Analysis of UGR Values and Results of UGR Calculations in Commercial Lighting Simulation Software

Abstract

ABSTRACTThe Unified Glare Rating (UGR) is an international index presented by the CIE that quantifies discomfort glare and has become of recent important. The UGR can be calculated using commercial lighting simulation software such as Relux 2013, AGi32 v2.04, and Dialux 4.11, but the values vary depending on which software is used. It appears that because the UGR input variables used in the UGR calculations of commercial lighting simulation software differ, there are differences in the calculated UGR values. Therefore, this study modified the UGR calculation modeling and made it possible to calculate UGR values with various calculation conditions of input variables. Then, the UGR values were calculated by changing calculation conditions under the following three input variables: field of view for the calculation of the background luminance (Lb) and for the calculation of luminance of the luminous parts of each luminaire (L) and the position index (P). Among the calculation conditions under these three input variables, the conditions that have an effect on the UGR values have been analyzed, and these UGR values were compared to those from commercial lighting simulation software, from which we could speculate the UGR calculation algorithm in commercial lighting simulation.