The delonghi ac100 portable air purification system has a 3 level filtration and ioniser for reduction in exposure to house dust mite catdog allergen pollen fungi and cigarette smoke the hepa filter is effective against dust particles as small as 03 micrometer in diameter while the carbon filter is effective against various harmful gases and odours thanks to the properties of active carbons the ioniser neutralises the particles of dust pollen car fumes and smoke contained in the air th