Quantitative evaluation of passive cooling of the UCL microclimate in hot regions in summer, case study: urban streets and courtyards with trees

Abstract

This paper presents a quantitative analysis for predicting the air temperature variations within urban clusters with trees. The clusters considered are streets and attached courtyards which together constitute a major part of the residential areas. In this study, the cooling effect of trees is quantified, using the analytical “Green CTTC model” developed recently by the authors. The results are validated by empirical estimates of measurements in situ. The empirical and analytical approaches provide corroborative estimates and conclusions. Sensitivity analysis on the thermal impact of certain major control factors for design purposes, such as cluster deepening, albedo modification, and orientation in the presence of shade trees were obtained by simulations using the analytical model. The results indicate that the combined simulated cooling effect of the above three factors is about 4.5 K , at midday in summer (July–August) in the Mediterranean coastal region of Israel, a cooling which is about 50% of the air temperature rise from sunrise to noon hours.