"Plenum" is a Latin word meaning "fullness" or "completeness". It often refers to a space or chamber filled with air at atmospheric pressure, typically used in air conditioning systems.
Here are some examples of how "plenum" is used:
* Plenum chamber: A space in a building's ceiling or floor used to distribute air.
* Plenum return: A duct that carries air back to the air handler from a plenum chamber.
* Plenum fire suppression system: A system that uses a fire-suppressing agent to extinguish fires in a plenum.
It's important to note that while "plenum" is often used in the context of HVAC systems, it can also be used more broadly to refer to a state of fullness or completeness in other contexts.