What is the function of a plenum in an HVAC system?

A plenum serves a crucial role within an HVAC system by acting as a central distribution chamber for conditioned air. Its primary function involves receiving air from the air handling unit or furnace and then channeling that air into the ductwork for distribution throughout the building. The plenum collects the air in a centralized location, which maximizes efficiency by ensuring uniform airflow to different areas of the structure.

In this context, the plenum can either be a supply plenum that distributes heated or cooled air into the duct system, or a return plenum that collects air from the occupied spaces and directs it back to the HVAC system for reconditioning. This centralization helps maintain consistent temperature control across various rooms and enhances overall system performance. Its design is integral to the effectiveness of the entire HVAC system, allowing for better airflow management and energy efficiency.