What the devices share
Both systems use fans to bring outdoor air inside and expel indoor air through separate airstreams. A heat-exchange core transfers some energy between those streams, reducing the conditioning load compared with untreated outdoor air.
HRV behavior
A heat recovery ventilator primarily exchanges sensible heat. Depending on climate and operating conditions, condensate management and frost protection can be important. It is not an air conditioner and does not replace filtration.
ERV behavior
An energy recovery ventilator transfers some heat and some moisture. This may help moderate incoming humidity, but it does not eliminate the need to consider dehumidification, infiltration and actual indoor conditions.
Selection questions
Compare required ventilation airflow, local climate, measured efficiency at operating conditions, filtration, controls, sound and maintenance. The right core depends on the whole building, not a universal HRV-or-ERV rule.
Sources and further reading
- US Department of Energy: Heat Pump Systems
- US Department of Energy: Central Air Conditioners and Heat Pumps