J. Orbesen Teknik ApS has the markets best greenhouse automatic vent openers. We have made vent openers for more than 30 years, and are the world’s leading manufacturer of vent openers.

Find your perfect greenhouse auto vent openers in our wide selection. Listed below are a few of our innovative vent openers. Please take a tour on our website for more information on these fantastic vent openers. You are welcome to give us a call if you have any questions about our vent openers or vent openers in general.

Automatic greenhouse vent openers – Optivent® 

Optivent® vent openers are our most sturdy vent openers in the small range. The piston rod is completely sealed off in an aluminium enclosure. This makes these vent openers extremely applicable for dusty environments. The Optivent® vent openers are often used in stables and storage rooms. This opener, like the other small range vent openers, uses our standard hydraulic cylinder.

Automatic greenhouse vent openers – Megavent Storm®

Megavent Storm® openers are compact, strong and powerful greenhouse vent openers. These vent openers are able to lift up to 70 % more than our small range vent openers. Due to the compact design, these vent openers will at all times be within the frame of the window.

Just like all our vent openers, Megavent Storm® is featured with a long opening stroke ensuring optimal conditions for your plants in the greenhouse. Megavent Storm® vent openers feature liquid phase transition to adjust the opening temperature. Our powerful Megavent Storm® vent openers are equipped with a shock absorber to prevent the window being ripped open by windy gusts or strong winds.

More than 30 years of experience in vent openers

We have been manufacturing automatic greenhouse window openers for hobby greenhouses since 1981.

The core technology in our window openers is the hydraulic cylinder that contains a plant-based wax. The special designed cylinder containing this wax, works as the greenhouse window openers thermostat, leaving no need for an electrical power supply.

Our automatic vent openers use no electricity

Due to this fact, you don’t need any electricity for the window openers in your greenhouse. Furthermore, the window openers are very environmental and CO2-friendly throughout its lifetime.
The hydraulic cylinders used in our greenhouse window openers, are also used in a wide variety of applications e.g. roof hatches; helicopters; power plants etc.

For Professionals/B2B
For Professionals/B2B


Please contact us

Phone: (+45) 59 65 17 17

Monday-Thursday: 8:00 am – 16:00 pm

Friday: 8:00 am – 14:00 pm