Bayliss Autovent Opener
This non-electric roof vent opener is simple to install and is completely automated. A threaded adjuster bolt can set the Bayliss to start opening the vent at approximately 55 degrees fahrenheit. This vent opener uses a very simple principal - Special waxes have an expansion rate of about 18% when heated by the sun. As the air in the greenhouse heats up it also heats the powertube in the vent opener. As the wax expands it pushes out a stainless steel piston that slowly opens the vent up to 13 inches. The hotter the temperature the wider the opening. When the temperature cools the weight of the vent and a 6 1/2 pound stainless steel spring closes the vent and holds it closed.
Bayliss Autovent Opener (PDF)
The Bayliss Autovent Opener works. It opens a window when it gets hot.
I just wish it it opened the window wider. Is there a way to reconfigure it for more throw?
They work excellent I have two of them, one on each end of the greenhouse. once you dial them don't have to think about it again.Love it
Bought unit as a replacement for existing Bayliss units. They fit and worked great.
The part did not fit my greenhouse exactly but I did not expect it to. With a slight modification I was able to install it, and it worked perfectly. Much better quality than the part it replaced. Definitely would shop this company again.
Put this on my little Palram Hybrid greenhouse. This product was not specifically designed for this greenhouse so it took some extra hardware and ingenuity to get it attached. Palram does offer an auto vent opener that would attach must easier, but it didn't look like adjusting the opening temperature was possible with that one. On this one, you just tighten or loosen the adjuster knob and it will open when you want, that's a very nice feature. Only had it on a week but working so far.
I liked it so much better than the one that came with my greenhouse that I ordered another one. It works well and is much easier to set for the temperature you want.
Works well, easy to adjust for opening temp. This is replacement for original. I have found I can buy just the operating piston for only $31.
My greenhouse window hangs vertically from a horizontal hinge. Instructions say a different model Bayliss with more springs should be used in this application. Catalog should warn the buyer and offer the alternative model. Ventilator works fine anyway. If more closing force is needed then a better way than springs to provide it is a weight hanging from a horizontal lever projecting outside from the hinge pin. That way, the ventilator can still open fully. Spring F = kX. Avoid increasing k by using 3 springs instead of 1.
My Bayliss Autovent was very easy to install. It works mysteriously GREAT! No complaints! It has been working now for a couple of weeks with no issues. Figuring out when I want it to open has been a little tricky - but logically expected! Thank U GhMS for your excellent prices.