Many fanlights in offices, schools and stairwells are still opened by crank, rod or lever. This is cumbersome, and the windows often simply stay closed. An electric fanlight opener solves the problem: the window opens via switch, timer or sensor. This guide shows which solutions exist and what to look out for.
Mechanical fanlight opener or chain actuator?
A mechanical fanlight opener moves the sash via rods and stays. An electric chain actuator, by contrast, is mounted directly on the frame and pushes the sash open via a chain. The stays of the old opener are no longer needed, and the rods can be removed.
| Solution | Suitable for |
|---|---|
| VS-KA chain drive | Standard fanlights, 250–1500 N, 24 V or 230 V |
| Built-in chain drive VS-CKA 300 | concealed installation in the window profile |
| Mechanical chain actuator VS-MKA | operated by crank, without power |
Safety: don’t forget the safety stay
Overhead bottom-hung sashes must be secured against falling. If the fanlight has no safety stay or it is removed during conversion, a suitable stay must be retrofitted. The actuator does not replace this safety device.
For windows installed below a height of 2.5 m, anti-trap protection is also required.
How the conversion works
- Determine sash dimensions and weight, define the opening width.
- Select actuator and stroke – calculate the stroke with the guide Calculate chain length.
- Remove the old opener and rods, check the safety stay.
- Mount the actuator with brackets on the frame and align it precisely.
- Connect electrically – see Connecting a chain actuator – and carry out a test run.
Operation and automation
For a single fanlight, a 230 V actuator with a Ventilation buttonis sufficient. If several fanlights are to move together or close automatically when it rains, a 24 V solution with control unit and sensor makes sense. Details in the guide Ventilation control for window actuators.
Frequently asked questions
Can I mount the chain actuator on a wooden window?
Yes. Chain actuators can be mounted on wooden, PVC and aluminium windows if the appropriate brackets are used.
How far does an electric fanlight open?
That is determined by the actuator stroke. 150 to 300 mm is usual for ventilation fanlights; the stroke is selected when ordering.
Can the fanlight still be opened during a power failure?
Electric actuators hold their position during a power failure. If you want a solution completely without power, choose the mechanical chain actuator VS-MKA.
Converting fanlights?
Send us the number, dimensions and a photo of the fanlights – we will put together the right solution, from stock in Hamburg. To the contact form or call +49 40 50694631.

