Design of urban green square in dry areas: Thermal performance and comfort

Abstract

The paper evaluates the thermal behavior and comfort conditions in different structures (center, woodlots and meadows) that usually compose the urban squares of Mendoza city. The main objective of this research is to propose combinations of variables (vegetation, materials, green-sealed ratio, distribution of internal pathways and spaces, among others) for an efficient design of squares. The current thermal performance and the comfort degree were explored through measurement campaigns, both fixed and mobile, during the summer season 2012-2013. Fixed measurements were taken by a grid of T-HR sensors and mobile data through weather stations registering global solar radiation, PAR, wind speed and direction, air temperature, mean radiant temperature, pressure and relative humidity. On the basis of the collected data the comfort degree of the spaces was calculated by the COMFA method. Results indicate that two main variables regulated the thermal conditions of squares: the green-sealed ratio and the combined effect of the different structures, their solar access and sky view factors. Even if squares play a key role as urban green spaces in dry cities, it is imperative to focus on the different variables defining their design since better decisions can guarantee and strengthen their environmental functions.