Passive Cooling Using Phase Change Material and Insulation for High-rise Office Building in Tropical Climate

Abstract

Buildings consumed 40% of the world’s primary energy consumption. In hot climate countries, more than 50% of building’s energy was spent on the cooling system. Aimed to reduce building’s cooling load in a tropical country, this study compares building’s construction configuration for two types of air-conditioned rooms in a high-rise office building. The two types of air-conditioned rooms are: (a) air conditioned rooms operating during office hours and (b) IT rooms and data centre with 24hours cooling. Six scenarios were compared using four building’s configurations (baseline, adding insulation, adding phase change material (PCM), and adding both insulation and phase change material) to evaluate the most efficient construction and cooling settings for both room types. It was found that for air conditioned rooms operating during office hours, adding PCM with melting point 29°C and force night time ventilation is the most effective in reducing cooling load. Meanwhile, for a room with 24hours cooling load, adding insulation material is the most efficient. PCM was only fully effective when night time ventilation was introduced which allows the PCM to discharge. High thermal conductivity walls have the potential to create a mould problem in the building (due to differences in moisture pressure at night time between the internal and external of the building) which can be eradicated by using night time ventilation or adding insulation to the wall. PCM installation reduced the sensible cooling load but not the latent cooling load. Hence, mechanical cooling or dehumidifier is still required.