They didn’t know.
Have a question? WHY? In Japan air purifiers include 2-3 extra replacement filters. Every 6-12 months you’ll need to change filters. Expect to pay $250-325 (and don’t pay more). ’t room air filters think ahead so they overcharge. Because of allergies and asthma I’ve owned over 56 air purifiers since 1974. And I even became a Health Practitioner in 1982 because of the way I overcame allergies and asthma naturally. CONCLUSION: Look for an air purifier that has HEPA, and 3-5 additional technologies such as UV and ion. It promises to bring greater allergy relief. honeywell air purifier I’ve owned: Ozone air purifiers, Ionic air purifiers, Zeolite, HEPA air purifiers, UV light, Catalytic plate air purifiers, and water air purifiers with brnad namesincluding – Alpine Air, EcoQuest, Hunter, Panasonic, Austin, IQair, SunAir, and about 23 other “non-name” Chinese brands. Finally a tech said: “One per hour”.