Units with preheating register and additional pre-heating

If pre-heating (brine earth heat exchanger, electric heating register) is also fitted upstream and controlled via the unit controller, the pre-heating ensures that the unit remains free of frost.

The pre-heating switches on if the temperature falls below the minimum air inlet temperature (factory setting) + T air inlet offset heating.

Should the air inlet temperature fall to the minimum air inlet temperature despite this, the preheating register is also activated.