f5025c66_ermaculture_Research_Institute__Applied_in_our_stove_
[0] 7 [Principle] The opening into the fire, the size of the spaces within the stove through which hot air flows, and the chimney should all be about the same size. This is called maintaining constant XSA. [Applied in our stove?] 
Yes
N o
Y e s
C o u l d b e b e t t e r
Working With Principles for Creating More Efficient Cooking Stoves (Ethiopia) - The Permaculture Research Institute
Applied in our stove?