The Automatic Vent Opener was designed to automatically control the temperature and humidity amounts and offer additional ventilation when needed, making gardening easier. As the atmosphere within the greenhouse warms, the vent gradually opens to allow the correct amount of ventilation into the greenhouse and closes when the temperature cools. The vent arm was designed with a metallic cylinder that contains wax which expands when heated to push a piston, which raises the screen, as the atmosphere gets warmer, then contracts since it cools, closing with the use of a spring and resetting the piston. All you have to to do is to install it on your own roof vent screen and it instantly starts functioning. The Automatic Vent Opener operates without the usage of electricity and is compatible with all Palram greenhouse models only. The solar driven Vent Opener will start to open as temperature ranges within your greenhouse reach 68 degrees F with full-open at 80 degrees. It installs quickly and easily and can provide care-free ventilation.
Ingenious temperature-sensitive device that automatically opens and closes coldframe lids, greenhouse windows and even skylights. Works during the day and maintain a constant interior climate, something extremely hard to achieve by manual adjustments.

Requires simply no batteries or electricity.
It can be adjusted to begin opening between 60-77°F. Fully open up at 86-90°F. Fully Greenhouse Vent Opener closed at 55°F.
Strongly recommended for almost all our glazed season extenders because it dramatically enhances plant growth.
The hydraulic cylinder has a 1 year warranty. The average lifetime of the cylinder is definitely 5-10 years, even though some can last up to 20 years.

Screw straight into polycarbonate panels, wood, or metal frames. THE TYPICAL Vent Opener can open a hinged windows or vent weighing as much as 32 lb. For bigger panes use the stronger Gigavent with all metal building, to lift up to 65 lbs.