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.

Total beast of a wood stove. That thing should last 100 years.

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!

Build yourself a cold air intake and plumb it in from outside. Warm air in the shop is going strait up the chimney.

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.

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.

Aliens will find this furnace 400 years from now still in working condition. This thing is robust. Great build.

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.

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.

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.

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!

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

Clicks video for a cool wood stove. Sees a steam boiler from the Titanic. Backs away slowly.......

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.

from one fabricator to another ... great work ... (no one could ever know how much all he material costs or time involved)

6:08 that's how I got the last kid😢

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.

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

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.

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.

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 !

It’s nice to see someone who knows how to weld not just tack stuff together

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

Put a dampener in the chimney. All you have is a regulator for the air intake. Hold that heat inside that stove not let it out the chimney

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.

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!

Frankinstove. Im loving it. Cant wait to see the next gen.

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!

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!!

Stove? I thought it was a missile launcher

Keep up the good work by the way and keep us posted on how well this heater works.

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!!

Great to see your still rocken👍👍👍 time for some great heat now😊

Bout f-in time we get part 3

Absolutely the best I have ever seen no improvement needed

Looks great you should keep warm now thanks for sharing

Great build. We shared this video (with parts 1 and 2) on our homemade tools forum this week 😎

Fantastic stove you built. Good luck with it.

Now that's industrial strength.💪 Well done.👍

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...

Put Hardy backerboard On the studs behind it they put behind tile the cement board that's what's recommended and residential woodstove applications

Thanks for part 3. Excellent build. I don't recall how big the space is that you are trying to heat. Look forward to more work on the RD 4.

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.

Use a magnet on a stick & go over the ash pile, each time.

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.

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.

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!

Boy that's some nice welding boss that's a really nice fab job

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 only thing I would add would be a limit switch so the fan would kick on and off automatically. Nice build it ought to heat the shop up nicely.

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.

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

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.

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.

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!

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!

Cool! Looks almost like a steam train boiler. Looks awesome

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 !

How do you clean the flue out? If you cool the exhaust to much it makes water like a 90% furnace. A 90% furnace exhaust gas temperature is 90 degrees your was at a 100 degrees. The water it make is very corrosive and could rot out your flue in no time. I like what you did but it worries me just a little bit.

Neat project. Thanks for sharing.

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.

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.

Minor point but would rain ingress cause internal corrosion during summer - I didn’t see a cowl on the exhaust. Great construction work.

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.

That's awesome! 😃 It makes me think of an old Gatling gun! Nice job.

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.

Kyle.... Nice stove... Works very well... Dave

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!!

I think you did a great job building that stove.

That thing is a beast. Thanks for the video.

Oh my what a lovely BUILD. Thats some build. love this BUILD . whats the next BUILD?

This fire pit is one of a few covered pits that is on the list kzfaq.infoUgkxAU9pOCSV9Y5JprooHvfxTpOrt4hx8uRM 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.

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.

Great stove Kyle."I love your video's" And I love your dog's. Could you please show more video of your sweet animal friends, Your shepherds. They make my day Thank you.

Man that stove is impressive! I think it's going to work very well for you. Cheers 🍻

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.

Awesome work!

Stay safe and warm. I do agree with you though, the door should seal tighter.

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.

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.

Nice professional job

That's the best looking welding rod oven I ever did see

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

Be proud of that great shop stove. Its gonna give you years of heat !! Imagine if you were feeding it split logs ? burn allot longer than an hour

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.

Quite the project you've made. That has to come in over a ton, maybe double that. Put a *lot* of time into that project. Always nice to be able to experiment. Can still use fine fine tuning though. That's a long wait from match to really warm air. IMO

Would you be able to tell us all on KZfaq your thought process of flow for the smoke and heat extraction part Kyle ?? I and others here would very interested. This is a beast for sure. I personally would feel a lot safer with wider legs cause of the top heavy weight. Look forward to performance at your shop Kyle. Keep us all informed. Peace LOL.

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

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.

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.

Massif! Another rocketman.

Hi Kyle. Do you have any estimate of the efficiency of your stove? Do you know what is the temperature of the exhaust gases by chance when they live the exhaust pipe?

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.

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.

You can add a fresh air inlet to the heat sink to turn it into a secondary burn chamber which will create significantly more heat output

I'm very intrigued by this design.

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.