William Bronson wrote: I would build the biggest batch box you can.
J tubes are less efficient and take more tending.
They also need a longer heat riser to be effective, and just as much insulation.
Most advocates for the J will say it takes less skill to use, but they also recommend building them in a location that is in the center of family life.
William Bronson wrote:I would not build a coil, rather I would use a directly heated tank that was connected to my giant storage tanks.
The steel tank from a gas water heater can be had for free.
I would use this instead of a coil so I could avoid finessing the size /safety factor and to save money.
It would be unpressurized of course.
William Bronson wrote: Wow 275 is huge
No matter how many women are assigned to the project, a pregnancy takes nine months. Much longer than this tiny ad:
rocket mass heater risers: materials and design eBookhttps://permies.com/wiki/188812/rocket-mass-heater-risers-materials