Because air is essential to our survival, our bodies are constantly interacting with it. Air can enter our bodies through our mouths and noses. Inhalation is the process of breathing air through the mouth and nose into our lungs. Once air has entered the lungs, cells take the oxygen from the air and distribute it throughout the body. Once the cells have finished with the oxygen, our body exhales and pushes out the remaining air from our lungs as carbon dioxide .
Air is necessary in many activities.
Air is working when things, such as leaves and branches and clouds, are moving. There are many things which rely on air to move. All buildings, schools, and houses need ventilation, which is the process of supplying outdoor air to indoor areas. Most modern schools use mechanical ventilation, such as a HVAC system, to bring in outdoor air when the building is occupied. However, some schools still use natural ventilation, such as windows, doors, or exhaust fans to exchange air flow.