Space between the structural ceiling slab and the finished ceiling.
The space between the ceiling and the floor or roof above.
An air compartment maintained under pressure, and connected to one or more ducts.
The space between acoustic tile in a suspended ceiling and the underside of the floor above.
An air compartment or chamber to which one or more ducts are connected and that forms part of an air distribution system. NOTE: The definition of plenum is not intended to apply to the space above a suspended ceiling that is used for environmental air referred to in NFPA 70-2002 300.22(C).
A heat exchanger using forced air convection to remove heat from an electronics assembly.
The ceiling plenum is the volume defined by the area above the back of the ceiling tile, and below the bottom of the structural slab above. Within this plenum is usually found a combination of HVAC ducts, electrical and electronic conduits, water pipes, traditional masking sound speakers, etc.
The main supply air or return air duct leading from a heating or cooling unit.
A connection chute or duct used in heating or ventilation ducting. Usually the point of connection between the heating unit and the main ducting system or the ducts and the diffusers.
An air-handling space such as that found above drop-ceiling tiles or in raised floors. Also, a fireĀcode rating for indoor cable.
A part of an HVAC system, the main air duct supply or return air, open plenum as expressed when using the space above a ceiling or below a floor as the air return.
A space or enclosure in which air or other gas is at a pressure greater than that of the outside atmosphere.
A space within the building created by building components, designed for the movement of environmental air (a space above a suspended ceiling or below an access floor).
A chamber at which air or gas is held at higher than ambient pressure.
In modern buildings, the ducts carrying the heat return are not metal ducts but are actually part of the ceiling. This is called plenum ceiling. If you run cabling through a plenum ceiling, you are not to use cabling sheathed in PVC (polyvinyl chloride). When it burns, PVC emits a toxic smoke. Plenum cable is low smoking so that if there is a fire in your building it won't be a hazard. Plenum cable is often made of Teflon, so it is typically more expensive than normal cabling.
A chamber, located between the throttle body and the runners of an intake manifold, used to distribute the intake charge evenly and to enhance engine breathing.
(1) Container designed to contain compressed gas, when the pressure surrounding the container is less than that within. (2) HVAC system accumulation and distribution chamber for connection of ducts.
Air compartment connected to a series of ducts. For example, a ceiling plenum is the space above the suspended ceiling and below the floor above that is used as part of the air distribution system.
piece of ductwork that connects the air handler to the main supply duct.
The space between the ceiling of one floor and the surface of the floor above. HVAC ducts, VAV boxes, pipes, lighting fixtures and other building equipment is generally located in the plenum space. HVAC systems with air distribution can use the plenum for returning air to the fan system.
The area between the access floor panels and the concrete slab. Typically used as an air duct and a cableway for the data center. Can also refer the area above the suspended ceiling and the concrete slab above.
The air handling space between the walls, under structural floors, and above drop ceilings used to circulate and otherwise handle air in a building. Such spaces are considered plenums only if they are used for air handling. Work spaces are generally not considered plenums.
1. A chamber containing air under pressure. 2. A chamber containing a gas such as air or an air/fuel mixture under higher than atmospheric pressure.
A space between the aquarium bottom and substrate, created by supporting the substrate above the bottom using UGF plates or some other support structure. Used to keep Nitrate levels low in a saltwater aquarium. Water and organic waste diffuses down into the plenum where the wastes concentrate. Nitrifying bacteria in the upper levels of the substrate use the oxygen and produce nitrate in the water as it moves down into the space. Denitrifying bacteria living in the oxygen-poor lower levels of the substrate slowly convert Nitrate into harmless nitrogen gas.
The space within walls or ceilings that is available for distribution of services.
an enclosed space in which the air pressure is higher than outside
a chase, typically an HVAC return or supply, be it ducted or unducted
a form of biological substrate filtration which removes organic contaminants
a gap or void space underneath the one to four inches of live sand at the bottom of the tank
a large chamber on the engine side of the throttle body that helps to even out the pulses in the inlet tract by providing a buffer of incoming air
a large space through which the air must travel, lined with absorbent material
a physical water space underneath a deep bed of sand
a space used to circulate environmental air, either supply air or return air
a space within a building that is used for the movement of environmental air
The air return path of a central air handling system, either ductwork or open space over a dropped ceiling.
A completely filled space.
An air-filled space in a structure, especially one that receives air from a blower for distribution as part of a ventilation system
Air flow passage made of duct board, metal, drywall or wood. Joins supply and return ducts with HVAC equipment.
In some buildings, the entire space above the drop ceiling is used as a return air pathway instead of a set of ducts. Therefore air circulated within that space gets distributed throughout the floor, or the building. If a cable located in an open air plenum has a PVC jacket and catches fire, the toxic fumes would spread throughout the entire floor via the open plenum, thereby suffocating or at least impairing people's ability to get out of the building. To overcome this, some cables are coated with Teflon to prevent the spread of flame and toxic fumes. Individual states and provinces regulate what types of cables are acceptable as a minimum standard. Extreme care must be taken by the installer and designer to ensure the proper cables are specified and installed
A building space where environmental air moves but wiring is also allowed. A suspended ceiling is a good example.
The space between the ceiling of a room and the structural floor above.
An enclosure that is part of the air-handling system and is distinguished by having a very low air velocity. A plenum often is formed in part or in total by portions of the building.
An enclosure in which air or other gas is at a pressure greater than that outside the enclosure.
A sealed chamber at the inlet or outlet of an air handler. The duct attaches to the plenum.
Unducted air compartment used to return air to central air handling unit.
An air-return area in a HVAC system. Plenum is NOT a type of cable coating, but rather a rating of cable for use in a 'plenum' area. Some plenum grade cable is PVC jacketed.
Air compartment connected to a duct or ducts.
A chamber that houses environmental air transfer.Plenum-rated cable is required in such locations.
A compartment or chamber to which one or more air ducts are connected and that forms part of the air distribution system.
an enclosed space into which the air from forced air heating or cooling equipment is blown directly. The main distribution ducts are connected to the plenum to distribute the air throughout the home.
A designated area used for transport of environmental air as part of the air distribution system. Because it is part of the air distribution system, cables installed in this space require a higher fire rating.
A CHAMBER WHICH CAN SERVE AS A DISTRIBUTION AREA FOR HEATING AND COOLING SYSTEMS, GENERALLY LOCATED BETWEEN A FALSE CEILING AND THE ACTUAL CEILING OR ON AN HVAC UNIT ITSELF.
A type of network cable used thorough air ducts. The sheathing surrounding the cable is made from polymers that do not give off toxic or carcinogenic fumes when burned. Plenum-rated cable is intended to prevent the spread of hazardous fumes, not to prevent the spread of a fire itself. Plenum cable costs about 4 times that of regular CAT5 cable.
Airflow passage made of duct board, metal, drywall, or wood. Joins supply and return ducts with HVAC equipment. Genz-Ryan makes all plenums of metal.
The main hot-air supply duct leading from a furnace.
Pressure equalizing chamber.
Chamber or container for moving air under a slight positive pressure to which one or more ducts are connected.
The space between a hanging ceiling and the floor above or roof; usually contains HVAC ducts, electrical wiring, fire suppression system piping, etc.
Chamber or space forming a part of an air conditioning system.
box on furnace from which ducts run to outlets.
The air handling space between walls, under structural floors, and above drop ceilings, which can be used to route intrabuilding cabling.
An enclosure through which gas or air passes at relatively low velocities.
The main heat distribution box attached to a forced air furnace duct system.