EFFECTIVENESS OF ROOF POND SYSTEM FOR COOLING BUILDINGS IN SINGAPORE

Abstract

With the challenge of “Urban Heat Island” effect in Singapore, there is essentially a need to find solutions to move Singapore towards achieving sustainable urban development. As more buildings are built, it is important to incorporate passive cooling designs in buildings to achieve energy efficiency as well as to ensure thermal comfort. This dissertation aims to explore one of such designs – Roof pond system to study its effectiveness for cooling buildings in Singapore. An experimental approach is done to assess its effectiveness in reducing roof surface temperature through three types of heat transfer methods. Experiments are conducted on two types of roof pond systems which are fabricated using fiberglass water tanks. In addition, field measurements are conducted at the reflection pool at Bras Basah MRT Station to determine if they are coherent with the experimental data collected. Analysis of both experimental data and field measurements show that both still water open pond and moving water open pond are able to significantly reduce roof surface temperature and provide ambient cooling. Moving water open pond is found to be the most effective and its performance is improved with increasing wind velocity. At higher water levels, roof ponds are able to perform better. The findings prove that roof pond system is effective and feasible to be implemented in Singapore. However, considering Singapore’s high humidity level, it can limit the cooling potential of roof ponds. Several concerns have to be addressed for implementation of roof pond systems in Singapore.