Comparative study on analysis of daylight glare from windows for different seasons

This paper deals with the comparative study on visual comfort level as experienced by the occupants in a daylit room and is assessed by the parameter DGI (daylight glare index) - a measure of discomfort glare level due to window. Matlab programs are developed to compute DGI values corresponding to a set of occupant's position and directions of view. Four window orientations, viz. N, E, S, W and two directions of view, viz. directed to the window and 45° away from the window are considered for the assessment of visual comfort. The assessment is done on the basis of computed DGI compared with the three reference values of DGI, viz. 22, 24 and 28 representing “Acceptable”, “Just uncomfortable” and “Just intolerable” discomfort glare respectively for three different seasons, summer, winter and equinox. Here, coloured glass Oceanic Blue, manufactured by Asahi India Glass Ltd (AIS) is considered as glazing material for window.