Document mpQkXkoR348DZDyEbmLKJpb4d

American Society of Heating and Ventilating Engineers Guide, 1932 Table 1. Variation in Dimensions and Catalog Rating of 10-Section Tubular Radiators Made by Six Manufacturers No. of Tubes____ __ ____________ ,, Width of Radiator................. ...... Inches Length per Section.... .......... ,, Inches 3 4.6-5.1 2.5 4 6.0-7.0 2.5 56 2-i ' 9.1-10.4 2.5 7/ 11.4-12.8 2.5-3.0/ Height with Legs--Inches Heat Emission--Equivalent Square Feet . -i Iv----; .; . .. 13-14 16-18 20-21 22-23 .............. 30-32 > - , : 36 38 15.0-17.5 20.0-21.3 20.0-26.7 25.0-30.9 30.0-36.7 20.0-22.5 25 25.0-27.5 33.3-35.0 40.0-42.5 20 28.5 25.0-31.2 . 30 30.0-33.9 35 32.5-39.8- 37.5-40.0 40.0-48:6 so 50.0-56.5- 60 25.0-32.5 30.0-38.3 36.7-45.0 40.0-45.2 50.0^53.5 63.3-62.5 70.0-75.4 tKe equivalent heating surface made up of; 13^-in. pipe coils. Wall radiators are particularly adapted for direct heating of industrial build ings, for heating small rooms such as baths or toilets, or for use at the Ceilings of basement rooms or just below the skylights. . ./ .These radiators are assembled at the factory in stacks of from 3 to 5 sections, and these stacks may be connected later by right and left .hexagon nut shoulder nipples to obtain large units. The method of hanging.or supporting wall radiators is of great importance as the ten dency: of'these radiators to. tear loose the brackets or hangers is very marked, due to, the .expansion and contraction strains produced by the piping system as well as by weight of the radiators themselves. . Wall sections are always installed with bars vertical in order to obtain the greatest efficiency. Window. Radiators . Low'.window-radiators are usually of the-flue type or of the tubular type arid are designed to be placed below the.stools orgeats of very low windows. In construction, the flue type differs from the column and tubular radiators only in that the sections are usually flat hollow slabs with vertical ribs so cast upon them as to form flues of the interior sur faces of the radiator. This type is not made in heights above 20 in-. Table 2. 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 coil per hour (not linear feet of pipe) Size op Pipe A i* IK' mm / Single Row..................................... _..... Four.:.. ................................ ___ ;____ Six..... _____ :..... :.... ............ ........... Eight-.l... .'. .1 ......./...... :............. ....--. _..................... .:......... ...... Twelve.'.. .. ..... 1..._______._.................. 132 252 440 . 567 651 732 812 162 312 545 702 796 ' 907 1005 185 348 /' 616 / 793 / 907 1020 1135 96 Chapter - &--Radiators Pipe-Coil Radiators Pipe-coil radiators are in more or less general use in factory and in dustrial plants and are usually made up of 1 or 134-in- standard black pipe screwed into manifolds. These coils may be of the: miter type, or of the return or box-coil type using manifold tees or headers of cast-iron in each Case. A coil made up of return bends and straight pipe is sometimes used, and is called a trombone coil. Its use is questionable since the long, continuous coil offers excessive friction to the steam or water. Pipe coils are intended to be hung on the side walls or from the ceiling, and suitable provision must be made for expansion. Vertical pipe radiators have also been used extensively in the past, and are made up by screwing short pieces of capped pipe into a cast-iron base forming a portable radiator very similar to the ordinary cast-iron column radiator. Special Radiators The circular radiator is often placed around columns in entrance lobbies and can be obtained in the one-, two-, and three-tube patterns, in all regular heights, but usually only on special order. The corner radiator is also often used in entrance lobbies where the wall space is limited. It can be obtained in practically all patterns and heights except in the four-tube and in the ventilating flue style. As from 3 to 5 sections are required to make the corner, depending on the style of radia tor, it is necessary to specify the number of sections in each arm as well as in the corner. The supply and return ends must be indicated also to provide the proper hub for each end. OUTPUT OF RADIATORS In the past the unit of measure recognized in computing heat emission of radiators was the square foot of actual surface. The use of this unit is gradually being discarded, however, for the reason.that heat emission de pends upon the design of the heating unit as well as upon its surface area. The engineer is interested primarily in the amount of heat emitted by, rather than.the amount of surface in a heat-transferring agent. As a re sult, radiators are now rated on the heat given off either in Btu per hour or in equivalent square feet, based on 240 Btu per hour. Output of Tubular Radiators Table 1 illustrates the difficulty in tabulating tubular radiator outputs since there is so much variation, between the products of the different manufacturers. Only on the four-tube and six-tube sizes is there any practical'agreement in output value. The heat emission values appear as square feet but are entirely artificial, being based on the heat emission of the radiator and not on the measured surface. Output of Pipe Coils The heat emission of vertical pipe coils placed on a wall (pipes hori zontal) is given in Table 2. This table has been developed by ai rnejthod of deductioh from the available data on such experimental work dn pipe coils as has been recorded and does not represent definite experimental results of tests. For vertical wall coils (pipes vertical) the heat emission 97