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Author Topic: More on Nucs and ventilation ...  (Read 3646 times)

Offline little john

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More on Nucs and ventilation ...
« on: November 12, 2015, 06:01:07 am »

I produced more nucs this year than I had boxes for (does that sound familiar ?), and until a couple of weeks ago 8 of them were still living in mating boxes - which I'd made from 10mm plywood and without ventilation, and so are not really suitable for overwintering.

But - earlier this year I'd started to make a Long Hive, divided into 4 x 5-frame Nucs for over-wintering, and - although I'm not entirely 'sold' on this idea - "any port in a storm".  And so I decided to finish building it and, as I'd already cut wood for a second 'Quad-Nuc Long Hive', I've near enough finished building a second one so that all 8 Nucs can now have a better chance of surviving.

BTW - if anyone needs to see what a plywood nuc box looks like without any ventilation - here's an example:



Every one I've opened looks just like this: wet, damp and mouldy. Now this might well be similar to conditions within the mythical 'ideal' tree nest cavity - i.e. those conducive to the rotting of the tree's heartwood - but I noticed that upon opening these, that in each case the comb adjacent to the wettest and mouldiest wall of the box had been left unused, which suggests to me that bees don't actually like such conditions very much, and that perhaps they have survived for millenia despite living in tree nests, and not because of them.

But whatever the truth of that, I've now installed 3 small colonies into the following box, downsizing them from 6 to 5-frames in the process. Each 5-frame compartment has an OMF approximately 25% of the floor area, and there is 3"+ of polystyrene insulation on top of the crown boards (inner covers).



So at least now they have a better chance of survival. But - time will tell.

LJ
A Heretics Guide to Beekeeping - http://heretics-guide.atwebpages.com

Offline Dabbler

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Re: More on Nucs and ventilation ...
« Reply #1 on: November 12, 2015, 08:33:04 am »
Nice looking hive ! (. . . the new one that is  :happy:)

OMF ?
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Offline little john

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Re: More on Nucs and ventilation ...
« Reply #2 on: November 12, 2015, 08:54:41 am »
Yes - the nuc box is a bit grim ... but then, bees do survive (somehow) amongst rotting wood.

OMF ? Open Mesh Floor - here's a shot of the 2nd box taken during construction:



These OMF's are a little bigger than the first, at around 30% of floor area. The only reason for the increase in size is that these are a little easier to make: 1" holes (hole saw) made at the corners, and a small (worn-out) zip disk used to join 'em up.

LJ
A Heretics Guide to Beekeeping - http://heretics-guide.atwebpages.com

Offline derekm

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Re: More on Nucs and ventilation ...
« Reply #3 on: November 12, 2015, 12:51:36 pm »
Look at this. it shows that bees are significantly warmer in trees without top ventilation.
http://link.springer.com/article/10.1007%2Fs00484-015-1057-z

Ratios of colony mass to thermal conductance of tree and man-made nest enclosures of Apis mellifera: implications for survival, clustering, humidity regulation and Varroa destructor.

Abstract

In the absence of human intervention, the honeybee (Apis mellifera L.) usually constructs its nest in a tree within a tall, narrow, thick-walled cavity high above the ground (the enclosure); however, most research and apiculture is conducted in the thin-walled, squat wooden enclosures we know as hives. This experimental research, using various hives and thermal models of trees, has found that the heat transfer rate is approximately four to seven times greater in the hives in common use, compared to a typical tree enclosure in winter configuration. This gives a ratio of colony mass to lumped enclosure thermal conductance (MCR) of less than 0.8 kgW-1 K for wooden hives and greater than 5 kgW-1 K for tree enclosures. This result for tree enclosures implies higher levels of humidity in the nest, increased survival of smaller colonies and lower Varroa destructor breeding success. Many honeybee behaviours previously thought to be intrinsic may only be a coping mechanism for human intervention; for example, at an MCR of above 2 kgW-1 K, clustering in a tree enclosure may be an optional, rare, heat conservation behaviour for established colonies, rather than the compulsory, frequent, life-saving behaviour that is in the hives in common use. The implied improved survival in hives with thermal properties of tree nests may help to solve some of the problems honeybees are currently facing in apiculture

If they increased energy bill for your home by a factor of 4.5 would you consider that cruel? If so why are you doing that to your bees?

Offline BeeMaster2

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Re: More on Nucs and ventilation ...
« Reply #4 on: November 12, 2015, 01:04:31 pm »
So basically it is saying that the more insulation we add to the hive the better. Especially for the northern beeks.
Jim
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Offline derekm

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Re: More on Nucs and ventilation ...
« Reply #5 on: November 12, 2015, 01:46:22 pm »
So basically it is saying that the more insulation we add to the hive the better. Especially for the northern beeks.
Jim
No its not as simple as that.
 Its colony mass divided by conductance or in other words colony mass  times insulation that count.. So you can either insulate or increase the size of the colony. They both get to the same point thermally, however you cant keep increasing colony size, as that is difficult and it adds lots condensation, and big colonies will have a higher chance of finding disease. It shows You will need the biggest practical size of colony(4Kg) in a top ventilated wooden langstroth and you might only just get to the same point as smallish (1Kg) colony in an average poly langstroth. or a really small colony 0.5 kg or smaller  in a tree. "
   If your average colony has a problem mid winter and they lose numbers,  what would be "game over" for a wooden hive, might be just a set back for the polyhive or higher level insulated hive.
If they increased energy bill for your home by a factor of 4.5 would you consider that cruel? If so why are you doing that to your bees?

Offline little john

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Re: More on Nucs and ventilation ...
« Reply #6 on: November 13, 2015, 05:13:16 am »
Look at this. it shows that bees are significantly warmer in trees without top ventilation.

But why are you making a reference to top ventilation - when I'm not using any ?

LJ
A Heretics Guide to Beekeeping - http://heretics-guide.atwebpages.com

Offline texanbelchers

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Re: More on Nucs and ventilation ...
« Reply #7 on: November 13, 2015, 02:56:46 pm »
Look at this. it shows that bees are significantly warmer in trees without top ventilation.

But why are you making a reference to top ventilation - when I'm not using any ?

LJ


I can't read more than the linked abstract, but I don't see reference to ventilation in the quoted article or the listed concepts.  In the tree I cut bees out of they had multiple entrances from top to bottom and were using them all.  I've watched numerous videos with bee trees both horizontal and vertical, each with many entrances.  I don't think one can assume that natural bee hives only have a single entrance on the bottom of the hive.

So, separate this into 2 concepts.  Both ventilation and hive wall density are interesting topics and they probably apply to all hives, not just nucs.  Things just seem to happen faster in the small nuc environment.

I suspect that temperature and humidity controllability are factors the scout bees consider for swarm destinations.  It may not be directly volume of the space.  But, I can't read their minds.

From a beekeepers standpoint these issues may play into sizing the right hive space for a given group of bees.  We know they don't perform well if given too much space and may abscond if not given enough space.  In both cases we are generally working with the same basic box.  The ratio of bees to space would probably be different if the hives had a wall value of say R3 or R4 instead of R1.

I really don't want to schlep around heavy boxes made like house walls, so I stick with 3/4" material.  Maybe year round insulation would be a good thing.  I don't know anything about this site, but found it on a quick search on insulated hives. http://www.stewartfarm.org/bees.php