Retail: $31.95
Price: $24.95
Availability: In Stock - Usually ships in 1 to 2 days.



 Price Each 


The Ventomax opener allows solar powered control of top mounted window vents for a very affordable. Ventomax window openers have an adjustable opening temperature of 60° F to 75° F and an 18" maximum opening which would be reached at approximately 20° to 30°F above opening temperature. Ventomax openers are made from corrosion resistant electro galvanized steel painted black. Recommended for roof vents only. Order more than one and save!

Ventomax Features

  • Adjustable opening temperature of 60° F to 75° F
  • Maximum opening of 18"
  • Recommended for vents up to 15 lbs.
  • For use with roof vents only
  • Made in Denmark

How does a Greenhouse Autovent work?
A strong metal tube contains a mineral wax which expands with heat. This pushes a piston which opens the auto vent via a balanced linkage. As the temperature drops, the wax shrinks and a strong spring closes the vent and resets the piston.

Product Manuals, Tips, Specs, & Guides
Ventomax Opener Instruction Manual
Ventomax Opener Installation Video

Overall Customer Rating of 3 Reviews:
Port Orchard,WA

Temperature Automatic Operation

Received on time, operation is as installation manual described!


VentoMax Vent openers

The VentoMax vent openers are an excellent addition to any greenhouse. When building your greenhouse install these automatic openers from the beginning. Don't put it off for the future. I installed them on the (very popular) Harbor Freight 10' x 12' greenhouse.

Gas vent actuator

Works great. easy to install