A cord of wood equals how many gallons of fuel oil?

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Shari

Minister of Fire
Oct 31, 2008
2,338
Wisconsin
I'm trying to figure out roughly how much wood we will need for a 'season'. I've got a rough idea how much fuel oil we burned per season Isn't there a theory out there somewhere that says a cord of wood roughly equals 225 gallons of fuel oil?

Shari
 
I think it varies to much based on stove efficiency and placement, + wood species have fairly large differences in btu's available. That's a pretty good chart in zap's link, but I would take it all with a large grain of salt and err to the high side. Based on what we burned since Feb 1st, I figure 2 1/2 cords a year, of cherry, since that's all I had stacked and ready(ish) when we started burning. Next year the wood will be better, and a better mix, but I am going to lay on 3 1/2 cords.
 
How many square feet, built when? What type of wood(s)?

We are heating 90% of a 2,200sf ranch with good insulation with about 4 cords of mostly Ash. Gas bill is about $25 for hot water and dryer.

I'm feeling pretty blessed. My son & I were able to cut and haul nearly 2 cords of Ash home on Saturday. I'd like to be done before it gets warm & buggy.

The dog seems a bit sad/lost now when it's too warm for a fire in the morning.

ATB,
Mike
 
Shari said:
I'm trying to figure out roughly how much wood we will need for a 'season'. I've got a rough idea how much fuel oil we burned per season Isn't there a theory out there somewhere that says a cord of wood roughly equals 225 gallons of fuel oil?

Shari

how many btus is your stove?


ok its 70,000 btu and where you live in the dead of winter your going to use every btu+ it has a 9 hour burn time if your running 24/7 your going to use 7-9 cords if burning in the shoulder months as well..
 
I find another problem in compareing amount of wood to Gallons of oil . I don't know about the rest of you but my house heating with wood is a lot warmer than it would be if I was heating with gas .
 
For the mix of hardwoods that I generally burn I use a figure of 150 gals of fuel oil per full cord.

That being said there are big differences in how the heat is distributed.

My oil burner spreads the heat much more efficiently thru the baseboards all around the house, while my stove is a point source that relies on convection and radiation.

We are very cozy where the stove is but the far reachs of the floor plan require furnace heat to stay at a minimal heat level.

A right sized stove in a central location is probably the most efficient.
 
ok, you are probably asking so you know how many cord you need to heat your house next winter. if you list the following, then I bet we can get a pretty close estimate:

1. What efficiency is your oil burning furnace running at?
2. How much oil did you use last year (or as many years back as you can give us info on)
3. What wood stove/efficiency are you using?
4. What kind of wood will you be burning?

basically, if you tell me you are heating your house with 1000 gallons of fuel oil (140K BTUs per gallon) and you are using a 75% efficient furnace then you are probably only getting 1000x140,000x.75 = 105mBTUs into the house.

So, if you are using 20mBTU wood per cord in a 72% efficient woodstove, then it would take (C=#cord) Cx20,000,000x.72=105,000,000 C=7.3.......

but some woods are more than 20Mbtus and some are less than that.

these numbers aren't exact, but i bet we can get a better estimate that way than saying 140gallons of oil is the same as a cord of wood (and that number actually should be pretty close to true depending on what wood you are using)
 
Around here the rule of thumb is a cord of hardwood equals 150 gallons of fuel oil (like gerry100 stated). If you used that figure you would not go wrong as it should allow for extra wood which one should always have on hand.
 
Well, for some reason I didn't get any notices there were replies to my post - so sorry if it seems I am slow to respond.

Our furnace is only about 5 yrs. old (not a high efficiency) so it is probably around 75-80% eff.

We use(d) around 850 gallons per heating season. Our stove, Oslo, is rated at 75%+ efficient.

We are heating about 1500 sq. ft. (two bedrooms are not used/heated in the winter, with these two rooms we are at about 1750 sq. ft.).

Right now, I have a mix of soft maple, hard maple, elm, locust and a touch of birch on hand. Some is cut/split/stacked & seasoned now, all will be cut/split/stacked and ready for next season. I'm really bad at guesstimating volume of wood before it's all split and stacked but would guess I should have around 4-1/2+ cords by the time I get everything cut/split/stacked.

The reason for my question is hubby & I are having a disagreement - he says "No more wood!" I say "The more the merrier - stack for future years." :) I will continue to scrounge this year but just need an idea how many cords you gurus think we might need per heating season.

Shari
 
Shari, I hope you can talk some sense into his head. You should have a minimum of a 2 year supply on hand.....always. Three years is even better. Why? You will get more heat from your wood (so less needed) and have less problems with fires (dry wood burns nice) and with dirty chimneys (not much creosote when you burn dry wood). That is enough argument to support a 2-3 year wood supply. Good luck.

btw, it looks like you should need from 5-6 cords per year as an estimation.
 
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BS - Heh heh heh - We've been married enough years that he knows he will lose this argument. Besides, I am working on a large storage area in the back yard to store 'future wood'. And, yes, I agree it is a good idea to be at least 2 yrs. ahead.

Shari
 
Hey Shari, you can teach an old dog new tricks. lol
 
i would say go by climate.. for me here, i try to do it by worst case .. .. which I shld burn about a cord a month dec-jan .. so i usually need about 4 ... so i try to keep about 8 cord in my yard as i cannot really store more than tht (10 max) ... anything else i just let the furnace do it.. i love wood but its what ever makes the most sense financially here... this year because of a new little one in the family, i burned about 100 gallons of oil... (mom was home oct -1st week of march) so i wont complain!
 
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I find it hard to actually judge just how much wood I need. I have about a 2800 SF house and the wood burning furnace is tied in with the heating system. Usually burning from when I get home, till when I leave again in the morning. I figure between 8 and 10 cord a year. Usually some left over depending on the winter.. I used to keep it going all day, but we went through a crapload of wood! (and no one is home to enjoy it) The oil will kick in when needed... I do agree with a previous post that the wood is a "warmer" heat! Its like this, the tank will maintain between 180 and 200 degrees when burning, with the oil, ot gets UP to 180, then as the water cycles through, the temp drops... colder water, not warmer room...
 
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