MEP Engineering · Engineering Glossary
An Energy Recovery Ventilator (ERV) or Heat Recovery Ventilator (HRV) is a mechanical ventilation device that transfers heat and moisture (ERV) or heat only (HRV) between the outgoing exhaust air stream and the incoming outdoor air stream, reducing the energy required to condition outdoor ventilation air.
ASHRAE 90.1 and some Title 24 editions require energy recovery on HVAC systems that exhaust large volumes of air — above threshold airflow rates and in climate zones where the energy savings justify the added cost. ERVs use a total energy wheel or plate heat exchanger to transfer 60–80% of the heat (and moisture for ERVs) from the exhaust air to the incoming outdoor air. HRVs transfer only sensible heat, making them more suitable for cold climates where indoor humidity control is important. The mechanical engineer evaluates whether energy recovery is required by code and designs the ERV/HRV into the air handling system. Apex Grid includes energy recovery analysis in all commercial HVAC designs where code requirements or energy goals warrant it.
Apex Grid Engineering maintains this glossary as a resource for architects, contractors, developers, and property owners who encounter unfamiliar engineering terminology on their projects.
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