Q. What’s the Difference Between an HRV and ERV? Which Should I Choose?
A. An HRV (heat recovery ventilator) is primarily designed for heating climates while an ERV (energy recovery ventilator) is designed for cooling climates. While the basic mechanisms are the same for both, an HRV uses an aluminum core as the thermal transfer mechanism and an ERV uses a cellulose core. The cellulose core of the ERV allows it to not only transfer the energy but also to remove moisture from warm outdoor air entering the house. In other words, an ERV helps redirect the humidity from the intake air and send it back outside, reducing the moisture burden on the A/C system and creating a dryer indoor environment. An HRV’s aluminum core does not transfer any moisture; it will exhaust moisture just like a traditional exhaust fan and will allow moisture to enter in the summertime. An HRV’s core will last forever; an ERV’s core will have to be replaced every 3-5 years. In northern climates where humidity is not a significant concern, an HRV is preferred.