Document e7yNgp71DxJMGrwnanaKE44ap

American Society of Heating and Ventilating Engineers Guide, igjj Table 5 gives the final temperature of the air leaving cast-iron indirect convectors corresponding to different entering.temperatures different cubic feet of air per hour per square foot of surface. Table 6 illustrates the difficulty in tabulating any definite ecu outputs, since there is so much variation between the product of different manufacturers. Only on the four-tube and six-tube sizes1 there practical agreement in output value. Pin-Type Conductors Table 5 is for % in. pin-type convector using steam at 1 lb. pressur For 1 in. pin-type the temperature rise of the air is about 95 per cent' the corresponding rise for % in. pin-type, and for hot water at 170 dr, fahr. the temperature rise of the air ranges from 80 to 85 per cent of tly corresponding temperature rises, with steam at 1 lb. pressure. Table 3. Heat Emission of Direct Pipe Coil Conductor for Steam Steam Temperature 215 deg. fahr. Room Temperature 70 deg. fahr. WALL COILS--Coils Placed Vertical--Pipes Horizontal B.t.u. per Lineal Feet of Coil per Hour (Not.Lineal Feet of Pipe) Size or Pipe Coil Conductor Single Row.............................................. Two___ -.......... i.:......... ....... ................. Four........................................ ................. Six....................................... ...................... Eight................... ..................................... Ten....................... ..................................... Twelve....... .........................................-..... l* 132 252 440 567 651 732 812 or 162 312 545 702 796 907 .. 1005 Of 185 348 616 793 907 1020 1135 WALL COILS--Coils Placed Vertical--Pipes Vertical Emission varies in inverse ratio of the height of the coil Use 100 B.t.u. per lineal feet of pipe as an average for 1J4 in. coil, 10 ft. high CEILING COILS--Coils Placed Horizontally--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 cash use: 126 B.t.u. per lineal feet of pipe for 1 in. coils. 156 B.t.u. per lineal feet of pipe for 1J4 in. coils. 175 B.t.u. per lineal feet of pipe for 1% in. coils. Table 4. Cubic Feet of Air per Hour per Square Foot of Heating Surface for Cast Iron Gravity Indirect Convectors Indirect heaters supplying 1st .floor registers.1........................ ............. 150 cu. ft. per hour Indirect heaters supplying registers 7 ft. above first floor.-....... _....... 200 cu. ft. per hour Indirect heaters supplying 2nd floor registers.............. ....................... .300 cu. ft. per hour Indirect heaters supplying 3rd floor registers.................................. .....350 cu. ft. per hour -Radiators and Convectors %_ , tfmperature of Air Leaving in. Pin, Cast-Iron, Gravity 5' Final Indirect Convectors j 175 200 Ho 275 300" 325 350 105 103 109 107 113 111 117 115 121 119 125 123 129 127 133 131 V; LOCATION OF HEATERS V It should be made a rule to install heaters beneath or near the area of greatest heat loss. The best place is underneath an outside window. This seems logical for the following reasons: ' : i. Heat emitted by radiation from the heater will counteract the effect of heat radiated out through the window from occupants in the room. ' 2. Cold air leaking in through the window is warmed before it reaches the interior o>f 3th.eAroirocmu.rrents from the heaters pass upward, mingling with the cold infiltering air, and form a screen of warm air protecting against cold window drafts. 4. There is less discoloration of walls from dust arising from the heater. If the heater cannot be placed underneath the window, then it should be located as near the window as possible, near outside doors, underneath skylights, near to very exposed walls or corners, etc. y` SELECTION OF HEATERS ,: .In selecting the proper heater for heating a given room or space, the following procedure should be followed: 1. Estimate the total loss from the room or space to be heated in accordance with Chapter 5, making proper allowance for exposure, wind velocity, height of ceiling, etc. " .Table 6. Variation in Dimensions and Catalog Rating of 10-Section Tubular - M.TMt bv Six Manufacturers o. of Tubes. 4 6.0-7.0 2.5 5 8.0-8.9 2.5 6 9.1-10.4 2.5 7 11.4-12.8 2.5-3.0 Height wits Legs--Inches Heat Emission--Sudake Feet 25.0-32.5 28.5 15.0-17.5 20.0-21.3 20.0-26.7 20.0-22.5 25 25.0-27.5 25.0-31.2 30.0-33.9 32.5-39.8 25.0-30.9 30.0-36.7 33.3-35.0 40.0-42.5 40.0-48.6 50.0-56.5 30 35 37.5-40.0 50 60 30.0-38.3 36.7-45.0 40.0-45.2 50.0-53.5 63.3-62.5 70.0-75.4