Outdoor Wood Furnace Info
Outdoor Furnaces - Manufacturers with NON EPA-Certified Models Only => Home Made => Topic started by: jksweld on October 27, 2011, 07:46:17 PM
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Hey Guys
Im new here, been lookin around on the forum for the last 3 days, alot of info and talented people here. I live in central WV in a 1600 sq ft home, everything is electric in it. Ive been welding and fabricating for 12 years and Im lookin to build a OWB boiler. The plan is using the stove just for heat. I understand the concept of how they work with a firebox inside a water jacket and the lines running to the house with a radiator in my forced air system, dont completely understand the whole circulation pump, aqua stat, and etc. also how to keep the water from gettin to hot. Im lookin for simplicity as $$ is very, very, tight. Lookin to build out of items that can be found insted of buyin steel, and other items new. I have an abundance of wood so thats no problem. Any advice, tips, or critism is apprecited. Thanks in advance!!
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Welcome to the site, the aquastat controls the water temp by opening the firebox vent when the water gets to low and closing it when the temp gets to your max setting. It also controls a blower to put more air into the fire if your design calls for one. The pump circulates the hot water to your house to the heat exchanger that you add to your furnace.
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Welcome :thumbup:
Lots of good info here for you to research. Take your time and have a plan layed out.you will finds all kinds of little things that you will want to change as you go.
Good luck
Just ask if you don't know.someone will always be glad to help ya out.
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Thanks Guys, thats the way I had the aqua stat figured. How many gallon boiler would i need just to heat my 1600 sq ft home. Could I get by with say 50 gal water jacket after my system is full?
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Thanks Guys, thats the way I had the aqua stat figured. How many gallon boiler would i need just to heat my 1600 sq ft home. Could I get by with say 50 gal water jacket after my system is full?
I heated my home for the last 3 or 4 months of the winter with an Empyre Pro series 100. It holds about 30-35 gallons of water. It worked beautifully for me. There are a few different theory's about which is better- namely- small tank cycling frequently, or large tank cycling infrequently. I guess I'm a bigger fan of small water capacity with a fairly large wood capacity. The technicians and engineers that I've spoken to have agreed that cycling frequently helps keep condensate and creosote at a minimum. They've explained to me that a smoldering fire is the worst kind to have if boiler longevity is expected. My first homebuilt OWB had(has) around 80 gallons of water capacity, and for what it was(is), that seemed to be just about right. Mine was a 2' well pipe 4' long inside of a 3' well pipe 5' long. My home is close to 1800 sq.ft., not insulated all that well, and that size worked except for 10-15 days/year when I'd have to load it 3x/day.
BTW- welcome to the forum!
Marty
BTW-
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thanks marty!! If you wouldnt mind could you explain to me what you used for a circulation pump, and radiator, and how you controlled your heat in the tank or firebox?!?! Or if its on here ill gladly look it up myself, just tell me where to go!!
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Well I just scored the first part of my OWB!!!! 500 gal propane tank. Havent seen it yet so im unsure of the actual sizes. Called the neighbor and he said he had one and I could have it for free!!!!
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just make sure you purge tank with a inert gas or this could be your last post..lol
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grate find be sure you vent that burgger before you cut it down. i would use it as fire box it is 3/8 thick this is how mine is i used 1/2 plate for front and back. used a a/c coil for the water that i modified not quite done but getting closer have about 600.00 into it thease guyes have been the best of help with much talent some improvements i would like to do is the door hinges like willeg has best i can tell you is the old junk can be trying over new steel by the way i would take all the valves off shoot a couple of holes in it then start a fire around it but then again this is me not telling you how to do it ive been told that iam not right ha ha ha ha ha :o
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There is some good info over on the Hearth website's forum about those guys cleaning out and modifying LP tanks.They used some different chemicals or soaps to remove most of the scent agent from inside the tank.I believe they were putting a little solution in then rolloing the tanks around.
You could also fill the tank with water and then start cutting the tank.
Different ways to do things.Good luck with it :thumbup:
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thanks marty!! If you wouldnt mind could you explain to me what you used for a circulation pump, and radiator, and how you controlled your heat in the tank or firebox?!?! Or if its on here ill gladly look it up myself, just tell me where to go!!
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I use a 3 speed Grundfos pump(cheapest one they sell at Lowe's), a love controller(aquastat) and probe from Graingers, a cheap Dayton blower, around 150 CFM I believe, from Graingers also, and a 18"x20"or21" water to air heat exchanger. I'll try and remember to bring my receipts home from work and post the part #'s- if I can find them! I had around $2000.00 in to mine, but other than the pipe, every component was purchased new, so if I'd scrounged around for used, I'm sure the cost would have been half.
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Well I was informed today that the tank may still have some LP left in it, so they will be some purging and flushing in order!! Also called my uncle who set his house up for a wood boiler and never went through with it. I was askin bout his heat exchanger, which my brother (who does HVAC work) took out last summer, uncle said to give him a day or so to think about it and if he decided he was never gonna use it he would just give it to me!! Brand new, never used!! Hoping for score #2!!
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I might suggest the fill with water to displace the lp method once you have released all the pressure as 500 gallons would burn up most of a 125 cu.ft. bottle of inert gas and you could still have lp left over even afterwards. If you have your own well then the water is almost free and once filled to the point where it is over flowing you can be sure there is absolutely no flammable gas left inside. Fill it to the brim with water, lay out some cuts, and use a cordless drill to make a small hole and let it drain out and it will he full of air afterwards.
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I believe water is what im gonna go with to purge out the tank. I found a piece of 24" pipe today about 5' long, its got a few pieces of angle welded to it and some dents in it but there is enough there to make a good firebox out of, and both ends are capped with plate so one end is already done!!
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Well i got my firebox home and got the coil off of my uncle!! 20" x 22" 4 stack!! never used!! Gonna try and get the propane tank home today!!
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i would use the propane tank as the fire box dont think the 24 will be big enough grate find on the coil from the uncle :thumbup:
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24" diameter by 60" long makes about 15.7 cubic feet. If you get your burn dialed in well it will be plenty of space for about 8-10 hours and have enough coals left for an easy restart of fresh wood. If your looking for longer burn times then the above may be true. But you also have a large water capacity so it may balance out. If the fire dies you have heat stored in the water till you refill. The way it sounds you could turn the lp tank on end with the pipe vertically inside and have one heck of a gasifier ;)
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that would bee a great idel to stand it up never thought of it that way i was only looking at the chucking the wood in the front five foot is long way and lot of ash
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Im not to familiar with the whole gasifer deal?? Could one of you guys help explain to me what your meaning by standing the tank on end??
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Hes refering to standing the tank on end then have your burn chamber inside of it.That way you are taking up less space ,but still have large amounts of water to store heat in.
I plan to have 4 500 gallon tanks standing on end super insulated to create mass storage.Maybe in a few more years it will happen. :thumbup:
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Im not to familiar with the whole gasifer deal?? Cou
ld one of you guys help explain to me what your meaning by standing the tank on end??
(http://farm7.static.flickr.com/6045/6322164564_e7eed7c087.jpg) (http://www.flickr.com/photos/68676926@N06/6322164564/)
Secondary burn (http://www.flickr.com/photos/68676926@N06/6322164564/#) by Quicksilver99 (http://www.flickr.com/people/68676926@N06/)
(http://farm7.static.flickr.com/6038/6320315325_0448a0e195.jpg) (http://www.flickr.com/photos/68676926@N06/6320315325/)
Gasifier (http://www.flickr.com/photos/68676926@N06/6320315325/#) by Quicksilver99 (http://www.flickr.com/people/68676926@N06/)
5 is the primary chamber, 7 is the nozzle, 8 is the secondary chamber, 10 are the heat exchangers. The wood is consumed in the primary burn chamber at a very controlled rate. The resulting wood gas is forced down through the bed of glowing coals which is hit enough to consume and break down all the particles to basic elements of flammable gasses like hydrogen and carbon monoxide. It then passes through the nozzle where super heated secondary air is introduced to allow the compatible gasses to burn at extremely high temps (2000 degrees) and from there the heated flue gas goes up the exchangers and out the chimney. Very clean and very efficient. The burning wood gas looks like the top picture as it goes through the secondary chamber.
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Dont think Im gone to build a gasifier, too much work for right now. but since the mention of standing the tank on end ive came up with this drawing. This is nothing to scale, just a quick paint drawing. The exhulst pipe wont be that close to the side of the tank either, im gonna try to center it up through. Do you guys think it will work?? will i get enough heat like this??
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The heat exchanger would seem like a good idea, but I fear it plugging up over time. My impression was that the heat exchanger was for in the house. What ever you may run for heat exchanger will have to be easily accessible for routine cleaning, at least every couple weeks, if you don't have a gasifier. Although, if you go back to the original idea of laying the tank horizontally you could build a mini Garn very easily. I'm going to look for a diagram or pic and will put it up in a few minutes to give you an idea. Then you could even use 4" schedule 40 pipe for the heat exchanger and route it back and forth a couple times with a horizontal flue out the back. Your fire box could have the flue gas exit low in the back almost at the bottom, into a small square box about 2 feet long lined with some fire bricks. One air inlet down low below the fill door for primary air and one up high and above for secondary air. Coming from the door blowing straight towards the back.
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A 26" round x 28" deep burn chamber yields less than 9 cu. ft. That might be a bit on the small size, unless you're building a gasser.
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(http://farm7.static.flickr.com/6050/6324151091_7d5ba15951.jpg) (http://www.flickr.com/photos/68676926@N06/6324151091/)
Garn (http://www.flickr.com/photos/68676926@N06/6324151091/#) by Quicksilver99 (http://www.flickr.com/people/68676926@N06/),
Here is a diagram of the garn.
A is air in
B is primary air
C is door
D is secondary air
E is burn box with fire brick bottom
F is fire brick lined hunt chamber
G is 4" heat exchanger, single pass, very long
H is induces fan
I is exhaust
Here is a link to someone in my neck of the woods that built his own.
http://www.hearth.com/econtent/index.php/forums/viewthread/11262/ (http://www.hearth.com/econtent/index.php/forums/viewthread/11262/)
Notice in the third post, the first and fifth pictures, you can see the clean outs that stick through the ends of the water jacket. Also, the Garn unit uses a suction fan. At the very bottom of the third post is an actual Garn. They batch burn at about 450,000 btu per hour and use an induction (suction) fan instead of forced draft. They also only use 4 inch pipe for the heat exchanger, about 60 feet of it. The incoming air passes through the water mass to preheat it also. Your lp tank may have promise for a mini Garn, and your 24" pipe would be of the perfect size for it also.
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CANCELLING THE BUILD!!!!! My father in law calls me last monday and says the guy he works with has a OWB that he is no longer using and said I could have it if I came and got it. So I borrowed my dads Chevy diesel and 16' tandem axle trailer last friday, picked up my buddy, and 180 mile round trip and I now have a 20 year old Taylor Outdoor Wood Burning Boiler setting beside the house, know as Bob, and hes been puffin smoke and heatin the house since saturday evening!!!!!
Thanks to all of you that have given me guidance and ideas on my plans to build!! Iam sure I will build one next spring, just for the heck of it!!
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Congrats on the find, the best kind of OWB is a free one LOL
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great deal! Now you wont have to worry about rushing to get a build done.Glad to hear our new stove is working good. :thumbup:
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great find :thumbup: i think i would still do the build even for giggles and grines at the most you could sell
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wow awesome find FREEBBEEEE
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Awesome find :thumbup:
Maybe that tank you have could turn into extra mass storage ;)
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Thanks Guys
gonna try and get some pics on here in the next few days. Bobs been burnin for a lil over a week now and I love it!!!! And havent even gotten the power bill yet!!!!
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Free !!! Thats great ,Best stove out there is a free one. Sure will make a difference in power bill.