Vince Coppola wrote:
 
>snip>... A few
>years ago a beekeeper named Hoover wrote for Gleanings. He advocated the
>use of eleven frames per broodnest for the above reason. Of course the
>frames were special. I doubt if nine per box results in more ventilaton
>because the bees will just draw the combs thicker.
 
Hi Vince -- Hoover planed down the shoulders on his frames, to get eleven
into a hive body.  According to him, this was ideal, and provided enough
brood space in a single chamber.  He seemed bound and determined to prove
that double brood chambers were not necessary.
 
However, Ormond Aebi (in MASTERING THE ART OF BEEKEEPING) notes that he and
his father thought the idea was great, too, and they also tried it.  It was
an utter failure for them.  Even if it could be workable for a while, after
a couple of seasons it would certainly be a great disadvantage, and a big
time-waster!      I believe what Mr. Hoover did was to space the brood
combs 1.25" instead of 1 3/8", thereby allowing room for one extra comb.  I
read all those articles of his, back in the 70's.  He seemed to come up
with quite a few odd ideas (including supers without frames, hives
disguised as air conditioning units, "preventing" swarming with
entrance-excluders,  etc.).
 
I contend that there IS considerably more ventilation with 9 brood frames.
For one thing, you have extra space at the hive walls, giving the
honey-laden bees easy access right up through at the sides.  The bees will
not draw the combs thicker, if they are brood combs.  There is an optimum
depth to a brood cell.  Honey-combs on the other hand, they will draw out
fatter.
 
At the peak of spring buildup, if you were to pry and tip up the upper
brood chamber, and look up between the brood combs, the difference between
a 9-frame brood chamber and a 10-frame brood chamber would be obvious.  The
one with 9 frames would be clearly less congested.
 
I have never seen brood comb extended out at all, except occasionally in
the upper corners, where new honey had been stored.      . FWIW