What is a Plenum-Rated Cable?

A plenum is a space between the structural ceiling and a drop-down ceiling used for air circulation for heating, cooling, and ventilation. Plenum-rated cables have special insulation that makes them fire-resistant and non-toxic during a fire condition. If your space has a plenum ceiling, the cables used in the ceiling space need to be plenum-rated to avoid a building code violation. 

Plenum-rated cables are more expensive than non-plenum-rated cables. Sometimes, even for very experienced technicians, it can be very difficult to tell if a ceiling is a plenum ceiling, especially in older buildings. When in doubt, we use plenum-rated cables despite their higher cost to ensure the safety and security of our clients.