Greetings BEE-Lers,
 
 I. Watson brought up the subject of ventilation vs condensation.
 
Here's my 2 cents:
   In a wet pacific coastal environment it gets cold but there's few serious
frosts and no snow. Masonite covers such as inner covers and tele covers
invite major condensation problems. I like to use an inner cover with window
screen stapled over the hole for ventilation year around. In the cold season
I cover that with 3/4" to 1" thick styrofoam and make a thumb sized hole over
the screen. Add some spacers and a big plywood raintop and my bees stay warm
and dry. I've seen all kinds of ventilation doodads.
Experiment and use what works. Good Luk.
 
H.Sweet