Crawl Space Encapsulation - Cut out for the flood vent.

What makes these vents so "smart?" It's their elegant simplicity. Unlike traditional air vents, these vents open automatically and passively once floodwaters reach a certain level by using patented internal activation floats. No human intervention is required and no electricity is needed. The vents provide a 3-inch clearance for small debris and trash to easily pass when the vent door is opened to avoid clogging. For vented crawl spaces, there are even Smart Vent models with a metal coil that's sensitive to temperature changes that open and close the vent louvers automatically without manual intervention. For a lowly vent, that's sheer genius!