Document mQJ98wygNo12Q4nMbqNM21Q4

266 CHAPTER 12 1955 Guide! Notes for Table 8. * The inside-outside temperature difference is 70-- (--10) or 80 F except where otherwise noted. b Volume of infiltration, cfh = (no. air changes) x (floor or ceiling area) x (ceiling height). * From Equation 5a. _' d The ceiling heat losses are calculated by estimating the attic temperature and then calculating the loss's through the ceiling using.the,proper temperature difference. This unheated attic is hot ventilated during winter months. The attic temperature is estimated from Equation 1 to be 30.2 F when the outside tetq/ perature is --10 F and room temperature is 70 F. The temperature difference is then 70--30.2 or 39.8 deg' For the insulated residence, attic temperature become 4.6 F and temperature difference 70--4.6 = 65.4 deg' * Temperature in garage assumed to be 35 F. ... f.Coefficient for wall adjoining garage calculated on basis of metal lath and plaster on both sides of studs'- (U 0.39). f * One half of value from Table 4, Chapter 11, for storm windows or weatherstripping. \* h Exposed on two sides, weatherstripped windows offset by fire-place. Use 1Yi. '' Window on one side weatherstripped but double-doors are hard to dose tightly. Hence, conservative value of 1H- * Assuming kitchen vent, door to vestibule usually open, allow full table value of 1)4. ^ k One-half value in Table 4, Chapter 11, increased to 1H by nearby outside door in vestibule. 3 1 Full value in Table 4, Chapter 11, to allow for frequent opening of outside door. m Two sides exposed, large doors but large volume.' Use value V/t as given in Table 4, Chapter 11. n Two small unweatherstripped windows in pn>j tected location, but fireplace, indicate 1 change. p Heat losses from these rooms into garage are heat gains for garage. q Neglect heat loss to basement, as losses from boiler, piping, etc.t will probably keep basement near,. if not above, 70 F. r Upstairs hall ceiling figures with downstairs.^ Heat should be provided downstairs for both. " Linear feet of exposed edge. - BASEMENT PLAN Fig. 2. Floor Plans of Residence Heating Load 267 Table 9. Summary of Heat Losses of. Uninsulated Residence (Btu Per Hour) Room or Space Walls Ceiling and Roof Floor Glass and Door Into,- TRATION Totals 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*1 : 5330 3490 2560 2650 670 1640 7260 3720 2850 3000 870 -1030* 840 33,850 33,850 38.4 6910 4660 3540 3020 1510 960 2390. -I270b 21,720 21,720 24.6 960 3io 1060 570 2,900 . 2,900 3.3 1440 1440 970 720 500 320 1800 3100 950 1100 640 3710 720 17,410 17,410 19.7 2180 1470 1260 950 630 400 5400 3080 2300 550 1600 1920 2890 24,620 12,310 14.0 15.860 11.060 8,330 8,300 3.310 3.630 14.460 9,900 6,100 4,650 5,500 4,380 5.020 100,500 88,190 100.0 Wall heat loss of 2120 Btuh minus wall beat gains of 1280, 700 and 1160 Btuh. Heat gains of 960 andb 310Btuh. c Based on H computed infiltration. d Based on operating totals. are to have storm sash. The building is constructed as follows (heat transmission coefficients V are 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 averaging 70 percent glass (0.45; from Chapter 9, Table 19, Section D, the U value for wood windows with storm sash is 0.53 x application factor; by interpolation this factor is 0.85). Steel casement sash in garage and basement (1.13; from Chapter 9, Table 19, U is 1.13 for all glass and the application factor iB 1.00). French doors in dining room 50 percent glass, no storm doors (0.85; from Chapter 9, Table 19, U is 1.13 for all glass; by interpolation the application factor is 0.75). 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 8, and a summary Table 10. Summary of Heat Losses of Insulated Residence (Btu Per Hour) Room or Space Walls Ceiling and Roof Floor Glass and Door Infil tration Totals Bedroom A Bedroom B Bedroom C Bedroom D Bathroom 1 Bathroom 2 Lining Room Joining Room Aitchen Lavette Entrance Hall Garage Recreation Totals Operating Totals Percentages*1 2480 1620 1190 1230 310 760 3370 1730 1320 1390 410 --470* 840 16,180 16,180 29.1 2460 1660 1260 1080 540 250 850. -910b 7,190 7,190 12.9 690 220 1060 570 2,540 2,540 4.6 1440 1440 1-70 720 500 320 1800 3100 950 1100 640 3710 770 17,410 17,410 31.3 2180 1470 1260 950 630 400 5400 3080 2300 550 1600 1910 2390 24,620 12.310 22.1 8.560 6.190 4.680 4.670 1,980 1,950 10.570 7.910 4.570 3.040 3,500 5,300 5,020 67,940 55,630 100.0 - heat loss of 980 Btuh minus wall heat gains of 590, 320 and 540 Btuh. b Heat gains 690 and 220 ub. c Based on computed infiltration. d Based on operating totals.