Device for disinfecting air in an interior space, comprising: a housing having a longitudinal extension and an upper side for installing on an interior wall of the interior space, in particular an interior ceiling of the interior space; an air inlet at a lower side of the housing opposite the upper side, such that the air can be drawn in, transversely to the longitudinal extension of the housing, through the air inlet from below, the air inlet having a first cross-sectional area (A1); an air outlet at a front side of the housing connecting the upper side to the lower side, such that the air can be discharged into the interior space substantially in the longitudinal extension of the housing through the air outlet , the air outlet having a second cross-sectional area (A2) that is smaller than the first cross-sectional area (A1); a flow duct extending in the housing from the air inlet to the air outlet ; a disinfection cell which is arranged in the housing and/or forms a part of the housing , forms a part of the flow duct and in which the flow duct has a flow cross section (S) that is smaller than the second cross-sectional area (A2), wherein the disinfection cell comprises, on an input side, at least one first fan for drawing in air from the air inlet and discharging the drawn-in air into the disinfection cell and, on an output side, at least one second fan for drawing in the air from the disinfection cell and discharging the drawn-in air to the air outlet , and wherein the first fan and the second fan each comprise at least one or more rotor blades, which are configured such that they do not allow any light to directly pass through when viewed in the flow direction of the air; and at least one UV light source arranged in the flow duct in the disinfection cell for irradiating the air flowing through the flow duct . a housing having a longitudinal extension and an upper side for installing on an interior wall of the interior space, in particular an interior ceiling of the interior space; an air inlet at a lower side of the housing opposite the upper side, such that the air can be drawn in, transversely to the longitudinal extension of the housing, through the air inlet from below, the air inlet having a first cross-sectional area (A1); an air outlet at a front side of the housing connecting the upper side to the lower side, such that the air can be discharged into the interior space substantially in the longitudinal extension of the housing through the air outlet , the air outlet having a second cross-sectional area (A2) that is smaller than the first cross-sectional area (A1); a flow duct extending in the housing from the air inlet to the air outlet ; a disinfection cell which is arranged in the housing and/or forms a part of the housing , forms a part of the flow duct and in which the flow duct has a flow cross section (S) that is smaller than the second cross-sectional area (A2), wherein the disinfection cell comprises, on an input side, at least one first fan for drawing in air from the air inlet and discharging the drawn-in air into the disinfection cell and, on an output side, at least one second fan for drawing in the air from the disinfection cell and discharging the drawn-in air to the air outlet , and wherein the first fan and the second fan each comprise at least one or more rotor blades, which are configured such that they do not allow any light to directly pass through when viewed in the flow direction of the air; and at least one UV light source arranged in the flow duct in the disinfection cell for irradiating the air flowing through the flow duct . <EOS>