Experimental and numerical study on the thermal performance of earthbag-wall units incorporated with phase change materials

Abstract

The demand for temporary housing for refugees and displaced communities has led to the development of earthbag buildings. While these structures are affordable and sustainable, they often struggle with thermal discomfort in extreme climates. This study aims to examine the integration of phase change materials (PCM) into earthbag walls to improve thermal performance. The research involved incorporating paraffin wax and microencapsulated PCM into scaled-down earthbag walls, with their performance evaluated in a controlled environment. The results were validated against a numerical simulation model developed in EnergyPlus. The study revealed significant thermal improvements with PCM integration. Wall-2, with paraffin wax A31, demonstrated a surface temperature reduction of up to 1.9 °C, while Wall-3, with microencapsulation Inertek26, showed a decrease of 2.4 °C compared to the reference wall. A parametric analysis highlighted the importance of PCM layer thickness. Specifically, Wall-2 with a 6 cm paraffin wax layer achieved a maximum reduction of 4.0 °C compared to the base case. The study identified the transition temperature of PCM as a critical factor in thermal performance, with paraffin wax A31 emerging as the optimal choice. Placing the PCM layer on the interior surface of the wall was more effective than exterior placement. Overall, PCM integration in earthbag walls offers a promising solution to enhance thermal comfort in temporary housing, addressing the critical needs of refugees and displaced communities. This research fills existing gaps in thermal comfort in temporary housing and demonstrates the potential of PCM as an innovative passive design strategy.