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 within the greenhouse warms, the vent steadily opens to enable the right amount of 
ventilation 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 push a piston, which raises the screen, as the air flow gets warmer, then contracts since it cools, closing with the use of a spring and resetting the piston. All you need to do is to install it on your own roof vent windowpane and it automatically starts operating. The Automatic Vent Opener functions without the use of electricity and works with with all Palram greenhouse versions only. The solar driven Vent Opener will begin to open as temperatures 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 device that automatically opens and closes coldframe lids, greenhouse windows and even skylights. Works during the day and maintain a constant interior climate, something not possible to accomplish 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 closed at 55°F.
Strongly recommended for almost all our glazed season extenders since it dramatically enhances plant growth.
The hydraulic cylinder includes a 1 year warranty. The common duration of the cylinder can be 5-10 years, although some can last up to twenty years.
Screw directly into polycarbonate panels, wood, 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 more powerful Gigavent with all metallic structure, to lift up to 65 lbs.
Note from the manufacturer: Recommended to lubricate the piston rod annual, this can help extend the duration of the hydraulic cylinder. Don’t use solid grease, as dirt particles “glues” quickly onto the piston rod and can damage the rubber. Also do not forget to unlock the vent in the wintertime if leaving the vent openers set up. A good weak winter sun can high 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 is the only solar-run control with a quick-release mounting Automatic Greenhouse Vent bracket. Simply grasp the “clutch” arm and squeeze for easy detachment. This enables vent to be fully opened for usage of the interior.