Air cleaning units; Air cleaning units containing an air filter, ultraviolet lights and a photocatalytic filter; Air exchangers for cleaning and purifying air; Air filtering installations; Air filters for air conditioning units; Air filters for domestic use; Air humidifying apparatus; Air purification units; Air purifiers; Air purifying apparatus; Air purifying apparatus and machines; Filters and filtering devices for air and gas conditioning; Gas purification machines; Gas scrubbing apparatu...