I've got a mostly hip-type roof, without a long continuous ridge-line. Based on what I've read, you are correct that having a powered ventilator is a good idea. And my roof does have one.
But if there aren't enough soffit vents, the fan won't ventilate as good as it should. Based on some calculations I did, the original vents in the wood soffit might have been sufficient. But the vented aluminum soffit pieces which were put over the old vents have much smaller holes, so I'm thinking that the venting has been much reduced from what it was originally. When I'm getting quotes, I'll see what the roofers say about the vents.
Also, based on what I read, you aren't supposed to combine ridge vents with a powered ventilators, as that may pull in air from the ridge vents instead of in through the soffit vents. It looks like I have 2 small sections of ridge vents in addition to the fan. So that might be a problem too.
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chiming
Re: roof mounted power attic ventilator
Date: 2011-06-23 07:04 pm (UTC)From:But if there aren't enough soffit vents, the fan won't ventilate as good as it should. Based on some calculations I did, the original vents in the wood soffit might have been sufficient. But the vented aluminum soffit pieces which were put over the old vents have much smaller holes, so I'm thinking that the venting has been much reduced from what it was originally. When I'm getting quotes, I'll see what the roofers say about the vents.
Also, based on what I read, you aren't supposed to combine ridge vents with a powered ventilators, as that may pull in air from the ridge vents instead of in through the soffit vents. It looks like I have 2 small sections of ridge vents in addition to the fan. So that might be a problem too.