# Question regarding airtight (closed cell foam) insulation



## ralleia (Feb 26, 2018)

We've been burning wood in our Vermont Castings Dutchwest 2460 wood stove for over a decade. The house was a drafty 1930 farmhouse, and we got half of it insulated with closed-cell insulating foam a few years ago, and are planning to finish the insulating and remodeling this year.

Closed-cell foam insulation is very airtight however, so what considerations will we need to take into account to make sure that there is ample combustion air for firing the wood stove? The wood stove is located centrally on the main floor of the house, which is two stories plus a basement.

We also have a natural gas central furnace which we run if we aren't burning wood and a natural gas water heater, both located in the basement. Each has their own dedicated air intakes and exhausts.

We plan to insulate the basement as well.


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## rowerwet (Feb 26, 2018)

If you are concerned,  look into installing an outside air to air heat exchanger


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## semipro (Feb 27, 2018)

You can install a dedicated outside air supply to your stove.  It sounds like you could route it through a wall in your basement and along the basement ceiling to a point where it can go through the 1st floor and connect with your stove.  It is constructed much like a clothes dryer vent.  You'd probably want a direct connection to your stove which is commonly called an outside air kit or "OAK". 
There are many posts on installing OAKs and outside air connections in the Hearth Room.


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## woodgeek (Feb 28, 2018)

Its unlikely to be a problem in a retrofit to old construction.   Unless you have one of those MASSIVE exhaust fans over your stove that can depressurize your whole house (think 500 cfm).

In other words, in terms of air leakage you went from, like, having 6 windows open all the time to only having 2.


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## ihookem (Apr 7, 2018)

We have a new 9 yr old house so airtight I have to open windows to get the moisture out in t early winter. We use our gas fireplace with now issues. With an old farmhouse you wont have a problem, the only difference you will notice if it was insulated well is you will burn a lot less wood.


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