Difference in Evaluation of Discomfort Glare from Windows between Middle-Eastern and Japanese Students
Abstract
Recent studies suggest that discomfort caused by glare from windows depends on more factors than the four main variables: the glare source luminance, the background luminance, the angular size of the source, and the relative position of the source. It is possibly affected by climatic conditions to which occupants are accustomed. In this study the difference in glare evaluation between Japanese and Middle-Eastern students was investigated. A simulation using weather data shows that in Riyadh (24.71 deg N), 70 % of the working hours had more than 4000 cd/m2 of luminance of the window area including venetian blinds, while in Tokyo (36.18 deg N) it was only 50 %. The results of the subjective experiment with an actual window showed no significant difference in glare evaluation between the Japanese subjects and the Middle-Eastern subjects. In the artificial window experiment, when the window had a uniform luminance and the luminance is high, glare evaluation by the Middle-Eastern subjects was lower than that by the Japanese subjects. Glare evaluation by the Japanese subjects showed a higher correlation with PGSV, DGP and DGImod, while the evaluation by the Middle-Eastern subjects showed a lower correlation.