Abstract

The mean radiant temperature (m.r.t.) is usually assessed as the radiation received at a point (or by a small sphere), but it is clearly important to know how adequately this parameter describes the heat load on a man, for in the presence of hot surfaces his shape and orientation may have significant effects. This paper presents the results of experiments designed to assess the radiant heat received by a man in a controlled temperature room in which non-uniform environments were achieved by locating a heated panel either overhead or on one wall. The m.r.t. was determined with reference to a point using (a) the solid angle and temperature of each surface of the room, (b) a radiation thermopile, and (c) a globe thermometer. The m.r.t. was also determined with reference to (a) a cylinder 68 in. in height and 12 in. in diameter, and (b) models of standing and sitting men. It seems that in indoor environments, where there is no intense radiation from sharply localized sources, the single estimation of m.r.t. with a globe thermometer at 45 in. above the floor will generally give a satisfactory indication of the heat load on a standing or sitting man.