Comment by adrianN
9 hours ago
Thermal storage benefits from the square/cube scaling, so the amount of insulation goes down as you scale up the storage.
9 hours ago
Thermal storage benefits from the square/cube scaling, so the amount of insulation goes down as you scale up the storage.
Even better than that: the thermal time constant is proportional to the square of the radius. There's the square/cube effect that causes a factor of r ratio in the volume to surface area, but there's also a factor of r from the temperature gradient (which, from the center of the pile to the surface, is inversely proportional to r).