Plenums

• A plenum space is an area used for airflow in a building. Plenum spaces are kept separate from functional spaces and are often situated above the ceiling but below the structural ceiling, or below rooms and hallways. Plenum spaces are not part of the duct system of a building; instead, they are part of the structural makeup.
  
  

Dampers

• From an architectural standpoint, a damper is a metal plate, sometimes equipped with a valve for opening and closing, put in place to control the flow of air. More complex dampers can draw air out or pump air into a section of a building.
  
  

Function

• Dampers are used throughout buildings, with the number of dampers employed depending on the size of the structure. Dampers are not used only in plenums; they can be used in a variety of locations. A plenum damper is one specifically used in a plenum space.