Plenum

A plenum is an enclosed space or chamber in an HVAC system, typically located between the air handler or furnace and the ductwork. It serves as a central hub where conditioned air (heated or cooled) is collected and then distributed to various ducts that lead to different rooms or locations within the building. There are two types of plenums: supply plenums, which deliver air to the ducts, and return plenums, which collect air from the rooms to be reconditioned. This system helps ensure even airflow throughout the HVAC system.