Document MJV4dDNGRnwO90pk7BBr2X50k

American Society of Heating and Ventilating Engineers Guide, 1924-25 in the time in which the room was supposed to be heated. This heatingup factor is sometimes taken care of by increasing the radiation by 10 per cent. If the building is to be heated intermittently after long inter vals of unheated periods, this can be figured as above or 25 per cent is often added to the radiation to take care of this difference. Table 20 conforms very closely to the ratings for direct radiation as given for radiators of heat shown with sections 2]^ in. on centers, except in the case of four-column radiation, which are 3 in. on centers. Pipe coils should be of the header type, with provision made for ex pansion by a mitre piece. The steam supply should be at the mitre end and all coils should be securely anchored at the return header so as to throw the expansion toward the mitre end. The coils should be made of 1J4 or in. P'Pe and not over 60 ft. in length, not including the mitre, which should be at least one-tenth the length .of the coil. SELECTION OF RADIATION It is usually necessary to select the type and location of radiation to conform to the conditions and space available in the room. In general it is usually most convenient and practical to locate the radiation on the exposed side of the room. The size of the radiator to take care of any particular heat loss can be best selected from the sheets compiled by the Society's Research Laboratory in cooperation with the U. S. Bureau of Mines Experiment Station, which are based on experiments by the late Director, John R. Allen, and F. B. Rowley. As the heat emitted per square foot of radiation varies in radiators of different heights, widths and lengths, and also with the steam pressure and the temperature of the room, errors will occur if the same factor is used for all radiators. Examples for the Use of Tables.--Assume that the heat loss from a room is 15,497 B.t.u. per hr., to heat the room to 70 deg. fahr. Two-column 38-in. radiators have been selected using steam at 1-lb. gage or approxi mately 215 deg. fahr. Solution.--In Table 18 for two-column radiators, under 38 in., it will be found that a 17-section radiator will.emit 15,960 B.t.u. There fore a 17-section two-column 38-in. radiator will be required with a rated surface of 68 sq. ft. If in the same example steam at 5-lb. pressure or approximately 227 deg. fahr. was used and the room was heated to only 60 deg. fahr. re quiring 13,300 B.t.u. and three-column 26-in. radiators are selected the radiation would be estimated as follows: Solution.--In Table 24 following down the first column to 5-lb. gage pressure and then over horizontally to 60 deg. fahr. room temperature the conversion factor 0.864 will be found. The heat loss 13,300 X 0.864 (the equivalent heat loss) = 11,480 B.t.u. In Table 16 for three-column radiators under the heading 26 in. it will be found that a 13-section radiator will supply 11,242 B.t.u. under standard conditions which is the closest to the amount required. Therefore a 13-section three-column 26-in. radiator will be required. 24 American Society of Heating and Ventilating Engineers Guide, 1924-25 Total B.t.u. per hr. 770 1293 1807 2321 2835 3348 3863 4377 4891 5404 5918 6432 6947 7459 7974 8489 9000 9515 10028 10544 R esearch L abo rato ry Sta n d a r d D a t a -- A m e r ic a n So c ie ty of H e a t in g a n d V e n t il a t in g E n g in e e r s Result of Cooperative Work With U. S. Bureau of Mines Experiment Station, Pittsburgh. Pa. Copyright 192l z 3 8 o M0\NONOers*bOO*c'0Nr'--OroimoOOcOtlO'^O'irOdr-cONoNOr-tO--O0^0OOT}* i/54/>i0u`5O|0000l/}U,> p-N)^,Or'0M(*)<0'0000^Me"Ob*000 Rated 1 Surface sq. ft. ai o '5o H<Z ^Mt- OS S Total B.t.u. per hr. lOO ----ilOOOOi'^^O,oOONf'OOrO'<'ONa'OfnOOvOjOCS"tOoOOt'AorrO-^.o'rro-O-o'O0OO0' Zs I Z cp ou sJM OccOOtOO'otOO'O^O'OfOO'OfOOO^ cr) to >0 OO OHf*5<Ah<Or-CO 'fv| cq cCo4 *C0* \CN oCON CO CO* fCOO ao 2 2O P <z t<oN O o& Rated Surfaci sq. ft. csTt'OcoCrJ.--Tf'^O^ecMoeogcesNtje*M'OCoSocooctosc^o'cCoccoo-Q^* 1? =? & NV0)>CO`OOHM--MN>rNJ'0ct^^o^lao0^tNr^0*VicO0)oiO^Oo'O"P'OO>'-CrlCO*4rO'e0'oOo*0O^Cl0O-O'^riC''O^-','^(iCI0O^0NOO>O''t'O-N'^|N'iN0OeNlo0^ z CO *00*00*0l0t00>0>0 I|s N*Ob*Nl^O^--rqNr<qcO4t0^4cCocNocontio^^'TNfT}O`'xtj>'io III w < 2a cl S HoO*i. i("oNH->'od*Q-'\^cOOMorOrcO'or`OO'vOO^iOo"t^io^M'^'fO<OiDM'0OOCcO7O'0'OO0oCTOotO-ir-OOO^vbOOO*t'OM^-C'l'NDpO4CioeOri^^f--Ol-O44rc40i,o0'4oist' z CCOO cO'OO'f'-HO-HOrtOM--Mf'Md,CCO'OCcOoC,0O0C'COSxilO'xlC'xOl'iO-<iATlfDt^OO Rated Surface sq. ft. Vzi Oh2 2h u V) -HcscOxrv!Ot'OOCiO-C--N*HCnO-i 'e,u7^'O*t^*OO-HOC'0SI 25