Updated: 07.11.2026
The Wind load is the force that wind exerts on a window – as pressure on the windward side and as suction on the leeward side. For window actuators it matters mainly with open sashes and on tall or exposed buildings.
What does the wind load depend on?
- Wind zone of the site (in Germany zones 1 to 4 according to DIN EN 1991-1-4, highest on the coast)
- Building height and surroundings (open country, city, coast)
- Position on the building: suction is greater at corners and edges
- Size and opening width of the sash
What does this mean for the actuator?
An open sash offers the wind a surface to attack. The actuator has to hold it and be able to close it against the wind. That is why we plan a larger Reserve of +50 % for exposed locations. When closed, the Holding force holds the sash against wind suction.
Frequently asked questions
Does the window actuator calculator compute the wind load?
No. An exact wind load depends on the building and belongs in the planning. In the calculator you cover wind via the reserve setting.
How do you protect open windows in a storm?
With a wind sensor on the ventilation control unit: it closes the windows as soon as a set wind speed is exceeded, for example with the VS-WRLS wind/rain/light sensor.
Read more
See also in the glossary: Wind zone · Terrain category
Tools: Calculate force and stroke with the Window actuator calculator, find the right model in a few questions with the actuator finder.
Not sure which actuator fits? Call us at 040 50694631 (Mon–Fri 8 am–5 pm) or use the actuator finder.
Related terms: Ventilation control (window control) · Opening width · Shape coefficient (snow load) · Dome rooflight
