Location optimization of phase change material for thermal energy storage in concrete block for development of energy efficient buildings

Improving Thermal Energy Storage (TES) of buildings using Phase Change Material (PCM) is widely used to develop energy efficient building envelope. In this study, optimum location of PCM, thermal insulation, and air were investigated in a concrete block to improve indoor thermal comfort of the building. A comparative study of six Thermal Efficient Concrete Block (TECB-1, TECB-2, TECB-3, TECB-4, TECB-5, and TECB-6), having three slots each, embedded with PCM, PU Foam, and air in varying order was conducted to identify the optimum location of PCM for improving indoor thermal performance. Additionally, TES characteristics and thermal stability of PCM were also evaluated. TECB-4 and TECB-5 obtained a time lag of 127.5 min and 125 min respectively in comparison with TECB-0. Maximum average percentage reduction of 12.5% in indoor peak temperature and lowest average thermal amplitude of 13.4 °C was shown by TECB-5. The temperature profiling of indoor surfaces validates the improved thermal behaviour of TECB-4 and TECB-5. This study signifies that optimum location of using PCM, PU Foam, and air in the building concrete block is PCM on outer side, PU Foam on inner side, and air in middle for improving indoor thermal performance of buildings in tropical climates.