Introducing myself

Hi everyone. I live in California and my house has solar to generate hot water in the summer and wood stove for hot water in the winter.
I am preparing to make a pocket rocket stove to heat the water in my hot tub.
My plan is to make a pocket rocket stove from a 30 gal steal drum, and set that inside a 55 gal drum. Space between the drums will be the water to be heated.
I like the clean burning pocket rocket stove design, but must confess I have no idea how much wood, or how long it will take to heat the roughly 300 gal hot tub water to 102 to 104 degrees.
Does anyone have experience with this type of setup?

if you are going the way of rocket burner id consider making a system that creates as much heat as possible

ppottys has a good range of heat and so does greenenergyexperimenter

theres also a few other system that can produce hot enough for water heating with water the more heat is required to get it to optimum temperature

I've never built a pocket rocket stove, but I can see its appeal thanks to the simplicity of design and construction. If the setup that you propose will work to warm up water efficiently, I do not know, that is something you will have to build and make some experimentation. Of course if you do not post pictures/videos of this construction and stove use, it never happened...

You have to take into consideration that water has a high thermal mass and it will absorb a lot of heat from the pocket rocket stove combustion chamber, rendering combustion less efficient, you will have to use more wood to reach the same temperature and it will produce more smoke.

I suggest you make the pocket rocket stove as a first trial to learn how to warm up water with wood stoves and as you get more experienced on the issue you can try other stove designs.