.I am trying to improve energy efficiency in my house. I live in central Va. with summer temp. 95 degree +, winter low 15 to 30 degrees. I have brick ranch home 2500 sq ft. Built in 1973. Heat pump located in attic. Attic is well insulated. Crawl Space , vented, no insulation, powder dry, no mold, outside entrance, no ground vapor barrier. Located in the crawl space is the water pressure tank. I like the idea of sealing the crawl space, trying to insulate between the floor joists would be difficult due to electrical, plumbing, central vac, tel, tv cables, etc. I was a telephone installer for years and spent a great deal of time under houses, I never saw a vapor barrier I liked, they either had water puddles or terrible dampness under the barrier. I had a crawl space at another location and a termite inspector recommended I put down a vapor barrier on a dry dirt crawl space, a year later I had a damp dirt crawl space that had rusted stored bicycles, lawnmowers, and other stored metals. OK enough about vapor barriers, I think they draw moisture. I am open to suggestion, recommendation, and comments. Thanks , Richard