# Urban legend or repeated garbage?



## MapMan (May 24, 2007)

Make sense, sort of like me eating a bowl of Golden Crisp® in the morning, and going outside to contribute to Global Warming.

Scientifically, are there any studies measuring temperature of clusters and the ambient air space in different parts of the hive? This should support your logic.

MM


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## MountainCamp (Apr 12, 2002)

I think that the problem is that most do not know or understand the thermodynamics of convection, conduction, or radiant heating.

In winter do I heat the great outdoors? Intentionally, no - in fact, yes. Waste and lost heat energy from my outdoor boiler, heat energy lost through the walls, windows, doors, and roof. So the ambient temperature within close proximity to my home is raised as compared to further away.

I intentionally raise the internal temperature of my home. I input energy into the home system and create a living space that I can freely move around in regardless of the outside ambient temperature.

That said...

The cluster does not heat the hive space in any manor other than by "lost" or wasted energy. Just as my home loses heat / energy to it's surroundings, so does the cluster. They do not try to regulate the temperature of the hive space outside of the cluster space in any manor or way. 

The cluster forms and a layer forms around the edges of bees who have been tapped and designated as the insulation layer. The clusters size and shape changes with the ambient temperature. The bees in the insulation layer are rotate in and out of the inner cluster to rewarm them. This is because the amount of heating of the surrounding hive space is NOT sufficient to keep them alive.

The cluster does NOT heat the hive as a whole so that the cluster or individuals can freely move regardless of the ambient temperature.

The temperature gradients within the hive are dependent on the cluster's location, the hive's layout, and the ambient conditions.

Too be continued...


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## BjornBee (Feb 7, 2003)

MM,
Anyone can set a thermometer one inch from the bottom of the bottomboard, and another one inch under the inner cover. It's no "fancy-pantsy peer reviewed sent for publication in a scientific journal" type thing I did, but it proves it just the same. Just wait till the bees cluster and do your own testing. I didn't write it all down, but I just wanted to see for myself. This was a couple years back. I felt like a fool taking the time to tell myself something I already knew. (Heat rises)

BTW MM, how do you get that little "r" encircled. Is my keyboard out of date? Or is there a trick?


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## Hobie (Jun 1, 2006)

I have seen just such a study, but darned if I can find it now! Will keep looking. Someone had positioned thermocouples throughout a hive. Bottom line, temps where the cluster was were in the 90's (F). Temps at the edges of the box were in the 30s. Can't recall what outdoor temp was in the experiment. The warm spot moves around with the cluster. Kind of like penguins in the Antarctic.

I always read that statement to mean that bees do not warm the entire hive, like people heat their houses. They warm the living room, and close off the den and spare bedroom. I agree that some of the heat they generate is trapped, and helps them maintain the cluster warmth (hence the benefit of popolizing shut cracks and wrapping hives and wind breaks.) But outside of the cluster it is still cold (hence the issue of starvation with honey stores 2 inches away.)


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## WVbeekeeper (Jun 4, 2007)

There have been a lot of studies measuring temperature and humidity at different level within hives. I read about about study not long ago that had some nice flow charts with it. The flow charts depicted the temp and humidity below, within, and above the cluster in subsequent days as relating to exterior hive temeratures and humidities. I can't remember where I seen it so I don't have a link.


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## BjornBee (Feb 7, 2003)

I disagree about it being "lost" or "wasted" heat.

If you allow one hive to use the upper box for spring buildup, and rotate the next hive's cluster to the bottom box, more bees will be raised in the hive with the cluster in the upper box. I have done this a number of times. 

How can it be "lost" or 'wasted' heat, when the bees can in fact take advantage of this same heat?

I also know some who use insulation board and other material to enhance or maximize the trapped heat so not much is lost. They do this for early buildup, they swear by it and claim it makes a difference.

Get your thinking caps on. We'll probably be talking insulated hives and other items very soon....


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## Keith Jarrett (Dec 10, 2006)

BjornBee said:


> Get your thinking caps on. We'll probably be talking insulated hives and other items very soon....



Been putting on plastic pallet covers on mine for years, mainly to keep the wind out.


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## MountainCamp (Apr 12, 2002)

Here is the study, I think you were looking for. http://www.beesource.com/pov/usda/thermology/techbulletin1429.htm


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## BjornBee (Feb 7, 2003)

Mountaincamp.

Yep, just as I said.

You can read through it. But some interesting points. When the upper entrance closed....the bees moves upwards (I'll assume towards the warmth.)

The pack (insulated) hive had more brood than the checked (Uninsulated) hive. (Heat retention).

The bees gravitated to the sun side of the hive. As I thought, heat outside the cluster was important, and the bees do benefit and seek out these warmer areas. Same thinking as the trapped heat in the upper chamber. If warmth outside the cluster meant nothing, these patterns would not be evident.

I'll say, much of this study is not in reference to what I was talking about. And in making statements in one point, it seems to contradict a point about another.

Figure 1, 2 , and 3 do show that as you go lower in the brood chamber outside the cluster, temps do fall. The clusters were top heavy, and I can see that the bees benefit from the warmth caught at the top of the hive. Even if this study does not really address that.


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## buckbee (Dec 2, 2004)

*bee thermography*



MountainCamp said:


> Here is the study, I think you were looking for. http://www.beesource.com/pov/usda/thermology/techbulletin1429.htm


No big surprises there, then.

* Bees are good at keeping themselves warm, unless the outside temp drops off the scale.
* Keeping bees in the Arctic probably won't work.
* The lower the temp, the tighter the cluster.
* Some colonies are better than others at generating heat.

Interesting about nosema being rife in chilled colonies - that might be worth looking into.
There was a suggestion that a middle level entrance might be better than a bottom entrance from the point of view of bees flying in winter.

What we really need now is a similar study that has humidity as a variable, so we can see the effects of different climates and condensation, which might have implications for ventilation.


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## b_z_genius (Jan 25, 2007)

Why don't we all put a solar heater under the hive so they can move around the whole house and not just the living room? I have seriously considered trying one but I am afraid they would just eat all their stores up faster and I would have to feed them but that is just my thinking what do you all think would happen? This would heat most of their home during the day.

For those that don't know what a solar heater is: take a shallow box and paint the inside black, place glass on it for a lid. Place the box so as to take advantage of most of the winter sun usually on a 30~70 degree angle facing south. cut a hole in the lower portion of the box for fresh air intake and a hole on the upper portion of the box with a duct run to whatever you want to heat. And now you have free heat during the day. If you search around the net you can find better descriptions.


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## MountainCamp (Apr 12, 2002)

Wintering the hive is a balancing act with a number of balls in the air all at the same time. Where you winter your bees will influence how you set them up and how they will cluster, move and use stores.

The colony does not rear brood on the outer occupied area of the cluster because it is too cold, heat and energy are lost and wasted to the surrounding.

Heat rises from convection, heat moves along the frames, bees, and hive parts by conduction from warmer to cooler (one reason aluminum frames failed) where they are in contact, and in all directions by radiation.

The cluster will move toward the sunny side of a hive as long as the solar gain is greater than the heat loses due to being closer to the colder ambient temperatures.

The cluster will move vertically through the hive as winter progresses. They will move to the top of the hive as they eat their stores. The cluster will move toward and away from the inner cover and top, toward and away from the side walls, toward and away from the entrances, all based the ambient temperature changes and heat loss.

A "mass" above the cluster abosrbs some of the "waste or lost" heat energy from the cluster. This mass then radiates some of that absobed energy back at the cluster. The closer to the mass the more radiant energy received, but the loses to conduction may increase depending on the emissivity of the mass and the thermal conductivity of the material, and the outer ambient temperature.

Much of the lost heat from the cluster is lost due to convection of the warm, moist air from resporation. With upper ventilation to reduce condensate formation, this heat is lost and wasted.

You know I set my hives up for winter, with sugar on paper in an empty box. There is some ventilation simply because of cracks and how boxes fit up. I wrap them them to reduce wind infiltration and increase solar gain. The paper and sugar are the "mass" that absorbs heat from the warm moist air. 

Do clusters move and make use of their surroundings to their best advantage? 

Yes, however the heat that escapes the cluster's insulating shell and it's required energy expended to create it would better serve the cluster if it were kept within the cluster. Hence, it is lost or wasted.


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## dcross (Jan 20, 2003)

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

Infrared pics of beehives in winter.


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## Hobie (Jun 1, 2006)

MountainCamp said:


> Here is the study, I think you were looking for.


Yes, that or something similar. I don't recall the experiment of killing the cluster with cyanide, which just about turns my stomach.


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## Jeffzhear (Dec 2, 2006)

MountainCamp said:


> "Wintering the hive is a balancing act with a number of balls in the air all at the same time....Much of the lost heat from the cluster is lost due to convection of the warm, moist air from resporation. With upper ventilation to reduce condensate formation, this heat is lost and wasted.
> 
> You know I set my hives up for winter, with sugar on paper in an empty box. There is some ventilation simply because of cracks and how boxes fit up. I wrap them them to reduce wind infiltration and increase solar gain. The paper and sugar are the "mass" that absorbs heat from the warm moist air.


So, the way I am interpreting this, is that you don't have an upper vent hole in the box that you have sugar on paper...did I make the right assumption? Maybe I have to plug up the ventilation holes?


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## Jim Fischer (Jan 5, 2001)

Somehow, the title of this thread does not provide much hope
that the presentation of facts or published studies might change 
the views of some who seem to already have their minds made up. 

So, I'll ask a question, instead:
Let's assume for a moment that the bees DO heat the air in the hive,
and that the heated air stays in the hive. If that were the case, *how
do the bees breathe*, rather than suffocate on the CO2 from their own
breath? Which creates a larger volume of this heated air, respiration, 
or convection from the outer bees in the cluster?

We know that they somehow keep breathing, so it follows that there
must be a *steady supply of fresh air*, and a *steady exhaust *sufficient
to remove the CO2. That's why the actual thermography always shows
a temperature very near the cluster that is about the same as the
outside temperature.

Here's a decent paper on the subject of "how bees keep warm":
http://jeb.biologists.org/cgi/content/full/206/2/353?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=infrared&searchid=1139251218748_2955&FIRSTINDEX=0&resourcetype=3&journalcode=jexbio

And here's some decent thermography in higher-rez from the paper:
http://jeb.biologists.org/content/vol206/issue2/images/large/JEB00082F1.jpeg

Note that in the paper, there is no mention at all of the ability of any
hive to keep bees warmer. What IS mentioned is the insulating 
abilities of the outermost bees in the cluster. This indicates that
the cluster is radiating minimal heat, giving the gestalt impression
that more heat is being given off via respiration.

While one can wrap a hive as is done in Alberta, this is more of a 
protection from the bitter winds than a way to keep the interior air 
in the hive warm, as once again, ventilation is key.

In attempts to overwinter colonies in buildings, the biggest issue
is providing sufficient ventilation. Even a power failure can be 
fatal here, as fans are required to move enough air in and out. 
(This approach rare, but several people have attempted it, once 
again in the far North of Canada.)

Yes, there is some heat loss due to the combination of radiation
and convection. But there is not a whole lot one can do to
"fix" this without creating a more serious problem of suffocation.

And these new-fangled high-resolution thermographs show the
actual situation in real time, and are hard to dispute.

And let me channel the late George Imrie for a moment when I
repeat: "Cold does not kill bees. Lack of ventilation and
resulting dampness kills bees." I find that to be true everywhere
except places like Alberta Canada, where bees simply cannot
survive winter without extraordinary measures being taken by
the beekeeper, and would not survive at all on their own.
(This implies that places like Alberta are simply beyond the
natural range of honey bees, and a very special case.)


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## MIKI (Aug 15, 2003)

BjornBee said:


> Mountaincamp.
> 
> Yep, just as I said.
> 
> ...


As you said you are assuming.

Along your line of thought if bees intended to heat thier environment then they would store much more and continue with full blown brood rearing and hive activites. They would not have to worry about a spring build up because they could already be in good position for spring. That would just be a good survival tactic. But they don't, they cluster and attempt to conserve which means expend as little energy as possible. The studies all support the theory. To call it an urband legend based on assumptions is pretty bold. I do not agree with your interpretation of the data.


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## BjornBee (Feb 7, 2003)

MIKI, Did I say "intended'. Go back and read it again, then come back and make claims about me "assuming", after your finished doing the same yourself.

Your entire first sentence after incorrectly commenting on me, deals with "assuming". Nice try.

Did you even read the study posted? Or see the infrared pictures? Maybe its just me, but the top of the boxes certainly look hotter than the bottom. Yes, the picture does not clearly state so, some I'll assume just the same. Looks to me that a whole lot of warmth is in the top half, whether intended or not.

I am glad you jumped in here since it was your comment that started this thread.

And Yes, I believe using a follower board allows the cluster heat to be maintained within a TBH or trench style hive. Thus allowing an easier time for the cluster to hold heat, expand cluster size, and even fend off the coldest time of the year.

I know getting three frames of brood in an early season split to build, is easier in a 5 frame box, as opposed to a ten frame box or a hive with two deeps. Try building a nuc in a large hive next to a nuc box, and its rather easy to see the difference. there is no doubt that bees benefit from trapped heat, whether intended or not.


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## MountainCamp (Apr 12, 2002)

The empty boxes don't general have a vent / entrance hole. 

If I grab a deep that had one, I don't bother plugging it. It is cover by the felt paper anyway.

If I was keeping bees somewhere that was significantly colder, I might worry about it. I would also look closer at packing / insulating my hives.

But, with the temperatures here and balancing the work involved in packing / insulating vs. wrapping and what I currently do and my average losses. I do not lose good strong hives over the winter as I currently do things. So there is no economic force to change.

When I lose a hive, there is almost always a good clear reason or I screwed something up. But, either way packing would not have changed things.


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## Jeffzhear (Dec 2, 2006)

Ok then, I have clear direction on the way forward. I'm not going to worry about buying corks to plug the entrance holes. I'll just put the felt paper right over the holes. I had actually been thinking of cutting holes in the felt paper to provide a vent, but now I won't. 
Thanks Mountain for the clarification...


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## BWrangler (Aug 14, 2002)

Hi Guys,

>Get your thinking caps on. We'll probably be talking insulated hives and other items very soon....

In the mid 90's ABJ, an article by Bernhard Mobus, describes some research with a series of overwintering conditions. Cluster sizes were varied by creating super cluster through dinks. Insulation was varied as well.

It was found that an optimum cluster size existed. Larger and smaller clusters suffered greater losses.

He also observed than bees suffered greater losses when insulation was increased and postulated that water balance and not temperature were the main factors controlling cluster behavior.

Cold was actually good for the bees. I've observed the same. So, has brother Adams.

And were supposed to have the coldest fall day here, tomorrow. Low 53 and high of 71. I'm freezing already :>))))

Regards
Dennis
Couldn't find the actual study. Misplaced it during my move to Florida.


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## Michael Bush (Aug 2, 2002)

>This whole comment that "bees only warm the cluster, not the hive" is misleading, not fully accurate, and makes understanding the workings of the hive questionable.

Amen.

The thermodynamics of anything, including a hive, are more than just temperatures. Anyone who has stayed in the winter in large tents, small tents, tents with thicker or thinner fabrics, white tents, black tents, and double wall tents, knows, that while you are not heating the tent in any of these, all of these things make a difference. You want a small double walled white tent with thick fabric. You can FEEL the radiant heat bounce off the walls and back at you if the tent is small. The larger it is the more this goes away and you can feel the space around you sucking the heat away. The less reflective the walls are the more it sucks the heat away.

You can heat a batch of baby chicks in February with a heat lamp. The air between the heat lamp and the chicks is quite cold. You are not heating the air. But the chicks are warm. You can put your hand NEAR an observation hive and feel the radiant heat from the bees. The bees might not be heating that air, but when the radiant heat hits your hand it makes it warmer. When it bounces off a wall, it returns heat. When it goes off into the empty space, it does not.

If any of you doubt this, try winter camping in a variety of tents and you'll realized how huge a difference things other than temperatures make.

As Bjorn pointed out, watch what the bees do and you'll see what they think is warm.


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## Jim Fischer (Jan 5, 2001)

> You can FEEL the radiant heat bounce off the walls

But Mike, if this is true, why doesn't this ever show 
up in any of the thermography?

Maybe it is because the outer shell of a bee cluster, where
bees are holding fairly still, and acting as insulation isn't
radiating much heat at all. (See photos below)

It is really really hard to argue with the black areas of the
thermograph here:
http://jeb.biologists.org/content/vo...EB00082F1.jpeg

But I'm willing to read if you want to try.

But I'd still like someone who thinks that bees are heating
the air in the hive, and keeping the air in the hive warm 
tell me how that warmer air stays in the hive, given that 
the bees are breathing, warm air rises, and if their was not 
good ventilation, the bees would suffocate on their own CO2.

Actual thermodynamics includes concepts like "warm air rises",
so I don't think that it should be too hard to educate me on
this point.

> The bees might not be heating that air, but when the radiant 
> heat hits your hand it makes it warmer. When it bounces off 
> a wall, it returns heat. When it goes off into the empty space, 
> it does not.

But to "bounce off a wall", would at least partly warm the wall
in the process. It is not like light and a mirror. So, we can
see from the thermographs that there just isn't enough of a
temperature delta between the outermost bees and the
ambient air in the hive to result in any "bouncing" radiant 
heating. So, we don't ever see any warmer walls unless the 
bees are packed up against the wall (conduction).

But we will see a warmer area around all the possible
openings above the bees, showing the release of both
respiration, and any air warmed by convection.

And the reason that you felt cool air between your lamp and
your chicks is exactly because the air HAS been heated by the 
lamp you pointed at your chicks. It feels cool to you because 
you are feeling a slight breeze as cool air from below replaces 
the air heated by the lamp, which has moved upward due to 
the lighter density of warmed air. 

One can warm air! 
Its a decent way to heat houses.

(Note that I deserve extra points for having refrained from
using the term "_hot air"_.)


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## Hobie (Jun 1, 2006)

BWrangler said:


> And were supposed to have the coldest fall day here, tomorrow. Low 53 and high of 71. I'm freezing already


You're breaking my heart. 30 degrees, 30-40 mph winds, and lake effect snow today. Do you feel warmer now??? 

For what it's worth, based on the debris pattern on the bottom tray last winter, my hive clustered on the far _north_ side of the hive, and came into spring quite strong. Just goes to show you that bees will be bees.


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## tecumseh (Apr 26, 2005)

bwrangler writes:
And were supposed to have the coldest fall day here, tomorrow. Low 53 and high of 71. I'm freezing already :>))))

tecumseh thinks:
yer kind of turnin' the screw on them yankees bwrangler?

as to the hypothesis presented.... it does sound like a good simple rule that explain a lot but not everything. if you desire to determine for yourself what it does not explain then be willing to expend a lot of time and energy on something that likely means little (little in regards to survival or profit).

you could likely construct an entire book out of question that fall into the same category of answer that explain a lot but not everything. I typically classify these for myself as good general operating rules... it is good to recognize where or when the rules does not apply or when and why the rule need to bend a bit.


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## MIKI (Aug 15, 2003)

Jim,
I agree and most of what I got on the subject I got from research to include George's Pink Pages and the many German beeks around me. I believe that there will be differences from region to region and some regions may need follower boards while others wil not. I also posted just to see if Bjorne's little visit to the TBH forum was a lame attempt to start argument and now I am convinced it was. I fell for that once not again.


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## Hillside (Jul 12, 2004)

I think it's perfectly clear.

1. The cluster produces heat, but not a huge amount.
2. The insulating layer insulates the cluster, but not perfectly.
3. This loss of heat warms the hive, but hardly at all.
4. Adequate ventilation reduces the warming even more by allowing more heat to escape.
5. Conserving heat is a better idea as you get farther north.

By insulating the surfaces of the hive as much as possible, while limiting ventilation to only what's necessary the hive could warm significantly. That might be good on cold nights but would be a problem on warm days.

I've been to many a New Year's party in Minnesota. It's a cozy 68 degrees in the house when the party gets under way. It's a bone chilling ten below outside, so the furnace has been running to keep the house warm. People begin to arrive and the house gets crowded. People are telling jokes; there is plenty of laughing and dancing. It's getting hot in the house. By midnight, a window has been opened and the furnace hasn't run for nearly two hours. The temp outside has dropped to fifteen below. 

Bees just need to party more.


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## BjornBee (Feb 7, 2003)

Oh MIKI, grow up. I made my comment on the other thread and started no such argument.

I further ignored you by starting this post on another forum, and did not even mention or quote you. But you followed here and now is crying about it.
Am I arguing with anyone here? No. I actually have stepped back and have let others talk. You see, I started this thread to actually learn. I appreciate the research input and the infrared pictures...They are pretty cool.

But for anyone reading this thread, I can't see how anyone could come to the conclusion that I started this to argue. Except for you. 

Now for the second time, you stuck out your neck, and don't like my input or position. That's fine, but quit cry in' about it.

For anyone interested, please see the "follower board" thread in the TBH forum. My two comment are brief and to the point. Not exactly "arguing" in any sense of the word.


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## Jim Fischer (Jan 5, 2001)

Not a bad summary at all:

> 1. The cluster produces heat, but not a huge amount.
> 2. The insulating layer insulates the cluster, but not perfectly.
> 3. This loss of heat warms the hive, but hardly at all.
> 4. Adequate ventilation reduces the warming even more by allowing more 
> heat to escape.
> 5. Conserving heat is a better idea as you get farther north.

When one then considers the first three laws of thermodynamics, 
which say, in essence:

a) You can't win.
b) You can't even break even.
c) And you can't ever stop playing, either.

One then realizes that one wants to leave well enough alone,
and provide the bees with what nature would, which would
be a cavity with adequate ventilation, and an entrance that
the bees can reduce to a size of their liking.

Now, if you want to try to keep bees up near Ice Station Zebra
or something, all bets are off, and one must get hyper technical
and do some counter-intuitive things.

But I've been shown hives containing a sopping wet mess 
of bees and a soaked inner cover and been asked 
"_what did I do wrong?_" by a hapless beekeeper far too
many times to think that one can screw up and kill one's 
hive(s) with ventilation anywhere near as easily as one 
can screw up and kill one's hives trying to keep them warm 
and cozy.


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## BjornBee (Feb 7, 2003)

Jim Fischer said:


> One then realizes that one wants to leave well enough alone,
> and provide the bees with what nature would, which would
> be a cavity with adequate ventilation, and an entrance that
> the bees can reduce to a size of their liking.


Good point JF.

If you notice, one of the points I referred too was the comment earlier about "unnatural" spaces. That in nature, bees actually prefer a smaller cavity than what almost all beekeepers provide.

Couple that thought process with the idea that it's NOT good to manipulate hives late in the season, something I have said many times.

And I think your comment about the bees reducing entrances is right on target. I have lower and upper entrances year round. Some hives will reduce and almost close off the upper entrance, IF the bees are given time to adjust and regulate the hive as they see fit.

Interesting these studies are all centered around UNNATURAL homes provided by man. I have studied a good number of tree cavities, and have come to a number of observations..... 

Among them being that most tree cavities provide much more insulation than the standard 1 inch (3/4" wood) boards we use to construct hives.

Most of the natural cavities do not have upper entrances. Where does the moisture go? I think bees are great at regulating the cavity as they need too. I wonder how much of that excess moisture is a result of beekeepers feeding late in the fall. I know I can almost tell 100% from the inner cover moisture, which hives had been recently fed or not by the amount of moisture collected.

Where does that moisture go in a feral colonies? Does the tree cavity or other chosen cavity allow moisture to escape or be regulated better due to the wood thickness and perhaps natural elements that we don't use in our traditional hives. Certainly painting the wood and enclosing the top with metal is a lot different than what a tree provides in the wild.

I think comments along the lines that because moisture escapes, no heat retention value is to be recognized is wrong. I certainly have moisture control in my nucs, but also recognize that building nucs in smaller boxes greatly benefits the bees in spring. Its not black and white, its a balancing act in the middle. Oftentimes best left to the bees to determine. 

As a beekeeper, its for me to understand that having bees build in winter or earlier in spring makes a difference between a hive with bees in the second box, and how that may be different than having a hive raise brood with four boxes on top of the brood. I see much better build up with a smaller space, and some benefit of trapped heat in the hive. Is that to say bees can not survive one way or the other? No. 

But I know the same amount of bees in a nuc, or in two ten frame boxes, act differently and build brood differently.

We all say that bees don't purposely heat the hive. But in studies, it has been shown that bees prefer smaller cavities. And by this selection factor alone, perhaps they do that because they know its easier to not just regulate air flow, but perhaps benefit from trapped heat in a smaller cavity.

Maybe we just don't see that because we take bees and place them into the hives we have determined best for the bees, and run tests and take fancy pictures, based on not what the bees would choose, but what we give them.....


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## peletier (May 5, 2007)

I still want to know how to get the "R" in the little circle.


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## yoyo (Jun 13, 2007)

I always was amazed how eskimos could stay warm in an igloo. 
We know that ventilation is a good thing. The bees do this all summer, by flying with their legs holding them in place, creating a breeze to evaporate the moisture in the honey as well as cooling the hive. Kind of a two-for-one special. In winter, ventilation is still a good thing, as the bees are exhaling moist air that will condense on the inner cover and may drip back and chill the cluster. This moisture is the same as the condensation that forms in your windows during winter.The bees are not going to create any airflows to dry this up, as evaporative cooling can still happen. The bees are in the cluster and are sharing the insulation job. ANY airflow will remove heat from the cluster as well as the hive interior. ( why do you blow on hot soup before putting it in your mouth?) With all that said, dead air space IS an insulator and is used in double-pane windows and artic winter clothing( ask a duck). Now, the bees are loosing heat into a dead air space. If this dead air space is large, they might as well be outside (naked) and all heat will be lost, but if small, the heat loss will try to find a equalibrium between the differences in temperatures with less heat being lost,and more heat being retained in the outside of the cluster. Are the bees heating the inside of the hive? Yes, but only because of their losses. What can we do to lessen the heat loss? We can decrease the temperature difference between the cluster and the outside. This can be accomplished by hive location, and by solar energy gain. By providing windbreaks and maximum sun exposure, and maybe black wrap to absorb even more heat, we have decreased the temperature difference and have provided the bees with an edge to stay warmer. 
I can't wait to see the photos of some christmas lights decorating and heating some hives! Don't tell me you haven't thought of that already!
Or maybe you can move your bees to Florida for the winter, and turn them into snowbirds!


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## Michael Bush (Aug 2, 2002)

o Heat and temperature are not equivalent. The temperature of an object is not directly proportional to the heat of that object. 100 gallons of room temperature water contain much more heat than a quart of boiling water. The amount of heat it takes to raise 90 C water to 95 C water is significantly less than the amount of heat it takes to raise 95 C water to 100 C and make it boil. Heat is not directly proportional to temperature. This is one of the reasons why temperature by itself is not very useful in understanding the thermo dynamics of a beehive or anything else.

o Radiant heat does not directly increase the temperature of the air. Anyone who has used an infrared heat lamp to heat animals knows this. Put a brood lamp in the corner of a -10 F barn to keep some baby chicks warm in February. The temperature of the air even close to the chicks is no significant amount above the ambient temperature of the barn. But the chicks are, if you get the distance right, about 100 F. The ground around the chicks is also about 100 F. Since you can google on “thermal radiation” or “infrared heat” or “radiant heat” and read literally millions of references to this effect I will not bother with trying to defend what is a commonly known fact, that it does not heat the air. Reading just a few should be convincing enough, but they all say essentially that same thing. Radiant heat does not directly increase the temperature of the air, only the objects it strikes. Now some air will move over the surface of those things and increase the air temperature a little, but the surface of those things will be warmer than the air by a significant amount. There are many simple ways to prove this to yourself. One would be putting a thermometer in the shade and one in the sun. Obviously the one exposed to the radiant heat is much warmer. Another would be just to sit in front of an outdoor fire where the wind is carrying the warm air away but the radiant heat will keep you toasty or inside by a woodstove in a wood heated house where your front, which is getting the radiant heat, is warm and your back, which is getting the temperature of the air, is still cold.

o All warm blooded animals give off radiant heat. You can feel it easily by putting your hand close to any of them, but if you think its just the air close to them being warm, take a thermometer with some foil on the back and face it away from them in that space. After a while turn it around and see what you get. They will be different. The colder the air, the more obvious the difference. Hold your hand over, under or next to a cluster of bees and you will feel the heat.

o Radiant heat falls off at half the distance. This means if you double the distance of the object being struck by the Radiant heat, you halve the energy. If you have a reflective barrier (something white or something silver) the further you are from it, the less heat is reflected back at you. This means, all other things being equal, if you are in a room with walls close to you, you are warmer than in a room with walls further from you. As I've said, easy to prove in a small tent and a large tent. But try this. Get a sheet of foil backed insulation and have someone hold it more than 10 feet away from you in a cold room. Then have them gradually move it closer until you start feeling warmth coming back from it. You'll find you have none when it's a long ways and a lot as it gets close. Note that the temperature of the room has not changed. There are two ways this can warm you. The preferred one is to reflect the heat back. The less efficient one is to at least have the heat hit something near you and warm that object, which will in turn warm some of the air near you and radiate some heat back at you.

o Measuring how "cold" a warm blooded animal is experiencing is not just a matter of measuring the air around them nor the core of the animal. When I'm working outside in -10 F weather, I'm exactly the same temperature as I am inside in my 70 F house. Note, that I am NOT trying to heat the air in either situation. My body is being heated internally, and my body is not trying to make any adjustment to the ambient temperature. It is only trying to keep my core warm. In the same way a cluster of bees is not trying to heat the hive, only the cluster. Measuring the temperature of the cluster tells me nothing. The only thing that will change the temperature of the cluster if is they decide to make more heat to warm brood, or they die. Measuring the temperature of the hive tells me nothing. Measuring the heat loss to the cluster is the only thing of importance. But that's not so easy to measure as they will compensate by making more heat. It's like saying that the temperature of my house is the same with the back door open or closed. Well, yes, but that's because it's thermostatically controlled, as is the heat of a warm blooded animal or a cluster of bees. Many people who wrap, insulate, or use foam hives have commented on how much less stores they use and how much larger the clusters are in the spring. Are their bees warmer? No. But they didn't have to burn as much to stay that way. Making even a very small difference in the temperature around you, when it is bitter cold, makes a huge difference in your comfort

o How cold your weather gets makes a lot of difference in how significant all of this is. My guess is that Virginia or Maryland seldom gets subzero F weather in the winter. We seldom DON'T get subzero F weather sometime in the winter here in Nebraska. In Alaska or Finland or Saskatchewan or the high plains or mountains of Wyoming or Montana you sometimes don't get above 0 F for a month or more. If your hives never face bitter cold, it's doubtful that much of anything is going to make that much difference in wintering. Bees are adaptable enough to survive in less than ideal conditions when they aren't TOO cold. However, the colder it is the more the little things make a big difference. One degree difference in temperature makes a noticeable difference at around –10 F and is almost unnoticed at 10 F. I would get advice on how to handle the cold where you are from people who face a similar climate to yours, not people who have a less harsh climate.

o I know people will disagree, and of course they are entitled to. But we've discussed this before and everyone seems to keep the same opinions so I see no reason to belabor it all again. When it comes to HOW to winter in severe cold, and how important space or insulation is, though, I would defer to Finman and Dick Allen and Keith Malone who have faced worst winters than any of us. Let's hear what they have to say.


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## Oldbee (Sep 25, 2006)

Michael Bush.........................WOW!...............what a complete description/analysis of the thread! Anyway,.......who cares?...as long as OUR bees survive the winter!!ACTUALLY;................................I didn't know that honeybees DO NOT keep ALL of their hive warm during the winter. Until now,.......... of course.
Michael Bush: Regarding little chickens/chicks. Has anybody done research about how far from "under" the heat source those chicks will "venture" out for food before they "give up"? .............In relation to honeybees "starving" with food/honey a few inches away.


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## crofter (May 5, 2011)

Here is an oldie!

5 or 6 years ago the saying " bees only heat the cluster not the hive" was oft used to infer that insulation was of no value. It seems the thinking has changed a bit!


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## psm1212 (Feb 9, 2016)

First law of thermodynamics: Energy is neither produced nor destroyed. The quantity of energy stays the same.

Second law of thermodynamics: All things naturally degenerate from an ordered state to a disordered state. Entropy. 

So bees transfer energy from their bodies into the cluster in the form of heat. That heat will dissipate or become disordered into the surrounding air.

If the bees (or the beekeeper) can harness this dissipating energy (heat) and slow its entropy for the benefit of warming the hive, stands to reason that would be a good thing. 

If these actions cause condensation that soaks the bees -- bad thing.

If these actions cause an oven-like environment -- bad thing. 

But what do I know about trying to retain heat in south Alabama?

I have been keeping bees for a little over 5 years now. Prior to getting my first bees, I had read probably a half-dozen books about bees and how to keep them alive. So when winter came that first year, I knew just what to do. I went down to the hardware store and bought a roll of roofing felt and wrapped the heck out of my hives the day after Thanksgiving. After all, that is what the books said to do. 

There is an older, local beekeeper who happened to come by my house shortly after I had done this.

5 years later, he still bends double laughing at me every time he sees me.


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## crofter (May 5, 2011)

I wouldnt worry much about insulation either if I was in Alabama! I think, though, that I might still slip a piece of 3/4 thick styrofoam under the top cover forcing the cooler sides to to be the condensation panels. Wet bees are not happy bees!


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## dudelt (Mar 18, 2013)

I believe the better way to phrase it is that the bees do not "intentionally" heat the hive. Any heat source in a colder environment will dissipate heat to its surroundings. I don't worry too much about wrapping or insulating either because our coldest temperatures in winter are generally in the mid 20's. And that is only for a few days. As far as using insulation in Alabama, doing that in the winter is pretty amusing. You really need to do it in the summer to keep the heat out and cool air inside the hive!


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## little_john (Aug 4, 2014)

> This question of dissipation of the moisture thrown off by the bees is a very important one; much more so, I believe, than packing and double-walled hives, for in my opinion bees do not need to be insulated, packed or ****ered up in any way in Britain. After all, *they winter perfectly well in chimneys, roofs, and all sorts of cold, draughty places.* I remember one lot in an old pollard willow when I was beginning to take an interest in bees. The combs were all of four feet long, *the tree was split from top to bottom,* and the combs could be seen in half a dozen places. It had been there for many years, the farm men said, and might have been there much longer had I not come along.
> Again, I saw some of Madoc's hives in Norfolk one winter, when woodpeckers had made large holes. In some cases *the holes were big enough to put your fist into, and the clustered bees could be seen through them, but the bees wintered all right,* I believe. I have seen bees come through the winter well when housed in old cracked boxes that were about as airtight as a colander ...
> *Rob Manley, Honey Farming, 1945.*


Not a great deal of advantage to be gained by bees 'heating' hives such as the above. 

I run with fully open Open Mesh Floors all-year-round. Bottom entrances with sealed tops. Insulation on top only - to prevent excessive condensation there - no insulation otherwise. Zero winter losses last 7-8 years.
LJ


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## JWPalmer (May 1, 2017)

I don't know how to respond to this thread without it appearing snarkey, but here goes. If you are among those that think the bees are heating the entire hive, just look at an infrared image of the hive during winter. A great deal of the hive will be close to ambient while the cluster appears as a bright spot (hot). Not sure how much more proof you need. That does not mean that in very cold climates a wrap won't help, but my belief is that the bees have the temperature control thing figured out. My limited contribution is SBB with the insert slid in so it doesn't get too drafty and insulation on the top cover. Otherwise, the bees do just fine in single digit temps, as long as food is readily available.


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## crofter (May 5, 2011)

Nah, not snarkey at all! I wouldn't buy the idea that they effectively heat the whole hive. The bees own insulation results in most of the heat they produce staying within the cluster but no insulation is perfect. What heat is lost will rise to the area above the cluster. See LJ post #40 Insulation of the top to reduce transfer of this small amount of heat which results in the top surface being the warmest. Condensation will occur on the cooler surfaces which are the sides. His system seals the top so the heat is not swept out by drafts. This is the system used by many of the insulated styrene hives in Scandinavia too.

This system will require much more open bottoms to allow 0xygen/CO2 exchange and evaporation of any moisture that runs down the sides of the hive. Very similar to the thermodynamics of the Inuit snow dome that will keep temperatures habitable inside with little more than a candle and the body heat of the occupants.

To me, the top insulation is the most important and the wrapping secondary. I actually use 4" thick styrofoam slabs on top because they were free. If I had to buy it 2" probably is the best bang for the buck


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## psm1212 (Feb 9, 2016)

dudelt said:


> I believe the better way to phrase it is that the bees do not "intentionally" heat the hive.


I think you have hit on some of the confusion surrounding this "debate." We seem to anthropomorphize bees and their intentions, when the fact is that we know -- regardless of the most determined of bee intentions -- that the heat created by the bees in the cluster does, at least to some extent, dissipate into the hive. So the question really is, is it worth the beekeeper's time and resources to attempt to capture and retain this heat as it dissipates from the cluster through some form of insulation?

Since I have shared my one and only experience with attempting to keep my poor south Alabama bees from freezing to death, I have no value to add to that debate. But I do have an almost new roll of roofing felt I will sell you cheap.


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## mgolden (Oct 26, 2011)

Retaining some of the heat that escapes the cluster is critically important for northern beekeepers. Cluster needs to be able move laterally but can get stranded in cold. Honey can be mere inches away but cluster can't move to get to it.

My temperature measurements show interior temperature 20-30F warmer than ambient, when measured just above the inner cover. Temperature near outside walls near the bottom is marginally above ambient.

I also think 3/4 inch or more of head space above the frames as well as sugar blocks on top of the frames assists in the cluster being able to move.


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## tom0354 (May 25, 2018)

The statement _"bees only warm the cluster and not the hive"_ is 100% correct but people are taking it in the wrong context. The bees are only intended to heat up the cluster and not the hive. However, the temperature in the cluster is higher than the surrounded temperature so the heat will escape from the cluster into the air. This causes the temperature inside hive to be higher than the outside hence the bees indirectly heat up the hive. 

If you remove the hive wall, the cluster temperature would remain the same vs having the hive wall since the bees are trying to keep the cluster at desired temperature but it has to work harder due to heat lost since the surrounded temperature is lower in the one without a wall vs the one with the wall.

In a not extreme temperature, the hive won't die from the cold because the bee will heat up the cluster to keep it at desired temperature but it will consume more food the colder the temperature get (spend more energy to heat up the cluster).

So wrapping the hive minimize the heat lost from the air inside the hive to the air outside which essentially save some food but does it worth the trouble for region with temperate temperature? IMO, if you have enough food in the hive, it is not worth it. However for hobbyist that has time they want the secure of knowing that they keep the hive warmer the it is worth it.

JWP,
This is from the article that someone linked about the study to point out that the bee only heat the cluster not the hive. The conclusion is quite opposite of the argument.



> Body temperatures were lowest in the outer bees and increased towards the core (Figs 1, 2; Table 1). In the bees on the outer surface of the flat side of the combs, which were exposed to the highest thermal strain, mean thorax surface temperature (Tthorax) was 12.1°C. Only three out of 134 bees (<3%) had a Tthorax below 9°C. By contrast, abdominal temperature (Tabdomen) was frequently below 9°C. On the central comb, Tthorax increased from 16.9°C in the outermost ring of bees to 22.8°C in the bees between the outer ring and the core, and to 30.4°C in the core bees (Table 1). Bees were counted as being in the core when Tabdomen was not more than 3°C below the lowest Tabdomen in the centre. Ambient temperature was 0.9°C to 6.3°C within 3 cm of the clusters and -1.1°C to 3.7°C 1 m outside the cage, the difference amounting to 0.6-3.1°C. For comparison,* the temperature difference between the outermost air space inside the hive and the air temperature outside the hive amounted to 3.6-6.1°C* with the Plexiglas side walls of the cage closed. In standard colonies, it amounts to approximately 8-9°C


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## Rader Sidetrack (Nov 30, 2011)

Below is a graphic from a USDA study on wintering bees. The temperature OUTSIDE the hive was 7 degrees. Note that all the temperatures shown inside the hive - even beyond the cluster - were higher than 7 degrees. 








_FIGURE 2. – Temperature readings (º F.) and brood and bee location one comb west of center of cluster at outside temperature of 7º._

The USDA study can be found in the Beesource "Resources" section (off the Home page).

Direct link to the study: https://beesource.com/resources/usda/the-thermology-of-wintering-honey-bee-colonies/
Some additional material at sub-links: https://beesource.com/resources/usd...intering-honey-bee-colonies-support-material/
and
https://beesource.com/resources/usd...honey-bee-colonies-support-material/figure-4/


The full USDA series is here:
https://beesource.com/resources/usda/


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## Greeny (Jun 27, 2016)

peletier said:


> I still want to know how to get the "R" in the little circle.


Hold down the "Alt" key and type 0174.


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## JRG13 (May 11, 2012)

I never understood this argument. Biologically when you think about it, bees don't really intend to heat anything, they generate heat to stay active/alive just as we do. It's a little different for us since we can still remain active even when the outside temperature is extremely cold but the concept is the same. At some point, depending on how well insulated we are and how cold it it outside, we cannot generate enough heat to stay active, the concept is the same with a beehive. The better insulated it is, the easier and longer bees can maintain activity burning a certain percentage of calories generating the warmth they need.


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## JWPalmer (May 1, 2017)

I cant help but think of dairy cows in a barn in the middle of winter. The barn is uninsulated and drafty. One cow is going to be cold. 30 cows or so and the entire barn is downright warm. Makes a good case for overwintering strong hives. The question really ought to be "at what temp does insulation make a difference?" And "how many bees do you need to generate enough heat to keep the cluster warm in what sized box?" Here in VA we just don't get cold enough for long enough. Hives and nucs alike winter without additional insulation other than a piece of styrofoam in the telescoping top to reduce condensation. Other parts of the country may need the extra protection to keep the heat transfer to the outside from occuring so quickly. Amazed when I see pics of hives that are nothing more than bumps in a snow mound. But even then, the snow is an insulator and I am sure the hive is doing just fine. I encourage folks to seek out ir images (not the one in the beginning of this thread which shows the hives practically glowing) and see how well defined the heat signature of the cluster really is.


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## mgolden (Oct 26, 2011)

Cows in an uninsulated barn and the interior is warmer than outside ambient. Kind of like a good sized cluster of bees in an uninsulated hive. 

The interior of the walls in an uninsulated cow barn, in a cold climate get approx. 3/4 of frost build up on the walls, inside. Drafts are eliminated. On the first warm spell, frost melts and water runs down the walls. Makes a damp barn and a damp hive.

Add insulation to the exterior and interior temperature is warmer than the exterior and warmer than the interior of an uninsulated hive. 

The hive needs modest ventilation to exhaust moisture however don't open the front door and the back door and defeat the value of insulation.


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## JWPalmer (May 1, 2017)

Insulation as moisture control makes a more compelling argument than trying to warm a hive to keep the bees warm even if that is what happens as a by-product. Thanks for pointing that out.


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## Michael Bush (Aug 2, 2002)

This is one of those issues where neither "side" is correct. Yes, the bees are not trying to heat the hive. But yes, to some degree they do. No they do not keep the entire hive the same temperature as the cluster by any means. It's a mistake to think they heat the hive and a mistake to think insulation doesn't matter at all. For one thing you are trying to measure the temperature of something that is thermostatically controlled. The bees make more heat to make up losses. It's the amount of heat they are losing that matters. Not the temperature that is a result of them producing heat. 

http://www.bushfarms.com/beesscientificstudies.htm#overwintering


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