water wood heater

[The Breeze]

ya i was thinking about a old propane tank as the fire box but you can't find steel laying around like you use to everybody is broke and selling it.

[spotsineyes]

Get ready for some explosions! How are you going to have a blazing-hot fire without turning the water to steam? If your house gets up to 100 degrees, you're going to have to do something. If you shut down the water flow with a big fire, boom goes the boiler! If you bypass the flow to the house and keep it circulating through the boiler, it will just take longer before it explodes.
The DEB design website says their plans use a thermostatically controlled water jacket temperature, and until you fully understand how they do this, you are taking you and your family lives into your own hands.
Boilers are dangerous however they are fueled. Natural gas-fired boilers have several safety controls to kill the fire in event the pressure gets too high, or the temperature gets too high, or if the water level gets too low, or if the water quits flowing.
What kind of safety control is there that can shut off a wood fire fast enough to prevent disaster?
I'm sure there is something because of all of the wood-fired boilers that have lately become available to the consumer, but until you are familiar with them, you are playing a risky game.
Just for example, did anybody see the episode of Mythbusters when they blew up a water heater? All they did was to plug the releif valve and jumper the thermostat. With the electric heaters that the factory put in the tank, the explosion was enough to cause the heater to go through the roof of the model house that they built, and way up into the sky.

[Jeepnford]

The household water furnaces are not pressurized. They have a vent tube out the top of the tank for relief. Most of them have a temp sensor on the side of tank and are used to control a draft blower for the fire.

[shortarc]

I'll give a little clarification on my post with the heater pictures.

When they install this type of heater for the greenhouse the discharge pipe comes out of the top of the heater and up to an open expansion chamber, such as an open ended 55 gal drum. this way there is no way any pressure can build up. No steam just hot water. It circulates on it's own, hot goes up cool comes down, no pumps involved.

I DON'T cut the propane tanks they have them cut were they buy them.

Merry Christmas to everyone.

[fun4now]

i had no intention of pressurizing it. not heating with steam, just hot water. worst case is it leaks water all over the house and the house heater kicks in to keep us warm. in the morning i just have a wet floor to deal with. no boom option.

shortarc
It circulates on it's own, hot goes up cool comes down, no pumps involved.


i was planing to use a pump for circulation, how did you make it un-needed ??
can you elaborate ?? would be nice to take the pump out of the system.

[shortarc]

i had no intention of pressurizing it. not heating with steam, just hot water. worst case is it leaks water all over the house and the house heater kicks in to keep us warm. in the morning i just have a wet floor to deal with. no boom option.

shortarc
It circulates on it's own, hot goes up cool comes down, no pumps involved.


i was planing to use a pump for circulation, how did you make it un-needed ??
can you elaborate ?? would be nice to take the pump out of the system.

On the ones I build for them they have a pipe coming out of the top of the tank, it goes up maybe 5 feet with an elbow then runs the length of the building (greenhouse) then it drops to the floor into a manifold that runs to about 5 or 6 pipes that run the length of the house to a manifold on the other end which it turn feeds back into the bottom of the tank.

The way I understand it as it heats up it comes out of the top and cools during the circulation and re enters at the bottom. Seems to work well.

From what I've been told some of the first John Deere tractors worked the same way with no water pump. That was a little before my time I guess.

[shortarc]

These are pictures of a bigger one I made last year, shows the plumbing a little better.

The valve was inoperable and only used for the flange connecting point and was installed vertical.

[spotsineyes]

The household water furnaces are not pressurized. They have a vent tube out the top of the tank for relief. Most of them have a temp sensor on the side of tank and are used to control a draft blower for the fire.

Oh. Never mind.

[jackel440]

I too have been looking into designing ,and building my own outdoor wood boiler.There is a lot of info on the hearth.com website.I have got lots of ideas for system design there.
I would like to build some sort of Gassification style boiler if i could get all the details on one.They burn much more efficiantly and use less wood.Since i am layed off now would be the time to start on one,but i have no cash for the materials
Keep us informed of what you do as i know i would be interested in your experiance.

[tigman 27]

built one last summer. 36 inch pipe 48 inhes long. box 4x4x5 ft long to hold water. approx 475 gals. 12inch pipe 36 inches long for expansion tank. this is connected to bottom piece by 3 nch pipe. air tight with blower unit on back. 2 two inch combustion air lines inserted near bottom. 1" return with diffuse on bot corner and 1" supply on top opposite. pump runs continous through coil in warm air furnace. furnace only runs when calls for heat. stove is airtight and combustion blower only runs when water is under 160. vent out top of 12" prevents pressure build.12 to 18 hour fill time for wood. works great have to make another. also built hot air model