Natural Ventilation of Moderate-Height and Wide-Area Buildings with Double Roofs for Solar Heat Dissipation

摘要

The presence of air cavity in an inclined double roof was found to be an effective measure to release excessive solar heat gain by natural ventilation primarily in moderate-height and wide-area buildings. The highest cavity efficiency was obtained when the two ends of the cavity were fully opened to the ambient. Since the experiment was carried out without considering the wind effect hence the only motive force to move hot air from the cavity be by its own buoyancy. Therefore, the double roofs are seemingly workable during little or no wind, which is usually found in the peak of summer.