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HEATING VENTILATING AIR CONDITIONING GUIDE 1942 Table 4. Summary op Heat Losses of Uninsulated Residence Heat losses given in Blu per hour Room ob Space Walls Celling and Roof Floor Glass and Door Infiltration Totals Bedroom A Bedroom B Bedroom C Bedroom D Bathroom 1 Bathroom 2 Living Room Dining Room Kitchen Lavette Entrance Hall Garage Recreation Totals Percentages 5330 3490 2560 2650 670 1770 7260 3720 2850 3000 870 -1030* 3850 36,990 40.2 6660 4400 3300 . 3300 1510 960 2490 22,620 24.6 960 310 -2450t 4600 3,420 3.7 1440 1440 970 720 500 320 1800 3880 950 1100 640 3410 720 17,890 19.5 Wall heat loss of 2110 Btu minus wail heat gain of 3140 Btu tHeat gains; 960, 310 and 1180 Bto. 1010 1010 500 500 500 420 1120 870 760 530 560 2700 490 10,970 12.0 14,440 10,340 7,330 8,130 3,180 3,780 10,180 8,470 4,560 4.630 4,560 2.630 9,660 91,890 100.0 Table 5. Summary of Heat Losses of Insulated Residence Heat losses given in Btu per hoar Room or Space Walls Ceiling and Roof Floor Glass and Door Infiltration Totals Bedroom A Bedroom B Bedroom C Bedroom D Bathroom 1 Bathroom 2 Living Room Dining Room Kitchen Lavette Entrance Hall Garage Recreation Totals Percentages 2670 1750 1280 1320 340 820 3580 1860 1400 1460 440 -400* 1430 17,950 32.5 2370 1570 1170 1170 540 340 . 690 220 850 8,010 14.5 -2090t 1580 400 0.7 1440 1440 970 720 --500_ 320 1800 3880 950 1100 640 3410 720 17,890 32.4 1010 1010 500 500 500 420 1120 870 760 530 560 2700 490 10,970 19.9 Wall heat loss of 1050 Btu minus wail heat gains of 590, 320 and 540 Btu, THeat gains; 690. 220 and 1180 Btu. 7.490 5,770 3,920 4.400 1,880 2,120 6.400 : 6,610 3,110 3,090 2.490 3,620 4,220 : 55,220 100.0 138 Chapter 7 COOLING LOAD Design Outside Temperatures, Components of Heat Gain, Normal Heat Transmission, Solar Heat Transmission, Solar Radiation Through Glass, Heat Introduced by Outside Air, Heat Emission of Appliances LOAD calculations for summer air conditioning are more complicated than heating load calculations because there are more factors to be considered. Due to the variable nature of some of the contributing load components and the fact that they do not necessarily impose their maximum effect simultaneously, considerable care must be used in determining their phase relationship so that equipment of proper capacity may be selected to maintain specified indoor conditions. The conditions to be maintained in an enclosure are variable and depend upon several factors, especially the outside. design conditions, duration of occupancy and relationship between air motion, dry-bulb and wet-bulb temperatures. Information concerning the proper indoor effective temperature to be maintained is given in Chapter 2, for different geographical locations and for various age groups of individuals. Summer dry-bulb and wet-bulb temperatures of various cities are given in Table 1. The temperatures are not the maximums but the design temperatures which should be used in air conditioning calcu lations. The maximum outside wet-bulb temperatures as given in Weather Bureau reports usually occur only from 1 to 4 per cent of the time, and they are therefore of such short duration that it is not practical to design a cooling system for them. The temperatures shown in Table 1 are based on available design conditions known to be successfully applied. COMPONENTS OF HEAT GAIN A cooling load determination is composed of five components which are classified in the following manner: 1. Normal heat transfer through windows, walls, partitions, doors, floors, ceilings, etc. 2. Transfer of solar radiation through windows, walls, doors, skylights, or roof. 3. Heat emission of occupants within enclosures. 4. Heat introduced by infiltration of outside air or controlled ventilation. 5. Heat emission of mechanical, chemical, gas, steam, hot water and electrical appliances located within enclosures. 139