婷婷

Chapter 1 General
1-1 Introduction.
An air duct system has the potential to convey smoke, hot gases, and flame from area to area and to supply air to aid combustion in the fire area. For these reasons, fire protection of an air duct system is essential to safety to life and the protection of property. However, an air duct system抯 fire integrity also enables it to be used as part of a building抯 fire protection system. (See Section 1-4.)
1-2 Scope.
This standard shall apply to all systems for the movement of environmental air in structures that serve the following:
(1) * Spaces of over 25,000 ft3 (707.9 m3) in volume
(2) * Buildings of Types III, IV, and V construction over three stories in height, regardless of volume
(3) * Buildings and spaces not covered by other applicable NFPA standards
(4) * Occupants or processes not covered by other applicable NFPA standards
1-3 Purpose.
1-3.1
This standard prescribes minimum requirements for safety to life and property from fire. These requirements are intended to accomplish the following:
(1) Restrict the spread of smoke through air duct systems within a building or into a building from the outside
(2) Restrict the spread of fire through air duct systems from the area of fire origin whether located within the building or outside
(3) Maintain the fire-resistive integrity of building components and elements such as floors, partitions, roofs, walls, and floor- or roof-ceiling assemblies affected by the installation of air duct systems
(4) Minimize the ignition sources and combustibility of the elements of the air duct systems
(5) Permit the air duct systems in a building to be used for the additional purpose of emergency smoke control
1-3.2
Nothing in this standard is intended to prevent the use of new methods or devices, provided that sufficient technical data are submitted to the authority having jurisdiction to demonstrate that the proposed method or device is equivalent in quality, strength, durability, and safety to that prescribed by this standard.

搜索更多相关主题的帖子: 空调英语

婷婷

1-3.3
The provisions of this standard are not intended to be applied retroactively. Where a system is being altered, extended, or renovated, the requirements of this standard shall apply only to the work being undertaken.
1-4* Smoke Control.
1-5* Maintenance. (Reserved.)
1-6 Definitions.
Air Cleaner. A device used to reduce or remove airborne solids from heating, ventilating, and air-conditioning systems by electrostatic means.
Air Connector.* A conduit for transferring air between an air duct or plenum and an air terminal unit or an air inlet or air outlet.
Air Distribution System. A continuous passageway for the transmission of air that, in addition to air ducts, can include air connectors, air duct fittings, dampers, plenums, fans, and accessory air-handling equipment but that does not include conditioned spaces.
Air Duct. A conduit for conveying air.
Air Duct Covering. A material such as an adhesive, insulation, banding, a coating(s), film, or a jacket used to cover the outside surface of an air duct, fan casing, or duct plenum.
Air Duct Lining. A material such as an adhesive, insulation, a coating(s), or film used to line the inside surface of an air duct, fan casing, or duct plenum.
Air Filter. A device used to reduce or remove airborne solids from heating, ventilating, and air conditioning.
Air Inlet.* Any opening through which air is removed from a space and returned to an air distribution system.
Air Outlet.* Any opening through which air is delivered to a space from an air distribution system.
Air Terminal Unit. An appliance receiving, conditioning, and delivering air supplied through an air distribution system.
Air Transfer Opening. An opening designed to allow the movement of environmental air between two contiguous spaces.
Approved.* Acceptable to the authority having jurisdiction.
Authority Having Jurisdiction.* The organization, office, or individual responsible for approving equipment, materials, an installation, or a procedure.
Ceiling Damper.* A device installed to limit radiant heat transfer through an air outlet or air inlet opening in the ceiling of a floor- or roof-ceiling assembly having not less than a 1-hour fire resistance rating. Such a device is described in the construction details for some tested floor- or roof-ceiling assemblies.
Combination Fire and Smoke Damper. A device that meets both the fire damper and smoke damper requirements.
Environmental Air. Air that is supplied, returned, recirculated, or exhausted from spaces for the purpose of modifying the existing atmosphere within the building.
Fan. An air moving device that creates a pressure difference causing airflow.
Fire Damper.* A device, installed in an air distribution system, that is designed to close automatically upon detection of heat, to interrupt migratory airflow, and to restrict the passage of flame.
Fire Resistance Rating.* The time, in minutes or hours, that materials or assemblies have withstood a fire exposure as established in accordance with the test procedures of NFPA 251, Standard Methods of Tests of Fire Endurance of Building Construction and Materials.
Fire Wall. A wall separating buildings or subdividing a building to prevent the spread of fire and having a fire resistance rating and structural stability.
Flame Spread Index.* A number obtained according to NFPA 255, Standard Method of Test of Surface Burning Characteristics of Building Materials.

婷婷

Limited-Combustible Material. A building construction material not complying with the definition of noncombustible material that in the form in which it is used, has a potential heat value not exceeding 3500 Btu/lb (8141 kJ/kg) where tested in accordance with NFPA 259, Standard Test Method for Potential Heat of Building Materials, and complies with (a) or (b):
(a) Materials having a structural base of noncombustible material, with a surfacing not exceeding a thickness of 1/8 in. (3.2 mm), that has a flame spread index not greater than 50; (b) Materials, in the form and thickness used, other than as described in (a), having neither a flame spread index greater than 25 nor evidence of continued progressive combustion, and of such composition that surfaces that would be exposed by cutting through the material on any plane would have neither a flame spread index greater than 25 nor evidence of continued progressive combustion. Materials subject to increase in combustibility or flame spread index beyond the limits herein established through the effects of age, moisture, or other atmospheric condition shall be considered combustible.
Listed.* Equipment, materials, or services included in a list published by an organization that is acceptable to the authority having jurisdiction and concerned with evaluation of products or services, that maintains periodic inspection of production of listed equipment or materials or periodic evaluation of services, and whose listing states that either the equipment, material, or service meets appropriate designated standards or has been tested and found suitable for a specified purpose.
Noncombustible Material. A material that, in the form in which it is used and under the conditions anticipated, will not ignite, burn, support combustion, or release flammable vapors when subjected to fire or heat. Materials that are reported as passing ASTM E 136, Standard Test Method for Behavior of Materials in a Vertical Tube Furnace at 750 Degrees C, shall be considered noncombustible materials.

婷婷

Plenum. A compartment or chamber to which one or more air ducts are connected and that forms part of the air distribution system.
Shall. Indicates a mandatory requirement.
Should. Indicates a recommendation or that which is advised but not required.
Smoke. The airborne solid and liquid particulates and gases evolved when a material undergoes pyrolysis or combustion, together with the quantity of air that is entrained or otherwise mixed into the mass.
Smoke Barrier.* A continuous membrane, either vertical or horizontal, such as a wall, floor, or ceiling assembly, that is designed and constructed to restrict the movement of smoke.
Smoke Control. A system that utilizes fans to produce pressure differences so as to manage smoke movement.
Smoke Damper.* A device within the air distribution system to control the movement of smoke.
Smoke Detector.* A device that senses visible or invisible particles of combustion.
Smoke Developed Index.* A number indicating a comparative measure derived from smoke obscuration data collected during the test for surface burning characteristics in accordance with NFPA 255, Standard Method of Test of Surface Burning Characteristics of Building Materials, that measures visible smoke.

婷婷

Chapter 2 HVAC Systems

2-1 General Requirements for Equipment.
2-1.1
Equipment shall be arranged to afford access for inspection, maintenance, and repair.
2-1.2
Equipment shall be selected and installed based on its proper application with respect to the manufacturer抯 installation instructions and listing as applicable.
2-1.3
Equipment shall be guarded for personnel protection and against the intake of foreign matter into the system.
2-1.4
Electrical wiring and equipment shall be installed in accordance with NFPA 70, National Electrical Code?
2-1.5
Air-handling equipment rooms shall meet the requirements of Section 3-1.
2-2 System Components.
2-2.1 Outside Air Intakes.
2-2.1.1
Outside air intakes shall be located to avoid drawing in combustible material or flammable vapor and to minimize the hazard from fires in other structures.
2-2.1.2
Outside air intakes shall be protected by screens of corrosion-resistant material not larger than 0.5-in. (1.27-cm) mesh.

婷婷

2-2.1.3
Outside air intakes shall be located so as to minimize the introduction of fire into the building from combustible buildings and hazardous facilities, or the intakes shall be equipped with an approved fire damper.
2-2.1.4
Outside air intakes shall be located so as to minimize the introduction of smoke into the building, or the intakes shall be equipped with an approved smoke damper. (See Section 4-3 for smoke damper operation to restrict the intake of smoke.)
2-2.2 Air Cleaners and Air Filters.
2-2.2.1
Electrostatic air cleaners shall be listed in accordance with UL 867, Standard for Safety Electrostatic Air Cleaners, and shall be installed in conformance with the conditions of the manufacturer抯 listing.
2-2.2.2*
Air filters shall be rated either as Class 1 or Class 2 in accordance with UL 900, Standard for Safety Air Filter Units.
2-2.2.3
Liquid adhesive coatings used on air filters shall have a minimum flash point of 325癋 (163癈) as determined by ASTM D 93, Standard Test Methods for Flashpoint by Pensky-Martens Closed Cup Tester.
2-2.2.4
Where air filters are flushed with liquid adhesives, the system shall be arranged so that the air cleaner cannot be flushed while the fan is in operation.
2-2.2.5
Combustible adhesive coatings shall be stored in accordance with NFPA 30, Flammable and Combustible Liquids Code.

婷婷

2-2.3 Fans.
2-2.3.1 Installation.
Fans shall be installed in accordance with the applicable NFPA standards and the manufacturer抯 instructions. Fans shall be approved for the specific installation.
2-2.3.2 Access.
Fans shall be located, arranged, and installed to afford access for inspection and maintenance.
2-2.3.3 Exposed Inlets.
Exposed fan inlets shall be protected with metal screens to prevent the entry of paper, trash, and similar foreign materials.
2-2.4 Air-Cooling and Heating Equipment.
2-2.4.1 Installation.
Heating and cooling equipment shall be installed in accordance with the applicable NFPA standards and the manufacturer抯 instructions. The equipment shall be approved for the specific installation. (See 2-3.3.1.)
2-2.4.2 Materials.
Materials used in the manufacturing of fan coil units, self-contained air-conditioning units, furnaces, heat pumps, humidifiers, and all similar equipment shall meet the requirements of 2-3.3.1 and 2-3.3.2.
Exception No. 1: Equipment tested and listed in accordance with UL 1995, Standard for Safety Heating and Cooling Equipment.
Exception No. 2: Unlisted solar energy air distribution system components shall be accompanied by supportive information demonstrating that the components have flame spread and smoke developed indexes that are not in excess of those of the air duct system permitted by this standard.
2-2.4.3 Mechanical Cooling.
Mechanical refrigeration used with air duct systems shall be installed in accordance with recognized safety practices. Installations conforming to ANSI/ASHRAE 15, Safety Code for Mechanical Refrigeration, shall be considered to be in compliance with these requirements.

婷婷

2-2.4.4 Furnaces.
Heating furnaces combined with cooling units in the same air duct system shall be installed in accordance with NFPA 31, Standard for the Installation of Oil-Burning Equipment, where oil fired, and NFPA 54, National Fuel Gas Code, where gas fired.
2-2.4.5 Duct Heaters.
Where electrical resistance or fuel-burning heaters are installed in air ducts, the air duct coverings and their installation shall comply with the provisions of 2-3.5.3. The installation of electrical duct heaters shall comply with the provisions of NFPA 70, National Electrical Code, Article 424, Part F, 揇uct Heaters.?
2-2.4.6 Evaporative Coolers.
Combustible evaporation media shall not be used.
Exception: Evaporation media meeting the requirements of 2-2.2.2 shall be permitted.
2-2.4.7 Heat Recovery Equipment.
Equipment not covered by other provisions of this standard and used for heat transfer or air movement shall be constructed so that all material in the air path meets the requirements of Section 2-2.
2-3 Air Distribution.
2-3.1 Air Ducts.
2-3.1.1
Air ducts shall be permitted to be rigid or flexible and shall be constructed of materials that are reinforced and sealed to satisfy the requirements for the use of the air duct system, such as the supply air system, the return or exhaust air system, and the variable volume/pressure air system.
2-3.1.2
Air ducts shall be constructed of the following materials:
(1) Iron, steel, aluminum, copper, concrete, masonry, or clay tile.
(2) Class 0 or Class 1 rigid or flexible air ducts tested in accordance with UL 181, Standard for Safety Factory-Made Air Ducts and Air Connectors, and installed in conformance with the conditions of listing.
Exception No. 1: Class 0 or Class 1 rigid or flexible air ducts shall not be used as vertical air ducts that are more than two stories in height.
Exception No. 2: Class 0 or Class 1 rigid or flexible air ducts shall not be used for air ducts containing air at temperatures in excess of 250?F (121废).
(3) Where the temperature of the conveyed air does not exceed 125癋 (52废) in normal service, negative pressure exhaust or return air ducts shall be permitted to be constructed of gypsum board having a maximum flame spread index of 25 without evidence of continued progressive combustion and a maximum smoke developed index of 50.
Exception: The maximum conveyed air temperature of 125癋 (52废) shall not apply to gypsum board material used for emergency smoke exhaust air ducts.

婷婷

2-3.1.3
All air duct materials shall be suitable for continuous exposure to the temperature and humidity conditions of the environmental air in the air duct.
2-3.1.4
The materials, thickness, construction, and installation of ducts shall provide structural strength and durability in conformance with recognized good practice. Air ducts shall be considered to be in compliance with this requirement where constructed and installed in accordance with the following:
(1) * SMACNA Fibrous Glass Duct Construction Standard; SMACNA HVAC Duct Construction Standards ?Metal and Flexible; or SMACNA HVAC Air Duct Leakage Test Manual, whichever is applicable
(2) ASHRAE Handbook ?HVAC Systems and Equipment
2-3.1.5
Where no standard exists for the construction of air ducts, they shall be constructed to withstand both the positive and negative pressures of the system.
2-3.2 Air Connectors.
2-3.2.1
Air connectors are limited-use, flexible air ducts that shall not be required to conform to the provisions for air ducts where they meet the following requirements.
2-3.2.1.1
Air connectors shall conform to the requirements for Class 0 or Class 1 connectors when tested in accordance with UL 181, Standard for Safety Factory-Made Air Ducts and Air Connectors.
2-3.2.1.2
Class 0 or Class 1 air connectors shall not be used for ducts containing air at temperatures in excess of 250癋 (121癈).
2-3.2.1.3
Air connector runs shall not exceed 14 ft (4.27 m) in length.
2-3.2.1.4
Air connectors shall not pass through any wall, partition, or enclosure of a vertical shaft that is required to have a fire resistance rating of 1 hour or more.
2-3.2.1.5
Air connectors shall not pass through floors.
2-3.2.2
Vibration isolation connectors in duct systems shall be made of an approved flame-retardant fabric or shall consist of sleeve joints with packing of approved material, each having a maximum flame spread index of 25 and a maximum smoke developed index of 50.
Exception: Approved flame-retardant fabric having a maximum length of 10 in. (25.4 cm) in the direction of airflow.

婷婷

2-3.1.3
All air duct materials shall be suitable for continuous exposure to the temperature and humidity conditions of the environmental air in the air duct.
2-3.1.4
The materials, thickness, construction, and installation of ducts shall provide structural strength and durability in conformance with recognized good practice. Air ducts shall be considered to be in compliance with this requirement where constructed and installed in accordance with the following:
(1) * SMACNA Fibrous Glass Duct Construction Standard; SMACNA HVAC Duct Construction Standards ?Metal and Flexible; or SMACNA HVAC Air Duct Leakage Test Manual, whichever is applicable
(2) ASHRAE Handbook ?HVAC Systems and Equipment
2-3.1.5
Where no standard exists for the construction of air ducts, they shall be constructed to withstand both the positive and negative pressures of the system.
2-3.2 Air Connectors.
2-3.2.1
Air connectors are limited-use, flexible air ducts that shall not be required to conform to the provisions for air ducts where they meet the following requirements.

婷婷

2-3.2.1.1
Air connectors shall conform to the requirements for Class 0 or Class 1 connectors when tested in accordance with UL 181, Standard for Safety Factory-Made Air Ducts and Air Connectors.
2-3.2.1.2
Class 0 or Class 1 air connectors shall not be used for ducts containing air at temperatures in excess of 250癋 (121癈).
2-3.2.1.3
Air connector runs shall not exceed 14 ft (4.27 m) in length.
2-3.2.1.4
Air connectors shall not pass through any wall, partition, or enclosure of a vertical shaft that is required to have a fire resistance rating of 1 hour or more.
2-3.2.1.5
Air connectors shall not pass through floors.
2-3.2.2
Vibration isolation connectors in duct systems shall be made of an approved flame-retardant fabric or shall consist of sleeve joints with packing of approved material, each having a maximum flame spread index of 25 and a maximum smoke developed index of 50.
Exception: Approved flame-retardant fabric having a maximum length of 10 in. (25.4 cm) in the direction of airflow.

婷婷

2-3.3 Supplementary Materials for Air Distribution Systems.
2-3.3.1
Pipe insulation and coverings, duct coverings, duct linings, vapor retarder facings, adhesives, fasteners, tapes, and supplementary materials added to air ducts, plenums, panels, and duct silencers used in duct systems shall have, in the form in which they are used, a maximum flame spread index of 25 without evidence of continued progressive combustion and a maximum smoke developed index of 50. Where these products are to be applied with adhesives, they shall be tested with such adhesives applied, or the adhesives used shall have a maximum flame spread index of 25 and a maximum smoke developed index of 50 when in the final dry state. (See 2-2.4.2.)
Closure systems for use with rigid and flexible air ducts tested in accordance with UL 181, Standard for Safety Factory-Made Air Ducts and Air Connectors, shall have been tested and listed in accordance with UL 181A, Standard for Safety Closure Systems for Use with Rigid Air Ducts and Air Connectors, or UL 181B, Standard for Safety Closure Systems for Use with Flexible Air Ducts and Air Connectors, and used in accordance with the conditions of their listings.
Exception No. 1: This requirement shall not apply to air duct weatherproof coverings where they are located entirely outside of a building, do not penetrate a wall or roof, and do not create an exposure hazard.
Exception No. 2: Smoke detectors required by 4-4.2.
2-3.3.2
Air duct, panel, and plenum coverings and linings, and pipe insulation and coverings shall not flame, glow, smolder, or smoke when tested in accordance with a similar test for pipe covering, ASTM C 411, Standard Test Method for Hot-Surface Performance of High-Temperature Thermal Insulation, at the temperature to which they are exposed in service. In no case shall the test temperature be below 250癋 (121癈).
2-3.3.3
Air duct coverings shall not extend through walls or floors that are required to be fire stopped or required to have a fire resistance rating.
Exception: Where such coverings meet the requirements of 3-4.6.4.

婷婷

2-3.3.4*
Air duct linings shall be interrupted at fire dampers to prevent interference with the operation of devices.
2-3.3.5
Air duct coverings shall not be installed so as to conceal or prevent the use of any service opening.
2-3.4 Air Duct Access and Inspection.
2-3.4.1*
A service opening shall be provided in air ducts adjacent to each fire damper, smoke damper, and smoke detector. The opening shall be large enough to permit maintenance and resetting of the device.
2-3.4.2
Service openings shall be identified with letters having a minimum height of 1/2 in. (1.27 cm) to indicate the location of the fire protection device(s) within.
2-3.4.3
Horizontal air ducts and plenums shall be provided with service openings to facilitate the removal of accumulations of dust and combustible materials. Service openings shall be located at approximately 20-ft (6.1-m) intervals along the air duct and at the base of each vertical riser.
Exception No. 1: Removable air outlet or air inlet devices of adequate size shall be permitted in lieu of service openings.
Exception No. 2: Service openings shall not be required in supply ducts where the supply air has previously passed through an air filter, an air cleaner, or a water spray.
Exception No. 3: Service openings shall not be required where all the following conditions exist:
(a) The occupancy has no process that produces combustible material such as dust, lint, or greasy vapors. Such occupancies include banks, office buildings, churches, hotels, and health care facilities (but not kitchens, laundries, and manufacturing portions of such facilities).
(b) The air inlets are at least 7 ft (2.13 m) above the floor or are protected by corrosion-resistant metal screens of at least 14 mesh (0.07 in.) that are installed at the inlets so that they cannot draw papers, refuse, or other combustible solids into the return air duct.
(c) The minimum design velocity in the return duct for the particular occupancy is 1000 ft/min (5.08 m/sec).
2-3.4.4
Inspection windows shall be permitted in air ducts provided they are glazed with wired glass. However, service openings shall be provided as required in 2-3.4.1.

婷婷

2-3.4.5
Openings in walls or ceilings shall be provided so that service openings in air ducts are accessible for maintenance and inspection needs.
2-3.4.6
Where a service opening is necessary in an air duct located above the ceiling of a floor- or roof-ceiling assembly that has been tested and assigned a fire resistance rating in accordance with NFPA 251, Standard Methods of Tests of Fire Endurance of Building Construction and Materials, access shall be provided in the ceiling and shall be designed and installed so that it does not reduce the fire resistance rating of the assembly.
2-3.5 Air Duct Integrity.
2-3.5.1
Air ducts shall be located where they are not subject to damage or rupture, or they shall be protected to maintain their integrity.
2-3.5.2
Where an air duct is located outdoors, the air duct, together with its covering or lining, shall be protected from harmful elements.
2-3.5.3
Where electrical, fossil fuel, or solar energy collection heat sources are installed in air ducts, the installation shall avoid the creation of a fire hazard. Air ducts rated as Class 1 in accordance with UL 181, Standard for Safety Factory-Made Air Ducts and Air Connectors, air duct coverings and linings shall be interrupted at the immediate area of operation of such heat sources in order to meet the clearances specified as a condition of the equipment listing.
Exception No. 1: Appliances listed for zero clearance from combustibles where installed in accordance with the conditions of their listings.
Exception No. 2: Insulation specifically suited for the maximum temperature that reasonably can be anticipated on the duct surface shall be permitted to be installed at the immediate area of operation of such appliances.

婷婷

2-3.6 Air Outlets.
2-3.6.1 General.
Air supplied to any space shall not contain flammable vapors, flyings, or dust in quantities and concentrations that would introduce a hazardous condition.
2-3.6.2 Construction of Air Outlets.
Air outlets shall be constructed of noncombustible material or a material that has a maximum flame spread index of 25 and a maximum smoke developed index of 50.
2-3.6.3 Location of Air Outlets.
2-3.6.3.1
Air outlets shall be located at least 3 in. (7.6 cm) above the floor.
Exception: Where provisions have been made to prevent dirt and dust accumulations from entering the system.
2-3.6.3.2
Where located less than 7 ft (2.13 m) above the floor, outlet openings shall be protected by a grille or screen having openings through which a 1/2-in. (1.27-cm) sphere cannot pass.
2-3.7 Air Inlets ?Return or Exhaust or Return and Exhaust.
2-3.7.1 General.
Air shall not be recirculated from any space in which flammable vapors, flyings, or dust is present in quantities and concentrations that would introduce a hazardous condition into the return air system.
2-3.7.2 Construction of Air Inlets.
Air inlets shall be constructed of noncombustible material or a material that has a maximum flame spread index of 25 and a maximum smoke developed index of 50.
2-3.7.3 Location of Air Inlets.
2-3.7.3.1
Air inlets shall be located at least 3 in. (7.6 cm) above the floor.
Exception: Where provisions have been made to prevent dirt and dust accumulations from entering the system.
2-3.7.3.2
Where located less than 7 ft (2.13 m) above the floor, inlet openings shall be protected by a grille or screen having openings through which a 1/2-in. (1.27-cm) sphere cannot pass.

婷婷

2-3.8 Fire Dampers.
Approved fire dampers shall be provided as required in Chapter 3 and installed in conformance with the conditions of their listings.
2-3.9 Smoke Dampers.
2-3.9.1
Approved smoke dampers shall be provided as required in Chapter 3 and installed in conformance with the conditions of their listings.
2-3.9.2
Smoke dampers shall be installed in systems with a capacity greater than 15,000 ft3/min (7080 L/sec) to isolate the air-handling equipment, including filters, from the remainder of the system in order to restrict the circulation of smoke.
Exception No. 1: Where the air-handling unit is located on the floor that it serves and serves only that floor.
Exception No. 2: Where the air-handling unit is located on the roof and serves only the floor immediately below the roof.
2-3.10 Plenums.
2-3.10.1 Storage.
Plenums shall not be used for occupancy or storage.
2-3.10.2 Ceiling Cavity Plenum.
The space between the top of the finished ceiling and the underside of the floor or roof above shall be permitted to be used to supply air to the occupied area, or return or exhaust air from or return and exhaust air from the occupied area, provided that the following conditions are met:
(a) All materials exposed to the airflow shall be noncombustible or limited combustible and have a maximum smoke developed index of 50.
Exception No. 1: The following materials shall be permitted in the ceiling cavity plenum where listed as having a maximum peak optical density of 0.5 or less, an average optical density of 0.15 or less, and a maximum flame spread distance of 5 ft (1.5 m) or less when tested in accordance with the specified test method:
(a) Electrical wires and cables and optical fiber cables ?NFPA 262, Standard Method of Test for Flame Travel and Smoke of Wires and Cables for Use in Air-Handling Spaces
(b) Pneumatic tubing for control systems ?UL 1820, Standard for Safety Fire Test of Pneumatic Tubing for Flame and Smoke Characteristics
(c) Fire sprinkler piping ?UL 1887, Standard for Safety Fire Test of Plastic Sprinkler Pipe for Visible Flame and Smoke Characteristics
(d) Optical-fiber and communication raceways ?UL 2024, Standard for Safety Optical-Fiber Cable Raceway
Exception No. 2: Smoke detectors.
Exception No. 3: Loudspeakers and recessed lighting fixtures, including their assemblies and accessories, shall be permitted in the ceiling cavity plenum where listed as having a maximum peak optical density of 0.5 or less, an average optical density of 0.15 or less, and a peak heat release rate of 100 kW or less when tested in accordance with UL 2043, Standard for Safety Fire Test for Heat and Visible Smoke Release for Discrete Products and Their Accessories Installed in Air-Handling Spaces.
Exception No. 4: Supplementary materials for air distribution systems in accordance with 2-3.3.
(b) The integrity of the fire stopping for penetrations shall be maintained.
(c) Light diffusers, other than those made of metal or glass, used in air-handling light fixtures shall be listed and marked 揊ixture Light Diffusers for Air-Handling Fixtures.?
(d) The temperature of air delivered to these plenums shall not exceed 250癋 (121癈).
(e) Materials used in the construction of a ceiling plenum shall be suitable for continuous exposure to the temperature and humidity conditions of the environmental air in the plenum.
(f) Where the plenum is a part of a floor-ceiling or roof-ceiling assembly that has been tested or investigated and assigned a fire resistance rating of 1 hour or more, the assembly shall meet the requirements of 3-3.3.

婷婷

2-3.10.3 Duct Distribution Plenum.
A duct enclosure used for the multiple distribution or gathering of ducts or connectors shall be constructed of materials and methods specified in 2-3.1.
2-3.10.4 Apparatus Casing Plenum.
A fabricated plenum and apparatus casing shall be permitted to be used for supply, return, or exhaust air service and shall be constructed of materials and methods specified in 2-3.1 and in accordance with the following:
(1) The casing and plenum construction standards in SMACNA HVAC Duct Construction Standards ?Metal and Flexible
(2) ASHRAE Handbook ?HVAC Systems and Equipment
(3) Paragraph 2-3.3 for all air duct coverings, duct lining, acoustical liner/cells, and miscellaneous materials
2-3.10.5 Air-Handling Unit Room Plenum.
2-3.10.5.1
Individual rooms containing an air-handling unit(s) gather return air from various sources and combine the return air within the room for returning to the air-handling unit. Duct covering, duct lining, acoustical liner/cells, and miscellaneous materials shall comply with 2-3.3.
2-3.10.5.2
Air-handling unit room plenums shall not be used for storage or occupancy other than during equipment servicing

婷婷

2-3.10.6 Raised Floor Plenum.
The space between the top of the finished floor and the underside of a raised floor shall be permitted to be used to supply air to the occupied area, or return or exhaust air from or return and exhaust air from the occupied area, provided that the following conditions are met:
(a) All materials exposed to the airflow shall be noncombustible or limited combustible and shall have a maximum smoke developed index of 50.
Exception No. 1: The following materials shall be permitted in the raised floor plenum where listed as having a maximum peak optical density of 0.5 or less, an average optical density of 0.15 or less, and a maximum flame spread distance of 5 ft (1.5 m) or less when tested in accordance with the specified test method:
(a) Electrical wires and cables and optical fiber cables ?NFPA 262, Standard Method of Test for Flame Travel and Smoke of Wires and Cables for Use in Air-Handling Spaces
(b) Pneumatic tubing for control systems ?UL 1820, Standard for Safety Fire Test of Pneumatic Tubing for Flame and Smoke Characteristics
(c) Fire sprinkler piping ?UL 1887, Standard for Safety Fire Test of Plastic Sprinkler Pipe for Visible Flame and Smoke Characteristics
(d) Optical-fiber and communication raceways ?UL 2024, Standard for Safety Optical-Fiber Cable Raceway.
Exception No. 2: Raised floors, intermachine cables, electrical wires, listed plenum communication and optical-fiber raceways, and optical-fiber cables in computer/data processing rooms where these rooms are designed and installed in accordance with NFPA 75, Standard for the Protection of Electronic Computer/Data Processing Equipment.
Exception No. 3: Smoke detectors.
Exception No. 4: Supplementary materials for air distribution systems in accordance with 2-3.3.
(b) The integrity of the firestopping for penetrations shall be maintained.
(c) The temperature of air delivered to these plenums shall not exceed 250癋 (121癈).
(d) Materials used in the construction of a raised floor plenum shall be suitable for continuous exposure to the temperature and humidity conditions of the environmental air in the plenum.

婷婷

2-3.11 Corridor Air Systems.
2-3.11.1* Egress Corridors.
Egress corridors in health care, detention and correctional, and residential occupancies shall not be used as a portion of a supply, return, or exhaust air system serving adjoining areas. An air transfer opening(s) shall not be permitted in walls or in doors separating egress corridors from adjoining areas.
Exception No. 1: Toilet rooms, bathrooms, shower rooms, sink closets, and similar auxiliary spaces opening directly onto the egress corridor.
Exception No. 2: Where door clearances do not exceed those specified for fire doors in NFPA 80, Standard for Fire Doors and Fire Windows, air transfer caused by pressure differentials shall be permitted.
Exception No. 3: Use of egress corridors as part of an engineered smoke-control system.
Exception No. 4: In detention and correctional occupancies with corridor separations of open construction (e.g., grating doors or grating partitions).
2-3.11.2 Exits.
Exit passageways, stairs, ramps, and other exits shall not be used as a part of a supply, return, or exhaust air system serving other areas of the building.
2-3.12* Smoke Control.
Where a smoke-control or exhaust system is required, it shall conform to the requirements of the building code of the authority having jurisdiction.