C.I.E. 標準曇天光による直接照度の計算式

Abstract

This paper reports some formulae for computing the direct daylight factors which are attributable to those particular parts of the sky which are seen through the windows of different shapes and represented here in some fundamental forms. The brightness of the sky is so distributed that B(θ)=(1+2sinθ)/3, where B (θ) is the brightness, B_z is the brightness at zenith, and θ is the altitude of that part of the sky where the brigthtness equals B (θ). Some examples of computation by these formulae are given, and the results are compared with those that are obtained on the assumption that the brightness is distributed uniformly all over the sky. In order to simplify the computation, the writers are planning to report on the computation charts of these formulae in another paper.