Abstract: A chimney cap that permits compact storage and quick installation is described. The chimney cap is at least partially hinged, which permits the cage to be quickly set up from a folded condition. This is accomplished by hingeably coupling the sides of the cage to the bottom of the cage. The sides are coupled together by inserting a pin into concentric knuckles formed when corresponding edges are joined together. The folded product may be stored for transport or sale in a substantially flat box.

Abstract: A chimney liner adaptor is provided to allow air to flow between the outside environment and an annular space in a lined chimney flue. The adaptor may allow an air cooling system to operate but prevents undesirable elements from entering the annular space. The liner adaptor may be disposed between the chimney cap and the top walls of the chimney system and around the chimney liner. The adaptor may include perforated material, such as an expanded metal mesh, a metal screen, stamped metal screen, rugged netting, or the like. The perforated material permits gas flow, provides structural support for other elements of the adaptor, and filters out undesirable objects from entering the chimney.