If you can remember all the natural, in the wall and in the tree openings you have seen over the years.
most I have noticed is way smaller than the full width 3/4 opening at the bottom of the hives we use.
Do you think that having a 1/2 inch hole about even with the hand hold, to one side would amount to about the same thing as a piece of pipe? Or is it maybe something in the pipe? Or extend the pipe out from the side surface?
I try to have an entrance hole in one of the supers above the brood chambers.
Think I'll close my bottom entrances up and give another higher up entrance and give some top ventilation. I strip mine down every year and clean the bottom board anyhow.
Going with long hives also. See if I can minimize my lifting. :)doak