wood boiler

[handpa]

we have an attached garage if i put a 55 gallon drum burryed in sand with copper pipe running threw it will the house insurance go up?  http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_20894_20894

is this worth it and will it work, i am planing on using forced air so that there is less smoke and the wood will burn hotter and faster.  if i can not put this in the garage i am planing on building a small shed right outside and running the water threw some pex, inbetween i will put 3 in. pvc with some kind of insolation inside it. how big of a water storage tank will i need, i was thinking 2 of those blue 55 gallon drums?

[hiker]

same kit i bought up here in alaska--door cracked after the first fire up [small hairline crack]..other than that it works okay..

as far as your insurance--its up to you to let them know..  me-i would just keep it to myself.-insurance is the biggest scam out there[car]!!

i dont think i would use plastic barrels for hot water storage--not with the way your doing it -forced air-fast burn=some mighty hot water..was thinkin the same but just wrapping  a big coil of copper tubing all the way around the outside of the barrel--gets mighty hot there when you build a proper fire and close up your stack flipper and close the air intake down..will burn for hours like that[hot]..plus you would save a whole lot of wood that way..

[handpa]

well this is not my house its my dads but a got a room thats open on 3 sides, is ontop of our unheated garage, and has snow on the other side of the roof.  its the coldest room in the house and noone els seems to think i need a room i dont freez in.  was thinking this would be cheaper than a electric heater, and give me somthing to do (build and split/feed it wood). how safe is somthing like this? i dont see any way it could start a fire if is on a cement flor covered by tons of sand. also we dont have any dry wood for this season because im spliting it now is there somthing els that could be burnt in it, im thing sticks and leafs, maby cardboard and wast paper?

[nailed]

You don't need to have aged wood.  You're going to be burning this stove hot witch means your flue will be hot.  You should not get a build up.  If you put it in a small shed then you could put 2 days of wood in it and dry it part way out that way.  

As far as building a shed you should go for at least 3 feet off the house. I would try for 10 feet.  I would run 12" PVC with a 6" PVC in side of it.  Insulate between and don't let the copper pipes touch the PVC.  

I would think an open system would be the best setup.  Large water tank 55 gallons (2 would be better) or more, then a pump that pushes the water around the coils of the stove, and gravity return system.  Just remember when the pump is off the water draining out of the system will need somewhere to go.  

I would not burn cardboard or paper.  

[jmk]

 I have a wood boiler and they tell you not to burn paper, leaves, plywood, treated wood, or garbage. You can burn regular lumber in it because it doesn't have any glue in it. All those things will make an acid smoke that will eat your furnace up. Just like a burn barrel. I buy a product from them called ashtrol. Once a day I trough in a spoonfull at a differant spot and it helps to nutrolize The acid build up.  

[handpa]

well i need to have a clean burning fire with out to much smoke because i live in town and dont want others to get mad at us.  and i think that freshley split wood would burn colder because of all the water that has to be boiled off before the wood will burn fast and this takes a lot of heat a way from the fire creating more smoke or so i under stand.  i dont realy care about build up if this ends up in its own shed because i plan to clean the chimny by starting the build up on fire. then cleaning it with a brush.

[mikey ny]

Hello Handpa,

         A little more info would be helpfull.#1, As far as Home owners ins. is concerned, you should definitly check on that. In some state's it is only a $50 dollar increase in the yearly premium.#2, Don'nt forget, unless you get free materials and free wood and free labor, everything has a payback period. #3 you should only burn good seasoned wood in any wood burning stove, not card board or other stuff .Roughly do the math and see what  it is worth to you. If you build a shed, install a wood boiler ( homebuilt or aquired free) buy the pipe, fittings and controls and spend the time to collect cut and split the wood, you may think twice about how to go about heating a room above a garage. It may be best to put in a good stainless steel chimny and a small wood stove. I have a big old house and heat it with a wood boiler in my detached garage, but if I had a big room over a garage I think I would use a wood stove with a good chimny. Again, add it all up and do what works for you and your family. Definitly keep safty in mind.

[nanotech]

I work at Woodmaster where we make exactly what you're talking about.

I have one myself that I just recently (last weekend) finished installing.

You can check out the reconstruction here as I stripped it all down to do a pressure check on the water jacket to check for any possible leaks.

If you have any questions, please feel free to ask as I've been involved in one way or another in every aspect of the construction of these stoves from a flat piece of metal all the way out to what you see here:

What you see there is a round tube firebox surrounded by a larger round tube water jacket.  The firebox on that one is three feet in diameter and four feet long, while the water jacket is four feet in diameter and five feet long for a capacity of 112 gallons.  There are two sets of one inch ball valves on the back leading to pipes that force circulation of the water in the jacket.  There are also four heat tubes that go through the top of the firebox to transfer as much heat from the fire as possible to the water, along with the selectable heat baffle.  There's a forced air fan on the front of the door which has a solenoid controlled flapper on it to close the firebox off completely of air.  A temperature probe and snap disk mounted on the back of the water jacket allow the little computer controller to switch the fan on and off as needed (it can also be done without the computer, I have the parts to do it that way).

The biggest selling point the company has for these stoves is the REDUCTION to most peoples' homeowner's insurance as it takes ALL high heat sources out of the house.  The hottest interior component you'll get is if you let the boiler go to 212 degrees F and boil all your water to steam, in which case the water in your house piping would only get to about 210 degrees with an EXTREMELY well insulated piping system, as the pumps will cavitate and fail if they come across steam.  So with one of these you are actually better off house-safety-wise than with any other form of internal heat source.

As I say, if you've got any questions, I'll either be able to answer them myself or be able to ask the R&D folks at work on Monday to get answers to anything I don't know.

With looking at what you linked to, I'd get a 55 gallon drum as a water jacket and a 30 gallon drum as a firebox.  Weld the 30 gallon inside and create a tunnel throat to connect the doorway into the firebox.  Then weld a piece of 6" pipe for a chimney at the back through both.  Then insulate it with 6" unbacked fiberglass insulation.  Then weld in three pipe fittings on the back for water access (inlet, outlet, and drain).  Then all you need is a filler pipe welded in the top that doubles as a pressure vent to run the whole system at atmospheric pressure.  No sand required.

[handpa]

a i was thinking more of somthing like this http://www.backwoodshome.com/articles2/lee90.html and wouldent all that water lose a lot of heat to the out side if it is kept out side, i was thinking i would have the water in the basement so all the heat lost goes to heating our house and not the air out side.  i am planing to have 1 or 2 fast and hot fires a day and then let all the water drain into the basement so it will not freeze in the pipes. and wouldent the water jacket make the fire colder and create more smoke?

[Titantornado]

Boy, that BHM article has got me thinking.  I like the idea of the thermal mass, but my mind has got another angle to his design.  The 275 gallon heating oil tank is a great idea, but I think I can do better. (better design or better complications, you decide)

So the tank is about 27 inches wide, 44 inches tall, and 60 inches long.  Now, how about this.  A 55 gallon drum averages 24 inches in diameter, by about 35 inches long.  How about we cut a hole in the end of the lower portion of the tank to insert the drum, then route a 6 inch stove pipe out the back of the drum, about 2/3 down from the back of the tank, then 90 degrees up, and another 90 degrees to come forward over the drum, and finally one more 90 to go out the top of the tank near the front.  A large grate would be placed in the bottom of the drum and come up with a way to provide fresh air beneath the grate, and a loading/cleanout door would be installed on the front.  Now the good part.  Once it's all welded together, and placed in position, fill the tank cavity with sand.  

It would look a bit like this:

Now that's thermal mass.  And nothing stopping you from going forward and adding additional thermal mass around the outside the tank.  Seems like a pretty frugal way to build a heater, since tanks and drums can be acquired pretty easily. (in my parts anyhow)  

So, waddaya think?  My appologies to anyone who may have thought of this before me.

[nanotech]

The backwoods home one would certainly be more efficient at heating the house, but then you've got the problem of the actual fire-conatining part inside the house again - bad for insurance.

Also you have to bring the wood inside, too.  And anyone who's heated with wood will tell you that there's not just wood in that there wood pile!!

As for it losing heat quickly, you'd be surprised.  A couple nights ago it was 37 degrees F outside and I didn't restoke the fire when I came home from work.  I figure the fire went out about 2AM.  At 1AM when I came in the temp on the waterjacket read 172 deg F.  When I sent my son off to school a 7:30AM it still read 165.  When I finally got up the outside temp was 58 deg F and the stove still read 135.  I lumped three small cardboard boxes and 6 two foot lengths of 2X4 in there and that brought it back up to 178 deg.

And I have mine continuously drawing heat out of the radiator in my crawl space.  That's currently my only form of heat until the local prefab shop can get around to making the blower box for my squirrel cage fan.  Then I can get to ducting air directly into the house for heat.  

But for now I'm heating a 20' X 26' X 3' airspace which is bordered on all four sides by only 2" foam insulation and bare dirt on the bottom.

So I'm drawing a fair amount of heat out of the system, but nothing in comparison to what 112 gallons (plus what's in my piping and the radiator) can hold.  Plus the double layer of R-19 fiberglass insulation all the way around the waterjacket (all six sides) does a really good job of holding the heat in the barrel.  And the metal siding over the top keeps the wind from affecting the insulation.

Yes, there are more efficient and cheaper methods out there.  But not for me.  I only paid $750 for mine (mainly because I work there and am friends with the salesman).  I was also able to side it in the same color as my house to keep the wife happy.  And the firebox is small enough that the biggest hunk of wood I'll ever throw in there my 12 yr old son is still able to pick up and throw, so one of the stoking times is taken care of during the week - "Hey, Patrick.  Throw a couple hunks of wood in the furnace on your way out to the school bus, would you?"  

[nanotech]

That's pretty much what Woodmaster did with thier stoves, except the fire door is at the back of your version and the sand is water.....  

[nanotech]

The bit about a couple fast hot fires a day will also work with something like mine.  You could crank the heat up to about 190-200oF and let the system just circulate for the rest of the 12 hours, it should only come down to about 90-100oF in that time.  Then another 10-15 minute fire would bring it all the way back up again.

Don't forget when it comes to cold temps, I live in the King of cold temp areas - just north of Fargo, ND!!  

It's not uncommon for us to hit -40 for a week or two at a time!!

[Titantornado]

Boy, if I could come into such a good deal on one, I'd be happy to buy one.  But for the general population, we have to accept a price that carries an additional 3, 4, 5, or even sometimes a 6 on the front of the price you got yours for, and other commercially available wood boilers.

I'm pretty sure Handpa is looking for a frugal solution to his dilemma. (say, a few hunderd dollars vs. a few thousand)

Please don't take this as a knock.  It's certainly not meant to be.  I have no doubts that such a boiler would be a great thing to have, but for some of us, we got to find more affordable solutions.

[nanotech]

Oh, tell me about it.  Do you remember my "redneck outdoor woodburning stove"?  

If only he lived a little closer to me.  I've still got 200 feet of 3/8" copper tubing in 50ft lengths!!  I just could never get it to seal up.  Every time I turned the pump on I had a rainbow outside.

Your idea you posted a picture of is what I originally had in mind, but I couldn't get a hold of a decent sized oil barrel in my price range that wasn't rusted out.

I'm just trying to point out the merits of using water as the transfer medium vs putting the furnace inside and using sand.  The idea that I don't have to haul wood inside my house is VERY appealing to me.  Far and above the down side of having to go outside twice a day to load the stove.  And due to having 7 cats and an autistic child running around the house, the fact that the hottest anything can get inside the house is 165-175 degrees is also very appealing.  And at a later date when I can afford it, I'll hook an additional channel up and heat my hot water off it as well, saving me on my next biggest electricity user........

[thefinis]

How would you do the water heater circuit? Would you use it to preheat the water and still have the electric water heater or somehow use it as the primary source? I keep wanting to put in a solar water heater for most of the year but I end up with a fair amount of wood each year due to clearing and trimming. I like using wood heat in the winter but haven't in years due to the mess and draft. I like the build a fire now and enjoy it later process.

Finis

[nanotech]

There's some sort of valve that goes in the "T" at the top to prevent you from just drawing your hot water directly through the heat exchanger instead of pulling it from the hot water heater, I just haven't a clue as to what it's called right now.

There's no need for a recirc pump, just use thermal siphoning.  We have these types of heat exchangers at work, but they're kinda spendy, hence why I'm not hooking one up right now.

You'd probably also need some sort of diverter valve on the "hot water from boiler" pipe so that you're not cooking your hot water heater to the point that your T&P valve trips.

But that pic shows the basics of how it works, anyways....

Hope that helps.

[nanotech]

I forgot to answer the second part of your question.  Yes, you keep the electric heating as a backup in case you forget to stoke the fire, or you take the firebox offline for cleaning or whatever.

But if you keep the circulating hot water from the boiler a little higher temp than the thermostat for the elctrics is set at, they'll never kick on.  But they're there in case something goes south with the fire......

[steviep101]

IS it possible to do this. I have a wood boiler that was given to me. Instead of putting it in my house I would like to build a building for it outside. It is setup for a presureized system and I figure it well work if I hook it up like an agua-therm outdoorboiler. My question is how much heat will I lose, how much and what kind of insulation do I use. Also what is the best way to insulate the pex pipe undergound.

[jonas302]

I wish my central boiler worked as well as your theretical ones in centeral mn I use 15-20 cords of wood to heat a two storie house and a 36x34 shop I load it full at 10 pm 4x3x3 firebox about half  a truck load of wood if I sleep in until 8 am water temp is 80-120 depending on outside temp not putting any ideas down but don't expect  miracles unless you have an endless supply of free wook and labor the payoff is very slow I'm working on replacing the system with waste engile oil heating

Jonas302

[libra]

Yes and hurrahh?

I just happened to read your article about heating with an outdoor heater.

I plan on building a outdoor burner for used oil. The burner will be on a concrete pad built with cement blocks, insulated on the inside  of the block walls with 2 " foam and filled with sand. The burner will be an upright 1/4 " walled shell and there will be copper coils around the burner but not actually in contact.

Since this will be higher than the water storage which will be two 250 gal fuel tanks the water will always drain back to the tanks. These tanks will be located in the lower portion of the attached greenhouse along with (50) 45 gallon drums of water already there for heat storage.

The way that this is setup now, if the temp in the greenhouse raises above 60 F the fans cutin and the airflows under the basement and up the back wall to the top of the house andback down again to the green house. It is called the thermal envelope design.

Ok hope that this makes sense to you and I am open to possible problems that you may think of that I haven't. I would only run this till I got the heat storage  (earth)up to 80-90 so it would be a hot burn and hopefully more effeicient this way.

Appreciate comments

Libra

[Willd37]

Insurance companies are a scam. They are so good at scamming that if you put some sort of wood burning sytem in (and who knows what else) without notifying them and you burn the place down they won't honor the policy. Even it it had nothing to do with your set up. They do know how to get our money and keep it so you beware!

  Will

[TomW]

nano;

Yeah, yeah. Best thing for wood heating since the wood splitter.

Except.

Everyone I know that has one of these things [outside boiler] complains they use whole forests full of trees, they smoke horribly and they don't work in a power outage. All 3 items are deal breakers in my book.

The way they work is just silly. burn it hard with forced air  then cut off the air only based on water temp rather than some sensible attention to the wood load just seems stupid.

Other than that, they seem fine.

I don't / won't have a commercial one thats for sure. Gimme a stove any day.

Cheers.

TomW