Evaluation of energy consumption in apartment buildings with biochar and phase-change material aggregate-applied artificial stone finishing materials

Artificial stones for architectural finishing satisfy the aesthetic needs of building occupants and can be easily mixed with other materials. In this study, the thermal inertia of specimens prepared using lightweight aggregate vacuum impregnated with n-octadecane was improved, and the thermal conductivity was improved by mixing biochar having micropores with cement. The applicability of the specimens to apartment buildings in various climatic zones was analyzed. The specimens showed noPCM leakage and were stable in terms of strength and morphology. In addition, they exhibited low thermal conductivity depending on the use of biochar. Simulation results revealed that apartments in the climatic zone with the highest average annual temperature exhibited the highest reduction in cooling energy. The monthly cooling energy reduction was generally evenly distributed in the Bsh, Cfa, and Cfb regions, and the cooling energy decrease was concentrated in cold climate regions, such as in the Dfa and Dfb regions. In the Dfa region, there is a risk of heating energy increasing when the seasons change, and in regions having extreme climatic conditions (ie, excessively hot or cold), the PCM does not change its phase appropriately. Therefore, the application of a PCM appropriate for the climate can help effectively save energy consumption in buildings. Highlights: Biochar and PCM can contribute to the thermoregulation of buildings and increase indoor thermal comfort. Artificial stone for interior finishing of buildings that integrates biochar and PCM was manufactured. Building energy simulations for eight climatic zones were performed. Interior finishes incorporating biochar and PCM contribute to building energy savings.