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286 CHAPTER 12 1958 Guide of the results in Table 9. The values in column F of Table 8 were obtained by multi plying together the figures in columns C, D, and E. The heat losses are calculated to the nearest 10 Btu. See reference notes for Table 7 for further explanation of data. Attention is called to the summary of heat losses (Table 9) for the uninsulated resi dence. As storm windows are used in this instance the glass and door transmission heat losses of 19.8 percent are relatively small. The infiltration losses of 14.0 per cent are also comparatively small because the storm windows are equivalent to weatherstripping. In this problem, the wall, ceiling and floor transmission losses comprise 66.2 percent of the total. Example 7: Calculate the heat loss of residence shown in Fig. 2 based on the same conditions as in Example 6 but having construction improved or insulated to obtain coefficients as follows: Walls, 0.13; Walls of Dormer over Garage, 0.12; Attic Walls, 0.28; Walls Adjoining Garage, 0.18; Basement Walls (Recreation Room), 0.10. Roof, 0.53. Ceiling (Second Floor), 0.15. Windows (Same as in Example 6). Floor (Bedroom D), 0.18. Solution: The procedure for calculating the heat losses is similar to that for Example 6. A summary of the results is given in Table 10. REFERENCES i ARJ Application Engineering Standards for Air Conditioning tor Comfort, 1947 (Air-Conditioning and Refrigeration Institute). * An Analysis of Winter Temperatures for One Hundred and Twenty Cities, by Clark M. Humphreys (Carnegie Institute of Technology Bulletin 1939). Investigation of Oil-Fired Forced Air Furnace Systems in the Research Residence, by A. P. Krats and S. Konzo (University of Illinois Engineering Experiment Station Bulletin No. 318). Performance of a Hot-Water Heating System in the I=B=R Research Home at the University of Illi nois, by A. P. Kratz, W. S. Hams, M. K. Fahnestock, and R. J. Martin (University of Illinois Engineering Experiment Station Bulletin No. 349). * A Study of Radiant Baseboard Heating in the I=B=R Research Home, by A. P. Kratsand W. S. Harris (University of Illinois Engineering Experiment Station Bulletin No. 358). Performance of a One-Pipe Steam System in the I=B=R Research Home, by W. S. Harris (University of Illinois Engineering Experiment Station Bulletin No. 383). ? A.S.H.V.E. Research Report No. 1011--Tests of Three Heating Systems in an Industrial Type of Building, by G. L. Larson, D. W. Nelson, and John James (A.S.H.V.E. Transactions, VoI. 41, 1935, pv 185). - * Methods of Moisture Control and Their Application to Building Construction, by F. B. Rowley, A. B. Algren and C. E. Lund (University of Minnesota, Engineering Experiment Station Bulletin No. 17). AS H.V.E. Research Report No. 1213--Heat Loss Through Basement Walls and Floors, by F. C; Houghten, S. 1. Taimuty, Carl Gutberlet and C. J. Brown (A.S.H.V.E. Transactions, Vo!. 48, 1942, p. io Measurements of Heat Losses from Slab Floor, by R. S. Dill, W. C. Robinson and H. E. Robinsoa (U S Department of Commerce, National Bureau of Standards, Building Materials and Structures Report BMS 103). n Temperature and Heat Loss Characteristics of Concrete Floors Laid on the Ground, by H. D. Bareither. A. N. Flemming and B. E. Alberty (University ofIllinois, Small Homes Council Technical Report). it Concrete Floors for Basementless, Houses (University of Illinois, Small Homes Council Circular No. F 4.3). a Warm-Air Perimeter Heating, Part III--Heat Losses from Floor Slab, by J. R. Jamieson, R. W. Boo* and S. Konzo. (ASHVE Transactions, Vol. 58, 1952, p. 217). m Warm-Air Perimeter Heating--Manual 4, National Warm Air Heating and Air Conditioning Association; * i Heat Requirement Tables for Intermittently Heated Buildings (Engineering Experiment Bulletin No. 60, A. and M. College of Texas, College Station, Texas) contains a set of tables applicable to intermittent hasting or cooling. Further information may be found in a paper, A Method of Compiu" Tables for Intermittent Heating, by Elmer G. Smith (A.S.H.V.E. Journal Section, Heating, Ptptng on Air Conditioning, June 1942, p. 386). u Slab-on-Ground Construction for Residences, (Publication No. 385, Building Research Advisory Boar*^, National Research Council). CHAPTER 13 COOLING LOAD Cooling Load Calculations; Design Conditions; Instantaneous Heat Load; Solar Ra diation; Periodic Heat Flow; Tables for Calculating Solar Heat Gain Through Walls, Roofs and Glass; Instantaneous Heat Gain vs. Cooling Loads; Load from Interior Partitions,. Ceiling and Floors; Load from Outdoor Air, Ventilation and Infiltration; Effect of Outdoor Air on Load; Heat Sources Within Conditioned Space; Moisture Transfer Heat Load; Miscellaneous Heat Loads; Apparatus Dew Point and Required Air Quantity Through Conditioning Equip ment; Minimum Entering Air Temperature; Ex ample Cooling Load Calculation THE variables affecting cooling-load calculations are numerous, often difficult to define precisely, and always intricately inter-related. Most of the components of the cooling load vary in magnitude over a wide range during a 24-hour period, and as the cyclic changes in load com ponents are not usually in phase with each other, careful analysis is re quired to establish the resultant maximum cooling load for a building or zone. A zoned system must often handle peak loads in different zones at different hours. Economic considerations must be of particular influence in the selection of equipment for cooling season operation in comfort air conditioning, and this fact, coupled with present-inadequacies in available data and knowl edge of the air-conditioning art, places a premium on the experienced judg ment essential to successful design or practice. Variations in the weather, building occupancy, and other factors affecting load, necessitate carefully coordinated controls to regulate simultaneously the components and the equipment in order to maintain the desired room conditions. The calculation procedures presented in this chapter deal with the vari ous instantaneous rates of heat gain, both sensible and latent, in a condi- loned space. There may be an appreciable difference between the net instantaneous rate of heat gain and the total cooling load at any instant. This erence is caused by the storage and subsequent release of heat by the nort and c.ontents. This thermal-storage effect may be quite im- lackf m ^e^enrnn'nE 311 economical cooling equipment capacity. The entirt adecluate means of treating this storage quantitatively in its cedii ^ j a comP^ete structure, must be recognized in judging the pro- not - 6*S ai}d data presented for calculating individual components of the net rate of instantaneous heat gain. calcul \-^eaiinS calculations involve the same principles as cooling load pan . atlons. Many of the data on solar radiation given in this chapter 1 be USRd m calculations for solar heating. COOLING LOAD CALCULATIONS aDDliraF61 cooliri? lad calculations, whether for industrial or comfort wns, require consideration of the following factors: lation^rateSn ^'07l^!ilons: (1) indoor conditions; (2) outdoor conditions; (3) venti- B /^tontaneous Heat Load, Sensible and Latent: (1) load from solar radiation, 287