Too much air?

[wayne]

 Out in the yard I have a hive from a late cutout. I ran out of equipment on that one and haven't had time to make up any more yet.
  They are in 2 deeps, with an inner cover made for bottle feeding. That cover has 2 large holes that fit a canning jar. On each side of the holes is a 3/8ths lathe about 8 inches long. I used an old migratory cover over that.
  The lathes made a great top entrance as they held the cover up.
  But now winter is here.  Should I close it up more?
  I have a block of insulation on top but am worried about that opening under the cover.

[Brian D. Bray]

If the bees are using the top entrance I would close up the bottom one.  The top entrance is much better at venting condensation that can turn to rain inside the beehive.  I use Screened Bottom Boards (SSB) and top entrances and have much less worry with moisture problems harming the bees during t he winter.

[wisconsin_cur]

If the bees are using the top entrance I would close up the bottom one.  The top entrance is much better at venting condensation that can turn to rain inside the beehive.  I use Screened Bottom Boards (SSB) and top entrances and have much less worry with moisture problems harming the bees during t he winter.

I understand that this is an old thread but I would like to ask a clarifying question.

Right now I am using top entrances that span the length of the hive.  Should a build a reducer for the winter?  I am wondering if heat might escape too quickly from the hive or if it even matters as long as the hive is otherwise "tight" to avoid a draft.

[bassman1977]

Right now I am using top entrances that span the length of the hive.  Should a build a reducer for the winter?  I am wondering if heat might escape too quickly from the hive or if it even matters as long as the hive is otherwise "tight" to avoid a draft.

In the winter I prop the inner covers with door shims thus creating a top entrance spanning the length of the hive.  I don't reduce them as the outer cover keeps wind from blowing directly into the hive.  I do keep the bottom entrance reduced.  I find that I have more success with this setup than if I kept the inner cover sealed up and/or opened the screened bottom board.  So, to answer your question...I don't think reducing the top entrance would harm anything.

Hope that helps.

[Brian D. Bray]

Since I posted that entry I have switched to bottomless hives with a slatted rack as the bottom.  I still use a top entrance but keep it about 50% reduced.  Most bees enter through the bottom but some still use the top entrance.  The slatted rack helps prevent bearding and inhibits varmits from raiding the hive. 

I have overwintered my bees on solid bottom boards and migratory tops and had hive losses, I've overwintered using SBB with magritory tops and had fewer hive losses, I've overwintered using SBB and top entrances and experienced even fewer hive losses.  Now with bottomless hives and full or partial top entrances I've gone 2 winters without a hive loss.  The consistant factor in all cases was the ventilation, or lack thereof, of the hive.