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Cold Basement....


dwolf's Avatar
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01-27-14, 08:40 AM   #1  
Cold Basement....

Last year we had the house insulated. Attic, Walls, door jams and in the basement they sealed around the ceiling line of the walls with foam. Sealed all leaks to the upper floor. It's a cinder block foundation. Hot water heat with the boiler in the middle. It seems like the basement is colder than it was before ?? We don't use the basement all that much but is this effecting the rest of the house ?

 
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01-27-14, 09:42 AM   #2  
Generally, when you air seal and insulate a home the basement will get warmer. I would inspect around the top of the foundation to see if they missed some leaks. When a house is air sealed it can shift the internal pressures and possibly increase the cold air leaking into the basement.

Your boiler is also drawing combustion air from the house which now has fewer pathways. Is the boiler a sealed combustion or typical naturally drafted one?

Bud

 
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01-27-14, 09:57 AM   #3  
It's a 9 year old Buderus.. Oil. The basement does have the typical windows that are just single pane.. Something I cannot replace. I will check the top of the foundation but it looks like they did a nice job with stuffing fiberglass and using foam.


Last edited by dwolf; 01-27-14 at 10:21 AM.
 
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01-27-14, 10:29 AM   #4  
Stuffing fiberglass would be questionable if any of it is left exposed. On a cold day just run a wet wash cloth over your hand and then feel around above the foundation. Your hand can do almost as well as my $8,000 IR camera. Foam can be hit or miss when they go fast. It may be in place but not well sealed.

It doesn't sound like your boiler is sealed combustion. That means it may be drawing cold air from outside. You may need to consider a sealed adapter if there is one for that unit or a combustion air source. What type of chimney do you have?

Bud

 
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01-27-14, 10:43 AM   #5  
old brick one... that's all I know about it.
House was built in 1952

 
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01-27-14, 11:55 AM   #6  
It is not sealed combustion, so it uses air from the house. When they air seal they shut off much of that supply of air and can starve the boiler for combustion air. A combustion appliance zone (CAZ) test can be conducted to be certain there is sufficient air when all competing appliance are running. A bath fan or kitchen fan will further reduce the available necessary air.

I'm not saying you have a problem, but it is something all contractors should be aware of and test along with any air sealing and insulation work.

In any case, it is pulling air from the basement which will be replaced by air from outside (cold air).

Besides the CAZ issues, the only thing it changes is to give you cooler floors. If that is not noticeable, then it is just a case of looking to see what they might have missed and seal it to further improve the upgrade.

Bud

 
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01-28-14, 05:00 PM   #7  
cold basemant

This could be the result of this winter's extreme weather or it could be the result of you having the rest of the house insulated and the furnace not having to run as often thus not generating the waste heat that previously warmed the basement.

You may have to look to insulate the foundation walls with Thermax or design some alternate insulation system that includes adequate fire rated finish construction.

 
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