Impacts of Building Geometries and Radiation Properties on Urban Thermal Environment

Abstract

Urban thermal environment highly affects the livability and life quality of residents, especially in a tropical megacity like Singapore. To identify impacts of building geometries and radiation properties on urban thermal environment, a numerical model is developed and different cases with specific configurations are simulated. It is found that urban thermal environment is quite sensitive to building geometry resolution, building height and the gap width in between buildings. With more detailed information of building geometry, it is able to capture the heating effects of trapped radiations in the recessed area of buildings. More than 1°C hotter air will accumulate around the roof top of higher buildings, while air temperature at 1m above the around is 1°C hotter around low-rise buildings. Absorptivity is found to contribute most to around 3°C hotter thermal environment. With new materials of low absorptivity and high reflectivity, it is possible to improve urban thermal environment.