The indoor climate in residential buildings is affected by the people that live in the house and their activities. One of the goals of a ventilation system is to prevent excess humidity in the house by removing part of the moisture. The moisture balance can however be distorted in winter with a low humidity in the house as a result.
An enthalpy exchanger can be used in a recovery ventilation system to reduce the risk of very low indoor humidity levels in winter. While heat recovery ventilation (HRV) is recovering energy in terms of temperature, enthalpy recovery ventilation (ERV) is recovering energy in terms of both temperature and moisture.
In a house in Rotterdam, The Netherlands, the temperatures and humidities of the air streams in a recovery ventilation system were monitored. Eight day periods with HRV and ERV are compared with each other during mild outdoor conditions.
In the monitored house, the measured recovered amount of absolute humidity with ERV is about 1-2 g/kg with an average humidity recovery efficiency of 65%. In the monitored house, ERV brings the indoor relative humidity up to 10 percentage point higher than HRV.
The measured average thermal efficiency and humidity efficiency correspond well with the laboratory values from the specifications.