Quick update:

About a month into my study now. Very interesting to see how the cluster moves, contracts and behaves under different temperatures and beekeeper actions (e.g. my final 3 sided shelter was install on Oct 17th around 2pm. I created a macro to help me copy calculated hourly values like heat loss, % of area >15C, misc average Ts, and metabolic rates based on a couple of different internal temperatures. The Southwick metabolic chart clearly fails under insulated hive conditions where the ectothermic heat (resting metabolism) does actually help maintain internal temperatures. It will be interesting to see where the transition occurs and endothermic heat (heater bees within the cluster) is required to maintain the outer mantle layer at 10C. But based on last year's data it seems to work once the cluster truly forms in the polys. Just at much lower ambient temperatures. You will also notice that the heat calculations are based on the heat sharing between hives. The single brood hove so far prefers the center location and the double brood hive (lower box) has been located along the cold side (non shared wall). The upper box on this double show the warm spot to be along the front (south side) which would make a very interesting cluster shape (or is it due to convective heat movement).

I recently installed a few more sensors above my slatted racks and just below. I am hoping to use these values to help me "calculate heat loss" from the lower cluster. I use no top entrance, as you will see in one of the diagrams, my screen bottoms open into a dead air space (similar to a crawl space) to drain excess condensation. My single brood hive center sensor location above the cluster is at 75% RH with with 4 outer corners in the mid 80s%RH but at lower Temperatures. The hive is dry (no condensation) and the cluster looks good with bees from wall to wall at Ts of about -5C.

My heat equation assumes a balance between heat generated and the heat lost. Each square on the temperature heat map is equivalent to 1 square inch so as the internal temperatures shift I can relate it back to cluster location and size. So far the biggest reduction of area below 15C has been 30% (or 0.3 x 187sqin = 56sqin). The 3 sensors above the slatted rack will help me determine volume of the cluster. Unfortunately one of the sensor likely turned off after I installed it as it isn't reporting any data. I'll have to wait for a warm day likely not for a while (currently -28C) to reset it. We just had almost 24" of snow here in the last 2 days. So the bees now have an additional insulating layer. I also have an extension cable coming (lightning cable with both a male & female end) so I can saran wrap my IR camera and insert it below the cluster through the entrance to take pictures of the lower cluster. I also collected my 1st dead bee samples (old summer foragers) to check them for Nosema.

I am going through a bunch of papers Heinrich, Owens, Omholt, Kovac, Randy Os wonderful website to name a few. My goal is to approximate heat loss of the lower cluster (likely radiative) and add it to my heat equation. 

Here are a couple of timelapse video clips of both temperature (hourly snapshots) and RH% values. https://youtu.be/q9CVhGQvw5g (RH%) & https://youtu.be/g3_1Viha4pg (Temperature). My macro now copies the results of each snap to allow me to trend, calculate and compare the data.

Fun stuff!! Feedback always appreciated. 

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