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Solar chimney is a combination of solar assisted stack and wind driven ventilation where air in the solar chimney expands under heating from solar irradiance and being relatively lighter, rises out from the chimney outlets, drawing the cooler air into the building through the fenestrations. This pull effect is complemented further by the push effect from the outdoor ambient wind. The study of solar chimney system within the zero energy building in tropical Singapore aims to determine the effects of ambient air speed and internal heat load on the thermal environment of the solar chimney ducts and classroom’s interior. Experimental and computational results show that high ambient air speed greater than 2.00 m/s improves the air speed within the solar chimney ducts; both low and high ambient air speeds are found to improve the classroom’s interior air speed. However, the significance of ambient air speed drops when solar irradiance is greater than 700 W/m 2 . Furthermore, under the tropical weather conditions of high solar irradiance and low ambient air speed, cross ventilation performs better compared to solar chimney; hence, solar chimney is recommended to be employed under zero ambient air speed. Lastly, results show that the influences of internal heat load on the air temperature and speed within solar chimney ducts as well as classroom’s interior are limited. 2014 Elsevier Ltd. All rights reserved. |
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