Novel functional materials capable of humidity regulation and thermal storage for building energy conservation

Functional materials with large hygrothermal inertia can passively mitigate indoor temperature and humidity variations, thus improving indoor environmental quality and reducing energy demand for heating, ventilation, and air-conditioning (HVAC) systems. In this study, a novel functional phase-change humidity control material (PCHCM) was developed based on the integration of microencapsulated phase-change material (MicPCM) and novel moisture adsorbent: Metal-Organic Frameworks (MOFs). The novel MOF-based PCHCM is a dual-functional composite material. It can simultaneously uptake/release heat and humidity from indoor air and control the hygrothermal environment passively. The materials characterizations show that the new MOF-based PCHCM has better thermal and moisture buffering ability than most conventional building materials. The effect of the new material on building energy conservation was calculated by a newly developed HAMT-enthalpy model. The simulation results show that MOF-based PCHCM can effectively moderate the fluctuations of temperature and relative humidity and reduce building energy consumption in most climates worldwide. The maximum energy-saving potential could reach up to 35% in hot-dry climates. The paper will guide the application and further development of dual-functional PCHCM composites under different climates.