Disclosed are radiator units for generating ultraviolet radiation, in particular for use in grocery processing or in water processing, comprising a UV-radiator with a radiator tube made of quartz glass, or comprising a UV-radiator which is surrounded by a cylindrical cladding tube made of quartz glass and which has a radiator tube made of quartz glass. Proceeding hence, in order to provide a radiator unit for generating ultraviolet radiation, which is suitable for emitting a high radiation power for a long operation period and which is also simple and cheap to produce, a dirt- and water-resistant coating is applied to the radiator tube and/or cladding tube, which coating is produced using silicon dioxide or titanium dioxide nanoparticles.
