Enhancing thermoregulation in double glazed windows with PCMs and black films: An experimental study

This study presents an experimental analysis of the thermoregulation characteristics of double-glazed windows integrated with phase change material (PCM) packages and black film coatings. The research focuses on varying the PCM area ratios (ARs) within the vertical glazing, specifically 15 %, 30 %, and 45 %, to evaluate their impact on thermal management and thermoregulation. The experimental setup consists of a test chamber subjected to controlled heating and cooling cycles, utilizing constant and continuous solar radiation. Temperature fluctuations and light intensity levels were recorded to assess the performance of the PCM packages, both with and without black film coatings. The results indicate that incorporating PCM into the glazed units significantly enhances thermal management by stabilizing temperature variations and delaying the attainment of steady-state conditions. The peak temperature in the test chamber with 45 % AR PCM packages during the heating period is 3.9 °C lower than that of the reference case; however, during the cooling period, temperatures remain above the reference case. This effect allows the indoor environment to maintain a temperature trend that is more aligned with thermal comfort conditions. Additionally, the application of black film coatings improved thermal absorption, leading to slightly higher temperatures (up to 2.6°C) in the PCM-filled units, but also resulted in a reduction in light transmittance. Specifically, light intensity decreased by 68 % in the 45 % AR case compared to the reference, with an additional 8–11 % reduction due to the black film coating. These findings highlight the dual role of PCM and black film in enhancing thermal comfort, while also acknowledging the trade-offs in natural lighting.