Managing coals

[smokee]

Man, I hate to post a question such as this but I'm a month into owning a firplace insert and I guess I have to learn somewhere.

With the colder air upon us here in Pennsylvania, I've been burning my new fireplace insert hotter. I've noticed that the amount of hot coals has been building as a result. If I don't put more wood in and try to burn them down the temp drops in the room, even with the air supply wide open - the blower fans wont kick on as much either. If I add more wood it seems like I'm just adding to coal buildup. Is there a "rule of thumb" on how much coals I should have? How deep of coals do you usually have under normal burning?

I do stir them up regularly - I find the bottom stuff to be black and not really burning.

 

[kodiak]

I clean the ashes out of our zero-clearance fireplace when they get so deep they want to start coming out the front. On ours I suppose they are 3"-4" deep by then?

I normally do it in the morning when the coals are the fewest. I scoop out an area on the side of the firebox, push enough hot coals into this cleaned out area to restart the fire with then scoop out the rest of of them. Depending on the type of wood we're burning I suppose I clean it out every 3 days or so.

Edit: I notieced I didn't answer your question... I'd guess that fewer ashes would be best considering they act as an insulator between the fire and the bottom of the box.

 

[smokee]

I clean the ashes out of our zero-clearance fireplace when they get so deep they want to start coming out the front. On ours I suppose they are 3"-4" deep by then?

I normally do it in the morning when the coals are the fewest. I scoop out an area on the side of the firebox, push enough hot coals into this cleaned out area to restart the fire with then scoop out the rest of of them. Depending on the type of wood we're burning I suppose I clean it out every 3 days or so.

Edit: I notieced I didn't answer your question... I'd guess that fewer ashes would be best considering they act as an insulator between the fire and the bottom of the box.

Interesting. So you don't try to burn them down you just remove and dispose? I was thinking of trying to leave the door open a crack in the mornings for an hour or so while stirring frequently to see if that reduces the coals.

Thanks for the reply!

 

[jonsered630]

I have had a lot of sucess in getting the coals burned down to ash by piling them in the middle towards the front of my Lopi with the air wide open to it. I try to remove some ash everyday in the morning to keep it as low as possible to pile more wood in when I need to bank the fire.

 

[howellhandmade]

The idea of removing ashes while leaving coals is a good one, I just haven't been able to make it work. I do what you're thinking of. When the coals get so deep that I can't get enough wood in to make the heat I need (takes close to a week), the next morning instead of loading up I stir the coals, open the air wide open, and let the gas heat take over for a few hours while the coals burn down to ash, pretty much anyway, then clean it all out and start over. There's a day where there aren't enough coals in the morning, then a couple of days when the coals are perfect, then they start getting to be a pain until I start over.

 

[smokee]

The idea of removing ashes while leaving coals is a good one, I just haven't been able to make it work. I do what you're thinking of. When the coals get so deep that I can't get enough wood in to make the heat I need (takes close to a week), the next morning instead of loading up I stir the coals, open the air wide open, and let the gas heat take over for a few hours while the coals burn down to ash, pretty much anyway, then clean it all out and start over. There's a day where there aren't enough coals in the morning, then a couple of days when the coals are perfect, then they start getting to be a pain until I start over.

I'm a night owl and usually don't go to be till 2 so my over-night burn times are rather short. I'll try that tomorrow - letting them burn with the door open/cracked.

I see you're from Pitt. I live in Lancaster now but was born/raised in Uniontown, Fayettenam. Lol. I still like it out there. Seems like I see a lot of O'Sage trees out there, especially now I'm looking for them.

 

[cnice_37]

I try my best to burn in complete cycles. This makes the temperature of the house go up and down, but sort of mitigates too much coal buildup. So a 250 F stovetop start to finish.

This probably gives me a 4 degree swing over 6 hours assuming the house is warm already.

Ashes get scooped out Sunday morning, make it a point to wait a bit longer to avoid too many coals.

 

[Shmudda]

Coal stockpile..........

Smokie,

I have a Lopi Liberty and when I burn it hard I have the same problem. First off, I never throw the coals out as those are the cleanest burning part of the log. What I do is stick the poker in the fire box and stir them up. This allows the ash to fall to the bottom and the coals to rise to the top. After stirring them up I rake a big pile of them into the middle of the stove and take a very big split and lay it directly on top of the hot coals. I close the door, then the bypass damper and push open the air supply the whole way so it burns wide open. After a while it will burn down the coals and the split. The fire will actually use the hot coals to burn up the big split, and after a while the coals will be burnt down with the split burning nicely.

The reason you are having this problem is you are trying to burn your stove to hot and wide open. Basically you are trying to get to much out of it in a short period of time, and you are not allowing the fire to completely consume or burn the wood completely into ash. You need to get a good hot fire going then choke back the combustion air so the fire burns slower and more complete, thus the log will transform from wood to coals and then finally ash. At that point the log has no more BTU's to give up into heat.

I bet you have ash after a all night long burn, right? The reason you do is you are allowing the wood to burn complete exhausting and giving up all it's BTU's.

It's a fine dance on getting it all to work right, but once you understand the complete process you will get more heat with less wood, and your stove efficiency goes up!

Craig

 

[trophyhunter]

Try this when your last load of wood has burned down and the coals are really building up in the stove.

Rake your coal bed towards the front of the stove in a uniformly shaped bed that runs side to side in the stove with your shovel. Then, part the coal bed right in the middle 2-3" wide. Take a single small split, the smaller the better and lay it across the bed of coals with the part below the middle of the small split, make sure the draft control is wide open.

What you will find is that the small split will ignite and burn with a flame, and that coal bed is going to flare up underneath and burn way down while making some serious heat. Once you learn this technique you will rarely throw coals out anymore.

 

[smokee]

Try this when your last load of wood has burned down and the coals are really building up in the stove.

Rake your coal bed towards the front of the stove in a uniformly shaped bed that runs side to side in the stove with your shovel. Then, part the coal bed right in the middle 2-3" wide. Take a single small split, the smaller the better and lay it across the bed of coals with the part below the middle of the small split.

What you will find is that the small split will ignite and burn with a flame, and that coal bed is going to flare up underneath and burn way down while making some serious heat. Once you learn this technique you will rarely throw coals out anymore.

JonSered630 suggested doing the same which I did about 15 minutes ago. It looks like it working nicely - that's where the air enters the box and the coals in this area are glowing the brightest. I'll go and throw a split on as well.

Thanks for all the input, guys. I'm taking it all in and should work this out with all the good ideas that are being suggested.

 

[trophyhunter]

In the newer EPA reburn stoves with glass doors they all dump the primary air right down the inside face of the glass at the floor of the stove, which is why getting them forward is beneficial. That part in between the coal bed allows air to flow under the small burning split above the bed and it helps feed air into the coal bed as well.

You'll be amazed how much better it works with just a tiny split burning on top of that coal bed, add another one if needed after the first one burns down to nothing. It get's the coals burned down to ash without making any more of them.

 

[CTYank]

I clean the ashes out of our zero-clearance fireplace when they get so deep they want to start coming out the front. On ours I suppose they are 3"-4" deep by then?

I normally do it in the morning when the coals are the fewest. I scoop out an area on the side of the firebox, push enough hot coals into this cleaned out area to restart the fire with then scoop out the rest of of them. Depending on the type of wood we're burning I suppose I clean it out every 3 days or so.

Edit: I notieced I didn't answer your question... I'd guess that fewer ashes would be best considering they act as an insulator between the fire and the bottom of the box.

I'd suggest that you'd be wrong with that guess. Why? Because keeping firebox temps as high as possible promotes combustion efficiency- a Very Good Thing. Some mfgs recommend keeping at least a couple of inches of ash in the firebox; Morso does.

In my little Morso, you can easily see how heat conduction happens AFTER the gases have left the firebox. This sort of management would be impossible in a big open box, yer basic smoke dragon of yore.

 

[dingeryote]

Smokee,

You're in the middle of the learning curve and starting to notice the "Rythm" of the stove/Insert.
Cool!! This is where things get fun and art meets science for me. It's kinda offbeat to consider heating the Hooch as an informal hobby, but apparently it's a common interest and fascination, or we all wouldn't be here yakking about it.

The newer and more efficient stoves and inserts are most efficient when run with a optimum stoichiometric mix of air/fuel.
Choke 'em down for a lower fire, or slower start/longer burn, and the Coals start building up.

Ya can't stand there constantly adjusting the air flow, like a Human Throttle position sensor, so adjusting the firebox load volume, or fuel density has to be done, and dealing with Coals when ya can't be as flexible with the fuel.

Some things to try, assuming your wood is well seasoned.
(Half seasoned and green stuff just means ya gotta fuss more with coals.)

Run the stove "hotter"...smaller loads run with more air, and more frequent loading with the denser species.
It's a time/temp/air thing. Ya can't cheat one leg of the triangle without altering the other.
Coals come from not enough air in an incomplete burn at too low of a temp.

A firebox load of Oak is not the same as a load full of Cottonwood.
Oak is a hell of lot more dense, and will need more air to achieve the same fuel/air mix.

Run loads of less dense species with the good stuff, mix the two species to get longer burns with more complete combustion without increasing the amount of heat produced overall.

Overnight, run the good stuff and in the morning rake the coals(Sift, segregate coal from ash, and clean the ash out) to the sweet spot and load some of the less dense stuff split small, for a quick start and warm up, while taking the coals down. 4-5 wrist sized splits, and let 'er rip!


And just to nag, because nobody has yet, and not to say you are "WRONG" or some such, but just to make sure you didn't overlook something.
Make sure your wood is dry and seasoned well. The new stoves absolutely SUCK with marginaly seasoned wood, because of the need for running HOT. If you're gonna run Iffy wood that only has a partial season on it, absolutely mix in some fast burning stuff to keep the heat up, and accept the fact that you're gonna be going through more wood than you would like.

The lesser species of fast burning stuff like Pine, Sassafrass, Cottonwood, and silver maple are darn handy to have around.

There's no wrong in the game. Don't worry about that. There's also a hundred ways to skin the same Cat.
Keep tinkering, and fussing, and learning to run your insert by "Feel". You'll get a handle on it in a while.

Stay safe!
Dingeryote

 

[PEKS]

Same drill here..
The coals pile up at the back of my stove while the ash falls to the front.
This makes it easy for ash removal, as the ash clean-out port is at the front.
Any excess in coals, I rake to the front, spread out and let them burn down to ash, this is great BTU'S.
Save the Coals..

 

[mountainmandan]

For a while I have been wanting a tool like a landscapers rake, but with holes instead of tines. It would work like a sieve, and allow you to get that last little bit of black charcoal to burn. I have not seen anything like it before, but what I have pictured in my mind would be a great tool.

I always rake them to the air supply, they will burn to ash. It would be handy to have an efficient separator though.

The hedge we are burning has a monster coal phase, so managing it is important for best performance. My wife is pretty on top of it, but it would be nice to give her the best tool for the job.

Dan

 

[cnice_37]

For a while I have been wanting a tool like a landscapers rake, but with holes instead of tines. It would work like a sieve, and allow you to get that last little bit of black charcoal to burn. I have not seen anything like it before, but what I have pictured in my mind would be a great tool.
Dan

I will take the beta version Dan. I have been meaning to look for something to make it out of, just never high enough on the project list to remember.

 

[bert0168]

I will take the beta version Dan. I have been meaning to look for something to make it out of, just never high enough on the project list to remember.

Sounds like the shaker grates on the old cook stoves. They had a handle you put on the end of a stub that when rotated back and forth, moved a set of interlocking fingers to keep the coals up and let the ash fall through.

You could achieve this with something as simple as an ash shovel with some holes drilled in it to shake the ash through and save the coals to place where you wanted.

patent pending :hmm3grin2orange:

 

[smokee]

As always, lots of good feedback! Thanks guys.

I did notice last night after posting how fast the coals burned down. I have just a little more than ash down there now and have opened the door a crack to get a nicely spread out layer to burn up.

I tend to agree that these coals should be kept. They throw a good bit of heat and I have to wear a glove to stir them. Piling them up in front of the door is a great idea as well. I did that last evening and they did go down quickly... especially with a smaller split laid on top with a small "trench" in the middle of the ashes.

I don't get worked up about this, just curious, so it's all fun fooling with it. Hopefully by sometime next week I'll have my half of the garage framed and drywalled so I can get my office out of this beautiful family room that we haven't used in 10 years. Man I miss that down there! Going to put my surround sound back up and move the big screen down there. I'll be able to sit in my "throne" and watch the fire without moving.

 

[trophyhunter]

Smokee it sounds like you and that new stove are getting dialed in pretty quick, enjoy it man! These few little methods on burning habits are really cool when you get more familiar with them, You'll be an old pro at it real quick the way you have searched out information.

This time next year you'll have it made! :msp_tongue:

 

[Mac88]

I was trying to think of something to say, but I keep getting distracted by your avatar.