In this paper, a simulation study on analyzing the impacts of building envelopes integrated with phase change materials (PCMs) on the night time cooling load reduction in a bedroom in sub‐tropics is reported. Firstly, the efficacy of incorporating PCMs into a west‐ facing external wall for night time cooling load reduction in a bedroom in subtropics was investigated in the benchmark study. Results showed that incorporating PCMs into the west‐facing external wall effectively reduced the night time cooling load and improved the thermal comfort in sleeping environments. Secondly, parametric studies were carried out to reveal important factors and underlying mechanisms that governed thermal performance of building envelopes integrated with PCMs. Results showed that proper selection of PCM with suitable phase change temperatures, shapes of enthalpy– temperature curve and the thicknesses of PCM was critical to reduce nighttime cooling load in bedrooms in subtropics.
Keywords Phase Change Material (PCM), Night Cooling Load, Phase Change Temperature, Energy Performance