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252 CHAPTER 14 1948-Guide Table 6. Summary ok Heat Losses of Uninsulated 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 Hal] Garage Recreation Design Totals Operating Totals* Percentages* Walls 5330 3490 2560 2650 670 1640 7260 3720 2850 3000 870 -1030* 840 33.850 33.850 38.6 Ceiling andRoof 6910 4660 3540 3020 1510 960 960 "310 2390 -1270> 21.720 21.720 24.8 -280* 570 1.560 1.560 1.8 Glass and Door " 1440' 1440 970 720 500 320 1800 3880* 950 1100 640 3710 720 18.190 18.190 20.7 Infil tration. 2180 1470 1260 950 630 400 5400 3080 2300 550 1600 1910 2890 24.620 12.310 14.1 Totals 15:860 11.060 8.330 8.30a 3.310 3.630 14.460 10.680 6.100 4.650 5.500 3.040 5,020 99.940 87.630 100.0 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* 840 16,180 16.180 29.4 Ceiling and . Roof 2460 1660 1260 1080 540 250 850 -910> 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 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 4.680 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 ^ 690.220 Btuh. REFERENCES *--ACRMA Application Engineering Standards for Air Conditioning for Comfort; (1947). Air Con* ditioning and Refrigerating Machinery 'Association, Inc. pages 4 to 7. 2--An Analysis of Winter Temperatures for One Hundred and Twenty Cities, by Clark M. Humphreys (Carnegie Institute of Technology Bulletin). *--Investigation of Oil-Fired Forced Air Furnace Systems in the Research Residence, by A. P. Kratz and S. Konzo (University of Illinois Engineering Experiment Station Bulletin No. 318)'. 4--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, 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). 6 --A.S.H.V.E. Research Report No.1213--Heat Loss Through Basement Wails and Floors, by F. C. Houghten, S. I. Taimuty, Carl Gutberlet and C. J. Brown (A.S.H.V.E. Transactions, Vol. 4S, 1942. P. 369). 7--Measurements of Heat Losses from Slab Floor, by R. S. Dill, W. C.` Robinson'and H. E. Robinson (17. 5. Department of Commerce, National Bureau of Standards, Building Materials and Structures Report . BMS 103). ' *--Heat Requirement Tables for Intermittently Heated Buildings. (Engineering Experiment Station vBulletin. No. 60. A. and M. College of Texas, College Station, Texas), contains a set of tables applicable to either intermittent heating or cooling. Further information may be' found in a paper. A Method of Com piling Tables for Intermittent Heating, by Elmer G. Smith (A.S.H.V.E. Journal Section, Heating, Piping and Air Conditioning,'June, 1942, p. 386). Chapter 15-. :\.v >............................................................ GOOUNG LOAD Cooling Load Calculations; Design Conditions; Instantaneous Heat Load; Solar and Sky Radiation, and Heat Transmission Losses; Principles of Periodic Heat Flow; Class Areas arid Design Tables; Load from Interior Partitions; Ceiling and Floors; Load from . Outside Air9 Ventilation or Infiltration; Heat Sources Within Space; Moisture Heat Load; Regional Air Quantity; 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 required to establish the resultant maximum codling load for a building Or zone. A zoned system must often handle peak loads in different zones at different hours. . Economic considerations must be particularly influential in the selec tion of equipment for cooling season operation in comfort air conditioning and this fact, coupled with present inadequacies, in available data and knowledge of the air-conditioning art, places a premium on the experi enced judgment essential to successful design; or practice. Variations in the weather, building occupancy, and other factors affecting load neces sitate carefully coordinated controls to regulate simultaneously the com ponents and .the equipment to maintain the desired room conditions.' The calculation procedures presented in this chapter deal with the various instantaneous rates of heat gain both sensible and latent, in a conditioned 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 important in determining.an economical cooling equipmentcapacity. The lack of any' adequate means of treating this storage quantitatively in its entirety for a complete structure must be recognized in judging the procedures 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: (l).Indoor conditions. (2) Outdoor conditions. (3) Ventilation rate. . B. Instantaneous Heat Load, Sensible and Latent(1) Lead from sojar radiation, sky radiation and from outdoor-indoor temperature differential for glass areas and exterior,: walls and roofs, modified by periodic heat flow or lag factors depending on the type of structure. (2) Load due to heat gain through interior partitions,: ceilings ..and floors.; (3) Load due to ventilation either natural or mechanical. (4) Load due to heat sources within the conditioned space such as people, lights, power equipment and appliances. (5) Load due to moisture transfer through' permeable building materials. (6) Miscel laneous heat sources. ... C.. . Determination of Air Quantity and Apparatus Dew-Point. 253