Influence of key site parameters on the thermal performance of double skin facades in naturally ventilated buildings in a tropical climate.

Double skin façades (DSFs) have gained recognition as architectural elements in modern office buildings which, when appropriately applied, can potentially lead to improvements in the indoor thermal comfort and reduction in building energy consumption even in warm or tropical climates. This technology that utilises the renewable resources of solar and wind to reduce the air-conditioning demand in such climates is a potential solution to the current environmental challenges. This study examines the influence of key ‘site’ parameters, by keeping the ‘building’ parameters constant, on the thermal behaviour of an optimized building model with DSF. The site parameters represent the variables of two local environmental conditions: the level of local solar incidence, which relates to the influence of hours of the day, solar angle, sky conditions (cloudy and clear) and façade orientation on the building behaviour; and the wind conditions, which account for the effects of speed and direction acting on the DSF. Using the climate data of Rio de Janeiro city as the tropical environmental context, building energy simulations are performed to the defined DSF models. Airflow levels and periods of thermal acceptance, based on the adaptive comfort criteria in relation to the outdoor environmental variations, are analysed to demonstrate the site conditions under which the technology is likely to operate effectively.