Solar irradiance simulation for evaluating thermal comfort in urban environment

Urbanization has led to high-density living in many large modern cities like Singapore, which creates the challenge of reducing the Urban Heat Island effect (UHI) and to achieve higher liveability in residential towns. In order to study thermal comfort in residential areas, a method that uses solar irradiance as the criterion to investigate thermal comfort is proposed. In this method, surface temperatures in urban areas are measured and the amount of solar irradiance reaching urban surfaces is predicted, and hence a correlation between incident solar irradiance on a surface and surface temperature may be made. Solar radiation exposure for four different neighbourhood designs in a given residential area is evaluated thereafter. Both solar short-wave and long-wave radiation in pedestrian areas for these designs are then predicted and used as the criteria to assess thermal comfort in these areas. UHI effects are also analysed based on the surface temperatures measured.