The cost of the fire

[jcg31]

This may seem a tad OCD-ish but for the past few months I have taken to weighing the wood before putting it into the oven to get a better sense for costs and consistency between fires. I am using a $5 hand scale lifting the wood in a home depot bucket. What I have found is that on average it takes me about 73 pounds of wood to get the oven up to Pizza temps (42" hemispherical dome). 73 pounds of wood equates to approx 373,760 BTUs.

I received a pretty good deal from a local apple orchard on some aged apple paying $126 for a full cord. There are 4100 pounds in a cord of apple so I am paying $2.25 to fire up the oven and probably another $.50 to keep the flame going during the festivities. Not bad, particularly considering that the residual heat lasts all week for various delectable's on the way down.

There are wood species conversion charts all over the internet, the one I used is here:

http://www.daviddarling.info/encyclo...value_BTU.html

It will tell you that each pound of wood (any variety) will generate approx 6400 BTUs. I am guessing that that is 0% moisture and I am at about 20% moisture so I knocked the number down to 5120 BTU/lb .

Cost using other fuels (hypothetically):
Electric: $11.65
Natural Gas: $4.55
Propane: $7.28

Jim

[Archena]

Re: The cost of the fire

It's not OCD-ish, it's CDO-ish...


Okay, out of curiosity, how are you getting your pricing? Did you actually weigh the entire cord?

[jcg31]

Re: The cost of the fire

It's not OCD-ish, it's CDO-ish...


Okay, out of curiosity, how are you getting your pricing? Did you actually weigh the entire cord?

Yeah with a real big bucket from Home Depot and my trusty hand scale. Actually as mentioned above, there are a bunch o sources out there that will tell you volume and weight by species of wood. the one I used was:

http://www.daviddarling.info/encyclo...value_BTU.html

[gjbingham]

Re: The cost of the fire

73 pounds of wood sounds like a bunch to me. Perhaps I will weigh my next load prior to firing. My 37", I would guess, uses about 40 - 50 pounds of mixed wood to get to cooking temps. Interesting observation. I wonder what others are thinking.
G.

[Frances]

Re: The cost of the fire

I am thinking... how many cubic meters was that to a cord again? I pay 100 USD per "ster" (which works out as one cubic meter)

Hum... very interesting though.

[Wiley]

Re: The cost of the fire

Frances,
This link says 2.55 cubic meters per cord.
Conversion tables Cord to cubic meter

Wiley

[Wiley]

Re: The cost of the fire

Frances that link must have a different idea of what a cord is than what I am used to. A cord of wood to me is 4 ft x4 ft x 8 ft for 128 cu ft. A cubic meter contains 35.3146 cu ft. 128 divided by 35.3146 gives 3.624 cu meters per cord. In my minds eye that seems a better answer, as well.
Wiley

[carioca]

Re: The cost of the fire

Hi all!

The type of firewood I produce on our land from long-felled trees (mostly) is high-density hardwood such as iron bark, stringy bark or messmate. Such timber costs Sydney folk $A260 per tonne (ca. 2.1 cubic metres), plus delivery.

(I haven't factored in my $A2000 Stihl chainsaw nor the Fiskars block splitter and axe, but...)

Ciao,

LMH

[nissanneill]

Re: The cost of the fire

When I could buy very old, dead and thoroughly dry River Red Gum (during the cold months) I would put between 80 and 90Kg into the boot of my little sedan and costing usually around $20-25 (cost is $280/ton).
This will generally give me 4 burns which averages out to $5 per bake. I have around 29 tons of wood currently and will use that rather than buying it which is quite difficult out of season.

Neill

[david s]

Re: The cost of the fire

If I.m cooking a roast I'll use about one 10 L bucket of wood. For pizza about double that, but my oven is pretty small. Have never bought wood, just use fallen eucalypt sticks and branches.

[Wiley]

Re: The cost of the fire

Carioca, Do you use a standard chain when cutting iron bark?

We have switched to a skip tooth chain and find for our needs it works well, but then our hardest wood is madrone/arbutus, I have had some experience with iron bark in the S Pacific and eucalyptus when I lived in California. The gum wasn't that hard to cut when wet but dried was much harder to cut and split. I would think that in spite of the high cost a carbide chain might be worth the investment if I was cutting iron bark and such like regularly.

Wiley

[berryst]

Re: The cost of the fire

wow, some of you are using a lot of wood.

I have a 36" x 28". I use a lot of variety. Mostly I use douglas fir, some maple and a little cedar to get things started.

I use about 30 to 35 pounds of wood but I'm going to measure to make sure. I just use what is lying around. There is a lot of wood here in the northwestern US. Madrone is the best but I save that for burning inside the home because it lasts so long. I burn a lot of wood for heating...about 2 cord a year. I don't pay for wood just cut it in the back yard. Once in a while a neighbor needs to get rid of a tree.

Currently I'm working on a covered space for a picnic table. 20'x15' I'm hand splitting cedar shakes. I use the electric log splitter. The hand froe just didn't hold up.

Berryst

[carioca]

Re: The cost of the fire

Carioca, Do you use a standard chain when cutting iron bark?
....
Wiley

Hello Wiley,

no, so far I've been using the standard Stihl chain - and I've got a bucket full of these soaking in oil for the day when I get around to sharpen them...

But I'll have a look for carbide-tipped chain that you mention.

Cheers,

LMH

[stidik]

Re: The cost of the fire

Jim,
Your post is extremely interesting and helpful. I'm almost done with a 36 in. Pompeii, so your post answered some of my questions
Thanks,
Stephen