Phase Change Materials (PCMs) for passive Cooling: Performance in urban buildings

The intersection of urbanization, climate change, and escalating cooling demands has underscored the urgent need for passive thermal regulation strategies in buildings. Among these, Phase Change Materials (PCMs) stand out due to their latent heat storage capabilities, offering the ability to passively regulate indoor temperatures by leveraging thermodynamic phase transitions. This paper provides an in-depth analysis of phase change materials (PCMs) in the context of passive cooling for urban environments, with a particular emphasis on their applications in building envelopes, such as walls and roofs. Through a combination of material science fundamentals, thermal modeling, building simulation studies, lifecycle analysis, and empirical case data, we elucidate the performance thresholds, integration mechanisms, and long-term viability of PCM-based systems. The study concludes that PCM-enhanced designs can lead to reductions in HVAC energy consumption by 15–40%, flatten diurnal temperature fluctuations, and contribute significantly toward net-zero energy building objectives.