what is our efficiency?

Yanche wrote:The term efficiency is an often misused and misunderstood. What is being discussed here is combustion efficiency. How well the fuel is burned, compared to it's theoretical maximum. This has nothing to do with overall efficiency, the efficiency of the appliance burning the fuel. For example I could burn fuel at theoretical efficiency in a fireplace and it wouldn't heat my house very well.

Of course! Thanks John for your post. So our critical desicions related to efficiency are to first select a coal burning appliance with the greatest ability to extract the most BTU's out of the coal and then to operate it at the most efficient level it will burn. Controlling over fire and vent draft being the most critical. That points up the importance of a barometric damper. Not trying to start an argument with those of you that are die hard MPD devotees, just saying.

As I said earlier, the most important thing to me is the cost and the comfort. I don't want to be a slave to the oil man. Plus it just gives me a very satisfying feeling everytime I walk in from outside and my house is nice and warm AND I think about how it's all being done by a fairly tiny coal fire. Thank God for C240H90O4NS!

Here's my efficiency--$750.00 per season.( that's about 6 months up here) Hand fired doing 2500 sq. old farm house. Plus, I sure do miss my firewood activities.

freetown fred wrote:Here's my efficiency--$750.00 per season.( that's about 6 months up here) Hand fired doing 2500 sq. old farm house. Plus, I sure do miss my firewood activities.

I don't know if that is efficient, but it sure is economical.

Berlin, if there is enough oxygen available, CO will continue to burn off because it's an unbalanced molecule. There's a lot of reactions going on in the blue flames, some but not all attributed to burning methane. If the blue flames are just CO, it's not combusting all the way and energy is being wasted. Check out Yanche's formula for anthracite and you'll see allot of available carbon and some is fixed to Hydrogen to make up some Methane. It's why we see the blue flames in the beginning and they tapper off as the anthracite glows red as the carbon is combusted for most of the burn cycle. This is the part where Yanche changes us to defer to our High School Chemistry books - mine's not handy but here goes anyway

Nature likes to balance out or neutralize all electrical charges and given the chance, it will. Kind of like lightning during a thunderstorm. That's what we strive for when we burn fuels - to rearrange the charges in a way that releases the stored energy by recombining (combusting) them with Oxygen. Free elemental Carbon (C) has the negative charge of -4. An Oxygen molecule has a positive charge of +2 but in nature Oxygen hooks up with another Oxygen molecule and is naturally found as O2 (two Oxygen molecules=+4). It's more complex, but this example is simplified. If there's enough Oxygen in the firebox, the Carbon in the anthracite will convert completely to CO2 (carbon dioxide) to make a more balanced molecule and release all the heat available. If it happens half way**there's still energy to be released , CO(carbon monoxide) is formed. The Carbon Monoxide molecule (CO) still has a charge to be neutralized by the charge of another single Oxygen (O) molecule to make CO2 (carbon dioxide):

C(carbon)+O2(two oxygens)=CO(carbon monoxide**)+O(one oxygen = CO2(carbon dioxide) When this happens, all the heat available is released. That's the combustion efficiency of Yanche's post.

We all know it doesn't happen completely at 100% all the time and CO is one of the combustion byproduct gasses to be concerned about.

Methane (CH4) is the first simple 'balanced' formula for carbon. The simplest hydrocarbon. It's the main component of coal gas - the gas of ' the Canarie in the coal mine' infamy. It balances with four Hydrogen (electrical charge or valance of +1) to make Methane gas. Combusting methane with oxygen releases the energy stored in the carbon/hydrogen bond: CH4+2(02)= (H2CO + H2O)+O2= CO2 + 2(H2O)

Actually 3 ton--2 things rberq--bigger stove, that thanx to this forum, I've got down to being as efficient as it can be--plus I've opened up the nooks & cranny's with small or large archways plus a ceiling fan for distibution & floor registers for upstairs--bedrooms stay 66-68*, I like sleeping cool. Just my way, but I never open my ash door vents, MPD is always closed, I let the metallic thermo do what it's meant to do. I never use my stove blower either. Just the way I do it, after much trial & error. As cold & long as it was last year, I had to buy 20 bags of 40??? lb Blashack nut on top of my regular 3 ton.

rberq wrote:

freetown fred wrote:Here's my efficiency--$750.00 per season.( that's about 6 months up here) Hand fired doing 2500 sq. old farm house.

How do you do that? That's only 2 1/2 tons, from the sound of it. I burn almost 4 tons over 7 months, and only heat about 1400 sq. ft. Also an old farm house, but the coal heat does not reach some parts. What do you have for insulation?

VigIIPeaBurner wrote:Berlin, if there is enough oxygen available, CO will continue to burn off because it's an unbalanced molecule. There's a lot of reactions going on in the blue flames, some but not all attributed to burning methane. If the blue flames are just CO, it's not combusting all the way and energy is being wasted. Check out Yanche's formula for anthracite and you'll see allot of available carbon and some is fixed to Hydrogen to make up some Methane. It's why we see the blue flames in the beginning and they tapper off as the anthracite glows red as the carbon is combusted for most of the burn cycle. This is the part where Yanche changes us to defer to our High School Chemistry books - mine's not handy but here goes anyway

Nature likes to balance out or neutralize all electrical charges and given the chance, it will. Kind of like lightning during a thunderstorm. That's what we strive for when we burn fuels - to rearrange the charges in a way that releases the stored energy by recombining (combusting) them with Oxygen. Free elemental Carbon (C) has the negative charge of -4. An Oxygen molecule has a positive charge of +2 but in nature Oxygen hooks up with another Oxygen molecule and is naturally found as O2 (two Oxygen molecules=+4). It's more complex, but this example is simplified. If there's enough Oxygen in the firebox, the Carbon in the anthracite will convert completely to CO2 (carbon dioxide) to make a more balanced molecule and release all the heat available. If it happens half way**there's still energy to be released , CO(carbon monoxide) is formed. The Carbon Monoxide molecule (CO) still has a charge to be neutralized by the charge of another single Oxygen (O) molecule to make CO2 (carbon dioxide):

C(carbon)+O2(two oxygens)=CO(carbon monoxide**)+O(one oxygen = CO2(carbon dioxide) When this happens, all the heat available is released. That's the combustion efficiency of Yanche's post.

We all know it doesn't happen completely at 100% all the time and CO is one of the combustion byproduct gasses to be concerned about.

Methane (CH4) is the first simple 'balanced' formula for carbon. The simplest hydrocarbon. It's the main component of coal gas - the gas of ' the Canarie in the coal mine' infamy. It balances with four Hydrogen (electrical charge or valance of +1) to make Methane gas. Combusting methane with oxygen releases the energy stored in the carbon/hydrogen bond: CH4+2(02)= (H2CO + H2O)+O2= CO2 + 2(H2O)

Yes, if there is enough oxygen available CO will form CO2 which is (CO) by far the predominant gas being burned in the "blue flames". A number of substances will burn with a bright blue flame, sulfur, CO, H, CH4 to name a few.

One of the important things that has to be remembered is that combustion of a complex hydrocarbon like coal is a process. Given enough oxygen a complex hydrocarbon does not simply burn instantly and form CO2 and H20 (nevermind all the other substances in coal). It's a process that is very complex and requires a lot of intermediate products during combustion to be "created and destroyed". Even ignoring the other elements and looking only at hydrogen and carbon, it's very complicated with many stages.

The methane present in coal beds is not due to decomposition of the coal or hydrocarbons in the coal itself, it is due to methane present separate from the bonded chemical makeup of solid coal and is mostly the result of bacterial action and found in pockets in the coal by itself. Coal has very little methane content once mined and processed and even during volatile fraction decomposition during initial heating and combustion methane is a paraffin formed only briefly and in conjunction with a vast number of other hydrocarbon gasses. As the simplest and lightest alkanes are the first to fully decompose and bond with oxygen, The remaining volatiles are mainly heavier aromatics and alkenes. With anthracite the blue flames that eventually die down are not blue due to methane. The initial bright blue is not formed mostly from hydrocarbon flair, but rather cool combustion temps formed by fresh coal which lead to CO production and, as the gas makes its way above the fuelbed and finds fresh oxygen, it forms bright blue flames. Methane is very insignificant in anthracite combustion.

Does the BTU rating include fan-forced air blowing through the heat exchanger surfaces of stove?
Just by radiant surface area alone, your questions are valid.

Greg L

That surface sq footage doesn't seem like much, but it is what it is. Even comparing the 30-95 to the 50-93--same design and all but the sq footage surface wise makes all the difference no matter how minimal it seems.

I wonder how many square feet of surface area the DS-1600 stove has?

Also, does anyone know the square inches of grate surface area for the various popular hand fired stoves?

lsayre wrote:I wonder how many square feet of surface area the DS-1600 stove has?

Also, does anyone know the square inches of grate surface area for the various popular hand fired stoves?

I was thinking the same thing,forgot the ds machine.I have the basement #4 which is rated at 130,000 btu. 40" height 28" wide 29" deep, Fire box is 16x20 plus hopper....

coal bob wrote:

lsayre wrote:I wonder how many square feet of surface area the DS-1600 stove has?

Also, does anyone know the square inches of grate surface area for the various popular hand fired stoves?

I was thinking the same thing,forgot the ds machine.I have the basement #4 which is rated at 130,000 btu. 40" height 28" wide 29" deep, Fire box is 16x20 plus hopper....

I think the Basement #4 and the DS-1600 are dimensionally very similar, if not the same.

I don't see the big deal abut combustion efficiency. A Chubby is 85% and perhaps the best of the best is early nineties. So amongst the grade A coal only stoves perhaps there is a few percent either way. I see the argument about hydronics as it's easier to convey heat but it depends on your set up. I had a Pocono 110K in the same spot as my AnthraKing 110K. Same firing system and yet the AnthraKing works SOOO much better (in my application). So multiply combustion efficiency by distribution efficiency and you estimate approximately how good the stove works. This has been stated by other posters before and remains very true. It can be a stand alone hand fed or a super complex hydronic system and in the end it just depends on what works for you. My AnthraKing is about 90% efficient but I don't care if it's 87% or 94% it's can I get the air to where I want it. Mathamatics above simple addition gives me a headache anyway.

Lots of good points in this thread, but we are going in different directions in our definition of "efficiency". You can burn the coal perfectly and send all the heat up the chimney, or you can burn zero coal and sit in a cold house...each case is 0% efficient in my eyes. Combustion efficiency is important, but it doesn't mean *censored* if you can't put the heat where you need it. Sleep easy knowing that the guys that designed our coal-burning appliances knew a thing or two about how to burn coal. Read the manual, read some books, listen to the guys that have been burning the black rocks a while, and do your best to get the heat where you need it.