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FILE NAME: Trade Publications (TR) DATE: 1948 DOC#: TR028 DOCUMENT DESCRIPTION: Heating, Ventilating & Air Conditioning Guide  H i f ' HEATING VENTILATING AIR CONDITIONING GUIDE 1948 An Instrument of Service Prepared for the Profession containing A TECHNICAL DATA SECTION o f r e f e r e n c e m a t e r ia l o n t h e DESIGN AND SPECIFICATION O F HEATING, VENTILATING AND AIR CONDI TIONING SYSTEMS BASED ON-- T H E TRANSACTIONS-- THE INVESTIGATIONS o f t h e R esea r c h L aboratory and Co o pera tin g I n st itu t io n s-- and t h e P r a ct ic e o f t h e M e m b e r s and frien ds o f t h e S o c ie t y ; A MANUFACTURERS' CATALOG DATA SECTION c o n t a in in g e s s e n t i a l AND RELIABLE INFORMATION CONCERNING MODERN E Q U IP M E N T : THE ROLL OF MEMBERSHIP OF THE SOCIETY; COMPLETE INDEXES t o T e c h n i c a l a n d C a t a l o g D a t a S e c t io n s . $ 7 .SO p er Copy P ublished Annually by Am erica n So c ie t y o f H ea tin g and Ven tilating Engineers 51 M adison Avenue I- labrary , C o p y r ig h t 1948 BY T H E A m er ic a n Society o f H e a t in g and V e n t il a t in g E n g in ee r s fc- A|TO RY IT D edicated To t h e A d v a n c e m e n t o f The P r o f e s s io n and I ts A l l ie d I n d u stries text and illu stra tio n s are fu l ly pr o t e c t e d BY COPYRIGHT AND NOTHING -THAT. APPEARS MAY BE REPRINTED EITHER WHOLLY OR IN PART WITHOUT SPECIAL PERMISSION, Printed, and Bound by T he H orn-Shafer Company BALTIMORE MARYLAND U. S. A. PREFACE TO THE 26th EDITION \*Z a T H E 26th edition of The Heating, Ventilating, Air Conditioning Guide contini|&ijjggm. the tradition of previous Guides in presenting current engineering practice and ^ up-to-date products, of manufacturers. Among the chapters given most extensive revision j,n the 1948 edition, the following should be noted: _ OTsry Chapter 10, Air Contaminants, contains revised limits for toxic gases, vapors, fumes, mists and dusts, in conformity with recent conclusions of industrial hygienists. Chapter 11, Instruments and Measurements, has been enlarged to include a greater number of instruments, as well as more information on test methods and the use of instruments. Chapter 12, Physiological Principles, incorporates some additional findings based upon recent research. Chapter 13, Air Conditioning in the Prevention and Treatment of Disease, has been revised to agree with current thought and research. Chapter 14, Heating Load, includes an enlarged list of approximately 350 localities, including city office and airport stations, for which weather data and design temperatures are given. The list includes data obtained from the U. S. Weather Bureau and Canadian Air Services, Meteorological Division. A new map showing isotherms of outdoor tem perature has been provided. Chapter 15, Cooling Load, has been increased to 45 pages to permit inclusion of an enlarged list of 315 localities for which weather data are listed. T he chapter has also been rewritten to assist the user in applying the principles of periodic heat flow, and ' the data from most recent ASHVE research on solar heat transmission. Chapter 20, Estimating Fuel Consumption for Space Heating, includes an enlarged list of 211 U. S. cities and 25 Canadian cities showing monthly degree-day values. The information has been obtained from latest statistics of the U. S. Weather Bureau and Canadian Air Services, Meteorological Division. Chapter 21, Gravity Warm Air Systems, has been rearranged to facilitate use of the design tables. Chapter 22, Mechanical Warm Air Systems, contains an added section referring to method of designing large systems. I n Chapter 23, Steam Heating Systems and Piping, revised descriptions of various types of system s keep the chapter up to date. Many new diagrams have been added to illustrate current practice. I n Chapter 25, Radiators, Convectors and Coils, there has been added a section on baseboard radiation. I n Chapter 26, Unit Heaters, Unit Ventilators, Unit Humidifiers, piping diagrams and text have been changed to comply with current practice. I n Chapter 27, Pipe, Fittings and Welding,' the section on welding has been expanded with reference to proper welding procedure and applicable code requirements. Chapter SO, Electric Heating, includes an enlarged list of pertinent references.' Chapter 82, Fans, has been improved by addition of typical sound level curves to the fan performance curves. A new diagram illustrating accepted designations of direction of rotation and discharge for fans has been added. The chapter also contains a sectio.n on attic fans which has been transferred from Chapter 36. Chapter 34, Automatic Control, has been rewritten to include more detailed treatment of typical controls and control combinations for all types of systems. . Chapter 36, Unit Air Conditioners, Unit Air Coolers, has been revised and improved in both text and illustrations. Chapter 87, Spray Apparatus, has been rearranged and includes new information on design and use of air washers, cooling towers and spray ponds. Chapter 40, Air Distribution, has been completely revised by the ASHVE Technical Advisory Committee on Air Distribution and Air Friction. It contains new definitions and formulas for air distribution. Charts have been included for graphical solution of problems involving flow of air from slots and jets, residual velocity and size of openings. ' Information on location of outlets has been enlarged, and more information is given on control of air streams in spaces. M553558 Chapter 10 AIR CONTAMINANTS Classification of Air Contaminants; Sizes of Airborne Particles; Air Pollution by Smoke, Ash and Cinders; Smoke Abatement; Odor Nuisance; Maximum Allowable Concentrations of Industrial Air Contaminants; Flammable Gases and Vapors; Combustible Dusts; Atmospheric Pollen; Air borne Bacteria THE norma! constituents of the earth's atmosphere are oxygen, nitrogen, carbon dioxide, water vapor, argon, small or negligible amounts of other inert gases, hydrogen, variable traces of ozone, and small quantities of microscopic and submicroscopic solid matter, sometimes called permanent atmospheric impurities. From the viewpoint of the air conditioning engineer, all other airborne substances may be termed con taminants, This term is applied preferably, however, to undesirable or chance impurities, since the occasion may arise for adding to the air controlled amounts of substances such as: solid or gaseous diluents for the prevention of explosions; germicidal mists or aerosols for bacteria control; masking substances for odor control; or a substitute for one of the normal gases, as, for example, when helium is used to replace nitrogen in atmospheres for compressed air workers or divers. The control of air quality is one of the functions of complete air con ditioning, and some knowledge of the composition, concentration and properties of air contaminants under various circumstances is therefore essential. Air contaminants arise from the normal processes of wear, erosion, windstorm, sea-spray evaporation, thermal disintegration, earthquake, volcanic eruption, combustion, manufacturing, transportation, agricul ture, and the biochemical or biological processes of life. They are classi fied at various times as organic and inorganic, visible or invisible, micro scopic or macroscopic, particulate or gaseous, toxic or harmless, beneficial or destructive. The following classification is based chiefly upon the origin or method of formation of air contaminants, using distinctions that are necessarily arbitrary in some cases. CLASSIFICATION OF AIR CONTAMINANTS Dusts, Fumes, and Smokes are solid particulate air contaminants. Dusts are solid particles projected into the air by natural forces, such as wind, volcanic eruption or earthquake, and by mechanical or man-made processes, such as crushing, grinding, milling, drilling, demolition, shovelling, conveying, screening, bagging and sweeping. Some of these forces produce dust from larger masses, while the others simply disperse materials that are already in dust or pulverized form. Generally, particles are not called dust unless they are smaller than about 100 microns in size. Dusts may be of mineral type, such as rock, ore, metal, sand; vegetable, such as grain, flour, wood, cotton, poller.; or animal, such as wool, hair, silk, feathers, 'leather. Fumes are solid particles commonly formed by the condensation of vapors from normally solid materials such as molten metals. Metallic fumes generally occur as the oxides in air because of the highly reactive nature of finely divided matter. Fumes may also be formed by sublimation, distillation, calcination, or chemical reaction, whenever such processes create airborne particles predominately below the 1 micron size. Fumes permitted to age tend to flocculate into clumps or aggregates of much larger size and this tendency may facilitate removal from air under controlled conditions. Smokes are the extremely small solid particles produced by incomplete combustion of organic substances such as tobacco, wood, coal, oil, tar and other carbonaceous 166 Air Contam inants 167 materials. The term smoke is commonly applied to the mixture of solid, liquid and gaseous products of combustion, although the technical literature prefers to distinguish between such components as soot or carbon particles, fly-ash, cinders, tarry matter, unburned gases, and gaseous combustion products. The finest particulate constituents are characteristically much less than 1 micron in size, often in the range of 0.1 to 0.3 micron. Mists and Fogs are liquid particulate air contaminants. M ists are very small airborne droplets of materials that are ordinarily liquid at normal temperatures and pressures. They may be formed by atomizing, spraying, splashing, mixing, violent chemical reaction, electrolytic evolution of gas from a liquid, or escape of a dissolved gas upon release of pressure. The very small droplets expelled or atom ized into the air b y sneezing constitute m ists containing microorganisms that become air contaminants. Fogs are limited by some classifications to airborne droplets formed by condensation from the vapor state. This arbitrary distinction between mist and fog is of minor importance, as both terms are used to indicate the particulate state of airborne liquids (occasionally termed aerosols). Fog nozzles are so named because of their ability to produce extra fine droplets as compared to the mist from ordinary spray devices. T he highly volatile nature of some liquids quickly reduces their airborne droplets from the mist to the fog range, and eventually to the vapor phase until the air becomes saturated with that liquid. M any droplets in fogs or clouds are microscopic and submicroscopic in size, and may be conceived as the transition state between the larger m ists and the vapors. Vapors and Gases are non-particulate air contaminants. Vapors are the gaseous phase of substances that are either liquid or solid in their commonly known state, examples being gasoline, kerosene, benzene, carbon tetrachloride, mercury, iodine, camphor. Vapors may be changed to the solid or liquid form by in creasing the pressure, decreasing the temperature or applying both processes sim ultan eously. They are removed from the air by condensation with less difficulty than are the gases. Gases are normally formless fluids which tend.to occupy a space or enclosure com pletely and uniformly at ordinary temperatures and pressures. The following substances qualify as gases: oxygen, nitrogen, carbon dioxide, carbon monoxide, hydrogen, ammonia, sulfur dioxide. Gases, likewise, may be solidified or liquefied by the proper control of tem perature and pressure. The preceding classification is not suitable for the airborne living organisms, which range in size from the submicroscopic viruses to the largest pollen grains, not considering the smallest insect life. Bacteria range from about 0.2 to 5 microns in size, fungus spores from 1 to 10 microns, and pollen from 5 to 150 microns. SIZES OF AIRBORNE PARTICLES Fig. 1 is a graphic tabulation of the properties of airborne solids and liquids arranged according to size on the micron scale. There are 25,400 microns in 1 inch. Particles larger than 10 microns are unlikely to remain suspended in air currents of moderate strength, but settle out by gravity at speeds dependent upon the shape, the size and specific gravity of the particle, the wind velocity, the orientation of the collecting surface, and the topography. These larger particles are of major interest to the engineer in the solution of nuisance problems, but it is usually the smaller particles, or those below 10 microns, that remain in the air long enough to be of hygienic as well as economic significance. The great bulk of industrial dust particles is of the order of 1 micron in size. Tremendous numbers are also present in the sub-microscopic range below 0.5 micron, but those below 0.1 micron are not believed at 268 CHAPTER IO 1948 G uide Compiled by W. G. Frank and Copyrighted. F ig . 1. Sizes and C haracteristics of A ir b o r n e P a rticu la te M a tter present to be of any practical importance, possibly due to their exceed ingly small mass in comparison with the balance of airborne matter. In fact, particles this small may become the permanent atmospheric impuri ties that have little if any opportunity of settling because of the continual motion imparted to them by air currents and the molecular activity of tljeir supporting gases (Brownian Movement), The survey' of atmospheric pollution in 14 American cities conducted from 1931 to 1933 indicated the average size of outdoor dust particle to be 0.5 micron, as collected by the Owens jet dust counter and measured under the microscope. The inability of the light field microscope to Air C ontam inants 169 reveal particles in the 0.1 micron vicinity may have influenced the determination of average particle.size. The lower limit of particle size visible to the naked eye cannot be stated definitely. It depends notronly upon the individual eye, but also upon the shape and color of the particle, the intensity and quality of the light, and the nature of the background or the opportunity for contrast. Under ideal conditions a particle of 10-micron sizfe might be recognized, while under less favorable conditions it may be impossible to distinguish a particle smaller than 50 microns. The lower limit of visibility probably ranges from 10 to 50 microns. Dusts, powders and granular materials are frequently classified by reference to the size of screens used for separation. Particles above 40 microns are said to be the screen sizes and those below, the sub-screen or' microscopic sizes. The approximate or theoretical sizes of particles corresponding to the mesh scale of the U. S. Standard Sieve Series are given in Table 1. Microscopic examination of screened dust indicates that the average diameter of a sample of irregular particles may be substantially larger than the openings of the screen through which it has passed, if the particle T a b l e 1. R e l a t io n of S c r e e n M e s h to P a r t ic l e S iz e U, S. Standard Sieve Mesh........ 400 325 200 140 100 60 35 18 Nominal Sieve Opening in Microns.............. 37 44 74 105 149 250 500 1000 shapes deviate considerably from the spherical form 2. The smallest dimension of many such particles will correspond with the maximum permissible distance between the wires of commercial screens made to A S T M Standard specifications. Screening does not give sharp separation into size groups, and accordingly such a classification is statistical rather than absolute. AIR POLLUTION BY SMOKE, ASH AND CINDERS The total airborne solids settling in urban areas are usually reported as soot fall in tons per (square mile) (month). Such data published for the cities in this country range from 20 to 200 tons per (square mile) (month). To the air conditioning engineer this information may indicate the effectiveness of smoke abatement or fuel combustion control methods in his locality, but it does not provide a suitable index of the suspended dust that air cleaners in a ventilating system are expected to capture3' *6. Gravimetric or weight data of the type given in Table 2 are preferable. In some cases airborne particle counts may be necessary, as for pollen, bacteria, spores, and insoluble dusts causing illness or lung disease. Dust concentrations by weight cannot be converted readily to con centrations by particle count because of the variability of particle size, shape and specific gravity, and the inherent characteristics of dust counting and weighing procedures. One milligram of dust per cubic 170 CHAPTER JO 1948 G u ide meter of air may represent dust counts from 1 million to 100 million particles per cubic foot of air (lightfield microscope technic) according to the size distribution of the airborne dust sample. Information of this type for a specified application is best obtained by simultaneous sampling for both counting and weighing and noting carefully at the time all factors that might affect the reproducibility of the count-weight ratio. Smoke Abatement Successful abatement of atmospheric pollution caused by smoke re quires the combined efforts of the combustion engineer, industrial execu tive, public health officer, city planning commission and the community at large. Electrification of industry and railroads, increases in the use of domestic oil and gas furnaces, and segregation of industrial districts is gradually providing effective aid in the solution of this problem. In the large cities where nuisance from smoke, fly-ash and cinders is more serious, limited areas obtain some relief by the use of district heating. Time, temperature and turbulence are fundamental requirements for smokeless combustion. Increase of any one of these factors will reduce T able 2. D ust Concentration Ranges L ocation Rural and suburban districts .......................... . Metropolitan district................................................ Industrial districts...................................................... Ordinary factories or workrooms........................... Excessively dusty factories or mines... _ . . Minimum explosive concentrations...................... Grains per lOOQ Cu Fr 0.02-0.2 0.04-0.4 0.1 -2.0 0.2 -4.0 4-400 4000-200,000 1 grain per 1000 cu ft 2.3 milligrams per cubic meter. 1 0 2 per cubic foot =* 1 gram per liter = 1000 grams per cubic meter. Mullgrams per Cubic Meter 0.05- 0.5 0 .1 - 1.0 0.2 - 5.0 0.5 -10 10-1000 10,000-500,000 the quantity of smoke discharged, although excessive turbulence in furnances may increase the output of ash and cinders. Special care must be taken in hand firing the bituminous coals. (See Chapters 16, 17 and 18 for further discussion on fuel burning technic). Legislative measures at the present time are largely concerned with reduction of the visible smoke discharged from chimneys of boiler plants. Practically all ordinances limit the number of minutes in any one liour that smoke of a specified density may be discharged, as measured by comparison with a Ringelmann Chart (Chapter 11, Instruments and Measurements). Ordinances generally do not make specific provision for control of the corrosive and irritant gases, such as oxides of sulphur and nitrogen discharged with the gases of combustion. Where high sulfur coals are burned, sulfur gases present a serious hazard to property, health and vegetation. In foggy weather the accumulation of these gases in the lower strata of the atmosphere may be such as to cause irritation of the eyes, nose and respiratory passages, and possibly even more dangerous consequences. The Meuse Valley (Belgium) fog disaster (1930) has become a classic example in the history of gaseous air pollution. It is believed that sulfur dioxide and other toxic gases released in a rare combination of atmospheric Air C ontam inants 171 calm and dense fog were responsible for about 60 human deaths, injuries to several hundred persons, and also the death of many dom estic''and wild animals. ' Absorption of Solar Radiation The absorption of solar ultraviolet light by smoke and soot, is recog nized as a health problem in many industrial cities. Measurements of solar radiation in Baltimore6 by actinic methods demonstrated that ultraviolet light intensity in the country was 50 per cent greater than in the city. In New York City 1 a loss as great as 50 per cent in visible light was found by photo-electric ceil. ODOR NUISANCE A problem companionate with smoke abatement is the control of odor nuisance in the neighborhood of industrial plants discharging noxious or offensive air contaminants. Community planning and zoning will avoid much of the difficulty in the future, but meanwhile many industrial cities must resort to corrective measures by requiring the installation of air cleaning devices, the alteration of manufacturing processes, or by legal termination of the offensive operation in residential or commercial districts. The control of outdoor odor nuisance is especially troublesome because of the extremely minute quantities of contaminant that are capable of offending through a wide area. New industrial chemicals with strange or unfamiliar odors tend to receive much more attention from the neigh borhood than the customary odors generated by well known processes and raw materials. Methods of odor control currently in use include charcoal adsorption, scrubbing towers and air washers, chlorination, condensation, masking, passage of the odorous air through combustion chambers, and best of all, substitution of less offensive materials whenever possible 8l "I0, n. The control of air quality within buildings ventilated for human occupancy is discussed in Chapter 12. Tobacco smoke odors, cooking odors and body odors are air contaminants of the nuisance type which now command a decisive position in the standards of air quality for indoor comfort. However, the engineer will find, at times, that odors originating outside buildings in industrial or business districts may determine the kind and capacity of equipment he must provide for a high quality air supply installation. INDUSTRIAL AIR CONTAMINANTS Many industrial processes are sources of contaminants. Their control is an important function of the ventilating or air conditioning engineer, because the atmosphere within buildings is the medium whereby such finely divided matter is dispersed and transported from the source to remote locations where it may cause property damage, nuisance, fire, explosion, disease and even death. Tables 3, 4 and 5 give the maximum allowable concentrations for industrial air contaminants as currently accepted in most sections of the country. They apply to exposures of 8 hours per day, and refer to the quantities of contaminant permissible in the workers' breathing zone. Some of these figures may be altered as the result of continuous research, and some may differ from those in force in a few cities or states, The 172 CHAPTER 10 1048 G uide Table 3.. Physiological Response to G ases and Vapors Concentrations in Parts of Substance per Million Parts of Air by Volume (ppm) Substance A cro lein A m m onia ................. Amvl acetate A n ilin e ............................................ A rsin e ............................................ Rapidly Fatal 2,000 siooo 250 D angerous to L if e in 14 to 1 H r M aximum Allow able Concentration for D aily E xposures 100 2,500 200 10 0.5 100 200 5 0.05 B e n z e n e (b e n z o l) ..................... B ro m in e ................................ ....... B n tv l a c e t a t e ......................... C a rb o n d io x id e ........................ C a rb o n d isu lfid e ....................... 20,000 500 100,000 2,000 5,000 40 10,000 5o;ooo 1,000 100b 1 200 5,000 20b C a rb o n m o n o x id e -- ............... C a rb o n te tr a c h lo r id e .............. C h lo rin e ................. ....................... D ic h lo ro b e n z e n e ....... ................ D ic h lo r o e th y l e th e r ................. 4,000 50,000 1,000 1,000 1 500 100b 50 1 50 15 E th e r ( d i e t h y l) ......................... E th y l a c e t a t e ............................. E th y l a lc o h o l........................ F.thylene riiohloride , , Form aldehyde (rasolfne. 40,000 3 5 ,0 0 0 10,000 4 ,0 0 0 400 400 1,000 100 10b 500 H y d r o g e n c h lo r id e .- ............. H y d r o g e n c y a n id e ................... H ydrogen fhm ride H y d r o g e n s u lfid e ...................... M e th y l a c e t a t e ....................... M ethyl alcohol (M ethanol) M e th y l b r o m id e ........................ M e th y l c h lo r id e ........................ M e th y le n e c h lo r id e ............ M o n o c h lo ro b e n z e n e .-.......... N itr o b e n z e n e .- ........................ 1,000 '2 0 0 600 ................ 20,000 150,000 100 50 200 2,000 2 0 ,0 0 0 10 20 3 20b 200 200b 20 100 500 75 1 N itr o g e n o x id e s ......................... P h o s g e n e ...................................... P h o s p h in e .................................... S ty re n e . .................................... Sulfur d io x id e ............................. 300 50 1,000 400 100 25b 5 1 400 0.05 . 400b 150 10 T etrachlornethane T ^ e tra c h lo ro e fh v le n e ,.... . ... T o lu e n e ( to lu o l) ........................ T ric h lo r o e th y le n e ............ T urpentine X y le n e ( x y lo l) .......................... 7,000 20,000 20,000 5,000 5,000 l 5 100 200 200b 100 200b Adapted from: Manual of Industria] Hygiene, by YV. M. Gafafer et al, U. S. Public Health Service (YV. B. Saunders Co., 1943); Analytical Chemistry of Industrial Poisons, Hazards and Solvents, by M. B. Jacobs (Interscience Publishers, 1941); Noxious Gases, by Henderson and Haggard (ReinhoJd Publishing Co., s\ Y., 1943). 1947 report of the Committee on Threshold Limits of the American Conference of Governmental Industriai Hygienists; and other authoritative sources. ^Adopted by the American Standards Association (American Standard 2-37). prudent engineer will design equipment using these values as the upper limits of air contamination, and will incorporate a reasonable margin of safety in his estimates of ventilation capacity. Information on the properties and effects, with respect to health, of Air C ontam inants 173 T able 4. Maximum Allowable Concentrations of, Dusts, F umes and Mists21. Substance A ntim m ry ... ............................ . ........................... -...................... A rsenic; arsen ic trinxide. .............................................. ..................... C a d m i u m , a n d c o m p o u n d s ......... ..................................................................... C ^hlnm diphenyls . ............................. ............................................................. C 'h m m iV a r i d m i s t a n d C h r o m a t e s ( a s C r O ^ ) ................................ F l u o r i d e s .......................................................... ..................................................... L e a d ; lead c a rb o n a te ;, lead ch lo rid e ; lead n itr a te ; lead o x i d e s ; le a d s u l f a t e .. ... ..... .... ........................ ................. .................. M a n g a n e s e a n d c o m p o u n d - 5? . M ercury and com pounds ......................... ..................................... .................................... P e n t a c h l o r o n a p h t h a l e n e ...................................................................................... S elenium ______________ _________ 1..................... 1........................ T ellu riu m . 'T rirh lo rn n a p h th a le n e ................................ ........................ T rin itro to lu en e ................ ... ...................... .................................... Z inc oxide fu m e ........................ ............... . .......................................... M illigram s p e r C ubic M e t e r , D a il y E x p o s u r e s ! , 0.1 0 .1 5 c 0 .1 c 1 .0 0 .1 2 .5 0 .1 5 6 .0 e 0.1 0 .5 0.1 0.1 5 .0 1.5 15.0 sAdapted from: Manual of Industrial Hygine, by W. M, Gafafer, et al, U. S. Public Health Service (W B. Saunders Company, 1943); and other authoritative sources. bl milligram per cubic meter 0,44 grain per 1000 cu,ft. cAdopted by the American Standards Association (American Standard Z-37). T able 5. M aximum Allowable Concentrations of D usts* Substance A lu m in u m o x id e a h ra siv e ........... .................. ..................................... A s b e s to s .- ........................................................................................................... ("'arh o m n d iim (silicon c arb id e) .............. ....................................... C e m e n t ( P o r t l a n d ) _--............................................................................... ("oal (less th a n per cen t fju artz) ........... .................................. Dftci-c r/-m tnJng 1a t h a n 10 p e r c e n t silica ........... G r a n i t e ................................................................................................................... G v p s n m ( h v d r a tp d c a lc iu m s u l f a t e ) ............ ......................................... L im e s to n e (c a lc iu m c a r b o n a t e ) ........................... ................................... M a r b le ( c a lc iu m c a r b o n a t e ) ........................................................................ M i c a ............................... ............................................................. ........................... N u is a n c e d u s t s ( n o n -to x ic , n o n - s ilic a ) ........................... ...................... Q u a r t z (silic o n d io x id e ) ..... ............................................................................ S a n d (silic a , silic o n d io x id e ) ................................................................*...... S a n d s to n e .................... ............................ ............................................................ S ilic a (Jtee o r u n c o m b in e d silic o n d io x id e ) ........................................ S ilic a te s (c o m b in e d silic o n d io x id e ) ..................* ................................... S la te -- ................................................... ............................................................. T a l c ............................................................................................................................ T o ta l ( m a x im u m c o n c e n tr a tio n f o r m ix e d d u s ts ) .,--..................... M illion P articles per ' > Cubic F oot of Air , D aily E xposures* 15-100 ' 5 15-100 50-100 50-100 10-100 1 0 -2 5 .; 50-100 50-100 50-100 10-100 50-100 5 5 o 5 15-100 15-100 1 0 - 50 50-100 aAdapted from: Study of Asbcstosis in Asbestos Textile Industry, IJ. S Public Health Service Bulletin No. 241, 1938; Industrial Dust, by Drinker and Hatch (McGraw Hill Book Co., 1936); Industrial Code Bulletin No. 35, New York State Department of Labor; recommendations of state and local industrial hygiene agencies compiled by the American Conference of Governmental Industrial Hygienists; and other authoritative sources. ^Includes only particles from 1 to 10 microns approximately, as determined by the light field microscope counting technic, using the 10 X objective. Dark field counts (and the corresponding allowable concen trations) are anywhere from 2 to 100 times the light field counts for the same sample, according'to the proportion of dust smaller than 1 micron (See Industrial Dust, Chapter VIT, by Drinker and Hatch, McGraw Hill Book Co.) specific industrial air contaminants has developed rapidly within the past decade into an extensive literature. Some of the more readily available publications are listed at the end of this chapter. 174 CHAPTER 10 1948 C u ide T able 6. Approximate Limits of F lammability of Single Gases and Vapors I n Air at O rdinary T emperatures and Pressures3 G as or Vapor Acetaldehyde.......................... A c e to n e .................................... Acetyleneb...... ......................... Allvl n lr n h r A Ammonia.- ....................-....... Amyl 5*Jrr>hrl, Amvl r.hlnririf .... .............. Amylpp# Benzene (benzol)................... Benzyl chloride...................... Butane....................... ............. Butyl acetate.......................... Butyl alcohol.......................... Biitvl^nfi ___ ______ ______ Carbon disulfide.................... Carbon monovid^ .... ........ Crotonaldehyde...................... C y c lo h e x a n e ............................ Cyclnpropa of*............ Decane-- ................................. Dichloroethylene (1, 2 )._ .... D io x a n ................................. -- . Ethane.__________________ Ether (d ieth yl)-.................... Ethyl acetate.......................... Ethyl alcohol.......................... Kfhyi hrnmirip. ... ............ Ethyl cellosolve...................... Ethyl chloride........................ Kfhvlfn#> Ethylene dichloride............... Ethyl formate.-- .................. Kfhvl n i t r i t e .................. ....... Ethylene oxide....................... Furfural CA ... Gasoline...... ............................. Heptane...... ............................. Hexane...... ............................... Hydrogen cyanide................. Hydrngron ...... Illuminating gas , _ Iso-butyl alcohol................... Tso-ppnfanf ....... Iso-propyl acetate................. Iso-propyl alcohol......_....... M ethaneh...... ........................... Lower L imit P er cent by V olume 4.0 2.1 2.5 2 .4 16.0 1.2 1.4 1.6 1.4 1.1 1.6 1.7 1.7 1.7 1.0 12.5 2.1 1.3 2.4 0.67 9.7 2.5 2.0 3.1 1.7 2.2 3.3 . 6 .7 2.6 3.6 3.0 6.2 2.7 3 .0 3.0 2.1 1.3 1.0 1.2 5.6 4.1 4.3 5.3 1.7 1.3 1.8 2.5 5.0 Upper L imit P er cent by Volume 57 13.0 80 27.0 8 .0 8.5 15.0 9.0 50 74 15.5 8.4 10.3 2.6 12.8 22.2 15.0 48.0 11.5 19.0 11.3 15.7 14.8 3 4 .0 15.9 16.5 80 6.5 6.0 6.9 40.0 74 45.5 31.0 7.8 15.0 Closed Cup Flash P oint F D ego -1 7 0 70 91 12 140 -7 6 72 84 -2 2 55 1 115 43 65 -2 0 24 55 104 -5 8 56 -4 -3 1 140 -5 0 25 -7 0 82 43 53 ^Adapted from: Limits of Inflammability of Gases and Vapors, by H. F. Coward and G. W. Jones <U. S. Bureau of Mines. Bulletin No. 279, 1939); Properties of Flammable Liquids. Gases and Solids (Assoclated Factory Mutual Fire Ins. Cos., January, 1040); and National Fire Codes for Flammable Liquids, Gases, Chemicals and Explosives--1945 (National Fire Protection Association). ^Turbulent mixture, (Closed cup refers to the equipment used in flash point determinations. Air Contam inants 175 T able 6. Approximate Limits of F lammability of Single Gases and Vapors I n Air at Ordinary T emperatures and Pressures3 (Continued) Gas or Vapor M e th y l a c e t a t e --........................ M e th y l a lc o h o l........................... M ethyl hm m irle M e th y l b u ty l k e to n e ,,..... M e t h y l c h lo r id e ...................S... M e th y l c y c lo h e x a n e ________ M e t h y l e t h y l e t h e r --......... ..... M e th y l e t h y l k e t o n e ............... M e th y l f o r m a te ......................... M e th y l p r o p y l k e t o n e ............ N s ty r a l jrps, i ,,, N a p h t h a ( b e n z in e ) ................... N aphthalan# N o n a n e ........................................... O c ta n e ............................................. P a rald eh y d e P entane P ro p a n e P r o p y l a c e t a t e ............................ P r o p y l a lc o h o l............................ P ro p y le n e P r o p y le n e d ic h lo r id e ............... P r o p y le n e o x id e ......................... P y r id in e (7 0 C ) .......................... T o lu e n e ( to lu o l) ......................... Turpentine............................... V inyl efher V inyl fhlnfide W a f e r g a s ( v a r i a b l e ) .......... Xylene (xylol)......................... L ower L imit P er cent by V olume 3.1 '6 .0 13.5 1.2 8.0 1.1 2 .0 1.8 5.0 1.5 , 4 .8 1.1 0 .9 0.74 ' 0 .8 4 1.3 1.4 2 .4 1.8 2.5 2.0 3 .4 2.1 1.8 1.3 0 .8 1.7 4.0 6.0 1.0 U pper L imit P er cent by Volume 15.5 36.5 14.5 8.0 19,7 10.1 . ' 11.5 22.7 8.2 13.5 6.0 2.9 3.2 8.6 9.5 8.0 11.1 14.5 21.5 12.4 7.0 27.6 22.0 70 6.0 Closed C up Flash Point F D eco 15 54 25 -3 5 30 -2 20-45 174 88 56 58 59 59 68 40 95 63 FLAMMABLE GASES AM) VAPORS Adequate ventilation is a primary requirement for eliminating or minimizing the hazard of fire or explosion due to gases and vapors. The need for good ventilation is not removed by the use of other precautions, such as the elimination of known ignition sources, segregation of hazard ous operations, adoption of safe building construction, and installation of , automatic alarms. Some safety engineers regard overventilation of an operation employing flammable liquids as a legitimate operating charge for the privilege or necessity of using a dangerous process. However, it is not possible to apply a reasonable safety factor to the ventilation estimate without consideration of the concentrations of gases or vapors that ap proach the danger point. Safety engineers prefer to limit the concen tration to M or ^ of the lower explosive limit, and this fact should be given full weight in determining the capacity and design of ventilating equipment. Rarely should consideration be given to operation above the upper explosive limit in the open areas of buildings or rooms--even though unoccupied--because the danger of temporary drop of gas concentration to a point within the explosive range is too great. 176 CHAPTER 10 1948 G uide The ability o f a flammable liquid to form explosive mixtures is de termined largely by its vapor pressure, volatility, or rate of evaporation. Flash point is a convenient method of expressing this property in terms of the temperature scale. It may be defined as the temperature to which a combustible liquid must be heated to produce a flash of flame when a small flame is passed across the surface of the liquid. The higher the flash point, the more safely can the liquid be handled. Liquids with flash points ilnder 70 F should be regarded as highly flammable. The upper and lower limits of flammability of gases and vapors, and the flash points of the corresponding liquids are given in Table 6. Methods for estimating the flammable limits of mixtures of gases or vapors must be applied with caution; the reader is referred to other publications for this information12,1S. Design of equipment for the control of combustible anesthetics is outlined in Chapter 13. Construction of equipment for handling air containing flammable substances, or operating in atmospheres so con taminated, is discussed in Chapter 46. It is customary to report the concentrations of flammable gases or vapors in per cent by volume, or volume per cent, Comparison with concentrations on the part per million scale used in chemical, medical or industrial hygiene literature is readily made by the conversion: 1 per cent = 10,000 ppm (parts of contaminant per million parts of air, by volume, or in other words, cubic feet of contaminant per million cubic feet of air). It will be noted in Table 6 that nearly all of the substances listed have lower explosive limits above 1.0 per cent, while the maximum allowable concentrations for gases and vapors in Table 3 are below 1000 ppm or 0.1 per cent in most cases. Therefore, control of toxic or injurious vapors in workrooms to levels below their maximum allowable concen trations for health usually requires much more effective ventilation than for the prevention of a fire hazard. COMBUSTIBLE DUSTS A dust explosion is essentially a sudden pressure rise caused by the very rapid burning of airborne dust. The primary explosion often originates from, a small amount of dust in suspension exposed to a source of ignition, and the pressure and vibration it creates may be sufficient to dislodge large accumulations of dust on horizontal ledges or surfaces of the building and equipment, thereby creating a secondary explosion of great force. Thus the air conditioning engineer is involved for two reasons: (1) to obtain a movement of dust-laden air into exhaust hoods or openings and through ventilating or pneumatic conveying ducts in a manner that will prevent accumulation of highly flammable dust at points where it could ignite inside the equipment; and (2) to so design process ventilation as to prevent the escape of dust which might settle on horizontal surfaces and become a potential source of disaster at some distance from the dusty operation. (See Chapter 46). The intensity of a dust explosion depends upon: the chemical and thermal properties of the dust; the particle size and shape; the concen tration in air; the proportion of inert dust in the air; the moisture content and composition of the air;the size and temperature of the ignition source; and the degree of dispersion of the dust cloud. Investigations on the explosibility of dusts require a determination of the maximum pressure developed during an explosion of a known' air concentration, as well as Air C ontam inants 177 determination of the rate of pressure rise. Investigators frequently experience difficulty in obtaining dust suspensions of uniform dispersion, and this should be kept in mind when comparing results from several sources u. The minimum explosive concentrations of airborne dusts already tested range from 0.01 to 0.5 oz per cubic foot, or 10 to 500 grams per cubic meter of air'. Maximum pressures generated have been reported as high as 500 psi, although the are more likely to be of the order of 50 psi. Investigations on the flammable characteristics of dusts are currently made at 0.1 and 0.5 oz per cubic foot-*6"21. ATMOSPHERIC POLLEN The properties of pollen grains discharged by weeds, grasses and trees and responsible for hay fever are of special interest to engineers who design equipment for their removal from indoor air (see Allergic D is orders in Chapter 13, and Air Cleaning Devices, Chapter 33). Whole grains and fragments transported by the air range chiefly between 10 and 50 microns in size, but some have been measured as small as 5 microns and others over 100 microns in diameter. Ragweed pollen grains are fairly uniform in size within the range of 15 to 25 microns. Pollen grains can be removed from the air more readily than the parti cles of dust prevalent in outdoor air and found near dusty industrial processes, since the latter predominate in the range of 0.1 to 10 microns in size. Most grains are quite hygroscopic and therefore vary in weight with the humidity. Illustrations and data on individual pollen grains are available in the botanical literature 21532i. .The geographical distribution of plants known to produce hay fever is also recorded 28,2S. The quantity of pollen grains in the air is generally estimated by exposing an adhesive-coated glass plate outdoors for 24 hr and then counting calibrated areas under th microscope. Methods are available for determining the number of grains in a measured volume of air 2&27 28 but their greater accuracy has not caused them to replace themore simple gravity slide method used for most pollen 1counts. Counting technics vary somewhat, but the daily pollen counts reported in local newspapers during the hay fever season usually represent the number of grains found on 1.8 sq cm of a 24-hr gravity slide. Hay fever sufferers may notice the first symp'toms when the polln coiint is 10 to 25, and in some localities the maximum figures for the seasonal peak may approach 1000 for a 24-hr period, depending upon the sampling and reporting methods of the laboratory.1Translation of gravity counts by special formulas to a volumetric basis, or the number of grains per cubic yard_or per cubic foot of air, is still uncertain because of the com plexity of the modifying factors. When such information is important, it is best obtained directly by a volumetric instrument. The number of pollen grains per cubic yard of air evidently varies from 2 to 20 times the number found on 1 sq cm of a 24-hr gravity slide, depending on grain diameter, shape, specific gravity, wind velocity, humidity and physical placement of the collecting plate26,30,81. AIRBORNE BACTERIA Study of the occurrence and significance of micro-organisms in the atmospheres of the indoor world is currently absorbing the energies of a 178 CHAPTER 10 1948 G u ide substantial number of physicians, bacteriologists, aerobiologists, physi cists, public health workers, engineers and hospital personnel. Some data are available on the types and quantities of bacteria found in a variety of occupied and unoccupied spaces, but it is not possible at I> present to use this information as a conclusive index of the potential health hazard of a given environment. The reported number of airborne organisms may vary from 1 to 1000 per cubic foot of air, influenced some what by the method of testing 32. Many are attached to the dust particles which are also present in the air. Where it seems advisable or desirable to control the bacterial content of rooms, public conveyances or buildings, highly effective methods are available (see Chapter 13), and their extended use may do much to assist the workers in this field in .accumulating the necessary mass of evidence that will decide the practical value of air sterilization for the control of communicable disease. It is now well established that ultraviolet radia tion is commercially feasible for the protection or preservation of phar maceuticals, cosmetics, and food products. REFERENCES ' --Atmospheric Pollution of American Cities for the Years 1931 to 1933, J. E. Ives et al (U. 5. Public Health Service Bulletin No. 224, March 1936). 2--Micromcritics, The Technology of Fine Particles, by J. M. DallaValle (Pitman Publishing Cor poration, 1943). 3~Atmospherlc Pollution Due to Smoke, by A. C. Stern (Heating and Ventilating, May, 1945). Atmospheric Pollution Due to Dust and Cinders, by A. C. Stern (Heating and Ventilating, July, 1945). 4_SootfalJ Studies for New York City, by J. Siegel and B. Feiner (A.S.H.V.E. J ournal Section. Heating, Piping and Air Conditioning, September, 1945, p. 495). 5-- 1The Use of Fuel Consumption and Equipment Data in the Abatement of Atmospheric Pollution, by A. C. Stern (A.S.H.V.E. J ournal S ection, Realing, Piping and A ir Conditioning, August, 1945, p. 447-454). 6-- 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, Vol. 19, 1929, p. 7). 7-- Studies in Illumination--III: A Study of the Loss of Light Due to Smoke on Manhattan Island, by J. E. Ives (U. S. Public Health Service Bulletin No. 197, June, 1930). Study and Control of industrial Atmospheric Pollution Nuisances, by F. M. Stead (American Journal of Public Health, Vol. 35, May, 1945, p. 491-498), Evaluation of Odor Nuisance in the Manufacture of Kraft Paper, by J. M. DallaValle and H. C. Dudley ( U. S. Public Health Service Reprint No. 2022, Public Health Reports, Vol. 54, January 13. 1939, p. 35-43). ' --Disposal of Refinery Wastes, Section II: Waste Gases, Vapors, Sludges and Dusts (American Petroleum Institute, New York City, 1938). i ' --Offensive Trades, by David Ronald (William Hodge and Co., London). Limits of Inflammability of Gases and Vapors, by H. F. Coward and G. W, Jones (U. S. Bureau of Mines, Bulletin No. 279, 1939). ' 3--Inflammation Limits and Their Practical Application in Hazardous Industrial Operations, by G. W. Jones (Chemical Reviews, Vol. 22, February, 1938). n --Private Communication, by Hylton R. Brown (Bureau of Mines, College Park, Maryland). lB--Explosibility of Agricultural and other Dusts as Indicated by Maximum Pressure and Rates of Pressure Rise, by P. W. Edwards and L. R. Leinbach (U. S. Department of Agriculture Technical Bulletin No. 490, October, 1935). 16--Dust Explosion Hazards in Plants Producing or Handling Aluminum, Magnesium, or Zinc Powder, by H. R. Brown (U. S. Bureau of Mines Information Circular No. 7148, March, 1941), ' 7--Inflammability and Explosibility of Metal Powders, by I. Hartman. J. Nagy and H. R. Brown (7. S. Bureau of Mines Report of Investigation No. 3722, October, 1943). ' --Inflammability and Explosibility of Powders Used in the Plastics Industry, by I. Hartman and J. Nagy (TJ. S. Bureau of Mines Report of Investigation No. 3751, May, 1944). 1?--Industrial Dust Explosions, by H. R. Brown (V . S Bureau of Mines, Information Circular No. 7309, January, 1045). Air Contam inants 179 2 0 -- proposed Code for the 'Prevention of Dust Explosions in the Plastics Industry (Notional Fire Protection Association, Boston, May, 1945). 21-- National Fire Codes for the Prevention of Dust Explosions (National Fire Protection Association, Boston, 1944). Contains codes for aluminum, magnesium, coal, pulverized fuel, flour, spice, starch, sugar, cocoa, sulfur and wood. 22_An Introduction to Ppllen Analysis, by G. Erdtman (Chronica Botanica Co., Waltham. M^ss, 1943) 2 3 --pollen Grains, by R. P. Wodehouse (McGraw Hill Book Co., New York, 1935). 24"-Atmospheric Pollen, by R. P. Wodehouse (Aerobiology, p. 8-31, Publication No. 17, American Association for the Advancement of Science, Washington. D.C., 1942). 25~Hayfever Plants, by R, P, Wodehouse (Chronica Botanica Co., Waltham, Mass., 1945). 26_Hay Fever: A Geographical and Botanical Survey, by E. R. Squibb and Sons. New York, 1937, 27_Techniques for Appraising Air-Borne Populations of Microorganisms, Pollen and Insects (Phyto pathology, Vol. 31. March, 3941, p, 201-225). 28--Apparatus for Determining the Pollen Concentration of the Atmosphere, by B. J. Cody, W. F. Kinney and N. A. Kerstein (Research Department, the Detroit Edison Company,^Detroit). 2fi--The Volumetric Incidence of Atmospheric Allergens, by O. C. Durham (Journal of Allergy, Vol. 14, September^ 1943, p. 455-481), so--The Volumetric Incidence of Atmospheric Allergens, II: Simultaneous Measurements by Volumetric and Gravity Slide Methods, by O. C, Durham (Journal of Allergy, Vol. 15, May, 1944, p. 226-235). 31--Air-Borne Fungus Spores as Allergens, O. C. Durham (Aerobiology, p. 32*47, Publication No. 17, American Association for the Advancement of Science^ Washington, D. C., 2942). 32~Sampling Devices, by H. G. DuBuy and A. Hollaender (American Journal of Medical Science, Vol. 209. February, 1945, p. 172-177). BIBLIOGRAPHY Abstracts and Bulletins (monthly, annual and special) Industrial Hygiene Founda tion, Inc., Pittsburgh, Pa. Aerobiology, Publication No. 17 (A m erican Association jo r the Advancement of S ci ence, Washington, D . C., 1942). Air Sanitation and Industrial Ventilation, by W. N . Witheridge (Detroit, Mich., 1945). Analytical Chemistry of Industrial Poisons, Hazards and Solvents, by M. B. Jacobs (Interscience Publishers, New York, 1941). . Bibliography of Industrial Hygiene, 1900-1943 ( U. S. Public Health Service B u l letin N o. 289, 1945). Clouds and Smokes, by W. E, Gibbs (P. Blakiston's Son & Co., Philadelphia, Pa,, 1924). Determination and Control of Industrial Dust, by Bloomfield and DallaValle ( U. S. Public Health Service B ulletin No. 217, 1935). Dust, by S. C. Biacktin (The Sherwood Press, Cleveland, 1934). (The) Environment and Its Effect upon Man (Harvard School of Public Health, Boston, 1937). Industrial Dust, by Drinker and Hatch (McGraw Hill Book Co., New York, 1936). Journal of Industrial Hygiene and Toxicology (monthly) (Harvard School of Public Health, Boston, Mass.). See cumulative abstract and subject indexes. Manual of Industrial Hygiene, by W. M. Gafafer et a! ( U. S. Public H ealth Service, W. B. Saunders Co., Philadelphia. 1943). Noxious Gases and the Principles of Respiration Influencing their Action, by Henderson and Haggard (A m erican Chemical Society Monograph Series No. 35, Reinhold, New York, 1943). Occupation and Health, two volumes (International Labor Office, Washington, D. C.). Toxicology and Hygiene of Industrial Solvents, by Lehmann and Flury, translated by Eleanor King and H. F. Smyth, Jr. (Williams and Wilkins, Baltimore, 1943). A ir Conditioning Unit Heaters and Cooiors The TRflflE Company 2021 Cameron Avenue, La Crosse, W isconsin COMPLETE LINE OF HEATING, COOLING, AIR CONDITIONING AND AIR HANDLING EQUIPMENT Over 70 XJ. S. Branch Offices Albany, N ew York Albuquerque, N . M. Allentown, Pa. Amarillo, T exas Appleton, W is. Atlanta, G eorgia Aurora, I llinois Baltimore, M d. Billings, Montana B irmingham, Alabama Boston, M ass. B uffalo, N, Y. C anton, O hio C hattanooga, T e n s . Chicago, Illinois C incinnati, Ohio Clarksburg, W. Va. Clarksville, T enn. Cleveland, Ohio Columbus, Ohio Dallas, T exas D avenport, Iowa D ayton, Ohio D enver, C olorado D ps Moines, Iowa D etroit, M ich. F lint, M ichigan Gainesville, F la. G rand R apids. M ich. Greensboro, NYC. G reenville, S C. H arrisburg, P a. H ouston, T exas Indianapolis, I n. K ansas City, M o. K noxville. Tenn. La Crosse, W is. Lake Charles, La. Los Angeles, C alif. Louisville, Ky. Memphis, T ennessee M ilwaukef.. W is. M issoula, M ontana Newark, N ew J ersey N ew Orleans, La. N ew York. N. Y. O klahoma C it y , Okla. Omaha, N ebraska P hiladelphia, P a Phoenix. Ariz. P ittsburgh, Pa. P ortland, Maine P ortland, Oregon PKOVIDENCEy R. I. Sales Connections All Over The World R ichmond, Va . Roanoke, Va. R ochester, N. Y. Salt L ake C ity, Utah San F rancisco, Ca u f . Seattle, Washington Sioux C ity, Jowa South B en, I n. Spokane, W ash. St. Louis, M oSt . P aul. M in n , Syracuse, N Y. T oledo, O hio T rumbull. Conn W ashington. D C. W, H artford, Conn. W ilkes-Barre, Pa. W ilmington, D el. W orcester, M ass. In Canada: T rane Company of Canada, L td,, M owal & King Sts., \V,, Toronto. O nt. (1 Branches) A COMPLETE LINE The Trane Company fabricates a complete line of heating, cooling, air conditioning and air handling equipment. Long years of experience with practical knowledge gained from close field contact, have developed products for every requirement. Trane S ystem s--So com prehensive is the Trane Line that any number of complete heating and air conditioning system s can be designed in which all the major parts are made by Trane. Examples: Trane Custom-Air System of Air Conditioning for multipleroom buildings: central and unit systems of air conditioning for comfort and processes; steam and hot water heating system s. P roducts used in these systems are designed and made together for use together. Undivided responsibility. Trane C onvector-radi a to r--The modern successor to the old-fashioned radiator, the Trane Convector-radiator is a compact, light-weight, easy-toinstall unit. Available for either steam or hot water heat ing system. It combines attrac tive appearance with long life and economical service. Currently easier to obtain and install than ever, new Type A Units are available _from stock throughout the nation, Trane C oils--There are Trane Extended Surface Coils for every heating or cooling, comfort or process application, in all types and sizes. Types 7'ype E Healing Coil Torridor Unit Heater Projection Healer 1000 include coils for steam, hot water or booster heating, direct expansion or water cooling. Trane Blower Type Unit H eaters--Better known as Torridcrs, Trane Blower Type Unit Heaters are available for large space or duct work ap plications. Ideal for heating large spaces, exposed areas requiring a blanket of beat, and for process applications. Trane Projection Heaters --A Trane development, the Projection Heater taps the usually wasted heat reservoir at the ceiling bringing it down where it-is needed. Installed at 8 to 50 ft. he.ights, it projects warm air to the floor in a circular, vertical air stream. Ideal for low or high pressure systems in factories, ware houses, etc. Trane P rop eller Unit H eaters--Featuring a quiet operating, wide-bladed (an that pushes rather than bats the heated air through the coil, the Trane Propeller Unit Heat er incorporates many unusual features, including adjustable louvers or grilled outlets di recting heated air to the floor line, rugged motor supports, attractive appearance. The Trane Company Air Conditioning U nit Heaters a n d C oolers Trane Air C onditioning M a n u a l-- Trane offers the engineering profession a straight-forward and unbiased textbook covering the funda mentals of air conditioning, in a new enlarged edition. The Manual not only shows how to design every type of air conditioning system, but also clarifies underlying principles, enabling both student and engineer to reason out their own problems. Price--S5.00. Trane R efrigeration M anual published primarily as an aid in understanding and correcting installation and service problems. Price --$1.50. Trane Clim ate Changers --Trane Climate Changer, a unit type air conditioner, is designed for summer, winter, or year 'round air condition ing, commercial and indus trial application, comfort or process installations. Avail able in various coil combina tions with or without humidfication equipment. Trane R efrigeration E quipm ent -- Outstanding in the refrigeration field is the Trane Turbo-Vacuum Compressor, a completely self-contained hermetically sealed centrifugal type water chiller, available in SO, 70, 100 and 200 ton sizes. Year 'round efficiency in constant operation with a minimum of maintenance is assured by the scientific simplicity of this machine. Trane also furnishes a com plete line of Reciprocating Compressor and Condensing Units with capacities ranging from 3 to 100 tons. Also available are Trane Self-con tained Air Conditioners for shop and office spaces. Trane Roof Ventilators --The Trane Roof Ventilator can be used wherever an effective roof ventilator is required. This unit is avail able for cither exhaust or supply purposes. Trane Centrifugal Fans --Recommended for all types of heating, cooling, and air handling applications. In Climate Changer Reciprocating Compressor 1001 direct or belt-driven units, single or double widths, and all standard discharges in both backward and forward curved blade construction. Capacities 200 to 330,000 cfm. Trane Steam Heating Specialties--There are over fifty valves, traps, vents, strainers, all allied specialties in the Trane Line. Among them are the famous Trane Hermetic Valve with the Lifetime Diaphragm that ab solutely prevents steam leak age around the stem and the Thermostatic Radiator Trap which when used together provide an ideal combination for convectors and radiators. Trane Hot Water H eat in g Specialties -- Included among Trane Hot Water Heating Specialties are the Trane Circulator, Fio Valves, and Fittings. They combine with Trane Convectors or Unit Heaters to provide an ideal Warm Water Heating System for a great variety of applications. Other Trane Equipm ent --The complete Trane Line also includes-- 1. Trane Unit Ventilators for schoolroom air conditioning; 2. Trane Condensation and Centri fugal Pumps for a large variety of uses; 3 Trane Dry Type W ater Chillers; 4. Trane Evaporative Conden sers to condense refrigerants ill the air conditioning system with a minimum use of water; 5. Trane Cooling Towers; 6. TraneForce-Flo Heater for quiet heat and neat appear ance; 7. Trane Railroad and Bus Air Conditioning Equip ment of all kinds; 8. Trane Shell and Tube Heat Ex changers for cooling and heat ing vapors or liquids in a closed system;9. Evaporative Coolers for cooling fluids in a dosed system; 10. Trans former Oil Coolers; II. Air Washers. Write today for Trane Condensed Catalog PB290 which describes completely all of the products listed here as well as providing sufficient data for their selection. 108 H e a tin g V e n tila tin g A ir C o n d itio n in g G u id e 1948 TOWNE, R obin M . (J 1945) Asst. Engr., Richard M. Stem. Cons. Engr., 1331 Third Ave., Bldg., Seattle 1, and #4020 East 135th St., Seattle 55, Wash. TOW NER, C harles E. (A 1944) Testing Engr., Crane Co., 836 S. Michigan Ave., Chicago, and 9141 S. Mayfield, Oak Lawn, 111. TOWNSEND, J o h n M. (M 1942) Sales Engr.. Servel Inc., 122 S. Michigan Ave., Chicago, and 6138 Kirabark, Chicago 37, Hi. TRACY, J o h n W. (M 1945) Sales Engr.. Minneapolis-Honeywell Regulator Co., 415 Brainard St., Detroit 1, and *18687 Pennington Dr., D etroit 21, Mich. TRACY, W illiam E. (A 1943; J 1938) 906 N. Austin Blvd., Oak Park, 111. TRAMBAUER, C harles W, (M 1945; A 1941; J 1936) Sales Mgr., Herman Nelson Corp., 424 Book Bldg., Detroit 26, and 9262 Piedmont, Detroit, Mich. TRANE, R euben N.* (M 1915) Pres., T heT rane Co., and 208 South 15th St., LaCrosse, Wis. TRAUGOTT, M o rtim er (A 1930) Bryant Air Conditioning Corp., 915 N. Front St., Phila delphia 23, and 8208 Westminster Rd., Elkins Park Pa TRAUTMAN, F red L. {M 1944) Owner, T rautman Engineering Co., 1122 East 17th Ave., Denver, Colo. TRAYNOR, H arry S. (A 1942; J 1937) Mgr., Regent Knitting Co., 219 Washington Sq., Syracuse, and 137 Edwards Dr., Fayetteville, N. Y. TRAYNOR, J o h n H . (M 1946) Sales Engr., Johnson Service Co., 1031 W yandotte St., Kansas City 6, and 232 Rainbow Lane, Kansas City, Mo. TREADWAY, J . Q u e n tin (A 1936; J 1932) Dist. Sales Mgr., Clarage Fan Co., 706 Reynolds Arcade, and 826 Winona Blvd.. Rochester, N. Y. TR EFT S, J o h n C ,, J r . (M 1944) Vice-Pres. and Gen. Sales Mgr., Farrar & Trefts, Inc., 20 Milburn St., Buffalo 12, and East Quaker Rd., Orchard Park* N. Y. TRELEAVEN, H . M . (A 1946) Mgr., Air Cond. Dept., Trane Company of Canada, Ltd., 4 Mowat Ave., Toronto, Ont., Canada. TRENHAILE, D ale T. (J 1945) Mech. Engr.. Ind. Design, Vent., Htg., Refrig. & Air Cond. G. R. P.. Ind. Design Br., Nav. Shipyard, Pearl Harbor, and 2188 Helumoa Rd., Honolulu 20, T . H. TRICKEY, George (A 1945) Sales Engr., Pease Foundry Co., Ltd.. 227 Victoria St., and 97 Oakwood Ave.. Toronto, Ont., Canada. T R ICK LER, Earl E. (M 1942) Chief Engr., New York Blower Co., 32nd and Shields, and #8219 Kenwood Ave., Chicago 19, 111. T R IEG EL, E rich V. (M 1942) Mech. Engr., Francisco & Jacobus, 511 Fifth Ave., New York, N. Y., and R. F. D. 3, Danbury, Conn. T R IG G S, F red E , (M 1938) Factory Repr., 215 Plymouth Bldg., Des Moines 9, and 3901 Second Ave., Des Moines 13, la. TRIM BLE, C larke R, (Af .1946) Pres. & Treas., C. R. Trimble Co., Inc., P. O. Box 6066, and *205 Cottage PI., Charlotte 7, N. C. TRIM BLE, J o h n I. (M 1945) Mgr., Janitrol Engrg., Surface Combustion Corp., 400 Dublin Ave., Columbus, and 2038 Bedford Rd., Colum bus 8, Ohio. TRITL E, H arold J . (A 1946) Sales Mgr., S. T. Carlson Co., P. O. Box 961, and 1114r-37th, Des Moines, la. - TRODD, E dw ard R . (A 1946) Asst. Engr., .Canadian Pacific Railway Co., Room 401, Windsor Station, Montreal, and 848 - Wolseley Ave,, Cote St. Luc., Que., Canada. TROLLER, T . H.* ( M 1943) Vice-Pres.. Charge of Engrg., jo y Manufacturing Co., 333 Oliver Bldg., Pittsburgh 22, Pa., and 1250 Sunsetview Dr., Akron 2, Ohio. TROSTEL, O tto A. (M 1935) Engr., Standard Distributing Co., 406 E.-Wells -St., Milwaukee 2, and Rt. 2, Thiensville. Wis. TRO U P, J o h n D. '{M 1938) Managing Dir., ' John D. Troup, Ltd., 90 High Holborn, London, W. C. 1, and 48 Plough Lane, Purley, Surrey, England. TROW BRIDGE, C arl Y. (A 1944) Secy.-Treas. and Gen. Mgr., R ay F. Fischer Go., 323 N.W. T enth St., Oklahoma City 3, and 3420 Northwest 25th St., Oklahoma City, Okla. ' TRUCHON, L ouis P . (A 1947) Sales Engr. & Draughtsman, Trane Company of Canada, Ltd.. 926 Price Bldg., and 429 St. Vallier St., Quebec City, Que., Canada. TRUM BO, S. M . (A 1926) Sales, Buffalo Forge Co., 20 N. Wacker Dr., Chicago 6, and 921 Frank lin St., Downers Grove, 111. TUCK, R o b e rt G. (A 1946) Engr., International Sales Co., 2045 Evans Ave., San Francisco, and 1061 San Raymundo Rd., Hillsborough, Calif. TUCKER, F ra n k N. (M 1926) Field Engr., Ilg Electric Ventilating Co.. Crawford Ave., Chicago, 111., and 239 Whaley St., Freeport, L. I., N . Y. TUCKER, J , R o b e rt (A 1945) Engr., Com mercial Testing, United States Testing Co., Inc., 1415 Park Ave., Hoboken, and *86 Bergen Ave., Teaneck. N. J. TUCKER, L eonard A. (M 1935) Service Mgr., J . J. Pocock, Inc., 1920 Chestnut St., Philadelphia 3, and 220 Buttonwood Way, Glenside, Pa. TUCKER, R a lp h E. (M 1947) Bldg. Supt.. Foley Bros., 407 Main St., Box 1971. Houston, and 228 Santa Fe D r,, Houston 12, Texas. TUCKER, Sydney <M 1945) Chief Engr.. Ftzgibbons Boiler Co., Inc., and 247 W. Sixth St.. Oswego, N. Y. TUCKER, T h o m a s T . (M 1938; A 1936) Chief Engr., Armor insulating Co., 1102 Candler Bldg., and 800 Forrest St. N.W., Atlanta, Ga. TUCKERMAN, George E . <M 1932) Special Repr., Air Cond. and Refrig. Div., Worthington Pump & Machinery Corp., 2905 N. Broad St.. Philadelphia 32, and #20 Meridith Rd., Green Hill Farms, Merlon, Pa. TUFFLY, H arry J . (S 1946) Student, Texas A. & M. College, Box 5605, College Station, and 715 Skillman St., Dallas, Texas. TU ITE, Ja m e s M. (A 1947.) Asst. Mgr., B. P. Tuite Co., Oneida, and 1156 Taylor Ave., Utica, N. Y. TUNZIN, B ernard (M 1947) Mgr.. Etablisse ments Tunzinl 69 Rue Legendre, and 126 Quai Louis Blriot, Paris 16, France. TUPPER, E dw ard B. (A 1948; J 1944; S 1941) Refrigerative Supply, 2211 Fifth Ave., and 6231-- 34th N.E., Seattle 5, Wash. TURLAND, C harles H en ry (M 1934; A 1930) E n g r.,# R . E. Johnston Co., Ltd., 1070 Homer St,, and 4553 W. Third Ave., Vancouver, B. C., Canada. TURNBULL, E rn e s t R . (A 1948) Designer, Karel R. Rybka, Cons. Engr., 96 Bloor St. W., and 211 St. Germain Ave.. Toronto, Ont., Canada. TURNBULL, F ra n cis J . (M 1945) Engr., Fay Spofford & Thorndike, 11 Beacon St., Boston, and 625 Pleasant St., Milton 86, Mass. TURNER, E d m o n d S. (A 1939) Partner, W il liam S. Turner & Co., 432 Pacific Bldg., Portland 4, and 3455 Northeast 36th Ave., Portland 13, Ore. TURNER, G eorge G . (A 1945) Western Mgr., Heating & Ventilating Magazine, 228 N. LaSalle St., Chicago 1, and 827 Hininan Ave., Evanston, III. TURNER, George W. (M 1944) Mgr., George B. Mallory Co., .1436 Blackstone Ave., and 203 Shields, Fresno, Calif. TURNER, J o h n F. (M 1947; A L946) Asst, to Pro ject Engr., Monsanto Chemical Co., and 142 Georgia Ave., Oak Ridge, Tenn. TURNER, J o h n P ., Jr* ( M 1942) Field Sales Mgr., Air Cond. Dept., General Electric Co.; 5 Law rence St., Bloomfield, and 727 Mosswood Ave., Orange, N. J. TURNER, -W illiam M , (A 1945) Supvsr. Engr., The Ripstra Co., 1016 E. Douglas, and *4802 E. English, Wichita, Kans. TURNO, W alter G. W. (M 1917,; A 1912) Secy., H. W. Porter & Co., Newark, and *71 Lafayette Ave,, East Orange, N . j ; TUSCH, W a lte r (U 1917) Retired, 881 Sterling PL. Brooklyn 16, N . Y. ' TUTHILL, A rth u r F . (A 1947; J 1940; 5 1938) Asst. Prof., Dept, of Mech. Engrg., University of Vermont, Burlington, and 78 E. F ort E than Allen, Winooski, Vt. . ' *- . TUTSCH, R odney J . <A 1943; J 1939) Sales & Appl. Engr., Cleavr-Brooks Co.. 326 E. Keefe Ave., Milwaukee 12, and 4455 N. Oakland Ave., Milwaukee, Wis. TU TT, R ich a rd D. (M 1946; J 1942) Chief Engr., Tuttle & Bailey, Inc., and 99 Sylvan Rd., New Britain, Conn.