Abstract: An air treatment system may create an air flow pattern in a vehicle interior space, using air discharges in multiple directions and louvers such that some vanes within a louver are not parallel to other vanes within the louver. An air treatment system may provide bulk air flow to the vehicle interior and directed airflow to a driver region. An air flow system may comprise, internally, a constriction bounded by an edge of a UV light shield and an edge of a filter housing. Such air treatment systems, using filtration and UV light, effectively remove or kill viruses and other pathogens, for use in buses and similar vehicles.