In old crawlspaces, we often find vents. It was believed that these vents could dry out crawlspaces with outside air. However, we now know that these vents are a detriment, as outside air is often more humid and wet than the air in the home. They also allow frigid winter air and pests inside. Our CleanSpace vent covers are designed to install quickly, attaching mechanically to form an airtight bond.