Bayliss XL Autovent - Automatic Greenhouse Window Opener - Temperature Sensitive Solar Vent Opener

I built a custom greenhouse with a wood frame, and needed a way to automatically open a window for ventilation. I bought the $20 one from Harbor Freight, but it didn't appear to ever work, so I returned it. Decided to pay up for this one. So far, it works perfectly and reliably for about a week now. Installation was easy. I made an adjustment this morning so the closure is now flush. I love having a greenhouse that doesn't need constant monitoring. It's a bit expensive, but all the good ones are. So, until Wal-Mart starts selling these, I will have to live with the price. But, it was worth it to me, to have automatic ventilation. I also like that the hardware never extends more than an inch or two into the greenhouse, which will allow me to build a screen frame that will keep rodents out.

I build a cold frame using some 2x's and an old window, but needed something to handle venting it as I work full time. This thing has been fantastic, allowing me to easily and without any effort acclimatize my plants as I transition them outside. Once I get the real tender plants out I'll be removing the window and the venter to grow lettuce until things get chilly enough again to need it. Highly recommend, great quality!

A great asset to your greenhouse!

Most of the openers that I saw on amazon had the opening cylinder protruding from the back of the opener, which I felt might get in the way. This opener cost twice what others cost, but the cylinder did not protrude from the end. I live in a fairly mild climate which usually drops to the 30's or 40's at night, and rises to the 50's or 60's during the day in winter. Under these conditions, the opener opens during sunny days, and closes at night which is what I wanted it to do. I cant rate its durability yet, since I have had it for about one month.

these work great and very easy to install, also very quick delivery

These are my second order of bayliss vents They can be left up year round and just unscrew the threaded screw to not open when unpredictable Texas cold front arrives

This is the first time I have ever given an Amazon purchase one star. And it’s too bad, really. It’s a nice unit, and installed quite well into my greenhouse. That was in April. But about three weeks ago (late June), the contents of the piston leaked out and the unit stopped opening. I would have been ok up to that point, as I bought it, so I was willing to fix it. However, the one star rating is because of two things: 1) even though the Amazon page states “2 year manufacturer warranty”, the company that shipped it said they didn’t manufacture it and it wasn’t their problem. And buying a piston and having it shipped from the UK would have been far more than the original cost, even if I could have. 2) Replacement pistons are NOT available on Amazon or anywhere else! I would have bought one (prob 2 or 3) if I could have. All the replacements you can find do not have the same thread profile as these, so they won’t work. So, I am forced to take apart the vent I built and find another style of autovent that will fit... and that bothers me. My recommendation is that others learn from me, and don’t purchase this vent, or the “Palram” vent that looks like this. Buy one based partially on the piston type, so you can replace the piston if (when) it fails.

I have had this installed for 3 yrs. Each year its performance weakens. It is not like it's lifting open a heavy window. I am sorry I didn't get the Baylis Mk7, heavier duty openers I have on the other greenhouse windows. They have worked for years without issue. This one however, is a flimsy toy and a waste of money.

Excellent. Il faut BIEN suivre les instructions. L'ouverture est facile à mettre en place et fonctionne à merveille.

Opens vent fully at warm temperatures in the sun

Bought to replace a broken window system in an old metal greenhouse. It's been commented as 'easy to install' whilst this is true, it is not difficult, it IS fiddly. The instructions are very clear and very good, it can be fitted on a lip present in metal framed greenhouses or screwed into a wooden greenhouse frame. We have metal so I can only really comment on this. So, it uses a metal lip on the hinged window and a metal lip on the frame below this window. It basically makes a 'vice' between the metal lip and a metal plate you 'screw' onto the contraption. You are tasked with creating this vice on one side of the item and tightening it into place and then flexing it to get the vice on the other side. It basically needs you to put pressure on the spring and to hold and tighten the vice at the same time. It would absolutely be easier with four hands, so if you think you might struggle, borrow a friend for a few minutes. But the time needed to fit it, is very much so, about 4 to 5 minutes (not including half an hour in the fridge so get the gas chamber easy to fit- you don't want it expanding in the heat as you work on it - covered in the instructions). Easy to install, but a bit fiddly if you're by yourself. It arrived quickly, installed quickly and we noted the next day in the variable warmth of early May, it was working, both to open and close carefully. Very happy with the product, opens a lot wider than the one we had before (it was about 10 years old) and the tomatoes seem to like it. Be careful when you tighten the hinge to close it using the end screwing system at the final stage of the process, the metal was a bit sharp and again, quite fiddly to get fingers in, use a tool or wear gloves or it may scratch your knuckles/fingers as you turn it.

Sehr stabil und zuverlässig. Es ist in einem kleinen Gewächshaus ein großer Vorteil, dass der Zylinder nicht hervorsteht, wie bei günstigeren Hebern. Hebt problemlos mein schweres Dachfenster aus druckimprägniertem Holz im Selbstbaugewächshaus (siehe Foto). Ich werde noch eines bestellen, um die Lüftungsfläche zu vergrößern. Update nach 4 Jahren: Funktioniert noch immer perfekt. Der Zylinder wird im Winter bei mir nicht ausgebaut.

Great product, easy installation, recommended!