USING PHYSICAL EXPERIMENT FOR PREDICTING HOURLY DAYLIGHT QUANTITY IN ARCHITECTURAL SPACES WITH COEFFICIENT OF UTILIZATION METHOD.

Developed from physical experiments, Coefficient of Utilization (CU - the ratio of interior illuminance to unobstructed exterior illuminance) was examined in a previous paper in terms of its effectiveness in predicting hourly daylight quantity in wall-based sidelighting designs [1]. The results showed that the CU method, which was based on exterior illuminance on a vertical plane, was effective in studying climate-based daylighting performance in building spaces with vertical glazing (Wall-based). In the present paper, the validity of the CU method is examined for spaces with upward-facing apertures (Roof-based). The results show that the CU method significantly improves the accuracy of the daylight performance assessment for toplighting systems with upward facing apertures. This study, along with the previous one focusing on wall-based apertures, provides an effective and efficient method for predicting hourly daylight quantity in buildings on a year-round basis by using an approach based on physical experiment testing. [ABSTRACT FROM AUTHOR]