UPCM-EQF: a theoretical framework for climate-responsive energy and comfort optimization using phase change materials

• A universal framework (UPCM-EQF) is developed for PCM performance quantification. • Climate-responsive metrics integrate thermal comfort and energy efficiency. • Suitability Ratio (SR) and Enhanced Suitability Index (ESI) are introduced. • Empirical relations enable simulation-free PCM evaluation across climates. • Framework validated using FEM simulations and real-world climate data. Phase Change Materials (PCMs) are widely recognized for reducing HVAC energy loads and enhancing indoor comfort, yet their effectiveness remains highly climate-dependent and difficult to generalize. This study introduces the Universal PCM Effectiveness Quantification Framework (UPCM-EQF), a unified, climate-responsive methodology that integrates heat transfer principles, thermal comfort indices (PMV/PPD), and adaptive climate metrics. Novel metrics, including the Suitability Ratio (SR) and the Enhanced Suitability Index (ESI), are developed to quantify dual-season PCM performance. In addition, empirical relations are derived to estimate energy savings, comfort improvements, and payback periods, enabling practical design-stage decision-making. Validated through finite element simulations and multi-climate case studies, UPCM-EQF demonstrates predictive accuracy across tropical, temperate, and continental climates. It thus provides a universal, scalable, and simulation-free tool to support PCM integration for energy efficiency and thermal comfort.