Ventilation (noun)

1. The process of supplying fresh air to an enclosed space, room or building.
2. A system or means of providing fresh air in an enclosed space.

Origin:

From the latin word ventilatio, from ventus, meaning "wind".

Examples:

1. Proper ventilation is important to maintain indoor air quality.
2. The ventilation system in the building is not working properly.
3. The ventilation in the mine kept the workers safe.
4. The ventilation in the car is not working properly.
5. He installed an exhaust fan for proper kitchen ventilation.