Eq 2 is a complete series consisting of two jointly controlled room ventilators. The units provide balanced ventilation with heat recovery in single rooms. While one of the room ventilators exhausts polluted air, the other one supplies tempered and filtered fresh air. The heat exchanger recovers heat from the exhaust air and uses it to warm up the supply air. The two room ventilators switch between supply and exhaust air every 70 seconds. During warm periods, the room ventilators can be set to ventilation mode for ventilation without heat recovery. Both units are controlled by a common control panel connected through signal cables. The control panel is permanently connected to the mains. Eq 2 is equipped with filter warning and timer function.