HRV vs ERV: Key Differences and How to Choose
HRV vs ERV: The Short Answer
Both are air-to-air heat exchangers for ventilation, but an HRV (Heat Recovery Ventilator) transfers only heat, while an ERV (Energy Recovery Ventilator) transfers heat and moisture. That single difference decides comfort, humidity, and running cost in different climates.
What Each One Does
An HRV uses a plate or wheel core to move sensible heat between exhaust and supply, leaving indoor humidity where it is. An ERV uses an enthalpy core (often a special polymer or desiccant wheel) that also carries water vapour, balancing indoor humidity with the outdoors.
When to Choose an HRV
- Cold, dry winters — you want to keep indoor humidity, not exhaust it.
- Heating-dominated climates — recovery of heat is the priority; moisture transfer adds little value.
- Simple make-up air where humidity is already controlled by other means.
When to Choose an ERV
- Hot, humid summers — an ERV keeps muggy outdoor air from pumping moisture into the building, cutting cooling and dehumidification load.
- Mixed climates — it balances humidity year-round and reduces over-dry winter air.
- Schools, offices, homes with tight envelopes where humidity swings cause comfort or mould issues.
Climate Rule of Thumb
Cooling-dominated or very humid → ERV. Heating-dominated and dry → HRV. Mixed → ERV for balanced humidity. In all cases keep the streams separated when hygiene demands it — see our plate cores for leak-tight recovery.
Cost and Efficiency
ERVs cost a little more up front but often pay back through lower dehumidification and cooling energy. Both reach 70–85% effectiveness. The bigger saving comes from recovering conditioning energy on every air change, not from the unit price.
Conclusion
Neither is "better" — the right unit follows your climate and humidity needs. Match the core to your separation rules and size it from our selection guide, and the ventilation bill drops whether you pick HRV or ERV.