Air cleaning units containing an air filter, ultraviolet lights and a photocatalytic filter; Air exchangers for cleaning and purifying air; Air filtering units; Air filters for air conditioners in vehicle passenger compartments; Air filters for air conditioning units; Drying apparatus for use in heating, ventilation systems, air conditioning systems and refrigeration systems; Fabric air dispersion ducts for distributing and dispensing air as part of a HVAC system; Fibrous filtering media for general industrial use in the purification of air and industrial fluids; Filter cartridges for industrial dust collection systems for use in pulse-jet cleaning; Filters and filtering devices for air and gas conditioning; Filters for air conditioning; Metal cylindrical chamber and screen for use in filtering and removing settleable solids from liquid; Separators for the cleaning and purification of air; Ventilating exhaust fans for household use, etc.; Water filtration and purification units and replacement cartridges and filters therefor