The Automatic Vent Opener was designed 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 allow the right amount of air flow into 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 screen, as the air gets warmer, then contracts as it cools, closing with the use of a springtime and resetting the piston. All you have to to do is definitely to install it on your roof vent window and it automatically starts operating. The Automatic Vent Opener functions without the use of Greenhouse Vent Opener electricity and is compatible with all Palram greenhouse models only. The solar powered Vent Opener will start to open as temperatures within your greenhouse reach 68 degrees F with full-open at 80 degrees. It installs efficiently and will provide care-free ventilation.
Ingenious temperature-sensitive device that automatically opens and closes coldframe lids, greenhouse windows and also skylights. Works during the day and maintain a constant interior climate, something impossible 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 all our glazed season extenders because it dramatically boosts plant growth.
The hydraulic cylinder comes with a 1 year warranty. The average duration of the cylinder can be 5-10 years, although some can last up to twenty years.
Screw directly into polycarbonate panels, wooden, or metal frames. The Standard Vent Opener can open a hinged windows or vent weighing just as much as 32 lb. For bigger panes use the more powerful Gigavent with all metallic structure, to lift up to 65 lbs.
Note from the maker: Suggested to lubricate the piston rod annual, this will help extend the lifetime of the hydraulic cylinder. Avoid solid grease, as dirt particles “glues” very easily onto the piston rod and may harm the rubber. Also do not forget to unlock the vent in the wintertime if departing the vent openers installed. Even a weak winter sun can temperature the hydraulic cylinder sufficiently to make 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-run 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 usage of the interior.