Most backyard hobby greenhouse kits come with built in roof vents for ventilation / cooling of the greenhouse. These work pretty well for most areas if sized properly by the manufacturer. Roof vent windows allow hot air inside the greenhouse to escape out while cooler fresh air from outside the greenhouse flows in to replace it. These greenhouses typically only come with manual openers for the vents, but they are easy to upgrade with automatic vent openers. These openers are cheap to add and simple to install in most instances. Automating your greenhouse kit's cooling system is one of the most recommended upgrades and adding automatic vent openers is cheap, and they are simple to install in most instances as well. ACF Greenhouses offers several different automatic vent openers starting at only $24.95.
Watch a Video of an Automatic Vent Opener in Action
How does an Automatic Greenhouse Vent Opener Work?
These are often referred to as solar power vent openers because they do require any electricity to work. Instead a force called hydraulic pressure creates the opening and closing of the openers. A strong metal tube contains a mineral wax which expands with heat. This pushes the piston inside it outwards which opens the auto vent. As the temperature drops, the wax shrinks and a strong spring closes the vent and resets the piston. Most automatic openers have adjustable opening and closing temperature ranges which allows you to fine tune them to your greenhouse kit.
How do I Know Which Vent Opener to get for my Greenhouse Kit?
Some automatic openers work better than others for different applications. For instance, Univent openers have unique a quick disconnect feature which makes them ideal for cold frames and most any vent that you want to be able to quickly open and/or close the vent manually without having to remove the opener. If you live in a really windy area or want to automate a vertical hinged vent (also referred to as a side or end wall vent), Bayliss triple spring openers are recommended because of their superior wind resistance and closing strength. Lastly, there is the Gigavent for large heavy vent windows. They can lift up to 65 lbs. and have a unique built-in damper to keep an extreme wind gust from blowing an attached vent window open.
How do I Know I am Getting a Quality Automatic Vent Opener?
Hydraulic automatic vent openers were invented in Europe, home to the two most respected manufacturers in the world, Bayliss Autovents & J. Orbesen Teknik ApS. They are both well known for producing the best quality vent openers which are made to last, which is why ACF Greenhouses only offers their products. We have tested many copies from China and other regions which look very similar, but the quality is just not the same. They typically are made with thinner and cheaper materials and the power cylinders tend to fail in the first few months of operation instead of lasting for several years like their European counterparts.