Outdoor Wood Furnace Info
Outdoor Furnaces - Manufacturers with NON EPA-Certified Models Only => Home Made => Topic started by: boone on April 02, 2014, 07:39:04 PM
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Here is my build. Water jacket is 52'' diamiter by 5' 3/8'' and firebox is 27'' dia. by 4'8''. Flue is 8'' and set about 3'' off of bottom of firebox. I still need to finish the door and back side of boiler. Was thinking of using the flange to bolt the back side on so I could remove it if I had any problems. If you see anything I can approve on I welcome comments. I have a few questions on the pump and piping size I should use. House will be around 200' run slighly down hill and is 2400 sq. ft. with basement. And my shop is 40x56 fully insulated and furnace will only be about 25' from the shop. What size pumps and supply lines should I run?
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Welcome to the forum boone, and thanks for the pics. Worth a 1000 words as they say.
It looks like you have a very good start. Sorry I don't have much knowledge about pump sizing but from what I have learned, with a 200' run to the house you may need to use 1 1/4" lines for your feed and return.
The idea of bolting on the back side is very interesting, maybe a bit more work and expense drilling all those holes and buying the hardware. But it might be useful for future repairs.
It seems that most of the builds, mine included have a much closer ratio in fire box size to water jacket. My water jacket is 47" and firebox is 36", as seen in my build thread. I am not saying which is better because I don't know. My guess is you will have longer burn cycles to get your water up to temp but maybe it will be more efficient over all. It will be interesting to find out.
It seems that I have more questions than answers. Like what and where did you get that 52" flanged pipe from. Also what is the small pipe or nozzle pointing up towards your flue pipe.
I'm also curious about your flue pipe being 3" off the bottom. I have mine about halfway down into my firebox but maybe lower is better. You can always cut some off if needed.
Are you going to have a fan forced draft and how and where do you plan to put that?
This site has a wealth of knowledge available so please keep us posted on your progress and go through old threads to learn as much as you can. I know I learned a lot here and many helpful members helped me with my build as it went along.
By the way what part of the country are you in?
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Thanks for the input. The nozzle your referring to is actually the door opening after I cut it out. The nozzle is where I pressure tested with air before cutting it out. I'll put the flu down that way because a guy at work has a central boiler that's the way his is. I figured it would be easier to cut off some of it if needed rather than adding to it. All my materials I got from work for free. Yes its going to be forced air. Planning on putting in on the door. I wanted a bigger fire box but that was the biggest peace of pipe I could find. What do you think about not filling the water side all the way up? As far as the flange holes I was going to use my torch.
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Yep the flue is definitely easier to cut off than add on. I'm thinking about trying some sort of baffle on mine or adding a bit on to go lower. I do hit it with wood when loading it now though.
I would have loved to have a 52" pipe for my build. It's great that you can get most of the materials for free. I was able to scrounge up some of mine but had to buy a lot of it.
It's an open system so you don't have to be completely full, but I would try to have it pretty much full to begin with just to see how it works once you do get it up to temperature.
One other thing I wonder about is with the flue inlet basically down in the fire and an 8" straight up, is sparks coming out when you have a hot fire going and the fan pushing air out. I know mine is only a 6" flue and it makes 2 turns before going out, and the other morning it was still dark and I threw some cardboard in there and closed it up. Then I went to the wood shed to get some wood, and when I came back it was shooting sparks 5-10 feet in the air and some of them reaching the ground. I'm glad it wasn't dry out.
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Hopefully with the flue being low I won't get to much sparks. I'm sure I will have to do some tuning to it. I can always reduce the size of the flue to 6" if needed. We will see!
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You may be right with the lower flue it will be harder for sparks to get there. My outlet is quite a bit higher.
Everyones build is a bit different, based on what they have to work with and different ideas. We all learn by doing and by seeing others projects.
Keep us posted.
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Hopefully with the flue being low I won't get to much sparks. I'm sure I will have to do some tuning to it. I can always reduce the size of the flue to 6" if needed. We will see!
i think reducing the size of your flue would cause the velocity to increas and actually suck harder and pull more embers up the stack? (just thinking, could be wrong)
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Something as simple as a spark arrester found on dirt bike exhaust might eliminate errant embers. Or extending the chimney with a larger pipe for 24-36". Going from 6" to 10" will create an area that will slow down the exhaust velocity to allow embers to fall back down.