Plenum cable and riser cable are both types of data cables that are used in building construction for networking and communications systems. The main difference between the two is the location where they are typically installed.
This following table summarizes the key differences between Riser and Plenum Cat6 cables.
| Feature | Riser Cat6 Cable | Plenum Cat6 Cable |
|---|---|---|
| Primary Use | Used in vertical runs through elevator shafts or between floors of a building. | Used in plenum spaces of buildings (areas used for air circulation for heating and air conditioning systems). |
| Material | Typically made from PVC (Polyvinyl Chloride). | Made from fire-retardant material, usually FEP (Fluorinated Ethylene Propylene) or low-smoke PVC. |
| Flame Resistance | Has a degree of flame resistance but is not as high as plenum-rated cables. | High flame resistance and does not emit toxic smoke when burned. |
| Smoke Emission | Emits more smoke compared to plenum cables when exposed to fire. | Low smoke emission in case of fire, reducing the risk to individuals and equipment. |
| Cost | Generally less expensive than plenum-rated cables. | More expensive due to the materials used for fire resistance and low smoke production. |
| Code Compliance | Complies with fire safety codes for riser applications but cannot replace plenum cables in plenum spaces. | Meets stricter fire safety standards, making it suitable for use in plenum spaces where air circulation could spread toxic smoke. |
| Installation Environment | Ideal for vertical runs in non-plenum areas, such as between floors. | Necessary in spaces that are part of the building’s air circulation system, like above drop ceilings or below raised floors. |
| Flexibility | Similar to plenum cables but the material can be slightly stiffer due to PVC. | Tends to be more flexible due to the materials used, which can aid in installation. |
| Signal Attenuation | Comparable signal attenuation to plenum cables, suitable for high-speed data. | Similar signal attenuation, ensuring reliable high-speed data transmission. |
| Safety Considerations | Should not be used as a substitute for plenum cables in air handling spaces due to higher smoke emission. | The preferred choice for air handling spaces due to its low toxicity and smoke production during a fire. |
Plenum cable or CMP is typically made of materials that are more fire-resistant than those used in other types of cables. This is because plenum cable is installed in the plenum space of a building, where air is circulated for heating and cooling. In the event of a fire, the plenum space can act as a chimney, allowing smoke and toxic gases to quickly spread throughout the building.
The jacket of plenum cable is made of a flame-retardant material, such as a Low Smoke Zero Halogen (LSZH) material, Teflon or FEP. These materials release minimal smoke and no halogens when exposed to high temperatures, which helps to reduce the spread of toxic smoke and gases in the event of a fire.
The conductors inside plenum cable are made of copper or aluminum and are coated with a fire-retardant material to help slow the spread of a fire.
In summary, plenum cable is made with fire-resistant materials, such as LSZH, Teflon or FEP for the jacket and the conductors inside are made of copper or aluminum coated with fire-retardant materials. These cables are used in environments where the release of toxic or corrosive smoke or gases could pose a serious threat to people and equipment, such as in public buildings, transportation systems, and data centers.
Riser cable or also CMR (Communications Riser), on the other hand, is designed to be installed in a vertical shaft, known as a riser, that runs between floors in a building. Riser cable is used to connect different floors in a building and does not need to be fire-resistant. Riser cables are commonly used in commercial and industrial buildings, and in particular in multi-story buildings, to connect equipment and devices between floors. They are also used in data centers, where they are used to connect servers, switches, and other networking equipment between different levels of the facility. In addition to this, Riser Cables are also used in the elevator shafts, stairwells and in other areas where a vertical run of cable is required.
In summary, Plenum cable is fire-resistant cable for use in plenum spaces and Riser cable is for use in vertical shafts between floors.
Why is Plenum Cable expensive?
Plenum cable is typically more expensive than other types of data cables because of the materials and manufacturing process used to make it.
First, the materials used to make plenum cable, such as the flame-retardant jacket and the fire-retardant coating on the conductors, are more expensive than those used in other types of cable. This is because these materials are specifically designed to be more fire-resistant than other materials, which is a key requirement for plenum cable.
Second, the manufacturing process for plenum cable is more complex and time-consuming than that for other types of cable. This is because plenum cable must be tested to ensure that it meets strict fire-resistance standards. The manufacturing process may include additional steps such as special testing, inspection and certification that increases the cost of production.
Finally, the demand for plenum cable is usually lower than other types of cable, due to the specific application and regulations that require it, which results in the cost being higher.
Ontario fire code for low voltage cabling
The Ontario Fire Code (OFC) regulates the installation and maintenance of low voltage cabling in the province of Ontario, Canada. The OFC sets out requirements for the installation and use of electrical equipment and wiring, including low voltage cabling, in order to minimize the risk of fire.
According to the OFC, low voltage cabling must be installed in accordance with the Canadian Electrical Code (CEC) and the manufacturer’s instructions. Additionally, the OFC requires that low voltage cabling be installed in a manner that prevents the spread of fire and smoke, and that it be constructed of materials that do not contribute to the spread of fire.
The OFC also requires that low voltage cabling be installed in a manner that will not interfere with the operation of fire protection systems, such as sprinklers and smoke alarms.
In addition to this, the OFC also has specific requirements for the use of LSZH (Low Smoke Zero Halogen) cables in certain areas, such as in transportation systems, buildings that are used for assembly or care of persons, and buildings that are used for residential or personal care occupancies.
It is the responsibility of the building owner, or their representative, to ensure that low voltage cabling is installed and maintained in compliance with the OFC.