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Attic vent or not? Post New Topic | Post Reply

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josephny
Posted: Oct 06, 2017 10:28 AM
Attic vent or not?

I have a small home (upstate NY) and just had open cell sprayed in the attic -- underside of roof, between rafters.

Did a very nice job.

But, we had a gable powered exhaust fan that, during the summer, sucked out so much hot air and kept the house comfortable without AC.

The foam contractor says that it is important to keep the entire attic sealed.

I am concerned about moisture and hot air accumulating in the attic during the warm months.

Should I have an exhaust vent reinstalled?

Thank you!
jimcoler

I have over 10 years of experience specifying and installing open and closed cell spray foam. I've sold my business but I'm still selling for the new owners and consulting on large and custom specific jobs. 

I've expanded my knowledge into t

Posted: Oct 06, 2017 02:01 PM
I too am from upstate NY and I recognize the issue you're struggling with. Should you vent your attic or not? The heat will build up in the attic but it's only about 10 degrees cooler than the inside temperate based on past experience and my own home.

My answer to your question is two fold:
1- you can leave it unvented as the thermal boundary is now the underside of the roof and the attic only gets 10 degrees cooler than the inside of the home. There is also no issue with moisture if you manage the moisture coming into your home. This can be done through basement walls and crawls space mediation with good vapor barriers. If you want you can go one step further, you can install a heat pump water heater which will hep mitigate the moisture in the attic, reduce the temperature and save you on your utility bill.

2- You have the option to vent it and then close it off in the winter time with foam board.

Email me if you have additional questions - jimcoler@yahoo.com

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