Units with preheating register

The preheating register keeps the unit free of frost and protects the heat exchanger from icing over. The ventilation unit controls the temperature at the unit inlet to the minimum air inlet temperature (factory setting).

If the outgoing air temperature falls below the outgoing air min. value set in the factory, despite the presence of the preheating register, the ventilation unit switches off. A frost protection fault appears on the control unit.