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256 CHAPTER 13' 1946 Guide CHAPTER 14 A.S.H.V.E. Research Report No. 654--Some Physiological Reactions of High Temperatures and Humidities, by W. J. McConnell and F. C. Houghten (A.S.H.V.E. Transactions. Vol. 29. 1923, p. 129). > "-A.S.H.V.E. Research Report No. 1054--Fever Therapy Induced by Conditioned Air. by F. C. Houghten. M. B. Ferderber and Carl Gutberlet (A.S.H.V.E. Transactions, Vol. 43. 1937. p. 131). A.S.H.V.E. Research Report No. 1161--Fever Therapy Locally Induced by Conditioned Air, by M B Ferderber. F. G. Houghten and Carl Gutberlet (A5.H.V.E. Transactions, Vol. 46, 1940, p. 307). - H,,os3p4it_a?l,<i6?4?:S86,r.a1ti9?.4n.5,),.or Anesthesia and Therapy, by L. W. Crossman and S. K. Safford (The. Modern , , "_Air Cleaning as an Aid in the Treatment of Hay Fever and Bronchial Asthma, by Leo H. Criep and M. A. Green (Journal of Allergy, 7:120. 1936). .. .. ""The Effect ofLow Relative Humidity aiid Constant Temperature on Pollen Asthma, by B. Z. Rappa- port, T. Nelson and W. H. Welker (Journal of Allergy, 6:111) 1935). . - _ .''-Hospitai Air Conditioning, by C. P. Yaglou (The Environment and Its Effect Upon Mail, 'Harvard School of Publtc Health, p. 244, 1939). . : ; "f-Manual of Oxygen Therapy Techniques,- by A. H. Andrews. Jr. (Tie Year Book Publishers Inc ' 1943). -- , . "rPrinciples and Practices of Inhalational Therapy, by A. L. Barach (J. B. Llppincbtt Co!. Phila- ' deiphia, London, Montreal, 1944).' ' ; " ... 4--The Management of Pneumonia, by j. G. M. Bullowa, (Oxford University Press, p. 260. 1937). ^JJcatiruj cjCoad General Procedure, Outside Temperatures, Inside Tempera tures, Attic Temperatures, Temperatures in XJnheated Spaces, Ground Temperatures, Basement Temperatures and Heat Loss, Transmission Heat Loss, Heat Loss Through Ceilings and Roofs, Infiltration Loss, Selection of Wind Velocities, Auxiliary Heat Sources, Intermittently Heated Buildings, Residence Heat Loss Problems IN the design of a heating system, an estimate must be made of the maximum probable heat loss of each room or space to be heated, based on maintaining a specified inside air temperature during periods of minimum selected design weather conditions. The heat losses may be divided into two groups, namely (1) the transmission losses or heat losses through the confining walls, floor, ceiling, glass or other surfaces and (2) the infiltration losses or heat losses due to air leakage through cracks and crevices, around doors and windows, opening of doors and other sources of interchange of air between the inside and outside. - ; . GENERAL PROCEDURE The general procedure for calculating heat losses of a structure is: 1. Select the outside design temperature. The data on climatic conditions given in Table 1 and the Design Temperature Zone Map, Fig. 1, will be.useful but should be applied with judgment as suggested in the section Outside Design Temperatures. 2. Select the inside air temperature, at the 60-in. breathing line or the 30-in. line, which is to be maintained in the building during the coldest weather. (See Table 2). 3. Estimate temperatures in adjacent unheated spaces and the attic. The attic temperature need not be estimated if the combined roof and ceiling coefficient is used. 4. Select or compute the heat transmission coefficients for outside walls and glass; also for inside walls, floors, or top-floor ceilings, if these are next to. unheated space; include roof if next to heated space. (See Chapter 6). ' 5. Measure amount of net outside wall, glass and roof next to heated spaces, as well as any cold walls, floors or ceilings next to unheated space. Such measurements are made from building plans, or from the actual building, .using inside dimensions. 6. Compute the heat transmission losses, for each kind of wall, glass, floor, ceiling and .'roof in the building fjy multiplying the heat transmission coefficient in each case by the area of the surface in square* feet and the temperature difference between the inside and outside air. (See Items 1, 2, and 3). 7. Select unit values and compute the heat equivalent of the infiltration of cold air taking place around outside doors and windows. These unit values'depend on the kind or width of crack and wind velocity, and when multiplied by the length of crack and the temperature difference between the inside and outside air, the result expresses the heat required to warm up the cold air leaking into the building per hour. (See Chapter 8). 8. The sum of the heat losses by transmission (Item 6) through the outside wall and glass, as well as through any cold floors, ceilings or roof, plus the heat.equivalent (Item 7) of the cold air entering by infiltration, or required, to replace mechanical exhaust, represents the total heat loss equivalent for any building. OUTSIDE DESIGN TEMPERATURES There are no hard.and fast.rules for selecting the outside: design tem perature to be used for a given locality or type of building or heating system, and the problem is to some extent a matter of judgment, and experience. The outside design temperature is seldom, taken as the lowest temperature, or even the lowest daily mean temperature ever recorded & in a given locality. Such temperatures are rarely repeated in successive '! years. A temperature somewhat higher than the minimum or the lowest daily mean on record may properly be assumed in making the heat loss 257 *................................................... --* - /.- *