Synergistic effects of Phase Change Material and Hygroscopic Materials on heat and moisture transfer in building envelopes

Enhancing building envelopes’ hygrothermal performance is crucial for improving indoor comfort and energy efficiency. Phase change materials (PCM) and hygroscopic materials are commonly used in walls to regulate temperature and humidity, respectively. However, existing studies primarily focus on the application of a single material in walls. There is little research on the combined use of PCM and hygroscopic materials, and the synergistic mechanisms between these materials in walls remain poorly understood. This study explores the combined application of PCM and hygroscopic materials in walls to simultaneously regulate indoor temperature and humidity, aiming to uncover the synergistic effects of these materials on heat and moisture transfer processes.

A coupled heat and moisture transfer model was developed, and the synergistic mechanisms of the materials were analyzed through numerical simulations. The results indicated that the combined use of PCM and hygroscopic materials significantly stabilized indoor temperature and humidity conditions compared with common walls. In hot and humid climates, this combined approach resulted in a 10.16% reduction in temperature fluctuation and a 39.57% reduction in relative humidity fluctuation compared to the PG wall.