ASSESSMENT OF EDIBLE VERTICAL GREENERY SYSTEM'S THERMAL PERFORMANCE IN TROPICAL CLIMATE: A CASE STUDY IN SINGAPORE

Abstract

The proliferation of urbanisation has built a highly dense urban city, causing a rise in local temperatures. The radiation of solar heat and surface absorption from the built-up area result in Urban Heat Island (UHI) effects. They affect the thermal comfort of indoor and outdoor spaces, making occupants feel less comfortable with the heat, which may increase the cooling load and, therefore, increase energy demand for buildings. In order to limit the heating, a widely used method is to introduce greenery to urban areas. Vertical greenery systems (VGS) are renowned for reducing heat transmission. The emergence of Edible Vertical Greenery System (EVGS), a more promising 2 in 1 sustainable approach, can help overcome the UHI effect and even food security. EVGS could be deployed in underutilised spaces like the Housing & Development Board (HDB) common corridor. This study aims to examine the food resilience and thermal performance of EVGS with natural ventilation in a tropical climate such as Singapore. An experimental procedure was used to measure outdoor and indoor temperatures and humidity. Winged Bean and Malabar Spinach were selected because of their fast growth, edible parts, and ability to withstand heat gain. The data were collected for a month, from late February to late March. An analysis of the results showed that, on average, with 30% leaf coverage by EVGS, the outdoor humidity, outdoor surface, and indoor temperature reduced by 2.6%, 1.8°C, and 1.0°C, respectively.