I would appreciate your thoughts on which brands are good/bad/indifferent as I am going to invest in four autovents at least and probably an auto louvre as well.
I have Bayliss autovents on my greenhouse, got them as a special offer at GWL one year. I have also got an autovent for the louvres, but have never gotten around to fitting it....think I got that off eBay, might be worth a look.
I did have trouble with one of mine popping off in hot weather when it's fully open, OH superglued it underneath the clamps in the end..... :-\
We have had 8 Bayliss for 30 years & they have been faultless.
I've got two Bayliss (a triple spring for the windy side).
After causing much frustration and mayhem in the KP household while fitting them, I have to say they work ! Only put them on this year so haven't really got enough experience of them to share. Internal temp still seem to soar but obviously not as high as it would otherwise have been.