Abstract
The Calculation of luminous transfer in spaces bounded by surfaces that exhibit specular and/or diffuse reflections were extensively studied by O'Brien and associates in the middle of 1960's.
In the conventional calculation, the number of terms of the φ-function and consequently computation time increase as the number of surface elements increses.
This paper describes an approximate calculation of interreflections in rooms with both diffuse and specular surfaces. The approximation is based on the assumption that surfaces with both diffuse and specular reflections can be treated solely as uniform diffusers for any interreflection.
For evaluation, luminous exitance is calculated for luminous panels of different sizes in a room of any shape.
The results showed that approximation errors were less than one percent.
