Daylight modelling with passport-light

This paper describes the use of daylight coefficients in a computer tool which is based in Monte Carlo backward ray tracing merthod and was developed under the frame of DAYLIGHT- Europe EC Project. Following the daylight coefficients approach the intereflection calculation is carried out once for each zone and it doesn’t have to be repeated if the sky luminance distribution changes. It is obvious that the advantage of the approach is that hour by hour calculations of interior lighting in a building for a whole year can be performed fast without the repetition of the intereflection calculation even if the building contains innovative daylighting systems like mirrored lightselves or prismatic glazing.