Bell question...

Merry Xmas everyone  

I'm building a 6.5" batch box rocket water boiler and I wonder if the recommended bell size of ~65 square feet still applies when insulating the bell to transfer as much heat as possible into a water tank located inside the bell?

Thanks!
Henric  

Hi Henric;
I would say that if you are insulating for heat retention in your water tank.
You can disregard the ISA size and make your bell whatever size you need it to be.