# Anyone using top entrance have moisture problem?



## Cyan (Jan 27, 2015)

I too am starting off using a similar cover as his (MB) on 10 frame boxes. But half way through the project, I decided to let the top overhang the entrance on the nucs. I'd be interested in hearing the answers on this as well. Sorry about the loss.


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## Ravenseye (Apr 2, 2006)

I wouldn't discount moisture from coming in but yes, I've had deadouts that are "wetter" than live hives. Especially in the spring. If they run out of food but they started rearing brood you have a mass of organic material that is dead but not dry. And without circulation from live bees, the hive gets pretty dank and musty. When you say that you think the queens failed, are you saying that the colony just dwindled down to a small number of bees? Are you sure they didn't starve out?


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## Kofu (Jan 26, 2011)

Was there any vent at the bottom? If not, the moisture from respiration might add up to enough to condense on the walls and trickle down over the winter.


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## Acebird (Mar 17, 2011)

Kofu said:


> Was there any vent at the bottom?


A single upper entrance will not ventilate any better than a single lower entrance. In order for air to move out the same amount of air has to move in. Did you see any evidence of water in the center of the frames?


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## Rader Sidetrack (Nov 30, 2011)

Acebird said:


> A single upper entrance will not ventilate any better than a single lower entrance. In order for air to move out the same amount of air has to move in.


But there is reason to believe that air inside a hive is _warmer _than air outside the hive under many conditions. And what does warm air want to do? :scratch: *Rise*? :s What grade did we learn that? 

The warm air rises up - out through the upper hole, and in turn cooler outside air moves in through the same hole. The process is called _convection_. 

[hr] [/hr]
My hives have top entrances exclusively. Those hives don't have a moisture problem, even in relatively humid Tennessee.


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## Cyan (Jan 27, 2015)

Same principal as cracking the windows of a parked car when it's hot- makes a huge difference. I would only argue that convection is slower than what Acebird may be referring to. MB did tell me a while back to be careful of over-ventilating in the northern climes. Perhaps convection is better for northern beeks?

Edit: Almost forgot the fact that an active hive isn't a dead airspace. The bees circulate that air, thus making the convection process occur more quickly.


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## Mike Gillmore (Feb 25, 2006)

All of my covers are similar to MB's. During the winter, moist air in the hive does rise and sometimes moisture will condense on the cold wood of the lid and drip down on the bees. Air circulation or not. 

What I do now to really reduce that is to add a 2" foam board on top of the cover for wintering. That insulates the cover from the outside air and keeps the temperature of the wood on the bottom side of the cover much closer to the internal temperature of the hive. The result has been less condensation.


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## Michael Bush (Aug 2, 2002)

There is always more moisture in a dead out. An overhang just catches the wind and drives in more rain, unless it hangs over a really long way and then it catches the wind and the cover blows off. I've done hives with a simple cover that has no shims and was just back 3/4" from the front for the entrance with the entrance facing the sky. No moisture problems. It runs down the front of the hive, not the bees, and runs out the bottom anywhere you let it.


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## homesteader824 (Jun 9, 2012)

Thanks everybody, I think it is mostly the moisture you expect from not having live bees ventilating the hive. The one with the mold on the bottoms of the frames does have me wondering though.

The reason I think these hives died out due to queen failure is that there was very little brood, and it was scattered over a couple of frames. The clusters that were left were small. Last August I did a sugar-shake test for varroa and was just seeing 1 or 2 mites to about 300 bees. Two of these were swarms I caught last April. One I think still had the same queen, so she was getting old. Another hive was a split I did early August--that was a free queen that had been a good survivor, but again, she was getting old and I knew she might not make it. The one that surprised me was one that I got from a swarm last April. I never had to feed it and it was very heavy through winter with honey. The others I was feeding with sugar blocks. The hive with all the honey put off a small swarm in July so they should have had a new queen then. Their disposition improved a few weeks later.

Regarding the bottom, these are on solid bottom boards with no bottom entrance or holes of any kind. I noticed a lot fewer SHB with this configuration--I literally saw two SHB all of last summer (I do know there where probably more I didn't see, but still it seems an improvement.) This setup does save on woodenware too, another plus.


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## Acebird (Mar 17, 2011)

Cyan said:


> Same principal as cracking the windows of a parked car when it's hot- makes a huge difference.


I am sorry but the analogy is wrong all cars have constant ventilation. Convection is heat not air. Heat moves from high to low. Moisture can move from high to low but it would be extremely slow if there is a small entrance and it doesn't matter if it is upper or lower. Air will not move out of a closed box unless there is a way for the same amount of air to get into the box. This is basic.


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## Rader Sidetrack (Nov 30, 2011)

Acebird said:


> Convection is heat not air.


OK, Ace, here is _convection _in a nutshell ...



> Convection is heat transfer by mass motion of a fluid such as air or water when the heated fluid is caused to move away from the source of heat, carrying energy with it.
> 
> 
> http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/heatra.html


_*"heat transfer by mass motion of a fluid such as air or water "
*_
Note the concept of air (as air in a hive) behaving as a _fluid_, carrying heat.



Acebird said:


> This is basic.


As in _basic science_! :lpf:


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## Barry (Dec 28, 1999)

Yes, this is basic. One will witness this if you get the pleasure of working in an attic during the summer. Most homes do not have balanced attic ventilation. Either too few ridge vents or too few soffit vents. You can have a roof full of ridge vents and still have the air sit still in the attic if you don't have the same amount of venting down at the bottom in the eaves. My last house had a gabled roof and I had copious amounts of soffit vents as well as gable vents to move the air out the upper roof vents. I could stand in my attic and my hair would move about from the cross breeze.


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## Cyan (Jan 27, 2015)

Convection isn't heat (or cold for that matter). Heat is thermal energy and cold is the lack thereof. Convection is basically the movement of molecules through liquids & gasses. How do those molecules move? By thermal energy acting on them. Air is made of many different molecules, and I guarantee that as a top entrance hive heats up those molecules begin to move. If air moves out, air has to move back in to fill the void unless it is a vacuum, in which case it is not. Thus we have convection currents. Furthermore, without wind or the blower motor running, how does a parked car have constant ventilation? It does not. Crack the windows and convection currents will cool that car even if only by a few degrees.


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## BadBeeKeeper (Jan 24, 2015)

homesteader824 said:


> Thanks everybody, I think it is mostly the moisture you expect from not having live bees ventilating the hive. The one with the mold on the bottoms of the frames does have me wondering though.


In Winter I use solid bottom boards, and both upper and lower entrances, and a moisture absorbing board on top. Dead bees on the bottom boards are always damp, no matter if the hive is live or a deadout. Dead bees hold moisture. Damp, dead bees in the dark will get moldy. If the pile of dead bees is deep enough to touch the bottoms of the frames, the frames will get moldy too. Nothing to wonder about.


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## Acebird (Mar 17, 2011)

Of for God sake, molecules moving, yes within the box, circulating around and mixing up until the temperature is equal if it can happen. But air doesn't move outside the box unless air can move inside the box.

Cyan, the vents are open in your car. The hot air moves out the window and cool air moves inside the open vents. You don't need a motor. Tape up all your vents and then see how well your cracked window works.


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## Barry (Dec 28, 1999)

Cyan said:


> If air moves out, air has to move back in to fill the void unless it is a vacuum, in which case it is not.


I think this is my (and Brian's) point. Air won't move out with a single opening, at least any significant amount. How does air get back in? Through the same hole? Basically the air is trapped inside.


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## Rader Sidetrack (Nov 30, 2011)

Ace, and now Barry, the heated air within a box (with only one opening) is at a _higher pressure_ than the outside air as a result of the temperature differential.

Air (or water) under pressure will certainly move *out *of a box (tank) even if the box only has one opening.


BASIC SCIENCE!

:ws:


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## Acebird (Mar 17, 2011)

LMAO Rader, go for it, now a pressurized hive.


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## Barry (Dec 28, 1999)

Rader Sidetrack said:


> Air (or water) under pressure will certainly move *out *of a box (tank) even if the box only has one opening.


Okay Mr. smarty pants, tell us how much air is moving out! 

https://www.youtube.com/watch?v=7t-srXrQxk0


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## Rader Sidetrack (Nov 30, 2011)

How big is the box? :scratch: How big is the opening? :s How high is the temperature differential? :kn:

Obviously there are a lot of factors, likely including more than just those 3 questions. And no, if you do answer those questions, I am not likely to provide an answer to the specific volume of air moving. That is not the point.


Ace's claim was that heated air would not move through single opening in a hive box. And _that is just plain wrong_. 

[hr] [/hr]


Acebird said:


> LMAO Rader, go for it, now a pressurized hive.


 OK, Ace, why don't you provide your own explanation? Does air in a closed container increase in pressure as the temperature in that (tank) rises? What happens if one opens the valve to that tank? 




Come on, Ace, the world is awaiting your _wisdom_ .... :bus ...


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## Barry (Dec 28, 1999)

Rader Sidetrack said:


> Ace's claim was that heated air would not move through single opening in a hive box. And _that is just plain wrong_.


I think most of us understand this to mean _"would not move through single opening in a hive box of any significant amount"_.


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## Rader Sidetrack (Nov 30, 2011)

How big is the single opening in that hive, Barry? How big is the volume of the box (# of boxes on the hive)? What is the temperature differential? I would say that there are multiple unanswered questions, and the calculation is complex.


To assert that the amount of air movement is not significant without ascertaining the input factors seems like _another Aceism _to me!


... yes, there is a link there to another _fun _Ace thread ...


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## Kofu (Jan 26, 2011)

I'm one of those who think a vent at the bottom and one at the top will together make a much stronger air flow, from the bottom upward if heat is added inside and it's warmer inside the hive than outside. You get a "chimney effect." Maybe for a hive of bees in winter that's more air flow than you _want_, but it's definitely going to be _more_.

Add in the *five gallons of water* that get added to the hive during the winter (assuming the bees eat and burn off 60 pounds of honey). All these posts about dead-outs at the end of winter being dank, moldy, and just plain wet! Maybe _some_ of the moisture comes from the dead bees themselves, when they give up the ghost, but a lot of it came from them when (and because) they were alive, just keeping themselves warm.

Nearly three-quarters of that water (that five gallons of water!) comes from the sugars in the honey, not from the water that was in the honey before they ate it.

Apparently this is a little-known fact, so maybe it's time to keep saying it until people understand. Five gallons. If it doesn't get out somehow, it's going to stay in. Science.

opcorn:


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## Rader Sidetrack (Nov 30, 2011)

Much better to have that 5 gallons of water on top of the hive (in a bucket) than _inside _the hive! :thumbsup:


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## BadBeeKeeper (Jan 24, 2015)

Rader Sidetrack said:


> Ace's claim was that heated air would not move through single opening in a hive box. And _that is just plain wrong_.
> OK, Ace, why don't you provide your own explanation? Does air in a closed container increase in pressure as the temperature in that (tank) rises? What happens if one opens the valve to that tank?
> 
> Come on, Ace, the world is awaiting your _wisdom_ .... :bus ...


I gotta go with Barry and Ace on this one...if the box is otherwise sealed well, with only a single top entrance, there would be *small* movements of air being expelled as the temperature rises (gasses expand as temp increases) and then re-entering as the temperature drops and the air in the box becomes more dense, in order for the pressure inside the box to equalize with the pressure outside the box. However, for the purposes of this discussion, the effects of that exchange would be negligible. (Also, it has to be noted that the pressure/density of the air outside the box is also changing, reducing the differential.)

In the extremely literal sense, yes, there would be -some- air movement, but the net effect would be so small that it can be ignored.

There needs to be an air *flow*- entering from one area and exiting from a different area.

In the example of cracking a car window in the Summer, one typically does not open only -one- window, usually at least -two- windows are opened on opposite sides, which allows the breeze (if any) to *flow* through the vehicle and carry off the warmer air from inside it. If only one window is cracked, the amount of heated air escaping is considerably smaller, so much so that you almost might as well not have bothered to do it.


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## Kofu (Jan 26, 2011)

homesteader824 said:


> Thanks everybody, I think it is mostly the moisture you expect from not having live bees ventilating the hive. The one with the mold on the bottoms of the frames does have me wondering though. [...]
> 
> Regarding the bottom, these are on solid bottom boards with no bottom entrance or holes of any kind. [...] This setup does save on woodenware too, another plus.


So perhaps, with this discussion about vents at top (and/or bottom), we can guess that there were cracks between your bottom box and the solid board it was sitting on -- in the other two deadouts but not in the one that was so wet and moldy. Just enough, in the other two, to provide an upward flow of air during the winter, to carry a lot of the moisture out. 

It's the same in a house in summertime, when you open the windows at the top of the house, there's enough air seeping in at the bottom that you can get a good exhaust of hot air. (Maybe a car too?  )


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## crofter (May 5, 2011)

You could put a single opening of lets say 2 sq. inches at the top of the hive. If the air at the top of the hive is warmer than air outside there will be flow out of the top of the 2 Sq. in. opening and external air will flow inward through the lower part of the opening; counter currents, so not very efficient.

If instead you made an upper opening of 1 sq. in and a lower one the same area you will have unimpeded flow through each opening. The pressure differential created by the different density due to temperature difference will result in a much higher flow rate. This is harnessing thermosiphon effect which is related to convection but not exactly an interchangeable term.

Barry is correct in his analogy of the eve and ridge vents. Rader is correct about pressure equalization occurring but I think that is a momentary effect and not sustained.

There is another effect at play here because of the fact that, at a given temperature, higher moisture air is lighter than drier air. 

I see the benefit in both upper and lower vents. ( I also llike to consider my shavings quilt to be effectively an opening for some air flow. Controlled is the key word; controlled ventilation to rid the hive of excess moisture without over ventilating and losing valuable heat. If you believe them, charts show that honey consumption (thus moisture production) goes up as temperature goes down in the hive.

Cold air (or gasses heavier than air) can indeed become virtually trapped in an _open topped_ container with only slight mixing at the boundary.


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## bigeddie (Feb 19, 2008)

I know I'm not very smart but dosen't this have to do with temperature equalization? If you set a sealed plastic gas can in the sun it will expand and build up pressure, when you open the vent air comes out. It was sealed so no air got in but the gas or air must have expanded to have air come out once the vent was opened. The same can in my shop at a constant temp. and sealed will create no pressure. The same can outside in the sun but unsealed creates no pressure. So dosen't air pass in and out of the same vent hole? I really don't know. If you do know, how do you know or is it just a guess like mine was.


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## crofter (May 5, 2011)

bigeddie; I may have added confusion with my last sentence which I have edited. You are correct; change of temperature of a sealed container will result in creation of pressure differential. If the container is vented flow will occur either in or out and prevent any pressure differential. When there is equal pressures inside and out, flow through the vent will virtually cease.


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## Rader Sidetrack (Nov 30, 2011)

Thank you, _bigeddie_, for that perfect example of hot air flowing out of a _closed container with only one opening_. 

To take it a step further, who here will be so *bold *as to claim that gasoline (or water) will _not _evaporate out of a closed container with only one opening, if that container is left outside with the cap off*? :scratch: _How does that evaporation occur if there isn't air exchange through that single opening?_ :s



* Note: cap off, but opening is protected so that rain doesn't get in


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## Cyan (Jan 27, 2015)

opcorn:

Too many variables and I think the obvious is being overlooked. 

Air will move in and out of a hive with 1 opening by way of temperature changes, even if it is a small amount- Fact. Is it enough to move excess moisture out of a hive in summer? Who cares? Because, there are thousands of bees per hive and many have the job of circulating said air- nature's little ventilators if you will. What happens when bees nest in a hollow tree with a top entrance, do they die because of heat build up? Obviously not because they regulate the temperature.

However, in the winter you have thousands of bees both expelling moisture and producing heat. Heat rises and carries the moisture with it. Some of this moisture will condense when it hits the sides of the hive, but most will go right out the top entrance and colder (hopefully drier air) will creep back in. The whole thing changes because the variables are different. Temperature inversion in this scenario happens quicker than in the car scenario because of the dynamics involved. Regardless, in a lot of ways we are all right to different degrees.


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## Cyan (Jan 27, 2015)

And BTW, this has made me realize that regardless of whose more right or wrong I messed up again. When I build my BB's, which I intended on using as feeders (long story) I sealed them. Apparently, I have to at the very least allow for condensed moisture (water) to escape. Good point on the cracks in traditional BB's- I never really thought of that. They would definitely help quicken the exchange of air, but as a newb, I don't really have a feel for exactly how much ventilation there should be. We may share a similar climate, but you or I may have winter wind issues to consider. Is there a general rule of thumb for this short of if they freeze it was too much ventilation?


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## Kofu (Jan 26, 2011)

Cyan said:


> in summer ... there are thousands of bees per hive and many have the job of circulating said air- nature's little ventilators if you will. What happens when bees nest in a hollow tree with a top entrance, do they die because of heat build up? Obviously not because they regulate the temperature.
> 
> However, in the winter you have thousands of bees both expelling moisture and producing heat. Heat rises and carries the moisture with it. Some of this moisture will condense when it hits the sides of the hive, but most will go right out the top entrance and colder (hopefully drier air) will creep back in.


Two things: First is that in the winter the bees are huddled and not perched near the entrance to direct air traffic. So you have to count on air-temperature hydraulics to move air and moisture out of the hive.

Second, and this came up in our discussion about how much moisture is generated, in a tree the ceiling is probably not flat. Comb is attached at the top, but most of the water that condenses inside will trickle down the walls of the cavity and accumulate at the bottom. In a tree, that may be a good thing! Wood rots, hole expands. There may even be a fissure in the tree that drains water away at the bottom.

Phil Chandler (the 'barefoot beekeeper' in the UK) commented elsewhere on this topic: 
If the hive is properly designed and constructed, that water is not added to it, but drains away. My eco-floor is designed to absorb some of the water in order to provide a more balanced ecosystem, including at least some of the other 1700-odd species known to live in hollow trees.​
I keep going back to the original problem that started this thread. If there's no way for water to drain away, and if it doesn't vent out quickly enough (through that small hole at the top), the water accumulates in the hive.


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## Kofu (Jan 26, 2011)

Cyan said:


> Apparently, I have to at the very least allow for condensed moisture (water) to escape. ... I don't really have a feel for exactly how much ventilation there should be. ... Is there a general rule of thumb for this short of if they freeze it was too much ventilation?


Cyan, I've been reading around the Beesource threads for awhile, and I have definitely seen some people arguing that open BBs and a steady airflow are perfectly acceptable even in some of the coldest parts of this country. On the other hand, over and over again I've seen everyone agree that water dripping down on the bees is bad for them. Everything in between seems to be up for debate.

It is pretty remarkable how the bees manage to get air circulating in the hive, even with just one small hole, as long as they can get out by the entrance to wave their wings. I think as a general rule, they can handle just about anything the stupid beekeeper throws at them — except cold water in wintertime.


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## crofter (May 5, 2011)

Rader Sidetrack said:


> Thank you, _bigeddie_, for that perfect example of hot air flowing out of a _closed container with only one opening_.
> 
> To take it a step further, who here will be so *bold *as to claim that gasoline (or water) will _not _evaporate out of a closed container with only one opening, if that container is left outside with the cap off*? :scratch: _How does that evaporation occur if there isn't air exchange through that single opening?_ :s
> 
> ...


There doesn't have to be any air exchange. The vapor pressure of the _volatile liquid_ will send it out the single opening quite handily. I dont know whether it is a fair comparison to water vapor in air, but you will have to take that one up with your dancing partner!


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## BeekeepingIsGood (Aug 12, 2012)

It's amazing with how much debate there is about top or bottom entrances or both (Dennis Murrel, Ed Clark, Roger Delon) that there isn't some good research on the topic to point to on these topics somewhere.

The best I can come up with is some mathematical models of different bottom board parameters.




> Controlled is the key word; controlled ventilation to rid the hive of excess moisture without over ventilating and losing valuable heat.


I've seen wet hives that had both top and bottom entrances, and I've seen dry hives that had only a fairly small bottom entrance...so I'm a little lost in knowing what's best.


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## rwurster (Oct 30, 2010)

Rader Sidetrack said:


> Much better to have that 5 gallons of water on top of the hive (in a bucket) than _inside _the hive! :thumbsup:


Lol, my thoughts exactly :thumbsup::thumbsup:


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## Acebird (Mar 17, 2011)

Rader Sidetrack said:


> Does air in a closed container increase in pressure as the temperature in that (tank) rises?


Does the whole hive heat up to 110 degrees in the middle of winter? How many CC of air would be expelled from a hive due to expansion for lets say 40 degree differential. And now how many mm of water would be taken with it?

Experiment for you Rader ... fill up a 5 gal water jug to the top and put it in a refrigerator (about 45 degrees) with top off. I will bet you in 5 years there is still water in the jug. We are talking about expelling 5 gal. in 3-4 months in a bee hive.


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## Acebird (Mar 17, 2011)

Cyan said:


> Good point on the cracks in traditional BB's- I never really thought of that.


That is not something that I would rely on. Condensation running down the sides will run on to the bottom boards and swell the boards plus there is a lot of junk on the boards in the winter time that fill these cracks. It is better to have something that won't plug up.


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## Acebird (Mar 17, 2011)

BeekeepingIsGood said:


> so I'm a little lost in knowing what's best.


There is no best. You decide what is best for you and how you want to manage your hives. Both ways are completely successful.


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## Acebird (Mar 17, 2011)

bigeddie said:


> The same can outside in the sun but unsealed creates no pressure. So dosen't air pass in and out of the same vent hole?


Of course it can but can it take 5 gal. of water out of the hive by the mere expansion and contraction of air? That is a definite no.


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## Rader Sidetrack (Nov 30, 2011)

Acebird said:


> Experiment for you Rader ... fill up a 5 gal water jug to the top and put it in a refrigerator (about 45 degrees) with top off. I will bet you in 5 years there is still water in the jug. We are talking about expelling 5 gal. in 3-4 months in a bee hive.


Sure thing, Ace, I'll get right on that! :lpf:

Have you forgotten that the referenced 5 gallons of water is presumably related to the consumption of honey by *LIVE BEES* over the course of a winter? Are you now advocating keeping bees in an operating refrigerator? 

:ws:


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## Acebird (Mar 17, 2011)

Yep Rader another fork in the road. I know when you start doing this you have been beaten.

For you and only you just use one small entrance where ever you like and your bees will heat up your hive creating 2 atmospheres of pressure to vent that 5 gal of water they need to expel in the winter.


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## Cyan (Jan 27, 2015)

I've already made and fixed a lot of mistakes when I built parts for my hives and every time I think I have it all squared away, someone throws another wrench in the gears. Not saying that they are wrong, but what I am saying is that until I get a hands on feel for the do's & don'ts with my own colonies and in my own climate; I'm at a huge disadvantage. 

So I agree to disagree from this point on. I'll do my own experimentation where needed and figure it all out in line with the experience of a few well experienced gurus as a base line. I have no problem admitting when I'm wrong, when I'm certain that I am wrong. But my own personal observations in other areas cast enough doubt to make me question some of what's being said. And like I said, without the knowledge gained from hands on experience, it wouldn't be right to push or rescind my arguments any further.


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## Rader Sidetrack (Nov 30, 2011)

Acebird said:


> For you and only you just use one small entrance where ever you like and your bees will heat up your hive creating 2 atmospheres of pressure to vent that 5 gal of water they need to expel in the winter.


Ace, what do you think happens with a bee colony in a tree with only one hole? What happens to the moisture released by the bees consuming honey over the winter? 


Why aren't those 'tree' bees all dead? :scratch: :kn: :s


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## Kofu (Jan 26, 2011)

crofter said:


> There doesn't have to be any air exchange. The vapor pressure of the _volatile liquid_ will send it out the single opening quite handily. I don't know whether it is a fair comparison to water vapor in air, but you will have to take that one up with your dancing partner!


Frank, that's another, different way that water vapor might get out of the hive with a single entrance toward the top. We can put it in the list. As gasoline evaporates in the can, the vapors create their own pressure that press some of it out. Since gasoline is more volatile than water, it evaporates very quickly (at the temperatures we're talking about), creating continuous pressure, and the gasoline leaves the canister much quicker than water. The same process happens with water, just more slowly.

In the summer, with higher temperatures, this may be a significant effect -- especially for water evaporating off of ripening honey. In winter, with temperatures in the hive at 45 or even lower, this particular mode would take a lot longer. In a refrigerator, to take that example, and assuming we open it from time to time to (get an occasional beer, and) tap off some of the water vapors that accumulate in the fridge outside our 5-gallon jug, I'm guessing it would take less than five years for the 5 gallons of water to bleed off.

So this has to be considered as one way to get water out of a hive, at least some of it. Vapor pressures probably have to do with relative humidity (of water or gasoline) inside and outside the container, and temperatures.


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## BeekeepingIsGood (Aug 12, 2012)

> 5 gallons of water is presumably related to the consumption of honey by LIVE BEES over the course of a winter?


Can someone explain where this number is coming from? One hive I'm looking at right now I'd estimate lost about 40lb between November till now. Wouldn't that amount to slightly less than a gallon of water? How would you ever have 5 gallons of water needing to exit the hive in winter?



> There is no best. You decide what is best for you and how you want to manage your hives. Both ways are completely successful.


Then why is there so much argument on the subject? Perhaps best is the wrong word. What I'm after is a clearer understanding of how different variables really effect moisture co2 buildup in the hive.


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## enjambres (Jun 30, 2013)

Water weighs 8.34 lbs /per gallon, so a forty pound loss could account for the loss of 4.79 gallons of water.

Could, of course, is the operative word, since dead bees, wax cappings blown out through the entance, debris carried out by the bees, solids contained in bee-poop, etc. would also be fractional components of the reduction in weight. But water, would I think be the largest share.

Enj.

Enj.


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## BeekeepingIsGood (Aug 12, 2012)

But isn't ~82% of that 40lb in the form of sugar rather than water?


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## Kofu (Jan 26, 2011)

Great discussion! Here's a list of some of the ways to get moisture/water out of a hive through a top-only entrance:


Water vapors accumulate in the warm, humid air at the top of the hive, and slip out through the top-side of the hole, at the same time that less-saturated air comes in through the bottom-side of the hole.
Water vapors accumulate, and "burp" out periodically, with fresh air coming in moments later to equalize pressures.
I'm picturing an upside-down version of water pouring from a bottle. Tip it slightly and air comes in while water pours out, simultaneously. Tip it more (with a full bottle) and water glugs out and air burps in, alternately.


Water evaporates and creates vapor pressure inside the hive, which continuously pumps the water vapor out through the hole.
This is the "just leave the bottle standing upright and let the water evaporate out" approach.

Then there are effects coming from outside factors, like changing temperatures, changing humidity levels outside the hive, and sunshine. Phil Chandler points to and provides a book, published in 1918, that covers most of this bumpier ground, '_'Constructive Beekeeping'_' by Ed H Clark.

Clark makes the common mistake of thinking (p. 37 of his book) the water that comes from honey is just the H[SUB]2[/SUB]0 that was mixed with sugars before the bees metabolized the honey. But leaving that aside, he considers at length the process of condensation inside the hive and how that's affected by temperature changes during the daily cycle. He offers his own design of a top-lid that lets water condense, when temperatures are cooler outside, and drip off outside the hive.

Finally, we have some real-world considerations, like cracks at the bottom of the hive that might


Allow water to seep out at the bottom, or 
Allow air to seep in at the bottom, creating a "chimney effect" (Frank calls it "thermosiphon") to pull air through the hive, carrying the water vapors with it.
None of these listed above consider the role of the bees, except in generating heat to produce the "chimney effect." Bees might carry water out of the hive (cleansing flights). They might use water that condenses inside the hive (see Clark's book for more on this) to raise brood that, as adult bees, will be partially constituted by the water that we started with. And they might, on warmer days, leave the hive and "exhale" the water vapors into the air outside.

There are probably some other ways to get the water out of the hive... Anyway, I hope we can agree that somehow it does get out, except for the times when it doesn't. Most of this discussion, for me, is not about whether it does or doesn't, but how it does (when it does) and why it doesn't (when it stays in). And when it stays in, perhaps we all agree that it can create problems that may produce deadouts at the end of winter?

opcorn:


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## Kofu (Jan 26, 2011)

BeekeepingIsGood said:


> But isn't ~82% of that 40lb in the form of sugar rather than water?


Here's a "cellular respiration equation" for pure glucose. (C[SUB]6[/SUB]H[SUB]12[/SUB]O[SUB]6[/SUB]) + 6(O[SUB]2[/SUB]) => 6(CO[SUB]2[/SUB]) + *6(H[SUB]2[/SUB]O)* + heat


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## Rader Sidetrack (Nov 30, 2011)

>> Can someone explain where this number is coming from? 

There is another current thread that brought the 5 gallons of winter water issue to the forefront:
http://www.beesource.com/forums/sho...-to-the-hive-from-respiration-over-the-winter





... and no, that thread linked above is _not _about Ace's Aqueous Hurricane Hive Holddown[SUP]®[/SUP]™


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## bigeddie (Feb 19, 2008)

crofter said:


> There doesn't have to be any air exchange. The vapor pressure of the _volatile liquid_ will send it out the single opening quite handily. I dont know whether it is a fair comparison to water vapor in air, but you will have to take that one up with your dancing partner!


I don't dance, smarty pants.


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## Rader Sidetrack (Nov 30, 2011)

A slight miscommunication there, _bigeddie_. I'm confident that _Crofter _was referring to me vis-a-vis Acebird, not you.


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## Acebird (Mar 17, 2011)

Kofu, FYI when you open the door to a refrigerator you let moisture in (frost proof refrigerator). The process of melting frost removes water that is evaporated from underneath the fridge into the room. It will get pretty darn dry in a fridge when you don't open the door.


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## Kofu (Jan 26, 2011)

Acebird said:


> Kofu, FYI when you open the door to a refrigerator you let moisture in (frost proof refrigerator). ... It will get pretty darn dry in a fridge when you don't open the door.


Okay. So I bet that the 5 gallons doesn't last five years in the jug in the fridge, then. Heck, it might be gone in less than 3-4 months. Problem solved! :applause:


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## crofter (May 5, 2011)

Sorry, bigeddie: you definitely were not the target! I agree with what you described. 

Rader and Ace have been dancing around for several years now! 

I think we are a bit like the seven blind men and the elephant; each has hold of a different part and feels it best describes the whole beast! This thread got waylaid by references to ideas in another thread about the vast amount of moisture given off from the bees metabolization of honey.

I like a small amount of both top and bottom ventilation and find that most often by spring time the bottom one is often blocked by the normal die off of bees. Many people, can just about guarantee the bottom will be covered deep in snow. I am at 46.200' N so quite a variation from the beeks in Florida.


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## Kofu (Jan 26, 2011)

But it was such an _innocent_ question... 



Kofu said:


> Was there any vent at the bottom? If not, the moisture from respiration might add up to enough to condense on the walls and trickle down over the winter.


Acebird followed: 



Acebird said:


> A single upper entrance will not ventilate any better than a single lower entrance. In order for air to move out the same amount of air has to move in.


And Radar took issue:



Rader Sidetrack said:


> But there is reason to believe that air inside a hive is _warmer _than air outside the hive under many conditions. ... The warm air rises up - out through the upper hole, and in turn cooler outside air moves in through the same hole. The process is called _convection_.


Both parts of the problem are in the thread's title: top entrance and moisture. And in the story told by homesteader824, who originally posted. So how was the thread "waylaid"??? 

Yes, Frank, a few of us had already rehearsed our lines in the other thread. But they're relevant here as part of a discussion of top-entrances. In the other thread we talked about quilt boards. Here it's top entrances.


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## Michael Palmer (Dec 29, 2006)

Barry said:


> Yes, this is basic. One will witness this if you get the pleasure of working in an attic during the summer. Most homes do not have balanced attic ventilation. Either too few ridge vents or too few soffit vents. You can have a roof full of ridge vents and still have the air sit still in the attic if you don't have the same amount of venting down at the bottom in the eaves. My last house had a gabled roof and I had copious amounts of soffit vents as well as gable vents to move the air out the upper roof vents. I could stand in my attic and my hair would move about from the cross breeze.


I agree. And, the reason I have both top and bottom entrances for winter. I never find wet conditions in my hives and they winter well...less than 10% loss this year.


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## Mike Gillmore (Feb 25, 2006)

If colonies in the northern US or Canada are surrounded with 2+ feet of snow for most of the winter, how can there be ventilation from the bottom? The hives are encapsulated in snow. I don't have an answer, just wondering. 

How does all that "5 gallons" of moisture escape the hives, and not soak the bees?


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## Rader Sidetrack (Nov 30, 2011)

Obviously, there IS air exchange occurring. Even with just _one _hive opening.

Its not just a moisture issue - bees are air breathing* creatures just like us, and if there was no air exchange, then the bees would suffocate long before the cold condensation did them in. If the hive only has _ONE OPENING_, then obviously that _one opening_ provides adequate air exchange to prevent asphyxiation. If oxygen/CO[SUB]2[/SUB] are moving in/out, what is the big deal to accepting that moisture from the higher humidity inside the hive is *also * moving out during that air exchange process?



* OK, bees have spiracles instead of lungs, but its the same old _oxygen in - CO[SUB]2[/SUB] out_ routine.


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## BeekeepingIsGood (Aug 12, 2012)

> how can there be ventilation from the bottom? The hives are encapsulated in snow.


Every year someone around here will talk about shovelling their bees out so they can breath, and every year someone will reply to them 'snow does breath'. It's ice that's a problem.

I don't know personally, I live just out of reach of the snow belt. I do know the snow in front of the entrance seems to melt faster than the snow on the other sides of the hive..


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## rwurster (Oct 30, 2010)

Rader Sidetrack said:


> Obviously, there IS air exchange occurring. Even with just _one _hive opening.


That 3/4" hole I have drilled into the top box of my 2 story nucs has gotten them through many winters. Either my bees can hold their breaths for 5 months or that little hole is doing the trick. Maybe the great physicist/engineer Ace has some invaluable insight on that one


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## Matt F (Oct 7, 2014)

Rader Sidetrack said:


> Obviously, there IS air exchange occurring. Even with just _one _hive opening.
> 
> Its not just a moisture issue - bees are air breathing* creatures just like us, and if there was no air exchange, then the bees would suffocate long before the cold condensation did them in. If the hive only has _ONE OPENING_, then obviously that _one opening_ provides adequate air exchange to prevent asphyxiation. If oxygen/CO[SUB]2[/SUB] are moving in/out, what is the big deal to accepting that moisture from the higher humidity inside the hive is *also * moving out during that air exchange process?


Rader, I usually side with you on these wrestling matches but you're dead wrong here. Sure, there's SOME air exchange through a single upper, just like there's SOME with a single lower entrance. But there's FAR FAR FAR more with a single upper and a small lower opening. The convection is allowed to work that way, warm air rises and passes out the upper while cool fresh air comes in the lower opening. With a single opening, the warm air has to exit the hole while the cool air comes in simultaneously, so the flow is much restricted. Two upper entrances would help, but an upper and a lower will always be much better.

The easy answer is a small lower opening or vent hole. It also works in a poorly sealed hive where air can freely come through the cracks, but that's generally not the case with our manufactured and propolis sealed hive bodies.

And yes, this is basic science. Sorry if that prompts another ridiculous analogy or series of laughing emoticons.


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## Rader Sidetrack (Nov 30, 2011)

Perhaps you have misunderstood my position.

I'm pretty sure that there is *nowhere *in this thread that I have adopted a position that TWO holes/entrances doesn't offer more air flow than one.

I simply pointed out that hives with one entrance can survive and prosper - that there can be adequate air exchange, including moisture escaping through that *one *hole.

Just one smiley for this post ... 


P.S. Read more about top entrances, including ... _gasp _... a _*single *_top entrance, here:
http://www.bushfarms.com/beestopentrance.htm


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## Matt F (Oct 7, 2014)

nobody said it wasn't possible to survive with one entrance, top or bottom. The question was whether or not a single top entrance could lead to moisture problems, and that has led us down this rabbit hole of speculation about the potential convective exchange and evaporation of the two solutions. Clearly we agree that and upper and a lower is better than a single of either, so the answer to the original question is (and always has been) maybe. It's possible that a small upper entrance could be a restriction in moisture control.

The gas can is actually a really good analogy -- sure, some fuel evaporates through the hole, and a little bit of air gets back in, but you can be sure that the vapor content inside the can is close to 100%. The evaporative pressure will ensure that the flow through the opening is almost exclusively out, and little to no air comes back in. When you add the temperature fluctuations, condensation inside the hive is all but guaranteed.


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## Acebird (Mar 17, 2011)

rwurster said:


> That 3/4" hole I have drilled into the top box of my 2 story nucs has gotten them through many winters. Either my bees can hold their breaths for 5 months or that little hole is doing the trick.


You are in a bone dry climate and your nucs do not put out 5 gal of water per hive. No one is saying that a single entrance can not work for some people in certain locations. It won't work in a lot of locations if the hole is too small. In many damp areas there has to be a way for the condensed moisture to get out of the hive by way of draining, not by going out the entrance.


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## Rader Sidetrack (Nov 30, 2011)

One thing that may be getting overlooked here is that top entrances can come in a variety of sizes. One of those is a 'full width' top entrance ...








photo credit

That photo is linked from Michael Bush's Top Entrance page that I mentioned in post #66. There are more photos there as well.


I am confident that there are plenty of hives in North America with a single 'bottom' entrance that are doing OK. Why is a single 'top' entrance so hard to accept?


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## crofter (May 5, 2011)

There certainly is an issue about "how much" air exchange is necessary. Is more better? Climate will dictate! To simply supply CO2 and oxygen exchange, fairly small openings obviously will work.

Matt F has a point that air can stratify under certain conditions and almost cease to circulate. Diffusion, another very real phenomenon will still occur but it is not nearly as powerful as convection which in turn is not nearly as powerful as the thermosiphon effect. Moisture can also be moved by other methods that require very little outside air exchange. That aspect is far more important to those of us in the coldest climates and of virtually of no interest to beeks in the south. 

Definining and understanding the terms is not necessary to achieve ventilation if you have a working method to copy. Explaining exactly how and why a system works in a certain climate (or does not work) requires some definition and understanding of the physical effects at play, or otherwise things just go in circles of he said, she said, he said. Some people are interested in the nitty gritty terms and others think it is all a bunch of horse feathers!


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## Kofu (Jan 26, 2011)

Matt F said:


> nobody said it wasn't possible to survive with one entrance, top or bottom. The question was whether or not a single top entrance could lead to moisture problems... It's possible that a small upper entrance could be a restriction in moisture control.
> 
> The gas can is actually a really good analogy -- sure, some fuel evaporates through the hole, and a little bit of air gets back in, but you can be sure that the vapor content [aka "relative humidity"?] inside the can is close to 100%. The evaporative pressure will ensure that the flow through the opening is almost exclusively out, and little to no air comes back in. When you add the temperature fluctuations, condensation inside the hive is all but guaranteed.


Thanks, Matt. You've explained succinctly what I was struggling with.

Perhaps if we call it the "relative humidity" inside the hive (rather than vapor content) and think of it as relative to the dew point or saturation point, given the temperatures inside the hive and on the inner surface (and inside the top). So in this model, as you've explained, with one upper entrance there may (sometimes) be a steady outflow of moist air, keeping the humidity inside at or near the saturation point. When temperatures drop outside the hive, water condenses on the walls (and under the lid) and either it trickles down the walls (collecting at the bottom, if there's no way for it to drain out), or it drips down on the unfortunate bees.

If the set-up and conditions allow for an air exchange, then more of the water vapor will get out, and less water will accumulate inside (in liquid form).


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## bigeddie (Feb 19, 2008)

If my house is air tight but I leave one window open will air flow in and out of the same opening or will I use up all the air that was there when I first opened the window and die? I'm surprised how over thought this subject is. If you need more air flow open a bigger window. By the way Crofter I took no offence with the dancing partner comment, I thought it was funny!


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## Kofu (Jan 26, 2011)

bigeddie said:


> If my house is air tight but I leave one window open will air flow in and out of the same opening or will I use up all the air that was there when I first opened the window and die? I'm surprised how over thought this subject is.


The simple fact is that many if not most of the hives that die during the winter (at least most of the few dozens of deadouts that I know about) are killed by too much water in the wrong place, or at least it's an aggravating factor... From all this wrangling I've learned a lot, and I'm hoping that my bees might benefit from the back and forth in this thread.


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## homesteader824 (Jun 9, 2012)

Rader Sidetrack said:


> One thing that may be getting overlooked here is that top entrances can come in a variety of sizes. One of those is a 'full width' top entrance ...
> 
> 
> 
> ...


I should have posted a picture with my post. This is exactly the top entrance I have. In addition, the cover is not perfectly sealed along the sides because of the shims. So there may be some cross ventilation going on as well. I think the top entrance is capable of allowing moisture from the bees' respiration to escape. I was more wondering about if people had any problems with too much rain blowing in, or if they had any other moisture problems with this type of hive.

Thanks for all the posts. It's given me a lot to consider.


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## BeekeepingIsGood (Aug 12, 2012)

> When temperatures drop outside the hive, water condenses on the walls (and under the lid)


Is there any reason to believe it's better to solve this problem with increased air flow vs hive walls/tops that are better insulated?


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## dudelt (Mar 18, 2013)

To answer the original question, I used top entrances for the first time this year (thank you Michael Bush for the recommendation!). I saw a huge differences in my hives. I am in a moisture rich area in winter with lots of rain but very little really cold weather. The top entrances were a big improvement. As far as the air exchange argument goes there is one scientific principal that has not been addressed here. When the wind blows into the entrances of a sealed hive the pressure in the hive increases (more air in the hive). When the wind slows down, the pressure decreases (less air in the hive). As long as the wind continues to blow, there is a constant exchange of air from in the hive to the outside. The reverse happens if the wind is blowing from the back of the hive and a slight vacuum is created. There is way more air exchange happening that just the convection from the bottom to the top.


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## Matt F (Oct 7, 2014)

homesteader824 said:


> I should have posted a picture with my post. This is exactly the top entrance I have. In addition, the cover is not perfectly sealed along the sides because of the shims. So there may be some cross ventilation going on as well. I think the top entrance is capable of allowing moisture from the bees' respiration to escape. I was more wondering about if people had any problems with too much rain blowing in, or if they had any other moisture problems with this type of hive.


Sorry I guess I misunderstood slightly. If your opening is this big with some additional side venting then yes you almost certainly have adequate ventilation for the moisture to escape. Maybe too much for the bees to maintain temperature -- but to your question, yes, I'd look elsewhere for the sources of moisture in the hive.


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## Matt F (Oct 7, 2014)

BeekeepingIsGood said:


> Is there any reason to believe it's better to solve this problem with increased air flow vs hive walls/tops that are better insulated?


In my case, I added three 1/2" holes in the feeder ring, barely below the lip of the top cover, and insulated above the holes, so my opinion is that a little of both air flow and insulation is best.


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## homesteader824 (Jun 9, 2012)

BeekeepingIsGood said:


> Is there any reason to believe it's better to solve this problem with increased air flow vs hive walls/tops that are better insulated?


I think I will at least add some foam board insulation to the covers next winter.


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## blamb61 (Apr 24, 2014)

Convection comes in two types. Free and forced. Free convection occurs due to density differences of the fluid (air, water, or whatever) caused most likely by temp differences. Forced convection is caused by the fluid being moved by a fan, wind, bees or some external mechanism. At least that is what I remembet from my heat transfer class.


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## bigeddie (Feb 19, 2008)

Go to the head of the class! Sounds simple enough that even I can understand. Thank you, o voice of reason!!


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## Colobee (May 15, 2014)

Michael Palmer said:


> I agree. And, the reason I have both top and bottom entrances for winter. I never find wet conditions in my hives and they winter well...less than 10% loss this year.


In the winter, I use a reduced bottom entrance (mouse resistant) & a small upper, for the reasons Barry mentions. In the summer - generally full open bottom and offset super medium upper entrances, partially closed. My climate is so dry that moisture is almost never a concern.

It's unfortunate when a thread spirals away from the OP question. I find it frustrating when searching through old posts for meaningful information. I can only imagine the frustration of new beeks.


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## bigeddie (Feb 19, 2008)

I agree with you Colobee 100% You should go to he head of the class to, another voice of reason heard from. Thanks


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## blamb61 (Apr 24, 2014)

blamb61 said:


> Convection comes in two types. Free and forced. Free convection occurs due to density differences of the fluid (air, water, or whatever) caused most likely by temp differences. Forced convection is caused by the fluid being moved by a fan, wind, bees or some external mechanism. At least that is what I remembet from my heat transfer class.


During free or forced convection, heat is transferred from the fluid to the surface it touches if the fluid is hotter than the surface or heat is tranfered from the surface to the fluid if the surface is hotter than the fluid.


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## Acebird (Mar 17, 2011)

Keep in mind that mass will hold more heat then something of lesser mass. So it is hard to transfer a lot of heat with air for example as opposed to water.


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## Rader Sidetrack (Nov 30, 2011)

Acebird said:


> Keep in mind that mass will hold more heat then something of lesser mass.


Well, you have got that _wrong_:no:, Ace.  Again!
Its not the mass - its the *material *that is the variable.

Consider two common materials, water and concrete, each used as a heat storage medium. Water has significantly more specific heat capacity than the same mass of concrete - the water has more than 4 times as much specific heat capacity than the *same *mass of concrete. See this link for the details: http://www.schoolphysics.co.uk/age1...ml?PHPSESSID=b2810791ba27022d9331843c394d05c5

The Specific heat capacity of Water is at 4200 (J/(kgK)
The Specific heat capacity of Concrete is at 880 (J/(kgK)

(those abbreviations reference _Joules per Kilogram_)


:gh:

... apparently this is a continuation of Ace's HVAC by _ESP_ theories ... 

.


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## Cyan (Jan 27, 2015)

I can't believe this is still up for debate. lol


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## Acebird (Mar 17, 2011)

Rader Sidetrack said:


> Well, you have got that _wrong_:no:, Ace.  Again!


Don't think so. Check your link.


> Heat energy =	mass x specific heat capacity x temperature change


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## Rader Sidetrack (Nov 30, 2011)

And??? :scratch: :s

How about some *numbers *supporting your contention, Ace?

:kn:


... course, the math might present some difficulty for Ace ...
Acebird sez: "I am not going to teach you third grade arithmetic Rader."
... but has that arithmetic completely _wrong_! :lpf:


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