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Condensation and varroa! Missing link to survivalists
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Heleen
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Location: Limburg Netherlands

PostPosted: Sun Apr 22, 2012 10:33 pm    Post subject: Reply with quote

Thank you for the reference, Papilion!

Has anyone seen this site? I would love to have any comments on it or futher explaination. The translation out of Russian is bad, probably done by google automatically.

http://www.sama.ru/~yerko/yerko_us/articl_04.htm

It is authentically known, that in a range of temperatures from 30-37,5˚C development of bees is possible during all stage post embryonic development (E.K.Es'kov " Ecology of a melliferous bee " M. 1990.) With the minimal losses. The optimum temperature for development of eggs mite at relative humidity of 60-80 % makes 34˚C ("Beekeeping" 8, 1983, I.A.Akimov, I.V.Piletskaja " About viability of eggs Varroa mite"). And at long influence of temperature 35-36˚C the destruction of eggs mite can achieve 50-95 % depending on relative humidity. The difference of temperatures in 1-2˚C with at the appropriate relative humidity is capable to be a real barrier for mite. But as mite successfully parasitizes on bees it means, that this difference of temperatures is not present. Or, mite has adapted to temperature 35-36˚C, or in broodnest the temperature makes parts 34˚C and relative humidity of 60-80 %. The second circumstance is more plausible, that proves to be true publications. Such microclimate in broodnest parts of a jack keeps, not because the beehive, that is why that at us such a beehive is badly warmed. Existing designs of beehives are adapted to beekeepers, than for bees more. Are guilty as also beekeepers who, press towards to not admit (allow) swarming of bees, unduly expand volume of a beehive. Thus bees probably are not capable to provide optimum a microclimate in beehive.
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Papillon
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PostPosted: Sun Apr 22, 2012 11:15 pm    Post subject: Straw along sides of hive? Reply with quote

Gareth wrote:

This suggests that a perfect hive for Varroa control would be one that allows the bees to maintain as a high a humidity as possible in the brood cells.

So


    Small entrance
    No through ventilation
    No bottom screen
    Old comb if possible (to buffer humidity)
    Small cells??
    Non-porous hive walls??


How about arranging some straw along the sides of the hive? Straw should get some condensation on it if it's hot enough in the hive. And then the bees would find it easy to use the water drops in raising the relative humidity in the brood cells, which if I understand correctly, is what we're trying to achieve? Perhaps this might be worth a try as would be easier than trying to find a propolis-like material that we could apply to the inside of the hive. Just trying to think of natural ways of keeping things simple while still imitating the environment inside a feral colony. Also, with straw, the bees could apply layers of propolis to it with time - is that what they do with skeps? It does seem like it from what I've seen on youtube.
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Che Guebuddha
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PostPosted: Sat Jun 02, 2012 4:23 pm    Post subject: Sunflower/Olive oil as varnish inside the hive body Reply with quote

Hi all,

Im going the route to permanently close the floor and to remove the meshfloor too and let the bees seal any remaining gaps with propolis as they see fit.

I am also going the Bush Route with High Entrances.

The problem with closed floors is the mould I read, so I researched a bit and found a site talking about applying sunflower/olive oil varnish (two coats) inside the hive body especially bottom parts and the the floor.

From the web site;
"Apply two coats of sunflower oil to your new hive bodies (especially the bottom body) and bottom boards as you would apply regular paint. You can use a paintbrush or a small piece of cloth."
Source;
http://www.beebehavior.com/natural_beekeeping.php

What is your opinion on this? Did anyone here try this and what results did you get?

Thank you very much.
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zaunreiter
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PostPosted: Sun Jun 03, 2012 1:51 pm    Post subject: Reply with quote

Me thinks one should see, that a permanent closed bottom is a natural thing, not appropiate for an unnatural cavity as any sort of beehive is. This is because the walls in a natural tree cavity has 15 to 30 cm thick walls. Not in a beehive of any sorts, especially the tree has fresh wood that still is alive! Dead wood is a totally different thing.

Thin walled and with little space a bee hive is not ideal. What I have seen so far, that a closed bottom helps in cold weather but does not in a strong honey flow. So if all beekeeping is local, I open up the floors on warm sunny weather with strong honey flows.
My bees do very well with this sort of adaption.

I have tried top entrances and find them working poor where I live. Do not use them except in strong flows.

So in the end, everyone has to figure self what is working best in your locality. What right in the one locality is absolutely wrong in the other. So try this and that and observe yourself. Do not follow dogmas and keep an open mind. (And eyes.) Adapt!

Bernhard
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biobee
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PostPosted: Sun Jun 03, 2012 2:52 pm    Post subject: Reply with quote

zaunreiter wrote:


So in the end, everyone has to figure self what is working best in your locality. What right in the one locality is absolutely wrong in the other. So try this and that and observe yourself. Do not follow dogmas and keep an open mind. (And eyes.) Adapt!

Bernhard


I couldn't agree more!
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Gareth
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PostPosted: Sun Jun 03, 2012 10:58 pm    Post subject: Reply with quote

Quote:
From the web site;
"Apply two coats of sunflower oil to your new hive bodies (especially the bottom body) and bottom boards as you would apply regular paint. You can use a paintbrush or a small piece of cloth."
Source;
http://www.beebehavior.com/natural_beekeeping.php

What is your opinion on this? Did anyone here try this and what results did you get?


This might work BUT, sunflower oil and olive oil are thought to mimic the smell that dead insects give off - the fatty acids are similar. So you could find that you are making the hive smell like a bee mortuary.

Just a thought.
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Che Guebuddha
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PostPosted: Mon Jun 04, 2012 6:02 am    Post subject: Reply with quote

Gareth,
Isnt the bee mortuary the very part of their colony life? After winter many bees die, during the summer too. Oil smell + Lemongrass EO might complement each other no?

Zaunreiter,
When you say "work poor" what do you mean by that? They bring in less honey or they colaps as a collony? Care to elaborate please?
Im not after the honey but after the well being of the collony.

biobee,
In that case me spending time on this forum is useless as a beginner and it would be of more benefit for my bees to talk to the locals instead (who keep their floors open in this cold swedish winter).

OT; I cant help but notice you posting very short replies lately which I dont find helpful at all. Actualy they kind of irritate me and make wanna sting you Wink As an Admin more is expected from your replies. Gareth seems to be the oposite and Im happy he actualy focused on my question about using oil inside the hive. Good man Gareth.
Btw, the reason I joined beesource is the lack of replies or incomplete answers, or answers saying to not follow dogmas yet the very hTBH is a Dogma Im happy to test and you are happy to preach it (via your book). Yet you agree with "Dont follow dogmas" as if one can start without some kind of reference (roll eyes).
Please excuse my stings Im a Guard Bee on this forum afterall Wink
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Gareth
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PostPosted: Mon Jun 04, 2012 9:02 am    Post subject: Reply with quote

Quote:
Gareth,
Isnt the bee mortuary the very part of their colony life? After winter many bees die, during the summer too. Oil smell + Lemongrass EO might complement each other no?


Death is indeed part of the cycle of life. And the death of individual bees is part of the life of the colony.

I have not tried it myself but apparently, if you put a little olive oil or sunflower oil on a bee, and place the bee at the hive entrance, other bees will throw it out. Even if it is alive and healthy. To them it smells like a dead bee. That sort of reaction would make me nervous about giving the hive the 'wrong' smell. You could easily try this and see what happens, of course. Smile
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zaunreiter
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PostPosted: Mon Jun 04, 2012 5:17 pm    Post subject: Reply with quote

Che Guebuddha wrote:
When you say "work poor" what do you mean by that?


They shrink in size and get diseases. It could be because we have a lot of wind here, so a lower entrance doesn't catch as much wind maybe. I am not sure, but they don't seem to do well with top entrances here where I live. It also leads to brood spread throughout the hive, which is not nice in a Warre, because you can't get boxes full of just honey.

Bernhard
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Che Guebuddha
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PostPosted: Mon Jun 04, 2012 9:28 pm    Post subject: Reply with quote

@ Gareth
If the hive smells like sunflower/olive oil from the beggining and is mixed with the smell of Lemongrass and Wax on the top bars I dont think it will cause a problem. I see the colony in your example smelling a bee with a different scent flying into the collony, killing it and removing from the hive. Is this not a very valid possibility?
BTW, the guy in the link sais that he applies two coats of sunflower oil. I assume he waits for it to dry somewhat before introducing it to the bees. The bee in your example had a fresh oil on itself.

@ zaunreiter
When you talk "high entrance" is this with mesh-less and sealed floors? The one and only entrance? It seems you talk about high entrance in Ware hives. Im not concerned with Ware Hives at this time only with hTBH and it seems air circulation is not the same in those two.
Do/Did you keep bees in horisontal TBHs with sealed floors (no draft) and a high entrance ( la Michael Bush ) ?

@ biobee
My sencere apologies for the OT post above. I was edgy when i wrote those stingy words. Good man for writting the Barefoot Beekeeper, it sure helped me look into the right dirrection.

Thank you
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zaunreiter
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PostPosted: Mon Jun 04, 2012 9:39 pm    Post subject: Reply with quote

In skeps and Warre hives, no TBHs. Closed floors, no mesh.

Bernhard
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zaunreiter
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PostPosted: Mon Jun 04, 2012 9:44 pm    Post subject: Reply with quote

Any oil won't prevent the buildup of molds. Once there is water or damp, it will get sluggish. The droppings of the bees will rott and soon it starts to stink. If you ever smelled it, like rotting flesh, you probably want to prevent it...

However, if it works for you, it works. It depends much on where you are and what you are doing. With all the questions and good thoughts, I am sure you'll find and sort out a lot of things yourself.

Bernhard
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Che Guebuddha
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PostPosted: Sun Jun 10, 2012 8:46 pm    Post subject: Reply with quote

Thanks Bernhard.

I am reading through Dennis Murrell's site and find this observation very interesting ;
http://beenaturalguy.com/observations/condensation/

Regards
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MObeek
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PostPosted: Mon Jun 11, 2012 1:18 am    Post subject: Reply with quote

To Che: the article is very interesting indeed. Thanks for posting it.
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biobee
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PostPosted: Mon Jun 11, 2012 6:47 am    Post subject: Reply with quote

Che Guebuddha wrote:


@ biobee
My sencere apologies for the OT post above. I was edgy when i wrote those stingy words. Good man for writting the Barefoot Beekeeper, it sure helped me look into the right dirrection.



Don't worry, I have a thick skin.

And just to be clear, by 'dogma' I mean statements such as - 'you must do x' or 'you must not do y', as compared with 'you could do x' or 'you could try doing y'. Of course, we may all slip into that kind of language occasionally when we are governed by emotion rather than logic, but I know that I prefer to be given suggestions than orders!
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Che Guebuddha
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PostPosted: Sun Jun 17, 2012 7:28 am    Post subject: Reply with quote

Quote:
For example we could use a clay roof in summer during flow


Hi Bernhard,
can you please explain why do you suggest Clay Roof in summer? Also why not in winter?

Thanks
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zaunreiter
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PostPosted: Sun Jun 17, 2012 1:38 pm    Post subject: Reply with quote

Especially in summer, to help drying hive air and thus nectar to honey transformation.
I use this sort of roof/quilt and I am very satisfied with it. Works as intended. I implement it into all of my hives.

http://www.biobees.com/forum/viewtopic.php?t=11214

Bernhard
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Maryland Beekeeper
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Joined: 27 May 2012
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PostPosted: Wed Jun 20, 2012 3:01 pm    Post subject: Perone hive Reply with quote

Hi all,
I believe Oscar Perone has designed a hive that attempts to address these issues. Just finished my first one and am awaiting swarm. Will report observations.
Cheers,
Drew
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CCD
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PostPosted: Mon Jun 25, 2012 10:11 pm    Post subject: Reply with quote

Apart from either varnishing the inside of the hive or waiting for the bees to do it themselves, I am wondering what else can be done to provide a good condensation surface in the hive?

One of the studies referred to above had plexiglas as a cover board. Is this now perhaps something to recommend as a permanent feature to provide condensation? Other non-breathable materials too such as glass, stone (slate), glazed tiles (large bathroom tiles) etc.

Bernhard - you mentioned using ceramic material for the roof. I think that if it wicked away moisture, as unglazed ceramics would, then the point would be lost? Maybe glazed ceramic would be necessary.

I am reminded of the photo of dozens of log hives on a hillside in France. They looked like mushrooms because all of them had slabs of stone as roofs. That would certainly provide condensation under the roof.

Also, in the days of the skeps, they used to place glass bells on top of the hive as supers for the bees to store honey inside.

Any thoughts as to hive design alterations?
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biobee
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PostPosted: Mon Jun 25, 2012 11:21 pm    Post subject: Reply with quote

My vertical hives are getting crown boards but I may try Bernhard's ingenious multi-purpose condensation traps.

The French 'brusc' hives have a wooden cap on the hive and the rock is placed on top for weather protection and to keep the goats out. The wooden cap would be propolised, however, and the stone roof would certainly encourage condensation.

I think the big trick is in getting rid of excess moisture, which is what my deep floor should do. I have already made something similar for the vertical hives.
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CharlieBnoobee
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PostPosted: Fri Jul 20, 2012 3:54 am    Post subject: Ventilation/condensation Reply with quote

Che—
First check out: www.biobees.com/forum/viewtopic.php?p=72102&highlight=#72102 Subject: Ventilation and scent retention.
When I first joined this site I was ivory-skulled ignorant. Since then (2/ 2012) I've made great progress. I'm now at least twice (or more) as ignorant as when I posted the above in March. And just reading through this thread has driven my ignorance to all new depths! Hoo-ah! Some of the confusion/ disagreement re open bottoms in winter probably stems from not separating the cooling effects of ventilation vs. what's known in the trade as wind washing. That's the English/American term. (Vindtvätning på Svenska, kanske? Sannolikt icke) Sounds a little goofy, but it's not the same dynamic as ventilation. Ventilation is a result of a static pressure differential, whereas wind washing, such as happens when wind blows, not just across the hive bottom, but somewhat up and into it as well, pushing warm air out before it, is more of a forced displacing or flushing action. Also a good reason to close off, or at least baffle, the bottom in winter.
About condensation: A few thoughts and mostly open questions—
1. What Phil and The Mods (a late 60's Brit rock band no doubt?) are proposing seems to resolve something I was puzzling over. Namely, how does all that nectar water get removed in the summer, especially from a Warré hive, where there's very little means for true ventilation to take place? Answer: Vaporization, then condensation within the hive with subsequent recapture of liquid water into a suitable reservoir. Elegant. But then other questions immediately raise their bothersome heads.
2. For condensation to take place there must be a condensing surface that is simultaneously a) below the dew point temperature, and b) has a sufficiently high heat mass to absorb the latent heat of vaporization. Materials like sawdust and straw may not have enough such mass.
3. The underside of a sheet metal roof will tend to alternate between being an excellent condensing surface during the night, and an excellent drying oven at midday. That may or may not be desirable.
4. A large tree cavity certainly has the heat mass, insulation, and the reservoir capacity right there in the wood surrounding the colony to moderate swings in temperature and humidity, as well as keeping a safe separation between the colony and all that lovely, moist, decomposing compost at the bottom of the cavity. But—
5. How do we emulate such conditions short of not-very-practical two-ton oak trunk hunks. Do practically sized ferro-cement (steel mesh + cement) slabs suggest themselves as possibilities? For roofs? Sides? Bottoms? Dunno. You tell me. Or tiles if they can be arranged to be air tight with the other parts of the hive?
6. However in the world do the bees control the atmosphere to achieve the delicate balance between just warm and dry enough to evaporate nectar water but not so dry (or cool) to allow mites to flourish?

What a great thread!

Ever more ignorant, Charlie B [/url]
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catchercradle
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PostPosted: Fri Jul 20, 2012 9:45 am    Post subject: Reply with quote

Quote:
two-ton oak trunk hunks.


If I could afford to get them delivered I would love to house my bees in two-ton oak trunk hunks. Sadly as you say they are not very practical. One day perhaps I will get a chance to do some chain saw carving to make a hive out of solid oak, (or other wood.) Transition Cambridge are looking at the idea of a community owned woodland and that would be a good place to do this I think.

Dave
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biobee
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PostPosted: Fri Jul 20, 2012 10:40 am    Post subject: Re: Ventilation/condensation Reply with quote

CharlieBnoobee wrote:

About condensation: A few thoughts and mostly open questions—

2. For condensation to take place there must be a condensing surface that is simultaneously a) below the dew point temperature, and b) has a sufficiently high heat mass to absorb the latent heat of vaporization. Materials like sawdust and straw may not have enough such mass.


Sawdust/wood shavings above will certainly collect and absorb some water vapour: that is clear by simple observation. The question remains as to whether or not this is desirable, in that we (via Ed Clarke) are positing that water vapour being effectively re-cycled within the hive is better than removing it in a vapour trap above the hive.

In other words - the fact that water condenses on the side walls is a Good Thing rather than something to be avoided. Good because it is thermally efficient - heat is released back into the hive and thus conserved - and because it maintains a high humidity in which mites cannot thrive. Also, it provides the bees with a source of distilled water.

Quote:
3. The underside of a sheet metal roof will tend to alternate between being an excellent condensing surface during the night, and an excellent drying oven at midday. That may or may not be desirable.


That would only apply if the sheet metal had no insulation above it. I would not use sheet metal in any case.

Quote:
4. A large tree cavity certainly has the heat mass, insulation, and the reservoir capacity right there in the wood surrounding the colony to moderate swings in temperature and humidity, as well as keeping a safe separation between the colony and all that lovely, moist, decomposing compost at the bottom of the cavity. But—
5. How do we emulate such conditions short of not-very-practical two-ton oak trunk hunks. Do practically sized ferro-cement (steel mesh + cement) slabs suggest themselves as possibilities? For roofs? Sides? Bottoms? Dunno. You tell me. Or tiles if they can be arranged to be air tight with the other parts of the hive?


We cannot fully emulate those conditions for the obvious, practical reasons you describe. However, we can go some way towards it by careful use of lighter materials. There could even be a case for using recycled plastics.

Quote:
6. However in the world do the bees control the atmosphere to achieve the delicate balance between just warm and dry enough to evaporate nectar water but not so dry (or cool) to allow mites to flourish?


IMO knowing that they do so control their environment and taking this awareness into the design of hives is more important that knowing exactly how they do it, interesting though that may be.
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catchercradle
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PostPosted: Fri Jul 20, 2012 12:23 pm    Post subject: Reply with quote

Quote:

IMO knowing that they do so control their environment and taking this awareness into the design of hives is more important that knowing exactly how they do it, interesting though that may be.


Agreed, however, knowing how they do it may help us in optimising hive design to make it easier for them. Besides curiosity is inevitably aroused!

Having said that, some answers we are only going to get through a cycle of observing and tweaking so it may be a way of whatever the clever people who come up with the theories are doing.
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DocBB
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PostPosted: Sat Jul 21, 2012 6:46 am    Post subject: Reply with quote

hello,

A lot of science here , but i'd like to ad some of my thought :

according to the good authors the mean feral nest dimensions are 22,7 cm diameter for 156 cm height, if we assume that it is almost a cylinder the surface should be around 11 934 cm2 for a 45000 cm3 volume.

Thus a condensing propolised surface with a 1:4 surface /volume ratio.

Now what's the ratio for a TBH : 80000/13610 or 1 : 5,8
or a Warre on 4 bodies : 74800 / 12000 or 1 : 6,2

in each case a lack of condensation surface compared to a feral nest.

should we build narrower TBH more or less like the traditionnal african beehives ? Like the ones described here

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biobee
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PostPosted: Sat Jul 21, 2012 7:58 am    Post subject: Reply with quote

You are assuming an 80 litre volume for a colony in a TBH, which is rarely the case: 40-60 liters would be closer to the average.

How does that affect your sums?
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DocBB
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PostPosted: Sat Jul 21, 2012 12:06 pm    Post subject: Reply with quote

taking a count of the converse issue :

how to get a 12000 cm2 condensing surface for an "ideal" 45000 cm3 hive volume

Do we need a more efficient condenser than the (handmade) hive itself ?

a special follower board for spring or summer and another one for wintering?
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CharlieBnoobee
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PostPosted: Sat Jul 21, 2012 12:48 pm    Post subject: Ventilation/condensation Reply with quote

catchercradle wrote:
Quote:

IMO knowing that they do so control their environment and taking this awareness into the design of hives is more important that knowing exactly how they do it, interesting though that may be.


Agreed, however, knowing how they do it may help us in optimising hive design to make it easier for them. Besides curiosity is inevitably aroused!




I, too, think I might, sort of, agree (rather conditionally). Maybe. I mean, was it important to Otto L. and the Wright bros. to know just how birds fly in order to design an aircraft? Maybe not. On the other hand, it was very important for them to understand the rudiments of lift, thrust and drag and how to sort out an arrangement of those elements that would get them to their goal. I could go on and on about the design process, but this is probably not the place or time.

That said, the thought occurred to me that, since we're dealing with condensation here rather than whole hive ventilation, wouldn't it make sense that the bees' fanning activity is creating hive air circulation rather than ventilation? The faster the circulation speed over the condensing surfaces, the greater the rate of condensation, yes? And since the condensate is draining away into a sump/reservoir and not immediately re-evaporating again, there's a net lowering of humidity. Which the bee's are controlling by their fanning speed. Sounds reasonable, doesn't it? BTW, I can't see there would be a net heat gain. The latent heat of vaporization never leaves the hive, it,s just transferred (via the circulating air) from the nectar to the condensing surfaces; net gain is zero, unless those surfaces further transfer it to the great outdoors.

Thanks for your input.
CharlieB
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biobee
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PostPosted: Sat Jul 21, 2012 1:41 pm    Post subject: Reply with quote

DocBB wrote:


according to the good authors the mean feral nest dimensions are 22,7 cm diameter for 156 cm height, if we assume that it is almost a cylinder the surface should be around 11 934 cm2 for a 45000 cm3 volume.

Thus a condensing propolised surface with a 1:4 surface /volume ratio.



Just checking your maths - please correct me if I am wrong (never my best subject!).

Volume of a cylinder with a diameter of 22.7cm and a height of 156cm
= area of Xsection x length
= 11.35 x 11.35 x 3.14 x 156
= 63,102.41

The surface area of the cylinder is the sum of the area of the ends plus the area of the side
= 2 x(11.35 x 11.35 x 3.14) + (156 x 3.14 x 22.7)
= 809 + 11,119.368
= 11,928.37

So with a little rounding, our cylinder has a volume of 63 litres and a surface area of 12,000 square centimetres.

Giving a ratio of 1:5.25

Which is rather close to the ratio of 1:5.8 you give for the top bar hive...

(In fact, the floor of the cylinder can be eliminated from the equation, as this will not be a condensing surface, but rather a water collecting surface, unless it drains. The area of roof that would be an active condensing surface would be reduced by - I would guess - at least 50% by the fact that it would have comb built on it. So a more realistic surface area would be around 11,300 sq cm, giving a ratio of 1:5.58 - looking even better for the TBH!)

The volume contained under each bar of a TBH
= length of active area of bar x width x average depth of hive
= 36 x 253 x 280
= 2,550,240 cu mm
= 2.55 litres per bar

or 51 litres for a 20 bar colony using 36mm bars.
and 25 bars would give us our 63 litres, equivalent to the cylinder above.

The surface area of the walls of a 25 bar colony would be
= 2 x side wall area + 2 x follower board area
= (300 x 25 x 36 x 2) + (253 x 280 x2) sq mm
= 540,000 + 141,680
= 681,680 sq mm

And we should add in something fro the roof, but given bees' habit of building wider comb a the top and leaving only a bee space clear between combs near the bars, we can only add in 380 x 6mm per bar,
= 380 x 6 x 25
= 57000 sq mm

And if we ignore the floor, that gives a total theoretical condensing area
= 738,680
= 7387 sq cm

Giving us a ration of 1:8.5

BUT I suggest that, in practice, there will be very little condensation on the 'roof' at all, as this is directly above the source of heat and will therefore - assuming good insulation above - be above the dew point. Significant condensation will, therefore, occur only on the side walls and to some extent on the followers.

This suggests that there may be a shortfall in the condensing area of a 25-bar hive with standard x-section.

But I suspect that maximizing the effectiveness of the available surface area by means of a resin-based varnish may compensate for any theoretical shortfall.

Feel free to challenge me on any of the above!
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biobee
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PostPosted: Sat Jul 21, 2012 6:18 pm    Post subject: Re: Ventilation/condensation Reply with quote

CharlieBnoobee wrote:


That said, the thought occurred to me that, since we're dealing with condensation here rather than whole hive ventilation, wouldn't it make sense that the bees' fanning activity is creating hive air circulation rather than ventilation? The faster the circulation speed over the condensing surfaces, the greater the rate of condensation, yes?



I agree. I think that is eactly what they are up to.

Quote:
And since the condensate is draining away into a sump/reservoir and not immediately re-evaporating again, there's a net lowering of humidity. Which the bee's are controlling by their fanning speed. Sounds reasonable, doesn't it?


Not really, as fresh nectar (c. 80% water) is coming in all the time during the build-up/consolidation period, which is when brood is around.

Quote:
BTW, I can't see there would be a net heat gain. The latent heat of vaporization never leaves the hive, it,s just transferred (via the circulating air) from the nectar to the condensing surfaces; net gain is zero, unless those surfaces further transfer it to the great outdoors.


Heat gain is not their aim, but environmental stability. Their algorithm for this must take into account factors such as:

- number of bees present at night
- number of active foragers
- number of home and visiting drones
- rate of lay by queen
- amount of brood requiring stable temperature
- quantity of open stores
- thermal capacity of comb + contents
- ambient outside temperature
- death rate of workers
- quantity of pollen requiring storage
- relative humidity inside/outside
- temperature gradient (how quickly temp is rising/falling)

...and a thousand or so things I have not yet thought of.

Must make Google's algorithm look like a beginners exercise in coding in comparison!

And remind me - how big are their brains?
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