A Few Questions on Burning Bit

OK, heres the story. My Dad uses a Hitzer 55UL to heat his house sometimes. He did try anthracite but his chimney just doesnt have the draw it needs and it is not possible to get enough draft for it without cutting down a lot of nice trees, and that is not going to happen. Its as tall as I can make it plus other issues. Trust me, it wont work to burn ant.

However, it burns wood just fine. No problems at all with draft with wood. Well, pro-pain has jumped to about $5/gallon here. he has a small supply of wood so is going to burn it up. I ran across some bit online and went and bought some to help stretch out his wood. We are hoping he can kind of mix them together some and still have draft.

heres the specifics of the coal. Its from west central Kentucky. 13300-13500 BTU, 1 1/2% sulfer, 6% ash. It is small in size however, being 1/2"-2 1/2" in size. Its not like I have a lot of choices in my area and this was 60 miles from him, compared to 160 miles for a bigger size. We did throw some in the stove yesterday and it does seem to burn good, not much smoke, fuses together and heats well. But we don't know a lot about burning bit and want to get a little efficiency from it. So heres my questions:

1. Will the flue run hotter with this coal then with ant?
2. How much overfire air does it need compared to underfire for optimum burn?
3. When added, should the stove be ran hot to get it burning good before turning the in air down, or let it smolder away?
4. And any other suggestions you might have.

thank you in advance

Sure, you can try the bit coal. But I wouldn't give up on the anthracite. There are ways to help draft. What seems to be the problem with the ant coal? Is there a manometer installed? Maybe he isn't clearing ash enough for the ant coal to burn well.

Manometer would read zero on occasion. chimney is 8 feet past the roof. Chimney is on outside of house in the shade with nice 60' trees around. I elimated all the t's and made 45's. No problem with ash. Stove was filled to top of firebrick. Everything is sealed. Just to many issues to fix. Trust me, ant doesnt work without an inducer and not putting one on. Wish it did work but I doubt my Dad would even want to try it again after waking up twice to a dead fire and a cold house, having to dump about 70 pounds of coal and relighting. He is 77 and got pretty frustrated about it. He does love using the stove and it seems very efficient with wood or ant when that worked. Thanks for the encouragement though.

The bit coal needs quite alot of over fire air much like wood does. The bigger chunks the better, tennis ball and soft ball size lumps. Hopefully the more experienced members with bit coal could chime in.

I thought it needed over fire air but didnt know how much. he has it open and I'll tell him to keep it open. Its pretty small coal but does seem to burn and not smother. The seller told me a lot of his local Amish are using it alone in their handfires and they had been paying $450 a ton for ant, where this is half that price.

If it worked good with wood it will work better with soft coal they have similar but different burn characteristics.

"1. Will the flue run hotter with this coal then with ant?"

Yes and no When the coal is in the first part of the burn it can be as hot if not hotter than wood. However when the hydrocarbons burn off it will be a lot like charcoal or anthracite.

"2. How much overfire air does it need compared to underfire for optimum burn?"

It will vary from coal to coal so I cannot tell you the exact proportions, but I would start out with the over fire open all the way and adjust it down from there. Once you get it set where you like it then leave it there when you add more coal.

"3. When added, should the stove be ran hot to get it burning good before turning the in air down, or let it smolder away?"

I would try to ramp it up a little. Just shake the ashes out of the fire and open the ash door up and let the fire "breath" till most of the coke is a nice yellow color then take a hoe and push the coke to the back. Then add the fresh coal onto the grate in a pile that is higher towards the fire door and gently slopes towards the pile of burning coke in the back. Note do not completely cover the burning coke because you are more likely to get a poof or more likely a lot of poofs.

"4. And any other suggestions you might have."

If at all possible you might want to see if there is any way to preheat the over fire air. What often happens with soft coal is the "tars" and "oils" in it will cook off and go up the chimney even if there is secondary air provided for it. The reason for this is the oil/tar vapors come off hot enough to auto-ignite right at the fire, but they cant burn because they have little or no O2 so it cant burn. Then comparatively cold room air mixes with it and by then its to cool to auto-ignite, however if the room air that enters is heated to say 200*F-300*F then it is more likely to burn.

Good luck and don't be afraid of soft coal. If it starts to act like it wants to go nuclear on you then shut down the underfire air and leave the over fire air open a crack. Shutting down the under fire air will slow down the oils from cooking off and leaving the over fire air cracked open will help keep the puff packs down.

Thanks Carl. Thats a lot of info and I'll call my Dad and read it to him.

And thank you too Lightning.

The over fire air is just one of those turn knobs on the loading door so I doubt I could pre-heat it. Now I know why the hotblasts are mentioned when I was reading thru the bit section.

My Dad burned some bit 40+ years ago. Its bringing back some happy memories for him.

Others have given good advise so I don't have much to add...

Just go slow at first...add small amounts of coal to a lively fire to get a feel for how it burns and how this stove installation will handle it. Both soft coal and wood can be burned at the same time.
Banking fresh coal to the front, back, or side of the firebox is best when burning smaller sizes of soft coal.
Be careful not to cover the entire live coal bed with fresh coal or you'll be guaranteed a puffback/explosion.
There will be some soot build-up in the flue when hand stoking soft coal, so you'll need to check the chimney frequently until you see how fast it accumulates. Also, if there is a chimney cap/screen on this chimney, soot can build up very quickly and the cap may have to be modified so it doesn't catch so much soot.

Be sure he has a couple of CO detectors...Just last night, 2 people died here in Utah from CO poisoning.

[attachment=0]image.jpg[/attachment][quote="carlherrnstein"]If it worked good with wood it will work better with soft coal they have similar but different burn characteristics.

"1. Will the flue run hotter with this coal then

It will vary from coal to coal so I cannot tell you the exact proportions, but I would start out with the over fire open all the way and adjust it down from there. Once you get it set where you like it then leave it there when you add more coal.

"3. When added, should the stove be ran hot to get it burning good before turning the in air down, or let it smolder away?"

I would try to ramp it up a little. Just shake the ashes out of the fire and open the ash door up and let the fire "breath" till most of the coke is a nice yellow color then take a hoe and push the coke to the back. Then add the fresh coal onto the grate in a pile that is higher towards the fire door and gently slopes towards the pile of burning coke in the back. Note do not completely cover the burning coke because you are more likely to get a poof or more likely a lot of poofs.

"4. And any other suggestions you might have."

If at all possible you might want to see if there is any way to preheat the over fire air. What often happens with soft coal is the "tars" and "oils" in it will cook off and go up the chimney even if there is secondary air provided for it. The reason for this is the oil/tar vapors come off hot enough to auto-ignite right at the fire, but they cant burn because they have little or no O2 so it cant burn. Then comparatively cold room air mixes with it and by then its to cool to auto-ignite, however if the room air that enters is heated to say 200*F-300*F then it is more likely to burn.

Good luck and don't be afraid of soft coal. If it starts to act like it wants to go nuclear on you then shut down the underfire air and leave the over fire air open a crack. Shutting down the under fire air will slow down the oils from cooking off and leaving the over fire air cracked open will help keep the puff packs down.[/quote]
I'm using this valve on the back of my stove to control over the fire air. I was thinking I could add a nipple to the valve so it sucks air in from real close to the stove pipe and I guess I was thinking that would pre-heat my secondary air? My one concern is the pipe will get too warm and start drawing smoke out like my chimney?? Would love to hear some input