Experience with outdoor woodburners?

[Jimmy Joe]

I have been interested in outdoor boilers for years, only thing holding me back is my wife thinks they are not too efficient. I can buy pulpwood for $8o.00 a cord or less delivered in 10 to 12 cord loads this is hard wood! The question I can't seem to get an answer to is how much wood will I burn in a year. My house is 8 years old, 1800 square feet, well insulated with forced air heat. I also have a 26by 34 by 10 shop with in floor heat. I live in central Wisconsin where -20 is not uncommon but most times 0 or above. Anyone have any ideas?
JJ

 

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I have been interested in outdoor boilers for years, only thing holding me back is my wife thinks they are not too efficient. I can buy pulpwood for $8o.00 a cord or less delivered in 10 to 12 cord loads this is hard wood! The question I can't seem to get an answer to is how much wood will I burn in a year. My house is 8 years old, 1800 square feet, well insulated with forced air heat. I also have a 26by 34 by 10 shop with in floor heat. I live in central Wisconsin where -20 is not uncommon but most times 0 or above. Anyone have any ideas?
JJ

Well if its any help, I have 2 people I know who heat their abodes. One is heating a house with no insulation and a work shop and his dhw of course. He has no other back up system and his boiler is made by Garn. He uses 12 cords per year loading 3 times per day. My second friend uses a new Central boiler with new technology. He's using about a cord per month heating a 15oo sq ft home which is well insulated. He loads once per day but it cost him $15000 to install.

 

[Floydian]

I highly recommend spending some time on Hearth.com. Go to "the boiler room".
Your wife is correct, most outdoor wood boilers (OWB) are extremely inefficient.
Burning efficiently means burning hot, burning fast. Any boiler is less efficient if it's cycling on and off.A Wood gasification boiler set up with a water storage tank can achieve up to 90% system efficiency. Most OWB's range from 25-40%.
Most wood gasification boilers need to be in an enclosed building or basement or shop. As far as I know, there are only a few outdoor gasifiers out there. The Central Boiler E2300 being one of them. If you can spare the room in your shop for a boiler+storage, assuming its not to far from your house, you could have a nice heating system that could also take care of your domestic hot water year round.Anyway, check out that site-its the best.

Good luck,
Noah

 

[Diesel-ME]

I have been interested in outdoor boilers for years, only thing holding me back is my wife thinks they are not too efficient. I can buy pulpwood for $8o.00 a cord or less delivered in 10 to 12 cord loads this is hard wood! The question I can't seem to get an answer to is how much wood will I burn in a year. My house is 8 years old, 1800 square feet, well insulated with forced air heat. I also have a 26by 34 by 10 shop with in floor heat. I live in central Wisconsin where -20 is not uncommon but most times 0 or above. Anyone have any ideas?
JJ

My brother lives up in the Park Falls area - he burns about 8 pulp cords of hardwood (seasoned) a year heating an older but similarly sized house. He has a hot air furnace inside acting as the hydro-air for the outside wood bolier.

I burn about 12-14 cords heating a larger and way older house in Maine. I loose some efficiency in a water-water flat plate heat exchanger between my OWB and my inside boiler. I save about $4000-$5000 a year as compared to oil so I could care less about the relative efficiency. Having said that I will add that I have a boiler with a forced draft and don't usually burn any green wood, so I get as much heat as I can out of my wood and with little excess smoke.

Your mileage may vary, Paul

 

[Jimmy Joe]

Thanks for the responses so far. Park falls isn't that far north of me and I often thought if I could get by on 10 pulp cords or less it would be worth while. I have a lot of sources of free wood I could get but if I ever didn't want to do it I wanted to know what it would cost if I bought the wood instead. Paul, what brand of boiler does your brother have. Thanks
JJ

 

[Diesel-ME]

Thanks for the responses so far. Park falls isn't that far north of me and I often thought if I could get by on 10 pulp cords or less it would be worth while. I have a lot of sources of free wood I could get but if I ever didn't want to do it I wanted to know what it would cost if I bought the wood instead. Paul, what brand of boiler does your brother have. Thanks
JJ

An older Central boiler - smallish model.

I guess they sell lots of boilers and their new models belch less smoke. But I still don't like the fact that you have to let the fire die out weekly so as to shovel the ash out. I have a Heatmor which has both forced draft (less smoke one might argue) and grates that the ash falls through for easy clean out (auger). Conversely, I wonder if the Central extracts more heat out of the wood than the Heatmor....

~paul

 

[Jimmy Joe]

I looked at the Heatmor, looks like less chance for it to get leaks with no water under the fire box where the ashes lay. But I also wonder about losing heat out the bottom of the unit.

 

[Diesel-ME]

I looked at the Heatmor, looks like less chance for it to get leaks with no water under the fire box where the ashes lay. But I also wonder about losing heat out the bottom of the unit.

That has not been a problem. Between the concrete pad and the boiler you just lay a sheet of that Reflectix (or similar) foil/bubble insulation. It works because I have snow all around the base of my boiler all winter. Plus the sand and firebricks retain lots of heat. A good design in my opinion.

~paul