Air Vent ridge vents feature an advanced designed, external baffle that is one of the keys to the ridge vent's outstanding performance. The baffle deflects wind up and over the vent, creating an area of low pressure above the vent openings that causes lift. This is called the Bernoulli Effect. It's the same effect that causes airplane wings to lift. This low pressure works to pull air out of the attic. The baffle also deflects wind over the vent to help prevent wind-blown rain and snow from entering the attic.