Summer bypass function:
On cool summer nights, in addition to normal ventilation (e.g., through window ventilation), the unit's bypass function can also be used. The bypass directs the exhaust air around the heat exchanger, thus preventing the "cool" fresh air from being heated by the warm exhaust air.
Heat recovery in winter
The warm exhaust air preheats the cold fresh air – this keeps the heat in the house and saves energy.
Mechanical bypass in summer
A flap prevents heat exchange - cool fresh air flows in and the exhaust air continues to be discharged