Paper Conference

Proceedings of BSO Conference 2018: Fourth Conference of IBPSA-England


Validation of Simplified Visual Discomfort Calculations

J. Alstan Jakubiec

Abstract: This paper presents a novel study comparing advanced annual visual discomfort calculations to typical illuminance-based overlighting metrics. The Unified Glare Rating (UGR), Daylight Glare Probability (DGP), and simplified Daylight Glare Probability (DGPs) are calculated at an occupant’s eye level and are compared to the Useful Daylight Illuminance Exceeded (UDI-e, % time ≥ 3,000 lx) climate-based daylighting metrics. 720 designs are tested annually comprising 10,121,583 individual visual discomfort calculations. The author finds that UDI-e can predict discomfort correctly or provide extra scrutiny on discomfort analysis in between 93.1% and 98.9% of cases; therefore, it is sometimes a reasonable replacement for more arduous visual discomfort calculations. Prudence is still necessary in using illuminance-based replacements in spaces susceptible to experiencing strong contrast.
Pages: 17 - 23