Vertical Greenery System as the Passive Design Strategy for Mitigating Urban Heat Island in Tropical Area: A Comparative Field Measurement Between Green Facade and Green Wall

Abstract

Abstract. During the last decade, greenery aspect in the building envelope starts to increase their presence in the building design. Vertical greenery system became the one of alternatives that potential to energy-saving in the building. However, in tropical area, researches related to vertical greenery system are enigmatic since reducing heat in tropical area are crutial for maintaining space in comfort condition. In this study, a comparative thermal analysis between green facade and green wall will present. A model called house miniature set up with climbing plans as model of green facade. While for green wall, data measurement was conducted in the office building with green wall as building envelope. The results showed a high potential for energy savings during peak time in the afternoon for green wall (1.5%) and green facade (1.3%) in comparison to the bare wall. While for interior facade are 2.6% for green wall and 2.2% for green facade. Effect of vertical greenery also found in the outdoor air temperature around greenery system. Results show at the hottest time of the day, the green wall and green facade reduced outdoor temperatures by 3.0°C and 1.2°C, respectively. Based on the analysis, compared to green facade, the cooling effect produced by green wall is faster. Possibility, the substrate properties in the green wall also help to decrease temperature. The reduction can be due to the foliage density as the leaves of green wall is denser than leaves in green facade. Keywords : building envelope, green facade, green wall, vertical greenery system 1