Emergency Heat. A quick, crude woodburner made from furnace / cooling ducting, or other metal.

[Howard Boldt]

The massive New Madrid Fault Line adjustment and related events will likely occur this winter. Widespread disruption of utilities will be one big problem, including those which provide heat - natural gas and electricity. Many people will probably suffer and die from cold, but many can probably be saved.

Ideally, we all already have a good, safe, working wood stove and chimney in our homes, and a large supply of firewood, but few people actually do. So, can a stove and chimney be cobbled together during an emergency? In many cases, yes, I believe. If you're slightly handy or even just willing to try, and have some ducting in your home or other building, or suitable other items around, you can probably do it and it probably won't take very long. Then you can burn scrap lumber, dead branches or anything else which burns and produces heat. You can even take apart wooden fences and parts of your house to burn, if it means survival. Necessity is the mother of extreme measures and innovation.

I haven't done this, yet, but feel certain it will work, even if improvements to my ideas are needed, and/or adaptations for your specific situation. Any home or other building with forced air heating / cooling, will probably have steel sheet metal ducting. There will probably be pipes, elbows and so on. From your basement, you can perhaps see it in the ceiling, or you can when you remove ceiling panels. It's usually held together with screws. Keep the screws as you dismantle whatever parts you need and use them to assemble your award-winning emergency stove, or use suitable other screws. Screwdrivers, pliers and tin snips are probably the main helpful tools. A cordless drill and small drill bits will also be useful, but you can also make holes with a hammer and nail. Pilot holes will be needed for screws. You can also wire a parts together, but likely need to make some holes for that, as well.

This will probably be fairly long, so I'll continue and elaborate on my plans in additional posts. And hopefully provide sketches. Ideally, I will also build one and take pics. Let's see how my time goes. If I just buy the parts from the local hardware store instead of destroying the heating system in this house (it's in use), I reckon I can make the whole thing in an few hours.

 

[Howard Boldt]

I will now begin to describe how I would attempt to build such an improvised wood stove and chimney, as I began to explain above. In this house, which I believe is typical of countless homes in North America with forced air heating, there is rectangular ducting measuring 8" x 14" and there is 5" diameter round ducting. I would use the rectangular stuff to make a small wood stove and the round stuff for the chimney.

The stove must be kept off the floor, so that it doesn't start burning from the heat. Use bricks or metal pieces or something nonflammable to achieve this. Pots and pans might work. It would also be good to have an inch or two of sand or wood ash in the bottom of the stove, so the bottom sheet metal doesn't get too hot, and so is less prone to wearing out or warping. There will likely be some warping on all sides from heat, but you can monitor it and make adjustments, adding screws or pieces of sheet metal, or whatever is required. I wouldn't make the fire too hot. This thin air duct metal is far from being suitable for a proper stove and chimney, so bear that in mind. Better to make two stoves, if one is not providing enough heat, than have too hot a fire.

Chimneys best go straight up, through the ceiling and roof, so if you have a good, safe way to achieve that, great. If not, I would plan to go through a window. Remove the window or break the glass.

Choosing a section of the rectangular ducting which has round ducting attached to it for the burner part is probably a good idea. No need to figure out how attached the chimney to the stove if it's already attached. But it will probably begin with an elbow. Since the first leg of chimney probably has to go up to the height of the window, you could plan the burner with a side chimney hole. So, the first 90 degree elbow can turn and head the first section of round ducting upwards.

I will continue with chimney in my next post.

 

[Howard Boldt]

I should say that I'm talking about steel ducting. Aluminum is probably not good enough, except perhaps for tiny fires.

The best way to do the chimney is probably usually to go up, then sideways through the window, then up again, heading past the eavestroughing (gutters). It can be wired onto the eavestrough. It can also be supported and stabilized with wire and whatever else. Think about the possibility of strong winds pushing it around. Ideally, the chimney should extend at least 2 feet past the eavestrough, so that the draw of the smoke will be better. A level top to the last piece of ducting is important and will mean that it will probably draw well, no matter which direction the wind is from. There could be some reversal of the smoke as the fire dies, so watch out for that. Don't allow a lot of smoke to come into the house.

Where the chimney passes through the window, you will need to fill in the space around the pipe, in order to close in the window opening. Next to pipe, for at least 6", this should be done with metal. Aluminum flashing is the easiest to work with. You can even cut it using a utility knife. Score it and bend it back and forth until it breaks. For steel ducting, you will need a tin snips or something.  It can be done in several pieces, if this helps accommodate the round shape of the chimney pipe. However, if you have a way to stuff the cracks, you can even make the hole square. Fiberglass insulation, usually found in walls and attics, will probably work, and/or aluminum foil. The rest of the window opening can be closed with plywood or something else. However, monitor anything flammable near the stove or chimney. If things get too hot, cover them with sheet metal or aluminum foil. This will reflect the heat away and keep it from smoldering and starting on fire.

That's my basic plan. If I think of more to add or build a prototype, I will post again.   

 

[Carlos Villa]

Use you car as a generator
When my off grid system was 12v, I had a junk car wired in to my 30 lead acid batteries and when they got too low, I would start the car and charge the batteries. Now I have a much larger system so I no longer use the car

[Howard Boldt]

Thanks guys, but since of this thread is mainly about improvised wood stoves, I feel like your posts would be better placed in other discussions. Heating by battery power is usually not an adequate solution. The exception may be for 1) less severe cold weather 2) a small space 3) a larger battery bank 4) reliable ways to continually recharge them. Even so, battery power topics, etc, are probably better placed in an off-grid power discussion.

[KM]

Think in the short -term it will prove to be useful and over time will or can be adapted as needed - We are attempting to help people from all over the world with differing circumstances and weather.

Howard Boldt said:

Thanks guys, but since of this thread is mainly about improvised wood stoves, I feel like your posts would be better placed in other discussions. Heating by battery power is usually not an adequate solution. The exception may be for 1) less severe cold weather 2) a small space 3) a larger battery bank 4) reliable ways to continually recharge them. Even so, battery power topics, etc, are probably better placed in an off-grid power discussion.

[Nancy Lieder]

Cobbling together an emergency wood burning stove is also doable, as many YouTube videos show. Here is an example form Ben’s Backwoods.
https://www.bensbackwoods.com/
Ben sells many inexpensive portable wood-burning stove and heating products. And from Far North Bushcraft and Survival.
https://www.youtube.com/watch?v=-jReTCLf6uk
This is not complicated. Get prepared folks.

SHTF Emergency Preparedness How to Heat Small Buildings with a Portable Woodstove
https://www.youtube.com/watch?v=rvG4fe4o77U
How to set up a portable wood stove to meet your Shelter, Fire and Water needs in a grid down situation. These ideas on set up can be used in a emergency to heat many different types of shelter.

[Howard Boldt]

They seem to be good posts, but there's value in a certain level of organization, which is why I don't make posts in the off-grid electricity section about improvised wood burners, LOL.

KM said:

Think in the short -term it will prove to be useful and over time will or can be adapted as needed - We are attempting to help people from all over the world with differing circumstances and weather.

Howard Boldt said:

Thanks guys, but since of this thread is mainly about improvised wood stoves, I feel like your posts would be better placed in other discussions. Heating by battery power is usually not an adequate solution. The exception may be for 1) less severe cold weather 2) a small space 3) a larger battery bank 4) reliable ways to continually recharge them. Even so, battery power topics, etc, are probably better placed in an off-grid power discussion.

[Howard Boldt]

Very good. Far better to have an actual stove and chimney, than to have to piece one together during a crisis.

Nancy Lieder said:

Cobbling together an emergency wood burning stove is also doable, as many YouTube videos show. Here is an example form Ben’s Backwoods.
https://www.bensbackwoods.com/
Ben sells many inexpensive portable wood-burning stove and heating products. And from Far North Bushcraft and Survival.
https://www.youtube.com/watch?v=-jReTCLf6uk
This is not complicated. Get prepared folks.

SHTF Emergency Preparedness How to Heat Small Buildings with a Portable Woodstove
https://www.youtube.com/watch?v=rvG4fe4o77U
How to set up a portable wood stove to meet your Shelter, Fire and Water needs in a grid down situation. These ideas on set up can be used in a emergency to heat many different types of shelter.

[Howard Boldt]

You can run a small electric heater off a big car battery, or similar sized other type of battery, for maybe an hour. Maybe. The battery will then be dead and useless, so no more heat can come out of it. Heating takes a lot of energy. Batteries are depleted very fast by it. This is why I say posts about batteries and methods of charging them belong in off grid power discussions, not in heating discussions.

KM said:

Think in the short -term it will prove to be useful and over time will or can be adapted as needed - We are attempting to help people from all over the world with differing circumstances and weather.

Howard Boldt said:

Thanks guys, but since of this thread is mainly about improvised wood stoves, I feel like your posts would be better placed in other discussions. Heating by battery power is usually not an adequate solution. The exception may be for 1) less severe cold weather 2) a small space 3) a larger battery bank 4) reliable ways to continually recharge them. Even so, battery power topics, etc, are probably better placed in an off-grid power discussion.

[Howard Boldt]

I'm getting information now which tells me that heating galvanized metal significantly gives off toxic fumes. Typical air ducting in buildings is made of galvanized steel. I don't know how much one should be concerned about such fumes from an improvised wood stove, but to minimize the possibility, you can initially fire the wood stove outside, along with those chimney pipes that will be inside of the house. Build a big, hot fire in it and let it bake for a while. Then it will be safer to use indoors. One source says this is adequate. However, if you don't have time for this, perhaps just venting the room for a while will do. If choosing between freezing and fumes, compromises might have to be made. I welcome further research and comments on this.

[Howard Boldt]

After looking at a video about tent wood stoves, I think I know more about putting stove pipes (chimneys) through holes. 1) It may not be necessary to close the window space around the chimney completely. Gaps between the chimney pipe and whatever is closing off the rest of the window space might be okay or even desirable. Depending, of course, on how big the gaps are, how much fresh air you want coming in, how cold it is outside and what direction the wind is from. Of course, if it is -30 outside, you will want smaller gaps and may need to stuff the cracks. 2) It may not be necessary to use metal to close off the window area immediately around the pipe, but obviously you can't do it with anything too flammable, as the pipe will throw. Plywood or other wood wrapped in aluminum foil might do. Thumb tacks could hold the foil onto the wood. I would likely keep the gaps to an inch or two, and stuff with fiberglass insulation.  

[Howard Boldt]

A few more thoughts. 1) Anything you can do through a window opening, you can of course do through a wall. 2) A good material to wrap around a stove pipe going through a window or wall to plug the cracks, if there are too many of them, is "welder's blanket", a fabric which will not burn. Look for it where you can buy welding supplies. 3) In some cases, you may be able to make the chimney (stove pipe) as just one straight pipe, going out and up at an angle. However, again, it's best to make the top of it horizontal, so that wind from the wrong direction doesn't push smoke back down the pipe.