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Old 11-04-11, 11:48 AM   #145
MN Renovator
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Originally Posted by MetroMPG View Post
I wonder if some kind of seasonally adjusted venting would be the way to optimize this setup.
In common construction, there needs to be enough venting to prevent ice dams when the roof has a snow load. When there is a snow load that doesn't let the sun hit the roof, there is no light hitting the black surface to heat up the attic. It gets more dangerous when half the snow has melting so you've got a roof exposed to light(and heat) but there is a chunk of snow towards the bottom of the roof where it is cool but will melt enough on the bottom bottom side from attic heat to become an ice chunk. Of course if there are attic air bypasses that heat in many attics may very well not be the 'free heat' from the sun but rather heat that decided to make its way into the house. least that is how I understand it all.

It seems the alternate idea is to create a house to where the attic is all living space and the space between the roof and living attic is fitted with a properly installed radiant barrier and super insulated. ...then you really don't have any attic heat to harvest.

In the summer, extra venting would be beneficial to keeping the attic cool. I asked my energy auditor about adding extra venting to keep the house cool in the winter, he looked at the vents and told me that there were enough vents and vent area but the fact that they were painted over reduced their effective opening to the attic. He suggested that I replace the ones I have or clean them up.
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