Glare from Windows Assessment at Offices with Three Types of Internal Solar Shadings

Successful daylighting requires trade off and optimization between competing elements of façade, space, and lighting system. It also requires reliable tool for assessing the indoor visual comfort, especially discomfort glare from windows. The objective of the study was to investigate the users' glare perception due to the use of internal solar shading systems by using laboratory experimentation with subjects and measurements. The purpose was to compare these results with a glare rating equation and Luminance Distribution Ratio (LDR) and to assess the reliability of this glare assessment tool to be used for assessing glare from window and in the context of humid tropics climate. The laboratory experimentations were conducted at three identical office rooms at the Department of Architecture of ITS in which each of the room's windows was covered with different internal solar shading types e.i. Venetian, Horizontal, and Roller Blinds. Results showed good correlation between Luminance Distributions Ratio (LDR) with the users' responses. Among the three internal shading, the Roller blind type had the highest correlation on both working activities and sitting positions to the glare perception as well as the fittest value complying the standard of luminance distribution. The research concluded that the Luminance Distribution Ratio method can be a reliable tool for assessing glare from window for many office situations in humid tropical climate.