Automatic Vent Opener - Standard

Use on Coldframes or Greenhouses

Item Number: SEF110


In Stock! Ships from Northern CA.


In Stock! Ships from Northern CA.

Buy Big, Save Big! As low as $31.49 each!
  • Buy 10 for $31.49 each


Ingenious temperature-sensitive device that automatically opens and closes coldframe lids, greenhouse windows and even skylights. Works throughout 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 improves plant growth.
  • The hydraulic cylinder comes with a 1 year warranty. The average lifetime of the cylinder is 5-10 years, although some can last up to 20 years.

Replacement cylinders are available.

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 stronger Gigavent with all metal construction, to lift up to 65 lbs.

Note from the manufacturer: Recommended to lubricate the piston rod yearly, this will help extend the lifetime of the hydraulic cylinder. Don't use solid grease, as dust particles "glues" easily onto the piston rod and can damage the rubber. Also do not forget to unlock the vent in the winter if leaving the vent openers installed. Even a weak winter sun can heat the hydraulic cylinder sufficiently to make it start pushing the piston rod outwards.


  • Replacement Parts Available

Useful Information

Use Instructions

Videos & Articles


What You May Need

Shipping Information

Shipping Weight: 2.00 lbs. Dimensions: 15"L x 3.75"W x 2"H


From an 10+ year veteran

I was looking for this product to recommend to other gardeners in a forum, wondering if it was still made. I have had the Redwood cold frame (also sold here) with one of these vent openers attached to the cover that I got over 10 years ago from a local company. It's been outdoors all year in all kinds of weather and still works reliably. The cold frame is still in good shape, too. Thought those of you contemplating purchasing one would like to know.

Reviewed by on

Amazing Product

We build greenhouses in Colorado and use the vent openers on a regular basis. They are easy to install and work like a charm. They respond quickly to temperature changes, something we see frequently here in the Rocky Mountains, and they never fail to work. It is recommended that the wax pistons be removed for the sub freezing temperatures of winter, but even when clients leave them in their greenhouses over winter they rarely have issues. Great product by a great company.

Reviewed by on

Works great!

Reviewed by on

the opener worked perfectly for our community garden greenhouse

This is the second opener we have purchased. We did the first one last year for our community garden greenhouse. It worked perfectly. We purchased the second one this year for the other vent due to funding. Love how it works.

Reviewed by on

Vent Opener

Built my own greenhouse, and the vent opener had to be placed on a small window on top. Some of the wood frame had to be cut out for the arm to have space to work. It's working well.

Reviewed by on

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