Numerical analysis of heat and energy recovery ventilators performance based on CFD for detailed design

Abstract

This paper presents a detailed numerical analysis of heat and membrane-based energy recovery ventilators (HRV/ERV), using computational fluid dynamics (CFD). The CFD model includes conjugate heat and mass transfer mechanisms for laminar flow to investigate the thermal performance of these systems. Both co-current and counter flow designs were investigated under typical summer/winter Canadian conditions. The model was validated with data obtained from the open literature. It was then applied to investigate the effect of a wide range of parameters on ventilators sensible and latent effectivenesses.The numerical results confirmed the superior effectiveness of counter flow over the co-current flow. The results showed a decrease in the HRV/ERV effectiveness with the increase in supply/exhaust air velocity. The ERV effectiveness in the summer was found to be higher than the winter. The effectiveness decreased noticeably and slowly with the increase in membrane spacing and thickness. The latent effectiveness increased significantly with the diffusivity of water in the membrane. The results also indicated that the outdoor temperature and humidity had only minor effects on HRV or ERV performance.CFD simulations proved to be an effective approach for detailed design of HRVs/ERVs.