Hi
I haven't posted anything in a while. I am currently setting up 3 of my hives for another more detailed winter trial. I am setting up a grid sensor array on 2 levels in a double, single level  in a single brood hive and a couple of sensors in a 5 frame nuc. Summer here was tough we only got 2 days over 25C with most of the Ts below 20C. Lots of rain.

Here are some questions that I want to answer. Do the bees actually heat the hive and keep it at ideal metabolic rate temperatures to consume the least amount of honey? This is only possible in an insulated hive due to a much lower heat loss. My results from my winter 2019-20 monitoring points to this conclusion as 90% of the internal temperatures (north corner away from a shared wall with another hive) are between 0C and 11C. From some of the reading I have done (ABJ OCT Frank Linton article) the edge of the cluster is typically at the 7C to 10C isotherm.

The goal of my 2020-21 monitoring will be to get more granular T data on the whole interior of hive (hourly data). I will be able to confirm presence of cluster and its location and confirm my hive heat loss calculations. 

As my bees don't really cluster tightly during winter (not the primary factor in wintering success), and I get similar wintering success between "northern queens" and those from California then the behaviour of managing the internal hive environment (Ts and RH%), to winter stores consumption is critical for my location. Not much for studies on this topic as I have seen very few studies studying internals and most discuss clustering as typical winter behavior. A few people believe clustering is an emergency mechanism which makes sense to me. 

I don't advocate folks go out an insulate their hives but consider the possible benefits under the right conditions. In subarctic climates, R40 covers and R10 to R15 sides seem to reduce my hives winter exposure to something equivalent to say Nebraska (5 times lower intensity). My winters have an intensity of 100K heating degrees (Cluster Degrees Hours) vs about 20K heating degrees in Nebraska.

Where insulation does seem to make a huge difference is after brood rearing commences. Heating needs remain low when hives are insulated. Another point is increased honey production in cooler climates (Derek Mitchell wrote a paper on this). My hives are always insulated so I am unable to confirm but another local beekeeper ran a small trial this summer in 2 different locations to compare honey production on an insulated vs non insulated. Differences were significant but trial and methodology would not pass a scientific rigour test. 

I attached a couple of images so if you don't get them let me know.

             ***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software.  For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html