Investigation of used PCM-integrated into building exterior walls for energy savings and optimization of PCM melting temperatures

In the study, the effects on the building's thermal energy performance of using two different phase change materials (PCMs) integrated into the exterior walls at various thicknesses and melting temperatures have been investigated. Four exterior wall types have been designed by changing the position of PCM integrated into the exterior wall for the purpose to decrease heating and cooling energy demand. For each wall type, three different thicknesses (layers) have been studied and energy savings that PCM provided by decreasing the heating and cooling energy demands have been calculated on a monthly and annual basis. According to the energy simulation analyses, the configuration provided the highest heating energy savings (21.32 %) on an annual basis is the three-layer BioPCM27 integrated exterior wall with a melting temperature of 21 °C. The monthly optimum melting temperatures of PCMs have been determined based on the charge and discharge processes of PCM integrated into the exterior walls by evaluating the results of hourly energy simulation analysis. The annual average optimum melting temperature varies between 18 and 19 °C, depending on the exterior wall and material types. The three-layer (3L) InfiniteRPCM21C configuration (Type 3) has the best thermal energy performance among all exterior wall types, with 24.45 % total energy savings in the cooling season and 14.76 % in the heating season.