# THERMODYNAMICS OF THE BEE HIVE



## Mike Gillmore (Feb 25, 2006)

Thank you for your insight. You just answered a question I have been considering lately. 

I was wondering if leaving an empty deep over the brood boxes through the winter, with fondant on the brood frames, would create a problem with all that empty "dead space" above. The wind tunnel description is very interesting. I may try filling that empty box with shallow frames, above the feed, to act as a baffle. 

A very fresh perspective... thanks again.


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## power napper (Apr 2, 2005)

Psycokeeper--welcome to the forum.


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## Aspera (Aug 1, 2005)

You might wish to consider that bees actively regulate airflow, temperature and relative humidity. This is the raison d'tere of being a colonial insect. The goal of a good hive is to allow them to do this efficiently. The goal of the keeper is to manipulate hive so that they not only do this efficiently, but also will have lots of bees on the most abundant necter source, without creating a swarm. With most forms of animal housing, heat conservation, lowering humidity, and exchanging CO2/O2 are trade offs. We are very fortunate that bees actively help us is this regard (unlike swine, chickens and other kept animals).


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## suprstakr (Feb 10, 2006)

NOW THATS WHAT I CALL INPUT
THANKS


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## AstroBee (Jan 3, 2003)

First off, you make some good points and I appreciate your enthusiasm. However, I would like to point out that real-world flow field conditions are not always the same as your premise suggests and may alter your conclusions. It is possible, and quite often the case, that either natural terrain or man-made structures create flow fields that are not always perpendicular to the the hive walls as given in your description. Hive stands are great for producing an updraft at the base of the hive during high winds. Other flow effects can also possibly produce some non-zero pressure gradient across the cylinder. The result would then be some non-near zero cold air flux through the hive and could result in substantial heat loss during high winds.

Regarding baffles, well the "old-timers" came up with solutions a very long time ago to directly address this issue. They are call slatted bottom racks.

See: http://www.beesource.com/plans/bottomrack.htm

I spoke to a very knowledgeable beekeeper and he believes that leaving bottom boards open sets the hive back more than a week in the spring. I'm not sure I completely agree, but I'm experimenting with his premise.

Again, I appreciate your enthusiasms, just trying to point out that real-world conditions are never simple to analyze. And that there are some REALLY smart old-time beekeepers (many frequent this site) out there with lots of great experience and knowledge to share.


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## Aspera (Aug 1, 2005)

I agree with your oldtimer. I am now leaving my bottom boards open only until Feb or so. After that I am closing them up again to allow for better brood development.


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## psycokeeper (Nov 2, 2006)

astrobe,

as i mention in my conclusion i am not suggesting exposure to extreme winds. for the most part in western pa. we experience NW wind direction most of the winter. but it really does not matter what direction the wind is coming from. if you keep a protected air space under the hive stand even if it would be a piece of plywood with some 1/2 inch holes in it to allow air flow and reduce the velocity of the wind you are creating a more favorable situation for the bees to live in. most hobbists seek out protected areas. back side of a hill, trees, buildings, what ever. even a snow fence set up five yards away would have a dramatic effect on reducing wind velocity. the reality is you have the power to control certain perameters around the hive. falure to control them makes a difference and that difference could jeopardise the success of the hive to see it through winter.


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## psycokeeper (Nov 2, 2006)

aspera,

you are missing the point of my scenario. i am addressing specifically a winter situation where the bees are feeding, generating heat energy, and in a cluster. the activity level is at the lowest of levels for the colonie. what you discribe is in my eyes is more a spring time or early summer situation where the factors you mention would have far more significance. because i don't have experience i may not see the big picture like someone with 30 years of working hundreds of hives. but from my vantage point i am seeing things from a different angle. it seems logical to me to control the velocity of wind in the immediate area the hive or hives are located during the coldes part of the year. it would be interesting to see the results of a place like MIT had done on bee hives to know more about what is going on inside them. from a thermodynamic point of view.


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## psycokeeper (Nov 2, 2006)

Questions: Does a colony shed more varroa in the winter naturally? Less in the winter? No one knows?
or:
only with the use of chemicals or essential oils the mites tend to drop. more in winter? or less? no data.

to have the screen open during the winter would allow the mites to hit the ground like they are supposed to and die rather than make it back up into the hive. 

it would seem an advantage to have the bees in this clustered state so that the treatments would cover the whole colony at once and be very efficient. 

if they shed many in the winter then to control the wind around the hive during winter and let them drop out would be a huge plus. since i have no experience i don't know what to think. but i am thinking.


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## kensfarm (Jul 13, 2006)

"Lets face it though, the old timers are still going to stick with wood products for years to come and there is nothing wrong with that. The next generation of beekeepers are going to embrace the new technology "

W/ a little more reading you will find this not to be true.. I have found that the "old timers" are the ones leading & teaching others w/ the best methods they have found. 

Go here to see Infrared pictures of hives w/ bees in winter clusters. There are a lot of interesting projects being done by "old timers" and newbees alike. Welcome.. and happy reading! 

http://www.beebehavior.com/infrared_camera_pictures.php


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## naturebee (Dec 25, 2004)

Here's some material related to your discussion:

THE THERMOLOGY OF WINTERING HONEY BEE COLONIES

http://www.beesource.com/POV/usda/thermology/techbulletin1429.htm


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## psycokeeper (Nov 2, 2006)

pcolar,

thanks for this link. there was so much info i just saved it to review off line. this is exactly what i was asking for. wonderful.


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## Michael Bush (Aug 2, 2002)

>Lets face it though, the old timers are still going to stick with wood products for years to come and there is nothing wrong with that. The next generation of beekeepers are going to embrace the new technology

I suppose I'm an old timer. I've changed virtually everything about how I keep bees in the last five years. The size of boxes, the depth of the frames, the location of the entrance, the kind of bottoms and tops, the arrangement of the hives for winter, the foundation, or lack of it, the genetics, even my hive tool and smoker have changed.









Yes, I'll stick with wood.









As far as thermodynamics, there are some easy ways to get a feel for this. Try camping in the winter in a large tent, a small tent, a tent made of heavy cloth, at tent made of thin cloth, with good ventilation and virtually no ventilation, with light colored cloth and dark colored cloth. With no heater of course. You are not trying to heat the tent, and yet you will find dramatic differences in how warm one is compared to the other.

Thermodynamics isn't only about temperature. It's not only about temperature and humidity. It's about many things including radiant heat, reflected radiant heat, distance to the walls, draft, ventilation, humidity, convection, size, thermal flywheels etc.


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## Oldbee (Sep 25, 2006)

I am here in Wisconsin and it is 14 deg. F. It will be 0 deg. F. tonight and mqaybe 40 Deg. F. on the weekend. So tell me what should I do to help my poor bees survive according to your theory of "Thermodynamics"??


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## psycokeeper (Nov 2, 2006)

The increase in the internal energy of a thermodynamic system is equal to the amount of heat energy added to the system minus the work done by the system on the surroundings. 

this is not a theory this is the first law of thermodynamics.

"It was James Prescott Joule, who first laid down the foundation of The First Law Of Thermodynamics, saying that Heat and Work are mutually convertible through his extraordinary series of experiments.

The first explicit statement of the first law of thermodynamics was given by Rudolf Clausius in 1850" this is from wikipedia under the heading "First Law of Thermodynamics." 

a theory is a proposed explanation whose status is still conjectural, in contrast to well-established propositions that are regarded as reporting matters of actual fact.

some of the information i offered is "theory on my part" because i have no practical experience with beekeeping. i hope that will change and this forum is helping that to move forward. 

what i was proposing is to control the amount of wind that gets to the bottom of an open screen bottom board to counter any draft that may be generated by wind. the reason i see for doing this is to allow the mites to drop out of the hive over the winter never to return. 

no one answered the questions i asked especially the one about applying anti mite products during the cluster phase of the winter cycle. from my view point to have the bees so close together would be an advantage. you could apply the treatment and expect nearly all the bees in the cluster to recieve a dose of the the treatment. as opposed to bees foraging about perhaps bringing more mites back from the flight out. rather than the bees remaining in the hive. i wish i knew more but i don't.

the goal is to reduce or eliminate the mites if they are present. if you don't have any mites then my proposal is worthless. you can keep the hive buttoned up all winter nice and cozy and leave it at that. however i did try to explain what i visualize in my mind based on observations i have seen of wind tunnel and hydro dynamic experiments.

i know you "old" guys are scolding me for what i said. there are progressive thinkers in all walks of life including seasoned beekeepers. i am sure i didn't offend you. you just like to make me aware is all. thanks for sharing your thoughts on this subject by the way.


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## George Fergusson (May 19, 2005)

>Questions: Does a colony shed more varroa in the winter naturally? Less in the winter? No one knows?

During the winter when hives are essentially broodless, varroa die off naturally at the rate of about 10% of their population per month. Unfortunately, that isn't enough to significantly reduce the mite load in part because there are bees dying off too. If you go into winter with a 5% level of infestation, you're likely to come into spring about the same, even with less mites. If you go into winter with a 10% level of infestation, you're likely to come into spring dead









>or:
only with the use of chemicals or essential oils the mites tend to drop. more in winter? or less?

Mite drop in the winter is a small fraction of that during the rest of the year when the hive is actively raising brood, and the mites are breeding. Phoretic mites are by and large happy, safe mites.

>to have the screen open during the winter would allow the mites to hit the ground like they are supposed to and die rather than make it back up into the hive. 

Eh. They're not dropping. Those that do are dying of old age.

>it would seem an advantage to have the bees in this clustered state so that the treatments would cover the whole colony at once and be very efficient. 

That is the premise behind using oxalic acid in the fall when the temperatures are cold enough to keep the bees loosely clustered. Efficacy drops off somewhat when the bees are tightly clustered presumably because the bees are in fact tightly clustered and the oxalic acid isn't as evenly distributed amongst the bees. Most treatments work by direct contact with the acarcide.

I have no experience with essential oils.

>the goal is to reduce or eliminate the mites if they are present.

I agree. Winter doesn't seem to be the right time to do it however, at least with the methods we have available at this time.

>i know you "old" guys are scolding me for what i said. there are progressive thinkers in all walks of life including seasoned beekeepers. i am sure i didn't offend you.

Heh. Well, progressive thinking is a good thing, but it isn't always right. No, you didn't offend us, or me anyways. I enjoyed your stab at hive thermodynamics, we've discussed it before and there has been considerable discussion and disagreement on the questions of heat transfer, heat loss, ventilation, etc. It is a topic that hasn't been run ragged yet.

When thinking progressively or otherwise about hive thermodynamics and ventilation, it's a useful exercise to go out and look at some hives in the winter time and note how the snow is melted away from around the hives, and to read about Canadian experiments of overwintering hives indoors and what they learned about the need for hive ventilation.

Anyways, welcome to the phorum.


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## Aspera (Aug 1, 2005)

pschokeeper,

You should take another look at that thermology paper posted on Joe's link. Winter bees are metabololically very active and bocome more so as temperatures decrease. As for the virtues of wood, I will say that it is probably not so good as a straw skep, but people continue to use it after 20+ years of synthetic hives. Wood hives are legal, durable, warm, flexible, reusable and well liked by bee and keeper alike. More importantly, wood is inexpensive and it works, thus fulfilling the two primary criteria of every agricultural endevor ever encountered.


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## Hillside (Jul 12, 2004)

The first law of thermodynamics applies to a "closed" system. A beehive is certainly not a very well closed system; especially when it's missing it's top or bottom!!!!

I think the "draft" (convection loss?) is a lot greater than you might think.


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## George Fergusson (May 19, 2005)

>I think the "draft" (convection loss?) is a lot greater than you might think. 

I'm inclined to agree Hillside. In particular, I think many significant factors are overlooked or minimized when contemplating the thermal characteristics of a beehive in winter such as the insulative value of dry air vs. wet (humid) air, the deleterious effect of convection currents, even small ones on the insulative quality of dead air, the effects of conduction, black body radiation, the R-value of the hive materials, etc. Beehives are honey-powered furnaces.

Here's a thread from last year that touches on some of this:

http://www.beesource.com/cgi-bin/ubbcgi/ultimatebb.cgi?ubb=get_topic;f=2;t=004229;p=1

Wish I could find those infrared photographs of some wintering beehives...

Say, can one break the laws of thermodynamics? If so, what's the punishment?


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## George Fergusson (May 19, 2005)

Ah... found em









http://www.honeybeeworld.com/diary/2004/diary011004.htm


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## psycokeeper (Nov 2, 2006)

really interesting photos in infra-red.

thanks for finding it


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## pahvantpiper (Apr 25, 2006)

Went out to one of my yards yesterday and found two lids that either got blown off or pushed off by cattle. We've had several nights below zero (record breaking temps. for us at this time of year). I think the lids had been off for quite a while because they were snowed on and we haven't snow for several days. Anyway, I expected to see two dead hives but to my surprise the bees were still alive. Bees can take more than I thought. 

-Rob


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## dickm (May 19, 2002)

I feel remiss if I don't join in. 
Mike: you and I think alike. You can learn a lot by camping. 

I drew on cold weather camping, in part, for an ABJ article on this subject.Watch for it soon.

An early learning I had was that the bees don't heat the space. Since we humans assume that the rest of the world follows our example it's hard to imagine that. This is old news. 2" outside the cluster it's as cold as it is outside. If you consider the size of a double deep and the amount of energy it would take to heat it to, say, 50 degrees for a northern winter, I suspect that you couldn't pack in enough fuel.

Psycokeeper: You said several times that you lack in experience. You make some good points, wrong, but good, and I'm sure that with experience you'll be a lot of fun.
>>>>I find it amusing that so many folks are worried about open bottom boards, the wind, and providing vents at the top of the hive.<<<<

It's not amusing. It's the life or death of the hive.


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## Michael Bush (Aug 2, 2002)

In Western Nebraska and Eastern Wyoming, I didn't find a top vent necessary. But those are dry climates. Still they might have done better with one. In Eastern Nebraska I find them essential to the survival of the hive because of the condensation. We get some sub zero weather most every winter, and that's not what kills my bees. That icicle on the inner cover melting and dripping on the cluster sure does slow them down though.

As dickm says, "It's the life or death of the hive."

>I find it amusing that so many folks are worried about open bottom boards, the wind, and providing vents at the top of the hive.

I WANT air coming in the bottom and going out the top. Slowly? Yes. But moving? Yes. ESPECIALLY when it's cold, so I can avoid the ice on the top.

With an open bottom and a 60 mph wind (not at all unusual here), it may not be so slowly. At -43 F on rare occasions, it also may not be so warm.


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## David Stewart (Jan 22, 2005)

In my climate we get very mild winters. Dec 08 was one of the coldest I suspect we'll get this winter (teens) so I went out to take a look at a weak hive that is destined for my newly completed observation hive as soon as it's sufficiently off gassed and I get a decent day. My question is concerning the formation of ice- We have what I would call moderate-high humidity but what confuses me is even at temps in the teens you can clearly see in the picture that there is enough heat transfer through the 1/2 plywood lid to prevent frost. Would it not make sense that if frost cannot form on the outside that ice could not form on the inside (over the cluster)? Picture is also a decent illustration of heat transfer within the hive.

P.S. Before anyone throws a shoe.....The "pesticide" container in the background is a thoroughly rinsed container that it used for soapy water insecticide applied to garden plants in the garden just out of the shot.

http://i30.photobucket.com/albums/c301/stewaw/Bees/100_0352.jpg

http://i30.photobucket.com/albums/c301/stewaw/Bees/100_0351.jpg

David

[ December 09, 2006, 06:52 AM: Message edited by: David Stewart ]


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## BjornBee (Feb 7, 2003)

David, don't sweat it. I throw rocks, but almost never hit the target intended.  

I don't use chemicals, and yet some are perplexed when they visit my place. I have a bottle of sucrocide sitting on my bookshelf, a new box of apistan sitting on my desk, an empty container of checkmite in the garage somewhere, an instruction and use label for maverik somewhere, etc. Usually someone makes mention of one or another, and are surprised when I pull out the mentioned product. They were given to me or collected for informational purposes. Even if I don't use them, I like to keep up on all the current stuff so I can give solid sound advice.

Your question can somewhat be answered by relating to a car window. Sometimes the outside is frosted over, and yet the inside is frost free. The "glass" however is below the freezing point both inside and out. Much of it has to do with the humidity level. If the humidity level is high inside the hive, and it is, then ice can form more easily than the outside of the hive, which in winter and below freezing temps has a very low humidity level. 

The heat from the cluster on a strong hive will keep most ice from forming on top of a hive(outside). But that increased moisture causes condensation to still build inside the hive and is more prone to freeze with extreme temps. Alot happens inside the hive that is not directly related to observations outside the hive.


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## Hillside (Jul 12, 2004)

The whole thing is a balance between respiration and heat production by the bees, dew point of the air inside the hive, and temperature of the hive walls.

The bees will do their best to control their environment so that they can survive, but you can help them along by setting up the hive in an "optimal" fashion. You can change insulation and ventilation, but you don't have control over much else. The best balance depends on the size of the cluster, the outside temp, the length of winter, the humidity, etc. 

You need to find the balance that works best for your bees in your environment and hope that this particular winter has the kind of weather that you planned for. In the final analysis, for *most* of the US, a standard hive with a small top vent is sufficient for most bees to survive the winter. In the extreme areas you have to do more and if you want the strongest spring hive, there may be some things you can do to get the best balance. 

There's a reason they say all beekeeping is local. Or was it all beekeeping is loco?


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## psycokeeper (Nov 2, 2006)

after reviewing the link to the Thermology report from george furgusson i found several things that actually support some of what i stated in my opening to this thread. but to avoid sounding like a show off or smart guy, i want to with hold my findings and wait for some positive indications from you all. people who are compelled to have the last word on something are generally not well recieved. i don't want to appear to be that way, that is not who i am. if a majority want to review my findings then i will post them. if not thats fine no problem. i hope this is an arena of ideas and exchange of thoughts and views.


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## George Fergusson (May 19, 2005)

>if a majority want to review my findings then i will post them.

I'm a majority of 1 and as such, I'm waiting for your findings. Don't keep us in suspense! If you think you're going to have the last word on this matter, you ain't been around Beesource very long









George-


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## Aspera (Aug 1, 2005)

George,
I really liked that beekeepers diary link. There is much good reading there.


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## George Fergusson (May 19, 2005)

Ayuh. Seems I'm always confusing Allen Dick and Dick Allen. Why is that?


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## Tom Chaudoir (Nov 20, 2005)

> Where I see the confusion is with draft. Draft is: a current of air in any enclosed space, esp. in a room, chimney, or stove. a current of air moving in an upward or downward direction.


Our bee chimney is heated. Convection moves the air upward.



> Since the bees are not actively dissipating the heat by fanning their wings,...


That's exactly what they do if they perceive an area of the hive to be too warm.



> Since honey and brood are water based the water holds a lot of kinetic energy.


The only times that my hives have measurable kinetic energy is when they are being moved.



> If a colony moves in a vertical direction during the winter months then would it be logical to assume that the inverse would occur as spring approaches and nectar and pollen are again available?


Bees like to put their stores overhead. It's common practice in the spring to find the brood cluster and move that box to the bottom. I don't know if they would move the brood down if the space was available, and I'll let someone else try it first











> I find it amusing that so many folks are worried about.....


That's the bit that tripped my trigger a little. Sorry. Let us contrast that with:



> Let me begin by stating I know nothing about beekeeping short of what I am reading on this forum.


You can be amused when you test your ideas and they prove to be better than the usual methods.

A lot of things have been tried. Some things worked. Trial and error involves both trying and failing. People tried moving hives into root cellars, or insulating with bales of straw. It sounded good, but threw the bees off kilter. For many thousands of years they have been living in hollows of trees. (Wooden trees) Insulate the tree and they put the cluster too close to an outside wall.

I'm not against advancement or experimentation. This spring my hives will be long and low and open on the bottom with no traditional entrance other than the open bottom. It may fail. If it works for several years, and it works better, and I tell people about it, and they don't listen, *then* I might allow myself to be amused.

You have some ideas about beekeeping. Welcome! We all have ideas. Get yourself a couple of hives. You won't be sorry.


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## Ian (Jan 16, 2003)

>>Does a colony shed more varroa in the winter naturally? Less in the winter? No one knows?


Our guys are finding a significantly higher mite drop on indoor wintered bees when ventalation is kept to a minimum. They seem to more actively groom the mites in this situation,. Why? Dont know.
For what its worth,


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## George Fergusson (May 19, 2005)

>Our guys are finding a significantly higher mite drop on indoor wintered bees when ventalation is kept to a minimum.

Excessive ventilation may keep them clustered tighter. Are these indoor wintered bees raising brood over the winter? If they are, that and the looser clusters could contribute to higher mite drop.


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## psycokeeper (Nov 2, 2006)

i stand corrected on kinetic energy. wrong choice as kinetic energy is dealing with motion. not sure what term to use for "stored heat energy". potential energy? what do you call energy stored by a watch spring? what ever the proper term is i mean stored heat energy which is basically held by the surrounding.

perhaps amused was also a poor choice. curious. or contemplative is maybe a better term.

> Since the bees are not actively dissipating the heat by fanning their wings,...

Tom, you are taking my scenario out of context. my premise is that the bees are clustered in a winter mode only. they are not engaged in any other activities except consuming food, generating heat and moving about very slowly. i am suggesting external temperatures at or below freezing for a more specific situation. i am sorry if i did not fully discribe things well. once the air warms to the point that you have bee activity out side the hive everything i described is irrelevent.


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## Aspera (Aug 1, 2005)

The term is simply heat, or in some cases, pressure. Pressure is a direct measure of average translational energy of a particles in a gasseous form, but I think that heat is what you describe. Thanks for stimulating a good disscussion on an important topic.


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## Dick Allen (Sep 4, 2004)

http://www.theonion.com/content/node/28308


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## George Fergusson (May 19, 2005)

Yeah Dick, that's what I'm talking about.


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## drobbins (Jun 1, 2005)

psyco,

I think you want this

http://en.wikipedia.org/wiki/Enthalpy

Dave


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## psycokeeper (Nov 2, 2006)

i looked at theonion link. these people are on the fringe of the Christian far right. it is too bad they can't spend more time helping the guy down the street who just lost his wife to cancer or help consol a parent who's child just od'ed on drugs. it is not the Churches job to debate scientific principles. if the Church would do the job they were instituted to do our country would fare far better than it is right now. this discussion is moving in a direction to a different topic. focus please.


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## kc in wv (Feb 1, 2006)

One thing that I haven't seen mentioned in this string is the difference in the way that moisture in the hive is stabilized to some degree by wood. Plastic on the other hand does but not absorb or give off any moisture. I hear from my cattle farmer friends that hay wrapped in plastic has a different curing result than hay kept dry in the barn. They even stay there is a difference between black plastic and white plastic.

quote; " it is not the Churches job to debate scientific principles. "

I think if you look back into the history of the church, you will find that much of your early scientific research was conducted at the churches

This is a very interesting string of posts. It shows that we all are trying to deal with and solve the same problems and trying to apply our expertise when possible.


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## dickm (May 19, 2002)

>>>>bees will do their best to control their environment<<<<

Am I the only one that sees the bees doing dumb things? Like trying to close off an upper entrance, or forming the cluster on top of a store of honey? The bees that go into winter have never seen a winter. What they have to work with is genetic. 

Dickm


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## psycokeeper (Nov 2, 2006)

everything outside of these symbols>< are excerpts from the Thermology Report. 

>comment< = my comment on the exerpt

this looked and made more sense with bold type and italics but i don't know how to send that to this reply screen. sorry if it is confusing in any way.

If the number of bees within the insulating shell >referring to the bees on the outside of the cluster of the colony< remains constant, then the density of the bees must change. Also, as shown in figure 5, there is a large temperature change within a very short distance outside the cluster. This suggests that the airflow around the cluster was small. 

>Supports my premise that there is a micro-draft. leaving the bottom screen open or partially so but controlling wind velocity outside the hive by some sort of baffle is correct and reduces or eliminates windchill effect.<


The location of the cluster's outer edge and the temperature outside the cluster changed with outside temperature. Frequent temperature readings showed that the change in hive temperatures lagged behind the outside temperature by 1 to 2 hours. 

>Supports my premise that kinetic energy is stored, one could also conclude it will take that amount of time to reheat cold honey,frames,etc<
Normally no temperature in the check hives reached the daily maximum or minimum outside temperatures, but it fluctuated in accordance with them.

Figure 2 shows that the temperature at the outer edge of the cluster was about 44º F. Since the bees on the outer edge were facing into the cluster, this temperature was measured at the abdomen of the outermost bees. The bees were densest just inside this outer edge, where the temperature was 55º to 56º They >the adult bees< were in all empty cells and as close together as possibie in the interspaces. 

>Suggests economy and efficient use of space, maximum heat exchange achieved due to contact of cell walls by the bees.<

The bottom entrances were closed and the top entrances remained open on all colonies for a few days and then the openings were reversed. The bottom entrance had no effect on the reaction of the cluster because of temperature. Nor did the bottom entrance affect the temperature in the bottom body of the check or packed colonies. The tape colonies had a 2º F. rise in the bottom body when the bottom entrance was closed. When the top entrance was closed, the cluster moved closer to it and did not draw back at night as it did when it was opened. Except for temperature changes caused by the cluster movement, the temperature distribution in the hives was not altered by changing the entrances. 

>Supports my premise for leaving the screen open or partially open and providing good top ventilation and or a top entrance. Finman says he keeps top entrances on most of his hives I believe<

> Astrobee I spoke to a very knowledgeable beekeeper and he believes that leaving bottom boards open sets the hive back more than a week in the spring. I'm not sure I completely agree, but I'm experimenting with his premise. 
> report findings do not support this premise<

6 The unprotected colonies had the tightest insulating shell >cluster of bees<, or the least distance between the 44º and 60º isotherms.

7 A colony protected by insulation will have a less compact cluster that will fluctuate more in size with temperature change than a cluster in an unprotected colony. 

>this would allow them to move to additional stores in the hive through out the winter as opposed to a non insulated hive. The report also found that uninsulated hives had a higher incidence of death because the colony was tight and did not move to adequate stores only inches away.<

17 Honey bees make no attempt to maintain the temperature in the domicile outside the winter cluster. >passive heat retention by insulation or a poly hive would help to retain heat in the areas the bees do not actively heat.<

18 A cluster held for long periods under freezing conditions declines in strength. The rate of decline is dependent on pollen stores available, but it is slower in insulated than in unprotected colonies.

19 Brood rearing will occur under subzero conditions in insulated colonies with plenty of pollen and honey stores in the cluster.

20 Under normal winter conditions either insulated or noninsulated colonies should survive at Madison, Wis.

The evidence is strong that colonies can withstand cold and even subzero temperatures for weeks. However, bees can maintain cluster temperatures easier if the colony is insulated. Brood can be reared under low external temperatures provided sufficient pollen and honey are available to the cluster. Fluctuation in the cluster is due in part to temperature change, which may be in the daily mean or in the differential of day to night. >Supports my premise that controlling wind velocity by baffles helps to reduce or eliminate windchill effect.<

>One finding I read in the Thremology paper was that many of the tests done in refrigerators ended with nosema in the colonies.< 

>It would appear that a protocol for administering Fumagilin-B to all colonies in march or april could be effective preventative treatment?<

>Poly hives would have an advantage in allowing a colony to seek, find and move to winter stores with more success because the cluster is not so tight than with wood. This would also give a weaker colony a better chance to survive than wood as well.<

>Skilled and knowledgeable beekeepers are able to have more success in over wintering in wood because they know how to build strong colonies into the fall and combine weak colonies.<

> A beginner would have better initial success over wintering any colony strength with a poly hive due to the insulation effect which allows the bees to seek and find stores since they do not form such a tight cluster.<

The change in a packed insulated colony for a 2-day period when the outside temperature was increasing. The cluster generates enough heat to warm the entire hive to over 40º F. when the outside temperature was over 30º. There was little effect due to solar radiation, but the 76º isotherm was farther away from the entrance at night.
Without an upper entrance the bees were confined to the hive most of the winter and thus their chance for winter survival possibly was decreased. The lower body of the unheated check and packed hives never warmed up enough to permit the bees to fly from the bottom
> Supports the use of top entrances>


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## George Fergusson (May 19, 2005)

>i looked at theonion link. these people are on the fringe of the Christian far right.

They're fringe alright... fringe lunatics, like some of us here on Beesource









>Am I the only one that sees the bees doing dumb things?

Not at all Dick. Sometimes they seem to do things that are not in their best interest, like stinging me, but they do it anyways







Still, I almost always conclude that the bees know what they're doing and that it's my understanding of the circumstances that is flawed, or incomplete. I can conclude nothing else. No doubt, our management efforts complicate things for the bees and no doubt confuse them sometimes. Whose fault is that? Maybe some of our hives that survive do so in spite of what we've done to "help".


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## albee (Nov 16, 2006)

I just use 2" of blue building foam. I got the idea from Dave Cushman.

http://website.lineone.net/~dave.cushman/ventilation.html


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## Michael Bush (Aug 2, 2002)

You do know that the Onion is satire and NOT news don't you? It's a spoof. It is not real.

http://en.wikipedia.org/wiki/The_onion


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## Tom Chaudoir (Nov 20, 2005)

The onion is indeed purely satire, and some of the best on the internet, or in print for that matter. We fans slap high fives when one of the big news outfits mistakenly take an onion story as real and quotes it. For perspective, just look at the headlines on the front page. 

Back to the subject of our winter hives, and these are just some thoughts:
Some might have a mental picture of a static system. Temperature probes show this at one point and that at another. Period.

Let's take that frame down for a bit, and put up another, more dynamic model. Feature, if you will, the hive as a lava lamp, and the cluster of bees as the little bulb that drives the flow of air via convection. Ok, it's not a perfect model, but you see what I mean. Now we might be closer to visualizing the "microcurrents" of air.

The products being consumed are honey, air, and water when available.

The outputs products are heat, water vapor via respiration, carbon dioxide, and solids that are stored in the abdomen until they can be purged in a cleansing flight.

The fresh air is really important. We have a community of insects that in some ways can be considered to be one animal, and that animal weighs a few pounds. Let's assume that our animal needs as much air as, oh, let's say, a squirrel. Whatever the animal, the fact that it's alive in there proves the flow of air through the system.

Heat is useful in more than one way. It not only keeps the animal at a temperature where it can continue to metabolize it's food. It keeps the overhead stores from freezing and becoming useless.

Water vapor in our artificial hives is seen as a nuisance. If it doesn't leave the top of the system with the outgoing stale air it will condense. A dry hive is a happy hive, for the most part. Then again, open a jar of honey and put it in a cool place with low humidity. Before very long you have a crystalline chunk. It's harder to eat and doesn't have the water content that the bees depend on in really cold temperatures. 

A balance of heat and humidity is needed, and I suspect that the bees "know" what it is. Perhaps a good hive design would incorporate many small gaps in the cover that the bees are free to stop up if they feel the need.

Just me thinking out loud.

Best,
Tom


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## db_land (Aug 29, 2003)

"The onion is indeed purely satire, ..."
Sadly the far-left fringe lunitics believe this stuff.To them it is their Gospel!

The only thing I would add to Tom's hive-thermo model is that CO2 is heavier than air or water vapor. It sinks to the bottom and, by doing so, contributes to a small up-welling of fresh, dry air. It's very bad to seal off the bottom to the extent the outflow of Co2 and intake of fresh air is stopped.


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## Aspera (Aug 1, 2005)

Yes, its true. I belief that the Onion has every bit as much factual basis as the Gospels have. However, I have no fringes, left or right, and vote for whoever will do the greatest good for the greatest number.

Back on topic....Modelling a hive is a bit foolish when empirical evidence is so abundant and easily obtained. I can't tell you how many hours I wasted thinking about better hives when I should've been focused on better management, or possibly on better bees. Technology can only do so much for insects, and probably even less for their wardens.

[ December 12, 2006, 11:30 AM: Message edited by: Aspera ]


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## Keith Benson (Feb 17, 2003)

"The onion is indeed purely satire, ..."
Sadly the far-left fringe lunitics believe this stuff"

Um, nope - they just laugh at it. It is a joke publication. Pure and simple, nothing factual in it.

Keith "been an onion fan since living in Madison" Benson


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## Ian (Jan 16, 2003)

>>Are these indoor wintered bees raising brood over the winter? If they are, that and the looser clusters could contribute to higher mite drop.

George,
they have a tool, an infa-red camera that shows them the heat differences in the hive through out the wintering situation.
It seems as the ventalation is slowed donw, the cluster temperature rises, and the bees tend to exibit more grooming behaviour, dropping the mites. There is no link to brood rearing, but mearly ventalation regualtion. 
They are also finding this to be a useful tool to find the higher grooming behaviour bees without having to do a bunch of studdy on each hive. The higher cluster temp seems to be a good marker,


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