# Newbie advice sought. Looking to replace forest eater...



## bhanks55 (Jan 5, 2014)

Ive been lurking on this site soaking up as much as I can and first I just want to say thanks for all the information. It is a touch daunting though and I finally joined after reading posts since october trying to figure out what I needed to do.
Yeah. I meant my title too. I have a Hardy H4 at the 100 year old 3000sq ft poorly insulated house I just purchased. Apparently everything appears to be updated except the darn insulation. Very frustrating, but I am starting there and foaming in the crawl space,etc and I found out there is NO attic, they sealed in the rafters just like the walls for extra space. So, im loosing quite a bit of heat there. But doing my best. The first priority is replacing the propane furnace as it is 20 years old and my wife says I "must" do that first.

I am looking to figure out the best option for a replacement for the Hardy (still have lines and heat exchangers that function "reasonably" given they were installed in 1990. I measured not ideal but about 5% temp loss over the run (so double that for both ways). I know this needs to be fixed but it isn't "horrible" but the Hardy is terribly inefficient and literally eating wood. Propane would make me bankrupt of course.

What are some reasonable alternatives to upgrade the Hardy without dropping 10K+? Assuming I can just plug it up to what I have? I may upgrade to something very high end but it will be another 5-10 years.

I also cant find any dealers locally cause I don't know where to look I guess except standard OWB like Bryant (forced air, Hardy is EVERYWHERE, and a various others that don't even appear to have a secondary burn chamber.

For a frame of reference when I say "forest eater" the Hardy is literally eating slightly more than a cord a WEEK since Dec 9 when I first cut it on. Heats the house well, but Dang man.


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## maple1 (Jan 5, 2014)

5% each way? So maybe 10° coming & another 10° going? I'd call that a lot. I think you'd see much better ROI just replacing the in-ground piping THE RIGHT WAY than you would in replacing the boiler. But you'd still be stuck with the Hardy. I'm pretty sure I wouldn't just replace it with another OWB & leave those lines the way they are. Any chance of doing an indoor boiler?


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## Bob Rohr (Jan 5, 2014)

bhanks55 said:


> Ive been lurking on this site soaking up as much as I can and first I just want to say thanks for all the information. It is a touch daunting though and I finally joined after reading posts since october trying to figure out what I needed to do.
> Yeah. I meant my title too. I have a Hardy H4 at the 100 year old 3000sq ft poorly insulated house I just purchased. Apparently everything appears to be updated except the darn insulation. Very frustrating, but I am starting there and foaming in the crawl space,etc and I found out there is NO attic, they sealed in the rafters just like the walls for extra space. So, im loosing quite a bit of heat there. But doing my best. The first priority is replacing the propane furnace as it is 20 years old and my wife says I "must" do that first.
> 
> I am looking to figure out the best option for a replacement for the Hardy (still have lines and heat exchangers that function "reasonably" given they were installed in 1990. I measured not ideal but about 5% temp loss over the run (so double that for both ways). I know this needs to be fixed but it isn't "horrible" but the Hardy is terribly inefficient and literally eating wood. Propane would make me bankrupt of course.
> ...




I'm in Missouri Hardy country also, four of my neighbors smoke up the countryside with them.

One, maybe simple, upgrade is to insulate around it better.  I'd guess they lose 20- 30% of the energy to the great outdoors, very thin fiberglass insulation around them  A additional shed around it would be one method to limit that loss.

Here is what one friend did, he spray foamed a container, put the Hardy and a 1000 gallon dairy tank inside.  It cut the wood consumption down, and allows him to store some wood inside to dry it out.  The additional storage inside an insulated container allows him to coast a few "non-burn" days. He's a heavily armed prepper type dude, so you don't want to drive up and surprise him.  Call ahead if you want to visit 

Most hardy owners are convinced green and wet wood is the best fuel source as it smolders for days.  Don't buy  into that theory.

Insulate the beast, use some dry hardwood and you will see a world of difference, but you still have an appliance that runs about 40% efficient.


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## Coal Reaper (Jan 5, 2014)

Cord/week?!?  What kinda cord we talkin here?


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## sjfrench (Jan 5, 2014)

I'm also in Missouri.  We are down in the Joplin, MO area.    My father had a Hardy next door to us and he fed the beast constantly.  It was installed properly and he had great insulation, that Hardy just seemed to eat wood for breakfast, lunch and dinner, and occasionally a late-night snack.  He was heating about 5000 sqft.  I got the pleasure of feeding it on several occasions when he was out of town.  Hated it.  I always reeked of smoke when I was done.  I will say that the Hardy did a great job at keeping his house very warm.  He had radiant floor heat and I'd nearly break out in a sweat when I walked into the house.  It just took a lot of wood to keep it satisfied.  He built himself new home and didn't put in an OWB...if that tells you anything. 

We've got acres and acres of woods, so I knew I wanted to heat with wood,  I just wanted something that I deemed more efficient that his Hardy system.   So, just like you I started the search for the "best" boiler.  My system is probably not the answer since you want to avoid dropping $10k, but you are more than welcome to come take a look.  I just finished a Garn WHS2000 install about three weeks ago.  It's going to be -4 here tonight and we are toasty warm.  I'm heating about 8500 sqft and two 50-gallon DHW tanks.   I've loaded the unit twice today and the Garn has no trouble keeping up with demand.  Over the last week, I usually loaded the system twice a day.  It may be more than you want to spend, but you could also look at a smaller unit like the Garn Jr.   I've got a great sales rep in Ken Oaks with Oaks Sales that I can pass along.  He could help you estimate the actual costs for a Garn install.  He is great to work with.  

Overall, I'm using about the same amount of wood in my Garn to heat my entire house than I was using in our expensive and so-called "efficient" insert that had duct work w/ blower system that went out to a several large rooms.  I stopped feeding the fireplace insert and sacrifice all my wood to the Garn now, since I'm getting twice the heat with the same amount of wood.  My electric heating system hasn't kicked on for three weeks...and I love it!  I've got no idea on how much wood I'll use this year, I scavenged the house under construction next door and took all their scrap they were piling up to burn.  Without the construction scraps...I'd guess that I'd be using about two cords per month.  That's just a guess.

Our current forced air system is all electric, and in the last two weeks of December, the Garn has already cut our monthly electric expenses by about half since we've been running it.  Can't wait to see what it does with a full month of operation.  

Again, I'm not suggesting this would be a plug and play with your Hardy, but it would at least help you consider alternatives.  Let me know if you want to come by and take a look at the Garn.  I feel your pain.  I researched this forum for four months before I pulled the trigger on the Garn and the entire install process (building, wood shed, mechanical) took us about four months. So glad it is all done now.


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## lexybird (Jan 5, 2014)

I couldn't imagine feeding a cord of wood Into a furnace every week  . That's what I use in a. 5 week period in my epa drolet wood furnace  to heat a 2,000 sq ft house


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## bhanks55 (Jan 5, 2014)

yup. It really does eat that much. I wanted to see what it would do and I kept it at 71 in my house tonight and it kept up just fine, but I have filled it up 3 times since first thing this morning. Almost empty each time, I filled it at least 3/4 full and it has a 9cubic foot box. You do the math in this weather...My definition of a cord is a 128 cubic feet. I found out after the fact that the previous owner routinely would cut 20-22 cords per year. He also told my neighbor he spent 900 bucks in one month on propane so fired this beast back up. Obviously something has got to give...

When it rains it pours I guess. Made a move to try to get more room and better location for my ever expanding family and ended up with a money pit.
I just replaced 500 ft of water line around the barn and house this fall, so I am more acquainted than I want already with the excavator operators locally. The only thing left is to redo the main house supply and that would be crossed by the furnace lines. Hadn't wanted to spend that extra 5K, mainly because ive already dropped 20K on this place unexpectedly already. Main thing I want is to get something sustainable. If that requires sucking it up taking out even more money on a loan and redoing it all I guess such is life I just need to figure out my options.

Sjfrench I would love to talk to you more about your Garn at some point. That is what I was hoping to eventually go to, but I figured based on what I have seen here that would top 20K pretty easily without a building. Do you use a heat exchanger or do you use radiant. I hear it excels at radiant.


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## maple1 (Jan 6, 2014)

Don't have an unused chimney in the house that you can get a stove hooked into quickly by chance?

That would give some quick relief for this winter, maybe, using less wood - but you'd need dry wood to run it.

Good luck, either way.


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## Coal Reaper (Jan 6, 2014)

that is an asinine ammount of wood.  a neighbor came over to check out my system, he actually built my house and used at least 1200 gallons of oil each year when he lived in it.  i told him i expect to go through 6 cords of wood this heating season and he said he will do 12-15 with his OWB.  then laughed "you really think this little thing is going to heat the whole house?"  i am on par to be the one laughing when the trees start blooming soon...


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## sjfrench (Jan 6, 2014)

bhanks55 said:


> Sjfrench I would love to talk to you more about your Garn at some point. That is what I was hoping to eventually go to, but I figured based on what I have seen here that would top 20K pretty easily without a building. Do you use a heat exchanger or do you use radiant. I hear it excels at radiant.



Just shoot me a PM and we can set up a time to talk about the Garn and/or let you come take a look.


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## bhanks55 (Jan 6, 2014)

I do actually. It has an inefficient insert I sealed up with foam board. It is in the addition that isn't too bad to heat. The main 2300ft did but the sealed it off. Thought the same thing. Have two real young kids and wife isn't thrilled about red hot objects in middle of area either. Again main issue is the main house with no chimney. I"had" 2-3 cords of very seasoned wood until last week I started in on it too. Expected I am gonna have to just suck it up this winter but more planning for spring so I don't end up here again.


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## heaterman (Jan 6, 2014)

Sounds like a great application for a Garn. Yah they are not cheap but you'll buy it one time and be set for the next 20-30 years given decent maintenance. We service more than a few that are 25 + years old and we rebuilt an ancient 1500? for a guy that was serial number 44. That places it in the first year or two of production circa 1982-83.
There is no simpler wood burner on the market when it comes to just fire and forget operation. No air adjustments, no dampers to play with, no O2 sensors, just a good design that is very efficient, rugged and almost idiot proof......(I have experience with the almost idiot proof part....)

Putting one in an outbuilding or in a shipping container works great. In fact, the factory makes a prepackaged, pre-piped unit that they ship primarily to Alaska, all bundled up in a container. Huge dollars but it's literally plug and play. Not something that you would buy for your application but it's a proven concept and could easily be done locally. 

I know it's like the ice age out there right now and the panic button has been mashed flat but now is not the time to make a hasty or temporary decision on a wood burner. My advice would be to struggle through the next 3 months and do something rational when spring gets here and you can take your time figuring out what to do.


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## heaterman (Jan 6, 2014)

Coal Reaper said:


> Cord/week?!?  What kinda cord we talkin here?




Those would be full 4'x4'x8' cords. One of my sons has an H4 that came with the house when he bought it. He's saving his shekels until he can buy something else but in the meantime he burns about a cord and a half per week in this kind of weather.
They are literally "forest eaters". We've had the combustion analyzer stuck in the flue pipe a few times just playing with different types, and dryness of wood. The best efficiency we ever observed with that thing was 34% with seasoned oak. Most times it is under 30%. ....There oughta be a law.....The fuel consumption is absolutely criminal with those things.


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## bhanks55 (Jan 6, 2014)

Agreed. I was thinking about spring and figured I have the cards dealt for now. I won't have money for a garn for at least 2-3 more years at minimum more like5/10. Trying to fill the gap til then. Looks like at minimum best Roi is gonna be replumbing and whatever I hook it too will work even the forest eater. Figured most 2 stage units of any kind was better than the hardy and was looking for recommendations that will get me through a few years and I could resell I guess. May not be good to do that and just replumb and hook to hardy until I can do for good. Just don't know efficiency differences.


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## heaterman (Jan 6, 2014)

bhanks55 said:


> Agreed. I was thinking about spring and figured I have the cards dealt for now. I won't have money for a garn for at least 2-3 more years at minimum more like5/10. Trying to fill the gap til then. Looks like at minimum best Roi is gonna be replumbing and whatever I hook it too will work even the forest eater. Figured most 2 stage units of any kind was better than the hardy and was looking for recommendations that will get me through a few years and I could resell I guess. May not be good to do that and just replumb and hook to hardy until I can do for good. Just don't know efficiency differences.




For now, the best advice here would be Hot Rod's (Bob Rohr). Insulate the Hardy as best you can and think about how you could get it in a container or building of some kind.  Having enough room to get a cord of wood inside to thaw out makes a big difference!  
If there is ANY way you can stop in and yak with Bob for a while you will find him to be a wealth of knowledge regarding piping, hydronics in general, burning wood efficiently and just simply one of the nicest guys you'll ever meet. An hour or two picking his brain face to face is worth hundreds if not thousands of $$. One of the best hot water heating guys in the USA and that is not a joke.


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## Bob Rohr (Jan 6, 2014)

bhanks55 said:


> Agreed. I was thinking about spring and figured I have the cards dealt for now. I won't have money for a garn for at least 2-3 more years at minimum more like5/10. Trying to fill the gap til then. Looks like at minimum best Roi is gonna be replumbing and whatever I hook it too will work even the forest eater. Figured most 2 stage units of any kind was better than the hardy and was looking for recommendations that will get me through a few years and I could resell I guess. May not be good to do that and just replumb and hook to hardy until I can do for good. Just don't know efficiency differences.




There are plenty of companies around SW Missouri that build those outdoor storage buildings, metal or wood.  Some are built without floors and you could drop one right over the Hardy, size it large enough for some wood storage, garden tools. etc, Buy a roll of fiberglass batt insulation and seal it off nice and tight.  Pipe the blower air intake thru the side.  This might be the least expensive way to limp the Hardy along until you can upgrade,  and provide a building for other uses.

I can barely purchase the materials for what the Amish build and sell those portable building for around here, nice workmanship, PT lumber, metal roofs.

If you have a large DHW load add some solar panels to that building.  -2F here today near Springfield and my solar DHW kicked on before 9:00!

Here is one of the buildings I had build to house a gasification boiler.  I put glass on one side to turn it into a solar heated greenhouse and tool shed.


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## maple1 (Jan 6, 2014)

heaterman said:


> There is no simpler wood burner on the market when it comes to just fire and forget operation.


 
If the Garn has a fan - I humbly submit my objection.


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## Fred61 (Jan 6, 2014)

There's a fan in your computer.


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## maple1 (Jan 6, 2014)

Ya, but it doesn't burn wood.

I don't think.


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## heaterman (Jan 6, 2014)

maple1 said:


> If the Garn has a fan - I humbly submit my objection.



I hear what you're driving at...

What I was referring to was the overall design, integral storage, no adjustments needed for optimum operation.


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## bhanks55 (Jan 6, 2014)

sounds like a plan. How do you get the stack off to get the creosote out? The darn thing is not insulated and I get a ton of buildup without a double wall. Will the building retain enough heat to solve that problem? They seem to only have single wall and not sure if a double wall connection for the top will adapt as it goes through the roof. Also no sure how to plumb an intake in the back.


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## bhanks55 (Jan 6, 2014)

I get much less with the seasoned wood but still get much more than I would like.


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## leon (Jan 6, 2014)

bhanks55 said:


> Ive been lurking on this site soaking up as much as I can and first I just want to say thanks for all the information. It is a touch daunting though and I finally joined after reading posts since october trying to figure out what I needed to do.
> Yeah. I meant my title too. I have a Hardy H4 at the 100 year old 3000sq ft poorly insulated house I just purchased. Apparently everything appears to be updated except the darn insulation. Very frustrating, but I am starting there and foaming in the crawl space,etc and I found out there is NO attic, they sealed in the rafters just like the walls for extra space. So, im loosing quite a bit of heat there. But doing my best. The first priority is replacing the propane furnace as it is 20 years old and my wife says I "must" do that first.
> 
> I am looking to figure out the best option for a replacement for the Hardy (still have lines and heat exchangers that function "reasonably" given they were installed in 1990. I measured not ideal but about 5% temp loss over the run (so double that for both ways). I know this needs to be fixed but it isn't "horrible" but the Hardy is terribly inefficient and literally eating wood. Propane would make me bankrupt of course.
> ...


 

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

About your boiler;


You lack thermal mass, that is the elephant hiding in the
refridgerator after he puts his toes in the pumpkin pie. 


Now as far as what I did with my boiler which is an
inside coal wood boiler:

I filled the boiler half full of the full sized firebrick to create thermal mass.

I purchased piece of channel iron 12 inches wide and 12 inches long and laid
it on the angle iron that carries the coal grates to avoid having problems with
shaking the grates.

You could most likely fill it half full or better with two standard pallets of fire bricks and
you will have a huge amount of thermal mass that will keep the fire hot, reduce the smoke
and reduce the amount of cycling on and off.

Even the smallest fire kept burning will heat the firebrick and the fire brick will shed the heat
back into the combustion chamber increasing the burn temperature simply because the
heat is radiating from the firebrick.


You need to find a wholesale retail cement stone products distributor to get a good price
rather than buying the fire brick from a local shop.

I am sure they could deliver and off load two pallets of firebrick for you with no issues.

Ideally pizza oven firebrick would be excellent also as it would be larger-12" by 12"

I am sure they could get it or point you to someone else who sells it.


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## maple1 (Jan 6, 2014)

That's assuming the boiler has good heat transfer efficiency and is very well insulated. If it is neither, it will always be a forest eater.


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## heaterman (Jan 7, 2014)

maple1 said:


> That's assuming the boiler has good heat transfer efficiency and is very well insulated. If it is neither, it will always be a forest eater.



Yep. Kinda like the old silk purse out of a sow's ear thing. It will never be efficient as there is no secondary combustion and very limited heat transfer surface area.


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## heaterman (Jan 7, 2014)

bhanks55 said:


> sounds like a plan. How do you get the stack off to get the creosote out? The darn thing is not insulated and I get a ton of buildup without a double wall. Will the building retain enough heat to solve that problem? They seem to only have single wall and not sure if a double wall connection for the top will adapt as it goes through the roof. Also no sure how to plumb an intake in the back.


..

Getting the Hardy inside will reduce creosote somewhat simply due to less cooling of the stack. I think you could probably get a single wall x Class A chimney adapter and go up with insulated pipe but you will still get a gob of creosote in the stack. It's just the nature of the beast. 
I don't know as I would spend the money on it.

However.....if you do put it inside and run the stack up through the roof, make sure you allow a lot of clearance to combustible materials around it. Keep anything that will burn at least 6" if not more, away from the stack. Reduced clearance would probably be a logical reason to go with a Class A chimney.


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## bhanks55 (Jan 7, 2014)

how large of a building is recommended for most applications? Assuming the largest unit (Garn) how big of a building would I need if I was to house that unit, a cord of wood,etc, in the future? Basically, if I am going to the trouble and expense of building a building I figure I should just build once.


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## maple1 (Jan 8, 2014)

I would build it big enough to hold my whole winters wood, if I had the room.

Or, if you don't want to build the whole 'boiler shed' itself that big, add on a simple wood shed type thing so you could at least get the whole winters wood under a roof & easy to get at from the boiler. Moving firewood in the winter to burn it is an absolute drag - even worse if it's full of ice & snow. If it's warm & dry it will burn a LOT better, and it will make feeding a lot easier.


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## bhanks55 (Feb 1, 2014)

Also got some nice confirmation on where my heat losses are. The second story peak is my largest heat loss. I noted there was never frost there (obviously a bad sign, but it melted a 1/4 inch of ice). OUCH. cant imagine the heat load im losing there. No real way to insulate more either. They boxed in all the rafters with drywall and there isn't an actual attic.


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## NE WOOD BURNER (Feb 1, 2014)

I wonder what the temp difference would be if you ran new thermo pex or logster above ground temporally.


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## STIHLY DAN (Feb 2, 2014)

bhanks55 said:


> Also got some nice confirmation on where my heat losses are. The second story peak is my largest heat loss. I noted there was never frost there (obviously a bad sign, but it melted a 1/4 inch of ice). OUCH. cant imagine the heat load im losing there. No real way to insulate more either. They boxed in all the rafters with drywall and there isn't an actual attic.



Is there any space up there at all? If so they can drill a 3" whole from the outside and blow in insulation.


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## bhanks55 (Feb 7, 2014)

STIHLY DAN said:


> Is there any space up there at all? If so they can drill a 3" whole from the outside and blow in insulation.


Problem is no attic per se. Gonna get a foam contractor to see what he can do when money allows. This winter has bled me dry.


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## lexybird (Feb 8, 2014)

heaterman said:


> Those would be full 4'x4'x8' cords. One of my sons has an H4 that came with the house when he bought it. He's saving his shekels until he can buy something else but in the meantime he burns about a cord and a half per week in this kind of weather.
> They are literally "forest eaters". We've had the combustion analyzer stuck in the flue pipe a few times just playing with different types, and dryness of wood. The best efficiency we ever observed with that thing was 34% with seasoned oak. Most times it is under 30%. ....There oughta be a law.....The fuel consumption is absolutely criminal with those things.


That's incredible to me .. I would think an open campfire would not even use that much wood in such a short time


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## Frozen Canuck (Feb 8, 2014)

lexybird said:


> That's incredible to me .. I would think an open campfire would not even use that much wood in such a short time



Yes most have no idea just how much wood an OWB will go through. Now factor in standby losses from the shell as these all sit outside exposed to whatever the weather is & the typical <30% can quickly become <20%. Makes one wonder what is really going through the minds of folks who get upset at OWB's having a bad rep. They earned it. Yep there oughta be a law indeed.


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## bhanks55 (Feb 8, 2014)

Ad that to how they recommend the lines be installed. Just put them in a pipe and foam the ends to keep the water out. Seriously, my local hardy dealer is saying that. So factor in that loss too. Crazy thing is even at that horrid efficiency I can BUY wood here right now and save half compared to my 80% lp furnace. Nutts





Frozen Canuck said:


> Yes most have no idea just how much wood an OWB will go through. Now factor in standby losses from the shell as these all sit outside exposed to whatever the weather is & the typical <30% can quickly become <20%. Makes one wonder what is really going through the minds of folks who get upset at OWB's having a bad rep. They earned it. Yep there oughta be a law indeed.[/quot


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## Frozen Canuck (Feb 8, 2014)

Yes I have read the posts about LP prices, they went up fast. Kind of a double edged sword, when the price of a product is low millions of barrels of it's production gets set aside as distillate for the bitumen in the pipelines. Which always seems to lead to a shortage of said product & a rise in prices.


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## bhanks55 (Feb 8, 2014)

Always rubbed me too when I lived down south. The gas (believe natural gas) wells were forced to burn off x amount because of gov regs not allowing them to take but so much. Couldn't cap apparently and had to burn of not piping or storing it I was told repeatedly by the people working those fields.


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## Frozen Canuck (Feb 8, 2014)

Yes same here wells flaring 24/7/365. I swear if I hear about a NG shortage I may just crawl right out of my skin. Billions of btu's/hr to warm the atmosphere….for what?


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## coyote556 (Feb 11, 2014)

bhanks, which hardy dealer are you dealing with.  I have been looking around for different dealers in central missouri so I can look at all different OWB models.  I did not know there was a hardy dealer in central MO (not that I really want one after this thread)


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## bhanks55 (Feb 11, 2014)

His name is Jason Moore. Lives north if centralia. If interested I can get contact info.

On a side note, I was looking more into a building for this and don't see his I can build one much karger than the unit itself. Here is why. If I have enough room in front to work and pile wood inside I honestly think without a vent hood I would need a gas mask with all the smoke that bellows out the front door.  Vent hoods appear to be pretty pricey  too. Anybody use one they like that is reasonable in cost?


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## bhanks55 (Feb 19, 2014)

Well,
We just got a heat exchange test today. I imagine that is a significant part of the problem as anticipated. 91% per hour.....


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## leon (Feb 20, 2014)

So it sounds as if you are not interested in a coal stoker for much less money and work?


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## bhanks55 (Feb 20, 2014)

Don't know much about them. You have info to share?


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## leon (Feb 20, 2014)

Coal stokers use anthracite coal(hard coal) to heat with forced air, hot water or steam
which is the most efficient method for heating using low pressure steam single or two
pipe radiators(single pipe radiators being the preferred method with less plumbing
required and they use thermostat/regulator attached to each radiator.


Stoker coal sizes 

1. rice,
2. pea
3. buckwheat   


Most coal stokers are CSA, UL, ASTM certified or can be certified to the ASTM standard
which is the highest testing standard in the United States for steam  heating and the
ASTM rating garantees your insurer will except it as long as a certified licensed plumber
does the installation.  

Stokers types are classified as either: 

1. underfed/screw fed 

2. walking grate

3. pusher plate with an overfed combustion grate

4. coal gun


The underfed screw fed/burn pot "retort" stokers use an auger that does three jobs

1. meters the amount of coal fed to the burn pot/retort 

2. has a gear powered coal feeding auger drive that is either belt driven or powered
    through a reduction gearbox

3. the underfed coal stokers have a gear driven auger that feed the coal to the burn pot/retort
    with an auger and tube assembly.    

a. underfed coal stokers have an adjustable air shutter that regulates the combustion air volume
    entering the burn pot/retort.

The coal stokers using the overfed coal pusher plate type combustion coal grates  have combustion air that is forced up through the coal bed and the burnt coal falls off the end of the grate assembly(wood pellet burners use the same method).

There are two manufacturers of walking grate coal stokers for residential/ commercial use.

The walking grate coal stokers use pea or buckwheat sized anthracite coal.

The walking grate stokers uses either a belt drive or direct drive single speed combustion fan with.


One manufacturer uses an auger fed system that feeds the coal to the walking grate as required by the aqaustats calling for heat

The other manufacturer uses a gravity fed storage hopper that is either fed manually with a pail of coal or by an auger from a bin with a coal level sensor switch in the hopper.

The walking grate is pulled back and forth with a gear driven arm that pushes and pulls the grate which in turn meters
the coal in the coal inlet tube to the fire which is burning on the walking grate and the coal continues to burn under a
forced draft until the coal is burned to a fine ash and falls off the end of the walking grate to the collection basket.



There is more to them but I do not want to wear out my welcome on the forum.

If you visit the NEPA digital coal burning forum you will find awealth of information
about coal stokers.


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## bhanks55 (Feb 25, 2014)

Frozen Canuck said:


> Yes most have no idea just how much wood an OWB will go through. Now factor in standby losses from the shell as these all sit outside exposed to whatever the weather is & the typical <30% can quickly become <20%. Makes one wonder what is really going through the minds of folks who get upset at OWB's having a bad rep. They earned it. Yep there oughta be a law indeed.


Well, I was able to do calculations based off my usage of propane on cold days (for MO). This slightly overestimated for a year's usage, but definitely shows a huge difference. Trying to justify with my wife a new gasser. Also, assumes BUYING wood. Which honestly I only have time to cut like 4-6 cords a year MAX, so I figure I will have to work in the estimate of a furnace two full years of wood (one already seasoned,to get ahead so to speak). At a rate of expected cost of 20K it is hard to "sell" an 8-10 year payback when our funds are low. I guess I will keep scrounging to save up so one day, so to speak.

On a positive note, I tore a TON of drywallout of the attic and found some kneewalls that allow pretty good access. It was APPAULING the lack of insulation. The foam guys are gonna foam ALL my accesses, the entire crawl space, and the basement Wednesday. Has to make a difference, just nobody knows how much yet. This place is " very drafty" currently with 91% heat exchange per hour. Good part is my county electric company has large rebates going right now that are gonna cut the price almost in HALF. So, it was a nobrainer this was the place to start.


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## leon (Feb 25, 2014)

AAAAYYY Caramba Lucy,
I realise we burn here but
your house is as leaky as
mine is


Even with Eastern anthracite coal being $13.00 a (100 lbs.)
picked up in bags you will spend less money than burning wood.

you can certainly afford a coal stoker like an Alternate Heating Systems S130
AB Vanwert 90, Keystoker KA6, Axeman Anderson 130-M.

Adding a domestic loop will save you even more money versus propane OR wood


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