An air-to-air heat exchanger transfers heat between two separate air streams without mixing them. It is the core component of HRV and ERV systems, letting you cut heating and cooling load while keeping supply air volumes intact.
How an air-to-air heat exchanger works
Warm, stale exhaust passes one side of the core while cooler fresh supply passes the other. Through a stationary plate, a rotating wheel, or sealed heat pipes, energy crosses the divider. Sensible units move temperature only; enthalpy (total-energy) units also transfer moisture via a permeable or desiccant surface.
Main configurations
- Fixed plate – stationary, no moving parts, easiest to clean.
- Rotary wheel – higher effectiveness, carries a small carryover stream.
- Heat pipe – passive, separates the two airstreams by distance.
- Run-around coil – for streams that cannot share a core.
Key specifications
| Parameter | Typical range |
|---|---|
| Effectiveness (sensible) | 50–85% |
| Face velocity | 1.5–3.5 m/s |
| Pressure drop | 80–300 Pa |
| Materials | Aluminum, 304/316L, coated |
| Temperature range | -40 to 200 °C |
Typical applications
Commercial HVAC, data-center make-up air, cleanrooms, paint booths, drying and industrial ventilation. See counter-flow air-to-air applications.
Read the full heat exchanger guide, or compare the plate heat exchanger and rotary heat wheel.