Overwintering poly nuc

[Finman]

If there is any condensation in these poly nucs, it is minimal and does not present any problems for the bees. In fact I've seen the bees drinking it.

Food store generates 67% water from its original weight.
If bees drink condensation., the hive is absolutely too, - not moist, - but wet.

The thing with poly is that it doesn't absorb any moisture, so any excess will only run down the sides and out of the OMF.

Don't use mesh floor in nucs. It keeps the hive too cold. It is enough that if you have 5 frames, 3-4 cm is enough for ventilation in main entrance.
Then make a upper 10 mm upper entrance through knop groove.

Put the floor slanting a little that water drills out from floor. Condensation water is not lethal to bees. It is quite normal, but lead it out in wise way.

10 kg winter food produces 7 litres water. It is much. On average 1 litre every month. That needs condensation to get out. Cold air cannot carry such amount vapour.

Survivability of the bees is the real question, is it better in poly or not ?

Absolutely poly or what ever insulated box is better to small colony. It does not need to work so much to produce energy. But if you use mesh floor in the nuc, poly gives no better protection than ply. It is same as you would keep your door open during frost night.

Yes, I have used poly boxes since year 1987 and last 10 years I have had spare hives in poly nucs every winter. I have splitted normal polyboxes with table saw.

You may make a nuc box or then devide the normal box with insulated dummy board.

in Finland a 1000 hive owner keeps normal hives out but 5 frame nucs he carry to the wintering cellar. Warmer environment makes life easier to nucs.
Try the same with your nucs in Br. --- easier wintering, not harder.

Wind protection is important to nucs

After winter small nucs have often build up problems when they loose bees during wintering and spring. That is why 3-frame nuc is not a good for wintering even if it is alive in spring. But you may help them when you guive a frame of emerging bees from big hive.

Varroa or nosema reduce often even normal hives to 3 frame nucs.
Keep them in warm box and a small entrance. 2x2 cm entrance hole is enough to 3 frame colony. Build up is almost impossible. Take help from bigger hives.

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[Finman]

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Don't say anything about different climate. It is not needed.
Our winter half of year is such that we have 4 months very same what you have there winter. We have here only 3-4 months, when snow is all the time on ground.

Every two Christmas is black here and it rains water.

It takes 2 days when the same low pressure arrives from Britain to Finland.

 

[user 6228]

...

. But if you use mesh floor in the nuc, poly gives no better protection than ply. It is same as you would keep your door open during frost night.
....

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This statement is incorrect. While it may be intitutively attractive, when measured in the abscence of wind the prescence of the mesh floor makes little difference to the temperatures and heat losses.

 

[oliver90owner]

the mesh floor makes little difference to the temperatures and heat losses.

Presumably mainly radiation losses can be reduced and are relatively a small part of the heat lost from the colony; air changes and removal of water vapour, without condensation in the hive, are the others.

There are lots of potential improvements possible for the experimentalist.

The free area of a normal full floor OMF is far in excess of what is needed (according to the John Harding book); radiation losses are very directional and could be attenuated with either more wax comb below the cluster; or a baffle absorber/reflector just above the mesh.

The latent heat angle is likely an important contributor.

RAB

 

[Finman]

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In weaker 10 frames colonies I use 5 cm2,

 

[Finman]

uifg,jh
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[Finman]

This statement is incorrect. While it may be intitutively attractive, when measured in the abscence of wind the prescence of the mesh floor makes little difference to the temperatures and heat losses.

And wind is a theoretical phenomenom on British Isles?

Look those who use solid floor users. Do they have allways entrance widely open like in summer?

- Do they use entrance reducer?

- Ho many tens fold size is mesh floor compared to 10 mm x 75 mm entrance. Just now I use that size entrance and no bees are ventilating.
They are silent in cluster.

- Why ventilation hole should be 100 cm2 if 7,5 cm2 is enough?

- Why in summer 5-box hive has same ventilation as one box hive in winter?

- In weaker 10 frames colonies I use 5 cm2, when active season is over.

- In summer a normal hive consumes 1 kg food in 2 days. In autumn in winter cluster it consumes 1-1,5 kg in one month.

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100: 7,5 = 13 fold​

PS: just now wind seems to be same at night and by day, 4-6 m/s in London and in Milton Keynes.

In my place it is just now 4 m/s. Temp is +6C

http://www.foreca.fi/United_Kingdom/London
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[Finman]

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If you try electrict heating in spring, then you will understand what means heat and warm hive to the colony. Before heating I thought that I can not do anything: It is what it is.

Just try and compare with full size hives

- ply hive
- poly hive
- heated ply and heated poly hive


- Hive in windy place
- wind protected place

 

[user 6228]

the mesh floor makes little difference to the temperatures and heat losses.

Presumably mainly radiation losses can be reduced and are relatively a small part of the heat lost from the colony; air changes and removal of water vapour, without condensation in the hive, are the others.

There are lots of potential improvements possible for the experimentalist.

The free area of a normal full floor OMF is far in excess of what is needed (according to the John Harding book); radiation losses are very directional and could be attenuated with either more wax comb below the cluster; or a baffle absorber/reflector just above the mesh.

The latent heat angle is likely an important contributor.

RAB

I will re do the experiments to double check, and to have a fully documented dataset when the apparatus has a free slot. However, you can reset the initiution if in your mind you divide the cavity into horizontal slices, which conduct through their sides and top and bottom.
The slice with the entrance loses so much heat through one side that any left to heat flow downwards is very small.
Thus this downward boundary conductance for this slice has very little effect, regardless if its metal, mesh or perfectly insulating.

 

[Finman]

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About Britis Wind

text has a little bit Hollywood impression, but says something...
It says that during winter winds are biggest.

Winds over the British Isles can be a resource and a hazard. Hundreds of wind turbines have been installed in exposed parts of the British Isles, adding extra megawatts of electricity to the National Grid, and exploiting this wind resource.

.......

Coastal areas bear the brunt of gales from the Atlantic, especially during the winter when the low pressure cells are particularly active and well developed. These gales can pose extreme hazards for

*************

Wind speed can achieve 100 m.p.h.

http://www.metlink.org/weather-clim...s/key-stage-4-weather/ks4-uk-climate.html#2.3



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[Finman]

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I remind you all. They are your bees....Words do not hurt them.

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[oliver90owner]

The slice with the entrance loses so much heat through one side that any left to heat flow downwards is very small

I was intrigued by pics showing the amount of snow melted around and underneath hives with OMFs this last winter.

Seemed more than an insignificant amount to me. Can you hypothesise/expand on that?

 

[Erichalfbee]

Is there a case for sliding in an inspection tray with maybe a 10 cm square cut out of the middle.....just in winter? You could take it out every week or so to clean it

 

[user 6228]

The slice with the entrance loses so much heat through one side that any left to heat flow downwards is very small

I was intrigued by pics showing the amount of snow melted around and underneath hives with OMFs this last winter.

Seemed more than an insignificant amount to me. Can you hypothesise/expand on that?

to get heat to go downwards it has to be one of
1)warmer liquid/ or solid falling from hive,
2)conduction from stand
3)radiation down wards
4) gas denser than air (CO2)

2) is unlikely unless the stand is very low
3) the mesh is going to act as a partial screen and will radiate at its lower temp rather than bee temp.

1) seems to be likely. surface water, snow melting from the hive faces or roof or condensate are the candidates
4) is possible as well

The thermofluid behavoiur with condensation, recirculation etc.. is intriguely complex with only a simple heat source or a simple heat/ water vapour source. To understand what complexity the bees add you need to understand the "simple" first. Hence the experiments

 

[REDWOOD]

Is there a case for sliding in an inspection tray with maybe a 10 cm square cut out of the middle.....just in winter? You could take it out every week or so to clean it

I have been thinking the same, make a board and punch some small holes around the edge where I think the condensation might run down the walls and then out of the bottom and away from the cluster in the middle, but there again I haven't had a problem with leaving the inspection board out

 

[REDWOOD]

The good old south west prevailing winds that for thousands of years has shaped the landscape of Wales and some old timers too

 

[jenkinsbrynmair]

, make a board and punch some small holes around the edge where I think the condensation might run down the walls and then out of the bottom and away from the cluster in the middle,

Plese sir please! I know what we can do!..........................................

To save punching holes in the board and whatever we could make the hive floor out of some kind of open meshy stuff - what does everyone else think? we could call it an open....................

 

[Finman]

to get heat to go downwards it has to be one of
1)warmer liquid/ or solid falling from hive,
2)conduction from stand
3)radiation down wards
4) gas denser than air (CO2)

2) is unlikely unless the stand is very low
3) the mesh is going to act as a partial screen and will radiate at its lower temp rather than bee temp.

1) seems to be likely. surface water, snow melting from the hive faces or roof or condensate are the candidates
4) is possible as well

The thermofluid behavoiur with condensation, recirculation etc.. is intriguely complex with only a simple heat source or a simple heat/ water vapour source. To understand what complexity the bees add you need to understand the "simple" first. Hence the experiments

You forgot the heat of soil

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[REDWOOD]

Plese sir please! I know what we can do!..........................................

To save punching holes in the board and whatever we could make the hive floor out of some kind of open meshy stuff - what does everyone else think? we could call it an open....................

It could be put down to a touch of winter blues setting in but if you don't try you will never know

 

[jenkinsbrynmair]

It could be put down to a touch of winter blues setting in but if you don't try you will never know

\Or just sheer devilment