Heating water with a rocket stove.

I have taken a stainless steel coil and put it in a pan in my rocket stove, so I have created a heat exchanger. I have found that this out put water comes out at a temp that would be a little too warm for a shower, but if I added another pump I should be able to add some cold water to this and have an on demand hot shower powered by my rocket stove.



So, far I have pump in cold tank  ->

Coil inside pot on Rocket stove ->

->  returns to cold water tank.

No pressure, radiator hose.

This is a prototype...  

So Mart ; When are you firing it up? OR When is the big explosion???
No , Sorry Mart couldn't help myself!
Nothing wrong with your idea.  Are the heater hoses 3/4" ?

When are you going to try it?

thomas rubino wrote:So Mart ; When are you firing it up? OR When is the big explosion???
No , Sorry Mart couldn't help myself!
Nothing wrong with your idea.  Are the heater hoses 3/4" ?

When are you going to try it?

Boom Squish...


I have tried it,  water is too hot to shower with directly....  I guess for right now I could put the water to a 5 gal bucket and mix it with cold water till it is the right temp....    


The other idea I had was to have two pumps and then mix the water for hot / cold with valves.


Or I use a 5 gal bucket and recirculate the water until it hits the right temp.


I have done this with a bread machine coil heating water with solar panels,   the easiest is to heat water to just over then add cold to just the right mixture in the barrel.



Using the 5 gal bucket I have heated the water before, and just brought the water inside and used a camping shower to dispense the water in my home shower....

I do have a tent I got to shower in, but you have to tie it down if there is wind...

Using this setup I did a test run today..

I took water 4 gallons at 60 degrees and took it to 116 degrees in a 5 gallon bucket in 33 minutes.


It is at this point I could take the 4 gallons inside and have a decent shower with 4 gallons of water.    The other idea is I could take it to 180 degrees take it in pour half into another 5 gal bucket then mix with cold water to get the right temp.     I am not sure what the highest I could go with my 5 gallon bucket but 33 minutes to a hot shower  from the time I light the fire is a good deal for me.


Mart

What pump are you using at the end of that hose? As the water begins heating at the pump depth in the barrel, does the pump get to hot and shut down? I would like to do something similar and then pump the warm water into a heat exchanger and then use the transferred heat in a hydronic heating system in my basement floor.

David Matt wrote:What pump are you using at the end of that hose? As the water begins heating at the pump depth in the barrel, does the pump get to hot and shut down? I would like to do something similar and then pump the warm water into a heat exchanger and then use the transferred heat in a hydronic heating system in my basement floor.

Small 12 volt pump I got off ebay.    

Since I was only heating water for a shower I am there watching the process I stopped it before It got too hot for a shower....  about 115 deg F.


Since the pump is in the cold water it never see high temps the high temps come in from the return pipe for that I use radiator hose.

More experimenting with this rig.     Thanks to another forum member here they mentioned the real power of the rocket stove is to force hot gasses pass something you want to heat.     with that in mind, I added an air duct tube 8 inch to the top of this setup to draw more air,   I used a 8 inch pipe.

The results Floored me.     I was able to boil 2 1/2 gal of water in 18 min.

The extra draw of the chimney effect was very impressive,   I  want to try this experiment again using multiple chimneys as my setup has room for them....

This is starting to make me want to build my own custom heat exchange...      Or,  I need to increase the power of the motor that is circulating the water in my tank....  

18 min to boil 2 1/2 gal is some serious BTU's being harvested.

I did some calculations, and I am getting 2,000 watt equiv    of energy input into this system.


https://bloglocation.com/art/water-heating-calculator-for-time-energy-power

This is great information.  Thank you for sharing.  In the next week or two I want to make a small water heater to warm the pool water.  We have had a few days of 70 degrees so the kids are asking about the pool.  I was thinking about pumping pool water through metal tubing inside the chimney but I have metal barrels so maybe I will work out something with the barrel over the chimney.  Maybe have the chimney enter the bottom of the barrel on the left side and offset the hole in the top to the right side, and running tubing in the barrel around the wall of the barrel.
I don't know yet, but I like the idea.

Paul released a video with some more information about rocket water heaters from Tim Barker's instruction at the 2017 Appropriate Technologies Course.  It's pretty informative.


ATC: Rocket Water Heater