Abstract: An ozone generator of the corona discharge type having a housing which is dimensioned to fit into one of a male end and female end of an air duct of a building and a glass tube of a radius substantially less than a width of the housing. An electrically conductive inner mesh is fitted over an interior surface of the glass tube and an electrically conductive outer mesh is fitted over an exterior surface of the glass tube. The ozone generator also has means for generating a high electric potential difference across the electrically conductive meshes.