Table of Contents
What is a plenum and where would I find one?
In building construction Plenum is a separate space provided for air circulation for heating, ventilation, and air-conditioning. It is commonly found in the space between the structural ceiling and a drop-down ceiling or under a raised floor.
What is a plenum rated ceiling?
Plenum spaces are the open spaces above the ceiling or below the floor that are used for air circulation. Technically, any ductwork is considered a plenum space too. Any cable that you run through plenum spaces must be plenum rated, even wiring used for information transfer, like Cat5 wiring.
Is an open ceiling considered a plenum?
Any ceiling space that has open ductwork, including open space or vent between rooms protected by a fire wall, is concidered a plenum ceiling.
Where would you find a plenum cable?
Plenum cable is mandated to be installed in any “air handling” space. For example, most large office buildings use the ceiling to return air to the AC unit. This qualifies this ceiling as a plenum ceiling, and all the cables that go through that ceiling must be plenum rated.
What is the difference between a plenum and 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.
How does a plenum work?
A plenum is an air-distribution box attached directly to the supply outlet of the HVAC equipment that heats or cools the air to make the house comfortable. The HVAC equipment has a blower that forces heated or cooled air into the supply plenum and from the plenum into the rooms through the supply duct system.
How does a plenum ceiling work?
Plenum ceilings use the area between the dropped ceiling and the floor slab above as a return air path, but when these dropped ceilings are removed, the plenum area is reduced and can restrict the flow of return air.
What is plenum vs non plenum?
Plenum-rated cable has been manufactured to withstand higher temperatures in the event of a fire and does not cause the same level of smoke or toxicity when burning. Non-plenum does not have these characteristics, and as a result costs much less (usually half as much).
What’s the difference between plenum and non-plenum?
What is the difference between plenum and non-plenum cable?
Is a plenum necessary?
If there is no sheet metal duct; just the open ceiling or wall space, then you are required by law to use Plenum Rated cable. The lack of wall or ceiling return air grates is usually a sure sign that you require Plenum Rated Cable. Computer Rooms typically use a raised flooring system for the server racks.