Ventilation is the process of removing air from or supplying air to an interior space.

In the travel, transport, and hotel context, "ventilation" refers to the process of introducing fresh air into a building or vehicle, and removing stale air to maintain a healthy and comfortable environment for the occupants. Proper ventilation is important for maintaining air quality, reducing the spread of airborne illnesses, and controlling temperature and humidity levels.

For example, in a hotel, proper ventilation can help to reduce the spread of germs and improve indoor air quality by ensuring that fresh air is circulated throughout the building. In a transportation context, such as airplanes, trains, buses or ships, proper ventilation can help to prevent the buildup of carbon dioxide and other pollutants, as well as controlling the temperature and humidity levels.

Examples of ventilation systems include mechanical systems such as HVAC (heating, ventilation, and air conditioning) units and natural ventilation systems such as windows and vents that allow fresh air to circulate. Some transportation and hotels also may have air purification systems, such as HEPA filters, to remove pollutants and allergens from the air.

Proper ventilation is especially important during the current COVID-19 pandemic, where it is crucial to maintain good air quality and reduce the spread of the virus.