Development of a substitutive light source for indoor daylight calculations

The central focus of the paper is to present the results of the last 2 years of the research work on development of a substitutive light source for daylight calculation of the illuminance indoors. In the paper, calculation of spatial distribution of daylight according to the new CIE standard is discussed. Another focal topic is the calculation of photometric data of a light source which substitutes vertical window or vertical window opening in computer calculations. Through the development of photometric data for a light source, so that it can be imported into calculation software, this software becomes more powerful and useful.