Like a hollow tree. Let the bees do it. I think ventilating is the most over rated thing in beekeeping today.
A 3/4 inch hole near the top on the front of the hive body is all they need in this area. It also works as a top entrance if the bottom gets covered. They can reduce or block it with propolis if they see the need.
I think ventilating is the most over rated thing in beekeeping today.
it does represent a real problem here and almost every year. for almost every box on a hive with 10 frames the consequence of poor ventilation is quite obvious.... typically 1 to 2 frames at least partially melted down.
ventilation at the top of the stack here is unnecessary during the winter time. during the coldest months I close mine off (see below description) with a bit of cloth or duct tape.
I use modified migratory covers. modified in that they have a thin rim built on the bottom side of the migratory cover to lift the cover slightly (1/4" or so). on one end I leave a 1' to 1 &1/2" gap in this built up rim. the extra space and air gap at the top of the stack seems to allow for much more positive ventilation. if I didn't have the time or inclination to modify my top covers I would use building shims which are commonly available in building supply stores. I would use two of these to produce a small crack at the top the the stack. I commonly use building shims with queen excluders during the honey collection season (although their placement is much lower in the stack).