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American Society of Heating and Ventilating Engineers Guide, 1926-27 Table 17. Heat Emitted by Persons per Hour at Different Room Temperatures H = Heat emitted by man at rest per hour. HI = Heat emitted by man at light labor per hour. Ha = Heat emitted by man at average labor per hour. Hh = Heat emitted by man at hard labor per hour. HE -- Heat Energy =, (Foot^ound^pmjiour^ = M R t u 16g B t u and 252 B.t.u. respectively for light, average and hard labor. T = Room Temperature. H = 13.2 (98.6 -- T) Heat due labor = T ^ HI, Ha, or Hh = 13.2 (98.6 - T) plus T E Room Temp. Deg. Fahr. Rest Heat Emitted by Man* B.t.u. per Hour at 84 B.t.u. 168 B.t.u. 252 B.t.u. Light Average Hard Labor Labor Labor Condition Required to Balance Excess and Shortage in Heat Emission 30 905 931 954 981 Increasing Humidity 40 773 807 838 874 Heavy Clothing for Reduction or Pre .50 642 684 723 768 vention of Radiation 60 509 559 606 660 68 404 461 518 575 Normal Condition 70 378 436 491 . 554 75 312 375 438 501 Decreasing Humidity 80 246 313 375 447 Air Currents for Producing Evapora 85 180 251 322 394 tion of Perspiration 90 114 189 259 342 For children use one-half of table values. If power is transmitted to the machinery from the outside, then only the heat equivalent of the brake horsepower supplied is used. In the . , , Motor horsepower . first case the B.t.u. supplied per hour = Effic-i-e--n--c-y---o- ;f-m----o-t--or X 2t>46, and in the second case B.t.u. per hr. = b.hp. X 2546, in which 2546 is the B.t.u. equivalent of 1 hp. hour. In high-powered mills this, is the chief source of heating and is frequently sufficient to overheat the building even in zero weather, thus requiring cooling by ventilation the year round. For intermittent heating allow 10 per cent additional for rooms heated in the day time only, and for longer intervals of several days or more, add 25 per cent in determining minimum heating requirements, and size of plant. Application to Factory Heating3 (See Fig. 6) Lowest outside temperature for Philadelphia, Pa. = -- 6 deg. fahr. (Table 2), hence use ( -- 6 + 10) = + 4 for heat loss computations. Average wind movement (Table 2) for December, January, February = 11.0 miles per hour from the Northwest. Long axis of building is north and south. Inside breathing line temperature = 60 deg. fahr. Walls: 9 in. concrete (stone), furred with 2 in. tile, plastered Yi in. X, = 0.93 plaster in still air, (Table 4). Xs = 3 X 1.3 concrete moving air, (Tables 4 and 6). c, = 8.3 for stone concrete, (Table 5). c2 = for tile as shown use 0.99 (not per 1 in.), (Table 5). 3In this example a design temperature only 10 deg. fahr. above lowest on record instead of to deg. fahr. above was used. Infiltration values were taken from Table 14 for a plain window. 30 American Society of Heating and Ventilating Engineers Guide, 1926-27 _L 4. -- 4- 4- i--- 1--i--|--?--_L_ X, X, ^ c, ^ c, 0.93 ' 3.9 ~ 8.3 ` 0.99 0.292 from equations (6) and (7). The air temperature at the mean height of inside walls is greater than at breathing line. Mean heightof walls is 16 -r- 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 = 63.4 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. Wall-vSection A-A FfG. 7. Elevation of Factory Building Roof: 3 in. concrete (stone), with JJj in. tar paper and slag. I, i, , s. 1 i 1 , 3 , 0.125 X,1'^'1; c, "* c2 1.3 4.2 ' 8.3 ` 0.40 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. 31