The Secret to Aircraft Safety from COVID-19... HEPA Filters and Air Circulation Systems

Korean Air Completes Special Inspection of HEPA and Air Circulation Systems

[Asia Economy Reporter Yu Je-hoon] Korean Air announced on the 27th that it has recently completed a special inspection of the HEPA (High Efficiency Particulate Air) filters and the cabin air circulation system installed on its aircraft.

Through this special inspection aimed at preventing the spread of the novel coronavirus infection (COVID-19), Korean Air carried out HEPA filter replacement work based on the inspection results and checked the overall performance of the air circulation system, including verifying the normal operation of the air circulation fans.

According to Korean Air, HEPA filters help create a virus-free environment inside the cabin by filtering recirculated air. These high-performance filters block particles such as dust, viruses, and bacteria. Particles larger than 0.3 micrometers (㎛) are completely blocked, and smaller particles adhere to the internal fibers depending on airflow and speed, blocking nearly 100% (99.97%) of particles.

The size of droplets (飛沫, saliva droplets), known as the transmission medium of the COVID-19 virus, is 5㎛, and aerosols in the air are 1㎛, which cannot pass through HEPA filters. Korean Air explains that the size of the COVID-19 virus itself, ranging from 0.07㎛ to 0.12㎛, also makes it difficult to pass through HEPA filters.

Additionally, the air circulation system operates from the ground stage inside the cabin. The outside air at cruising altitude is at minus 50 degrees Celsius and has humidity below 1%, an environment where bacteria or viruses cannot survive. The cabin air circulation system absorbs this outside air and compresses it at high temperature and high pressure before introducing it. The internal air is filtered through HEPA filters, and since the outside air is introduced under such conditions, it is difficult for viruses to survive.

Furthermore, the direction of airflow inside the cabin also helps prevent the spread of viruses such as COVID-19. Korean Air stated, "Cabin air enters through ceiling inlets and exits through floor outlets in an 'air curtain' method, so even if virus particles are present, they fall to the floor, reducing the likelihood of spread," and emphasized, "Considering that cabin air circulation occurs within 2 to 3 minutes, the risk of COVID-19 infection inside the cabin is significantly low."

This content was produced with the assistance of AI translation services.