Evaluation on the cooling performance of the green façade system under different microclimates in a tropical area

Abstract

This study conducted a one-year experiment of a green façade system under various microclimates in the tropical zone. The aim is to reveal the thermal effects and heat energy exchange from the green façade to the wall and the ambient air. Days with sunny, cloudy, and rainy weather were selected as the focus of discussion to understand the green façade performance. Evapotranspirative cooling was found to contribute the best cooling performance on the external wall surface behind the green façade (Tse_ev) at 10.8 °C (sunny), 9.6 °C (cloudy), and 6.5 °C (rainy). The most significant average temperature reduction on the green façade was observed during the sunny day of 3.2 °C (Tse(GF)) and 0.9 °C (Tea(GF)), respectively. Calculation on the heat energy exchange between the ambient air (Taa) and the exterior wall surface (Tse) showed that the sunny days also performed the smallest energy transfer compared to the rainy and cloudy days. However, the unstable weather conditions during rainy and cloudy days lead to insignificant temperature changes in the green façade and affected the heat energy exchange.