Re: Surprised by how damp the quilt box was...
Quilt box material needs to able to slowly vent from bottom to top and thereby get the moisture to the top. Shavings work very well to allow this slow ventilation of air and moisture to the top.
Once the moisture makes it to the top, it needs to be exhausted. You need a space above the shavings and a min of a 3/4 hole on front side of quilt box. Hole should be above the shavings. I also have 2 1/2 inches of Styrofoam permanently fixed in under side of outer cover. Frost does not form in the center of the underside of the outer cover but there is at times some frost around the perimeter.
I also have two top entrances that exhaust most of the moisture. This system worked quite well before quilt boxes. The addition of quilt boxes made it better yet. The top entrances are a 3/4 round hole in a feed shim and an open 1 1/2 notch on top side of front of an inner cover. Inner covers have a 3 1/2 round hole in the center and are immediately above the feed shim.
Having no moisture problems at all. Ponder whether interior is too dry as there is so little moisture in the interior. Feces from cleansing flights is stringy in appearance.
Zone 3b. If you always do what you always did, you'll always get what you always got!