Thermal assessment of lightweight building walls integrated with phase change material under various orientations

Abstract

This paper presents a comparison of four different wall structures aiming to study the impact of using PCM “phase change material” on the thermal performance of lightweight building walls. The comparison was done using simulation based on the weather conditions in Sharjah, UAE, and five different wall orientations were involved in the comparative analysis: horizontal, east-facing, west-facing, south-facing, and north-facing walls. The wall without PCM (with 60 mm insulation) was considered the reference case, while the three other walls included an additional inner layer of 10 mm thickness (insulation, PCM-31, and RT-41). All walls were tested at different orientations to find the influence of PCM and orientation on energy consumption. The results showed that the incorporation of PCM has a significant contribution to stability improvement and inner wall temperature fluctuation reduction. This was more considerable in the case of using PCM-31 as PCM where the inner wall temperature was highly stable with minor fluctuations between 26 °C and 27 °C. Compared to the reference case, PCMs reduced the inner wall temperature peak by more than 2 °C. Similarly, PCM-31 demonstrated the best performance regarding indoor heat flux with a peak reduction of 78.6 %, while the performance of RT-41 was also acceptable with a corresponding percentage of 46.4 %. Furthermore, the greatest amount of energy can be saved by utilizing PCM implemented in the roof of the building and on the south facing surfaces of Sharjah.