Abstract
In a long-term analysis (1965-2020), primary energy usage (EU) grew by 48.7% and in China by 1226%. In this study, considering the cold climate in the China region, Eu in the residential sector was investigated. The building uses the Trombe wall on the south side to consume less heat energy to regulate the temperature. In the residential building, a schedule was applied to take into account heat gains of occupancy, lighting and equipment, and then the summer and winter temperatures were defined following people's presence. To improve the effectiveness of the Trombe wall, PCM was mounted in it. To study the natural convection, the momentum and energy equations for the indoor space were extended along with the area enclosed in the Trombe wall. The energy equation for all the walls was then discretized using finite difference methods to determine the thermal flux at boundaries. Energy analysis was performed for residential buildings, and the results showed that the Trombe wall had an acceptable performance in reducing EU by 26.5% in winter while increasing EU by 5.5% during the year. With the addition of PCM to the Trombe wall, the EU in all months decreased, and in one year, EU decreased by 18%.