Table of Contents
When should plenum cable be used?
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. This qualifies this ceiling as a plenum ceiling, and all the cables that go through that ceiling must be plenum rated.
What are plenums in HVAC?
A plenum is an air-distribution box attached directly to the supply outlet of the HVAC equipment that heats or cools the air to make the house comfortable. The ductwork that distributes the heated or cooled air to individual rooms of the house connects to the plenum.
What is an HVAC air device?
HVAC systems are milestones of building mechanical systems that provide thermal comfort for occupants accompanied with indoor air quality. Primary HVAC equipment includes heating equipment, ventilation equipment, and cooling or air-conditioning equipment.
What is a plenum used for?
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 is the difference between CAT5e and CAT6?
The main difference between CAT5e and CAT6 cable lies within the bandwidth, the cable can support for data transfer. CAT6 cables are designed for operating frequencies up to 250 MHz, compared to 100 Mhz for CAT5e. This means that a CAT6 cable can process more data at the same time.
What is CMR cable?
CMR cable, often called “riser-rated cable,” is constructed to prevent fires from spreading floor to floor in vertical installations. It can be used when cables need to be run between floors through risers or vertical shafts. Even higher rated is CMP (plenum-rated cable).
What are duct plenums?
A plenum box is an important part of your home’s HVAC system, which connects to ducts to distribute heated or cooled air throughout your home. Generally, an HVAC system includes two plenum boxes, a supply and a return plenum. These plenums feature insulated lining for reduced noise and efficient air delivery too.
Is MC cable plenum rated?
Yes it is rated for a plenum ceiling– as it is called. It also can traverse an actual duct plenum.
What kind of work is HVAC?
An HVAC or HVACR technician installs, repairs, or maintains heating, ventilation, air conditioning, and refrigeration systems that control the temperature and air quality in buildings. In some cases, an HVAC technician may specialize in installation, repair, or maintenance.
What is unitary HVAC equipment?
Unitary heating, ventilation, and air conditioning (HVAC) systems, which combine heating and cooling in one unit (packaged) or a few sections (split), are one of the most common technologies used for space conditioning in commercial buildings.
What is riser cable?
What is Riser Cabling? Riser cables, designated as CMR by the NEC, is cabling that meets the fire resistivity standards for installation within a vertical riser or within an area designated specifically as a non-plenum environment.
What is the difference between Cat6 and Cat6 plenum?
Plenum cables have the strictest flame ratings with higher cost, since they have a special coating on the wire. They are usually used in plenum spaces for preventing flame spreading and reduce the smoke amount. For example, plenum rated Cat6 and riser rated Cat6 perform the same in the data transmission.
Why do you use plenum cable in air ducts?
Article 800 of the National Electrical Code (NEC) states that plenum cable should ALWAYS be used in plenum airspaces and air ducts to slow down the spread of flames and reduce smoke and toxic fumes from circulating throughout the building.
When to use CMR or non-plenum HVAC cable?
You must use CMR (riser-rated) cable when running cable between floors through risers or vertical shafts. Some buildings with HVAC systems have return air ducts which transport air back outdoors. If there are no leakages and the space above a drop ceiling is not circulating air, you may use non-plenum cable.
When to use non plenum rated cable waveform?
If there are no leakages and the space above a drop ceiling is not circulating air, you may use non-plenum cable. Of course, this is only true as long as the cable is not running inside the air ducts themselves. Non-circulating plenum airspace may become active due to disconnected ductwork
Is the HVAC system an extension of the DHC network?
Although HVAC is executed in individual buildings or other enclosed spaces (like NORAD’s underground headquarters), the equipment involved is in some cases an extension of a larger district heating (DH) or district cooling (DC) network, or a combined DHC network.