Modern energy codes push recovery hard. ASHRAE 90.1 (and the IECC it informs) requires energy recovery on many systems once outdoor-air flow and a temperature band are exceeded.
The gist
- Recovery is typically required when outdoor-air flow exceeds a threshold (often about 2,000 to 5,000 cfm depending on edition) and the climate is outside a narrow temperature band.
- Exceptions exist for hazardous exhaust, frost and specific occupancies.
- Local adoption varies, check the edition enforced in your jurisdiction.
Design impact
Specifying recovery early avoids costly redesign at permit stage. Pair with the sizing guide and retrofit article.
Specifying a unit for your project?
EN159 builds plate, rotary, heat-pipe and counterflow air-to-air exchangers that meet code recovery requirements. Send airflow (m3/h), inlet temperatures and available space and we will size it.
Request a quote