Suggest replacing the HEPA filter every year the most to maximize the performance.
Fellowes Replacement HEPA Filter for Fellowes PT65 Pet Air Purifier
Fellowes True HEPA Filter (compatible with AeraMax DX5, 90, DB5, & 100)NIB
Fellowes True Hepa Filter 300 for AP-300PH Air Purifier - White 16" X 13" X 1"
Fellowes True HEPA Filter with AeraSafe Antimicrobial Treatment
Fellowes True HEPA Filter AeraSafe Antimicrobial Treatment, 12 mo. 99.97% Sealed
True HEPA Filter + Activated Carbon Pre Filter Set Compatible with Fellowes A...
