Oh No! Not Matchsticks Again?

[pargyle]

yes it does make it colder at least from radiative losses. If the wire and the ground below are at outside temperature you are losing around 3W. Heat loss =F.Area.Sigma(T1^4-T0^4).
F is the factor based on how much the bees is visible to the cold surface. The area is area of the bees exposed. T1 is the temperature of the exposed bees, T0 is the colder surface ( the wire mesh and the ground below). Sigma is the Stephann-Boltzman constant.
Then you get air flow through the mesh caused by turbulences which can occur at even low external wind velocities less than 1mph . Did I ever mention its complicated?

All the time ... however I spent several years measuring hive temperatures and comparing them to the ambient temperature and it is really only the lowest couple of inches above the mesh floor that is affected as soon as you get further up the hive the temp is what the bees choose it to be in well insulated hives with no holes above the colony ... but you know that anyway and you were doing the same as me all those years ago but in a much more scientific way with your temperature senders than my rudimentary ones ... I would agree that keepimg them draught free is a big plus... Bill Bielby hit that one back in 1972 ... page 42 Home Honey Production " the best way to overwinter bees is to keep them as draught free as possible" and "there is no such thing as too much insulation". Took a few years for the science to catch up but you got there eventually!

 

[jenkinsbrynmair]

Did I ever mention its complicated?

Only if people are insistent on making it so

 

[Apple]

Only if people are insistent on making it so

I have an oscilloscope and am not afraid to use it!
Yeghes da

 

[victor meldrew]

What's more dangerous to bees in winter, cold or moisture?

When bees use their winter stores they require water to dilute same . Moisture within the hive saves water carriers from having to venture outside !
moisture to the extent that it drips on the colony is a no no !

 

[user 6228]

Only if people are insistent on making it so

Ignorance is bliss but quite boring and full of errors

 

[user 6228]

What's more dangerous to bees in winter, cold or moisture?

What is dangerous is heat loss. Low temperature fluids, air or water, do this.
Moisture is just condensation... It can be low temperature or high temperature. Bees like higher temperature water. They need water in winter. To make the condensation have a higher temperature insulate and in particular the roof. To make sure thay can get water don't top ventilate. To make sure the water is warm, insulate.

 

[Newbeeneil]

What is dangerous is heat loss. Low temperature fluids, air or water, do this.
Moisture is just condensation... It can be low temperature or high temperature. Bees like higher temperature water. They need water in winter. To make the condensation have a higher temperature insulate and in particular the roof. To make sure thay can get water don't top ventilate. To make sure the water is warm, insulate.

I put a takeaway container of fondant in a pocket within 4" of PIR on the top of my hives. Recently the fondant has gone but there is plenty of condensation ( nice warm water) on the plastic. In a couple of hives I could see bees collecting the condensate.

 

[madasafish]

I cover my overwintering poly mini nucs with an OSB3 full cover. It has insulation in the roof but none of the sides. Purely for wind chill and cooling through evaporation of rain and snow on the external side walls.

It works, They survive - Apidea with super and Kielers (supered and single)

 

[The Poot]

What is dangerous is heat loss. Low temperature fluids, air or water, do this.
Moisture is just condensation... It can be low temperature or high temperature. Bees like higher temperature water. They need water in winter. To make the condensation have a higher temperature insulate and in particular the roof. To make sure thay can get water don't top ventilate. To make sure the water is warm, insulate.

A bit simpler than your post 80. I can understand this one

 

[Boston Bees]

Indeed, so, moisture then

What is dangerous is heat loss. Low temperature fluids, air or water, do this.
Moisture is just condensation... It can be low temperature or high temperature. Bees like higher temperature water. They need water in winter. To make the condensation have a higher temperature insulate and in particular the roof. To make sure thay can get water don't top ventilate. To make sure the water is warm, insulate.

Yes, I know.

But your statement, read without caveats, suggests that the optimal condition inside a nest is a warm, moist fug (like a Turkish bath house!). I do not believe this to be the case. Which is why I make sure there is plenty of bottom ventilation.

 

[user 6228]

Indeed, so, moisture then


Yes, I know.

But your statement, read without caveats, suggests that the optimal condition inside a nest is a warm, moist fug (like a Turkish bath house!). I do not believe this to be the case. Which is why I make sure there is plenty of bottom ventilation.

yes RH 75% + except when there is honey being desiccated or substantially open when its 40 to 55% -note honey bees evolved with a small knot hole for ventilation and actively chose sites with entrance less than 15 sq cm. Here are some of the references .

Ellis MB, Nicolson SW, Crewe RM, Dietemann V. Hygropreference and brood care in the honeybee (Apis mellifera). J Insect Physiol [Internet]. 2008;54(12):1516–21. Available from: Redirecting
Schmehl DR, Tomé HV V, Mortensen AN, Martins GF, Ellis JD. Protocol for the in vitro rearing of honey bee ( Apis mellifera L.) workers. J Apic Res [Internet]. 2016;55(2):113–29. Available from: https://www.tandfonline.com/doi/full/10.1080/00218839.2016.1203530
Doull KM. The effects of different humidities on the hatching of the eggs of honeybees. Apidologie [Internet]. 1976;7(1):61–6. Available from: THE EFFECTS OF DIFFERENT HUMIDITIES ON THE HATCHING OF THE EGGS OF HONEYBEES | Apidologie
Doull KM, Mew P. The Hygroscopic properties of different solutions of honey. Apidologie. 1977;8(1):19–24.
Seeley TD, Morse RA. Nest site selection by the honey bee,Apis mellifera. Insectes Soc [Internet]. 1978;25(4):323–37. Available from: http://dx.doi.org/10.1007/BF02224297
Seeley TD. Honeybee Democracy. Princeton University Press; 2010.

 

[Boston Bees]

yes RH 75% + except when there is honey being desiccated or substantially open when its 40 to 55% -note honey bees evolved with a small knot hole for ventilation and actively chose sites with entrance less than 15 sq cm. Here are some of the references .

Ellis MB, Nicolson SW, Crewe RM, Dietemann V. Hygropreference and brood care in the honeybee (Apis mellifera). J Insect Physiol [Internet]. 2008;54(12):1516–21. Available from: Redirecting
Schmehl DR, Tomé HV V, Mortensen AN, Martins GF, Ellis JD. Protocol for the in vitro rearing of honey bee ( Apis mellifera L.) workers. J Apic Res [Internet]. 2016;55(2):113–29. Available from: https://www.tandfonline.com/doi/full/10.1080/00218839.2016.1203530
Doull KM. The effects of different humidities on the hatching of the eggs of honeybees. Apidologie [Internet]. 1976;7(1):61–6. Available from: THE EFFECTS OF DIFFERENT HUMIDITIES ON THE HATCHING OF THE EGGS OF HONEYBEES | Apidologie
Doull KM, Mew P. The Hygroscopic properties of different solutions of honey. Apidologie. 1977;8(1):19–24.
Seeley TD, Morse RA. Nest site selection by the honey bee,Apis mellifera. Insectes Soc [Internet]. 1978;25(4):323–37. Available from: http://dx.doi.org/10.1007/BF02224297
Seeley TD. Honeybee Democracy. Princeton University Press; 2010.

So you leave your varroa trays in all winter then, and keep entrance reducers in too?

 

[Arfermo]

Ignorance is bliss but quite boring and full of errors

What a friendly chap you are to be sure. Suggest you are in the wrong place?

 

[user 6228]

A bit simpler than your post 80. I can understand this one

Yes, I can go a bit deep at times. Because of the experimantal validation of my computer models, I've just done a radiation loss estimate for hives through the varroa mesh ,so out it came.

So you leave your varroa trays in all winter then, and keep entrance reducers in too?

I put black correx over the top of the mesh, but I really should put foil or paint on the correx because its quite transperant to infra red, but it get very dusty/propolised quickly so not that bad really.

 

[Boston Bees]

I put black correx over the top of the mesh, but I really should put foil or paint on the correx because its quite transperant to infra red, but it get very dusty/propolised quickly so not that bad really.

OK, fair enough, we'll agree to disagree on whether leaving varroa trays in winter is a good idea in managed hives (which are completely different to tree nests, not having floors covered with wood mulch and other absorbent material for a start).

I note another new post today about fondant pouring down through a queen excluder, which by coincidence has happened after a varroa board was left in, which doesn't discourage me in my scepticism.

I am sure all our bees will survive our efforts OK though - they tend to manage, whatever we do.

 

[drex]

I like to try to work with my bees, giving them the best I can. Have just read " the lives of bees" by Tom Seeley. A good read and has given me a few good ideas, but I am not trying to save micro watts in their energy usage As Bb says they tend to survive us beekeepers

 

[user 6228]

I like to try to work with my bees, giving them the best I can. Have just read " the lives of bees" by Tom Seeley. A good read and has given me a few good ideas, but I am not trying to save micro watts in their energy usage As Bb says they tend to survive us beekeepers

Good book "Lives of Bees" has some very interesting stuff.

Derek Mitchell

 

[beekeepershens]

Some great effort has gone into creating "warm roof" loft structures. One simple way being under drawing the rafters with insulation board, allowing air to circulate between the insulation and the sarking and tiles. Other methods are available

we have an almost passive house ....the airtightness was checked on completion but since then the windowframes have shrunk slightly leading to ingress of cold air when its blowing a hooley outside however it is wonderful having a warm loft. and yes our energy bills are pretty low. however returning ton the cold v damp question, as a varroa free locality (but also very wet) the bees were on solid floors and in Spring they died out and it was obvious that the hive was excessively wet, we now have them on varroa floors and they do much better

 

[elainemary]

I'v

So you leave your varroa trays in all winter then, and keep entrance reducers in too?

I've left varroa trays in with varroa boards, on all my hives this year bar one, as an experiment. Has been good to observe varroa drops and any brood cappings, to help time sublimation. I've also been looking for water and only seen water drops on some hives at the very end of the board, which supports what @Into the lions den has said re any moisture running down the inside extremes of the boxes. I have top kingspan insulation over glass crownboards, have seen v little moisture. I have WBC sliders with notches in so enough airflow at the front & keeps any mice out too. The odd hive where I've seen water through the glass crown board is a small amount at the edges, nowhere near the cluster. I quite like seeing a little bit of water as the bees can use to dilute stores, on warmer days when they break cluster. As there is a small gap between the OMF and the varroa slide, some air must flow through underneath too. Think it will help them conserve energy as they start brood rearing, by leaving the sliders in during Feb & March. I will take them out when the weather warms up in the Spring.

 

[Tommo]

Matchsticks not used them for thirty years. I overwinter my bees with insulation above the crown board, which stays on all year, fondant on the crown board if necessary. My mesh floor is open fully my hives sit on a stand around which I wrap a polypropylene weed suppressant blanket. This has all the advantages of fully ventilating the hive without loss of heat and subjecting the underside of the colony to any draughts especially from the beast from the east but also keeps the condensation low. I also have a polypropylene wrap with insulation round my non poly hives