I've got a vented crawl space with no vapor barrier and no insulation between the floor joists. I live in a fairly humid environment in Virginia where the ground under the house is always damp, but there is never any standing water. I'm considering installing R30 insulation between the floor joists, but should I start with a vapor barrier or should I fully enclose the space making it an unvented space? My goal is simply to reduce moisture and mold in the house and keep the temperature better controlled during the winter and summer. I'm not looking to break the bank either, so I'm interested in budget options.