Crawl Space Insulation - Open Vents
The idea of a vented crawl space was that in the summer if the vents were open it would offer enough airflow to keep the crawl space dry, but it did not work this way. In hot, humid, damp climates like ours, the vents allow moisture to flood into the crawl space and become trapped. In the winter, closed vents were supposed to keep cold air out and the floors warm. This does not work either. The vents aren't airtight, cold transfers through the block into the crawl space, and all the gaps in the foundation allow cold air in any way leaving homeowners with cold floors and drafts.