Double versus single skin facades in hot arid areas

Double skin facades are defined as two layers of facade separated by an air gap, that varies in its depth creating a solar chimney effect where warm air rises by buoyancy. As a facade technology, its thermal and daylight performance is still under scientific scrutiny. The bulk of research on the performance of this facade configuration is carried out in moderate climates.However, little is understood about the performance of double skin facade configurations in extreme hot arid climates. This investigation adopts an analytical approach using a dynamic simulation software (IESVE), to convert general intuitions on the performance of a double skin facade, in hot arid areas, into the grounds of understanding its performance based on research. It is an opportunity to study this facade configuration before the technology is transferred into construction in hot arid areas. In this paper, a comparative analysis of cooling loads on a single skin base case is compared against three possible changes to the physical properties of the external layer of the double skin facade. A dynamic thermal performance software APACHE-Sim is used (integrated environmental solutions IESVE, version 5.1). Simulation results indicate that a reflective double skin facade can achieve better energy savings than a single skin with reflective glazing.