Co- 21st and Racine Ave- Chicago, and (for mail), 1231 S. El Molino Ave- Pasadena, Calif. ' ' GIGUERE, George H. (Af 1920), Consulting Engr. (for mail), 4 Glenwood Ave., Silver Creek, N. Y. .. GILBOY, John P. (Af 1924), Mfrs- Sales Agt. (for . mail). John P. Gilboy Co- Leonard Bldg., and 521 Arthur Ave., Scranton, Pa. GILFRIN, George F. (Af 1932), Gen. Repr. (for mail), Carrier-Brunswick-Internl., Inc., Apartado 63 Bis, and Explanada 715, Lomas de Chapulte- pec, Mexico. D. F. GILLE, Hadar B. (Af 1930), Skoldungagatan 4, Stockholm, Sweden. . GILLESPIE, J. D. (A 1930). 4202 S. Broadway. Los Angeles, Calif. ,, GILLETT, M. C. (Af 1916), Engr- 6600 Rising Sun Ave- Philadelphia, Pa. GILLHAM. Walter E. (Af 1917), (Treas- 1926 1929; Council, 1926-1929). Consulting Engr. (for mail), 314 Inter-State Bldg- and 3427 BeUefon- tain Ave- Kansas City, Mo. GILLING, William F., Jr, (Af 1933; A 1919), Asst. Mgr., American Radiator Co- 127 Federal St- Boston, and (for mail), 29 Abbott Rd- Wellesley Hills, Mass. GILMORE, Louis A. (5 1930). Vice-Pres. (for mail), John Gilmore & Co., 13 N. Tenth St- and 6186 Westminster PL, St. Louis, Mo. GILMOUR, Alan B. (A 1932), Salesman, B. F. .Gilmour Co- Inc., 152-41st St- and (for mail), 625 Ocean Ave., Brooklyn, N. Y. GINI, Aldo (Af 1933), Via Coreggfo 18, Milano, Italy. GIVIN, Albert W. (A 1925), West. Mgr. (for mail). The Gurney Foundry Co- Ltd- 566 Beatty_St- and The Devonshire, Vancouver, B. C- Canada. GLANZ, Edward (A 1930), Pres, (for mail), Glanz & Killian Co., 1761 W. Forest Ave- and 3865 Lakewood Ave- Detroit, Mich. - GLASSEY, J. Wilbur (Af 1922), Partner (for mail). Vapor Engrg. Co- 10 South 18th St- Phiiadelphia, and 7818 Ardleigh St- Chestnut Hill. Philadelphia, Pa. 17 American Society of Heating and Ventilating Engineers Guide, 1934 GLEASON, Gilbert M. (it 1923). Partner (for mail). Gilbert Howe Gleason & Co., 25 Hunting ton Ave., Boston, and 10 Edgehill Rd., Win-' Chester, Mass. *, , GLORE, Evins Foree (A 1916), Pres., Evins F. Glore & Son, Inc., Grand Central Terminal, and (for mail), 644 Riverside Drive, New York, N.Y. GODFREY, Paul S. (A 1933), Mgr. (for mail). Iron Fireman of Milwaukee, Inc., 1222 W. Cly- bourn St., Milwaukee, and 1620 North 70th St., Wauwatosa, Wis. GOELZ, Arnold H. (Af 1931), Pres, (for mail), GREEN, Joseph J. (A 1933), Mfrs. Repr., Joseph J. Green Co., Buffalo, and (for mail), 328 W. Girard Blvd., Kenmore, N. Y. , GREEN, William C. (Life Member; M 1906), Dist. Mgr. (for mail), Warren Webster Sc Co., 704 Race St., and 244 Erkenbrecher Ave-, (Arondale), Cincinnati, Ohio. . CREENBURG, Dr. Leonard (M 1932), Assoc. Dir. (for mail), John B. Pierce Lab. of Hygiene, 290 Congress Ave., and 519 George St., New Haven, Gontu \ Kroeschell Engrg. Co., 2306 N. Knox Ave., GRIFFIN, Byron H. (Af 1928). Sales Engr., Box ` Chicago, and 827 Greenwood Ave., Wilmette, III.. 371, Stony Brook, L. I., N Y. GOENAGA, Roger C. (Af 1931), Tech. Director (for mail). Ateliers Veutil, 109 Cours Gambetta, Lyon, and 33 Avenue Valioud, Ste Foy7les-lyon, Rhone, France. " ' GOERG, Bernhard (M 1928), (for mail), Ameri can Radiator Co., 675 Bronx River Rd., Yonkers, and 325 Rich Ave., Mt. Vernon, N. Y. GOLDSMITH, Otto E. (M 1915), Consulting Engr. (for mail), 110 West 40th St., and 29 Washington Sq., New York, N. Y. . COMBERS, Henry B. {Life Member; A 1901), v Secy., Emeritus, Heating, Piping and AiT Con-.' ' ditioning Contractors Natl. Assn., 1250 Sixth GRIFFIN, DeWitt C. (M 1933), Secy-Treas. (for mail). May & Griffin, Inc., 412 Orpheum Bldg., and 9717-47th Ave. S.W.. Seattle, Wash. . GRIFFIN, John J< (Af 1921; A 1918), Vice-Pres., 3852 Castleman Ave., St. Louis, Mo. GROSECLOSE, John B. (4 1929), Student, University of Texas, and (for mail), 1204 Park way, Austin, Texas. GROSS, Lyman C. (Af 1931), Sales Engr. (for mail), Crane Co., 400 Third Ave. N.. and 4653 13th Ave. S., Minneapolis, Minn. GROSSMAN, Harry E. (A 1933; J 1927), 95 , Ave., New York, N. Y., and (for mail), 160 Halsted St., East Orange, N. J. GOODRICH, Charles F. (M 1919), Andrews & Washington Ave., Oceanside, N. Y. GROSSMANN, Harry A. (Af 1931), 3122 Geyer Ave., St. Louis, Mo. Goodrich. Inc., arid (for mail), 336 Adams St., Dorchester, Boston, Mass. GOODWIN, Samuel L. (M 1924), Consulting Engr., 247 Madison Ave., Hasbrouck Heights, N. J. GOODWIN, Walter C. (M 1033), Div. Engrg.,. Air Cond. Equip. Div. (for mail). Supply Engrg. Dept., Westinghouse Electric & Mfg. Co.. East GUNTHER, Felix A.* (Af 1925), Sales Engr. (for mail), 429 B, Oliver Bldg., Pittsburgh, and Box 226 R. D. 9, S. Hills Branch, Pittsburgh, Pa. GURNEY, Edward Holt (Af 1929), (Council. ^ 1931-1933), Pres, (for mail), Gurney- Foundry Co., Ltd., 4 Junction Rd., and 347. Walmer Rd., Toronto, Ont., Canada. . Pittsburgh, and 6032 St. Marie St., Pittsburgh, Pa. H GORDON, Edward B., Jr. (M 1908), Pres., Pillsbury EngTg. Co., 1200 Second Ave. S.f and (for mail), 2450. West 24th St., Minneapolis, Minn. HAAS, Emil, Jr. (J 1929), Secy-Treas. (for mail), Natkin & Co., 2020 Wyandotte and Newbern Hotel, Kansas City, Mo. GORDON, Robert H. (4 1932; J 1930). Natl. Carbonic Mchy. Co., 640 Michigan Theatre Bldg., Detroit. Mich. CORNSTON, Michael H. (A 1923). Custodian Engr. (for mail). Junior H. S. 109, 430 Dumont Ave., Brooklyn, and 8504 Woodhaven Blvd., . Woodhaven, N. Y. HAAS, Samuel L. (M 1923), Pres, (for mail). Advance Htg. Co., 117-19 N. Despiaines St., and 1513 Fargo Ave., Chicago, IU. HAAS, William (Af 1915), 429-E. Third St., . Dayton, Ohio. ,. HACKETT, H. Berkeley (Af 1921), 901 Architects Bldg., 17th and Sansom Sts., Philadelphia. Pa. GOSSETT, Earl J. (M 1923), Pres, (for mail). Bell & Gossett Co., 3000 Wallace St., Chicago, and 314 Woodland Ave., Winnetka, 111. GOTTWALD, C. (A 1916), Pres, (for mail). The Ric-wiL Co., Union Trust Bldg., Cleveland, and 2225 Stillman Rd., Cleveland Heights, Ohio. GOULDING, William (4 1933), Tech. Op., Engrg. Dept., National Broadcasting Co., Radio City, New York, and (for mail), .1100 Ocean HADDOCK, Isaac T. (A 1926), New England Gas & Electric Assn., 719 Massachusetts Ave., Cam bridge, Mass. HADEN, G- Nelson (A 1928: J 1922), Director (for mail), G. N. Haden & Sons, Ltd., Lincoln House, 60 Kingsway, London W.C. 2, and Owens Wildwood Rd., London N.W. 11, England. HADEN, William Nelson (Life Member; M1902), Chairman, G. N. Haden & Sons, Ltd., St. . Ave., Brooklyn, N. Y.. GRAHAM, William D. (Af 1929; A 1925; J 1923), Dist. Mgr., Carrier Engrg. Corp., 890 Union Trust Bldg., Cleveland. Ohio. GRAHN, Victor F, (M 1927), Heat & Vent. Engr., 101 Park Ave., New York, N. Y., and (for mail). 120 Greenwood Ave., East Orange,' N, J. CRANSTON, Ray O. (5 1930), 4558 Fourth Ave. . N.E., Seattle, Wash. ' Georges Works, and (for , mail), Arnolds Hill, Trowbridge, Wilt, England. HADESTY, Alfred L., Jr, (Af 1921), 130 E. Broad ` St., Tamaqua, Pa. . HADJISKY, Joseph N. (Af 1930), Consulting ' Engr., 744 Bates SL, Birmingham, Mich. HAGAN, William V. (4 1933; J 19?6), 2459 George St., Sioux City, Iowa. HAGEDON, Charles H. (M1919), S. E. Fenster- GRANT, Walter A. (4 1933; J 1929). Develop maker & Co., 939 Architects-Builders Bldg., , Indianapolis, Ind. . ment Engr., Carrier Corp., 750 Frelinghuysen Ave., Newark, and (for mail).' 1120 Anna St., Elizabeth, N. J. . . HAGERMAN, James J. (M 1931), Bishop & Babcock Sales Co., 1219 Washington Blvd.. Chicago, III. GRAVES, Willard B. (M 1906), Pres; (for mail), W. B. Graves Htg. Co., 162 N. Despiaines St., ' Chicago, 111. ' GRAY, George A. (M 1924), C. A. Dunham Co., HAIGNEY, John E. (S 1933). 8621 Shore Rd., Brooklyn, N. Y. HAINES, John J. (Af 1915), Pres, (for mail). The Haines Co., 1933 w. Lake St., Chicago, and 623 Ltd., 404 Plaza Bldg., Ottawa, Ont., Canada. 17th Ave., Maywood, 111. GRAY, Richard F. (4 1930), Asst- to Regional Dir. (for mail), 180 N. Michigan Ave;, Chicago, and 2340 Marcy Ave., Evanston, Hi. GRAY, William E. (Af 1922), Box 264, High Point, N. C. HAJEK, William J. (Af 1932). Br. Mgr. (for * mail), Minneapolis-Honeywell Regulator Co., 285 Columbus Ave., Boston, and 272 Tappan St., Brookline, Mass. HAKES, Leon M. (Af 1932; A 1932; J 1929), Sales GREBE, Henry W. (Af 1919), Central Asbestos & -Magnesia Co., 214 W. Grand Ave., Chicago, 111. Engr. (for mail). The R. T- Coe Co., 400 Reynolds Arcade Bldg., and 159 Forgham Rd., Rochester, N. Y. 18 Roll of Membership HALE, John F. (Af 1902), {Presidential Member), (Pres.. 1913; 1st Vice-Pres., 1912; Bd. of Gover nors, 1908-1910, 1912-1913), Dist. Mgr. (for mail), Aero&n Corp., Room 1104, Burnham Bldg.. Chicago, and 408 S. Brainard Ave., LaGrange, III. HALEY, Harry S.* (Af 1914), Consulting Engr., " Partner (for mail), Leland & Haley, 58 Sutter St., and 735-21st Ave., San Francisco, Calif. HALL. John R. (J 1932), Mech. Engr., U. S. Air Cond. Corp., 2101 N. E. Kennedy St., and (for mail), 5305-37th Ave. S., Minneapolis, Minn. HALLAS, Robert S. (S 1933), 5227 Philip St., Bedford, Ohio. . HAMBURGER, Fred G. (S 1933), 185 West 102nd HARRIS, Jesse E. (Af 1930), 405 Abbottsford Rd., Philadelphia, Pa. HARRISON. Arthur B. B. (Af 1931), Multicell Radiator Corp., Lockport, N. Y. HARRISON, Charles G. (Af 1930). 4510 Cortland St., Detroit, Mich. HART-BAKER, Henry W. (Af.1918), Director (for mail), Merritt, Ltd., 8 Quai de France, and 37 Rte Rene Delastre, Shanghai, China. . HART, Harry M* (Af 1912). (Presidential Member), (Pres., 1916; 1st Vice-Pres., 1915; Council, 1914-1917), Pres, (for mail), L. H. Prentice Co., 1048-50 Van Buren St., and 5409 Winthrop Ave., Chicago, 111. . HARTMAN, Frank E * (Af 1924), Pres., Biological Engrg. Lab., Inc., 2604 Pratt Ave., and (for mail), St., New York, N. Y. . HAMENT, Louis (A 1933), Mgr. (for mail). Aquatic Chemical & Metallurgical Engrs., 118 East 28th St., and 568 East 166th St., New York, 6545 N. Mozart St., Chicago, 111. HARTMAN, Fred Stewart (4 1933), Dist. Mgr., Industrial Dept, (for mail), General Electric Co., 570 Lexington Ave., New York, N. Y., and 168 N. Y. HAMILTON, James E. (4 1933), Mgr. (for mail), U. S. Radiator Corp-. 4004 Duncan Ave., St. Louis, and 7715 Shirley Dr., Clayton, Mo. HAMLIN, Harry A. (4 1916). Br. Mgr. (for mail), Johnson Service Co., 427 Brainard St., Detroit, and 120 Winona, Highland Park, Mich. HAMMOND, Martin J. (J 1930), Mgr. and Prop., M. J. Hammond, Htg., Plbg. &.pil Burners, 426 Bath Ave., Long Branch, N. J. HANBURGER, Fred W. (Af 1930), Hotel Willard, 252 West 76th SL, New York, N. Y. HANLEY, Edward V. (4 1933), Pres, (for mail), S. V. Hanley Co., 1653 N. Farwell Ave., Mil waukee, and 844 E. Birch Ave., Whitefish Bay, Montclair Ave.. Montclair, N. J. HARTMAN, John M. (Af 1927). Engr. (for mail), Kewanee Boiler Corp., and 719 Henry St., Kewanee, 111. HARTWEIN, Charles E. (Af 1933), Supervisor House Htg. Dept., St. Louis County Gas Co., 231 W. Lockwood, Webster Groves, and (for mail), 6271 Magnolia Ave., St. Louis, Mo. ' HARTWELL, Joseph C- (Af 1922), East Dist. Mgr. (for mail), GrinnelJ Co., Inc., 260 W. r Exchange St., and. 16 Freeman Pkwy., Provi dence. R. I. HARVEY, Alexander D. (A 1928; J 1925). Nash Engr. Co-. South Norwalk, Conn. . HARVEY, Lyle C. (Af 1928), Vice-Pres. (for mail), HAWNisL.EY, Thomas F., Jr. (Af 1933), Pres, (for mail), Hanley & Co., 1503 S. Michigan Ave., and 4940 East End Ave., Chicago, 111. HANSEN, Carl J. {S 1933), 939 Lakeshore Dr., Bryant Heater Co., 17825 St. Clair Ave., and 3388 Glencarin Rd., Cleveland, Ohio. HASHAGEN, John B. (Af 1930), 121 Manhattan Ave., Jersey City, N. J. HATTIS, Robert E. (M 1926). Consulting Engr. Port Arthur, Texas. > HANSEN, Charles C. (Af 1928) Engr., Chase Brass & Copper Co., 200 Fifth Ave., New York, N. Y., and (for mail), 428 Prospect St., South (for mail), 180 N. Michigan Ave., and 4251 N. Mozart St., Chicago, 111. HATTON, Albert E. (Af 1931), Supt. and Esti mator (for mail), Lome Plbg. & Htg. Co., 641 Orange, N. J. HANSON, Edward W. (M1922), W. N. Sauer Co., 806 Chestnut St. N.S., Pittsburgh, Pa. HANSON, Leon C. (A 1918), Secy-Treas. (for mail), 712 Tenth St. S., and 2410 Colfax Ave. S., Minneapolis, Minn. . HANSON, Leslie P. (5 1933), Engr., U. S. Air Cond. Corp., and (for mail). 3219 Lyndale Ave. S-, Apt. 303, Minneapolis, Minn. . HARDING, L&uis A* (M 1911), (Presidential Member), (Pres., 1930; 1st Vice-Pres., 1929; 2nd Vice-Pres., 1928; Council, 1922-1931), Pres, (for mail), L. A. Harding Construction Corp., Pru dential Bldg., and 85 Cleveland Ave., Buffalo, W. Congress, Detroit, and R. R. No. 1, Bir- mingharo, Mich. HAUAN, Merlin J. (Af 1933), Consulting Engr., 3412-16th S., Seattle, Wash. HAUPT, Howard F. (A 1929), 614 E. Beaumont Ave., Milwaukee, Wis. . HAUSS. Charles F* (Charter Member; Life Member; Af 1922), 305 Southern Ave., Cincinnati, Ohio. HAYDEN, Carl F. (A 1930), Br. Mgr. (for mail), Barber-Colman Co., 221 N. LaSalle St., Chicago, and 2309 Forestview Rd., Evanston, 111. HAYES, James J. (Af 1920), Sales Engr. (for mail). Room 925, 53 W. Jackson Blvd., and 7443 N. Y. HARE, W. Almon (Af 1930). Pres., Hare Stoker Corp., 4853 Rivard St., Detroit, Mich. HARMS, . William T* (M 1917) 1015 Vinewood Ave.. Detroit, Mich. HARPER, Samuel H. (Af 1929; A 1927), Prop, (for mail). Heating Equipment Co., Oliver Bldg., Pittsburgh, and 223 DalzeU Ave., Ben Avon, Jeffrey Ave., Chicago, III. .. HAYES, John J. (A 1933), Auburn Stoker Sales Corp., 406 N. Wells St., Chicago, and (for mail), 918 Michigan Ave., Evanston, 111. HAYES, Joseph G. (Af 1908), Pres, and Engr. (for mail), Hayes Bros., Inc., 236 W. Vermont St., and 2849 N. Capitol Ave., Indianapolis, Ind. HAYMAN, A. Eugene, Jr. (5 1930), 2500 Wash Pittsburgh, Pa. HARRIGAN, Edward M. (Af 1915), (for mail). Harrigan & Reid Co., 1365 Bagley Ave.. and 7450 LaSalle Blvd., Detroit, Mich. HARRIGAN, Edward R, (J 1930), Harrigan & Reid Co., 1365 Bagley Ave., Detroit, Mich. HARRIGAN, Howard H. (4 1930), 15874 Ohio Ave., Detroit, Mich. HARRINGTON, Charles (Af 1923), 43 Indian Grove, Toronto, Ont., Canada. . HARRINGTON, Elliott D.* (Af 1932; A 1930). Engr. (for mail). Air Conditioning Dept., Com mercial Engrg. Div., General Electric Co., and 1580 Wendell Ave., Schenectady, N. Y. HARRIS, Charles R. (J 1929); Carrier-Brunswick Intem'l. Inc., 850 Frelinghuysen Ave., Newark, N. J. ' HARRIS, Jesse B. (Af 1918), Pres, (for mail). Rose & Harris, 452 N. W. Natl. Life Insurance Bldg., and 3620 Colfax Ave. S., Minneapolis, Minn. . . ington St., Wilmington, Del. HAYNES. Charles V. (Af 1917), (1st Vice-Pres., 1933; 2nd Vice-Pres., 1932; Council, 1926-1929, 1933), Vice-Pres.. Hoffman Specialty Co., 3709 Chrysler Bldg., New York, N. Y., and (for mail), 115 Llanfair Rd., Ardmore,.Mont. Co., Pa. HAYWARD, Ralph B. (Af 1909). Pres, (for mail), R. B. Hayward Co., 1714 Sheffield Ave., Chicago, and 201 S. Stone Ave., LaGrange, 111, HEAGLER, John M. (Af 1922), 1646 Igelhart Ave., St. Paul, Minn. , HEARD, John A. E. (J 1930), Carrier Engrg-Co., Ltd., Sardar Sujan Singh Block, Connaught PI., New Delhi, India. HEARD, Roderick G. (A 1933), Oil Burner Dept, (for mail). Imperial Oil, Ltd., 56 Church SL, and 6 Walker Ave., Toronto, Out., Canada. HEATH, Frederick R. (Af 1913), Sales Engr. (for mail), E. B. Badger & Sons Co., 75 Pitts St., Boston, and 89 Trowbridge St., Cambridge, Mass.' 19 American Society of Heating and Ventilating Engineers Guide, 1934 HEATH, William R. (Af 1931), 674 Crescent Ave.. Buffalo, N. V. HECHT, Frank H. (Af 1930), Sales Engr. (for mail), B. F. Sturtevant Co., 2635 Koppers Bldg., and 1467 Bamesdale St., Pittsburgh, Pa. HECK, George L,, Jr. (A . 1921), Chief Engr., Garden City Fan Co., McCormick Bldg., and (for mail), 8340 Maryland Ave., Chicago, 111. HECKEL, E. P. (M 1918). Vice-Pres. and Mgr., Chicago, Dist. (for mail). Carrier Engr. Corp., 180 N. Michigan Ave., Chicago, and 314 Cut. triss PI., Park Ridge, IU. ` HEDGES, H. Berkley (Af 1919). 1021 Park Lane, Plainfield, N. J. HEDLEY, Park S. (Af 1923), Park S. Hedley Co., Curtiss Bldg., Delaware at Tapper, Buffalo, N.Y. HEEBNER. Walter M. (Af 1922), Sales Engr., Warren Webster & Co., 470 Fourth Ave.. New York, N. Y., and (for mail), 282 Highwood Ave., *Teaneclc, N J KErBEL, Walter E. (Af 1917), Dist. Mgr. (for mail), Aerofin Corp., 11 West 42nd St., New York, N. Y., and Old Greenwich,. Conn. HEIDENREICH, George (Af 1928). 325-326 Bd. . of Trade Bldg., Indianapolis, Ind. HEILMAN, Russell H* (Af 1923), Senior In* dustrial Fellow (for mail). Mellon Institute, and 5637 Wilkins Ave., Pittsburgh, Pa. HELBURN, I. B. {hi 1929; J 1927), Junior Assoc, (for mail), Wyman Engrg., Chamber of Com* merce Bldg., and 700 Chalfonte Pi., Apt. 17., Cincinnati, Ohio. HELLSTROM, John (A 1929). Vice-Pres. (for mail), American Air Filter Co., 215 Central Ave., Louisville, and Anchorage, Ky. HELSTROM, Herman G. (Af 1928). Sales (for mail). Kewanee Boiler Corp., 70S Builders Exchange, and 4608 Arden Ave., Minneapolis, Minn. HEMINGWAY, William S. (Af 1906), Mesa Grande, Calif. .* HENVRICKSOS, John J. (A 1932), Prod. Engr. (for mail), Bryant Heater & Mfg. Co., 17825 St. Clair Ave., Cleveland, and 1475 Genessefe Rd., South Euclid, Ohio. ' HENION, Hudson D. (A 1923). Sales Mgr. (for mail), C. A. Dunham Co., Ltd-. 1523 Davenport Rd., and 45 Ridge Dr., Toronto, Ont., Canada. HESS, David K. (S 1932), Student, University of Wisconsin, Madison, Wis., Hess Warming & Vtg. Co., 1211-1227 S. Western Ave., Chicago, III., and (for mail), 627 Mendota Court, Madison Wis. ` HESTER, Thomas J. (M 1919), Vice-Pres- and Treas. (for mail), Hester-Bradley Co., 2835 Washington Blvd., and 67 Aberdeen Pi., St; Louis, Mo. HEXAMER, Harry D. (Af 1931), Sales Engr. (for mail). Excelso Products Corp., 65 Clyde Ave., and 163 E. Delavan Ave., Buffalo, N. Y. HEYDON, Charles G. (A 1923), Mgr. Sales of Western Div., Wright-Austin Co., 315 W. Wood- bridge St., and (for mail), 2681 Nebraska, Detroit, Mich. HIBBS, Frank C. (M1917), Htg. Engr., The H. B. Smith Co., 2209 Chestnut St., and (for mail), 846 North 65th St., Philadelphia, Pa. HICKEY, Daniel W. (A 1931), 278 W. Fourth St., St. Paul, Minn. HICKEY, James W. (S 1932), P. O. Box 245, Carnegie Institute of Technology, Pittsburgh, Pa. HICKS, William W. (A 1929). Mgr., W. W. Hicks & Co., 567 Banning St., Winnipeg, Man., Canada. HIERS. Charles R. (M 1929; A 1929; J 1927), Apt. 10-D, 23 N. Columbus Ave., Mt. Vernon, N. Y. HIGGINS, Dan T. (Af 1928), McCarthy & Co., 529 S. Cascade Ave., Colorado Springs, Colo. HIGGINS, Thomas J. (M 1927; A 1927; J 1923), Vice-Pres. (for mail), J. 0. Ross Engrg. Corp., 122 East 42nd St., New York. N. Y. HILL, Dr. E. Vernon* (M 1914; A 1912), (Presi dential Member), (Pres., 1920; 1st Vice-Pres., 1919; 2nd Vice-Pres., 1918; Council; 1915-1921), Pres, (for mail), E. Vernon Hill Co., 121 N. Clark at., and 1126 Farwell Ave., Chicago, 111. HILL, Fred M. (M 1930), 225 East Ave. 39, Los Angeles, Calif. ' HILLIARD, Charles E. (M 1932; A 1932; J 1927), Htg. and Vtg. Engr. (for mail). E. C. Hilliard Co., 27 B St., South Boston, and 1301 Washing* . ton St., South Braintree, Mass. HILLIARD, Forrest H. (A 1930), 2508 S. Flower St., Los Angeles, Calif. . HILLS, Arthur H. (M 1924). Mgr. (for mail), Sarco Canada, Ltd., 1002 Federal Bldg., and HENRY, Alexander S., Jr. (Af 1930), 300 Central Park W., New York, N. Y. 1005 Shaw St., Toronto, Ont., Canada. HINCHMAN, Ernest G. (Af 1923), 14 Nancy HERENDEEN, Frederick W. (Af 1920). Secy., Blvd., Merrick, L. I., N. Y. The Institute of Boiler and Radiator Mfrs., 29 HINKLE, Edwin C. (Af 1911), Htg. and Vtg. Seneca St., Geneva, N. Y. . Engr., Atlantic Htg. SrEngrg. Co.. 170 N. Frank HERLIHY, Jeremiah J. {Life Member; M 1914), lin St., Hempstead. L. I.; N. Y. Pres, (for mail), J. J. Herlihy, Inc., 810 W. Con* HINRICHSEN, Arthur F. (Af 1928), Pres-Tre^s., gress SL, and 3634 N. Keeler Ave., Chicago, HI. A. F. Hinrichsen, Inc., 50 Church St., New York, HERMAN, J., Jr. (A 1932* J 1930), 1349 E. Vernon Ave., Los Angeles, Calif. HERRICK, Daniel A. (M 1923). Gen. Mgr. (for mail), Julian d'Este Co., 6 Spice St. (Charles*, town Dist.), Boston, and 27 Agassiz St., Cam bridge, Mass. HERRING, Edgar (M 1919), Chairman and Governing Director (for mail), J. Jeffreys & Co., Ltd., Bartons PI., Waterloo Rd.. London S.E., and " Kenia" Keswick Rd., Putney, London S.W., England. N. Y. ' HIRES, J. Edgar (Af 1927), Pres., Hires-Castner & Harris, Inc., 123 S. Broad St., Philadelphia, and (for mail). 107 Linwood Ave./Ardmore, Pa. HIRSCHMAN, William F. (Af 1929), Pres, and Chief Engr., W. F. Hirschman Co., Inc., 220 Delaware Ave., Buffalo, and (for mail), 165 Le Brim Circle, Eggertsville, N. Y. HIRST, James Noble (Af 1930; J 1927). Engr. (for mail), Carrier Products Corp., 850 Frelinghuysen Ave., Newark, and 146 DeHart PI., Elizabeth, N. J. HERRMAN, Harold C. (5 1932), Instructor. Milwaukee Vocational School, and (for mail), 4523 North 22nd St,, Milwaukee, Wis. HITCHCOCK, Frederick P. (Af 1917), Buckeye' Blower Co., 213-214 Lathrop Bldg., Kansas City. Mo. -. HERSH, Franklin C. (AT933; J 1930), Carrier Engrg. Corp., 2022 Bryan St., Dallas, Texas. HITCHCOCK, Paul C. (Af 1931), 4939 Girard Ave. S., Minneapolis/Minn. HERSHEY, Leon A. (A 1933), 316 Huntington Ave., Boston, Mass. , HERTY, Frank B. (hi 1933), House Htg. Sup* ' ervisor, Brooklyn Union Gas Co.. 176 Remsen St., and (for mail), 50 East 18th St., Brooklyn, . N. Y. HERTZ, H. Porter (M 1924), Routledge & Herts, .204 Exchange Natl. Bk., Hutchinson, Kans. HJERPE, Clarence A., St. (J 1931). 73 Arch St., New Britain, Conn. . ... HOBBS, J. Clarence (Af 1920), 60 Wood St.. Painesville, Ohio. - HOCHULI, Henry, W. (Af 1925), Sales Engr., Natl. Radiator Corp., 55 West 42nd St., New ' York, N. Y., and (for mad), T13 Chester Ave:, . Bloomfield, N. J. \ HERTZLER, John R. (J 1928), Air Cond. Sates Engr. (for mail), York Ice Machinery Corp., 42nd St. and Second Ave., Brooklyn, and 1 University PI., New York, N. Y. HODEAUX, W. L. (M 1931), Owner (for mail), W. L. Hodeaux Plbg. & Htg. Co.. 215-17 N. Flagler Dr., and 310 Tenth St., West Palm ' Beach, Fla. . 20 Roll of Membership HODGDON, Harry A. (M 1919), 153 Norfolk St.. HOWELL, Frank B. (Af 1920), Tech. Advisor (for mail), American Radiator Co., 40 West 40th St., Wollaston, Mass. HOERSTING, Frank J. (Af 1921), Pres, (for mail). The Hoersting & Holtmann Co., 1133 W. Third St., and 2045 Philadelphia Dr., Dayton, Ohio. HOFFMAN, Charles S. (Af 1924). Vice-Pres. (for mail). Baker Smith & Co., Inc., 576 Greenwich St., and 25 Central Park West, New York, N. Y. HOFFMAN, James D.* (Af 1903), (Presidential Member). (Pres., 1910; 1st Vice-Pres., 1908: Bd. of Governors, 1911-1912), Prof, of Practical Mechanics, Head of Dept., Director of Practical Mech. Lab. (for mail), Purdue University, and 323 University St., W. Lafayette, Ind. HOFT, Paul J. (Af 1925; A 1924), (for mail). 245 S. Eighth St., and 1119 Wyoming Ave., Phila and 15 Central Park West, New York, N. Y. HOWELL, Lloyd (Af 1915), Consulting Engr., Htg., Vtg., Cooling, 2239 W. Lake St., and (for mail), 7601 Yates Ave., Chicago, 111. . HOYT, Charles W. (A 1931), Pres-Treas. (for mail). Wolverine Htg. and Vtg. Equip. Co., 80 Boylston St., Boston, and 45 Thaxter Rd., New- tonville, Mass. HOYT, Leroy W. (Af 1930), N. Stamford Ave., Stamford, Conn. HOYT, William B.* (Af 1919), The Hoyt-Grant Co., 52 Whitney Ave., New Haven, Conn. HUBBARD, George Wallace* (Af 1911), Chief Mech. Engr. (for mail), Graham, Anderson, Probst & White, 1417 Railway Exchange, Chicago, and 710 Bonnie Brae, River Forest, IU- delphia, Pa. HOGAN, Edward L.* (Af 1911), Consulting Engr. (for mail), American Blower Co., 6000 Russell St., and 700 Seward Ave., Detroit, Mich. HOLBROOK, Frank M.* (Af 1923), Engr. (for . mail),- Congoleum-Naim, Inc., Kearny, and 52 Walnut Crescent. Montclair, N. J. HOLLADAY, W. L. (A 1933), Engrg. Mgr. (for mail), The George Belsey Co., Ltd., 406 Archi tects Bldg., Los Angeles, and 110 Loma Alta Dr.,. Altadena, Calif. HOLLISTER, Edmund W. {/ 1931). Supt.' Plbg. Htg. Vtg. Div., Hudson Falls Hardware Co., 186 Main St., and (for mail), 88 Oak St., Hudson HUCH, A. J. (Af 1919), Secy-Treas. (for mail). Central Supply Co,. 312 S. Third St., and 4037 Harriet Ave., Minneapolis, Minn. HUCKER, Joseph H. (Af 1921), Partner, 1700 Walnut St., Philadelphia, and (for mail), 715 Stranbridge St., Norristown, Pa. ' . HUFFAKER, Herbert B. (Af 1933), Htg. Engr. (for mail). Dail Steel Products Co., Lansing, Mich., and 1106 Fourth Ave., Council Bluffs, Iowa. HULL, Harry B. (Af 1931), Mgr. Research Eng., Frigidaire Corp., and (for mail), P. O. Box 671 Dayton, Ohio. ' HUMPHREY, Dwight E * (Af 1921), Htg. and Falls. N. Y. HOLLISTER, Norman A. (Af 1933), 7101 Colonial Rd., Brooklyn. N. Y. . HOLT, James (Af 1933), Asst. Prof, (for mail), Massachusetts Institute of Technology, Cam bridge, and 1062 Massachusetts Ave., Lexington, Id ass r HOLTON, John H. (Af 1927), Director of Opera tions (for mail). Carrier Research Corp., 750 Frelinghuysen Ave., Newark, and 30 Hickory Dr.< Maplewood, N. J. * HOOD, O. P. (Honorary Member 1929), (for mail). Chief, Technologic Br.. U. S. Bureau of Mines, 17th and F St. N.W., and 1831 Irving St. N.W., Washington. D. C. HOOPER, Vernon F. (Af 1929), 61 Eastern Ave.. Ossining, N. Y. HOPPER, Garnet H. (Af 1923), Engr., Taylor Forbes, Ltd., 1088 King St. W., and <for mail), 19 Brummell Ave., Toronto, Ont., Canada. HOPSON, William T, (Af 1915), The Hopson & Chapin Mfg. Co., New London, Conn. HORNUNG, John C. (Af 1914), Engr. (for mail). Central Heat Appliances, 343 S. Dearborn St., Chicago, and 854 Bluff St., Glencoe, 111. HORTON, George H. (M 1930), 4938 Rosewood Ave.. Los Angeles, Calif, HORTON, Homer F. (Af 1925), Sales Repr. (for mail), Natl. Regulator Co., 2301 Knox Ave., Chicago, and 343 Green Bay Rd., Glencoe, 111. HOSHAJLL, Robert H. (Af 1930). Associate (for mail), Thos. H. Allen, Consulting Engr., 65 McCall St., and 789 N. Evergreen St., Memphis, Vtg. Engr. (for mail), Goodyear Tire &: Rubber Co., 1144 E. Market St., Akron, and 2499 Sixth St., Cuyahoga Falls, Ohio. HUMPHREYS, Clark M. (Af 1931), Asst. Prof, (for mail). Carnegie Institute of Technology, Scheniey Park, and 932 Flemington Ave., Pitts burgh, Pa. HUMPHREYS, James (Af 1930). Sharp Hill Rd., Wilton, Conn. HUNGER, Robert F. (Af 1927), Associate Dist. Mgr. (for snail), Buffalo Forge Co., 763 Canard Bldg., and 4618 Chester Ave., Philadelphia, Pa. HUNGERFORD, Leo (Af 1930). Pres, (for mail). Pacific Eleq. & Mech. Co., Inc., 524 Loew's State Bldg., and 105 N. Berendo St., Los Angeles. Calif. HUNTER, Verne W. (Af 1932), Supt. (for mail), 417 Grant Bldg., and 3125 Middletown- Rd., Sheridan Sta., Pittsburgh, Pa. HURLEY, Joseph C. (Af 1915). Pres- (for mail). Petroleum Fuel Engrg. Co., Inc., 4028-32 Filbert St., Philadelphia, and 134 Lansdowne Court, Lansdowne, Pa. HUSBAND, Edward W. (Af 1922). 9 Savings St., Providence, R. I. .` HUST, Carl E. (Af 1932), Htg. Engr. (for mail). The Union Gas & Elec. Co., Room 1008, Fourth and Main Sts., and Hillcrest Apts., 15 Mason St., Cincinnati, Ohio. - HUSTOEL, Arnold M. (A 1930), 2623 N. Ballou St., Chicago, 111-. HUTZEL, August F, (Af 1916), Partner (for mail), 119 E. Washington, and 2115 Wallingford Rd., Tenn. . HOSKING, Homer L. (Af 1930), Br. Sales Mgr. (for mail), Pacific Steel Boiler Corp., 370 Lexing ton Ave., New York, and 5 Church Lane, Ann Arbor, Mich.. ' HUTZEL, Hugo F. (Af 1918), Mgr., Er$kine Radiator Div. (for mail)'. Chase Brass & Copper Co., Inc., and 72 Hewlett St., Waterbury, Conn. . Scarsdale, N. Y. HOSTERMAN, Charles O. (Af 1924), 25 Bates- HVOSLEF, Fredrik W. (Af 1931; A 1921), Htg. Research Engr. (for mail). Kohler Co., and 523 well Rd., Dorchester, Mass. Audubon Rd., Kohler, Wis. HOTCHKISS, Charles H. B. (Af 1927), Hearing and Ventilating, 148 Lafayette St., New York, N. Y. HOUGHTEN, Ferry C.* (Af 1921) Director (for mail), Research Lab., A.S.H.V.E., U. S. Bureau HYMAN, Wallace M. (Af 1920), Vice-Pres. (for mail), Reis & O'Donovan. Inc,, 255 West 28th St., and 23 West 73rd St., New York, N. Y. HYNES, Lee P.* (Af 1919). (for mail), 240 Cherry St., Philadelphia, Pa., and Haddonfield, N. J, of Mines, 4800 Forbes St., and 1136 Murray Hill Avei, Pittsburgh, Pa. .I HOULISTON, G. Baillle (A 1928), Secy, (for mail), W. C. Green Co., 704 Race St., Cincinnati'. Ohio, and 112 Forest Ave., Ft. Thomas. Ky. HOWATT, John* (Af 1915), (Council, 1927-1933). Chief Engr. (for mail). Bd. of Education, 228 N, LaSalle St., and 4940 East End Ave., Chicago, 111. ICKERINGILL, John (Af 1923), Salesman. Spencer Heater Co., 1718 Fairmount Ave., Philadelphia, and (for mail), 235. Rector St;, Roxborough, Philadelphia, Pa. ., INE. Frank H. (A 1930), 699 Layton Blvd..' Milwaukee, Wis. 21 American Society of Heating and; Ventilating Engineers Guide, 1934 INGALLS. Frederick D..B. (M 1906). Consulting Htg. Engr., 1 Hopkins St., Reading, Mass. INGELS, Margaret* (M 1923; J 1918), Mech. Engr. (for. mail). Carrier Engrg. Corp., 850 Frelinghuysen Ave., Newark, and Hotel East Orange, East Orange, N. J. INGOLD, John W. (S 1933), 3036 PerrysviUe Ave. N.S.. Pittsburgh, Pa. INNIS, Helen R.* (M 1921; J 1918), Largent, W. Va. ISSERTELL, Henry G * <M 1913*. A 1912), Consulting Engr., 31 Park Terrace W., New York, N. Y. JOHNSON, Clarence W. (Af 1933; A 1933; J 1931), Br. Mgr. (for mail), Canadian Sirocco Co., Ltd., 630 Dorchester St. W., and 5549 Queen Mary Rd., Montreal, P. Q., Canada. JOHNSON, Edward B. (M 1919), Sales Engr., Staten Island Supply Co., and (for mail), 154 Wardwell Ave., West New Brighton, S. I., N. Y. JOHNSON, Edgar E. (M 1926), Sales Engr. (for mail), Buffalo Forge Co., 490 Broadway, and 103 University Ave., Buffalo, N. Y. JOHNSON, Helge S. (A 1933; J 1927), Buffalo Forge Co., 414 Standard Bldg.. Albany, N. Y. JOHNSON, James M. (A 1928), Apt. 207, 3446 J Connecticut Ave. N.W., Washington, D. C. JOHNSON, Leslie O. (J 1930), 3307 Berteau Ave., JACKSON, Alton B. (M 1932), Carrier Products Chicago, 111. Corp., 20 Providence St., Boston, and (for mail), 15 Herrick St., Winchester, Mass. JOHNSON, Louis H. (M 1931), 918 LaSalle Ave.. Minneapolis. Minn. JACKSON, Charles H. (M 1923). Vice-Pres. (for mail). Blower Application Co., 918 N. Fourth St., and 2706 N. Farwell Ave., Milwaukee, Wis. JOHNSON, Paul H. (A 1914), E. H. Sheldon & Co., Muskegon, Mich. JOHNSTON, J. Ambler (M 1912), Partner (for JACKSON, Marshall S. (Af 1919), Repr. (for mail). Powers Regulator Co., 250 Delaware Ave. '. and 108 Larchmont Rd., Buffalo, N. Y. mail), Carneal, Johnston & Wright, 806 Electric Bldg., and Richmond, Va. JOHNSTON, John F,, Jr. (A 1932), (for mail), JACOBSON, Ruben A. (S 1933), 1626 Sixth SL S.E., Minneapolis, Minn. Johnston Bros., Inc., Ferrysburg, and Grand Haven. Mich. JACOBUS, Dr. David S. (Life Member; M 1916), JOHNSTON, Robert EUiott (M 1929; A 1926), The Babcock & Wilcox Co., 85 Liberty St., New York, N. Y. 3342-33rd Ave. W., Vancouver, B. C., Canada. JOHNSTON, William H,(Af1924), 306 East 26th JALONACK, Irwin G. (A 1933; S 1930); Engrg. St., New York, N. Y. - Mgr. (for mail), 82 Railroad Ave., and 15 South JONES, Alfred (M 1928), Chief Consulting Engr. St., Patchogue, N. Y, . (for mail), Armstrong Cork Co;, P. O. Box 540, JAMES, Hamilton R. (M 1931), Service Equip. and 402 President Ave., Lancaster, Pa. Engr., United Engineers & Constructors, Inc., JONES, Alfred L. (M 1926), Plbg. & Htg. Con ' 1401 Arch St., Philadelphia, and (for mail), 55 W. Drexel Ave., Lansdowne, Pa. tractor (for mail), 21 Church St., Greenwich, and Box 121, Riverside, Conn. JAMES, John W. (J 1933), Research Fellow in JONES', Bernard C. (Af 1928), Mgr. (for mail). Heat. & Vent, (for mail), Mech. Engrg. Bldg., . University of Wisconsin, and 1905 Common Acme Fan & Blower Co., Ltd., 868 Arlington St., and 542 Raglan Rd., Winnipeg, Man., Canada. wealth Ave., Madison, Wis. JANCO, Nathan (S 1932), Asst, in Mech. Engrg. JONES, Charles R. (A 1928), Jones Supply Co., Siloam Springs, Ark. New York University, and (for mail) 2476 Grand Ave., New York, N. Y. JONES, Edwin (M 1933; J 1924), Box 582, Tulsa, Okla. ` JANET, Harry L. (Af 1920), Engr. (for mail). Carrier Engrg. Corp., Chrysler Bldg., New York, and 688 Decatur St., Brooklyn, N. Y. . JONES, Edwin A. (M 1919), C. E. (for mail). L. J. Mueller Furnace Co., 2001 XV. Oklahoma, and Shorecrest Hotel, Milwaukee, Wis. JARDINE, Douglas C. (M 1929; A 1926), Pres, JONES, Edwin F. (M 1923), Consulting Engr. (for (for mail), Jardine & Knight Plbg. & Htg. Co., 312 N. Custer Ave., and 1326 N. Wahsatch Ave., mail), 420 New York-Bldg., and 220 Montrose PI.. St. Paul, Minn. ' Colorado Springs, Colo. JONES, Harold L. (M 1920), Asst. Supt. (for JARRETT, Paul R. (A 1931), .117 Fifth Ave. N., mail), W. W. Farrier Co., 44 Montgomery St., Nashville, Term. Jersey City, and 11 Cambridge Rd., Glen Ridge, JELLETT, Stewart A.* (Honorary Member, 1929), N. J. - . (Charter Member; Presidential Member), (Pres., 1895; Bd. of Mgrs., 1896-1899; Secy., 1898), JONES, Noel W. (S 1933), 1315 East 28th St., Minneapolis, Minn. . Pres, (for mail), Stewart A. Jellett Co., 1200 . JONES, Raymond E. (M 1919), Asst Supervisor Locust St., Philadelphia, and 6701 Lincoln Dr., Fuel Oil Sales, Gulf Refining Co.,.1515 Locust Mt. Airy, Philadelphia, Pa. . St., Philadelphia, Pa., and (for mail),>39 West JENNEY, Hugh B. (A 1933), 1322 Dufferin St., End Ave-, Haddonfield, N. J. Toronto, Ont., Canada. .. JONES, William T. (M 1915), (Pres., 1933; 1st JENNINGS, Irving C. (M1924), Nash Engrg. Co., South Norwalk, Conn. Vice-Pres., 1932; 2nd Vice-Pres., 1931; Council,. 1925-1933), Treas. (for mail), Barnes &- Jones, JENNINGS, Warren G. (A 1930). Minneapolis- Honeywell Regulator Co., 2065 Daily News Bldg., Chicago, 111. JENNINS, Henry H. (Life Member; M 1901), E. Oldroyd & Co., Ltd., Black Bull St., Leeds, England. , JENS, Jens (J 1930), Mech. Engr. (for mail). 128 Brookside Ave., Jamaica Plain, and 1886 Beacon St., Waban, Mass. JORDAN, Richard C. (S 1933). 2518 Grand Ave. ' S., Minneapolis, Minn. JOYCE, Harry B. (M 1922), Consulting Engr. (for . mail), 810 Commerce Bldg., and 501 Liberty St., Erie, Pa. Carrier Lufttechniscbe Gesellsehaft, Archiv. Strasse 14, Stuttgart, Germany, JENSON, Jean S.(Af 1912), Consulting Engr. (for mail), Neiler-Rich 8c Co., 431 S. Dearborn St., and 1634 West 106th St., Chicago, 111. JOHN. Victor P. (Af.1931), 136 Berryman Dr., Snyder, N. Y. ' JUNG, John S. (M1930; A 1923),- Htg. Contractor (for mail), 2409 W. Greenfield Ave., and 1516 S. Layton Blvd., Milwaukee, Wis. ' JUTTNER, Otto J- (M 1915), Pres, (for mail), Juttner Htg. Co., 814 N. Milwaukee St., and 910 E. Wells St., Milwaukee, Wis. JOHNS, Harold B.* (M 1928; J1927),.(for mail). Peoples Gas Co., 122 S. Michigan Ave., Chicago, and 543 N. Elmwood Ave., Oak Park, 111. JOHNSON, Carl E. (J 1930). Holland Furnace Co., 2001 N. Broad St., Philadelphia, Pa. JOHNSON, Carl W. (Af 1912). Pres, (for mail), C. W, Johnson, Inc., 211 N. Desplaines St., and 1809 Morse Ave., Chicago, 111. K KACZENSKI, Chester (J 1933), 18 Vine St., Natrona, Pa. . KAGEY, Isaac B.t Jr. (J 1929), Metropolitan Life Insurance Co., 1 Madison Ave., New York, N. Y. KAHAN, Charles (5 1933), 6 Marie Ave., Cam bridge, Mass. 22 Roll of Membership KAMMAN, Arnold R. (A 1925; J 1921), (for mail), Chippewa Plbg. Co.. Inc., 279 Chicago St., Buffalo, and R. F. D. 1, Hamburg, N. Y. KAPPEL, George W. A. (M 1921), Pres-Treas. (for mail), Camden Htg. Co., Wilson Blvd. and Waldorf Ave., Camden, and 347 W. Kings Highway, Haddonfield, N. J. KARGES, Louis (5 1933), 605 E. Pearl St., . KERN, Raymond T. (M 1927), Chief Engr., Jennison Co., Fitchburg, and (for mail), 51 Claflin St., Leominster, Mass. KERNEY, Thomas F. (A 1930; J 1925), Engr., H. B. Hackett Consulting Engr., 901 Architects Bldg., and (for mail), 4524 N, Reese St., Phila delphia, Pa.. KERSHAW. Melville G. (M 1932; A 1926; J 1921), Vtg. and Air Cond. Engr. (for mail), . KABRuLtleSrO, PNa,. Alfred F. (M . 1918), Chief Engr. (for mail), Parks-Cramer Co., 970 Main St., Fitch-. burg, and 186 Prospect St., North Leominster, E. I. Du Pont de Nemours & Co., Wilmington, Del., and 7313 North 21st SL, Philadelphia, Pa. KEYES, Robert E. (M 1913), Chief Engr., The Cooling & Air Conditioning Corp., Hyde Park, KAMRaTssO. RIE, V. T. (5 1933). 2982 East 102nd SL, Mass- ` . KICE, M. S., Jr. (Af 1920), Asst. Chief Engr. (for KACSleTvNelEanRd,. GOehoior.ge C. (S 1933), 654 East 226th mail), American Blower Corp., 6000 Russell St., . Detroit, and Glengarry Rd., Bloomfield Village St.. New York, N. Y. KATSUMOTO, Eijiro (M 1926), Katsumoto Sc Co., Ginza St., Dairen, Manchuria, China. KAUFMAN, William M. (S 1933), 2875 Sedg wick Ave., New York, N. Y. . KEEFE, Edmund T. (M 1931), 75 Pitts SL, near Birmingham, Mich. KIEFER, Carl J. (Af 1922), Consulting Engr. (for mail), 918 Schmidt Bldg., and 984 Lennox PI., Cincinnati, Ohio. KIEFER, E. J., Jr. (A 1932; J 1928), Treas. and Gen. Mgr. (for mail), H. C. Archibald Co., 8 S. KEBEoLstEoRn,, MAansss.on H. (M 1932), Sales Engr. (for mail), Vento Div., American Radiator Co., 2212 Walnut St., Philadelphia, and 906 Concord Ave., Sixth St., and 108 N. Sixth St., Stroudsburg, Pa. KIESLING, Justin A. (M 1930), Pres, (for mail), Robischung Kiesling, Inc., 1609 Congress Ave., P. O. Box 1295, and 1806 Holman Ave., Houston, Drexel Hill, Pa, KEELING, Harry B. (M 1930; A 1930), 305 Union Insurance Bldg., Los Angeles, Calif. . KEENEY, Frank P. (A 1915), Pres-, Engrg. Publications, Inc.. 1900 Prairie Aye., Chicago, IU, KEHM, Horace Stevens (M 1928), 51 E. Grand Texas. KIEWITZ, Arthur A. (M 1912), 23-80-28th St., Astoria, L. I., N. Y. KILNER, John S. (M 1929). Sales Engr. (for mail). Kilner-Mill3 Co., 427 Stormfeltz-Loveley Bldg., and 1091 Seminole Ave., Detroit, Mich. . Ave., Chicago, 111. KEIST, Walter E. (4 1931), Engr., 393 Center Ave., West View, Pittsburgh, Pa. KELBLE, Frank R. (M 1928), Vice-Pres. and Mgr. (for mail), Huffman-Wolfe Co. of Phila delphia, 11 W. Riltenhouse SL, Philadelphia, and KIMBALL, Charles W. (M 1915). Richard D. Kimball Co., 6 Beacon St., Boston, Mass. KIMBALL, Dwight D.* (M 1908), (Presidential Member), (Pres., 1915; 2nd Vice-rres., 1914; Bd. of Governors, 1912-1916), Consulting Engr. (for mail), 205 East 42nd St., and 21 East 90th St., 115 Rosyln Ave., Glenside, Pa. KELLEY, James J. (A 1924), Vice-Pres. and Gen. Mgr. (for mail), Arthur H. Ballard, Inc., 535 Commonwealth Ave., Boston, and 142 Governors Ave., Medford, Mass. - KELLNER, Day C. (S 1933). Carnegie Institute of Technology, Pittsburgh, Pa. KELLOGG, Alfred (M 1916), (Council, 1920 1921; 1923-1924), Consulting Engr, (for mail), 585 Boylston St., Boston, and 6 Hawthorne St., New York, N. Y. KING. Roy L. (S 1933), 2538 Clinton Ave. S.. Minneapolis, Minn. KINGSLEY, Edwin A. (M 1926), 370 Lexington Ave., New York, N. Y. K1NNER, James E. (M 1924), The Bryant Heater & Mfg. Co., 17825 St. Clair Ave., Cleveland, Ohio. KINNEY, William H. (M 1931), Bureau of Sub ways, 20 N. Wacker Dr., Chicago, IU. KINTZ, Leslie H. (Af 1930), Htg. Engr.. 210 Belmont, Mass. . KELLY, Charles J. (M 1931), New York Repr., Jas. P. Marsh Corp., 551 Fifth Ave., New York, N. Y., and (for mail), 162 Fairview Ave., Jersey Highland Ave., Highland Park, Mich. KIPE, J. Morgan (M 1919), 801 Homestead Ave., Beechwood, Del. Co., Pa. KIRK, Charles D. (M 1909), Mgr. (for mail), City, N. J. KELLY, Hugh (M 1927), Mgr. (for mail), H. Kelly & Co., Ltd., 10041-101 A Ave., and 10235-124th. Chas. D. Kirk Co., Sargent and Colleen/> and 774 McMillan Ave., Winnipeg, Man;, Canada: . KIRK, Leonard G. (Af 1923), Kirk & Story. 12 St., Edmonton, Alta., Canada. KELLY, John G. (A 1919), 374 Park Ave.. Yonkers, N. Y. .. KELLY, Joseph A. (A 1931), 3042 N. Franklin Wavedy PI., New York, N. Y. KIRKPATRICK, Arthur H. (J 1931), Ilg Electric Vtg. Co., 2850 N. Crawford Ave., and (for mail), 4251 Irving Park Blvd., Chicago, 111. St., Philadelphia, Pa. ' KENDALL, Edwin H. (A 1932; J1930), Engr. (for mail). English-Lauer, Inc., 1224 $. San Pedro, KITAURA, Shigeyuki (Af 1918), 191 Shimoohsaki near Tokyo, Japan. KITCH, Stanley B. (M 1928; A 1928; J 1925), Los Angeles, and 1470 Poppy Peak, Pasadena, 2024 Berwyn Ave., Chicago, 111. Calit. . KENNEDY, Maron (J 1930),.Sales Engr. (for - mail), York Ice Machinery Corp., 5051 Santa Fe . Ave., Los Angeles, and 3465 Walnut St., Hunt ington Park, Calif. KENNEDY, Owen A. (S 1933). 1051 Morewood Ave., Pittsburgh, Pa. ., KENT, J. King (J 1928), Pres, (for mail), J. King Kent & Co.. Inc., 124 N. Main St., St. Louis, and 1030 Commodore Dr., KENT, Laurence F. (A Richmond Heights, Mo. 1927;' J. 1924), Pres, (for . mail), Moncrief Furnace Co., P. O. Box 1673, Atlanta, and R. F. D. No. 2, Smyrna, Ga. KENWARD, Stanley B. (S 1933), 45 Fifth Ave,, KITCHELL, Herbert N. (A 1926), 4528 Circle Ave., Cincinnati, Ohio. KITCHEN, Francis A. (A 1927; J 1923), Pres, (for mail), American Warming & Vtg. Co., 1514 Prospect Ave., Cleveland, and 3552 Glencairn,' Shaker Heights, Cleveland, Ohio. ', KITCHEN, John H. (M 1906), Owner (for mail), John H. Kitchen Co., 1016 Baltimore Ave., and 5015 Westwood Ter., Kansas City, Mo. . KLEIN, Albert (M 1920),' Managing Dir. (for mail). Carrier Lufttechnische Gesellschaft mbH, Stuttgart, Archivstrasse 14/16 and Stuttgart,. Panoramastrasse 23, Germany. . ' KLEIN, Edward W. (M1917), S. E. Dist."Mgr. Bay Shore, N. Y. KEPL1NGER, William. L. (Af 1929), Special Repr. (for mail). Carrier . Engrg. Corp., 408 Chrysler Bldg., New. York, and 103 Sunset Dr., . (for mail), Warren Webster & Co., 152 Nassau St. N.W., and 456 Peachtree Battle Ave., Atlanta, Ga. KLIE, Walter (Af 1915), Pres, (for mail). The Hempstead, L. I., N. Y. KEPPNER; Harry W. (M1930), (for mail), H. W. Keppner,. 1310 South 56th Ave., and 1245 S. Austin Blvd., Cicero, IU. . .' Smith & Oby Co., 6107 Carnegie Ave.. Cleveland, - ., and 18411 S. Woodland Ave., Shaker Heights, Ohio. ... 23 American Society of Heating and Ventilating Engineers Guide, 1934 KLONOWER, Arthur A. (M 1920), Vice-Pres. ` LANDAUER, Leo L. (7 1932), Mech. Engr. (for (foT mail), J. S. Cassedy, Inc., 132 Austin SL, and Hotel Commander, Cambridge, Mass. ' KNECHT, Charles H. (A 1930), Vice-Pres. (for mail), Harry Knecht Co., Inc., 410 Richey Ave., West Collingswood, .and 7225 Ruddirow Ave., Merchantville, N. J. KNIBB, Alfred E. CM1930), Htg. Engr. (for mail), mail), C. L. Kribs, Jr., Consulting Engr., 704 S. W. Life Bldg., and 5707 Velasco St., Dallas, Texas. ' LANDERS, John J. (M 1930; A 1924: J 1924). Sales Engr. (for mail), U. S, Radiator Corp., 303 Crosby Bldg., Buffalo, and Seneca SL, Ebenezer, N. Y. 1003 Maryland Ave., and 9333 E. Jefferson Ave., Detroit, Mich. - KNOPF, Charles (S 1933), 1201 Liberty Ave., Brooklyn, N. Y. KNOX. James R. (Af 1930), Htg. Engr., 20 S. Eckar St., Irvington, N. Y. KOCH, Harry O. (M 1916), 212 Centre St., Tamaqua. Pa. KOETZ, Lester CM 1933; A 1933; 7 1929). Sales Engr. (for mail), Zion Institutions 8c Industries, 2633 Sheridan Rd., and 3110 Elim Ave., Zion, 111. KOHLER, Walter J., Jr. (A 1933). Htg. Sales Supervisor (for mail), Kohler Co., and 605 W. Park Lane, Kohler, Wis. KOITHAN. William S. (M 1913), Sales Mgr. (for mail), Koithan & Pryor, 39 Cortlandt St-, New York, N. Y., and 46 Linden PI., Summit, N. J. KONZO, Selchi* (7 1932), Special Research Associate, Engrg. Exper. Station, University of Illinois, and (for mail), 1108 W. Stoughton St... Urbana, UJ. ' LANGENBERG, Everett B. (M 1914). (Council, . 1926-1931), Pres., E. B. Langenberg Co., 3800jW. Pine Blvd., and (for mail), 6031 Enright, St. Louis, Mo. LANNING, E. K. (A 1927), Warren Webster & Co., Camden, N. J. - LANOU, J. Ernest (M 1931), Mgr. (for mail), 90 St. Paul St., and 48 Brookes Ave., Burlington, Vt. LARSON, Gustus L * (M 1923). (Council, 1929 1933), Prof., Steam and Gas Engrg., and Chair man of DepL of Mech. Engrg., University of Wisconsin, Madison, Wis. LARSON, J. M. (M1924), National Regulator Co., 2301 Knox Ave., Chicago, 111. LaSALVIA, James J. CM 1930), Air Cond. Engr.. Frigidaire Corp., and (for mail). Commodore Apts., 522 Grand Ave., Dayton, Ohio. LAUTENSCHLAGER, Fred CM 1915), Vice- Pres-Treas. (Offices), Kroeschell Boiler Co., 3253 N. Kedzie Ave., Chicago, (Factories), 100 Reichert Cl, Radne, Wis., and (for mail), 3846 KOOISTRA, John F. (M 1933), Engr. (for mail). Alta Vista Ter., Chicago, 111. Carrier, 748 E. Washington St. and 346 N. LAWLER, Matthew M. {J 1930). 403 North Robinson St., Los Angeles, Calif. , Lucerne Blvd., Los Angeles. Calif. ' KORN. Charles B. (M 1922), Member of Firm, Reber-Korn Co., 817 Cumberland St., and (for mail), 1022 S. Eighth.SL, Allentown, Pa. KOZU, Tamiichro CM 1930). No. 1701 Yonchome. Shimoochiai. Yodobashiku, Tokio, Japan. KRAMIG, Robert E., Jr. (A 1933), .(for mail) . R. E. Kramig 8c Co., 222-4 East 14th St., Cincin nati, and 51 Central Ter., Wyoming, Ohio. KRATZ, Alonzo P * (M 1925), Research Prof, (for mail). Dept- of Mech. Engrg.. University of Illinois, and 1003 Douglas Ave., Urbana. 111. KREISSL, Hans George {M1925), Mgr., "Vento" Dept, (for mail), American Radiator Co., 816 S. Michigan Ave., Chicago, and 408 Lee St., Evanston, III. LAWTON, Frank C. (M 1928), 145 Buena Vista Ave., Hawthorne, N. J. LeBEAU, John F, (M 1924), 158-2l-S4th Dr., Jamaica, L. I., N. Y. LEEK, Walter (M1930), Managing Dir. (for mail), . Leek & Co.; Ltd., Htg. Engrs., 1111 Homer St., and 4769 W. Second Ave., Vancouver, B. C., ' Canada. LEES, Herbert K. (M 1924; J 1912), (for mail), 548 Washington Blvd., and 5855 N, Kenneth Ave., Chicago, 111. LEES, John T. (S 1933), (for mail), 60 Boylston St., Cambridge, Mass., and 1218 N. New St.. Bethlehem, Pa. LEFFINGWELL, Robert R, (S 1933), 2747 Sedgwick Ave., New York, N. Y. KREITNER, William GJ (A 1931; 7 1926), 200 Sterling PI., Brooklyn, N. Y. LEGLER, Frederick W. (A 1933). Mgr. Retail Sales (for mail), 1121 Jackson SL N.E., and 2919 KRIEBEL, Arthur E. (M 1920), Sales Engr. (for mail). Haynes Selling Co., 1518 Fairmount Ave., Philadelphia, and Berwyn, Chester Co., Pa. KROUPSKY, Vladimir CS 1933), 220 East 16th St., New York, N. Y. KRUEGER, Bill (A 1931), 91 Tremont. Kenmore. N. Y. KRUEGER, James I. CM 1921). Mfrs. Repr. (for mail). 357 Ninth SL, and 1920 Sacramento SL; San Francisco, Calif. KRUSE, Rpbert W. (A 1930), Kruse Co., 353 West 16th PI.. Indianapolis, Ind. KUEHN, Walter C. (A 1933), Kuehn Htg. & Vtg. Johnson SL N.E., Minneapolis, Minn. LEIGH. Robert L. (5 1933), 1034 Cadillac Dr., Grand Rapids, Mich. LE1LICH, Roger L. (M 1922), Pres, (for mail), Baltimore Heat Corp., 2000 W. Pratt St., and 2810 Elsinor Ave.. Baltimore, Md. LEINROTH, J. Paul (M 1929), Gen. Industrial Fuel Repr. (for mail). Public Service Electric & Gas Co., 80 Park PL, Newark, and 366 N. Mountain Ave., Montclair, N. J. LEITCH, Arthur S. (M 1908), Pres, and Manag ing Dir. (for mail). The Arthur S. Leitch Co., Ltd., 1123 Bay SL, and 421 Russell Hill Rd.. Toronto, Out., Canada. Co., 915 Seventh Ave. S., Minneapolis, Minn. KUEHNERT, Albert C. (A 1930), 301 Station SL, McDonald, Pa. . LELAND, Warren B. (M 1929), Sales Engr., The H. B. Smith Co,, Westfield, and 34 Leyfred Ter., and (for mail), P. O. Box 1522, Springfield, Mass. KUEMPEL, Leon L. (J 1929), 3836 Vincent Ave. S., Minneapolis, Minn. KUHLMANN, Rudolf (M 1928), 122 East 42nd ` St.. New York. N. Y. . KWAN. 1. K. CM 1933). Gen. Mgr.. China Engrg. Co., 30 Brenan Rd., Shanghai, China. LELAND, William E. (M 1915), Partner (for mail), Leland and Haley, 58 Sutter SL, San Francisco, and 704 The Alameda, Berkeley, . Calif. . LENNON, Joseph O. (M 1929), Mgr. (for mail). Ilg Electric Vtg. Co., 15 Park Row, ancf 180 West' 59th St., New York. N. Y. L LENONE, J. M. (M 1919), Wilson & Co., Inc., 41st SL and S. Ashland Ave., Chicago, 111. LABOV, Milton (5 1933), 212 AdriaUc Ave., Atlantic City, N. J. . LAGOPZINSKI, H. J. (A 1927; 7 1920). 3628 N. Tripp Ave., Chicago, 111. LAMMERS, Cornelius (A 1931), 236 Winter Ave. N.W., Grand Rapids, Mich. LaMONTAGNE, John M. (A 1930), Westing- house Electric & Mfg. Co., 420 S. San Pedro St., Los Angeles, Calif. LEONARD, J. H. (M 1931), Mgr. (for mail); J. H. Leonard Co., 508 Scott Bldg., and 844 Grosvenor* Ave., Winnipeg, Man., Canada. .` LESLIE, Donald E. (S 1933), 3541 Bloomington Ave., Minneapolis, Minn. LEUPOLD, Herbert W. (J 1933), Engr., Metro politan Life Insurance Co., 1 Madison Ave., New York, and (for mail), 12 Cambridge PL, Brooklyn, N. Y. 24 Roll of Membership LEVY, Marlon I. (7 1931), Sales Mgr. and C. Engr. (for mail), Air Controls, Inc., Div. of Cleveland Heater Co., I960 West 114th SL, and 1273 West 108th St., Cleveland, Ohio. ` LEWIS, Carroll E. (M 1930). Pres, (for mail), Lewis Air Conditioners, Inc., 829 Second Ave. S., Minneapolis, and 1454 Chelmsford St., SL Paul, Minn. LEWIS, Edward B. (M 1924), Htg. and Vtg. Engr., 2283 Commonwealth Ave.. St. Paul, Minn. LEWIS. George C. (M 1919), Secy-Treas. (for mail), American Htg. & Vtg. Co., 1505 Race St., Philadelphia, and 812 Summit Grove Aye., Bryn Mawr, Pa. LEWIS, J. Clifford (M 1913). Anchorage, BCy. LEWIS, John G. (M 1926) 412 East 31st St.. . Kansas City. Mo. LEWIS, John P. (M 1931), 39 Hanover St., Lebanon, N. H. LEWIS, L. Logan* (M 1918), Secy, (for mail), Carrier Engrg. Corp., 850 Frelinghuysen Ave., Newark, and 724 Carlton Ave., Plainfield, N. J. LEWIS, Samuel R.* CM 1905), (Presidential Member), (Pres.. 1914; 2nd Vice-Pres., 1910; Bd. of Governors, I909-I9I0-I922; Council, 1924 1915), Consulting Engr. (for mail), 407 S. Dear born St., and 4737 Kimbark Ave., Chicago, III. LEWIS, Thornton* (M 1919), (Presidential Member), (Pres., 1929, 1st Vice-Pres., 1928; 2nd Vice-Pres., 1927; Council, 1923-1930), Executive Vice-Pres. (for mail). Carrier Corp, 850 Freling huysen Ave., Newark, and 4 Halsey PL, South Orange. N. J. . LEWIS, Will (M 1931), 1484 Lathrop St., Omaha, Neb. LIBBY, Ralph S. (7 1933). B. C. Electric Power and Gas Co. (Gas Division) and (for mail), 575 East 50th Ave., Vancouver, B. C.. Canada. LICHTY, Charles P. (M 1920), Pres, (for mail), C. P. Lichty Engrg. Co.. Inc., 400)4 South 21st St., and 125 Windsor Dr., Birmingham. Ala. LINDBERG, Arthur F. (5 1933), 1484 Van Buren, SL Paul, Minn. LINDSEY, William J. (A 1931), Sales Repr., The Herman Nelson Corp., Moline, and (for mail), 2204 N. Sheridan Rd., Peoria. 111. LINER, John J. (A 1916), Philadelphia Asbestos Co., 2010 N. Tenth St., Philadelphia, Pa. LINN, Homer R. (M 1914), Engr-. Western Exec. Office, American Radiator Co., 816 S. Michigan Ave., Chicago, and (for mail), 321 S. Ashland Ave., La Grange, 111. . LINTON, John P. (M 1927), Managing Dir. (for mail), The Garth Co.; 50 Craig St. W., and 247 Brock Ave. N., Montreal, West. Canada. LITTLE, Edwin R. CM 1916), Pres, (for mail), LOWE, Howard H. (S 1932), 508 Oak St. S.E.. . Minneapolis, Minn. LOWNSBERY, Benjamin F. (Af 1920). Htg. Engr., Benjamin F. Shaw Co., P. O. Box 953, and (for mail), 21 S. Sycamore St., Wilmington, Del. LOWY, M. R. (5 1933), 2305 Loring PL, New York. N. Y. LUCK, Alexander W * (M 1919). Pres, and Gen. Mgr. (for mail), Reading Heater & Supply Co., ..Church and Woodward Sts., Reading, and Reiffton, Pa. LUCRE, Charles E. CM 1924). Consulting Engr., Babcock & Wilcox Co., 85 Liberty SL, and Stevens Prof, of Mech, Engrg. (for mail),. Columbia University, Physics Bldg., and 110 Riverside Dr., New York. N. Y. LUND, Clarence E. (5 1933), Research' Fellow, University of Minnesota, and (for mail), 2729 18th Ave. S., Minneapolis, Minn. LUNDQUIST, Ralph A. (7 1931), Pres., Isaac Coffin Co., 121 Chandler St., Boston, and (for mail), 6 Highland PL, Roxbury, Mass. LUTY, Donald J. (M 1933), Experimental Engr. (for mail), Gar-Wood Boiler Div., 7924 Riopelle SL, Detroit, and 911 Forest Ave., Ann Arbor, Mich. LUTZ, James H., Jr. (M 1928), 140 Paxton SL. Harrisburg, Pa. LUTZ, Paul R. (A 1931; 7 1929), Engr, J. P. Badenhausen, 1211 Stephen Girard Bldg., and (for mail), 625 South 55th St., Philadelphia, Pa. LUTZ, WalteT 4. (S 1933). c/o S. A. E. House. 4915 Forbes St., Pittsburgh, Pa. LYLE, Ernest T. CM 1919), Vice-Pres., Carrier Engrg. Corp., Room 408 Chrysler Bldg., New . York, N. Y. LYLE, J. Irvine* CM 1911), CPresidertlial Member), (Pres., 1917; Council, 1917-1918), Pres, (for mail). Carrier Corp., 850 Frelinghuysen Ave., Newark, and 1200 W. Seventh St., Plainfield, N. J. LYMAN, Samuel E. (A 1924). 728 Canton St., Elizabeth, N. J. , LYNCH, William L. CM 1928), Pres-Treas. (for mail), Rome Tumey Radiator Co., and 1413 N. George SL, Rome, N. Y. LYNN, John H. (A 1933). Bldg. Supt. and Chief Engr. (for mail), Dallas Power & Light Co., and 3431 Shenandoah St., Dallas. Texas. LYON, P. S. (M 1929), Commercial Engrg. Div,, Air Cond. DepL (for mail),.General Electric Co., 570 Lexington Ave., New York, and 200 Chit- . tenden Dr., Crestwood. N. Y. LYONS, Cornelius J. (A 1932), Sales Engr. (for mail), Nash Engrg. Co., Wilson Ave., and. 22 . Havi'land St., South Norwalk, Conn. E. R. Little Co., 1805 Ford Bldg., Detroit, and 447 Rivard Blvd., Gro3se Pointe Village, Mich. M LIVINGSTON, Bernard B. CM 1927). Gas Engr., Dept, of Public Utilities, and 2720 W. Grace St., and (for mail>. Box 976. Richmond, Va. . . LLOYD,-Edward C. (M 1927), (for mail), Arm MacDADE, Ambrose H. (M 1923), Sales (for mail), Burnham Boiler Corp., S.E. Cor. 3lst and Jefferson Sts., Philadelphia, Pa., and 225 Haddon strong Cork & Insulation Co., and 429 W. Walnut St-, Lancaster, Pa. LOEFFLER, Frank X. (M 1914). Pres, (for mail), Ave.. Westmont, N. J. - MacDONALD, Donald B. (M 1930), C. A. Dunham Co., Kingston Corners Bldg., Kingston, Frank Loeffler Supply Co., 710 N.. Hudson SL, and 320 West 26th St., Oklahoma City, Okla. LOFTE, John Allen CS 1933), Mondovi, Wis. LOH, Nan-Shee (M 1933; A 1931; J 1927), House 42, Lane 88, Connaught Rd., Shanghai, China. LONG, David Raymond CM 1927), Partner, Trout-Fritz Machine Co., Lancaster. Pa., and (for mail), 117 Christopher St., Montclair, N. J. Pa. MacDONALD, Everett A. (A 1933), Br. Mgr. (for mail), Spencer Heater Co., 145 Broadway, Cam bridge, and 154 Standish Rd., Watertown, Mass. MacKENZIE, John J. (M 1925), 664 Shaw St.. Toronto, OnL, Canada. MacLEOD, Kenneth .F. (A 1933), Mgr. Htg. Dept., Crane Co., 419 Second Ave. S., and (for LONGCOY, Grant B. CM 1933), Maintainance Engr., Board of Education, E. Sixth St. and Rock well Ave., Cleveland, and (for mail), 1462 mail). 7703 First Ave. N.R., Seattle, Wash. MacMAHON, William K. CM 1932), Asst, Mgr. (for mail). Rosslyn Gas Co., Clarendon, and 408 Wyandotte Ave., Lakewood, Ohio. . LOO, Ping Yok (M 1933), Managing Dir., China Greene Ave., Aurora Hill. Alexandria, Va. MADDUX, Oliver L. (A 1933), Chief Engr., " Engrg. Co., Hsin Chia Kow, Chung San Rd., and (for mail), 35-36 Chung Ling Feng, Chung San United Gas & Fuel Co. of Hamilton, Ltd., and (for mail), 18 Whitten Rd., Hamilton,' Ont., Rd., Hsin Chia Kow, Nanking, China. LOVE; Clarence H. {M 1919). Mfrs. Agent, Nash Engrg. Co., 317 Chamber of Commerce, and (for mail), 289 Norwalk Ave., Buffalo, N. Y. LOVE, Harold G. CM 1930), Weiss & Niestadt, 343 S. Dearborn St., Chicago, ill. . Canada. . MADISON, Richard D. CM 1926). Buffalo Forge Co., 490 Broadway, Buffalo, N. Y. MAEHLING, Leon S. CM 1932), Supervisor Sales. Equitable Gas Co., 427 Liberty Ave.. and (for mail), 448 Sulgrave Rd., Pittsburgh, Pa. 25 '1 I A American Society of Heating and Ventilating Engineers Guide, 1934 MAGINN, Peter F. (Life Member; M1908), Mfgrs. Agent, 1140 S. Negley Ave., Pittsburgh, Pa. MATHIS, Julian W. (A 1921), New York Blower Co., 32nd St. and Shields Ave., Chicago, 111. MaGIRL, Willis J. (A 1931; J 1927). Chief Engr. (for mail). P. H. McGirl Foundry & Furnace MATHIS, Victor John (S 1933), 11307 S. Long- . wood Dr., Chicago, 111. ' Works. 401-13 E. Oakland Ave., and 1528 N. Clinton Blvd., Bloomington, 111. MAGNEY, Gottlieb R. (Af1931). Pres, (for mail). s " Maguey & Tusler, Inc., Archts. and Engrs., 104 MATZEN, Harry B. (Af 1919). Vice-Pres. (for mail). Carrier Engrg. Corp., 890 Union Trust Bldg., Cleveland, and 3115 Chadboume Rd., Shaker Heights. Ohio. S. Ninth St., and 5329 Washburn Ave. S., Minneapolis, Minn. ` MATULLO, Joseph R. (S 1933), 485 North 13th St., Newark, N. J. MAHONEY. David J. (Af 1930; A 1926). Br. Mg* (for mail), Johnson Service Co., 503 Franklin : St., and 99 Delham Ave., Buffalo. N. Y. * .MAIER, George M. (M 1921), American Radiator MAUER, William J * (Af 1919). Sales Mgr., Unit Heater Div. (for mail), C. A. Dunham Co., 450 E. Ohio St., Chicago, and 2525* Colfax St., Evanston, 111. Co., 8007 Jos Campau, Detroit, Mich. MAIER, Herman F. (Af 1926), 7124 Morgan St., Chicago, 111. MAIMAN, Herbert (5 1932), 79-04-78th Ave., Glendale, L. I., N. Y. MALLIS, William (M. 1914), 330 Lyon Bldg., - Seattle, Wash. ~ MALONE, Dayle G. (M 1929; A 1925). 7315 Merrill Ave., Chicago, 111. MAURER, Edward D. (Af 1921), 1527 Mars Ave., Lakewood, Ohio. MAUTSCH, Robert (A 1928), Engr., Managing Dir. (for mail), Compagnie Beige Des Freins Westinghouse 97 Avenue Louise, and Avenue des Klauwaerts 38 Brussels, Belgium. MAXWELL, George W. (S 1932), Owner, Kenealy 8c Maxwell Co., and (for mail), Harwich Port, Mass. MALVIN, Ray C. (M 1929), Pres, (for mail), Malvin & May, Inc,. 332 S. Michigan Ave., and 8211 Langley Ave., Chicago, 111. MANDEL, Henry J. (A 1929), Indiana Gas Utilities Co.. Cherry St., Terra Haute, Ind. MAY, Clarence W. (Af 1933), Pres, (for mail), May & Griffin, Inc., Consulting Engrs., 329 Perkins Bldg., and 711 N. L St., Tacoma, Wash. MAY, Edward M. (Af 1931), 1814 Longview Dr., Springfield. Ohio. * MANDEVILLE. Edgar W. (M 1914), 1171 East 37th St., Brooklyn, N. Y. MANN, Arthur R. (M 1930), Archt., Mahn & Co., Archts. and Engrs., 721 R. W. Bldg., Hutchinson, Kan. MANN, Lee B. (J 1930), Engr. (for mail). Carrier Engrg. Corp., 12 South 12th St., and 4527 Walnut St., Philadelphia, Pa. MANNING, Walter M. (Af 1930), P. O. Box 365, MAY, George Elmer (Af 1933), Air Cond. Engr. (for mail). New Orleans Public Service, Inc., 317 Baronne St., and 2031 Short St., New Orleans, La. MAY, Maxwell F. (Af 1929), Malvin &. May, 332 S. Michigan Ave., Chicago, IU. MAYNARD, J. Earle (Af 1931), Chief Htg. Engr.,' Fox Furnace Co., and (for mail). Telegraph Rd:, Elyria, Ohio. Clarks. Nebr. ' MARINO, Dominic A. (S 1933). New York Uni versity, University Heights, and- (for mail), 209 McCarthy, Charles J, (Af 1919). Plbg. and Htg. Contractor, 3419 Haverford Ave., Phila delphia. Pa. . East 110th St.. New York, N. Y. MARKS, Alexander A. (A 1930), 3441 W. Queen Lane, Philadelphia, Pa. ' MARKUSH, Emery U. (Af 1931), Mech. Engr., ' Secy, (for mail), Weitbeer Plbg. Corp., 225 East 21st St., New York, and 860l-85th St., Wood- haven. L. I., N. Y. McCAULEY, James H. (Af 1921), James H. McCauley, Inc., 5321 West 65th St.,>Chicago, 111. McCLANAHAN, Luther C. (Af 1930), 1113 Lancaster St., Pittsburgh, Pa. McClellan, James E-. (Af 1922), Mgr. (for mail), American Blower Corp., 228 N. LaSalle MARSCHALL, Peter J. (Af 1930; A 1930; J1927), Secy, (for mail), E. Vernon Hill Co., 121 N.. Clark St., and 8228 Langley Ave., Chicago, 111. St., Chicago, and 4741 Washington St., Niles Center, III. ` . - MCCLELLAND, Harvey s. (A' 1930), 1928 S. MARSHALL, H. Hall (Af 1923). 37 West 43rd St., Compton Ave., Los Angeles, Calif. , New York. N. Y. McCLINTOCK, Alexander, Jr. (Af 1928; J 1920), MARTEN1S, John V. (Af 1918), Associate Prof., Member of Firm (for mail), A. McClintock & University of Minnesota, and (for mail), 4800 Bloomington Ave., Minneapolis, Minn. ' Sons, 1937 Ridge Ave., and 121 Rochelle Ave., Wissa, Philadelphia, Pa. . MARTIN, Albert B. (M 1917), Kewanee Boiler McCOLL, Jay R.* (Af 1916), (Prest<Jnlial Co., 1858 S. Western Ave., Chicago, 111? ' Member), (Pres.. 1922; 1st Vice-Pres., 1921; 2nd MARTIN, George W.* (Af 1911) Supervising Vice-Pres., 1920; Council. 1920-1923), 2304 Engr. (for mail), U. S. Realty & Improvement Penobscot Bldg., Detroit, Mich. ` Co., 597 Madison Ave., New York, N. Y., and 340 Prospect St., Ridgewood, N. J. MARTINEZ. Juan J. (/ 1929), Paseo de la ' Reforma 183, Mexico, D. F. ' MARTY, Edgar O. (Af 1916), Pres, and Gen. Mgr., Sherman Coal Corp., and (for mail), 1775 Howard Ave., PotLsville, Pa. . MARUM, Otto (Af 1931), Plant Engr. (for mail), Agfa Ansco Corp., 29 Charles St., and 12 Grand Blvd., Binghamton, N. Y. . MATCHETT, James C. (A/ 1923), Vice-Prea. and Gen. Mgr. (for mail), Illinois Engrg. Co., 21st and Racine Ave., and 9936 S. Winchester Ave., Chicago. III. ' McCONACHIE, Lome L. (A 1928). Htg. and Plbg., 8817 Mack Ave., and (for mail), 1379 . Maryland Ave., Detroit, Mich. * McCONNER, Charles R. (A 1925; J 1922), Gen; Sales Mgr. (for mail), Clarage Fan Co., and 1904 . Waite Ave., Kalamazoo. Mich. ' McCORMACK, Denis (Af 1933), Mgr., Air Cond. Instruments Dept, (for mail), julien P. Friez & Sons, Inc., 4 N. Central Ave., and 100 W. University Pkwy.. Baltimore, Md. McCOY, Thomas F. (Af 1924), Mgr. (for mail)* The Powers Regulator Co., 125 St. Botolph St., Boston, and Glen Rd., Wellesley Farms, Mass. MATHER, Harry H. (A 1929), Philadelphia- McCREA, Lester W. (Af 1920). Vance-McCrea Electric Co., 1000 Chestnut St., Philadelphia, Pa. MATHEY, Nicholas J. (Af 1915), Mathey Plbg. Sales Co., West 27th and Sisson Sts., Baltimore, Md. & Htg. Co., 31 Third Ave. N.E., Le Mars, Iowa. McCREERY, Hugh J. (Af 1922), (for mail). MATHIS, Eugene* (Af 1922), New York Blower Marine Bldg., and 1617-49th Ave. W., Van Co., 32nd St. and Shields Ave., Armour P. O. Sta., Chicago, 111. ' MATHIS, George A. (A 1931), Asst. Supt. (for mail). New York Blower Co., and 108 Highland Court. La Porte, lnd. MATHIS, Henry (Af 1921), The New York Blower Co., 32nd and Shields Ave., and (for mail), 10317 . Oakley Ave., Chicago, IH. couver, B. C. .* McCUNE, Byron V. (Af 1928), Sales Engr. (for mail). 101 W. Yakima Ave., P. O. Box 385, and 2310 W. Yakima Ave., Yakima, Wash. McDonald, Thomas (A 1931), Mgr. (for mail). Minneapolis-Honeywell Regulator Co., Ltd., 117 Peter St., and 56 Kingsway, Toronto, Ont., Canada. 26 Roll of Membership McDONNELL, Everett N. (Af 1923). Pres, (for mail), McDonnell & Miller, 400 N. Michigan Blvd., and 105 E. Delaware, Chicago, 111, ' McELGIN, John \V. {J 1931), 180 Rowland Park, Cheltenham, Pa. ` McELLROY, George S, (Af 1925), Consulting Engr., 427 Oliver Bldg., Pittsburgh, and (for mail), R. F. D. No. 2, Glenshaw, Pa. McFarland, William P. (A 1923). 1258 Pratt Blvd., Chicago, 111. - McGINNESS, J. E. (Af 1903), Pres.( for mail). McGinness, Smith. & McGinness Co., 527 First Ave., and 142 Bellfield Ave., Pittsburgh, Pa. McGLENN, G. Raymond (Af 1915), 259 Lormore - ' St., Elmira, N. Y. McGONAGLE, Arthur (Af 1932), Consulting Engr. (for mail), 1013 Fulton Bldg.. Pittsburgh, MEINKE, Howard G. (Af 1933), Asst. Engr., Civil Engrg. Dept, (for mail). New York Edison Co,. 4 Irving Pi.. Room 1517-S, New York, N. Y., and 41, Harte St., Baidwin Nassau Co., N. Y. MEISEL, Carl L. (J 1931), 350 Central Park W., New York, N. Y. MELIGHAR, Wolfgang J; (/ 1932), Johannes Haag VII, Neustiftgasse 98, and (for mail), XII, . Thunhofgasse 6, Vienna, Austria. - MELLON, JamesT. J. (Af 1911). (Council, 1915). (for mail), Mellon Co., 4415-21 Ludlow St., and 431 North 63rd St., Philadelphia, Pa. MENSING, Frederick D. (Af 1920), (Natl.Treas., 1931-1932; Council. 1931-1932), Consulting Engr. (for mail), Mensing & Co., 12 South 12th . St., and 2845 Frankford Ave., Philadelphia, Pa. MERKEL, Fred P. (Af 1924), 204-llth Ave., and 6815 Prospect Ave., Ben Avon, Pa. McGRAIL, Thomas E. (Af 1926), 3465 Belmore Ave., Montreal, P. Q., Canada. . McGUIGAN, L. A. (A 1919), 724 Hastings St., Pittsburgh, Pa. - McHENRY, Robert W. (Af 1921). 236 Eglinton Ave. E., Toronto, Ont., Canada. McILVAINE, John H.* (M 1929). 749 Custer Ave., Evanston, and (for mail), Mcllvaine ' Burner Corp., 663 W. Washington Blvd.. Chicago, 111. '. . McINTIRE, James F. (Af 1915; A 1914), (Coun cil, 1926-1928-1933), Vice-Pres. (for mail), U. S. . Radiator Corp., 1056-44 Cadillac Sq., P. O. Box 686, and 3261 Sherboume Rd., Detroit, Mich. McIntosh, Fabian C. (M 1921; J 1917), (Treas.. 1930; Council, 1929-1933). Br. Mgr. (for mail), Johnson Service Co., 1238 Brighton Rd., . and 302 Marshall Ave., Pittsburgh, Pa. McKELVEY, David M. (Af 1930), 60 East 42nd St., New York, N. Y. McKlEVER, William H.* (M 1897; J 1896), Pres, (for mail), William H. McKiever, Inc., 247 West 13th St., New York, and 479 Eighth St., . Brooklyn. N. Y. . . McLARNEY, Harry W. (Af 1933), Air Cond. Engr. (for mail). Union Electric Light & Power . Col 315 North 12th St., and 5053 Lindenwood Ave., St. Louis, Mo. McLAUGHLIN, Joseph D. (A 1930; J 1928), 166 Abom St., Providence, R- I. McLEAN, Dermld (Af 1917), McColl, Snyder & McLean, 2304 Penobscot Bldg., Detroit, Mich. Belmar, N. J. MERRILL. Carle J. (Af 1919), C. J. Merrill, Inc., 54 St. John St., Portland, Me. MERRITT, C. J. (Af 1925), Dir., Merritt. Ltd.. 8 Quai de France, Shanghai, China. MERTZ, Walter A. (Af 1919). Kehm Bros., 51 E. . Grand Ave., Chicago, 111. MERWIN, Gile E. (Af 1924; / 1923). Secy.. Rockford Plbg. Supply Co., and (for mail), 316 Ellsworth St., Rockford, 111. MEYER, Charles L. (Af 1930), 198-25 Foothill Ter., Hollis. L. I., N. Y. MEYER, Frank L. (Af 1923; J 1928), Vice-Pres., The Meyer Furnace Co., and (for mail), 9 Cole Court, Peoria, III. 1 MEYER, Henry C., Jr* (Af 1898). (Council, 1915-1916), 101 Park Ave., New York, N. Y. MEYER, John W. (A 1929), Asst, to Mgr., Industrial Sales Dept, (for mail), Philadelphia Electric Co., 1000 Chestnut St., and 5000 Pine St., Philadelphia, Pa. MICHIE, D. Fraser (A .1930), Boiler and Rad. Div., Crane, Ltd., 93 Lombard St., and (for mail), 5B, 553 Wardlaw Ave., Winnipeg, Man., Canada. MILLAR, Rowland J. (Af 1925), Mgr. (for mail), Pease Foundry Co., Ltd., 118 King St. S., and 53 Oakmount Rd., Toronto, Ont., Canada. MILLARD, Junius W. (Af 1929), Dist. Mgr. (for mail), Carrier Corp., 410 Asylum St., Hartford, and Manchester, Conn. MILLER, Alan A. (A 1926), Mgr. (for mail). National Radiator Corp., 508 Liberty Trust Bldg., Philadelphia, and 731 Cornell Ave., McLEISH, William S: (A 1932; J 1928), Dist. Engr. (for mail), The Ric-Wil Co., Room 1838 .. 101 Park Ave., New York, N. Y., and 1646 Wagar Ave., Lakewood, Ohio. * McLENEGAN, David W. (Af 1933). Asst. Engr., Drexel Hill, Pa. ` MILLER, Bruce R. (A 1930), 1533 N. W. 25th St., Oklahoma City, Okla. .MILLER, Charles A. (A 1917), Salesman (for mail), The H. B. Smith Co., 10 East 41st St., and . ' Air Cond. Dept, (for mail). General Electric Co., and 1686 Rugby Rd., Schenectady. N. Y. McMURRER, Louis J. (Af 1928; A 1928; J 1924), . Pres., The McMurrer Co., 303 Congress St., Boston, and (for mail). 190 Harvard Circle, 2870 Marion Ave., New York, N. Y. MILLER, Charles W. (Af 1919; J 1908), Pres, (for mail). The Rado Co., 338 S. Second St., Mil waukee, and R. 1, Box 42, Menomonee Falls, Wis. MILLER, Edgar S. (Af 1931), 3012 Campbell St., ' Newtonville, Mass. . McNAIR, Edward E. (M 1915), (2nd Vice-Pres.. Kansas City, Mo. MILLER, Floyd A. (Af 1911), 477 Federal Bldg., 1923; Council, 1921-1923), Vice-Pres. (for mail), U. S. Radiator Corp., Pres., Pacific Steel Boiler Corp., 1056 First Natl. Bk. Bldg., Detroit, and Chicago, 111. MILLER, Harry M. (Af 1920), 3938 N. Stowell Ave., Milwaukee, Wis. R. F. D. No. 1, Birmingham, Mich.' McNAMARA, William (A 1930), Sales Engr. (for MILLER, Henry F. (A 1928), Dist. Mgr. (for mail), Keasbey 8c Mattison Co., Ambler and mail). The Trane Co., 722 Plymouth Bldg., Ridley Park, Pa. Minneapolis, and 1355 Como Ave. W., St. Paul, MILLER, James E. (Af 1914; J 1912). Vice-Pres. Minn. McPHERSON, William A. (Af 1929). Chief. Htg. (for mail), C. W. Johnson, Inc., 211 N. Desplaines St., Chicago, and 2210 Colfax St., Evanston, 111. and Vtg. Div., Dept, or School Bldgs., 11 Beacon MILLER, John F. G. (Af 1916), Vice-Pres. (for St., Boston,, and (for mail), 86 Dwinnell St., mail), B. F. Sturtevant Co., Hyde Park, Boston, West Roxbury, Mass. and Longwood Towers, Brookline, Mass. McTERNAN,-Felix J. (A 1931), 1523 Main St., MILLER, Leo B. (Af 1926), Refrigeration Div. (for Buffalo, N. Y. . MEAD, Edward A. (Af 1926), Asst. Sales Mgr. (for mail), Minneapolis-Honeywell Regulator Co., 2753 Fourth Ave. S., and 2010 James Ave. S., mail), Nash Engrg. Co., South Norwalk, ana 5 Minneapolis, Minn. Thames St., Norwalk, Conn. . MILLER, Prof, Lorln G. (Af 1933), Prof. Mech, MEFFERT, George H. (J 1930), Engr. (for mail). Carrier Engrg. Corp., 2022 Bryan St., and 4154H Prescott Ave., Dallas, Texas. MEHNE, Carl A. (Af 1929), Htg. and Vtg. Expert (for mail). Room 821, 101 Park Ave., New York, N. Y.p and Livingston St., Valhalla, N. Y. Engrg. (for mail), Dept, of Mech. Engrg.. Michigan State College, Engrg. Bldg., and 920 Sunset Lane, East Lansing, Mich. ' MILLER, Merl W. (Af 1932; A 1932; J 1926), Mgr. of Lab. (for mail), Trane Co., and 308 North 22nd St., LaCrosse, Wis. 27 American Society of Heating and Ventilating Engineers Guide, 1934 MILLER, Robert A* (At 1931), Tech. Sales Engr. (for mail), Pittsburgh Plate Glass Co., 2200 Grant Bldg., Pittsburgh, and 1211 Carlisle St., Tarentum, Pa. / MILLER. Robert T. (A 1927), Chief Engr. (for mail). Masonite Corp., Ill W. Washington St., and 1608 Sherwin Ave., Chicago, III. MILLER, Tolbert G. (A 1929; J 1921). Supt.. Htg. and Vtg., and (for mail), 11 N. Second St., Wormleysburg, Pa. MILL1KEN, James H * (M 1923). Dist. Repr. (for mail), American Air Filter Co., Inc.. 20 N. Wacker Dr., Chicago, and 1021 Ridge Ct., Evanston, 111. M1LL1KEN, Vincent D. (A 1930), Sales Mgr. (for mail), Skidmore Corp., St. 'Joseph and Colfax Ave., Benton Harbor, Mich. . MILLI5, Linn W. (M 1918), 3534 Wabash Ave., Kansas City, Mo. MILWARD, Robert K. (A 1920), Mgr. (for mail). ' U. S. Radiator Corp., 127 Campbell Ave., and 2441 Calvert Ave., Detroit, Mich. . MITCHELL, Charles H. (M 1924), Htg. Engr.. 179 Thatcher St., Mattapan P. O., Milton, Mass. MITTENDORFF, E. M. (At 1932), Sales Engr.. Sarco Co., Inc., 222 N. Bank Dr., Chicago, and (for mail), 2220 Sherman Ave., Evanston, 111. MODIANO, Ren (At 1925), 55 Boulevard Beausejour, Paris 16, eme, France. MOFFITT, Roy M. (A 1930), Br. Mgr., L. J. Mueller Furnace Co., 211 W. Wacker Dr., Chicago, III. MOLER, William H. (M 1927; J 1923), Mech. Sales Engr., R. F. D. No. 1, Box 37-B, Irving, Texas. * MONDAY, Charles E. (M 1920), Chas. E. Monday & Co., 1323 Fairmount Ave., Phila delphia. Pa. MONROE, Meade (5 1933), 1228 Southern Blvd., New York., N. Y. MONROE, Raymond R. (A 1929). Nash Engrg. Co., South Norwalk, and (for mail), Kellogg Park, Norwalk, Conn. MONTGOMERY, Ora C. (Af-1933), Asst. Supt. of Power (for mail), N. Y. C. R. R.f Grand Central Terminal, Room 1842, and 255 West 84th St., New York, N. Y. MOON, L. Walter (At 1915), (Council. 1933). Pres, (for mail), Bradley Htg. Co., 3834 Olive St., and 5006 N. Kingshighway. St. Louis, Mo. MOORE, Herbert S. (A 1923), Mfrs. Agent, 107 Clendenan Ave., Toronto 9, Ont,. Canada. MOORE, Robert E. (J 1933), Salesman, Sarco Co., Inc., 183 Madison Ave., New York, and (for mail), 1730 East 46th St., Brooklyn, N. Y. MOORE. Robert E. (A 1928), 744 Dobson St.. Evanston, 111. . MOREAU, Donato (A 1932), J. Knox Corbett Lumber Co., Tucson, Ariz. MORGAN, C. Stanley (A 1919), 445 W. Lamed St., Detroit. Mich. MORGAN, Glenn C. (At 1911), Partner (for mail). Morgan-Gerrish Co., 307 Essex Bldg., and 4308 Fremont Ave. S.. Minneapolis, Minn*. MORGAN, Robert C. (At 1915), 314 W. Seymour St., Philadelphia, Pa. ' MOREHOUSE, H. Preston (At 1933), General Air Cond. Repr. (for mail), Public Service Elec. & Gas Co., 80 Park PI., Newark, and 85 Halsted St., East Orange, N. J. ' MORRIS, Edward J.. (5 1931)', 3414 Gwynn's Falls Pkwy., Baltimore, Md. MORRIS. Fred H. (A 1929), 1233 East 125th St.f Cleveland, Ohio. MORRISON, Chester B. (At 1931), Mgr. (for mail), York Shipley, Inc., 21 Jinkee Rd., and 882 Rue Retard, Shanghai, China. MORSE, Clark T. (M 1913), Pres, (for mail), American Blower Corp., 6000 Russell, and 16222 Shaftsbury Rd.. Detroit, Mich. MORTON,. Charles H. (A 1931), 1106 Sherman St. S.E., Grand Rapids, Mich. . MORTON, Harold S. (At 1931). Dist. Mgr.. Modern Coal Burner Co., and (for mail), 58 N. Mississippi River Blvd., St. Paul, Minn. MOSHER, Clarence H. (A 1919), C. H. Mosher Co., 423 Ashland Ave., Buffalo, N. Y. MOSS, Edward (At 1920), 1130 Atlantic Ave., Brooklyn, N. Y. * MOTZ, O. Wayne (At 1932), Mech. Engr., Samuel Hannaford & Sons, Archts., 1024 Dixie Terminal Bldg., Cincinnati, and '(for mail), 2587 Irving PI., Norwood, Ohio. MOULDER, Albert W.* (M 1917), Mgr. Htg. Power and Industrial Piping Div. (for mail), Grinnell Co., Inc., 260 W. Exchange St., Provi dence, and Bluff Rd., Barrington, R. I. .MOULTON, David (At 1926), 99 Chauncy St., Boston, Mass. MOWER, William P. (M 1924), Warren Webster & Co., 76 Summer St., Boston, Mass. MUELLER, Harold C.'(A 1930), Sales Engr. (for mail). Powers Regulator Co., 2720. Greenview Ave., Chicago, and 2720 Lawndale Ave., Evan ston, 111. MUNDER, John F., Jr. (At 1927: J 1924), Sales Supervisor (for mail). Carrier rroducts Corp., Chrysler Bldg., New York, N. Y., and 81 Joyce Rd., Tenafly, N. J. MUNIER, Leon L. (At 1919; J I'915), Pres, (for mail), Wolff & Munier, Inc., 222 East 41st St., New York, N. Y., and 63 Columbia Ave., Harts- dale, N. Y. . '. MUNRO, Edward A. (Charter Atembef; Life Member), Htg.vand Vtg. Engr., 56 Jarvis PI., Lynbrook. N. Y. MURPHY, Edward T.* (M 1915), Pres, (for mail). -Carrier Engrg. Corp.; 180 N. Michigan Ave., Room 907, and 200 E. Chestnut St., Chicago. III. MURPHY, Howard C * (At 1923), Vice-Pres. (for mail), American'Air Filter Co., Inc., 215 Central ' Ave., and 495 Lightfoot Rd., Louisville, Ky. MURPHY, Joseph R. (A 1925), Riverside Ter.. Riverside, Conn. MURPHY, WlUlam W. (At 1930), Treas. (for mail), W. W. Murphy Co., 171' Chestnut St., and 25 Mansfield St-, Springfield, Mass. ' MURRAY, John J. (A 1933), Salesman, Vice- Pres., Pierce Perry Co., Boston, and (for mail), 60 Commonwealth Park W.. Newton Centre, Mass. MURRAY, Thomas F. (M 1923), State Architect. and (for mail), 14 S. Lake Ave., Albany, N. Y. . MYERS, Eddie V. (A 1931), Vice-Pres.. A. S. Hunter & Son, Inc., and (for'mail), 816 ClarkSt., Willard, Ohio. MYERS, Frank L. (M 1933), Sales Engr., Owens, Illinois Glass Co., and (for mail), 3406 Detroit Ave., Toledo, Ohio. MYERS, George W. F. (At 1930; A 1928; J 1923), Mfrs. Repr., Htg., Vtg. and Air Cond. (for mail), Myers Engrg. Equip. Co., Mart Bldg., 401 South 12th St., St. Louis, and 476 Pasadena Ave., Webster Groves, Mo. N- NAGELSEN, Lou M. (At 1930), Sales Engr. and Mfrs. Repr., 1847 California Ave., Ft. Wayne, Ind. NAROWETZ, Louis L., Jr. (At 1929; A 1912), Secy, (for mail),Narowetz Htg. & Vtg. Co., 1711 Maypole Ave., Chicago, and 112 South Park Ave., Park Ridge, III. . NASON, George L. (M 1929; A 1929; J 1927). 31 N. Franklin St., Holbrook, Mass. NASS, Arthur F. (At 1927), Secy-Treas. (for mail)', McGinness, Smith & McGinness Co., 527 First Ave., Pittsburgh, and Elmhurst Rd., R. D. No. 8, Crafton, P.O., Pa. NATKIN, Benjamin* (M 1909; J 1907), Gen. 'Mgr. (for mail). Nation Engrg. Co., 314 W. Tenth St., and 5211 Rockhill Rd., Kansas City, Mo. NAYLOR, Charles L. (At 1931), Supt., Heat. Light and Power Dept, (for mail). The Atlantic Refining Co., 3144 Passyunk Ave., and 2315 ` North 18th St., Philadelphia, Pa. NEAL, Harry W. (M 1928), Neal Furnace Co.. 2705-7 Northwestern Ave., Indianapolis, Ind., . 28 Roll of Membership NEALE, Laurance I. (A 1927), Vice-Pres. `(for mail), Atlantic Gypsum Products Co., Inc., 60 East 42nd St., and 125 East 57th St., New York, N. Y. NEARY, Daniel A. (S 1933), 444 East 66th St., New York, N. Y. NEEDLER, J. H. (At 1933), Phillips Getschow Co., 32 W. Austin Ave., Chicago, 111. NEFF, Charles J. (S 1930), Canfield, Ohio. NEIDECK, Albert A. (J 1927), 2134 Wallace Ave., New York, N. Y. NEILER, Samuel G. (At 1898), Consulting Mech. . and Elec. Engr. (for mail), Neiler, Rich & Co., 431 S. Dearborn St~, Chicago, and 737 N. Oak Park Ave., Oak Park. 111. NELSON, Chester L. (J 1929), 62 Monona Ave., Rutherford, N. J. NELSON, D. W.* (At 1928), Asst. Prof, of Steam and Gas Engrg. (for mail), Mech. Engrg. Bldg-, University of Wisconsin, and 3906 Council Crest, Madison, Wis. NELSON, George A. (At 1928), Sales Engr; (for mail), 112 East 19th St., and 2336 University Ave., New York, N. Y. * NELSON, George O. (At 1923), Carstens Bros., Ackley, Iowa. NELSON, Harold A. (M 1926), 236 S. La Pere St.. NORDHEIMER, Clyde L. (S 1931), Student, Carnegie Institute of Technology, and (for mail); .622 Mellon St., Pittsburgh, Pa. NORDINE, Louis F. (At 1914), 1170-25th St., - Moline, 111. NORRIS, William D. (At 1930), 1314 Forest Ave., Wilmette, 111. NORTHON, Louis (At 1929), Consulting Engr., 132 Park Ave., Mt. Vernon, N. Y. NOTTBERG, Gustav (A 1933), Htg. Estimator (for mail), U. S. Engrg. Co., 914 Campbell, and 1835 East 68th St. Ter., Kansas City, Mo. NOTTBERG, Henry J.. Sr. (At 1919), Vice-Pres. (for mail), U. S. Engrg. Co., 914 Campbell St., and 3508 Anderson Ave., Kansas City, Mo. NOVOTNEY, Thomas A. (At 1928), Mgr., Research and Sales Engrg. Depts., National Radiator Corp., 221 Central Ave., and (for mail), 403 Wayne St.. Johnstown, Pa. NOWITZKY, Herman S. (A 1931), Supt., Con struction, Repairs and Maintenance, Wilmer & Vincent Theatrical Circuit, and (for mail), 151 Tenth St., Norfolk, Va. NUSBAUM, Lee* (At 1915), Owner (for mail), Pennsylvania Engrg. Co.. 1119-21 N. Howard St., Philadelphia, and 315 Carpenter Lane, Germantown, Philadelphia, Pa. Beverly Hills, Calif. . NELSON, Herman W. (At 1909), Pres, (for mail). O The Herman Nelson Corp., 1824 Third Ave., and 2500-llth St., Moline, III. NELSON, Richard H. (A 1933; J 1928), Director, Herman Nelson Corp., 1824 Third Ave., and (for mail), I303-30th St., Moline, 111. NESBITT, Albert J.* (At 1921; J 1921), Secy- Treas. (for mail), John J. Nesbitt, Inc., State Rd. and Rhawn St., Philadelphia, and Rockfield Farm, Tennis Ave. and Welsh Rd.. Ambler, Pa. NESBITT, John J. (M 1923), Pres, (for mail), John J. Nesbitt, Inc., State Rd. and Rhawn St., Philadelphia, and Rockfield Farm, Tennis Ave. and Welsh Rd., Ambler, Pa. NESDAHL, Eilert (At 1915), c/o Colben Nesdahl, Route 1, Shevlin, Minn. NESMITH, Oliver E. (A 1928), 107 Warner Ave., Bloomington,' 111. NESS, WlUiara H. C. (At 1931), Gen. Mgr. (for mail). Master Fan Corp., 1323 Channing St., and 215 N. Kingsley Dr., Los Angeles, Calif. NESSI, Andr6 (At 1930), Ingr. des Arts et Manu factures, tablissement Nessi FrSres & Cie, 43 Rue le la Vanne, Montrouge (Seine), and (for mail), 1 Avenae du President Wilson, Paris VIII, France. -. NEU, Henri J. E. (A? 1933), Pres., Etablissements Neu, 47-49 Rue Fourier, Lille (Nord), France. NEWMAN, Charles T. (A 1931), 2729 Hooper OAKEY, William . (At 1932), Consulting Engr., Oriskany, N. Y. OAKS, Orion O. (At 1917), Executive Engr., American Radiator Co., 40 West 40th St., New York, N. Y., and (for mail), 119 Oak Ridge Ave., Summit. N. J. OATES, Walter A. (At 1931), Htg. and Industrial Engr., Lynn Gas & Electric Co., 90 Exchange St.,. and (for mail), 285 Lynn Shore Dr., Lynn, Mass. O'BANNON, Lester S * (At 1928), University of Kentucky, Lexington, Ky. OBERG, Harry G. (A 1933), Mgr. Engrg. Dept., Crane Co.. Fifth and Broadway, and (for mail), 1362 W. Minnehaha St., St. Paul, Minn. OBERT, Casln W.+ (M 1916), Consulting Engr., Union Carbide & Carbon Research Lab.. Thomp son Ave and Manley St., Long Island City, and (for mail) 122 N. Columbia Ave., ML Vernon, N. Y. - O'BRIEN, J. H. (At 1923), 228 N. LaSalle St., Chicago, 111. O'CONNELL, Presly M. (At 1916), 5749-31$t Ave. N.E., Seattle, Wash. OFFEN, Ben (At 1928), Owner (for mail), B. Offen & Co., 608 S. Dearborn St., and 1100 N. Dear born St., Chicago, 111. OFFNER, Alfred J* (At 1922), Consulting Engr. Ave., Los Angeles, Calif. NEWPORT, Charles F.* (At 1906), Sales Engr., (for mail), 139 East 53rd St., New York, and 160-15-llth Ave., Beechhurst, L. L, N. Y. Weil-McLain Co., Michigan City, Ind., and (for O'HARE, George W., Jr. (5 1932), Student, New . mail), 10001 Longwood Dr., Chicago, 111. NICELY, John E. (A 1925), 1208 Marion St., York University, University Heights, and (for mail), 201 West 72nd St., New York, N. Y. Reading, Pa. NICHOLLS, Percy* (At 1920), Supervising'Engr., O'HAVER, Hubert M. (J 1931), Foss' Htg. & Engrg. Co., 21 S. Chester Ave., Pasadena, Calif. Fuel Section (for mail), U. S. Bureau of Mines, OLCHOFF, Maurice (M 1933), Mgr.. Olchoff Pittsburgh, Pa. NICOL, Norman C. (M 1923), P. O. Box 146, Trinity Sta., New York, N. Y. NIGHTINGALE, George F. (A *1931), 621 S. Maple Ave., Oak Park, 111. NOBBS, Walter W. (At 1919), 50 Fairhaxel Gardens, London N.W. 6, England. NOBIS, Harry M. (At 1914), 1827 Stanwood Rd... East Cleveland, Ohio. NOBLE, Theodore G. (5 1933). Engr.. Minne- Engrg. Co., 423 Dwight Bldg., and (for mail), 5341 Holmes, Kansas City, Mo. OLSEN, Carlton F. (A 1925; J 1920), Kewanee Boiler Corp., and (for mail). 7914 Wabash Ave., Chicago, 111. - OLSEN, Gustav E. (At 1930), 6809 Amstel Blvd., Arverne, L. I., N. Y. ' OLSON, Gilbert E. (M 1930), 440 Ward Pkwy.. Kansas City, Mo. OLSON, Robert G. (At 1923), Sales Engr. (for mail), c/o Hydraulic Coupling Corp., 1349 , apolis Gas Light Co., and (for mail), 523 Oak St., Harper Ave., and 111 Putnam Ave.,^ Detroit, S.E., Minneapolis, Minn. ' NOLAN, James J. Jr. (J 1929). Carrier Engrg. Mich. OLSTAD, Martin H. (A 1933; J 1931), Engr. (for Corp., 604 Washington Bldg., Washington, D. C. mail), Niagara Blower Co., 6 East 45th St., New NOLAND, Lloyd U. (At 1915), Noland Co., Inc., Newport News, Va. NOLL, WlUlam F. (At 1924), Htg. Contractor. 629 North 27th St., and (for mail), 2850 North 47th St., Milwaukee, Wis. York, and 2940-210th PL, Bayside, L. I., N. Y.: OLVANY, William J. (At 1912), Pres, (for mail). . William J. Olvany, Inc., 100 Charles St., New York, and 109-40-71st Rd., Forest Hills, L. L, N. Y. 29 Vt American Society of Heating and Ventilating Engineers Guide, 1934 O'NEILL, James W. (34 1929; A 1927; 7 1925). Chief Engr., Trane Co. of Canada. Ltd., 439 King St. W., and (for mail), 8 Springmount Ave., Toronto, Canada. O'NEILL, Peter (34 1920), Treas- (for mail), Bartley-O'Neill Co., 240-42 Blvd. of Allies, Pittsburgh, and 2448 Charles St, N.S., Pitts burgh (14), Pa. OPPERMAN, Everett F. (5 1933), 169 Milbank Ave., Greenwich, Conn. OREAR, Andrew G. (34 1930), Sales Engr. and Mfrs. Repr. (for mail), Room 501, San Fernando Bldg., Los Angeles,-and 1015 E. Raleigh St., . Glendale, Calif. ORMSBY, H. Kingsley, Jr. (34 1930; A 1930; 7 1928), 668 Roberts Ave., Syracuse, N. Y. ORR, H. B. (34 1928), (for mail), "Carrier"- Dravo Doyle Co., 302 Penn Ave., Pittsburgh, and Central Sq. Apt. B-5, Mt. Lebanon, Pa. OSBORN, Wallace J. (A 1927), 599 Old Post Rd., Fairfield, Conn. OSBORNE, Gurdon H. (34 1922), Gen. Mgr., The.Vtg. & Blow Pipe Co., Ltd., 714 St. Maurice St., Montreal, and (for mail), 836 Pratt Ave., Outremont, Montreal, Que., Canada. OSBORNE, Maurice M. (M 1925), 367 Beacon St., Boston, Mass- OSBURN, Richard'M. (S 1933), 2241 Sedgwick Ave., New York, N. Y. OSMUNDSEN, Harry B. (M 1930), 129 Haddon Pi., Montclair, N. J. ' OSTER, George R.' (A 1930), 921 Hollingsworth Bldg., Los Angeles, Calif. OTIS, Gerald E * (34 1922), Vice-Pres. (for mail), The Herman Nelson Corp., and 1921-23rd Ave., . Moline, 111. OTT, Oran W. (34 1925), Consulting Mech. Engr. (for mail), Washington Bldg., and 123 S. Virgil Ave., Los Angeles, Calif. ' OTT, Rush C. (34 1931), Refrigerating Equip. Corp., 927-31 N. Meridian St., Indianapolis, Ind. OTTO, Robert W. (34 1912), 2147 Carroll Ave., St. Paul, Minn. ' OURUSOFF, L. (34 1931), Engr. of Utilization (for mail), Washington Gas Light Co., I100-29th St. N.W., Washington, D. C., and 25 W. Irving St., .Chevy Chase, Md. . OVERTON, Sidney H. (34 1929), 34 Church St., Kensington, London W, 8, England. P PAETZ, Herbert E. (M1922), Div. Sales Mgr. (for mail), American Blower Corp., 2539 Woodward Ave., and 17568 Roselawn, Detroit, Mich. PAGE, Harry W. (34 1923), Pres., Wisconsin Equipment Co., 204 W. Wisconsin Ave., Mil waukee, and (for mail), 7927 Warren Ave., Wauwatosa, Wis. PARK, Clifton D. (34 1929), 22 Otis St., Need- PARK, J. Frank (7 1930), Sales Engr., Air Cond. (for mail), 748 E. Washington Blvd., Los Angeles, and 4142 Linden St., Long Beach, Calif. PARKER, Philip (34 1915), .8 Middle S>, Woburn, Mass. .. '- - PARKS, William N. (A 1927), Br. Mgr. (for mail), U. S. Radiator Corp.,. 688 Hampden Ave., St. Paul, and 5348 First Ave. S., Minneapolis, Minn. PARROTT, Lyle George CM 1922), Consulting Engr., McColl, Snyder & McLean, 2306 Penob scot Bldg., and (for mail), 4678 Seebaldt Ave., Detroit, Mich. PARSONS, Roger A. (7 1933), Sales Engr., Dail Steel Products Co., and (for mail), 525 W. Grand River Ave., Laasiag, Mich. PARTLAN, James W. (Life Member; M 1916),14290 Goddard Ave., Detroit, Mich. PATERSON, James S* (M 1922), Mech. Engr. (for mail), Bd. of Education, 155 College St., and 23 Norton Ave., Toronto, Onri, Canada. PATORNO, Sullivan A. S. (34 1923). Chief Draftsman, (for mail), Meyer, Strong & Jones, Inc., 101 Park Ave., and 1269 Findlay Ave:, New York, N. Y. '. PATRICK, Horace M. (A 1933; J 1929), Lafa yette Rd., Colonial Village, Wayne, Pa. PAUL, Donald I. (7 1932), Sales Engr. (for mail), Gurney Foundry Co., Ltd., 4 Junction Rd., and 222 Fern Ave., Toronto, Ont., Canada. ,, PAULDING, Lewis G. (M1926), Secy-Treas. (for mail), Frank Paulding & Son, 51 East 42nd St., New York, and 8733-117th St.. Richmond Hill, L. I.. N. Y. . PEACOCK, James K. (M 1921), 440 Fowler Ave., Pelham Manor, N. Y. - . PEEBLES, John K,, Jr. (A 1925; J 1924), (for mail), Peebles & Ferguson, 733 Law Bldg., and 1111 W. Princess.Anne Rd., Norfolk, Va. PELLETIER, Albert (34 1930), Mech. Engr., , Samuel R. Lewis, 407 S. Dearborn St., Chicago,1 and (for mail), 708 S. Ninth Ave., Maywood, 111. PENCE, Millard D. (A 1930; 7 1927). C. A) Dunham Co., 450 E. Ohio St., Chicago. 111. PENNEL, Reed (J 1933), Buckeye Blower Co., 501 Martin Bldg. N.S., Pittsburgh, Pa. PENNOCK, William B. (M 1927), 170 McNab St. S., Hamilton, Ont., Canada. PERINA, Arthur E, (S 1933), 126 Courtiand St.1. Staten Island, N. Y. PESTERFIELD, Charles H. (S1932), Ozark, Ark. PETERS, Herbert H. (M 1930), 1842 North 40th St., Milwaukee, Wis. , PETERSEN, Adolph J. (J 1929), Sales Engr. (for mail), Philadelphia & Reading Coal & Iron Co., 332 S. Michigan Ave., and 1220 N. State Pkwy., . Chicago, 111. PETERSON, Sterling D. (A 1930), Br. Mgr. (for mail), Johnson Service Co., 473 Colman Bldg.', and 5051 Prince St., Seattle, Wash. PFEIFER, Otto J,, Jr. (J 1932), Engr., Ralph D. Thomas & Associates, 1200 Second Ave. ., and (for mail), 1515 Monroe St. N.E., Minne- ' apolis, Minn. PFEIFFER, John F. (M 1930; 7 1925), 346 ' Louisa St., Williamsport, Pa. - PFUHLER, John L. (A 1925; J 1923), Plbg. and Htg., 600 Manor Rd., West New Brighton, S. I., N. Y. PHELPS, Harold R. (34 1932; A 1932; J 1927), 16262 Appoline St., Detroit, Mich. PHILIP, William (34 1930), 74 Bastedo Ave., Toronto, Ont., Canada. - PHILLIPS, Frederic W,, Jr. (M 1921), 825 East 38th St., Brooklyn, N. Y. PHILLIPS, William J. (A 1929), (for mail), 520 . W. First St., and 1103 Forestdale Rd., Royal Oak, Mich. PHIPPS, Frederick George (34 1930), Htg. Engr., Engrg. Equipment Co., Suite 420, New . Birks Bldg., and (for mail), 2054 Merder Ave., Montreal,'P. Q., Canada. ` PIERCE, Edgar D. (7 1933), Engr., Carrier Engrg. * Corp., 748 E. Washington, and (for mail), 360 West 68th St., Los Angeles, Calif. ' PIERCE, William MacL. (S 1933), 31 Potter St., Melrose. Mass. .. PIHLMAN, Arthur A. (34 1928), (for mail), Con solidated Gas Co- of New York, 4 Irving PL, New York, N. Y., and 235 Dwight St., Jersey City, N. J. -. PILLEN, Harry A. (A 1933), Mfg. Repr., Htg. & Power Equipment (for mail), 622 Broadway, and 2208 Crane Ave.,'Cincinnati, Ohio. PINDER, Percy H. (341919), 366 Third Ave., New York, N. Y. ' PINES, Sidney (M 1920), Vice-Pres. (for mail), Natkin & Co., 2020 Wyandotte St., and *5225 Charlotte St., Kansas City, Mo. PISON, Donato, Jr. (S1933), c/o Philippine Natl. 'Bk., New York. N. Y. PITCHER, Lester J. (M 1929; A 1928; J 1924), 8129 Dante Ave., Chicago, III. PITTOCK, Louis B. 1930), ((or mail). 429-B Oliver Bldg., and 80 Berry St., Crafton Sta., Pittsburgh, Pa. ' ' PLACE, Clyde R. (34 1924), Consulting Engr. (for ; mail), 420 Lexington Ave., and 333 East 57th St., ' - New York, N. Y. PLAENERT, Alfred B. (A 1933; 7 1927), 1102 S. Park St., Madison, Wis. % 30 . Roll of Membership PLASS, Charles Webster (34 1928), 826 E. Haines St., Philadelphia, Pa. PLAYFAIR, George Alexander (A 1924), Mgr. (for mail), Johnson Temperature Regulating Co. of Canada, Ltd., 97 Jarvis St., Toronto, and West Hiil, Ont., Canada. PLEWES, Stanley E. (M 1917), Philadelphia Mgr. (for mail), Johnson Service Co., 2853-North PURINTON, Dexter J. (A 1923), Associate (for mail), Voorhees, Gmelin & Walker. Archts., 101 Park Ave., New York, N. Y., and 23 Sachem Rd., Greenwich, Conn. PURSELL, H. E. (34 1919), Special Repr.. Kewanee Boiler Corp., Kewanee, 111. PYLE, John W. (M 1919), Peru Htg. Co., 30 W. Canal St., Peru, Ind. 12th St., North Philadelphia, Sta. 8., Phila delphia, and 309 Evergreen Rd.', Jenkintown, Pa. PLUNKETT, John H- (M 1925), Chief of Inspec tions, Dept, of Public Safety, 3 Hancock St.,and (for mail). 81 Woodrow Ave., Boston, Mass. POEHNER, Robert E. (34 1928), Vice-Pres.-Secy., W. H. Johnson & Son Co., 330 E. St. Joe St,, and (for mail), 2308 Coyner Ave., Indianapolis. Ind. POGALIES, Louis H. (34 1931), Mech. Engr., 4614 Prospect Ave., and (for mail), 4102 Arch wood Ave., Cleveland, Ohio. POHLE, Kenneth F. (A 1930), Vifce-Pres., W. F. Hirschman Co., Inc., 205 East 42nd St., New York, N. Y. POLDERMAN, Lambert H. (34 1927), Vice- Pres. (for mail). Carrier Engrg. Corp. of Calif., 748 E. Washington Blvd., and 1330 Colorado Blvd., Eagle Rock, Los Angeles, Calif. POLLARD, Alfred L. (A 1932), Gen. Supt.. Steam o QUAY, D. M.* (Charter Member; Life Member; - Presidential Member), (Pres., 1900; 1st Vice- ip- Pres. 1896-1899; 2nd Vice-Pres., 1895), 725* - Eastern Ave., Beilefontaine, Ohio. ^, QUEER, Elmer Roy* (34 1933), Research Engr. (for mail), Engrg. Experiment Sta., Pennsylvania State College, and Arbor Way. State College, Pa. QUINLIVAN, Laurence P. (S 1933), Asst., Case School of Applied Science, and (for mail), 13711 Earlewood Rd., Cleveland, Ohio. QUIGLEY, William J. (34 1920). 27 Knowlton . Ave., Kenmore, N. Y. QUIRK, Clinton H. (34 1916; 7 1915). Sales Engr. (for mail). Vento and Arcoblast Div., American Radiator Co., 40 West 40th St., and 465 Front St., New York, N. Y. Heat Dept, (for mail), Puget Sound Power & Light Co., 601 Electric Bldg., and 3009 28th W. R Seattle, Wash. - POPE, S. Austin (M 1917), Pres, (for mail), William A. Pope Co., 26 N. Jefferson Sri, Chicago, and 831 Ashland Ave., River Forest, 111. PORTER, Herbert M. (34 1931), 65 North 17th St., Minneapolis, Minn. PORTER, Richmond Clay (A 1931; 7 1930), College of Engrg., University of Kentucky, Lexington, Ky. POSEY, James (34 1919), Consulting Engr., 4005 Liberty Heights Ave., Baltimore, Md. POWELL, Knox A. (S 1933), 1008-18th Ave. S.E., Minneapolis, Minn. POWERS, Fred I. (34 1920), Factory Repr. (for mail). Box 324, and 605 S. Sixth Ave.,'Bozeman, Mont. ` POWERS, Fred W. (341911), Pres, and Gen. Mgr. (for mail). The Powers Regulator Co., 2720 Greenview Ave., and 900 Castlewood Ter., Chicago, 111. . POWERS, Lowell G. (7 1930), Air Cond. (for mail), 1501 Carew Tower, Cincinnati, Ohio, and 325 W. Diamond Ave., Hazelton, Pa. PRENTICE, Oliver J. (A 1927), (for mail), C. A. Dunham Co., 450 E. Ohio St., and 850 Lake Shore Dt,, Chicago, 111. - PRESDEE, Cliff W. (A 1926), Adv. Mgr;, Hearing RACHAL, John M. (7 1930), Mgr. Air Cond. Dept, (for mail), Carrier-Brunswick International Inc., 850 Frelinghuysen Ave., Newark, and 61 S. Munn Ave., East Orange, N. J. RACK, Edgar C. (34 1931), Construction Engr., Johns-Manville Corp., 22 East 40th St., New York, N. Y., and (for mail). 288 Park Ave., East Orange, N. J. . RAFFES, Abraham (S 1932), Student, New York . University, 181st St.-and University Ave., and (for mail), care of I. Pontak, 977 East 178th Sri, New York, N. Y. -- RAINE, John J. (34 1912), Vice-Pres. (for mail). The G. S. Blodgett Co., 190 Bank Sri, and Essex Jet., V.P., Burlington, Vt. RAINGER, Wallace F. (A 1930; 7 1924), 441 Hawthorne Ave., Yonkers, N. Y. RAISLER, Robert K. (A 1933; 7 1930), Treas. (for mail), Raisler Htg. Co., 129 Amsterdam Ave.; and 25 East 77th St., New York, N. Y. RAMSEY, Raymond F. (S 1933), 1522 Coutant, Lakewood, Ohio. - RANCK, Guy L. (A 1933), Office Mgr., C. A. Dunham Co., 3605 Laclede Ave., Sri Louis, and (for mail), 472 Pasadena Ave., Webster Groves, Mo. - RANDALL, W. Clifton* (34 1928), Detroit Steel ; and Ventilating, 148 Lafayette St., New York, Products Co., 2250 E. Grand Blvd., Detroit, N. Y. Mich. . - PRICE, Charles E. (A 1933), Treas. (for mail), RANDOLPH, Charles H. (34 1930: A 1928; Keeney Publishing Co.. 1900 Prairie Ave., 7 1926), Air Cond. Engr., The Milwaukee Chicago, and 1151 Chatfield Rd., Winnetka, Hi. . Electric Railway & Light Co., 231 W. Michigan PRICE, Ernest H. (S 1932), c/o Haff Supply, Inc., Box 328, Riverhead, L. L, N. Y. - PRYIBIL, Paul L. (A 1932), Partner (for mail), Hucker-Pryibil Co., 1700 Walnut St., and 328 E. Phil Ellena St., Philadelphia, Pa. PRYOR, Frederick L. (34 1913), 5 Colt St.. Paterson, N. J. PURCELL, Arthur J. (34 1914), 631 New Britain Ave., Hartford, Conn. PURCELL, Frederick C. (34 1926), Disri Mgr. (for mail). National Regulator Co., 2847 Grand River Ave.. and 18680 Santa ROsa Dr., Detroit, Mich. ,. ' . PURCELL, Robert E. (M 1916), Htg., Plbg. and Vtg. (for mail), 1735 Willis Ave. W., and 4061 Seebaldt Ave., Detroit, Mich. PURDY, A. K. (34 1922), Pres, (for mail), Purdy Mansell^ Ltd., 63 Albert St., and 30 Glenrose Ave., Toronto, Ont., Canada. PURDY, Randall B. (A 1927), Assoc. Editor Power (for mail), McGraw-Hill Publishing Co., 330 West 42nd St., New York, and 224-05-139th Ave., Laurelton, L. I., N. Y. St., and (for mail), 1925 N. Prospect Ave., Milwaukee, Wis. - RASMUSSEN, Robert P. (34 1931), Pres., Air Conditioning Economy Equipment Co., 6835 Wentworth Ave-, and (for mail). 1243 East 46th St., Chicago, IU. RATHBUN, Perry W. (34 1933), Inspector, U. S. War Dept., Ft. Sill, and (for mail), 301 Ft. Sill. Blvd., Lawton, Okla. . RATHER, Max F. (34 1919), Johnson Service Co., 2142 East 19th St., Cleveland, Ohio. RAY, Lewis B. (34 1932), Pres, (for mail), Ray Engrg. Co.; Inc., 800 Broad Sri, Newark, and 151 Augusta St., Irvington, N. J. RAYMOND, Fred I.* (A 1929), Pres, (for mail), F. I. Raymond Co., 629 W. Washington Blvd., Chicago, and River Forest, 111. . REARDON, John A. (34 1921), Reardon Bros. Co., 341 Union Sri, Lyirn, Mass. . ` RECK, William E. (34 1927),. 15 Esromgade, Copenhagen, Denmark. .. REDFIELD, Clarke (5 1932), 318 Engle Sri, Tenafly, N. J. . 31 L American Society of Heating and Ventilating Engineers Guide, 1934 REDSTONE, Arthur L. (M 1931), Research Engr. (for mail), Proctor & Schwartz, Inc., Seventh St. and Tabor Rd., and Park Towers, Kemble and Ogontz Ave., Philadelphia, Pa. REED, John F. (Af 1927; A 1923), Vice-Pres, (for mail), American Air Filter Co., 420 Lexington . Ave., New York, and 67 Sagmore Rd., Bronxville, N. Y. REED, Paul L. (A 1932), Assoc. Editor, ``Air Conditioning/' 167 Madison Ave., New York, N. Y., and (for mail), 1030 Childress Ave., St.` Louis, Mo. ' REED, Van Applegate, Jr. (Af 1930), Federal Engrg. Co.. 239 Fourth Ave., Pittsburgh, Pa. REED, William M. (Af 1927), American Air Filter Co., 216 Central Ave., Louisville, Ky. REESE, Philip R. (Af 1931). Mgr. (for mail). Herman Nelson Corp., 410 Essex Bldg., and Maryland Hotel, Minneapolis, Minn. REHLING, Hugo F. (Af 1928), 993 South St., Roslindale, Mass. REID, Henry P. (Af 1931; A 1927), Special Engr. (for mail). Universal Atlas Cement Co., 208 S. LaSalle St., Chicago, and 3607 Oak Park Ave., Berwyn, 111. REID, Herbert F. (A 1932), Reid-Graff Plbg. Co., . 1417 Peck St., Muskegon Heights, Mich.' REILLY, Charles E. (J 1928), 4920 City Line Ave., Philadelphia, Pa. REILLY, J. Harry (Af 1931; A 1931; J 1929), 14 Watson Ave., East Orange, N. J. RE1NKE, Alfred G. (J 1933), Group Leader on Relays, Westinghouse Electric & Mfg. Co., 96 Orange St., Newark, and (for mail), 319 Park; PI., Irvington, N. J. RENOUF, E. Prince (Af 1933). Sales Engr. and Dist. Supervisor (for mail), Carrier Corp., 2022 Bryan St., and 3330 Rosedale St, Dallas. Texas. RENTE, Horry W. (Af 1931), Htg. Engr., Oil Burners, 70 W. Chippewa St, and (for mail), 114 Morris Ave., Buffalo, N. Y. RENTE, Sidney R. (A 1930), 18 Charleston Ave., Kenmore, N. Y. RETTEW, Harvey F. (Af 1929), Htg. and Vtg. Engr., Bd. of Education, 21st and Parkway, and (for mail). 6821 Martins Mill Rd., Philadelphia, Pa. REUSS, Edward H., Jr. (Af 1921; A 1919), 49th and Grays Ave., Philadelphia, Pa. REYNOLDS, Jack A. (S 1933), Box 1230, College Sta., Texas. REYNOLDS, Thurlow W. (Af 1922), Consulting Engr., 100 Pinecrest Dr., Hastings-on-Hudson, N. Y. ' REYNOLDS, Walter V. (A 1928), Janes-Reynolds Co., Inc., 218 East 52nd St., New York, N. Y. RHEA, Chester A. (A 1931), Steel Boiler Repr., National Radiator Corp., and (for mail), 722 Car penter Lane, Philadelphia, Pa. RICE, C. J. (A 1923), Pres, (for mail). Sterling Engrg. Co., 3738 N. Holton St, and 3376 N. Summit Ave., Milwaukee, Wis. s RICHARD, Edwin J. (Af. 1933), Owner (for mail). Chamber of Commerce Bldg., and 3564 Paxton Rd., Cincinnati, Ohio. RICHARD, I. T. (A 1928), Steamfitter and Engr., James G. Gillespie Co., 708 Columbia Rd., and (for mail), 29 Virginia St., Dorchester, Mass. RICHARDSON, Henry Thomas (A 1930), VicePres. (for mail), Richardson & Boynton Co., 244 Madison Ave., and 156 East 79th St, New York, N. Y. RICHMOND, John (S 1933), 5035 Forbes St., Pittsburgh, Pa. RICHTMANN, William M.* (A 1932; J 1926), 'Instructor in Mech. Engrg. (for mail), Texas College of Arts & Industries, and 729 W. Alice St., Kingsv/Ile, Texas. RIDDLE, Kemble L. (5 1933), 4150 Windsor St, Pittsburgh. Pa. RIES, Lester S. (Af 1929), Asst. Supt of Bldgs, and Grounds, University of Chicago, 960 East 58th St, and (for mail), 5614 Blackstone Ave., - Chicago, 111. ' R1ESMEYER, Edward H., Jr. (J 1930), Htg. Engr., Schaffer Htg. Co., 231-33 Water St., and (for mail), 4702 Stanton Ave., Pittsburgh, Pa. RIETZ, Elmer W.* (Af 1923). Gen. Sales Mgr., Powers Regulator Co., 2720 Greenview Ave., Chicago, and (for mail), 940 Greenwood Ave., Winnetka, 111. RILEY, Champlain L. (Af 1908), {Presidential Member), (Pres., 1921; 1st Vice-Pres., 1920; Council, 1918-1922), Clark-MacMullen & Riley, Inc., 101 Park Ave., New York, N. Y. RILEY, Edward C. (S 1933), Roughwood, Plain field. N. J. . RINEHART. Wilson R. (J 1932), Research and Elec. Engr., W. F. Hirschman Co., and (for mail), 5 Craigie St., Le Roy, N. Y. . R1NKENBERGER, George (Af 1924), Htg. and Vtg. Engr. (for mail). P. O. Box 955, and 1036. Broad St., Johnstown, Pa. RITCHIE, A. Gordon, (Af 1933), Pres, and Mgr. (for mail), John Ritchie, Ltd., 102 Adelaide St. E.t and 41 Garfield Ave., Toronto, Ont., Canada. RITCHIE, Edmund J. (Af 1923). Vice-Pres.. Sales (for mail), Sarco Co., Inc., 183 Madison Ave., New York, and 19 Grace Court, Brooklyn, N. Y. RITCHIE, William (Af 1909) Vice-Pres., Boyn. ton Furnace Co., 373 Fourth Ave., New York, N. Y.P and (for mail), 17 Van Reipen Ave., Jersey City, N. J. RITTER, Arthur (Af 1911), New York Dist. Mgr. (for mail), American Blower Corp., 401 Broad way, New York, N. Y., and 29 Edgeraont Rd., Scarsdale, N. Y. ROBERTS, Edward F., Jr. (/ 1929), 2622 Columbia Ave., Philadelphia, Pa. ROBERTS, Henry L. (Af 1916), Engr. and Con tractor, 228 North 16th St., Philadelphia, and' (for mail), 1014 Allston Rd., Brookline. Delaware ' Co., Pa. ROBINSON, Harry C. (Af 1930), Htg. Engr., 676 Pleasant St., Worcester, Mass. ROCKWELL; Theodore F. (Af 1933; A 1933; J 1932), Instructor (for mail), Carnegie Institute of Technology, Schenley Park, and 5721 Stanton Ave, E.E., Pittsburgh, Pa. ' RODENHE1SER, George B. (Af 1933), Head Htg. and Vtg. Dept, (for mail), David Ranken, Jr., School of Mech. Trades, 4421 Finney Ave., and 3639 A, Dover PI., St. Louis, Mo. RODMAN, Robert W. (M 1922), Supt. of Plant Operation (for mail), Bd. of Education.' City of New York, 500 Park Ave., and 175 West 73rd .St., New York, N. Y. ROEBUCK, William, Jr. (Af 1917), Junior Partner (for mail), R. T. Coe Cos., 311 Jackson Bldg., and 66 Summer St., Buffalo, N. Y. ' ROEMER, Julius (Af 1928), J. Roemer Htg. Co., ' Builders Exchange, Cleveland, Ohio. ROHLIN, Karl W. (Af 1930). Engr., Warren Webster & Co., 17th and Federal Sts., Camden, and (for mail). 4453 Terrace Ave., Merchantville, N. J. ` ROOKS, Alfred W. (Af 1931). 146 Santa Ana Ave., Long Beach, Calif. * ROSE, William K. (Af 1930).. Tall Timbers. North Park, Gerrards Cross. Buckinghamshire,. England. . ROSEBERRY, John H. (Af 1931), 32 Wardman Rd., Kenmore, N. Y. ROSEBROUGH, Robert M. (Af 1920). Br. Mgr. (for mail), L. J. Mueller Furnace Co., 4246 Forest Park Blvd., and 6012 McPherson Ave., St. Louis, Mo. ROSENBERG. Philip (A 1928), Pres.. Philros Sheet Metal Works, Inc., 112 Lincoln Ave., and (for mail), 811 Walton Ave., New York, N. Y. ` ROSKE, Frederick M. (/ 1930), Secy.. Automatic Combustion Engrs., Inc., of New Jersey, 17 DeNorraandie Ave., Fair Haven, and (for mail), 22 Mason PI., Keansburg, N. J. ROSS, John O.* (Af 1920), Ross Industries Corp., 122 East 42nd St., New York, N. Y. 32 Roll of Membership ROTH, Charles F, (A 1930), Mgr., International Htg. and Vtg. Exposition, Grand Central Palace, New York, and (for mail). 141 East ,36th St., New York, N. Y. (Nov. 1 to. April 30), and Dreamthorp, Bedford Village, N. Y. (May 1 to Oct. 31). ROTHROCK, John T. (Af 1920), 311 ManOT Rd., Douglaston, L. I., N. Y. ROTTMAYER, Samuel I. (A 1933; J 1928), Mech. Engr. (for mail), Samuel R. Lewis, 407 S. Dearborn St., and 1310 Lunt Ave., Chicago, HI. ROTZ, John M. (Af 1918), Owner (for mail), J. M. Rotz Engrg. Co., 817 Merchants Bk. Bldg., Indianapolis, and R. R. No. 2. Carmel, lnd. ROWE, William A. (Af 1921), (Council. 1929 1931), 718 Longfellow Ave., Detroit. Mich. 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.. Univereity of Minnesota, and (for ' mail), 4801 E. Lake Harriet Blvd., Minneapolis, Minn. ROYER, Earl B. CM 1928), Designing Engr., Fosdick & Hilmer, Consulting Engrs., 1703 Union Trust Bldg., and (for mail), .6635 Iris Ave., Cincinnati, .Ohio. ROZETT, William, Jr. (51932), 3528 E. Treraont Ave., New York, N. Y. RUDIO, H. M. (Af 1921), Gustin-Bacon Mfg. Co., 1412 West 12th St,, Kansas City, Mo. RUFF, DeWitt C. (Af 1922), Healy-Ruff Co., 765 Hampden Ave., St. Paul, Minn. RUGART, Karl (A 1924), Dist. Mgr. (for mail), Warren Webster & Co., 158 North 20th St., Philadelphia, and 5830 Willows Ave., W. Phila- .delphia, Pa. . RUPPERT, Edward H. (A 1923), 85 Eastern Pkwy., Brooklyn, N. Y. RUSSELL, Joseph Nelson (Af 1899), Managing Dir. (for mail), Rosser & Russell, Ltd., Romney House, Marsham St., Westminster and Dart mouth House. Gerrards Cross, Buckinghamshire. England. RUSSELL, W. A. (Af 1921). Mgr., K. C. Br. (for mail), U. S. Radiator Corp., 1405 West 11th st., and 1440 West 61st Ter., Kansas City, Mo. RUSSELL, William B. (Af 1928). Colorado Ave., R. F. D. No. 1-. Joliet, III. RYAN, Harry J. (Af 1922), 47 Harris Ave., Albany. N. Y. RYAN, John E. (Af 1931). 660 Locust St., Mt. Vernon. N. Y. RYAN, William F. (/ 1933), Sale Engr., Lee Hardware Co., and (for mail), 609 East Iron- Salina, Kan. RYDELL, Carl A. (Af 1931; A 1931; J 1928), Co-partner (for mail). Clarid Engrg. Co., 168 Dartmouth St., Boston, and 280 Quinobequin Rd., Waban, Mass. . s SABIN, Edward R. (Af 1919), E. R. Sabin & Co.. 4710-12 Market St., Philadelphia, Pa. SACHLEBEN, Edward H. (A 1921), E. H. Sachleben & Co., 1923 Washington Ave., St. Louis, Mo. SADLER, G. Boone (Af 1928), Design Draftsman (for mail). Public Works Office, 11th Naval District, and 4440 Point Loma Ave., San Diego, Calif. SAITO, Shozo (Af 1923), Marunouchl -Bldg., Opposite Tokyo Sta., Tokyo, Japan. . SAKOUTA, Mathieu L. (Af 1924), Consulting Engr. and Expert, Gavan, Simanskaia 4-A, Leningrad, U. S. S. R. SALISBURY, William C. (Af 1930). Hinckley Elec. Co., OsterviUe, Mass. . SANBERN, E. Nute* (Af 1923), Engr. (for mail), Mensirig & Co., 12 South 12th St., and 119 S. Haviland Ave., Philadelphia, Pa. SANDS, Olive C. (Af 1929), G. P. O. Box 601 F. F., Sydney.N. S. W.. Australia. SANDS, John S. (A 1930), 3479 Bowman St., Philadelphia, Pa. SANFORD, Arthur L, (Af 1915), Space Htg. Engr. (for mail), Minneapolis-Honeywell Co., 43 East Ohio St., and 2302 Fremont Ave. S.f Minne . apolis, Minn. . SANTEE, Helen C. (Af 1930), Asst, to Arch, and Engr., 81 N. Washington St., and (for mail), 900 S. Franklin St., Wilkes-Barre, Pa. SAUER, Robert L. (A 1930), Dist. Sales Mgr. (for mail). Riley Stoker Corp., Ft. of Walker St., and - 3315 W. Philadelphia, Detroit, Mich. . SAUNDERS, Laurance P. (Af 1933), Dir. of Engrg., Harrison Radiator Corp., Lockport, N. Y. * SAWDON, WH1 M. (Af 1920), Prof. Experimental Engrg. (for mail), Cornell University, and 1018 E. State St., Ithaca, N. Y. SAWYER, J. Neal {J 1933), Research & Develop ment, Holland Furnace Co., and (for mail), 206 West 11th St., Holland, Mich. SCHANZE, A. Gale (A 1925), Sales Engr., Inter national Engrg. Works, Inc., Framingham, and (for mail), 71 Gilbert Rd., Belmont, Mass. SCHE1DECKER, Daniel B. (A 1919), Secy, (for mail), Hunter-Clark Vtg. System Co., 2800 Cottage Grove Ave., and 4626 N. Kilboum Ave., Chicago, III. SCHERNBECK, Fred H. (A 1930). Salesman (for mail), Wm. Bros., Boiler & Mfg. Co., Nicollet Island, and 5045 Portland Ave., Minneapolis, Minn. SCHLEYER, Emil F. (A 1931), 1725 East 37th St.. Brooklyn, N. Y. SCHLICT1NG, Walter C. (Af 1932), Mgr. Air > Cond. Dept., Clarage Fan Co., and (for mail), 528 Pinehurst Blvd., Kalamazoo, Mich. SCHLOSSMAN, Melvin. B. (S 1933), c/o L. . Farbman, 601 West 160tb St., New York, N. Y. SCHMUTZ, Jean (Af 1933), 40 Rue Amelot, Paris (II), France. SCHNEIDER, William G. (Af 1932), (for mail). Copper and Brass Research Assn., 25 Broadway, Room 1326. New York, and 45 Wayne Ave., White Plains, N. Y. SCHOENIJAHN, Robert P. (Af 1919), Consulting Engr. (for mail), 304-5 Industrial Trust Bldg., and 719 Nottingham Rd., Wilmington, Del. SCHOENOFF, Alfred E- (S 1930), Schoenoff Plbg. & Htg. Co., 515 E. Second St., Menomonie, Wis. SCHOEPFLIN. Paul H. (Af 1920), Niagara Blower Co., 6 East 45th St., New York, N. Y. SCHRADER, Charles C.* (A 1925; J 1923),,. Armstrong Cork Co., Research Div., Lancaster, Pa. SCHROTH, August H. (Af 1911), Pres., Master Boiler Corp., 1440 Broadway, New York, and (for mail), 90 S. Oraton Pkwy., East Orange, N. J. SCHULTE, Ross R. (Af 1931), Consulting Engr. (for mail), 1000 Guardian Bldg., and 1781 Hague Ave., St. Paul, Minn. *. SCHULZ, Howard I. (A 1915), Crane Co.. 1223 W. Broad St., Richmond, Va. j SCHULZE, Benjamin H. (Af 1921), Dist. Mgr. (for mail). Kewanee Boiler Corp., 37 West 39th St., and 7 Park Ave., New York, N. Y. SCHWARTZ, Jacob {J 1929), Htg. Contractor (for mail), Samuel Schwartz & Son, Inc., 30 West 27th St., Bayonne, and .134 Corbin Ave., Jersey City, N. J. ' * SCHWEIKERT, John N. (Af 1931), 17825 Si. Clair Ave., Cleveland, Ohio. SCHWEIM, Henry J. (Af 1928), Chief Engr. and Secy, (for mail). Gypsum Assn., 211 W. Wacker Dr., and 7360 N. Hoyne Ave., Chicago.TU. SCHWERTFEGER, Anton (S 1932), 111 Linden' Ave., Arlington, N. J. SCOFIELD, Paul C. (.J 1933), Engr. (for mail). Carrier Engrg. Corp., 748 E. Washington Blvd., and 830 N. Occidental Blvd., Los Angeles, Calif. SCOTT, Charles E. (Af 1907), Pres, and Treas. (for mail). Vapor Engrg. Co., 489 Fifth Ave., New York, N. Y., and Darien, Conn. 33 American Society of Heating and Ventilating Engineers Guide, 1934 own, Vjeorge x*i. (Af 1915), Vice-Pres. (for SHELNEY, Thomas (Af 1931), Pres, and Treas, mail). Child & Scott-Donohue, Inc., 112 Wooster (for mail), Pierce Blower Corp., 27 Carolina St;. St., New York, N. Y., and 66 Bowman Ave., Port and 196 North St., Buffalo, N. Y. . Chester. N. Y. SHEPARD, Edward C. (Af 1932), Owner (for SCOTT, William P., Jr. (7 1933), 9 Scenic Way, mail), Shepard Engrg. Co., 370 Lexington Ave., . San Francisco. Calif. and 978 Grant Ave., New York, N. Y. SCRIBNER, Eugene D. (A 1933; 7 1929). Engr.' SHEPARD, John deBerard (7 1929), Sales (for mail). Carrier Engrg.-Corp., Chrysler Bldg., Engr. (for mail). Carrier Engrg. Corp., 12 South Room 408, New York, N. Y., and 264 Prospect 12th St., and 1337 Tabor Rd., Philadelphia, Pa. St., Westfield, N. J. SHEPPARD, Frank A. (Af 1918), Salesman SEBREE, George M. (A 1930), Baker Ice Machine. (for mail), Johnson Service Co., 411 E. Tenth St., ' - Co., Inc., 2733 Bauman Ave., Omaha, Nebr. . and 27 East 70th St., Kansas City, Mo. ' SEELBACH, Herman (Af 1931), 610 Erie County SHEPPARD, William G. F. (Af 1922), Partner Bk. Bldg., Buffalo, N. Y. (for mail), Sheppard & Abbott, 119 Harbord St., SEELEY, Lauren E.* (Af 1930), Asst. Prof. Mech. and 1 Clarendon Ave., Toronto, Ont.', Canada. ` Engrg. (for mail). Mason Laboratory, Yale SHERET, Andrew (Af 1929; A 1925), Pres, (for University, New Haven, and 1227 Whitney Ave., Hamden, Conn. mail), Andrew Sheret, Ltd., 1114 Blanshard St., and 1030 St. Charles St., Victoria, B. C., Canada. SEELIG, Alfred E. (Af 1926), Pres, and Gen. SHERMAN, Ralph A. (Af 1933), Fuel Engr. (for Mgr., L. J. Wing Mfg. Co., 154 West 14th St., mail), Battelle Memorial Institute, 505 King and (for mail), 310 Convent Ave., New York, N. Y. * Ave., and 1893 Coventry Rd., Columbus. Ohio. SHERRY, Raymond W. (Af 1927), 601 Peace St., SEELIG, Lester (Af 1925), Mech. Engr., Museum Hazelton, Pa. of Science & Industry, Jackson Park, and (for SHIPP, Clarence C. (Af 1923), C. C. Shipp & Co., mail), 725 Irving Park Blvd., Chicago, 111. ' ' Room 210, 230 E. Ohio St., Indianapolis, Ind. SEEPE, Paul E. (A 1933), Sales Engr., Minne- SHIVERS, Paul F. (Af 1930), Minneapolis- - apolis-Honeyweli Regulator Co., and (for mail), Honeywell Regulator Co., W. Canal St., Wabash, 5838 Enright Ave., St. Louis, Mo. Ind. ' SEITER, J. Earl* (Af 1928). Asst. Mgr., New SHODRON, John G. (Af 1921), Consulting Engr.. Business Dept., Consolidated Gas, Electric Light and Research, 419 E. Milwaukee Ave., Fort & Power Co., and (for mail), 7117 Bristol Rd., Atkinson, Wis. Baltimore, Md. . , SHORB, Will A. (Af 1909), Treas., The Field & .SEKIDO, Kunisuke (Af 1903), Consulting Engr., Shorb Co., 709 N. Pine St., and (for mail), 3 ' Marunouchi Bldg., No. 885, and (for mail), 19 Lincoln PI., Decatur, 111. - Momozono Nakano, Tokyo, Japan. SHROCK, John H. (Af 1924), Mgr. (for mail). SELLMAN, Nils T. (Af 1922), Dir. of Sales and New York Blower Co., Factory St., and 1524 * . Utilization and Asst. Secy, (for mail). Con Michigan Ave., La Porte, Ind. . solidated Gas Co. of New York, 4 Irving PL, New SHUELL, Frank W. (A 1921), Pres, and Gen. York, and 56 Walworth Ave., Scarsdale, N. Y. . Mgr., Ever Hot Heater Co., 5241 Wesson Ave., SENIOR, Richard L. (Af 1925), (for mail). R. L. Detroit, Mich. Senior, Inc., 103 Park Ave., New York, and 10 SHUFELT, Howard M. (A 1928), 10245 Charles Cherry Ave., New Rochelle, N. Y. St., Chicago, 111. SEVERNS, William H.* (Af 1933), Prof, of Mech. : SHULTZ, Earle (A 1919), Vice-Pres. (for mail), Engr. (for mail). Dept, of Mech. Engrg., Uni Illinois Maintenance Co., 1136-72 W. Adams St., versity of Illinois, and 609. Indiana Ave., Urbaaa, and Edgewater Beach Apts., Chicago, III. . 111. SIEBS, Claude T. (A 1927), Service Systems ' SEWARD, Perdval H.* (Charter Member; Life Engr. (for mail). Western Electric Co., Inc., 11 , * Member), Research, 369 Washington Ave., Park PL, New York, N. Y., and Russell Rd., Brooklyn, N. Y. Fanwood, N. J. SHANKLIN, Arthur P. (M 1929), Sales Engr. (for SIEGEL, Leo (Af 1928; A 1925; J 1924), Mech. mail). Carrier Engrg. Corp., 12 South 12th St., Engr., 1508 Ave. S, Brooklyn, N. Y. Philadelphia, and 40 Amherst Ave., Swarthmore, Pa. SIGMUND, Ralph W. (Af 1932), Dist. Mgr. (for mail), B. F. Sturtevant Co., 913 Provident Bk. . SHANKLIN, John A. (M 1928), Secy-Treas. (for Bldg., and 304 Oak St., Cincinnati, Ohio. mail). West Virginia Htg. & Plbg. Co., 233 Hale SIMKIN, Milton (S 1933). 103 Brighton Ave., St., and 1507 Quarrier St., Charleston, Va. Perth Amboy, N. J. SHARP, Floyd H. (M 1929), 117 E. Third St., SIMONDS, Abe H. (7 1929), Sales Engr. (for Jamestown, N. Y. mail, Carrier Engrg. Corp. of California, 748 SHARPE, Norman (A 1933; J 1930), 748' E. E. Washington Blvd., and 446 Westminster ' Washington St., Los Angeles, Calif. Ave., Los Angeles, Calif. SHAVER, Herbert H. (A 1929), Asst. Gen. Sales SIMPSON, Donald C. (Af 1932), Supt. of Re Agt. (for mail), Hudson Coal Co., 424 Wyoming search, Industrial Mat Div. (for mail), Owens- Ave., and 1507 Wyoming Ave., Scranton, Pa. Illinois Glass Co., and 878 Keltori Ave., Colum SHAW, Edgar (Af 1923), Pres, (for mail), Lynch - bus, Ohio. * . & Woodward, Inc., 320 Dover St., Boston, and 51 SIMPSON, William K. (Af 1919), Vice-Pres- (for . Royal St., Quincy, Mass. mail), Hoffman Specialty Co., and 9 Sands St., SHAW, Norman J. H. (Af 1927; 7 19^5), 37 Waterbury, Conn. .' Benjamin Rd., Arlington, Mass. . SKELLY, John F. (Af 1921), 314 Ford St.. . SHAWL1N, Walter C. (A 1931), 696 S. Oak Park Ogdensburg, N. Y. Court, Milwaukee, Wis. SKIDMORE, John G. (7 1930), Apt. 104, 321 SHEA, Michael B. (Af.^1921), Sales. Dept, (for Elmora Ave., Elizabeth, N. J. mail), American Radiator Co.. 1344 Broadway, SKINNER, Henry W. (Af 1920), Consulting Engr. Detroit, and 117 Massachusetts Ave., Highland (for mail), Box 1334, and 4816 Dexter, Fort - v Park, Mich. Worth, Texas. ` SHEARS, Matthew W. (Af 1922), 39 Sylvan Ave., / SKLENARIK, Louis (7 1928), 305 East 72nd St., - Toronto, Ont., Canada. ._ New York, N. Y. .- SHEFFIELD, Edward B. (Af 1921), Armstrong SLAYTER, Games (Af 1931). (for mail). '711 Cork & Insulation Co., 522 King St., W. Toronto,' Southwood Ave., and 68 Walhalla Rd., Colum Ont., Canada. bus, Ohio. SHEFFLER, Morris (Af 1921), Pres, (for mail),. SLIGHT, Irvin (A 1925), Slight Bros., 741 York Sheffler-Gross Co., 203 Drexel Bldg., and 5451 way PL, Jenkintown, Pa. Lebanon Ave., Philadelphia, Pa. SMAIL, A. Melville .(Af 1931), Chief Engr. .. SHELDON, Nelson E. (Af 1927), Dist. Sales Mgr. Custodian (for mail), Bd. of Education, Wright * (for mail). Carrier Products Corp., 916 Temple Junior High School, 3400 N. Austin Ave., . . Bldg., and 942 Genesee Park Blvd., Rochester, Chicago, and 1810 North 79th Court, Elmwood N. Y. . Park, 111. . .' 34 ! X Roll of Membership SMALL, Bartlett R. (7 1932), Office Engr. (for mail), Carrier-York Corp., 1408 Independence Bldg., and 948 Queens Rd., Charlotte, N. C. SMALL, John D.* (Af 1910), Consulting Engr. (for mail), 127 N. Dearborn St., Chicago, and 411 Maple Ave., Wilmette, 111. SMALLMAN, Edwin W. (Af 1920), 833 Allison SPOFFORTH, Walter (Af 1930), Chief of Mech. Services (for mail), U. S. Penitentiary, McNeil island, and 1850 West Blvd.i Day Island,. Tacoma, Wash. - SPROULL, Howard E. (Af 1920), Div. Sales Mgr. (for mail), American Blower Corp., 10005 American Bldg., and 3588 Raymar Dr., Cincin St. N.W., Washington, D. C. nati, Ohio. SMITH, Elmer G.* (Af 1929), Asst. Prof, of SPURGEON, Joseph H. (Af 1924), Mfrs. Repr. Physics, Agricultural and Mechanical College of (for mail), 5-203 General Motors Bldg., and Texas, College, Sta., Texas. " 17215 Pennington Dr., Detroit, Mich. SMITH, Card W. (Af 1927), Salesman. Premier STACEY, Alfred E., Jr.* (Af 1914), Wootton Rd., Warm Air Heater Co., Dowagiac, Mich, and (for Essex Fells, N. J. mail), 1131 Guilford St., Huntington, Ind. STACK, Frank Charles (5 1933), 140-23 Cherry SMITH, Harold P. (Af 1928), Pres.; Automatic Ave.. Flushing, N. Y. Combustion Engrs., Inc. of New Jersey, 17 STACY, Stanley C. (Af 1931), Mech. Engr. (for DeNormandie Ave., Fair Haven, N. J. mail), Bd. of Education, 13 S. Fitzhugh St., and SMITH, Jared A. (A 1933), Br. Mgr. (for mail), 91 Cobbs Hill Dr., Rochester, N. Y. . , The Bryant Heater Co., 626 Broadway, and 3817 STAMMER, Edward L. (Af 1919), Supt. Htg. Indian View Ave., Mariemont, Cincinnati, Ohio. and Vtg., Bd. of Education, Bldg., and (for mail), SMITH, J. Darrell (Af 1933), Mech. Engrg. Dept., 4430 Tennessee Ave., St. Louis, Mo. ' Philadelphia & Reading Coal & Iron Co. (for STANGER, Ralph B. (Af 1920), Mgr. (for mail), mail), 317 North 19th St., PottsviUe, Pa. Robinson & Stanger, Empire Bldg., Pittsburgh, SMITH, Milton S. (Af 1919), Vice-Pres.. Carrier and Deer Creek, Church Rd., Glenshaw, Pa. Corp., 850 Frelinghuysen Ave., Newark, and (for STANGLAND, B. F. (iCharter Member), (2nd mail), 13 N. Terrace, Maplewood, N. J. Vice-Pres., 1908, Bd. of Governors, 1905-1906 SMITH, Philip C., Jr. (Af 1928), Northport, L. I., 1909; Bd. of Mgrs., 1895-1899; Council, 1896 N.Y. 1897), Morton, N. Y.- SMITH, Robert Hugh (,S 1933), 4921 Forbes St., STANNARD, James M.* (Af 1906), Pres-Treas. Pittsburgh, Pa. (for mail), Stannard Power Equipment Co., 53 SMITH, Wilbur F. (Af 1920), 422 Bryn Mawr W. Jackson Blvd., Chicago, and 1402 Elinor PI., Ave., Cynwyd, Pa. Evanston, III. . SMYERS, Edward C. (A 1933), Sale Engr., Minneapolis-HoneyweU Regulator Co., 1013 STAPLES, William H. (A 1924), Gillis & Geoghegan, 537 W. Broadway, New York, N. Y. ' ' Penn Ave., Wilkinsburg, and (for mail), 3702 STARK, W. Elliott* (Af 1926), (Council, 1932-33), Ruggles St., Pittsburgh, Pa. . Research Engr., Bryant Heater & Mfg. Co., SNELL, Ernest (Af 1920), 3914 LeMay Ave., Detroit, Mich. * 17825 St. Clair Ave., Cleveland, and (for mail), 1875 Rosemont Rd., East Cleveland, Ohio. SNIDER, Lewis A. (Af 1927), Pres, (for mail), STEELE, Alfred N. (Af 1930), 220 S. Maple Ave., L. A. Snider Engrg. Service, Inc., 605 N. Michi Oak Park, 111. gan Ave., and 649 Buena Ave., Chicago, 111. STEELE, John B. (Af 1932), Chief Engr. (for , SNYDER, Allen K. (7 1930), Sales Engr.. Air Cond. Dept., N. K. Ovalle, Inc., G. E. Distri- mail), Engrg. Dept., Winnipeg School Bd., Ellen and William Ave., and 215 Niagara St., Winnipeg, 4 butors, and (for mail), 1820 Market St., Harris- ' Man., Canada. ' burg, Pa. STEELE, Maurice G. (Af 1929), Sales Mgr. (for SNYDER, Jay W. (M 1917), McColl-Snyder. McLean, 2304 Penobscot Bldg., Detroit, Mich. mail). Revere Copper & Brass. Inc., Rome Radi ation Div., and 906 N. Madison St., Rome, N. Y. SNYDER, Joseph S. (A 1925), Sales Repr., STEEN, Joseph M. (Af 1929), Iron City Htg. Co., Detroit Lubricator Co., 374 Delaware Ave., 843 Jacksonia St., Pittsburgh, Pa. and (for mail), 9 Knowlton Ave., Buffalo, STEINHORST, Theodore F. (Af 1919), Engr. and N. Y. Treas., Emil Steinhorst & Sons, Inc., 612 South SODEMANN, Paul W. (Af 1926; 7 1920). Sales St., and (for mail), 1664 Brinckerhoff Ave., Engr., 2306 Delmar Blvd., and (for mail), 4136 Utica, N. Y. Farlin Ave., St. Louis, Mo. i STEPHENSON, George A. (Af 1931), Apt. 3, 121 SODEMANN, William C. B. (Af 1919), Pres, (for Virgil Ave., Buffalo, N. Y. mail), Sodemann Heat -& Power Co., 2306 STEPHENSON, L. A. (Af 1917), Mgr-, (for mail). Delmar Blvd., St. Louis, Mo. Powers Regulator Co., 409 East 13th St., and SONNEBORN, Charles (Af 1930), Vice-Pres. in 801 West 57th Ter., Kansas City, Mo. charge of Production, Shaw-Perkins Mfg. Co., STERN, H. Richard (Af 1923), Johnson & Morris, West Pittsburgh, and (for mail), R. D. No. 3, Inc., 233 West 18th St., New York, N. Y. New Castle, Pa. SOULE, Lawrence C.* (Af 1908), Secy, and Chief Engr. (for mail), Aerofin Corp., 850 Freling STERNBERG, Edwin (A 1932; 7 1931), Air Cond. Engr., Arctic Engrg. Co.. 123 White St., and (for mail), 58 East 92nd St., New York, N. Y. huysen Ave., Newark, and Essex Fells, N. J.. . STETSON, Lawrence R. (Af 1913), 303 Congress SPAFFORD, Allen (A 1927), Factory Supt., Wood St., Boston, Mass. Conversion Co., Cloquet, Minn. STEVENS, Harry L. (A 1927; 7 1924), (for mail), SPAFFORD, Lewis B. (A 1929), Consulting Engr. (for mail). Box 145, and 66 River St., Buchanan, M. M. Stevens Co., 108 West Sherman, and 7 West 22nd St., Hutchinson, Kans. Mich. . STEVENS, John M. (A 1933), 4643 Morris St., SPECKMAN, Charles H. (Af 1918), Prof. Engr., Philadelphia, Pa. . 375 Bourse Bldg., Philadelphia, Pa. STEVENSON, Alexander R., Jr. (Af 1932), SPELLER, Frank N * (Af 1908), Dir., Dept, of General Electric Co., 1 River Rd., Schenectady, Metallurgy and Research (for mail). National N. Y. - ' Tube Co., 1922 Frick Bldg., and 6411 Darlington STEVENSON, Wilbur W. (Af 1928), Steam Htg. Rd., Pittsburgh, Pa. Engr. (for mail), Allegheny County Steam Htg. SPIELMAN, Gordon P. (A 1931; 7 1923). Co., 435 Sixth Ave.. and 1125 Lancaster Ave., Harrison-Spielman Co., 480 Milwaukee Ave., Pittsburgh, Pa. Chicago, 111. STEWART, Charles W. (Af 1919; A 1918), SPIELMANN, Harold J. (Af 1933). Air Cond. Engr., The Vilter Mfg. Co., and (for mail), 2549 Hoffman Specialty Co., 3707 Chrysler Bldg., New York, N. Y. N. Lake Dr., Milwaukee, Wis. . STEWART, Duncan J. (A 1930), Mgr., Electric SPITZLEY, Ray L. (Af 1920), 1200 W. Fort St., Detroit, Mich. Apparatus Div. (for mail), Barber-Colman Co., and 214 Franklin PI., Rockford, 111. 35 American Society of Heating and Ventilating Engineers Guide, 1934 STILL, Fred R.* {M 1904), {Presidential Member)', (Pres., 1918; 2nd Vice-Pres., 1917; Council, 1916 1919), Vice-Pres. (for mail), American Blower Corp., 401 Broadway, and 1 East End Ave., ' New York, N. Y. STILLER, Frederick Wilbur (71933), Estimator (for mail), F. C. Stiller & Co., 129 S. Tenth St., and 138 West 49th SL, Minneapolis, Minn. STITT, Arthur B. (5 1933), Group Div. Head, Sears Roebuck & Co., 210 S. Broadway, and (for mail), 260 Valentine Lane, Yonkers, N. Y. STITT, Eugene W. {M 1917), Sales Engr., Gas Htg. Div. (for mail). National Radiator Corp., 221 Central Ave., and 233 Mifflin St., Johnstown, . Pa. STOCKENBERG, Ruben {M 1922), Johnson Service Co., 1365 W. Washington Blvd., Chicago, 111. STOCKWELL, William R. (M 1903 ; 7 1901), Weit-McLain Co., Michigan City, Ind. STOEVER, George H. (M 1930), 7014 Cottage St., Tacony, Philadelphia,' Pa. STONE, Eugene R. (M 1913), 171 Harrison Ave., Boston, Mass. STONE, George F. (Life Member; M 1918), , Estimator. 16 Elmwood Rd., Verona, N. J. STRACHAN, John S. {M 1928). 121 Furman St., Schenectady, N. Y. STRICKLAND, Albert W. (A 1929). Htg. and Vtg. Engr., Big Timber, Mont. ' STROBL, John Arthur {M 1933), Eng. and Est., The Kirk & Blum Mfg. Co., 2838 Spring Grove Ave., Cincinnati, and (for mail), 13 Martin St., St. Bernard, Ohio. STROCK, Clifford (A 1929), Associate Editor (for mail). Heating and Ventilating, 148' Lafayette St., and 150 East 182nd St., New York, N. Y. STROUSE, Sidney B. (M 1921), (for mail), 429 Guarantee Trust Bldg., and. 22 S. Illinois Ave., Atlantic City, N. J. STRUNIN, Jay (7 1933), Supt. (for mail), 408 Second Ave., and 54 West 89th St., New York, N. Y. ' SULLIVAN, Daniel A. (M 1923), Engr. and Con tractor, 3178 Rochambeau Ave., New York, N. Y. ... `. . 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. (S 1933), 3040 Longfellow Ave., Minneapolis, Minn. SUTCLIFFE, Arthur G. (M 1922; A 1918), Chief Engr., llg Elec. Vtg. Co., 2850 N. Crawford Ave., and (for mail), 4146 N. St. Louis Ave., Chicago, 111. SUTTON, Frank (Af 1932), Consulting Engr. (for mail), 140 Cedar St., New York, and Babylon. L. I., N. Y. . SWANEY, Carroll R. (M 1929; 7 1921), Gilbert Howe Gleason, 25 Huntington Ave., Boston. Mass. . - SWANSON, Harry (M 1933), Engr. (for mail),The Fels Co., 42 Union St., Portland, and Box 135, Cape Cottage, Maine. SWANSTROM, Alfred E. {S 1932), Construction Foreman, U. S. Dept. of'Interior, and (for mail), 1444 Van Buren St., St. Paul, Minn. SWENSON, John E. (A- 1930), Industrial Engr. (for mail), Minneapolis Gas Light Co., 800 Hennepin Ave., and 1102 S.E. 13th Ave., Minne apolis. Minn. SYLVAN, Stig G. (M 1930), 215 Central Ave., Louisville, Ky. SYSKA, Adolph G. {M 1933), Consulting Engr., Syska & Hennessy, 420 Lexington Ave., New York. N. Y. SZEKELY, Ernest (M 1920), Vice-Pres. and Gen. Mgr. (for mail), Bayley Blower Co., 1817 South 66th St., and 3104 W. Kilbourn Ave., Mil waukee, Wis. SZOMBATHY, Louis R. (A 1930), Ferguson Sheet Metal Works, Inc., 34 N. Florissant Blvd., Ferguson. Mo. T TAGGART, Ralph C.* (M 1912), 14 Lyon Ave., Menands, Albany, N. Y. TALIAFERRO, Robert R.* {M 1919). Air Cond. Engr., 12 South 12th St., Philadelphia, and (for mail), 838 Beechwood Rd., Upper Darby, Pa. TALLMADGE, Webster fM 1924), Pres, (for . mail), Webster Tallmadge & Co., Inc., 255 North I8th St., East Orange, and 7 Claremont PI., Montclair, N. J. * TARR, Harold M. (Af 1931), Htg. Engr., 21 . Montague St,,.Arlington Heights, Mass. TAVANLAR, EUglo J* (7 1931), Graduate Student, Mech. - Engr., Yale University, 400 ' Temple St., New Haven, Conn. - TAVERNA, Frederick F. (M 1928; A 1927; 7 1924), Engr., Raisler Htg. Co., 129 Amsterdam Ave., New York, N. Y., and (for mail), 406-12th St., Union City, N. J. TAYLOR, John H. (A 1928), 9344-215 PI., Queens Village, L. I., N. Y. TAYLOR, Kenneth A. (7 1930). 1375 Fremont PI.. Elizabeth, N. J. TAZE, Donovan L. (M 1931), Br. Mgr. (for mail), American Blower Corp., 401 Broadway, New York, N. Y. TEASDALE, Lawrence A. {M 1926), Partner (for mail). Office of Hollis French, 20 Ashmun St., and 199 Nicoll St., New Haven, Conn. TEELING, George A. (M 1930), Consulting Engr.. Htg. and Vtg., 12 Pine St.. Albany. N. Y. TEMPLE, Walter J. {M 1931), Engr., J. A. Temple & Co., 919 E. Michigan Ave., and (for mail), 1215 Reed St., Kalamazoo, Mich. TEMPLIN, Charles L. {M 1921). Dist. Mgr. (for mail). Carrier Corp., Bona Alien Bldg., and 781 Sherwood Rd. N.E., Atlanta, Ga. ten BROOK, Charles S. (7 1930), 1009 W. Fourth St., Duluth, Minn. TENKONOHY, Rudolph J, (M 1923), Vice-Pres. (for mail), Airthena Mfg. Co., 1474 S. Vande- venter, St. Louis, Mo., and Route 1, Dearborn, Mich. TENNANT, Raymond J. J. (A 1929), Supervisor of Sales (for mail), Duquesne Light. Co., 435 Sixth Ave., and 529 Navato PI., Pittsburgh, Pa. TENNEY, Dwight (M 1932), Pres, and Chief Engr. (for mail), Tenney Engrg., Inc., 49 Dicker son St., Newark, and 33 Summit Rd., Verona. N. JTETEREVNIKOFF, Nikolas N. (M 1930). Consulting Engr., 3 Fifth Soviet St., Leningrad, U. S. S. R. THEORELL, HugoG. T.* {Life Member; M 1902), Consulting Engr., Hugo Theorells Ingeriieussbyra, 4, Skoldungagatan, Stockholm, Sweden. THINN, Christian A.* {M 1921), C. A. Dunham Co., 450 E. Ohio St., Chicago, 111. . THOMAS, Melvern F. {M 1909), Consulting Engr. (for mail), Thomas & Wardell, 229 College St., and 24 Rivercrest Rd., Toronto, Ont., Canada. THOMAS, Norman A. (M 1928), Pres, (for mail), Thomas Htg. Co., 11th and Herrick Ave., and 824 Monroe Ave., Racine, Wis. THOMAS, Richard H. {M 1920), Economy Pumping Machinery Co., 3431 West 48th PL, Chicago, 111. THOMMEN, Adolph A. (A 1929),'3400 West 61st PI., Chicago, 111. THOMPSON, Charles (A 1927), 720-13th St., Sacramento, Calif. THOMPSON, Donald (7. 1932). 1434 West 77th St., Cleveland, Ohio. THOMPSON, Nelson S * {M 1917; 7 1897), 1615 Hobart St. N.W., Washington, D. C. THOMPSON, Richard C. {M 1927), 250 Stuart St., Boston, Mass.. - THOMPSON, William J. (A 1929), Imperial Iron Corp., Ltd., St. Catharines, Ont., Canada. THOMSON, Thomas N.* {M 1899), Consulting Engr., 37 Irwin PI., Huntington, L. I., N. Y. ; 36 Roll of Membership THORNBURG, Harold A. (M 1932; A 1932; 7 1929), Field Engr. (for mail). Carrier Engrg: Corp., 850 Frelinghuysen Ave., Newark, and 810 N. Broad St., Elizabeth, N. j. THORNTON, Frank, Jr. (A 1930), Engrg. Mgr., TRUMBO, Silas M. (A 1926), Sales (for mail), Buffalo Forge Co., 15 N. Jefferson St., Chicago, and 921 Franklin St., Downers Grove, III. TUCKER, Frank N. {M. 1926). Field Engr., Ilg Electric Vent. Co., Room 1108, 13 Park Row, Association Activities, Westinghouse Elec. & New York, and (for mail), 239 Whaley St., Mfg. Co., East Pittsburgh, Pa. THORNTON, Roger T. {M 1919), Buffalo Forge . Co., 490 Broadway, Buffalo, N. Y. THORNTON, William B.* {M 1931), Sales Engr. (for mail). Carrier Engrg. Corp., Bona Allen Bldg., Atlanta, and 155 Coventry Rd., Decatur, Ga. ' THRUSH, Homer A. {M 1918), H. A. Thrush & Co.. 21-23 E. River St., Peru. Ind. TIBBITS, John C. (M 1920), Engrg. Dept., B. & O. R. R. Co., and (for mail), P. O. Box 106, Eliicott City, Md. TICHENOR, Leslie R.. Jr. (7 1930), L. R. Freeport. L. I., N. Y. TUCKERMAN, George E. {M 1932), 6202 Ogontz Ave., Philadelphia, Pa. TULLOSS, Joseph C. {M 1930), 814 Connecticut Ave., N.W., Washington, D. C. TURLAND, Charles H. (A 1930), Mgr., Htg. and Vtg. Dept., Kipp-Kelly, Ltd., 68 Higgins Ave., and (for mail), 325 Centennial St., Winnipeg, Man.. Canada. TURNAU, Edmund H. (S 1933), Cadet Engr.. Koppers Seaboard By-Product Coke Co., and (for mail), 23 Polifly Rd., Hackensack, N. J. TURNER, John {M 1930), 115 Myrtle St., Boston. Tichenor & Son., 1259 Robert St., Hillside. N. J. TILDEN, Elwyn E. (M 1924). Asst. Mgr. (for Mass. ` TURNER, John W. {M 1928), 26031 Concord Rd.. - mail), Warren Webster & Co., 76 Summer St., Boston, and Holbrook, Mass. TILLER, Louln (S1933), 1135 Northwest 41st St.. Royal Oak, Mich. TURNO, Walter G. W. {M 1917; A 1912), Secy., H. W. Porter & Co., Newark, and (for mail), . Oklahoma City, Okla. ,,v TILTZ, Bernard E. (M 1930), Pres, (for mail), 71 Lafayette Ave.. East Orange, N. J. ` TUSCH, Walter {M 1917), H. & V. Engr., Tenney Tiltz Air Conditioning Corp., 480 Lexington Ave., New York, and 24 Bamum Rd., Larch- ^ftiont, N. Y. TIMMIS, Pierce {M 1920), Service Equip. Engr. & Ohmes, Inc., 101 Park Ave., New York, and (for mail). 881 Sterling PI., Brooklyn, N. Y. TUTTLE, J. Frank {M 1913), Mgr., Warren Webster Co., 76 Summer St., Boston, and 2 (for mail). United Engineers & Constructors, Inc., 1401 Arch St., Philadelphia, and 202 Midland Ave., Wayne, Pa. TIMMIS, W. Walter (M 1923; A 1925), Engr. (for mail), American Radiator Co., 40 West 40th St., New York, and Oak Lane, Glen Cove, N. Y. TISNOWER, William {M 1923), 131 Livingston St., Brooklyn, N. Y. TITUS, Marvin S. {M 1928), 478 Lamson Ave., Bedford, Ohio. TJERSLAND. Alf {M 1916; 7 1906), E. Sunde & Co.. Ltd., Oslo, Norway. TOBIN, George J. {M 1905), Owner, Sanitary, Htg. and Vtg. Engr., 187 North Ave., Plainfield, N. J. . TOOKER. Charles C. (M 1918). Owner (for mail), Tooker Plbg. & Htg., 116 North 27th St., and Elmwood Ave., Winchester, Mass. TUVE, George L. (M 1932), Asso. Prof, of Mech. Engrg. (for mail). Case School of' Applied Science, and 1294 Cleveland Heights Blvd., Cleveland, Ohio. " TWIST, Charles F. (M 1921). Secy, (for mail), Ashwell-Twist Co., 67 Thomas St., and 2310 Tenth Ave. N., Seattle, Wash. TYLER, Roy D. (M 1928), East Sales Mgr. (for mail), Modine Mfg. Co., 101 Park Ave., New York, and 15 Highbrook Ave., Pelham, N. Y. TYSON, William H. {M 1928), -Mgr. of Engrg. (for mail), Goodyear Tyre & Rubber Co., Ltd., and "Kipewa" Codsall Rd. N.R., Wolver hampton, England. u 208 Terry Ave., Billings, Mont. ` UHL, Edwin J. {M 1925), Partner, Uhl Co:, 132 TOONDER, Clarence L. {M 1933), Air Cond. S. Tenth St., Minneapolis. Minn. Eng., Sales Engrg. Dept., Kelvinator Corp., Plymouth Road,and (for mail), 12761 Strathmoor Ave., Detroit, Mich. UHL, Willard F. {M 1918). Partner (for mail), Uhl Co., 132 S. Tenth St., and 4716 Lyndale Ave. S., Minneapolis. Minn. TORR, Thomas W. {M 1933), Rudy Furnace Co., Dowagiac, Mich. ' TORRANCE, Henry {M 1933), Pres.. 175 Christo pher St., and (for mail), 112 East 17th St., New -UHLHORN, W. J. {M 1920), 733 S. Highland Ave., Oak Park, 111. ' ULLMAN, Herbert G. (A 1928). Secy, of Lab., American Radiator Co., 675 Bronx River Rd.. York, N. Y. Yonkers, and (for mail), 107 White Rd., Scars- TOUTON, R. D. (M 1933), Tech. Dir. (for mail), * Bayuk Cigars. Inc., Ninth and Columbia Ave.. H Philadelphia, and 19 Lodges Lane, Cynwyd, Pa. dale. N. Y. URDAHL, Thomas H. {M 1930), Consulting . Engr. (for mail), 726 Jackson PI. N.W.. and TOWER, Elwood S. {M 1930), Consulting Engr., 1505-44th St. N.W., Washington, D. C. . 1411 Wightman St., Pittsburgh', Pa. TRANE, ReOben N.* {M 1915), The Trane Co.. V and (for mail), 126 South 15th St., LaCrosse, Wis. TRAUGOTT, Mortimer (A 1930), East Sales . VALE, Henry A. L. (M 1929), Managing Dir. (for Mgr. (for mail), Bryant Heater & Mfg. Co., 152 North 15th St., Philadelphia, and 721 Meeting mail), Vale Co.. Ltd., 141-43 Armagh St., Christ Church, and 241 llara Rd., Fendalton. Christ House Rd., Elkins Park, Pa. Church, New Zealand. TREADWAY, Quentin (7 1932), Sales Engr. (for VAN ALEN, Walter T. {M 1924), 1300 Darlington mail), Clarage Fan Co., 707 Security Bank Bldg., Rd., R. D. 1, Beaver Falls, Pa. ` and 2618 Collingwood, Toledo, Ohio. VAN ALSBURG, Jerold H. {M 1931). Mgr., TRIMMER, Charles M. {S 1933), Meter Testor, Specialty Sales, Hart & Cooley Mfg. Co., and (for Meter Dept., Rockland L. & P; Co., Middletown, mail), R- F. D. No. 3, Holland, Mich. and (for mail), 28 Prospect St., Port Jervis, N. Y. VANCE, Louis G. {M 1919), Partner (for mail), TROSKE, Joseph J. (A 1931). Vice-Pres. and Gen. Mgr. (for mail), Vander-Troske Co., 236 Vance-McCrea- Sales Co., West 27th and Sisson Sts., and 3800 Egerton Rd., Baltimore, Md. . Winter Ave. N.W.. and 233 Brown St. S.E., VAN COURT, Walter Gearing (M 1930), Htg. Grand Rapids, Mich. Engr-, 557 Communipaw Ave., Jersey City, N.J. TRUITT, Joseph E. {M 1920; A 1911), Pres., VANDERHOOF, Austin L. (A 1933), Northern Autovent Fan & Blower Co., 1805 N. Kostner Ohio Mgr., Kewanee Boiler Corp., and (for mail), . Ave., Chicago, 111. Warren Webster & Co., 2341 Caniegie Ave.. TRULSON, Arthur F. {M 1930), Mech. Engr., Cleveland, and 3120 Yorkshire Rd., Cleveland 1509 W. Sixth St.. Ashland. Wis. Heights, Ohio. 37 American Society of Heating and Ventilating Engineers Guide, 1934 VAN HORN, Howard T. (A 1933). Dist. Mgr., WALLACE, William M., II (Af 1929), 8908-l96th Detroit Stoker Co., 1217 McKnight Bldg., and ' St.. Hollis, L. 1., N. Y. (for mail), 4537 Grand Ave., Minneapolis, Minn. WALLICH, A. C. (Af 1919), (for mail), Wallich VAN SICKLE, William B. (Af 1915). Mgr. (for mail), W. B. Van Sickle Co., 1623 St. Clair Ave. Ice Machine Co., 517 E. Lamed St., and 1667 Burlingame, Detroit, Mich. .. N.E., Cleveland, and 1530 Grace Ave., Lake wood, Ohio. . VERMERE, Earl J. (Af 1929), Sales Engr., WALTERS, Arthur L. (Af 1926; A 1925; 7 1924), 7284 Richmond Pi., MaRlewood, Mo. , WALTERS, William T. (Af 1917), Engr., Illinois Warren Webster & Co , 2341 Carnegie Ave., and. EngTg. Co., Cor. 21st St. and Racine Ave., and (for mail), 2125 Wyandotte Ave., Cleveland, Ohio. .. . (for mail), 7965 Phillips Ave., Chicago, 111. WALTHER, Vernon H. (Af 1928; 7 1925), Mech. VERNIER, Marcel G. (5 1933), 730 Hill Ave., Engr., 6821 Osceola Ave., Chicago, 111. Wilkinsburg, Pa. WALTERTHUM, John J. (A 1922), Htg. Con VERNON, J. Rerford (Af 1928; A 1926), (for tractor, 173 East 62nd St., New York, N. Y., and mail), Johnson Service Co., 1355 Washington . (for mail). 42-A Van Reipen Ave., Jersey City, . Blvd., Chicago, and 1020 Austin St., Evanston, N. J. III. WALTON, Hiram L.* (Af 1916), Member of Firm VETLESEN, G. Unger (Af 1930), 3 East 84th St., New York, N. Y. (for mail), Smith-Hinchman & Grylls, 800 Marquette Bldg., Detroit, and Lake Angelus, VINCENT, Paul J. (Af 1931), Paul J. Vincent Co.. Pontiac, Mich. 1010 Chandler Bldg., Washington, D. C., and WANDLESS, Franklin W. (Af 1925), Haynes (for mail), 3807 Beech Ave., Baltimore, Md. VINSON, Neal L. (5 1932), (for mail), 630 Clyde Selling Co., Inc., 1518 Fairmount Ave., Phila delphia, and Berwyn, Pa. St., Pittsburgh, Pa., and Box 1438, Bisbee, Ariz. WARD, Oscar G. (Af 1919). Dist. Mgr. (for mail), VIVARTTAS, E. Arnold (Af 1910), Consulting . Johnson Service Co., 1230 California St., and Engr., 121 Parkaide Ave., Brooklyn, N. Y. 1607 Jasmine St., Denver, Colo. VOGEL, Andrew (Af 1926), Engri (for mail), General Electric Co., and 1821 Lenox Rd., WARD, William T. (Af 1930), 18 Castlefield Ave., Toronto, Ont., Canada. Schenectady, N, Y. WARING, J. M. S. (Af 1932), Consulting Engr. VOGELBACH, Oscar (Af 1923). 23 William St., North Arlington, N. J. . VOGT, John H. (A 1925), Mech. Engr. (for mail). New York State Dept of Labor, 80 Centre St., New York, and 87 Grant Ave., Brooklyn, N. Y. VOGT, Joseph B. (Af 1933; A 1933; 7 1929), Asst. Htg. and Vtg. Engr.. New York State D. P. W.. Albany, and (for mail), 1403 Park Blvd., Troy, N. Y. VOISINET, Walter E, (Af 1930), Sales Repr. (for mail), Herman Nelson Corp., 250 Delaware Ave., Buffalo, and 151 Warren Ave., Kenmore, N. Y. VOLK, Joseph H. (Af 1923), Pres, and Treas.'(for mail), Thos. E. Hoye Htg. Co., 1906 W. St. Paul Ave., and 2965 South 43rd St., Milwaukee, Wis. VOORHEES, G. A. (Af 1922), Engr. (for mail), Lakeside Co., Hermansville, Mich. (for mail), Chase & Waring, 17 East 42nd St., and 277 Park Ave., New York, N. Y. . WARREN, Clarence N. (Af 1919), 419 East 48th St., Indianapolis, Ind. - WARREN, Harry L. (Af 1930), 1303 Huntington Dr., South Pasadena, Calif. WARREN, Walter J. (Af 1930), Engr. (for mail). 180 N. Michigan Ave., Chicago, and 118 Gillick St., Park Ridge, 111. WASHINGTON, Laurence W. (Af 1929). 2301 Knox Ave., Chicago, 111. , WATERMAN, John H. (Af 1931), 201 Devon shire St., Boston, Mass. ' WATERS, George G. (Af 1931; A 1926). American Blower Co., 801 First Natl. Bk. Bldg., Pittsburgh, Pa. WATSON, M. Barry (Af 1928), Consulting Engr.. VROOME, Albert E. (Af 1932), Engr., P. H. & V. Engrg. Co., 327 McClatchy Bldg., Upper Darby, 121 Welland Ave., Toronto 5, Canada., ' WAUNG, Tsing F. (7 1933), Htg. Engr., Andersen and (for mail), 412 Morton Ave.,. Rutledge, Pa. Meyer & Co., and (for mail), .103 Route Remi, Shanghai, China. . w WACHS, Louis J. (7 1930), Engr., Carrier Engrg. WEAGER, T. A. (Af 1920). Dist- Mgr. (for mail), Buffalo Forge Co., 418 Rockefeller Bldg., and 3124 Berkshire Rd., Cleveland, Ohio. ' Corp., Chrysler Bldg., New York, and (for mail), 354 East 21st St., Brooklyn, N. Y. . WAECHTER, Herman P. (A 1930; 7 1927), Air Cond. Engr.. York Ice Machinery Corp., Brook WEBB, John S. (Af 1920), Sales Mgr., Webster Tallmadge Co., Inc., 300 Madison Ave., New York, N. Y., and (for mail), 16 Brookline St., Needham, Mass. . lyn. and (for mail). 89 Sherman Ave., Tompkinsville, N. Y. WAGNER, A. M. (A 1921), Mgr. (for mail), American Radiator Co., 1741 W. St. Paul Ave., and 1857 N. Prospect Ave., Milwaukee, Wis. WAITE, Harry (A 1929). 1409 North 17th St.. Superior, Wis. WEBB, John W. (Af 1926), 6 Meadows Rd., Heaton Chapel, Stockport, England. WEBSTER, E. Kessler (Af 1915), Warren Webster & Co., 17th and Federal Sts., Camden, N. J- WEBSTER, Warren (Life Member 1933; Af 1906; A 1899), Pres., Warren Webster & Co., 17th and Federal Sts., Camden, N. J. WALDON, Charles D. (A 1932), 32 Fernd&le . Ave., Toronto, Ont., Canada. WALKER, Alexander (A 1925), C. A. Dunham WEBSTER. Warren, Jr. (Af 1932; A 1932; J 1927), Vice-Pres. and Treas. (for mail), Warren Webster & Co., 17th and Federal Sts., Camden, Co.. Ltd., 1307 Fifth St. W., Calgary, Alta., Canada. and Washington and Colonial Ridge Dr., Haddonfield, N. J. WALKER, James H.* (Af 1916), Supt. of Central Htg. (for mail), The Detroit Edison Co., 2000 WECHSBERG, Otto (Af 1932), Pres, and Gen. Mgr., Coppus Engrg. Corp.. 344 Park Ave., and Second Ave., Detroit, and 432 Arlington Rd., Birmingham, Mich. WALLACE, Bruce (Af 1930), Proprietor (for mail), (for mail), 12 Rosemont Rd., Worcester, Mass. WEGMANN, Albert (Af 1918), 6206 North 17th St., Philadelphia, Pa. . B. Wallace, 5 Eden St., Newmarket, Auckland S.E. 1, and 113 Western Springs Rd-, Morningside. Auckland S.W., 1, New Zealand. WEHRLE, Robert H. (7 1933), Sales Engr. (for mail), 323 E. Fourth St., and 2368. Victory Pkwy., Cincinnati, Ohio. WALLACE, George J. (Af 1923), Principal. 331 East 54th St., New York', and (for mail), 27-36 Ericsson St. E.t Elmhurst, N. Y. WALLACE, Kenneth S. (Af 1931), Gas Htg. Engr., Peoples Gas Co., and (for mail), 5737. Kenmore Ave., Chicago, 111. WEIL, Martin (A 1925), Vice-Pres. (for mail). ,WeiI-McLain Co., 641 W. Lake St., and 4259 . .. Hazel Ave., Chicago, 111. WEIL, Maurice I. (A 1928). Pres, (for mail). Chicago Pump Co., 2336 Wolfram St., and 1409 Elmdale Ave., Chicago, III. 38 Roll of Membership WEIMER, Fred G. (A 1919), Local Mgr., Kewanee Boiler Corp., and (for mail), 3958 N. Stowell WIGGINS, Oswald James (S 1933), Walnut. . Grove, Minn. . Ave., Milwaukee, Wis.. . . WIGGS, G. Lome (A 1932; 7 1924), Mgr., WEINSHANK. Theodore* {Life Member 1933; M 1906), (Bd. of Governors. 1913), 2323 N. Ksdzie Blvd., Chicago, 111. ' Montreal Sales Office (for mail), C. A. Dunham Co.. Ltd., 608 University Tower, and 4797 Grosvenor Ave., Montreal, Que.. Canada. WEISS, Arthur P. (Af 1928), 134 Farrington Ave., North Tarrytown, N. Y. , WEISS,, Carl A. (A 1924), Supt. (for mail). Kombrodt Komice Ko., 1811 Troost Ave., and 29 East 68th St., Kansas City, Mo. WIGLE, Bruce M. (A 1926), Pres, (for mail). Bruce Wigle Plbg. & Htg. Co., 9117 Hamilton Ave., and 18114 Oak Dr., Detroit, Mich. WILD, Walter H. (Af 1927; A 1921), Union Iron Works, Land Title Bldg., Philadelphia, Pa. WELAMB, Victor N. (Af 1918), V. N. Welamb Co., 105 N. Watts St., Philadelphia, Pa. * WELCH, Louis A., Jr. (A 1929), 443 Second St., Schenectady, N. Y. WELDY, LJoyd O. (Af 1930), Powers Regulator Co., 2720 Greenview Ave., Chicago, III. WELLS, Eric E. (Af 1930), 1453-155th St., Beech WILDER, Edward L. (Af 1915), Mgr., Gas Sales (for mail). Utility Management Corp., 120 Wall St., New York, and 149 Mt. Joy PL, New Rochelle. N. Y. ... WILEY, Edgar C. (Af 1909), Wiley & Wilson, Lynchburg, Va. * . WILKINSON, Farley J. (Af 1933), Engr., Mont gomery Ward Sc Co., Chicago, and (for mail), . hurst, L. I., N. Y. 18257 Martin Ave., Homewood, 111. ^ WELSH, Harry S. (Af 1906), Sales Engr. (for mail), Weil-McLain Co., 404 Atlantic Ave., and 53 Kemphurst Rd., Rochester, N. Y. WILLARD, Arthur C * (Af 1914), (Presidential Member), (Pres., 1928; 1st Vice-Pres., 1927; 2nd Vice-Pres., 1926; Council, 1925-1929), Prof. Htg.. -WELTER, M. A. (A 1925), Htg. Engr. (for mail). ' and Vtg. and Head o! Dept, of Mech. EngTg. (for Welter Furnace Co., 2118 Lyndale Ave. S., and mail). University of Illinois, and 1208 W. 4306 S. Garfield, Minneapolis, Minn. California St., Urbana, 111. WENDT, Edgar F. (Af 1918), Pres, (for mail), . Buffalo Forge Co., 490 Broadway, and 731 Lafayette Ave., Buffalo, N. Y. WEST, Perry* (Af 1911), (Council. 1920-1925; Treas., 1924-1925), Consulting Engr. (for mail),- 13 Central Ave., and 445 Ridge St., Newark, N.J. WHALEY, Ralph S, (Af 1931), 1933 Fifth Ave., Seattle, Wash. WHEELER, Charles A. (A 1931), Sales Engr. (for mail), Herman Nelson Corp., 400 Ninth Vincent Bldg., Cleveland, and 2121 McKinley Ave., Lakewood, Ohio. . WHEELER, Otto J. (Af 1923), Pres-Treas. (for mail) The Samuel A. Esswein Htg. & Plbg. Co., 548^558 W. Broad St., and 2044 Collingswood jRft. Columbus, Ohio. WHELLER, Harry S. (Af 1916), Vice-Pres., L. J. - Wing Mfg. Co., 154 West 14th St., "New York, N. Y., and (for mail), 725 Union Ave., Elizabeth, N.J. . WHITE, Everett A. (Af 1921). Engrg. - Dept., Crane Co., 30 South 16th St., and (for mail), 5244 Nottingham, St. Louis, Mo. . WHITE, Elwood S. (Af 1921), Pres, (for mail), Taco Heaters, Inc., Room 1224, 342 Madison ' Ave., New York, N. Y.f and Meadowbank Rd., Old Greenwich, Conn. WHITE, James J. (A 1930), 6035 Nassau St., Philadelphia, Pa. WHITE, John C. (Af 1932), State Power Plant Engr. (for mail), 624 E. Main St., and 622 E. Main St., Madison, Wis. WHITELAW, H. Leigh (Af 1916), Vice-Pres. (for mail), American Gas Products Corp., 40 West 40th St., New York, N. Y., and Overbrook Lane, Darien, Conn. WHITELEY, Stockett M. (Af 1933), Consulting Engr. (for mail), Baltimore Life Bldg., and 3931 Canterbury Rd., Baltimore, Md. 1 WHITTALL, Ernest T. (A 1933), Vice-Pres. and Managing Dir. (for mail). May Oil Burner of Canada. Ltd., 196'Adelaide St. W., and 11 Cottingham Rd., Toronto, Ont., Canada. WHY, H. Berkeley (Af 1919), 640 W. Sedgwick St.. Philadelphia, Pa. WIDD1COMBE, Robert A, (Af 1903), U20 Lake Shore Dr., Chicago, III. WIEGNER, Henry B. (Af 1919). Mgr., Boston Office, Johnson Servie Co., 20 Winchester St., , Boston, and (for mail), 143 Standish Rd., . Watertown, Mass. : WIERENGA, Peter O. (A 1931), Vice-Pres. (for mail), C. C. James Co., 49 Coldbrook St. N.E., ' and 231 Brown St. S.E., Grand Rapids, Mich. WILLIAMS, Allen W. (A 1915), Managing Dir. . (for mail). Natl. Warm Air Htg. & .Air Cond. ' Assn., 50 W. Broad St., Columbus, and 51 ' Meadow Park Ave., Bexley, Ohio. WILLIAMS, J. McFarland, Jr. (A 1928; 7 1927), Sales Engr., 1407-35th St. N.W., Washington, ' D. C. WILLIAMS, J. Walter (Af 1915), Pres, (for mail). Forest City Plbg. Co., 332-36 E. State St., and 923 E. State St., Ithaca, Ni Y. WILLIAMS, Leo E. (A 1933; 7 1930), 225 Arch St., Meadville, Pa. WILLIS, Roy C. (Af 1927), Mgr. New York Office (for mail). Vapor Engrg. Co., 597 Fifth Ave., New York, and 253 Lindell Blvd., Long Beach, N. Y. W1LMOT, Charles S. (Af 1919). 406 Essex Ave., Narberth, Pa. WILSON, Benjamin W, (Af 1922), The Ballinger Co., S.E. Cor. 12th and Chestnut Sts., Phila delphia, Pa. : WILSON, George T. (Af 1925), Tyre Ave,, Islington, Ont., Canada. WILSON, Harold A., Jr. (7 1933). Student sales man, American Radiator Co., 40 West 40th St., and (for mail), 1133 Park Ave., New York, N. Y, WILSON, Harry A. (Charter Member; Lift Member), P. O. Box 155, \Vashington, R. I. WILSON, W. H. (A 1932), Stearafitter Foreman, Pullman Car & Mfg. Corp., 11001 Cottage Grove Ave., and (for mail), 22 West 110th PL, Chicago, 111. ' . WILSON, William H. (A 1923), Br. Mgr. (for mail), Johnson Service Co., 507 E. Michigan St., and 2023 E. Olive St., Milwaukee, Wis. ' WINANS, Glen D. (Af 1929). Engr. of Steam Distribution (for mail). The Detroit Edison Co., 2000 Second Ave., and 16183 Wisconsin, Detroit, Mich. . WINCH, Franklin R. (Af 1925), Consulting Engr., Signal Oil Bldg., and (for mail), 1058 Bedford St., Los Angeles, Calif. WINQUIST, Walter J. (A 1930), Htg. and Vtg; Engr., 294 Nostrand Ave., Brooklyn, N. Y. WINSLOW, C.-E. A* (Af 1932), Prof, of Public Health (for mail), Yale University, 310..Cedar St., and 314 Prospect St., New Haven Conn. WINTERBOTTOM, Ralph F. (Af 1923). Htg. Engr., Winterbottom Supply Co., Commercial Miles, and (for mail), 1002 Riehl St., Waterloo,. . Iowa. WINTERER, Frank C. (Af 1920), Sales Mgr. (for mail), Cochran Sargent Co., Broadway and Kellogg Blvd.. and 836 Juno St., St. Paul, Minn. 39 American Society of Heating a?td Ventilating Engineers Guide, 1934 WINTHER, Anker (J 1932), Air Cond. Engr.. York Ice Machinery Corp., 2116 Gilbert Ave., Cincinnati, Ohio. WOLF, John C. (Af 1923), (for mail), B. F. Sturtevant Co., and 265 Fairmount Ave., Hyde Park, Mass. ' WOLFF, Oscar H. (Af 1926), 6232 Oakland Ave., St. Louis, Mo. WOLFF, Richard A. (Af 1919; J 1915), Insurance ' also Secy, (for mail), Wolff & Munier, Inc., 500 Fifth Ave., New York, and 888 Woodmere PL, Woodmere, iL. I., N. Y. WOOD, Frederick C. (J 1931), Sales Air Cond Engr. (for mail), Westerlin & Campbell Co., 1113 .Cornelia Ave., and 1905 Estes-Ave., Chicago, 111 WOOD, J. Sydney (Af 1926), Estimator (for mail), . Bennett & Wright, Ltd., 72 Queen St. E., and 50 Davisville Ave., Toronto, Ont., Canada. WOODLING, MlneT D. (Af 1926). Owner, 1002 Greenway Ter., Kansas City, Mo. ` WOOLSTON, A. H. (Af 1919), 2015 Sansom St., Philadelphia, Pa. . WORSHAM, Herman (if 1925; J 1918), 103 N. Walnut St., E. Orange, N. J. WRIGHT, Clarence E. (5 1933), (for mail), 276 N. Bellefield Ave., Pittsburgh, Pa., and* 854 Maiden Lane, Roanoke, Va. ` WRIGHT, Kenneth A. (Af 1921), Mgr. (for mail), Johnson Service Co., 1113 Race St., Cincinnati, Ohio, and 113 Orchard Rd., Ft. Mitchell, Ky. WRIGHT, M. Birney (A 1932* J 1929), Instructor (for mail). Case School of Applied Science, Cleveland, and 1056 Nela View Rd., Cleveland Heights, Ohio; ` . WUNDERLICH, Milton S * (Af 1925), Insulite Co., Minneapolis, Minn., and (for mail), 1598 Laurel Ave., St. Paul, Minn. ,, WYLIE, Howard M. (Af 1925; J 1917), Vice-Pres. in charge of Sales (for mail), Nash Engrg. Co., and 51 Elmwood Ave., S. Norwalk, Conn. WYMAN, Dwight M. (Af 1931), R. F. D. 421, Barrington, R. I. WYMORE, Fred C. (S 1933), 100 Westport Rd.f Kansas City, Mo. , . Y - .... YAGER, John J. (Af 1921), 425 Woodbridge Ave., Buffalo, N. Y. ' YAGLOU, Constantin P.* (Af 1923), Asst. Prof, of Industrial Hygiene (for mail). Harvard School of Public Health, 55 Van Dyke St., Boston, and 24 Wade St., Brighton, Mass. YARDLEY, Ralph W. (Af 1920), Asst. Archt., Bd. of Education, City of Chicago, 228 N. LaSalle St., Room 568, and (for mail), c/o Judge J. W. Galbraith, Farmers Bk. Bldg., Suite 601, Mans* field, Ohio. : YATES, Walter (Af 1902), Governing Dir., Matthews & Yates, Ltd;. Swinton, Lancs, England. YEAGER, George F. (Af 1933), Inspector Test Dept., Pennsylvania Railroad, Test Dept., P. R. R,, Altoona, and (for mail), 516 Crawford Ave., Altoona, Pa. YEOMANS, Paul H. (Af 1930). 1177 Spring Grove Ave., Lancaster, Pa. YOCKEL, Thomas J. (A 1929), 1074 Franklin Ave., New York, N. Y. ` . z ZACK, Hans J. (Af 1928), Mgr., Zack Co., 2311 W. Van Buren St., Chicago, 111. .. ZECK, Alexander (Life Member; Af 1904), Pres, (for mail), Alex Zeck & Son Co., 902 University Ave., and 324 Willy St., Morgantown, W. Va. ZIBOLD, Carl Edward (Af 1929), Mech. Engr., Htg. and Vtg. Co., Colonial Ter., Westminster Ridge, White Plains, N. Y. ZIESSE, Karl L. (A 1931). Secy-Treas. (for mail), Phoenix Sprinkler & Htg. Co., 115 Catnpau Ave. N.W., and 315 Hampton Ave. S.E., Grand Rapids, Mich. . . ZIMMERMAN. Alexander H. (A 1930), Venti lation Engr., Chicago Bd. of Health, 707 City Hall, and (for mail), 3748 Irving Park Blvd., Chicago, 111. ZINK, David D. (Af 1931), Sales Mgr., E. K. Campbell Cos., 2441 Charlotte St., Kansas City, Mo., and (for mail), C. O., 980th Co., CCC., Drain, Ore. ZOKELT, C. G. (Af 1921), Consulting Engr., 3810-24th Ave. S., Seattle. Wash. ZUHLKE, William R. (Af 1928). 530 McLean Ave., Yonkers, N. Y. 40 Summary of Membership (Corrected to January 1, 1934) UNITED STATES Alabama................... ....:...................... Arizona............................ :................... Arkansas............... ........................... California...... ............................... .'..... Colorado................... ........................... Connecticut-.......... .......................... Delaware.-................ ........................... 1 l 2 51 4 32 5 '7 Pi 201 Indiana...... :............. .................:......... Iowa........................... ............................ Kansas--.................... ...... ;........... :....... Kentucky................. ........................... 24 5 5 11 3 3 Maryland................. ....................... 14 Massachusetts____ ............... ............ Ill Michigan.................. ........................... 112 Minnesota............................ ............... 87 Missouri................................ .............. 79 Montana.-..... ..............................:....... 4 Nebraska.--!.................................:....... 5 New Hampshire................. ............... 1 New Jersey..................;....... ................ 109 New York............................. ............... 378 North Carolina................... ............... 7 Ohio..............................................-...... 95 Oklahoma............................ ....... :....... 6 Oregon--................................ ............... 1 Pennsylvania................. !.... ............ . 240 Rhode Island..................................... : 8 Tennessee.... ........................ ............ . 5 Texas........................... ............... 20 Vermont............................... ............... 4 Virginia................................................ 12 Washington......................... .:............. 22 West Virginia................. _.................. 5 Wisconsin.... ........................ ............... 48 1746 FOREIGN COUNTRIES Austria................................... -.............. Australia....... ..................1...............-- Belgium........................................... --.. Cana'da.................................................. China...... .............................................. Czechoslovakia ..............--________ Denmark....................... :..................... England........................... France................................. -............ . Germa.ny.l_.......................................... India...................................................... Ireland.................................................. 1 2 1 80 10 1 1 14 8 3 2 1 Italy....................................................... 2 Japan.-................................................. ' 4 Mexico........................-.......................... 3 New Zealand....................................... 3 Norway.................................... 2 South America.................... .............. 1 Sweden.................................... 2 U. S. S. R....... ......................... 2 143 Total Membership........................ 1889 SUMMARY OF MEMBERSHIP BY GRADES Honorary Members......... ............. ................................ 2 Presidential Members........................................ 22 ( Members....!............... -................................................... 1244 Associate Members.......................................... 364 Junior Members--..................... 132 Student Members.......................................................... 125 1889 41 LIST OF MEMBERS Geographically Arranged UNITED STATES ALABAMA Birmingham-- Lichty, C. P. ARIZONA Tucson-- ' . Moreau, D. ARKANSAS Ozark-- Pesterfield, C. H. Siloam Springs-- Jones, C. R. CALIFORNIA Altadena-- Bremser, H. A.. Berkeley-- Duncan. G. W., Jr. Beverly Hills-- Nelson, H. A. . Huntington Park-- Barnum, W. E., Jr. Long Beach-- Rooks, A. W. Los Angeles-- Barker, C. M. . Binford. W. M. Bouey, A. J. Bullock, H. H. . Bunker, K. S. : Cranston, W. E., Jr. Ellingwood, E. L. Gillespie, J. D. Herman, J., Jr. Hill, F. M. . Hilliard. F. H. Holladay, W. L.' . Horton, G. H. Hungerford, L. Keeling, H. B. Kendall, E. H. Kennedy, M. Kooistra, J. La Montagne, J. M. Lawler, M. M. McClelland, H. S. Ness, W. H.*C. . Newman. C. T. Orear, A. G. , Oster, G. R. ... . Ott. O. W. Park, J. F. . Pierce, E. D. ' Polderman, L. H. Scofield, P. C. . Sharpe, N. . Simonds, A. H. Winch, F. R. Mesa Grande-- Hemingway, W. S. Oakland-- Cummings, G. J. Pasadena-- . Gifford, R. L. O'Haver, H. M. Sacramento-- . Thompson, C. San Diego-- Sadler, C, B. San Francisco-- Corrao, J. Haley, H. S. Krueger, J. I. Leland, W. E. Scott, W. P., Jr. South Pasadena-- Campbell, W. E. ' Warren, H. L. COLORADO Colorado Springs--' Higgins, D. T. Jardine, D. C. Denver-- . Daly, J. H. Ward. O. G. . CONNECTICUT Bridgeport-- Feydt, J; C. Colchester-- Adams, W. H. Fairfield-- Osborn, W. J. Greenwich-- Jones, A. L. Oppennan, E. F. Hartford-- Purcell, A. J. Manchester-- Buck, L. Millard, J. W. New Britain-- Hjerpe, C. A., Jr. New Haven-- ^ Greenburg, L. Hoyt, W. B. : Seeley. L. E. Tavaniar, E. J. Teasdale, L. A. Winslow, C. E. A. .New London-- ' Chapin, G. G. Foraberg, W. ' Hopson, W. T. Noroton Heights--' Ashley, E. E. . Norwalk-- Monroe, R. R. . Riverside-- . Murphy, J. R. , South Norwalk-- Adams, H. E. Harvey, A. D. Jennings. I. C. Lyons,*C. J. ; Mead, E. A. Wylie. H. M. ' Stamford-- . Hoyt* L. W. .Waterbary-- Ahlberg, H. B. Hutzel, H. F. Simpson, W. K. . Wilton-- Humphreys, J. DELAWARE Wilmington-- Gawthrop, F. H. Hayman, A. E., Jr. Kershaw, M. G. Lownsbery, B. F. Schoenijahn, R. P. DISTRICT OF COLUMBIA ; Washington-- Beitzell, A. E. ' Coward, H. Dalla Valle, J. M. Febrey, E. J. ' Feltwell, R. H. Fenn. C. V. O. Frankel, G. S. Gardner, S. F. ' Hood. O. P. Johnson, J. M. Nolan, J. J., Jr. Ourusoff. L. S. Powers, L. G. 42 Smallman. E. W. Thompson, N. S. Tulloss, J. C. Urdahl, T. H. Williams, J. M., Jr. FLORIDA Ft. Lauderdale-- Charlton, J. F". Palm Beach-- Hodeaux, W. L. GEORGIA Atlanta-- Clare, F. W. Kent. L. F. Klein, E. W. Templin, C. L. - Thornton, W. B. ILLINOIS Bloomington-- MaGirl, W. J. v Nesmith, O. E. Chicago-- , Aeberly, J. J. Arenberg, M. K. Bailey, J. H. . Balsam, C. P. . Baumgardner, C. M. Bennett, R. E. Black. F. C. Bolte, E. E. . Bracken, J. H.. Braun, L. T. Brayton, W. M. Broom, B. A. Brown, A. P. Carman, G. G. Cartier, C. E. Casey, B. L. Christman, W. F. Close, P. D. Crone, C. E., Jr. .Currier, C. H. . Cutler, J. A. . Davis, H. H. DeLand, C. W. Doherty, R. _ Dunham, C. A." Emmert, L. D. Ericsson, E. B. Finan, J. J. Foster, T. R. Frank, J. M. Gardner, W., Jr; Gaylord, F. H. Getschow, G. M. Getschow, R. M. . Gibbs, F. C. Goelz, A. H. Gossett, E. J. Graves, W. B. Roll of Membership Gray, R. F. ' Grebe, H. W. Haas, S. L. Hagerman, J. J. Haines, J. J. Hale. J. F. Hanley, T. F., Jr. Hart, H. M. . Hartman, F. E. Ttattis, R. E. Hayden, C. F. Hayes, j. J. Hayward, R. B. Heck, G. L.. Jr. Heckel, E. P. Herlihy, J. J. Hill, E. V. Hornung, J. C. Horton, H. F. . Howatt, J. Howell, L. Hubbard, G. W. Hustoel, A. M. ' Jennings, W. G. Jenson, J. S. Johns, H. B. v Johnson, C. W. Johnson, L. O. Keeney, F. P. Kehm, H. S. Kinney, W. H. Kirkpatrick, A. H. Kitch, S. B. Kreissl, H. G. Lagodzinski, H. J. Larson, J. M. Lautenschlager, F. Lees, H. K. Lenone, J. M- Lewis, S. R. Love, JL G. Maier, H. F. Malone, D. G. Malvin, R. C. Marschall, P. J. Martin, A. B. Matchett, J. G Mathis, E. Mathis, H. Mathis, J. W. Mathis,. V. J. Mauer, W. J. May, M. F. McCauley, J. H. McClellan, J. E. McDonnell, E. N. McFarland, W. P. Mcllvaine, J. H. Mertz, W. A. Miller, F. A. . Miller, J. E. Miller, R. T. Milliken, J. H. Moffitt, R. M. Mueller, H. C. Murphy, E. T. Narowetz, L. L., Jr. Needier, J. H. Neiler, S. G. i Newport, C. F. O'Brien, J. H. Offen, B. Olsen, C. F. Pence, M. D. . Petersen. A. J. Pitcher. L. J. Pope. S. A. Powers, F. W. Prentice, O. J. Price'*. C. E. Rasmussen, R.-P." Raymond, F. 1. Reid, H. P. Ries, L. S. . Rottmayer, S. I. ' Scheidecker, D. B. Schweim', H. J. . Seelig, L. Shufelt, H. M. Shultz, E. Smail, A. M. Small, J. D. Snider, L, A. Spielman, G. P. Stannard, J. M.' Stockenberg, R. Sutcliffe, A. G. Thinn, C. A. Thomas, R. H. Thommen, A. A. Truitt, J. E. ' Trumbo, S. M. Vernon, J. R. Wallace, K. S. Walters, W. T. Walther, V. H. Warren, W. J. Washington, L. W. Weil, M. Weil, M. I. Weinshank, T. Weldy, L. O. Widdicombe, R. A. Wilson, W. H. Wood, F. C. Yardley, R. W. Zack, H. J. ' Zimmerman, A. H. Cicero-- . Keppner, H. W. Decatur-- Shorb, W. A. . Evanston-- Hayes, J. J. Mittendorf, E. M. Moore, R. E. Highland Park-- Gifford, E. W. Joliet-- Beasom, G. R. Russell, W. B. Homewood-- Wilkinson, F. J. Kewanee-- Bronson, C. E. Dickson, R. B. Hartman, J. M. Pursell, H. E. LaGrange-- Linn, H. R. ' Maywood-- Pelletier, A. Moline-- Beling, E. H. . Nelson, H. W. Nelson, R. H. Nordheimer, L. F. Otis, G. E. Oak Park-- Barnes, R. B. Blanding, G. H. Nightingale, G. F. Steele, A. N. Uhlhora, W. J. Peoria-- . Farnsworth, J. G. Lindsey, W. J. Meyer,- F. L. Rockford-- Braatz, C. J. Merwin, G. E. Stewart, D. J. Urbana-- Broderick, E. L. Fahnestock, M. K. Konzo, S. Kratz, A. 'P. Sevems, W. H. Willard, A. C. Villa Park-- Armspach, O. W. Western Springs-- Brakenridge, C. E. Wilmette-- Norris, W. D. . Winnetka-- Ellis, E. E. Rietz, E. W. Zion-- . Koetz, L. INDIANA Evansville-- . Bulleit, C. R. Fort Wayne-- Nagelsen, L. M. ' Huntington-- Smith, G. W. Indianapolis-- ' Ammerman, C. R. Fenstermaker, S. E. Hagedon, C. H. . Hayes, J. G. Heidenreich, G. Kruse, R. W. Neal, H. W. ' Ott, R: C. . Poehner, R. E. . Rotz, J. M. Shipp, C. C. Warren, C. N. LaPorte-- - Mathis, G. A. Shrock, J. H. Michigan City-- Stockwell, W. R. Peru-- , Pyle, J. W. . Thrush, H. A. St. Mary-of-the- Woods-- Bisch. B. J. , -Terre Haute-- Mandel, H. J. 43 Wabash-- Shivers, P.'F. West Lafayette-- Hoffman, J. D. IOWA Ackley-- Nelson, G. O. Cedar Rapids-- Chandler, C. W. LeMars-- Mathey, N. J. Sioux City-- Hagan, W. V. Waterloo-- Winterbottom, R. F. KANSAS Emporia-- Bumap, C. W. Hutchinson-- Hertz, H. P. Mann, A. R. Stevens, H. L. Sallna-- Ryan, W. F. KENTUCKY Anchorage-- Lewis, J. C. , BlandvUle-- Belt. N. O. Lexington-- Anderson, F. P. O'Bannon, L. S. Porter, R. C. London-- Edwards, D. C., Jr. Louisville-- . Birkholz, H. E. Hellstrom, J. Murphy, H. C. Reed, W. M. Sylvan, S. G. LOUISIANA New Orleans-- Gammill, O. E., Jr. May, G. E. Rochelle-- Abel, D. M. \ MAINE Portland-- Fels, A. B. Merrill, C. J. Swanson, H. ' American Society of Heating and Ventilating Engineers Guide, 1934 ' MARYLAND Baltimore-- Axeman, J. E. Collier. W. I. Leilich, R. L. McCormack. D. McCrea. L. W. Morris, E. J. Posey, J. Seiter. J. E. Vance, L. G. Vincent, P. J. Whiteley, S. M. Eillcott City-- Tibbets, J. C. Rockville-- Brunett, A. L. Roland Park-- Dorsey, F. C. MASSACHUSETTS Arlington--- . Shaw, N. J. H. Arlington Heights-- Tarr, H. M. Belmont-- Schanze, A. G. Boston-- Bartlett, A. C. Berchtold, E. W. Boyden, D. S. . Boynton, D. W. ' ,, Brinton, J. W. Brissette,.L. A. Bryant, A. G. Bullock, T. A. Calvert, N. W. Cummings, C. H. Drinker, P. Dusossoit, E. A. Edwards, D. J. Foulds. P. A. L. . Franklin, R..S. Gleason, G. H. Goodrich, C. F. Hajek, W. J. Heath, F. R. Herrick, D: A. Hershey, L. A. Hilliard, C. E. Hoyt, C. W. Keefe. E. T. Kelley, J. J. Kellogg, A. Kimball, C. W. McCoy, T. F. Moulton, D. Mower, W. P. Osborne, M. M. Plunkett, J. H. Rydell, C. A. Shaw, E. . Stetson, L. R. Stone, E. R. Swaney, C. R. Thompson, R. C. Tilden, E. E. Turner, J. Tuttle, J. F. Waterman, J. H. Yaglou, C. P. Cambridge-- Baker, R. H. Buford, J. W. Flint, C. T.. Haddock, I. T. I^dUdU, u. Klonower, A. A. Lees. J. T. MacDonald, E. A. Riley, E. C. * Cochituate-- Aheam, W. J. Dorchester-- Brown, M. . Hosterman, C. O. Richard, I. T. Fitchburg-- Karlson, A. F. Harwich Port-- Maxwell, G. W. Holbrook-- Nason, G. L. Hyde Park--' Ellis, F. R.' Fritzberg, L. H. Keyes, R. E. . Miller, J. F. G. Wolf, J. C. Jamaica Plain-- Jones, W. T. Lawrence--^ * Bride. W. T. " Leominster-- Kern. R. T. Lexington-- ' Brigham, F. H. Burdoin, A. J. Lynn-- ' Feehab, J. B. Oates, W. A. Reardon, J. A. Medford-- Cushman, L. D. Dane, I. S. Melrose-- Cole, E. Q. Gerrish, G. B. Pierce, W. M. Milton-- Mitchell; C. H. Needham-- Park, C. D. Webb. J. S. Newton Centre-- Murray, J. J. Newtonville-- Emerson. R. R. McMurrer, L. J. Osterville-- Salisbury, W. C. Quincy-- Gesmer, J. Reading-- ' Ingalls, F. D. B. Revere-- . Foulds, S. T. N. Rosllndale--' Rehling, H. F. Roxbury-- Lundquist, R. A. Springfield--' Brown, W. M. Cotter, L. F. Cross, R. E. ' Leland, W. B, . Murphy, W. W. .Watertown-- Wiegner, H. B. Wellesley Hills-- Barnes, W. E. . Gilling, W. F., Jr. West Roxbury-- Abboud, A. Christie, A. Y. McPherson, W. A. Weymouth-- Clough, L. - Winchester-- Jackson, A. B. Winter Hill-- . Cummings, C. A. Woburn-- Parker, P. Wollaston-- Hodgdon, H. A. Worcester--- Robinson, H. C. Wechsberg, O. MICHIGAN Ann Arbor-- Backus,.T.-H. L. Hutzel, A. F. Battle Creek-- Christenson, H. Birmingham- Blackmore, F. H. Hadjisky, J. N. Buchanan-- Spafford, L. B. .. Detroit-- Akers, G. W. Arnoldy, W. F. Baldwin, W. H. Barth, H. E. Bishop, F. R. Boales, W. G. Booth. H. N. Brown, T. Carroll, W. J. . . 44 Chester, T. Collamore, R. Connell, R. F. Coon, T. E. Cooper, F. D. Corlett, L. D. Cummins, G. H. Darlington. A. P. Dauch, E. O. Davis, L. J. Dolan, H. P. Dubry. E. E. Eggleston, L. W. Feely, F. J. Fortune, J. R. . Gallarno, C. A. . Glanz, E. ' Gordon, R. H. Hamlin, H. A. Hare, W. A. Harms, W. T. Harrigan, E. M. Harrigan, E. R. ' Harrigan, H. H.< Harrison. C. G. Hatton, A. E. Heydon, C. G. Hogan, E. L. Kice. M. S., Jr. Kilner, J. S. Knibb, A. E. . Little, E. R. Luty, D. J. Maier, G. M. McColl, J. R. McConachie, L. L. McIntire.J. F. McLean, D. McNair, E. E. Milward, R. K. Morgan. C. S. Morse, C. T. Olson, R. G. Paetz, H. E. Parrott, L. G. Partlan, J. W. Phelps. H. R. Purcell, F. C. Purcell, R. E. RandaJJ, W. C. Rowe, W. A. Sauer, R. L. Shea. M. B. Shuell, F. W. Snell, E. Snyder, J. W, Spitzley, R. L. Spurgeon, J. H. Toonder, C. L. Walker, J. H. WaJlich, A. C. . Walton, H. L. Wigle, B. M. Winans, G. D. Dowagiac-- Firestone, J. F. Torr, T. W. E. Lansing-- Miller, L. G. . Ferrysburg-- Johnston, J. F.,.Jr. Grand Rapids-- Bradfield, W. W. Lammers, C. Leigh, R. L. . . Morton, C. H. Taze, D. L. Troske, J. J. . Wierenga, P. O. ' Ziesse, K.- L. Roll of Membership Herniansville-- Bernstrom, B. Voorhees, G. A. Highland Park-- Kintz, L. H. Holland-- Cherven, V. W. Sawyer, J. N. Van Alsburg, J. H. Kfllamazoor-- Downs, S. H. McConner, C. R. Schlicting, W. G. Temple, W. J. Treadway, Q. . Lansing-- . Distel, F. Huffaker, H. B. Parsons, R. A. ' Muskegon-- ' Johnson, P. H. Muskegon Heights-^ Reid, H. F.# Pontiac-- Chappell, H. D. Royal Oak-- Coughlin, R. J. Phillips. W. J. * Turner, J. W. St. Joseph-- Milliken, V. D. . MINNESOTA Cloquet-- Spafford, A. Duluth-- Foster, C. Ten Brook, C. S. Minneapolis-- Algren, A. B. Amundson, L. R. Anderson, D. B. Armstrong, A. D. Bell, E. F. Betts, H. M. Bjerken, M. H. Bradford. H. H. Bredesen, B. P. Bull, A. S. Burns, E. J. Burritt, C. G. Cash. T. T. Copperud, E. R. - Dahlstrom, G. A. Dock, C. J. Fitts, C. D. Forfar, D. M. Gerrish, H. E. Gordon, E. B., Jr. Gross, L. C. Hall, J. R. ' Hanson, L. C. Hanson, L. P. Harris, J. B. Helstrom, H. G. Hitchcock. P. C. Huch, A. J. Jacobson, R. A. Johnson, L. H. Jones, N. W. Jordan, R. C. King, R. L. Kuehn, W. C. Kuempel, L. L. Legler, F. W. Leslie, D. E. Lewis, C. E. Lowe, H. H. Lund, C. E. Magney, G. R. Martenis, J. V. McNamara, W. Miller, L. B. Morgan, G. C. Noble. T. G. . Pfeifer. O. J., Jr. Porter, H. M. Powell, K. A. Reese, P. R. Rowley, F. B. Sanford, A. L. Stiller, F. W. Sundell, S. S. Swenson, J. E. Uhl, E. J. Uhl, W. F. Van Horn, H. T. Welter, M. A. Nicollet Island-- Schembeck, F. H. Owatonna-- Clarkson, W. B. Rochester-- Adams. N. D. Shevlin-- Nesdahl, E.` St. Paul-- Arnold, E. Y. Backstrom. R. E. Buenger, A. Cha11man, S. A. Gausman, C. E. Heagler, j. M. Hickey, D. W. Jones, E. F. Lewis, E. B. Lindberg. A. F. Morton, H. S. Oberg, H. C. Otto. R. W. Parks, W. N. Ruff, D. C. Schulte, R. R. Swanstrom, A. E. Winterer, F. C. Wunderlich, M. S. Walnut Grove-- Wiggins, O. J. Winona-- DeLancey, R. W. MISSOURI Ferguson-- Szombathy, L. R.' Kansas City-- Adams, C. W. Arthur, J. M. Betz, H. D. Bliss, G. L. Buckley, M. B. Caleb. D. Campbell, E. K. Campbell, E. K., Jr. Chase, L. R. Clegg, C. Cook, B. F. Dawson, T. L. Dodds, F. F. Downes, N. W. v Fehlig, J. B. Filkina, H. L. Flarsheim, C. A. Gillham, W. E. Haas, E., Jr. Hitchcock, F. P. Kitchen, J. H. Lewis, J. G. Miller, E. S. ' Millis, L. W. .Natkin, B. Nottberg, G. Nottberg, H. Olchoff, M. Olson, G. E. Pines, S. Radio, H. M. Russell, W. A. Sheppard, F. A. ' Stephenson, L. A; Weiss, C. A. Woodling, M. D. Wymore, F. C. Maplewood-- Walters, A. L. St. Louis-- ' Barry. J. G., Jr. Bayse, H. V. Bowers, J. S. Bradley. E. P. Carlson, E. E. Clegg, R. R. Cooper, J. W. Corrigan, J. A. Davis. C. R. DuBois, L. J. Edwards. D. F. Evteth, E. B. Fagin, D. J. Falvey, J. D. Foster. J. M. Gilmore, L. A. Griffin, J. J. v.Grossmann, H. A. Hamilton, J. E. Hartwein, C. E. Hester, T. J. Kent, J. K. . Langenberg, E. B. McLarney, H. W. Moon, L. W. Myers, G. W. F. Reed. P. L. . ' Rodenheiser, G. B. Rosebrougb, R. M. Sachleben, E. H. Seepe, P..E. Sodemann, P. W. Sodemann, W. C. B. Stammer, E. L. Tenkonohy, R. J. White, E. A. Wolff, O. H. Webster Groves-- Axthelm, F. G. Gabelman, H. D. Ranck, G. L. MONTANA Big Timber-- Strickland, A. W. 45 Billings-- Cohagen. C. C. Tooker, C. C. Bozeman-- Powers, F. I. NEBRASKA - Clarks-- Manning, W. M. Omaha-- Eaton, B. K. Lewis, W. Sebree, G. M. Scotts Bluff-- Davis, O. E. NEW HAMPSHIRE Lebanon-- Lewis, J. P. NEW JERSEY Arlington-- Adler, A. A. Bock. B. A. Schwertfeger, A. Atlantic City-- Labov, M. Strouse, S. B. Bayonne-- Schwartz, J. Belmar-- Merkel, F. P. Bloomfield-- Hochuli. H. W. Camden- Brown, W. M. Kappel, G. W. A* Lanning, E. K. Webster, E. K. Webster, W. Webster, W., Jr. East Orange-- Gombers, H. B.' ; Grahn. V. F. Rack, E. C. Reilly, J. H. Schroth, A. H. Tallmadge, W. Tumo, W. G. W. Worsham, H. , ' Elizabeth-- Burke. J. J. Cornwall, G. I. Grant. W. A. Lyman, S. E. Skidmore, J. G. Taylor, K.- A. Wheller, H. S. Essex Fells-- Carrier, E. G. Stacey, A. E., Jr. Fair Haven-- Smith, H. P. American Society of Heating and Ventilating Engineers Guide 1934 Grantwood-- Butler, P. D. Haddonfield-- * Dobbs, Cl E. Jones, R. E. Hackensack-- Turnau, E. H. ! . Hasbrouck Heights-- Goodwin, S. L. i Hawthorne-- Lawton, F. C.- Soule, L. C. Tenney, D. Thornburg, H. A. West, p. North Arlington-- Bermel, A. H. Emery, H. Vogelbach, O. Palmyra--Cassell, J. D. Paterson-- Cox. H. F. Pryor, F. L.. Hillside-- Ti'chenor, L. R., Jr. Perth Amboy-- Simkin, M. Irvington-- Freas, R. B.' Reinke, A. G. Plainfield-- Hedges, H. B. Tobin, G. J. Jersey City-- Dunbrack, A. P. Hashagen, J. B. Jones, H. L. Kelly, C. J. Ritchie, W. . Van Court, W. G. Walterthum, J. J. Jobstown-- Allinson, O. H. Ridgefield Park-- Davis, A. C. Ridgewood-- Fitts, J. C. . Riverton-- Brunt, T. B. Rutherford-- Nelson, C. L. . Keansburg-- Roske, F. M. Short Hills-- Fouiihoux, J. A. Long Branch-- Hammond, M. J. . South Orange-- Hansen. C. C. Maplewood-- Ehrlich, M. W. Evans, W. A. Smith, M. S. Merchantville-- Binder, C. G. Rohlin, K. W. . Summit-- Oaks, O. O. Teaneck-- . Heebner, W. M. Tenafly-- Redfieid, G. Montclair-- Bentz, H. Holbrook, F. M. Long, D. R. Osmundsen, H. B. . Newark-- Alt, H. L. . Ashley. C. M. . Atkinson, K. B. Bryant, P. J. Bynum, O. W. Carey, P. C. . Carrier, W. H. Day, V. S. Finney, G. J. French, D. E. Harris, C. R. Hirst, J. N. Holton, J. H. Ingels. M. Leinroth, J. p. Lewis, J. L. Lewis, T. Lyle, J. i. Matullo, Ji r. Morehouse, H. P. ` Rachal, J. M. ' Ray. L. B. Union City-- Tavema, F. F. Upper Montclair-- Armagnac, A. S. Fernaid, H. B., Jr. Verona-- Stone, G. F. . West Collingswood-- Knecht, C. H. . NEW YORK Albany--. Anker, G. W. . Bond, H. A. Johnson, H. S. Murray, T. F. Ryan, H. J. Taggart, R. C. ' Teeiing, G. A. Binghamton-- . Brown, R. F. Marum, O. BronxviUe-- Doraheim, G. A. Buffalo-- Barnett, S. J. . Beman, M. C. Booth, C. A. Burke, F. H. Candee, B. C. Cherry, L. A. Cheyney, C. C. Corbin, w. E. Cressy, R- E. Criqui, A. A. Danforth, N. L. Dyer, O. K. Erdle, G. F. , Evans, C. A. Farnham, R* Farrar, C. W. Fraser, W. G. Harding, L. A. Heath, W. R. Hedley, P. fHexamer, H. D. Jackson, M- S. Johnson, E- E. Kamman, A. R. Landers, J- J* Love, C. ,H. . Madison, R. D. Mahoney, D. J. McTernan, F* J. Mosher, C. H. Rente, H. W. . Roebuck. W., Jr. Seelbach, H. Shelney.T. Stephenson, G. A. Thornton, R- T. . Voisinet, W. E. Wendt, E. F. Yager, J. J- Eggertsvllle-- Eiss. R. M. Hirschman, W. F. Elmira-- Davis. B. CMcGlenn, G. R. Geneva-- Herendeen, F. W. Hamburg-- .. Dempsey. H.-P- Hastings* onHudson-- Reynolds, T. W. Horrrell-- Brill. J. W. Hudson Falla-- ' 5 Hollister, E. W. Irvington -on - Hudson-- Bastedo, A. E. Knox, J. R. Ithaca-- Barns, A. A. Sawdon, W. M. Williams. J. W. Jamestown-- Sharp, F. H. 46 Kenmore^- Davis, J. Green, J. J. ,, Krueger, B. Quigley, W. J. Rente, S. R. Roseberry, J. H. Snyder, J. S. . Larchmont-- Beirn, J. U. Gaylor, W. S. LeRoy-- Rinehart, W. R. Lockport-- Bishop, C. R. Harrison, A. B. B. Saunders, L. P. Morton-- Stangland, B. F. Mount Vernon-- Freitag, F. G. Hiers, C. R. . Northon, L; Obert, C. W. Ryan, J. E. . New Rochelle--. Abrams, A. Farley, W. F. New York City-- Addams, H. : Ahlff, A. A. . Alvord, A. M.' Ames, C. F. Atherton, G. R. Austin, H. F., Jr. (Patchogue, L. I.) Bachler, L. J. ' Bampton, C. M. . . (Brooklyn) Barbera, H. A. ' (Corona, L. L) Barbieri, P. J. Barnum, M. C. Baum, A. L. Beebe. F. E. W. Bennett, E. A. Bennitt, G. E. Berman, L. K. Bernhard, G. (Lawrence, L. I.) Birch, H. R. . Birukoff, R. R. . Blackburn, E. C4, Jr. (Hempstead, L. i.) Blackman, A. O. ' Blackmore, J. J. Blitz, E. Bodinger, J. H. Bolton, R. P. Bowles, P. Brassington, A. F. Brown, W, A. . . Browne, A. L. ; , Bruckmann, J. C. \ Buensod, A. C. Bulkeley, C. A. ' Burbaum, W. A. . Callaghan, P. F., Jr. (Brooklyn) Campbell, F. B. Carpenter, R. H. Chase, C. L. (Brooklyn) . Cohagen, N. Cooper, j. R. Crone, T. E. Roll of Membership Cued, V. J. Johnson, E. B. Price, E. H. Dailey. 3- A. (Astoria, L. I.) Daly, R. E. . Darts, J. A. (W. New Brighton, S,, I.) Johnston, W. H. Kagey, I. B., Jr. (Riverhead, L. I.) - Purdy, Bl B. Purinton, D. J. Quirk, C. H, Donnelly, R. . Kastner, G. C. ' - Raffes, A. Downe, E. R. ' Kaufman, W. M. . Raisler, R. K. Dresen, W. D. Kenward, S. B. Reed, J. F. (Jackson Heights, (Bayshore) Reynolds, W. V. L. I.) -' Driscoll, W. H. Keplinger, W. L. Kiewitz, A. A. V , Richardson, H. T. Riley, C. L. Duff. K. Dulfield, T. J. (Astoria, L. I.) Kimball, D. D. , Ritchie, E. J. Ritter, A. Durkee, M. E. Kingsley, E. A. Rodman, R. W. Duryea, A. A. Kirk, L. G. Rosenberg, P. (City Island) Knopf, C. Ross, J. O. ' Dwyer, T. F. Koithan, W. S. Roth, C. F. (Brooklyn) Eadie. J. G. Easterbrooks. C. G. EelU. H. B. Kreitner, W. G. (Brooklyn) Kroupsky, V. Kuhlmann. R. Rothrock, J. T. (Douglaston, L.I.) Rozett, W.f Jr. Ruppert, E. H. (Brooklyn) Le Beau, J. F. (Brooklyn) Elliott. L. . (Jamaica, L. I.) Schleyer, E. F. Engle, A. Everetts. J-. Jr- Lefingwell, R. R. Lennon, J. O. (Brooklyn) Schlossman, M. B. Fansler, P. E. Leupold, H. W. Schneider, W. G. Fay, F. C. Fegley. D. R. (Brooklyn) Lowy, M. R. Schoepflln, P. H. Schulze, B. H- * Feldman, A. M. Lucke, C: E. Scott, C. E. Fenner, N. P. Lyle. E. T. Scott, G. M. Fenton, F. A. Lyon, P. S. . Scribner, E. D. Ferrero, H. J.. Maiman, H> Seelig, A. E. Fife, G. D. . (Glendale, L. I.) Sellman. N. T. Finch, S. B. (Brooklyn) Mandeville, E. W. . (Brooklyn) Senior, R. L. Seward, P. H. Fleisher, W. L. . Marino, D. A. (Brooklyn) Flink, C. H. Markush, E. U. Shepard, E. C. Frank, O. E. Marshall, H. H. Siebs, C. T. . Friedman, A. ' Martin, G. W. - Siegel, L. Friedman, M. McKelvey, D. M. (Brooklyn) Gautesen, A. McKiever, W. H. Sklenarick, L. Genchi, B. McLeish, W. S. Smith, P. C., Jr. (Brooklyn) . Mehne, C. A. . (Northport. L. I.) Giannini, A. A. Meinke, H. G. Stack. F. C. Gilroour, A. B. Meisel, C. L. (Flushing, L. I.) (Brooklyn) ' Meyer, C. L, Staples, W. H. * Glore. E. F. (Hollis, L. L) Stern, H. R. 'Goldschmidt, O- E. Meyer, H. C., Jr. Sternberg, E. Gornston, M. H. . Miller. C. A. Stewart, C. W. . (Brooklyn) Monroe, M. * SU11, F. R. Goulding, W. Montgomery, O. C. Strock, C. (Brooklyn) Moore, R. E. ' Strunin, J. Griffin, B. H. (Brooklyn) - Sullivan, D. A. (Stony Brook L.I.) Moss, E. Sutton, F. Grossman, H. E. (Brooklyn) Syska, A. G. (Oceanside, L. I.) , Munder, J. F. ,Jr. Taylor, J. H. Haigney, J. E. Hamburger, F. G. Munier, L. L. . Munro, E. A. (Queens Village, . (L. 1.) Hament.L. ' Hamburger, F. W. (Ljmbrook L. J.) Neale, L. I. Thomson, T. N. (Huntington, L.I.) Hartman, F. S. Neary, D. A. Tiltz, B. E. Heibel, W, E. Neideck, A. A. . Timmis, W- W. Henry. A. S., Jr. Nelson, G. A. Tisnower, W. . Herty, F. B. Nicol, N. C. Torrance, H. . (Brooklyn) Offner, A. J. Tucker, F. N. Hertzler, J. R. O'Hare, G. W., Jr. (Freeport, L. I.) (Brooklyn) Olsen, G. E. . Tusch, W. Hiegins. T. JHinchman, E. G. , (Arverne, L. I.) -Olstad, M. H. (Brooklyn) Tyler, R; D. (Brooklyn) . Olvany, W. J. Vetlesen. G. U. Hinkle, E. e: Osburn, R. M. Vivarttas, E. A. . (Hempstead. L. I.) Patomo, S. A. S. (Brooklyn) Hinrichsen, A. F. Paulding, L. G. Vogt, J. H. Hoffman, C. S. Perina, A. E. Wachs, L, J. Hollister, N. A. - (Staten Island) (Brooklyn) (Brooklyn) Pfuhler, J. L. Waechter, H, P. Hosking, H. L. Hotchkiss, C. H. B. (W. New Brighton, (S. i.) (Tompkinsville, S. J.) Howell, F. B./ Phillips, F. W., Jr. ; Wallace, G. J. Hyman, W. M. Issertell, H. G. ' Jacobus, D. S. Jalonack, I. G. (Patchogue, L. I.) Pihlman, A. A. Pinder, P. H. . Pison, D., Jr. Place, C. R. . (East Elmhurst, (L. I.) Wallace, W. M., II (Hollis, L. I.) Waring. J. M. S. Janco, N. Janet, H. L. Pohle, K. F. Presdee, C. W. Wells, E. E. (Beechhurst, L. L) White. E. S. Whitelaw, H. L. Wilder, E. L. Willis, R. C. WUson. H. A., Jr. Winquist, W. J. (Brooklyn) Wolff, R. A. Yockel, T. J. : North Tarrytown-- Derfy, J. J. . Ogdensburg-- Skelly, J. F. . Oriskany-- Oakey, W. E. * Ossining-- Hooper, V. F. Pelham Manor-- Peacock, J. K. Port Jervis-- .Trimmer, C. M. . Poughkeepsie-- Doherty, J. J. Rochester-- Cherne, R. E. Coe. R. T. Cook. R. P. * Hakes, L. M. Sheldon, N. E. Stacy, S. O. Welsh, H. S. - Rome-- Lynch, W; L. Steele, M. G. Scarsdale-- Cumming, R. W. Fiedler, H. W. Ullman, H. G. Schenectady-- Cannon, C. N. , Faust, F. H. Harrington, E. D.' McLenegan, D. W. Stevenson, A. R., Jr. Strachan, J. S. Vogel' A. ; Welch, L. A., Jr. Silver Creek-- Giguere, G. H. Snyder-- John, V. P. Syracuse-- =' Acheson," A. R. Cook, C. J. Ormsby, H. K., Jr. Tarrytown-- Abraham, L. " Weiss, A. P. Troy-- Vogt, J. B. . Utica-- ' T Steinhorst, T. F. 47 American Society of Heating and Ventilating Engineers Guide, 1934 White Plains--. Zibold, C. E: Yonkers-- Archdeacon, H. K. Brabbee, C. W. Deutchnian, J. Goerg, B. Kelly, J/G. Rainger, W. F. Stitt, A. B. Zuhlke, W. R. NORTH CAROLINA Charlotte-- Bailey, J. L. < Beaty, G. M-, Jr. Brandt, E. H., Jr. Christian, C. W. Small, B. R. High Point-- Gray, W. E. ,, Winston Salem-- Bahnson, F. F. OHIO Akron-- ' Humphrey, D. E. Bedford-- Hallas, R. S. Titus, M. S. Bellefontaine-- Quay, D. M. Canfield-- Neff. C. J. Cincinnati-- . Bachman, A. Bostain, J. C. Breneman, R. B. Coombe, J. Doyle, W. J. Floyd, M. Green, W. C. Hauss, C. F.. Helbum, I. B. Houliston, G. B. Hust, C. E. . Kiefer, C. J. Kitchell, H. N. Kramig, R. E., Jr. Pillen, H. A. Richard, E. J. Royer, E. B. Sigmund, R. W. Smith, J. A. ' Sproull, H. E. Wehrle, R. H. Winther, A. Wright, K. A. Cleveland-- . BenOlict, E. R. Black. W. B. Bridges, F. G. Brueggeman, A. R. Carson, C. C. Cohen, P. Colby, C. W. Connor; R. M. Deex, G. J. Eveleth, C. F. Farley, J. W. Fox, O. Gottwald, C. Graham, W. D. Harvey, L. C._ . Hendrickson, j. J. Kartorie. V. T. Kinner, J. E. Kitchen, F. A. Klie, W. Levy, M. I. . Matzen, H. B. Morris, F. H. Pogalies, L. H. Quinlivan, L/P. Rather, M. F; Roemer, J. . Schweikert, J. N. . Thompson, D. Tuve, G. L. Vanderhoof, A. L. Van Sickle, W. B. Vennere, E. J. Weager, T. A. Wheeler, C. A. Wright, M. B.. ' Cleveland Heights-- Bailey, E. P., Jr. Davis, R. G. Columbus-- Brown, A. I. . Sherman, R. A. Simpson, D..C. Slayter, G. Wheeler, O. J.. Williams, A. W. Dayton-- Gibbons, M. J., Jr. Haas. W. Hoerstihg. F. J. Hull, H. B. LaSalvia, J. J. Defiance-- Carey, T. M. East Cleveland-- Eaton, V. Nobis, H. M. Stark, W. E. Elyria-- Maynard, J. E. Lakewood-- Longcoy, G. B. Maurer, E. D. Ramsey, R. F. Martins Ferry-- Giffen, J. K. Norwood-- Braun, J. J. Motz, O. W. Painesville-- Hobbs, J. C. St. Bernard-- Strobl, J. A. Springfield-- May, E. M. Toledo-- Baker, H. C. Myers, F. L. Willard-- Myers, E. V. Youngstown-- Choffin, C. C. OKLAHOMA ,, Lawton-- Rathbun, P. W. Oklahoma City-- Dolan,' R. G. Loeffler, F. X. Miller, B. R. Tiller, L. Tulsa-- Jones, E. OREGON Drain-- Zink, D. D. PENNSYLVANIA Allentown-- Korn, C. B. Altoona-- Yeager. G. F. Ambler-- ' Miner, H. F.. Ardmore-- Haynes, C. V. Hires, J. E. . Beaver- Armstrong, J. A. Comstock, G. M. . Beaver Falls-- Van Alen, W. T. ' Beechwood, Del. Co.Kipe. J. M. Bethlehem-- Adlam, T. N. Brookline, Del. Co.-- Roberts, H. L. Butler-- Karges, L. Cheltenham-- McElgin. J. W. Conshohocken-- Bolsinger, R. C. ' Gynwyd-- Smith, W. F. E. Pittsburgh-- Goodwin, W. C. Thornton, F., Jr. Elizabethtown-- Dibble, S. E. Erie-- Joyce, H. B. 48 Glenshaw-- McEllroy, G. S. Harrisburg-- Eicher, H. C. Geiger, 1. H. Lutz, J. H. Snyder, A. K. * Haverford-- Black, E. N., 3rd Hazelton-- Sherry, R. W. Jenklntown-- Slight, I. . Johnstown-- . Novotney, T. A. Rinkenberger, G. . Stitt, E.W. '' Kingston-- ' Dockeray, F. MacDonald, D. B. Lancaster-- Jones, A. ; Lloyd, E. C. Schrader, C. C. Yeomans, P. H. Lansdowne--. James. H. R. McKeesport-- Dugan, T. M. McKees Rocks-- Bucher, H. G. Meadville-- Williams, L. E.* . Merlon-- Atkins. T. J. Narberth-rWilmot. C. S. Natrona-- Kaczenski, C. , New Castle-- Sonnebom, C. Norristown-- . Frost. R. V. Hucker, J. H. . Philadelphia-- Adams, B. Anderson. W. M., Jr. Arnold, R. S. Aronson, H. H. Bartlett, C. E. . Benson, J. C. Black,' H. G. U Blankin, M. F. Bogaty, H. S. Boon, G. Bomemann, W. A. Braemer, W. G. R. Breitenbach, G. C. Caldwell, A. C. Clarkson, R. C., Jr. Clodfelter, J. L. Cornell, J. C. v Roll of Membership i. Culbert, W. P. Dambly, A. E. Davidson, L. C. Davidson, P. L. Donovan, W. J. Eagan, W. H. Eakins, W. Eggly, H. J., Jr.. Eichberg, W. R. Elliot, E. Engel, E. Erickson, H. H. Ewald. W. Faltenbacher, H. J. Familetti, A. R. Fest. L. T. Galligan, A. .B. Gant, H. P. Gillett. M. C. Glassey. J. W.' Hackett, H. B. Harris, J. E, Hibbs, F. C. Hoft, P. J. Hunger, R. F. , Hurley, J. C; Hynes, L. P. Ickeringill, J. . Jellett, S. A. Johnson, C. E. ' Keeler. A. H. Kelble, F. R. Kelly. J. A. Kemey, T. F. Kriebel, A. E. Kuehnert, A. C. Lewis. G. C. Liner, J. J. Lutz, P. R. MacDade, A. H. Mann, L. B> Marks. A. A. Mather, H. H. ' McCartlty, C. J. ' McClintock, A., Jr. Mellon, J. T. J. Mensing, F. D. Meyer, J. W. Miller, A. A. Monday, C. E. Morgan R. C. Naylor. C. L. Nesbitt, A. J. Nesbitt? J. J. Nusbaum, L. Plass, C. W. Plewes, S. E. Pryibil, P. L. Redstone, A. L. Reilly, C. E. Rettew, H. F. Reuss, E. H., Jr. Rhea, C. A. Roberts, E. F., Jr. Rugart, K. . Sabin, E. R. Sanbem, E. N. Sands, J. S. Shanklin, A. P. Sheffler, M. Shepard, J. deB. Speckman, C. H. Stevens, J. M. Stoever, G. H. Tiramis, P. Touton, R. D. Traugott, M. Tuckerman, G. E. Wandless, F. W. Wegmann, A. Welamb, V. N. White,'J. J. Why, H. B. Wild, W. H. Wilson, B. W. . Woolston, A. H. Pittsburgh-- Alcott, W. L. Aston, J. Babbitt, W. D. . Beighel, H. A. Benson, M. A. Blackmore, G. C. Blackmore, J. S. . Blackshaw, J; L. Bowers, R. C. . Brauer, R. Brewer, J. G. Burns, J. R. Bushnell, C. D. Carr, M. L. Collins, J. F. S., Jr. Dice, E. S. Digby, H. E. Dorian, M. I. Edwards, P. A. ' 1 Evans, E. C. Fitzsimons, J. P. Fritz, C. V. Gunther, F. A. - Hanson, E. W. Harper, S. H. Hecht, F. H. Heilman, R. H. Hickey, J. W. Houghten, F. C. Humphreys, C. M. Hunter. V. W. Ingold. J. W. Keist, W. E. . Kellner, D. C. Kennedy, O. A. Lutz. W. J. Maehling, L. S. . Maginn, P. F. McClanahan, L. C. McGinness, J. E. McGonagle, A. McGuigan, L. A. McIntosh, F. C. Miller, R. A. Nass, A. F. Nicholls. P. Nordheimer, C. L. O'Neill. P. Orr, H. B. Pennel, R. Pittock, L. B. Reed, V. A., Jr. Richmond, J. Riddle, K. L. Riesmeyer, E. H., Jr. Rockwell, J. F. . ` Smith, R. H. Smyers, E. C. Speller, F. N. Stanger, R. B. Steen, J. M. Stevenson, W. W. Tennant, R. J. J. Tower, E. S. * Vinson, N. L. . . Waters, G. G. . Wright, C. E. Pottsville-- Marty, E. O. Smith, J. D. Reading-- . Luck. A. W. Nicely, J. E. Rutledge-- Vroome, A. E; Scranton-- Gilboy, J. P: Shaver, H. H. Sewickley-- Black, G. E. State College-- Queer, E. R. Stroudsburg-- Kiefer, E. J., Jr. Tamaqua-- Hadesty. A. L., Jr. Koch, H. O. Upper Darby-- Eastman, C. B. Taliaferro, R. R. Vernon-- Etheridge, G. T., Jr. Villanova-- Barr. G. W. Carey, J. A. Wayne-- Patrick, H. M. Wilkes-Barre-- Santee, H. C. Wilkinsburg-- Campbell, T. F. Vernier, M. G. TEXAS Amarillo-- - Burnett, E. S. Austin-- . Groseclose, J. B. College Station-- Badgett, W. H. Giesecke, F. E. Reynolds, J. A. Smith, E. G. . Dallas-- : Cunningham. T. M. Doming, E. H. Hersh, F. C. Landauer, L. L. ' Lynn, J. H. Meffert, G. H. Renouf, E. P. Fort Worth-- Skinner, H. W. Houston-- Kiesling, J. A. _ Irving-- Moler, W- H. Kingsville-- Richtmann, W. M. Williamsport-- Pfeiffer, J. F. Port Arthur-- Hansen, C. J. : Wormleysburg-- Miller, T- G. York-- Baker, I. C. San Antonio-- Diver, M. L. Ebert, W. A. . VERMONT RHODE ISLAND Barrington-- Wyman, D. M. Providence-- Coleman, J. B. Gibbs, E. W. Hartwell, J. C. Husband, E. W. McLaughlin. J. D. Moulder, A. W. Washington-- Wilson, H. A. TENNESSEE Memphis-- Campbell, A. Q., Jr. D'lmor, E. J. Hoshall, R. H. Nashville-- Brown, F. Jarfatt, P. R. Burlington-- Austin, F. L. Lanou, J. E. Raine, J. J. ' North Ferrisburg-- Breckenridge,-L. P. VIRGINIA Clarendon-- _ MacMahon, W. K. Danville--Farley, W. S. East Falls Church-- Casey, H. F. --. Lynchburg-- Doering, F. L. Wiley, E. C. Newport News-- Noland, L. U. 49 American Society of Heating and Ventilating Engineers Guide,' 1934 Norfolk-- Nowitzky, H. S. Peebles, J. K., Jr. Richmond-- Carle, W. E. Johnston, J. A. Livingston, B. B. Schulz, H. I. WASHINGTON Seattle-- Beggs, W. E. Bouillon, L. Careten, W. H. Cook, H. A. Cox, W. W. Davis, R. J. Dudley, W.'L. Eastwood. E. O. Granston, R. O. Griffin, D. C. . ' Hauan, M. J. MacLeod, K. F. . Mallis, W. O'Connell, Pi M. Peterson, S. D. Pollard, A. L. Twist, C. F. Whaley, R. S. Zokelt, C. G. Tacoma-- May, Cl W. Spofforth, W. . Yakima-- McCune, B. V. WEST VIRGINIA - Alderson-- , Anderson, S. W., Jr. Charleston-- Shanklin, J. A. Largent-- Donnelly, J. A. Innis, H. R. . , . Morgantown-- Zeck, A. WISCONSIN Ashland-- Trulson, A. F. Ft. Atkinson-- Shodron, J. G. Kohler-- Hvoslef, F. W. Kohler, W. J., Jr. La Crosse-- Anderegg, R. H. Miller, M. W. . Trane, R. N. Madison-- ' Dean, C. L. Hess, D. K. James, J. W. . Larson, G. L. Nelson, D. W. Plaenert, A. B. White, J. C. Menomonle-- Schoenoff, A. E. ' Mondovi-- Lofte, J. A. Milwaukee-- Berghoefer, V. A. Bowers, A. F. Brown, W. H. Effis. H. W. Freeman, A. M. Godfrey, P. S. Hanley, E. V. r Haupt, H. F. Herrmann, H. C. Ine, F. H. Jackson, C. H. Jones, E. A. Jung, J. S. Juttner, O. J. Miller, C. W.. Miller, H. M. NoU. W. F. ' Peters, ,H. H. Randolph, C. H. Rice, C. J. Shawlin, W. C. Spielmann, H. J. Szekely, E. Volk, J. H. Wagner, A. M. Weimer, F. G. Wilson, W. H. Racine-- Dixon, A. G. ' Thomas, N. A. Superior-- ^ Waite, H. Wauwatosa-- Page, H. W. West Allis-- Erickson, M. E. \ t 50 Roll of Membership AUSTRIA Vienna-- Melichar, W. J. AUSTRALIA Sydney-- Duncan, J. R. ' Sands. C. C. BELGIUM Brussels-- Mautsch, R. ^ CANADA Brockville, Ont.-- Davenport, R. F. Calgary, Alberta--. Clarke, S. S. . Walker, A. Edmonton, Alberta-- Kelly, H. Halifax, N. S--- Eagar, R. F. Hamilton, Ont.-- Best. M. W. Maddux, O. L. Pennock, W. B. . Islington, Ont.-- Wilson, G. T. Kitchener, Ont.-- Beavers, G. R. . Montreal, P. 0*-- Darling, A. B. Friedman, F. J. Garaeau. L. . Johnson, C. W. . McGrail, T. E. Osborne, G. H. Phipps, F. G. Wiggs, G. L. Montreal, West, P. o -- Linton, J. P. ' Ottawa, Ont.-- Coldough, O. W. Gray, G. A. Quebec, P.Q.-- Dube, W. . St. Catharines, Ont.-- , Thompson, W. J. Toronto, Ont.-- _ Angus, H. H. Birrell, A. L. . Blackball, W. R. Boddington, W. P. Brown, T. FOREIGN COUNTRIES Church, H. J. ! Cole. G. E. Dickey, A. J. Duncan, W. A. Effis. F. E. Flanagan, E. T. Flett, H. R. Gaby, F. A. Gurney, E. H. Harrington, C. Heard, R. G.' Henion, H. D. . Hills, A. H. ' Hopper, G. H. Jenney, H. B. Leitch, A. S. MacKenzie, J. J. McDonald, T. McHenry, R. W. Millar, R. J. Moore, H. S. O'Neill, J. W. Paterson, J. S. Paul. D. I. Philip, W. Playfair, G. A. Purdy, A. K. * Ritchie, A. G. . Shears. M. W. Sheffield, E. B; Sheppard, W. G. F. Thomas, M. F. Waldon, C. D. Ward, W. T. Watson, M. B. Whittall, E. T. Wood. J. S. V^eston, Ont.-- Blake, A. H. Vancouver, B. C.-- Givin, A. W. Johnston, R. E. Leek, W. Libby, R. S. McCreery, H. J. Victoria, B. C.-- Sheret, A. Winnipeg, Man.-- Hicks, W. W. Jones, B. G. Kirk, C. D. Leonard, J. H. Michie, D. F. Steele, J. B. Summers, E. T. Turland, C. H. CHINA Dairen, Manchuria-- Katsumoto, E. _ Nanking--. Loo, P. Y. Osaka-- Fukui, K. Shanghai-- Doughty, C. J.' Hart-Baker, H. W. Kwan, I. K. Loh, N. S. . Merritt, C. J. Morrison, C. B. Waung, T. F. CZECHOSLOVAK! A Prague-- Brust, O. DENMARK Copehagen-- Reck, W. E. ENGLAND B uckinghamshlre-- Rose, W. K. - Leeds-- . Jennins, H. H. London-- Bailey, W. M. Butt, R- E. W. Haden, G. N. Herring, E. Nobbs, W. W. Overton, S. H. Middlesex-- . ` Case. W. G. Stockport-- . Webb, J. W. Swinton-- Yates, W. Trowbridge-- Haden, W. N. Westminster-- Russell, J. N. Wolverhampton-- Tyson, W. H. - FRANCE Dijon-- Bur, J. R. C. LiUe-- Neu, H. J. E. Lyon-- Goenaga, R. C. Paris-- Beaurrienne, A. Downe, H. S. . Modiano, R. Nessi, A. Schmutz, J. GERMANY Berlin-- Brandi, O. H. Stuttgart-- Jens, J. Klein, A. 51 INDIA Calcutta-- Casperd, H. W. H. New Delhi-- Heard, J. A. E. IRELAND . Cork-- Barry, P. I. ITALY Milan-- Donzelli, E. , Gini, A. JAPAN Tokyo-- Kitaura, S. Kozu, T. Saito, S. Sekido, K. . MEXICO Lomas de Chapultepec-- Gilfrin, G. F. Martinez, J. J. - Mexico City-- Croft, T. NEW ZEALAND Auckland-- Wallace, B/ Christchurch-- Vale, H. A. L. Dunedin-- , Davies, G. W. NORWAY Oslo-- . Alfsen, N. Tjersland, A. SOUTH AMERICA Santiago, Chile-- Carrasco, _S. SWEDEN, Stockholm-- GiUe, H. B. Theorell, H. G. T. U. S. S. R. Leningrad-- Sakouta, M. L. Teterevnikoff, N. N. PAST OFFICERS American Society of Heating and Ventilating Engineers 1894 President.-----------------------:--------------- .Edward P. Bates 1st Vice-President...... ...... 1__ _____ Wm. M. Mackay 2nd Vice-President________________ Wiltsie F. Wolfe 3rd 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 2nd Vice-President................................... Henry Adams 3rd 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 2nd Vice-Presidents......................Chas. S. Onderdonk 3rd Vice-President............... ........................ 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 Stewart A. Jellett, Pres. L. H. Hart, Secy. ' Council . . Chairman, R. C. Carpenter Henry Adams T. J. Waters Edward P. Bates Albert A. Cryer, Secy. 1898 President............... ............. .............. .....Wiltsie F. Wolfe 1st Vice-President------------------------------- J. H. Kinealy 2nd Vice-President;....................... __....... _A. E. Kenrick 3rd Vice-President........ ........ .................... John A. Fish Treasurer..........................--..........Judson A. Goodrich Secretary------ ------------- .-------------Stewart A. Jellett Board of Managers . Chairman, Wm. M. Mackay Thomas Barwice 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. President........ ........... 1st Vice-President... 2nd Vice-President.. 3rd Vice-Presidents. Treasurer_____ Secretary....... .......... 1896 ------ R. C. Carpenter ................ D. M. Quay ......Edward P. Bates ............. F. W. Foster Judson A. Goodrich .................. 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, Secy. 1899 President...... ..................... ---. ...........Henry Adams 1st Vice-President._____________________ D. M. Quay 2nd Vice-President................. -............... A. E. Kenrick 3rd 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. 52 Roll of Membership 1900 President____ _____ D. M. Quay 1st Vice-President_____ __________ ---A. E. Kenrick 2nd 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 Gornjy Wm. M. Mackay, Secy. 1905 Presidents______ __________________;--------- Wm. Kent 1st Vice-President------ ------------------------- R- P. Bolton 2nd Vice-Presidenti--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 2nd Vice-President____________ ____ Andrew Harvey Treasurer.................... .....................Judson A. Goodrich. Secretary............................. _................Wm. M. Mackay Board of Governors 4Chairman, J. H. Kinealy Wm. Kent, Vice-Chm. John Gormly R. C. Carpenter C. B. J. Snyder R. P. Bolton Wm. M. Mackay, Secy. 1906 President........................... .................. ........ John Gormly 1st Vice-President_________ _C. B. J. Snyder 2nd Vice-President---------------.----------------T. J. Waters Treasurer__________ __________--Ulysses G. Scollay Secretary^.................:_________ r.,,,Wm. M. Mackay Board of Governors . Chairman, John Gormly C. B. J. Snyder,James Mackay R. C. Carpenter B.' F. Stangland Frank K. Chew T. J. Waters . A. B. Franklin Wm. M. Mackay. Secy. 1902 President_____________ A. E. Kenrick 1st Vice-President............................... -Andrew Harvey 2nd Vice-President________ Robert C. Clarkson Treasurer_______ Judson A. Goodrich 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 2nd Vice-President_______________ ___ .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 Wm. M. Mackay, Secy. 1903 President........................................................ H. D. Crane 1st Vice-President.......................................... Wm. Kent 2nd Vice-President_____________ ____P. Bolton Treasurer __________________ Judson A. Goodrich Secretary .............................................Wm. M. Mackay Board of Governors . . Chairman, H. D. Crane C. B. J. Snyder, Vice-Chm. A. E. Kenrick R. C. Carpenter Geo. Mehring John Gormly Wm. M. Mackay. Secy. 1908 Presidents........................... -................ James Mackay 1st Vice-President_1...............................Jag. D, Hoffman 2nd Vice-President............................... B. F. Stangland Treasurer_____ __________ ______-Ulysses G.' Scollay Secretary ............................... ........ ~.Wm. M. Mackay / Board of Governors _ Chairman, James Mackay Jas. D. Hoffman, Vwe-Chm. John F. Hale B. F. Stangland August Kehm R. C. Carpenter C. B. J. Snyder Frank K. Chew Wm. M. Mackay, Secy. 1904 President..................... ........ ................. -Andrew Harvey 1st Vice-President_______________ -....... John Gormly 2nd Vice-PresidentRobert C. Clarkson Treasurer........................ .............. .....Ulysses G. Scollay Secretary.............................................. .Wm. M. Mackay 1909 . President.......-________ ____________ ___Wm. G. Snow 1st Vice-President__ August Kehm 2nd Vice-President.......... ......................~B. S. Harrison Treasurer________________________ Ulysses G. Scollay Secretary.......... ...... ...... -................ .Wm. M.^Mackay Board of Governors . Chairman, Andrew Harvey John Gormly t H. D. Crane Robert C. Clarkson - . A. E. Kenrick J. J. Blackmore C. B. J, Snyder R. C. Carpenter Wm. M. Mackay, Secy. Board of Governors ` Chairman, Wm. G. Snow August Kehm, Vice-Chm. Samuel R. Lewis John R. Allen James Mackay R. C. Carpenter B. F. Stangland B. S. Harrison Wm. M. Mackay, Secy. 53 American Society of Heating and Ventilating Engineers Guide, 1934 1910 President-------------------------------------------------------Jas. D. Hoffman 1st Vtce-PresiierU.................... ......... ....._R. P. Bolton end Vice-President..... ....................... Samuel R. Lewis Treasurer--------------------- .---------------Ulysses G. Scollay Secretary_--_______________________ Wm. M. Mackay Board of Governors - 1915 President.................. :;:.Dwight D. imball 1st Vice-President_______________ --Harry M. Hart 4nd Vice-President-------------------- Frank T. Chapman Treasurer.-------------------------------------------------------Homer Addams Secretary........--............................................... J. J. Blackmore 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. * 1911 President.--......;R. p. Bolton 1st Vice-President__ _________________ John R. Allen Snd\Vtee-President; j\.. B. Franklin Treasurer--................ .................... Ulysses G. Scollay Secretary------------------- :__________ ___Wm. W. Macon 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. Ohtnes Wm. M. Kingsbury J. J. Blackmore, Secy. . 1916 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 Janies H. Davis Wm. W. Macon, Secy. President______ Harry M. Hart 1st Vice-President.___ __,,______ Frank T. Chapman Snd Vice-President-.^--------------------------Arthur K. Ohmes Treasurer.------------------------ !Homer Addams Secretary-.___Casin W. Obert 1912 President___________ 1st Vice-President.__________ Snd Vice-President_____ ____ Treasurer.......... .....;________ . Secretary______________ ______ .......... John R. Allen ......... --John F. Hale .Edmund F. Capron ..James A. Donnelly ------Wm. W. Macon Board of Governors . Chairman, John R. Allen John F. Hale, Vice-Chm. Dwight D. Kimball Edmund F. Capron Samuel R. Lewis R. P. Bolton Wm. M. Mackay. Jas. D. Hoffman Wm. W. Macon, Secy. President____________ 1st Vice-President...... Snd Vice-President__: Treasurer. Secretary 1913 .John F. Hale ...A. B. Franklin ----------- Edmund F. Capron ------------ James A. Donnelly ------- ----- ----- Edwin A. Scott Board of Governors . Chairman, John F. Hale . A. B. Franklin, Vice-Chm. James A. Donnelly John R. Allen Dwight D. Kimball Edmund F. Capron Wm. W. Macon R- P. Bolton / James M. Stannard Frank T. Chapman Theodore Weinshank Ralph Collamore Edwin A. Scott, Secy. 1914 President------------------------------ ---------Samuel R. Lewis 1st Vice-President_____ --___ --Edmund F. Capron Snd Vice-President....... ----___ Dwight D. Kimball Treasurer------ --------------.......James A. Donnelly Secretary-----------------------l----------------- J. J. Blackmore Council Chairman, Samuel R. Lewis E. F.Cajpron, Vice-Chm. John F. Hale Dwight D. Kimball Harry M. Hart John R. Allen Frank G. McCann Frank T. Chapman Wm. W. Macon Frank I. Cooper James M. Stannard James A. Donnelly J. J. Blackmore, Secy. . 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--------------------------------_------. J. Irvine Lyle 1st Vice-President'________________ Arthur K. Ohmes ' Snd Vice-President______________ ______Fred R. Still. Treasurer.--_ Homer Addams Secretary--..................... ..........................Casin W. Obert Council Chairman, J. Irvine Lyle A. K. Ohmes, Vice-Chm. Harry M. Hart Homer Addams E. Vernon Hill Davis S. Boyden James M. Stannard Bert C. Davis Fred R. Still Milton W. Franklin Walter S. TimmiS Charles A. Fuller Casin W. Obert, Secy. 1918 President_____________________Fred R. Still 1st Vice-President.--Walter S. Timmis Snd Vice-President_________ _________ E. Vernon Hill Treasurer.;_________________________ Homer Addams Secretary........ .__ _______ ______ j___ Casin W. Obert Council Chairman, Fred R. Still ` W. S. Timmis, Vice-Chm. J. Irvine Lyle' Homer Addams . E. Vernon Hilt William H. Driscoll ,, Frank. G. Phegley . Howard H. Fielding H. P. Gant ' Fred. W. Powers Champlain L. Riley C. W. 'Kimball Casin W. Obert, Secy. 54 Roll of Membership 1919 - . . 1923 . President-________________________Walter S. Timmis President.............................. ............................ H. P. Gant 1st Vice-President--_____________ E. Vernon .Hill 1st Vice-President:------------------ ------------- Homer Addams Snd Vice-President______ --~ Milton W. Franklin Snd Vice-President------------------ ------------E. E. McNair Treasurer. J..................................... ...... ..Homer Addams - Treasurer............. .--..................--Wm. H. Driscoll Secretary............. -- ____ ____ Casin W. Obert Secretary.........;--................... ......... -..........C. 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 . 4 Champlain L. Riley Harry E. Gerrisb P Fred R. Still t George B. Nichols Casin W. Obert. Secy. 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. y , 1920 President_________ _________ ________ E. Vernon Hill . 1st Vice-President__ __________..Champlain L. Riley Snd Vice-Presided.................---------Jay R. McColl Treasurerii______________ Homer Addams . Secretary_____ ...._________________ --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. 1924 * President........--....-_________ Homer Addams 1st Vice-President------- ------------------------- S. E. Dibble Snd Vice-President-------- .---------- William H. Driscoll Treasurer--___ _______ _--.--------------------Perry West Secretary....... .................... ....... ..........--F. C. Houghten Council Chairman, Homer Addams . S. E. Dibble. Vice-Chm. W. E. Gillham F. Paul Anderson W. H. Carrier J. A. Cutler L. A. Harding . . Alfred Kellogg Thornton Lewis . William H. Driscoll H. P. Gant Perry West F. C. Houghten. Secy. . 1921 1925 PresidentiJ--____________________Champlain L. Riley President--------------------........... --............... S. E. Dibble 1st Vice-President________ Jay R. McColl 1st Vice-President------------------------------------------- .Wm. H. Driscoll . Snd Vice-President._____________________ H. P. Gant Snd Vice-President------- -----------------F. Paul Anderson Treasurer. ________ _Homer Addams . Treasurer-------- ---------------- ---- ------- --------- Perry West Secretary____ ____________::____Casin W. Obert Secretary.--................... ;--------------------F. C. Houghten ' 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 Wm. H_ Drifipnll E. E. McNair PprTV West Council Chairman, S. E. Dibble Wm. H. Driscoll, Vto-CAm. W. T. Jones tHromer AAdda--m--s TTIhinomrntAtonn TLjfei wis F. Paul Anderson J. H. Walker W. H. Carrier Perry West 1922 . 1926 President ......... ...............____ Jay R. McColl President--------------------------------------------W. H. Driscoll 1st Vice-President...... ........................ ...........H. P. Gant 1st Vice-President........... --............ F. Paul Anderson Snd Vice-President_______ __ ____ .Samuel E. Dibble Snd Vice-President--------- r-------- r-----------A.* c- Willard Treasurer ............JHomer Addams Treasurer.------------ --------------------------- W. E. Gillham Secretary...............1,______________Casin W. Obert Secretary........................................................................................A. V. Hutchinson Council 1 Chairman, Jay R. McColl H. P. Gant, Vice-Chm. Homer Addams . L. A. Harding E. E. McNair Jos. A. Cutler ` H. J. Meyer Samuel E. Dibble Wm. H. Driscoll E. S. Hallett ' C. L. Riley .: Perry West Casin W. Obert, Secy. ' Council " Chairman, W. H. Driscoll F. Paul Anderson, Vice-Chm. C. V. Haynes ; W. H. Carrier J. A. Cutler W. T. Jones E. B. Langenberg S E. Dibble Thornton Lewis W. E. Gillham J- F. Mclntire A. C. Willard 55 American Society of Heating and Ventilating Engineers Guide, 1934 1927' President.....................................;____ F. Paul Anderson 1st Vice-President_________ :__________ A. C. Willard Snd Vice-President.:Thornton Lewis, Treasurer._____________________ ____ _W. E. Gillham Secretary^........... ................ _............. A. V. Hutchinson . Council Chairman,'F. Paul Anderson A. C. Willard, Vice-Chm. John Howatt H. H. Angus W. T. Jone3 . W. H-. Carrier J. J. Kissick W. H. Driscoll E. B. Langenberg Roswell Famharh Thornton Lewis H. H. Fielding J. F. Mclntire' ' W. E. Gillham . . H. Lee Moore C. V. Haynes . F. B. Rowley ' 1928 President................................... .............;.,,A. C. Willard 1st Vice-President_________________ Thornton Lewis Snd Vice-President__________________ X. A. Harding Treasurer_________ ________________ W. E. Gillham Secretary..................___................. ..... A. V. Hutchinson Council Chairman, A. C. Willard ' Thornton Lewis, VicerChm: 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 ' - 1931, President--------- -------------- ..................... W. H. Carrier 1st Vice-President,_J__________ ________ F. B. Rowley Snd Vice-Presidents.....................................W. T. Jones Treasurer..------------- ------------ ----- --------F. D. Mensing Secretary------------------------------- ........A. V. Hutchinson Technical SecretaryJ............ ...................,....P. D. Close Council Chairman, W. H. Carrier F. B. Rowley, Vice-Chm. - D. S. Boyden * E. K. Campbell R. H. Carpenter J. D. Cassell L. A, Harding -Jo- hn -H- owatt ' W. T. Jones E. B; Langenberg G. L. Larson ` E. O. Eastwood Roswell Farnham F. C. McIntosh F. D. Mensing E. H. Gurney W. A. Rowe 1932 President.................................. ................... F. B. Rowley 1st Vice-President__ .1...........................W. T. Jones Snd Vice-President___________ ____ __ C. V. Haynes Treasurer.;..................................................F. D. Mensing Secretary...... ......:_____ ;-- ________A. V. Hutchinson Technical Secretary_______ ...... .................. P. D. Close 1929 President--.............................. .............Thornton Lewis 1st Vice-President__________________'...X. A. Harding Snd Vice-President____________ ______ W. H. Carrier Treasurer.................................. ..............I.W. E. Gillham Secretary._____________ _____ __ ___A. V. Hutchinson Technical Secretary_____________________ P. D. Close Council . Chairman, Thornton Lewis L. A. Harding, Vice-Chm. John Howatt H. H. Angus W. T. 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 1930 ` President_______ ____________ ____ ____X, A. Harding 1st Vice-President________________ ___ W. H. Carrier Snd Vice-President_____________.______ F. B. Rowley Treasurer._____________________ _______ C. W. Farrar Secretary.__________ ___ __________ A. V. Hutchinson Technical Secretary__________.....................P. D. Close Council kL. A. Harding John Howatt W. T. Jones E. B. Langenberg G. L. Larson Thornton Lewis F. C. McIntosh W. A. Rowe F.. B. RowleyS ' Council Chairman, W. T. Jones, Vice-Chm. D. S. Boyden E. K. Campbell. R. H. Carpenter W. H. Carrier John D. Cassell E. O. Eastwood .Roswell Farnham r. B. Rowley F. E. Giesecke ' E.. Holt Gurney C. V. Haynes John Howatt G. L. Larson J. F. Mclntire F. D. Mensing W. E. Stark 1933 President__ ____ ___________________ _____W. T. Jones 1st Vice-President.___ ___________ _____. V. Haynes Snd Vice-President...John Howatt Treasurer______ _________ _______ ....D.'S. Boyden Secretary...... .................. ......................A. V. Hutchinson Council ' . Chairman, W. T. Jones C. V. Haynes. Vice-Chm. R. Hi Carpenter F. D. Cassell G: L. Larson J. F. Mclntire W.. E. Stark D. S. Boyden John Howatt F. C. McIntosh , L. W. Moon F. E. Giesecke E. K. Campbell E. O. Eastwood R. Farnham E. H. Gurney F. B. Rowley 56 i