top lit updraft (TLUD) wood cook stove

Ken Miller, tin-can-ologist, shows off his top lit updraft stove.  Made from a one gallon paint can and a couple of tin cans, he used a tiny amount of wood to boil some water. 

You light the fire on top of the fuel and then put your heat riser on top.  Smokeless. 

Better than a rocket stove in that it is easier to save your fuel.  And you don't have to keep feeding in the wood.

I'd like to see somebody use this to deep fry a turkey.

Might be an economical way to scald poultry for plucking in the yard.

Great video Paul.

I'm new to the forums, so this may have been discussed previously...

Does anyone know of any adaptations you can make to a wood burning stove to make it more efficient? We're in the process of buying an older home, and it has a traditional wood stove in the basement. Any insights into increasing it's efficiency would be great. 

Thanks a bundle.

Dave

ditty wrote:
Does anyone know of any adaptations you can make to a wood burning stove to make it more efficient? We're in the process of buying an older home, and it has a traditional wood stove in the basement. Any insights into increasing it's efficiency would be great. 

How to make a conventional wood stove more efficient:  I was sure we had a thread that talked about it.  A lot of really excellent info.  but I can't find it.  So, go ahead and start a new thread on that.

I've built and used these things and they're great!
I've gotta agree, as a camp-out stove I'd MUCH rather have a TLUD than one of those tin can rocket stoves..
They burn wood-gas very efficiently (when you get the top air right) and leave charcoal behind as a by-product. I built a 10 gallon model and use the charcoal in my home-made forge and for BBQ-ing. Some-time in the future, I plan to build a 30 gallon one as well.
You can build 'em by the numbers, but I'm not THAT kinda guy, so I've found how to do it by intuition and experiment.. It's not that hard and quite rewarding when you get it right.

Donkey - I don't understand *why* it leaves charcoal behind. 

Is it because more air is coming from near the top rather than right up from the bottom through the fuel?  Or is it because when you've finished cooking you close it up to put the fire out?  Or is it a combination of those things?  Or something different altogether?

Also, how do you light the things?  Do you need a drop of diesel or will it light from just a match and bit of kindling?  I've never used pellets so I've no idea how easily they catch fire...

Burra Maluca wrote:
Donkey - I don't understand *why* it leaves charcoal behind. 

Is it because more air is coming from near the top rather than right up from the bottom through the fuel?  Or is it because when you've finished cooking you close it up to put the fire out?  Or is it a combination of those things?  Or something different altogether?

A combination of them both.
The air from below is choked, which allows enough heat (to develop) to push off the wood-gas (basically producing a whole lot of smoke) but not enough heat to burn carbon. The secondary air above allows oxygen to mix with the wood-gas and burn it off. When it's done, the top fire will go out. If you look in, you'll typically see a little blue flame which is the carbon starting to burn a little. At that point, toss on the cap and close the bottom holes, usually by setting the can on the ground and maybe banking dirt around it.

Also, how do you light the things?  Do you need a drop of diesel or will it light from just a match and bit of kindling?  I've never used pellets so I've no idea how easily they catch fire...

Kindling and a match works fine by me. The finer the kindling, the easier the light. Heck, I don't even use paper much any more.
I ALSO don't use the pellets (ever), I use ACTUAL wood.

So how do you get the balance right?  Do you just keep punching holes in the bottom of the can and then experimenting?  And what are the 'symptoms' of not enough air holes at the bottom? 

Sorry, but I can feel an experimenting session coming on as soon as found some suitable cans...

Burra Maluca wrote:
So how do you get the balance right?  Do you just keep punching holes in the bottom of the can and then experimenting?  And what are the 'symptoms' of not enough air holes at the bottom? 

Sorry, but I can feel an experimenting session coming on as soon as found some suitable cans...

Hmm.. Well, when I did mine, I somehow got the holes in the bottom of the can right the first try.. It was the top air that needed fiddling with. That's kinda easy, put a few holes in it and try it, if it smokes out the top, put a few more in and repeat till you see a smokeless flame.
I suppose that if you get too many in the bottom, you will have a lot of ash left over afterwards. Easy enough to work with though, I tried kicking dirt against the sides and lowering the can to see what would happen. When I'd covered it up too much, the fire would start to go out.

Dunno, just gotta play.

These might be a little more sophisticated, but, will give a good insight to the process:

http://www.vrac.iastate.edu/ethos/files/ethos2009/Stove%20Developments/Construction%20Plans%202009-01-21%20PSA.pdf

Thanks for that advice Donkey, and for that link John.

I found another one for dumb-asses like me who need more background on the micro-gasification stuff...

http://www.hedon.info/docs/BP53-Anderson-14.pdf

paul wheaton wrote:

Better than a rocket stove in that it is easier to save your fuel.   And you don't have to keep feeding in the wood.

How does it save - or if I read your right - use less fuel that a rocket stove?  In my thinking, when your pot boils on a rocket stove, you pull out the burning sticks and stomp them out - saving them for later.  With the basic TLUD, it seems to me the fuel you start with (probabaly more than you need) is pretty much is committed to burn.

This isn't a TLUD, but uses wood to cook with and uses the extra heat to do things like charge batteries/cellphones. Seems like a good backcountry stove. http://www.biolitestove.com/BioLite.html

What modifications would be needed to have it burn with a partly blue flame. Maybe a small fan at the bottom of the fuel bin would help
or maybe it should be through side jets near the bed of burning fuel near the top of the bin/fuel chamber. I watched this and may other linked videos on these kind of stoves with great interest. I am going to take a serious interest in building one of these. I would also like to use one as a dedicated water heater with in-out piping.

I'd be very interested in ongoing discussion of design mods and fabrication ideas about this unique stove. I'll photograph any of my fab efforts an post them here.

Thanks to Paul for making this video; never heard of a TLUD stove before.

LL

LL and others,
Here are some links to making the 1g toucan as shown in the video. Also one using a fan.

http://biochar.bioenergylists.org/content/1g-toucan-tlud-biochar-jan-2010

http://biochar.bioenergylists.org/content/how-make-high-and-low-adsorption-biochars

Starting from scratch with my experimental heavy duty TLUD.
(original post)
I have a pile of used machine parts, tractors, trucks, etc . disk brake rotors, brake drums, cylinder sleeves plus stock steel tubing.
I am experimenting with stacking various combinations of components to see if I can get a TLUD to work using heavy duty parts
for long term use. I tried the prototype pictured below today. It did not work as hoped so I rearranged the parts and added a few new ones; will try it tomorrow and see if this new design works any better. My challenge is to make a TLUD out of heavy steel parts that works efficiently with minimum pollution.

I am going to turn this into a fully documented project and will post progress updates here at permies.com, in this thread,
which I hope we can keep rolling.

Here are some photos of a local builder of tluds.

https://picasaweb.google.com/114261170173561967216/PrototypeFor55GallonDrumTLUD

Ken wrote:
Here are some photos of a local builder of tluds.

https://picasaweb.google.com/114261170173561967216/PrototypeFor55GallonDrumTLUD

This is more what I am interested in, not making biochar but cooking, heating water and associated space heating:

https://picasaweb.google.com/114261170173561967216/HowToUseYourEstufaFinca

I have made these as well. I cook meals on them and heat water too.

Scott911 McCoy wrote:

paul wheaton wrote:

Better than a rocket stove in that it is easier to save your fuel.   And you don't have to keep feeding in the wood.

How does it save - or if I read your right - use less fuel that a rocket stove?  In my thinking, when your pot boils on a rocket stove, you pull out the burning sticks and stomp them out - saving them for later.  With the basic TLUD, it seems to me the fuel you start with (probabaly more than you need) is pretty much is committed to burn.

You didn't read that right. It's not that it uses less fuel than a rocket stove. The rocket stove burns the wood more completely down to ash, whereas the TLUD stove has a natural tendency to make charcoal. Rather than pulling out burning sticks and stomping on them, all you have to do is block the air holes at the bottom and let the fire die out and you will have fuel for later.

meet the TLUD family: mini, midi and max: double walled stainless steel bodies, cheap and fun

Andor Horvath wrote:meet the TLUD family: mini, midi and max: double walled stainless steel bodies, cheap and fun

Do you have website, contact, ordering, product line pricing info on this TLUD?

Tnx in advance

LFLondon

I was just suggesting the above for the material properties. I could sell you one;
but it would be faster and cheaper for you to find a surplus stainless steel "thermos"
bottle or carafe at a second hand store/rummage sale and drill/punch some holes.

Hi folks,
First post here; I've been playing with small TLUDs for a couple of years now; only just got the cojones to light one in the fireplace inside the house. Works exceptionally well! Here is a pic of the current iteration "Eye of Sauron": EYE_OF_SAURON. The core is a 5 litre paint can with lots of nail holes in the bottom and larger holes around the rim for the secondary air. It's topped off with an old sweet tin with a can chimney - probably a little bit longer than strictly optimal for indoor use. Fuel is chipped up branches from the graden, topped off with wood pellets to get it started and to act as a nice char layer to facilitate a secondary reaction to scrub out any gases that aren't going to burn nicely in the secondary burn.

There's something about these things that I find endlessly fascinating, so I have backed the Kickstarter project, and really look forward to the DVDs!
Cheers,
-Shane

Hey there, I wanted to post my video of a fire pit I built. It is basically a tlud. I wanted a pit I could burn pellets in.... I make them for a living.... So I test built this one for a friend... All of the flame.... None of the smoke...

Comments..?

https://www.youtube.com/watch?v=AfnmbxUJN_c&feature=youtube_gdata_player

Hmmm. I wonder am I likely to find any inspiration in here...?

I do love TLUDs though

I just discovered this site and this stove grabbed my attention right away. I see myself building a few of these in different sizes

I can see scalding water to pluck my chickens, boiling down maple sap, endless possibilities

took 20 minutes and put together a prototype TLUD. Boiled some water while starting my chimney for some wood fired pizza.

I wanted to share an idea. I have tried to make a few of these updraft stoves and when it is really cold it is hard to get them to light because the updraft is not hot enough. I could add a layer of insulation but instead I decided to make the updraft come from the center. I made a prototype out of a 28 oz tomato can and a 12 oz tomato soup can. I am happy with the result. I clearly got a good secondary burn and I think it is the simplest design that I have come across. I put the third can on top just to show that you could cook on the stove as is in another 12 or 14 oz can - have a look.

A good technique for TLUDs (if they're passive draw, as opposed to fan-assisted) is to raise the height of your chimney - this can dramatically increase the pull-through of both primary and secondary air, and get that baby singing. I used a 4ft chimney pipe on one running on turf (peat) nuggets, and it was like a bloody jet engine! My elderly neighbour toddled over and put his hand over it before I could stop him; almost lost his fingers! [He was OK actually - just a little singed].
What I like about the TLUD design is that it allows you to use many fuels that would otherwise go to waste, such as turf dust in Ireland. I was expecting the smell to have that peaty aroma that you get from turf fires here, but because it's such a clean burn, there was hardly any smell at all. And it put out masses of heat for quite a long time.

Can one cook and make primitive biochar with just a shovel?
http://hopefulvision.blogspot.com/2021/05/make-biochar-with-merely-shovel-dakota.html

Brian
-

Does anyone use these on a daily basis? I am hoping to use one for boiling 2 litres of water every morning. maybe the bottom can of a 1G paint can can be filled up half way?

I want to be able to use this, I am also wanting it to be straight forward so it can be used by my partner as well.