Mechanical Systems (HVAC)

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

• CRC § 801.0 High relevance — show source text

  Part I

  E 801.0 Heating, Ventilation, and Air Conditioning Systems Commissioning. E 801.1 Applicability. The provisions of this section apply to the commissioning of commercial and institutional HVAC systems.

  E 802.0 Commissioning. E 802.1 Commissioning Requirements. HVAC commissioning shall be included in the design and construction processes of the project to verify that the HVAC systems and components meet the owner’s project requirements and in accordance with this appendix. Commissioning shall be performed in accordance with this appendix by personnel trained and certified in commissioning by a nationally recognized organization. Commissioning requirements shall include the following:

  (1) Owner’s project requirements

  (2) Basis of design

  (3) Commissioning measures shown in the construction doc uments

  (4) Commissioning plan

  (5) Functional performance

  (6) Testing

  (7) Post construction documentation and training

  (8) Commissioning report

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  APPENDIX E

  HVAC systems and components covered by this appendix as well as process equipment and controls, and renewable energy systems shall be included in the scope of the commissioning requirements. E 802.2 Owner’s Project Requirements (OPR). The performance goals and requirements of the HVAC system shall be documented before the design phase of the project begins. This documentation shall include not less than the following:

  (1) Environmental and sustainability goals

  (2) Energy efficiency goals

  (3) Indoor environmental quality requirements

  (4) Equipment and systems performance goals

  (5) Building occupant and O&M personnel expectations E 802.3 Basis of Design (BOD). A written explanation of how the design of the HVAC system meets the owner’s project requirements shall be completed at the design phase of the building project, and updated as necessary during the design and construction phases. The basis of design document shall cover not less than the following systems:

  (1) Heating, ventilation, air conditioning (HVAC) systems and controls

  (2) Water heating systems

  (3) Renewable energy systems E 802.4 Commissioning Plan. A commissioning plan shall be completed to document the approach to how the project will be commissioned, and shall be started during the design phase of the building project. The commissioning plan shall include not less than the following:

  (1) General project information

  (2) Commissioning goals

  (3) Systems to be commissioned. Plans to test systems and components shall include not less than the following:

  (a) A detailed explanation of the original design intent.

  (b) Equipment and systems to be tested, including the extent of tests.

  (c) Functions to be tested.

  (d) Conditions under which the test shall be performed.

  (e) Measurable criteria for acceptable performance.

  (4) Commissioning team information.

  (5) Commissioning process activities, schedules, and responsibilities. Plans for the completion of commissioning requirements listed in Section E 802.5 through Section E 802.7 shall be included.

  E 802.5 Functional Performance Testing. Functional performance tests shall demonstrate the correct installation and operation of each component, system, and system-to-system interface in accordance with the approved plans and specifications. Functional performance testing reports shall contain information addressing each of the building components tested, the testing methods utilized, and readings and adjustments made.

• CRC § 503.7.1 High relevance — show source text

  (8) Where a heat pump equipped with auxiliary internal electric resistance heaters is installed, controls shall be provided that prevent supplemental heater operation where the heating load is capable of being met by the heat pump alone during both steady-state operation and setback recovery. Supplemental heater operation shall be permitted during outdoor coil defrost cycles. The heat pump shall be controlled in accordance with one of the following:

  (a) A digital or electronic thermostat designed for heat pump use that energizes auxiliary heat where the heat pump has insufficient capacity

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  APPENDIX E

  to maintain setpoint or to warm up the space at a sufficient rate.

  (b) A multistage space thermostat and an outdoor air thermostat wired to energize auxiliary heat on the last stage of the space thermostat and where outdoor air temperature is less than 40°F (4°C).

  Exceptions: Heat pumps that comply with the following:

  (1) Have a minimum efficiency regulated by NAECA.

  (2) In accordance with the requirements shown in Table E 503.7.1(2).

  (3) Include all usage of internal electric resistance heating.

  (9) The system controls shall not permit reheat or other form of simultaneous heating and cooling for humidity control.

  (10)Systems serving spaces other than residential spaces, that do not require continuous operation with a cooling or heating capacity more than 7000 Btu/h (2.1 kW) shall comply with Section E 503.4.6.3.1 and Section E 503.4.6.3.2.

  (11) Systems serving residential spaces other than hotel/motel guest rooms shall comply with Section E 503.4.6.3.1 and Section E 503.4.6.3.2 except for electric resistance heaters rated at 5000 Btu/h (1.5 kW) or less with a readily accessible manual control that lowers the set point or turns the unit off.

  (12) Systems serving hotel/motel guest rooms shall comply with Section E 503.4.6.3.5.

  (13) Except for piping within manufacturer’s units, HVAC piping shall be insulated in accordance with Table E 503.7.3(1) and Table E 503.7.3(2). Insulation exposed to weather shall be suitable for outdoor service, e.g., protected by aluminum, sheet metal, painted canvas, or plastic cover. Cellular foam insulation shall be protected as above or painted with a coating that is water retardant and provides shielding from solar radiation.

  (14) Ductwork and plenums shall be insulated in accordance with Table E 503.7.2 and shall be sealed in

  accordance with Section E 503.4.7.2.

  (15) Construction documents shall require a ducted system to be air balanced in accordance with industryaccepted procedures.

  (16) Outdoor air intake and exhaust systems shall comply with Section E 503.4.6.4 through Section E 503.4.6.5.

  (17) Where separate heating and cooling equipment serves the same temperature zone, thermostats shall be interlocked to prevent simultaneous heating and cooling.

  (18) Systems with a design supply air capacity more than 10 000 ft [3] /min (4.7195 m [3] /s) shall have optimum start controls.

• CRC § 2.1 Medium relevance — show source text

  Exceptions:

  (1) HVAC systems intended to operate continuously.

  (2) HVAC systems not serving residential spaces and having a design heating capacity and cooling capacity less than 7000 Btu/h (2.1 kW) that are equipped with a readily accessible manual ON/OFF controls. [ASHRAE 90.1:6.4.3.3]

  E 503.4.6.3.1 Automatic Shutdown. HVAC systems shall be equipped with not less than one of the following:

  (1) Controls that can start and stop the system under different time schedules for seven different day-types per week, are capable of retaining programming and time setting during loss of power for a period of not less than 10 hours, and include an accessible manual override, or equivalent function, that allows temporary operation of the system for up to 2 hours.

  (2) An occupancy sensor that is capable of shutting the system off when no occupant is sensed for a period of up to 30 minutes.

  (3) A manually operated timer capable of being adjusted to operate the system for up to 2 hours.

  (4) An interlock to a security system that shuts the system off when the security system is activated.

  Exceptions:

  (1) Systems serving residential occupancies with controls that can start and stop the system under at least two different time schedules per week.

  (2) Systems serving non-residential occupancies where heating or cooling capacity is less than 15 000 Btu/h (4.4 kW) with controls that can start and stop the system under not less than 2 different time schedules per week. [ASHRAE 90.1:6.4.3.3.1] E 503.4.6.3.2 Setback Controls. Heating systems shall be equipped with controls capable of and configured to automatically restart and temporarily operate the system as required to maintain zone temperatures above an adjustable heating setpoint of not less than 10°F (6°C) below the occupied heating setpoint. Cooling systems shall be equipped with con

  trols capable of and configured to automatically restart and temporarily operate the mechanical cooling system as required to maintain zone temperatures below an adjustable cooling setpoint of not less than 5°F (3°C) above the occupied cooling setpoint or to prevent high space humidity levels.

  Exception: Radiant heating systems capable of and configured with a setback heating setpoint at not less than 4°F (2°C) below the occupied heating setpoint. [ASHRAE 90.1:6.4.3.3.2] E 503.4.6.3.3 Optimum Start Controls. Individual heating and cooling systems with setback controls and DDC shall have optimum start controls. The control algorithm shall, as a minimum, be a function of the difference between space temperature and occupied set point, the outdoor temperature, and the amount of time prior to scheduled occupancy. Mass radiant floor slab systems shall incorporate floor temperature into the optimum start algorithm.

  Exception: Residential spaces are not required to have optimum start controls. [ASHRAE 90.1:6.4.3.3.3] E 503.4.6.3.4 Zone Isolation. HVAC systems serving zones that are intended to operate or be occupied nonsimultaneously shall be divided into isolation areas.

• CRC § 0.293 Medium relevance — show source text

  
  chilled-water, or hot-water system have DDC| |Alteration or addition|Air-handling system or fan coil|Where existing air-handling system(s) and fan-coil(s)
  served by the same chilled- or hot-water plant have DDC| |Alteration or addition|New air-handling system and all new zones
  served by the system|Individual systems with fan system bhp of 10 hp or more
  and supplying more than three zones and more than 75 per-
  cent of zones are new| |Alteration or addition|New or upgraded chilled-water plant|Where all chillers are new and plant design cooling capac-
  ity is 300 000 Btu/h or more| |Alteration or addition|New or upgraded hot-water plant|Where all boilers are new and plant design heating capacity
  is 300 000 Btu/h or more|

  For SI units: 1000 British thermal units = 0.293 kW, 1 horsepower = 0.746 kW

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  APPENDIX E

  cation or DDC system accessible by operating or service personnel, or annunciated locally on zone thermostats. [ASHRAE 90.1:6.4.3.12]

  E 503.4.7 HVAC System Construction and Insu- lation. HVAC Ducts shall be constructed in accordance with provisions contained in the SMACNA HVAC Duct Construction Standard. HVAC system construction and insulation shall comply with Section E 503.4.7.1 and Section E 503.4.7.2.1.

  E 503.4.7.1 Insulation. Insulation required by this section shall be installed in accordance with industry-accepted standards. These requirements shall not apply to HVAC equipment. Insulation shall be protected from damage, including that due to sunlight, moisture, equipment maintenance, and wind, but not limited to the following:

  (1) Insulation exposed to weather shall be suitable for outdoor service (e.g., protected by aluminum, sheet metal, painted canvas, or plastic cover). Cellular foam insulation shall be protected as above or painted with a coating that is water retardant and provides shielding from solar radiation that can cause degradation of the material.

  (2) Insulation covering chilled-water piping, refrigerant suction piping, or cooling ducts located outside the conditioned space shall include a vapor retardant located outside the insulation (unless the insulation is inherently vapor retardant), all penetrations and joints of which shall be sealed. [ASHRAE 90.1:6.4.4.1.1]

  E 503.4.7.1.1 Duct and Plenum Insula- tion. Supply and return ducts and plenums installed as part of an HVAC air distribution system shall be thermally insulated in accordance with Table E 503.7.2.

  Exceptions:

  (1) Factory-installed plenums, casings, or ductwork furnished as a part of HVAC equipment tested and rated in accordance with Section E 503.4 through Section E 503.4.4.1.

  (2) Ducts or plenums located in heated spaces, semi-heated spaces, or cooled spaces.

• CRC § 102.3.2 Medium relevance — show source text

  ** Commercial HVAC systems both existing and new, and parts thereof shall be inspected and maintained in operating condition in accordance with ASHRAE/ACCA 180. The owner or the owner’s designated agent shall be responsible for maintenance of mechanical systems and equipment. To determine compliance with this subsection, the Authority Having Jurisdiction shall be permitted to cause a HVAC system to be reinspected. 102.3.2 Residential HVAC Systems. Residential HVAC systems both existing and new, and parts thereof shall be inspected in accordance with ACCA 4 QM. The owner or the owner’s designated agent shall be responsible for maintenance of mechanical systems and equipment. To determine compliance with this subsection, the Authority Having Jurisdiction shall be permitted to cause a HVAC system to be reinspected.

  102.4 Additions, Alterations, Renovations, or Repairs. Additions, alterations, renovations, or repairs shall conform to that required for a new system without requiring the existing mechanical system to be in accordance with the requirements of this code. Additions, alterations, renovations, or repairs shall not cause an existing system to become unsafe, insanitary or overloaded.

  Additions, alterations, renovations, or repairs to existing mechanical system installations shall comply with the provisions for new construction, unless such deviations are found to be necessary and are first approved by the Authority Having Jurisdiction. 102.5 Health and Safety. Where compliance with the provisions of this code fails to eliminate or alleviate a nuisance, or other dangerous or insanitary condition that involves health or safety hazards, the owner or the owner’s agent shall install such additional mechanical system facilities or shall make such repairs or alterations as ordered by the Authority Having Jurisdiction. 102.6 Changes in Building Occupancy. Mechanical systems that are a part of a building or structure undergoing a change in use or occupancy, as defined in the building code, shall be in accordance with the requirements of this code that are applicable to the new use or occupancy. 102.7 Moved Structures. Parts of the mechanical system of a building and part thereof that is moved from one foundation to another, or from one location to another, shall be in accordance with the provisions of this code for new installations and completely tested as prescribed elsewhere in this section for new work, except that walls or floors need not be removed during such test where equivalent means of inspection acceptable to the Authority Having Jurisdiction are provided. 102.8 Appendices. The provisions in the appendices are intended to supplement the requirements of this code and shall not be considered part of this code unless formally adopted as such.

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  DIVISION II SCOPE AND ADMINISTRATION

  103.0 Duties and Powers of the Authority Having Jurisdiction.

  103.1 General. The Authority Having Jurisdiction shall be the Authority duly appointed to enforce this code. For such purposes, the Authority Having Jurisdiction shall have the powers of a law enforcement officer. The Authority Having Jurisdiction shall have the power to render interpretations of this code and to adopt and enforce rules and regulations supplemental to this code as deemed necessary in order to clarify the application of the provisions of this code. Such interpretations, rules, and regulations shall comply with the intent and purpose of this code.

• CRC § 503.4.6.3.1. Medium relevance — show source text

  Each isolation area shall be controlled independently by a device meeting the requirements of Section E 503.4.6.3.1. For central systems and plants, controls and devices shall be provided to allow stable system and equipment operation for any length of time while serving only the smallest isolation area served by the system or plant.

  Exceptions: Isolation devices and controls are not required for the following:

  (1) Exhaust air and outdoor air connections to isolation zones where the fan system to which they connect is not more than 5000 ft [3] /min (2.3597 m [3] /s).

  (2) Exhaust airflow from a single isolation zone of less than 10 percent of the design airflow of the exhaust system to which it

  connects.

  (3) Zones intended to operate continuously or intended to be inoperative only when all other zones are inoperative. [ASHRAE 90.1:6.4.3.3.4]

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  APPENDIX E

  E 503.4.6.3.5 Automatic Control of HVAC in Hotel/Motel Guest Rooms. Hotels and motels with more than 50 guest rooms shall be provided with automatic controls for the HVAC equipment serving each guest room capable of and configured according to the requirements in Section E 503.4.6.3.5.1. [ASHRAE 90.1:6.4.3.3.5]

  E 503.4.6.3.5.1 Guest Room HVAC Set-Point Control. Within 30 minutes of all occupants leaving the guest room, HVAC set points shall be automatically raised by not less than 4°F (2°C) from the occupant set point in the cooling mode and automatically lowered by at least 4°F (2°C) from the occupant set point in the heating mode. When the guest room is unrented and unoccupied, HVAC set points shall be automatically reset to 80°F (27°C) or higher in the cooling mode and to 60°F (16°C) or lower in the heating mode. Unrented and unoccupied guest rooms shall be determined by either of the following:

  (1) The guest room has been continuously unoccupied for up to 16 hours.

  (2) A networked guest room control system indicates the guest room is unrented and the guest room is unoccupied for no more than 30 minutes.

  Exceptions:

  (1) A networked guest room control system shall be permitted to return the thermostat set points to their default occupied set points 60 minutes prior to the time the room is scheduled to be occupied.

  (2) Cooling for humidity control shall be permitted during unoccupied periods.

  E 503.4.6.4 Stair and Elevator Shaft Vent Dampers. Where stair and elevator shafts have vents, they shall be equipped with motorized dampers that are capable of and configured to automatically close during normal building operation and are interlocked to only open as required by fire and smoke detection systems, or by thermostatic control systems.

• CRC § 101.5 Medium relevance — show source text

  101.5 Validity. Where a provision of this code, or the application thereof to a person or circumstance, is held invalid, the remainder of the code, or the application of such provision to other persons or circumstances, shall not be affected thereby.

  102.0 Applicability. 102.1 Conflicts Between Codes. Where the requirements within the jurisdiction of this mechanical code conflict with the requirements of the plumbing code, the plumbing code shall prevail. In instances where this code, applicable standards, or the manufacturer’s installation instructions conflict, the more stringent provisions shall prevail. Where there is a conflict between a general requirement and a specific requirement, the specific requirement shall prevail. [OSHPD 1, 1R, 2, 3, 4 & 5] See Chapter 1, Division I, Section 1.1.7

  102.2 Existing Installations. Mechanical systems lawfully in existence at the time of the adoption of this code shall be permitted to have their use, maintenance, or repair continued where the use, maintenance, or repair is in accordance with the original design and location and no hazard to life, health, or property has been created by such mechanical system.

  102.3 Maintenance. Mechanical systems, materials, and appurtenances, both existing and new, of a premise under the Authority Having Jurisdiction shall be maintained in operating condition. Devices or safeguards required by this code shall be maintained in accordance with the code edition under

  which installed.

  The owner or the owner’s designated agent shall be responsible for maintenance of mechanical systems. To determine compliance with this subsection, the Authority Having Jurisdiction shall be permitted to cause a mechanical system to be reinspected.

  102.3.1 Commercial HVAC Systems. Commercial HVAC systems both existing and new, and parts thereof shall be inspected and maintained in operating condition in accordance with ASHRAE/ACCA 180. The owner or the owner’s designated agent shall be responsible for maintenance of mechanical systems and equipment. To determine compliance with this subsection, the Authority Having Jurisdiction shall be permitted to cause a HVAC system to be reinspected. 102.3.2 Residential HVAC Systems. Residential HVAC systems both existing and new, and parts thereof shall be inspected in accordance with ACCA 4 QM. The owner or the owner’s designated agent shall be responsible for maintenance of mechanical systems and equipment. To determine compliance with this subsection, the Authority Having Jurisdiction shall be permitted to cause a HVAC system to be reinspected.

  102.4 Additions, Alterations, Renovations, or Repairs. Additions, alterations, renovations, or repairs shall conform to that required for a new system without requiring the existing mechanical system to be in accordance with the requirements of this code. Additions, alterations, renovations, or repairs shall not cause an existing system to become unsafe, insanitary or overloaded.

  Additions, alterations, renovations, or repairs to existing mechanical system installations shall comply with the provisions for new construction, unless such deviations are found to be necessary and are first approved by the Authority Having Jurisdiction. 102.5 Health and Safety. Where compliance with the provisions of this code fails to eliminate or alleviate a nuisance, or other dangerous or insanitary condition that involves health or safety hazards, the owner or the owner’s agent shall install such additional mechanical system facilities or shall make such repairs or alterations as ordered by the Authority Having Jurisdiction. **102.6 Changes in Building Occupancy.

• CEC § 384 Medium relevance — show source text

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  APPENDICES

  The appendices are intended to supplement the provisions of the installation requirements of this code. The definitions in Chapter 2 are also applicable to the appendices.

  TABLE OF CONTENTS

  »

  »

  Appendix A Page

  Residential Plans Examiner Review Form for HVAC System Design..............................................................387

  Appendix B

  Procedures to be Followed to Place Gas Equipment in Operation..................................................................391

  Appendix C

  Installation and Testing of Oil (Liquid) Fuel-Fired Equipment ..........................................................................395

  Appendix D

  Fuel Supply: Manufactured/Mobile Home Parks and Recreational Vehicle Parks ..........................................403

  Appendix E

  Sustainable Practices ......................................................................................................................................411

  Appendix F

  Sizing of Venting Systems and Outdoor Combustion and Ventilation Opening Design ..................................533

  Appendix G

  Example Calculation of Outdoor Air Rate........................................................................................................545

  Appendix H

  Professional Qualifications ..............................................................................................................................549

  Appendix I

  Indoor Horticultural Facilities ..........................................................................................................................553

  Appendix J

  Clean Air Delivery............................................................................................................................................559

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  CALIFORNIA MECHANICAL CODE – MATRIX ADOPTION TABLE

  APPENDIX A – RESIDENTIAL PLAN EXAMINER REVIEW FORM FOR HVAC SYSTEM DESIGN

  (Matrix Adoption Tables are non-regulatory, intended only as an aid to the code user. See Chapter 1 for state agency authority and building applications.)

  Adopting Agency	BSC	BSC- CG	SFM	HCD	Col6	Col7	DSA	Col9	Col10	OSHPD	Col12	Col13	Col14	Col15	Col16	Col17	BSCC	DPH	AGR	DWR	CEC	CA	SL	SLC
  Adopting Agency	BSC	BSC- CG	SFM	1	2	1-AC	AC	** SS**	** SS/CC**	1	1R	2	3	4	5	6	6	6	6	6	6	6	6	6
  Adopt Entire Chapter
  Adopt Entire Chapter as amended (amended sections listed below)
  Adopt only those sections that are listed below
  Chapter/Section

• CRC § 304.8 Medium relevance — show source text

  For SI units: 1 foot = 304.8 mm, 1 pound-force per square inch = 6.8947 kPa

  1112.12.5 Simultaneous Operation. When outlets of two or more relief devices or fusible plugs, which are

  TABLE 1112.12.4

  ATMOSPHERIC PRESSURE AT NOMINAL INSTALLATION ELEVATION ( Pa )

  [ASHRAE 15: TABLE 9-2]

  For SI units: 1 foot = 304.8 mm, 1 pound-force per square inch = 6.8947 kPa

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  REFRIGERATION

  1113.2 Type of Protection. Pressure vessels with an internal gross volume of 3 cubic feet (0.1 m [3] ) or less shall use one or more pressure relief devices or a fusible plug. Pressure vessels of more than 3 cubic feet (0.1 m [3] ) but less than 10 cubic feet (0.28 m [3] ) internal gross volume shall use one or more pressure relief devices. Fusible plugs shall not be used.

  [ASHRAE 15:9.7.2.1, 9.7.2.2]

  1113.3 Discharging into Lowside of System. For pressure-relief valves discharging into the lowside of the system, a single relief valve (not rupture member) of the required relieving capacity shall not be used on vessels of 10 cubic feet (0.28 m [3] ) or more internal gross volume except under the conditions permitted in Section 1112.11.3. [ASHRAE 15:9.7.3]

  1113.4 Parallel Pressure-Relief Devices. Two or more

  pressure-relief devices in parallel to obtain the required capacity shall be considered as one pressure-relief device. The discharge capacity shall be the sum of the capacities required for each pressure vessel being protected.

  1113.5 Discharge Capacity. The minimum required discharge capacity of the pressure-relief device or fusible plug for a pressure vessel shall be determined in accordance with ASHRAE 15.

  1113.6 Three-Way Valve. Pressure vessels of 10 cubic feet (0.28 m [3] ) or more internal gross volume shall use one or more rupture member(s) or dual pressure-relief valves where discharging to the atmosphere. Dual pressure-relief valves shall be installed with a three-way valve to allow testing or repair. Where dual relief valves are used, the valve shall comply with Section 1113.5.

  Exception: A single relief valve shall be permitted on pressure vessels of 10 cubic feet (0.28 m [3] ) or more internal gross volume where in accordance with the following conditions:

  (1) The relief valves are located on the lowside of the sys tem.

  (2) The vessel is provided with shutoff valves designed to allow pumpdown of the refrigerant charge of the pressure vessel.

  (3) Other pressure vessels in the system are separately protected in accordance with Section 1113.1. [ASHRAE 15:9.7.2.3]

  1114.0 Special Discharge Requirements.

• CMC § 2025 Medium 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.

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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.

• CRC § 4.1 Medium relevance — show source text

  4.1||||||||||†||†|†|†|†|||||||||| |603.4.1.1||||||||||X||X|X|X|X|||||||||| |603.9.2||||†|†|||||||||||||||||||| |603.9.2.1|||||||||||||||||||||X|||| |605.1||||||||||X|X|X|X|X|X|||||||||| |605.2||||||||||X|||X|X|X|||||||||| |605.3||||||||||X||X||X|X|||||||||| |606.1||||X|X|||||||||||||||||||| |606.4.1|||X|||||||||||||||||||||| |607.1.1||||||||||X|X|X|X|X|X|||||||||| |609.1|||X|||||||||||||||||||||| |609.1.1|||X|||||||||||||||||||||| |609.2|||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 6

  DUCT SYSTEMS

  601.0 General.

  601.1 Applicability. Ducts and plenums that are portions of a heating, cooling, ventilation, or exhaust system shall comply with the requirements of this chapter, Chapter 5 for exhaust ducts, and Chapter 7 for combustion air ducts. 601.2 Sizing Requirements. Duct systems shall be sized in accordance with applicable standards in Chapter 18 or by other approved methods.

  Exception: Residential duct systems shall be sized in accordance with ACCA Manual D, ACCA Manual Zr, as applicable, or by other approved methods.

  601.2.1 California Energy Code Residential Return Duct Sizing Requirements. California Energy Code Tables 150.0-B and 150.0-C specify return duct sizing requirements for single return and multiple return duct systems, respectively, that are applicable as an alternative to confirming system airflow via field verification and diagnostic testing. See California Energy Code Section 150.0(m)13 for provisions applicable to newly con- structed buildings, and Section 150.2(b)(1)(F)(ii)(a) for alterations.

  602.0 Material.

  602.1 General. Materials used for duct systems shall comply with Section 602.2 through Section 602.7 as applicable. Exception: [OSHPD 1, 1R, 2, 3, 4 & 5] See Section 407.4.2.

• CRC § 503.0. Medium relevance — show source text

  The heating, ventilation, and air-conditioning system of other buildings shall be in accordance with Section E 503.0. E 502.2 Heating, Ventilating, and Air-Conditioning Systems and Equipment. This section shall regulate only equipment using single-phase electric power, air conditioners, and heat pumps with rated cooling capacities less than 65 000 British thermal units per hour (Btu/h) (19 kW), warm air furnaces with rated heating capacities less than 225 000 Btu/h (66 kW), boilers less than 300 000 Btu/h (88 kW) input, and heating-only heat pumps with rated heating capacities less than 65 000 Btu/h (19 kW). [ASHRAE 90.2:6.2] E 502.2.1 Nonresidential Type Systems and Equipment. Heating, ventilating, and air-conditioning systems and equipment that do not fall under the requirements of Section E 502.0 shall be in accordance with the applicable requirements of Section E 503.0. E 502.3 Balancing. The air distribution system design, including outlet grilles, shall provide a means for balancing the air distribution system unless the design procedure provides a system intended to operate within plus or minus 10 percent of design air quantities. [ASHRAE 90.2:6.3] E 502.3.1 Balancing Dampers. Balancing dampers shall be installed in branch ducts, and the axis of the damper shall be installed parallel to the direction of airflow in the main duct.

  E 502.4 Ducts. Ducts shall be sized, installed, and tested in accordance with Section E 502.4.1 through Section E 502.4.4.

  E 502.4.1 Insulation for Ducts. Portions of the air distribution system installed in or on buildings for heating and cooling shall be R-8. Where the mean outdoor dewpoint temperature in a month exceeds 60°F (16°C), vapor retarders shall be installed on conditioned-air supply ducts. Vapor retarders shall have a water vapor permeance not exceeding 0.5 perm [2.87 E-11 kg/(Pa•s•m [2] )] where tested in accordance with Procedure A in ASTM E96.

  Insulation shall not be required where the ducts are within the conditioned space. [ASHRAE 90.2:6.4] E 502.4.2 Ducts and Register Penetrations. Joints, seams, and penetrations of duct systems shall be made airtight by means of mastics, gasketing, or other means in accordance with this code. Register penetrations shall be sealed to the wall or floor assemblies. Where HVAC duct penetrates a conditioned space, the duct penetration shall be sealed to the wall or floor assembly to prevent leakage into an unconditioned space.

  2025 CALIFORNIA MECHANICAL CODE 415

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  APPENDIX E

  E 502.4.3 Duct Leakage Test. For systems with a duct or air handler outside of the conditioned space, a duct leakage test shall be performed in accordance with Section E 502.4.3.1.