What is plenum definition?

A plenum is a space or chamber used in HVAC (Heating, Ventilation, and Air Conditioning) systems to distribute air. It is a part of the air handling system. The plenum is a duct or space where air is circulated through by the HVAC system. It is used to circulate air from the HVAC system to the rest of the building, and helps to move hot or cold air effectively.

Plenums are typically located above ceilings or in the space between floors, and are often used to connect multiple HVAC components like ducts, air filters, and grilles. The plenum is also used as a space for return air to flow back to the HVAC unit, getting warmed or cooled again before being released back into the building.

In short, a plenum is an essential part of an HVAC system as it is responsible for circulating air throughout a building, ensuring that the conditioned air reaches all necessary areas.