Thinking of Switching From Wood to Coal

nepa641 · Post by **nepa641** » Sun. Jan. 12, 2014 10:22 pm

I'm tossing around the idea of switching from wood to coal in my outdoor stove, the stove is designed for either wood or coal. Bought a few bags of nut coal today to try it out and I really like the way it burns. Wondering which is more efficient and therefore more cost effective to heat with, wood or coal?

The coal I'm trying out today is anthracite nut(?) coal which is all roughly golf ball sized. Do larger lumps of coal burn better or last longer? I've seen some of the local coal distributors with coal that is much larger than the stuff I'm trying out today.

I'd love to be able to only have to mess with the stove once a day or less. As it is right now with wood I'm out there at least 4 times on a good day.

Forgot to mention my stove is a Heatmor 200CSS.

Hambden Bob · Post by **Hambden Bob** » Sun. Jan. 12, 2014 11:05 pm

Where are you located? Berlin has done an awful lot of Coal Burning,and may have some ideas for you as far as your OWB/Coal Burber is concerned. I had one friend try Eastern Kentucky Bit,I think it was Lump,with some success. That sure would be a Monster set of Grates and Coal bed Area,and it would be interesting to see what tending relief you could gain. Shakedown duration to manage ash would be a question....Good Luck !

GoodProphets · Post by **GoodProphets** » Sun. Jan. 12, 2014 11:52 pm

If you have tried both, than factor and do the math.

coal should be much cheaper,but it depends on your location.

lzaharis · Post by **lzaharis** » Mon. Jan. 13, 2014 4:59 pm

As your boiler hearth is 28 inches wide you will
need do some work to make it more efficient.

I filled my wood and coal boiler half full of firebrick to the
flue and It has made huge difference as my chimney
does not clear the peak of the house..

You may just be better off have a fabrication shop build a
firebox reducer box for you to make the grate area smaller
so the combustion air is more concentrated under one
section of grates.

OR

SO if you purchased a piece of 12 inch channel iron 28 inches
long you can cover half the grates.
AND
You will be able to lay nine bricks flat per layer or 16 and one half bricks
laying them on edge..

BUT buying pizza oven firebrick which is 12 by 12 by 2 will be simpler and
then you can fill in the end with the smaller fire brick.

The issue is grate shaking and if you look at the stadler coal boilers they have
a sloped feeding method that allows the coal to drop into the fire by gravity

If you have no one to shake the grates every couple of hours or so it will be an issue.

windyhill4.2 · Post by **windyhill4.2** » Mon. Jan. 13, 2014 5:44 pm

We tried to burn nut coal in ours,actually burned 1.5 ton,but what a hassle,our firebox is 60" x 28",we hadn't read anything on this forum for doing this,we did not reduce the "grate"area.We got it lit,it worked till the fire migrated to fresh coal ,we do not have shaker grates,we rake the ashes from above &since coal doesn't like being disturbed,it just was a big hassle to use up the coal we bought. We have recently tried a few bags,just is too much of a mess when coal & wood ashes mix,would have tried stove size,couldn't find it in bags to try,we went back to wood,plan to replace with a coal boiler sometime.

scottshotgun · Post by **scottshotgun** » Mon. Jan. 13, 2014 7:25 pm

Last fall I swapped out my wood stove for a stoker,, sure don't miss all that work and mess and when you go for coal you get what you pay for, not a 6ft pickup tossed full of what ever kinda wood "CORD"... I do like the stoker and with the Coal Trol the temp stays right at 70degs all the time never hot nor cold just nice and my gas boiler is set at 40 and hasn"t ran since last winter with the wood stove Did I say I like my coal stoker fill up the hopper and switch out the ash bin not even 5min work a day. compare that to cut'n, split'n, haul'n, stak'n, dry'n, and then the all day chore of sitting by the stove keeping it fired when it's cold out only to wake to a cold house in the morning and the guys around here are just the greatest when you need help ,, you just don't get that with wood

nepa641 · Post by **nepa641** » Mon. Jan. 13, 2014 10:08 pm

Not a bad idea to reduce the firebox size but for now I need to keep the ability to burn multiple fuels. Burned very well during my test run with the unreduced firebox, probably takes about 6 bags to cover the grates to a working depth. I feel I can make it work with the current firebox but it's gonna take a good bit of coal. Gotta build a coal bin so I can get coal in bulk before I give it another go.

nepa641 · Post by **nepa641** » Mon. Jan. 13, 2014 11:00 pm

Not a bad idea to reduce the firebox size but for now I need to keep the ability to burn multiple fuels. Burned very well during my test run with the unreduced firebox, probably takes about 6 bags to cover the grates to a working depth. I feel I can make it work with the current firebox but it's gonna take a good bit of coal. Gotta build a coal bin so I can get coal in bulk before I give it another go.

Rick W · Post by **Rick W** » Thu. Jan. 16, 2014 6:44 pm

Nepa - I replaced a Central Boiler wood burner last year as I too was outside multiple times a day filling it with wood. I sold the wood unit and put in a Keystoker boiler and have never looked back. However, I also replaced the underground pex with true 1.25" ID pex from .88" ID pex. So even though the coal boiler has more BTU, I can also attribute more BTU's getting to where it's needed. More BTU's delivered is less burn time.
Now, there are many, many more experienced posters on this site (that I would listen to their advice), I also am wondering when you switch are you still having the same issue? How many squares are you heating and what is your underground pipe size?

nepa641 · Post by **nepa641** » Thu. Jan. 16, 2014 7:02 pm

Probably heating around 3,ooo and pretty sure the pex is the true 1.25" as it was EXPENSIVE. When the stove was installed they didn't bring enough tubing so it's certainly not below the frost line. When we get a frost or a dusting of snow you can see a line on the ground where the pipe runs. Not at all pleased with the customer service and installers for my unit.

windyhill4.2 · Post by **windyhill4.2** » Thu. Jan. 16, 2014 7:10 pm

Rickw, I reread this entire thread,& can't find any mention from the original poster that he had a BTU problem,seems he would like to cut down on the work load & tending frequency. We are currently into 7+ yrs. heating with an OWB with 1" pex & have never had an issue with BTU delivery & we are heating 2 houses & a 30x40 repair shop with this unit & DHW for both houses .We have tried coal in ours as I stated earlier,we loaded fuel less often but tended as much if not more than we do with wood,because this stove is not set up for coal,we couldn't keep the fire lit because of raking the coal from above. We also buried the pex between 3-4 feet deep as we have very good soil water drainage,no snow melt line here.

Rick W · Post by **Rick W** » Thu. Jan. 16, 2014 7:23 pm

You're correct there isn't a mention of BTU's, I surmised that from NEPA's post of feeding the OWB 4 times daily. My comparison is from knowing many people using OWB's that only feed them twice daily and some of them supply a lot of square feet. My experience with the OWB wasn't good, and talking to different people they attribute the dissatisfaction to 100' run of 1" OD pex and not below the frost line.

windyhill4.2 · Post by **windyhill4.2** » Thu. Jan. 16, 2014 7:39 pm

Well,i guess our system works because i'm too simple too know better

,we have 180' to house then on to second house then back to owb = 500' 1" pex, 2 houses .. heating & dhw in that loop,bumble bee wings are to small to fly,he doesn't know that & he flies, I only recently learned that 1" pex won't work,after using it this way for 7+ yrs.Feeding times are not dependent on size of pex but rather on the heat used. By the way we are not sending ice cold water back to the stove either. Jan.6 2014 perfect example, I loaded stove multiple times because heat demand was so high from the high of 8* & strong winds we had that day,bigger pex would not have burnt less wood.We are no longer "happy" with wood burning either,not because of heat delivery but the work load,we want to go coal,but $$$ to switch systems.

nepa641 · Post by **nepa641** » Thu. Jan. 16, 2014 7:40 pm

No shortage of BTU's here, I can crank my thermostat up as high as it goes and it'll keep up. I'm just trying to cut down on labor and if I can save money that'd be great too.

My pex run is probably less than 20FT from the stove to where it enters my basement. Along with the heat I'm also generating hot water but our heat exchanger is on the hot water heater instead of a separate set pex lines running to a separate heat exchanger on the stove.

What does the stoker mechanism consist of? Is it a long screw like on a locomotive or just something to agitate the coals?

windyhill4.2 · Post by **windyhill4.2** » Thu. Jan. 16, 2014 7:47 pm

Stoker as used in the Pocono is more like a tilted tray with holes in the bottom to allow fan air to blow up thru the burning coal which slides down the tilted "tray"by gravity,just a quick simple explanation,best look at threads on stokers & see the pics for better understanding.