Put this in a small greenhouse with light weight roof panels. Works wonderfully.

I purchased the heavy duty Bayliss Autovent MK7 with triple springs to replace a light duty Autovent in the roof of my greenhouse. The push rod became bent during a severe wind storm. The triple spring MK7 was a perfect fit 10-minute replacement. I highly recommend the Bayliss Autovent. Except for the one wind-damaged vent, mine have been trouble free for three years.

I like this autovent very much, it's well built and works well. The one limitation is that I've attached it to a cold frame, need to get into the cold frame to water, and sometimes have to open the top far enough that the piston comes out of the end. A quick release of some sort would be helpful.

Installed on a Sunshine Gardenhouse. Needed to move the roof vent strut up an inch so this could screw into the flat rather than into the 1/4" width. Measure several times and predrill your holes.

You can remove the 2 outer springs to make installation easier as you check the motion. It feels a bit wobbly as you install, but the action is smooth.

 

Easy to install and I went with the one that had springs because I live in a windy area.

Well, they don’t seem to be working, but we saw after they were installed that you are supposed to put them in the refrigerator prior to installation. Who would have thunk it, and now nobody wants to climb back up there to take them out on the chance that that might be the problem...

I am using automated openers on wood-framed 10 ft x 2 ft side vents on a high tunnel greenhouse with the hinges on the bottom (top opening). The springs on the Univents are not strong enough to consistently close these vents, so I tried the Bayliss and they seem to be working great; much stronger springs. They open at a lower temperature than the Univents, probably about 10 degrees F lower.

Easy install, lots of mounting options, they work as expected except the maximum opening of 12" is a bit misleading. I originally had these cranked to the maximum opening distance, but I was in the greenhouse while it was about 50F outside and the windows were still open. So I backed off the opening setting to be closed at that position, now they are open and closed at the expected and desired temperatures, but only open about 4".

Would I prefer they still open a bit more? Yes.

If I could do it again would I still buy them? Also yes. Its only been about a month but so far they are a wonderful addition to the greenhouse (I was manually opening and closing the windows based on a remote temperature sensor with notifications to my phone)

ACF Greenhouses: I don't think you completely understand how they work. The opener is stopping a 4" because the greenhouse is not getting hot enough to cause the opener to expand further. This is common when the air outside is cooler. In warmer months, the opener will open the vent further because more cooling is needed to maintain the temperature setpoint.

The item was easy to install with the directions. Waited for a warm day at saw that it worked great. Was a little concern because of the weight of the vent because it is glass. But it had no problem what so ever to work. Just make sure to follow the instructions before use.

We are using the Bayliss MK7 to open a top hinged wood-framed window in the roof gable of our greenhouse. Initially I was concerned if it would be too heavy for the opener, but have had no issues. Installation was easy and it works great!