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.
Non-plenum cable or “polyvinyl chloride” cable is often less much less expensive than plenum cable. … Larger building like warehouses and distribution centers with less people tend to lean toward non-plenum rated cable, whereas hospitals and schools will tend to lean towards the safer chose with plenum cable.
Thereof, What is considered a plenum space?
Simply stated, the NEC defines a plenum area as, “a compartment or chamber to which one or more air ducts are connected and that forms part of the air distribution system.” It also references, “the space over a hung ceiling used for environmental air-handling purposes,” and, “areas beneath raised floors for information …
Also to know is, Why would you use plenum cable? Why Use Plenum Cable? Plenum rated cable has a special insulation that has smoke and low flame characteristics. It is mandated to be installed in any “air handling” space. For instance, most large office buildings use the ceiling to return air to the AC unit.
Subsequently, question is, Where is plenum rated cable required? Most building codes mandate that only plenum-rated (CMP) cable be used in “plenum spaces” and air ducts. For large public spaces like hospitals, schools, and airports, building codes in some cities and towns mandate plenum cable even for non-plenum spaces.
Also, How do I know if I have a plenum ceiling?
Space between the structural ceiling and the dropped ceiling or under a raised floor is typically considered plenum; however, some drop-ceiling designs create a tight seal that does not allow for airflow and therefore may not be considered a plenum air-handling space.
What is a plenum ceiling?
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’s the difference between plenum and non plenum?
Non-plenum cable usually serves to run through non-air circulating areas. Non-plenum includes riser rated cable, and other rated cables like CM cable, etc. … The fire rating of riser cable is not as strict as the plenum cable since plenum cable uses less hazardous and lower smoke materials.
Why do you need plenum cable?
Why Use Plenum Cable? Plenum rated cable has a special insulation that has smoke and low flame characteristics. It is mandated to be installed in any “air handling” space. For instance, most large office buildings use the ceiling to return air to the AC unit.
What is considered a plenum ceiling?
Simply stated, the NEC defines a plenum area as, “a compartment or chamber to which one or more air ducts are connected and that forms part of the air distribution system.” It also references, “the space over a hung ceiling used for environmental air-handling purposes,” and, “areas beneath raised floors for information …
What defines a plenum space?
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.
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?
Non-plenum cable usually serves to run through non-air circulating areas. Non-plenum includes riser rated cable, and other rated cables like CM cable, etc. … The fire rating of riser cable is not as strict as the plenum cable since plenum cable uses less hazardous and lower smoke materials.
Why is plenum cable more expensive?
When running cables within plenum spaces, plenum cables are a must. Because plenum cables are built to a higher fire resistance standard than riser cables, plenum cabling is more expensive than riser cabling.
What does plenum area mean?
Simply stated, the NEC defines a plenum area as, “a compartment or chamber to which one or more air ducts are connected and that forms part of the air distribution system.” It also references, “the space over a hung ceiling used for environmental air-handling purposes,” and, “areas beneath raised floors for information …
What is the difference between plenum and riser cable?
Plenum rated cables are used in plenum areas meant for use in commercial and residential spaces. … Riser rated cables run between floors through cable risers or in elevator shafts in non-plenum areas. These cables must also self extinguish and prevent the flame from traveling up the cable in a vertical burn test.
Why is plenum rated cable?
Plenum rated cable has a special insulation that has low smoke and low flame characteristics. 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.
Can riser cable be used in plenum?
Cable that is run between floors in non-plenum areas is rated as riser cable. The fire requirements on riser cable are not as strict. Thus, plenum cable can always replace riser cable, but riser cable cannot replace plenum cable in plenum spaces.
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