Illumination distribution and daylight glare evaluation within different windows for comfortable lighting

Abstract

Although the application of natural light illumination has great benefits in energy saving and physical and mental health of occupants, it also potentially causes glare which affects people's visual comfort. The illumination distribution and daylight glare with different windows were investigated in the paper. For illumination distribution, the results show that as the height of the windowsill increases from 0.8 m to1.6 m, the maximum illumination decreasing by 2148 lx, the minimum illumination gradually increased and changed less, increasing by 93 lx. Circular window results in the smallest indoor illumination, the maximum and minimum of the indoor illumination show little difference for the other four window shapes with the same windowsill heights and window area. And the indoor illumination increases gradually with the glass transmittance increasing. For daylight glare evaluation, the results show that the glare gradually decreases as the height of the windowsill increases from the ground. The rectangular window produces the strongest glare, the circular and square windows produce almost the same glare, less than the rectangle window. The ribbon and arched windows produce similar glare with the minimal extent under the same windowsill height and window area. Moreover, the greater the glass transmittance, the worse the glare is.