What is the difference between plenum and non plenum ceiling?
Plenum cables are run in that space (the plenum) to minimize the hazard from burning cables in a fire. Non-plenum, often called riser cables are less expensive and are used in spaces that do not intermingle with normal air circulation: attics, closed walls, conduit, etc.
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 does a plenum do?
Plenum boxes are usually situated on either side of the fan or heat exchanger and have the important function of bringing in, distributing, and removing air. They are the air’s first stop after being heated or cooled and its last stop before going back into your AC, heat pump, or furnace.
Is an open ceiling considered a plenum?
If you have a large wall or ceiling return air grate; remove and see if there the air is channeled through sheet metal ducting. 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.
What is considered plenum?
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.
Where is plenum required?
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.
Are plenums necessary?
Q: Is a plenum necessary? A: In modern forced-air HVAC systems, you must have a plenum installed.
What is plenum ventilation?
Definition of plenum ventilation : a system of ventilation that applies the motive force at the inlets, drives the air through the rooms which become plenums, and avoids the incoming of cold drafts.
What is the space above the ceiling called?
If there is a horizontal ceiling that is attached to the tie-beams of a roof, creating a space above it, the space above is called an “attic” whether used as a living, storage, or simply ventilation space.
Do houses have plenum?
Plenum spaces in any building are those spaces that have regular air circulation. These spaces are for air-conditioning and heating in any infrastructure. Generally, spaces between the structural floor or a dropped ceiling are plenum spaces.
What is considered a plenum?
What is a ceiling plenum floor?
The floor of a ceiling plenum is the ceiling of the zone below so you will often define the plenum floor as ‘Ceiling tiles’ construction or similar. If the building you are modelling has more than one plenum zone, each serving multiple zones you should use zone plenums.
What is a plenum space?
Plenum space. A plenum space is a part of a building that can facilitate air circulation for heating and air conditioning systems, by providing pathways for either heated/conditioned or return airflows, usually at greater than atmospheric pressure. Space between the structural ceiling and the dropped ceiling or under a raised floor is…
Can plenum cable be used above ceiling tiles?
Even if a cable is only used temporarily, only plenum cables should be used above ceiling tiles or below dropped floors… it is surprising how permanent “temporary” fixes can be. Plenum cables use treated jackets, usually low-smoke PVC (polyvinyl chloride) or FEP (fluorinated ethylene polymer).
Why paint an open plenum ceiling black?
Painting an open plenum ceiling black creates a lot of drama and, if carefully planned, can draw highly focused attention to displays. There are many design Issues to recommend an open ceiling, not the least being that they increase the ceiling height, thereby the amount of usable space in a store.