BioPCM-Integrated Smart Façade for Hospitals: Thermal Performance Across Floor Levels in a Hot-Arid Climate

Hospitals are among the most energy-intensive building types because they operate around the clock and must maintain strict indoor environmental conditions, especially in hot-arid climates. Improving their performance calls for façade solutions that can store thermal energy effectively and help cut carbon emissions. This study evaluates the use of macro-encapsulated BioPCM® within the south façade of a high-rise hospital in Mansoura, Egypt, using dynamic simulations in DesignBuilder (EnergyPlus). The analysis focuses on two vertical levels, the third floor as a typical ward and the seventh floor as a rooftop ward, to investigate how elevation influences PCM performance, an aspect rarely explored in previous research. A parametric assessment was carried out using three melting temperatures (23 °C, 25 °C, and 27 °C) and multiple thickness configurations. The results show that the most effective PCM varies relying on height: BioPCM Q91/M23 (23 °C, 37.1 mm) provided the highest savings on the typical floor, while Q91/M27 (27 °C, 37.1 mm) was more effective on the rooftop. Together, the optimized configurations reduced annual energy costs by up to 15% and CO₂ emissions by 14.22%. Overall, the findings highlight that adopting a heightsensitive PCM design strategy can significantly enhance façade thermal performance and offer a practical guide to mitigate operational carbon in healthcare facilities located in hot-arid regions.