My quest will never be over :).
Owens is a great temperature study focused on 3 scenarios (Great "What" study). There are tons of measure points (but nothing on humidity), many great observations and very good summary. The part on observations around entrances is lack luster (what is a few days, what temperature was it outside, what was the packing R-Value, was there a settling period between the changes, etc...). Basic learnings, in Wisconsin (44K CDH8) bees can survive with and without insulation, bee mortality is worse in check hives (no insulation) at very cold temp, heating hives adds no benefits is detrimental, smaller clusters are less able to move around, solar radiation affects the movement of the cluster, type of entrance not really studied in depth. (No health measures other than similar in size, not sure if hives were weighed regularly during the study). Either way, I enjoyed reading it but we have new realities (varroa+viruses, Nosema C) that were not present at the time.
10 frames of honey equals close 90 lbs which is equivalent to 2MW of thermal mass energy (@20C), and is about 144 kW-h of food energy. A cluster(4.95kg or 45,000 bees) producing a constant 15W heat energy would need 65 kW-h of food energy for a 180 day winter. That would be about 40lbs of honey consumption. Now let's throw in Nosema C infection - what will be the impact? Let's add a top entrance. what's the impact? Let's reduce the hive enclosure volume to bee ratio, what's the impact? Let's make it a really wet and humid winter? This is the type of info I am looking for or trying to determine. Probably why I like the behavioural model studies better. They try to understand the why... I attached my "Bee Math" summary sheet from last winter. It assumed the cluster was spherical based on the studies I had read. Now, I know from my own observations in my location/hive enclosure, it is more of a hemisphere, it will change things a bit. The single estimate heat output is 8.33W (my educated guess last year), my calculation this year based on my monitoring puts it at about the same. With my data I will be able to develop a relationship between R-Value, cluster size and external climate. I think I have just about figured a way to get a good estimate for heat loss off the bottom of the cluster.
Bee biological behavioural drivers and their use either through evolutionary adaptations (survived because they do it) or they have learnt to do it on purpose to survive. This is what drives everything I do in beekeeping. ("WHY")
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