Air filters are a common part of most automobiles. Cars, trucks, SUVs are other automobiles typically feature multiple air filters. While available in different types, all air filters are designed to remove particulate matter from the air. As air travels through an air filter, it will leave behind particulate matter.
Airplanes, however, often feature air filters as well. They are used for the same purpose of removing particulate matter from the air.
Cabin Air Filters
Airplanes need cabin air filters. Cabin air filters are designed specifically for cabins. Most airplanes have an intake system for their respective engines. Some of this excess air will be bled off for use in the cabin. Rather than entering the engines’ combustion chamber, for instance, the excess air will enter a network of ducts before being expelled into the cabin. As the excess air is bled off, though, it will pass through a cabin air filter.
Cabin air filters are exactly what they sound like: air filters that clean the cabin air. They remove particulate matter from the bled-off air, resulting in fresh and clean air being pumped into the cabin.
Engine Air Filters
In addition to a cabin air filter, some airplanes feature engine air filters. Engine air filters are designed specifically for use in turbine engines. Turbine engines work in a similar way as automotive combustion engines by burning a mixture of fuel and air. Each turbine engine has a combustion chamber. To generate propulsion, it will burn a mixture of fuel and air inside of the combustion chamber.
The air used in turbine engines comes from the exterior of the airplane. Some airplanes, however, will pass this air through a filter. Engine air filters are those used to remove particulate matter from the air before it enters the combustion chamber.
It’s important to note that not all airplanes use engine air filters. The air is typically cleaner at high altitudes than at low altitudes. Upon reaching cruising altitude, most commercial airplanes won’t need engine air filters. The air will be clean enough to burn efficiently without polluting or otherwise harming their turbine engines.
But smaller airplanes may still use engine air filters. Smaller airplanes fly at lower altitudes than wide-body commercial airplanes. And when flying at lower altitudes, they are exposed to more particulate matter in the air. Engine air filters will clean the air by removing this particulate matter.
Air filters aren’t limited to automobiles. Most airplanes feature air filters as well. They may feature a cabin air filter as well as one or more engine air filters.