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attic gets cold on windy days

Posted by stick4 (My Page) on
Mon, Mar 25, 13 at 19:10

Our home (2200 sf) with an 8 in 12 roof pitch has the required soffit vents and two roof vents of about 12" in dia. These are just basic vents with no moving parts on the North side near the peak of the roof. One close to each end.
We live on a hill so it gets windy here. On cold days when the wind is from the North our heater runs much more than when the wind isn't blowing even with R50 insulation in the attic. I understand the need for attic ventilation but it would seem prudent to have a type of vents that can be closed off for just the windy days. Does anyone know if they make a remote operated shutter type vent that would save us on our heating bills?


Follow-Up Postings:

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RE: attic gets cold on windy days

It is a bad idea to reduce the ventilation of the attic in the winter. You want to attic to be cold in order to prevent ice damming. Ventilation is also needed to allow moisture to escape.

A better option is to seal the attic. All the penetrations between the ceiling and attic are sources for air leakage.

Are the windows tight? Are they other penetrations through exterior walls which could cause air leakage?


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RE: attic gets cold on windy days

I was interested in a device that could close the two large roof vents just for the few days the wind blows 25-40 mph from the North. No issues with ice dams in Oklahoma.
It's a new home with Low E windows. No compromised exterior walls. The attic ladders are in the garages. Thanks for the reply.


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RE: attic gets cold on windy days

A 25-40 mph wind will find its way into most houses. Even a house carefully built to be rather tight will still be leaky when the wind is strong, though hopefully less so than others.

You suggest it's just for a few days each year. If so then I'd think this really isn't much of a problem.


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RE: attic gets cold on windy days

We're able to monitor our electricity usage on the internet here and the days when the wind blows from the North doubles our bill for that day. $11+ vs $5 or $6. We'll have a good 20 of those days a year so $300-$400 spent on closeable vents would have a short payback.


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RE: attic gets cold on windy days

You say you don't have ice damming problems in Oklahoma. Does this mean it never snows where you live?

Can you explain how closing the vents will save energy? You attic has R50 insulation which is very good and much higher than your exterior walls (R19?) and your windows (R3?). The heat loss is much greater through the walls and windows. I don't see how closing the vents is going to have much of an impact on your energy bill.

I have never heard anyone propose what you would like to do. I am curious to hear other people's opinions.


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RE: attic gets cold on windy days

Yes it snows. It's gone in a few days when it does too. That's immaterial anyway b/c I'm only wanting to close the two vents for a short time. You'd think builders would also see the benefit in this as far as energy use goes.
I know the attic gets much colder when the wind blows out of the north than when it's just cold with no wind. I've went up there. Also the heater runs much more on cold windy days than it does on cold days. As I said, I can view my energy use online and cold windy days vs cold no wind days require about two times the amount of electricity use. (we're all electric here)


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RE: attic gets cold on windy days

Think hypothetically of how it would be if you had a refrigeration unit in the attic, and the temps were 10 degrees colder than outside. You're convinced your ceilings are sealed and you have R50 insulation. Don't you realize you'd still be losing far more heat through walls, windows, and openings on a windy day than through the ceiling into the attic? When you step outside when the wind's howling, you feel a wind chill that makes it feel colder. The same is happening to your walls and windows and that's pulling heat out of the house, without even considering the air gaps which you most likely have.

I think you're chasing a ghost, you're convinced that something is a certain way and that's that.

We're (mostly) just homeowners sharing our own experiences. If you'd like to see what the experts say, start a thread in the AOP (Ask Our Professionals) Residential part of Hvac-talk.com


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RE: attic gets cold on windy days

Wind won't make the bricks on a homes exterior any colder that calm air will.
Not sure why everyone doesn't understand that if you have a layer of air that's 55 degrees between your insulation and your roof that that would be preferable to that air being 25 degrees.


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RE: attic gets cold on windy days

vented attics reflect ambient temps.
if you want a semi conditoned attic..then
go foam unvented route.

if it is 25 degrees outside, then it wil be
25 degrees in a vented attic.

improve the air barrier at
the ceiling/attic floor.

the insulation on the attic floor is to keep attic temps
seperate from indoor temps. how much insulation
and what type do you currently have??

insulation over holes in ceiling/attic floor
does little as air is moving through the insulation.

improving the air tightness of the house, at
ceiling & walls is the better use of time effort
& monies.

best of luck.


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