The technology behind upper-room ultraviolet germicidal irradiation is decades old but with the global devastation of the coronavirus pandemic it is gaining attention again. These devices can be mounted on walls or ceilings to cast the UV-C light across the top of the interior space of a room. They can be used to safely remove pathogens from the air in occupied spaces like stores, restaurants, classrooms, and other enclosed spaces that could promote the spread of COVID-19.