I say some windows in a beekeepers honey house in Canterbury, New Zealand that did away with escapes.
 These had aluminium window frames with two pains overlapping but made like the old sash windows.   The old ones had weights in the wall and when you lifted the bottom window, the top half of the window came down also. Hot air out the top, cooler air in at the bottom.
 
In the honey house when the bees started gathering at the top of the window, he just lifted the bottom up a little (the top came down to the same degree) and they flew out. He closed the window again until a few more built up. No messy windows and no bees in the honey extracting room.
 Frank Lindsay
 
  		 	   		  
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