Investigating the Application of PCMs Integrated Into Building Envelopes to Promote Energy Efficiency in Hot Climates: A Case Study in Riyadh.

Abstract

Amid rising global energy demand, Saudi Arabia saw a significant 40% rise in energy consumption between 2010 and 2020. The Saudi government has thus set ambitious sustainability goals under Vision 2030 to address such concerns, and as the housing sector alone accounts for 44% of all energy consumption in the country, this area demonstrates a significant need for innovative approaches to mitigate increasing demand. Although many studies on reducing energy consumption in Saudi Arabia have already been undertaken, investigations regarding phase change materials (PCMs) remain limited. This study seeks to fill this research gap by conducting a comprehensive analysis of the possibility of increasing the thermal efficiency of buildings in hot climates, with a focus on the Riyadh region of Saudi Arabia. Using three cases, the study sought to evaluate the optimal performance of PCMs integrated into walls and roofs within a typical housing model in Riyadh. To achieve such evaluation effectively, the heat transfer, heating and cooling loads, the impacts of PCM thickness variation, and cost efficiency aspects were examined using Design Builder software. The results confirmed the effectiveness of case Ⅲ, which offered significant reductions of 18.7% and 6.3% in terms of heat transfer and heating and cooling demand, respectively. In contrast, case Ⅱ yielded only 5.2% and 2.4% marginal reductions for those parameters. A clear trend also emerged whereby increasing the PCM thickness from 1 cm to 5 cm offered significant enhancement, reducing the heating and cooling loads by 2,001 and 3,877 kWh in cases Ⅱ and Ⅲ, respectively. However, despite these promising results, economic viability appears to potentially be a limiting factor, an issue attributable to the significant costs associated with PCM alongside the relatively low energy costs in Saudi Arabia by global energy price. The implications of this research are multifaceted. Stakeholders, including individuals, government agencies, and private organisations within Saudi Arabia, should benefit from the resulting evidence-based insights that may act to guide the judicious selection and implementation of PCM types and methodologies tailored to the region's unique requirements. In addition, this study may serve as a pivotal scholarly resource to begin addressing the current paucity of research on PCM applications within Saudi Arabia.