So you want to build an OWB you say...

Well, if you're reading this then you probably can build your own. I have about $2400 into it with everything included but my time. It works better than I could have hoped and makes me smile every time I load it.
Here's a little documentary to the build:

250 and 500 gallon propane tanks (ah, the revenge!)

32" and 42" diameters

Welded plate to inner tank, offset to bottom

Insert firebox into water tank

Holes for stack

Welding stack

Internal baffle for smoke - there is a vertical fin on top (not pictured) which forces smoke up, around the fin, and back to the stack. Captures more heat and REALLY keeps the sparks down

Simple hinged door and latch with adjustment

Gasket for door seal

Slight taper for swing of door

Insulated door

Opening for fan to feed fire

Legs welded on

Neighbor moving into place, trench ready (note pond for later use...)

Hole bored through concrete foundation

Pump mounting directly under living room and it is extremely quiet

Heat exchanger in furnace

Operational!

Insulation held on with chicken wire

Shed nearly complete

Keep going,we want to see more.

RW

I got a programmable Johnson Controls aquastat and that is a very nice option (have yet to get a good picture of that.) There is a second thermostat in the house slaved off the primary thermostat so the furnace is fully operational on propane as a backup. I didn't spend 1 cent on propane to heat the house after I got the OWB installed though! Have a few tweaks to finish the shed and clean up a few things but it works great.

I generally load it twice a day and try to estimate how much/what type of wood to put in based on outside temperature and time to next load. I burned one fire the entire season, though I had to work at it a few times when there were just a few coals left. The aquastat is set to kick the blower on at 150 degrees which seems to work well.

I'll try to answer any questions for those considering fabricating their own. Better get started NOW if you want it this season!

R W Ohio said:

Keep going,we want to see more.

RW

Click to expand...

You have a sweet set-up RW! Wish my woodshed/OWB area was as slick as yours. Something to aspire to for me for next season.

Free A/C from woodburner!

Oh yeah - I mentioned the pond in one of the photos.

So in addition to heating the house in the winter I think I can cool the house in the summer too! The pond has it's own well to keep it filled (previous owner did it for irrigation purposes.) It's only 40 feet from the woodburner so the plan is to plumb the well through the PEX line to the house, through the heat exchanger in the furnace, and dump it back into the pond. 110 foot well should be around 55 degrees, plenty cool to keep the house cool in the summer. Sure wishing I had gotten to that project over the last several weeks.

Nice work! I have built a few boilers and the only thing I would be concerned about is the door warping, I see you insulated it but without water in the door I am not sure. I use adjustable aquastats and I love them. Anyway Good luck.

woodman6666 said:

Nice work! I have built a few boilers and the only thing I would be concerned about is the door warping, I see you insulated it but without water in the door I am not sure. I use adjustable aquastats and I love them. Anyway Good luck.

Click to expand...

I did consider running water through the door but decided against it for complexity. The door is at least 1/2" plate and with the insulation you can usually put your hand on it so it's not much over 150 degrees. I didn't even have to adjust the hinges after the first season so I'm not worried about it at all now.

Love to see one of your builds if you have a pic.

Dang man, how much of that 2400 was in welding rods?

Seriously, that's some nice backyard fab work.

What supports the back end of the firebox?

Warmer water coming back from cooling the house should help any fish in that pond grow faster!!!

Rep coming at ya!

Steve NW WI said:

Dang man, how much of that 2400 was in welding rods?

Seriously, that's some nice backyard fab work.

What supports the back end of the firebox?

Warmer water coming back from cooling the house should help any fish in that pond grow faster!!!

Rep coming at ya!

Click to expand...

Ha! Forgot to mention that - 100% arc welded. I might have 20 pounds of rod in it, but I think that's less than my buddy who talked me into building mine. He welded 2 square boxes inside and out with MIG for his and says he took 5 years off his life with the fumes. That's one of the advantags of using the propane tanks - almost all of the welding is already done/certified by professionals. I only had the stack and the smoke baffle to weld inside the tank.

I have a couple of small feet to support the inner tank and it's welded at the front all the way around.

Good thought on the fish - might be time for a bass tourney after using the A/C for a year!

One more thing I have used fiberglass insulation on the outside and then the spray on which is more money but the difference in wood use with the spray on was way way less. just food for thought

Very impressive fabrication.....

MNGuns said:

Very impressive fabrication.....

Click to expand...

as is the swinsuit on your avitar!!

That kicks butt. What part of MI are you in if you want to show it off?

Looks awesome

I've had a similar thought about doubling the system for ac but was concerened about condensation inside my furnace at the hx.

woodman6666 said:

One more thing I have used fiberglass insulation on the outside and then the spray on which is more money but the difference in wood use with the spray on was way way less. just food for thought

Click to expand...

Great real world advice. Yeah, the fiberglass is really cheap - maybe cheap enough to warrant another wrap. The shed should come off pretty easy so if I have reason to have spray insulation here for the shop might be easy to add the OWB.

tex said:

That kicks butt. What part of MI are you in if you want to show it off?

Click to expand...

I'm in western SE Michigan. Wish I was back in western Michigan sometimes but I love my place where I'm at too.

applefarmer said:

I've had a similar thought about doubling the system for ac but was concerened about condensation inside my furnace at the hx.

Click to expand...

Hmmm... that's a possibility I suppose. Be something to monitor - if it became a problem then stop using it and I will have wasted a few bucks on PEX line. Thanks for the thought.

nice job!!!! i built one also but not even close to like that and its a wood hog and very inefficent....but heats my house just fine and 1800sqft .....im working on chainging the design i dont weld so mine was all threaded pipe and pex...im a master plumber so that part was easy for me...

and yea get rid of them hose clamps on the pex your killin me...i know there aint much pressure youll be fine!

basiclly a old fuel oil tank with a black pipe loop above the fire right inside the fire box...then the water gets pumped to a old 50 gallon water heater that sits next to the burner....

then gets pumped under ground into the house into another old 50 gallon water heater then into the furnace were i reworked a old A-coil to accept 3/4 CTS pipe....and the needed pump gauges/expansion tank/ t&p.....i built a steel stud frame arond it and wraped it with pole barn siding...and i also used fiberglass insulation like you did.....


Once again great job!!!!