Suggestion: I was hanging out with a neighbor who was using his oil-barrel smokeless incinerator and his has a few additional features: 1. an internal 45-degree bevel that redirects the air rising up directly to the upper holes, and 2. an external bevel just like #1 but more like a beveled lip just above the holes to slightly narrow down the fire pit/incinerator opening and giving more time for the secondary air supply to mix with the smoke and make the secondary combustion more effective. The external beveled lip is around 1.5 to 2 inches in width which at 45-degress should only narrow down the fire pit opening by a total of 1.5-2 inches. I was surprised his incinerator hasn't produced any visible smoke at all and I just thought that those features might have helped.
I like the fact that he didn't edit out the mistakes he made and what didn't work in order to demonstrate how the various changes effect the outcomes. Great video!
Absolutely that way if the next person thinks that what he did is the best way they can see that it's not and it'll save them time and headaches. They say that failures are steps toward success.
Why wouldn't he... you people were paying him to experiment... it cost him nothing and he probably made thousands above what it cost him... not to mention he had a sponsor paying him...
@@t.c.2776 I suppose for the same reason 9/10 youtubers edit out any flubs, mistakes, bloopers, mishaps, and anything else that may not project a polished and professional appearance to their audience.
I appreciate you doing all of the homework and expenses. Saving me time and money. I'm a single dad, and I enjoy doing little things like this with my daughter to show her love. Burning firewood and hugging my little one is so great. Every dollar counts, so thanks again.
My daughter has also been quite enamoured with our fires we build together. She has expressed an interest in doing some branding. Next weekend we will try just a small quick one on her right hip.
Just had to say one of the best integration of a sponsor and not taking the whole frame of the video and giving us continued progress of the project at the same time! 👏👏👏
THIS! I appreciated that you didn't take a break or tack the ad on at the end. And honestly, that meant I heard the entire ad. When I see ads on other videos I just move on or fast forward.
I'm thinking the only thing you could have done that would improve the performance of your fire pit is more depth. The Solo stoves are much smaller in diameter than your fire pit and they are taller in height. That gives much more space for the air to really heat up as it rises from the bottom to the top of the air channel. Great video! I know I learned a lot by watching it.
Yes, and the fire needs to be big enough to really heat the wall of the fire pit. This makes it so the air gets proper flow and is superheated so it really combusts the smoke. I own a solo stove and it works really great, as long as you keep it properly fed. When it's really hot it burns green wood mixed in without any smoke.
0:27 fun fact! (Assuming you don't say it later) the reason smoke seems to always be blowing into your face is because of convection. With nothing obstructing the air's movement toward the fire(and no wind) the smoke will rise straight up. BUT! since there is often a person or group of people somewhat clumped together around the fire, the air that would come from behind them is slowed meaning the air on the other side of the fire that isn't slowed will assert more force bending the convection current and thus the smoke towards the people blocking the air. Of course with the wind blowing the smoke will follow the wind but still be affect by the convection
This is why I often add a large, flat vertical stone on the far side of a campfile fire. However it doesn't aways work, because smoke following people is based on the universal law of attraction... whatever you fear will come :)
Really liked your pit design. There is another way to have a less smokey fire. You don't construct a tipi. Instead you pack in tightly the logs at the bottom. You add smaller pieces and at the top you construct the twig, pinecone, dried orange peel pile. One lights the top, not the bottom. The fire burns gradually downwards but having the fire at the top means it burns the gases coming out of the gradually heated logs. Much less smoke and significantly more heat.
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Tip for calculating the airflow: Measure your 4 gaps in the bricks. That's the surface area of the inflow. Ideally the outflow should be similar in size to the inflow, or slightly larger. Number of holes * pi * diameter is the surface area of the exhaust. Compare the two numbers and then adjust the hole size (or number of holes) until the inflow area matches the outflow.
Would you want the airflow to be the same between the top and bottom? Would it not eventually choke the fire if the bottom weren't receiving more air to feed it? Or would the heat of the fire just naturally pull in more air from the bottom regardless; provided the holes weren't smaller and/or less numerous than the top holes.
Surface area of the exhaust = (number of holes) ⋅ π (diameter / 2)² (Number of holes) ⋅ π ⋅ diameter would give you the total circumference of all of the holes, not the total area.
@@flennboyd6413Probably Automotive Engineering or Furnace tech/engineer. There's a big world out there man, lots of really cool things that people do.
Brad, your relentlessness toward seeing a job through to the and and your relentlessness in maintaining a great attitude is one of the most inspiring things about you and this channel. It is easy to see it is not a show for the video - it is authentically you. Thank you for all you do and the videos you make - this is truly one of my favorite channels in the maker space. Keep up the great work man!
@@Fixthisbuildthat Hey Brad, I’m totally high jacking this comment just to ask you a question. In one of your videos I heard you live in the Nashville area. If this is correct, I was wondering if you could help me out. I’m wanting to build a “big girl bed” for my soon to be 3 year old daughter. I don’t have a workshop and am looking for an easy way to build this twin bed. Reply back and let me know if there’s a possibility you could help.
There is one detail about fire pits that people keep forgetting. If the fuel (firewood) is higher than the secondary holes, the secondary burn will become a primary burn for said wood and thus produce smoke. If you want to keep your current system then do not build the fire higher than the secondary holes (maybe an inch shorter). If you are going to mod the system, add a 4th layer of stones and keep the firewood below the holes.
Wow! I have zero intentions of doing this to my fire pit. I don’t even know how this video found me. But, I certainly appreciate the amount of time, money, and work you put into this video. You’ve earned a like. Great job 👏
I agree with everything @scottvriethoff6633 said. My hats off to you FIX THIS BUILD THAT for all the labor and money you put into this test for others to benefit.
Actually the solution is a three quarter size burn barrel, with a lid ( that opens) and a pipe that has a flue… perfectly distributed heat, no smoke whatsoever .much better heat source ..use it in backyard for gatherings and at hunt camps
@@brentfarvors192 its too wide to properly work, the air needs to get hotter so it will rise above the smoke, taller narrower versions do actually work to some degree
Meh... do a search for 'dakota fire hole' or 'dakota fire pit'. I've been building low-smoke fires most of my adult life without anything special. You just have to watch the wind direction. Air feed is the key along with a hot fire.
Loved this, I have a Solo fire and it does smoke to begin with even with dry logs. You also get a better secondary burn with a full fire across the width (rather than a tall fire) as the air passing along the side to come up through the holes is heated more... Great job!
What you tried to build is a gasifier stove. However, that design relies on two things: small enough diameter to heat up the walls, making the secondary air rise up by draft, and small enough diameter to deliver that air into the flames. It's not really well suited for a large but flat firepit, but kinda works if you make the fire crazy big, as seen.
I'd argue that one thing the pit would benefit from would be for the bottom airflow to come out from _under the logs._ In the current iteration, it just tries to get to the flames from the sides, which is better than trying to enter from the top, but you still get convection pushing most of it upwards, rather than allowing it to get near the actual fuel and thereby replenishing the oxygen levels more effectively.
Yeah, I was just writing about diameter/height ratio - and drainage: seems likely to collect water when it rains, and moss and a little ecosystem! The DIY double skin drum I saw on here before I saw the solo stove advertising everywhere - that had legs built from the base of the drum. Rocket stoves have built in thermal mass and, like, hardcore substance - as do pizza ovens. Which is kinda what you want in a garden feature. Even though the solo stove looks very futuristic, it's not everyone's vibe and it probably dents and tarnishes as much anything else. And a drum is already a relaxed & utilitarian DIY vibe. Not pretty.
One suggestion I would make to reduce smoke, indoors or out, is to build an "upside down" fire. Put the biggest pieces on the grate, on the bottom, then the next smaller, at a right angle to the biggest ones. Keep alternating layers, leaving some space between the pieces for air, then put newspaper and small kindling on TOP, NOT on the bottom. You may have to feed a bit more small kindling at first, but not for long. You will be amazed at how much cleaner, quicker and hotter the "upside down" fire will burn. Each layer heats the layer below as the fire goes DOWN (trust me, it will, even though fire generally does go up), so each successive layer burns readily, and there is hardly any smoke. When you make a fire the usual way, the bigger wood on top isn't hot or dry enough, so there is quite a bit of smoke until the big pieces get going. Once the "upside down" fire gets down to the bottom layer, you just feed it more wood on top as usual. If you try this method once, you'll never go back.
We always do the stacked cabin type fire with the newspaper or kindling underneath the “roof”. I’m going to try this way next. I’ve actually never heard of it before.
In most cases this will not work. Heat rises. Ashes smother flame. If you need to get a fire going use log cabin or teepee style. Some genius taught this method to our kids for 'winter survival'. Apparently cold branches won't burn this way. Everyone had to eat cold weinies.😥🍖🥶
When wood gets hot enough in a low oxygen environment, it produces wood gas, which is flammable. Combustion needs oxygen, so you see fire "shooting out" of the vents, which is actually the boundry of wood gas and oxygen mixing and burning. Gas burners have this same boundry flame, but inverted, with a stream of flammable gas into an area of oxygen. Fun fact, the fire we see is mostly comprised of incandescent soot, material that gets so hot it glows like a lightbulb or forge metal.
So it's true that wood doesn't burn. It gets hot and produces flammable gas. If you look very close to wood burning there is a slight gap between the wood and the flame.
Correct, if you're seeing flames out of the top holes, it has to be wood gas being drawn into the lower holes, & mixing with the air to then be ignited as it exits, looking like the burner you talked about. Just air coming out wouldn't really do anything... My woodstove has secondary burning, but the flue comes outta the middle of the firebox (damper can be slid open to load wood, so it exits the stove by flue not door, lol)
This guy is brilliant! How beautifully he explained the various tests he conducted! He was so determined to achieve the objective of building a smokeless fire pit, and he finally met the objective!
Super fun project, Brad - had me glued to the screen start to finish! I hadn’t really heard of smokeless fire pits unless they were propane or gas fed so that was pretty rad. Great video!
@@Dgiztred Yes. My "experience" is exactly as posted; The ONLY WAY to control the quantity of smoke, is to burn on a clear (high pressure), windless day, using the driest and most finely cut fuel available...Using the method posted here will make the fire burn HOTTER (More air flow= A hotter flame), but will do NOTHING for the smoke; Especially when starting the fire, and when it starts to burn out...I've tried with Pits/Barrels, and everything in between; You aren't going to beat physics...
I'm usually not huge fan of these videos but you by far have a great presentation that would actually help people that have very little experience making things. If want I'd give few simple ideas to maybe make that an easier set up work better or you might take the things I do make them better. I just been working way to many hours and really just learning the video stuff
I think the next step in efficiency would be to add spiraling channels around the outside so that the air in the walls of the fire pit can't just go straight up, but has to go at like a 45 degree angle around the outside, increasing the time it spends in the wall and therefore the time it spends heating up. This would likely result in a secondary burn happening sooner after starting the fire, and a more complete secondary burn due to potentially increased velocity.
Another feature to help secondary burn might be to add a lip above the top holes, as is seen on the retail fire pit design he's imitating. This would force the air exiting the top holes towards the fire a bit before it can rise above the firepit, along with adding some radiative insulation to that region to help keep temps up and maintain the secondary burn
The amount of work, time and investigation you went through to figure out how to exactly create the closest thing to a smokeless fire pit was pretty impressive to me. You went beyond my expectations and I appreciate the days it took to film this and do all the drilling, experiments & etc. I’m subscribing for more of your videos. Your thoroughness in figuring out the perfect method will save me so much time and error.
Great video! I liked it! Here's what you missed when you looked at the patent for the solo stove. The secret of why it generates almost no smoke isn't to do with the size or number of holes in the top/bottom. That is a factor though. The biggest factor is to look at the ratio of the height of the pit to the circumference. Basically, the solo stove is skinnier and taller. With a pit of this diameter, you'd have better performance by building the height of the pit upwards. This increases the effective space of that insulating layer, providing more area for smoke and gasses to slow, cool, get trapped.
If you ever decide to return to this project, you could place a small lip around the top of the internal circumference of the pit forcing the air for the secondary combustion in rather than straight up as it exits the holes while simultaneously trapping some smoke underneath the lip which may increase the combustion but also possibly reduce the airflow. I am curious to see the effect. It's a similar approach the reducing the diameter of the pit without making it look like a soda can.
dude tried it with a wet wood, did bunch of improvements that didn't help. Eventually he added dry wood and omg - it didn't emit as much smoke as it used to. Definitely a good design :D
Yes, the stacking of the wood has more of an influence on the smoke compared to the fire pit's design. What works for me is stacking the wood to create a closed high temperature chamber, like a furnace, with smallish entrance holes for the air, and corresponding exit homes for the smoke.
It would be interesting to have done a control burn using dry wood before drilling the fire ring holes. This would show how much of the improvement in smoke reduction was due to the modification of the fire ring and how much was due to the drier wood. Great video otherwise. Very easy to understand. Will use your tactics when I build my next fire pit.
A lot of time and effort to make this video! A BIG THANK YOU! Had a fire pit at our summer home and always wanted to figure this out. You did it. Great personality!
the smoke is always in your face because the smoke will travel towards the tallest things around the pit. Think of it as smoke traveling up a wall. At one end of my pit I have a tall rock (almost 4ft at the peak) I am not sure the science behind it but this makes the smoke always migrate towards it and then up the rock and up. Just something to think about. great build as usual.
Air rises over the fire, pulling outside air towards it. You block that inflow, so rather than it flowing in to the fire it can get pushed out towards you
No your body acts like an air dam. It blocks air from getting to the fire . What creates a vacuum and the fire smoke moves towards you. The more people that sit around you the bigger the vacuum. So sit alone and the smoke will not bother you.
Pretty sure it would be exponentially better if you placed a another layer of stones on top of the steel liner to add as a "ledge" so that the top opening is a little tapered.
He’s onto something here. By narrowing the top of the fire pit, you will achieve what is known as the Bernoulli effect. A greater force of air thrusting through the whole system, and theoretically more fweefwee
Wow , I love the whole concept of knowledge OF A GOOD FIRE , EVERYBODY DOESNT HAVE THIS TRAIT , LOL ..BUT DUDE THANK YOU FOR YOUR INSIGHT , BEEN BUILDING MY FIREPIT IN MY HEAD FOR YEARS , AND TODAY I GOT A VISUAL ON THE CONCEPT ! YOUR AWESOME !
Probably could've saved 6 hours of work by switching to dry wood. I burned very old and dry oak flooring last night in an open pit and it was smokeless.
I really liked your video, I've watched many and this video was the best. I loved how you actually tested the different size holes until you got what you were shooting for. I've got a similar situation and wondering what size the bottom holes are and how far down from the top are the 1/2" holes and how far up from the bottom are those holes? Thanks!
After doing this project years ago, what I learned was it's easier to get the smokeless results with a smaller firepit ring. I think this is because in order to get smokeless results you need higher temperatures which is easier to get with smaller pits, unless you plan on burning A LOT of wood at one time. This is probably why the solos aren't that big.
Great video. It would have been good to see the unmodified original version with the same dry wood you used at the end. As I feel like that's what actually made the difference
Yes, correct me if I'm wrong, but nothing seemed to work until the fuel type and amount changed. So the conclusion should be: don't change the pit, just dry the wood and add more. I like the attempt to engineer the pit though, and I'll probably do something similar because it's cool :)
This is the first video of yours I've come across and I hit the subscribe button half way through. I love your nerdy enthusiasm. Your curiosity and methodology. Then I came to the WD-40 ad, and holy batman, that was smooth! The way you integrated it in to your content, I didn't skip it! And I wasn't bothered by it either. Also made good points on their product and reminded me I should go buy a can, lol. So excited to have found your channel.
I have made similar fire pit from the laundry inner tub, which has tons of holes. It works great with no smoke. It seems like in your experiment, the fire pit is too low so it doesn't allow much of the air flow. The upper holes should be at bit higher. Thank you for the experiment and share!
@@bam5732 - They both play a role....Even with the driest wood, you'll still get lots of smoke if the fire doesn't have an ample oxygen supply. Likewise, even with the best possible air supply in the word, if the wood is wet it's gonna smoke. It would have been nice though if he'd actually shown the old pit with dry wood.
@@scottcates most of the time they are stainless steel, or at least the older ones are. Also, the older ones are driven by a big pulley, which can be left in place and serve as a stand. :)
Thanks for making this. I used your first video to build my firepit recently and it's producing way too much smoke so will definitely be giving this a go!
Great video. However, the part that's missing is the ratio of stove height to diameter. There a powerful convective element with this process you just aren't going to get with such a wide and shallow fire-pit. The point is to increase the secondary burn which takes place at the top of the fire. In your stove the top of the fire (flames and smoke) is already outside of the fire-pit. It's just NEVER going to work like that. You pit needs to be 2 or 3 times higher for that diameter. Notice on the patent how the top is tigher than the rest of the pit and the ratio of heigh-to-width. The secondary combustion has to take place BELOW the top surface of the stove. Dry wood for the final tests but wet wood for the preliminary is also quite misleading. A lot of people will fail following this advice.
You brought up a point that I was thinking. The idea that he is copying does have a higher ratio, meaning the fire pit should be taller. Everything else about this is good and I think I'll build one of these.
At first I was ready to rip out my stainless steel insert on my garden BBQ (we don't call it a fire pit) and spend a Saturday in May drilling 2500 holes...thanks to this post I'll save the effort...title of the video should be wet wood is great for smoking
If you notice on the Solostove the top opening is necked down smaller than the diameter of the main burn chamber. That increases the velocity of the air leaving the chamber and this increased velocity produces a slight vacuum in the chamber. The vacuum pulls more air through the secondary combustion holes making a more efficient second burn and less smoke.
Try arranging your logs into a lincoln log cabin style. lay 2 wood splits parallel to each other and then stack 2 more splits parallel but perpendicular to the bottom splits. like a tic tac toe cross. helps promote airflow! I use that technique when i smoke meat! Great vid Brad!
I have a different brand than Solo and it is completely amazing. Really cool almost welding type flames coming out of the sides at the inner top and bottom. Some smoke but only on super wet stuff (I've burned mulch). I have 3 problems with the setup. 1) They are all very tall so its not really a firepit feel. 2) they are completely closed in except at the very top so heat is focused basically completely up. So they are not as warm either. 3) wood burns really well and super hot so it also burns fast. It's all very impressive physics and thermodynamics but it does not feel like a campfire pit type thing. Feels very "efficient factory produced fire that can melt metal." haha great video!
Good observations. I wonder if it would help to suspend a flat plate above the fire? Theoretically that should redirect the hot air toward the outside of the firepit. I expect that the fire will eventually destroy the plate unless it’s made of ceramic or fire brick or something. And I wonder if a cone sticking out of the middle of the plate might encourage more even distribution of the hot air than only the flat plate. Seems like there should be a way to get the benefit of the efficient, smokeless fire without losing out on the warm, comfy firepit.
Seeing how the air travels by using the smoke pellets was cool to see and helpful to see what size hole works best. I’m making a smokeless pit right now and this was very helpful. Thanks!
Thank You for sharing. I really appreciate your experimentation and exploring and showing me/ us your results. Makes lots of sense. I am planning to add one to my backyard soon and I hadn't even considered the smoke element. Until I came across your post. THANK YOU THANK YOU THANK YOU 😊
I've watched all of these hoping that someone will get to where they "somewhat" match the commercial available ones. This is getting it a step closer! I think, and I could be way off, that possibly these DIY self attempts are not matching the height/width ratio of the commercial ones. Being so much wider, I wonder if the air going up the sidewalls doesn't have enough time to heat up. You need a much "wider" fire to heat the sides, and the air traveling up the sides is so short. *** BIG CREDIT goes out to all those trying.
yes, 100%. I don't think I'll ever get the consistent secondary flames on this design because it's so short. The air doesn't have enough time to get superheated consistently. A taller smaller version would be much better to achieve that
@@Fixthisbuildthat I don’t think your fire pit is too short. It’s too wide. Over the years my family has owned a solo stove and two breeo fire pits. We’ve learned that smaller diameter fire pits make it easier to produce a smokeless fire, and they consume way less wood. Consider fabricating a wider top ring that reduces the inside diameter of the opening and covers the upper vent holes, protecting them from wind Lastly, spreading coals closer to the walls and adding logs to the perimeter reduces excessive smoke much faster than keeping your fire centered Great work! This is one of the best DIY smokeless fire videos I’ve seen
I think that having the same air source for the primary and the secondary burn is an additional 'mistake." You want the secondary burn air to heat up and exit the top holes with pressure. Having the primary air come from the same flow reduces that pressure. Notice how the patent separates the airflow much more distinctly.
Everyone saying it needs to be taller or skinnier is alluding to the fact that there is an optimal way to make this fire most efficient AKA not have any smoke. You are right, but the patent exists for a reason, there is much more thought/calculations and actual enhineering going on behind the scenes that would take more than just winging it with random materials. There is a lot of thermodynamics and heat transfer going on here that isnt as simple as “just make it tall and skinny” because there is obviously a sweet spot on both those constraints.
The way you took a scientific approach was great and the colored smoke bombs were a brilliant. Nice work as always. This had to take about a week of experimenting to do all that and I appreciate that.
Great video and tests! Love the tape idea for drilling, I'll remember that. For my outdoor fireplace, I added a 12V 4" boat bilge blower underground, contained in drain pipe that draws air in from about 8 feet away and exits under the center of the pit. When I need to get the fire going quick, or reduce smoke, I turn that on (hooked up to a 120V to 12V adapter and a smartplug) with my phone app and boom...raging fire and no more smoke!
I'd like to see a video on that! I've thought about doing something like it for my fire pit. How do you keep water out of the air duct? What did you use for the duct to keep it from decaying from the heat?
You will eat a LOT of wood that way. Just make pit smaller so coals air mor in contact and heat that metal more. As I posted above 450F is minimum to get secondary burn.
The fire shooting out of the holes is actually the wood gases burning. Honestly, fire ring is too large a diameter, and not tall enough to create those jets...It takes convection to create them, and the larger diameter keeps that from happening consistently around the ring.
Just stumbled onto your video and I have to compliment you on how fun and entertaining you approach these concepts while still being incredibly educational. I have gone ahead and subscribed and look forward to more of your content :)
Or, more likely, your original fire was simply too small for the size (and wetness) of the wood you were using. You'll note that in the 'after', the fire is substantially larger than the 'before'.
That and getting it large enough to cause secondary combustion. Big fires burn hotter. I have a 24 inch Breeo and am astonished by the amount of wood it burns through. I can't imagine the 30 inch version!
Thank you for doing all of the trial and error for me. I really liked the comment also about adding screen to the bottom air intake holes to keep any small pets and rodents out - smart! This is going to be my spring project (or sooner if weather permits).
Interesting experiment, Brad. Keep in mind that equivalent area of holes doesn't equate to the same flow through them. For example it takes more than four 1/2" holes to equal the flow through a 1" hole. That's the engineer in me coming out now. Bill
I think the geometry of the fire pit may have a lot to do with it. Smaller diameter and/or taller pit. You want the steel wall closer to the fire to transfer more heat into the incoming air. Taller wall gives the air longer to get hot on its way up and out.
This is what I was thinking the whole time. His fire pit is way too wide and shallow for this application, and using extra dry wood for the final test means his before/after doesn't mean much. If you build a super hot fire with super dry wood you're not going to have much smoke, it has nothing to do with the "smokeless" pit.
Its definitely the geometry of the pit. The way the solo stove works is that the upper air vents provide fresh oxygen to hot, combustible fuel and burns off any solids. With the current diameter of his pit there is too much room for a heat gradient to form, this causes the upper air vents to pool cool air into a region of cool air and smoke.
I came here only to look for someone that has noticed the wide diameter of the fire pit. Definitely, an underrated perspective looking at the rest of the comments.
For that design, smaller fires will be more prone to smoke. That's why the large fire worked better. The fire has to be large / hot enough to heat the air in the gap so that it's primed for secondary combustion when it reaches the holes at the top. For that you either need a hot fire, or taller walls to allow my travel time which equals more heat.
I rarely get heavy smoke with any pit, but it’s because of box fire in conjunction with tee pee style. It creates it own vacuum the hotter the fire the faster it’s heat is ejected along with its smoke. Needless to say, I like raging fires. Fill my truck bed once every two months with good dry wood.
Smaller solo stoves get a much better secondary combustion. I have one and I've made a tincan version as well. The tincan one worked just as well. So basically what I'm saying is that a smaller fire ring would give a much better secondary combustion. Large holes on the bottom small on the top. What else could have worked even better here would be to put a raised grate lining the bottom to allow more flow through the inner chamber and up through the secondary holes. Great video though, I'm going to build one i think as well soon.
Wow 🤩, the amount of effort you put into this video making that fire pit is that of the top home improvement professional! I didn’t think I’d enjoy watching this so much. 😂 I need to put more effort into my fire pit now. 😆
I've used my old 21 inch BMW aluminum rim as the inside of my fite pit with them stones around and a gravel base & I deliberately left a little slit of space between the stones for the air to go through & 10 yrs later that Aluminum rim isn't burned or rusted etc. Still looks and works GREAT
Awesome video Brad! I always think of your videos from the perspective of your neighbors and it makes me laugh. “Honey, looks like Brad is lighting the 47th fire of the past 24 hours, let’s see what happens with this one!” 😂
I think your Math's off a bit. In 24 hours we would not have but twelve or so of 'daylight' and fewer of the sort of light seen in the video clips. Lets say, ten hours or 600 minutes MAX. Allowing for time to load the pit, start each fire and get a respectable burn going would consume not less than ten minutes per instance (in a dream world perhaps), leaving but 130 minutes for the forty-seven video clips or 2.7 minutes per clip. The first fire and smoke (edited) clip ran a minute twenty plus with several obvious cuts/clips cobbled together along with some quite rapid talking. Let us assume it took significantly longer that 2.7 minutes to film that first clip. Now, between takes, we need to cool the pit down to remove the ash and such and reassemble things, add combustibles, ignite, etc. Then there is all the work to perforate the ring - not starting fires then, was he? Not sure where he lives in TN, but outside of town with a few acres, folks don't pay much attention to their neighbors - esp if they have Cable and Internet and a place to take care of or a job in town.
Brad, the best part was you used the lighter, when the fire was already going. I love it man. Seriously. it shows we're purpose driven humans...I have a need..I have a tool..I'll use the tool. Haha Nice video!
It's heating the air that's injected at the top that stops the smoke. The hot air hits the smoke and combusts. Same system as "clean-burn" log burners. I think you struggled a bit until you put tons of wood in due to the size of the metal ring. A small one heats up faster and gives more heat to the air being pulled in.
Yikes, there is a lot more science here than I had conceived, but the rewards are great…nothing worse than teary eyes around the camp fire, thank you for showing the way!
Nothing worse than teary eyes around the camp fire? How about if someone fell in the fire?! That's third degree burns, KIRK! Sheesh, you and your first-world problems.
the main factor i've noticed when it comes to smokeless fire is temperature. the hotter the fire, the less smoke gets produced. So when you look at the before / after at the end of the video, you can see theres alot more wood in the after, more flame, more heat - less smoke. Airflow obviously is a huge factor when it comes to fire, and also temp of a fire. im not entirely sure if there are any other factors that go into smokeless fire other than temperature and airflow by extension if i'm honest, but you can get really good smokeless fires just by dumping metric butt tons on wood onto them without much real thought.
I dont even have a fire pit but this video was suggested to me. I loved your energy and it was perfect editing, i love how you integrated the sponsor in the video while showing you drilling the holes and not making it just a seperate segment
I use an old washing machine tub for a fire pit. It's stainless steel and it has a ton of little holes all the way around it. I always get flames shooting inwards through the holes. It's super cool to see.
I give you quite a bit of credit to be patient, and keep trying different things to reduce the smoke. I had built my first firepit in the ground, and level with the yard, and was getting lots of smoke blown my way, so the next year I made the exact same firepit above the ground using the same stones, and metal fire ring. I didn't get as much smoke, so I am satisfied with the same firepit you started out with. Somebody will come out with a suction on the inside of the firepit, that travels through a tunnel, and the smoke with come out 10 feet , or more away from the sitting area. Like the vents that suck out the cigarette smoke in a room. Keep the videos coming.
When I build a fire pit, I insert a small metal pipe that ends in about the middle. It also has a hole about 2/3 of the length. As the fire burns, it sucks air in at the bottom of the fire. It makes it practically smokeless.
We did something very similar by leaving bricks out of the bottom layer around the outer ring to create air gaps, and then I put regular brick [yes I know could've/should've used fire brick] flat on the ground with expanded metal on top of that to ensure constant airflow under the fire. Also using an old washer drum works really well. Cool video btw.
I think your fire pit is just a bit large for how low it is so you'd need an absolute inferno in there to get the secondary combustion really shooting out flames. You need the height to give the air more time to heat up and to separate the secondary flames from the primary fire
I'm surprised that he didn't understand this concept. It's kinda like watching someone try and copy the design of a car, without understanding how a car actually moves. You can put four wheels on a frame, and add a pedal. But if you push the pedal, it's not gonna do anything UNLESS you also have a drive train. It might LOOK like a car from the outside, but it's missing the science under the hood. His design is fine - it's just massively oversized, like you said. He's never gonna get the temperature differential necessary to cause the draft he's going for
@@zp944 Well, air does heat up quite fast tho so it might be easy to overlook. I'm not an expert on any of this so even though I'm kinda confident in what I said I can't really back it up with anything else than 'That's what it looks like to me' :D
I've always thought that fireplaces and cast iron stoves should have outside air intakes. Would reduce smoke in addition to not drawing cold air into the house. Thanks for sharing.
My fireplace is nearly 100 years old and it does actually have an air intake at the back of it! It can be opened or closed with a 90 degree turn. Quite a good addition.
Most homes w wood burning fire places have an ash dump with an outside door. I put an grate over the hole at the back of the fire place so I don't lose coals. I'll open the ash door all the way and close my fireplace glass when I start the fire and it's like a rocket stove. Fire gets roaring in no time. After you get a hot bed of coals you almost have to close the ash door all the way tho. That cold oxygen blowing right on the bottom of the fire will burn thru some wood!
Apart from the diameter issue, the solo stove has a rolled in top lip which shapes airflow. You can approximate this with a cap ring as long as the upper breather holes are set at the right spacing (I suspect it's 1/3 the internal overhang down from the top edge in order to get the right rolling turbulence to achieve good secondary combustion)
I think the cap is what helps guide the top air holes into the heat to combust. With the cap ring off or upside down it won't have the secondary combustion.
Wow, this is EXACTLY what I was looking for!!! Great video, thanks a bunch!!! Oh, and also, keep the flame going at all times, it helps burn up the smoke!😊
Diameter vs. how deep the firepit is, seems to be your main issue. Also, you could try making a bed of the firering to force the air intake to exit closer to the center of the firepit. EDIT: DAMNIT, bumboclat was 22 hours earlier than me! EDIT2: Also, another way of improving would be, assuming you make a firering bed as I suggested, would be for iron rods to entertwine with the middle of the firepit - this would act both as a way to easier set up a fire, but could even be bend into being able to support a stove - as well as absorb a lot of the heat from the fire, and since it being iron and connected to the firering, also heat up the firering quicker, and more, which in turn would make the firering more effective at pulling air to the upper holes.
analyzing stuff and discovering what forces are at play is one thing... balancing those forces to obtain the perfect result is a whole different ballgame.
Watch this next: Will Concrete EXPLODE in a Fire Pit? - ruclips.net/video/TJP4iQlV8qU/видео.html
Suggestion: I was hanging out with a neighbor who was using his oil-barrel smokeless incinerator and his has a few additional features:
1. an internal 45-degree bevel that redirects the air rising up directly to the upper holes, and
2. an external bevel just like #1 but more like a beveled lip just above the holes to slightly narrow down the fire pit/incinerator opening and giving more time for the secondary air supply to mix with the smoke and make the secondary combustion more effective.
The external beveled lip is around 1.5 to 2 inches in width which at 45-degress should only narrow down the fire pit opening by a total of 1.5-2 inches.
I was surprised his incinerator hasn't produced any visible smoke at all and I just thought that those features might have helped.
what size was the holes on the bottom . you said 1/2 inch at top but I did not hear what size was at the bottom.
I like the fact that he didn't edit out the mistakes he made and what didn't work in order to demonstrate how the various changes effect the outcomes. Great video!
Absolutely that way if the next person thinks that what he did is the best way they can see that it's not and it'll save them time and headaches. They say that failures are steps toward success.
Why wouldn't he... you people were paying him to experiment... it cost him nothing and he probably made thousands above what it cost him... not to mention he had a sponsor paying him...
@@t.c.2776 I suppose for the same reason 9/10 youtubers edit out any flubs, mistakes, bloopers, mishaps, and anything else that may not project a polished and professional appearance to their audience.
He did build a bigger fire at the end to get more heat into the system. Did it have less smoke when it was a smaller fire with the dry wood?
😊y❤@@SmokinOakd❤h😢😅😅
I appreciate you doing all of the homework and expenses. Saving me time and money. I'm a single dad, and I enjoy doing little things like this with my daughter to show her love. Burning firewood and hugging my little one is so great. Every dollar counts, so thanks again.
My daughter has also been quite enamoured with our fires we build together. She has expressed an interest in doing some branding. Next weekend we will try just a small quick one on her right hip.
I don't get your reply. If you're being funny, I don't find it humorous.
@@a.m.2339 I'm on the 3rd brand...
@@a.m.2339 That's a great way to teach her that branding and burning skin, HURTS! So don't do it to your animals folks. 😂
@@Icedel777 Puzzled as to how your comment attracted such bitter losers but I hope you're taking it in stride. It's early, but, Happy Holidays.
Just had to say one of the best integration of a sponsor and not taking the whole frame of the video and giving us continued progress of the project at the same time! 👏👏👏
THIS! I appreciated that you didn't take a break or tack the ad on at the end. And honestly, that meant I heard the entire ad. When I see ads on other videos I just move on or fast forward.
Absolutely
“Build a man a fire, and he'll be warm for a day. Set a man on fire, and he'll be warm for the rest of his life.” -- Terry Pratchett, from Jingo.
This is so deep. I'm in tears of virtue
I loved to read terry pratchetts books for years. May he rest in peace
Lol
I actually loled 😂
I thought if you set a man on fire, for sure he would die. 😆
I'm thinking the only thing you could have done that would improve the performance of your fire pit is more depth. The Solo stoves are much smaller in diameter than your fire pit and they are taller in height. That gives much more space for the air to really heat up as it rises from the bottom to the top of the air channel. Great video! I know I learned a lot by watching it.
thanks! definitely would be better taller
A taller, narrower pit also concentrates the heat more. You want maximum heat and oxygen to maximize combustion.
@@Fixthisbuildthat As a mason if you didnt get the fire clay or at least fire mortar that quick set is going to crack with higher heats
Yes, and the fire needs to be big enough to really heat the wall of the fire pit.
This makes it so the air gets proper flow and is superheated so it really combusts the smoke.
I own a solo stove and it works really great, as long as you keep it properly fed.
When it's really hot it burns green wood mixed in without any smoke.
@@Fixthisbuildthat or deeper. It doesn't have to be taller 💁♂️
Came for the DIY ideas, stayed for the experimenting! It was so entertaining to watch all of the thought process going behind it
0:27 fun fact! (Assuming you don't say it later) the reason smoke seems to always be blowing into your face is because of convection. With nothing obstructing the air's movement toward the fire(and no wind) the smoke will rise straight up. BUT! since there is often a person or group of people somewhat clumped together around the fire, the air that would come from behind them is slowed meaning the air on the other side of the fire that isn't slowed will assert more force bending the convection current and thus the smoke towards the people blocking the air. Of course with the wind blowing the smoke will follow the wind but still be affect by the convection
Came here to say just this.
Comments like these are why I always peruse the comments section of videos. 10/10 solid fun fact.
This is why I often add a large, flat vertical stone on the far side of a campfile fire. However it doesn't aways work, because smoke following people is based on the universal law of attraction... whatever you fear will come :)
Physics 👍👍💯
Yes was going to say this. The reason it seems like the smoke follows you is because it does. For the reason you mentioned
Really liked your pit design. There is another way to have a less smokey fire. You don't construct a tipi. Instead you pack in tightly the logs at the bottom. You add smaller pieces and at the top you construct the twig, pinecone, dried orange peel pile. One lights the top, not the bottom. The fire burns gradually downwards but having the fire at the top means it burns the gases coming out of the gradually heated logs. Much less smoke and significantly more heat.
that sounds like a cool idea, definitely going to try that!
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Known as the Council fire. Boy Scout style. Works great.
Interesting! Can you build your fire this same way in an indoor fireplace? Less smoke and more heat is good there too.
Yes
Tip for calculating the airflow: Measure your 4 gaps in the bricks. That's the surface area of the inflow. Ideally the outflow should be similar in size to the inflow, or slightly larger. Number of holes * pi * diameter is the surface area of the exhaust. Compare the two numbers and then adjust the hole size (or number of holes) until the inflow area matches the outflow.
Would you want the airflow to be the same between the top and bottom? Would it not eventually choke the fire if the bottom weren't receiving more air to feed it? Or would the heat of the fire just naturally pull in more air from the bottom regardless; provided the holes weren't smaller and/or less numerous than the top holes.
Surface area of the exhaust = (number of holes) ⋅ π (diameter / 2)²
(Number of holes) ⋅ π ⋅ diameter would give you the total circumference of all of the holes, not the total area.
@@flennboyd6413Probably Automotive Engineering or Furnace tech/engineer. There's a big world out there man, lots of really cool things that people do.
@@flennboyd6413 pyromaniac! 😂
@@Philitron128 probs not as his math ain't right tho. There's also thermal expansion to consider if the air is heating up
Brad, your relentlessness toward seeing a job through to the and and your relentlessness in maintaining a great attitude is one of the most inspiring things about you and this channel. It is easy to see it is not a show for the video - it is authentically you. Thank you for all you do and the videos you make - this is truly one of my favorite channels in the maker space. Keep up the great work man!
thank you, Adam. Appreciate the support!
Took the words out of my mouth. The effort you put in to this is amazing. Great video!
@@Fixthisbuildthat
Hey Brad, I’m totally high jacking this comment just to ask you a question.
In one of your videos I heard you live in the Nashville area. If this is correct, I was wondering if you could help me out. I’m wanting to build a “big girl bed” for my soon to be 3 year old daughter. I don’t have a workshop and am looking for an easy way to build this twin bed. Reply back and let me know if there’s a possibility you could help.
There is one detail about fire pits that people keep forgetting.
If the fuel (firewood) is higher than the secondary holes, the secondary burn will become a primary burn for said wood and thus produce smoke.
If you want to keep your current system then do not build the fire higher than the secondary holes (maybe an inch shorter).
If you are going to mod the system, add a 4th layer of stones and keep the firewood below the holes.
So stack four high
Yes, very true. Still worked very well despite, but yeah, that would improve it even more
Also, he should put some pipes or whatever for the air to have access to the center of the flame, not just its outside.
Stack 4 high
Mortor mud it
Fire hole metal
.5 inch hole every 1.5 predrill the center
Punch
2 inches of gravel
Pavers
Wow! I have zero intentions of doing this to my fire pit. I don’t even know how this video found me. But, I certainly appreciate the amount of time, money, and work you put into this video. You’ve earned a like. Great job 👏
@Hello there, how are you doing this blessed day?
I agree with everything @scottvriethoff6633 said. My hats off to you FIX THIS BUILD THAT for all the labor and money you put into this test for others to benefit.
Great video. But having owned several Solo Stoves, the most important factor in the intensity of smoke is the dryness of the wood.
That, and the speed/direction of the WIND...This doesn't work...
Actually the solution is a three quarter size burn barrel, with a lid ( that opens) and a pipe that has a flue… perfectly distributed heat, no smoke whatsoever .much better heat source ..use it in backyard for gatherings and at hunt camps
@@brentfarvors192 its too wide to properly work, the air needs to get hotter so it will rise above the smoke, taller narrower versions do actually work to some degree
Meh... do a search for 'dakota fire hole' or 'dakota fire pit'. I've been building low-smoke fires most of my adult life without anything special. You just have to watch the wind direction. Air feed is the key along with a hot fire.
Dang dude, you put so much work into this video. Thanks for satisfying everyone’s curiosity
EXTREMELY THOROUGH!!!!!!!
Loved this, I have a Solo fire and it does smoke to begin with even with dry logs. You also get a better secondary burn with a full fire across the width (rather than a tall fire) as the air passing along the side to come up through the holes is heated more... Great job!
What you tried to build is a gasifier stove. However, that design relies on two things: small enough diameter to heat up the walls, making the secondary air rise up by draft, and small enough diameter to deliver that air into the flames. It's not really well suited for a large but flat firepit, but kinda works if you make the fire crazy big, as seen.
I'd argue that one thing the pit would benefit from would be for the bottom airflow to come out from _under the logs._ In the current iteration, it just tries to get to the flames from the sides, which is better than trying to enter from the top, but you still get convection pushing most of it upwards, rather than allowing it to get near the actual fuel and thereby replenishing the oxygen levels more effectively.
Yeah, I was just writing about diameter/height ratio - and drainage: seems likely to collect water when it rains, and moss and a little ecosystem! The DIY double skin drum I saw on here before I saw the solo stove advertising everywhere - that had legs built from the base of the drum.
Rocket stoves have built in thermal mass and, like, hardcore substance - as do pizza ovens. Which is kinda what you want in a garden feature. Even though the solo stove looks very futuristic, it's not everyone's vibe and it probably dents and tarnishes as much anything else. And a drum is already a relaxed & utilitarian DIY vibe. Not pretty.
Nice! We can’t wait to see your video🎉
I came to the same conclusion with no knowledge about fire pits, and only the information he provided.
This is what I came down here to say. In fact, everyone seems to be saying the same thing
One suggestion I would make to reduce smoke, indoors or out, is to build an "upside down" fire. Put the biggest pieces on the grate, on the bottom, then the next smaller, at a right angle to the biggest ones. Keep alternating layers, leaving some space between the pieces for air, then put newspaper and small kindling on TOP, NOT on the bottom. You may have to feed a bit more small kindling at first, but not for long. You will be amazed at how much cleaner, quicker and hotter the "upside down" fire will burn. Each layer heats the layer below as the fire goes DOWN (trust me, it will, even though fire generally does go up), so each successive layer burns readily, and there is hardly any smoke. When you make a fire the usual way, the bigger wood on top isn't hot or dry enough, so there is quite a bit of smoke until the big pieces get going. Once the "upside down" fire gets down to the bottom layer, you just feed it more wood on top as usual. If you try this method once, you'll never go back.
I'm going to try this out. Burned my first fire of the season tonight.
I agree, this man knows what he is talking about
We always do the stacked cabin type fire with the newspaper or kindling underneath the “roof”. I’m going to try this way next. I’ve actually never heard of it before.
In most cases this will not work. Heat rises. Ashes smother flame. If you need to get a fire going use log cabin or teepee style. Some genius taught this method to our kids for 'winter survival'. Apparently cold branches won't burn this way. Everyone had to eat cold weinies.😥🍖🥶
@@blairzettl3933 Upside down is THE way if you have a wood stove/fireplace, not so much an outdoor fire.
When wood gets hot enough in a low oxygen environment, it produces wood gas, which is flammable. Combustion needs oxygen, so you see fire "shooting out" of the vents, which is actually the boundry of wood gas and oxygen mixing and burning. Gas burners have this same boundry flame, but inverted, with a stream of flammable gas into an area of oxygen.
Fun fact, the fire we see is mostly comprised of incandescent soot, material that gets so hot it glows like a lightbulb or forge metal.
wood gas...I like that 👍
So it's true that wood doesn't burn. It gets hot and produces flammable gas. If you look very close to wood burning there is a slight gap between the wood and the flame.
Correct, if you're seeing flames out of the top holes, it has to be wood gas being drawn into the lower holes, & mixing with the air to then be ignited as it exits, looking like the burner you talked about. Just air coming out wouldn't really do anything... My woodstove has secondary burning, but the flue comes outta the middle of the firebox (damper can be slid open to load wood, so it exits the stove by flue not door, lol)
I really appreciate the “I’m not going to give up no matter how long it takes” attitude in this video.😂
This guy is brilliant! How beautifully he explained the various tests he conducted! He was so determined to achieve the objective of building a smokeless fire pit, and he finally met the objective!
Super fun project, Brad - had me glued to the screen start to finish! I hadn’t really heard of smokeless fire pits unless they were propane or gas fed so that was pretty rad. Great video!
Thanks, Nils! It was a fun one to try
Wont even bother watching this BS; It doesn't work...
@@brentfarvors192 Did you try? What's your experience? I'd like to learn.
@@Dgiztred Yes. My "experience" is exactly as posted; The ONLY WAY to control the quantity of smoke, is to burn on a clear (high pressure), windless day, using the driest and most finely cut fuel available...Using the method posted here will make the fire burn HOTTER (More air flow= A hotter flame), but will do NOTHING for the smoke; Especially when starting the fire, and when it starts to burn out...I've tried with Pits/Barrels, and everything in between; You aren't going to beat physics...
I'm usually not huge fan of these videos but you by far have a great presentation that would actually help people that have very little experience making things. If want I'd give few simple ideas to maybe make that an easier set up work better or you might take the things I do make them better. I just been working way to many hours and really just learning the video stuff
I think the next step in efficiency would be to add spiraling channels around the outside so that the air in the walls of the fire pit can't just go straight up, but has to go at like a 45 degree angle around the outside, increasing the time it spends in the wall and therefore the time it spends heating up. This would likely result in a secondary burn happening sooner after starting the fire, and a more complete secondary burn due to potentially increased velocity.
Another feature to help secondary burn might be to add a lip above the top holes, as is seen on the retail fire pit design he's imitating. This would force the air exiting the top holes towards the fire a bit before it can rise above the firepit, along with adding some radiative insulation to that region to help keep temps up and maintain the secondary burn
The amount of work, time and investigation you went through to figure out how to exactly create the closest thing to a smokeless fire pit was pretty impressive to me. You went beyond my expectations and I appreciate the days it took to film this and do all the drilling, experiments & etc. I’m subscribing for more of your videos. Your thoroughness in figuring out the perfect method will save me so much time and error.
Great video! I liked it!
Here's what you missed when you looked at the patent for the solo stove. The secret of why it generates almost no smoke isn't to do with the size or number of holes in the top/bottom. That is a factor though. The biggest factor is to look at the ratio of the height of the pit to the circumference. Basically, the solo stove is skinnier and taller. With a pit of this diameter, you'd have better performance by building the height of the pit upwards.
This increases the effective space of that insulating layer, providing more area for smoke and gasses to slow, cool, get trapped.
Or you can use an old washer tub....
I agree. Also he should taper the top a bit too
Also, the solo stove has holes under the burn area too.
Thanks!
This is a really fun experiment! I enjoyed your explanations for why you were doing each step and that tape trick for the drilling stage is a keeper!
If you ever decide to return to this project, you could place a small lip around the top of the internal circumference of the pit forcing the air for the secondary combustion in rather than straight up as it exits the holes while simultaneously trapping some smoke underneath the lip which may increase the combustion but also possibly reduce the airflow. I am curious to see the effect. It's a similar approach the reducing the diameter of the pit without making it look like a soda can.
dude tried it with a wet wood, did bunch of improvements that didn't help. Eventually he added dry wood and omg - it didn't emit as much smoke as it used to. Definitely a good design :D
Yes, the stacking of the wood has more of an influence on the smoke compared to the fire pit's design. What works for me is stacking the wood to create a closed high temperature chamber, like a furnace, with smallish entrance holes for the air, and corresponding exit homes for the smoke.
I agree
It would be interesting to have done a control burn using dry wood before drilling the fire ring holes. This would show how much of the improvement in smoke reduction was due to the modification of the fire ring and how much was due to the drier wood.
Great video otherwise. Very easy to understand. Will use your tactics when I build my next fire pit.
What is most important is to keep the wood consistent (the same wood) from burn to burn in order to make the best comparison.
I agree cuz I was like so just use dry wood then?
A lot of time and effort to make this video! A BIG THANK YOU! Had a fire pit at our summer home and always wanted to figure this out. You did it. Great personality!
@Hello there, how are you doing this blessed day?
the smoke is always in your face because the smoke will travel towards the tallest things around the pit. Think of it as smoke traveling up a wall. At one end of my pit I have a tall rock (almost 4ft at the peak) I am not sure the science behind it but this makes the smoke always migrate towards it and then up the rock and up. Just something to think about. great build as usual.
Air rises over the fire, pulling outside air towards it. You block that inflow, so rather than it flowing in to the fire it can get pushed out towards you
Yeah, flue effect sucks the air through air speed differential.
No your body acts like an air dam. It blocks air from getting to the fire . What creates a vacuum and the fire smoke moves towards you. The more people that sit around you the bigger the vacuum. So sit alone and the smoke will not bother you.
I would hang a lantern there. lol
Pretty sure it would be exponentially better if you placed a another layer of stones on top of the steel liner to add as a "ledge" so that the top opening is a little tapered.
Hm probably true, just like the solo stove
He’s onto something here. By narrowing the top of the fire pit, you will achieve what is known as the Bernoulli effect. A greater force of air thrusting through the whole system, and theoretically more fweefwee
@@CharlesThomas-xv2yn - Yes i can answer, but please, stop calling me "in more detail"
:oP
Wow , I love the whole concept of knowledge OF A GOOD FIRE , EVERYBODY DOESNT HAVE THIS TRAIT , LOL ..BUT DUDE THANK YOU FOR YOUR INSIGHT , BEEN BUILDING MY FIREPIT IN MY HEAD FOR YEARS , AND TODAY I GOT A VISUAL ON THE CONCEPT ! YOUR AWESOME !
Aside from comparing wet wood "before" to dry wood "after", this is not a bad video.
Keep building awesome stuff :)
Exactly.The real demonstration here was on the importance of burning properly dried wood.
Probably could've saved 6 hours of work by switching to dry wood.
I burned very old and dry oak flooring last night in an open pit and it was smokeless.
I really liked your video, I've watched many and this video was the best. I loved how you actually tested the different size holes until you got what you were shooting for. I've got a similar situation and wondering what size the bottom holes are and how far down from the top are the 1/2" holes and how far up from the bottom are those holes? Thanks!
Wiele razy myślałem nad tym. Zrealizowałeś moje przemyślenia! Jesteś super!
After doing this project years ago, what I learned was it's easier to get the smokeless results with a smaller firepit ring. I think this is because in order to get smokeless results you need higher temperatures which is easier to get with smaller pits, unless you plan on burning A LOT of wood at one time. This is probably why the solos aren't that big.
Great video. It would have been good to see the unmodified original version with the same dry wood you used at the end. As I feel like that's what actually made the difference
It was a good video and I learned some ideas, but iam also thinking the dry wood is what the key factor was !
Yes, correct me if I'm wrong, but nothing seemed to work until the fuel type and amount changed. So the conclusion should be: don't change the pit, just dry the wood and add more.
I like the attempt to engineer the pit though, and I'll probably do something similar because it's cool :)
This is the first video of yours I've come across and I hit the subscribe button half way through. I love your nerdy enthusiasm. Your curiosity and methodology. Then I came to the WD-40 ad, and holy batman, that was smooth! The way you integrated it in to your content, I didn't skip it! And I wasn't bothered by it either. Also made good points on their product and reminded me I should go buy a can, lol. So excited to have found your channel.
I have made similar fire pit from the laundry inner tub, which has tons of holes. It works great with no smoke. It seems like in your experiment, the fire pit is too low so it doesn't allow much of the air flow. The upper holes should be at bit higher. Thank you for the experiment and share!
I have 3 of them, every one is surprised they do not smoke. I also use dry wood, which makes a big difference.
I think the only factor here is using dry wood. 🤔
@@bam5732 - They both play a role....Even with the driest wood, you'll still get lots of smoke if the fire doesn't have an ample oxygen supply. Likewise, even with the best possible air supply in the word, if the wood is wet it's gonna smoke. It would have been nice though if he'd actually shown the old pit with dry wood.
Laundry tubs are great. I believe they can also be stainless steel.
@@scottcates most of the time they are stainless steel, or at least the older ones are. Also, the older ones are driven by a big pulley, which can be left in place and serve as a stand. :)
I love the excitement and genuine pursuit in the experimentation! I learned something to improve my fire pit and enjoyed the presentation. Thank you!
Thanks for making this. I used your first video to build my firepit recently and it's producing way too much smoke so will definitely be giving this a go!
Great video. However, the part that's missing is the ratio of stove height to diameter. There a powerful convective element with this process you just aren't going to get with such a wide and shallow fire-pit. The point is to increase the secondary burn which takes place at the top of the fire. In your stove the top of the fire (flames and smoke) is already outside of the fire-pit. It's just NEVER going to work like that. You pit needs to be 2 or 3 times higher for that diameter. Notice on the patent how the top is tigher than the rest of the pit and the ratio of heigh-to-width. The secondary combustion has to take place BELOW the top surface of the stove. Dry wood for the final tests but wet wood for the preliminary is also quite misleading. A lot of people will fail following this advice.
You brought up a point that I was thinking. The idea that he is copying does have a higher ratio, meaning the fire pit should be taller. Everything else about this is good and I think I'll build one of these.
correct to get the chimney effect
At first I was ready to rip out my stainless steel insert on my garden BBQ (we don't call it a fire pit) and spend a Saturday in May drilling 2500 holes...thanks to this post I'll save the effort...title of the video should be wet wood is great for smoking
If you notice on the Solostove the top opening is necked down smaller than the diameter of the main burn chamber. That increases the velocity of the air leaving the chamber and this increased velocity produces a slight vacuum in the chamber. The vacuum pulls more air through the secondary combustion holes making a more efficient second burn and less smoke.
Great video! I loved learning about the dynamics of smoke/air flow
Try arranging your logs into a lincoln log cabin style. lay 2 wood splits parallel to each other and then stack 2 more splits parallel but perpendicular to the bottom splits. like a tic tac toe cross. helps promote airflow! I use that technique when i smoke meat! Great vid Brad!
That's what I started with originally. The teepee definitely smoked less on start up though.
@@Fixthisbuildthat really?? Dang. Ok ill shut up haha
I love when there are smart knowledgeable comments, thanks everyone I am getting my degree in life from y’all!
I really like how you incorporated the commercial part for WD40 with your "action montage".
I have a different brand than Solo and it is completely amazing. Really cool almost welding type flames coming out of the sides at the inner top and bottom. Some smoke but only on super wet stuff (I've burned mulch). I have 3 problems with the setup. 1) They are all very tall so its not really a firepit feel. 2) they are completely closed in except at the very top so heat is focused basically completely up. So they are not as warm either. 3) wood burns really well and super hot so it also burns fast.
It's all very impressive physics and thermodynamics but it does not feel like a campfire pit type thing. Feels very "efficient factory produced fire that can melt metal." haha great video!
Good observations. I wonder if it would help to suspend a flat plate above the fire? Theoretically that should redirect the hot air toward the outside of the firepit.
I expect that the fire will eventually destroy the plate unless it’s made of ceramic or fire brick or something. And I wonder if a cone sticking out of the middle of the plate might encourage more even distribution of the hot air than only the flat plate.
Seems like there should be a way to get the benefit of the efficient, smokeless fire without losing out on the warm, comfy firepit.
What brand?
So what brand do you have so I can check it out?
Hi-Flame Bonfire Stove fire pit. 20.5 inches
Seeing how the air travels by using the smoke pellets was cool to see and helpful to see what size hole works best. I’m making a smokeless pit right now and this was very helpful. Thanks!
Thank You for sharing. I really appreciate your experimentation and exploring and showing me/ us your results. Makes lots of sense. I am planning to add one to my backyard soon and I hadn't even considered the smoke element. Until I came across your post. THANK YOU THANK YOU THANK YOU 😊
I've watched all of these hoping that someone will get to where they "somewhat" match the commercial available ones. This is getting it a step closer! I think, and I could be way off, that possibly these DIY self attempts are not matching the height/width ratio of the commercial ones. Being so much wider, I wonder if the air going up the sidewalls doesn't have enough time to heat up. You need a much "wider" fire to heat the sides, and the air traveling up the sides is so short. *** BIG CREDIT goes out to all those trying.
yes, 100%. I don't think I'll ever get the consistent secondary flames on this design because it's so short. The air doesn't have enough time to get superheated consistently. A taller smaller version would be much better to achieve that
Next project - bury a smokeless barrel system!
@@Fixthisbuildthat I don’t think your fire pit is too short. It’s too wide. Over the years my family has owned a solo stove and two breeo fire pits. We’ve learned that smaller diameter fire pits make it easier to produce a smokeless fire, and they consume way less wood.
Consider fabricating a wider top ring that reduces the inside diameter of the opening and covers the upper vent holes, protecting them from wind
Lastly, spreading coals closer to the walls and adding logs to the perimeter reduces excessive smoke much faster than keeping your fire centered
Great work! This is one of the best DIY smokeless fire videos I’ve seen
I think that having the same air source for the primary and the secondary burn is an additional 'mistake." You want the secondary burn air to heat up and exit the top holes with pressure. Having the primary air come from the same flow reduces that pressure. Notice how the patent separates the airflow much more distinctly.
Everyone saying it needs to be taller or skinnier is alluding to the fact that there is an optimal way to make this fire most efficient AKA not have any smoke. You are right, but the patent exists for a reason, there is much more thought/calculations and actual enhineering going on behind the scenes that would take more than just winging it with random materials. There is a lot of thermodynamics and heat transfer going on here that isnt as simple as “just make it tall and skinny” because there is obviously a sweet spot on both those constraints.
The way you took a scientific approach was great and the colored smoke bombs were a brilliant. Nice work as always. This had to take about a week of experimenting to do all that and I appreciate that.
I love the experimentation/exploration behind this, and how he just didn't give up!
Thumbs Up! Not only for the information provided, but mostly for the incredible amount of work required for a 16-minute video.
Great video and tests! Love the tape idea for drilling, I'll remember that.
For my outdoor fireplace, I added a 12V 4" boat bilge blower underground, contained in drain pipe that draws air in from about 8 feet away and exits under the center of the pit.
When I need to get the fire going quick, or reduce smoke, I turn that on (hooked up to a 120V to 12V adapter and a smartplug) with my phone app and boom...raging fire and no more smoke!
I'd like to see a video on that! I've thought about doing something like it for my fire pit. How do you keep water out of the air duct? What did you use for the duct to keep it from decaying from the heat?
You will eat a LOT of wood that way. Just make pit smaller so coals air mor in contact and heat that metal more. As I posted above 450F is minimum to get secondary burn.
Okay, was not expecting the portal gag. LoLs. This whole video is far more engaging than you'd expect from a video about a fireplace. Well done!
The fire shooting out of the holes is actually the wood gases burning. Honestly, fire ring is too large a diameter, and not tall enough to create those jets...It takes convection to create them, and the larger diameter keeps that from happening consistently around the ring.
Yep, exactly what I found. This is pretty much the best you can do with this style ring. But still way better than stock
I'm thinking the same thing, a taller and/or smaller diameter ring could work better. Either way, nice testing with the fire pit you already built!
If you want a prtable pit you can use the drum of an old dryer
It has all over the place holes and is really cheap
This is what we use. Works great.
Just stumbled onto your video and I have to compliment you on how fun and entertaining you approach these concepts while still being incredibly educational. I have gone ahead and subscribed and look forward to more of your content :)
Or, more likely, your original fire was simply too small for the size (and wetness) of the wood you were using. You'll note that in the 'after', the fire is substantially larger than the 'before'.
So if I'm getting this right, the biggest factor is use dry wood!
That and getting it large enough to cause secondary combustion. Big fires burn hotter. I have a 24 inch Breeo and am astonished by the amount of wood it burns through. I can't imagine the 30 inch version!
Thank you for doing all of the trial and error for me. I really liked the comment also about adding screen to the bottom air intake holes to keep any small pets and rodents out - smart! This is going to be my spring project (or sooner if weather permits).
Interesting experiment, Brad. Keep in mind that equivalent area of holes doesn't equate to the same flow through them. For example it takes more than four 1/2" holes to equal the flow through a 1" hole. That's the engineer in me coming out now.
Bill
Wow we have a genius among us
@@daveklein2826 No, just a retired engineer.
So, should I drill 1" holes?
I think the geometry of the fire pit may have a lot to do with it. Smaller diameter and/or taller pit. You want the steel wall closer to the fire to transfer more heat into the incoming air. Taller wall gives the air longer to get hot on its way up and out.
This is what I was thinking the whole time. His fire pit is way too wide and shallow for this application, and using extra dry wood for the final test means his before/after doesn't mean much. If you build a super hot fire with super dry wood you're not going to have much smoke, it has nothing to do with the "smokeless" pit.
Its definitely the geometry of the pit. The way the solo stove works is that the upper air vents provide fresh oxygen to hot, combustible fuel and burns off any solids. With the current diameter of his pit there is too much room for a heat gradient to form, this causes the upper air vents to pool cool air into a region of cool air and smoke.
I came here only to look for someone that has noticed the wide diameter of the fire pit. Definitely, an underrated perspective looking at the rest of the comments.
My thoughts exactly!
Your energy and creativity is goals. Im similar I can’t stay still for long and need to be creative and productive or I feel unaccomplished
A great video. I do love your experimental approach and showing things step by step. Very instructive and yet enjoyable.
Glad you enjoyed it!
For that design, smaller fires will be more prone to smoke. That's why the large fire worked better. The fire has to be large / hot enough to heat the air in the gap so that it's primed for secondary combustion when it reaches the holes at the top. For that you either need a hot fire, or taller walls to allow my travel time which equals more heat.
yeah I'm looking at that manufactured one and I'm thinking, just taller walls
I rarely get heavy smoke with any pit, but it’s because of box fire in conjunction with tee pee style. It creates it own vacuum the hotter the fire the faster it’s heat is ejected along with its smoke. Needless to say, I like raging fires. Fill my truck bed once every two months with good dry wood.
Loved this video, though it's way too complicated for me. It's very interesting to watch and I appreciate all the effort you put into this.
Smaller solo stoves get a much better secondary combustion. I have one and I've made a tincan version as well. The tincan one worked just as well. So basically what I'm saying is that a smaller fire ring would give a much better secondary combustion. Large holes on the bottom small on the top. What else could have worked even better here would be to put a raised grate lining the bottom to allow more flow through the inner chamber and up through the secondary holes. Great video though, I'm going to build one i think as well soon.
Wow 🤩, the amount of effort you put into this video making that fire pit is that of the top home improvement professional! I didn’t think I’d enjoy watching this so much. 😂
I need to put more effort into my fire pit now. 😆
I've used my old 21 inch BMW aluminum rim as the inside of my fite pit with them stones around and a gravel base & I deliberately left a little slit of space between the stones for the air to go through & 10 yrs later that Aluminum rim isn't burned or rusted etc. Still looks and works GREAT
Awesome video Brad! I always think of your videos from the perspective of your neighbors and it makes me laugh. “Honey, looks like Brad is lighting the 47th fire of the past 24 hours, let’s see what happens with this one!” 😂
😂 😂 OH yeah, they definitely get a show
I think your Math's off a bit.
In 24 hours we would not have but twelve or so of 'daylight' and fewer of the sort of light seen in the video clips. Lets say, ten hours or 600 minutes MAX.
Allowing for time to load the pit, start each fire and get a respectable burn going would consume not less than ten minutes per instance (in a dream world perhaps), leaving but 130 minutes for the forty-seven video clips or 2.7 minutes per clip.
The first fire and smoke (edited) clip ran a minute twenty plus with several obvious cuts/clips cobbled together along with some quite rapid talking. Let us assume it took significantly longer that 2.7 minutes to film that first clip.
Now, between takes, we need to cool the pit down to remove the ash and such and reassemble things, add combustibles, ignite, etc.
Then there is all the work to perforate the ring - not starting fires then, was he?
Not sure where he lives in TN, but outside of town with a few acres, folks don't pay much attention to their neighbors - esp if they have Cable and Internet and a place to take care of or a job in town.
@@gooeytarballs you must be fun at parties…
@@ImYoutubing247 😂👍
@@ImYoutubing247 29.4% of party guests especially enjoy the first 13.7 minutes of the party. 😁 lol
Brad, the best part was you used the lighter, when the fire was already going. I love it man. Seriously. it shows we're purpose driven humans...I have a need..I have a tool..I'll use the tool. Haha
Nice video!
Really appreciate the efforts you have put in ! It was lot of work and you did it with lot of patience and enthusiasm. Good presentation as well
There you go, DRY WOOD MAKES ALL THE DIFFERENCE! problem solved
It's heating the air that's injected at the top that stops the smoke. The hot air hits the smoke and combusts. Same system as "clean-burn" log burners. I think you struggled a bit until you put tons of wood in due to the size of the metal ring. A small one heats up faster and gives more heat to the air being pulled in.
I hope you've gone over why smoke burning is an important way to help alleviate bad air in heavily wood burning communities, too. Great vid!
Yikes, there is a lot more science here than I had conceived, but the rewards are great…nothing worse than teary eyes around the camp fire, thank you for showing the way!
Nothing worse than teary eyes around the camp fire? How about if someone fell in the fire?! That's third degree burns, KIRK! Sheesh, you and your first-world problems.
the main factor i've noticed when it comes to smokeless fire is temperature. the hotter the fire, the less smoke gets produced. So when you look at the before / after at the end of the video, you can see theres alot more wood in the after, more flame, more heat - less smoke.
Airflow obviously is a huge factor when it comes to fire, and also temp of a fire. im not entirely sure if there are any other factors that go into smokeless fire other than temperature and airflow by extension if i'm honest, but you can get really good smokeless fires just by dumping metric butt tons on wood onto them without much real thought.
Make sure it's dry too lol
FANTASSSSTIC!!! Enjoyed watching your video, you made it fun and exciting!
I dont even have a fire pit but this video was suggested to me. I loved your energy and it was perfect editing, i love how you integrated the sponsor in the video while showing you drilling the holes and not making it just a seperate segment
I appreciate the amount of effort you put into this. Makes me want to try this someday!
thanks!
Lol I enjoyed your reaction to the flames coming out of the vent holes! Great video, great project!
... you have a fire in front of you. Why use a lighter😂
He probably read the instructions.
He would have melted/fried the tape on the end of the stick and dropped the smoker in the fire ya bozo. 😂
Came to ask this aswell..
BRUH!
I was thinking the same 😂thing
nah he could have just held it far enough way @28th_St_Air
I use an old washing machine tub for a fire pit. It's stainless steel and it has a ton of little holes all the way around it. I always get flames shooting inwards through the holes. It's super cool to see.
Make a short clip! It doesn't have to be fancy, just you sharing what your pit looks like. This is my pit..
.and that's it! 🙏
I give you quite a bit of credit to be patient, and keep trying different things to reduce the smoke. I had built my first firepit in the ground, and level with the yard, and was getting lots of smoke blown my way, so the next year I made the exact same firepit above the ground using the same stones, and metal fire ring. I didn't get as much smoke, so I am satisfied with the same firepit you started out with. Somebody will come out with a suction on the inside of the firepit, that travels through a tunnel, and the smoke with come out 10 feet , or more away from the sitting area. Like the vents that suck out the cigarette smoke in a room. Keep the videos coming.
Sehr gutes, aufwändiges Video, ich bin begeistert.
Denke das Feuer darf den Boden nicht berühren. Der Boden zieht zuviel Hitze und kühlt das Feuer ab
Einverstanden. Grüße aus Amerika! Einige meiner Vorfahren stammen aus Deutschland.
When I build a fire pit, I insert a small metal pipe that ends in about the middle. It also has a hole about 2/3 of the length. As the fire burns, it sucks air in at the bottom of the fire. It makes it practically smokeless.
Interesting.
We did something very similar by leaving bricks out of the bottom layer around the outer ring to create air gaps, and then I put regular brick [yes I know could've/should've used fire brick] flat on the ground with expanded metal on top of that to ensure constant airflow under the fire.
Also using an old washer drum works really well.
Cool video btw.
I think your fire pit is just a bit large for how low it is so you'd need an absolute inferno in there to get the secondary combustion really shooting out flames. You need the height to give the air more time to heat up and to separate the secondary flames from the primary fire
I'm surprised that he didn't understand this concept. It's kinda like watching someone try and copy the design of a car, without understanding how a car actually moves.
You can put four wheels on a frame, and add a pedal. But if you push the pedal, it's not gonna do anything UNLESS you also have a drive train. It might LOOK like a car from the outside, but it's missing the science under the hood.
His design is fine - it's just massively oversized, like you said. He's never gonna get the temperature differential necessary to cause the draft he's going for
@@zp944 Well, air does heat up quite fast tho so it might be easy to overlook. I'm not an expert on any of this so even though I'm kinda confident in what I said I can't really back it up with anything else than 'That's what it looks like to me'
:D
Hats off to you. You did lots of effort to prove your point. 👌🏿
and the point is that dry wood works much better :)
I watched a bunch of these builds and they all required crap I wasn't about to get or do. Yours I can do using the metal fire ring I have now! Thanks!
I've always thought that fireplaces and cast iron stoves should have outside air intakes. Would reduce smoke in addition to not drawing cold air into the house. Thanks for sharing.
My fireplace is nearly 100 years old and it does actually have an air intake at the back of it! It can be opened or closed with a 90 degree turn. Quite a good addition.
Most homes w wood burning fire places have an ash dump with an outside door. I put an grate over the hole at the back of the fire place so I don't lose coals. I'll open the ash door all the way and close my fireplace glass when I start the fire and it's like a rocket stove. Fire gets roaring in no time. After you get a hot bed of coals you almost have to close the ash door all the way tho. That cold oxygen blowing right on the bottom of the fire will burn thru some wood!
Apart from the diameter issue, the solo stove has a rolled in top lip which shapes airflow. You can approximate this with a cap ring as long as the upper breather holes are set at the right spacing (I suspect it's 1/3 the internal overhang down from the top edge in order to get the right rolling turbulence to achieve good secondary combustion)
I think the cap is what helps guide the top air holes into the heat to combust. With the cap ring off or upside down it won't have the secondary combustion.
Can these be used for cooking/grilling fires or would a traditional fire ring work better?
Wow, this is EXACTLY what I was looking for!!! Great video, thanks a bunch!!! Oh, and also, keep the flame going at all times, it helps burn up the smoke!😊
Diameter vs. how deep the firepit is, seems to be your main issue.
Also, you could try making a bed of the firering to force the air intake to exit closer to the center of the firepit.
EDIT: DAMNIT, bumboclat was 22 hours earlier than me!
EDIT2: Also, another way of improving would be, assuming you make a firering bed as I suggested, would be for iron rods to entertwine with the middle of the firepit - this would act both as a way to easier set up a fire, but could even be bend into being able to support a stove - as well as absorb a lot of the heat from the fire, and since it being iron and connected to the firering, also heat up the firering quicker, and more, which in turn would make the firering more effective at pulling air to the upper holes.
analyzing stuff and discovering what forces are at play is one thing... balancing those forces to obtain the perfect result is a whole different ballgame.
@@WithmeVerissimusWhostoned You sound like you're being barred from testing this.