Hygrothermal performance analysis at the wall scale based on various hysteresis models

The hygrothermal performance of building components (e.g., exterior walls) influences indoor thermal and humidity conditions as well as the energy consumption of associated heating, ventilating and air conditioning (HVAC) systems. To assess such performance under dynamic and constant indoor conditions, a coupled heat and moisture transfer model was built with incorporating four hysteresis models based on Modelica platform. A typical wall system was selected to analyse hygrothermal performance during a typical meteorological year in Shanghai. Results show hysteresis effects significantly influence hygrothermal responses under dynamic conditions, with 20–30% higher moisture peaks, 8–12% higher cooling loads, and 15–20% higher moisture flux compared to non-hysteresis models, while impacts are minimal under constant conditions. The Frandsen model performs well in simulating adsorption-desorption cycles.