Upper temp of a single all brick/stone bell?

On a single bell (no bench or anything) but sized exactly to suggested specs for 7" system size,  what can the upper part of the bell get to in temp.  Running with two loads per day on the coldest below zero days.

I am getting within 12" from ceiling  (raised stove and bell for easier loading) Just want to make sure it won't be over 451 F

thanks in advance.

By the way, my top 13.5"  are fire brick,  and very top flat roof the same, 2.5" thick  on T bars, all  covered with Granite sheet,  1.4" thick facade. (lots of mass)

 I think you are to close.  I would add another 2.5" of brick.  Remember the top of the bell will be the hottest spot on the unit.

Try this:   https://www.borstengineeringconstruction.com/Masonry_Heater_Performance_Calculator.html

Tom

Thomas Michael wrote:  I think you are to close.  I would add another 2.5" of brick.  Remember the top of the bell will be the hottest spot on the unit.

Try this:   https://www.borstengineeringconstruction.com/Masonry_Heater_Performance_Calculator.html

Tom

That is all fine, but I built a RMH, not a Masonry heater. Two different concepts.

I was just hoping there was someone who built a RMH with a single brick bell, that might have recorded the temps.  When the time comes, I will report mine.

cheers

Rocket mass heaters are a subset of masonry heaters. There are different configurations of masonry heaters, but if you find info on ones with bells, they should be comparable.