The EcoVent Verso KWL EC 45 fan from Helios for room ventilation scores with high quality, functionality and ecology. It works with heat recovery in the so-called reversing operation. This means it changes between a supply air phase and an exhaust air phase. During the exhaust air phase, the used air is led to the outside; a ceramic stone inside stores the warmth of the exhaust air. In the supply air phase, the fresh air from outside takes up this warmth. Thus, the fan saves additional energy, making it especially suitable for use in energy efficient houses. Durable EC fans as well as optimized elements, e.g. the inner valve, represent the high quality of the EcoVent.