A PLENUM area is the air return for an air conditioning system. In most buildings, the PLENUM area above a drop ceiling is used as the source of air for the air conditioning systems. Wire and cable are usually installed in the same area, and if that wire burns during a fire, it would emit toxic fumes. The fumes could carry to the rest of the building through the air conditioner, and, as a result, the fumes could harm others.
PLENUM cables are manufactured and tested to ensure the cable will not be the fuel to a fire. There are many materials that meet Plenum specifications. The most common is Teflon TM by DuPont. The materials required to pass PLENUM fire test specifications usually cause a price increase over non-plenum-rated cables. Usually, PLENUM fire resistant rated cables are two-three times the cost of PVC versions.
PLENUM cable tends to be a little more difficult to install because it sometimes will “kink” more readily during installation, and, it is more difficult to “strip” than PVC cable.
PVC means polyvinyl chloride, and it is a common plastic cable insulation or jacket. Special additives can be added to PVC to make it flame-retardant to meet plenum specifications in some installations.
For fire safety and code compliance concerns, choose PLENUM rated cable. If fire safety is not any concern or local code requirement, choose PVC for ease of installation and lower cost.