carbon calculator

Re: carbon calculator

I know that this is not what you asked for--but if you have multiple fuels available it is nice to compare prices based on BTU values of different fuels.

http://www.hearth.com/econtent/index.php/articles/fuel_cost_comparison_calculator/?id=47_0_1_0_M7

Here is a carbon calculator that includes Natural Gas and Heating Oil:

http://carbonfund.org/site/pages/calculator/

Here is another carbon calculator that is in the MKS units:

http://www.nef.org.uk/energyadvice/co2calculator.htm

So far, I have not found anything that says burn a pound of wood gives xx lbs of CO2... And most sites treat burning wood as being "carbon neutral"... However, you can probably equate the burning of wood with that of coal (and, in fact, it is probably worst than coal as there is, typically more water in wood which would tend to reduce wood's thermal efficiency).

Moving some numbers around from these various websites:

1 tonn of coal (metric ton ~ 2,200 lbs) = 2419 kG of CO2 or 1.1 lbs of CO2 per 1 lbs of coal...

2000 lbs of coal ~ 20 million BTU

17.5 Million BTU per Cord of Hardwood
11.3 MBTU per Cord of Softwood

So, as a VERY ROUGH ESTIMATE (based on equal thermal output between coal and wood: i.e., that 1 MBTU of Coal and 1 MBTU of wood output the same weight of CO2--just a SWAG):

2,200 lbs of CO2 per 20 million BTU of Coal (1 ton of coal)
2,200 lbs CO2 / 20MBTU of coal * 20/17.5 BTU/BTU for Hardwood = 2,500 lbs CO2 / 20 MBTU of Hardwood
2,200 lbs CO2 / 20MBTU of coal * 20/11.3 BTU/BTU for Softwood = 3,900 lbs of CO2 / 20 MBTU of Softwood

2,500 lbsCO2/20 MBTU * 17.5 MBTU/20 MTBU/Cord = 2,190 lbs of CO2 per Cord of Hardwood
3,900 lbsCO2/20 MBTU * 11.3 MBTU/20 MTBU/Cord = 2,200 lbs of CO2 per Cord of Softwood

Be warned--all of these numbers are probably not accurate to more than the first digit and are based on the estimate that burning coal and hardwood are approximately equal in their carbon production. My guess is that burning wood may even release more CO2 than coal--but these calculations can at least provided an estimate.

From here, a cord of wood weighs approximately 2-3 tons (seems to agree with my number above that a cord of (hardwood) is about equal in BTU's from a ton of coal):

A pile of wood 4 feet by 4 feet by 8 feet neatly stacked as shown in the diagram. This gives a volume of 128 cubic feet, although there may be only 80 to 90 cubic feet of actual wood allowing for space between the stacked pieces. Bulk firewood is usually sold by the cord or fraction of a cord. A cord of wood, depending upon the type of wood and its dryness, generally weighs between 2 and 3 tons. As a rough guide, it will yield the heat equivalent of a ton of coal or 200 gallons of fuel oil. A typical full size pick-up, bed level, will hold about half a cord.

And here is a link on BTU's from a cord of wood (over 25 species of wood listed):

http://www.daviddarling.info/encyclopedia/C/AE_cord.html

Species|Density (lb./cu.ft.)|Weight per cord (lb.)|BTUs per cord(millions)|Recoverable BTUs per cord millions)|Units needed to produce 1 million BTUs
hickory 50.9 4327 27.7 19.39 BTU/Cord 0.052
...(best to near worst)...
white pine 26.3 2236 14.3 10.01 BTU/Cord 0.100

There are just too many variables to be more accurate (hard coal/soft coal/dry wood/wet wood/species of wood/temperature of fire/etc.)...

Have Fun!
-Bill

Re: carbon calculator

From the links above--burning efficiencies:

http://www.hearth.com/econtent/index.php/articles/fuel_cost_comparison_calculator/?id=47_0_1_0_M7

Oil and Gas Furnaces
Older Models - 50% to 70%
Newer Models - 70% to 85%

Wood Hearth Products
Open Wood Fireplace - 5% to 25%
Older Non-Airtight Stoves - 25% to 35%
Older Airtight Stoves - 40% to 60%
Newer EPA Stoves and Fireplaces - 65% - 80%

Pellet Stoves
Older Pellet Stove (pre-1994) - 50% to 65%
Newer Pellet or Corn Stove - 65% to 80%

Gas (LP or Natural) Hearth Products
Vented Gas Fireplace Logs - 5% to 15%
B-Vent Gas Fireplaces and Stoves - 35% to 65%
Direct-Vent Fireplace and Stoves - 40% to 80%
Vent-Free Fireplaces, Stoves and Logs - 90%

Coal Heating Systems
Older Coal Furnace/Boiler - 50% to 65%
Modern Coal Stove - 60% to 80%
Stoker or Hopper-Fed Stove - 70% to 85%
Electric Resistance Heat - 95% to 100%

The other link where I got the wood heating BTU values has a bunch of links about stoves/fireplaces and such... And in one of those links, they say that a catalytic wood stove adds about 10% efficiency (replace caytalyst about every 6 years / 10-12,000 hours).

-Bill