I think I understand Derek, so it acts similar to double glazing?
yes a bit like it but actually a lot more effective. Its because for two horizontal plates, with an air gap, and a temperature difference, the air gap has to be bigger than a certain size for convection to start. If I have do the calcs right, bee space is very close:10mm is good for 19 C temp difference between the inside surfaces .9mm 24c difference 8mm 33C difference
wood shavings /sawdust is effective but messy. I tested it back in 2013 on a warre hive. (not with bees but instrumentation)
but is that made from poly what its name? Some folks have an aversion to it.
Extruded polystyrene rigid insulation. Aversion to it? I guess some do. I've used is for at least 40 years...replacing shavings that needed to be replaced every autumn. The foam is separated from the bees...above the crown board with feed hole closed with duct tape. I wonder why the aversion? Two crown boards? Overkill in my opinion.
I get asked for alternatives to plastic foams all the time. The rationalism goes something like plastics in the ocean bad, plastics mean CO2 and are doubly bad, bees good! Therefore must not use plastic with bees. The actual number on life time CO2 emissions per kg of honey or colony year show Polystyrene hives are better than wooden ones. But we are not talking hard facts and numbers but peoples "likes" and "dislikes"
No disposal…it lasts forever
I have put a supers full of straw on hives before above the crown board.
I use wool on some of mine. Convenient in some ways, awkward in others but does seem to attract moisture.
I used the wool you supplied on the teaching apiary hives this winter. Works very well as an insulant but you do get condensation on the top of the wool in some hives.
Hmm, a former member on here was adamant that wool was perfectly dry. To be honest, I have no doubt that wool fibres are waterproof but it's the gaps inbetween that tend to hold water.
