207.0 – E –
California Mechanical Code (Title 24, Part 4) · 2025 edition · updated 2026-09-10 · California
Italicized text is a California amendment to the model code, as printed in the official publication.
Easily Accessible. See Accessible, Readily . Effective Ground-Fault Current Path. An intentionally constructed, low impedance electrically conductive path designed and intended to carry current under ground-fault conditions from the point of a ground fault on a wiring system to the electrical supply source and that facilitates the operation of the overcurrent protective device or ground-fault detectors. [NFPA 54:3.3.33]
Electric Duct Heaters. A heater located in the airstream of a forced-air system where the air-moving unit is not provided as an integral part of the equipment.
DEFINITIONS
Family. [HCD 1] “Family” is an individual or two or more persons who are related by blood or marriage, or otherwise, live together in a dwelling unit. Field-Applied Grease Duct Enclosures. A listed system evaluated for reduced clearances to combustibles and as an alternative to a duct with its fire-rated enclosure. [NFPA 96:3.3.22.2.2]
Fire Barrier. A fire-resistance-rated wall or assembly of materials designed to restrict the spread of fire in which continuity is maintained.
Fire Code. Whenever the term “Fire Code” is used in this code, it shall mean the California Fire Code, Title 24, Part 9.
Fire Partition. An interior wall or partition of a building that separates two areas and serves to restrict the spread of fire but does not qualify as a fire wall.
Fire Resistance Rating. The time, in minutes or hours, that materials or assemblies have withstood a fire exposure as established in accordance with ASTM E119 or UL 263.
[NFPA 96:3.3.25]
Fire-Resistive Construction. Construction in accordance with the requirements of the building code for the time period specified.
Fire Wall. A wall separating buildings or subdividing a building to prevent the spread of the fire and having a fire resistance rating and structural stability. [NFPA 96:3.3.26] Fireplace Stove. A chimney-connected, solid-fuel-burning stove (appliance) having part of its fire chamber open to the
room.
Flammable Vapor or Fumes. The concentration of flammable constituents in air that exceeds 25 percent of its Lower Flammability Limit (LFL).
Flood Hazard Area. The greater of the following two areas:
(1) The area within a floodplain subject to a 1 percent or greater chance of flooding in any given year.
(2) The area designated as a flood hazard area on a community’s flood hazard map, or otherwise legally designated.
Floor Furnace. A completely self-contained unit furnace suspended from the floor of the space being heated, taking air for combustion from outside this space. [NFPA 54:3.3.45.5] With means for observing flames and lighting the appliance from such space.
Flue Collar. That portion of an appliance designed for the attachment of a draft hood, vent connector, or venting system. [NFPA 54:3.3.44]
Forced-Air Furnace. A furnace equipped with a fan or blower that provides the primary means for circulation of air.
[NFPA 54:3.3.45.6]
Downflow-Type Furnace. A forced-air-type furnace designed with airflow essentially in a vertical path, discharging air at or near the bottom of the furnace. [NFPA 211:3.3.79.2]
Enclosed Furnace. A specific heating or heating and ventilating furnace incorporating an integral total enclosure and using only outside air for combustion.
Horizontal-Type Furnace. A forced-air-type furnace designed with airflow through the furnace, essentially in a horizontal path. [NFPA 211:3.3.79.3] Upflow-Type Furnace. A forced-air-type furnace designed with airflow essentially in a vertical path, discharging air at or near the top of the furnace. [NFPA 211:3.3.79.4]
Fractionation. A change in composition of a blend by preferential evaporation of the more volatile component or condensation of the less volatile component.
Fume Incinerators. Devices that use intense heat or fire to break down, oxidize, or both, vapors and odors contained in gases or air being exhausted into the atmosphere. {NFPA 96:3.3.27} Furnace, Central. A self-contained appliance for heating air by transfer of heat of combustion through metal to the air and designed to supply heated air through ducts to spaces remote from or adjacent to the appliance location. [NFPA 54:3.3.45.1]
Fusible Link. A form of fixed-temperature heat-detecting device sometimes employed to restrain the operation of an electrical or mechanical control until its designed temperature is reached. [NFPA 96:3.3.28] Such devices are to be replaced following each operation. Fusible Plug. A device arranged to relieve pressure by operation of a fusible member at a predetermined temperature.
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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
Overview- 201.1 Applicability. For the purpose of this code, the followi…
- 202.1 General. The definitions of terms are arranged alphabeti…
- 203.0 – A –
- 204.0 – B –
- 205.0 – C –
- 206.0 – D –
- 208.0 – F –
- 207.0 – E –
- 209.0 – G –
- 210.0 – H –
- 211.0 – I –
- 212.0 – J –
- 214.0 – L –
- 215.0 – M –
- 216.0 – N –
- 217.0 – O –
- 218.0 – P –
- 220.0 – R –
- 221.0 – S –
- 222.0 – T –
- 223.0 – U –
- 225.0 – W –
- 224.0 – V –
- 228.0 – Z –
- Chapter 3 — GENERAL REGULATIONS
- 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 — GEOTHERMAL ENERGY SYSTEMS AND AMBIENT TEMPERATURE…
- Chapter 18 — 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 — SIZING OF VENTING SYSTEMS AND OUTDOOR COMBUSTION …
- Appendix G — EXAMPLE CALCULATION OF OUTDOOR AIR RATE
- Appendix H — PROFESSIONAL QUALIFICATIONS
- Appendix I — INDOOR HORTICULTURAL FACILITIES
- Appendix J — CLEAN AIR DELIVERY