Numerical analysis for energy performance optimization of hollow bricks for roofing. Case study: Hot climate of Algeria

•The thermal behavior of a brick-roof incorporated with three passive measures subjected to real thermal excitations was modeled and simulated.•The objective was to enhance this structural element's insulation performance.•A parametric study was conducted to determine the suitable configuration for hot climate.•Integrating PCM and EPS simultaneously in the brick generates better stabilization of the inner surface temperature. In this century, the world is undergoing an energy transition led mainly by renewable energy and smart technologies. The realization of the energy-efficient building concept is a promising direction for global energy savings. This work investigates the benefit of incorporating three passive measures in hollow clay brick (HCB-8) structures commonly used in Algeria to improve thermal comfort and energy savings in buildings subjected to the climatic conditions of the city of Bechar. Ansys-Fluent software was used to study the heat transfer through different configurations of (HCB-8) integrated with a combination of two different passive measures. The results reveal that coating the inner surfaces of the brick’s cavities with a low emissivity coating, filling cavities with expanding polystyrene (EPS), or using phase change materials (PCM) improves the thermal inertia of hollow clay bricks. It can be argued that capric acid is a more effective PCM than n-Eicosane and RT-42. In addition, the study results show that the simultaneous incorporation of PCM and EPS into the brick can reduce the internal heat flux by about 73.7 % and shift the external heat wave in the indoor environment by about 5.5 h compared to traditional hollow clay bricks.