Abstract: Device and method for a UV air sanitizer with boundlessly-extended sanitizing chamber are provided. The device comprises an enclosure with an inlet emitter area with directional louvers. The inlet emitter area optimized for drawing in outside air stream, while simultaneously emitting ultraviolet germicidal radiation into said outside air stream. The device further comprises a fan and a disinfection unit with at least one UV lamp. The UV lamp is uniquely positioned and directed inside the enclosure, so as to simultaneously irradiate: air moving inside the enclosure, air entering through the inlet emitter area, as well as a moving stream of air, said air located outside of the enclosure and drawn toward the inlet area by the fan. The method includes the steps required to use the device for creation of one or multiple germicidally-protective defensive air curtains.