Document 5bYV0Varb6RGZ5bGRvoLpRxx4

American Society of Heating and Ventilating Engineers Guide, 1930 Chapter 2--Heat Losses from Buildings Fig. 9. Elevation of Factory Building Table 45. Calculation Sheet Showing Method of Estimating Heat Losses of Building Shown in Fig. 9 Part of Building Expo sure Width IN Feet Height in Feet Net Surface Area or Crack Length Co effi cient Temp. Diff. Net B.t.u. <, Exposure Factor Total B.t.u. Brick, J4 in. plaster. _ Doors (2 in. Wood)__. M in. Crack ____ Brick, M in. plaster.-..______ Glass, (Single)___ >4 in. Crack___ __ N N N W w w 50 16 12 12 1 pair doors 120 16 15x4 9 Doubl * Hung Windo ws (15) 656 144 60 1380 540 450 0.277 0.382 3.34 59.6 57.2 57.2 0.277 1.13 1.67 59.6 60-2 60,2 10,820 3,150 11.440 1.15 12&^) 1.15 v 3,620 H x 1.15 6,580 22,800 36.800 45,200 1.15 1.15 _?6,200 42,400 Kx 1.15 26.000. South Wall Same See as N Above I9.6&) East WalU 1 Same as W See Above Roof, 3 in. Concrete and Slag-surfaced built-up roofing. No Ceiling 50 120 M 82,200 6000 - 0.610 69.3 254,000 . None 254,000 Floor, 5 in. Stone Concrete on 3 in. Cinder Concrete. On Dirt . 50 120 6000 0.521 5 15.630 None 15,630 *^wind.TOTAI" f heat required for buUdin* in B-t.u. per hour at +4 deg. with 11-mile northwest 488.780 Notes.--(1) This building has no partitions and whatever air enters through the cracks on the wind ward must leave through the cracks on the leeward side. Therefore, only one-half of the total crack will be used in computing infiltration for each side and each end of building. (2) An exposure allowance of 15 per cent is also to be added to the wall and glass transmission losses and to the infiltration losses on the two adjacent sides of the building most nearly facing the prevailing wind as stated in the first paragraph on page 73. (3) It is also possible to compute the heat required to take care of infiltration on the basis of half of an air change per hour as given in Table 33 for a factory with minimum conditions. Volume -- 50 X 120 X IS = 96,000 cu. ft. and heat required per hour is ' 96,000 X M X 0.075 X 0.24 X 59.6 = 51.500 B.t.u. Based on infiltration through one-half the total crackage in all walls, the heat to be supplied per hour is from'Table 45 6,580 + 26,000 + 5,720 + 22.600 = 60,900 B.t.u. The value based on crackage should be used, but if building is to be heated intermittently, not less than' one air change per hour should be allowed. . ' l'; 76 - Fig. 10. Floor Plan of Six-Room Residence3 Plan 6-F-3, Architects Small House Service Bureau. 13. Calculations: See calculation sheet. Table 45. RESIDENCE (See Fig. 10) 1. Location.......................... .............. ............. ................................................ ..Chicago, 111. 2. Lowest outside temperature (Table 3)________ ______ ____ ______ -- 23 deg. fahr. 3. Base temperature--,_________________ _____ ______ (-- 23 + 15) = -- 8 deg. fahr. 4. Direction of prevailing wind (during Dec., Jan., Feb., Table 3).Southwest 5. Inside temperature..... ................................. .........................................,........70 deg. fahr. 0. Temperature difference (item 5 -- item 3)........................ :...................78 deg. fahr. 7. Average wind velocity (during Dec., Jan., Feb., Table 3)___17 miles per hour 8. Construction: Walls--Wood siding, building paper, wood Sheathing, studding, wood lath, and plaster. Roof--Wood shingles on 1 x 4 strips spaced 2 in. Attic Ceiling--Wood lath and plaster on roof rafters First Floor (over basement)--Maple flooring on rough flooring on floor joists Doors (outside)--Three, 3 ft.x7 ft.xl% in.; one, 2 ft. 8 in. x7ft.x 1 ^in. No weatherstripping Windows--Double-hung, single glass, weatherstripped. 9. Transmission coefficients: Walls--(Table 24). .............. ....................... .................................... U = 0.263 Roof (including attic ceiling)--(Table 34)..._.................................. XJ = 0.285 Floor (over basement)--(Table 29)................. ......... ............ .......... V = 0.339 Doors--(Table 36)................................................................................ U = 0.421 Windows--(Table 36):.............................. .................................. V = 1.13 10. Infiltration coefficients: Windows---The leakage per foot of crack for weatherstripped, doublehung, wood sash windows is 27.0 cu. ft. per hour for a 17-mile wind velocity. (By interpolation from Table 39, Part II.) The heat equiva lent is 27.9 X 0.075 X 0.24 = 0.5 B.t.u. per hour per foot of crack. Doors--Assume in. crack. Leakage = 139 cu. ft. per hour. (Table 39, Part II). Theheat equivalent is 139 X 0.075 X 0.24 = 2.50 B.t.u. per hour per foot of crack. 77