FLEXIBLE PLENUM WITH RIGIDIFICATION FEATURES

An air distribution system that includes a plenum. The plenum has a top layer having one or more top layer corrugations; a bottom layer having one or more bottom layer corrugations; and an open space formed between the top layer and the bottom layer. The one or more top layer corrugations and the one or more bottom layer corrugations are spaced apart and oppose one another, and when the plenum flexes, the one or more top layer corrugations contact the one or more bottom layer corrugations.