AllerAir Pro 6 HEPA - Medical Grade & 6000 Medical Grade HEPA

• Pre-Filter: Can be visually inspected: When both sides are of similar color should be changed, regular household usage would require Renewal 3-6 months You can vacuum every 2-3 months and replace every 6 months if need be.
• Tar Trap Prefilter typically need to be changed more frequently.  Renewal 2-3 months
• UV lamp  (if applicable) is recommended to change yearly. Renewal 12 months
• HEPA Filter: Can be visually inspected: When both sides are of similar color = should be changed, regular household usage would require Renewal 2-3 years
• Carbon Filter: Found inside the unit in a canister from a few inches away, smell the exhaust and if an unpleasant sour odor is emitted that is an indication for renewal, regular household usage would require. Renewal 2-3 years

PS: The above estimated time periods all variable and dependent upon your usage and the contaminants in a given area. The above can be used as a general guideline.