The Automatic Vent Opener was made to automatically control the temperature and humidity amounts and provide additional ventilation when needed, making gardening easier. As the surroundings inside 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 
made with a metal cylinder that contains wax which expands when heated to force a piston, which raises the home window, as the air gets warmer, then agreements as it cools, closing with the use of a spring and resetting the piston. All you need to do is usually to install it on your own roof vent home window and it immediately starts operating. The Automatic Vent Opener works without the use of electricity and works with with all Palram greenhouse versions only. The solar powered 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-sensitive Automatic Greenhouse Vent device that automatically opens and closes coldframe lids, greenhouse windows and also skylights. Works throughout the day and maintain a constant interior climate, something impossible to achieve by manual adjustments.
Requires no batteries or electricity.
It could be adjusted to start opening between 60-77°F. Fully open up at 86-90°F. Fully closed at 55°F.
Strongly recommended for most our glazed season extenders because it dramatically enhances plant growth.
The hydraulic cylinder includes a 1 year warranty. The average duration of the cylinder is 5-10 years, even though some can last up to twenty years.
Screw straight into polycarbonate panels, wood, or metal frames. The Standard Vent Opener can open up a hinged screen or vent weighing just as much as 32 lb. For larger panes use the stronger Gigavent with all metal construction, to lift up to 65 lbs.
Note from the maker: Suggested to lubricate the piston rod yearly, this will help extend the lifetime of the hydraulic cylinder. Avoid solid grease, as dust particles "glues" quickly onto the piston rod and will damage the rubber. Also do not forget to unlock the vent in the winter if leaving the vent openers installed. A good weak winter sun can warmth the hydraulic cylinder sufficiently to make it start pressing 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-run control with a quick-release mounting bracket. Simply grasp the “clutch” arm and squeeze for easy detachment. This enables vent to be completely opened for usage of the interior.