Bill Bartlett wrote:
> How are the screened bottom boards going to effect the ability of the bees
> to maintain the brood area temperature of 92 -93 degrees F?

Easy answer is - it depends.
It appears that if you are south of a New Hampshire climate, no problem
since that has been demonstrated. It will also depend on winter stores- how
much and how good.
My guess is that here in Maine, which can get cooler than Southern NH,
there should be little problem. I have found that if I have good
ventilation in the hive over the winter, the colony is much better off
since it is not heat that is a problem but moisture. When the primary
advice you get is to increase ventilation in the winter by propping up the
outer cover and that advice is absent in the summer, screened bottom boards
should have little effect.
They may even be better. This is only a guess, but the heat transfer should
be about the same. The top opening will determine the transfer rate, since
the bottom opening will allow a flow rate that will balance the upper exit
flow. So with a smaller bottom opening, you just have a faster flow. A
faster flow will give more cooling in a smaller area which could result in
spot chilling of the bees. The open bottom will have much slower air flow
and could actually be beneficial by reducing the " wind chill factor"
inside the hive.
Bill Truesdell
Bath, ME