Solar-Wind Generated Roof Ventilation System (SiVATAS) for a Warm-Humid Climate

This research grows out of a desire to find a Solar-Wind Generated Roof Ventilation System for low-cost dwellings located in high building density urban areas where horizontal air movement is restricted. A general purpose computational fluid dynamics (CFD-ACE+) program was utilised to explore, analyse and develop a roof model based on its aerodynamics and thermal performance to obtain optimum wind pressure and temperature differences. Comparisons were made with physical scale models. The research found that a roof prototype with inclinations of 15o and 45o, curved ridge with cap, integrated roof chimney, black-matte steel sheet cover, combined with a perforated under floor channel (floor tunnel), can generate evenly distributed vertical cross ventilation within the occupants zone. The created indoor air velocity was in the range of 0.15 to 0.7 m/s, which is considered to be sufficient to produce a physiological cooling effect. As an ddition, the CFD program has proved to be a reliable, user-friendly and helpful research tool.