The ONLY way to move the water from your pan into a sealed water system is with an injector pump. And the hot water system could not be a closed system because when you inject ANY water into it, that same amount has to be eliminated somehow, usually by allowing it to backfeed into the incoming piping.
The truth is that trying to heat water with wood always ends up being a compromise. There have been many systems that have made the attempt over the years. Most if not all never meet expectations.
Absolutely the safest best way if just have to do it.
Originally Posted by hj
I also have had experience like SolarSteve. I used to live in a remote location where I had to haul water from a well, heat it on my woodstove for a bath.
It brought back good memories!
The problem with this idea is that once the circulator turns off, the water in the fire box coil will turn to steam. Worse yet you could get a water hammer when the pump turns back on.
Originally Posted by alternety
If You really want to go this route, I would suggest using some other method to control the heat flow.
One zany idea would be to Y out the flue and use two flue dampers to control which flew the gasses go out. and then have a coil in one of the flue's.
This would be a waste of money since it would cost more to set up and run.
A simpler option is a water pre-heater. Run the water that goes into the hot water heater threw a coil mounted on the wall near the wood stove. The idea is to heat the water to 80F or so. This reduces the amount of energy needed to heat the water.
Some math (I am using my numbers for reference)
60F incoming water temperature
120F hot water heater temperature
80F water after pre-heater
Usage Savings = ((120 - 80) / (120-60)) = .66 or %33% lower
StandBy savings = 0
Ok, that would be a wast of time as well.
Lets try this again
1. Copper coil $50
2. bronze Recirculating pump $200 + (80 watts * 24/7) = 60Kwh per month = ~$6 per month
3. Something... Something... Something...?