Investigation of PCM Thermal Effectiveness towards an Optimised Design of Cooling Building Envelope
The realization of the urgent need to tackle climate change has accelerated the growth of renewable energy. As solar energy is an intermittent source, it requires thermal energy storage to store the excess energy for nighttime use. Latent heat storage that uses phase change material (PCM) to absorb and release heat energy during the phase change process (melting and freezing) has a high heat-storing capacity, therefore it is an attractive option. In the past few decades, many researchers had proved the potential of PCM in providing a cooling effect to the building eco-friendly. However, the research on warehouses and tropics still requires more investigation, especially the effect of a rainy day on PCM performance, as rain would cool off surface temperature. As it might assist PCM to complete the melting and freezing cycle that is found challenging to be achieved by other researchers. In this paper, a warehouse that stored weatherproof material like brick without an air conditioner is being analysed under Malaysia’s weather and climates. The purpose of this paper is to study the thermal performance of the PCM in building envelopes and optimise the cooling effect by manipulating PCM’s melting temperature, environmental conditions, number of PCM layers, and positions of PCM. The 2D cross-sectional area of the building material will be modeled and simulate in Ansys Fluent software. The numerical result will be validated through a small lab-scale experiment. For analysis, the temperature distribution, heat transfer coefficient, and liquid fraction of PCM in each case will be compared to determine the optimum design of the building envelope while monitoring the cost-effectiveness. It is expected that a thicker PCM with a temperature slightly above Malaysia’s average lowest temperature (23.58 ℃) embedded in the building envelope, could reduce indoor peak temperature more effectively. In that case, PCM will be an alternative cooling solution for building in hot and humid climates which reduce the usage of air conditioners, consequently, save on electricity and reduce greenhouse gases emission.