visual comfort; discomfort glare; time-based; duration time
Daylight performance in a real space is dynamic, as a response, dynamic glare evaluations are more reasonable. Based on the fundamental of widely studied instantaneous assessment of visual comfort evaluations, the novelty of this research is duration in predicting visual comfort issues, aims to explore the relationship between human discomfort perceptions and glare integral in time. Subjective survey and 6-minute time interval eDGPs simulations was taken place in four east-facing test rooms in Guangzhou, China. 16 volunteers participated in this survey from July 6th to Sep 3rd, 2017, all participants ranked the visual discomfort condition three times a day in morning/midday/afternoon. The results of this survey illustrated that enhanced simplified DGP (eDGPs) is capable to instead of full-rendered DGP in predicting time-based visual comfort issues, and eDGPs has the advantage of being able to be rapid calculated in long-term survey or analysis. Moreover, there existed a strong correlation between the duration time above certain visual comfort thresholds with reported long-term visual comfort. The trigger duration time of 0.45>eDGPs≥0.40 is 12 minutes that occupant could evaluate the space visual intolerable and the corresponding median duration time is no less than 24 min. Meanwhile, the median duration time of 0.40>eDGPs≥0.35 is 6 min that a subject could rank the office space visual disturbing. The trigger duration time of 0.35>eDGPs≥0.30 is 6 min and the median value is 18 min that subject could probably evaluate the room space as glare perceptible.