An Air purifier now no longer to be harassed with an air ioniser or an air humidifier, may be utilised in a preventive and/or healing way, at home, in closed offices, open areas or cowering places, shops, hairdressing salons, inns or restaurants, scientific and para-scientific practices… By extension, due to Covid-19, its miles are turning into an increasing number of vital signs in schools, hospitals, the scientific and paramedical sector, the tertiary sector, etc.