Document v6poXbq061G3JDEQo2jQaEdwm

218 CHAPTER 14 1960 Guide. Table 1 .... Column-Type Cast-Iron Radiator Genenrfiy Accepted Bating per Section* Mglil In. One Column &,Ft Stab 15 18 20 i*s 360 22 23 IK 400 26 2 480 32 2M 600 38 3 720 45 Two Cotemn Three Column Sq FI Blub Sq Ft Blub 1X 2 2*6 2*6 2H3M 4 5 360 480540 560 640 800 960 1200 2*6 3 3K 4*6 5 6 540 720 900 1080 1200 1440 Few Cotemn Five Cotemn Six Cotemn Sq Ft Bfch SqFt Blub Sq Ft Btuh 13 3 720 16 3H 900 18 3 20 720 4H 1120 4*6 1080 5 1200 22 4 960 28 6 1200 7 16S0 32 6*6 1560 38 8 1920 10 2400 45 10 2400 * Tfaeaa mttac* ora booed on atom at <16 P aad air at 70 F. They apply only to *~**--* radiator* iijnnl in a normal manner; not to radiator* natalled KAind eadoeora, crillee, or neuter afaelra- For Btn per boor ratines at caber temperaiareo, divide table value* by (actors (onad 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 nailing is les 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 heat 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 heat 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 enelo- Table 2 .... Large-Tube Cost-Iron Radiators Stcfmaf, cadWrai, (ubuter-tfpe radiator* of (bo large-tab* pattern, that U, having tubes approximately ia. te diameter, 2*6 in. on canter*. Number of Tube* Catalog feting Height per Section* Width Section teg Canter Hafgfcf fo Spoong* Tapping SqFt Btuh In in. bv fai. 1H 420 20 2 480 23 3 2*6 560 28 3 720 32 3M 840 38 m 2*6 **6 2h 4h 2h 4h 2H 4H 2H 4*6 2*6 540 20 2X 600 23 2*6 4 2X 660 28 M-Q'X* 2*6 3* 840 32 2*6 4*6 1020 38 2*6 4*6 4*6 4*6 4*6 2X 640 20 3 720 23 5 3*6 840 26 4*6 1040 32 5 1200 38 2*6* 2Md 2*6d 2H* 2H" *x 4*6 4*6 4*6 4*6 3 720 20 3*6 840 23 6 4 960 26 5 1200 32 6 1440 38 9-10*6 2*6 4J6 2*6 4*6 2*6 4*6 2*6 4*6 2*6 4*6 2*6 600 14 2X 3 7 3 720 17 UH-IS'K* 2*6 3 m 880 20 2*6 3 or 4*6 * These mtififi ere baaed an steam et SIS F sad air at 70 F. They apply only t6 installed radiator* ixpcoed in a mannnr-. not to radiators installed be hind eadesuras. pin--, or under shelves. For Btu per hour ratings at oths tem peratures, divide table value* by factor* found in Table 7. b Marimi-- assembly CO sectwns. Length equals number cf o*rtinu times SH in. * Where greater then etsmbrd leg heights are required, this dimension shall be S in_ except (or 7-tube sections, in heights from 13 to SO in., inclusive, (or which this dimension shall be tjd in- Radiators may be furnished without tegs. 4 For 0-tubs hospital-type radiation, this dimessioa is I 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 dimensions 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 219 Table 3 .... Small-Tube Cast-Iron Radiators Heat loss 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. 500.1 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 heater composed of a finned-tube element fabricated from metallic tube to which 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 steam 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 .... Cast-Iron Wall Radiators Approximate Oioongocu--laches Heat Output* Height Length or Width Thkfan, Sq Ft Btuh 13*6 13*6 22 13*6 29 16*4 22 13*6 29 13)6 3 6*6 1560 3 8 1920 3 8 1920 3 11 2840 3 11 2640 *Tteoaratb^>ara baaed an atcem at 115 Fond air a* 70 F. Thy apply only to isstoiled radiator* expeoed in a norma] manner, not to radiators installed be hind cocksure*, grills, or tmdar ahelvta. For Bto per hoar rating* at other tompeastazm divide table valuta by frtor* found in Table 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 6te par hneor foot of coil per boor (not Bneer feet of pip*) Size of Fipe ? In. IX In. 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 1)35 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 dement 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 between the wail 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 back or may be installed tightly against the wall so that the wail itself forms the back. An enclosure may have a top, front, or inclined outlet. Finned-tube units are available in four tube sizes 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