Effect of Sky View Factor on Outdoor Temperature and Comfort in Montreal

Abstract

The relationship between the sky view factor (SVF) and the urban heat island (UHI) effect in Montreal is explored, by assessing the effect of SVF on air temperature (Ta) and mean radiant temperature (MRT). The amount of energy consumed by indoor heating and air conditioning is affected by Ta. The value of MRT is the sum of all short-wave and long-wave radiation fluxes absorbed by the human body that affects its energy balance and human thermal comfort. SVF in urban areas affects both Ta and MRT. We used a microscale urban climate model (ENVI-met) and simulated the effect of building geometry in four typical urban districts (each 300×300 m2 in size) in Montreal, on air and human weighted mean radiant temperature (MRThuman weighted) at 1.5-m height above the ground. Urban development consideration of a low SVF could mitigate the UHI effect, by decreasing urban temperatures and increasing outdoor thermal comfort. Most UHI studies are carried out for cities in hot and dry climates; however, UHI mitigation can also reduce energy consumption in colder cities, such as Montreal. Results of this analysis can be used in environmental urban planning standards.