Employing the double-PCM (Phase-Change Material) layer to improve the seasonal adaption of building walls: A comparative studies

Abstract

The single Phase-Change Material (PCM) only plays the thermal regulation capacity in the certain season, due to the fact that the narrow range of phase-change temperature cannot meet the thermal demand between summer and winter. According to this condition, the double-PCM layer is proposed to improve the seasonal adaption. In order to evaluate the efficacy of the double-PCM layer in improving seasonal adaptation, two walls with the double-PCM layer were constructed using different locations of Paraffin 13 and 27, while three walls without PCM or with single-PCM layers were taken as references. A dynamic heat transfer model with phase-change was developed and validated. The numerical results showed that the double-PCM layer is able to meet the thermal demands of summer and winter, although it may not achieve optimal performance in most months. Its overall performance was found to be the best in the entire year due to its high seasonal adaptability. Additionally, the delay time and the attenuation coefficient have the strong correlation with the variation range of liquid fraction and their linear fitting equations have been gained. The double-PCM layer increases the average delay time by 4.65 h and reduces the average attenuation coefficient by about 80 % in summer and winter, while the single-PCM layer could only demonstrate its effectiveness in one season.