Document O141BLGQy3dEvY4bp9Gd2Yg9v

208 CHAPTER 14 1959 Guide Table 1 .... Column-Type Cast-Iron Radiator Accepted Saiittg per Section* NelgM In. One Cobnut Two Cotwran Three Column SqFt Btuh Sq Ft Btuh Sq Ft Btuh 16 1H 360 IS 2H 540 20 360 2 480 22 2H 540 3 720 23 m 400 2X 560 28 2 480 2H 640 3H 900 32 2* 600 3H 800 4H 1080 38 3 720 4 960 5 1200 45 5 1200 6 1440 Few Cotamn Fbre Column Six Column Sq Ft Btuh Sq Ft Btuh SqFt Btuh 13 16 18 3 720. 20 22 4 960 26 5 1200 7 32 6H 1560 38 8 1920 - 10 45 10 2400 1120 1680 2400 3 5 720 900 1080 1200 . * These ratines ere based oa steam at 315 F sad sir at TO F. They apply only to installed radiator* exposed is a normal manner; not to radiators installed enclosures, (riUcs, or under shelves. For Bta per boor ratines at other temperatures, divide table values by factors found in Table 7. enclosure for the convector fit as snugly as possible so that the air passing through cannot bypass the heating element. BASEBOARD UNITS Baseboard heat-distributing units are divided into three types: (1) radiant, (2) radiant-convector, and (3) finnedtube.1 Radiant-type baseboard is made of cast iron or steel. This type of unit emits a large portion of its heat output by radia tion. Units are sometimes suspended from the ceiling in rooms having little or no available wall space for floor mounted units. As the convected heat obtained from these units when mounted at the ceiling is less than when they are mounted at floor level additional length must be added as recommended by the manufacturer to allow for the reduc tion. Radiant-convector type baseboard also is made of cast iron or steel. The units are provided with air openings at the top and bottom to permit circulation of room air over the wall side of the unit. The wall side of the unit has ex tended surface to provide increased beat output. A large portion of the heat emitted is transferred by convection. This type of baseboard having a greater output per linear foot than the radiant type is particularly adaptable where wall space is at a premium or the beat loss of the room is high. Finned-tube type of baseboard has a finned-tube heating element that is concealed by a long low sheet-metal enclo- Toble 2 .... Large-Tube Cast-Iron Radiators SccfMoerf, cestwreo, tufaufor-type redfotore of Che large-tube partem, |bet b, baring tabes approximately in. in dmneter, 2} in. on center*. of Tube* Catalog Rating Height per Section* Width Section Center teg Height* to Tapping Sq Ft Btuh In. h. In. In. m 420 20 2 480 23 3 2H 560 28 3 720 32 3M 840 38 2M 4K 2H 4h 2h 4M 2H 4H 2H 4M VX 540 20 2% 600 23 4 2H 660 26 840 32 1020 38 2H 4K 2M 4h 2H 4M 2M iX 2H 640 20 3 720 23 5 3H 840 26 1040 32 5 1200 38 8-8M. 2Hd 2hd 2W 2W . 2hd 4M 4M 4H 3 720 20 3M 840 23 6 4 960 26 5 1200 32 6 1440 38 9-10X 2X 4H 2K 4H 2X 4H 2M 2K iX 2* 600 14 7 3 720 17 3H 880 20 2X 3 214 3 2H 3 or4M * These ratine* ere baaed on steam at 315 F and atr at 70 F/They apply only to hmtalled radixtore expoeed in * normal manner; not to radiator* installed bohind enclosures, grilles, or under shdvra. For Bta per hour ratines at other tem peratures, divide table value* by (actor* found in Table 7. b Maximum eoembly 60 Beetlens. Lencth. eqoal* number of wetwna timet 3H in. * Where treater than ctandard let heights are required, this dimension shall be 6 in., except for 7-tobe section*, in height* from 13 to 30 in., indnaive, for which this dimension shall be 4H in. Btdat<w may be furnished without let*. d For 5-tube hospital-type radiation. this dimension i* 3 in. sure or cover. A major portion of the heat is transferred to the room by convection. The output varies over a wide range depending on the physical dimentions and the materials used. When selecting this type of baseboard the designer should avoid using a unit with too high an output per linear foot. Baseboard performs best when units are so selected that they are installed along as much of the exposed wall as possible. The basic advantage of the baseboard heat-distributing unit is that its normal placement is along the cold walls and under areas where the greatest heat loss occurs. Other advantages claimed for the baseboard heat-distributing unit are: it is inconspicuous; it offers a minimum of interference with furniture placement; and it distributes the heat near the floor. This last characteristic reduces the floor-to-ceiling temperature gradient to about 2 to 4 F deg, and tends to produce uniform temperatures throughout the room. It also makes baseboard heat-distributing units adaptable to base mentless homes, where cold floors are prevalent.* Radiators, Convectors, Baseboard and Finned-Tube Units 209 Table 3 .... Small-Tube Cast-Iron Radiators Heat 1063 calculations for baseboard heating systems are the same as those used for other types of heat-distributing units. The procedure for designing baseboard heating sys tems is given in / = B = R Installation Guide No. 5.* Rat ings for baseboard heat-distributing units' are expressed in Btuh per linear foot. FINNED-TUBE UNITS A finned-tube heat-distributing unit is a room-air beater composed of a finned-tube element fabricated from mutaHto tube to whicb metallic fins have been bonded. It does not include a fin-tube type baseboard element provided with an enclosure for replacement of. the conventional baseboard. The finned-tube unit can be used with either or hot water systems. It has advantages for installation where it is desired to distribute the heat along the entire outside wall and thereby prevent down drafts along the walls in buildings such as schools, churches, hospitals, and factories. Normal placement of finned tube is along the walls where the heat loss is greatest. If necessary, the units can be in stalled in two or three tiers along available wall space to meet the heating requirements. For hot water system instal Table 4 .... Cost-Iron Wall Radiators Appn.^,1. Heat Output* Height Length or Width -Thkknem Sq Ft Btuh 13H . 13x 22 13X 29 22 13H 29 13tf 3 6M \ 1560 3 8 1920 3 8 1920 3 11 2640 3 11 2640 . There rttS* berad oa steam *i 315 P and air at 79 P. They apply only to installed radiator* expoeed to norma] manner, not to radiator* be hind enclosure*, (rills, or under *helve*. Far Bta per hour rating* at other tem perature* divide table values by factor* found ia Tabla 7. Table 5 .... Heat Emission of Pipe Coils Placed Vertically on a Wall (Pipes Horizontal) Containing Steam at 215 F and Surrounded with Air at 70 F Btu per linear foot of cod per haw tnof linear feet el pipe) Size of Pipe 1 In. IX ftt. IX In. Single row..................... Two......................... Four................................ Six............................. Eight..................................... Ten............................... Twelve......................... 132 252 440 567 651 732 812 162 312 545 702 796 907 1005 185 348 616 793 907 1020 1135 lations where two or three tiers are required, a sinuous water flow through the heaters is recommended because a header connection with parallel flow may permit the water to short circuit along the path of least resistance. Protection of the heating element may be provided by open-type grilles fabricated of expanded metal or perforated materials covering the top and front of the finned-tube element. Covers and enclosures are also available to enhance the appearance and to increase heating efficiency. A cover is a fabricated shield having at least a portion of the front skirt made of solid material. It can be mounted on the finned-tube element so that there is clearance be tween the wall and the cover, and the rear of the finned-tube element is not completely enclosed. A cover may have a top, front, or inclined outlet. An enclosure is a shield of solid material installed so that the finned-tube element is completely enclosed at both front'and rear. An enclosure may have an integral hack or may be installed tightly against the wall so that the wall itself forms the back. An enclosure may have a top, front, or inclined outlet. Finned-tube units are available in four tube tiras from 1 in. to 2 in. IPS with various fin arrangements. The resis tance to the flow of water or steam is rather low so that a