• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.6
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• pp.7-15
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• 2003

The purpose of this simulation study is to determine the window transmittance by RADIANCE lighting simulation tool where the horizontal blind is installed. Parameters such as sky types, seasonal changes, altitude, azimuth, and horizontal blind angle at a 0$^{\circ}$, 45$^{\circ}$, 90$^{\circ}$ were considered. The simulation results present that measured directional transmittances have different values according to each directional property of the horizontal blind. In addition, methodology was described to apply window transmittance data to DayDim program which is a lighting calculation and analysis tool especially for the performance of daylight responsive dimming systems.