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Author Topic: Weak thermocline = Wet hive ?  (Read 4396 times)

Offline derekm

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Re: Weak thermocline = Wet hive ?
« Reply #20 on: January 16, 2013, 04:36:50 AM »
we take it as a given that thermal gradients exist in bee hives
you are postulating a discontinuity in the thermal gradient...

given that the bees are in heat conservation mode where do you think the energy to maintain the discontunity coming from?
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 Maryland Beekeeper

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Re: Weak thermocline = Wet hive ?
« Reply #21 on: January 16, 2013, 12:22:58 PM »
My understanding is too limited to answer. Is that what I am postulating ? :) As for the energy, it is the honey yes ?
 That infra-red cluster is just how I see it, my hives are airtight, the entrances are pvc pipe, they enter hive above floor, sometimes they look like moonshine still, I think those red holes in pick are what they would look like in infra-red ?  how to describe that system ?
« Last Edit: January 16, 2013, 12:59:06 PM by Maryland Beekeeper »

Offline BlueBee

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Re: Weak thermocline = Wet hive ?
« Reply #22 on: January 16, 2013, 12:50:46 PM »
Can you build a hive out of glass this month and move a hive of bees into it during our next warm spell and then take some photos!

Offline Maryland Beekeeper

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Re: Weak thermocline = Wet hive ?
« Reply #23 on: January 16, 2013, 01:13:03 PM »
Got the hives, might need new B's :( , and finally I am forced to admit,... that I blew it completely ! :) I think I  even remarked  at one point about the condensation pattern and completely failed to realize the significance,(if there is any). How I didn't take a pic ? I have no excuse save.....airheadedness :) Drew, why did you build a glass hive ?  :?
« Last Edit: January 16, 2013, 02:39:01 PM by Maryland Beekeeper »

Offline derekm

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Re: Weak thermocline = Wet hive ?
« Reply #24 on: January 16, 2013, 01:41:45 PM »
My understanding is too limited to answer. Is that what I am postulating ? :) As for the energy, it is the honey yes ?
 That infra-red cluster is just how I see it, my hives are airtight, the entrances are pvc pipe, they enter hive above floor, sometimes they look like moonshine still, I think those red holes in pick are what they would look like in infra-red ?  how to describe that system ?
what is your  level of knowledge in  the physics heat and mass flow?
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 Maryland Beekeeper

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Re: Weak thermocline = Wet hive ?
« Reply #25 on: January 16, 2013, 02:33:14 PM »
Not sufficient to describe that picture. It would have to be explained to me in laymen terms. If you draw vertical line to right of center hole,(imagining my hive), just where the green and yellow meet, condensation, Yes ? Or perhaps rather ?

p.s. In rereading posts, I think the tone is......not as I intend, perhaps because I hunt and peck ? And the ? is a pain ? Please add on my behalf in future should I omit :)
p.s.s Also I think the.....manner of speech, from all these old books is creeping on me :)
p.s.s.s. Occurred to me another way to ask ? I don't know what that pic is, I googled winter cluster, or if I'm seeing it wrong ? I can see my hive. Red, B's, yellow, thermocline?/thermal layer ? protecting Apis from green/blue ?
« Last Edit: January 16, 2013, 04:28:50 PM by Maryland Beekeeper »

Offline Maryland Beekeeper

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Re: Weak thermocline = Wet hive ?
« Reply #26 on: January 16, 2013, 05:02:22 PM »
This......coincidence(?).....gave me a slight chill :)

http://search.yahoo.com/r/_ylt=A0oG7nXPE_dQZR0A5NRXNyoA;_ylu=X3oDMTE1MzU1YXZnBHNlYwNzcgRwb3MDMQRjb2xvA2FjMgR2dGlkA1ZJUDA3N18xNjU-/SIG=136jjdjha/EXP=1358398543/**http%3a//www.scribd.com/doc/81342235/Open-cell-convection-and-closed-cell-convection
 
Any help appreciated,
Cheers,
Drew
« Last Edit: January 16, 2013, 05:14:29 PM by Maryland Beekeeper »

Offline BlueBee

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Re: Weak thermocline = Wet hive ?
« Reply #27 on: January 16, 2013, 05:36:34 PM »
Maybe I should send you a Thermodynamics textbook for some light weekend reading. :)

There’s so many variables at play in a bee hive the odds of recognizing all the variables and modeling them correctly is way more work than making a glass bee hive and observing what happens in real life.  Thermodynamic models aren’t always the most accurate way to learn things anyways.  Just watch the weather report some night.

You can buy plexiglass at Home Depot or Lowes for your glass hive, but it’s not the most cost effective material.  I like the polycarbonate they use for greenhouse glazing.  They sell and stock that stuff at Menards which is a home improvement chain in the Midwest.  Don’t know if they extend out to Maryland or not.  Here I can buy a 6 mm sheet of double wall polycarbonate (4’x8’) for about $50.  You should be able to make 3 or 4 hives from that.

Chop chop, let's get er done before the next warmup!

Offline Maryland Beekeeper

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Re: Weak thermocline = Wet hive ?
« Reply #28 on: January 16, 2013, 08:22:55 PM »
:) Got one, slow read :) Would like thermopane, w/ argon + glazing :) Anderson do custom ?

Offline BlueBee

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Re: Weak thermocline = Wet hive ?
« Reply #29 on: January 16, 2013, 09:15:52 PM »
How would you cut a glass thermopane (double pane) down to size for a bee hive?  The insulation value of a double pane or triple pane window is really the air space between the panes.  You can probably do better and cheaper with greenhouse polycarbonate.  I know you can buy at least 6 wall stuff.  The more walls, the higher the R value.  The polycarb cuts fairly easily with a table saw.  Just wear goggles. 

However if you’re going to cover the glass hive with a foam shell, then you don’t really need the extra walls, right?  Just a simple box made of plexiglass should work.  Just cover that with a foam shell when done.  The foam would provide the level of insulation you need (for winter in Maryland) for your thermocline and it also keeps the hive from melting when exposed to full sun. 

Let’s pencil you in to complete this job by Monday, OK?

The other problem going with pure glass is it’s conductivity of heat.  The pane against the bees is going to conduct heat from the top to the bottom of the hive.  It might mess up your thermocline.  A plastic pane really should be a better way to go.

Offline Maryland Beekeeper

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Re: Weak thermocline = Wet hive ?
« Reply #30 on: January 16, 2013, 11:55:53 PM »
Thinking, looking @ thermal pic, that weber grill hive might be just the thing I seek :) Gets tricky w/ the shape I guess, not insurmountable.
p.s. Wonder if it could be that simple, the shape. In square Apis can't build sufficient bubble ? + heat not reflected evenly ?
« Last Edit: January 17, 2013, 12:25:29 AM by Maryland Beekeeper »

Offline BlueBee

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Re: Weak thermocline = Wet hive ?
« Reply #31 on: January 17, 2013, 03:15:23 AM »
What makes you say the bees can make a heat bubble in a square hive?

My jumbos are almost square in size.  I don't see why they couldn't make a heat bubble if I closed off the top entrance and used a bottom one instead.  They are already quite warm even with the top vent.  I might be able to fry breakfast on the inner cover if I tried to convert them to heat bubbles.

If you have enough bees, they make enough heat to keep the top of the box relatively warm no matter what the geometry I would say.


Offline derekm

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Re: Weak thermocline = Wet hive ?
« Reply #32 on: January 17, 2013, 06:17:15 AM »
What makes you say the bees can make a heat bubble in a square hive?

My jumbos are almost square in size.  I don't see why they couldn't make a heat bubble if I closed off the top entrance and used a bottom one instead.  They are already quite warm even with the top vent.  I might be able to fry breakfast on the inner cover if I tried to convert them to heat bubbles.

If you have enough bees, they make enough heat to keep the top of the box relatively warm no matter what the geometry I would say.



So Bluebee the corollary:  if you have less bees you should change the aspect ratio of the hive? or just keep the bee density the same?
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 Maryland Beekeeper

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Re: Weak thermocline = Wet hive ?
« Reply #33 on: January 17, 2013, 11:02:19 AM »
I make no such assertion ! :) They make bubble regardless(?), but in square hive it might not reach corners for small cluster(?), thus wet corners ? + perhaps square corners reflect core heat..... inefficiently?  New word of day- aspect ratio, off to google :)

p.s. Could this b y Apis likes corner to corner in square ? Now round bubble covers whole space ?
« Last Edit: January 17, 2013, 11:49:04 AM by Maryland Beekeeper »

Offline BlueBee

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Re: Weak thermocline = Wet hive ?
« Reply #34 on: January 17, 2013, 12:29:58 PM »
If you have less bees, you have less heat being generating.  If your goal is to keep any condensation off the top of the hive, then one argument would be to minimize the surface are of the top.  In that case, one could argue against a square top.  On the other hand, if your aspect ratio is the other extreme (narrow rectangle), you may end up with condensation at the ends of the rectangle like in all the photos I posted in the top vs bottom thread.  What is the best answer?  I don’t know!  It’s complicated.  That’s why I experiment.

My guess is a square hive would be the most efficient geometry for wintering bees since it would allow the cluster to form the best sphere.  A sphere has the minimum surface area per volume enclosed and should be the most thermally efficient for the cluster.

My baby mating nucs are almost square too.  That allows the small amount of bees in them to cluster in a ball shape.  If I were going to invent bee keeping all over again, I might go with square hives. :)

Offline Maryland Beekeeper

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Re: Weak thermocline = Wet hive ?
« Reply #35 on: January 17, 2013, 04:25:41 PM »
I'm already drawing up my circle hive :)

 I see an upside down, infra-red pic of bhive :

http://en.wikipedia.org/wiki/File:RayleighBernardConvection.png

Cheers,
Drew
p.s. wish i had a infrared cam :)
« Last Edit: January 17, 2013, 04:49:59 PM by Maryland Beekeeper »

Offline derekm

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Re: Weak thermocline = Wet hive ?
« Reply #36 on: January 20, 2013, 03:13:32 PM »
If you have less bees, you have less heat being generating.  If your goal is to keep any condensation off the top of the hive, then one argument would be to minimize the surface are of the top.  In that case, one could argue against a square top.  On the other hand, if your aspect ratio is the other extreme (narrow rectangle), you may end up with condensation at the ends of the rectangle like in all the photos I posted in the top vs bottom thread.  What is the best answer?  I don’t know!  It’s complicated.  That’s why I experiment.

My guess is a square hive would be the most efficient geometry for wintering bees since it would allow the cluster to form the best sphere.  A sphere has the minimum surface area per volume enclosed and should be the most thermally efficient for the cluster.

My baby mating nucs are almost square too.  That allows the small amount of bees in them to cluster in a ball shape.  If I were going to invent bee keeping all over again, I might go with square hives. :)

tree nests have an aspect ratio of about ~7
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 BlueBee

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Re: Weak thermocline = Wet hive ?
« Reply #37 on: January 20, 2013, 08:22:57 PM »
Are you suggesting an ellipsoid is thermally superior to a sphere? 

Offline Maryland Beekeeper

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Re: Weak thermocline = Wet hive ?
« Reply #38 on: January 20, 2013, 10:46:18 PM »
I like the thought of that RB convection squeezed into ellipsoid


p.s. Found what I've been looking for ! Took long enough :)

http://www.naturalbeekeeping.com.au/Delon%20%27stable-climate%27%20hive.pdf


Drew
« Last Edit: January 21, 2013, 03:19:59 PM by Maryland Beekeeper »

Offline derekm

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Re: Weak thermocline = Wet hive ?
« Reply #39 on: January 21, 2013, 06:32:10 PM »
Are you suggesting an ellipsoid is thermally superior to a sphere? 
a sphere or cube is only applicable if the thermal conditions are isotropic.
as you get in  thin wooden hive as there is virtually no insulation in anydirection.

An insulated hive or tree nest is strongly ansiotropic... its got an open entrance at the bottom  and all this insulation on the top and sides.
A sphere is just not applicable as a valid solution
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?