Document mpj79L4Lxm1GOR6gJpMLvB92d

HEATING VENTILATING AIR CONDITIONING GUIDE 1943 TYPES OF RADIATORS Present day radiators may be classified as tubular, wall, or window types, and are generally made of cast-iron. There are two types of tubu lar radiators available, that known as large-tube which has a spacing of in. per section, and that known as small-tube which has a spacing of 1M in- per section. The tubes in the latter type of radiator are materially Table 1. Large-Tube Cast-Iron Radiators Sectional, cast-iron, tubular-type radiators of the large-tube pattern, that is, having tubes approximately 1 % in. in diameter, in. on centers Number of Tubes per Section Catalog Rating per Section^ Sq Ft 2% 2% 4 314 . 4% . 2% 3 5 3% 4% 5 4 66 7 2% 3% A Height In. 23 26 32<r 38<= 20 23 26 324 38 26 38e 14f 20 Section Dimensions B Width Minimum Maximum In.- In. , c Spadngb In. D Leg Heightc In. 6M 6% .2% 4% 6% 6% 2% 4% m 6% \ 2% 4% 6K 6% 2% 4% 8 8 8 8 8. 8% ' m 8% 8% 8% 2%s 2%R 2 %* 2%R 2%R 4% 4% 4% 4% 4% 9 10% -2% 4% 9 10% 2% 4% 11% 11% 12%6 12% 2% 3 2% 3 or 43-12 orci --- B--. /. [ -A- Al D *The square foot of equivalent direct steam radiation is defined as the ability to emit 240 Btu per hour, with steam at 215 F, in air.at 70 F. These ratings apply only to installed radiators exposed in a normal manner; not to radiators installed behind enclosures, grilles, etc. (See A.S.H.V.E. Code forTesting Radiators.) ^Maximum assembly 60 sections.. Length equals number of sections times 2H in. Where greater than standard leg heights are required, this dimension shall be .6 in., except for 7-tube sections, in heights from 13 to 20 in., inclusive for which this dimension shall be 4)4 in. Radiators may be furnished without legs. dAlternate height by 1 producer is 30 in. Alternate height by 2 producers is 36 in.; by another, 37 in. (Alternate height by 1 producer is 13 in.; by 2 producers 13H in.; by another, 15 in. For 5-tube hospital-type radiation, this dimension is 3 in. smaller than those in the large-tube type. Small-tube radiators occupy less space and are particularly suited for installation in recesses. After a complete study of the demand for various sizes of radiators, the Institute of Boiler and Radiator Manufacturers, acting for the manu facturers, in cooperation with the Division of Simplified Practice, National Bureau of Standards, established Simplified Practice Recommendation R174-41 for large-tube cast-iron radiators. Under this program the number of stock sizes of large-tube radiators was reduced to 13. A pro gram is now in progress for the establishment of a similar recommendation 260 CHAPTER 13. RADIATORS AND CONVECTORS for small-tube cast-iron radiators. Tables 1 and 2 show the sizes and dimensions of large-tube and small-tube cast-iron radiators which are being manufactured at the present time. Wall radiators are now rated in terms of equivalent square feet, the same as large-tube and small-tube radiators. Tests have shown that the heat emitted from a wall-type radiator may be reduced from 5 to 10 per cent if the radiator is placed near the ceiling with the bars horizontal and, in an air temperature exceeding 70 F. When radiators are placed near the ceiling, there is usually such a large difference in the temperature Table 2. Small-Tube Cast-Iron Radiators Number of Tubes per Section 34 Catalog Rating per Section3 Sq Ft 1.6 Section Dimensions _A Heightc In. 25 B Width Minimum Maximum In. In. H3 3% c Spadngb In. 1% 1.6 19 4%6 4% 1% 44 1.8 22' 4%s 4% 1% 2.0 25 4% 4% i% 2.1 22 5% 6%6 . 1% m54 2.4 25 5% 6% 3.0 32 5% 6% 1.6 14 6'% 8 2.3 19 6% 8 64 3.0 25 6% 8 3.7 32 6% ' 8 1% 1% i% 1% D Leg Heightc In. 2% ' 2% 2% 2% 2% 2% 2% 2% 2% 2% 2% rc 1 -- B -- w! 1 , rx[ T D The square foot of equivalent direct steam radiation is defined as the ability, to emit 240 Btu per hour, with steam at 215 F, in air of 70 F. These ratings apply only to installed radiators exposed m a normal manner; not to radiators installed behind enclosures, grilles, etc. (See A.S.H.V.E. Code for Testing Radi ators^) bEven number.of sections only available. Maximum assembly 60 sections. Length equals number of sections times 1H in. Overall height and leg height, as produced by some manufacturers is one inch (1 in.) greater than shown in columns A and D. Radiators may be furnished without legs. dOr equal. between the floor level and the ceiling that it becomes difficult to heat the living zone of the room satisfactorily. Pipe coils are assemblies of standard pipe or tubing (1 in. to 2 in.) which are used as radiators.. In older practice these coils were commonly used in factory buildings, but now wall type radiators are most frequently used for this service. When coils are used, the miter type assembly is to be preferred as it best cares for expansion,in the pipe. Cast manifolds or headers, known as branch tees, are available for this construction. The heat emission of pipe coils placed vertically on a wall with the pipes horizontal is given in Table 3. This has been developed from avail able data, and does not represent definite results of tests. For such coils the heat emission varies as the height of the coil. The heat emission of 261