Finsky, so what you seem to be saying to me is that, under the +17C they may be quite comfortably warm. Above +17C, then they become so warm that they need that extra ventilation. Correct? Wrong?
You must clarify what you are saying with this sentence. "In Canada recommendation they say too that make first enlargement under brood area" I don't understand, and it is important that I do understand. Please clarify.
Under 17C electrict heating is usefull
Our summers where I live will NEVER get so hot that I cannot go outside. Unless global warming has some extremely hot effects. We are temperate. Not much over +25C-+27C, if it goes higher, we are then very hot. It has reached +30C now and then and I will tell you that all I do is sit under the beech tree by the pool with a beer, or some iced tea, depending on the mood. But we can generally still function quite nicely in our warm summers with regard to working outside.
I just gived back to you when you have so nice weather now.
Finsky, are you saying that your country in summertime never goes above say +17C?
Why not move to a warmer place, along with your bees.
Whe can I get 160 lbs honey per hive? And here most of year bees are in winter cluster. It seems that in warm climate bees are starving all the time and you must feed them with candy, dry sugar an syrup year around. And you calculate mites on weekly base. I calculate never. I just kill them. Beekeeping in south is very difficult.