outdoor wood burner who has built one

[TWD]

Hi TWD,

You have several options, which one is best depends upon how you use your shop. If you use the shop frequently (every day, for example), heat in the floor is VERY nice. Infrequent use, then perhaps a coil with a blower. Radiators are another option but i doubt there are many shop arrangements that these would make sense for.

An OWB is nice for heating a shop if you are also using it to heat your house or if your shop is large and you are using it every day. It would normally be a bad solution if the situation was that OWB was used only for the shop which was occupied one day per week.

Feel free to PM or give more details/questions here if that is not considered thread hijacking.

Ken

Hi Ken, great information.

Right now the shop would be used only a couple times per-week for hobby usage. But in the next couple years I plan to move my office from the house to the upstairs of the garage, and heating that daily would be awesome :thumbsup: and probably required in winter

We also only have a wood stove for our house, so having the OWB to replace that or ??? would be great too. We have a full basement so plumbing most anything is very simple. We also have an on-demand propane water-heater... replacing that or additional heat/optional with an OSB would be great too.

I may just have to do an OSB as a project ocne I get my shop back to fully functioning after the rebuild.

Do you have any suggested resources?

 

[yomax4]

Most regular home type wood stoves have the pipe nearly flush with the top of the stove. Most all of the heat and smoke goes right out the pipe. With the OWB many builders extend the pipe well down into the fire box so the smoke has a hard time exiting the stove. While it swirls around it gets re-burned. This is what these guys call secondary combustion. To me it creates creosote but the creosote burns too making a very hot fire. If you decide on an OWB, Remember, It is at it's best when it is active ie: Draft Open, Pump running and the fire burning. If you have long lapses in calling for heat it will not be that efficient and it will smoke a lot. There are some very good plans for building a simple OWB on e-bay for $30.00 just search "outdoor wood furnace"
I have a life supply of hardwood and a friend with a sawmill who gives me as many 10x10x6 oak rejects as I can haul. If you have to buy wood, I would skip the Boiler. My boiler uses a simple waterheater thermostat to tell the draft fan when to kick on. You can use an aquastat too but they are $70.00. If you build, I would recomend and ash pan area below the grate. Mine blows air up into the fire box via the ash pan area.. OWB's are cool to build and save a ton of cash...I noted that I could build an 8000sqft OWB for $1000 or I could buy one for $7000.00.

 

[badbowtie]

Most regular home type wood stoves have the pipe nearly flush with the top of the stove. Most all of the heat and smoke goes right out the pipe. With the OWB many builders extend the pipe well down into the fire box so the smoke has a hard time exiting the stove. While it swirls around it gets re-burned. This is what these guys call secondary combustion. To me it creates creosote but the creosote burns too making a very hot fire. If you decide on an OWB, Remember, It is at it's best when it is active ie: Draft Open, Pump running and the fire burning. If you have long lapses in calling for heat it will not be that efficient and it will smoke a lot. There are some very good plans for building a simple OWB on e-bay for $30.00 just search "outdoor wood furnace"
I have a life supply of hardwood and a friend with a sawmill who gives me as many 10x10x6 oak rejects as I can haul. If you have to buy wood, I would skip the Boiler. My boiler uses a simple waterheater thermostat to tell the draft fan when to kick on. You can use an aquastat too but they are $70.00. If you build, I would recomend and ash pan area below the grate. Mine blows air up into the fire box via the ash pan area.. OWB's are cool to build and save a ton of cash...I noted that I could build an 8000sqft OWB for $1000 or I could buy one for $7000.00.

Can you give some more clues on how you can build one that cheep I am looking and figure I am going to have 1400 hundred in just steel. How thick are you using I could do it if I used 1/8 for the comlete job.

 

[yomax4]

My figures on cost are my situation. I have friends with a machine shop who rolled me a 36"IDx 54"Long X 3/8" thick cyllinder for my fire box for $80.00. The water jacket is 5/32" and it is square. Other than that all of the Suppport Angle iron was 1/4" and Gussets were 1/8. Then I had about 20' of 1" x 1/8" square tube. The stove pipe was a piece of 6' x 6" that was $8.00 at a recycle center. If you can buy your steel at a scrapyard,You can save 1/2.. I think my cost on the structure was about $750.00.. Anyway I used a blower from Grainger and a water heater thermostat. I bought a Taco 007 pump to pump the water to the house. I also ran an extra length of 3/4" pex to a coil of copper tube that is siliconed into my water jacket.( i can explain ) I hooked the return to a check valve and a ball valve so when it's time to add water ( which is evey 4 days ) I only have to flip the ball valve to fill. Plus I am using soft water to fill my stove. Anyway, I have 2 pumps now. 1 to pump water into my shop and 1 for the house heat. Sounds simple but I have done a lot of work to get here, Let me know if you have any questions..

:thumbsup:

 

[SpringHollow]

You have to add water every 4 days? wow. I have an open system and only have to add a couple of times per season, a few gallons each time. I wonder what the difference is.

Ken

 

[Egon]

[QUOTI wonder what the difference is.
E][/QUOTE]

Temperature and volume if it is an open to air system with no leaks on the distribution side.

 

[yomax4]

I just turn the valve for a few seconds every 4-7 days to make sure it is toped off. It has an overflow and i like to keep it full to prevent rust as long as I can. I also run mine at 180-190 degrees in the cold part of the Minnesota winter and that is hot enough to evaporate a little water. Im sure I have no leaks. I have had every problem under the sun working out the bugs but this is my second year with no troubles. The bigest problem I had was with using "Shark Bite" fittings. Not long after install, They leaked. I ended up removing a lot of plumbing and re-did it the old fashioned way. That was only one of many minor troubles that had to be worked on out in the cold.

 

[SpringHollow]

I have used shark bites in lots of situations including my boilers and my family's and friends boilers with no problems. Did you have them pushed in all the way - it can be hard sometimes with the stress on the pipe. My friend did install one that leaked but when i came over to look, i saw that although he thought it was pushed all of the way in, it was not. I have used them on pex, copper, and polybutylene with no problems so far. I have not tried some of the other brands.

Keeping the boiler completely full of water for rust prevention is a very good thing.

Ken

 

[yomax4]

Yeah, I didn't know much about shark bites and I may have tried to tighten them too tight. It would leak a little, I would tighten a little, Leak, Tighten. Break.. It was cold out and I just wanted to get the leaks done. They are a cool concept and I would try them again.

 

[smiley]

I was thinking about installing a plate steel stove in a cheap tin shed. Then ducting the shed air into the basement and using floor grills to let the heat rise. My lot slopes down favorably on the side where I'd do it so blowers might not be necessary with a big enough duct.

I've seen 3 built this way. 2 in garages 1 in a house. 2 were old wood furnaces in old insulated truck closed van bodies, the other in a steel shed. All were forced air though. My friend who heats his garage this way hasn't had any problems. It's about 8-10 ft from the garage and isn't pretty, but he has insulated ductwork both for heat and return air.