Warm and stale air out, fresh and clean air in: Dometic Fan-Tastic Vent does it in a matter of minutes. It’s pleasantly quiet and energy saving, too. The core of this truly fantastic ventilation solution is a high performance rotary fan which is firmly integrated in the standard 14 in. x 14 in. roof window and can be adjusted as required. Fan-Tastic Vent works with the roof window slightly open to create a pleasant, draught-free air flow.