FFL Window Rebate Vent

The FFL is a concealed, automatically regulating ventilation system designed for PVC windows. Installed within the window rebate, it allows a controlled supply of fresh air while remaining virtually invisible when the window is closed.

The system operates entirely mechanically and requires no electrical supply. As wind pressure increases, the internal vent flaps automatically restrict the airflow, helping to reduce uncomfortable draughts. When the pressure decreases, the vents reopen automatically.

By providing continuous background ventilation, the FFL can help remove excess indoor moisture and support a healthier indoor environment, while maintaining the clean appearance of the window without the need for a visible surface-mounted trickle vent.