Albedo impact on the microclimate of courtyards, potential implications on the UHI. A case study in Seville, Spain

The Urban Heat Island (UHI) effect is a phenomenon that threatens life in cities nowadays. Among other strategies to adapt cities to this phenomenon is the use of the tempering potential of courtyards and changes in the albedo of the surfaces. However, there is little literature about the influence of the albedo on the thermal performance of the courtyard. This research aims to analyze the effect of albedo alteration of the surfaces of a courtyard located in Seville on its tempering potential and the comfort of the users. Besides, it evaluates the accuracy and suitability of the simulation tool ENVI-met, widely used for the simulation of outdoor spaces, by contrasting monitoring and simulation results. It is concluded that high reflectance surfaces reduce the surface temperature by reflecting solar radiation, so they accumulate less heat during daylight hours and release less heat at night, however, the high reflection compromises user comfort.