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Author Topic: Top vs Bottom ?  (Read 8197 times)

Offline BlueBee

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Re: Top vs Bottom ?
« Reply #60 on: January 11, 2013, 08:17:02 PM »
Yes we are enjoying record heat here in Michigan and MOST of my bees are out taking advantage of the warmth.  All my wood hives (bottom entrances) and all my top entrance foam hives were active today.  What were not active were my double decker foam hives with just a bottom entrance.  They respond MUCH more slowly to the environment and I feel that is a negative of that design.  I also find much more condensation over the bees heads in those designs. 

(For the record most of my hives are foam, I only have about 4 colonies in wood.  The one good thing about wood is IF they survive the cold nights, they do warm up nicely on days like this).

Here’s a photo from today of a 4 frame medium nuc using the heat bubble design.  Lots of condensation AROUND the bees, but the colony looks pretty healthy to me.  If this were a double decker, all that condensation would be on the combs over their heads.



Offline Maryland Beekeeper

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Re: Top vs Bottom ?
« Reply #61 on: January 11, 2013, 09:15:29 PM »
If you cut the wet ends off that hive, around cluster, (decrease, I assume depth), what would the pic look like ?  In other words... the middle is dry, if you were to peel off that side I think you would see the condensation in a U pattern.  Yes ?
« Last Edit: January 11, 2013, 09:58:57 PM by Maryland Beekeeper »

Offline BlueBee

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Re: Top vs Bottom ?
« Reply #62 on: January 12, 2013, 05:55:53 AM »
That would be a good guess, but I don’t know.  I’ll have to take a closer look tomorrow.  More record heat tomorrow  :)(Saturday) before reality sets back in.  :(

I suspect if there were more bees in that box or the box was smaller the zone of condensation would be pushed down onto the end walls.  As you can see from my various photos, that condensation pattern repeats itself over and over in my heat bubble nucs. 

It will be interesting to see what happens to the condensation as we get into February and March and the bees start brooding.   Who knows, maybe the bees will start licking up some of that water?

Offline Maryland Beekeeper

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Re: Top vs Bottom ?
« Reply #63 on: January 13, 2013, 01:22:14 AM »
I believe that clue is a vitally significant one that was missed by Langstroth and everyone since. They didn't understand/comprehend significance of it, just as you are missing it, as did I :) They didn't understand thermocline layer.  Look again..... think in 3D, the VERTICAL pattern of condensation.  When you....admit?:) that if you squeezed in those ends the, "zone of condensation", must go down, then you have got the thing ! When executed properly no condensation will occur above top of bottom entrance.
p.s. more insulation, better seal, airtight critical
p.s.s Natures distillery :)
Last one :) If you go back, re-read Langsroth, Huber, the clues are there,they saw it, just like you and I, they missed the significance.
« Last Edit: January 13, 2013, 02:18:40 AM by Maryland Beekeeper »

Offline BlueBee

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Re: Top vs Bottom ?
« Reply #64 on: January 13, 2013, 02:29:15 AM »
Kind of interesting looking at the condensation patterns again today.  I put my hand on the combs today and some are starting to heat up.  The big hives were downright hot (top vents).  I assume they might be starting some brood.  The condensation in a couple of the single layer heat bubble nucs has disappeared (not so in the double deckers).  I don't know if that's because the temperature in the hive went up (and the condensation went back to vapor) or if the bees could be lapping some water up.

You make some good points Drew.  I think the optimal hive though is a combination of the hive's thermal characteristics AND the volume of the bees inside.  If either one of those is not right, you get condensation where you don't want it.  Even the perfect hive design is going to disappoint if you don't have a big enough volume of bees. 

Offline Maryland Beekeeper

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Re: Top vs Bottom ?
« Reply #65 on: January 13, 2013, 03:44:07 AM »
I don't know about perfect, but an improved hive design would......insure, the beekeepers control of thermocline/that the B's were always able to maintain a thermocline, below their cluster. And yes, when the heat goes up the thermocline decends.

Offline little john

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Re: Top vs Bottom ?
« Reply #66 on: January 15, 2013, 06:48:31 AM »
I've just found a webpage which may have some interest for those seeking to deal with the condensation vs heat loss trade-off: http://letok.narod.ru/zima.htm

Google does a reasonable job of translation, but if there any Russian speakers out there, there are a few words which could benefit from being tidied up !


Basically, what the guy has done now for 2 winters, is to completely seal the top of the hive using a layer of medium-thick polyethylene sheeting, with a thin layer (3mm) of polyethylene foam over. This is kept in place by means of an oversized eke, which holds the poly and foam in place in the same way as a drumhead is held down onto a drum by a rim. This combination allows the poly sheet to remain cold enough for water to condense on it's under side.

Then - and this is the simple but ingenious bit - he simply places a length of 2x2 under one side of the hive to allow the condensate to trickle down one of the walls.

I'm fast coming to the conclusion that there will always be a trade-off between moisture removal, and the amount of heat retention preserved - that is, unless/until some genius comes up with a really clever ground-breaking idea.




Later ...

I've just realised that there are 2 sheets of polyethylene involved (dodgy translation ...), and this is how I visualise this system operating:



Black lines being the polythene, and the red line being the foam. Moist air escapes through the gap in the lower barrier, only to condense on the upper barrier. Condensate then runs down along the polythene sheet, down the inside front wall of the hive, and exits via the entrance slot.

LJ


« Last Edit: January 15, 2013, 10:12:20 AM by little john »

Offline BlueBee

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Re: Top vs Bottom ?
« Reply #67 on: January 15, 2013, 11:10:05 AM »
That’s an interesting design LJ. 

As this point, I don’t think the condensation in my single layer heat bubble designs is going to be detrimental to the bees since winter is about half over and almost all the condensation is away from the bee cluster.  The only potential problem I see with my polyethylene sheeting is the condensate running down the sheeting in the wrong direction if it is not taught. 

Your post did give me another idea.  If I replaced my polyethylene sheet with double walled polycarbonate (greenhouse glazing), I might be able to get the condensation to form inside the polycarbonate cavities.  That might be a little more insurance against drips on the bees, but I don’t know if it would warrant the extra costs.

Offline Maryland Beekeeper

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Re: Top vs Bottom ?
« Reply #68 on: January 15, 2013, 11:22:54 AM »
Remember any devise designed to condense water vapor, does so at expense of heat.
p.s. In which direction would you surmise Apis might prefer to,......discharge, heat ?
« Last Edit: January 15, 2013, 11:33:22 AM by Maryland Beekeeper »

Offline little john

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Re: Top vs Bottom ?
« Reply #69 on: January 15, 2013, 01:59:08 PM »
What I think doesn't matter, and with respect, what you think doesn't matter.
What matters are what conditions bees consider important criteria within their preferential home.
 
Tom Seeley often says "If in doubt, ask the bees." 

So - what I would suggest is an experimental setup: a swarm of bees held within a very small central box which is connected to two identical hives by wide tubes - in a kind of 'two-wing' arrangement. Or perhaps - simply a swarm offered the choice of two empty hives.

One of these hives would be maintained warm, but damp; the other maintained somewhat cooler, but dry - then wait and see which set of conditions the bees select as being suitable for their home.

It may be necessary to run such an experiment multiple times in order to demonstrate validity, but my money would be on the bees making a definite choice. This would be a tad better approach methinks, than human beings trying to second-guess what conditions bees prefer ?

LJ

Offline Maryland Beekeeper

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Re: Top vs Bottom ?
« Reply #70 on: January 15, 2013, 03:10:08 PM »
Would not a glass hive, w/ horizontal plane, defined by line of condensation, do the trick ?

Offline BlueBee

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Re: Top vs Bottom ?
« Reply #71 on: January 15, 2013, 06:04:02 PM »
I will say this; you’re persistent  ;) 

The photos on this thread make it pretty clear that if condensation is a primary concern, that is easily solved with a top vent.  If you’re concerned about losing 10% of the bees heat due to heat escaping with the water vapor, then maybe adding some solar gain to your design would be a good idea. 

Bees aren’t generating many watts in the first place; just 10s of watts at best.   If you’re losing 10% with escaping water vapor, we’re only talking a couple of watts!  A couple of watts isn’t diddly squat compared to solar gain.  Solar gain can be about 100 watts per square foot. 

Offline Finski

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Re: Top vs Bottom ?
« Reply #72 on: January 15, 2013, 06:12:44 PM »
 If you’re concerned about losing 10% of the bees heat due to heat escaping with the water vapor,


To where you may loose hive energy:

- too much room for colony
- poor insulation
- windy site of hive
- feeding hole open/chimey effect
- mesh floor ventilation/ ( solid bottom has only 5% opening compared to MF)
- hive continues brooding
- beekeeper disturbes the hive very often and wake up from winter sleep with his honey balls and thanks giving presents
- knock knock, are you alive

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Offline derekm

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Re: Top vs Bottom ?
« Reply #73 on: January 16, 2013, 04:41:55 AM »
I will say this; you’re persistent  ;)  

The photos on this thread make it pretty clear that if condensation is a primary concern, that is easily solved with a top vent.  If you’re concerned about losing 10% of the bees heat due to heat escaping with the water vapor, then maybe adding some solar gain to your design would be a good idea.  

Bees aren’t generating many watts in the first place; just 10s of watts at best.   If you’re losing 10% with escaping water vapor, we’re only talking a couple of watts!  A couple of watts isn’t diddly squat compared to solar gain.  Solar gain can be about 100 watts per square foot.  

solar gain in winter is a myth, that appears at10am and is gone by 3pm( with the usual bee hive surfaces). You loose more during the night. Large swings in hive temperature  is all you get, but no net gain by the time the sun comes out on the 2nd day.
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: Top vs Bottom ?
« Reply #74 on: January 16, 2013, 12:47:52 PM »
Agreed.  But if you add a solar input to your hive WITHOUT degrading the insulation value, then I suspect you can get a significant net gain.  There is plenty of mass inside a hive to absorb heat during the day and to release it during the night.   

For example, say you put photovoltaic cells on the outside surface of your hive and fed the electrical power from those through two small wires into a power resistor inside the hive.  In that implementation you haven’t degraded the insulation of the hive and you have added some extra wattage inside the hive which it would not normally have. 

Photovoltaic is not the way I would go because it’s too inefficient.  I just used that as an example since it could clearly be implemented without altering the insulation value of a hive.   

Offline T Beek

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Re: Top vs Bottom ?
« Reply #75 on: January 17, 2013, 02:18:51 PM »
First time using foam shells around my hives this winter.  As of last week (w/temps in the low 40'sF) all 8 colonies are alive.

However, we're getting 20 below zero this weekend..  Kill them cut worms, kill them slugs, freeze the lakes..... 8-)

One observation so far; all hives w/ 'both a top and bottom' entrance still open (one or two beespace size) have some frost at the top entrances on colder mornings. 

I have two w/ just top entrances (and a LONG Hive) and they have not experienced this "new" (to me) frost phenomena. 

Any ideas?
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Offline edward

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Re: Top vs Bottom ?
« Reply #76 on: January 17, 2013, 09:28:29 PM »
I have always wondered why some BK wrap there hives in black tar paper??

I can understand the wind shielding aspect, but heating the hive on sunny winter days will cause the ball of bees to break prematurely and result in a higher consumption of winter stores.

Studies that I read show that a steady constant hive temperature makes things easier for the bees to maintain a warm bee ball in wintertime.
The bees need a quiet stable environment.

mvh edward  :-P

Offline BlueBee

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Re: Top vs Bottom ?
« Reply #77 on: January 18, 2013, 12:54:20 AM »
One reason beeks wrap hives in tar paper is because the bee keeping books here tell us to!

Most hives here are also 19mm thick wood hives.  Since there is virtually 0 insulation value in such thin wood, the hives most people use are going to cycle from the low of the day to the high of the day.  So there is already a lot of undesirable temperature cycling.   Worst yet, if it dips down to -20F/-28C at night, those wood hives fall to -20F/-28C too.  That has to be hard on anything that is alive!

If you’ve got a hive dipping to -20F, it might be a good thing to try to warm it up a little bit the next day and give the poor bees a chance to reposition themselves for the next nights bone chilling cold.  But I don't know.   

The whole way we keep bees in the Northern parts of America makes little sense to me.

Offline Finski

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Re: Top vs Bottom ?
« Reply #78 on: January 18, 2013, 01:32:27 AM »
.
Beeks make strange things.
The most amazing are Thanks giving day honey balls and Cristamas evening supper.
Open feeding is more than odd.
.

One experienced beek (now the beekeeper of year) told that his hives remembered evil boys who threw stones onto hive last summer.
(- Even if bee generations have changed few times. )

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Offline BlueBee

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Re: Top vs Bottom ?
« Reply #79 on: January 18, 2013, 01:59:19 AM »
Finski, just wait for what I have in store for my hives come Valentines day  :)