OWB wood usage comparison to oil

[cimalt]

Hello all, first post from Devon in the UK! I stumbled across this site whilst researching OWBs as we are considering buying/building one to replace the 8500 litres (2245 US gallons) of heating oil we use every year to heat our home, office and swimming pool.
The Shaver wood boiler distributer over here in UK says that 1000l oil (264 US gallons) is equal to about 2.25 / 2.5 cords of wood, so I guess 1000 gallons is just under 10 cords and 100 gallons would be 1 cord.
Can anyone confirm these figures based on experience of actually having swapped from oil to an OWB such as this or is this just sales talk.
Vigas wood gasificastion unit claims about half this wood usage (not sure you can get this particular unit in the US though).
I would be most grateful to anyone who can help with this as while we have wood available we don't want to end up having to process twice as much as we estimate after having gone through the process of buying/installing which will be quite some of money!

 

[Marc]

Hello all, first post from Devon in the UK! I stumbled across this site whilst researching OWBs as we are considering buying/building one to replace the 8500 litres (2245 US gallons) of heating oil we use every year to heat our home, office and swimming pool.
The Shaver wood boiler distributer over here in UK says that 1000l oil (264 US gallons) is equal to about 2.25 / 2.5 cords of wood, so I guess 1000 gallons is just under 10 cords and 100 gallons would be 1 cord.
Can anyone confirm these figures based on experience of actually having swapped from oil to an OWB such as this or is this just sales talk.
Vigas wood gasificastion unit claims about half this wood usage (not sure you can get this particular unit in the US though).
I would be most grateful to anyone who can help with this as while we have wood available we don't want to end up having to process twice as much as we estimate after having gone through the process of buying/installing which will be quite some of money!

A lot of people here are experienced with OWB's, but not so much with gasification/forced downdraft units (I've never seen Vigas here, but we have brands like HS Tarm, Eko, Wood Gun, Econoburn etc.). Try at the boards hearth.com.

 

[Husky137]

Those numbers seem unlikely. I gallon of home heating oil has 138,690 btu's. A cord of wood averages between 18,000,000 and 24,000,000 btu's, depending on species. A low end cord of hardwood is going to replace the btu's of 130 gallons of fuel oil. I guess the real question is how effcient the wood burner is at recovering the btu's from the wood.

 

[cimalt]

Apologies- make myself clearer

A lot of people here are experienced with OWB's, but not so much with gasification/forced downdraft units (I've never seen Vigas here, but we have brands like HS Tarm, Eko, Wood Gun, Econoburn etc.). Try at the boards hearth.com.

Sorry, I should have said, the Vigas is only a comparison. I am actually looking into the Shaver wood furnace (a traditional OWB http://www.nextlevelsolutionz.com/) I am simply wondering if any of you out there have switched from oil to an OWB and what your usage of oil WAS and what your usage of wood IS. Hope I have got my point over instead of rambling again!!

Bruce

 

[cimalt]

Those numbers seem unlikely. I gallon of home heating oil has 138,690 btu's. A cord of wood averages between 18,000,000 and 24,000,000 btu's, depending on species. A low end cord of hardwood is going to replace the btu's of 130 gallons of fuel oil. I guess the real question is how effcient the wood burner is at recovering the btu's from the wood.

Thanks. Do you mean unlikely as in a standard OWB is inefficient and will use more than the estimate or is great and will use less?

 

[fletcher0780]

A friend of mine went from using about 800-1000 gallons of oil to 4-5 cords of wood (oak/maple) in a woodmaster (I can't remember the model it's an older one - around 400 BTU's).

This isn't a real even comparison as when he was burning oil the thermostat was set much lower than it is now . FYI, the house is a 7 year old 2400 sq. ft. colonial with a finished basement apartment and hot water baseboard heat located in Connecticut.

I recently bought a Shaver 290 (waiting on delivery) to heat my 3000 sq. ft. log home (radiant heat), 400 gallon outdoor hot tub, 3 car garage (radiant heat), 800 sq. ft. apartment above the garage (baseboard heat). and all domestic hot water. I also plan to add a 24x36 barn in the future (radiant heat). I currently use 1000+ gallons of oil without burning the wood stove or 650 gallons with burning the wood stove and turning the thermostat down to 63. Hopefully I'll only use around 5 cord per year.

 

[mimilkman1]

Thanks. Do you mean unlikely as in a standard OWB is inefficient and will use more than the estimate or is great and will use less?

The standard OWBs are very inefficient, but can require less handling of the wood. In my CB I can cut the smaller pieces around 3ft long and the door on my stove is 24"square. I find it takes a lot less time to cut a truck load of wood for my OWB than it did for my fireplace insert at the last house I was at. Also you can burn green wood in the OWBs but of course you won't get the same btu from the wood. It all depends on how much wood you have access to, I have people calling me almost every week telling me they have trees for me to cut up, and I work for two farmers who have all of the wood I can handle as well. If your looking for efficiency I would look into a gassification unit or here in the US there is a company named Garn that I hear makes the most efficient OWB out there.

Kyle

 

[Marc]

The standard OWBs are very inefficient, but can require less handling of the wood. In my CB I can cut the smaller pieces around 3ft long and the door on my stove is 24"square. I find it takes a lot less time to cut a truck load of wood for my OWB than it did for my fireplace insert at the last house I was at. Also you can burn green wood in the OWBs but of course you won't get the same btu from the wood. It all depends on how much wood you have access to, I have people calling me almost every week telling me they have trees for me to cut up, and I work for two farmers who have all of the wood I can handle as well. If your looking for efficiency I would look into a gassification unit or here in the US there is a company named Garn that I hear makes the most efficient OWB out there.

Kyle

I'm pretty sure Garn boilers are all meant to be sheltered from the weather... but there are supposedly a few Seton style refractory and Tarm style downdraft gasifiers being developed as outside models.

 

[Husky137]

What he said.

 

[Marc]

A friend of mine went from using about 800-1000 gallons of oil to 4-5 cords of wood (oak/maple) in a woodmaster (I can't remember the model it's an older one - around 400 BTU's).

This isn't a real even comparison as when he was burning oil the thermostat was set much lower than it is now . FYI, the house is a 7 year old 2400 sq. ft. colonial with a finished basement apartment and hot water baseboard heat located in Connecticut.

I recently bought a Shaver 290 (waiting on delivery) to heat my 3000 sq. ft. log home (radiant heat), 400 gallon outdoor hot tub, 3 car garage (radiant heat), 800 sq. ft. apartment above the garage (baseboard heat). and all domestic hot water. I also plan to add a 24x36 barn in the future (radiant heat). I currently use 1000+ gallons of oil without burning the wood stove or 650 gallons with burning the wood stove and turning the thermostat down to 63. Hopefully I'll only use around 5 cord per year.

Depending on how cold the year is, from everything I've read, I'd be ready for something more on the order of 10 cords.

 

[dumbhunter]

mot sure on oil, but my house was plumber for propane, got rid of that as i know i couldnt afford to heat with it, picked up a furnace at an auction for $75. so:

furnace-75
wood-free
fuel to haul and process-30
electric for blowers-10 a month
total cost for winter- about 200
wood warmth heat-priceless

 

[fletcher0780]

Depending on how cold the year is, from everything I've read, I'd be ready for something more on the order of 10 cords.

I'm just a couple towns over from you, My friends only had his OWB running for the last two years, his has used 4-5 cords of unseasoned oak and maple. along with lots of junk mail 10 cords would still be a deal, even if I had to buy the wood a log truck load (aprox. 7-10 cord) is only $650 even two loads will be around 30% of what I'd spend on oil.

 

[cimalt]

Thankyou to all those who have replied so far. Very useful!
Yes $75 for a furnace and free wood beats the massive $$$ (£££ over here) of fossil fuels which are rising by the day!
Certainly would like some more comparisons from anyone who has swapped from oil to wood and the figures involved.

Bruce

 

[jdboy9]

I really don't think you will be unhappy with converting over, I don't know of too many people that aren't even if they do run through a lot of wood. At least around here and from what most people say in different states you can get wood for next to nothing, I bet if you try real hard you could find sources for it for free all year. With that in mind regardless of your wood consumption you will be a lot farther ahead in saving money and be able to pay off your initial investment of the boiler in a few years. The cost of fuel is crazy its probably not going to calm down ever so best to start changing your lifestyles before everyone jumps on and these boilers double in price. Plus it wouldn't hurt to try and locate a reliable source of wood because I have a feeling it might start to get pricey as time goes on if you have to buy it.

We converted over to a woodburner 13 years ago and cut our propane usage from 1500+ to less than 250 gallons a year. 2500sqft 1991 home well insulated everything gas also including the dryer.

 

[Marc]

I'm just a couple towns over from you, My friends only had his OWB running for the last two years, his has used 4-5 cords of unseasoned oak and maple. along with lots of junk mail 10 cords would still be a deal, even if I had to buy the wood a log truck load (aprox. 7-10 cord) is only $650 even two loads will be around 30% of what I'd spend on oil.

Definitely not saying it isn't worth it, I'd just prepare to use much more than 5 cord. We've got a lot of people in Woodstock using them, but unfortunately, most of them burn junk wood or wet wood, or let them idle a lot and create lots of low hanging smoke, and most of those people go through wood like it's going out of style. If your friend is indeed only going through 4-5 cords, he's doing very well, even for a well insulated home. My folks have a 2000 sq ft ranch and my old man will go through a very well seasoned 4 cord of good hardwood just burning his VC Encore (catalytic stove) each night and maybe 20% of the winter during the day. Not doubting your story or your friend (well, maybe his cord counting ability) but after hearing what five or six people in Woodstock go through for wood with their OWB, 4-5 cord (especially not seasoned) sounds pretty darn optimistic.

 

[HUSKYMAN]

You will be burning a MINIMUM of 10 cords a year heating the office and pool. The pool is going to eat a ton of wood, unless you only heat it for a month in the fall and one in the spring to extend the season.

Have at least 12 cords, preferably 14, if you plan on firing it at the end of September and running to May.

Depending on what you have to pay for wood, most OWBs pay for themselves in 3-5 years

 

[Hugenpoet]

The information that I have reviewed, mostly from Univeristy/Government sites, indicates that a full cord (128 Cu. ft.) of seasoned hardwood is equivalent to approx. 160 gallons of #2 Fuel Oil. Obviously you can research the equipment sites, but many stove manufacturers have been certified at between 70 and 80% efficient-as compared to the most efficient modern oil fired furnances (86%) and natural gas (91-92%). It is obviously the efficiency of your stove or OWB that drives the economics.

I use Jotul (Norwegian) free standing wood stoves that are approximatley 73% efficient. That obviously translates into a BTU cost that is calculated by dividing the cost of firewood (approximately $170 per cord) by 160 adjusted for the slightly lower efficiency of the Jotul compared to a state of the art oil furnace (approximately 17% less efficiency). The result is that a Jotul produces useable BTUs out of firewood (at $170) for less than 1/3 the cost of oil at $4.00 per gallon.

 

[cimalt]

Thanks to all of you who have contributed to this post. I hope you don't tak offence if I PM/email any of you if I have more in depth questions based on the info you have provided.
If of course you do mind then I guess I won't hear from you!!!