Energy performance based optimization of building envelope containing PCM combined with insulation considering various configurations

Phase change material (PCM) is considered as a promising solution for reducing heating and cooling energy consumption by integrating them into the building envelope, which in turn reduces CO2 emissions. In this paper numerical simulations were carried out to evaluate the energy performance based optimization of envelope building integrated PCM. The effect of several parameters (PCM melting temperature, PCM layer combined with insulation, PCM layer and insulation layer thickness, double PCM layer system in the double external wall, and air layer interaction with PCM in roof) on energy savings in two typical models of residential buildings in Tunisia are investigated. Results show that energy demand reduction of 73.81% and 76.46% can be achieved under the optimal conditions of application of the PCM integrated in simple wall and double wall buildings respectively. This is associated with significant reduction of CO2 emission. Moreover, PCM layer performance is improved by increasing its thickness with an optimal value of 6 cm. Two PCM layers located in the middle of the double wall involve higher energy saving than a simple PCM layer.