Nice fab job Kyle. Rick will be proud of you. Now we are going to need firewood videos. That should keep your shop warm and then you will be back to making RD-4 videos.
I very much enjoyed watching this build. Years ago we had a similar heat exchanger on our wood boiler made by Magic Heat. They still make them. It would throw so much heat you couldn't stand in front of it. It had a rod in the center with a handle and an internal scraper that would clean the creosote off of the exchanger tubes. It worked very well. You would simply slide the handle back and forth and it would clean the exchanger tubes. It does seem like a lot of work the way you described cleaning yours but it's important that it gets done.
One thing you can add to the tubes to help with the heat transfer is a plate 3" spiral flat plate in the tubes. This will cause the air to rotate outward against the sides of the heat ex-changer tubes.
Awesome build . I would think it will work good . One suggestion on the tubes . Instead of cutting can you stick weld them ? We build tube bundles for the oilfield and we have to stick weld the tight areas . Keep the videos coming !
@@noidontthinksolol yep, stick over mig, any on application like this. But chicken scratch welds will pull smoke around welds, the temperature difference also will make it draft out at those points also. Just saying, no disrespect to you.
Yeah, I was going to ask why he didnt stick weld also. Maybe he isnt comfortable with stick. Unless he lays the thing down they would be vertical stick welds and they can be tricky if you dont have experience
A consideration: shorten the sch40 air pipe back to the dumby riser to provide space on top of the fire box to add a small flat "hot" plate. You could keep a pot of coffee warm or toast up your tacos 🌮 🌮 🌮
@@Bob_Adkins pizza ovens that run that hot don't cook pies for 7 to 8 minutes.... they cook for 70 to 80 seconds then rotate 180° & back in for another 80 seconds... anymore than 3 or 4 minutes and it's burnt
@@RichardCranium321 I know. I bake mine at only 500F and it only takes 8 minutes! Some pizza ovens run at 800F! My point was, that's a large stove and should put out a massive amount of heat! Unless his home is very large, it will only take small fires to heat it.
We built a waste oil fired shop heater from a 500 gal tank. The tank is stood up on end with 48 used 2 1/4" boiler tubes. Our steam locomotives are fired on waste oil so the technology is familiar. It will easily turn red if not monitored.
Kyle, I would tap into your blower chamber and use it to run some air into the pipe between the firebox and the heat exchanger. That would give you a secondary burn when you are calling for heat. I would come up with some sort of check valve. Most of the secondary air systems preheat the air before introducing it. I guess you could restrict the opening of your mid-heat exchanger pipe and run it back from near the exit where it is warmer and use that air for a secondary burn.
Secondary chambers are amazing when they work correctly. There was almost no smoke from the stove at my old house when it was warmed up and full of wood.
I was thinking the same thing. It would really improve on efficiency and reduce the soot buildup on the heat exchanger tubes. A fellow could just drill an 1/8" hope of 2 completely through the 6" riser and schedule 40 pipe. Then weld the outer holes closed.
I'm not opposed to something like this, my only concern with this is pressurizing the burn chamber enough that I hurt or even take away the draft. The last thing I want is smoke coming back out of the door or air damper and into my shop
Wow that is huge I hope it's more than a garage you are heating. Also building a unit that heavy duty pretty much demands you make it into a hot water heat exchanger which would allow you to distribute heat anywhere and anyway you want with a variety of methods. It would still be easy to add a water heat exchanger coil to the end of those big tubes.
I already have a wood boiler that heats my house, I wanted something different and more on demand for my shop as I only work out there a couple nights a week. It's a 40x50 area I'll be heating
I love the idea. Cool video. I do feel like there should be a follow up video on this one with feedback on how effective the stove is working and any possible changes or improvements that you would like to do.
Nice job, and some nice toys to assist with that! Thanks for sharing. For ideas you might entertain (after the build is done, of course, and maybe you've addressed these, but having the fire exhaust pass around the tubes in the exchanger makes for a lot of surface area for creosote to accumulate. Creosote fouling reduces exchanger efficiency and requires frequent cleaning. Way back in my younger years, my dad added an eight inch stack heater to our wood stove flue which is pretty much your basic exchanger design, just a bit smaller. It had a free-running tube plate attached to a pull-rod that could be pulled out and in at any time which would scrape off the creosote debris. Another idea might be to pass the flue gasses through the inside of the tubing, and blow air around the outsides - reverse of your design, but that could be a bit more challenging and disruptive to cleaning since each tube would need brushed out individually by removing an access plate, much like I did on my oil boiler. Just some food for thought. Have a Happy New Year!
One thing that might help you recover more of the energy is to burn the wood gas that's collecting in the upper chamber. You just need controlled air inlet to let fresh air into that chamber and you might find the thing generates significantly more heat as well as reducing the "smoke" and other nasties. Cheers!
Problem is that steel surfaces inside have already sucked the heat away from the combustion and there is no more required heat to ignite that secondary fire even if putting additional air in... Fire wood should never be burnt inside steel casing since those surfaces quench the flame leaving a lot of unburnt gases.
Not true, if it is sucking air properly combustion will continue through the exhaust making a complete and smokeless burn which is essentially how "rocket stoves" work. If anything to be more efficient he should have the upper chamber split in two so it has to enter, go the length of the heat exchanger, then go back along the top portion before exhausting out the top that way more heat is effectively transferred. As it is this is a common design flaw I see with this same style.. Most of the heat is barely being used and going right out the exhaust specially with the double opening to the heat exchanger the back part won't be getting as much oxygen and thus burning more incompletely.
Great build. I'm very interested in seeing a finish/ update video on this stove. It's very interesting and reading the comments there's a lot of very good information here. Having heated with wood my whole life I see a lot of interesting thoughts here. I'm a door guy. 33 years installing overhead doors. I've seen a few buildings with wood heat and have various issues and owners contacts me thinking it's my installation issue. Looking forward to your next video on the stove and I'll be watching your trailer rebuild videos next. 😎🇺🇲🚜🦌
@Kyle Christ we heat our home with a Hearthstone woodstove. Have not turned our furnace on yet. We live in s/e Michigan so we burn through some wood. Best heat ever.
NIce idea and realy good executet. Carefull with your second transfer big pipe, the one is a dummy and dont transfer heat from the burner... is a air tight chamber and it will build up pressure. I dont know if it can explode with such thik material... but better dril a smal holl in it then to ruin your day later.
Neat project. I'm wondering about the lower tube - it seems like it would be blowing HOT air right in your face when tending the fire. Personally, I would consider cutting it back and putting a Y made out of a couple 90*s that would direct air to both sides.
Nice job! I made one of these about 30 years ago for my fathers off grid cabin, same design with 20”x1/2”wall pipe, only thing I did different was to add a stainless steel water tank off the back end, it generated steam for humidity and hot water for washing stuff, it would heat his 750sq ft cabin, so hot you had to open a few windows.
I may add a piece of flat stock to the side of the burn chamber to put a pan of water on, we will see, smaller things like that can always be added/removed down the road
I like the symmetry of the stove and I would maybe change a few things. I would add a plate that would slide on the tubes to scrape off soot or ash the make it more efficient and I would shorten the heat exchanger to about half the size. That would make it more enjoyable to load wood into. The large pipe at the middle is ok, but I think it's gonna be too restrictive. I would incorporate a 1/2 inch plate on the top of the burn chamber in the front to cook on.
A little late now, but for people building these make another plate with the hole pattern of the exchanger tubes but oversize the holes a little so it can slide. Then drill a hole in the middle of the exchanger end for a rod to go through. That way when soot builds up on the pipes you just pull the rod which drags the plate down the pipes and cleans them off
@@kylechrist Right now Midwest, left Eastern Europe long time ago … while still Yugoslavia was there. Enjoying your blogging, keep up the good work. Squatch253 send me.
Nice setup 👍😁One of the best setups I've seen ..... you put a lot of thought into that. Double barrel stove ... They get super hot 🔥 so be super safe with it.
My father built one very similar to this years ago from propane tanks. When it comes to wood and burnables We would throw anything and everything into it, its not efficient but it can clear up a mess. New home construction all the off cuts, I bet we would throw 100 lbs of material at a time and let it rip. Nice build.
Great looking wood burner. I wonder how many BTUs all that heavy steel will hold to release as it cools after the fire has burned out? Welding around those pipes makes me think of 50 years ago when a local man who worked at the John Deere works in Horicon said he used to stick weld wheel hubs without any sort of turntable. He said they would bend the rod, reach as far around the shaft as possible and weld all the way around without breaking the arc. So often progress makes old skills get lost.
I had a muffler replaced at a shop by an old greybeard, he acetylene torch welded the bottom that thin exhaust pipe, overhead, without looking, then heated up the middle of his filler rod, jammed it against my truck frame bending it into a J, and welded the top side of the exhaust, while looking at me, telling me a story. I was out of there in like 15 minutes. I crawled under and looked at that weld later, it was like a stack of dimes. Greybeard skill is real, and it is humbling.
Noticed the smoke did not rise out of chimney. If you scavenge so much heat from the flue gasses, convection will not propel the smoke up a chimney and on cold days you'll get CO2 problems. Need a blower to push out the chilled smoke.
My big concern is the dummy pipe between the upper and lower chamber is a sealed pressure vessel. If you don't already have a vent hole, please add one.
Kyle, i realize i'm a little late to the party and this thing is already in service. overall i have to say you did a really good job of putting this thing together, selected some good materials for the project, however, if and when you ever have to go back and redo parts of this, keep some of the following points in mind: you didn't give your heat exchanger pipes a means of expansion. in a steam boiler, the fire facing ends are welded to the face plate which you did correctly, however on the exhaust end they get rolled in. there is a device that swages the pipes out to tighten up against the holes in the rear face plate. this way they can still expand in length and girth without putting strain on the welds of the faceplates but still remain airtight. you could try using an automotive exhaust pipe expander unless there is a boiler shop near you... unless i miss my guess, you will back in there rewelding the lower registers of pipes as they take the brunt of the heat rising up and the heating/cooling cycles will cause your welds to crack and allow carbon monoxide to seep out and enter the shop air. if you have no other choice but to weld the exhaust ends of your heat exchanger pipes, i would suggest using a 3/16ths 6013 rod that is used in boiler and steam applications. it does a better job of expanding and contracting at the same rate as the parent material. i didn't catch what grade of wire you were running in the MIG welder which is why i am suggesting it. another advantage to using rod is that you can bend it to get into those nooks and crannies that you were having a hard time getting into with the MIG torch something else that to take into consideration is the size of your draft. since this is a naturally aspirated and not a forced draft, the fresh air intake should have a slightly larger cross section (5 to 10 %) than the smoke riser going into the heat exchanger with the obstruction of the primary heat exchange pipe. by undersizing the fresh air intake you are starving the fire for oxygen, making the fire smolder. this in turn generates a lot of creosote, nitrous oxides and carbon monoxide which will foul the heat exchanger requiring frequent maintenance. now, by putting a damper in the chimney outlet you create a dam effect that gives you a more complete burn thus increasing the amount of heat gleaned from your fuel as the gasses are slowed way down in the heat exchanger. by partially opening the intake damper and closing the chimney damper a lot of the soot elements carried up off the fire will be combusted as it exits the burn chamber. it also great reduces the amount of CO the stove will generate by giving you a more complete combustion. while stove roaring with a draft open is a cool thing to hear, the fire is subjected to high degree of turbulence. while it may seem you're getting a complete burn. most of your energy is going up the chimney. by closing the damper in the chimney and opening the draft you get a pyrolysis effect that re-combusts the VOCs released by the fire very efficiently. the smoke at 9:36 in part 3 of this series is about 30% of the thermal energy of your fuel going poof! next, a baffle plate of sorts can be put into the burn chamber to keep the flames from directly entering the heat exchanger during initial daily firing up. that causes the flames to take a more indirect route into the exhaust and re-combusts another large portion of the VOCs and soot released by the flames that will otherwise accumulate in the cooler parts of the system. the end plates on the burn chamber should have been bowled a slight bit as the expansion of the steel goes out in all directions. at some point in time you will see cracks forming along the weld seams and the endplates will also start to buckle and warp. by them being cupped slightly, it gives the material a place to go when it gets hot and not deform in doing so. grates are not the best thing to put into a wood burner but if you must then i would recommend cast iron grates. steel webbing will burn up in a few weeks and steel grates will last only marginally longer. you can get inconel grates that will outlast cast iron but those are insanely expensive and unless you get exactly the size you need, they are almost impossible to machine with conventional tooling on a milling machine now people are probably think i'm totally nuts, but here's a crazy tip for day to day operations: every 2 or 3 days throw a handful of rock salt in the coals of the fire or a few beer cans. there is a product on the market called "Red Devil" (it's kinda spendy) that you do the same thing with. this keeps your chimney pipe clean. it really eats the gunk in the chimney up. i'm not sure what chemical reaction is going on there, maybe somebody who has a better grasp of it can comment. many snows ago when i built my little cabin in Elk City ID, i would do that and never had to clean the chimney pipe...ever just for reference: i used to help run a 5MW wood fired, forced draft boiler and was tasked with rebuilding the refractory walls of the burn chamber and access hatch, did a lot of the welding of the additions to the low pressure steam distribution system, as well as a majority of the welding of the ductwork for the exhaust gas filtration system of that boiler. so the points i brought up in this comment are based on those experiences and observations good work, good show and good series, thanks for posting!! cheers! mike
Looks great so far. Only thing I see is your beads, they are pointed. Means traveling to fast, slow down a little. I am typing as the video goes one. One big issue I see. On your dummy pipe. Need to take like a 3/16 or so drill and make a hole in the dummy pipe. Heat will build and could get to a point it blows the dummy pipe some where. It is going to build pressure if it is fully capped off. Need some sort of relief hole in it somewhere.
Interesting build young man. I have an idea one day to build a solid fuel space heater using the flame tube system as seen on boilers. Not sure the scavenger pipe is a good idea because it might rob the heat exchanger of heat? Anyway, very interesting to watch young man!
Opinions Please !? I have a similar build planned in my head except the stove being contained to one oblong shape like a Oil tank. I'm picturing the top 1/3 or so having pipes running front to back just like this build. My question is would the heat exchanger pipes in most scenarios get hotter by being in the top of the actual fire box with what would seem to me to be the absolutely hottest air/gases/flames passing from front to back along the pipes and then exiting out the exhaust or by putting a flat plate separating the 'fire box' from the exchanger pipes so the exhaust escapes out the back of the plate up into the upper chamber along the exchanger pipes and then out the top on the front basically like this set up ? It would be smaller scale than this and made from whatever I'm able to salvage whether it's cutting up a Oil Tank and shrinking it or cutting a Cylinder in half and adding sides and a front & back. So making separate chambers would not necessarily be additional work. I'm just using common sense, heat rises, heat exchanges but it seems some on here understand wood burning much deeper.. I'm planning on lining the inside with refractory to make it more efficient. Oh quick question for another project, can you gain refractory properties almost as much if the refractory material is on the outside of the steel surrounding it ? Like in a outdoor scenario.. Thanks 👍
I love this build. Thoughts: -Gussets on the legs tying the legs into the body is cheap insurance. -I wonder if you could extract more heat out of the unit by placing a shop fan at a right angle to the heater and circulate air over the heater as it’s burning. It would draw heat off the external surface of the whole unit while it moves air around your shop. -It would be interesting to see what the exhaust gas temp is at the top of the heat exchanger. That would tell you how well the heat exchanger is doing its job. When I saw the size of this unit the first thing I thought was to put a secondary exchanger to pull more heat before the gas enters the flue. This could be thin wall, like 14 gauge steel. Just some ideas! Too quality build.
This could double up as an awesome water heater for a cabin, if you run some copper coils around the top heat exchanger with water running through it. you'll hit two birds with one stone. 😀
Make sure to add the thermometer on the output exhaust, I feel your exhaust might be too cool with all those heat exchangers. If the output exhaust gas is too cool you'll run a risk of back drip of an evaporated water from wood and also creation / accumulation of the creosote, which might cause a whole lot of trouble. The thermometer can be electronic and can drive/ adjust the speed of the air fan so the exhaust gasses are in the proper temperature range.
Good day. I can only say that I feel great admiration for his work, which is a true work of art. Congratulations! Obviously his channel now adds one more subscriber, as soon as I saw the video I decided to subscribe without hesitation for a moment. I just want to ask you a question: Do you think that a stove similar to the one you have built can work using diesel fuel burners instead of wood? Thank you very much in advance if you can answer this question that I am asking you. Greetings from Argentina.
Well buddy I don’t think you’ll have to worry about it melting on ya - shes built heavy duty! Nice work. One questions are you going to have the fan thermostatically controlled so it’ll only blow air through the exchanger tubes when it gets cooler than the temp you want so that it’s not just blowing all the time cooking you out of your shop? Great video, one of you best edited so far in my opinion.
It might not hurt to drill a small hole in the dummy pipe. You have that thing sealed up when it gets real hot there's going to be a lot of pressure in there. it'll probably be ok but over time IDK.
really cool build. the only issue i see is with the dummy riser not flowing air and the other one being choked with the cross pipe I think you have a undersized and restrikede airflow for a fire box that big. she is probably always let smoke out when the door is open.
While I love a over the top design. I think you may find that this stove isn't going to work so well. The heavy wall material is great for being heavy duty and providing heating after the fire has gone out. But it's also going to make it hard to get your fire hot enough to burn smoke free. So as your fire is heating up you're going to get a lot of creosote and water condensing in the heat exchanger. The water will evaporate later. But the creosote might become an issue if it accumulates. And once the fire box does get hot enough to burn clean, it's going to be dangerous to be around because it'll be so hot. I'd suggest lining the inside with ceramic wool or fire brick. You'll get a way cleaner burn and the outside metal will stay a bit cooler. Those tubes in the heat exchanger are so big that your not going to get great heat exchange. It could be improved by increasing the surface area the air you're trying to heat comes in contact with. Some sort of spiral inserts that force the air to take a longer path through the tubes would probably help quite a bit. And depending on how well sealed the space you're heating is, you may want to consider using outside air to feed oxygen to the flame . I hope I'm wrong, but if I'm not hopefully this can be still made to work well.
Its such a beautiful job, but i fear the exchanger is going to plug up with creosote. A second open chamber with a clean out would do nearly the same thing and not plug up.
I don't get why you wouldn't just have a snakework of pipe inside the main chamber where the wood is burning that sealed up, and you have air blowing through it into your shop. By all means vent the exhaust gas to the outside and use the whole mechanism as colossal radiator but it would be nice to have that air blowing through the pipe carrying the heated air to the center of your shop and blowing down with some sort of cascading vent louver to spread out the heat.
Ever think about making the air intake so it can draw air from outside the building insted of creating a vaccum in the building drawing in cold outside air?
I'm a little concerned about creosote build up in the heat exchanger but overall, i really like your design. Should last a long time. If you're not already, I'd consider an outside air intake.
That design is very efficient for heat transfer but for the way I burn wood, not so good. I need to get into the system to clean out soot and creosote from the inside.
There is a cleanout in back and if need be, the chimney could be unbolted as well and everything washed out, I'm hopeful it will burn hot enough that minimal buildup will occur
@@kylechrist It depends on temperature, oxygen content, and also the wood that is burned. I have never tried water for cleaning. I use steel brushes, scapers, and burning the pipe with diesel. Burning helps remove tars/creosotes. The wood that I burn under air starved conditions leaves a tarry residue. I stay away from pine and gum trees. Most of my wood is not very well seasoned. The upper chamber of my stove is a barrel with removable lid and in fact I just cleaned and five ft of pile going up to my ceiling. There is still another 14 ft of pipe above that and I will do that next week. If the pipes and stove are not clean, then chimney fire results.
Very good build. I always see people making these wood stove heat exchangers with the fire on the outside of the tubes. Typically with heat exchangers, the fluid more prone to fouling will be inside the tubes since they are easier to clean.
Very nicely done. The only thing that I'd add would be an intake for outside air. A firebox that big will suck up a LOT of air for combustion and, unless you draw that air from outside, it will suck a lot of your already heated air out of the room and up the chimney. Also, a damper (and/or a low speed inline fan) on the intake makes controlling the combustion rate a whole bunch easier than just a chimney damper. If you want to get fancy, you can thermostatically control the intake fan to increase the burn rate in response to room temperature.
@@jasongrinnell1986 most furnaces will have a exhaust and a fresh air/ combustion intake. Its common and called a sealed combustion furnace. With a fire this large (much larger than what occurs in standard furnace) it will require much more combustion air. He's recommending a combustion air intake basically. All new gas and propane furnaces have this, most are ran up through what's called a concentric vent kit.
@@jasongrinnell1986 wrong , the stove consumes AIR that's what going out the chimmey . many stove have a duct to bring in air from out side to feed in to the intake. rather than using the warm house air that get replaced via air leaks and cracks to the out side. its called make up air , same thing with big vent hoods over stoves
@@jasongrinnell1986 A typical furnace doesn't draw that much air compared to this. While I don't think this will be an issue with his shop, modern houses (Built within the last 20 years) often are so well sealed, a wood burning fireplace can't get enough oxygen and will cause draft issues. Many new houses have a 2" pipe that goes outside to bring air in for the fireplace.
For control of the flame you can probably run a bypass tube with a simple valve from the circulation fan and feed it into the burning chamber. It should allow you to control the oxygen going into the burn chamber increasing and decreasing the burn rate of the wood for when you first fire it up you can run a lot of air in, and when the shop is up to temp you can lower the air flow rate.
Three inch pipe running the length of the ash grates up the back of the stove and up through and into the top barrel. You will achieve mega secondary burn and your build will be close to 85% efficient
Secondary air won’t work well until stove is up to temp and you begin to dampen primary air intake which will increase the draw on the secondary air. You will also achieve longer burn times much longer.
Great idea, using boiler technology in reverse. In a boiler, the smoke goes through the tubes heating the surrounding water. You have the fire surrounding the tubes instead. Of course, here in Southern California, it wouldn't be needed. Thanks for the video. Jon
It's not technically in reverse, there are both water tube and fire tube boilers. This would be like a water tube boiler with the fire on the outside of the tubes, and instead of water I'm using air. Thanks for watching Jon
@@kylechrist Aren't water tube boilers a pain in the a** to clean? With sut inside tubes you can send a brush through them; with sut around tubes how do you proceed? And while I'm already smartassing: Aren't the media in heat exchangers usually moving in opposing directions? (Most cooled smoke gets coolest air and most heated air gets hottest smoke) Greetings and stay safe
Great looking stove well built but it is a good thing you own heavy equipment to move it. No worries about burn through It will be around long after we are both gone. 👍😎
You don't move this by hand, that's for sure. The 20" sch 40 pipe that makes up the two "drums" is 123.11lbs per ft, each piece is 4ft long, so 8ft total. That puts the weight of just those two pieces at 984.88lbs. I'm guessing total weight will be around 1500lbs
