Standard air conditioning filters work well to keep your system and its duct work clean, but they don’t really improve indoor air quality. To do that you need a media filter. The media filter rests between the main return duct and the blower cabinet and will improve dust and particle removal by seven times that of a standard furnace filter. However, upgrading to a pleated media filter will remove everything from insecticide dust to airborne viruses from the filtered air.
A media filter can have a life exceeding two years, and its only drawback is that its tight fiber weave can cause your air conditioner to have to work harder to blow air through the house. Always choose a filter that matches your blower’s capacity.