Evaluating the effects of different mitigation strategies on the warm thermal environment of an urban square in Athens, Greece

Abstract

The present study examines the effect of different mitigation strategies on the microclimate and thermal sensation in an urban open area in Athens. The microclimatic model ENVI-met was applied to simulate thermal conditions for a warm summer day (15.07.2010). Thermal conditions were assessed based on air temperature and the Mediterranean thermal sensation scales of the Physiologically Equivalent Temperature (PET) and the Universal Thermal Climate Index (UTCI). The spatial and temporal resolution of PET throughout the square was developed per design scenario and was compared to the Current design layout to analyse and quantify the effectiveness of the mitigation strategies on the amelioration of thermal conditions. Results showed that the combination of the design scenarios was found to be the most advantageous mitigation strategy. The average PET and UTCI reduction of 6.9 °C and 6.1 °C, respectively, achieved a 15.5% improvement in thermal comfort.The aim of this research was to set specific targets on thermal sensation improvement and, based on the obtained results, it suggests certain mitigation strategies that will allow the specification of the appropriate microclimatic interventions to improve thermal comfort to the desired extent in the context of developing urban design guidelines.