Round metal vents with fins are known as turbine ventilators. The turbo ventilator can start rotating with just a little bit of wind. The turbine will rotate more quickly and release heat, smoke, fumes, humidity, etc. the faster the wind blows. The air movement is governed by relatively basic mechanics.
The turbo air ventilator continuously circulates fresh air to replace hot, stale air. Turbo Air Vent rotates with the least amount of force from the wind, and it keeps processing even when the air supply is cut off. The flywheel of the ventilator will then use stored energy to rotate and maintain fresh airflow.