Hugo Activated Carbon Filter Replacements. Hugo uses an activated carbon filter with a photocatalyst layer and UV sterilizing light to capture and eliminate harmful VOCs such as smoke, odors, toxic fumes, dust, pollen, mold, mildew, pet dander and airborne germs.  Filters should be replaced every 3-6 months depending on use for maximum efficiency. 3 Replacement Filters included in this pack.