# Burning Coal In a Wood Furnace?



## links_56 (Jan 27, 2008)

Hi, I know this is a Wood forum but what do I have to do different to burn coal in my wood furnace? I have been but It only burns in the front where the air comes in from my draft blower. Do I need a grate to raise the coal up? Its stoker coal if that makes a difference. I ran out of wood because im wet behind the ears with this. The coal is free so i thought why not. any help would be appreciated thanks.


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## splittah (Jan 27, 2008)

I may be wrong in todays world but the old rule used to be you can burn wood in a coal stove if you want to but you should not burn coal in a wood stove because it burns much hotter.

However, I have never burnt coal. This is what I have been told before. Any other takes on this?


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## windthrown (Jan 27, 2008)

My brother bought a 100 lb bag of anthrosyte (sp?) coal once. We tried burning it in a woodstove, and it melted right through the steel. It gets that hot! Beware! I think that splittah is right; you can burn wood in a coal stove becasue it can take the heat. The opposite way cannot. 

My advice would be to burn a small amount raised up in some wood. No contact with the metal furnace. Or go get some more wood. It may cost you. Also try asking on the MEN forum too. Some of the guys over there know a lot obout this stuff and may have some tips.


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## Mike Van (Jan 27, 2008)

It won't work, mainly because you need grates, cast iron ones for the air to come up through the coal fire. Also, after 40 lbs. or so, you need to shake the grates & get the ash to go down through.


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## ktm rider (Jan 27, 2008)

Your stove/furnace has to be set up to burn coal. In order for coal to burn it requires the combustion air to come UP through the coal. Wood requires the combustion air to go OVER the wood. So, even though you have grates in your stove/furnace, you will not be able to burn coal with any success at all without the combustion air coming up through the grates.. Most stoves that are coal burners will have the air damper on the ash pan door. If it is above the door only, well, you are out of luck. You possibly could get it to catch, but you will not be able to get anywhere near its burning potential. The quality of coal makes no difference. (Anthracite of Bituminous) 

If you get your coal for free why in the world are you even thinking of burning wood?? I burn 95% coal after burning wood for years. I will NEVER go back to all wood. 

But, if you happen to have some grates AND the combustion air drawing from under the grates, by all means, fire that bad boy up, and leave the wood in the yard for "Start up " tender... 

here is an excellent coal burning forum that I am a long time member. it is very informative and new comers are always welcomed.

http://www.nepadigital.com/bb/


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## Hugenpoet (Jan 27, 2008)

Burning coal in most wood stoves voids the warranty, which, while only directly applicable to those whose stoves are still under warranty, tells me all I have to know about NOT burning coal.

Hugenpoet


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## Mr. Obvious (Jan 27, 2008)

To burn coal you could line the bottom and sides with some firebrick and then also use a grate. Buck stoves had a coal kit for their wood burning inserts. It was just the items I listed.


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## Vibes (Jan 27, 2008)

I have a freind who burns coal in an OWB that wasn't designed for it. He says it burns OK in small amounts. He puts it in a plastic shopping bag and sets the bag in the center of the fire box so it doesn't touch the sides.

I have a Shenendoah R-65 wood and coal burner. Grated and firebricked lined. It burns the coal good if the ash pan is less than 3/4 full and with the air opened all the way, and with the damper open.

The problem with coal is getting good house coal. It has to be the nugget size about the size of a walnut or golfball. If there is alot of skake [fine] it chokes the air flow and doesn't burn well.


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## paladin (Jan 27, 2008)

As someone said earlier if your stove isent rated for coal I wouldnt use it. It burns alot hotter I havent burnt any in a stove,but have used it in a traction steam engine. It is what we use when we need to work it hard as regular fire wood wont make enough heat to keep the steam up when working it hard.


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## MNTAINGAL23 (Jan 27, 2008)

We have a wood stove that someone burned coal in. It warped it because it got to hot.


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## goblin (Jan 27, 2008)

My understanding is that with the proper lining (firebrick) and proper grate (coal burning) installed, you could burn coal in virtually any wood stove. You just have to start out small and experiment and make sure that the temperature stays within the stoves tolerance range.

And it probably requires keeping the underneath of the grate clear of ash as much as possible to aid in the combustion, which my woodstove requires also.

With that said, I've never burned coal in my stove. But you better believe that if I fell into a pile of coal I'd convert it to burn coal in a New York minute.


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## timberwolf tree (Jan 27, 2008)

the only time i ever put coal in my wood stove is before i go to bed 5 to 10 pieces to help keep it going all night


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## Festus Haggen (Jan 27, 2008)

I burned coal for heat for a couple years, before my chainsaw addiction took over. My furnace that I have now will burn coal, only done it a couple times. My other coal stove was a stoker, that was a handy device for sure. My dad used to burn both a coal stove and a coal boiler at his business Used to have to tend the stove, hated carrying bucket after bucket of coal up the stairs. 

As others have said, the bottom draft is crucial when burning coal. A stove designed for coal is essential, anthracite really can throw heat. I just got tired of dealing with cinders all the time, and a lot of them at that. 

Also keep in mind that coal doesn't make much of a draft, and higher outdoor temps make it worse. You should never burn coal over 55F outdoor temps, won't be enough temp. difference to produce draft. My aunt and uncle almost died this way, they'd been burning coal for 50+ years. CO detectors are much more likely to activate while burning coal, just because of the low flue temps and draft. No creosote, though it will eat black pipe in a year or two. Make sure your pipe is rated for all fuel or coal. 

Coal can throw lots of heat if burnt correctly, or it can fill your stove with hot stinky rocks that you have to dig out. There is a steep learning curve, but it is well worth learning if you want to heat this way. 

A few chunks on a wood fire shouldn't hurt anything, though.


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## links_56 (Jan 27, 2008)

*Thanks!!*

Thanks for the help guys!! My wood furnace is about 50 years old and is lined with fire brick already. The way i understand it is, as long as I keep the coal below the the top of the fire brick i should be safe. I have a draft blower that I mounted on the front of the furnace myself. So If I add a draft control to the ash removal door then it would suck air through the coal. But would I need the draft blower above on or off? The Fire chief ones Ive seen have a draft blower and a air intake on the ash door and I assume they both run at the same time. Thanks.


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## Mike Van (Jan 27, 2008)

Links, you'll only want the draft up from the bottom - Check this other forum too, it's all about coal http://www.nepadigital.com/bb/index.php?sid=7e38ee25982d4f30c059fcf931847e1c


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## 046 (Jan 27, 2008)

my JUCA fireplace insert is constructed of 1/4in plate, lined with firebrick and rated for coal. draft is from bottom through ash dump. 

not too many sources for coal in Okla. at retail level. did finally locate a close by (45miles) coal mine that would sell a pickup truck load at a time. 

been really wanting to give coal a try.


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## ktm rider (Jan 27, 2008)

goblin said:


> My understanding is that with the proper lining (firebrick) and proper grate (coal burning) installed, you could burn coal in virtually any wood stove. You just have to start out small and experiment and make sure that the temperature stays within the stoves tolerance range.
> nute.




Sure the coal will burn somewhat but not to anywhere near it's potential. You also need the combustion air to come UP THROUGH the grates and the coal. If you don't have that You will not get a very good burn and it won't be worth the time or effort.


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## ktm rider (Jan 27, 2008)

046 said:


> my JUCA fireplace insert is constructed of 1/4in plate, lined with firebrick and rated for coal. draft is from bottom through ash dump.
> 
> not too many sources for coal in Okla. at retail level. did finally locate a close by (45miles) coal mine that would sell a pickup truck load at a time.
> 
> been really wanting to give coal a try.



there ya go ! Give it a Whirl. But be warned, you might get hooked on burning coal. I will have to also say that burning coal takes a totally different technique than burning wood. It is a fickle beast but once you get it figured out, it is an awesome fuel source. Check out the coal burning forum link I put up earlier in this thread. I will explain all the differences and answer any question you have. 

BTW, I am guessing you are ging to get Bituminous coal, make sure you find out what kind of coal it is. Each kind of coal requires different burning techniques.


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## stipton (Jan 28, 2008)

I have supplemented my wood burning with coal this season. I purchased 5 ton of bit and cut my wood consumption by 50%. 

Good points: Cheaper than wood by weight/btu (dont give me that free speech either folks), easier to feed, burns hotter for longer.

Bad points: Dirty, dusty, 2X more ash, did I say dirty?

Like ktm rider said, it is a MUST that the air comes up from the bottom. Before buying a single pound, check with your manufacture to see if you can burn coal.


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## Mountaineer (Jan 28, 2008)

*Corosive exhaust*



links_56 said:


> Hi, I know this is a Wood forum but what do I have to do different to burn coal in my wood furnace? I have been but It only burns in the front where the air comes in from my draft blower. Do I need a grate to raise the coal up? Its stoker coal if that makes a difference. I ran out of wood because im wet behind the ears with this. The coal is free so i thought why not. any help would be appreciated thanks.



I kind of breezed throught the post, so I am sorry if I missed someone saying this already. Besides the temperature and air requirements being different for a coal stove/furnace, you also have to worry about the exhaust. Coal has a tendency to make sulfuric acid because it releases sulfur when it burns. Your flu liner, cap, and flashing could all be negatively effected by this.


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## 046 (Jan 28, 2008)

bituminous if I remember correctly... the softer version is all that's produced in OK. 

thanks for the link to coal burning forums....

since I live in the city with neighbors close by. really concerned about smoke. except for startup getting up to temps, my JUCA insert burns very clean. can't tell it burning at all from a distance, almost no smoke. 

before I head down to buy a coal grate and a ton of coal. will burning coal really smoke? 



ktm rider said:


> there ya go ! Give it a Whirl. But be warned, you might get hooked on burning coal. I will have to also say that burning coal takes a totally different technique than burning wood. It is a fickle beast but once you get it figured out, it is an awesome fuel source. Check out the coal burning forum link I put up earlier in this thread. I will explain all the differences and answer any question you have.
> 
> BTW, I am guessing you are ging to get Bituminous coal, make sure you find out what kind of coal it is. Each kind of coal requires different burning techniques.


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## Mike Van (Jan 28, 2008)

Good hard anthricite won't smoke, I burned it for a few years. The soft, I don't know - Someone said twice the ash of wood - I think its more 3 or 4 times!


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## windthrown (Jan 28, 2008)

Mountaineer said:


> I kind of breezed throught the post, so I am sorry if I missed someone saying this already. Besides the temperature and air requirements being different for a coal stove/furnace, you also have to worry about the exhaust. Coal has a tendency to make sulfuric acid because it releases sulfur when it burns. Your flu liner, cap, and flashing could all be negatively effected by this.



Wow, this guy got banned before I could even reply to this post today...

Anyway, was reading yesterday that 20% of the mercury in Oregon rivers is from China burning coal and the smoke drifting across the Pacific. I also read a long time ago that there is a lot of uranium and other radioactive ilk that is also in some types of coal that gets released when burning it.

No coal available out here, really. Used to be a lot of coal mines in southwest Oregon in the 1800s. Coos Bay was a coal port for several decades. I do not know what type of coal seams they had here. Not much info on the subject, other tham historical.


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## ktm rider (Jan 28, 2008)

windthrown said:


> Wow, this guy got banned before I could even reply to this post today...
> l.



I would assume he was banned because of something other than what he posted above. I don't see anything wrong with what he said.


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## gtstang462002 (Jan 28, 2008)

ktm rider said:


> I would assume he was banned because of something other than what he posted above. I don't see anything wrong with what he said.



There was another posting where him and another guy seemed to be going at it. They are both banned now.


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## ktm rider (Jan 28, 2008)

gtstang462002 said:


> There was another posting where him and another guy seemed to be going at it. They are both banned now.




That explains it, thanks.


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## bama (Feb 1, 2008)

I burned a 55 gal. barrel of ND lignite throughout the season last year. I just threw in a few lumps on top of the wood. MAybe it wasn't as effective as in a coal burner, but I am sure I got some heat out of it. The coal was just going to waste in an old barn of my FIL's. Kind of messy compared to wood and the smoke doesn't smell near as nice.


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