Environmental air ducts and product-conveying systems

Grounded in the retrieved California Mechanical Code — click a citation to read the verbatim passage:

• CMC § 2025 High relevance — show source text

  The building’s structural stability is protected by the regulations for cutting and notching of structural members.

  Chapter 4 Ventilation Air. Chapter 4 regulates the minimum requirements for ventilation air supply, exhaust, and makeup air for occupiable spaces within a building. Building ventilation is one important factor affecting the relationship between airborne transmission of respiratory infections and the health and productivity of workers. Ventilation air may be composed of mechanical or natural ventilation, infiltration, recirculated air, transfer air, or a suitable combination of these. Providing a comfortable and healthy indoor environment for building occupants is of primary concern. When determining ventilation rates, typical and unusual significant sources of indoor pollution need to be controlled. Areas such as kitchens, bathrooms, and laundries are all built to allow specific functions. These spaces produce pollutants such as moisture, odors, volatile organic compounds, particles, or combustion byproducts. The purpose of local exhaust is to control concentrates of these pollutants in the room into which they were emitted and to reduce the spread of pollutants into other parts of the occupancy. Local exhaust ventilation is the source control for pollution that is expected in certain rooms. Using local exhaust to extract contaminants before they mix with the indoor environment is essential.

  Chapter 5 Exhaust Systems. Chapter 5 regulates the minimum requirements for exhaust systems. Chapter 5 contains two parts: Part I provides exhaust requirements for environmental air ducts and product conveying systems; Part II provides exhaust requirements for commercial hoods and kitchen ventilation. Environmental air ducts include exhaust ducts used for transporting the air from domestic kitchens, bathrooms, shower rooms, locker rooms, janitor’s closets, and clothes dryers. Systems that carry nonabrasive exhaust, such as smoke, moderate abrasives such as sawdust, and high abrasives such as manganese or acid vapors use product-conveying ducts. Part II provides the minimum fire safety requirements related to the design, installation, inspection, and maintenance of grease-type operations, such as cooking, for both fuel-gas and solid fuel. Cooking produces a significant amount of smoke, fumes, vapors, heat, and other pollutants. Therefore, acceptable kitchen ventilation is necessary to prevent fires from the build-up of grease and to provide the occupants protection from smoke, unpleasant odors, pollutants, and dangerous gases. There are two types of exhaust hoods (Type I and Type II) used in commercial kitchen applications.

  xiv 2025 CALIFORNIA MECHANICAL CODE

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  FORMAT OF THE UNIFORM MECHANICAL CODE

  Type I hoods are intended to be installed above equipment or appliances that generate grease or smoke. Type II hoods are intended to be installed above equipment or appliances that generate steam, vapor, heat, or odors and do not generate grease or smoke.

  Chapter 6 Duct Systems. Chapter 6 regulates requirements for ducts and plenums that are portions of a heating, cooling, ventilation, or exhaust system. This chapter contains material and installation requirements for metal, gypsum, factory-made, flexible, and plastic ducts. It also contains provisions for duct insulation, dampers, fire protection, and automatic shutoff for the building’s air distribution system. It is worth noting that exhaust ducts are regulated by Chapter 5, and combustion air ducts are regulated by Chapter 7.

• CMC § 504.0 High relevance — show source text

  Equipment used to exhaust explosive or flammable vapors, fumes, or dusts shall bear an identification plate stating the ventilation rate for which the system was designed.

  Fans located in systems conveying corrosives shall be of materials that are resistant to the corrosive or shall be coated

  with corrosion-resistant materials.

  504.0 Environmental Air Ducts.

  504.1 General. Where not specified in this chapter, exhaust ducts shall be constructed and installed in accordance with

  Chapter 6 and shall be airtight as approved by the Authority Having Jurisdiction. Environmental air ducts that have an alternate function as a part of an approved smoke control sys

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  501.0 General.

  501.1 Applicability. This chapter includes requirements for environmental air ducts, product-conveying systems, and commercial hoods and kitchen ventilation. Part I addresses environmental air ducts and product conveying systems. Part II addresses commercial hoods and kitchen ventilation.

  502.0 Termination.

  502.1 Exhaust Opening Protection. Exhaust openings terminating to the outdoors shall be covered with a corrosionresistant screen having not less than [1] ⁄ 4 of an inch (6.4 mm) openings, and shall have not more than [1] ⁄ 2 of an inch (12.7 mm) openings.

  Exception: Clothes dryers.

  502.2 Termination of Exhaust Ducts. Exhaust ducts shall terminate in accordance with Section 502.2.1 through Section 502.2.4. Classes of air shall be as defined in Section

  203.0 and classified in Section 403.9.

  502.2.1 Environmental, Class 1, and Class 2 Air Ducts. Environmental, Class 1, and Class 2 air duct exhaust shall terminate not less than 3 feet (914 mm) from a property line, 10 feet (3048 mm) above a public way, 3 feet (914 mm) from openings into the building and the minimum separation distance from ventilation system outdoor air intakes determined in accordance with Section 402.4.1. The discharge of dryer exhaust ducts shall not terminate over a public way or over an area where condensate or vapor could create a nuisance or hazard.

  502.2.2 Class 3 Air Ducts. Class 3 air duct exhaust shall terminate not less than 10 feet (3048 mm) from a property line, 3 feet (914 mm) from exterior walls or roofs that are in the direction of the exhaust discharge, 10 feet (3048 mm) from openings into the building, 10 feet (3048 mm) above adjoining grade, and the minimum separation distance from ventilation system outdoor air intakes determined in accordance with Section 402.4.1.

• CMC § 402.1 High relevance — show source text

  Table 4-B Filter Efficiencies for Central

  Ventilation and Air-Conditioning Systems In General Acute Care Hospitals, Outpatient Facilities,

  Licensed Clinics and Acute

  Psychiatric Hospitals . . . . . . . . . . . 91

  Table 4-C Filter Efficiencies for Central

  Ventilation and Air-Conditioning Systems In Skilled Nursing Facilities, Intermediate Care

  Facilities and Correctional

  Treatment Centers . . . . . . . . . . . . . 91

  Table 402.1 Minimum Ventilation Rates in

  Breathing Zone . . . . . . . . . . . . . . . . 92

  Table 403.2.2 Zone Air Distribution Effectiveness. . 95

  Table 403.7 Minimum Exhaust Rates. . . . . . . . . 96

  CHAPTER 5 EXHAUST SYSTEMS . . . . . . . . . . 97

  501.0 General. . . . . . . . . . . . . . . . . . . . . . 99

  501.1 Applicability. . . . . . . . . . . . . . . . . . . 99

  502.0 Termination. . . . . . . . . . . . . . . . . . . 99

  502.1 Exhaust Opening Protection. . . . . . 99

  502.2 Termination of Exhaust Ducts . . . . 99

  2025 CALIFORNIA MECHANICAL CODE

  Part I Environmental Air Ducts and

  Product-Conveying Systems . . . . 99

  503.0 Motors, Fans, and Filters . . . . . . . . 99

  503.1 General. . . . . . . . . . . . . . . . . . . . . . 99

  503.2 Fans . . . . . . . . . . . . . . . . . . . . . . . . 99

  504.0 Environmental Air Ducts . . . . . . . . . 99

  504.1 General. . . . . . . . . . . . . . . . . . . . . . 99

  504.2 Independent Exhaust Systems. . . 100

  504.3 Domestic Cooking Exhaust Equipment . . . . . . . . . . . . . . . . . . 100

  504.4 Clothes Dryers . . . . . . . . . . . . . . . 100

  504.5 Heat Recovery Ventilation (HRV) and Energy Recovery Ventilation (ERV) Systems . . . . . . 101

  505.0 Product-Conveying Systems . . . . 101

  505.1 General. . . . . . . . . . . . . . . . . . . . . 101

  505.2 Incompatible Materials . . . . . . . . . 102

  505.3 Flammability Limit. . . . . . . . . . . . . 102

  505.4 Air-Moving Devices. . . . . . . . . . . . 102

  505.5 Generating Flames, Sparks, or Hot Materials . . . . . . . . . . . . . . 102

  505.6 Fire Dampers . . . . . . . . . . . . . . . . 102

  505.7 Fire Detection, Smoke Control and Alarm Systems . . . . . . . . . . . . 102

• CMC § 502.2 High relevance — show source text

  Exception: Clothes dryers.

  502.2 Termination of Exhaust Ducts. Exhaust ducts shall terminate in accordance with Section 502.2.1 through Section 502.2.4. Classes of air shall be as defined in Section

  203.0 and classified in Section 403.9.

  502.2.1 Environmental, Class 1, and Class 2 Air Ducts. Environmental, Class 1, and Class 2 air duct exhaust shall terminate not less than 3 feet (914 mm) from a property line, 10 feet (3048 mm) above a public way, 3 feet (914 mm) from openings into the building and the minimum separation distance from ventilation system outdoor air intakes determined in accordance with Section 402.4.1. The discharge of dryer exhaust ducts shall not terminate over a public way or over an area where condensate or vapor could create a nuisance or hazard.

  502.2.2 Class 3 Air Ducts. Class 3 air duct exhaust shall terminate not less than 10 feet (3048 mm) from a property line, 3 feet (914 mm) from exterior walls or roofs that are in the direction of the exhaust discharge, 10 feet (3048 mm) from openings into the building, 10 feet (3048 mm) above adjoining grade, and the minimum separation distance from ventilation system outdoor air intakes determined in accordance with Section 402.4.1.

  502.2.3 Product Conveying, Flammable, and Class 4 Air Ducts. Ducts conveying Class 4 air or explosive or flammable vapors, fumes, or dusts shall terminate not less than 30 feet (9144 mm) from a property line, 10 feet (3048 mm) from openings into the building, 6 feet (1829 mm) from exterior walls or roofs that are in the direction of the exhaust discharge, 30 feet (9144 mm) from combustible walls or openings into the building that are in the direction of the exhaust discharge, 10 feet (3048 mm) above adjoining grade, and the minimum separation distance from ventilation system outdoor air intakes determined in accordance with Section 402.4.1.

  Exception: Type I Hood exhaust termination shall be in accordance with Section 510.9.

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  EXHAUST SYSTEMS

  tem in accordance with Section 505.7.3 do not require design as Class 1 product-conveying ducts.

  Exceptions:

  (1) Ductless range hoods where installed in accordance with the manufacturer’s installation instructions.

  (2) Condensing clothes dryers where installed in accordance with the manufacturer’s installation instructions.

  504.1.1 Backdraft Protection. Exhaust ducts shall terminate outside the building and shall be equipped with backdraft dampers or with motorized dampers that automatically shut where the systems or spaces served are not in use. [OSHPD 1, 1R, 2, 4 & 5] Exception: Back- draft dampers are not required when the exhaust fan must operate continuously.

  Exception: Where the exhaust duct does not discharge into a common exhaust plenum and one of the following:

  (1) The exhaust fan runs continuously.

• CMC § 502.2.4 High relevance — show source text

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  CHAPTER 5

  EXHAUST SYSTEMS

  502.2.4 Commercial Kitchen Ducts. Commercial

  kitchens exhaust ducts shall terminate in accordance with

  Section 510.9 for Type I exhaust systems or Section 519.5 for Type II exhaust systems.

  Part I – Environmental Air Ducts and Product-Conveying Systems.

  503.0 Motors, Fans, and Filters.

  503.1 General. Motors and fans shall be sized to provide the required air movement. Motors in areas that contain flammable vapors or dusts shall be of a type approved for such environments. A manually operated remote control installed at an approved location shall be provided to shut off fans or blowers in flammable vapor or dust systems. Equipment used in operations that generate explosive or flammable vapors, fumes, or dusts shall be interlocked with the ventilation system so that the equipment cannot be operated unless the ventilation fans are in operation. Motors for fans used to convey flammable vapors or dusts shall be located outside the duct or shall be protected with approved shields and dustproofing. Where belts are used, they shall not enter the duct unless the belt and pulley within the duct are enclosed. Motors and fans shall be accessible for servicing and maintenance.

  503.2 Fans. Parts of fans in contact with explosive or flammable vapors, fumes, or dusts shall be of nonferrous or nonsparking materials, or their casing shall be lined or constructed of such material. Where the size and hardness of

  materials passing through a fan are capable of producing a spark, both the fan, and the casing shall be of nonsparking materials. Where fans are required to be spark-resistant, their bearings shall not be within the airstream, and parts of the fan shall be grounded. Fans in systems handling materials that are likely to clog the blades, and fans in buffing or woodworking exhaust systems, shall be of the radial-blade or tube-axial type.

  Equipment used to exhaust explosive or flammable vapors, fumes, or dusts shall bear an identification plate stating the ventilation rate for which the system was designed.

  Fans located in systems conveying corrosives shall be of materials that are resistant to the corrosive or shall be coated

  with corrosion-resistant materials.

  504.0 Environmental Air Ducts.

  504.1 General. Where not specified in this chapter, exhaust ducts shall be constructed and installed in accordance with

  Chapter 6 and shall be airtight as approved by the Authority Having Jurisdiction. Environmental air ducts that have an alternate function as a part of an approved smoke control sys

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  501.0 General.

  501.1 Applicability. This chapter includes requirements for environmental air ducts, product-conveying systems, and commercial hoods and kitchen ventilation. Part I addresses environmental air ducts and product conveying systems. Part II addresses commercial hoods and kitchen ventilation.

  502.0 Termination.

  502.1 Exhaust Opening Protection. Exhaust openings terminating to the outdoors shall be covered with a corrosionresistant screen having not less than [1] ⁄ 4 of an inch (6.4 mm) openings, and shall have not more than [1] ⁄ 2 of an inch (12.7 mm) openings.

• CMC § 503.1 High relevance — show source text

  503.1 General. . . . . . . . . . . . . . . . . . . . . . 99

  503.2 Fans . . . . . . . . . . . . . . . . . . . . . . . . 99

  504.0 Environmental Air Ducts . . . . . . . . . 99

  504.1 General. . . . . . . . . . . . . . . . . . . . . . 99

  504.2 Independent Exhaust Systems. . . 100

  504.3 Domestic Cooking Exhaust Equipment . . . . . . . . . . . . . . . . . . 100

  504.4 Clothes Dryers . . . . . . . . . . . . . . . 100

  504.5 Heat Recovery Ventilation (HRV) and Energy Recovery Ventilation (ERV) Systems . . . . . . 101

  505.0 Product-Conveying Systems . . . . 101

  505.1 General. . . . . . . . . . . . . . . . . . . . . 101

  505.2 Incompatible Materials . . . . . . . . . 102

  505.3 Flammability Limit. . . . . . . . . . . . . 102

  505.4 Air-Moving Devices. . . . . . . . . . . . 102

  505.5 Generating Flames, Sparks, or Hot Materials . . . . . . . . . . . . . . 102

  505.6 Fire Dampers . . . . . . . . . . . . . . . . 102

  505.7 Fire Detection, Smoke Control and Alarm Systems . . . . . . . . . . . . 102

  505.8 Product-Conveying Duct Classifications. . . . . . . . . . . . . . . . 102

  505.9 Minimum Velocities and

  Circulation. . . . . . . . . . . . . . . . . . . 102

  505.10 Makeup Air . . . . . . . . . . . . . . . . . . 102

  505.11 Hoods and Enclosures . . . . . . . . . 103

  505.12 Pharmacies – Compounding Area of Parenteral Solutions . . . . 103

  506.0 Product-Conveying Ducts. . . . . . . 103

  506.1 Materials . . . . . . . . . . . . . . . . . . . . 103

  Table 505.9 Range of Minimum Duct Design Velocities. . . . . . . . . . . . . . . . . . . . 103

  Table 506.2(1) Minimum Sheet Metal Thickness for Round Ducts . . . . . . . . . . . . . . 104

  506.2 Construction . . . . . . . . . . . . . . . . . 105

  Table 506.2(2) Minimum Sheet Metal Thickness for Rectangular Ducts. . . . . . . . . . 106

  506.3 Penetrations . . . . . . . . . . . . . . . . . 106

  506.4 Condensate . . . . . . . . . . . . . . . . . 107

  506.5 Fittings . . . . . . . . . . . . . . . . . . . . . 107

• California Mechanical Code High relevance — show source text

  A mechanical code, as with any other code, is intended to be adopted as a legally enforceable document to safeguard health, safety, property, and public welfare. The code cannot be effective without satisfactory provisions for its administration and enforcement. The Authority Having Jurisdiction is to review the proposed and completed work and decide whether a mechanical system conforms to the code requirements. As a public servant, the Authority Having Jurisdiction enforces the code in an unbiased proper manner. The design professional is responsible for the design of a safe mechanical system. The contractor is responsible for installing the system in accordance with the plans.

  Chapter 2 Definitions. To maintain consistency and encourage the use of common terminology, Chapter 2 establishes definitions to provide clarity of terms and promote the use of a common language throughout the code. Understanding definitions within the context of their application enables greater collaboration, efficiency, standardization, and interpretation in applying and enforcing terms used throughout the code. Codes are technical documents, and every term can impact the meaning of the code text. Terms not defined have a normally accepted meaning.

  Chapter 3 General Regulations. Chapter 3 regulates the general requirements, not specific to other chapters, for installing mechanical systems. Many regulations are not specific mechanical requirements but relate to the overall mechanical system. This chapter contains safety requirements for appliance location and installation, appliance and system access, condensate disposal, clearances to combustibles, and return or outside air used in mechanical systems. Listing method of approval, based on applicable nationally recognized standards for the safe and proper installation of mechanical systems, is essential to ensure protection of public health, safety, and welfare. These safety requirements provide protection for piping, tubing, materials, and structures, including provisions for installation practices addressing stress and strain, sleeving, and hanger support. The building’s structural stability is protected by the regulations for cutting and notching of structural members.

  Chapter 4 Ventilation Air. Chapter 4 regulates the minimum requirements for ventilation air supply, exhaust, and makeup air for occupiable spaces within a building. Building ventilation is one important factor affecting the relationship between airborne transmission of respiratory infections and the health and productivity of workers. Ventilation air may be composed of mechanical or natural ventilation, infiltration, recirculated air, transfer air, or a suitable combination of these. Providing a comfortable and healthy indoor environment for building occupants is of primary concern. When determining ventilation rates, typical and unusual significant sources of indoor pollution need to be controlled. Areas such as kitchens, bathrooms, and laundries are all built to allow specific functions. These spaces produce pollutants such as moisture, odors, volatile organic compounds, particles, or combustion byproducts. The purpose of local exhaust is to control concentrates of these pollutants in the room into which they were emitted and to reduce the spread of pollutants into other parts of the occupancy. Local exhaust ventilation is the source control for pollution that is expected in certain rooms. Using local exhaust to extract contaminants before they mix with the indoor environment is essential.

  Chapter 5 Exhaust Systems. Chapter 5 regulates the minimum requirements for exhaust systems. Chapter 5 contains two parts: Part I provides exhaust requirements for environmental air ducts and product conveying systems; Part II provides exhaust requirements for commercial hoods and kitchen ventilation. Environmental air ducts include exhaust ducts used for transporting the air from domestic kitchens, bathrooms, shower rooms, lo

• CMC § 3.3.34 High relevance — show source text

  (3) The air passages of listed self-contained systems.

  Duct, Environmental Air. Ducting used for conveying air at temperatures not exceeding 250°F (121°C) to or from occupied areas of any occupancy through other than heating or air-conditioning systems, such as ventilation for human usage, domestic kitchen range exhaust, bathroom exhaust ducts, locker room exhaust ducts, shower room exhaust ducts, janitor’s closet exhaust ducts, and domestic-type clothes dryer exhaust ducts.

  Duct, Grease. A containment system for the transportation of air and grease vapors that is designed and

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  DEFINITIONS

  Electrical Code. The National Electrical Code promulgated by the National Fire Protection Association, as adopted by this jurisdiction. [HCD 1 & HCD 2] Whenever the term “Electrical Code” is used in this code, it shall mean the Cal- ifornia Electrical Code, Title 24, Part 3.

  Emergency Alarm System. A system intended to provide notification and warning of abnormal conditions and summon appropriate aid.

  Emergency Control Station. An approved location on the premises where signals from emergency equipment are received.

  Enforcing Agency. [HCD 1, HCD 2, SFM, OSHPD 1, 1R, 2, 3, 4, 5 & 6] “Enforcing Agency” is the designated department or agency as specified by statute and regulation.

  Energy Recovery Ventilation (ERV) System. A device intended to provide outdoor ventilation air, and in the process transfer energy between the intake and exhaust airstreams for the purpose of preheating, precooling, humidifying, or dehumidifying outdoor ventilation air prior to supplying such air to a conditioned space.

  Engineering Methods. Design methods that rely on the application of mathematics, sciences, empirical evidence, and engineering principles. [NFPA 54:3.3.34]

  Equipment. A general term including materials, fittings, devices, appliances, and apparatus used as part of or in connection with installations regulated by this code.

  Evaporative Cooler. A device used for reducing the sensible heat of air for cooling by the process of evaporation of water into an airstream.

  Evaporative Cooling System. Equipment intended or installed for the purpose of environmental cooling by an evaporative cooler from which the conditioned air is distributed through ducts or plenums to the conditioned space or zone.

  Evaporator. Part of a refrigeration system in which liquid refrigerant is vaporized to produce refrigeration.

  Excess Flow Valve (EFV). A valve designed to activate when the fuel gas passing through it exceeds a prescribed flow rate. [NFPA 54:3.3.98.3]

  Expansion Tank. A vessel used to protect closed systems from excessive pressure.

  208.0 – F –

  Fabrication Area (Fab Area). An area within a Group H Occupancy semiconductor fabrication facility and related research and development areas in that there are processes involving hazardous production materials. Such areas are allowed to include ancillary rooms or areas such as dressing rooms and offices that are directly related to the fab area

  processes.

• CMC § 3.3.34 High relevance — show source text

  Energy Recovery Ventilation (ERV) System. A device intended to provide outdoor ventilation air, and in the process transfer energy between the intake and exhaust airstreams for the purpose of preheating, precooling, humidifying, or dehumidifying outdoor ventilation air prior to supplying such air to a conditioned space.

  Engineering Methods. Design methods that rely on the application of mathematics, sciences, empirical evidence, and engineering principles. [NFPA 54:3.3.34]

  Equipment. A general term including materials, fittings, devices, appliances, and apparatus used as part of or in connection with installations regulated by this code.

  Evaporative Cooler. A device used for reducing the sensible heat of air for cooling by the process of evaporation of water into an airstream.

  Evaporative Cooling System. Equipment intended or installed for the purpose of environmental cooling by an evaporative cooler from which the conditioned air is distributed through ducts or plenums to the conditioned space or zone.

  Evaporator. Part of a refrigeration system in which liquid refrigerant is vaporized to produce refrigeration.

  Excess Flow Valve (EFV). A valve designed to activate when the fuel gas passing through it exceeds a prescribed flow rate. [NFPA 54:3.3.98.3]

  Expansion Tank. A vessel used to protect closed systems from excessive pressure.

  208.0 – F –

  Fabrication Area (Fab Area). An area within a Group H Occupancy semiconductor fabrication facility and related research and development areas in that there are processes involving hazardous production materials. Such areas are allowed to include ancillary rooms or areas such as dressing rooms and offices that are directly related to the fab area

  processes.

  Factory-Built Grease Duct Enclosures. A listed factory-built grease duct system evaluated as an enclosure system for reduced clearances to combustibles and as an alternative to a duct with its fire-rated enclosure. [NFPA 96:3.3.22.2.1]

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  installed to reduce the possibility of the accumulation of combustible condensation and the occurrence of damage if a fire occurs within the system. [NFPA 96:3.3.20.2] Duct, Product-Conveying. Ducting used for conveying solid particulates, such as refuse, dust, fumes, and smoke; liquid particulate matter, such as spray residue, mists, and fogs; vapors, such as vapors from flammable or corrosive liquids; noxious and toxic gases; and air at temperatures exceeding 250°F (121°C).

  Duct Furnace. A furnace normally installed in distribution ducts of air-conditioning systems to supply warm air for heating. This definition applies only to an appliance that, for air circulation, depends on a blower not furnished as part of the furnace. [NFPA 54:3.3.45.3] Duct Sealing. The use of approved adhesives, gaskets, tape, mastics, or combination thereof to close openings in the surface of the ductwork, field erected plenums, equipment, and casings through which air leakage would occur, or the use of continuous welds.

  Duct Sealing Classes. Seal Class A. All transverse joints, longitudinal seams, and duct wall penetrations. Seal Class B. All transverse joints and longitudinal

  seams.

• CMC § 7.3 High relevance — show source text

  7.3|||X|||||||||||||||||||||| |505.12||||||||||||||||||||||X||| |505.12.1||||||||||||||||||||||X||| |507.7||||||||||X||X|X|X|X|||||||||| |508.4||||||||||X|X|X||X|X|||||||||| |509.2.3|||X|||||||||||||||||||||| |509.2.3.4||||||||||||||||||X||||||| |513.2.2|||X|||||||||||||||||||||| |513.2.2 Exception 2|||X|||||X||||||||||||||||| |513.3.5|||X|||||||||||||||||||||| |513.10|||X|||||||||||||||||||||| |513.10.1|||X||||||||||||||||||||||

  This state agency does not adopt sections identified with the following symbol: The Office of the State Fire Marshal’s adoption of this chapter or individual sections is applicable to structures regulated by other state agencies pursuant to Section 1.11.0.

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  CHAPTER 5

  EXHAUST SYSTEMS

  502.2.4 Commercial Kitchen Ducts. Commercial

  kitchens exhaust ducts shall terminate in accordance with

  Section 510.9 for Type I exhaust systems or Section 519.5 for Type II exhaust systems.

  Part I – Environmental Air Ducts and Product-Conveying Systems.

  503.0 Motors, Fans, and Filters.

  503.1 General. Motors and fans shall be sized to provide the required air movement. Motors in areas that contain flammable vapors or dusts shall be of a type approved for such environments. A manually operated remote control installed at an approved location shall be provided to shut off fans or blowers in flammable vapor or dust systems. Equipment used in operations that generate explosive or flammable vapors, fumes, or dusts shall be interlocked with the ventilation system so that the equipment cannot be operated unless the ventilation fans are in operation. Motors for fans used to convey flammable vapors or dusts shall be located outside the duct or shall be protected with approved shields and dustproofing. Where belts are used, they shall not enter the duct unless the belt and pulley within the duct are enclosed. Motors and fans shall be accessible for servicing and maintenance.

  503.2 Fans. Parts of fans in contact with explosive or flammable vapors, fumes, or dusts shall be of nonferrous or nonsparking materials, or their casing shall be lined or constructed of such material. Where the size and hardness of

• CMC § 504.5 High relevance — show source text

  shaft for lint removal.

  504.5 Heat Recovery Ventilation (HRV) and Energy Recovery Ventilation (ERV) Systems. Heat recovery ventilators (HRV) and energy recovery ventilators (ERV) shall be installed in accordance with their listings and comply with the appliance manufacturer’s installation instructions. Non-ducted heat recovery ventilators shall comply with UL 1815. Ducted heat recovery ventilators shall comply with UL 1812. Heat recovery ventilator and energy recovery ventilator ducts shall comply with Chapter 6.

  505.0 Product-Conveying Systems.

  505.1 General. A mechanical ventilation or exhaust system shall be installed to control, capture, and remove emissions generated from product use or handling where required in accordance with the building code or fire code and where such emissions result in a hazard to life or property. The design of the system shall be such that the emissions are confined to the area in which they are generated by air currents, hoods, or enclosures and shall be exhausted by a duct system to a safe location or treated by removing contaminants. Ducts conveying explosives or flammable vapors, fumes, or dusts shall extend directly to the exterior of the building without entering other spaces and shall not extend into or through ducts and plenums.

  Exception: Ducts conveying vapor or fumes having flammable constituents less than 25 percent of their Lower Flammability Limit (LFL) shall be permitted to pass through other

  spaces.

  505.1.1 Mechanical Ventilation. A mechanical ven tilation system shall be interlocked to operate with the

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  EXHAUST SYSTEMS

  equipment used to produce vapors, fumes, or dusts that are flammable or hazardous.

  505.2 Incompatible Materials. Incompatible materials shall not be conveyed in the same system. [NFPA 91:4.2.2] 505.3 Flammability Limit. Unless the circumstances stipulated in Section 505.3.1, Section 505.3.2, or Section 505.3.3 exist, in systems conveying flammable vapors, gases, or mists, the concentration shall not exceed 25 percent of the lower flammability limit (LFL). [NFPA 91:4.2.3] 505.3.1 Higher Concentrations. Higher concentrations shall be permitted if the exhaust system is designed and protected in accordance with NFPA 69, using one or more of the following techniques:

  (1) Combustible concentration reduction

  (2) Oxidant concentration reduction

  (3) Deflagration suppression

  (4) Deflagration pressure containment [NFPA 91:4.2.3.1]

  Contaminated air shall not be recirculated to occupied areas unless contaminants have been removed. Air contaminated with explosive or flammable vapors, fumes, or dusts; flammable or toxic gases; or radioactive material shall not be recirculated.

• CMC § 903.2.7 High relevance — show source text

  SUSTAINABLE PRACTICES . . . . . . . . . . . . . . .Appendix E SWITCHES, ELECTRICAL SUPPLY LINE . . . . . . .903.2.7

  – T –

  TANKLESS WATER HEATERS . . . . . . . . . . . . . . . . .1203.3

  TERMINATION

  Chimneys . . . . . . . . . . . . . . . . . . . . .802.5.4, 802.5.4.2

  Environmental air ducts . . . . . . . . . . . . . . . . . . .502.2.1

  Exhaust duct systems,

  commercial kitchen . . . . . . . . . . . . . . . . .510.9, 519.5

  Exhaust

  ducts, clothes dryer . . . . . . . . . . . . . . . . . . . . . .504.4 Gas vents . . . . . . . . . . . . . . . . . . . . . . . .802.6, 802.6.1,

  802.7.2, 802.8, 802.8.1

  Product conveying ducts . . . . . . . . . . . . . . . . . .502.2.3 Type I hood exhaust system . . . . . . . . . . . . . . . . .510.9 Type II hood exhaust system . . . . . . . . . . . . . . . . .519.5

  TESTING

  Of boilers . . . . . . . . . . . . . . . . . . . . . . . . .1012.1, 1013.0

  Of ducts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .602.2

  Of exhaust systems . . . . . . . . . . . . . . . . . . . . . . . .514.0 Of fuel-gas piping . . . . . . . . . . . . . . . . . . .105.3, 1313.0

  Of hood assemblies . . . . . . . . . . . . . . . . . . . . . . .508.2

  Of insulating materials . . . . . . . . . . . . . .508.3.4, 602.2

  Of louvers . . . . . . . . . . . . . . . . . . . . . . .315.1.1, 315.1.2

  Of recirculating systems . . . . . . . . . . .516.2.2, 516.2.5,

  516.6.4

  Of refrigerating equipment . . . . . . . . . . . .105.3, 1114.3,

  1116.0

  Of safety interlocks . . . . . . . . . . . . . . . . . . . . . . .516.6.4

  Required by the Authority

  Having Jurisdiction . . . . . . . . . . . . . . . . . . . . .302.2.1

  TESTING AGENCY

  Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .222.0