TYPES OF VERTICAL GREENERY SYSTEM (VGS): EXPERIMENTAL COMPARISON OF THERMAL PERFORMANCE IN A TROPICAL CLIMATE

Abstract

Plants are essential towards climate change and Urban Heat Island (UHI) mitigation. A promising strategy for increasing the amount of green areas in cities are through the use of Vertical Greenery Systems (VGSs). Besides reducing heat gain through the building envelope (thus reducing the building’s cooling consumption), VGSs also reduces the surrounding surface and ambient temperature, resulting in the direct and indirect reduction of UHI effect on cities. However, there is an array of VGS available on the market, with differing thermal performance.

Therefore, this dissertation aims to provide a holistic understanding for the thermal performance of different VGS. Identification of VGS with the highest thermal performance (in terms of its outdoor cooling effects, envelope surface temperature reduction, and building heat gain reduction), is also the first step in the progress towards discovering a feasible possibility for the development of a multi-layered façade (interaction between VGS and Photovoltaics, leveraging on the complementary effects).

A literature review was first conducted to identify and narrow down the VGS with highest cooling potential. The pot system as well as lightweight substrate panel/pocket type VGS were then shortlisted for the experiment. Results of the experiment conducted in Singapore’s tropical climate found that the lightweight substrate panel/pocket type VGS has a superior thermal performance over the pot system in all evaluated thermal aspects. It also revealed that the density of foliage and leaf coverage on a VGS may have more impact on its thermal performance as compared to the thickness of its substrate.