Twirly Roof Vent


11 Years
May 21, 2008
Woodlawn, VA
Will one of those roof vent (bubble shaped twirly things) work for a chicken coop or does it vent too much? I notice a lot around my area on houses, barns, etc.. A friend has an extra one (not a HUGE one) laying around his barn and said he will give it to me if it will work. My main coop is 12x16 and faces south (about 8' high on front and a little over 6 on the back). I have some screened adjustable heater vents installed in the higher walls but have been wondering about the roof vents. If nothing else would it be better to use one of the roof vents in the summer and then close it off somehow for the winter (maybe screw-on plywood cover on the inside?) and revert to the smaller vents at the top of the walls? There are adjustable windows all around (or at least soon will be all finished) but I don't want to lose all their heat in the winter.

Not sure I understand the reason for those things. They only work if the wind is blowing an work progressively better as the wind speeds up. But when the wend is not blowing is the only time my coop and my attic needs more ventilation.
I dont have anything productive to say, but your description is great!! (bubble shaped twirly thing!!)
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Ha, "twirly roof vent", I like that description

IMHO they are somewhat pointless for a backyard coop, because they are no better than (actually, generally *worse than) intelligently designed passive ventilation ie. hardwarecloth-covered openings in the walls. They only do their twirly air-pulling thing when there is a breeze, and of course if there is a breeze then it is going to go in and out any actual openings in your coop walls, which can involve a much huger area and thus much huger air volume than a twirly roof turbine ever can.

They have some use in large spaces (like large barns, etc) that cannot have proportionately enough wall openings for their air volume. But they are of no particular value for a backyard coop.

Just build in lots of ventilation openings, ample size and closeable, including both summer-appropriate openings and winter-appropriate openings (will be different in some climates), and you will be FINE

Good luck, have fun,

These twirly things don't rely on wind at all, they spin by convection. As the heat rises out of your attic (or coop) they spin creating an updraft pulling more hot air out. If they are spun by the wind, they don't work as well.
I have 2 of the (twirly) roof vents in my 10x14 coop. I work for a company that sells roofing supplys and have the inside scoop.
They work on both wind and convection.
I have noticed that a lot of times there is no wind, but the sun is hitting the coop and they are spinning like crazy.
Also, I have sliding pannels so I can close the vents in cold weather..If I close the pannels in warm weather the coop begins to smell.
Just the fact that they spin when the sun hits the coop lets you know that they are doing there job.
As for the winter.. I would say they serve no purpose, but I can't imagine not having them spring, summer, and fall.
I can't take me anywhere, I'm aways saying bubble shaped twirly thing. You also have to put a hole in your roof for one of these vents snow will blow in.
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Sorry but if this were true they would be getting more energy *out* than was put *in*, and would thus be even better than a perpetual motion machine, it would be the ultimate free lunch, energy created out of nowhere

If you want an updraft created only by the natural rising of hot air, the most effective thing is a straight chimney, extended up from the hottest part of the building and ideally being *itself* somewhat heated by the sun. Which design actually IS used in architecture and farm buildings.

Having the hot air "push" a turbine on its way out slows it down. On a totally windless day, the twirly vent would exhaust (slightly) more air if you removed the turbine part than with the turbine part in place. (Yes, the rising hot air DOES turn the turbine, but at a cost.)


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