Here is the reason I don't worry about moisture in a well populated
condensing hive (Insulation and no top ventilation).

See charts attached:

at -40C and below Bee metabolic moisture accounts for ~100% of moisture
needs.
at -20C 93% of H20 needs
at -10C 84% ""
at 0C ~60%  ""
(Outside RH is near 90% all winter at whatever temperatures)
(Inside RH is from 65 to 80% (ABS H 10 to 15 g/m3 (no brood) and 30g/m3
(with brood)  depending on the hive type (Lysons are typically more
humid than the Paradise Bee Boxes) and some bees seem to like RH lower.
(M2 T is the center warmest sensor typically near center of cluster)

I typically have sensors along the side walls which does show occasional
condensation events (heating) but at warm DP temperatures during extreme
cold which is may be a way of recycling water and allowing outside bees to
rehydrate. During average winter temperatures, the T M2 (center) dew point
aligns pretty close to the 10-13C which aligns with mantle temperatures. Or
it will likely get condensed out via those vent channels that I see. This
aligns with the reason I go with 9 frames and use 3/4" pine board inserts
on the outside facing cold wall. The shared side wall I leave as is.

My observation prior to doing it this way was very high bee mortality and
mold along the cold side wall when I did my 1st spring inspection.

I would love to see others replicate some of these measurements under
different conditions, locations and setups.

I have also been dabbling with VPD (Vapour pressure deficit)
"VPD is the difference between the amount of moisture in the air and how
much moisture the air could potentially hold when it's saturated. It's
often measured in pounds per square inch (psi) or kilopascal (kPa). A high
VPD (greater than 1.0 kPa) means that the air can still hold a large amount
of water." For plants 0.4 is too low and 1.6 is too high... for insects?

I added a Winter RH - ABS H file in the shared folder.

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