The Automatic Vent Opener was made to automatically control the temperature and humidity amounts and offer additional ventilation when needed, making gardening easier. As the air flow in the greenhouse warms, the vent steadily opens to enable the correct amount of air flow into the greenhouse and closes when the temperature cools. The vent arm was made with a steel cylinder containing wax which expands when heated to drive a piston, which raises the window, as the atmosphere gets warmer, then contracts as it cools, closing with the use of a spring and resetting the piston. All you need to do is certainly to install it on your roof vent home window and it instantly starts operating. The Automatic Vent Opener functions without the use of electricity and is compatible with all Palram greenhouse models only. The solar driven 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 can provide care-free ventilation.
Ingenious temperature-delicate device that automatically opens and closes coldframe lids, greenhouse windows and also skylights. Works throughout the day and maintain a constant interior climate, something unattainable to accomplish by manual adjustments.
Requires simply 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 Automatic Greenhouse Vent recommended for all our glazed season extenders since it dramatically improves plant growth.
The hydraulic cylinder comes with a 1 year warranty. The average lifetime of the cylinder can be 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 up a hinged screen or vent weighing just as much as 32 lb. For larger panes use the more powerful Gigavent with all metallic construction, 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 dust particles “glues” very easily 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. Even a weak winter sun can high 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 strength. The solar vent opener is 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 fully opened for access to the interior.