Daylighting Efficiency of External Perforated Solar Screens: Effect of Screen Axial Rotation under Clear Skies

Abstract

This paper aims at developing solar screens for use in front of windows under the clear desert skies. These external perforated panels revitalize a traditional solution named “Mashrabeya”. They contribute to sustainability through utilization of natural light. In this paper, series of experiments were conducted using Radiance software. The impact of solar screen axial rotation on indoor daylighting of a residential setting was investigated. The effectiveness of the axial rotation was demonstrated. Screen influence on daylighting was strongly dependent on the orientation of the window and time. Illuminance adequacy was tested. The North and South orientations with upward and downward horizontal axial rotation were most affected when the rotation angle increased from 0° to 30°, especially in the summer season. In the East, the winter season was the most affected by the rotation. As a response to changing the rotation angle, a linear increase relationship was observed in all orientations.