Cold Air From Fireplace

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Hi-

I am a first time fireplace owner, so I apologize if my question is fairly basic and obvious, but I have searched the internet for answers and cannot find anything that addresses exactly my problem.

I have a wood burning fireplace that is located inside my living room den. As far as I can tell, the fireplace is surrounded by interior walls only, not exterior walls. It is NOT a traditional brick fireplace, but rather appears to be an metal chimney (probably aluminum) that is boxed in by ordinary sheetrock. The chimney exhausts through the slate roof immediately above the den. There is a flue at the bottom of the chimney that I can open and close, and there is also a decorative glass door on the fireplace that can be opened and closed.

My problem is this: The fireplace is a source of tremendous cold in the den. The entire area around the fireplace is noticably colder than the rest of the room. The marble stones on the floor and around the fireplace are very cold to the touch (I have taken measurements and they are sometimes as cold as 50 degrees!), and some parts of the sheetrock surroundign the chimney also get very cold.

As a result of all this cold air, I have to spend a fortune heating my den. But I am at a loss to understand where this cold air is coming from, because the damper is closed at all times, and so is the glass door on the fireplace. Why is the flue damper not blocking the cold air? when I put my hand to it, there is NO obvious air or breeze coming through the damper, so where is the cold air coming from?

Is it possible that the fireplace is not adequately insulated? Do interior fireplaces even need insulation? As far as I can tell, none of the walls surrounding the fireplace are exterior walls, so where is the cold air coming from?

I know my question is quite vague, but this is a real problem for us, and on cold winter nights we can no longer enjoy sitting in the den, because it is uncomfortably cold/

Any help would be greatly appreciated!

 

[SteveKG]

I also have a fireplace with the portion of the chimney below the roof all inside the house. But I don't have your "cold" problem unless I have to leave the damper open for a while to let the coals/remains of the latest fire completely oxidize.

Take a match, light it then blow it out, or light a small pc. of newspaper, blow it out, to get some smoke and hold it up in various places around the fireplace opening. To see whether the smoke blows back out into the room, of course. If it does, your damper is leaking, or there is a way for air to come in around the damper installation. If it does, you need to seal that off. If the damper is warped from heat, it will need replacing. Or if it has crud stuck to it so that it does not close completely, you need to clean it up. I use a small scraper, though I've only had to do it once in 20 yr. I did have to that one time [I had a person stay in my home while I was gone a month and she left the damper open the entire time and burned some unseasoned wood]. It takes only a tiny opening to let frigid air in.

If it isn't that, or some other leak, my next suspicion is that the cold air in the chimney is simply cooling down the fireplace and its surround. Without being there to look at it [and I am not a professional, just someone who has used my fireplace and stoves for many years], I can't say what to do from that point. The metal chimney boxed in sheetrock sounds absolutely minimum for a chimney system. But it's what you have, so.... How is the top of the chimney finished off up there at the end? Is it open to the atmosphere or completely boxed off? If not, it needs to be.

You might need to see about installing some sort of closeable cap on the chimney to prevent air circulation constantly carrying off the warmer air in the pipe and replacing it with cold air, basically a system which will continually cool your den very effectively.

If you are not familiar with these things, you will be money ahead, in the long run, by hiring a pro' to inspect this set-up and give you some options. It can be fixed. How extensive the "fixes" must be will depend on the quality of the installation and the chimney itself. Then you can go over those options and come up with a plan.

 

[EatenByLimestone]

So, if I'm understanding this correctly, there is a room on the other side of the chimney? Or is the side of the house flat and the chimney does not protrude out into the yard.

There are a few things that may help a bit even without knowing the placement of the chimney:

I don't believe dampers are ever tight. They just aren't precision instruments... they are just a metal plate. There are things you can do to stop air from moving up them though. You can seal the top of the flue like this: http://www.chimneydampersource.com/

and there are blow up things that seal it from below. http://www.amazon.com/dp/B000ILQN0W/?tag=googhydr-20&hvadid=3786900321&ref=pd_sl_2348yi0ark_b

I don't know anything about these companies.

Matt

 

[midwestcoast]

Is it possibe there's an out door air intake connected to the fireplace? It would probably be a grate on the fireplace floor inside the doors.

 

[jeremy29]

Is there an attic above the den? My guess would be (only because I'm dealing with something similar) that the chase is not well insulated from the attic, and the cold air is sinking down around the fireplace.