Linear actuator or spindle drive? Both mean the same thing: a motor turns a threaded spindle and pushes a rod straight out of the housing.
In brief: Spindle actuators open windows, flaps and rooflight domes via a threaded spindle – with high force in a compact design, also for hard-to-reach windows in ventilation and smoke and heat exhaust (SHEV). At Vent Systems: VS-LA with 600 to 5000 N from €110, VS-LA-i with Modbus and synchronised operation from €165 and VS-SA 2500 with 2500 N for heavy rooflight domes from €170 (net prices). We ship stock items from Hamburg within 24 hours; the delivery time of each version is shown on the product page.
The factor of 57.3 resulting from the conversion of degrees to radians (180/π).
Entries with a comma or a dot (for example, a 27.5 or 27.5).
The output is rounded to the nearest whole Millimeter.
VS-LA linear actuator, compact, with 600 N to 5000 N thrust.
Price includes standard bracket set.
excl. VAT
plus Shipping costs
Delivery time: Ships within 24 h
VS-SA 2500 spindle drive – powerful and specially designed for heavy skylights.
excl. VAT
plus Shipping costs
Delivery time: Ships within 24 h
VS-LA-i smart linear drive with 800 N to 5000 N, synchronization function and bus integration.
excl. VAT
plus Shipping costs
Delivery time: Ships within 24 h
| Model | Voltage | Push/pull force | Stroke | Speed | Protection class | Price |
|---|---|---|---|---|---|---|
| VS-LA | 24 V DC | 600–5000 N | 100–800 mm | 6–10 mm/s | IP65 | from 110 € net |
| VS-LA-i | 24 V DC | 800–5000 N | 20–1000 mm | approx. 6 mm/s | IP65 | from 165 € net |
| VS-SA 2500 | 24 V DC | 2500 N | 100–1000 mm | 25 mm/s | IP44 | from 170 € net |
Further data, data sheets and tender texts can be found on the respective product page.
| Actuator | Force | Special feature | Net price |
|---|---|---|---|
| VS-LA | 600–5000 N | Stroke 100–800 mm, standard for roof windows and rooflight domes | from 110 € |
| VS-LA-i | 800–5000 N | Modbus, synchronised operation of several actuators | from €165 |
| VS-SA 2500 | 2500 N | Stroke up to 1000 mm, for large and heavy rooflight domes | from €170 |
Spindle actuators convert the motor’s rotation into an even stroke movement via a threaded spindle. This gives them high forces in a compact design – the right choice for heavy dome rooflights, large vents and hard-to-reach windows. The VS-SA 2500 is a powerful spindle actuator designed specifically for heavy dome rooflights.
In addition, we show the smart linear actuator here VS-LA-i with 800 N to 5000 N thrust, synchronisation and bus integration. With synchronisation, several actuators on one sash run evenly; bus integration allows connection to the building management system.
Spindle actuators are used in daily ventilation as well as in smoke and heat exhaust systems (RWA). All models are available from stock in Hamburg. We are happy to clarify which actuator suits the sash weight, stroke and installation in a personal consultation. We also match the right control unit and accessories such as ventilation switches and sensors to your system, so you get everything from one source.
Further reading: practical examples can be found in our guides Retrofitting rooflights and Automated skylights in commercial construction.
Besides the VS-SA 2500 for heavy dome rooflights, our VS-LA linear drives (600–5000 N, from €110 net) are also spindle actuators – the standard solution for roof and facade windows.
Guide values for horizontal sashes with insulating glass (2 × 4 mm), actuator at the opening edge, including 50 % reserve as recommended for roof surfaces. Snow load is not included – calculate precisely with the Window actuator calculator.
| sash | Weight | Required force | Suitable actuator |
|---|---|---|---|
| Rooflight dome 1.0 × 1.0 m | approx. 22 kg | approx. 160 N | VS-LA 600 N |
| Roof window 1.2 × 1.5 m | approx. 40 kg | approx. 300 N | VS-LA 600 N |
| Glass roof sash 2.0 × 2.5 m | approx. 110 kg | approx. 810 N | VS-LA 1000 N |
| Heavy flap | approx. 200 kg | approx. 1,480 N | VS-LA 2000 N |
| Very heavy flap | approx. 300 kg | approx. 2,200 N | VS-SA 2500 or VS-LA 3500 N |
| Gate or hatch leaf | approx. 600 kg | approx. 4,400 N | VS-LA 5000 N |
From a sash width of 1.5 m we recommend two actuators running in sync, for example 2 × VS-LA-i; each then takes about half of the force.
Sash 1,200 × 1,200 mm, glazing 6-16-6, pitch 15°, snow load 0.5 kN/m². Weight approx. 48 kg, force from weight approx. 225 N plus snow approx. 350 N, together approx. 575 N. With 50 % reserve for the roof surface this gives approx. 860 N – the right choice is the VS-LA with 1000 N.
Send us these details via the Project enquiry – we will suggest the actuator, bracket and control unit.
From a sash width of about 1.5 m we recommend two actuators running in sync, for example two VS-LA-i with built-in synchronisation. Each actuator then takes about half the force, and the sash does not twist.
The motor turns a threaded spindle that converts rotation into an even stroke movement. This produces high forces in a compact design.
The VS-SA 2500 is a powerful spindle actuator designed specifically for heavy dome rooflights – even where the window is hard to reach.
For heavy dome rooflights, the spindle actuator is the robust choice. If several actuators need to run synchronously or be connected to the building management system, the smart VS-LA-i linear actuator is the better solution.
Send us the dimensions and weight of the dome rooflight or vent via the Contact form – we’ll advise you.
An old linear or spindle actuator from GEZE, Aumüller or Kingspan STG is defective? You will find the right alternative in the guide Replacing window drives.
Quick reference: What is a spindle drive? – function, force and use in the glossary.
See them in action: Project videos with drives from our range – large façades, a railway station and special solutions.
CAD data: Bracket sets for VS-LA and VS-LA-i as DWG (ZIP) – free, no registration required.
Note on SHEV: For use in smoke and heat exhaust systems (SHEV), there is no test certificate according to DIN EN 12101-2. Whether an actuator may be used in your SHEV system is decided by the installer.
Prepayment / bank transfer
Delivery time: many versions are in stock in Hamburg and ship within 24 hours; versions not in stock take approx. 3 weeks. The delivery time of each version is shown on the product page.
In stairwells: For rooflight domes and roof windows, the VS-LA 600/500 linear actuator (600 N, 500 mm stroke) is often used – suitable where no NRWG to EN 12101-2 is required. Smoke ventilation in stairwells