Thermal comfort in forested urban canyons of low building density. An assessment for the city of Mendoza, Argentina

Abstract

This research has established the degree of comfort achieved in road channels of Mendoza Metropolitan Area (AMM), in Argentina. They present different widths (16 m, 20 m and 30 m) with low building density and they are forested with First (Platanus acerifolia) and Second (Morus alba and Fraxinus excelsior) Magnitude species. The methodology is based on the selection of cases, the experimental observation and the assessment of thermal comfort condition by applying the COMFA method. The energy budget evaluation shows that the road channels forested with Platanus acerifolia -whose green structure is characterized for continuous tunnel over street and sidewalk-, has the best behavior. Nevertheless taking into account the urban problems of the city under study, it is necessary to settle the comfort conditions with the possibility of nocturnal cooling. During the daytime the solar radiation control is a key to getting comfort conditions. During the nighttime, sky vision is needed for radiative cooling. In addition, the forest structure combined with the urban morphology increase soil roughness and reduces the convective cooling. Therefore it is necessary to encourage those combinations of forest structure and urban morphologies that benefit both processes in order to reduce the urban heat island.