The current study explores the feasibility of employing an integrated system comprising an earthair heat exchanger (EAHE) unit and a photovoltaic/thermal (HPT) system equipped with a phase change material (PCM) to fulfill the heating, cooling, and electrical loads of a building. In this arrangement, ambient air is heated during cold months by passing it through the EAHE and PCMbased HPT systems, and during hot months, it is cooled by passing through the EAHE unit. Additionally, in warm months, the air exiting the building is utilized to lower the temperature of the PV panels. The electricity generated by the PV panels is harnessed to meet a portion or the entirety of the building’s electrical demand. Following the identification of factors influencing the system performance, the multi-objectives genetic algorithm (MOGA) approach is employed to ascertain the optimal values of these parameters, aiming to concurrently maximize both the thermal and electrical output of the HPT-EAHE system. The findings indicated that the optimal HPT-EAHE system can fulfill 132693.3 kWh of heating demand for the building during cold months, address 26536.1 kWh of cooling needs during hot months, and generate 9242.2 kWh electrical power throughout the entire year.