# Undecided about hive top ventilation for winter



## Daniel Y (Sep 12, 2011)

I thought venting and preventing condensation in the hive was a good thing until yesterday. then I saw a post on how the condensation is not really the problem for a healthy hive but a resource and supply of water.
Here is what I walked away with after that information.
Condensation is not a problem for a healthy hive than a rain shower is for us. if you have condensation get out of control and actually freeze a colony. it is just one result of many of a hive that was weak or failing already. Condensation for a weak hive is more like a flood than a shower. No top vent will help a healthy hive stay that way.

Now with that I still question that the right choice of vent or not vent may be different in different locations.

I think this comes back to there is no right answer to anything concerning bees. there is the ability to look at your bees, understand what you are seeing, and what does that tell you you need to do.


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## Adamd (Apr 18, 2009)

I guess your weather isn't too different from what we get here in the UK.
With an open mesh floor the bees will get plenty of ventillation so this is what I and many UK beekeepers do. condensation is a problem. cold isn't so much.

http://www.norfolkbee.co.uk/beekeepers-resource/winter-preparation

In the wild, what would bees do? Seal up the top of their tree or whatever to minimise draughts and allow one entrance below. Bees have been known to close up hive entrances with propolis if allowed and leave just a modest sized hole.


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## Michael Palmer (Dec 29, 2006)

astockman said:


> I'm considering removing the feeder, placing the inner on with shims beneath it for ventilation, then a piece of 1" foam, with the outer foam cover on top. Is this a valid plan? I am looking for suggestions.
> 
> Thank you,
> Adam


Is there a notch in the rim of the outer cover? If not, cut a 3/8x2" notch from the rim. Place rim down and notch in front of hive. That becomes your upper entrance for winter. Make sure the hole isn't covered by the tar paper when you wrap. Yes to your foam and cover.


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## squarepeg (Jul 9, 2010)

i have notched the front and back of my innercovers, in line with and the same width as in oval hole in their middle. i also wrapped these notches with window screen as a deterrent to shb and wax moths, (don't have to worry about deep snow and leaving upper entrance here).

on some of the hives, this screen has become partially propilized. i am going to let the bees decide if they want to keep it open or not.

i am also putting in half inch pink foam between the inner and telescoping outer covers, which will block the oval hole.


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## woodguyrob (Jul 29, 2010)

Michael Palmer said:


> Is there a notch in the rim of the outer cover? If not, cut a 3/8x2" notch from the rim. Place rim down and notch in front of hive. That becomes your upper entrance for winter. Make sure the hole isn't covered by the tar paper when you wrap. Yes to your foam and cover.


MP-along with the above vent/upper entrance, what size lower entrance do you use for the winter? 
Thx-


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## Michael Palmer (Dec 29, 2006)

I leave it wide open and shove a 1/2" hardware cloth wedge into the entrance to keep out mice.


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## Michael Palmer (Dec 29, 2006)

squarepeg said:


> i am also putting in half inch pink foam between the inner and telescoping outer covers, which will block the oval hole.


You might want to duct tape the escape hole (oval hole) so the bees don't chew the foam.


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## squarepeg (Jul 9, 2010)

did not know they would chew the foam, thanks mp.


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## flyingbrass (Jul 2, 2011)

Yes it's needed. I'm a newbie but here is my thoughts. I got the vented top covers from Honey Run Apiaries and recently put in the foam since it has been cool. However, I did notice that the bees have sealed up 80% of the top opening. The bees know best. At least I gave them the option for top ventilation and they adjusted the opening to suit their needs. If they didn't want a top opening they would have sealed the whole thing!


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## Eyeshooter (Mar 8, 2008)

Hey, Adam.
I'm not that far from you in the Keene area and use a slightly modified plan. You mention you have BetterBee equipment. Do you have BeeMax (polystyrene) hive bodies or their woodenware with the poly outer covers?

I started with, and still have, 3 of their BeeMax hives but have switched to wood for the rest of my equipment. I use sbb and top entrances throughout the year (shims under the inner cover) on all of my hives and nucs for ventillation and use the poly outer covers on the 10 frame boxes. For winter I close the bottom entrances and put the grid cards for checking mite drop in the sbb to close most of the opening. Mike convinced me to wrap the woodenware this year (not the poly) which I did Friday and Saturday before the nor' easter hit. Have not had a condensation issue using this plan.

Good luck,

John


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## wkinne (Jul 17, 2010)

The fact that bees in the wild do not prefer locations with top entrances does not necessarily mean they are not needed in a man made hive. Water condensates on the inside of the top cover because the temp of that cover is colder than the air inside the hive, this can be corrected with insulation. But in the wild, there is no frozen air 3/4" above their ceiling, there is a chunk of wood many feet thick. So in a wild hive that bees expect, ( a tree that is, not your attic ) there is little to no chance of condesation raining down on the bees.

Make sence?

But I am going to feed my bees water this winter as well has syrup and honey, I thought that part of his report was very insightful!

Wayne


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## Barry (Dec 28, 1999)

wkinne said:


> But in the wild, there is no frozen air 3/4" above their ceiling, there is a chunk of wood many feet thick.


"The wild" has to also include any structure bees decide to call home on their own, which in most cases are not trees. When bees take up residence in a roof eve, is there insulating material over them? Or in an exterior wall, or the floor joists of a shed?


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## mrpush (Jul 7, 2010)

Hi,

I have to agree w the "do not vent" camp. A man made hive is not typical of hives in the wild as noted here by some posters. The man made setup allows for increased condensation on the uninsulated inner or top covers with almost zero capacity to absorb moisture.

Yes, bees build hives in roof eves, exterior wall cavities etc, but MOST of these situations have a source of heat other than the bees increasing there chances to make it.

Mr Cushman has it right here: 

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

Some condenstaion in a hive is good, gives them a drink or recycled water. Having it drip on them from above is bad.

Having a "chimney effect" in a hive is essentially taking away heat forceing the hive to generate more potentially exhausting stores much faster that can result in hive starvation especially EARILY SPRING.

I believe statistics show starvation as the #1 cause of winter loss? (does this include hives that starved with lots of stores still in hive? I don't know)

Folks, you want to keep the heat in so they use less fuel and you don't want condensation dripping on them. To satisfy these two things logic says NO VENT (chimney effect taking away much heat) and insulation to slow heat losses and prevent condensation. When I read over and over how "the bees only heat the cluster, not the surrounding hive" I just laugh.

Say I place a space heater in the middle of a carboard box and set it at 90 degrees (heater representing the cluster). The heater will heat the entire box space over a gradient (meaning temp will decrease from the center point outward. Yes there are currents in the box but we will ignore those for simplicity))

If the cardboard box has low insulative value, the heat loss will be high and the heater will cycle on and off a lot using up more fuel.

If I insulate that box, the heat flux (heat loss) will slow down, and I'll use less fuel over the same time period. 

Either way, the heater (clusters) heats the "ENTIRE BOX" to some degree. If that box is insulated, the bees will use less fuel keeping themselves warm just like you insulate your house to keep yourself warm.

The bees don't magically "only keep the cluster warm", you can't stop heat from flowing, you only slow it down. It flows from cluster to surrounding air and hive parts by convention, conduction, radiation. 

Setting up a "chimney effect" with a top vent will draw more heat from the hive. The more ventilation, the more heat lost. If the vent is really small, it might not have a large impact, but it will likely also not be enough to get rid of the the condensation you are worried about as well. It takes some moving air to evaporate condensation well.

Did you know that air moving across the top of fiberglass batts in your attic reduces its insulative capacity by as much as 30+%? Why would we think that air moving past our bees will do anything less? Can you imagine your bees needing up to 30% more stores to survive the winter? That is why they tell you "seal up those air gaps to save energy!". Huh, the bees seal up the crack as well! Smart I'd say. 

If you are having issues with starving hives or hives with low stores going into winter, insulate the top at the very least and DO NOT VENT or you risk starvation / freezing.

I don't have Mr Cushman's experience but I see his wisdom, and 20 years of "no condensation here" with NO VENTS is a winner. 

I'd conclude with this:

Not so good option: 

Leave you hive covers un-insulated, Add top vent (because with no insulation you will probably get drippy condensate) and spend $25-30 per hive on syrup and extra medium super to make sure the bees have 30% more stores than the 60+ pounds they already need. In the spring, expect fewer bees (due to increased death because bees flexing their muscles to generate 30% more heat bees die faster)

Or a better option: 

Insulate the top covers, DO NOT VENT, and only spend ~$3 on a peice of board insulation and 5 minutes of your time for your hive top. In the spring, expect larger populations, higher output and be ready to split as these well fed, less cold stressed bees are going to build up FAST and try to swarm on you! Oh yeah, keep more honey for yourself.

The choice is yours.

Yes yes yes, by all means, people successfully overwinter bees with no-insulated hive tops and they vent and swear by it....but are their bees having to generate a lot more heat and using more stores? You can just about bet on it. If I live in a non-insulated house, my heating bill is going to be HIGHER even if I use the magic "bee clusters that only heat the cluster and not the hive space" for heaters!

In todays modern housing do we still use regular updraft chimney fireplaces? Yes, FOR FUN, not to keep us warm! When I use our OPEN fireplace regularily, MY HEATING BILL GOES UP AS ALL CHIMNEYS DRAW ALL THE HEAT OUT OF THE HOUSE!!!! Then all night long our furnace runs as the open damper mocks us while sucking the heat out of the house. Can't close it till every last ember is out less you fill the house with smoke! Furnace is running all night! Yeehaaa! But that fireplace is fun to look at and sit by for a quick radiant warming.....it's just really expensive! 

Watch the Scrooge this Christmas season....and look how the guy is dressed for bed and look at what he sleeps in / under......He has a coal burner with open chimney, so after a quick warming before bed, he would FREEZE if he did not get all bundled up like that as the chimney draws out all the heat!!!!

For those of you that like to vent, have fun but don't forget to call the chimney sweeps!

Thanks,

MP


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## astockman (Nov 24, 2010)

Hi John,
I have Betterbee's wooden hive bodies (7/8" thick), with the BeeMax polystryrene outer covers.
What does your top entrance consist of? A notched inner cover? Or a hole drilled in the top hive body?

After reading all of the great responses here and deliberating, I'm planning to insulate the hive tops, and not provide top ventilation, not even a top entrance.

The two deep hive bodies will be topped with an inner cover (oval hole sealed), and then a 1" piece of foam. I will next wrap the hives with tar paper, folding it over the top of the hive like a package, and then place the outer foam cover on top of the folded tar paper. This wrapping method is illustrated in The ABC & XYZ of Bee Culture. Someone in our bee club also insulates and wraps this way, and his colonies have survived the winter. Mrpush's insight about holding the heat in, and avoiding the chimney effect makes sense as well. Adequate insulation on top should prevent dripping condensation inside the hive, as there will be no cold inner surface causing condensation to form.
Now let's hope for the best!
Adam


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## TWall (May 19, 2010)

mrpush said:


> Folks, you want to keep the heat in so they use less fuel and you don't want condensation dripping on them. To satisfy these two things logic says NO VENT (chimney effect taking away much heat) and insulation to slow heat losses and prevent condensation. When I read over and over how "the bees only heat the cluster, not the surrounding hive" I just laugh.
> 
> Say I place a space heater in the middle of a carboard box and set it at 90 degrees (heater representing the cluster). The heater will heat the entire box space over a gradient (meaning temp will decrease from the center point outward. Yes there are currents in the box but we will ignore those for simplicity))
> 
> ...


MP,

Do you have data to back up your theory?

The data collected by the Bee Lab in Madison, now closed, does not support your example. They found that temps decreased rapidly as you moved from the center of the cluster to a low of about 40 in the bees on the outer edge of the cluster. Once out of the cluster the temp dropped to near ambient temps.

Heat is absorbed by layers of bees around the cluster so it does not heat the inside of the hive.

To use your example imagine if you wrapped the space heater in layers of insulation. You would eventually get to the point where the outer layer was not very warm. Yes, the heat would ultimately move out of the cluster but at such a slow rate that it would not increase the temp inside the hive.

We can all guess what is going on inside our hives. But, until we actually measure what is going on we are just guessing. We can come up with examples that support our theories. Without the data to support it, it is just that a theory.

Tom


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## mrpush (Jul 7, 2010)

Tom,

Well I don't have my own lab data if that is what you mean, however I do have several years of experience with physics and engineering and studied heat flux a good bit. Not to mention the laws of thermodynamics are just that, physical laws, not theories, that do a great job at predicting these properties.

From the studies you are refering to, do you know what the ambient outdoor temperature was? That can make all the difference in the world as heat flow is directly proportaional to temperature differential. 

Where did they test the ambient temps (top bottom middle)?

And lastly and most important, was the hive vented or non-vented, screen or closed bottom?

Now, it will be true that the cluster of bees has some insulative value in and of itself. However, most people picture a literal "round ball" of bees in a hive with nothing but "air" around them which is not the case at all. It is a group of bees, on 5+ frames, huddling tighter together, with wax and wood and plastic and such, all which have thermal coefficients and conduct heat away from the cluster, heating the frames wax and hive parts and air in the hive. 

Air is a very good insulator (as long as its NOT MOVING) but there would be restricted air flow inside a cluster.

Now, in the studies you read, was the hive vented or non-vented? If the air measured "immadietly outside the cluster" was nearly ambient, you can probably bet your boots that the hive was vented.

The MOVING air due to chimney effect immeaditly takes away the heat coming off the cluster as it draws in ambinet air from outside. This would quickly make the "air just outside the cluster" close to ambient.

Do a test yourself. Take a box with only the bottom missing, put an insulated heat source in it, turn it on. It's heat will warm the "air" in the box to some degree and as the long as the box has some insulative value and there is not a huge volume differential. Lets say we get a 5 degree difference from ambient and the source is 90-95 degrees. Now, vent that box and do the same test. The box air temp will soon close in on ambient as the air vented draws out the heat. (Natural chimney effect)

Now, the higher the insulative value of the box, the slower the heat will dissapate (from the box, AND from the source) and the less the heat source would need to work over time.

Dip your finger in water and hold it in still air. No put a fan on it and feel what that moving air does, the heat just flys away from your finger (it feels cold). 

Bottom line is that moving air REMOVES LOTS OF HEAT. It's heat that your bees need to make. They need to burn more fuel to make that heat. If you insulate their BOX with no moving air, reguardless of the thermal properties of the cluster, its a win -win....and the net heat flow out of the outer surface of the hive WILL BE LESS over time, resulting in the bees needing to burn less stores. 

And add to the equation that man made hives are less than an inch thick, and a hollow log might have 3 inche think walls, the tree hollow bees will need to burn less fuel over winter, decreasing their chances of loss due to starvation.

It's not a theory, its heat flux supported by thermodynamics.

If a 6-8" pipe can drain the huge "volume" of heat right out of my 4000 sf house in less than 2 hours, what will a square inch opening do to a small box in that same time? I did some quick math, my house has almost 190 times more volume / unit area chimney than a hive with a square inch opening and my house gets cold from an open damper in about 2 hours. It would probably take less than 10 minutes to turn over the total volume of 2 deep hive boxes, taking all that heat with it. 

Burrrr! Get those bees some mittens!

Go out on a chilly day 32 degree day, climb a tree and sit there 2 hours with no wind blowing. Now sit there with even a small draft coming by for the same time..... and tell me that you did not lose LOTS MORE heat from your body. BURRRRR!

I'm not trying to be condensending or anything, I'm just point out that you don't always need data to confirm certain physical laws. If most winter losses are due to not enough stores, then insulating hives and not venting make sense. If insulating hives cost less than a new package, it makes sense. If a life long bee keeper says he insulates top covers and never vents and never has seen condensation problems in 20+ years, why drill a bunch of holes in your hives. 

The study we need to look for here is the one that shows the effect of insulation on hive stores over winter.

To me it is kind of pointless however: better inuslated hives (anything) = less total energy generated by bees = less stores used = potential stronger hive in spring.



Thanks,

MP


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## Michael Palmer (Dec 29, 2006)

mrpush said:


> If a life long bee keeper says he insulates top covers and never vents and never has seen condensation problems in 20+ years, why drill a bunch of holes in your hives.


As a lifelong beekeeper who insulates and uses an upper winter entrance in the inner cover, I can say that my bees don't have condensation problems...or all the problems you relate with chimney effect. With my hives buried in snow for a few months of the year, and the bottom entrances plugged, the top entrance is critical if I want my bees to take a mid-winter cleansing flight...if the opportunity presents itself. I've kept bees here in northern Vermont for nearly 40 years and I wouldn't even consider not using the upper entrance.

Now I have great respect for Dave Cushman and enjoyed our talks together. He was a very knowledgable beekeeper, darter, and gadget-teer, and I only wish I had gone to Gormanston when I had the chance...to mee Dave and others I know there face to face. But, I have to disagree with Dave when it comes to wintering bees where there is a severe and cold winter...something England doesn't have. 

Why listen to me. Look up what David Eyre has to say about wintering bees. He's in Orilla, Ontario and has kept bees on both sides of the Atlantic. He talks about the need for an upper entrance to help with moisture control. www.beeworks.com

In my opinion, Dave E has it right...not totally though. I disagree on the amount of honey that a colony will consume in the winter. He says upwards of 140 pounds and I believe that's where Dave C gets his figures on winter honey consumption when using an upper entrance. I weigh every hive I have in my winter preparations. Most colonies will use up 60-90 pounds between the end of the Fall flow and Dandelion bloom. 

Sometimes we over-think what is going on in our colonies of bees. A good knowledge of physics is great to help you understand what might be happening in a hive...but extensive hands on experience over decades of work with the bees is better.


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## Andrew Dewey (Aug 23, 2005)

squarepeg said:


> i am also putting in half inch pink foam between the inner and telescoping outer covers, which will block the oval hole.


Put a piece of tape (duct works fine) over the hole in the inner cover or you may find that the bees will attempt to eat your foam.


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## Barry (Dec 28, 1999)

Michael Palmer said:


> With my hives buried in snow for a few months of the year, and the bottom entrances plugged, the top entrance is critical if I want my bees to take a mid-winter cleansing flight...if the opportunity presents itself.


Michael -

When your bees take mid-winter flights and the hives are buried in snow, do you not get a lot of dead bees? When we have that much snow, I keep the front of the hives cleared so if they do venture out on a warmer day, they have places to land (front of the hive) other than the snow, where they are likely to perish.


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## Barry (Dec 28, 1999)

Andrew Dewey said:


> Put a piece of tape (duct works fine) over the hole in the inner cover


Or put one of these on and see for yourself what happens with moisture during the winter.


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## tree_entz (Jan 11, 2006)

is that just a shim of some sort? Or is that plexi-glass? if the latter: i'm picking up the plexi-humor!


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## Barry (Dec 28, 1999)

plexi-glass inner cover. Check it every week, several times a day, you'll see the dynamics of moisture in the hive. No more guessing.


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## c10250 (Feb 3, 2009)

TWall said:


> MP,
> 
> Do you have data to back up your theory?
> 
> ...


I have seen infrared pictures of hives in the winter. THERE IS NO DOUBT that the hive is being heated! NO DOUBT!! These are the same instruments used to detect heat loss in houses. Now, the center of the cluster may be hotter than the outside of the cluster, but the inside of the hive is way warmer than the outside of the hive. Just hold your hand to an unisulated hive in the middle of winter . . . does it feel warmer than the outside air? Sure does. Why?? Because it's being heated.

Those who say the hive is not heated are just plain wrong.

Also, hive scale data shows that hives that are well insulated consume about 1/3 the amount of food that unisulated hives consume. Why is this?? Obviously it's because the bees need to generate more heat to keep warm in the uninsulated hives. I bet Finski will back that statement up. Finski??????

You don't see many hives hanging in the open under eves do you? Wasps do it, but they don't have to over winter. Bees could never generate enough heat in my area.

Finally, on a cold day, take off your outer cover and put your hand over the hole in the inner cover . . . HOLY HEAT BATMAN!!! It is like a stove pipe! So much for heating just the cluster. Do this . . . convince yourself.


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## c10250 (Feb 3, 2009)

Here's an infrared image I found on the internet. These hives are glowing because they are heated from the inside AND LOSING HEAT due to lack of unsulation. If the bees weren't heating the hive, you wouldn't see them glow. Note the snow on top of the hives. Look how more heat escapes from the handles (thinner wood). Certainly even less heat would escape if you added insulation. If your house looked like that you'd be adding some insulation!


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## wkinne (Jul 17, 2010)

Barry said:


> "The wild" has to also include any structure bees decide to call home on their own, which in most cases are not trees.


I was refering to what bees evolved to live in, trees, not what they find. Their reactions are from millions of years living in trees not under our eves for the past few thousand years. So bees have not evolved to live in homes yet. Perhaps in a few hundred million more year Honey Bees will have evolved to check the thickness of the wood above their hive with sounds waves or something.



Wayne


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## Barry (Dec 28, 1999)

Be sure to read the linked article on that page. I don't think it supports your thoughts.


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## wkinne (Jul 17, 2010)

TWall said:


> MP,
> 
> Do you have data to back up your theory?


All the data is here:

http://www.youtube.com/watch?v=6wrqG4DHPKE

Temp inside and out the hive is given as well as food consumption. I have just set up 21 hives just like this in a shed, I am heating the shed to 40 degrees. With the room at 40 the uper coner inside the hive is about 47 degrees, this is far from the cluster and still much warmer than the 40 drees inside the shed. When I get some pictures I will make a post called "Winter Quarters" if anyone is interested in seeing my setup. I have talked with the guy in the video and loved his results, getting a nuc through on just 6 pounds of honey!


Wayne


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## Barry (Dec 28, 1999)

wkinne said:


> I have just set up 21 hives just like this in a shed, I am heating the shed to 40 degrees.


 "I was refering to what bees evolved to live in"

Heated sheds?! Just like a tree huh?


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## wkinne (Jul 17, 2010)

I tried to grow hollow trees but the Kebler Elves keep moving in.


Wayne


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## c10250 (Feb 3, 2009)

wkinne said:


> I have just set up 21 hives just like this in a shed,



Cool setup. Did you ever think of painting your entrance holes different colors to help the bees find there way back?


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## amethysta (Jul 23, 2011)

Wayne- 

~giggle~


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## wkinne (Jul 17, 2010)

c10250 said:


> Did you ever think of painting your entrance holes different colors to help the bees find there way back?


Yes, I painted my wall on the outside of my shed with Green and Blue markings to help the bees find home, and used different colored roofs. 21 holes in the wall even confuses me! :s


Wayne


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## RiodeLobo (Oct 11, 2010)

wkinne said:


> I tried to grow hollow trees but the Kebler Elves keep moving in.


:lpf:


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## Michael Palmer (Dec 29, 2006)

Barry said:


> Michael -
> 
> When your bees take mid-winter flights and the hives are buried in snow, do you not get a lot of dead bees?


Not too bad Barry. Always a few.


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## c10250 (Feb 3, 2009)

Barry said:


> Be sure to read the linked article on that page. I don't think it supports your thoughts.


Here ya go, from this article they insulated hives with polyethylene and solar. . . 

"At all measuring positions, the °t was always higher in PE-covered colonies than in non-covered ones. The temperature outside the brood area in PE-covered hive was higher by 9.3 and 2.7°C during a bright day and clear night, respectively, than in non-covered ones. The brood area °t ranged between 34.8 and 36°C Brood area size in PE-covered hives increased by 59.2% (+ 2290 cm2) during the experimental period, but it went down by 8.4% (- 504 cm2) in non-covered hives (P=0.05). Adult bee population in PE-covered hives increased by 37.5% (3.8 occupied frames) during the winter, versus only 11.8% (1.8 occupied frames) in non-covered hives.

During the spring, PE-covered colonies produced ±20.8 kg honey/colony, while non-covered colonies produced only ±10.2 kg honey/colony (P=0.0004). We demonstrated that the temperature that prevailed in PE-covered populated hives was higher than non-covered ones, and resulted in a faster increase of the brood area size, colony population build-up and more spring honey per colony."

No doubt, the inside of the hive is heated. You will find no experimental results that show that the inside of the hive is the same temperature as the outside temperature during cold spells. Look at the better results from insulating the hives.


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## wkinne (Jul 17, 2010)

c10250 said:


> Here ya go, from this article they insulated hives with polyethylene and solar. . .


Very nice, thank you. Can't wait to see my results!


Wayne


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## c10250 (Feb 3, 2009)

So the moral of the story is:

1. Provide an upper entrance if you are not insulating, or if you expect the lower entrance to be blocked by snow. If you don't insulate you will experience condensation over the bees. An upper entrance helps eliminate this condensation over the bees.
2. No need to provide an upper entrance if you insulate.
3. The bees do indeed heat the interior of the hive. See this article.
4. Insulating the hive allows for a larger brood area, more bees, and more honey. (from the same article).
5. Insulating also lowers the amount of stores the bees go through.

Good stuff


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## Barry (Dec 28, 1999)

The moral of the story is different for me:

1. There is no final word on upper venting or not. I know beekeepers in cold winter climates that don't provide upper entrances and don't insulate. Condensation is not necessarily a bad thing. Use a plexi-glass inner cover during winter to see for yourself.
2. No need to insulate, typically. Bees are created to withstand cold temperatures.
3. The bees concern themselves with heating the cluster, not the interior of hive. See this article.
4. Linked article is nowhere near the temp range (_During this period, the ambient daily maximum temperature fluctuated between 12.8 and 23.1°C._) of a northern winter. Important to note from the study: _Some reports from temperate regions indicate that hive insulation may cause a decrease in honey consumption: In Germany, wintering bee colonies in an insulated and in control hive consumed 1.87 and 3.3 kg honey, respectively (Himmer, 1926). In Wisconsin, colonies covered with semi-transparent plastic consumed 25% less honey than those inside control hives (Detroy et al. 1982)._
_The above studies referred only to honey consumption, but did not reflect honey production, thus leaving the economic importance of hive insulation in temperate climates unclear on that point._
5. See #4


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## c10250 (Feb 3, 2009)

Barry, I agree with most of what you say.

You say "No need to insulate, typically. Bees are created to withstand cold temperatures". Agreed, however, if you are going into winter with light stores, you just might make it through if you insulate. If you have plenty of stores, no need to insulate. . . agreed. 

You say, "The bees concern themselves with heating the cluster, not the interior of hive". Again, I agree, however, the end result is a heated hive, which, if insulated causes the bees to operate at a lower metabolism to achieve their cluster heat. This causes a reduction in the amount of stores the bees consume (and possibly reduced cases of nosema).

You say, "The above studies referred only to honey consumption, but did not reflect honey production, thus leaving the economic importance of hive insulation in temperate climates unclear on that point." Here I disagree. From the article, it stated that "During the spring, PE-covered colonies produced ±20.8 kg honey/colony, while non-covered colonies produced only ±10.2 kg honey/colony (P=0.0004). We demonstrated that the temperature that prevailed in PE-covered populated hives was higher than non-covered ones, and resulted in a faster increase of the brood area size, colony population build-up and *more spring honey per colony*."

Here's a quote from the article:

"We, therefore, studied the impact of solar heating by covering hives with Infra-Red Polyethylene (PE)-sheets during the winter . . . on:

hive temperature; 
colony population; 
*spring honey production*. "

"*The colonies inside PE-covered hives produced twice as much as the colonies inside non-covered hives*"


So, if you do insulate, you will wind up wil less stores being consumed (that die out might just have made it if you insulated), a higher internal hive temperature, more brood, faster increase in brood area size, faster colony population build-up, *and more spring honey per colony*. . .


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## Barry (Dec 28, 1999)

c10250 said:


> if you are going into winter with light stores, you just might make it through if you insulate. If you have plenty of stores, no need to insulate. . . agreed.


I agree as well. Be aware that I approach all this from the practice of leaving plenty of honey on the hives going into winter. I don't strip all honey and then feed back in fall. A well stocked hive going into winter is my first objective.



> You say, "The above studies referred only to honey consumption, but did not reflect honey production, thus leaving the economic importance of hive insulation in temperate climates unclear on that point."


No, I didn't say that. That is a quote from the article.



> So, if you do insulate, you will wind up wil less stores being consumed (that die out might just have made it if you insulated), a higher internal hive temperature, more brood, faster increase in brood area size, faster colony population build-up, *and more spring honey per colony*. . .


Again, I don't think you can simply apply this study to the winter conditions we have here. There is a big enough difference that should evoke caution in applying it, especially since firsthand experience indicates a different outcome.


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## c10250 (Feb 3, 2009)

My current setup. Although you don't see it, I'm running an upper entrance that's as big as a small hole on an entrance reducer. Both hives have an empty super on top (over the inner cover) filled with the foam insulation.


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## WWW (Feb 6, 2011)

c10250, have you ever done a temperature check inside the hive and outside during cold weather, I would love to see the results, and if you had a way of checking for condensation it would be an added bonus. By the way what is being energized in the left hand hive that has a power cord running to it?


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## Barry (Dec 28, 1999)

The indoor spa! :lookout:


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## c10250 (Feb 3, 2009)

Barry said:


> The indoor spa! :lookout:


:lpf::lpf: "what is being energized" . . .nothing . . .it's a tie-down strap holding the insulation in place. If I had electricity down there I'd probably figure out something neat to do . . . but a spa?? I don't think so.


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## c10250 (Feb 3, 2009)

WWW said:


> c10250, have you ever done a temperature check inside the hive and outside during cold weather, I would love to see the results, and if you had a way of checking for condensation it would be an added bonus.


No I haven't. The article I cited did, though. Very interesting data.

As far as condensation goes, because of the insulation I don't get much. HOWEVER, this is not necessarily a good thing. Many say the bees need a little condensation as a water source. It's just bad to have condensation OVER the bees and dripping on them. I was actually thinking of leaving one wall uninsulated. That wall would have much condensation on it. It would kind of be like "controlled condensation". I never did this though.

Wrapping like this, we are 2 for 2, with no losses. 2 hives through 2 winters. We do treat for mites going into the winter, and make sure that all of the hives weigh at least 130 lbs (double deeps).


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## WWW (Feb 6, 2011)

2 for 2, that's not bad at all, I like your thoughts on condensation, and that sure did for the world look like a power cord to me LOL.


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## TWall (May 19, 2010)

c10250 said:


> Here ya go, from this article they insulated hives with polyethylene and solar. . .


The hives weren't insulated, they had a infrared transmiting plastic cover over then that acted similar to a greenhouse. The ambient temperatures inside the hives were increased because of solar gain, which resulted in increased brood production which lead to increased honey yields. This was in a subtropical region which has very few cloudy days during "winter." 

This would be somewhat analogous to wrapping a hive with a dark colored material, roofing felt, so the ambient temperature inside the hive warms enough for the bees to break cluster and move to stores.

Tom


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## c10250 (Feb 3, 2009)

TWall, I agree. It's probably more analogous to black felt.


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## ersatzS2 (Sep 24, 2009)

This has made me curious. I just came back from Lowes and they had some digital grill thermometers on sale so I opened a hive and stuck it in the middle of the boxes, ran the cord out a small groove i filed in a box edge, and velcroed the readout to the outside. At the moment with ambient temps of ~45-50F, it is 80F inside the hive...
I took a photo but still haven't cracked the code on how to upload on this site!


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## c10250 (Feb 3, 2009)

ersatzS2,

Did you stick it in the middle of the cluster or the empty area in the hive? Interesting results. Keep us posted.


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## MJuric (Jul 12, 2010)

mrpush said:


> From the studies you are refering to, do you know what the ambient outdoor temperature was? That can make all the difference in the world as heat flow is directly proportaional to temperature differential.
> 
> Where did they test the ambient temps (top bottom middle)?
> 
> ...


Interesting discussion. I think *THIS* is the study in question.

It looks like a very thorough study. Temps were taken throughout the entire hive at intervals of 1 1/4" on every frame of the hive, if I'm understanding it correctly.

The description of all hives used.

_All hives used for this study were three hive bodies high. The bodies were 20 inches square and 6-5/8 inches deep. There was a 1-inch entrance hole in the center body and a 3- by 3/8-inch entrance at the bottom board. The hives all faced south, and the combs were numbered from west to east. _

No "Top" entrance but a 1 inch hole in the middle body, which acts as a top entrance. 

Here's an interesting part that covers much of what is being discussed. This portion concerns the "Check hive" which is basically no special treatment at all.

_Prior to midnight on January 3 of the same year, the outside temperature was almost constantly 40º F. for 36 hours (fig. 6). After midnight the temperature steadily declined, reaching 0º at 0800 on January 5. On January 3 no temperature was under 46º in the colony and the highest was 90º. When the outside temperature reached 2º, the lowest hive temperature was 2º and the highest 89º. The insulating shell gradually became compacted and the cluster moved away from the front of the hive_.

So it seems that at higher temps the heat run off from the cluster does marginally heat the inside of the hive. However at lower temps ambient temp inside the hive outside the cluster is the same as outside the hive.

Another interesting tid bit concerning entrances.

_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._

Interesting stuff that appears to lean toward the idea that the cluster really doesn't heat the inside of the hive outside the cluster all that much.

I kind of picture the cluster much like a group of penguins at lower temps. The heat loss to the area and thru the hive walls itself is far greater than the ability of the hive to create heat, thus only the cluster is warmed. By comparison the penguins have no structure to heat and similarly only heat the cluster. I'd guess there is also a similar rotation in the cluster where bees take their time at the outside of the cluster and then move in toward the center, then back out.

Very neat study....although at this point I just hope my bees make it thru the winter no matter what I do  

~Matt


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## ersatzS2 (Sep 24, 2009)

ersatzS2 said:


> This has made me curious. I just came back from Lowes and they had some digital grill thermometers on sale so I opened a hive and stuck it in the middle of the boxes, ran the cord out a small groove i filed in a box edge, and velcroed the readout to the outside. At the moment with ambient temps of ~45-50F, it is 80F inside the hive...
> I took a photo but still haven't cracked the code on how to upload on this site!


Maybe this way:
http://i1189.photobucket.com/albums/z424/connaught1/Beekeeping/beethermometer.jpg


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## squarepeg (Jul 9, 2010)

looks like they're keeping cozy, very cool.


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## oldreliable (Jan 29, 2011)

Its simple..the cluster generates heat to keep the queen warm in the center..the bees in the cluster direct their heat towards the center. As bees on the outside get chilled they move towards the inside cluster while being replaced by warm bees whom are now on the outside, and they take over generating heat and passing food towards the center. Bee will only ue more honey if they have to stay cluster for extended periods. Remember bees dont hoddle up into cluster and remain their until spring.. they cluster and uncluster as needed..

severe winters = dead bees + dead hives
average winters = live bees + strong colonies
It is simple as nature taking her course 

BTW feral hives usually do have a 2nd exit/entrance


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## BeeGhost (May 7, 2011)

I built some of those insulated top covers and currently run it without the insulation. I did notice that the bees propolized the 3/8" x 2" top entrance to the point where there is just enough room for bee's to get in and out. They also did the same thing to the 3/4" hole I drilled into one of the deeps for an aditional entrance. I dont get the long freezing weather that the northerns do, but I do like the insulating top for summer use since it allows tons of ventilation for those 100+ degree days. I could feel the warm air coming out of the screened hole where the bee's were fanning!


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