A Non-Electric Alternative To Ventilation, These Vents Use The Natural Force Of Wind And Air Pressure To Spin And Vent Out Stale Attic Air. They Do It With A Series Of Specially Shaped Vanes That Catch The Wind And Provide Rotary Motion. This Pulls Hot, Humid Air From The Attic. Turbine Vents Provide A Low-Cost Ventilation Alternative In Areas Where Wind Speeds Of At Least 5 Mph Are Typical.