Evaluation of Daylight and Electrical lighting Performance in an Office Space

In this research, lighting performance was compared with actual measured data in a case study of an office area. Various design alternatives were then analyzed in a model of the case study in order to determine the optimum conditions for saving lighting energy and improving illuminance uniformity. Requirements from LEED 2.1 & 2.2 and CASBEE were used as indexes for the evaluation. Results showed that in Case 4 (WWR: 60%, TR: 44%, OH: 150cm), direct sunlight can be controlled near the window area, satisfying the LEED 2.2 requirement. In addition, in Case 2 (WWR: 34%, TR: 82%), where 2 light fixtures near the window were switched off, optimum lighting levels and illuminance uniformity were obtained at noon on the equinox.