Should I fully close my damper on an air tight stove?

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Swedishchef

Minister of Fire
Jan 17, 2010
3,275
Inuvik, Northwest Territories
Hi Guys

Question: I load my stove (non-cat EPA, Osburn 2300) and get the fire roaring. Here's my question, am I supposed to really "close it up"? When I do so, all I see is my secondary burn going for a bit..and eventually it almost goes out, so I open the damper about 1/5th. Should you really "close" the damper for a longer burn? Is this efficient? I thought that a poor combustion (due to a lack of oxygen) increases the risk of CO.

Looking for some advice!

Thanks

Andrew
 

snowtime

Minister of Fire
Oct 31, 2007
523
northern BC
First EPA stoves are not fully closed when you shut off the air. They are made to burn efficiently and need air to do that. Before you close it down for the night be sure you have a good bed of coals and the wood has blackened a bit. Its common theres only be a bit of flame when the stove is settled down for the night. That way the fire should go till all the woods gone. If the fire just dies you are closing the air supply to fast try doing it in 2 or 3 steps. If that does not work your wood might be to wet.
This is all for an overnight burn. During the day put the air control at the level of heat that you need.
 

Backwoods Savage

Minister of Fire
Feb 14, 2007
27,811
Michigan
Welcome to the forum Andy.

But, of course, put that air control at the level of heat you need day and night. We prefer a more even temperature in the house here so we keep it warm at night the same as we would during the day.

As for closing the draft full, generally that is not to be recommended and if you do that you probably will get lots of creosote. As snowtime stated, try closing it in stages. For example, on ours we will close from 4 (full open) down to 1. After a short time, depending upon heat, flame and charred wood we will dial down from there. However, we do have a cat stove so we can dial down further than most and let the cat burn the smoke. Usually you do want flame in the firebox; big flame upon reloading and then calm it down once the wood is burning nicely.

Remember that each stove and each installation may be a bit different as to how much draft that stove needs. And please do not forget that the fuel is the ultimate factor in how the fire is and how efficient it burns. Poor fuel = poor stove and heat plus creosote. Good fuel = great stove and wonderful heat.
 

Wood Duck

Minister of Fire
Feb 26, 2009
4,790
Central PA
Swedishchef said:
Hi Guys

Question: I load my stove (non-cat EPA, Osburn 2300) and get the fire roaring. Here's my question, am I supposed to really "close it up"? When I do so, all I see is my secondary burn going for a bit..and eventually it almost goes out, so I open the damper about 1/5th. Should you really "close" the damper for a longer burn? Is this efficient? I thought that a poor combustion (due to a lack of oxygen) increases the risk of CO.

Looking for some advice!

Thanks

Andrew

I have been under the impression that EPA stoves are not air tight (the secondary air is always open), and the term air-tight stove is used to refer to older stoves. Maybe I am wrong about that...

As for the damper being closed and causing CO, I think most people adjust the damper for comfort. Once the secondary burn cycl is over, i understand that most of the volatile gases are burnt off the wood, and you should get little creosote regardless of how you burn (hot or cold). It makes sense that you could be getting more CO with less air, but you still have the secondary air for combustion, and maybe that is enough. In any case the CO is going out the chimney, so your concern is for the environment and for efficient burning, not for your safety.
 

firefighterjake

Minister of Fire
Jul 22, 2008
19,505
Unity/Bangor, Maine
It's already been said, but worth reiterating . . .

The EPA stoves do not allow you to fully close off the air to the stove . . . they are made this way . . . but don't worry . . . it's a good thing as it allows the stoves to burn cleaner and more efficient . . . and you still get long burn times.

The key to closing down the air is that you really want to get the stove to the point where you have a sustained secondary combustion. Where this point is depends on your stove, draft and perhaps most important of all, how seasoned or unseasoned your wood supply is . . . last year I had semi-seasoned wood and I could only close down my air to the quarter mark . . . any less and the secondary flames would die out in 5 minutes . . . this year with better wood I can close off the air "all the way" (of course as mentioned it still allows some air in) and I get some spectacular secondary flames (think Bowels of Hell) which last for a long time.

Once you have the stove up to temp start shutting down the air . . . 3/4 to 1/2 to 1/4 . . . or 1/5 as mentioned . . . as you close off the air, wait 10-15 minutes at each point . . . if the secondaries keep going after this time shut it down a bit more . . . if the secondaries still and the fire looks like it is dying, open the air back up for a bit longer and then try to dial it down again. Eventually, you will reach a point where the air is as closed as you can get it while the secondaries stay lit.

Carbon monoxide should not be an issue regardless of where the air control is . . . providing you have a good draft.
 
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