A portable, variable speed cabin air purifier (10) operates independently of a vehicle HVAC system and is constructed as an armrest or console (114) that can be placed on any passenger seat and held in place by the seat belt. The air purifier (10) may also be strapped to the floor of a van or SUV, or be positioned in the trunk (100) of a sedan with ducting (104, 108) installed into the vehicle cabin. A 12 volt DC blower (48) can be connected to the cigarette lighter outlet (62) or permanently wired in. Three to five replaceable packed bed filter media packets (70-76), a HEPA filter (78) and a carbon impregnated filter (80) may be installed. The filter media packets (70-76) comprise filter media envelopes (86) of a non-woven, gross particulate filter material packed with other filter media (88), including desiccants, sorbents, chemisorbents, pelletized and granular carbon particles, and catalysts, and are placed between grates (82, 84) and installed in a selected sequence.