GLANCE (GLare ANnual Classes Evaluation): An approach for a simplified spatial glare evaluation

GLANCE (GLare ANnual Classes Evaluation) is a simplified method to evaluate glare conditions over a grid of points in a space on an annual basis. The method is based on three methodological assumptions: (i) the vertical illuminance (Ev) is adopted as the parameter to estimate the daylight glare condition in each point of the space; (ii) daylight glare conditions are expressed in terms of Daylight Glare Comfort Classes (DGCCs); (iii) the annual time-series of Ev and DGP for a single reference point are calculated and correlated to determine the DGCC of each point. The method allows faster glare analyses to be performed, compared to the time needed for spatio-temporal analyses using DGP. To describe the method and demonstrate its accuracy, a study was carried out using a sample space with three orientations (East, South, and West) and a glazing with various light transmittances in the range 0.05-0.75. A grid of 9 viewpoints, with 5 view directions, was assumed, for a total of 2160 combinations. The performance of the GLANCE method proved to be robust in estimating the DGCCs for the cases analysed, as shown by the Youden index, which was higher than 0.85 for over 90% of the cases considered.