While structured cabling contractors are very familiar with plenum cable, most business owners don’t learn about this type of cable until they are having a new facility constructed or are in the process of updating the voice and data network cabling in an existing structure.  Here is what you need to know about plenum cable and how it is used in the design of your cabling network.


The name of plenum cable refers to the space found between the actual ceiling of a structure and the dropped ceiling that the building occupants actually see.  That space is known as the plenum and is often used for running air conditioning and heating duct work.  The plenum is also ideal for running cabling from one office to another with relative ease.  In some cases, the cable installers will suspend the cable above the duct work. Other designs call for running the cabling adjacent to the ducts as they branch off into different rooms in the building.

What makes plenum cable so special is the casing. The jacket of this type of cable is specially formulated to be fire retardant.  This is because the cable is typically not surrounded with much in the way of exterior insulation.  The plastic casing or jacket must comply with governmental standards that ensure the wiring is self contained and not likely to create a fire hazard.  In the United States, those standards are set by Article 800 of the National Electrical Code.  This means that the cable must have a smoke density and a level of flammability that is in line with the provisions set forth by Underwriters Laboratories and the National Fire Protection Association.

Using plenum cable can help to reduce network cabling costs by making it easier to run cable safely through the open space above dropped ceilings.  You save time and money in comparison to attempting to tear into walls and run the cable through small crawl spaces. In addition, cable installers can position the cable so that fire marshals and others can easily inspect it when and as necessary.  As a bonus, the cable is sturdy and likely to hold up to the constant streaming of inbound and outbound data. Thanks to the nature of the cabling, your network is less likely to experience some sort of mechanical failure.