Climate-driven selection of phase change materials in buildings: A Köppen–Geiger-based analysis

Phase Change Materials (PCMs) are widely used to improve building energy efficiency; however, their performance is highly dependent on local climatic conditions, which limits their effective application. This review develops a climate-adaptive selection framework based on the Köppen–Geiger classification by analysing more than 150 experimental and numerical studies. The results identify a minimum diurnal temperature range (DTR) of approximately 10 K as a key threshold for effective PCM cycling, while additional factors such as humidity, solar radiation, and ventilation significantly influence performance. Recommended phase transition temperature (PTT) ranges are defined for major climate groups (A–D), together with optimal placement strategies and hybrid or multi-PCM systems for seasonal adaptation. These findings demonstrate that climate-specific PCM selection is essential to ensure reliable thermal performance and long-term energy savings, particularly under future climate change scenarios.