Overwintering,double brood or not?

[Finman]

I have about six to eight frames per box and fi

I don't think I'm giving then too much food, Finman - it's not been a problem so far.
Kitta

Strange frame number, but with 18 hives you surely know what to do.

 

[Hawklord]

I have about six to eight frames per box and fill the empty space with insulating dummies - so the space isn't too large, Hawklord.

That's how Peter Hewitt over xinters his colonys, using wide dummy boards like a sealed frame feeder, slightly less space and stores than would be in the 22 frames of a double brood. Hower I do something totally different. I have the dreaded hole in the crown board which stops any condensation. I also put an empty super below the brood box before I clear the supers. This provides space for the bees from the supers and reduces the risk of swarming. They usually draw comb under the frames so they end up with a similar amount of space to a 14 x 12.

 

[masterBK]

Peter Hewitt: he must be getting on these days. Decades ago I was prepared to travel miles to hear one of his talks given with his usual enthusiasm and good humour. I felt honoured a few years ago when he turned up to hear one of mine.

 

[beeno]

The reason I reduce to a single box over winter is that I can take the remaining brood box and clean it and get it sorted. In the spring I can start using demaree method of swarm control or I have a second box for doing an AS or I can add it back as a second brood box when they are strong to give extra space. If I overwintered on double then it reduces my options, doing an AS with a double is not easy, demaree is not easy etc( not impossible but not easy for a beginner) I was just suggesting that it leaves you more options using less kit and makes your bees more manageable when you are learning.
E

My thoughts entirely!

 

[Madge]

The reason I reduce to a single box over winter is that I can take the remaining brood box and clean it and get it sorted. ...
E

My thoughts entirely!

That's fine - but remove the extra box before winter, and not during winter ( or late winter) as Enrico said in his first post. Doing so in late winter you're just disrupting the colony unnecessarily.

 

[dommod]

In contrast a single box with no side dummies might be too large to keep warm.

I would think that double brood would be too large a space to keep warm. The bees arn't going to munch through all the stores and by the time the coldest part of winter arrives there will be a lot of space above the cluster.

I don't think that the bees keep the whole hive warm. From what I'd read, its the cluster itself that is well insulated and overwinter the temperature within the hive but outside the cluster is close to the temperature outside the hive.

 

[Finman]

I don't think that the bees keep the whole hive warm. From what I'd read, its the cluster itself that is well insulated and overwinter the temperature within the hive but outside the cluster is close to the temperature outside the hive.

A cavity gives a shelter to honey bee and protects against cold and wind.
Cluster is NOT well insulated. Without cavity chelter the colony burns its food storage quickly.

Inside temp of hive is not near out temp. It is easy to measure, and it has been measured thousands of times.

 

[dommod]

Cluster is NOT well insulated.

I don't think you are correct. If you do back of the envelope calculation for a cedar brood box, you would expect it to loose at least 3.7 Watts per degree difference between the inside temperature and outside temperature. Assuming a 20Kg surpless left on a hive for a conservative three winter months, this would only allow the bees to maintain an average temperature differential of 8.5 between the outside of the hive and the inside. When you consider that the cluster temperature needs to be in excess of 30 degrees centigrade the external temperature for the winter months (in England) wont be much higher than 7 degrees, this shows that the cluster must be extreamly well insulated.

This article seems to agree with my quick calculations. Giving the following figures of actual temperature readings:

The outside air temperature was 6.6°C. He measured 35°C in the center of the cluster, 21.6°C immediately above the cluster and 11.1°C in other empty portions of the hive. Other beekeepers have found similar temperature gradients.

Inside temp of hive is not near out temp. It is easy to measure, and it has been measured thousands of times.

Can you point me to any resorsces giving details of these measurments?

 

[Madge]

I don't think that the bees keep the whole hive warm. ...

Yes, they keep the cluster warm (not the whole hive) but it helps them if they're in a warm space - therefore reduce excess space surrounding the cluster.

 

[Madge]

...
Inside temp of hive is not near out temp. ...

I don't think you are correct.... Giving the following figures of actual temperature readings: ?

But even the figures you quoted, Dommod, shows a huge difference between general inside hive temperature and outside temperature. (?)

 

[BeeJayBee]

I don't think that the bees keep the whole hive warm. From what I'd read, its the cluster itself that is well insulated and overwinter the temperature within the hive but outside the cluster is close to the temperature outside the hive.

When you consider that the cluster temperature needs to be in excess of 30 degrees centigrade the external temperature for the winter months (in England) wont be much higher than 7 degrees, this shows that the cluster must be extreamly well insulated.

The cluster itself is not insulated, as such, it's a living group of bees doing their utmost to keep themselves and the queen from freezing, and they have to work very hard to survive if the space they are in is too large, or too poorly insulated. They don't choose to live in a thin-walled box, a beekeeper puts them there, they'd much prefer a hollow tree or similar!

I think you're missing the point of Rusty's article. The colony may, "make no attempt to heat the whole of the hive" but she goes on to say, "there is some heat lost from the cluster into the surrounding air, and because heat is lost, the bees must continually generate more" and, "The bees on the outside get so cold that they must rotate to the inside. If the inside of the hive were uniformly warm, this rotation would be unnecessary"

There's a lot of information on the forum about the benefits of well insulated hives; there's a lot about how bees tend to overwinter better in a poly hive or one with a decent amount of top insulation, and how good insulation means they use less energy, so use less food. (Maybe look up stuff on here by DerekM about tree nests; Finman also knows quite a lot about how bees survive in extremely cold conditions - or not.)

If you leave a small colony in a large box overwinter you may compromise their survival. Just because they can survive in a large space doesn't mean they always do. And don't mention matchsticks!

 

[user 6228]

I don't think that the bees keep the whole hive warm. From what I'd read, its the cluster itself that is well insulated and overwinter the temperature within the hive but outside the cluster is close to the temperature outside the hive.

arrgh... thats a false conclusion drawn from poor experiment.
(The Thermology of Wintering Honey Bee Colonies
By CHARLES D. OWENS, Agricultural Engineering Research Division, Agricultural Research Service)

all it proved was :
if you place a low value heat source in container with very poor insulation it doesnt raise the temperature of the cavity very much.

not a very interesting result

what do bees do when the insulation is 0.5W per degree C compared to 3W per degree C is a more interesting question

read this http://jeb.biologists.org/content/206/2/353.full

 

[Hawklord]

It has been said so many times that temperature is not an issue, it is dampness that will kill a colony. 19mm isn't going to do much to increase temperatures. In my opinion the bees need a appropriate amount of stores to munch and it is this that will keep them warm. On reading Cushmans website it seems he is against molly coddling bees and feels that the use of poly hives is not nessasary. I would thinj that bees have been kept in wooden hives for many years with good results. I wonder how the skep compares with other cavitys. Bees need a brood break for the oxalic treatment, I would imagine that some winters there isn't much of a brood break in a poly hive.

 

[oliver90owner]

Dommond,

Your information, calculation, assumptions are mostly flawed.

You clearly need to read more carefully. Finman is 100% more correct than you. That is summatively , not a multiple!

Per eg, the internal cluster tempemperature can fall to around 20C. Over30C is onlyrequired for brooding. The outer bees on the cluster must not drop below something just over 8C or they will fall away and be lost. That alone messes up all your calculations. You have similarly made other incorrect assumptions - temps within the hive and no account of insulation properties of wax comb or honey in frames.

Go back to the beginningvand start again!

 

[Finman]

.
Brood and half is not a problem in UK. Why douple brood is?

I have had douple brood wintering 50 years in difficult climate. It size of wintering colony which rules what they need.

 

[Finman]

Per eg, the internal cluster tempemperature can fall to around 20C. Over30C is onlyrequired for brooding. The outer bees on the cluster must not drop below something just over 8C or they will fall away and be lost. T!

Our hives start brooding in February even if it is outside -20C.
The hive really keeps bees warm.

Our bees survive under open sky in polys and in insulated hives even if temps are -30C. If they have too much space, colony will die. It wastes energy too much to open space.

 

[Hawklord]

So long as the hive has enough space to hold enough stores I can't see that it makes much difference the size of the cavity. The bigger the cavity, the further away from the outside elements the cluster will be. Just below the crown board will be the optimum place for the cluster as that area will less heat loss due to convection. Something else that comes into play is shape of hive ie a narrow deep box over a wide shallow box.

Do bigger colonies produce a bigger cluster for winter or does the cluster have an average size?

 

[Finman]

So long as the hive has enough space to hold enough stores I can't see that it makes much difference the size of the cavity. The bigger the cavity, the further away from the outside elements the cluster will be. Just below the crown board will be the optimum place for the cluster as that area will less heat loss due to convection. Something else that comes into play is shape of hive ie a narrow deep box over a wide shallow box.

Do bigger colonies produce a bigger cluster for winter or does the cluster have an average size?

It does not go this way. Not at all.

In big cavity surfaces are colder than in tight. A good colony produces 10 litres respiration water. It condensates much inside the hive and on food frames.
When cavity is tight, its temp is higher and relative moisture keeps surfaces dry.

I have explained this quite many of times in this forum.

Your winter in Britain is so warm that you out there need not much think about it.

.

.

 

[Dishmop]

going to try double nuc with solid insulated floors

I have two overwintered nucs which I doubled up and its suprising how quickly they grow and fill the frames. When I transfered one of them into a national brood box there were three frames of capped honey in the upper nuc..
The other one has only been as a double for a couple of weeks and is due for an inspection, so not sure what they have yet.

 

[Dishmop]

The bigger the cavity, the further away from the outside elements the cluster will be. Just below the crown board

The furthest they can keep away from the outside elements is slap bang in the middle of the hive........not under the crownboard which is quite possibly where the food is anyway, and I think youll find they dont cluster on food....

Also, having watched bees in my obs hive, I wonder if bees do the same as penguins in the cold weather.....they huddle but takes turns at the warmest area.

In my opinion the bees need a appropriate amount of stores to munch and it is this that will keep them warm.

They actually eat most of their winter stores in the spring..