Air disinfection device and method using same

An air disinfection device with a disinfection chamber (1) with an air inlet (11), an interior (10) and an air outlet (12), wherein air to be disinfected flows through the disinfection chamber (1) from the air inlet (11) to the air outlet (12), wherein UVC light source means (2) are provided in the disinfection chamber (1) and the disinfection chamber (1) is equipped in the interior with reflective surface(s), wherein as UVC light source means (2) a UVC laser (21) is provided and as reflective surface in the in the interior (10) of the disinfection chamber (1) a number of mirrors (17) are provided, wherein the UVC laser (21) and mirrors (17) are arranged in such a way that UVC laser beam(s) (26) emitted by the UVC laser (21) are reflect multiple times in the interior (10) of the disinfection chamber (1), wherein the disinfection chamber (1) is cuboid shaped, the UVC laser beam (26) is coupled in the disinfection chamber in a central plane (F), which is centered and perpendicular to the height extension of the cuboid disinfection chamber (1), the mirrors (17) are oriented perpendicular to this central plane (F), and wherein the disinfection chamber (1) has a height (H) corresponding to the diameter of a single UVC laser beam (26).