Glare perception in office lighting with LEDs for different working modes

The difference of perceived glare between two different working modes (i.e., computer work and reading/writing) caused by LEDs in office was investigated. Discomfort glare are evaluated in two aspects, the general glare and overhead glare. For general glare study, all the LED luminaires installed in the ceiling of the experimental room were switched on to realize a uniform lighting distribution like a normal office lighting design. While for overhead glare assessment, only one single LED luminaire just above the subject was switched on. The results show that the perceived general glare increased with the luminance level of the luminaires significantly in both working modes; and the perceived overhead glare was found to be significantly influenced by luminance level and viewing angle only in computer working mode. Both perceived general glare and perceived overhead glare in computer working mode were more serious than that in the reading/writing working mode.