An Air Conditioner Filter Allows Air to Pass

• Depending on the type of filter used, air conditioner filters are made of woven cotton and synthetic blend materials, fully synthetic panels, or electrocharged polypropylene. All of these materials allow air to pass through freely while restricting the flow of larger, unwanted particulates.
  
  

The Filter is Installed at the Air Intake

• Whether the air conditioner is a simple window unit or a large central air system, new air is brought in to the system through one or more air intakes. Each air intake must have an air filter installed, usually just inside a fitted recess covered by a metal or plastic grate. The recess where the filter is installed is designed to prevent the filter from being sucked into the air handler, and the grate prevents the filter from falling out when the system is not in use.
  
  

Air Filters Catch Particulates

• With the filter in place, air flows is sucked into the grate, through the air filter, and into the air handler assembly, where it is cooled and blown out of the air conditioning vents. As the incoming air passes through the filter, the cotton or synthetic materials catch loose particulates which may have come in with the air. Some particulates commonly caught by air filters include dust, dirt, hair, pet fur, and dander.
  
  

Advanced Filters Clean the Air

• Some advanced filters, like those comprised of electrocharged polypropylene fibers, actively clean the air as it is passes through. The electronic charge of the filter serves to attract microscopic particles like mold, dust, pollen, and bacteria, which would pass through a standard cotten or poly-blend filter. These filters are generally more expensive than traditional filters, but can be reused for a number of years and are well received by those who suffer allergies.