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With increasing population, urbanization, and expansion of cities to rural areas is happening. Compact built-up areas with asphalts and concrete land surface covers generally experiences higher surface and air temperature compared to undeveloped and rural or natural areas in their neighborhoods. This phenomenon is called Urban Heat Island (UHI) effect. This higher air and surface temperatures have several impacts on city microclimate, building energy consumption and pedestrians’ health and thermal comfort. As a result, one of the UHI mitigation strategies is to use cool materials for urban surfaces which have higher albedos compared to conventional building façade materials. Existing studies mainly focused on assessing the impact of these surfaces on the outdoor thermal environmental, and the implication this strategy may have on building energy consumptions need further investigations In this study, Envi-met model which is one of the most widely used software for urban microclimate simulation is used to investigate the effect of neighboring buildings’ façade albedo on the buildings energy consumption, urban air temperature and urban heat island intensity (UHII). To do that, first a part of an existing urban city with relatively high UHII is chosen and the topography of the area is modeled in Space module of Envi-met. Subsequently, various scenarios with different albedos ranging from black with very low to medium and cool color with very high albedo are simulated and results are compared. The simulation results suggest that by increasing the reflectivity of building facades from 0.1 to 0.4 the air temperature near façade and façade temperature decreases by up to 0.6°C (1.08°F) and 10°C (18°F), respectively, leading to a reduction of 32% in buildings’ energy consumption. Increasing the façade albedo, however, will increase the urban mean radiant temperature (Tmrt) which has a negative effect on urban thermal environment.

Product Details

Published: 2022 Number of Pages: 9 Units of Measure: Dual Product Code(s): DBldgsXV-C062