The more I read this forum the more it seems like moisture/ventilation is the TBH biggest problem.
In the building industry we divide climates into hot, cold and mixed and into dry or humid. (I live in the worst case scenario of mixed humid which gives me plenty of business). It seems to me that in any dry climate, hot or cold, it would be hard to go too far wrong. Bees cool themselves through evaporation, which works great in a dry climate, and cluster for warmth without the risk of condensation.
In a hot humid climate insulation would be pointless and you could not have too much ventilation. The classic jungle hut without any walls comes to mind. and now that I think about it jungle bees nest on open branches, so ...
The really tough situation is the cold or mixed humid climates. Evaporation has limited effectiveness and condensation is constant, and probably unavoidable, all winter.
In those climates the TBH has two disadvantages. Being shallow the bees are usually clustered near the top where condensation occurs and being wide the bees are less protected from drafts. (roughly equivalent to trying to stay warm by wearing damp clothes and taking shelter from the wind in a football stadium).
I'm trying to work out a better THB design for the cold/mixed humid situation. I'm playing with the idea of a sloped roof to encourage the condensation to run to the sides or maybe using some sort of absorbent layer above the bars that could dry to the exterior like attics in our houses. I'm also wondering how to eliminate drafts without restricting ventilation.
Comments? Suggestions? Ideas? I'm new at this so don't hesitate to point out that I'm a knucklehead. I'm also an avid wood worker so I probably tend towards overly complicated because its an excuse to cut wood, but any help/wisdom would be appreciated.