spinning roof vents???

Hey folks,
don't know what they are called, but the ones that are kinda like a louvered ball on top of a 6 inch or so pipe....

?? is, do they have to extend above roof level to work? I think I have the basement I've been asking about over the last couple years useable by just leaving the door open. Got the humidity down to between 60 & 70% but am gonna have to close the door soon to keep the temp above freezing. Have two shafts that were used to dump beets etc in from in and behind the barn. Was wondering if one of them vents would catch enough air to work just by running a pipe out about 6 ft..... that would let me close the door but still draw air thru (if I put a vent grill on the door)?
Or, would one of the bathroom vent fans that slip into a 6" pipe on a timer be the best option and could I get by with just venting it out the window a couple feet?
Thanks for any tips...

Dave

I put some on our roof and I believe they said to mount them next
to the peak of the roof. They are driven by hot air rising, I'm told,
so I don't know if they would spin with cold damp air.
Zach

"Rotary Ventilators" "Wind turbines", ect....Many names.

They're driven by wind. Even the slightest breeze will spin 'em. They don't have to be higher than the highest point of the roof, but they'll work better if they are.

You have to allow enough make up air to enter through soffit vents, or they can create negative pressure in a house, drawing air (and smell) back in through plumbing openings. They'll do the same work as a motorized exhaust fan.
Join the fan club

The turbine vents that I have used worked OK, but they need to be up where the wind can catch them, and then when it really blows they can get noisy if they are not real good quality.
Also if you blow the damp air out is cold air going to replace it?

They are called roof turbines. The ones I have on my roof are more like 12". When the wind blows they spin and help draw the hot air out of the attic. I have two on my house and you can feel the breeze when you are entering the attic. We got one freezing rain down here in Texas last winter and they froze up though...

Dave, some one else mentioned about loosing heat,
and I agree.

You might as well leave your door open if your
going to power vent the room.

Maybe just a pipe up like a chimney will vent
enough without loosing to much heat?

Here in Iowa the air is generally dryer in the
winter. So we just button everything up tight and
don't have moisture issues during winter months.My
well pit gets vented in the summer and closed up
for the winter.

Gary

maybe I won't need anything.......More of a "just in case" thing.....

I'll monitor the temp/humidity and see.....

Thanks, Dave

You have to replace the air vented with something. I do not know
if a dehumidifier would ice up in there.

Have you ever thot about just buying a Dehumidifier??????

I keep wanting to use a bicycal tire-wheel generator inside one of these turbines to charge fencer batterys. Would need small rectifier. Never get around to it building one.

(reply to post at 05:40:39 11/28/11)

Click to expand...

I put one of those on the roof of an addition that I built on my first house. It was near the peak. and it seemed like it was always turning in the slightest of breezes. I was depending on warm air wanting to rise, however, and I don't know if you would have that convection force going for you in a basement situation. If you had a place for cooler air to come in at ground level and it were significantly warmer at the ceiling of the basement, by say twenty degrees it may suck air out. If you had a vertical stack, say 8 ft tall that the sun were to hit and heat each day then I bet you would get some good suction. Speaking of suction, In the north where I live when it gets cold all the moisture gets sucked out of the air anyway, so I would say don't even think about venting in the winter.

They must make different brands, or quality of brands. If you are talking house and not barn, I've had two homes that I purchased that had them when I pirchased them, and as they were spinning, you could actually see through them, so apparently lower quality. Both houses ended up with extensive water damage caused by rain water either just getting into them, or being sucked into them. In the first home, the drywall ceiling just ended up cracking and collapsing not long after I purchased the home. In the second home, it ended up sagging from the weight after getting wet each time it got wet. In both cases, I ended up having to replace the drywall ceilings. From my experience, for what those type of vents are worth and cost in the long run, it just isn't possible to throw them that far. Both of my roofs ended up being tearoffs when redone, not because of the vents, but because code does not allow more than a second layer of shingles by me, and instead of going a second layer of shingles, I preferred to remove the existing bad layer, and replace any plywood that needed replacing, including the pieces with the holes cut in for the vents. I went with Cobra vents that ran the length of the peak, with increased ventilation in the soffets, and plenty of batting down in the ceiling. I do not have increased heat loss as noted because when the snow comes down, it isn't melting off the roof, or generating ice dams along the edges. Cobra roof vent goes down after the shingles the length of the peak that has been cut back at least 1" on either side, not more than 2", and then you cut extra shingles down into like 8"x8" squares, layed over the top of the Cobra's length, and nailed down with smart roof nails that go into the roof, but stay out about 1" because of the nylon sheath around them. Cobras vent and keep bugs and stuff out.

On my barns and tool sheds, I've done similarly with peak vents the entire lengths on steel roofs. To keep bugs, bees, and birds out, before I put the steel roofs on, I cut the lengths of the peak, layed down a layer of screen, then a layer of 1/2" square chicken wire, then another layer of steel screen. Keeps stuff our and stuff from digging or breaking through. Then I put down the steel roofs, then the steel peak vents. Have never had a problem.

Want my advice about those vented turban vents? If anyone gives you one, be nice and thank them, but after they leave, toss it/them into the trash, and if they ask where they are, why aren't they on your roof when they come over, tell them that burglars broke in and stole them before you had a chance to put them up, along with the cat.

Mark
Cobra Roof Vent

Long time ago lived near someone with an older one.
Squeaked and squealed constantly.
Always swore I was gonna load wads of grease in shotgun shells and shoot it a few times, but moved before I got around to it. :lol:

Here tiz.