Chapter 3 — GENERAL REGULATIONS
302.3 Alternative Engineered Design. An alternative
California Mechanical Code (Title 24, Part 4) · 2022 edition · updated 2026-09-10 · California
Italicized text is a California amendment to the model code, as printed in the official publication.
engineered design shall comply with the intent of the provisions of this code and shall provide an equivalent level of quality, strength, effectiveness, fire resistance, durability, and safety. Material, equipment, or components shall be designed and installed in accordance with the manufacturer’s installation instructions.
302.3.1 Permit Application. The registered design professional shall indicate on the design documents that the mechanical system, or parts thereof, is an alternative engineered design so that it is noted on the construction permit application. The permit and permanent permit records shall indicate that an alternative engineered design was part of the approved installation. 302.3.2 Technical Data. The registered design professional shall submit sufficient technical data to substantiate the proposed alternative engineered design and to prove that the performance meets the intent of this code. 302.3.3 Design Documents. The registered design professional shall provide two complete sets of signed and sealed design documents for the alternative engineered design for submittal to the Authority Having Jurisdiction. The design documents shall include floor plans of the work. Where appropriate, the design documents shall indicate location, sizing, and loading of appurtenances, equipment, appliances, and devices.
302.3.4 Design Approval. An approval of an alternative engineered design shall be at the discretion of the Authority Having Jurisdiction. The exercise of this discretionary approval by the Authority Having Jurisdiction shall have no effect beyond the jurisdictional boundaries of said Authority Having Jurisdiction. An alternative engineered design so approved shall not be considered as in accordance with the requirements, intent, or both of this code for a purpose other than that granted by the Authority Having Jurisdiction. 302.3.5 Design Review. The Authority Having Jurisdiction shall have the authority to require testing of the alternative engineered design in accordance with Section 302.2.1, including the authority to require an independent review of the design documents by a registered design professional selected by the Authority Having Jurisdiction and at the expense of the applicant. 302.3.6 Inspection and Testing. The alternative engineered design shall be tested and inspected in accordance with the submitted testing and inspection plan and the requirements of this code.
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Ask AI about this code▸Contents — California Mechanical Code (Title 24, Part 4)
- Chapter 1 — GENERAL CODE PROVISIONS
- Chapter 2 — DEFINITIONS
▸Chapter 3 — GENERAL REGULATIONS
Overview- 301.1 Applicability. This chapter covers general requirements …
- 301.2 Approval. Equipment or appliance shall be approved
- 301.3 Design of Equipment. The installer or contractor
- 301.4 Electrical Connections. For equipment regulated
- 301.5 Oil-Burning Appliances. The tank, piping, and
- 301.6 Personnel Protection. A metal guard shall be provided ar…
- 301.7 OSHPD 1R [OSHPD 1R]. For OSHPD 1R, refer to
- 302.1 Minimum Standards. Listed pipe, pipe fittings,
- 302.2 Alternate Materials and Methods of Construc-
- 302.3 Alternative Engineered Design. An alternative
- 303.1 Listed Appliances. The installation of equipment
- 303.2 Closet or Alcove Installations. [Not adopted
- 303.3 Unlisted Appliances. Except as otherwise permitted in th…
- 303.4 Anchorage of Appliances. Appliances designed to
- 303.5 Movement. Movement of appliances with casters
- 303.6 Identification of Equipment. Where more than one
- 303.7 Liquefied Petroleum Gas Facilities. Containers,
- 303.8 Appliances on Roofs. Appliances on roofs shall be
- 303.9 Avoiding Strain on Gas Piping. Appliances shall
- 303.10 Clearances. Appliances and their vent connectors
- 303.11 Installation in Commercial Garages. Appliances installe…
- 303.12 Installation in Aircraft Hangars. Heaters in aircraft h…
- 304.1 General. All appliances shall be located with respect
- 304.2 Sloped Roof. Where equipment or appliances that
- 304.3 Access to Appliances on Roofs. Appliances
- 304.4 Appliances in Attics and Under-Floor Spaces.
- 305.4 Elevator Shaft. Unless required for the functionality
- 305.5 Drainage Pan. Where a water heater is located in an
- 306.1 General. Heating appliances shall be equipped with
- 306.2 Building Automation Systems. [OSHPD 1]
- 305.1 Installation in Residential Garages. Appliances
- 305.2 Pit Location. Where excavation is necessary to
- 305.3 Flood Hazard Areas. For buildings located in flood
- 307.1 Fuel-Burning Appliances. Fuel-burning heating
- 307.2 Electric Heating Appliances. Electric heating
- 307.3 Heat Pump and Electric Cooling Appliances.
- 307.4 Absorption Units. Absorption units shall bear a permanen…
- 308.1 General. Piping or equipment shall not be so located as
- 309.1 Engineering Practices. Design, construction, and
- 309.2 Concealing Imperfections. It shall be unlawful to
- 309.3 Installation Practices. Mechanical systems shall
- 310.1 Condensate Disposal. Condensate from air washers, air-co…
- 310.2 Condensate Control. Where any equipment or
- 310.3 Condensate Waste Pipe Material and Sizing.
- 310.4 Appliance Condensate Drains. Condensate drain
- 310.5 Point of Discharge. Air-conditioning condensate
- 310.6 Condensate Waste From Air-Conditioning
- 310.7 Plastic Fittings. Female plastic screwed fittings shall
- 311.1 Source. A heating or cooling air system shall be provide…
- 313.7 Gas Piping. Gas piping shall be supported by metal
- 311.2 Air Filters. Air filters shall be installed in a heating,
- 311.3 Prohibited Source. Outside or return air for a heating o…
- 311.4 Return-Air Limitations. Return air from one
- 311.5 California Energy Code Requirements for Res-
- 312.1 General. Water supply, sanitary drainage, and backflow p…
- 313.1 General. Piping, tubing, appliances, and appurtenances s…
- 313.2 Material. Hangers and anchors shall be of sufficient
- 313.3 Suspended Piping. Suspended piping or tubing
- 313.4 Alignment. Piping or tubing shall be supported in
- 313.5 Underground Installation. Piping or tubing in the
- 313.6 Hanger Rod Sizes. Hanger rod sizes shall be not
- 314.1 General. Heating, ventilating, and air-conditioning
- 315.1 General. Louvers located in areas within hurricaneprone …
- 316.1 General. Piping or tubing passing under or through
- 316.2 Installation. Piping or tubing shall be installed so that
- 316.3 Corrosion, Erosion, and Mechanical Damage.
- 316.4 Protectively Coated Pipe. Protectively coated pipe
- 316.5 Fire-Resistant Construction. Piping, tubing, and
- 316.6 Steel Nail Plates. Plastic piping or tubing, copper
- 316.7 Sleeves. Sleeves shall be provided to protect piping
- 316.8 Firewalls. A pipe sleeve through a firewall shall have
- 316.9 Structural Members. A structural member weakened or impa…
- 316.10 Rodentproofing. Mechanical system shall be constructed …
- 316.11 Metal Collars. In or on buildings where openings
- 317.1 Trenches. Trenches deeper than the footings of a
- 317.2 Tunneling and Driving. Tunneling and driving shall
- 317.3 Open Trenches. Excavations required to be made for
- 317.4 Excavations. Excavations shall be completely backfilled …
- 318.1 Applicability. This part is applicable to health facil-
- 318.2 Services/Systems and Utilities. Refer to Section
- 319.1 Requirements for Hospitals and Optional Serv-
- 319.2 Requirements for Skilled Nursing, Intermedi-
- 320.1 Requirements for Hospitals and Optional Serv-
- 320.2 Requirements for Skilled Nursing, Intermedi-
- 320.3 Requirements for Outpatient Facilities and
- 320.4 Telephone and Technology Equipment Centers.
- 320.5 Psychiatric Services. [OSHPD 1, 1R, 2, 4 & 5] For
- 321.1 (Does not apply to OSHPD 3 surgical clinic.) All heat-
- 321.2 All heating equipment and fans necessary to maintain
- 321.3 Equipment necessary for humidification of the areas
- 321.4 All supply, return, and exhaust fans required to maintain
- 321.5 All control components and control systems necessary
- 321.6 Alarms for airborne infection isolation rooms and pro-
- 322.1 The following conditions shall be met for sensitive
- 323.0 Mechanical Equipment Schedules. [OSHPD 1,
- Chapter 4 — VENTILATION AIR
- Chapter 5 — EXHAUST SYSTEMS
- Chapter 6 — DUCT SYSTEMS
- Chapter 7 — COMBUSTION AIR
- Chapter 8 — CHIMNEYS AND VENTS
- Chapter 9 — INSTALLATION OF SPECIFIC APPLIANCES
- Chapter 10 — BOILERS AND PRESSURE VESSELS
- Chapter 11 — REFRIGERATION
- Chapter 12 — HYDRONICS
- Chapter 13 — FUEL GAS PIPING
- Chapter 14 — PROCESS PIPING
- Chapter 15 — SOLAR ENERGY SYSTEMS
- Chapter 16 — STATIONARY POWER PLANTS
- Chapter 17 — REFERENCED STANDARDS
- Appendix A — RESIDENTIAL PLAN EXAMINER REVIEW FORM FOR HVAC SY…
- Appendix B — PROCEDURES TO BE FOLLOWED TO PLACE GAS EQUIPMENT …
- Appendix C — INSTALLATION AND TESTING OF OIL (LIQUID) FUEL-FIR…
- Appendix D — FUEL SUPPLY: MANUFACTURED/MOBILE HOME PARKS AND R…
- Appendix E — SUSTAINABLE PRACTICES
- Appendix F — GEOTHERMAL ENERGY SYSTEMS
- Appendix G — SIZING OF VENTING SYSTEMS AND OUTDOOR COMBUSTION …
- Appendix H — EXAMPLE CALCULATION OF OUTDOOR AIR RATE