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I run into this everywhere it really winds me up!!!
Its even on the NBU web site
at best its sloppy use of words, but its really just wrong, fatally wrong
"damp rather than cold air kills bees" becomes the imperative to chill bees and increase ventilation regardless, in all circumstances, because this implies it doesn’t matter how much heat is lost by the air and the hive so long as you stop condensation
So here is my diatribe on the subject
A set of circumstances that reduces a animals key organs below its survival temp kill it.
for an individual honeybee that is around 7 to 9C.
To get a body to reduce its temperature you remove energy from it at rate greater that it can get it from other sources.
lets look at possiblities of the damp killing
If you immerse this bee in water or still air in a box that is at 10C it might drown, but it isnt going to die from the causes implied in the statement " Damp rather than cold kills bees". So it isnt the water killing the bees.
if you spray an object with water and the force air over the object it will evaporate the water lose energy and it can cool the object below the temperature of the air. Are they implying that there is significant air velocity in the hive when cluster is still and quiet..
So it isn’t forced evaporation killing the bees here.
The higher the heat capacity and the greater the effective conduction of heat of fluid, the more efficient it will be at changing the temperature of the object.
So cold water at the same temperature of the cold air will be more efficient at removing heat from the bees.
So we can truly say "cold water kills bees more efficiently than cold air" and it might remove enough heat to overcome a cluster.
But this relies on the water is in contact with the bees and the water is cold.
The statement "Damp rather than cold kills bees" implies the damp isnt cold, but warm water doesnt kill bees.
Do they really mean:
"Cold Damp rather than cold air kills bees"
but where is this damp coming from outside? is it condensation?
if this damp is a water leak then it is likely to be colder than the air inside the hive, but as this phrase is not usually mentioned with admonition to fix the roof. Perhaps they mean
"condensation rather than cold air kills bees"
Condensation with a temperature of 10C or above in still air falling from a roof isnt going to kill the bees. So do they really mean
" condensation below 10C falling on the bees can be more efficient at killing bees compared to air at a considerably lower temperature"
This is actually true... but this is a long way from the original statement. This statement enables different actions e.g.
Make the condensation warmer than 10C
and/or stop the condensation falling on the bees.
And thus prompts beekeepers to use instead of ventilation a slab of insulation instead of the crown board, moves the condensation from above the bees and/or makes the condensation warmer.
All of these actions can be done with out chilling the bees and adding ventilation
So please can beekeepers learn the differences between heat loss and temperature and how it really happens rather than rely on sloppy, wrong, saw cum adages.
And can budding Entomologists sstay awake during their secondary school physics lessons
Rant over
Its even on the NBU web site
at best its sloppy use of words, but its really just wrong, fatally wrong
"damp rather than cold air kills bees" becomes the imperative to chill bees and increase ventilation regardless, in all circumstances, because this implies it doesn’t matter how much heat is lost by the air and the hive so long as you stop condensation
So here is my diatribe on the subject
A set of circumstances that reduces a animals key organs below its survival temp kill it.
for an individual honeybee that is around 7 to 9C.
To get a body to reduce its temperature you remove energy from it at rate greater that it can get it from other sources.
lets look at possiblities of the damp killing
If you immerse this bee in water or still air in a box that is at 10C it might drown, but it isnt going to die from the causes implied in the statement " Damp rather than cold kills bees". So it isnt the water killing the bees.
if you spray an object with water and the force air over the object it will evaporate the water lose energy and it can cool the object below the temperature of the air. Are they implying that there is significant air velocity in the hive when cluster is still and quiet..
So it isn’t forced evaporation killing the bees here.
The higher the heat capacity and the greater the effective conduction of heat of fluid, the more efficient it will be at changing the temperature of the object.
So cold water at the same temperature of the cold air will be more efficient at removing heat from the bees.
So we can truly say "cold water kills bees more efficiently than cold air" and it might remove enough heat to overcome a cluster.
But this relies on the water is in contact with the bees and the water is cold.
The statement "Damp rather than cold kills bees" implies the damp isnt cold, but warm water doesnt kill bees.
Do they really mean:
"Cold Damp rather than cold air kills bees"
but where is this damp coming from outside? is it condensation?
if this damp is a water leak then it is likely to be colder than the air inside the hive, but as this phrase is not usually mentioned with admonition to fix the roof. Perhaps they mean
"condensation rather than cold air kills bees"
Condensation with a temperature of 10C or above in still air falling from a roof isnt going to kill the bees. So do they really mean
" condensation below 10C falling on the bees can be more efficient at killing bees compared to air at a considerably lower temperature"
This is actually true... but this is a long way from the original statement. This statement enables different actions e.g.
Make the condensation warmer than 10C
and/or stop the condensation falling on the bees.
And thus prompts beekeepers to use instead of ventilation a slab of insulation instead of the crown board, moves the condensation from above the bees and/or makes the condensation warmer.
All of these actions can be done with out chilling the bees and adding ventilation
So please can beekeepers learn the differences between heat loss and temperature and how it really happens rather than rely on sloppy, wrong, saw cum adages.
And can budding Entomologists sstay awake during their secondary school physics lessons
Rant over
