How is plenum size determined?
Also know, how does a plenum work?
A supply plenum works by taking in the new cool or warm air from the heater or air conditioning system and, in turn, distribute it throughout the building using the HVAC's ductwork. A return plenum takes in that used air and, using the ductwork, sends it back to the core HVAC system.
Herein, what is the difference between a plenum and a duct?
As nouns the difference between duct and plenum is that duct is a pipe, tube or canal which carries air or liquid from one place to another while plenum is (physics) a space that is completely filled with matter.
In building construction, a plenum (pronounced PLEH-nuhm, from Latin meaning full) is a separate space provided for air circulation for heating, ventilation, and air-conditioning (sometimes referred to as HVAC) and typically provided in the space between the structural ceiling and a drop-down ceiling.