Wood H2O heater?

[1stmate]

Anyone have any experience with heating (domestic) water with wood & not blowing themselves up into the next time zone?
These fuel prices are making me nutz...

[Deberosa]

We got a chofu heater for a wood fired hot tub but now that I see how it works, it is a really simple way to heat a body of water with wood.

The system consists of a fire box which is really like a barrel inside a barrel with the outside layer filled with water. Two hoses go to the tub of water - and it's the slope of the bottom hose that is important, the top one can be any where higher. That setup causes the water to naturally circulate - in the bottom hose and out the top. It gets very hot! We have to watch and often run cold water in to cool it down. It wouldn't take much to use it to heat water for the house.

[Vidman]

I would love to have a woodfired hot water heater. We own two small portable sawmills and have a 24 hour scrap fire buring 6 days a week.

[wy0mn]

I'm gonna call tomorrow to see if my woodstove is in stock, if it is I'll be Cheyenne bound!
For my small Ranch application I figured I'd just wrap a few coils of copper tubing around the stovepipe & gravity feed it.

[kbabin]

I found these links....

http://www.woodheat.org/dhw/dhw.htm

http://www.lehmans.com/jump.jsp?itemType=PRODUCT&itemID=4053

http://www.motherearthnews.com/Green-Homes/1984-01-01/A-Woodstove-Water-Heating-Attachment.aspx

Kev

[wy0mn]

Thanks
Good info on the creosote, OK, so stealing heat from the stovepipe is a really bad idea.
Time to develope 'plan B'... whatever that may be in my case. Probably just a cast iron kettle & a nifty wash basin.

[HockeyFan]

Thanks for posting the links.

[wildwood]

Well we have used this system for over 10 years with very little problems. We have combined it with a solar system for the summer. We lived in our shop and had a system there and just refined it some for our house. It has been on line for over a year and the only problem we have is too much hot water! We are acturally looking at running it through a radiator set up for a back room when we have too much.
Here are the basics
It is a thermosiphon system. To make it work your holding tank must be at the top of the system. Ours is in the loft eve above our upstairs shower. Now there are two ways to go here, presurized or not. Our shop system was a tank with hinged lid. (we used a tank float to control the water level). we never had to worry about anything blowing up. The house system is closed and we have a high pressure release valve that vents to the top of the shower. this has released twice on us as the water has gotten too hot. When it does we just run some hot water and the cold water filling it back in quickly dilutes the overheated water and the problem is solved.
now here is how it works. We ran coils inside the back of our wood stove. It is an old earth stove that was already set up for this, coils and all! The water runs from the bottem of the holdiing tank up in the eve, into the bottem of the coils, it heats up and then is literally flushed up into the top of the holding tank. This continues to circulate all on its own.
In the spring and fall when our wood stove is shut down and our solar is not yet up due to freezing nights. We light a fire and usually have hot bath and dish water within 3 hours.
We have added a few little touches to make it more effecient such as a cordless BBQ tempurature probe so we can check the water temp. (our shop one was were we could go up and lift the lid and stick our finger in it.) Pretty simple. We also have a shut off valve on the cold water inlet to the holding tank. This way if there are several showers to be had in a short amount of time. We shut this off and use the available hot water and then turn the cold back on and let it dilute down the tank and start heating again. The only draw back on this is you can't let the holding tank run dry or you could create steam and blow up a line. There are just 2 of us so we usually don't have a problem. Hope this helps