Thermo-regulating performance of concrete slab loaded with shape stabilized phase change material in tropical climate

Abstract

The building overheating problem is one of the most important problems facing all over the world. Various methods like using highly thermal resistive building materials, composite building materials were used to reduce the heat gain of the buildings. One of the method which can be used in place of traditional methods is using building elements with high thermal energy storage capacity. The significance of this study is to improve the thermal energy storage capacity of the building element for improving indoor thermal performance of the building. In this study latent heat energy storage capacity of the concrete slab is enhanced by incorporating Shape Stabilized Phase Change Material (SS-PCM) in it. SS-PCM was prepared by incorporating eutectic PCM (Paraffin Wax 70% and Coconut Oil 30%) in highly porous material called zeolite. The zeolite powder successfully incorporate 30 wt% PCM without showing any leakage at elevated temperature. Morphology of the SS-PCM was evaluated through Scanning Electron Microscopy (SEM) images. The SS-PCM at 0 wt%, 10 wt%, 20 wt%, and 30 wt% was used to prepare composite concrete slab by replacing fine aggregates. Composite concrete slabs were tested for indoor thermal behavior in real outdoor testing of 72 h. Indoor thermal performance was evaluated on the basis of peak temperature reduction, thermal amplitude, time delay, and decrement factor. The 30% SS-PCM has a high latent heat capacity, which significantly improves thermal energy storage in buildings. Various parameters like peak temperature reduction, time lag, thermal amplitude and decrement factor were evaluated. Concrete slab integrated with 30% SS-PCM shows maximum peak percentage temperature reduction of 10.04 % and percentage reduction in thermal amplitude of 23.71 % in comparison to conventional concrete. Additionally, infrared thermography of all the concrete slabs at different time of the day was done.