A carbon filter acts as the pre-filter. It filtrates larger particles and eliminates odors from the air before reaching the filter.
Carbon has the ability to absorb almost any type of gas and molecules. When a gas reacts with the surface of an activated carbon filter, it is absorbed down and condensed into liquid particles. By using a carbon pre-filter, it longs the life span of your HEPA filter. For optimal performance, it is recommended that you change your carbon filter every 2-4 weeks.