Really good post there… good read.
The subject of insulation and ventilation always seems to stir up some diverse views. As mentioned above I think it all boils down to hive geographical location and micro climate.
I never experienced condensation in the one hive I had probably due to excess ventilation and low ambient humidity. In my new hives I will only do gradual changes and monitor closely.
Regardless of ventilation, When warm air hits a cold surface, it reaches its dew point and condenses. Or. Warm air has more ability to hold water than cold air so when warm air hits the colder surface the air cools and the water drops out of suspension causing condensation.
Keeping the hive internal surfaces at a temperature above the dew point will mitigate this.A quilt box is really only roof insulation and there are other thinner, lighter materials with better insulating properties.
agreed- if I used a quilt box I woud cover the hole- as the quilt box would have some vents on its sides.
@skeggley also agreed- if the quilt box is actually an insulating quilt- then in theory it will be warmer than the walls of the hive and water will not condense on it much. However I am guessing that moisture will still be absorbed to some degree by the lower levels of the insulation, and around the edges where it is colder- and then transported out of the hive through the vents.
Rusty says that in her hives the boxes stopped moisture issue she had- but noted that the wood chips only became moist on the bottom- the top layer remaining dry:
I think a problem with standard hives with migratory lids with metal covers that are not insulated is that the roof can become very chilled in the night- leading to condensation that drips onto the brood (a hive mat helps to prevent that).
So what is the difference between a Moisture Quilt Box, and a Vivaldi Frame? Are they a variation of the same concept?
I see the Vivaldi Frame as a variation of the quilt box.
I am still sitting on the fence here. And as HillWallaby mentioned, the micro climate of your own locality will ultimately control where, how, what and when insulation is appropriate.
The benefit I see with a quilt box is that it will retain heat. The quilt be it burlap/hessian and/or wood chips will absorb and retain warm moisture and air. The heat is retained. Obviously the heat will filter out eventually, depending how insulated its top is, but it is less energy the bees have to expend.
A well insulated top will cause the air circulation as described in the article above. The hive will expel denser warm air out through the entrance/entrances as it sinks down along the sides. This heat energy has to be reproduced by the bees.
So one solution is not a simple solution for everybody unfortunately.
People use all sorts of stuff to keep the bees dry during the winter. Sometimes it boils down to what you can get your hands on. I use the Vivaldi boards because I was influenced by someone who explained it well on youtube. Plus it stores easily.