Floor Plenum Design

Plenums are air compartments or chambers that are sometimes found in buildings either above suspended ceilings in the gap between the ceiling and the floor slab or below raised floors in the gap between the raised floor and the floor slab.

Floor plenum design.

Within the underfloor plenum it is always desirable to the extent possible to have the supply air flow freely to the supply outlets. It is important that conditioned air in a floor plenum flows into the occupied zone and does not leak into cavities risers stairwells heating trenches or other adjacent zones. Plenum contents can have a major impact on the raised floor plenum performance. The number of plenum inlet locations is a function of the size of control zones access points available in the building amount of distribution ductwork used under the floor and other design issues.

Warm air from ducts is discharged into the underflow plenum rather than directly. The source of heat is the downflow or counterflow warm air furnace commonly used to force air into under slab ductwork. A floor plenum is a void between a building s floor structure and a raised access floor used for distributing conditioned air to the spaces above. The basic arrangement in a plenum floor is that the floor is supported above the slab to leave space below for the heating plenum and utilities.

The following list of questions is a good place to start in this process. Airfixture s underfloor air distribution system takes advantage of pressurized underfloor plenum spaces to provide air conditioning heating and ventilation. One of the main advantages of this setup is that plenum air supplies require less fan power to distribute air than through ducts improving efficiency and thus requiring less.