抄録
In terms of designing daylighting of good quality, it is very important and necessary to predict and evaluate in advance the luminous environment in an interior space. Therefore, not only illuminance but also luminance distributions by daylight in an interior space should be predicted as precisely as possible. A new method of daylight calculation was developed. This method predicts luminous environment in an interior space of arbitrary shape lit by sunlight and skylight through the translucent or transparent openings. A new daylight source model under all-weather conditions is developed for the direct illuminance calculation. The luminous flux transfer method is adopted for the indirect or total illuminance calculation. In the luminance calculation, the sky luminance distribution seen through the transparent openings is predicted as well as the interior luminance distribution. The method was applied to a computer program of daylight and artificial light calculation on a membrane structure with open and closed translucent roofs under any condition of weather, location, date and hour. The program predicts the illuminance distribution in the interior space and the luminance distribution on the visual field watched at any view point. The luminance contrast of the fly ball is also predicted in the case of a baseball stadium.