Air cleaning units; Air exchangers for cleaning and purifying air; Air filtering installations; Air purification units; Air purifying apparatus and machines; Air purifying units for commerical, domestic and industrial use; Air sterilizers for for hospitals, commercial use, and household use; Electric air deodorizers; Electric air sanitizing unit; Germicidal lamps for purifying air; Industrial air purifiers; Personal air filtering units for for use with masks and ventilators; Ventilating exhau...