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More advanced beekeeping discussion forum.
 #1763  by Chrisbarlow
 26 Jan 2019, 18:11
A post I found on facebook courtesy of Derek Mitchell.

Thermal efficiency extends distance and variety for honeybee foragers: analysis of the energetics of nectar collection and desiccation by Apis mellifera

https://royalsocietypublishing.org/doi/10.1098/rsif.2018.0879
 #1766  by Jim Norfolk
 26 Jan 2019, 21:57
In English I think that means that less energy is needed by the bees to evaporate honey in insulated hives so more honey is produced. Sounds like more closed feed holes and crown board insulation needed even in summer, which must seem counter intuitive to most beekeepers. I believe Derek is doing a PhD on this hence the need for all the high powered maths. His work on winter insulation of beehives was inspirational and ground breaking. The good thing is he is also able to present his conclusions to us ordinary beekeepers who lack the mathematical background.
 #1768  by NigelP
 27 Jan 2019, 09:29
Poly hives in summer can be a two edged sword. It's far to easy for large colonies to overheat as heat cannot escape easily. So they spend lots of energy wafting hot humid air downwards through open mesh floor. It's why I like the Abelo hives with their removable ventilation blocks. I had mine open in the supers last summer to help with cooling.

I learnt the hard way how much heat is retained in poly hives in summer when I was moving some bees up to the moors. I blocked the entrances to the hives I was moving (all open mesh floors) around midnight , but inadvertently left a varroa board in one of the Paynes hives. At 6AM in the morning honey was dribbling out of the hive, the combs had collapsed and the bees were fried. Not one of my greatest moments.
Derek talks a very complicated mathematical heat exchange theory but his practically of actual beekeeping is not great..
 #1773  by Chrisbarlow
 27 Jan 2019, 11:05
Jim Norfolk wrote:
27 Jan 2019, 11:01
Nigel why not try putting some matchsticks under the crownboard to increase air flow! :roll:
That comment cracked me up
 #1776  by NigelP
 27 Jan 2019, 13:07
AdamD wrote:
27 Jan 2019, 10:31
Ahh, but did it help though? Or did you just think you helped. :lol: :?: ;)
All I can say is the Paynes hives (no removable blocks) sounded like air conditioning units on steroids after dark...The "ventilated" hives merely hummed.
Matchsticks...now where have I come across that idea before ;)
Possibly not a bad compromise for hot summers...but for the winter a big NO NO.
 #1871  by MickBBKA
 06 Feb 2019, 01:53
Last year was my first time with some poly hives. I was amazed to see the bees fanning the entrance when my wooden hives were not. I did think the poly would provide insulation against the sun, but maybe the ambient air temp was too high. The roof of the Abelo poly hive has no vents so I placed some spacers under the roof and removed some of the ventilation blocks to give them some help. Well believe it or not the bees completely propilised the grills and carried on fanning the entrance. I guess they really do hate the chimney effect !
Cheers, Mick.
 #1909  by Chrisbarlow
 11 Feb 2019, 20:50
I wonder if the fanning was to evaporate of water from the nectar and not to cool the hive ie change moisture laden air for dry air. So the bees want the hive hot and humid and adding extra ventilation went against there plans.