ASHRAE Standard 90.1-2010 requires the use of energy recovery in a significant number of applications. In some climate zones, energy recovery devices with both sensible and latent recovery capability are needed to achieve a 50% total energy recovery effectiveness. We often still encounter resistance from facility managers to using enthalpy wheels, due to poor past experiences from 1st generation technology. Enthalpy wheels were previously more prone to failure and could not be easily cleaned. Today's technology allows segments of wheels to be removed if damaged and also allows cleaning using a hose and mild detergent.
There may be applications where small energy recovery units are needed. The Greenheck MiniVent series provides 300 to 800 cfm of make-up air in a compact package. WRL has incorporated these units in constrained spaces in conjunction with variable refrigerant flow systems.