PLENUM CHAMBER INSERT FOR PATIENT INTERFACE

The present invention discloses a plenum chamber insert for a patient interface for providing a flow of air at a therapeutic pressure to a patient for breathing, the plenum chamber insert comprising: a frame comprising: a plenum chamber insert port; an exterior surface; and a first channel recessed into the frame and below the exterior surface; and a heat and moisture exchanger (HMX) material positioned inside of the frame, the HMX material configured to receive and retain water from gas exhaled by the patient and to desorb retained water into the flow of air at the therapeutic pressure passing through the HMX material during use, wherein the first channel extends radially inward along the exterior surface and towards the plenum chamber insert port to form a flow path that allows air to travel around the frame without passing through the HMX material.