Protective window for an ornamental window in which the protective window has an outer frame, protective glazing and optionally mullions that protect the ornamental window while maintaining its beauty. The protective window has extension jambs on the frame that hide the structural portions of the building wall and any mullions in the ornamental window so the two windows have an attractive appearance undiminished by the sight of the edges of the building wall or undersides of the mullions between the two windows.
The present invention provides an apparatus for venting an airspace formed between an ornamental window and a protective panel. The venting means includes at least one pair of vent openings, one for air to enter the airspace and one for air to exit. These vent openings include a path through the frame holding the protective panel to an interior opening which is to the airspace. The vent openings, the paths and the interior openings must be of adequate size to minimize the range of temperature and moisture within the airspace. It is recommended that effective vent openings are at least one square inch for every 2000-2500 square inches of ornamental window.
