Getting to Know Aircraft Filters

While supplemented oxygen is necessary when flying at high altitudes, have you ever considered how breathable air is provided to the cabin? Within most commercial aircraft, air is divided equally between two ratios: recycled air and bleed air provided by the engine or auxiliary power unit (APU). Before this air can be circulated to the cabin and exposed to passengers, it must first undergo filtration to ensure quality, breathability, and comfort. As an installed feature among many fixed-wing aircraft, high-efficiency particulate air (HEPA) systems ensure circulating air is not only free from pollutants, but also help protect against dust, dirt, fibers, microbes, allergens, and more. Within this blog, we will go over the fundamentals of cabin air filters, how they are constructed, and why they serve a large role in keeping the cabin and crew safe.

Providing passengers with safe flight since the 1940s, HEPA air filters were first created under government contract by the Arthur D. Little firm to help mitigate the spread of radioactive contaminants produced during the Manhattan Project. Originally referred to as the “absolute filter” post-World War II due to its range in capabilities, by the 1950s, the HEPA filter became a registered trade name. Since their commercialization, HEPA filters have evolved to fit numerous sanitary functions within vehicle & aerospace demands, data processing applications, micro circuitry production, and more.

Today, with breakthroughs in technology, HEPA filters have been designed specially to combat viruses, bacteria, fungi, human matter, and other airborne contaminants. Additionally, these filters help reduce the spread of pathogens from one city to another, and are often seen functioning with higher standards in micro electrical and medicinal settings. Held to rigorous standards by the U.S. Department of Energy, these items must be manufactured to a precise standard of efficiency to restrict even the smallest of potentially hazardous pollutants with up to 99.95% success. This is made possible through randomly arranging 0.05 to 2 micrometers of fiberglass fibers into woven sheets. When air is being filtered through these compact layers of fibers, it is compressed with the aid of a motorized fan. This causes gas molecules to combine with particles in the air, making their joint mass larger and easier to be trapped by the filter.

Although filters help provide aircraft with clean air, they typically do not dispose of the pollutants they accumulate on their own. Not being able to dispose of this residual matter, some HEPA filters utilize powerful ultraviolet lights to kill off bacteria, viruses, and various other unwanted impurities. Simultaneously, activated carbon is typically implemented to diffuse odors and control volatile chemical molecules. To ensure air quality is always at its highest levels, these systems work together and can complete a full filtration cycle every two to four minutes, or roughly fifteen to thirty times per hour.

Critical in maintaining air safety, it is best to periodically check your air filters and accompanying components based on manufacturer recommendation. Produced in a variety of sizes to suit a myriad of industries and applications, if there is a specific filter you require, we have you covered. For reliable HEPA filters, compressed air purifiers, and more, look no further than Aviation Sphere, your trustworthy source for various aircraft parts and components. Due to our quality control and export compliance, we operate with AS9120B, ISO 9001:2015, and FAA AC 00-56B certification and accreditation. If you would like to request a quote for your comparisons, you can submit an RFQ form as provided on our website. Upon receipt, a dedicated account manager will quickly review and respond with a personalized solution to your needs in just 15 minutes or less, 24/7x365.