Assessing PCM Melting Range for Passive Cooling in Tropical Climate: An Infrared Thermography Approach Using Jamaican Climate Data

Phase change materials (PCMs) can reduce cooling demand in hot climates, yet their selection and characterization remain underexplored in the Caribbean. This study introduces a thermography-based workflow to identify suitable PCM phase change temperatures (PCTs) for passive cooling under Jamaica’s tropical conditions. Because PCMs are typically encapsulated in opaque materials, infrared (IR) thermography was used to capture heterogeneous solidification that single-point thermocouples tend to overestimate. Field tests on inorganic PCM tiles showed that IR imaging revealed spatial temperature variations and hysteresis effects, with nighttime measurements demonstrating strong agreement (mean bias 1.1 °C; RMSE 1.1 °C; R2 = 0.995). Four PCMs (24–27 °C) were then assessed under natural and forced convection modelling. At the cooler site all PCMs recharged over 20 nights per month, while at the warmer site only the 27 °C PCM exceeded 10 recharge nights in summer. Recharge reliability declined sharply when PCT fell within ~3 °C of the site’s median temperature, whereas PCMs with PCT \(\ge\) 3 °C above the median showed stronger year-round performance. Under forced convection (h = 30 W·m–2·K–1), PCMs ≥25 °C achieved full latent-heat recovery, offering a climate-tuned basis for PCM selection and passive cooling design in tropical regions.