Choosing Between an ERV and an HRV

Energy-recovery ventilators (ERVs), including the sub-type known as heat-recovery ventilators (HRVs), provide whole-building ventilation while reducing the amount of energy lost during air exchange. An HRV is a simpler system that enables exchange only of sensible heat (energy you can measure with a thermometer); the term “ERV” typically refers to more complex systems that exchange both sensible and latent heat (energy a thermometer can’t detect, typically because it’s being used to effect phase change; see “Dry-Bulb? Wet-Bulb? What’s the Difference?”).