An air delivery system for delivering a pathogen-free airflow can include an air intake manifold, a sterilizer unit with a tank and at least one ultraviolet (UV) unit, a cooling unit with at least one cooling manifold and at least one heat exchange unit, and a user output. The air intake manifold, the tank, the at least one cooling manifold, and a user output can be in fluid communication in that general order. The at least one ultraviolet (UV) unit can be mounted within the tank, with the at least one UV unit configured to generate ultraviolet light to promote killing of pathogens. The at least one heat exchange unit is configured to cool the outbound air flow to a temperature suitable for breathing by a user and to heat an incoming air flow in the air intake manifold.