The Automatic Vent Opener was designed to automatically control the temperature and humidity levels and offer additional ventilation when needed, making gardening easier. As the surroundings within the greenhouse warms, the vent steadily opens to enable the correct amount of ventilation in to the greenhouse and closes when the temperature cools. The vent arm was designed with a metallic cylinder containing wax which expands when heated to press a piston, which raises the windows, as the air gets warmer, then contracts since it cools, closing with the utilization of a spring and resetting the piston. 
All you need to do is definitely to install it on your roof vent windows and it immediately starts operating. The Automatic Vent Opener functions without the use of electricity and works with with all Palram greenhouse models only. The solar driven Vent Opener will begin to open as temps within 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 throughout the day and maintain a continuous interior climate, something unattainable to achieve by manual adjustments.
Requires simply 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 can be 5-10 years, even though some can last up to 20 years.
Screw directly into polycarbonate panels, wood, or metal frames. The Standard Vent Opener can open up a hinged screen or vent weighing as much as 32 lb. For larger panes use the stronger Gigavent with all steel structure, to lift up to 65 lbs.
Note from the maker: Recommended to lubricate the piston rod annual, this will help extend the duration of the hydraulic cylinder. Avoid solid grease, as dirt particles “glues” very easily onto the piston rod and can harm the rubber. Also do not forget to unlock the vent in the wintertime if departing the vent openers set up. Even a weak winter sunlight can temperature the hydraulic cylinder sufficiently to create it start pushing the piston rod outwards.
This solar vent control will open and close vents, in your solar gem greenhouse. It features two closing springs for extra power. The solar vent opener may be the only solar-operate control with a quick-release mounting bracket. Just grasp the “clutch” arm and squeeze for easy detachment. This enables vent to be fully opened for Greenhouse Vent Opener access to the interior.