[Greenbuilding] stealing heat from a woodstove for water heating

[Topher]

On 12/31/2013 3:40 PM, Reuben Deumling wrote:
> The further from the firebox one chooses to steal the heat the fewer
> + negative repercussions for the combustion process, and
> + BTUs per hr transfer into the water

> My inclination is to have him make the water jacket taller (more 
> surface area), and find a smaller tank (less cold water volume to 
> dilute the heat), but in the absence of some empirical work, or 
> others' experiences, this would be somewhat of a crap shoot .

Sounds like it is time for some calculations, to get you started:

Wood runs around 8000 BTUs per pound.
1 BTU raises 1 pint of water 1 degree F.
Figure out what you want for a flue temperature to ensure no creosote.
It is probably best not to think of 'stealing' heat, but rather as 
burning longer to heat both house and water.

Thank You Kindly,

Corwyn

-- 
Topher Belknap
Green Fret Consulting
Kermit didn't know the half of it...
http://www.GreenFret.com/
topher at greenfret.com