Optimization of Double-Skin Facades for High-Rise Buildings in Hot Arid Climates

Abstract

Adopting technologies to a region requires careful consideration of its functional performance under the given climate. This study investigated how the performance of the double-skin facade (DSF) concept is affected by the materials used to construct the outer skin, i.e. transparent glass and opaque concrete and phase change material (PCM) impregnated concrete, and the amount of perfora­tions or openings in the outer skin in a typical high-rise building under the hot arid climate of the UAE. Findings show that all DSF variants reduce solar gain reaching indoor conditioned spaces and provide an envelope of air in contact with conditioned spaces that is at a lower temperature than outdoor ambient. The combination of these effects provides savings in whole building annual cool­ing demands. These energy benefits are found to increase as the thermal mass of a DSFs outer skin increases. Whilst savings will be building specific, they can be expected to be in the region of 8% to 20% for a glass DSF, 15% to 45% for a concrete DSF, and 30% to 50% for a PCM impregnated DSF. Results show that increasing the amount of perforations up to 45.6% of external skin area has little impact on the extent of reduction in DSF cavity temperature for glazed and con­crete DSF but it does have a significant impact on that of PCM external skins.