Energy conservation and CO2 mitigation potential through PCM integration in building envelopes: Effect of façade orientation

Abstract

This research concentrates on assessing the energy conservation potential of latent heat activation achieved by incorporating PCM into the north, south, west, and east wall, one wall at a time or to all walls simultaneously, or to a flat roof. The results refer to a Mediterranean single-story house located in the Csa climate region according to the Köppen-Geiger classification system. Each scenario was examined on a yearly basis for combinations of PCM melting temperature and layer thickness, making up a total of 300 cases. These were analyzed and compared to identify solutions that offered the highest energy savings while using the least amount of PCM. For single-wall integration, the highest saving of 77 kWh was achieved in the case of south-wall orientation, 20 mm PCM thickness and 25 °C melting temperature. Latent heat activation represented 87.8% of total energy savings. Integration to all walls simultaneously yielded an energy saving of 397.8 kWh with latent heat contributing 91.2%, while flat roof integration saved 432.5 kWh of which latent heat represented 96.5%. The flat roof emerged as the most effective choice for PCM integration, providing savings ranging from 0.433 kWh to 0.140 kWh per kg of PCM. Single-wall integration offered only 0.259 kWh kg−1 to 0.119 kWh kg−1, indicating comparably poor energy-saving performance. Overall, up to 189.9 kg CO2 reduction was achieved depending on the PCM layer thickness and façade selection.