What does humidity control in ventilation systems with the comfort board 5/EC-FK mean?

Fans equipped with the comfort board 5/EC-FK have an independent humidity control. The standard control range is 50 - 70% relative humidity (RH) at 22°C and controls the fan between the set basic ventilation level and the demand ventilation level. Since warm air can absorb more moisture than cool air, the intelligent electronics always calculate the humidity at 22°C based on the measured relative humidity. This means that the control can also be described as a control according to absolute humidity. This means that even in a warm bathroom, for example, higher humidity values can be detected in the adjacent supply air rooms. When the automatic humidity control is activated, the exhaust air volume flow is constantly adjusted to the room humidity and room temperature and an optimum of comfort is achieved. Ventilation is only as much as necessary, but as little as possible, which saves energy, prevents over-humidification of the flat, and can avoid structural damage and mould.

The control is quasi stepless and in an "intelligent" way, by distinguishing between permanently high relative humidity or rapid increase (e.g. due to showers). If the relative humidity cannot be significantly reduced within a period of two hours (e.g. in summer), the fan is switched to the basic ventilation stage. If the relative humidity increases by more than 5% within one hour during setback operation, setback operation is terminated. If the value falls below the lower switching threshold and the basic ventilation level is set to OFF, the fan is switched off. If the fan is in the basic ventilation level OFF, the fan runs once an hour for 3 minutes at level 15 m³/h (sniffing mode). If a relative humidity is measured during this time that is above the set switching threshold, e.g. 50% RH at 22°C, the humidity control is activated. If the measured relative humidity is lower than the switching threshold, the fan is shut down again after these three minutes.

Note: Within the first two hours after mains connection, the fan runs at the level that corresponds to the currently measured value of relative humidity.