Influences of the window size and reflectivity on surrounding thermal environment

Abstract

Relevant researches on windows mainly focused on the influence on indoor lighting, thermal environment and energy consumption. And previous numerical simulation studies related to the effects of buildings on microclimate and thermal comfort have always simplified the building façade as a homogenized envelope, neglecting the impacts of windows' size and reflectivity on local thermal environment outdoors, which might affect the accuracy of the results. In this context, to determine and evaluate the relationship between window size/reflectivity and local climate, the ENVI-met model was employed and 40 scenarios were established and simulated in current study. This study quantified the impact of windows on the surrounding thermal environment, and revealed its spatiotemporal characteristics: windows' impact was time-dependent both in diurnal and seasonal dimension and varied with the distance from the building. Two parameters of earth-atmosphere energy balance, sensible heat flux and shortwave reflected flux, were selected and analyzed to better understand the functioning mechanisms of windows' impact. The interaction between window size and reflectivity was also figured out in current study. The findings could enhance our further understanding on the effects of buildings on local environment in urban areas and provide useful insights to architects and urban planners on how to create a more livable urban environment.