The Civil Aviation Administration of China has published an article saying that the vertical air supply system of the aircraft, combined with the HEPA filter element, can filter out 99% of the virus.

The air-conditioning system​ ensures a constant supply of fresh air and maintains a constant selected temperature in the three areas of the cockpit, front cabin and rear cabin, mainly by conditioning the air entering the interior of the cabin. The air entering the cabin is regulated by mixing cold air and bleed air to the right temperature.

The air circulation refrigeration system achieves refrigeration by adiabatic expansion of compressed air in the expander to obtain low-temperature airflow. Its ideal working process includes four processes: isentropic compression, isobaric cooling, isentropic expansion and isobaric heat absorption.