Passive ventilation – Compact and inconspicuous

Benefits at a glance

Save energy


Moisture protection

Noise protection


Autonomous operation

Passive window rebate ventilator

The GEALAN-CAIRE® flex passive ventilation system is based on pressure equalisation between indoor and outdoor air and can be compactly and inconspicuously mounted in the window rebate. If there is a pressure difference, the window rebate ventilators allow a compensating air flow, either inward or outward. In strong winds, the air flaps close, so that no draughts occur in your rooms. The passive ventilation system is simple but effective, reliable and inexpensive. It ensures permanent basic ventilation, prevents mould and works independently.

Application range

GEALAN-CAIRE® flex is a window rebate ventilator for existing and new buildings. The system allows for a permanent exchange of air when the window is closed and is especially useful for preventing mould by removing moist air to the outside. The passive ventilator does not need to be controlled, and is therefore resistant to faults and requires little maintenance. GEALAN-CAIRE® flex is easy to install and fits almost invisibly into various window systems. The air flow rate can be increased by installing several window rebate ventilators.

Indoor inflow

GEALAN-CAIRE® flex allows fresh air to flow into the window rebate through targeted openings and out into the room through the upper window area on the inside: perfect for comfortable basic ventilation that transports moisture outside and effectively prevents mould. Depending on the air pressure difference, the system achieves an air flow of 2 to 13 m³ per hour. In strong winds, GEALAN-CAIRE® flex closes by itself and prevents draughts.

Layout and function

GEALAN-CAIRE® flex can be independently used in PVC window systems with rebate seals of different installation depths. The window rebate ventilator is placed between the sash and frame instead of the sash rebate seal. In the respective colour of the window seal, it is almost invisible.

GEALAN-CAIRE® flex automatically responds to the slightest movement of air. In strong winds, the system creates the desired tightness of the windows. In normal weather, it allows fresh air to flow inside.

GEALAN-CAIRE® flex is only available from our partner companies, which are also responsible for proper installation. You will find nearby window manufacturers in our Manufacturer search.  

GEALAN-CAIRE® flex is almost invisible. The ventilator is concealed in the window rebate, is easy to install and retrofit. Even with the smallest pressure differences, it reliably brings fresh air into the house without you having to open the window. So mould doesn’t stand a chance.

Downloads for GEALAN-CAIRE® flex

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