Hi Jean-Pierre
 
>I would like to bring the discussion on the issue of HUMIDITY in the hive
>during the winter.
>
>The first question is how bad is humidity for the bees?  I know it has a bad
>effect on the stores, combs and wooden hive parts.  But how bad is the
>effect on the bees themselves?
 
We know that the bees need much water for brood rearing in spring before
they start flying and can get it from outside of hive. Also when there is much
crystallized sugar/honey in the hive the bees will need water to reliquefy it.
 
>If we recognize that the interior of the hive should be kept dry, are there
>alternate ways to so other that  the conventional 1 cm x  6 cm top hole.
>Personally I would be reluctant to eliminate it completely and lose the
>alternate bee entrance.  Could we make this top hole smaller in order to
>keep more heat?  Could we invent some design that would minimise the loss of
>heat?
 
There are very few beekeepers here (Sweden) that use top entrance during winter.
Personally I belive it's better to have a bottom board that provides sufficient
ventilation. There are different constructions on bottomboards that will do the
job, more or less complicated in construction. One of the best is probably
the "barras" bottom that I think originate from Norway. Tony would be more
suited to explain about it.
 
>What is the source of this moisture?  It probably origins essentially from
>the differential of temperature between the interior and the exterior of the
>hive, the walls and roof acting as condensation surfaces.
 
I think most of the humidity is produced by the bees themselves in the
metabolism when they consume the feed.
 
>Another old approach that could be looked at is the "moisture catcher" at
>the top of the hive.  Wood shavings and straw have been used quite
>extensively in the past and have almost disappeared, probably to the benefit
>of newer materials easier to handle.  Should we go back to using them?
>Would there be easier to use modern materials that would have similar
>absorbing properties?  A hobbyist in my area found that when he wraps his
>hives with the top feeders still on, the interior of the hive remains dry,
>even in the absence of a top entrance!  The condensation from the top drops
>in the feeder itself, not on the frames and cluster.
 
Wouldn't it be better to try to eliminate the need for a top entrance rather
then constructing "moisture catcher"? Put the effort in finding a bottom
construction that is efficient enought.
 
Are all beekeepers in the US and Canada using top entrance during winter?
What is the reason for it when it's not needed here? The north of Sweden has
as cold winters as Canada, and probably longer (lat 65).
 
Cheers  P-O