The Scope of the Glare Light Source of the Window with Non-uniform Luminance Distribution

Abstract

This paper presents a methodology to determine the area of the glare light source on the window with nonuniform luminance distribution. Experiments with observers were conducted in order to evaluate discomfort glare using a simulated window with a nonuniform luminance distribution. The simulated window is divided into three parts, each of which has a different luminance so that the window surface would have a non-uniform luminance distribution. Discomfort glare was evaluated in 21 different combinations of the luminance conditions. Hopkinson’s multiple-criterion was used for the evaluation; and 27 observers had volunteered for the test. The results of this study can be used to determine how much the luminance should be in the area around the window in order to reduce discomfort glare from the window. If the luminance around the window was less than 40% of the maximum luminance of the sky seen through the window, this would reduce discomfort glare. If the luminance around the window was higher than 40% of the maximum luminance of the sky seen through the window, the area around the window could be considered as a glare light source.