ARMY TM 5-745-1968 HEATING VENTILATING AIR CONDITIONING AND SHEET METAL WORKS《加热 通风 空调和金属板制品》.pdf

1、TM 5.745 1 DEPARTMENT OF THE ARMY TECHNICAL MANUAL HEATING, VENTILATING AIR CONDITIONING AND SHEET METAL WORKS HEADQUARTERS, DEPARTMENT OF THE ARMY Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- W 3535789 0213014 673 ACKNOWLEDGEMENT Acknowledgment

2、is gratefully made to the following organizations for their permission to use Figure 8-3, American Standard, Heat Transfer Producta Division Figures 9-6 and 9-8, Chrysler Airtemp Figures 9-9, 9-10) 9-11, and 9-12, Barber-Colman Company Figures 9-44, 9-45, 946, 9-47 and 9-48, Dunham-Bush, Inc. Figure

3、s 4-9, 4-14 and 4-18, ITT Bell and Gossett Figure 5-8, The Coleman Company, Inc. Figures 3-6 and 6-3, The Trane Company Figure 7-2, Trion, Inc. Figure 7-1 (3), Owens-Corning Fiberglas Corporation Figure 3-44, Johns-Manville Figure 3-4, American Radiator and Standard Sanitary Corp. Figure 3-62, McDon

4、nell and Miller, Inc. Figure 8-7, Minneapolis-Honeywell Regulator Company Figures 9-6, 9-17, 9-23, 9-24, 9-28, 9-29, 9-80, 9-31, 9-32, in this manual the illustrations and tables indicated: 3, 9-38, 9-39, 9-40) 9-41, 9- 51, 9-52, 9-63, 9-64, 9-66, 9-66, 9-67,9-69,940 an 7 9-61, Worthington Air Condi

5、- tioning Company Figures M-1, M-2, and M-3; Tables El, E-2, E-3, E-4, E-6, Ea, E-7, EaA, E-B, E- 9A, E-gB, E-lOA, E-lOB, E-ll, E-12, E-13, E-14, E-16, E-16, and E-17, The American Society of Heating, Refrigerating and Air Conditioning Engineers, Inc. ( ASHRAE Handbook of Fundamentals, 1967) Provide

6、d by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-3515789 0213015 50T W This manual contains colyrighted mterbl TECHNICAL MANUAL No . 5-745 *TM 5-745 HEADQUARTERS DEPARTMENT OF THE ARMY WASHINGTON. D.C., 29 October 1968 HEATING. VENTILATING. AIR CONDITIONING.

7、 AND SHEET METAL WORK CHAPTER 1 . Section I . II . III . Section 1 . II . III . IV . V . CHAPTER 3 . Section I . II . III . IV . CHAPTER 4 . Section I . II . III . IV . CHAPTER 5 . Section I . II . III . IV . CHAPTER 6 . Section I . II . III . CHAPTER 7 . Section I . II . III . CHAPTER 8 . Section I

8、 . II . III . IV . CHAPTER 9 . Section I . II . III . CHAPTER 2 . Paragraphs AIR AND COMFORT Introduction 1-1-1-3 Properties of air 141-6 Human comfort 1-7-1-11 HEATING LOAD Heat transmission . 2-1-2-3 Design temperatures . 24-2-5 Infiltration loss . 2-6-2-7 Allowances for piping losses and pickup 2

9、4-2-10 Combustion-air circulation 2-11-2-12 STEAM HEATING Description of equipment 3-1-3-10 Design of heating systems 3-11-3-17 Control . 3-18-3-20 Installation 3-212-22 HOT WATER HEATING Description of equipment 4-14-8 Design of hot water systems . 4-94-15 Installation . 4-194-20 WARM AIR HEATING .

10、 Controls . 4-1-18 Description of equipment . 5-1-5-6 Design of warm air systems . 5-7-5-10 Control 5-11-5-13 Installation . 5-14-5-17 VENTILATION Definition and available equipment . 6-1-6-4 Installation 6-9-6-10 AIR CLEANING Available equipment 7-1-7-3 Installation . . 7-4-7-5 Maintenance 7-6-7-8

11、EVAPORATIVE COOLING Description of equipment 8-1-8-3 Design of systems . 8-4-84 Control . 8-7-84 Installation . 8-9-8-14 AIR CONDITIONING Introduction 9-1-9-3 Types of systems . 9-4-9-7 installation . 9-8-9-10 Design of systems 6-5-6-8 Page 1-1 1-1 1-4 2-1 %3 2-4 24 2-5 3-1 3-9 3-26 3-31 4-1 4-7 4-1

12、2 4-14 5-1 5-16 5-24 5-26 6-1 6-4 6-9 7-1 7-4 7-6 8-1 84 8-6 8-7 9-1 9-16 9-31 This monuol rupersadcs TM 5-745. 5 November 1954 . TAG0 20073A 1850 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TM 5-745 Section IV. CHAPTER 10. Section I. II. III. IV

13、. V. VI. CHAPTER 11. Section I. II. III. APPENDIX A. B. C. D. E. F. G. H. 1. J. K. L. M. N. O. P. INDEX 3535789 023303b 44b Paragraphs Page Design calculations . - -. . -. - - - -. . -. - - - - - - . . - 9-11-9-23 9-34 DUCTS Uses and types . . . . . . . . - . . _. . . 10-1-10-2 10-1 Metal ducts _. .

14、 _ _. . . - ._._ _._ 10-3-10-5 10-1 Fasteners for metal ducts -. . . . -. . . . - - - -. . 10-6-10-10 10-2 Qualifications and duties of personnel used in fabri- cating and erecting metal ducts . . . . . . . _. 10-11-10-12 10-3 Equipment . -. . . . _. . . . . - -. . . . - -_ - 10-13-10-15 10-3 Nonmet

15、allic ducts -. . -. . . . . . - -. . . - - - - - 10-16-10-17 10-7 DESIGN AND LAYOUT Pattern making . . . . . . . ._._ 11-1-11-8 11-1 Air ducts ._._.- 11-9-11-13 11-11 11-21 Field practice . . . . . . . - - . - - - - REFERENCES . SIZES AND CHARACTERISTICS OF AIR- BORNE PARTICLES ._ . . _._. . . . . -

16、. PSYCHROMETRIC CHART . . _. COMFORT CHART . . . . . . . -. . . . _ . . . -. - - HEAT TRANSFER COEFFICIENTS -. . . . . - . INFILTRATION COEFFICIENTS . . . - - -. -. . . . - PIPING AND PICKUP ALLOWANCES . . . . . . RADIATOR OUTPUT RATINGS - . - . . . - - - . . CAPACITIES OF STEAM MAINS AND RISERS - C

17、APACITIES OF MAINS AND RISERS OF HOT WATER HEATING SYSTEMS . . -. .-. EXPANSION TANK SIZES . . . _._._. . . . . _ GRAVITY WARM-AIR HEATING SYSTEM DESIGN . DESIGN . SHEET METAL AND WIRE GAGES . _. . . RECOMMENDED GAGES FOR SHEET METAL DUCT CONSTRUCTION . . . . - . -. -. . . . AIR CONDITIONING SYSTEM

18、DESIGN . . FORCED WARM-AIR HEATING SYSTEM A-1 B-1 c-1 1)-1 E-1 F-1 Gl H-1 1-1 J-1 K-1 1-1 M-1 N-1 0-1 P-1 ._. .-. INDEX-1 _ Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-= 3515787 02l130l17 382 TM 5-745 CHAPTER 1 AIR AND COMFORT Section I. INTRODUC

19、TION 1-1. Purpose and Scope a. The purpose of this manual is to provide a guide and a reference text on sheet metal con- struction, heati,ng, ventilating, and air condi- tioning, for use by engineer troops while in training and when in the field. b. This manual describes the materials and explains t

20、he use of tools and equipment used in construction of heating, ventilating, and air conditioning systems. It provides information on thc selection, layout, operation, construc- tion, and maintenance of these systems. It cov- ers the principles of sheet metal construction to be used in hot and cold a

21、ir systems. c. For additional information relating to the subject matter contained in this manual, con- sult the Guide and Data Books and Handbook of Fundamnta,k, published by the American Society of Heating, Refrigerating and Air Con- ditioning Engineers, Inc., 345 East 47th Street, New York, New Y

22、ork 10017. 1-2. Comments Users of this manual are encouraged to submit recommended changes or comments to improve text. Comments should refer to the specific page, paragraph, and line of text pertinent to the recommended change, Correspondence should be forwarded to the Commandant, U.S. Army Engi,ne

23、er School, Fort Belvoir, Virginia 22060. 1-3. Maintenance Maintenance information for any particular model of equipment mentioned in this manual may be obtained in the appropriate five part manual for that model. Section II. PROPERTIES OF AIR 1-4. Physical Composition As it affects human comfort, at

24、mospheric air may be regarded as a mixture of dry air, water vapor, and small quantities of substances gen- erally considered as contaminants such as smoke, dust, bacteria, and odors. a. Dry Air. Dry air is a mixture of gases which averages by volume approximately 78 percent nitrogen, 21 percent oxy

25、gen, .O3 per- cent carbon dioxide and .O1 percent hydrogen, plus a group made up of argon and other rare gases which total less than 1 percent. The pro- portions of gases making up this mixture have been found to be substantially constant at all points on the earths surface. Therefore, they are not

26、considered separately but are treated AGO 20073A collectively as a mixture of gases and called dry air. b. Water Vapor. The amount of water vapor in air varies from almost none at all to the maximum amount that the air can hold, de- pending upon the weather or upon manmade air conditions. This water

27、 vapor may be con- sidered as very-low-pressure steam. It can be condensed and reevaporated in the same man- ner as ordinary steam. c. Contaminants. Air contaminants are by- products of normal processes, both natural, such as storms or volcanoes, and manmade, such as manufacturing and agricultural p

28、ro- cesses. These contaminants may be organic (plant or animal matter) or inorganic, visible 1-1 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-m 3535789 02l1303B 237 m TM 5-745 or invisible, solid or gaseous, and toxic or harmless. Solid air contam

29、inants may be termed dusts, fumes, or smoke. Dusts include only particles of the larger sizes and may be of mineral, animal, or vegetable origin. Fumes, which are smaller particles, consist of finely divided matter formed by the condensation of vapors from normally solid material such as molten meta

30、l. Smokes consist of extremely small solid particles produced by incomplete combustion. Liquid contaminants in the form of airborne droplets are termed mist or fog. Contaminants which are neither solid nor lis- uid are termed gases if they are normally in the gaseous state, or vapors if they are the

31、 gas- eous form of substances that are either solid or liquid in their usual state. For example, gaso- line is generally in liquid form. The sizes, characteristics, and general methods for remo- val of airborne particles are listed in tabular form in appendix B. 1-5. Temperature a. Dry Bulb. The dry

32、-bulb temperature of air is the commonly understood air tempera- ture as registered by an ordinary thermometer. b. Wet Bulb. The wet-bulb temperature of air is that temperature registered by a ther- mometer whose bulb is covered by a wick which is wetted and then exposed to a current of rapidly movi

33、ng air. Evaporation of water from the wick lowers the temperature below that registered by a dry-bulb thermometer. As the rate of evaporation is determined by the amount of water present in the air surround- ing the wick, the wet-bulb temperature can be used along with the corresponding dry-bulb tem

34、perature to measure or indicate the amount of moisture present in a specific air sample. 14. Humidity a. Definition. Humidity is the water vapor or moisture mixed with dry air in the atmo- sphere. The amount of moisture can hold var- ies with the temperature, increasing as the temperature increases,

35、 The amount of moisture usually contained in a given sample of dry air is less than the maximum amount possible. The amount of moisture or humidity in the air can be defined as a percentage of the maximum 1 -2 amount. This percentage is called relative hu- midity. Air which contains only one-half as

36、 much moisture as it could contain at a given temperature is said to have a relative humidity of 50 percent. b. Humidity-Temperature Relationship. Hu- midity-temperature relationships are shown graphically on a psychrometric chart in appen- dix C. This chart plots vertical lines of con- stant dry-bu

37、lb temperature against horizontal lines of constant specific humidity, or weight of water vapor per pound of dry air. Specific humidity is usually expressed in grains per pound of dry air, a grain being 1/7000 pound. The saturation or 100 percent relative humid- ity line curving upward from the lowe

38、r left- hand corner of the chart indicates the maxi- mum amount of moisture that air can hold at any given dry-bulb temperature. Between the saturation line and the base line are curving lines of constant relative humidity. Lines of constant wet-bulb temperature slope upward to the left. The complet

39、e chart plots the whole range of air moisture and temperature condi- tions within its limits. Any point on this chart represents a specific condition of air tempera- ture and moisture content and from the point can be read the dry bulb, wet bulb, relative hu- midity, and specific humidity correspond

40、ing to that condition. One other quality, the dew- point, can also be determined. Dewpoint is defined as the temperature to which an air sample must be cooled in order to produce condensation or ?dew?. To read the dewpoint, proceed horizontally to the left from a given air condition along a line of

41、constant specific humidity until the saturation line is reached. The wetbulb temperature at the point of satura- tion is the dewpoint. c. Humidity Measurement. The amount of humidity can be determined by a hygrometer or a psychrometer. Hygrometers are direc? reading ianstruments indicating relative

42、humid- ity. Their action depends upon the change in dimension of a hygroscopic substance such as human hair or thin strips of wood which gain or lose moisture and change their dimensions as the humidity changes. These instruments are not accurate unless calibrated frequently AGO 20078A Provided by I

43、HSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-3535789 0233039 355 TM 5-745 by the more dependable sling psychrometer. A sling psychrometer consists of two thermome- ters connected to a handle by a swivel, (i), figure 1-1, so that they may be whirled in the air

44、as shown in (3), figure 1-1. The bulb of one of these thermometers is covered by a cloth wick that is moistened with water at the same temperature as the surrounding air, (Z), figure 1-1. This must be done before taking a read- ing. The wick and water must be clean and free of soap. Now whirl the th

45、ermometers rap- idly to evaporate moisture from the wick (3), fig. 1-1). Read both thermometers and whirl the instrument again. Repeat this process until D the wet bulb settles at the lowest point it will reach. This is the wet-bulb reading. Note the dry-bulb reading also. By plotting the intersec-

46、tion of the wet- and dry-bulb temperatures on the psychrometric chart, the humidity can be determined. As an example, for measured air temperatures of 80F. dry bulb and 60F. wet bulb, the intersection of the vertical 80F. dry-bulb line and the diagonal 60F. wet-bulb line on the psychrometric chart,

47、appendix C, coincides with a relative humidity of 30 per- cent (curved line) and a specific humidity of 46 grains per pound of dry air (horizontal line). Figure 1-1. Measuring humidity with a sling psychrometer. Provided by IHSNot for ResaleNo reproduction or networking permitted without license fro

48、m IHS-,-,-3535789 0233020 977 = TM 5-745 MOISTENING PSYCHROMETER WICK (c) METHOD OF OBTAINING READIN Figure 1-1-Continued. Figure 1-i-Continued. Section 111. HUMAN COMFORT 1-7. Environmental Factors a. The comfort of human beings is affected by several qualities of the air that surrounds them, including dry-bulb temperature, humid- ity, air motion, and presence of airborne solids or odors. Human occupancy of confined space produces at least five changes in the conditions of the air that can affect comfort: (1) The chemical environment 14 1855 (a) Th