Updated: 08.11.2026
In warehouses, heat builds up under the roof in summer and condensation forms on cold surfaces in winter. Electrically opened rooflights and façade windows let warm, humid air escape at the top while fresh air flows in at the bottom. This helps staff and goods without the running costs of fans.
In brief: Linear or rack and pinion drives are suitable for continuous rooflights and rooflight domes, chain drives for façade windows. Openings at the top and bottom create the stack effect. A controller with rain and wind sensor closes the windows when the weather changes.
Which drive for which opening?
| Opening | Actuator |
|---|---|
| Façade window (bottom-hung or top-hung sash) | Chain actuator |
| Rooflight dome, roof hatch | Linear actuator |
| Continuous rooflight, shed window, long rows of flaps | Rack-and-pinion actuator |
You can read more about retrofitting roof openings in the guide Retrofitting rooflights in industrial halls.
How to plan the ventilation
- Supply air at the bottom via façade windows or doors, exhaust air at the top via rooflights.
- The greater the difference in height, the stronger the air exchange.
- Group several drives on one controller and switch them by push button, building automation schedule or sensor.
- For smoke ventilation requirements: an approved smoke control panel is required.
Frequently asked questions
How many drives do I need for a continuous rooflight?
It depends on the length, weight and snow load of the flaps. Long flaps often need two synchronised drives. Send us the dimensions and we will calculate it.
Can I retrofit existing rooflights?
In many cases yes. What matters are weight, opening width and a solid fixing point for drive and bracket.
For an assessment, use the Project enquiry.
Technically reviewed by Dietmar Heiken, Sales, Vent Systems HDI GmbH, Hamburg – around 20 years of industry experience. Questions? Phone +49 40 50694631 or info@ventsystems.de
Last updated: 08.11.2026
