Document GKEzRKGqMJp9YRox6Drex4m8Y

American Society of Heating and. Ventilating Engineers GWd, Fig. 4. Room Temperature Gradients and Steam Condensing Rates for Radiator with Improperly Designed Enclosures improperly designed enclosures. The effect of a well designed shield ptae^ above the radiator is shown by Fig. 5. The performance obtained by uof the shield was satisfactory as the condensation rate was decreased bjj 11 per cent, the temperatures above the breathing line were reduced, the breathing line temperature was unchanged, and slightly higher temperatures were obtained below the breathing line. The effect of a cloth cover (Fig. 6) extending downward 6 in. from the top of the radiator was to make the radiator performance unsatisfactory and inadequate. The de sign and performance of radiator enclosures should be carefully studied when radiation is to be selected for use with enclosures or when enclosures are to be applied to existing radiators. Care must be exercised to follow certain rules in designing enclosures'* the most important of which are: Chapter 12--Radiators and Convectors Enclosures should be insulated whir l in. magnesia or asbestos block, lined with jjgji'or non-corrosive sheet metal, placed next to the conductor. -- surface 0f the conductor should be painted flat black, maroon japan, white or white zinc. If the conductor is entirely concealed it may be unpainted JH^The free area of the grille or opening at the outlet should be not less than the SS'grea through the sections of the conductor. TjSfehe free area of the grille or opening at the inlet should be not less than 80 per cent gjrixee area at the outlet. > 5?If the outlet is in the face of the enclosure so that the air flow is horizontal, the SFarea of the outlet should be at least ISO per cent of the free area about the condoctor. and the clear height^tween the.top of the conductor and the underside of the fljp5o{the encIosure should be not less than the depth of the enclosure. "iS^Best results are obtained with a tight fitting enclosure, provided the free area SfiSat'the conductor at point of greatest restriction is not excessive. As a general rule ^efficiency of the conductor is inversely proportional to the depth of the enclosure - TYPES OF HEATERS Types, sizes, and heat emission for tube conductors and for the various other forms of cabinet convectors and for the extended surface-blast Fig. 5. Room Temperature Gradient and Steam Condensing Rate for Radiator with Shield 210 Fig. 6. Room Temperature Gradients and Steam Condensing Rates for Radiator with a Cloth Cover convectors now on the market, are riot sufficiently well standardized to |jye heat-emission tables applicable to all makes of a given type. For such information the reader is directed to manufacturers' guarantee in :the catalog data section of The Guide and elsewhere. Pipe Coil Convectors ` Table 3 has been developed by a method of deduction from the avail able data on such experimental work on pipe coils as has been recorded, and does not represent definite experimental results of tests. Cast-Iron Gravity Indirect Convectors gives the cubic feet of air per hour (measured at 70 deg. fahr.) usually allowed per square foot of heating surface, through cast-iron ^gravity indirect convectors. 211