Matt Walker continental stove build

Oh please let usknow how the hot water coupling goes! I want to do a similar system using a salvaged electric water boiler/storage tank but the practical part of it baffles me. Can it be passive flow or require a pump? Does it need an electric thermostat and what happens when the circulating water reaches too high a temp? I don't expect an answer now. Your continued photo journal will be a much more valuable tool to all of us wanting the luxury of hot water on tap!

i will be taking some pics of course ---its a thermosiphon system no electric pump or valves involved using a stainless steel water jacket ---roughly 12 x 13 inches at 1 3/4 inch width ---which has 1 1/4 inch sized piping in and out-----colder water feeds to the bottom of it and the heated water rising up into the top outlet----both pipes exit side ways out through the stove body and then do a 90 degree turn and vertical straight up through the ceiling /floor  above the stove ---through another ceiling/floor -----into the hot water tank --- about 13 feet above in hight ---using the psi calculator ---0.433 x 13 ---gives me about 5.6 psi of water  pressure downstairs. The hot water tank is a stainless steel barrel at 209 liters (45 gallons ) which is fed into by a separate cold water tank  above it ---the hot water tank also has an overflow pipe venting into the cold water  tank ---the  cold water tank is fed by its own supply line and regulated by a ballcock valve ---and  has an overflow pipe to outside the building. thats all for now ---took me ages of working out and the smoke pouring out of my ears with all the thinking and over thinking it  .

Thank you for that very detailed description. Before I start mine, I'll see how yours turns out :-). Why re-invent wheel! Looking forward to the photos and thanks for taking the time to reply.

Hi Tony, first of all, fantastic work, really fascinating.
I found Matt's stoves a few years ago, but I still don't have the space to build one. I'm from the south of Brazil, and it's cold here in the winter, so a wood stove that could be used for cooking, heating water and the environment, while keeping firewood consumption low has always seemed very interesting to me.

If you have time, could you please answer some questions I had about the process and your project.

I couldn't understand how the water heats up in your project, where does the heat come from?

Yes, I understand the thermosiphon, cold water goes in from below, heats up and rises, circulating between the stove and the boiler/hot water tank. However, it wasn't clear from the photos and explanations how you use the heat from the fire/stove, heat passages, etc., to heat the water. I understood the most traditional part of Matt's stove, which he made the video about on YouTube, but I couldn't understand this new part that you added for the water. If you have photos explaining it better, that would be great.

What are the total dimensions of your stove, height, length of the plates, width?

Another question would be about the stove plate, the part you cook on top of, in your case glass and other materials. Do you necessarily need to use 3 pieces, is there a specific reason?

My idea would be to use one or two pieces of steel or cast iron plates (specific for wood stoves, for example the one in the link below is 1m and 32cm long by 72cm wide) that I have access to here. For example, use a piece of steel of say 1.5cm in the hot water part or a smaller cast iron plate, and a whole steel or cast iron plate on the rest of the stove. To have a larger area for pots, kettles, with more space than the 4 spaces of the glass. I don't know if I was able to explain.
Would it be practical to use something like that, or would everything warp a lot with the heat.

Example of a cast iron griddle "https://pollofundidos.com.br/produtos/chapa-para-fogao-a-lenha-para-restaurante-8-furos-com-tampa-e-reducao/"

Have you been using it for a while now? Does it really consume less firewood?
Does it heat the water well? From the moment you turn it on, how long would it take to heat up the entire tank?
Does it work well for cooking, for example, how much firewood do you need to burn to cook a meal? How often do you need to add firewood?
Does the oven work well? Does it have good temperature control? Can you bake cakes, meat, chicken, etc.,
for example? Does it heat the room well, a lot, a little?
Have you used it in the summer?

Thank you very much for your attention

most of the answers would become self explaining  in the set of drawings /plans for these stoves --for the sizes and the layout of the internal flue passage ways , my build is an adaption of the continental stove design of Matts---- the water heating jacket is placed at the end of the stoves  flue heat path ---as per his advice  ,and the reasoning for this  he has explained in one of his  broaudio  youtube  posts . I contacted Matt via email when my build was at the stage of trying to work out the best way for me to re -route the hot flue gas over the water heating jacket ----a part of Matts customer service --that you get when you buy his plans ----sorry i lack the full understanding of the stoves internal layout as it designed around cross sectional sizes and internal surface areas matched to flue sizes and the volumes of the firebox plus the secondary burn chamber ---with heat outputs and fire burn times a part of the calculations ---also being tuned for this by the primary and secondary air inlet sizes---by sticking to the plans as close as possible the you get to its predicted output. Matt states the heat output as 1.9 kw -- for the riserless core in the 6 inch flue ---sorry must go ---will post more

my stove is 2030mm long 800mm wide and 930mm in hight , my dimensions are more than Matts design sizes as i tried to keep to use of full size bricks with minimal cutting and the extended length mostly to house the hot water jacket. The stove plans are a guide  and not an exact build brick by brick description  ----everyones build will become unique as it progresses  ---buy all the  common clay bricks from one source or batch ---clay bricks vary a lot from batch to batch --so if they are second hand make sure to buy more than needed ---then dry build your stove layer by layer---dont cut any of your chosen bricks ---or the expensive insulated firebricks /ceramic blokboard that the core is made from---use any other bits and pieces of old bricks /blocks/wood planks---cut these to suit ---build at your own pace and anywhere you have some space to use---its just a full size model---now you will be able to see how it works ----now other peoples build pictures and descriptions /advise  will start to make sense----and follow some of the builds ----then start to measure for where you would have to place /position the cooktop and oven --and the final top capping of the stove ----now you can shop for these pieces with sizes in mind ---and have a good idea of where you can re arrange the build to suit what you can find---or would like ---make some small changes or additions for cosmetic looks and style. Take your time ---it will come together and happen before you---then when you can get to do the final mortar build it ---it will be a much easier and relaxing paced build.

I see, so basically you heat water at the end of the heat pipe, before the chimney.
In your case, you added a few more paths, like a mass heater.
You recommend deciding on all the hardware after a dry construction to check dimensions. These seem to be very clear, objective and logical tips.

Unfortunately, I can't buy Matt's project. When converted to my currency, the price is too high. Of course, it's not his fault. The price is very reasonable for someone who works in dollars or euros.

In any case, I appreciate your answers and in the future, when I try to build one with the information I have access to, I'll post it here. Thank you very much. I recently discovered this forum and I'm finding it fantastic to see so many great people who are always willing to help. Thanks.

well sorry to read the plans are not in your budget , as they are vital to building one of these stoves---and without them trying to get the internal working and layout from pictures of other builds is difficult for a first time build of one of these---i know  as i thought in the same way---that i could save that outlay and put the money into buying materials for the build---but you can only back engineer this so far and lots of the important details are  are hard to make out clearly---as helpfull as majority  of people on this site are ---and many enthusiasts  for building these type stoves----we are also respectful to Matts design copyrights and the license . All of the questions you ask are talked about in Matts broaudio youtube  sessions , its all in those --takes some time and patience  to get through it all ---took me ages and repeated viewings plus reading as many posts as i could find of his --about stoves and how these really work and why they do---my own view points are limited compared to his experience---and i am still only a beginner  at this----so persevere and research ----success and goodluck for your future build

Having built one of these, I agree with Tony. If you have the technical know how, you can work out your own core and stove lay out. There is a lot of free info out there -especially from Peter Van den Berg. So if you only needs ratios to get the core right, you should be fine. But if, like me, you have never done this before, the plans are invaluable. Even following the design specs, I don't get as an efficient burn as Tony- I dont have the red glow through the top plate  :-(  So mine is not as efficient as it could be and that's probably because my measurements may be off slightly.  While I may tinker with it later on, at the moment I'm really happy with how it functions. It does save wood, heats my space, cooks my food and boils water in a water jacket. I don't use the oven as I haven't worked out yet how to seal the door effectively with what I have available and fireboard is too expensive for me, so it's sealed off with cob.
Yes the plans cost money-on a low income myself I fully understand your predicament. You have to weigh up the cost of fuel- gas electric or wood- for heating, hot water and cooking. If you have access to wood, factor in time spent cutting, curing, chopping and stacking enough for a conventional stove. Also,time and cost of mistakes - even getting it wrong entirely vs savings in the long run. A lot of work went into these plans. They are complete and come with many videos to help. Most importantly, Matt is fully commited to his product. He held my hand throughout the build, double checked my figures, approved my build as it went along and troubleshooted at the end. The photos in my thread are only a fraction of what I sent to him and he responded to every one. Matt doesn't just offer a product, he offers amazing customer service too! The nice thing about the plans is that they are adaptable to your needs and space. I changed the configuration (after consulting Matt) of my chimney and used things I had for the metal bits as I don't have Tony's skill set for metalwork-WOW! The only thing I had done offsite was welding the secondary air intake.
I think it's worth spending money on the plans and rather try to save on material - 2nd hand firebricks, scrap metal for doors,old ceramic hob glass, use clay mortar as advised - not bought refractory mortar. Use plain clay bricks which you can cob if you like - added layer of raidiant heat. Even rocks if you have them - and the time and space. The plans were the biggest cost of my build but well worth it!

Tony, Sarah, thank you very much for your answers. I agree with you. Plans are essential. With all the research I've been doing for a few years, I realized that there are many details that can make the difference between everything working perfectly or you getting discouraged and giving up. It's worth saving up and buying Matt's plans.

You've had the stove for a few years now. Is it durable?
How many years do you think it will last before some renovation work is needed?
Do you use it in the summer or is it too hot for that time of year?

Here in my region, we have two models that are the most common, wood-burning stoves. One made of steel and one made of masonry. The steel one was produced with great quality in the past, it would last for decades if well cared for and it was quite economical. Now, after a few years, it gets leaks and is already full of problems.
The masonry ones are good, but they consume a lot of firewood. What makes it easier is that you can use firewood cut to more than 1 meter.

I also have the idea of ​​building a Russian mass heater stove, modeled after Kuznetsov. Why, you might ask? Because he made his plans available on his website, showing the bricks row by row, and it seems to be quite easy to build.

My fear is that since I don't have access to either of the two types of stoves, neither Matt's nor Kuznetsov's, I'm just imagining something that doesn't work as I think it will. That they're much worse or much better/hotter than I imagine. And that in the end I'll end up not using them because they either don't heat up enough or heat up too much, becoming useless.
The good thing about them being made of bricks is that in the end, if nothing works out, I can use the bricks for other things. That's why all the research and questions.

Thank you again for taking the time to answer my questions. I hope to start a thread about my work in a few years. Thank you very much

If you're interested, below are two links with images of stoves that are common in the region.

Image 1  (https://lojasbecker.vtexassets.com/arquivos/ids/3746935-1600-auto?v=638750756557770000&width=1600&height=auto&aspect=true)

Image 2  (https://i.ytimg.com/vi/fnnQRcNc5Y4/maxresdefault.jpg)

this is for Sarah ,  ---Heating Water With Fire-Homewood Stoves ,   this article has been my guideline ,and the best i have ever found ---and hes not trying to just plug his own product----

My answers in bold

Samuel Ri wrote:
You've had the stove for a few years now. Is it durable?
As mine is clay bricks and slip, any repairs are a quick fix. A few of the tiles under the front of the hob were wobbly. I removed and reslipped them in about half an hour

How many years do you think it will last before some renovation work is needed?  
Mine has run for 1 and a half winters, as I mentioned, it's obviously not as efficient as Tony's. I still have black soot in the gas flow areas. I have posted photos after first year's 6 weeks of burning showing the soot. It's not much, but I will open it up again before I next need it in October. As the glass is only sealed in with clay slip, I found it very easy to lift off, sweep out and reseal. As far as I know, the firebricks in the core should be very durable, however if they need replacing it's quite simple to remove the top gas race bricksand open the core. But mine is put together with clay slip not refractory cemen

Do you use it in the summer or is it too hot for that time of year?
too hot in our 42C summers to use inside, but I plan to build another outdoors-perhaps with an oven on top of the firebox to get a nice hot, bread oven.  However, I did adapt many of my oven recipes to stovetop using a cast iron pot and a trivet to create an oven on the hob, also some dishes traditionally cooked in an oven -like lasagne -can be cooked on a low heated stove top which I can get by placing pots further away from the core exit or by using a trivet to raise a pot off the top

I also have the idea of ​​building a Russian mass heater stove, modeled after Kuznetsov. Why, you might ask? Because he made his plans available on his website, showing the bricks row by row, and it seems to be quite easy to build.
Wow, there is a lot of stuff there and the plans are very detailed -too detailed for my very simple mind. I would liken Matt's plans to an "idiot guide" (no offence Matt!) Very straight forward, layer by layer, easy readable dimensions etc

My fear is that since I don't have access to either of the two types of stoves, neither Matt's nor Kuznetsov's, I'm just imagining something that doesn't work as I think it will. That they're much worse or much better/hotter than I imagine. And that in the end I'll end up not using them because they either don't heat up enough or heat up too much, becoming useless.
Only you know what your expectations are. I went with the tiny cookstove because I only have a 4m x 5m space, my ceiling is only 2.4m high. But I do have single skinned walls which lower the temp of the room considerably if it's not heated. As the stove backs onto my 3.5m x 3m bedroom and the exhaust runs just below the ceiling, I benefit from radiant heat from the wall and exhaust pipe in my bedroom - I haven't had to use a gas heater this last winter. No, it doesn't reach 24C, which is supposed to be a pleasant, ambient temp, but it does mean I don't put off getting up when nature calls until the very last minute! And it's a pleasure to go into the kitchen at night or come in from outside during the day, it feels possitively cosy in there!
I dont't have hot water plumbed into my house, I have to boil a kettle on the gas. But in winter my stove provides constant hot water as I have an open topped receptical that BOILS when the fire is going and keeps warm between fires. And I do all my cooking on it in the winter.I could use the bottom oven as a slow cooker but I still have to sort my door arrangement. It definitely uses less wood than a traditional steel fireplace, it's easier to clean-no charcoal lumps and very little ash The exhaust is still less smoky-even if not perfect water vapour

If you're interested, below are two links with images of stoves that are common in the region.

Image 1  (https://lojasbecker.vtexassets.com/arquivos/ids/3746935-1600-auto?v=638750756557770000&width=1600&height=auto&aspect=true)
A lot of hot metal there and metal heats and cools quick- unless it's lined with firebrick??? Still a  multifunction mass heater/cooker though.I'm definitely not an expert but I would think it would burn less fuel and keep the space warmer than say a gas heater and a gas stove-which both give off gasses indoors unless vented to the outside

Image 2  (https://i.ytimg.com/vi/fnnQRcNc5Y4/maxresdefault.jpg)
Lots of mass, but lots of fuel use too! It looks like an L tube rocket - I presume the gas flows around the stove before exiting a chimney? It's an interesting concept and again I'm no expert, but I think you don't have the seconadry burn vortex in the chimney because of the oven. Someone more qualified than me needs to comment! But I can see Matt's core and gas path fitting into that design with a few modifications, even adding a hot water jacket would be possible. Thanks for that, It gives me an excellent idea for my outdoor kitchen model as using the flue system I can direct heat straight to the oven or bypass it to the stovetop and hot water storage, hmmmmm

Samuel, those images are interesting and I can see why they are inefficient.
Thomas has details of a 'shorty' stove has has built which may interest you.
I had a look at the site you speak of
Igor Kuznetsov
Where do you actually live?
thanks

tony uljee wrote:this is for Sarah ,  ---Heating Water With Fire-Homewood Stoves ,   this article has been my guideline ,and the best i have ever found ---and hes not trying to just plug his own product----

A big thank you Tony, this is exactly what I have been looking for!

Hi John,
Kuznetsov's free projects can be found on the website:  http://eng.stove.ru/products/otopitelnyie_pechi_oik/oik4

He provides several models. And from what I understand, if you need or want to modify them, he offers paid consulting.
I found everything thanks to the internet, if I'm not mistaken through a video on YouTube, a channel called "StoveAdvice", where he talks about the OIK 4 model. Before that, I had never even heard of it.

I live in the south of Brazil, in the Serra Gaúcha region. I am a descendant of Italians who immigrated to America, specifically to the south of Brazil, in the late 1800s. Here we have well-defined seasons: summer, spring, autumn and a cold, damp winter. Sometimes it snows, but just a few snowflakes. We have some cold snaps of 0 °C and some frosts. What bothers me the most is the cold with a lot of humidity.

I was talking to a Canadian man who came to live here and now resells Canadian fireplaces in the neighboring city. He said he had never been as cold in his life as he was here. Because the houses are not prepared and the weather is very humid, unlike where he comes from, which is much colder but dry, and the houses are prepared for this. He says that much of the discomfort we feel in winter is because of the humidity. From that point on, I started researching alternatives for heating and dehumidification in a future house.

Samual, I lived in Melbourne Australia for a long time.
A friend from Canada said the same thing about Melbourne.
Have you seen the German Pauhause system? Spelling  my not be correct.
It cret-ates a sealed environment where the airfow inside is managed through a heat exchanger and humidity control.
It may work for you.

I've never heard of this system, I'll look into it, thank you very much.

modified a stainless steel barrel for hot water tank , top manifold has 2 outlets --larger one to supply shower and smaller outlet will split into 2 for supply on two kitchen sinks---the 90 degree fitting at the bottom is the cold line in from the supply tank ---then 2 sections of pipe underneath ---one is exit for the cooler supply down into the water jacket ---second one is for the hotter water rising up from the water jacket ---this section of pipe protrudes about 9 inches up inside the barrel-----then a section of pipe to vent air bubbles and any overflow of hot water ----of course the barrel will be laying down in its final working position