I have, what I feel is an unusual problem with winter condensation in my crawl space.
I'm in the heartland of the country and it is currently about 18 degrees outside. I have floor joist batton insulation with the built-in vapor barrier toward the living space (up). There is condensation dripping from the floor joists and saturating the insulation, causing it to drop out away from the subfloor.
My crawl space vents are temperature controlled and are all shut properly.