ABSTRACT
The calculation of radiant interchange is commonly performed under the assumption that the participating surfaces are diffuse emitters and diffuse reflectors of radiant energy. As an alternative to the diffuse model, it is logical to consider other limiting cases that can be analyzed and evaluated without excessive complication. One such limit is the case of specular reflection. The chapter introduces the exchange factor and describes the analysis of radiant interchange in enclosures containing both purely specular reflecting surfaces and purely diffuse reflecting surfaces. It discusses the analysis is generalized to include the case in which each of the participating surfaces may possess both specular and diffuse reflectance components. A basic requirement in the analysis of radiant interchange is the knowledge of what fraction of the radiant energy leaving one surface arrives at a second surface. For the case of diffusely emitting and diffusely reflecting surfaces, this information is embodied in the angle factor.
