An air conduit for a respiratory therapy device comprises a first end, a second end, and a tube portion, wherein the tube portion comprises a tube wall and an auxiliary structure, such as a rib. The air conduit may deliver a flow of air from a respiratory therapy device or a humidifier to a patient interface. The air conduit may comprise a plurality of auxiliary structures, some of which may consist of a polymeric material, and some of which may comprise a polymeric material and an electrical conductor. An auxiliary structure may be a helical rib extending across a length of the tube portion.
