Document GKyvezgdp79YbqYXLJKG12GN

American Society of Heating and Ventilating Engineers Guide, 1930 Table 4. Heat Emission op 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 CoNiracTOa 1' W U4' 132 155 185 252 312 348 440 545 616 567 702 793 651 796 907 732 907 1020 812 1005 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 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 iri a higher temperature. In this case use: 126 B.t.u. per lineal feetof pipe for 1 in. coils. 146 B.t.u. per lineal feetof pipe for 1M in. coils. 175 B.t.u. per lineal feetof pipe for 1}4 in', coils. Table 5. Cubic Feet of Air per Hour per Square Foot of Heating Surface for Cast Iron Gravity Indirect Convectors Indirect heaters supplying 1st floor registers.-............................... 150 cu. ft. Indirect heaters supplying registers 7 ft. above first floor.-............... 200 cu. ft. Indirect heaters supplying 2nd floor registers........... 300 cu. ft. Indirect heaters supplying 3rd floor registers....................................... 350 cu. ft. perhour perhour perhour perhour Table 6. Final Temperature of Air Leaving 54 in.- Pin, Cast-Iron, Gravity Indirect Convectors Note.--Temperature of air entering room shall be assumed lower than temperature of air leaving convector as.follows: 1st Floor, 5 deg. lower; 2nd Floor, 8 deg. lower; 3rd Floor, 10 deg. lower. 284 Chapter 16--Conductors & Convectors for Heating by Steam & by Hot Water . Table 7 illustrates the difficulty in tabulating any definite conductor outputs, since there is so much variation between the product of the different manufacturers. Only on the four-tube and six-tube sizes is there practical agreement in output value. Pin-Type Conductors Table 6 is for % in. pin-type convector using steam at 1 lb. pressure. For 1 in. pin-type the temperature- rise of the air is about 95 per cent of the corresponding rise for % in. pin-type, and for hot water at 170 deg. fahr. the temperature rise of the air ranges from 80 to 85 per cent of the corresponding temperature rises, with steam at 1 lb. pressure. LOCATION OF HEATERS It should be made a rule to install heaters beneath or near the-space of greatest heat loss. The best place is underneath an outside window. 1 111 in u u / Ct V7 rfey. /T. ivj5*74, i/swe/osed/A bts'/i? -t.r AAef/b of S/e&mt Codk >.(A 74 ?c. -743 =ec1' --1 /?7C. V /r -- C/i<r/oa.us/-e M. C >-- vj 1 Veo - "eA 1 'Ale ? -- 1 1 [11-4- 1 111 l-L / /2 Fig. 5.' Room Temperature Gradient and Steam Condensing Rate for Radiator with Shield This seems logical for the following reasons: 1. 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 of t3h.eAroirocmu.rrents from the heaters pass upward, mingling with the cold ihfiltering 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. 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 2, making proper allowance for exposure, wind velocity, height of ceiling, etc.