Document 6Bwoz4y6v62bjEYQpO26B1pa6

270 CHAPTER 14 1949 Guide Table 7. Summary of Heat Losses of Insulated Residence (Btu Per Hour) Room or Space Bedroom A Bedroom B Bedroom C Bedroom D Bathroom 1 Bathroom 2 Living Room Dining Room Kitchen Lavette Entrance Hall Garage Recreation Design Totals Operating Totals'* Percentages* Walls 2480 1620 1190 1230 310 760 3370 1730 1320 1390 410 -- 470* S40 16.180 16.180 29.4 Ceiling and Roof 2460 lfifiO 1260 1080 540 250 850 --910b -- 7.190 7.190 13.0 Floor 690 220 -280* 570 1.200 1.200' 2.2 Glass and Door 1440 1440 970 720 500 320 1800 3880 950 1100 640 3710 720 . 18.190 18.190 33.0 Infil tration 2180 1470 1260 950 630 400 5400 3080 2300 550 1600 1910 2890 - 24.620 12,310 22.4 Totals 8.560 6,190 4.630 4.670 1.980 1.950 10.570 8.690 4.570 3.040 ' 3.500 3.960 5.020 67.380 55.070 100.0 * Wall beat loss of 980 Btuh minus wall heat gains of 590,320,540 Btuh. b Heat gains 690,220 Btuh. 6 Heat gain. d Based on i computed infiltration. "Based on Operating Totals. REFERENCES 1 ACRMA Application Engineering Standards for Air Conditioning for Com fort, (1947), Air Conditioning and Refrigerating Machinery Association, Inc. pages 4 to 7. * An Analysis of Winter Temperatures for One Hundred and Twenty Cities, by Clark M. Humphreys (Carnegie Institute of Technology Bulletin 1939). 3 Investigation of Oil-Fired Forced Air Furnace Systems in the Research Resi dence, by A. P. Kratz and S. Konzo (University of Illinois Engineering Experiment Station Bulletin No. 318). * A.S.H.V.E. Research Report No. 1011--Tests of Three Heating Systems in an Industrial Tyfce of Building, by G. L. Larson, D. W. Nelson, and John James (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. (University 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, 1942, p. 369). 7 Measurements of Heat Losses from Slab Floor, by R. S. Dill, W. C. Robinson and H. E. Robinson (17. S. Department of Commerce, National Bureau of Standards, Building Materials and Structures Report BMS 103). 8 Heat Requirement Tables for Intermittently Heated Buildings, (Engineering Experiment Station Bulletin, No. 60, A. and M. College of Texas, College Station, Texas) contains a set of tables applicable to either intermittent heating or codling. Further information may be found in a paper, A Method of Compiling Tables for Intermittent Heating, by Elmer G. Smith (A.S.H.V.E: Journal Section, Heating, Piping and Air Conditionirig, June, 1942, p. 386). CHAPTER 15 COOLING LOAD Cooling Load Calculations; Design Conditions; Instantaneous Heat Load; Solar and Sky Radiation, and Heat Transmission Losses; Principles of Periodic Heat Flow; Practical Tables for Calculating Solar Heat Gain Through Walls and Roofs; Glass Areas and Design Tables; Load from Interior Partitions; Ceiling and Floors; Load from Outside Air, Ventilation or Infiltration; Heat Sources Within Space; Moisture Heat Load; Required Air Quantity Through Conditioning Equipment; Minimum Entering Temperature; Example 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 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 idle 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 are useful in calculations for solar heating. COOLING LOAD CALCULATIONS Summer cooling load calculations, whether for industrial or comfort applications, require consideration of the following factors: A. Design Conditions: (1) Indoor conditions. (2) Outdoor conditions. (3) Ventilation rate. B. Instantaneous Sdat Load, Sensible and Latent: (1) Load from solar radiation, - 271