What is Filter types?

Filter types are the stages a purifier uses to trap particles, and each brand lists its own set. Every option in this group starts with a HEPA filter. Airtheal lists the broadest set, hepa h13, carbon and uv. Air Health adds a UV stage to hepa h13, carbon and uv, AirDoctor keeps it shorter with hepa h13 and carbon, and AirDoctor Europe and Alen Air Purifiers pair HEPA and carbon with an ioniser. UV and ioniser stages are additions, not replacements for the particle filter. More stages also mean more surfaces to keep clean, so check what each brand says about filter changes and costs before you buy.