insulation in hive

[pargyle]

Do open mesh floors make the hive colder over winter? I use them with sealed crownboard and top insulation

No ... plenty of evidence that they have little effect on the temperature inside the hive (which is governed by the bees desire to maintain the colony at the temperature they want).

As long as the top of the hive is sealed and there is insulation above the crown board as you have.

I actually sealed my crownboard to the top of the hive to ensure that there was definitely no chance of upward air flow but even before this the bees were well on the way to sealing the edges of the CB with propolis.

I think there is some benefit, if a hive is located in a windy or exposed area to make some provision for shielding the mesh floor from draughts - perhaps with a shallow frame under the floor.

My hive, although not in and exposed situation, has a drawer structure permanently in place beneatht the mesh floor with a sticky board in it. Kills two birds with one stone ...

 

[drstitson]

"The match stick under the roof , a 1.5mm gap, loses 50% of the heat even in wooden hive."

nearer 2.2-2.5mm - meaning that 4x46cm sides give a mahoosive 40-45cm2 odd hole at the top of the hive.

 

[MartinL]

. . . . . . . .
.
The explanation is all about convection cells and stratification.
. . . . . . . . . . . . . . .

So what are "convection cells"?
Should I invest in some or do they require a localised power supply?

 

[oliver90owner]

So what are "convection cells"?-

Try this for starters:

http://en.m.wikipedia.org/wiki/Convection_cell

RAB

 

[user 6228]

"The match stick under the roof , a 1.5mm gap, loses 50% of the heat even in wooden hive."

nearer 2.2-2.5mm - meaning that 4x46cm sides give a mahoosive 40-45cm2 odd hole at the top of the hive.

the square area on its own is a bit missleading its not like single 78mm dia hole its more like 1000 holes ~2 x ~2

 

[Amari]

"The match stick under the roof , a 1.5mm gap, loses 50% of the heat even in wooden hive."

nearer 2.2-2.5mm - meaning that 4x46cm sides give a mahoosive 40-45cm2 odd hole at the top of the hive.

I see that Pinguis Imperium (whoever he/she is) in February BBKA News (p.46) writes: "This [assessing stores] is particularly easy if you have raised the crown boards on matchsticks to ensure adequate winter ventilation."
It continues to amaze and intrigue me that pundits so often have diametrically opposing views. And who is to say who is correct?

 

[oliver90owner]

It continues to amaze ... ... who is to say who is correct?

It continues to amaze me how many people out there do not think.

Why not observe the bees? Why not consider that they might actually know best? Try it and see? Impose a two millimetre gap on the bees for at least two sides of the crownboard and actually see what they do about it. You are not in the beginner's section here.

Why two millimetres? About the same as a matchstick width.

Why only at least two sides? Work it out.

If you answer nothing, try again.

Just thinking about it should make it clear who is right. The beekeeper or the bees.

Thought. We are somewhat larger than a bee. Let's compare linear rather than volumetric or mass. About a hundred times?

How about you leaving your doors and upstairs windows (or the roof hatch) open by say, ten centimetres throughout the winter.

Yes, you may have noticed that ten centimetres is not one hundred times two millimetres. That comparison was just made to make you think.

RAB

 

[user 6228]

I see that Pinguis Imperium (whoever he/she is) in February BBKA News (p.46) writes: "This [assessing stores] is particularly easy if you have raised the crown boards on matchsticks to ensure adequate winter ventilation."
It continues to amaze and intrigue me that pundits so often have diametrically opposing views. And who is to say who is correct?

it just goes with the article on Western Red Cedar, completely missing out that Western Red Cedar is one of the abest(probably the best) insulating structural wood types.

and the review of hives in the previous edition which completely missed out polystyrene hives.

 

[BeeJayBee]

and the review of hives in the previous edition which completely missed out polystyrene hives.

In all fairness, I think that person was writing from personal experience, they probably haven't either seen or used a polystyrene hive.

Hopefully somebody will come along and write about them for another edition, which will balance things a bit.

 

[drstitson]

One mustn't forget that in September 2011 Pinguis Imperium also recommended using "2.2 Kg of sugar in 630ml of water for autumn feeding."

"I think that person was writing from personal experience"

presumably they have also personal experience of trying to dissolve 2+ kilos of sugar in 1.1 pints of water.

 

[MartinJG]

Does a tree cavity usually have an insulated inner part,other than the wood itself? So if feral bees (AMM) are able to survive without man's intervention in such tree cavities then why are beekeepers so preoccupied about insulating their bees?
Perhaps we are becoming molly coddling beekeepers, who keep otherwise non viable bees, viable by such actions; but could this be to the detriment of the lineage of the bees or are they now so intermixed, that it no longer matters?

 

[drstitson]

a tree cavity is often surrounded by >20mm timber PLUS has a large height of timber above the colony, not a few mm of ply and a sheet of metal.

decent wooden hive plus block of insulation above crown board isn't a bad start.

 

[Itchy]

I'm led to believe that a tree cavity is far superior in insulation terms to what awe have commercially.

Certainly my bees in insulated hives seem to be doing very well so far

 

[Dishmop]

Looking at all that insulation make me think that one should make top bar hives out of old chest freezers.

 

[user 6228]

a tree cavity is often surrounded by >20mm timber PLUS has a large height of timber above the colony, not a few mm of ply and a sheet of metal.

decent wooden hive plus block of insulation above crown board isn't a bad start.

Average tree cavity has 150mm wall thickness in the survey by t. Seeley
Average tree nest, with the colony clustered at the top loses heat at ~1/4 the rate of a wooden hive and ~1/2 rate of typical poly hive.
If you want more detail either wait for paper to be published or come to a lecture.

 

[Dishmop]

I doubt that the temperature in Norwich has been low enough for long enough so far this winter to worry about insulation.
Up until the last 3 or 4 days I think on average my bees have been out and about for approx 3 days a week. Sometimes for a couple of hours when its been a bright day.
I think they have spent more time outside than I have since November.

 

[drstitson]

"Looking at all that insulation make me think that one should make top bar hives out of old chest freezers."

well you can get those breeze block sarcophagi long deep hives.

also plenty of chest designs in the germanic/natural beekeeping circles - although can't imagine them allowing synthetic insulation, CFCs etc near their bees.

 

[drstitson]

"I doubt that the temperature in Norwich has been low enough for long enough so far this winter to worry about insulation."

insulation could have helped keep them cool in sub tropical norfolk!!!!

 

[Dishmop]

insulation could have helped keep them cool in sub tropical norfolk!!!!

It's all to do with traffic warming the atmosphere because of the low maximum speed they can attain due to no decent roads.

 

[Dishmop]

Mid day lunch break.