And many passengers also think that the plane is a confined space, and may not pay attention to the air circulation and filtration system of the cabin before experiencing the new crown epidemic.

During the development of China's civil aviation, the A320 aircraft air-conditioning system frequently broke down, and the failures were repeated and complicated, which brought great inconvenience to the flight crew. In the survey results of China's major airlines, it was found that the number of aircraft air-conditioning system failures has almost reached half of the total number.

With the gradual increase in the age of the aircraft, and the damage to the air-conditioning system caused by catkins and air pollution in certain seasons, the performance of the air-conditioning system will be attenuated or even deteriorated when the new aircraft is put into use for about two years.