Bell Efficiency - Tall vs short

[gerry]

Wondering that if 2 bells have the same isa, are made out of the same material and the same amount of heat is put into both of them, which one would be more efficient at extracting more heat, a tall tower bell or a short bench bell?
Of course, the roof will be the hottest part of both bells and that the short bench bell has more surface area in its roof than the tower bell but it lacks the depth the tower bell has allowing more stratification to occur.
So if a person doesn't have a lot of floor space to build a bell, the tower bell makes the most sense, but if less efficient, than how much taller, or more tower bells would be required to equal the same efficiency as the bench bell?

[Solomon]

I'm just about to start building mine. Just to start out (no marriage to the design) because CFB risers come in 2 foot lengths, my barrel/bell is going to be a full two barrels, so six feet tall.

Then the bench is going to be another two to three barrels split in half.

I'm no expert so take this for what it's worth, it seems to me the ISA is the important factor. "Efficiency" can be directly measured by exhaust gas temperature. Any number of systems with identical exhaust gas composition are identically efficient. Peter van den Berg's work on ISA seems to indicate to me that they are the same with the same ISA.

With a taller bell, I would think you could fit more ISA in the area because you neglect the floor in the calculation. However, you're going to get more heat in the top of a taller bell meaning heat distribution is up high, which I would think is less effective delivery.