Can't get good burn time with sub-bit coal

Well I'm getting the times but the temp on the furnace is still dropping. No matter if the span draft is at 1/2 or 4 temp on furnace don't go up please help or am I worrying about nothing

Each type of coal has different burning characteristics. All coal seems to have more heat energy in the first 30% of it's burn cycle, that 's from catching fire till it is burnt out to ash.

IWhen I was hand stoking my self designed and home [shop] fabricated 'big Bertha' boiler, I noticed that the fresh loads of coal produced the most heat, and a few hours later the coal was all red, making heat but at a much lower level than when first added to the fire.

I think this is why stokers appeal to me, whenever the water temp drops, the stoker fires up to reheat the water, and fresh coal is added, and this fresh coal burns much hotter than coal that is at it's 'half life'..

Since your coal has much lower BTU content than either Bit or Anthracite, I think you are doing as good as you can.

Can you get a ton or so of high quality Bit coal, and give it a try for a comparrison? maybe you could mix your free sub-bit with good bit and still
be on the 'less expensive' side compared to everyone else here on the forum.

Greg L

Well Greg this is the 2nd type coal in eastern KY I have gotten. Popular wood does better then the coal that just don't seam right. I'm not sure the type if it is sub or bit. Thanks for the help I just don't understand why I can't get coal to burn any better but the wood does samething

If it is Ky mined coal it is definitely bituminous coal. Sub bit coal is more common out west in states such as Wyoming and Montana

I know that we are supposed to have good coal in eastern. Ky so I wish I could get this 1500 hot blast to working right. I think it should. Hold the temp in furnace for longer time then 3 or 4 hrs. If I'm. Wrong please tell me then I guess I'll leave you'll alone and quit bothering you'll

It sounds like you need to run the 'hot blast' at maximum to stay at your desired heat level/output.. To me, it sounds like it's too small a unit for your
heating needs.

Greg L

So around 300 is where the hot blast should hold at after the first stage of burn. Greg thanks for the help

Dmay,
are you sifting or screening your sub-bit, not sure if you need to or not. Maybe your getting too much dirt and fines mixed in and smothering the fire.I saw stephen in soky thread on "run of the mine" and he was screening his lump coal. Maybe Berlin or someone with more experence with bit. coal can chime in and see if you need to screen your coal if your not already doing that. Dennis

The coal is dirty but I'm using big lump size from football to volleyball not smaller than baseball

I sure hope somebody can help me get it working right got fire going again at 7:00 and the furnace is still running at 500 at 9:00 at 1 and 1/2

Dmay,
does the house and DHW keep temps. that you need?

Yell the temp in the house well hold if temp don't drop in the 20s or lower

well,maybe with your coal and your furnace that may be all you will get out of the situation. Keep reading and tweeking you might stumble onto something that works. Are your heat ducts insulated going from the out building to the house. How cold does it get down there.

The duct work from furnace to the underground duct work is not.then it come out from under ground under the floor of house into flex duct in to the house the flex duct is insulated.it is 25 outside now at 10:30 .maybe I need to insulate ductwork in building .I'm getting the blue flame after about 3 hrs they are about 6" high in the furnace is that good

Defenitly would help to insulate, but at 25* that's a summer project.When temps. get that low many others have problems keeping up with heat also.As long as you can keep the house warm, that's the most important thing. Sounds like your getting good burn times now.