The decentralized heat recovery system Cuper 125 is an efficient controlled ventilation technology that for minimal heat loss all year round Fresh and healthy air, free of dust, pollen and allergens, without having to open the windows. In addition, the regular and sufficient ventilation Reduction of air humidity and to avoid mold formation. If the heat recovery device in winter The used air from the room sucked -init uses their warmth to heat the ceramic heat exchanger. If Then fresh outside air flows through the heat exchanger, the heat is transferred and The cold air heated to a temperature near the room temperature. The reverse process takes place in summer, with the incoming air already slightly cooled into the room. With this principle of heat recovery, the ventilation device saves en.