The pre-filter is used to filter out large particles (such as dust, hair, etc.) in the air and can be cleaned.
HEPA high efficiency particulate filter, can not be cleaned, need to be replaced regularly. Generally, Korean imported filter paper is used, and the HEPA grade is H12. It can effectively filter out cigarette smoke, PM2.5, pollen, aphids and other particles above 0.3 microns in the air.
Activated carbon filter, generally choose the same volume, high iodine value, high weight filter. It can effectively remove common air odors and harmful chemical pollutants such as formaldehyde, stupid, dioxins and ozone in the air. This filter also needs to be replaced regularly.
Ultra-efficient fiberglass filter. Generally imported medical grade, to meet the European EN1822 testing standard, can filter 99.95%, high efficiency filtration of bacteria, viruses, fungal spores, pollen, radon decay products, PM2.5 and other solid particles and bacteria as small as 0.003 microns virus. It is best to use this filter in smog days.