Membrane-based enthalpy exchangers for coincident sensible and latent heat recovery

Membrane-based gas-to-gas enthalpy exchangers have a significant position in energy recovery systems, especially in building ventilation. Membrane-based heat exchangers are similar in design to sensible heat exchangers, with a semi-permeable membrane instead of solid interface plates to recover sensible heat and moisture simultaneously. In the present work, all aspects affecting the non-isothermal performance of gas-to-gas membrane heat exchangers have been investigated. These include the effects of membrane core type and properties, moisture transfer mechanisms, module geometry, ways to increase sensible and latent heat recovery efficiency, and the use of these devices in ventilation systems under all climate conditions, other waste heat recovery applications, and industrial systems. Novel membranes, module geometries, and flow configurations developed for this purpose are also presented in this paper. In addition to state of the art in the enthalpy heat exchangers, the outlook and further suggestions are provided.