EPA stove low burn question

[dlaurinaitis]

I read a lot on here saying that slow burns are a bad thing.

My lopi answer, I load up at night and pull the air intake handle all of the way out, closing it to its lowest level.

In the morning, I have a decent bed of coals and I have seen it burning in the middle of the night.

The owners manual says this is how to do an overnight burn. However, what I read on this site says that is a bad thing, creating creosote.

Is it? Would a EPA stove, used as directed by the owners manual, have these negative characteristics?

Do I continue? Or do I have to get up in the middle of the night and reload?

I plan on checking my chimney the day after thanksgiving. A visual inspection today, shows a slight tar like substance on the stack.

Is this creosote? Or is it a normal by product of burning wood? I plan to clean it monthly or bimonthly.

Thanks!

 

[freeburn]

With an EPA stove you want to get the temp up and then shut it down so that the secondary flames overhead take over and burn over night. This first part is the most important part. If you keep those flames going in the firebox, and what looks like no smoke coming out of your chimney (even at night), then you are getting a clean burn and doing what an EPA stove is meant to do. Otherwise, you are making a smoke dragon out of an EPA stove and not only losing heat out the stack in th eform of smoke, but you are filling your chimney with creosote. Yes, that is the black tar like substance in your chimney.

 

[thewoodlands]

[quote author="MrFood" date="1290242034"]I read a lot on here saying that slow burns are a bad thing.

How seasoned is your wood that you are burning? We have the Liberty which we rarely close down all the way.


zap

 

[branchburner]

The key is the wood - the dryer it is, the less air you need to keep the burn clean once the fire is well established. How long cut/split/stacked is your wood?

Post some pics of your chim, and what you get out of it after cleaning, once you sweep it.

 

[Renovation]

I read a lot on here saying that slow burns are a bad thing.

I've read the opposite.

Slow burns are a great thing if done right, and terrible if done wrong. The key is heating up and running the stove so it burns correctly and cleanly, even under slow burn, and running it hot for a while each day to burn out any minor creosote that might have accumulated before it becomes a problem.

Check out the wood burning primers in the instructional articles--very helpful!

Good luck!

 

[Dexter]

We had an Answer, and loved it. For overnights, we waited until the firebox was really fully involved before shutting it down all the way. (No un-charred wood on any split, and even the light fluffy ash forming as max flames begin to subside) Experiment a few different times; if you wait long enough before shutting it down completely, your glass will be clean in the morning, except, perhaps, a dusty coating at the lower edges, which will easily wipe clean with dry T.P. or kleenex. We only had pine available, so to still have hot coals in the morning, we wouldn't load it up until 9 or 10, and wouldn't shut it down until 11:00 or 11:30 PM. It did a great job for a little stove. (We left it when we sold the house.)

Regards,

 

[dlaurinaitis]

Thanks for the replies. Ill keep experimenting and try to be more efficient.

 

[Backwoods Savage]

I read a lot on here saying that slow burns are a bad thing.

My lopi answer, I load up at night and pull the air intake handle all of the way out, closing it to its lowest level.

In the morning, I have a decent bed of coals and I have seen it burning in the middle of the night.

The owners manual says this is how to do an overnight burn. However, what I read on this site says that is a bad thing, creating creosote.

Is it? Would a EPA stove, used as directed by the owners manual, have these negative characteristics?

Do I continue? Or do I have to get up in the middle of the night and reload?

I plan on checking my chimney the day after thanksgiving. A visual inspection today, shows a slight tar like substance on the stack.

Is this creosote? Or is it a normal by product of burning wood? I plan to clean it monthly or bimonthly.

Thanks!

MrFood, you have a great question. George gave an excellent answer but I'll also touch on this.


Naturally my first question has to be on the fuel. This is the key to any good fire. If you have purchased your wood then it probably is not properly seasoned no matter what the guy told you. It is just one of those things we have to deal with when buying wood. The fact that you said you have a tar like substance gives the clue that the wood probably is not dry enough and/or you need to give the stove more draft.

Please also realize that each installation can be much different, which means that even if Joe down the street has the same stove, perhaps his flue is different or perhaps his house is a bit more leaky for air and, of course, it depends upon the fuel. Different types of wood burn differently. In addition, the weather makes a huge difference in any fires so you have to be a bit flexible. It takes some time and experimentation to get it down pat. I've burned wood for over 50 years and I still am learning!

btw, that tar like substance is not a normal by product of burning wood. The key is to give that wood a long time to dry. For example, I always recommend people have their wood cut, split and stacked in the wind for 2-3 years. Two years will get most and 3 years will get the rest. Of course there are also some exceptions to the rule. For example, I could cut some soft maple this winter and burn it next winter. I'd get it split by April and then stack it out in the open where it gets lots of air and wind and possibly some sun will help. I'd stack it loosely in single rows stacked around 4' high. I'd leave it uncovered until fall when I would then cover only the top of the pile. This wood would burn well the next winter but only because of the type of wood it is and the way it is dried.

For what its worth, we have a cat stove and we do turn the draft way down even to the point of no flames but do not get creosote. The key is the dry wood and the cat, which burns the smoke. No creosote problems for us. We've cleaned our chimney only once in the past 3 years. It is still clean today.

 

[sixman]

I have the Lopi Endeavor and have a really hard time getting clean burns. My wood has been cut and split for 3-4 years, mesquite and oak. I have to cut the air down almost all the way to keep it from getting too hot. The result is smoke and a very dirty glass. The only way I have found to avoid it is feed it just a little wood at a time , baby sitting, and leave the air open more. For the overnight burns I just live with the dirty burn if I load it up full or let the small fire burn hot and I have to relight it in the morning. Thinking maybe I should have gone with a cat stove.

 

[wood-fan-atic]

I could REALLY use some clarification ,here. My 'Flame' EPA insert (SBI) is a non-cat, with 4 secondary burn tubes running E/W across the top. When the stove is in the first 2 hours or so after re-load, there are nice flames emitted from the holes in the burn tubes. After that, the fire settles down and glows nicely - but the typical large "flames" are gone and there are no more flames from the burn tubes. However there is also NO SMOKE FROM THE CHIMNEY AT ALL. My stove will burn a load down to coals in 8-9 hours, heating the house very nicely in the meantime. Are you people telling me that I have to have fire emitting from the burn-tubes At ALL TIMES in order for my stove to be burning efficiently? By the way - my glass is ALWAYS clean , maybe just a little dusty....wipe with a napkin once a week.

 

[Backwoods Savage]

NO, you will not see those secondary flames all the time. The reason is the wood has burned down to the point where the smoke and gasses are not what they were earlier in the fire cycle.

 

[wood-fan-atic]

Two things that I knew - 1) That my stove was burning just fine.......and.....-2) that I could count on you,Dennis, to set the record straight. ;-P

 

[sixman]

Ex- wife under the same roof???

 

[dlaurinaitis]

I have the Lopi Endeavor and have a really hard time getting clean burns. I have to cut the air down almost all the way to keep it from getting too hot. The result is smoke and a very dirty glass. The only way I have found to avoid it is feed it just a little wood at a time , baby sitting, and leave the air open more. For the overnight burns I just live with the dirty burn if I load it up full or let the small fire burn hot and I have to relight it in the morning. Thinking maybe I should have gone with a cat stove.

This is what I am experiencing. If I shut it down after charring the splits, its burned down and is out in about 4-5 hours. Looks like its something I have to live with and clean the chimney regularly if I want coals when I get up at 5am.

 

[oldspark]

I have the Lopi Endeavor and have a really hard time getting clean burns. I have to cut the air down almost all the way to keep it from getting too hot. The result is smoke and a very dirty glass. The only way I have found to avoid it is feed it just a little wood at a time , baby sitting, and leave the air open more. For the overnight burns I just live with the dirty burn if I load it up full or let the small fire burn hot and I have to relight it in the morning. Thinking maybe I should have gone with a cat stove.

This is what I am experiencing. If I shut it down after charring the splits, its burned down and is out in about 4-5 hours. Looks like its something I have to live with and clean the chimney regularly if I want coals when I get up at 5am.

I having a hard time finding the sweet spot for my oak also (17% moisture), I have the stove figured out for startups and small fires but can not get it to do what I want with the bigger fires and denser wood, might get it figured out some day.

 

[DBoon]

I have a Lopi Answer also - not sure how a 2008 vintage Answer compares to a 1994 model.

In any case, you've gotten a lot of good advice here. Let me also add some Answer-specific advice. You should be able to burn overnight (4-5 hours for heat, 8-10 hours for coals). Your ability to do this will depend on the following:

1. Having dry enough wood - <20% moisture content. When my wood wasn't dry enough, I struggled to get a good, steady burn on full primary air shutdown.
2. Having a cold enough night - a nice cold outside temperature will pull more air into the firebox via the secondaries when the primary is at minimum air setting. This helps get the balance right for me.
3. Having a nice, straight flue that is not too long. My flue pipe goes straight up, and is ~15' long. Longer and straight and you will get more draft, and the fire will burn faster. More bends and shorter and you will have a harder time gettng the right balance of primary/secondary at minimum primary air.
4. Need sugar maple, hickory, locust, or oak for overnights. Pine, cherry, sycamore, elm, etc. won't last nearly as long.
5. Don't be too good about emptying your ashes out. A 1-2" ash bed will keep the coals hot longer.
6. Let the wood get good and charred, and shut down the primary in four steps about 5 minutes apart once the stovetop gets up to 500 degrees.

Good luck. PM me if you want to. The Answer is a nice little stove, but (probably) like other smaller stoves, the perfect operating range is a little narrower than with a bigger stove, I think.

 

[firefighterjake]

I read a lot on here saying that slow burns are a bad thing.

My lopi answer, I load up at night and pull the air intake handle all of the way out, closing it to its lowest level.
In the morning, I have a decent bed of coals and I have seen it burning in the middle of the night.
The owners manual says this is how to do an overnight burn. However, what I read on this site says that is a bad thing, creating creosote.
Is it? Would a EPA stove, used as directed by the owners manual, have these negative characteristics?
Do I continue? Or do I have to get up in the middle of the night and reload?
I plan on checking my chimney the day after thanksgiving. A visual inspection today, shows a slight tar like substance on the stack.
Is this creosote? Or is it a normal by product of burning wood? I plan to clean it monthly or bimonthly.

Thanks!

Um . . . I think there is a bit of miscommunication here. Slow burns done without getting the stove up to temp and achieving a sustained secondary burn = bad (i.e. smoky glass, smoldering fire that can creosote up a chimney, etc.) Slow burn achieved after bringing the stove up to temp and achieving a sustained secondary burn = good (i.e. long, clean burn with good amount of heat.)

It sounds like you may be doing things right . . . getting the stove good and hot before starting to close the air . . . but there are a couple tell-tale signs that would let you know if you are not . . . 1) does the glass blacken up? (if it is black then your wood is not seasoned enough or you are closing the air too soon before the stove comes up to temp -- at least this is the case most often) . . . 2) the real tell-tale sign is when you check and clean your chimney -- lots of creosote (black burned "popcorn" or "cornflakes" is bad -- worse is a shiny, glazed look in the chimney.

 

[firefighterjake]

I could REALLY use some clarification ,here. My 'Flame' EPA insert (SBI) is a non-cat, with 4 secondary burn tubes running E/W across the top. When the stove is in the first 2 hours or so after re-load, there are nice flames emitted from the holes in the burn tubes. After that, the fire settles down and glows nicely - but the typical large "flames" are gone and there are no more flames from the burn tubes. However there is also NO SMOKE FROM THE CHIMNEY AT ALL. My stove will burn a load down to coals in 8-9 hours, heating the house very nicely in the meantime. Are you people telling me that I have to have fire emitting from the burn-tubes At ALL TIMES in order for my stove to be burning efficiently? By the way - my glass is ALWAYS clean , maybe just a little dusty....wipe with a napkin once a week.

Negative . . . sounds like you're burning fine . . . bringing the stove up to temp, cutting back the air and getting a sustained secondary burn which burns off the bad "stuff" (i.e. combustibles) in the smoke . . . then the wood reaches the coaling stage at which time there is no secondary.

Keep burning . . .

 

[firefighterjake]

Ex- wife under the same roof???

Believe it or not . . . yes . . . if you do a search you may find the explanation . . . the Cliff note version: there was a divorce, his ex- was in a tough situation and his saint of a wife actually suggested letting the ex- stay at their place for a while. Seems to work for them . . . and according to Wood . . . there is nothing untoward going on.

 

[dlaurinaitis]

Looks like semi seasoned wood is my issue. I have some blacknd glass, but not too bad. I cleaned the chimney and had small black clumps of cresote, probably the size of match heads. Maybe about 2-3 per square inch. The brushed out easily. The cap was worse, I scraped it as clean as possible. All in all, not too bad I guess. This was after burning f
or almost two months. Thanks for all of the replys.

 

[Pagey]

I think one of the biggest mistakes new burners make is closing the air down all at once. These "reburn" style stoves react best to air adjustments in stages. Once I have a good load involved well, I close the air by 1/3 to 1/2. Then I wait a few minutes and close it a little more. Wait a few minutes, close a little more, etc. Once I have sustained secondary combustion and a stove top temp of around 600F, I consider the stove in "cruising" mode (this leaves me with the air control open about 1/4" or so). Most of the time, I cannot close the primary air all the way. If I do, within 3 minutes the flames disappear and I have clearly visible smoke from the flue. If this happens, I simply open the air a little, reestablish my flames, and adjust as needed.

Now, keep in mind that as others have said: you will NOT see flames during the entire burn cycle. With a full load, you might have 3 hours of nice, active secondary combustion. But after that, your wood is in the early stages of coaling. However, the nice thing about the coaling stage of the burn is this: it is by its nature clean. In other words, by the time you reach the coaling stage, you're not making creosote.

The key is to experiment with your stove during the day. Watch a full burn cycle from start to finish. Learn where the "sweet spot" for your air control is. Then you'll be comfortable knowing you have it set right for an overnight fire when it's bed time.

 

[Backwoods Savage]

Looks like semi seasoned wood is my issue. I have some blacknd glass, but not too bad. I cleaned the chimney and had small black clumps of cresote, probably the size of match heads. Maybe about 2-3 per square inch. The brushed out easily. The cap was worse, I scraped it as clean as possible. All in all, not too bad I guess. This was after burning f
or almost two months. Thanks for all of the replys.

Good to know you've cleaned the chimney. You should continue to do that at least every other month for the first couple of years. Also, the worst will always be near the top of the chimney and the cap will usually be the worst.

Now that you know your wood is only semi-seasoned, you know what to do about it. Get next years wood on hand as soon as humanly possible. Stack it in single rows where the wind will hit the sides of the pile. Then your wood will be better next year.

 

[firefighterjake]

Looks like semi seasoned wood is my issue. I have some blacknd glass, but not too bad. I cleaned the chimney and had small black clumps of cresote, probably the size of match heads. Maybe about 2-3 per square inch. The brushed out easily. The cap was worse, I scraped it as clean as possible. All in all, not too bad I guess. This was after burning f
or almost two months. Thanks for all of the replys.

Good to know you've cleaned the chimney. You should continue to do that at least every other month for the first couple of years. Also, the worst will always be near the top of the chimney and the cap will usually be the worst.

Now that you know your wood is only semi-seasoned, you know what to do about it. Get next years wood on hand as soon as humanly possible. Stack it in single rows where the wind will hit the sides of the pile. Then your wood will be better next year.

Or even better check the chimney monthly if you are using marginal wood . . . and consider getting some pallet wood to help you ignite the wood quicker by placing a few pieces in with the semi-seasoned wood.

And as Dennis said . . . now you know the issue . . . you can fix the issue by getting wood sooner rather than later. Good luck.