It would be nice to know the temp of the smoke coming out the chimney to gauge the relative heat exchange. Also, as you push volumes of air out your chimney, it will draw in the same volumes of air from any other airway to the outside. The best place to drawn new air in would have been down the length of the chimney. Putting your chimney inside of a pipe where the air is drawn from above the roof would have heated the new air coming in and retained the barometric pressure of the building right where the volumes of air are leaving.
I have the same issue dumping pallet ashes with nails. I bought a 150 pound rated magnet at harbor freight. I’ll be raking my ash dump spot dragging that magnet through it.
Suggestion from my own experience - take some long strips of thin steel that *just* fit in the tubes, and twist them into long “screws” and install them in the tubes - they’ll act as turbulators and slow down the air as it passes thru the tubes and increase heat transfer and overall efficiency. Looks great though!
Bud of mine built one like this back in the 70's made from two heavy wall military 55 gal drums. He used probably 20 2" pipes in the top chamber with a 10" squirrel cage fan on the back. His house was a 2,200 square ft. A frame. He loaded it with some cured spruce. It was -20F outside. After 20 minutes we were opening all the doors and windows. Yeah, it worked good.
Howdy Kyle. When i installed my wood stove I used concrete "Wonder Board" to cover the walls around the stove. I also used behind the Wonder board a product called Rockwool insulation that is made from spun fibers made from melting minerals. Unlike fiberglass insulation that will burn Rockwool will not even burn if you put a torch to it. It is also rodent proof and it does not mold if it gets wet. Over the Wonder Board I put ceramic tile that I obtained from a Tile store for cheap as the tile was end of run production and on a clearance sale, The tile retains heat and also reflects the radiant heat from the stove as well as looking nice. Great stove for your shop I always liked the dry heat from a good wood stove and free fuel is even better.
@@Entertainment_Enterprise meh. Ages old argument against cold air intakes. Only the tightest of homes need air circulation and make up air recovery systems. Shops like these with big man doors, huge garage doors that inevitably leak, do NOT need natural air circulation. A big shop like that needs to keep heat in to reduce wood consumption. A cold air intake would greatly add to reducing fuel consumption.
That's exactly why an intake is helpful, that circulation you speak of is bringing cold air in from outside. An externally sourced intake would reduce that significantly.
Cold air from outside drawn into heater >> converts to warm air >> adds to air inside >> increased volume of warm air inside displaces cold air >> prevents cold air from being sucked in from outside. Sounds legit. Wouldn't you need separate external air intakes for both the burner and heat exchanger? Otherwise you would be recycling your warm air through the fire and out the chimney... or would the air in/air out ratio not be drastic enough to notice?
My stepdad built one similar to yours for his shop when I was a kid... although his you could throw a full 8' railroad tie in long ways. Main difference was his all the fresh air/heat tubes were connected on the ends 180 degrees to make one continuous loop before heated air exited into the shop. Also the tanks were one right on top of the other touching with a chimney at the back That was 18" pipe and when you closed the flue it made the smoke go into the barrel around the heating tubes then eventually back into the chimney. It was big enough a barn owl fell down it past the flue one time and he made me crawl to the back as a kid and retrieve the owl with welding gloves on.
Hell of a build! I don’t know the size of the blimp hanger you’re trying to heat but I’m sure the stove will heat it just fine! Please bolt that top heavy nuclear fusion reactor down.
SUGGESTION: Wrap the firebox with refractory. Keeps your burn chamber hotter. Better gasification. Cold air intake for combustion. You building is sucking air in from every crack to feed her. Cold air intake added to blower fan inlet. Positive air pressure building. Keeps your doors from frosting up, and keeps condensation out of the wood in your walls. A venturi made from ductwork reducer with a small 1-1/2 pipe from outside works great. Keeps the fan cool too!
This fire pit is one of a few covered pits that is on the list ru-vid.comUgkxAU9pOCSV9Y5JprooHvfxTpOrt4hx8uRM of approved products for Disney Fort Wilderness. The product served its purpose well and provided excellent fires throughout the evening. We were able to open the door and do s'mores, but I had to be careful because the handle was a bit hot on occasions. Additionally, I wish they had replaced some of the standard nuts with lock nuts in some places. We lost the door handle after just a couple of days of usage. Not a deal breaker, just a recommendation. I still give it 5 stars.
That's a really cool design, kind of like a boiler. Would be interesting to measure the exhaust temp before and after, to get an idea of how much heat you're extracting.
I don't want to be a back seat video critic, but if I may throw in my two cents into the hat. A good hot fire is one that maintains a high temperature long enough to crack and combust the hydrocarbons released as smoke. Soot and carbon build up is from the smoke being cooled down too early and not being burned. Think of the smoke as a secondary fuel, hence why secondary burn stoves are so efficient. Your blower motor is doing just that, cooling the smoke down. Think about both an outside air intake, but also a secondary hot air intake into the top barrel close to the exhaust entrance (or bottom barrel just at the chimney into the top barrel). Research secondary burn. Second thought, the blower relies on electricity. Something you may not have at some point. If you were to incline the top barrel upwards (20 deg, maybe?) then you would create a natural draft thru the top barrel tubes. This would also increase the average operating temperature of the top barrel, helping to increase the combustion of the smoke. I have a rocket stove of 4" square tubing, 3/8 thick steel. The horizontal burn tube is 2 ft in length. Fuel is added only at the entrance to the tube. When it is at operating temp I get no smoke at all out the chimney, even with wet or green wood. This is because the smoke is held at a high enough temperature to be burned and release its heat. Anyways, just offering food for thought
Or just put some draft chimneys on the output side to induce a stronger natural updraft. Heck I'd put some piping on the back side to pull cooler air from the floor too if I really wanted to optimize it.
A damper on chimney would help to control air flow and slow the burn for longevity. It would help raise temp of heat exchanger by allowing exhaust gases to flow through slower and exchange more heat.
This, damper, flue etc...Rockwool insulation in that wall and something reflective to sheet it. Consider some sort of forced air intake maybe...the fire bricks will help it resist warping, if i had caught this in part 1 i would have suggested thicker wall air pipes on the bottom, we had heat exchanged air fireplace when i was a kid and the bottom tubes wore away after some years, Some crude bent rebar grate for the bottom to keep the wood and fire up off your screen on the bottom will allow more air to get under the fuel and back to the rear, those eat away pretty quick too..
I don't want a damper in the exhaust as I need the heat to keep any creosote buildup burnt off. There is a fine line between losing too much heat and choking it down so the chimney is cold and creosote builds up. I'd like to stay on hot side of that line 👍
At the son in laws i devised a single line oil drip on his double barrel stove.when turned all the way up after loaded with wood,it would preserve the wood for hours.it was a really great addition. It could be taken a step further by building a burner around the grate
You are quite a craftsman . Be careful if the flue temp gets too low the products of combustion will condense resulting in creosote in the pipe. Chimney fires are fun to watch !
Cool. That looks just like a stove I helped a cabinet shop in Arkansas build 20+ years ago! We tilted the top barrel backwards a little bit so any creasote that tried to form would run back down into the burner barrel. When we installed it we put a box fan a couple of feet behind it to blow air through the tubes. It worked great.
Burning that pine is where you'll get most of your creosote/buildup. Great firewood ! Especially Free !! Highly suggest using creosote powder ! Once a day? If I remember right
Bring outside air directly into the firebox A great way to improve the energy efficiency of your fireplace is to duct outside air directly into the firebox. This is even more effective when combined with the installation of glass doors, so that then the fireplace does not use room air for combustion at all (helpful accessory: fireplace back plates). With direct ducting of outside air, the vents on your glass doors can be sealed completely.
But..., pre-heating the outside air, is even better. My 4' long wood boiler fire box uses 3" pipe to bring the combustion air in, the pipe runs along the upper side of the cylindrical firebox, and exhausts a few inches from the front on the stove. Over the years of use, I've found that if I take the time to cut and use much shorter pieces of scrap lumber, and hold the fire forward, the remaining 3' is all heat exchanger, the smaller fire right near the inlet air burns real hot, no visible smoke, very little ash.
Great idea but this is dangerous, cooling the chimney as its going to cause a lot of buildup in the chimney. Maybe you could do controlled chimney fires to burn it out periodically? Idk how you would clean that.
Everyone has an opinion so I'll throw my two cents in. I'd look for a way to add secondary combustion air to the fire. This is usually a small amount of fresh air that can be delivered to the top of the combustion chamber. Makes for cleaner burn and more heat. Great fabrication work!!
Everyone think about this, it’s a meme at this point. Isn’t more straightforward to increase the temperature at the first burn than over engineer a second burn not knowing if it will be hot enough to actually burn?
I would definitely add a cold air intake for the firebox. You don't need one for the fan and tubes. Add a basic filter to keep that furnace fan motor running. Awesome build!!
Great stove and strong work!Volksgang 2 barrel stove kits back in the 80,s heated my shop and old farm house well for many years.Minimal work and very low price.Replaced about 10 yrs latter with fisher mama bears that where great stoves ,indestructable,available and affordable.Its good to see you work and build.You make us old men proud.
Very nice build, I am considering building a similar stove, but using a large 275 gallon fuel oil tank. I especially like the grate and ash pan idea, you can clean out ashes while the stove is going. I have been trying to figure out a magnetic nail collection apparatus to make ash disposal easier and faster. The fire looked and sounded great, nice ending scene!
If you don't have one already, a snap switch from Grainger will control your fan, both on and off, they are cheap and can be gotten at any temp you desire.
It would be great if you could draw your combustion air directly from outside instead of using heated air from the room which has to be replaced with cold air from outside through leaks in the building. Beautiful heater. It's going to be there for a while!
The higher the temperature of the burn, the less smoke and creosote buildup (the stuff of chimney fires...). You're re-creating a similar technology that was refined in the late 70s. Keep that door open!
The faster the air, the more heat is transferred to the room & less is let out the chimney. But if the heat is sucked away too quick, than the fire doesn't get hot enough to fully burn all the gasses. Hence creosote build up. Also, if you want the best results, than feed the firebox with air from outside. No sense sucking cold air all the way through a room. Plumb it directly to the firebox.
Rockwood insulation in walls at least where stove is. Say 5' out each direction from corner and up 8' in height will protect the wood. Cover this with the same delta style metal that exterior wall is made from. Can run it horizontally for easy screw locations, makes an awesome reflector also. I suggest a used oil drip going into the burner area, in the center of the top. Simple one, using 1/4" copper line ran to a oil resovoir on the wall with a ball valve for flow control.....This will blast your temps past 200f. Easily. My system is just 2 stacked water heaters enclosed in a "shed" with the same fan on the back and several vent holes on the sides. With the oil, the wood is essentially just a "wick" and the oil burns so cleanly you will not have a spot or smoke problem. In 8 hours, in a 30x30 uninsulated shop in Idaho, I will burn maybe 2-3 armloads of wood scrap and a gallon of old oil. And the shop stays roasting, even when the oil is almost turned off. Nice job on yours, just wanted to give you some ideas.
You can use concrete board like what you use in showers instead of steel. It is fire rated and would be super easy to tile or stone over if you ever wanted that look.
You should put an elbow of some sort on the top of the exhaust pipe on the roof. Otherwhise when it starts raining or snowing water will come down, fill up your stove and then start leaking outside the stove with all related problem like rust and dirt. Also to avoid any kind of bird to been able to make a nest inside during the hot season. For the rest, a beautiful pice of art! Congrats
Just learned about wood stove fans recently. They operate off the heat of the stove. Low speed should be easy for a stove fan. I've built air heaters before and I have a similar idea for a wood stove in my head. The air heaters I used to build had a stainless steel expansion joint between the tube sheet and the box to allow for the expansion and contraction of the tubes when they heat and cool so you don't break the welds on your tubes.
Merry Christmas! I love what you did with that old boiler! You have to insulate the unit with lagging, it would be more efficient and safer for people than insulating the building around it. You could fill that heat exchanger with water, set up a recirc system, and use it for shop hot water. A pressure washer with a hot water supply is a beautiful thing in the winter...
Nice job, should work well. In the late 50's early 60's we had a similar setup with 45 gallon drums but no air tubes. It was our night heat, get wood burning then shovel the sawdust on top.
That's a great build. As Leif H. says, the heat coming from central air/heat systems are around 100F, some go to 105F. Human skin temperature is around 90F so we feel any heat above that pretty easily. That much mass in the stove will continue to heat well as the fire burns down and I'm thinking you had that in mind all along.
I believe that you should have a dampener in the chimney a little ways above the bolt flange. Then you can get more heat from less wood!! Another suggestion is to burn up a couple of aluminum cans a couple times a week to turn the creosote dry and flakey. Especially since you are burning pallet wood. Wet wood and pinewood are awful for creosote and the combination of not retaining more residual heat adds to that as well. Put a weighted bucket upside down on the top of the chimney when you are done for the season will help keep the internal rust slowed up too. Good job bud!!
Seen the video earlier on the big screen. Looking Great Kyle. Nice design, once that puppy gets on step you'll have to open the large garage door to stay cool. 🤗 🔥
That's a beauty, what an interesting design with a heat exchanger of sorts. Why not scavenge the heat that would be lost out the flue........pretty clever!
You should try sheeting in the whole stove and add a couple exhaust ports to also trap the heat from the outside of both the burn barrel and your top barrel. With your forced air blowing through to the front. I hope I’m explaining that well enough that you catch what I’m trying to say. Great build. I love your idea with the bottom heat tube.
I think you are wise to keep the air speed low. One of the challenges with cooling the post-combustion air (which is the effect your heat exchanger has) is that it can cause an increase in emissions, and creosote buildup. I recommend you inspect the inside of your stovepipe regularly until you can determine the rate of buildup you are seeing from lower temps in the stovepipe.
Nice work, I really like this idea for a large shop heater to burn scrap in. Efficiency wise... I would guess this isn't much higher than a free standing fireplace though. With the added efficiency being from the heat exchanger. You could use a key damper in your flue pipe to help with that. Also, fabricating a secondary burn element from perforated pipes to go inside the top of the firebox would more than double it's current efficiency. Great job though man that sucker is certainly heavy duty and not going anywhere. Can't wait to see what mods you make to it!
They sold 55 gal barrel stove kits back in the late 70's early 80's. I bought the kit to assemble a wood stove for my auto body shop, so I didnt have to have a forced air furnace blowing dust into my paint work. I did a similar trick with 1'1/4inch tubes in the upper barrel and a fan to blow air through the tubes. It would absolutely run you out of the shop when burning oak and hickory.
I had a stove kit from a family owned company called SOTZ, just a great simple and cheap kit, all stamped steel no castings, air tight and man did it put out the heat!
Lower fan speeds sure helps. If it’s a good size shop ceiling fans help move the heat around very well. Pulls the heat back down as it rises in the building.
Kyle, if you burn a lot of green softwood, you may find that you get a lot of tar condensate on the top tubes, where it is coolest. In our last house we had a Franco-Belge wood fire burner with a back boiler connected into the water central heating system. I had to take the burner completely to pieces every year to clean out the tar build up on the boiler and that was in spite of doing a really fierce burn every two weeks to try and burn off the tar. The wood burners in our current house do not have a back boiler and get hot enough to burn off the tar, using something called an airwash system but we are quite careful only to use well dried hard wood fuel. My daughter's partner is a tree surgeon, which helps.
Pallet wood is kiln dried so shouldn't be much of an issue. The moisture I mention in the video is from the light rain we had in the morning and making the wood damp 👍
This is from the Premier Firewood Company: "Use of kiln dried firewood, which has low moisture levels, allows the fire to burn efficiently, create a lot of heat and very little creosote, if any at all." I'm not saying it will not creosote at all, but a dry wood will naturally not creosote anywhere near as much as a green wood
Premier firewood is using mixed hardwood, birch and cherry. Hardwood has MUCH less resin and tar than pine. It is not so much about the moisture content in this case as it is the specie.
Nice build. You have the same problem as most stove manufacturers, you're heating the mid air and up ! You need to make the heat come out of the bottom and blow across the floor !!!! Remer, heat rises, start with the heat across the floor. I can't tell you how many houses I've been in where my head is hot and my feet are cold !
140° - 170° is perfect for maintaining a well insulated space in negative outdoor temperatures. Slower air speed better heat exchange! Carbon Monoxide detector is a must as any pinholes in welds would leak undetected. You should have done a hydro test
Great presentation, thanks for sharing this video series. Do you know anyone who works with HVAC equipment. It should be possible to add a thermostat on the front of you tube array to control the blower motor speed. Setup as if for an air conditioner with minimal fan at 100°F and speeds going higher as heat increases. Add some rock-wool insulation to the stud wall and metal to preserve the heat. If you decide to cover the stud walls with metal, leave a couple inches gap at bottom to allow heated air to convect warmth into your shop. A ceiling fan above will help distributing warmth from ceiling back down to your shop floor. Peace
My only concern is with wood heat; it dries the air so much. I would suggest welding a small table, so as to be able to sit a Tea pot / kettle of water (say 10" inch square, 0.25" in. thick or thicker) to heat up and put moisture back into the air. Your throat and sinus will thank me. 25 year's wood heat in my home. Great build, and design. Thanks for sharing. PS the water does not need to boil, just get hot enough to evaporate in a couple of days or less.
@@kylechrist waiting for the thermal image video including temps at key areas like the clean out top, etc, very interesting design, can't wait for more vidyas thanks
Super neat design. I'd be curious to test one out where that top section is a water ballast. Almost like the wood boiler we use to heat our houses, just a bit more compact.
I've just arrived at your video, and immediately paused it 😁 ... I can't delay saying this: your stove looks like a menacing machine of war, like something that would hang off a wing of an Apache gunship, or Warthog, super cool! I wonder if it may not be possible to strategically paint your stove with high temp paint, perhaps like header paint, in cammo or something. ... that would just be too cool!
I suggest 5/16" GWB on the wall 2' to the side or back of the stove. That would provide fire protection for the wood stud wall. Also if wood is backing the metal panel wall.
Sweet Kyle looks like that stoves working nice. When I was turning wrenches for a garbage company in Norwich NY my boss wanted to make a pallet stove to burn whole pallets much to the same design only we used old thick walled fuel oil tanks and fed the pallets through into the bottom one and put thermal controls on two box fans behind forcing air through the heat chambers . Bays could accommodate 2 tractors and trailers. And that garage was a comfy 79 degrees in the furthest corner great garage to work in and yes the fans were set to low.
@@kylechrist it was Rick said he wanted it big enough to burn full sized pallets in it and to heat the whole shop and an added bonus came before I moved on we had added a waste oil feeder to the mix which helped a great deal with the hardwood pallets
The cold intake is a good idea😊. I remember seeing this a long time ago. I did not subscribe because I thought this was one of those projects that never gets finished. I want to see a complete review. Cold temp outside. How long it takes to heat the coldest part of the shop. Do this before the insulation and cold air intake. To see the difference. Talk about the temp outside before you start. Thinks for sharing the progress.
If you had additional clean air source into the top barrel you could probably get secondary combustion and burn off the wood gas. Would also get it hot enough to carry off the water and prevent it from condensing in your exhaust pipe.
While capturing the heat from the exhaust gases / smoke is great, you may find that the outside of the tubes will collect creosote and soot, eventually insulating the surface needed for heat transfer. With my stove I run in what I call free burn, letting the fire have all the air it wants, getting a more complete burn. Hotter burn, less creosote and soot. I also block off one side of my blower to reduce air flow, even low is too much air for my situation. Great job on the build. That is "Heavy Duty" in my book.
With the pine burning as hot as it does, I think creosote shouldn't be an issue. I did put a cleanout in the top chamber if need be, thanks for watching 👍
Lower fan speed will increase temps but reduce volume (CFM) thus reduce BTU output into the space. BTU = CFM x Delta T (inlet temp at the fan minus outlet air temp). There is a correction factor multiplier but we can ignore that. Also CFM can be arbitrary as long as you’re consistent. So if you bought a cheap anemometer you’d be able to determine if less air flow but higher temps is actually producing more heat. Often times this is NOT the case, for example if you turned the fan completely off the temps your measuring would be VERY high but without the fan you aren’t moving the heat into the room so you’ll get higher temp but lower BTU output. Running the fan on high won’t be as comfortable standing in front of it but more effective at heating the space. There is a point of diminishing returns which the above calculation aids in figuring out. However I’d balance this with exhaust gas temp to minimize condensation forming in the flue. Basically maximize heat output and equipment longevity.
On the back side of the burner barrel I'd add a small diameter (1/2" ?3/4" ish ?)pipe on the rear just under the grate and attach it to the fan box, possibly add a ball valve in for some flow control, then when the fan kicks on it'll pressurise the pipe with air allowing the wood nearer the back to get more oxygen laden air fed to it for a cleaner more efficient burn, as the stuff at the front where the grate is will have used most of it up, so your basically adding a small secondary air injection that'll kick in with the fan, the flow adjustment will allow you to tune it so you arent chucking so much air into it that your burning through your wood quicker, the chimney smoke will let you know when your getting a cleaner burn.
1- put baffles in the tubes so the air spends more time in contact with the hot surfaces 2- the squirrel cage blower needs some air restriction otherwise you’ll burn it out (take an amp draw to be certain) 3- unless that chimney is really tall, I’m sceptical the diameter is sufficient to expel all the products of combustion
This is a really genius idea, you have a really great design concept. I think a major design decision you could make on the next one is either to make the upper part half as small, or to double the size of the lower burn chamber. Remember when you attempt to make a thermal transfer, nothing performs at a 50/50 ratio, there will always be losses, especially when calculating volume at 50/50. While it sounds crazy to reduce your upper transfer unit, think about it like this,…. What would happen if you increased your lower burn chamber unit?….same same… so do one or the other for better efficiency in transferring that heat energy via air movement. And only then might you be able to run your fan at a higher velocity… Food for thought.
Very impressive build. As you protect the walls on both sides, consider adding some kind of masonry to provide thermal mass that absorbs and radiates heat after the fire dies down. This will moderate the temperature drop-off, extend the total time a fire warms the shop, and reduce how frequently you have to add wood.
you're actually cooling your flue and stove when you leave the door open. It will draw a tremendous amount of cool (room temperature) air in through the open door and up the flue and therefore reduce your temp readings.
From the looks of it your a welder by trade, and also looks like you did a lot of planning on your wood burner . You should never have to replace any parts on this beast. Great job.
We had a barrel stove in the workshop back in the 80's. It sucked so much heat from the flue gasses we had to clean the creosote once a month it would build up so fast.
