Abstract
The effective use of daylight is a function of the luminance of the sky exposed to the glazing system. Therefore, accurate data about the luminance distribution of the sky are necessary for the optimum use of daylight. This paper compares seven models for estimating the angular sky luminance distribution. They were selected based on the ability to be used with all sky conditions and to determine the luminance of the sky from solar radiation. Measurements of solar radiation, sky luminance, and sky radiance were taken in a "maritime desert region" in Saudi Arabia. The results showed that the "Perez 93" model performed better than the other models tested, but there is a need for more studies to identify more accurate models for use in similar climatic conditions.