Urban grid forms as a strategy for reducing heat island effects in arid cities

Abstract

The urban heat island (UHI) modifies the thermal behavior of cities. UHI effects increase the demand for electricity and decreases the livability of outdoor and indoor spaces. This paper seeks to identify forms of urban grids (UGs) that contribute to the reduction of the UHI in Mendoza-Argentina. The microclimates of 10 urban canyons (UCs) were monitored, analyzed and compared during the summertime. This investigation considers the thermal behaviors of open-forested and compact-non forested streetscapes using 4 UG forms. The data were statistically analyzed. The results suggest that the minimum air temperature is related to the combined effects of the neighborhood grid and the UC configuration. However, the maximum and average air temperatures are related to the UC configuration. The multi-azimuthal UG remains cooler. Additionally, the compact-non forested UC was found to be the hottest, which differs from what is known concerning the thermal behavior of UC configurations in the arid zone. When this streetscape is compared to the open-forested UCs, air temperatures differ up to 10.2°C during the afternoon, 1.7°C at night, and buildings consume up to 65% more electricity. In summary, creating thermally efficient cities in arid zones requires using the best combination of UG forms and UC design.