Coals Only Efficiency - Open Door Burn

[Snag]

I've an Isle Royal that likes to build a thick bed of chunk coals. The trouble with that is those coals alone aren't enough to warm the house. I can scoop many of them out and reload with more wood but being a btu miser, I think this is wasteful. The stove came with a wire screen that allows me to open the glass doors. By leaving the doors open so more air has access to the coals and they ash down quicker, I'm feeling great heat come out of the front of the stove and into the room but wonder if I'm creating a condition where I'm losing more warmish air up the chimney than than what's being heated by leaving the door open. Certainly wouldn't leave the fire unattended, someone is always planted in front of the sofa watching tv... Any thoughts?

Thanks,

Carolyn

 

[basswidow]

I've an Isle Royal that likes to build a thick bed of chunk coals. The trouble with that is those coals alone aren't enough to warm the house. I can scoop many of them out and reload with more wood but being a btu miser, I think this is wasteful. The stove came with a wire screen that allows me to open the glass doors. By leaving the doors open so more air has access to the coals and they ash down quicker, I'm feeling great heat come out of the front of the stove and into the room but wonder if I'm creating a condition where I'm losing more warmish air up the chimney than than what's being heated by leaving the door open. Certainly wouldn't leave the fire unattended, someone is always planted in front of the sofa watching tv... Any thoughts?

Thanks,

Carolyn

I'd say you are creating a condition where you could be losing warm air up the chimney. Open door burning would seem similar to a fireplace operation. I also agree that scooping them out to reload is wasteful.

I am not familar with your stove - but I would think the thick bed of coals is a result of something being done. How long have you owned and operated it? It happens on mine when my wife burns alot during the day and doesn't choke it down for secondary combustion. She runs it full throttle and keeps feeding it. I come home to a firebox that is half full of coals. I pile them up and run it open to burn them down to make room for a load. My stove operates best when you stuff it full - allow it to really get going, and then choke it down on the air instages. Running it this way is efficient burning and does not produce an over amount of coals.

 

[rustynut]

snag,
Seemed like my stove was being a bit stingy with the heat lately.
Also had a large bed of coals to go with that.
Figured need more heat give it more air.
Added 2- 4 inch pieces on top of the coals and opened the air up a bit.
next thing i knew it was mid 80's
Not sure what type of wood but that worked well.
Been burning mainly ash but storm blew threw 2 years ago and dropped a bunch in my lap.
Gonna watch this a bit better for my own benefit but thought i'd share
Give it a try
rn

 

[Battenkiller]

The stove came with a wire screen that allows me to open the glass doors. By leaving the doors open so more air has access to the coals and they ash down quicker

You're burning in "ambiance mode" that way. My stove also has a screen and is designed to be used in that fashion, but I rarely do. The worst part about that method isn't the increased warm air up the flue, it is the increased pull of cold air into the home. Open fireplaces suck a lot of air.

Best bet is to rake them near the air intake and put 2-3 very small splits on top of them. The flame from the burning wood will raise your flue temps, which will increase your draft, which will draw air through the mass of coals, which will make them burn faster/hotter. By using just a small amount of wood, you are not adding significantly to the pile as the splits burn down. This might take a couple cycles, but after each cycle the pile of coals will be smaller. This way, a lot more of the heat stays in the stove, and less gets drawn into the house.

 

[Snag]

I should mention that we placed a metal plate over the ash grate. It may be that the air normally provided through the ash pan access door helped burn the remaining coals to ash.

We're burning full or close to it for the most part, get the well temps up to about 400 and then backing half off on the "throttle". Thinking about it, I wonder if the cause of the excess coals is from what I'm currently burning. I've been concentrating on getting rid of a stash of wrist-sized/arm sized rounds from limbs, burning those during the day and then swapping over to thick splits of oak at night. I know the stove isn't in the best place for whole house heating. We've a long story and a half and the stove sits in the far corner of the short part of the house ;-)

I left the door open for about an 45 minutes and then cleaned out half of the ash (I only clean out 1/2 of it at any given time anyway). The coal bed was greatly reduced in that period of time, still don't know if it was worth it though.

Carolyn

 

[Adios Pantalones]

Ditto what Batt said. Rake up front, small splits, air open. I use pine for this and it can throw a lot of heat and reduce the coal bed that way.

 

[Snag]

Ah Ha!! Figures I was approaching the problem from the wrong angle. Will try your suggestions. Now, taking it a step further, maybe I should be raking the coals forward and load a larger split or two in the rear of the box before adding smaller splits on top of the coals? That may give me a bit more heat output han just coals and a few skinny splits while I wait for the "older" coals to burn down.

Carolyn

 

[Battenkiller]

I use pine for this and it can throw a lot of heat and reduce the coal bed that way.

Yes, thanks for bring up the pine, Adios.

Low density wood lights faster, burns hotter, and produces less coals. I use thin cherry or box elder splits left over from the splitting process. There is always a huge pile of these left after I stack my wood, and I rake them up and save them for special occasions like this (or, God forbid, the fire ever goes out, lol). I just got a 25 yard container of white pine logs to make chainsaw sculpture out of. I suspect my new coal burn-down cure will soon be pine scrap. ;-)

I see you are burning oak. Great wood, but very dense woods like oak, locust and hickory tend to make more coals. In general, the slower the wood burns, the more coals you will get in the end. That's why the first thing I suspect when I hear someone has an unmanageable coal bed is the quality of the wood. Wetter wood burns slower at the same firebox temps, so it makes more coals than the primo stuff.

This is one of the reasons why I like to mix my woods, putting some cherry or soft maple in with the hickory and locust. Last night the sub-zero temps predicted tempted me into loading with straight hickory, and like a fool, I listened to myself. This morning I woke up to a lot of coals and a cooler stove than I did yesterday with a mixed load. Not the kind of overnight burn I was looking for. I suspect those coals started to cool down somewhere around 4 AM, so even though I had the highly sought after "lots of coals in the morning", the temp of those coals left me with a cooler stove for a few extra hours and a chilly house. You'd think I'd learn, eh? :shut:

 

[firefighterjake]

And ditto what the Pantless One and Killer of Battens said . . . toss a split on the top, open it up and let it cruise . . . works well . . . like AP I tend to use either a softwood split/slab or one of my pieces of junkwood for the task . . . usually this is not an issue with effective reloading management . . . except when the temps are like they are today and yesterday when you want to keep the stove churning out the heat.

 

[Backwoods Savage]

Add one more to Battenkiller's suggestion.....except for putting 3 splits on. 1 or 2 should be plenty unless they are really small splits.


When we put in the new stove we also had some coaling problems but they were solved pretty fast. Here is how we approach the situation: Before the wood has burned down to all coals, we open the draft full (usually the stove top will be in the 400 + degree range but not more than 450). Usually this will burn down the coals by the time we need more heat. We have a few times put some kindling on top of the coals if we needed them burned down faster. Other times we may add a split but usually no more than one.

One word of caution: You probably have been advised on this but it bears repeating. Oak is probably the hardest wood there is to season. Around these parts we don't ever even think about burning oak until it has been split and stacked for 3 years. Therefore your wood is probably the biggest reason for all those coals because you get more coals if you burn the wood before it is really ready. As your wood dries more you will have less coaling problems.

I hope this helps. Good luck.

 

[Snag]

Hi guys,

Thanks for all your input. I think I've solved this coaling issue, I'm reserving big splits for the back, raking coals forward and putting two small limbs on top. I've been keeping stove temps up and coal bed down so far and I'm pleased. Next trip out to the woodpile, I'll restock my pine and poplar for on top of the coal bed rather than the small rounds of hardwood to see if that makes things even better.

As far as moisture in the wood, one of my first investments was a harbor freight moisture meter, as suggested by some on this list. I tested several splits from several scores of CL wood as well as the oak I've had seasoning behind the barn these last two years. I cut several of the bigger splits in half and everything was metering in the high teen's before I covered it for the winter so I don't "think" moisture is causing the problem. I think it's that I'm struggling to heat the whole house on a cold day and loading up more wood without managing the coal bed with better sense.

Carolyn

 

[CarbonNeutral]

I tried the open door method today to burn off coals, and, as it turns out, with a mostly blocked mesh on my cap. Both CO detectors went off. Nice to see they work......