Abstract
For the evaluating daylighting performance, field measurement, scale model test and a set of computer tools can be applied. For the scale model measurements, the sky simulator is a vital facility to represent the desired sky conditions consistently. Recently K university has developed a large size sky simulator, 6m-diameter and 3.7m-height, that is suitable for the international standard. To verify the reliability of the sky simulator, the luminance distribution on the inner sky surface was measured and compared with the CIE standard overcast sky model. It is found that the sky simulator can be reproduced the CIE standard overcast sky condition with 4.3% as mean difference. K university sky simulator is fully validated for usability and accuracy for daylighting researches.