Nowadays it seems that simpler Heat Recovery Ventilators are the go-to solution. They're more straightforward crossflow heat exchangers, with no moving parts (e

Nowadays it seems that simpler Heat Recovery Ventilators are the go-to solution. They're more straightforward crossflow heat exchangers, with no moving parts (except the fans, of course). Energy Recovery Ventilators are also available, built with a permeable interface to retain humidity as well as heat.