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268 CHAPTER 12 of the results in Table 9. The values in column F of Table 8 were obtained by multfP? plying together the figures in-columns C, I), and E. The heat losses are calculate^ 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 rest1? 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 peg- cent are also comparatively small because the storm windows- are equivalent?^' weatherstripping. In this problem, the wall, ceiling and floor transmission losses comprise 66?2 percent of the"total. -4" Example 7: Calculate the heat loss of residence shown in Fig. 2 based on the sifijs conditions as in Example 6 but having construction improved or insulated to obiB> coefficients as.follows: . u-. 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 * ARI Application Engineering Standards for Air Conditioning for Comfort, 1947 (Air-ConJttiomni and Refrigeration Institute). ;.J- 3 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. Krata and S Koneo (University of Illinois Engineering Experiment Station Bulletin No. 318). 4 Performance of a Hot-Water Heating System in the I=B=*R Research Home at the University of Illi nois, by A. P. Krata, W. S. Harris, M. K. Fahnestock, and R. J. Martin (University of lUinois Engineering Experiment Station Bulletin No. 349). ` * A Study of Radiant Baseboard Heating in the I=B=R Research Home, by A. P. Krata and W. S. Harm (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 (Univertiti of Illinois Engineering Experiment Station Bulletin No. 383). 3 A.S.H.V.E. Research Report No. 1011--Tests of Three Heating Systems in an Industrial Typeof Building, by G. L. Larson, D. W. Nelson, and John Jamies (A.S.H.V.E. Transactions. Vol. 41, 1935, P* 185). .. . Methods of Moisture Control and Their Application to Building Construction, by F. B. Rowley, A. B. Algren and C. E. Lund (Univereity of Minnesota, Engineering Experiment Station Bulletin No. 17). * A.S.H.V.E. Research Report No. 1213--Heat Loss Through Basement Walls and Floors, by F. C. Houghten, S. I. Taimuty, Carl Gutberlet and C. J. Brown (A.S.H.V.E. Transactions. Vol. 48, 1943, P369). 18 Measurements of Heat Losses from Slab Floor, by R. S. Dill, W. C. Robinson and H. E. Robinson (U. S. Department of Commerce, National Bureau of Standards, Building Materials and Structures Report BMS 103). 11 Temperature and Heat Loss Characteristics of Concrete Floors Laid on the Ground, by H. D. Bareithw. A. N. Flemming and B. E. Alberty (University ofIllinois. Small Homes Council Technical lieport). w Concrete Floors for Basementlesa Houses (University of Illinois, Small Homes Council Circular No. F 4.3). u Warm-Air Perimeter Heating, Part III--Heat Losses from Floor Slab, by J. R. Jamieson, R. W. Roo* and S. Ronzo. (A.S.H.V.E. Journal Section, Heating, Piping on<J A*r Conditioning, Feb. 1952, p. 138)* 14 Warm-Air Perimeter Heating--Manual 4, National Warm Air Heating and Air Conditioning Association- 14 Heat Requirement Tables for Intermittently Heated Buildings (Engineering Experiment Stotio* Bulletin No. 60, A. and M. College of Texas, College Station, Texas) contains a set of tables applicable to eithff intermittent heating or cooling. Further information may be found in a paper, A Method of Coinpili* Tables for Intermittent Heating, by Elmer G. Smith (A.S.H.V.E. Journal Section, Heating, Piping one Air Conditioning, June 1942, p. 386). 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 Outside Air, Ventilation and Infiltration; Effect of Outside 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 tioned space. There may be an appreciable difference between the net instantaneous rate of heat gain and the total cooling load at any instant. This difference is caused by the storage and subsequent release of heat by the structure and its contents. This thermal-storage effect may be quite im portant in determining an economical cooling equipment capacity. The lack of any adequate means of treating this storage quantitatively in its entirety for a complete structure, must be recognized in judging the pro cedures and data presented for calculating individual components of the net rate of instantaneous heat gain. Solar heating calculations involve the same principles as cooling load calculations. Many of the data on solar radiation given in this chapter ean be used in calculations for solar heating. COOLING LOAD CALCULATIONS Summer cooling load calculations, whether for industrial or comfort Pphcations, require consideration of the following factors: A- Design Conditions: (1) indoor conditions; (2) outdoor conditions; (3) ventilln rate. instantaneous Heat Load, Sensible and Latent: (1) load from solar radiation, 269 t.