Numerical Investigation of Combined Natural Convection, Conduction and Radiation Through Concrete Hollow Bricks

This work aims to examine combined heat transfers through concrete hollow bricks. The thermal behavior of hollow bricks is simulated using a mathematical model based on the conservation of mass, momentum and energy. The effect of internal surfaces emissivity, aspect ratio of inner holes and solid wall thermal conductivity on global heat transfer is investigated using practical values of the thermal excitations. The results show that the contribution of radiation to the overall heat transfer through hollow bricks increases progressively with higher values of the thermal emissivity. The results reveal also that the overall heat flux through the concrete bricks is greatly influenced by the solid walls’ thermal conductivity. Since thermal conductivity cannot be adjusted after construction, this finding emphasizes the importance of careful material selection in designing energy-efficient structures, especially in regions characterized by hot and arid climates. Based on these results, we propose a practical recommendation to opt for concrete with low thermal conductivity in such climates. By adopting this approach, construction practices can be tailored to enhance the overall energy efficiency and thermal performance of buildings, providing sustainable solutions for the challenges posed by extreme environmental conditions.