Document Yr1Md1akQZyxpYXLe2EXxwObE

American Society of Heating and Ventilating Engineers Guide, 1929 Fig. 9. Elevation of Factory- Building U .0.304 1 1 ,1.9 1 0.5 . v 0.5 1.34 ` 4.02 "r8.3 ' 1.14 _r8.0^2.32 The air temperature at. the mean height of inside walls is greater, than at breathing line. Mean height of walls is 16 -5- 2 = 8 ft., which 8 -- 5 = 3 ft. above breathing line. Allowing 2 per cent per foot above 5 ft., or 2X3 = 6 per cent, makes the mean.air temperature 1.06 X 60 = 63.6 deg. fahr. The triangular areas in the end wall are practically at the mean height of the roof at which level the air temperature is 78' deg. fahr. Roof: 3 in. concrete (stone), with slag surface built-up roofing. U = 0.610 (Roof No. 216-c, Table 11-A) 62 Chapter I--Heat Losses from Buildings The air temperature just below roof is higher than that at the breathing line. Mean height of roof is 16 + 4 = 20 ft., or it is 20 -- 5 = 15 ft. above breathing line. Allowing 2 per cent per foot above 5 ft., or 2 X 15 = 30 per cent, makes the under roof temperature = 1.30 X 60 = 78 deg. fahr. Floor: The 5 in. concrete floor is laid on the ground, and hence there is only one surface coefficient K, = 1.34 = Average for surface in still air (Table 4) U = ----i---- = 0.745 ------------ h -- The air temperature at floor level^= 60 -- 5 =.55 deg. fahr. Windows and Doors: Wood|satl and doors with/ single thickness of glass. Take coefficient U for glass as it 13 B.t.u. per sq. ft. per degree per hour for heat transmission (Table 13-A). Doors are solid wood 2 in. thick and coefficient U ,= 0^582 B.t.u. per sq. ft. per degree per hour (Table 13-B). Cfi f~) ' '. Infiltration's o'f-r;iiow crack assumed^rS in- and doors at -ft in. *B,y Table 15 tfi? pro// for a 10 mile wind'velocity the leakage per foot of crack is 84 be Ur ror a plain window. The heat equivalent per hour, per degree :or 0ru ' lesigneci . & X ,075 X 0.24 = 1.53 B.t.u. neon*''' * and allowing-for an il mile wind J:he factor becomes 1.53 X Jq = 1.68 (see preceding note). Allow twice this for door crack or 2 X 1-68 = 3.36. .. : Calculation Sheet ; .. Entire Building (See Fig. 9) Building Material Exposure Concrete and Tile. N N Doors (2 in. wood)_ N yi in. Crack;_______ N Coeffic. Area Trans. Width Height Sq. Ft. and Temp. in Ft. in Ft. or Lin. Infilt. Diff. Ft. H X SO 8M 213 0.304 74.0 50 16 656 0.304 59.6 12 12 144 0.382 56 1 pair doors 60 3.36 56 Net B.C.U. 4*800 11*850 3.080 11.300 Exposure Factor 1.15 1.15 1.15 M* X 1.15 Total B.t.u. 5,520 13.630 3,550 6,500 29.200 Concrete and Tile. W Class (Single) w ) in. Crack............ w South Wall Same as N East Wall___ Same as W Roof. 3 In. Concrete and slag-surfaced built-up roofing__ No Ceiling Floor. 5 in. Stone Concrete_________ On Dirt 120 ' 16 15 X 4 9 Double Hung Windows (15) See above See above 52.5 120 50 120 1380 0.304 59.6 540 1.13 59.6 450 1.68 59.6 24,950 36,200 44.900 . 6300 o;gio 74 285,000 6000 0.745 5 22,350 1.15 1.15 M* X 1-15 M* H* 28.700 41,600 25,800 96,100 25,380 83.600 None None 285.000 22,350 Grand total of heat required for building in B.t.u. per hour at + 4 deg. with 11-mile Southwest wind..............._........................................................................... 541,630 *Nota.--(1) This building has no partitions and whatever air enters through the cracks on the wind- 63