Water heating brick stove

[v12spirit]

Found myself obliged by the wife to let this project break into my steel oven build. To put it simple, electricity (which is the means to get warm water in my house after the solar energy system was blown) started to go frequently for whiles, diesel (which is the common feul for stoves) became rather expensive and hardly available that people started shifting to wood fire. The result was that I needed alternatives for elecricity heated water as well as diesel feuled stoves.
An idea came to me that I soon started turning it into reality. To build a brick wood fired stove that heats water by the heat escaping through the chimney. The water will be reserved in a tank that is penetrated by the chimney and will by some means be connected to the water piping system in the house. This is not an invention. These water tanks are so popular in my region but they are installed on diesel stoves that are becoming replaced by wood stoves all of steel and are installed right in the baths and have a hillbilly shape..
The main difference is that I will build a brick wood fired stove or fireplace in the sitting room, instal that tank on it, and connect the tank to the piping system in the house. The result is hopefully supposed to be that firing the brick stove will allow slow mild heating for the sitting room, and the exhausts from the chimney will provide the entire house with warm water for hopefully as a long period of time.

[TropicalCoasting]

Re: Water heating brick stove

Rocket stove would be the most efficient use of wood
https://www.youtube.com/watch?v=1oDpmmsqHwQ

[jeeppiper]

Re: Water heating brick stove

Cool idea V12!!!...You probably already know this but make sure you install a pressure relief valve, in case you end up generating steam.

[v12spirit]

Re: Water heating brick stove

Rocket stove would be the most efficient use of wood
https://www.youtube.com/watch?v=1oDpmmsqHwQ

Thanks for the video. I'm still trying to figure out the benifit of the twisted copper tube. I just let the water exchange heat right inside the big water drum.

[v12spirit]

Re: Water heating brick stove

Cool idea V12!!!...You probably already know this but make sure you install a pressure relief valve, in case you end up generating steam.

Have been worried about exploding the tank and the plan was to rely on careful observation of the tank temperature to be honest. Reading your input made me rethink safing myself against explosion. An idea came to me; to install an automotive radiater heat valve (It opens on 85 degrees I reckon) and connect it to a tube with an open end to the sink, passing through another room, so the excessive heat will warm the other room as a ponus.. Cold water will replace the escaping hot water cooling the tank down. Thanks for the input Jeepiper. Wouldn't think of that without your note.

[TropicalCoasting]

Re: Water heating brick stove

Thanks for the video. I'm still trying to figure out the benifit of the twisted copper tube. I just let the water exchange heat right inside the big water drum.

You are boiling the water in the big water drum and the twisted copper pipe runs fresh cold water through it absorbing heat without risking legionaries disease.
A bit like an instantaneous hot water service.

A friend here has a more primitive version where you light a fire under a 40 gallon drum full of water with the same curly copper pipe.
It works well but the rocket stove and insulation is a more efficient design.

[jeeppiper]

Re: Water heating brick stove

V12...the radiator heat valve is a thermostat and is driven by temperature, not pressure. The temperature can vary inside your tank since it is standing water.

What you really need is a pressure relief valve which is driven by pressure. It is a spring-loaded valve that opens when the pressure reaches a certain level. These can be found on any hot water heater (see picture). You want something that can dump the pressure in a hurry.

[v12spirit]

Re: Water heating brick stove

Hi Mikku,
Thanks for the details. The tank (drum) is sealed. I attached a sketch for the entire system. If you look at the sketch you can see a "safety tube". It may do the job of the expansion tank I think.

With the chimney only penetrating the tank, will you have enough surface transfer area to heat an adequate amount of water?

With the insulation over the tank, and fire underneath as in the sketch, I hope it is sufficient.

What do you think of a light gauge stainless steel tank that would surround your wood stove entirely? An open system

It is of galvanized steel that will not rust. I cannot afford a stainless one. The system is not open because I want to make use of the stove heat to heat the room too.

Could you elaborate on this:

Clean hot water on tap without using gravity or pumps. The water would never exceed 100C as long as there was water in the main tank.

and could you explain more how the water circulates in your friends setup? it sounds very interesting.

[v12spirit]

Re: Water heating brick stove

Here is the initial planning. Two walls for the stove. The one on the right side is parallel to the room wall that faces the outside, the wall on the left side is parallel to the wall mutual between the room and the next room. The first should be heavily insulated from the room outside wall, the second will not be insulated. Rather, the mutual wall between the two rooms wil be clipped by an area as wide as the area of the stove left wall enabling the stove heat to be shared between the two rooms. Any suggestions on how to do the clipping on the mutual wall?

[v12spirit]

Re: Water heating brick stove

Mikku,
The main purpose is to heat room2 and provide the bath with hot water. Heating room1 will be achieved by sharing the stove left wall between the two rooms. Any extra heat that would make the tank boil will be better returned to more rooms by the automotive valve and the water radiator. It is not an integral part of the system. It is all about utilizing the extra heat produced by a safety feature; the temperature valve. I don't want to incorporate any electronic or electrical equippment. I just want a mechanical system that naturally operates on wood. The whole project emerged from some exceptional circumstances obliging people to go back to nature (lack of electricity and cleaner feuls like natural gas or diesel), and I am one of them, but this is the way I want to make use of nature.

[v12spirit]

Re: Water heating brick stove

No loop actually. The excessive hot water in the tank is just drawn out. Instead of getting rid of it while it is hot, it just dawdles in another room by means of a water radiator and ends up cool at the end to a sink or a secondary tank for reuse. Diesel stoves are pretty similar but have some extra complications. The tank in the picture is designed especially for those diesel rocket stoves. Winter here hardly falls under -3 celesius.
Frankly jeepiper caused me to think of the radiator, but you are making me rethink of it more seriously. I liked the idea of self looping systems. Some modifications to the plan should be posted soon.

[v12spirit]

Re: Water heating brick stove

It is showers. Bath, toilet, and kitchen are fed from the very same hot water supply. Room1 is heated by three sources; any hot water request, the excessive hot water moving in the radiator, and the mutual stove wall between the two rooms (not shown in the sketch). Still thinking of a mechanism to refeed the cooled water at the end of the radiator into the hot water tank...

[SevenAcre]

Re: Water heating brick stove

Sounds like a great project v12, except for the part of having to do it out of necessity. Hopefully it won't turn into a chore. I'd like to just toss in my two cents here and join some of the fun. I think I'd look at this as two systems: You gravity feed cold house water down from the main tank into copper coils that are inside the chimney tank. Water is boiled under pressure in the chimney tank which heats the house water through the copper tubing before going out to your shower.

The pressure in your chimney tank is what you bleed off to the radiator to heat the house. The steam pressure should be enough to return the condensed water back to the chimney tank where the process begins again.

I have attached a very sloppy napkin diagram. It's just a rough sketch to illustrate what I was thinking (really rough). What do you think? Too complicated?

-J

[v12spirit]

Re: Water heating brick stove

I have attached a very sloppy napkin diagram. It's just a rough sketch to illustrate what I was thinking (really rough). What do you think? Too complicated?

-J

Great idea SevenAcre! Just will study how safe I can implement it.
Good sketch btw.

[v12spirit]

Re: Water heating brick stove

Before posting any updates for my project.
Just want to make clear first that THIS PROJECT IS EXPERIMENTAL and that this is NOT A FIREPLACE NEITHER A CENTRAL HEATING SYSTEM. The philosophy of this project is based on my own observations of fireplaces, wood fired rocket stoves, my shallow experience in plumbing, and some elementary basics of physics, and most importantly a good common sense and a strong well to device a custom solution for a given problem; lack of electricity and diesel as the source of hot water and stove feuls respectively in my region.
The build will move with two main guidlines in mind
1- To start from my custom requirements (convenience), and go ahead as long as the results are physically satisfying (functionality), and to steer away from "convenience" to the standards as soon as I can not obtain a good "functionality" anymore.
2- To make my build extensible, by which I mean
2-1- to make the project tolerate any functionaliy-driven modifications without too much tearing.
2-2- to make the project accomulatively built i.e. it can be run with its minimum options without the need to wait until it is finished (that is urgent because of the cold weather now) while I can manage to add its options as long as I can . I don't want it to take that time my steel oven has taken so far.
With this criteria, this project should be running soon. Some "luxury additives" like insulation, hot water radiators, sensor valves, and even decorative finishings can be applied anytime. The main concern now is some room warming and water heating.
The build naming included "brick stove" not "fireplace". This implies that the brick build does not comply with standard firplace design and dimensions even it exploits the properties of each in a way or another.