I recently purchased seven of the Univent Automatic Window Openers to use on our 14' x 20' greenhouse. In this video, I describe what is included with the opener and show how they are installed. The rod (piston) that threads into the hinge can be adjusted to open the window anywhere from 60F to 77F (17C to 25C). It fully opens the window at 86F (30C).

The Univent Automatic Window Opener can be found on Amazon:
https://amzn.to/2FYSxxl