Page 2 of 2

Re: Coal boiler vs wood boiler efficiency

Posted: Mon. Nov. 12, 2018 11:28 pm
by mikeandgerry
Forget wood, unless you are young, own a wood lot, and enamored with spending all your free time cutting, hauling, splitting and stacking wood. Wood isn’t cheap when you account for time spent dealing with the fuel, paying taxes on your wood lot, and tending fires. And that’s before discussing any wood burning efficiencies of various stoves, furnaces or boilers.

Coal requires more time tending a fire than oil or gas but far less than wood. Wood would be best left to giant power plants. Only then can handling efficiencies be combined with combustion efficiency.

Coal allows both handling and combustion efficiency for the individual on a small scale. Use the fuel cost calculator on this site to compare fuels. There you will find that purchased wood and bulk Anthracite cost about the same per btu assuming a slightly better efficiency with a stoker.

Then compare your time spent on wood supply with out times spent on coal. For me: twenty minutes a week to handle coal and ash. Copious quantities of heat and hot water are had for my 2200 Sq ft (heat loss of 80,000 btu/hr) on five tons, delivered for about $1100.
If your time is worth $30/hour (&20/hr at time and one half), then it costs me $10 per week times 30 heating weeks or 300+1100, $1400. Add two hours prepping my bin and filling it and two hours maintaining a coal boiler, $1530, total heating costs.

You would have to invest 20 minutes per day to tend a fire plus an hour per face cord to cut and split wood with another twenty minutes per face cord moving and stacking. Your 25 full cords would require 210x.33 x $30 hrs + 1.33hrs x 25 cords x $30; $2100+$1000=$3100 in labor. Your property tax on wooded lands would also add to that price. In NYS, taxes are high. A self sustaining wood lot might have $1000-$1500/yr in taxes. Your “free wood” is costing you $4100/yr for 25 full cord or 75 face cord. Around here split & delivered wood is $55/face. 75x55=$4125

Do yourself a favor, sell your wood stove and wood lot on Hearth.com, buy a used/refurbed stoker like Axeman-Anderson, AHS, EFM, Keystoker, VanWert, Or Eshland. Your back won’t regret it and your wife and kids will be happy to see more of you.

Re: Coal boiler vs wood boiler efficiency

Posted: Tue. Nov. 13, 2018 3:36 am
by Lightning
Mr.Ark wrote:
Mon. Nov. 12, 2018 10:02 pm
Do I have to operate with it full? Would it work with say 40lbs at a time?
Just to add to what Franco said, you do need to build it up to the proper depth during the first fire. Mine for example takes about 100-110 pounds. Then the next day after shaking ashes it might take 50 pounds to bring it back up to that proper depth again.

Re: Coal boiler vs wood boiler efficiency

Posted: Tue. Nov. 13, 2018 8:13 am
by Mr.Ark
Lightning wrote:
Tue. Nov. 13, 2018 3:36 am
Just to add to what Franco said, you do need to build it up to the proper depth during the first fire. Mine for example takes about 100-110 pounds. Then the next day after shaking ashes it might take 50 pounds to bring it back up to that proper depth again.
Your talking about hard coal usage right?
I was considering trying some soft coal but from what I gathered I might not like that indoors if it’s gonna smell in my shop.

You must start the fire first with wood and then add your coal on top?

Re: Coal boiler vs wood boiler efficiency

Posted: Tue. Nov. 13, 2018 8:37 am
by lsayre
Mr.Ark wrote:
Mon. Nov. 12, 2018 10:02 pm
Do I have to operate with it full? Would it work with say 40lbs at a time?
No, it won't work that way. As Franco stated, coal stoves must be filled to the full line.

Re: Coal boiler vs wood boiler efficiency

Posted: Tue. Nov. 13, 2018 10:04 am
by Lightning
Soft coal is wicked stuff. You can try it but be warned lol It releases a lot of gas in its first phase and wants to rage. And it does have a strong odor, smells like burning tires. Tending is more intensive, you can't really pile in a lot at once like anthracite.

Re: Coal boiler vs wood boiler efficiency

Posted: Tue. Nov. 13, 2018 10:32 am
by lsayre
Lightning, would you say that burning soft coal is like burning wood on steroids?

Re: Coal boiler vs wood boiler efficiency

Posted: Tue. Nov. 13, 2018 11:14 am
by Lightning
lsayre wrote:
Tue. Nov. 13, 2018 10:32 am
Lightning, would you say that burning soft coal is like burning wood on steroids?
Hmmm.... more like wood on meth amphetamines haha!

Re: Coal boiler vs wood boiler efficiency

Posted: Tue. Nov. 13, 2018 11:24 am
by lsayre
Lightning wrote:
Tue. Nov. 13, 2018 11:14 am
Hmmm.... more like wood on meth amphetamines haha!
Anything that erupts with rapid heat and then fizzles is not going to be conducive to even home heating unless a huge reserve tank of water can be incorporated to soak up the rampant early heat explosion. Chasing a solution to mitigating the heat explosion from this perspective seems like a waste of money.

Re: Coal boiler vs wood boiler efficiency

Posted: Tue. Nov. 13, 2018 2:25 pm
by lzaharis
I could see crushing and hammer milling eastern soft coal and compacting and pelletizing it and feeding a stoker with it like the AHS or Axeman units.

The fellow in Montana that has an AHS S130 is burning mined and crushed Semi Bituminous soft coal in his hopper and making lots of heat with a fine powder ash that makes me jealous.

If I was to do it I would want to feed the coal with an auger to the firebox of the AHS unit as it done with the Axeman Anderson units.

If the Wyoming or Montana Wyodak Seam Sub Bituminous Coal was used it would certainly cost less to buy even with freight cost per hopper carload.

Re: Coal boiler vs wood boiler efficiency

Posted: Tue. Nov. 13, 2018 6:46 pm
by CoalJockey
Lightning wrote:
Tue. Nov. 13, 2018 10:04 am
Soft coal is wicked stuff. You can try it but be warned lol It releases a lot of gas in its first phase and wants to rage. And it does have a strong odor, smells like burning tires. Tending is more intensive, you can't really pile in a lot at once like anthracite.
Eeeeeaassyyy now guys. Just be careful not to give bituminous a bad rap... when it is used properly the gas is very easily managed and presents danger to no one. Correct, it does not burn as clean and it will produce some soot. For those who want extended firing times over wood alone and perhaps cannot justify the cost of anthracite (twice as much money in our area) a rightly suited bituminous coal is a very economical option.

Remember there are both high-volatile and low volatile soft coals available. The low-vol can produce great long-term heat for the cost and a minimum of gas, soot, and smoke. I can sell every tri-axle load I can get ahold of so do not be fooled that there is no demand for soft coal. I have several customers who even tell me certain soft coals produce more heat in their opinion than the hard coal does.

Anthracite certainly spoils the user, myself included...but I just want to see bituminous fairly represented! :yes:

Re: Coal boiler vs wood boiler efficiency

Posted: Sat. Dec. 01, 2018 5:07 pm
by Volatile
You can still get decent burn times with bit coal, it just takes some getting used to. Still nothing like anthracite though. When I bank bit coal I'll shake and add 10-15 lbs at a time(every 20-30 minutes) until full(slightly heaped above fire brick) then shut the primary air down and leave the secondary air 1/4 turn(just as long as there's still visible flame on coal bed) then it's usually good 8-10 hrs. Some stoves optimized for bit coal can burn very clean and get some impressive burn times.

Re: Coal boiler vs wood boiler efficiency

Posted: Sun. Dec. 02, 2018 3:37 pm
by coaledfeat
I used to buy and burn 8 to ten cords of decent hard wood. When I wanted to go to coal, I cleaned out the boiler and ash grates (non shaker), got a small kindling fire going and loaded her up with three bags of nut anth. Used the ash door for air. When the water reached 190 deg I let it run for 24 hours. It maintained temp with no adjustments. Only when I wanted to remove the ash I raked up through the grate, loaded three more bags of nut and it went 24 more hours. We shopped for a decent hand fed but were always steered to a stoker. Been running an EFM 520. Only burn wood in the parlor stove. And they all lived happily everafter!!!