my pizza oven / pool heater build

[kor]

thank u for the fast answer

Considering I only need the heat to transfer into the water of the boiler I still find it an option (I only need the water heating part of this build). and of course I need to protect the wall from the outside elements. (and make it look nicer)

I can add extra mass to store extra heat on the inside of the isolating ytong wall.

but I guess I have to protect the inside wall also so it will not absorb to much humidity from the inside of to ?

The core and riser will of course be in chamote fire brick.

the thing is I don't know how hot it will become on the inside and if the ytong will hold up to that heat. I understand it is important to cover the in and outside of the ytong. would ordinary cement hold up to that task ? or do i need fireproof on that exterior wall?

ps I'm also living in belgium

[satamax]

Kor, you don't risk anything, as long as the Ytong doesn't touch the core. If the water takes the bulk of the heat, your bell shouldn't reach much over 100C° And if the water does, you're in trouble.

[bricoleur]

Dear Tom,

Very nice work.
May you post feedback with some months of usage ? is it still good ? anything you would change or recommand to whom would like to build one ?

Thanks,
Ben

[garethd]

I loved this, what a cool idea.
Its been a couple of years in use now, have you noticed any issues that would make you try a different design?
I am trying to design a rocket stove to heat my 10000litre pool, and, not needing a pizza oven, was planning to replace the 55gallon steel barrel bell on a standard rocket stove with a stainless pipe coiled to form a bee skep, then cob over the top to seal before insulating with loft insulation.

I'm intreagued by your design. I think I understand correctly that the exhaust gas travels around the cylinder which acts as a giant heat exchanger. What is the surface area of the cylinder approximately? In my idea the water will simply travel from pool through the steel pipe coil on the inside of the bell and then back to pool so knowing the heat transfer area you have would be a very useful comparison.

Does anyone have any views as to this idea? I was planning to pump the water as I don't think 32mm will be anything like enough to set up an efficient thermosiphon.