Think about it. You mentioned an important clue in your own hive. I think I posed the question to you before. If you, sealed airtight, added insulation, could you,.......push, the condensation, down the walls ? In other words, can you see how the heat of cluster would keep upper levels of cluster dry, in static atmosphere ? Water, condensing on walls, tells they are cold enough for vapor to condense, to cold. Solution is insulation not ventilation. IMHO