Simulation of Daylight Glare Probability in Rooms with Grating Smart Windows

Reducing the Daylight Glare Probability (DGP) is one of the important tasks of increasing the comfort of daylighting and insolation, especially in industrial and public premises with long stays of people during working hours. A method has been developed for modelling the DGP in a room with smart window with built-in grating optical filter having angular-selective light transmission. New equations have been obtained for calculating the diffuse light transmittance, vertical illuminance, and luminance in such rooms. Numerical simulation has been carried out to determine the parameters of the filter gratings, the temporal characteristics of light transmission, and to calculate the DGP at 12 points of the room. The proposed grating chromogenic smart window has minimal transmission at a designated time, in contrast to a conventional chromogenic smart window with a continuous surface coating and a conventional uncoated window, the transmittance of which changes only due to reflection and absorption losses depending on the incidence angle of the solar rays. The diffuse light transmittance of a grating chromogenic window is higher than that of a conventional chromogenic window in both coloured and bleached states, which increases daylight during months with insufficient solar radiation. The results of the DGP calculation showed that the best anti-glare performance is provided by the grating chromogenic smart window, intermediate by the conventional chromogenic smart window, and the worst by the conventional uncoated window. The developed method for modelling the glare probability is applicable to assess not only DGP, but also any other metrics of discomfort.