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HEATING VENTILATING AIR CONDITIONING GUIDE 1944 under basement and garage floors and 32 F adjoining basement walls. Estimate in filtration by crack method, assuming average wind velocity to be 12.5 rriph during December, January and February. No wall, ceiling or roof insulation is to be figured in this problem, but all first and second floor windows are to have storm sash. The building is constructed as follows (transmission coefficients (U) in parentheses): Walls: Brick veneer, building paper, wood sheathing, studding, metal lath and plaster (0.28). Walls of dormer over garage, same except wood siding in place of brick veneer (0.26). Attic Walls: Brick veneer, building paper, wood sheathing on studding (0.42).. Basement Walls: 10 in. concrete (0.10). Roof: Asphalt shingles on wood sheathing on rafters (0.53). Ceiling (Second floor): Metal lath and plaster (0.69). Windows: Double-hung wood windows with storm sash (0.45). Steel casement sash in basement (1.13). Floor (Bedroom D): Maple finish flooring on yellow pine sub-flooring; metal lath and plaster ceiling below (0.25). Floor (Basement and Garage): 4 in. stone concrete on 3 in. cinder concrete (0.10). Solution: The calculations for this problem are given in Table 4, and a summary of the results in Table 5. The values in column F of Table 4 were obtained by multiplying together the figures in columns C, D and E. The heat losses are calculated to the nearest i0 Btu. See reference notes for Table 4 for further explanation of data. Table 5. Summary of Heat Losses of Uninsulated Residence Heat'losses given in Btu per hour Room ob 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 5330 3490 2560 2650 670 1770 7260 3720 2850 3000 870 -1030 840 33,980 39.6 6660 4400 3300 3300 1510 960 2490 -- 22,620 26.4 960 310 --1550b 570 290 0.3 1440 1010 1440 1010 970 500 720 500 500 500 320 420 1800 1120 3880 870 950 760 1100~- - 530 640 560 3410 2700 720. 490, 17,890 10,970 20.9 12.8 14,440 10,340 7,330 8,130 3,180 3,780 10,180 8,470 4,560 4,630 4,560 3,530. 2,620 85,750 ,100.0 "Wall heat loss of 2110 Btu minus wall heat gain of 3140 Btu. bHeat gains; 960, 310 and 280 Btu. Attention is called to the summary of heat losses (Table 5) of the uninsulated residence (Fig. 2). As storm windows are used in this instance the glass and door trans mission heat losses of 20.9 per cent are relatively small. The infiltration losses (12.8 per cent) are also comparatively small in this case because the storm windows serve substantially the same purpose as weatherstripping. In this problem, the wall, ceiling and floor transmission losses comprise 66.3 per cent of the total. If the building is insulated, the relative heat loss percentages will materially change. (See Example 6 and Table 6.) Example 6. Calculate the heat loss of residence shown in Fig. 2 based on the same conditions as in Example 5 but insulated throughout as shown on the following page (coefficients in parentheses). 144 ! . ] ( < ! 1 CHAPTER 6. HEATINC LOAD Walls: Brick veneer, 2%2 in. insulation board sheathing, studding, 1 in. insulation board lath and plaster (0.13). Walls of dormer over garage same except wood siding in place of brick veneer (0.12). Attic Walls: Brick veneer, 2%2 in. insulation board sheathing on studding (0.28). Walls Adjoining Garage: Plaster on 1 in. insulation board, studding, metal lath and plaster (0.18). Basement Walls {Recreation Room): 10 in. concrete (0.10). Roof: Asphalt shingles on wood sheathing on rafters (0.53). Ceiling {Second floor): 1 in. insulation board and plaster; Yi in. insulation board on top of ceiling joists (0.15). Windows: Same as Example 5. Floor {Bedroom D): Maple finish flooring on yellow pine sub-flooring; in. insulation board and plaster ceiling below (0.18). Solution: The procedure for calculating the heat losses is similar to that for Example 5. A summary of the results is given in Table 6. Table 6. Summary of Heat Losses of Insulated Residence Heal losses given in Bin per hour Room ob Space Walls Ceiling and Roof Floob 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 2670 1750 1280 1320 340 820 3580 ' . 1860 1400 1460 440 -400 840. Totals 17,360 Percentages 31.9 2370 1570 1170 1170 540 340 ____ 850 8,010 14.7 ........ ____ 690 __ . 220 ........ -........ .__ -1190b 570 290 0:5 .1440 1440 970 720 500 320 1800 3880 950 110O 640 3410 720 17,890 . 32.8 1010 1010 500 500 500 420 1120 870 760 530 560 2700 490 10,970 20.1 "Wall heat loss of 1050 Btu minus wall heat gains of 590, 320 and 540 Btu. hHeat gains; 690. 220 and 280 Btu. 7,490 5,770 3,920 4,400 1,880. : 2,120 6,500 . 6,610 3,110 3,090 2,490 4,520 2,620 54,520 100.0 145