A new daylight glare evaluation method A comparison of the existing glare index and the proposed method and an exploration of daylighting control strategies

摘要

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 availble for daylight glare evaluation ona comparative basis. This paper introduces an improved glare evaluation method consisting of a standard monitoring protocol and advanced formulae, Daylighting Glare Index (DGI_N), where N refers to "New". The DGI_N method has been tested against the existing glare evaluation system of Chauvel on different types of window transmittances using Radiance, a lighting simulation program. Moreover, glare from another daylighting control strategy - the light shelf - was investigated. The proposed method appears to yield sensible and consistent glare values. 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. Given reliable results, the DGI_N method was coded into a small program and incorporated with Radiance to compute daylight glare indices. The future work, which is ongoing research, is to create the use of scientific-knowledge computational tools in the later stages of design in an effort to provide optimal choices of daylighting design with respect to light level and glare using the new glare algorithm.