Enhancing Building Envelope Performance Via Dynamic Pcm Integration in Biomaterial Concrete Walls: A Numerical Evaluation and Multi-Objective Optimization Study

Abstract

Phase change material (PCM) and biomaterials represent promising solutions for reducing building energy consumption and improving indoor comfort. However, the existing passive combination method of the PCM and biomaterials in building envelope limits the hygrothermal performance potential of the envelope. Therefore, the present contribution describes a dynamic PCM integration method within a biomaterial concrete wall to optimize energy and moisture storage in the building envelope. To this end, five distinct PCM-biomaterial configurations were evaluated in a numerical study to assess the dynamic system’s performance. 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. Moreover, 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. A long-term assessment further identified interstitial condensation and mold growth risks, particularly in humid climates. These findings suggest that dynamic PCM-biomaterial integration is a viable strategy for advancing sustainable, high-performance building envelopes, offering significant energy savings and indoor comfort improvements. However, to ensure long-term reliability and durability, attention should be given to potential condensation and mold growth risks, particularly in humid climates.

Keywords: Phase Change Material, Biomaterial, dynamic integration, Multi-objective optimization, Condensation risk