# Out Door Wood Boiler vs indoor EPA Wood Stove (which is better?)



## roknwoe (Jan 25, 2012)

For all the OWB guys out there, please do not take offence at the following.  

I am new to the Hearth forum.  I have researched OWB's in trying to make a future decision about some day about abandoning a 32 year old bullet proof indoor WoodChuck wood furnace in favor of an OWB.

I would appreciate others clarifying any mis-understandings I might have on OWB's in general.

Here it is:
   --I heard a number of $8-$10,000 OWB's only last 10 years or less.
   --Other understood disadvantages: Internal corrosion issues, stress cracking of the steel, OWB consume maybe 50% more wood than an indoor EPA or 
      non-EPA wood furnace?  This means: more wood buying, cutting, hauling, piling, loading more wood into the OWB each time.
   --The good stuff: The fire danger, bugs, dust, is now outside! No more chimney fires/cleaning on the roof of your house.  The wood pile is right next to
      the OWB.  (a big advantage, no more hauling wood into the house). 

    --Here is the assumption/conclusion: A hell of a lot of money for something that does not last very long, in addition to the maintenance, water testing,
       installation, digging 4+ foot deep trenches for the PEX,  etc.).

I have some neighbors, friends, relatives with the older super big units (HeatMor, Central Boiler).  They are used to heat multiple structures: a home and steel building.  Or just a large home.  The big HeatMor for example can burn 1/2 a solid cord per loading. (1 solid cord per day...if the weather is extremely cold).  My HeatMor acquaintence, indicated he once threw a dead deer carcase in the unit, and the next day only the teeth were left! (chuckle!) 

It appears for heating large structures, the $8-10,000 (or more) cost will pay for itself compared to heating these same large structures with oil or gas.

However, for the medium size home (2000 square foot) or less, is the $8,000+ cost for a super efficient boiler worth it compared to an EPA wood stove...if the above OWB disadvantages are true?


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## StihlHead (Jan 25, 2012)

I have had good OWBs and good wood stoves, and a lot of bad stoves, fireplaces and inserts that waste heat, or as in the case of my brick fireplace in California, it sucked up more heat than it gave out and smoked up the house. Currently a Classic Model Central Boiler (CB) is about half the price of a newer EPA CB Classic boiler. As you are near where they are made, shipping would be cheap. A good CB OWB will likely last 20 years, as far as the steel and corrosion go (if you maintain them and keep the anti-corrosion stuff at the right level in the water system). The anti corrosion additive from CB is rather good stuff actually, as tested by several people that I know in the engineering trades. CB has good welds and they hold up. However, their electornics are not all that great and the controller we had in our CB had to be replaced under warantee. They can be bought after the warantee runs out direct from the manufacturer though, and at a substantial reduction in price. I have the data on that around here someplace... 

CB has newer far more efficient EPA certified OWBs that are gassifiers. I have not used them, but they seem to be way better than the older models as far as efficiency goes. The advantages of the OWB are as you list; all the stuff is OUTSIDE. That is a huge advantage. Also there is the advantage of wood cutting size; you can burn LARGE unsplit long logs in an OWB. I smiled when we went to look at CB OWBs at the dealer. He was burning one foot round by 3 foot long logs in his boiler. No need for a splitter, and no need for cutting shrimpy 16" log lengths. You can also heat water with them, or anything that can take a heat exchanger (sidewalk de-icers, garage heaters, pools, hot tubs, etc.), and you can run them to multiple places. They are not long on asthetcs though. An indoor glass door wood stove adds an asthetic value that has no substitute for the GF wanting to be in front of a warm fire inside the house. However, it may not be easy to get heat around your house with a wood stove. For that reason we bought a CB at my ex's place and plumbed it in to replace a very spendy electric hydronic floor heating and hot water system. Her OWB paid for itself in the 4th year of use (no cost for wood, she has over 100 acres of trees there). 

One point also, in some states OWBs of all types are banned, like in WA state. In many states non-EPA OWBs are banned, like in much of New England and New York. OWBs are a lot more expensive than wood stoves. You can get a good indoor EPA wood stove with secondary air burners (62% std. efficiency) for about $1,000-1,200. That is 1/10th the price of a good EPA OWB system. The OWB can do more than heat the house though. So the answer to your question depends on quality of life that you want, your heating situation, asthetics, and how much money you have. If money were no object for me, I would get an CB E-Classic EPA gassifier OWB. Put the wood burning appliance outside and store the wood next to it in a large covered shed. Pipe the heat inside the house and use Hx to get heat where you want it. I am on a fixed budget so I am looking at replacing my older pre-EPA Earth Stove with a newer EPA wood stove. Probably an Englander 30 for about $900 from Home Depot. If I had it to do all over again, I would build a Russian style fireplace in the center of this house and use the radiant heat and cut my wood consumption in half (if not more). That is just not practical though. I do not know what the comparison between a newer EPA wood stove and a newer EPA certified CB E-classic OWB gassifier would be. I would presume that the stove would be more efficient, if only from the radiant heat that would otherwise be lost from an OWB outside. The EPA indoor stove would probably burn 30-50% less wood than the classic OWB (non-gassifier). My best guess. Cord wood has different ratings for different species and moisture content, and cords themselves can be tight or loose stacked. Many variables.


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## peakbagger (Jan 25, 2012)

In my somewhat biased opinion

If you have no neighbors and want to waste wood, go with a conventional OWB without storage. 

OWBs are great when there is a constant demand for heat, but most folks dont need the full output of the boiler all season and most of the time, the boiler has to idle. When they dont have a use for heat, the air supplie(s) typically close shut and the boiler smoulders along cranking out creosote and carbon monoxide. Typically the OWB chimneys discharge at a much lower elevation than a conventional chimney causing even more issues with smoke. Whenever the OWB goes into this mode, the efficiency goes way down so the unit needs far more wood than an equivalent output stove. 

The joke about the deer carcass is unfortunately not a joke to some. A lot of OWB marketing over the years indicates that the owners do not need to season their wood (can burn  green wood !) and dont need to split the wood (can burn full size logs!). Sure the unit can burn green logs but the efficiency drops accordingly and half the heating value of the wood is going to be wasted evaporating water, plus the water vapor drops the boiler combustion temperature below that needed to prevent creosote. Others use them as home incinerator and burn trash. These are all operator issues, its not the boilers fault but an OWB is out of sight and out of mind) 

As for neighbors, if you are in a rural area with hundreds or thousands of feet between neighbors they may not notice an OWB but you will. When the stove is in "smoulder" mode, the odor is not the pleasant smell of wood smoke, its a acrid odor similiar to that given off after a house has burned down and its still smouldering. I expect its not a great thing for the health of the family living near it either.  The smoke is generally worse during shoulder seasons or days when the temps swings signfiicantly from overnight to daytime.

Note my comments are about OWB's particularly non EPA units without signficant storage (which is the majority of the market). If there is enough storage so they can be fired only as long as it takes to heat up the storage, then they can be a lot less intrusive but most folks want to fill them and forget them, expecially if they are outdoors.    

A wood stove can also have some of these issues, its just a lot more obvious and the creosote is not so subtle reminder to learn how to burn. For most folks who want wood heat without the hassle there is a lot to be said for pellet stoves, they still require some attention but far less than a wood stove.

Whatever you do check with your state to see if OWB regulations are in effect, at a minimum you may need an EPA pahse 1 or 2 unit and many of the OWB's out there are not certified.


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## maple1 (Jan 25, 2012)

I see some mixing of terminology in the OP. You want to compare an OWB with an indoor EPA stove, or an indoor EPA furnace/boiler? Night & day difference there.


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## Noggah (Jan 25, 2012)

I am in the first year of a CB outside gasser. I have used about 3.5 cord of wood since 10-28-11. I have found it to have very little smoke. I clean it every two or three weeks, which is only cleaning out the fly ash. I have once cleaned the internal air ports. The stove is very well built and comes with a 25 year warranty. The controls are easy and thorough. Set temp and differential, plus they add air to the box at at set interval to keep the fire going when idle. I am very happy with the stove and think that alot of the rumors you have heard are about the old technology. In Maine you can only install the old technology stoves with 500 ft setbacks from all property lines, so that leaves us spending the money on a gasser. I now think that gasser is the way to go. You do get what you pay for. Just my opinion.


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## maple1 (Jan 25, 2012)

Furnace = central heating device that distributes its heat thru connected forced air ducting.
Boiler = central heating device that distributes its heat thru connected forced water piping.
Stove = space heating device that distributes its heat radiantly or with directed air movement over its surface.


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## stee6043 (Jan 25, 2012)

I have a family member with a Central Boiler (mid sized model) that is well beyond 10 years old and he has had zero problems with it.  He was hassled by his township when he built a new house and moved the unit but other than that, trouble free.

I haven't seen many posts on this site regarding quality problems with any of the popular OWB's aside from the struggles Central Boiler had when they launched their eClassic a few years back.  There were plenty of unhappy users during this first iteration of "customer funded beta testing".  But it sounds like those issues have been addressed.


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## Como (Jan 25, 2012)

When I was looking around I came across other sites that are much more focused on OWB's. There have been plenty of issues. They are not that complicated to make and there seems to be a lot of small companies entering and exiting the market.

But you do seem to be comparing apples and oranges.

I know somebody with a CB E Classic, 2 years old, no problem, but they burn it full on, no idling.

Idling as has been said seems to be where the problems arise.


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## webbie (Jan 25, 2012)

Longevity does have to figure in your decision!

Lots of Tarm boilers from the 70's are still in service today.


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## StihlHead (Jan 25, 2012)

In looking for the EPA efficiency numbers on EPA certified OWBs, the EPA has removed the efficiency ratings and numbers "for further review."


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## Como (Jan 25, 2012)

Shame

Always worth a look and a laugh.


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## Frozen Canuck (Jan 26, 2012)

Yep shame, we all had a good laugh at the 99% eff claim based on EPA tests.


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## StihlHead (Jan 26, 2012)

Well, yah know, we have the EPA efficiency number for all non-cat approved indoor wood stoves. They are all exactly 63%. 
Cat stoves are all exactly 72%, and pellet stoves are all 78%. The EPA magic numbers. 

Seems odd with all the design and material differences that they are all exactly the same.


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## roknwoe (Jan 26, 2012)

Stihlhead:
--Thank you for your large straightforward and interesting contribution. I mistakenly used the word "wood stove" two times in my post, instead of "wood furnace".  This caused confusion and derailment for a number of those that replied.  Sorry about that!   PS:  I thought I was over the top posting at 11:45 PM, but you are really excited about wood burning with a 1:41 AM post.

Peakbagger:
--Based on your comments about how the (non gasification) OWB's actually work, it appears they are not for me. I am not ready for one.  A big smoking unit would not work in the community I live in.  There are just enough homes in the general area, and they would be upset.  You reminded me these are a serious piece of machinery.  Thanks.

Maple1:
--Actually...no!...I don't want "to compare an OWB with an indoor EPA stove".  This was a mistake on my part as noted in the above comment to Stihlhead. I commented on a desire to "make a future decision about some day abandoning a 32 year old bullet proof indoor WoodChuck (basement) wood furnace in favor of an OWB",   as noted in the second paragraph of my post. 

My intention was to compare an OWB (super efficient EPA unit) to an indoor EPA wood furnace. Now that the confusion is hopefully cleared up, we can move forward to the thrust of my original post, and I would welcome your comment.  Anyone with 538 posts (yourself) must obviously have some OWB insights to share.  PS: We have a Wood Chuck "wood furnace" in the basement, and an (EPA) Hearth Stone Heritage soap stone "wood stove" in the living room.

Noggah:
--Thanks for the short to the point information.  You hit the bulls eye.

All Others:
--Thanks for clearing up misconceptions on OWB's in general.


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## StihlHead (Jan 26, 2012)

I live in the Pacific Time Zone... 2 hour time difference. 

No biggie about wood stove vs wood furnace vs OWB vs gasifier in my view. Wood burning appliance designs are all being tilted across the table by the EPA into becoming stoves with secondary burners or cats, and gasifier boilers and furnaces. Which is to say that they are all becoming wood gas burners one way or another. 

Older OWBs are not all smoke dragons. I will post pix of my CB at the ex's place in full operation. I mean really, after all the hype and hooplah about the gazillion tons of smoke that they produce, I have to say that the CB smoked less than my Earth Stove does here at my house, where I burn 1/3 as much wood. The anti-OWB lobby is stong after states like NY posted draconian web sites with photos of home made OWBs burning tires and railroad ties in them. It was a sad use of disinformation.


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