Investigation of Thermoregulation Effect of Stabilized Phase Change Gypsum Board with Different Structures in Buildings

The energy consumption in buildings is high currently, leading to the development of the building envelope with phase change material (PCM), while the application of PCMs to the building envelope has the potential to effectively regulate the temperature variations in the inner surfaces of walls. Eutectic PCM consists of lauric acid, myristic acid, and stearic acid (LA-MA-SA) and was synthesized first, while expanded graphite (EG) and diamote (DE) were used as additives. LA-MA-SA/10 wt.% EG/10 wt.% DE composite PCM was synthesized via the impregnation method; then, the phase change layer was compressed and formed under a pressure of 10 MPa. The sandwich phase change gypsum board was built with three layers, considering the phase change layer on the outside, middle and indoor sides of the board, respectively. The thermal responses of sandwich phase change gypsum boards were considered under various radiation conditions at controlled temperatures of 37 °C, 40 °C, 45 °C and 50 °C. The results indicated that the gypsum board with the addition of 16.7 wt.% composite PCMs showed a better relative time duration of thermal comfort in comparison with pure gypsum board. The indoor heating rate slowed down, and the environmental temperature fluctuation was within a smaller range, because of the latent heat of the phase change gypsum board. Comparing the phase change gypsum boards at different interlayer positions, we found that the phase change gypsum board with an interlayer on the indoor side shows better thermal performance and a relatively longer time duration of thermal comfort, e.g., when the setting temperatures were 37 °C, 40 °C, 45 °C and 50 °C, respectively, the relative time durations of the thermal comfort of the sandwich phase change gypsum board were 4825 s, 3160 s, 1980 s and 1710 s. This study provides insights into the thermoregulation performance of phase change walls, where the utilization of a PCM in a wall can increase thermal capacity and enhance the inner-zone thermal comfort. The findings can provide guidelines for phase change walls to ensure sustainable practices in the energy savings of buildings.