Experimental thermal performance of wallboard with hybrid microencapsulated phase change materials for building application

Combining phase-change materials (PCM) into building envelopes can improve indoor environmental comfort and reduce energy consumption. To adapt to seasonal changes (e.g., hot summer and cold winter), a novel type of hybrid PCM-containing wallboard (including three different PCMs) was fabricated. The hybrid PCM wallboard has a wide phase-change temperature range and can work under different climates for indoor thermal comfort and energy saving. Reduce-scale test cells, two hybrid PCM wallboard integrated test boxes (including Mode 1 PCM wallboard and Mode 2 PCM wallboard) and another equipped with gypsum wallboards, were compared to study the thermal performance of the PCM contained wallboard in both passive and active systems. The results indicate that the hybrid PCM system can narrow indoor air temperature fluctuations and maintain indoor thermal comfort at any time of the entire year. Mode 2 PCM wallboards were found to be more suitable for regulating the indoor thermal environment, as they exhibited more heat release to the indoors during the daytime and less heat loss at nighttime during winter. Under stimulations of different temperature fluctuations, three different layers of the PCMs worked to respond to the temperature fluctuations. Two indices (I and E) were put forward to evaluate the thermal performance of the PCM wallboards. The I index showed that Mode 1 PCM wallboard is suitable for reducing fluctuations of indoor temperature in winter and transition season scenarios. According to the E index, throughout one year, Mode 2 PCM wallboard has higher utilization efficiency than that of Mode 1. Finally, a comparative test was performed with the active system to evaluate the energy saving potential of the two hybrid PCM wallboards. The results show that energy consumption in the hybrid PCM wallboard box is nearly 30% less than that of gypsum wallboard.