Enhancing building envelope performance via dynamic PCM Integration in biomaterial concrete walls: A numerical evaluation and multi-objective optimization study

Phase change material (PCM) offers promising potential for enhancing the hygrothermal performance of building envelopes. This study proposes a dynamic integration method of PCM within a biomaterial-based concrete wall, aiming to optimize both thermal and moisture regulation in buildings. A numerical investigation is conducted on five wall configurations, with a focus on evaluating the dynamic PCM system. The results show the dynamic PCM wall’s superior performance, achieving temperature fluctuation reductions of 62.5 % and partial vapor pressure reductions of 63.2 % during summer, alongside significant winter improvements of 16.1 % and 6.3 %, respectively. Furthermore, a multi-objective optimization method to minimize the cost and energy consumption of the dynamic system is applied, obtaining the most balanced solution for different climate conditions, as well as demonstrating that a thinner exterior wall layer is preferred for producing lower energy consumption and wall cost. In addition, a long-term assessment further identified interstitial condensation and mold growth risks, particularly in humid climates. Overall, this work highlights the advantages of dynamically integrated PCM systems in biomaterial walls, offering a viable path toward energy-efficient and resilient building envelope designs.