Multivariate analysis of PCM glazing effects on office building energy performance in different climates

Ongoing greenhouse gas emissions continue to accelerate global warming, with buildings contributing substantially to carbon dioxide emissions. Improving building envelopes is crucial for enhancing energy efficiency and resilience, especially as passive design strategies may become ineffective under extreme climatic conditions. Phase Change Material (PCM) glazing emerges as a promising solution to increase thermal inertia, reducing cooling energy consumption, and improving occupant comfort in office buildings. However, its impact on energy consumption under diverse climatic and operational scenarios remains underexplored. This paper presents a multivariate analysis of PCM glazing design variables —window-to-wall ratio (WWR), façade orientation, and PCM type— across ten climates in Europe and North America, considering two internal heat gain scenarios. Using a validated heat transfer model integrated into EnergyPlus, 4320 simulations were conducted to evaluate annual electricity consumption for heating, cooling, and lighting. Results show that PCM glazing can significantly reduce cooling energy use between 19 % and 45 % in arid/semiarid climates, when melting temperatures are optimally matched to diurnal temperature cycles (21–25 C). Conversely, PCM glazing is less effective in tropical and cold climates due to limited phase change activation and high window U-values. Sensitivity analysis using Standard Regression Coefficients (SRC) reveals climate-dependent design priorities: PCM type dominates in arid/semiarid climates, WWR in tropical zones, and façade orientation in cold regions. The findings emphasize the need for climate-specific PCM glazing strategies and support the integration of adaptive glazing technologies into building codes and retrofit programs. This study offers actionable insights for architects, engineers, and policymakers to enhance building envelope performance and resilience in the context of climate change.