What is the function of a diffuser in a PCA system?

The function of a diffuser in a PCA system is to distribute the conditioned air evenly throughout the aircraft cabin, preventing drafts and ensuring consistent temperature distribution. A diffuser is a component designed to reduce the velocity of the incoming air and spread it out over a wider area. Without diffusers, the high-velocity air stream from the PCA hose would create localized cold or hot spots and uncomfortable drafts for passengers. Diffusers are typically located in the cabin ceiling or sidewalls and are designed to direct the airflow in a specific pattern to maximize comfort. By distributing the air evenly, diffusers help to maintain a uniform temperature throughout the cabin, creating a more pleasant environment for passengers and crew.