Multi-factor thermal analysis of phase change material integrated roofing elements

Abstract

In the present study, the PCM layer is integrated into the roof, analyzed, and compared for its thermal behaviour in terms of Indoor Air Temperature Reduction (IATR), Thermal Load Levelling (TLL), and Lag Time (LT) to determine the ideal position, thickness, and type of PCM. The observations from the experimental analysis were validated using COMSOL Multiphysics v6.0 with available literature. The results showed that PCM-integrated roofs reduced the interior temperature by around 30%. Furthermore, the fluctuations in the interior temperatures were reduced to 6.1% with PCM integration within the roof. A lag time of 5–8.25 h was observed for the PCM roofs. The study also found that the material properties impact the overall thermal behaviour of the PCM-integrated roofs. These properties were further explored using continuous cyclic thermal loading and variation of latent heat over a period of four days for three climatic zones in India. Abbreviations: PCM: Phase Change Material; CC: Conventional Concrete; AAC: Autoclaved Aerated Cement; TMY: Typical Meteorological Years; epw file: Energy Plus Weather File; mPCM: Microencapsulated Phase Change Material; PTC: Positive Temperature Coefficient; DHT: Digital Temperature And Humidity; IATR: Indoor Air Temperature Reduction (%); TLL: Thermal Load Levelling (%); LT: Lag Time (hours)