An Analytical Review of Humidity-Regulating Materials: Performance Optimization and Applications in Hot and Humid Regions

Humidity-regulating materials (HRMs) represent a promising class of passive, energy-efficient materials capable of autonomously modulating indoor environmental conditions, particularly in hot and humid regions where conventional HVAC systems account for up to 50% of building energy consumption. While prior reviews have focused on material classification and performance metrics, a systematic synthesis of performance optimization strategies and quantitative application outcomes remains lacking. This review addresses this gap by consolidating advances in HRM enhancement through material compounding, physical modification, and chemical functionalization, resulting in performance improvements such as a 70% increase in moisture absorption with 3% fiber addition, a 1.2-fold enhancement in adsorption capacity via pore optimization, and up to 50% energy savings in building applications. Furthermore, the integration of HRMs into radiant cooling systems elevates the dew point temperature difference by 181%, effectively mitigating condensation risks. Simulation tools—ranging from 1D to 3D multiphysics models—have advanced predictive accuracy for coupled heat and moisture transfer, supporting optimized material design and system integration. By systematically summarizing performance metrics, enhancement mechanisms, and real-world applications, this work provides a quantitative and structured reference for the development and deployment of next-generation HRMs in sustainable building systems.