Theoretical Modeling and Analysis of Energy Recovery Efficiency and Influencing Factors of Energy Recovery Ventilators Under Dynamic Thermal Environments

Energy recovery ventilators are essential for reducing building energy consumption, with the dynamic variation in their efficiency being a significant area of current research. To quickly analyze the parameters affecting the dynamic changes in energy recovery efficiency, this study develops a mathematical model for heat and moisture transfer. The model was validated through computational fluid dynamics (CFD) simulations and experimental data. The validation results showed that the discrepancies between the model’s sensible heat and enthalpy efficiencies and the experimental data were approximately 4%, while the error range for sensible heat efficiency compared to CFD simulations was between 3% and 7%. This model was used to evaluate various factors affecting energy recovery efficiency. The findings show that outdoor temperature and relative humidity have little effect on sensible heat efficiency, whereas latent heat efficiency increases with rising outdoor temperature and humidity. Both sensible and latent heat efficiency improve as airflow decreases, with latent heat efficiency being more sensitive to changes in airflow. Additionally, due to the very thin heat exchanger membrane, the mass diffusion coefficient has a more significant effect on efficiency than the thermal conductivity coefficient. In conclusion, energy recovery efficiency is dynamic, and the proposed model provides rapid predictions of how influencing factors affect the efficiency.