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  1. #1
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    Default Weak thermocline = Wet hive ?

    Please share your knowledge of thermodynamics.
    Cheers,
    Drew


    p.s. If anyone knows any entomologists or physicist/beeks could you please get opinion on thread. I'm dying a slow and painful death here
    Last edited by Maryland Beekeeper; 01-14-2013 at 02:23 PM.

  2. #2
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    Default Re: Weak thermocline = Wet hive ?

    From other forum:

    Quote from: Maryland Beekeeper on January 12, 2013, 10:15:37 PM
    Got any pics of condensation in a honeybee hive ?

    Reply:
    They make any sense. Idea is avoid condensation, not to make it.
    bees make condensation regardless ... this is about where it happens
    if it occurs inside the insulated space below the bees you get 10% heat back

    Re: Condensation in an observation hive
    Reply #34 on: Today at 01:51:47 PM
    Reply with quoteQuote Modify messageModify

    DING ! DING ! DING ! WINNER ! WINNER ! CHICKEN DINNER ! applause

    Also, (and more importantly), if it occurs in insulated space below bee's, you have dry B's !
    Cheers,
    Drew
    Last edited by Maryland Beekeeper; 01-14-2013 at 04:05 PM.

  3. #3
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    Default Re: Weak thermocline = Wet hive ?

    From other forum:

    No question should ever be considered unreasonable - the only unreasonable aspect of this thread are the responses from ... and his parrot, who cannot get their heads around a perfectly sound enquiry.

    Warm air rises, and cold air descends - therefore the formation of a thermocline is always possible. But I would suggest that the existence of a thermocline within a beehive is highly unlikely ... for 2 reasons.

    The first is the activity of the bees themselves. Wherever there is active circulation (often due to the cluster being located towards one side), there is unlikely to be stratification of thermal layers.

    The second is that a vortex is created near the entrance to any occupied hive, due to the movement of air through a narrow space. (Clearly this would not apply where OMFs are fitted.) Such vortices would also 'stir the air'.

    The only time I could envisage a thermocline being created would be when the bees are very tightly and centrally clustered, and when the upper part of the hive is 100% sealed. But the breaking of cluster would soon mix the air, thus destroying any temporary stratification.

    At least, that's how I see events within the hive. But I could always be wrong !


    Thermoclines are more usually associated with large outdoor expanses of water, where the water is heated (by the sun) from above. Warm water rises and the cooler water gradually migrates downwards (just check your domestic hot water tank) - thus creating the thermocline. I have often experienced these when diving in the Med - it's like moving through an invisible curtain between an oven and a fridge. Very strange.

    Having said that - an immersion heater does heats the water from below, and a thermocline is most certainly created within a hot water tank (but it's a tank which isn't stirred), so it's far from being a stupid issue to raise.
    Me:
    I to am a scuba diver, and sky. My contention would be...... ready for it ? The atmosphere is static ! remember combs now, can you visualize how the heat would disallow condensation above thermocline ? Smile The honeybee hive is natures perfect distillery ! Smile
    _Me
    Of course it could be wishful thinking but, if you go back, re-read Langsroth, Huber, I'm working thru Swammerdam now, the clues are there. They saw the thing, just, like all since, missed the significance. They didn't understand thermocline
    Me
    Go, look @ your honeybee organism, again for the first time,........ think upside down moonshine still,..... think hermit crab.....can you see it now ? Smile

  4. #4
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    Corvallis, OR
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    Default Re: Weak thermocline = Wet hive ?

    Insufficient context to really know what the debate is here, but a couple of thoughts.

    1. Most hives should not contain a real thermocline (i.e. a horizontal plane with warmer air above and cooler below). More likely the air in a hive will form a convection cell. Air within the cluster is 95 degrees. This warm air will rise. Rising air will cool through contact with the cooler top (with moisture condensing out), then sink along the walls and eventually flow back through the cluster where it will pick up heat and moisture. Insulation will slow the rate of convective flow but will not stop it. The only way to stop cluster-driven convection entirely would be to heat the hive from the top, which could happen with a black roof in sunny weather or if another hive is stacked above.

    2. An insulated tall hive with a bottom entrance and the cluster in an upper box could form a thermocline. In this case we would have a convection cell in the upper boxes above a pool of colder air in the lower box(es). Such a situation would not necessarily be good or bad, but as all of the moisture would stay in the upper convection cell there could still be plenty of condensation and dripping on the cluster.

    3. Moisture will condense on any surface cooler than the dewpoint of the air in contact with it. In an un-insulated hive, most of the moisture condenses on the top immediately above the cluster. With an insulated top, more condensation will occur on the walls. It should be possible to selectively condense moisture away from the bees by insulating the top and providing a very poorly-insulated wall (e.g. glass in an observation hive). Condensing moisture entirely below the bees will be a challenge, as placing a cold surface at the bottom will inhibit convection (cold air will pool against this surface, as in #2 above). I could see it working though with well-insulated walls and top, and especially if the bees actively mix the air to substitute for convective processes.

    This year I solved my moisture problems with wood-chip quilts (http://www.honeybeesuite.com/how-to-...ngstroth-hive/). Moisture condenses on the top but is caught by 3" of wood chips so doesn't drip down on the bees. Seems to be working great so far.

    Mark
    Last edited by Luterra; 01-14-2013 at 04:09 PM. Reason: did some more thinking

  5. #5
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    Default Re: Weak thermocline = Wet hive ?

    That you can't imagine is why you cannot see, I have a glass hive/shell, and have seen, but have only now come to understand, .....perhaps, ......we shall see
    Last edited by Maryland Beekeeper; 01-14-2013 at 04:41 PM.

  6. #6
    Join Date
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    Corvallis, OR
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    Default Re: Weak thermocline = Wet hive ?

    Quote Originally Posted by Maryland Beekeeper View Post
    That you can't imagine is why you cannot see, I have a glass hive/shell, and have seen, but have only now come to understand, .....perhaps
    What have you seen? What cannot I see? If you are going to bring over a discussion from another site, please don't assume that we are all readers of that site.

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