CONTINUOUS ROOFTOP VENTILATION CARDAN
For ventilation in wide-span greenhouses a continuous rooftop ventilation system is used most often.
With continuous rooftop ventilation, ventilation is achieved through usage of two air vents per roof, one on each side.
These air vents cross the entire length of the roof. Underneath the air vents, spanning across the length of the roof, the drive tube with a tooth rack system is situated. The tooth rack systems are attached to the air vents through a window bracket and push the vent upwards.
With indirect rooftop ventilation the drive tube is driven by a worm gearbox. Multiple worm gearboxes are driven by one fast moving motor gear reducer.