Coway HEPA Filter for the AP-1008DH - Coway's HEPA Filter is a powerful air filtration system that is fast enough to make cigarette smoke disappear right in front of your eyes. Not only can it break down 90% of harmful gases in 10 minutes, it can also quickly eliminate 99.97% of invisible dust, various viruses, germs and mildew. The HEPA Filter can be cleaned with a vacuum cleaner every two to 4 months and will last up to one year.