While some air purifiers only have filters, others contain both pre-filters and filters. If your purifier comes with a pre-filter (as mentioned above) you can clean it by vacuuming it on a low setting to remove any dust or lint, before placing it in the washing machine with a mild detergent on a gentle cycle. Then, air dry it completely before re-attaching it to the air purifier. Before cleaning your pre-filter, it’s always a good idea to make sure that you check the manufacturer’s care instructions.