Assessing Daylight Performance of Single vs. Double Skin Façade in Educational Buildings: A Comparative Analysis of Two Case Studies

The bulk of research on the performance of double skin facade is carried out in moderate climate with concern to ventilation and thermal performance. This research concerns day-light performance of double skin facades in hot arid zones, in Educational Buildings. This investigation adopts an inductive method using comparative analytical approach to convert general intuitions on the daylight performance of a double skin facade, in hot arid areas, into the grounds of understanding its performance based on research.Based on two case studies of lecture halls; the first with Single Skin Façade (SSF) and the second with Double Skin Façade (DSF); the impact of double skin façade on lighting performance is examined. The Protocol was applied to south facing models under overcast sky conditions to test significant effects of double skin façade on illumance values inside the lecture halls. Simulation results indicate that a double skin facade can achieve high lighting performance with better energy savings than a single skin façade; also the basic characteristics of width and distance of two walls are examined. It was expected that DSF fail to meet the acceptable standard indoor illuminance requirement of 200 to 300 lux. Comparing the single and double skin facade, the area percentage of the lecture hall, which covered with acceptable illumination level of 200 to 300 lux, are found in range of 10%, 50% respectively. In addition, the area percentage of the lecture hall, which covered with acceptable illumination level of 100 to 300 lux, is found in range of 30%, 80% respectively.