winter storage

I agree w/ Dutch. If a dusty area, keep closed and place charcoal in a few alum pans inside as this will aid in moisture absorption.. Come spring, either toss the charcoal or use in fire pit.

If no dust, crack open at least 1 vent.

According to a humidistat, ours stays drier inside with everything closed up.

Depends upon where it's stored? Is this a farm barn with birds and bats and rats and mice and bails of hay and horses, or is this a storage facility or an indoor garage that is not a barn or farm shed?

If it's a farm barn, I'd leave it completely closed up. If its an actual storage facility or a garage of some sort, that's clean, leave the vents open.

Ours is stored in enclosed also...we leave a roof vent open as Bob Sue posted above. We also keep a Dri-z-Air for some moisture control... Walmart, etc.(wet NW winters).

Dri-z-air....Link.

You need to open at least a ceiling vent, for some air movement inside the RV.