A new daylight glare evaluation method

Abstract

A proper glare prediction method is needed to promote visual comfort at workplaces. Only a few formulae have been proposed for discomfort glare of daylight origin, and they are inadequate in real daylight situations. No standard monitoring procedure is available for daylight glare evaluation on a comparative basis. This paper introduces an improved glare evaluation method consisting of a standard monitoring protocol and advanced formulae. The method has been tested against the existing glare evaluation system of Chauvel on different types of window size using Radiance, a lighting simulation program. Given reliable results, the DGI N procedure was coded into a small program and incorporated with Radiance to compute daylight glare indices. The method was developed with the hope that architects and lighting designers would adopt it as an easy and reliable method for evaluating discomfort glare from daylight. The future work, which is an ongoing research, is to create the use of scientific-knowledge computational tools in the later stages of design in an effort to provide optimum choices of daylighting design with respect to light level and glare using the new glare algorithm. Copyright © 2007 The Illuminating Engineering Institute of Japan.