Innovative Prefabricated Wall Panel for Solar Utilization and Energy Efficiency: Building-Integrated Heat Pipe-Embedded System for Cooling-Dominant Zones

Buildings are major contributors to carbon emissions, emphasizing the need for energy efficiency. However, existing solar-integrated building façades often face integration and adaptability challenges. The aim of this study is to propose and evaluate an innovative building-integrated heat pipe-embedded (BiHPe) prefabricated wall panel for sustainable building design. By embedding heat pipes into concrete walls, the system transfers solar energy to domestic water. The performance of the system is evaluated using a comprehensive approach that integrates dynamic modeling, experimental validation, parametric analysis, and a case study. A dynamic energy balance model was developed and experimentally validated, identifying key factors affecting system performance, such as heat pipe spacing, absorber material, and heat pipe placement and configuration. Parametric analysis was conducted to assess the impact of these variables. Simulation results from a case study in Hong Kong show that the system reduces wall heat transmission to 76.1%, achieves a water gain efficiency of 16.7%, and saves 162 kWh/m² of electricity annually. Additionally, the system stabilizes indoor temperatures, improving thermal comfort. The BiHPe panel offers a multifunctional solution that combines energy efficiency, thermal comfort, and water heating, demonstrating exceptional adaptability and performance in cooling-dominant zones, making it a promising option for sustainable building design.