Thermal inertia and energy efficiency enhancements of hollow clay bricks integrated with phase change materials

Abstract

This article examines the usefulness of incorporating three passive measures into hollow clay walls typically used in Moroccan structures to improve thermal comfort and energy savings in buildings subjected to the climatic conditions of Marrakesh city. The results revealed that coating the internal surfaces of the brick's cavities with a low emissivity paint, filling cavities with insulation material, or utilizing phase change materials (PCM) positively impacts cooling demand and enhances thermal inertia of hollow clay bricks. Thanks to a parametric study, the adequate PCM type and its optimum filling location were determined for maximum benefit from the PCM latent heat capacity to enhance the thermal inertia of the studied wall. The results indicated that filling the middle cavities with a PCM (melting temperature of 32 °C) combined with using a low emissivity paint or filling an insulation material in the internal and external cavities of the brick leads to the maximum enhancement in the thermal inertia characteristics of hollow clay walls. It can be stated that using the optimal configuration permits reducing the internal heat flux density by about 82% and retarding of the external thermal wave to penetrate the indoor environment by about 4 h compared to the traditional hollow clay bricks.