Increase wood stove efficiency during blackout

I live in Ukraine.  Due to rocket attacks (there was no electricity for several days).  measures had to be taken not to freeze.  The house has a stove and a fireplace, but it's not for blackout.  the gas boiler could be used until the battery was discharged, air conditioners do not work without electricity.  11 old fire extinguishers and two pieces of a thick pipe were bought.  When we started to give electricity for several hours, my friend and I welded a heat exchanger to take heat from the furnace.
https://vm.tiktok.com/ZMFcKQEFs/

Interesting! How do you get the flow going up the chimney when you start the wood stove?

Douglas Alpenstock wrote:Interesting! How do you get the flow going up the chimney when you start the wood stove?

the stove is fired, the smoke goes up the pipe with the thermometer, then the damper on the upper horizontal pipe opens and the damper on the vertical pipe with the thermometer closes.  After that, the smoke rises up, rests against the damper, goes down, goes to the left in the pipe under the ceramic tiles, rises up the vertical pipe on the left, then along the upper horizontal pipe to the right and to the street.  The entire circuit of four pipes is hot, total length of 4 pipes 7 meters diameter 120 mm.Aat the bottom there is a basement floor, a through hole is punched in front of the stove and a metal corrugated hose with a tap is inserted.  This provides a supply of combustion air.

Yes, that makes sense to me.

It is similar to the old wood burning kitchen stoves. First a direct draft to the chimney is established. Then some of the flow would be directed down and around the oven.

How tall is the outdoor chimney?

Douglas Alpenstock wrote:Yes, that makes sense to me.

It is similar to the old wood burning kitchen stoves. First a direct draft to the chimney is established. Then some of the flow would be directed down and around the oven.

How tall is the outdoor chimney?

length of the insulated chimney 7 meters

the stove works well, but there is an idea to improve it by replacing the stove with a small firebox; a metal stove with a metal thickness of 5 mm was purchased, which will be converted into a rocket stove

Bogdan,

Nice project!  Will you have any masonry/bricks next to the firebox to store extra heat (and release later)?  Also, out of curiosity, have you developed any alternative to regular grid electricity such as a solar panel?  This is all very interesting to me.

Eric

Eric Hanson wrote:Bogdan,

Nice project!  Will you have any masonry/bricks next to the firebox to store extra heat (and release later)?  Also, out of curiosity, have you developed any alternative to regular grid electricity such as a solar panel?  This is all very interesting to me.

Eric

no, I will not make a heat accumulator out of brick, this is a backup heat source whose task is to extract the maximum amount of heat from the firewood, on top of the stove there is a ceiling fan that mixes the hot air and distributes it throughout the house.  The main source of heat is a gas boiler and 3 inverter air conditioners that can operate up to -25. But if there is a missile attack and the lights go out, then there is a stove and a car battery that provides light and ensures the operation of the gas boiler pump.  Regarding solar panels, they are not effective in winter.  In war, specific solutions are needed: firewood and gasoline.  I found a solution for myself: a homemade charger for charging the battery from a car generator and engine for a brush cutter.  It produces 12 volts and will quickly charge the battery in the absence of light

Gotcha.  Your charger is an inventive solution.

What's the creosote build-up/situation with this arrangement?

Jim Fry wrote:What's the creosote build-up/situation with this arrangement?

there is no creosote, there is soot and unburned fuel particles, for this you do not need to set the power regulator to maximum so that there is no excessive draft.  The chimney needs to be cleaned once a year, for this purpose inspections have been made and the stove is easy to maintain.  The metal of fire extinguishers behaves well, especially since the thick pipe at the outlet takes the main load.  I clean the chimney with a plastic pipe, at the end of which there is a water bottle cut into strips.

Eric Hanson wrote:Gotcha.  Your charger is an inventive solution.

No, I am not the inventor of this device, I bought it from a person who found himself in difficult conditions and now makes them to order.

Still an inventive solution, and good for you for helping to support the creative one


May I ask why you don't want to accumulate heat from the stove? It would let you burn hotter fires keeping the exhaust cleaner, and not have to burn a small fire overnight.

Glenn Herbert wrote:Still an inventive solution, and good for you for helping to support the creative one


May I ask why you don't want to accumulate heat from the stove? It would let you burn hotter fires keeping the exhaust cleaner, and not have to burn a small fire overnight.

Frankly, I don’t have enough knowledge and resources and it seems to me that it’s better to take heat away from the stove and heat the house right away than to waste time heating brick or stone knowing that the heat will only be near the stove itself.  but this is my
opinion and I could be wrong.  Unfortunately, I have limited time, today we had another rocket attack, but fortunately there is still electricity.  Today my friend and I made grates from a cast iron storm grate, tomorrow we will make a door with glass and go to a scrap metal collection point to pick up a container for a rocket reactor at the chimney outlet.
P.S. I also need to take into account that the stove is on floor slabs and there is a basement below, and the accumulating mass will weigh a lot

I know people make stirling engine fans from scratch as a hobby. I believe they would suit your needs but realistically it's probably too complocated to be a solution right away. You can buy them from the UK but I would have no idea how the mail is running.

Stay safe.

Dan Fish wrote:I know people make stirling engine fans from scratch as a hobby. I believe they would suit your needs but realistically it's probably too complocated to be a solution right away. You can buy them from the UK but I would have no idea how the mail is running.

Stay safe.

Thank you for your help, I considered options with Peltier elements and a sterling engine, but the situation shows that the real source of energy is gasoline and firewood, even if military operations are taking place nearby, these energy sources are available, otherwise it is necessary to evacuate.

The process continues, the furnace is installed, the reactor will be a housing from an electric water boiler, a thick metal damper is welded to the top, oxygen will come from the bottom door and a metal pipe with holes.

Creative work
In order to get the most efficient combustion, the fire needs to be kept as hot as possible while burning, and not radiate heat directly from the firebox. Lining the firebox with thin bricks or other mass/insulating material would help you get the most efficiency from the stove.

Glenn Herbert wrote:Creative work
In order to get the most efficient combustion, the fire needs to be kept as hot as possible while burning, and not radiate heat directly from the firebox. Lining the firebox with thin bricks or other mass/insulating material would help you get the most efficiency from the stove.

do you mean insulating the firebox from the inside?

Yes, that would keep the fire hot and the steel from overheating. Insulating just outside of the firebox would keep the fire hot, but allow the steel to be overheated and corrode quickly.

Glenn Herbert wrote:Yes, that would keep the fire hot and the steel from overheating. Insulating just outside of the firebox would keep the fire hot, but allow the steel to be overheated and corrode quickly.

good, the size of the firebox allows it to be lined with fireclay bricks

I remember once visiting a 200 year old 1 room schoolhouse that was heated with a potbelly stove and the stove was in center in back of the room, the chimney pipe came up high enough so no one could hit head on it and was extended horizontal to the front of the building where it went up and out through the roof.

the door is made, the glass is taken from an old gas stove, the lock handle is made from wrenches

.The furnace is installed, I’m waiting for the heat-resistant sealant to dry and start it up.

the furnace was started and working perfectly, I had to add bricks and set the mirror to maximum mode, it’s very hot, thanks for the advice from Glenn Herbert, the first launch was made without fireclay bricks and the glass smoked very heavily, with fireclay bricks the combustion process became very calm and confident.  Today I’m experimenting with the bottom door closed, the air flows through a pipe from the basement directly into the firebox.  The glass remains clean after 3 hours of operation.  I melt it as follows: I stack thick oak firewood at the bottom and light it on top using homemade napalm (a mixture of laundry soap and gasoline).  When igniting, the lower door is open and the direct chimney is working, when the temperature on the direct chimney reaches 200 degrees Celsius (30 minutes), I close the direct chimney and the system starts working.  After that, I close the bottom door and the oven starts working in air from the basement.  Having read that the firebox is tightly loaded with wood, there is no need to add it.  Fireclay brick, although it reduced the volume of the firebox, in combination with cast iron grates, improved the quality of combustion.A ceiling fan with changing blade rotation (winter and summer) and 3 modes is installed above the stove, taking into account the consumption of 60 watt it can be used even during a power outage.  The fan mixes the hot air and this is felt well since there are stairs to the second floor nearby and without a fan it is very hot at the top. There is a fairly large amount of brick around the stove, which gets very hot and radiates heat; the stove is located on the floor, which also warms up well at a distance of 1.5 meters.  At the bottom, the floor slabs are insulated with 10 cm thick foam plastic, due to which the temperature in the basement dropped by 5 degrees.

4.5 hours of burning on one tab, I opened the bottom door slightly, the fire began to flicker, with the door closed the fire burned like a candle, the glass was practically not smoked.

5.5 hours of burning, switched the system to a direct chimney, the lower door is closed, the stove operates on air supplied from the basement, the fire burns like a candle near a pipe with holes in the firebox.

8 hours of burning, temperature on the stove 54.6 degrees, temperature on the tank 64.9 degrees, the glass was covered with soot, but not as much as it was when used without fireclay bricks.  My conclusions: it’s very convenient, there’s no need to add firewood, it works for 8 hours on one tray with the bottom door closed.  it works quietly, when the work was completed I switched to a direct chimney, but I think it will work with additional pipes.  There is a very big difference when insulating the firebox with fireclay bricks; the glass does not become dirty and the operation of the stove becomes smooth and quiet.  The air supply directly into the firebox works very interestingly; it can be operated with the bottom door closed.  Among the shortcomings: a tray was installed under the grate to collect ash, to clean it you had to lift one grate, now this grate is pressed with fireclay bricks, well, I’ll think of something.  Tomorrow I’ll show you how to load the stove with wood and the process of lighting it with “Home Napalm.”

the process of igniting the stove, firewood, oak trimmings from the sawmill, this year they are stored outside under a cover from an old swimming pool, so they are not dry enough.  The firewood is packed tightly into the firebox, a piece of briquette made from wood chips and sawdust is placed on top and a little homemade napalm is placed on top.  The bottom door is completely open.  The vertical chimney is opened and set on fire.  By the way, the glass was not covered in soot, but in fine dust, areas where the glass was stained with soot from pieces of burning wood.

after 30 minutes, the stove switches from a vertical chimney to a horizontal one.  Burns great, no smoke.

Now the question arose of how to add firewood to continue the top burning.  The coals are moved with a scoop to the far corner of the firebox under a chimney made of a metal sheet, firewood is placed and the firewood begins to burn in the area of the air supply pipe to the firebox.  in this case, the lower door is closed and the wood near the door does not burn.  But given that they are located near heated fireclay, they gradually dry out.

after opening the bottom door slightly, the dried firewood flares up and burns intensely

a piece of pipe remained from the project, so it was decided not to leave it idle.  An old barrel in which the bottom was cut out, a drum from a washing machine and off you go.  a trench was dug at an angle, a thick metal pipe was laid more clearly, then a hole was dug into which the drum from the washing machine was installed.  Nearby, a hole was punched in the ground with a crowbar to allow oxygen to flow under the drum.  A fire is ignited in the drum due to the side hole, creating an influx of oxygen.  The barrel is covered with an oak shield and the drum is covered with a barrel lid on top.  After the wood has burned out, a piece of apricot log is placed on top of the coals and the smoking process begins.  Not exactly healthy, but it helps preserve meat or bacon.

Enough time has passed for the oven to be fully operational.  My house has never been so warm; thanks to a ceiling fan that changes the direction of rotation, the heat is distributed across the first floor and rises to the second.  The brick around the stove and the floor get very hot.  A tray was made from the additions for pokers and tongs, and a sheet of duralumin was placed under the bottom door to prevent ash from falling out.  At the back of the stove I placed a bucket of wood chips for lighting.  I also installed a metal pet screen opposite the door.  I unload the ashes from the furnace once a week.  A few days ago I checked the pipes and removed the flasks; I was pleasantly surprised that there was practically no ash in the flask, and the thick gear that was welded from the inside to the top was absolutely clean and even shiny) There was some ash in the lower horizontal pipe.  Most of the time, the stove operates with the bottom door closed and air supplied to the firebox from the basement.  As a result, the glass becomes covered with soot.  But I found an interesting way, the soot is very difficult to wash off, I even tried to clean it off with a blade.  It is necessary to apply the detergent and leave it to dry and a reaction begins as a result of which the soot itself disappears.  By the way, the glass from the gas stove unfortunately burst and therefore was replaced with a special heat-resistant one

Enough time has passed for the oven to be fully operational.  My house has never been so warm; thanks to a ceiling fan that changes the direction of rotation, the heat is distributed across the first floor and rises to the second.  The brick around the stove and the floor get very hot.  A tray was made from the additions for pokers and tongs, and a sheet of duralumin was placed under the bottom door to prevent ash from falling out.  At the back of the stove I placed a bucket of wood chips for lighting.  I also installed a metal pet screen opposite the door.  I unload the ashes from the furnace once a week.  A few days ago I checked the pipes and removed the flasks; I was pleasantly surprised that there was practically no ash in the flask, and the thick gear that was welded from the inside to the top was absolutely clean and even shiny) There was some ash in the lower horizontal pipe.  Most of the time, the stove operates with the lower door closed, with air supplied to the firebox from the basement; also this year, the firewood is outside and is not dry enough, and sometimes just wet.  As a result, the glass becomes covered with soot.  But I found an interesting way, the soot is very difficult to wash off, I even tried to clean it off with a blade.  It is necessary to apply the detergent and leave it to dry and a reaction begins as a result of which the soot itself disappears.  By the way, the glass from the gas stove unfortunately burst and therefore was replaced with a special heat-resistant one

The photo shows how soot comes off in layers as a result of the reaction.  Unfortunately, the firewood is outside this year and is not dry enough, so the glass will become dirty.  but this method makes it easy to clean.  it’s bad that you can’t insert a video that shows how the soot comes off on its own

if necessary, it is even easier to clean the glass; the bottom door is opened slightly and the soot burns out due to the high temperature

a new function has been activated in the oven, pot roast)

bogdan smith, thank you for your posts. I think your experiments are extremely valuable to us.

I can't speak for others, but in my area I see a lot of stickers and cloths flapping in the breeze that include lovely colours such as blue and yellow, and personally that sits well with me.