Does an enthalpy heat exchanger increase humidity in a house?

Yes, an enthalpy heat exchanger can transfer part of the moisture from exhaust air back into the supply air, helping to increase indoor humidity. This is not just a theoretical feature – it has been confirmed in real-world operation.

In an independent test carried out by an experienced user in their home with an AEREX ventilation unit, the long-term issue was very dry indoor air, despite attempts to naturally increase humidity, for example by using a large number of plants.

After installing the RECUTECH METALPIC enthalpy heat exchanger, there was a measurable increase in indoor humidity and an overall improvement in living comfort.

Under typical conditions, indoor humidity increases by approximately 10–15% during the heating season. In ideal conditions, the increase can reach up to 25–30%, depending on indoor humidity levels, airflow settings, and building characteristics.

Real measurement of indoor humidity with an enthalpy heat exchanger

It is important to understand that an enthalpy heat exchanger does not generate moisture, it only transfers it from the exhaust air back into the supply air. Therefore, the effect is not immediate but builds up gradually over several days to weeks.

This principle is based on physical laws and long-term real-world experience. That is why enthalpy heat exchangers are an effective solution for homes where ventilation systems cause excessive drying of indoor air.

This is why an enthalpy heat exchanger is one of the most effective solutions for dry indoor air in homes with ventilation systems.