The highly effective multi-layer filter (HEPA and odour filter) reliably filters out pollutants such as dust, particulate ­matter (PM10, PM2.5 and minor), pollen and allergens, pathogens such as bacteria and mould spores, cigarette smoke, exhaust fumes and odours from the idoor air. On an average, the filters have to be changed after 12 months, depending on the intensity of the usage.