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American Society of Heating and Ventilating Engineers Guide, 1926-27 Table 29. Heat Emission op Direct Pipe Coil Radiation for Steam Steam Temperature at 240 deg. fahr.--Pressure 10 lb. per sq. in.--Room Temperature at 60 deg. fahr. WALL COILS--Coils Placed Vertical--Pipes Horizontal B.t.u. per Lineal Ft. of Coil per'Hour. (Not Lineal Ft. of Pipe.) Size of Coil Single Row.................... ................... Two.................................. ................... Four............................... ................... Six. ................................. ................... Eight.............................. ................... Ten................................... ................... Twelve........ .................... ......... .......... 1' 175 335 584 752 864 970 1075 IK' 215 413 724 930 1064 1200 1330 l K' 245 462 816 1050 1200 1350 1500 WALL COILS--Coils Placed Vertical---Pipes Vertical Emission varies in inverse ratio of the height of the coil. Use 133 B.t.u. per lineal ft. of pipe as an average for ll/f in. coil, 10 It. high. CEILING COILS--Coils Placed Horizontal--Pipes Horizontal Emission is equal to that of a single row coil. Allowance must be made however, if the coil is at the ceiling in a higher temperature. In this case use 167B.t.u. per lineal ft. of pipe for1 in. coils. 206 " " " " " " " \\i in. coils. 231 " " 1}$ in. coils. Note.--ThisTable hasbeen developed bya method of deduction from the available data on such experimental work on pipe coils as has been recorded, and does not represent definite results of tests as in Tables 17 to 30. The values are therefore approximate only but can be used with assurance that they are more accurate than those obtained by the usual method for calculating pipe coil surface. Table 30. Heat Emission of Direct Pipe Coil Radiation for Hot-Water Water Temperature at 180 deg. fahr. Room Temperature at 60 deg. fahr. WALL COILS--Coils Placed Vertical--Pipes Horizontal B.t.u. per Lineal Ft. of Coil per Hour. (Not Lineal Ft. of Pipe.) Size of Coil Single Row.-................................ Two. .......................................... Four............... ................. .'............ Six............ ......................-.............. Eight.............................................. Ten.............................. .................. Twelve.................-....................... . im 105 198 352 456 520 583 645 IK' 131 248 432 558 640 720 . 800 IK' 147 276 488 630 720 810 900 WALL COILS--Coils Placed Vertical--Pipes Vertical Emission varies in inverse ratio to the height of coil. Use 80 B.t.u. per lineal ft. of pipe as an average for \)4, in. Coil 10 ft. high. CEILING COILS--Coils Placed Horizontal--Pipes Horizontal Emission is equal to that of a single row coil. Allowance must be made however, if the coil is at the ceiling where the temperate is higher. In this case use 100 B.t.u. per lineal ft. of pipe for 1 in. coils. 125 " " " " " " " 1H in. coils. 138 " " " " " " " \y2 in. coils. Note.--See note under Ceiling Coils for Steam. 46 i t American Society of Heating and Ventilating Engineers Guide, 1926-27 RADIATION FOR ROOM TEMPERATURES The following table from the Establishment of Standard Methods of Proportioning Direct Radiation, by James A. Donnelly (Transactions, Vol. 21, p. 535) gives the proportionate heat losses from buildings, the proportionate transmission from direct radiators, and the proportionate radiation required (with steam at 210 deg.) for various room temper atures, when the outside temperature is zero: Table 31. Effect of Room Temperature on Heat Loss and Size of Radiator Room Temperature PROPORTIONAT E Loss in B.t.u. Difference in Temperature Between Radia tor and Room Proportionate Transmission in B.t.u. Room Temperature Proportionate Surface Required Sq. Ft. 35 40 45 50 55 60 65 701 75 80 85 90 95 100 105 110 115 120 0.50 0.57 0.64 0.71 0.79 0.86 0.93 l.OOf 1.07 1.14 1.21 1.29 1.36 1.43 1.50 1.57 1.64 1.71 175 170 165 160 155 150 145 140f 135 130 125 120 115 110 105 100 95 90 1.34 1.29 1:24 1.19 1.14 1.09 1.05 l.OOf 0.95 0.91 0.87 0.82 0.78 0.74 0.70 0.66 0.62 0.58 35 40 45 50 55 60 65 70 f 75 80 85 90 95 100 105 110 115 120 0.37 0.44 0.52 0.60 0.69 0.78 0.89 l.OOf 1.12 1.26 1.40 1.56 1.74 1.93 2.15 2.39 2.66 2.95 . f Standard Conditions. Assuming that the rate of heat loss from a building varies directly with the difference be tween the outside temperature and the building temperature, and considering the heat loss for zero outside, 70 deg. inside as the standard, or 100 per cent; the second column shows the proportionate loss of heat from a building when the outside temperature is zero, and the inside temperature is as given in the first column. Assuming that the rate of transmission from a direct radi ator to the air of a building is in proportion to their difference in temperature, with a variation in the rate of transmission of 2 per cent, greater or less, for each 10 deg. increase or decrease in their temperature difference, and considering 140 deg. differ ence in temperature (steam 210 deg., building 70 deg.) as standard, or 100 per cent trans mission, the second column shows the proportionate trans mission when the difference in temperature is as given in the first column. Assuming that under stand ard conditions of outside tem perature zero, building tempera ture 70 deg., and radiator tem perature 210 deg. (or 140 deg. difference between the radiator and room) the amount of radia tion necessary is 100 per cent, the proportionate amounts of radiation given in the second column are those necessary to heat a building to the tempera tures given in the first column, when the outside temperature is zero. Note.--The amount of surface required for heating is always obtained by dividing the heat loss from the building by the amount of heat transmitted per square foot of radiation. Therefore, as-may be seen from the above tables, the proportionate amount of surface required for heating is obtained by dividing the proportionate heat loss from the building by the proportionate transmission of the radiator, in each case. The preceding table may be used to find the proportionate amount of radiation necessary to heat a room to any desired inside temperature, other than 70 deg., when the outside minimum temperature is other than zero, arid with' a radiator temperature other than standard. Find the difference between the outside temperature and the room temperature in the first column; divide the proportionate heat loss opposite this amount, 47