Ventilating a hall façade with rack-and-pinion actuators: planning with an example

Updated: 08.11.2026

In brief: Large top-hung sashes in hall façades are best opened with rack and pinion actuators: they provide a long stroke and push and pull evenly. A sash measuring 2.5 × 1.2 m with double glazing needs around 150 N, about 190 N with reserve. Because it is wider than 1.5 m, we use two synchronously running VS-ZA-i .

The example

A workshop has ten top-hung sashes of 2,500 × 1,200 mm each in the façade, double glazing 4-16-4, hinges at the top. The sashes are to open together for daily ventilation and close automatically in rain and storm.

Step by step

1. Weight: 2.5 × 1.2 m × 8 mm × 2.5 kg/(m²·mm) × 1.1 ≈ 66 kg per sash.
2. Stroke: For about 24° opening at 1,200 mm sash height, about 500 mm stroke is needed (stroke = 2 × sash height × sin(angle/2)).
3. Force: 0.54 × 66 kg × 9.81 × 0.5 / 1.2 ≈ 146 N, with 30 % Reserve ≈ 190 N.
4. Number: A 2.5 m sash width is above 1.5 m – so two actuators per sash, each taking about 95 N. Two VS-ZA-i with 600 N have plenty of reserve and run evenly thanks to built-in synchronisation.
5. Control and sensors: Ten sashes with two actuators each make 20 actuators. We divide these into groups; the VS-C24-7A ventilation control unit drives up to 7 actuators. A wind and rain sensor closes all sashes in rain or storm.
6. Cables: Check the cross-section of the 24 V supply cable with the “Cable cross-section” tab in the Window actuator calculator.

Why rack-and-pinion and not chain?

A chain actuator is more compact and ideal for bottom-hung and top-hung windows up to medium size. With 500 mm stroke and more, with large sashes and on roof surfaces, the rack and pinion actuator shows its strengths: the rigid rack transmits push and pull over the entire stroke. The VS-ZA 800 has up to 1,000 mm stroke and protection class IP65.

Planning checklist for halls

• Number and dimensions of the sashes, position of the hinges
• Desired opening angle or free ventilation area (for SHEV from the specialist planner)
• Which sashes should move together (groups)
• Voltage: 24 V with control unit or 230 V with switch
• Sensors: rain, wind, temperature, CO₂
• Cable routes and length to the furthest actuator

Read more: Ventilating a warehouse naturally: window drives for continuous rooflights and façades

Frequently asked questions

Can the windows also be used for smoke exhaust?

For smoke ventilation the system is planned project-specifically and operated with an approved SHEV control panel. Vent Systems supplies actuators and ventilation controls, not SHEV control panels. Whether an actuator may be used in the smoke ventilation system is decided by the installer.

Is it possible without a control unit?

Yes, with 230 V actuators and ventilation switches. But then automatic rain closing and synchronised operation are missing.

Planning a hall? Send us the list of sashes via the Project enquiry, and we will suggest actuators, groups and control.

See also in the glossary: Top-hung sash · Continuous rooflight · Sawtooth roof

Tools: Calculate force and stroke with the Window actuator calculator, find the right model in a few questions with the actuator finder.

More guides: Ventilating sports halls · 10 common mistakes when choosing an actuator