Anybody tired of talking about insulation? How about another much loved subject among bee keepers; ventilation. Surely beeks can reach a common ground on top vs bottom ventilation? Yes? No?
I'd say no ...
My reasoning is that there may be 2 different mechanisms at work. Don't ask me exactly what they are - I just know that 2 conflicting dynamics are involved.
My evidence for saying this ? Observations.
Take clouds for example. They are evidence of suspended moisture, which has become visible by virtue of warm air containing that moisture rising up from sea-level and reaching the coldness of altitude. If that moisture should then become even colder, such as happens when the supporting air is forced to rise up over a mountain range, even more moisture will come out of suspension, and precipitate as rain (or snow if it's REALLY cold).
Ok - so far so good, no surprises there then.
Now lets take another scenario with this warm air containing moisture: when a belt of warm air (with it's suspended moisture) hits a cold front, then fog results, as the moisture comes out of suspension. Same principle, with humid air revealing the moisture it's carrying as a direct result of it suddenly becoming cold.
What we are witnessing are clouds of moisture occurring at high level, and clouds of moisture occurring at low level. One event taking place at high altitude (a dynamic which supports the upper entrance theory), but the other taking place near ground level (a dynamic supporting the bottom entrance theory).
Both events take place in the natural world - what is needed (imo) is for someone knowledgeable about such things to explain the conditions where one occurs and not the other - which may possibly go some way to solving this seemingly never-ending conundrum.
LJ