Insulation

[user 20297]

I don't. disagree. My point was that doubling the insulation does not half the heat loss, and the thicker it gets, the less benefit is gained per cm added.

I agree with that principle.....actually, it's not really necessary for me to agree with the Laws of Physics, is it.

 

[oliver90owner]

on the basis that heat rises and will be contained where the bees are most likely to be .

Only for convection.

Conduction and radiation occur in all directions. Conduction is limited to movement from higher temperature regions to lower temperature but can occur in any direction.

Radiation is unlimited in direction, but not normally considered within the the material as the radiation would be immediately re-absorbed. All surfaces above zero Kelvin will radiate heat. They will also absorb heat. It is radiated in equal amounts from both surfaces for an almost infinitely thin membrane (work that one out for yourself).

Convection is the upward movement of less dense material within a fluid. Convection moves heat away, upwards, by movement.

The earlier snowflake poster, who disagreed with me, obviously didn’t learn his science properly (if at all) while at school. The heat from the lower surface will be conducted to the air molecules; those air molecules will then be warmer, less dense and rise (yes, that means move) across the cavity, conducting their heat energy to the upper membrane by conduction. Simple enough? Convection is through the movement of a fluid. Got it yet?

For those that understand principles of heat transfer will know that vacuum flasks are useless once air leaks into the cavity - because the heat, while the flaak is in good operational condition, cannot be conducted or convected across the cavity (nothing to conduct or move and the heat loss is very much reduced by the mirror shiny surfaces radiating less and reflecting more of the heat. Yes, radiation can be reflected or absorbed by surfaces. Such a flask, with air in the cavity, can then lose heat by convection, conduction and radiation which renders it fairly useless.

I very much doubt that particular poster has ever heard of the Leslie’s Cube Experiment - a very basic Physics investigation at GCSE level of education. A simple demonstration of radiation from a hot body.

The reason why most heat could be potentially lost from the roof is because the vast majority of the heat lost by the bees is convected to the top of the hive and then lost by conduction. Hence the need for the insulation (and no top air leakage) so that the heat loss is minimised - not eradicated. The bees use their stores for heat production during the winter, while minimising any activity that wastes energy required for other life systems. They cannot avoid heat loss due to respiration or body losses, but they do minimise it as far as possible.

Likewise, the other poster who thinks convection losses are avoided by sealing the ends of tubes is delusional. It certainly reduces the movement but does not prevent convection.

 

[pargyle]

on the basis that heat rises and will be contained where the bees are most likely to be .

Only for convection.

Conduction and radiation occur in all directions. Conduction is limited to movement from higher temperature regions to lower temperature but can occur in any direction.

I agree ... my crownboards are 6mm solid polycarbonate and the bees seal them well and truly to the top of the brood box with propolis. On top of the crownboards, is a super full of PIR insulation. My hives are Paynes poly and so I have both limited convection and conduction heat loss as far as is practicable in beekeeping terms.

I'm no physicist - my Physics ended with an A level - but common sense (and practical observation) tells me that if you, effectively, have an insulated box with a sealed top and more insulation above then any heat created by the colony will be largely retained in the box and will dissipate relatively slowly.

All good news for the bees in my opinion.

 

[user 20297]

I very much doubt that particular poster has ever heard of the Leslie’s Cube Experiment - a very basic Physics investigation at GCSE level of education. A simple demonstration of radiation from a hot body.



Likewise, the other poster who thinks convection losses are avoided by sealing the ends of tubes is delusional. It certainly reduces the movement but does not prevent convection.

@oliver90owner , you are obsessed with the scientific minutiae of this. I'm sure that no-one thinks that insulation can completely prevent heat loss from a warm object. You undermine your own lines of "argument" by selectively quoting and distorting what others have said. @robmort did not claim that anything can prevent convection. You originally joined this conversation to imply that there is no benefit to be gained from using a product which is sold on the basis that one of its features is "superior thermal insulation properties. Do you agree that insulation will slow down the rate of (heat) loss from bees or not? If you do then there's no more to be said. If you really want to make me the object of your ridicule, the least you could do is to take me on for some of the ridiculous things I have said.

 

[Finman]

I agree ... my crownboards are 6mm solid polycarbonate and the bees seal them well and truly to the top of the brood box with propolis. On top of the crownboards, is a super full of PIR insulation. My hives are Paynes poly and so I have both limited convection and conduction heat loss as far as is practicable in beekeeping terms.

I'm no physicist - my Physics ended with an A level - but common sense (and practical observation) tells me that if you, effectively, have an insulated box with a sealed top and more insulation above then any heat created by the colony will be largely retained in the box and will dissipate relatively slowly.

All good news for the bees in my opinion.

My hives do not have sealed top, and it does not harm bees. Bees seal the top at late summer but I brake the seel many times. When I take off feeding boxes, seals are broken for ever. Next time I will brake seals to give oxalic trickling.

 

[pargyle]

My hives do not have sealed top, and it does not harm bees. Bees seal the top at late summer but I brake the seel many times. When I take off feeding boxes, seals are broken for ever. Next time I will brake seals to give oxalic trickling.

Perhaps if the bees are sealing everything up with propolis they are trying to tell you something? I'm sure they appreciate you opening them up in mid Finnish winter in order to douse them in oxalic .... so old school finnie.... I thought you could teach an old dog new tricks - have you not considered OA by sublimation if your bees need a winter treatment?

 

[Finman]

Perhaps if the bees are sealing everything up with propolis they are trying to tell you something?

They are telling nothing to me. I just must brake their sealings, and I break.

I cannot nurse my bees, if I think their feelings all the time.

If you think a bull or a cat, whose balls are cut off. Should we think first animals' feelings, and why they have such bells.

 

[jenkinsbrynmair]

If you think a bull or a cat, whose balls are cut off. Should we think first animals' feelings

My dog has no nose!

 

[Finman]

My dog has no nose!

It was wrong end, I assume

 

[jenkinsbrynmair]

It was wrong end, I assume

I don't know - it was cold and wet last time I felt it

 

[Finman]

I don't know - it was cold and wet last time I felt it

Sounds bad. Do you think, that the nose tried to tell to you something?

 

[pargyle]

My dog has no nose!

How does he smell ???

 

[jenkinsbrynmair]

Terrible - Almost as bad as the Blenheim Bee fable

 

[pargyle]

Terrible - Almost as bad as the Blenheim Bee fable

Boom Boom ....

 

[Amari]

Only for convection.

Conduction and radiation occur in all directions. Conduction is limited to movement from higher temperature regions to lower temperature but can occur in any direction.

Radiation is unlimited in direction, but not normally considered within the the material as the radiation would be immediately re-absorbed. All surfaces above zero Kelvin will radiate heat. They will also absorb heat. It is radiated in equal amounts from both surfaces for an almost infinitely thin membrane (work that one out for yourself).

Convection is the upward movement of less dense material within a fluid. Convection moves heat away, upwards, by movement.

The earlier snowflake poster, who disagreed with me, obviously didn’t learn his science properly (if at all) while at school. The heat from the lower surface will be conducted to the air molecules; those air molecules will then be warmer, less dense and rise (yes, that means move) across the cavity, conducting their heat energy to the upper membrane by conduction. Simple enough? Convection is through the movement of a fluid. Got it yet?

For those that understand principles of heat transfer will know that vacuum flasks are useless once air leaks into the cavity - because the heat, while the flaak is in good operational condition, cannot be conducted or convected across the cavity (nothing to conduct or move and the heat loss is very much reduced by the mirror shiny surfaces radiating less and reflecting more of the heat. Yes, radiation can be reflected or absorbed by surfaces. Such a flask, with air in the cavity, can then lose heat by convection, conduction and radiation which renders it fairly useless.

I very much doubt that particular poster has ever heard of the Leslie’s Cube Experiment - a very basic Physics investigation at GCSE level of education. A simple demonstration of radiation from a hot body.

The reason why most heat could be potentially lost from the roof is because the vast majority of the heat lost by the bees is convected to the top of the hive and then lost by conduction. Hence the need for the insulation (and no top air leakage) so that the heat loss is minimised - not eradicated. The bees use their stores for heat production during the winter, while minimising any activity that wastes energy required for other life systems. They cannot avoid heat loss due to respiration or body losses, but they do minimise it as far as possible.

Likewise, the other poster who thinks convection losses are avoided by sealing the ends of tubes is delusional. It certainly reduces the movement but does not prevent convection.

oliver90owner, you are insufferably pompous most of the time. We all did some science at school but maybe don't remember al the facts some decades later. Did you study Shakespeare/modern languages/history and remember all you were taught?
My first degree was in Natural Sciences at Cambridge but I've never heard of Leslie's Cube Experiment. My memory of conduction/radiation/convection is very hazy.
Please be a little more generous......

 

[user 20297]

oliver90owner, you are insufferably pompous most of the time. We all did some science at school but maybe don't remember al the facts some decades later. Did you study Shakespeare/modern languages/history and remember all you were taught?
My first degree was in Natural Sciences at Cambridge but I've never heard of Leslie's Cube Experiment. My memory of conduction/radiation/convection is very hazy.
Please be a little more generous......

"Pompous" ? "— People also search for: pretentious, egotistical, haughty, humorless, glib, obsequious, pedantic, conceited, smarmy, snooty, foppish, more..."

https://www.rhymezone.com/r/rhyme.cgi?typeofrhyme=perfect&loc=thesql&Word=pompous

 

[pargyle]

OK Guys ,,,, let's leave it at that shall we ? By all means challenge the content of oliver90owner's posts but there's no mileage in these direct personal slurs ....

 

[user 20297]

OK Guys ,,,, let's leave it at that shall we ? By all means challenge the content of oliver90owner's posts but there's no mileage in these direct personal slurs ....

Mr. "Oliver" does engage in conversations in an arrogant and condescending style and anyone can see that; it is not a slur .

 

[Erichalfbee]

Please. Pargyle has asked nicely....it's been ignored so the posts have been deleted

 

[Etton]

My ekes with insulation which go under my insulated roofs, then use for placing fondant under the crown board in January.