The Automatic Vent Opener was designed to automatically control the temperature and humidity levels and provide additional ventilation when needed, making gardening easier. As the air flow inside the greenhouse warms, the vent gradually opens to allow the right amount of air flow into the greenhouse and 
closes when the temperature cools. The vent arm was made with a metallic cylinder containing wax which expands when heated to press a piston, which raises the screen, as the air gets warmer, then agreements as it cools, closing with the use of a springtime and resetting the piston. All you need to do is to install it on your roof vent window and it instantly starts working. The Automatic Vent Opener functions without the usage of electricity and works with with all Palram greenhouse versions only. The solar driven Vent Opener will begin to open as temperature ranges inside your greenhouse reach 68 degrees F with full-open at 80 degrees. It installs efficiently and can provide care-free ventilation.
Ingenious temperature-delicate device that automatically opens and closes coldframe lids, greenhouse windows and even skylights. Works during the day and maintain a continuous interior climate, something unattainable to achieve by manual adjustments.
Requires no batteries or electricity.
It can be adjusted to start opening between 60-77°F. Fully open at 86-90°F. Fully closed at 55°F.
Strongly recommended for most our glazed season extenders since it dramatically increases plant growth.
The hydraulic cylinder has a 1 year warranty. The common duration of the cylinder is certainly 5-10 years, although some can last up to 20 years.
Screw directly into polycarbonate panels, wooden, or metal frames. The Standard Vent Opener can open a hinged window or vent weighing as much as 32 lb. For larger panes use the stronger Gigavent with all metal structure, to lift up to 65 lbs.
We’ve listened to from several people that utilised Greenhouse Vent Opener as well as are entirely satisfied.