Outdoor air intakes, makeup air and system details

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

• CMC § 407.1 High relevance — show source text

  407.1 General.

  407.1.1 All supply-air, return air, and exhaust-air sys- tems shall be mechanically operated and such systems for areas listed in Table 4-A shall be operated continu- ously. Natural ventilation through windows or other openings such as louvers will be considered as supple- mental to the required mechanical ventilation systems.

  Exceptions:

  (1) Natural ventilation shall not be used in airborne infection isolation rooms and protective environment

  rooms.

  (2) Unoccupied turndown shall be permitted in accor- dance with Section 407.7.

  407.1.2 Fans serving exhaust systems shall be located at the discharge end of the system. Ductwork within the building shall be under negative pressure. The ventilation rates shown in Table 4-A shall be considered as minimum acceptable rates and shall not be construed as precluding the use of higher ventilation rates if they are required to meet design conditions. 407.1.3 Services/Systems and Utilities. (Refer to Sec- tion 1224.4.1 of the California Building Code).

  407.2 Outdoor Air Intakes and Exhaust Outlets.

  407.2.1 Outdoor Air Intakes. Outdoor air intakes shall be located at least 25 feet (7.62 m) from exhaust outlets of ventilating systems, combustion equipment stacks, med- ical-surgical vacuum systems, cooling towers, and areas that may collect vehicular exhaust or other noxious fumes. Plumbing vents shall be located in relation to out- door air intakes per California Plumbing Code. The bot- tom of outdoor air intakes shall be located as high as practicable, but not less than 10 feet (3048 mm) above ground level. If installed above the roof, they shall be located 18 inches (457 mm) above roof level or 3 feet (914 mm) above a flat roof where heavy snowfall is anticipated. Outside air intakes located in a below grade areaway shall have the top of the areaway extend a minimum of 10 feet (3048 mm) above grade.

  Exceptions:

  (1) These dimensions may be reduced if it is demon- strated by the submission of details and calculations that location of intakes with respect to exhausts and

  their orientation, or the use of special filters, pro- vides equal performance.

  (2) The requirements regarding the bottom of outdoor air intakes and installation through the roof do not apply to skilled nursing facilities, intermediate-care facilities or nonsensitive areas in correctional treat-

  ment centers.

  407.2.2 Exhaust Outlets. Exhaust outlets shall be located a minimum of 10 feet (3048 mm) above adjoining grade and 10 feet (3048 mm) from doors, occupied areas, and operable windows.

  Exception: Airborne infection isolation rooms shall comply with Section 414.1.

• CMC § 402.1. High relevance — show source text

  Where:

  Vbz = breathing zone outdoor airflow, per Table 402.1. Az = zone floor area, the net occupiable floor area of the ventilation zone. Hvs = vertical separation between the center of the top and bottom openings’ free operable area; in case of multiple horizontally spaced pairs of openings, use shortest distance encountered. As = openable area of smallest opening (top or bottom); in case of multiple horizontally spaced pairs of top-and-bottom openings, use aggregated areas. Al = openable area of largest opening (top or bottom); in case of multiple horizontally spaced pairs of top-and-bottom openings, use aggregated areas.

  • Volumetric airflow rates used to estimate required operable area are based on the following:

  • Dry-air density of 0.075 lbda/ft [3] (1.2 kgda/m [3] ) at a barometric pressure of 1 atm (101.3 kPa) and an air temperature of 70°F (21°C)

  • Temperature difference between indoors and outdoors of 1.8°F (1°C)

  • Gravity constant of 32.2 ft/s [2] (9.81m/s [2] )

  • Window discharge coefficient of 0.6

  ical ventilation systems shall include controls, manual or automatic, that enable the fan system to operate wherever the spaces served are occupied. The system shall be designed to maintain minimum outdoor airflow as required by Section 403.0 under any load conditions.

  402.4 Outdoor Air Intakes. Ventilation system outdoor air intakes shall be designed in accordance with Section 402.4.1 through Section 402.4.5. [ASHRAE 62.1:5.5]

  402.4.1 Location. Outdoor air intakes (including openings that are required as part of a natural ventilation system) shall be located such that the shortest distance from the intake to any specific potential outdoor contaminant source listed in Table 402.4.1 shall be equal to or greater than the following:

  (1) The separation distance in Table 402.4.1 or

  (2) The calculation methods in ASHRAE 62.1 Normative Appendix B and shall comply with all other requirements of this section. [ASHRAE 62.1:5.5.1]

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  VENTILATION AIR

  TABLE 402.4.1

  AIR INTAKE MINIMUM SEPARATION DISTANCE

  [ASHRAE 62.1:TABLE 5-1]

  OBJECT	MINIMUM DISTANCE (feet)
  Class 2 air exhaust/relief outlet	10
  Class 3 air exhaust/relief outlet	15
  Class 4 air exhaust/relief outlet	30
  Cooling tower exhaust	25
  Cooling tower intake or basin	15
  Driveway, street, or parking place	5
  Garage entry, automobile loading area, or drive-in queue	15
  Garbage storage/pick-up area,

• CMC § 402.4.1 High relevance — show source text

  402.4.1 Location. Outdoor air intakes (including openings that are required as part of a natural ventilation system) shall be located such that the shortest distance from the intake to any specific potential outdoor contaminant source listed in Table 402.4.1 shall be equal to or greater than the following:

  (1) The separation distance in Table 402.4.1 or

  (2) The calculation methods in ASHRAE 62.1 Normative Appendix B and shall comply with all other requirements of this section. [ASHRAE 62.1:5.5.1]

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  VENTILATION AIR

  TABLE 402.4.1

  AIR INTAKE MINIMUM SEPARATION DISTANCE

  [ASHRAE 62.1:TABLE 5-1]

  OBJECT	MINIMUM DISTANCE (feet)
  Class 2 air exhaust/relief outlet	10
  Class 3 air exhaust/relief outlet	15
  Class 4 air exhaust/relief outlet	30
  Cooling tower exhaust	25
  Cooling tower intake or basin	15
  Driveway, street, or parking place	5
  Garage entry, automobile loading area, or drive-in queue	15
  Garbage storage/pick-up area, dumpsters	15
  Plumbing vents terminating at least 3 feet above the level of the outdoor air intake	3
  Plumbing vents terminating less than 3 feet above the level of the outdoor air intake	10
  Roof, landscaped grade, or other surface directly below intake	1
  Thoroughfare with high traffic volume	25
  Truck loading area or dock, bus parking/idling area	25
  Vents, chimneys, and flues from combustion appli- ances and equipment	15

  For SI units: 1 foot = 304.8 mm

  402.4.1.1 Exhaust/Relief Outlets. Separation criteria for Class 2 and Class 3 exhaust/relief outlets apply to the distance from the outdoor air intakes for one ventilation system to the exhaust and relief outlets for any other ventilation system. [ASHRAE 62.1:5.5.1.1]

  402.4.1.2 Fuel-Burning Equipment. The minimum distances relative to fuel-fired appliances shall be as required by NFPA 54/ANSI Z223.1 for fuelgas-burning appliances and equipment, NFPA 31 for oil burning appliances and equipment, and NFPA 211 for other combustion appliances and equipment.

  [ASHRAE 62.1:5.5.1.2]

  402.4.1.3 Roof, Landscaped Grade, or Another Surface Directly Below Intake. Where snow accumulation is expected, the surface of the snow at the expected average snow depth shall be considered to be a surface directly below an intake.

• CMC § 407.2.2 High relevance — show source text

  Plumbing vents shall be located in relation to out-_ door air intakes per California Plumbing Code. The bot- tom of outdoor air intakes shall be located as high as practicable, but not less than 10 feet (3048 mm) above ground level. If installed above the roof, they shall be located 18 inches (457 mm) above roof level or 3 feet (914 mm) above a flat roof where heavy snowfall is anticipated. Outside air intakes located in a below grade areaway shall have the top of the areaway extend a minimum of 10 feet (3048 mm) above grade.

  Exceptions:

  (1) These dimensions may be reduced if it is demon- strated by the submission of details and calculations that location of intakes with respect to exhausts and

  their orientation, or the use of special filters, pro- vides equal performance.

  (2) The requirements regarding the bottom of outdoor air intakes and installation through the roof do not apply to skilled nursing facilities, intermediate-care facilities or nonsensitive areas in correctional treat-

  ment centers.

  407.2.2 Exhaust Outlets. Exhaust outlets shall be located a minimum of 10 feet (3048 mm) above adjoining grade and 10 feet (3048 mm) from doors, occupied areas, and operable windows.

  Exception: Airborne infection isolation rooms shall comply with Section 414.1.

  407.2.2.1 Hazardous Exhaust Outlets. Haz- ardous exhaust outlets from airborne infection iso- lation rooms, bronchoscopy and sputum collection exhaust, hazardous drug compounding, morgues, autopsy rooms and laboratory chemical fume hoods shall discharge a minimum of 10 feet (3048 mm) above the adjacent roof surface and a minimum of 30 feet (9144.mm) from outdoor air intakes, build- ing openings and areas normally accessible to the public.

  407.3 Air Balance.

  407.3.1 The ventilation systems shall be designed and balanced to provide the general air balance relationship to adjacent areas, shown in Table 4-A. The ventilation systems shall be balanced in accordance with the latest edition of standards published by the Associated Air Bal- ance Council (AABC), the National Environmental Bal- ancing Bureau (NEBB), or the Testing, Adjusting and Balancing Bureau (TABB). Air balance tolerancing val- ues shall not result in noncompliance of the minimum required pressurization per Table 4-A.

  407.4 Air Circulation.

  407.4.1 Design of the ventilation system shall provide air movement that is generally from clean to less clean areas.

  407.4.1.1 All air distribution devices and supply air outlets shall meet the requirements of ASHRAE 170, Section 6.7.2 and Table 6-2.

  407.4.1.2 Supply outlets and return and exhaust air inlets shall be located to prevent short-circuiting.

• CMC § 402.2.1.6 High relevance — show source text

  402.2.1.6(A)(1) Single Openings . . . . . . . . . . . . . . . 71

  Table Minimum Openable Areas:

  402.2.1.6(A)(2) Two Vertically

  Spaced Openings . . . . . . . . . . . . . . 71

  402.3 Mechanical Ventilation . . . . . . . . . . 71

  402.4 Outdoor Air Intakes. . . . . . . . . . . . . 71

  Table 402.4.1 Air Intake Minimum

  Separation Distance . . . . . . . . . . . . 72

  403.0 Ventilation Rates . . . . . . . . . . . . . . 72

  403.1 General. . . . . . . . . . . . . . . . . . . . . . 72

  403.2 Zone Calculations. . . . . . . . . . . . . . 73

  403.3 Single-Zone Systems . . . . . . . . . . . 73

  403.4 One Hundred Percent Outdoor

  Air Systems . . . . . . . . . . . . . . . . . . 73

  403.5 Multiple-Zone Recirculating Systems . . . . . . . . . . . . . . . . . . . . . 73

  403.6 Design for Varying Operating Conditions. . . . . . . . . . . . . . . . . . . . 74

  403.7 Exhaust Ventilation. . . . . . . . . . . . . 74

  403.8 Dynamic Reset . . . . . . . . . . . . . . . . 75

  403.9 Air Classification and

  Recirculation. . . . . . . . . . . . . . . . . . 75

  Table 403.9 Airstreams or Sources

  Description Air Class . . . . . . . . . . . 75

  403.10 Air Balance . . . . . . . . . . . . . . . . . . . 75

  404.0 Alternative Procedure for

  Multiple-Zone Systems Ventilation Efficiency . . . . . . . . . . . 76

  xxx

  404.1 System Ventilation Efficiency . . . . . 76

  404.2 Average Outdoor Air Fraction. . . . . 76

  404.3 Zone Ventilation Efficiency . . . . . . . 76

  405.0 Ventilation for Residential

  Occupancies. . . . . . . . . . . . . . . . . . 77

  405.1 General. . . . . . . . . . . . . . . . . . . . . . 77

  405.2 Ventilation Air Rate. . . . . . . . . . . . . 77

  405.3 Bathroom Exhaust . . . . . . . . . . . . . 77

  405.4 Kitchen Exhaust . . . . . . . . . . . . . . . 77

  405.5 Ventilation Openings . . . . . . . . . . . 77

  406.0 Evaporative Cooling System for Health Care Facilities . . . . . . . . 78

  407.0 Ventilation System Details . . . . . . . 78

  407.1 General. . . . . . . . . . . . . . . . . . . . . . 78

  407.2 Outdoor Air Intakes and

• CMC § 403.3 High relevance — show source text

  403.3 Single-Zone Systems. For ventilation systems where one or more air handlers supply a mixture of outdoor air and recirculated air to only one ventilation zone, the outdoor air intake flow ( Vot ) shall be determined in accordance with Equation 403.3. [ASHRAE 62.1:6.2.2]

  Vot = Voz (Equation 403.3)

  403.4 One Hundred Percent Outdoor Air Systems. For ventilation systems where one or more air handlers supply only outdoor air to one or more ventilation zones, the outdoor air intake flow ( Vot ) shall be determined in accordance with Equation 403.4. [ASHRAE 62.1:6.2.3]

  Vot = ∑ all zones Voz (Equation 403.4)

  403.5 Multiple-Zone Recirculating Systems. For ventilation systems where one or more air handlers supply a mixture of outdoor air and recirculated air to more than one ventilation zone, the outdoor air intake flow ( Vot ) shall be determined in accordance with Section 403.5.1 through Section 403.5.2. [ASHRAE 62.1:6.2.4]

  403.5.1 Uncorrected Outdoor Air Intake. The uncorrected outdoor air intake ( Vou ) flow shall be determined in accordance with Equation 403.5.1. [ASHRAE 62.1:6.2.4.1]

  (Equation 403.5.1) Vou = D ∑ all zones ( Rp•Pz ) + ∑ all zones ( Ra•Az )

  403.5.1.1 Occupant Diversity. The occupant diversity ratio ( D) shall be determined in accordance with Equation 403.5.1.1 to account for variations in population within the ventilation zones served by the system.

  (Equation 403.5.1.1) D = Ps / ∑ all zones Pz

  Where the system population ( Ps ) is the total population in the area served by the system.

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  VENTILATION AIR

  Exception: Alternative methods to account for occupant diversity shall be permitted, provided that the resulting ( Vou ) value is not less than that determined in accordance with Equation 403.5.1.

  [ASHRAE 62.1:6.2.4.1.1]

  403.5.1.2 System Ventilation Efficiency. The system ventilation efficiency ( Ev ) shall be determined in accordance with Section 403.5.1.3 for the

  simplified procedure or Section 404.0 for the alternate procedure. These procedures also establish zone minimum primary airflow rates for VAV systems.

  [ASHRAE 62.1:6.2.4.2]

  403.5.1.3 Simplified Procedure for System Ventilation Efficiency. System ventilation efficiency ( Ev ) shall be determined in accordance with Equation 403.5.1.3(1) or Equation 403.5.1.3(2).

• CMC § 150.0 High relevance — show source text

  Filters and heat/energy cores behind access panels, access doors, or grilles located not more than 10 feet above a walking surface inside a space specified above comply with this requirement. Exception to Section 150.0(o)1Civa: Systems that require servicing from inside the attic shall have the following:

  1. A fault indicator display (FID) meeting the requirements of Reference Appendix JA17.
  2. An attic access door located in a wall or, where attic access is provided through a ceiling, an attic access hatch that includes an integrated ladder.
  3. A walkway from the attic access door to the HRV/ERV. b. IAQ system component accessibility: Fans, motors, heat exchangers, filters and recovery cores shall meet all applicable requirements of California Mechanical Code Section 304.0 accessibility for service. c. Outdoor air intake design: Outdoor air intakes shall comply with California Mechanical Code Section 402.4.1.

  d. Outdoor air intake location and accessibility: To provide access for cleaning, outdoor air intakes shall be accessible. Air intakes located not more than 10 feet above a walking surface comply with this requirement. If located on roofs, they shall meet the requirements of California Mechanical Code Section 304.3.1.

  Exception to Section 150.0(o)1Civd: Outdoor air intake serving equipment with an FID meeting the requirements of Reference Appendix JA17.

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  SINGLE-FAMILY RESIDENTIAL BUILDINGS— MANDATORY FEATURES AND DEVICES

  D. Air filtration. Air filtration shall conform to the specifications in Section 150.0(m)12. Compliance with ASHRAE 62.2 Sections 6.7 (Minimum Filtration) and 6.7.1 (Filter Pressure Drop) shall not be required.

  E. Reserved.

  F. Reserved.

  G. Local mechanical exhaust. A local mechanical exhaust system shall be installed in each kitchen and bathroom. Systems shall be rated for airflow in accordance with ASHRAE 62.2 Section 7.1. i. Nonenclosed kitchens shall have a demand-controlled mechanical exhaust system meeting the requirements of Section 150.0(o)1Giii. ii. Enclosed kitchens and all bathrooms shall have either one of the following alternatives a or b: a. A demand-controlled mechanical exhaust system meeting the requirements of Section 150.0(o)1Giii. b. A continuous mechanical exhaust system meeting the requirements of Section 150.0(o)1Giv. iii. Demand-controlled mechanical exhaust. A local mechanical exhaust system shall be designed to be operated as needed.

  a. Control and operation. Demand-controlled mechanical exhaust systems shall be provided with at least one of the following controls:

  1. A readily accessible occupant-controlled ON-OFF control.
  2. An automatic control that does not impede occupant ON control. b. Ventilation rate and capture efficiency. The system shall meet or exceed either the minimum airflow in accordance with Table 150.0-E or the minimum capture efficiency in accordance with Table 150.0-E, and Table 150.0-G. Capture efficiency ratings shall be determined in accordance with ASTM E3087 and listed in a product directory approved by the Energy Commission.
• CMC § 405.4.1 Medium relevance — show source text

  instructions.

  405.4.1 Exhaust Rate. For intermittent-controlled operations, the exhaust rate shall be not less than 100 ft [3] /min (47.2 L/s) for range hoods or 300 ft [3] /min (142 L/s) for mechanical exhaust fans including downdraft appliances. For continuous operated ventilation, the exhaust rate shall be not less than 50 ft [3] /min (23.6 L/s). 405.5 Ventilation Openings. Occupiable spaces shall be provided with a readily accessible ventilation opening openable to the outdoors. The opening shall be not less than 5 square feet (0.464 m [2] ) or 4 percent of the occupied floor area. The openable area shall be based on free, unobstructed area through the opening.

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  VENTILATION AIR

  406.0 Evaporative Cooling System for Health Care Facilities. [OSHPD 1, 2, 3, 4 & 5] Direct evaporative cool- ing systems where the air directly contacts the wetted surface or spray shall be limited in health facilities to nonpatient areas such as laundry rooms, and boiler or machinery rooms. Similar rooms with high heating-producing equipment will be consid- ered when specifically approved by the enforcing agency. The evaporative pads shall be a synthetic type. Filters shall be required in accordance with Tables 4-B and 4-C except utility rooms, i.e.: boiler or machinery rooms.

  407.0 Ventilation System Details. [OSHPD 1, 1R, 2, 3, 4 & 5]

  407.1 General.

  407.1.1 All supply-air, return air, and exhaust-air sys- tems shall be mechanically operated and such systems for areas listed in Table 4-A shall be operated continu- ously. Natural ventilation through windows or other openings such as louvers will be considered as supple- mental to the required mechanical ventilation systems.

  Exceptions:

  (1) Natural ventilation shall not be used in airborne infection isolation rooms and protective environment

  rooms.

  (2) Unoccupied turndown shall be permitted in accor- dance with Section 407.7.

  407.1.2 Fans serving exhaust systems shall be located at the discharge end of the system. Ductwork within the building shall be under negative pressure. The ventilation rates shown in Table 4-A shall be considered as minimum acceptable rates and shall not be construed as precluding the use of higher ventilation rates if they are required to meet design conditions. 407.1.3 Services/Systems and Utilities. (Refer to Sec- tion 1224.4.1 of the California Building Code).

  407.2 Outdoor Air Intakes and Exhaust Outlets.

  407.2.1 Outdoor Air Intakes. Outdoor air intakes shall be located at least 25 feet (7.62 m) from exhaust outlets of ventilating systems, combustion equipment stacks, med- ical-surgical vacuum systems, cooling towers, and areas that may collect vehicular exhaust or other noxious _fumes.

• CMC § 403.9 Medium relevance — show source text

  Table 403.9 Airstreams or Sources

  Description Air Class . . . . . . . . . . . 75

  403.10 Air Balance . . . . . . . . . . . . . . . . . . . 75

  404.0 Alternative Procedure for

  Multiple-Zone Systems Ventilation Efficiency . . . . . . . . . . . 76

  xxx

  404.1 System Ventilation Efficiency . . . . . 76

  404.2 Average Outdoor Air Fraction. . . . . 76

  404.3 Zone Ventilation Efficiency . . . . . . . 76

  405.0 Ventilation for Residential

  Occupancies. . . . . . . . . . . . . . . . . . 77

  405.1 General. . . . . . . . . . . . . . . . . . . . . . 77

  405.2 Ventilation Air Rate. . . . . . . . . . . . . 77

  405.3 Bathroom Exhaust . . . . . . . . . . . . . 77

  405.4 Kitchen Exhaust . . . . . . . . . . . . . . . 77

  405.5 Ventilation Openings . . . . . . . . . . . 77

  406.0 Evaporative Cooling System for Health Care Facilities . . . . . . . . 78

  407.0 Ventilation System Details . . . . . . . 78

  407.1 General. . . . . . . . . . . . . . . . . . . . . . 78

  407.2 Outdoor Air Intakes and

  Exhaust Outlets . . . . . . . . . . . . . . . 78

  407.3 Air Balance. . . . . . . . . . . . . . . . . . . 78

  407.4 Air Circulation . . . . . . . . . . . . . . . . . 78

  407.5 Variable Air Volume . . . . . . . . . . . . 79

  407.6 Economizers. . . . . . . . . . . . . . . . . . 79

  407.7 Unoccupied Turndown. . . . . . . . . . 79

  407.8 Building Pressurization . . . . . . . . . 80

  408.0 Filters . . . . . . . . . . . . . . . . . . . . . . . 80

  408.1 General. . . . . . . . . . . . . . . . . . . . . . 80

  408.2 Filters for Hospitals. . . . . . . . . . . . . 80

  408.3 Filters for Skilled Nursing Facilities, Intermediate Care Facilities, and Correctional

  Treatment Centers . . . . . . . . . . . . . 80

  408.4 Filters for Outpatient Facilities . . . . 80

  408.5 Filters for Recirculating

  Room Units. . . . . . . . . . . . . . . . . . . 80

• CMC § 8.13.6 Medium relevance — show source text

  [ASHRAE 15:8.13.6]

  »

  (1) Operated, where occupied, to supply not less than 0.5 CFM/ft [2] [2.54 L/(s•m [2] )] of machinery room area or 20 cubic feet per minute (9.44 L/s) per person.

  (2) Operable, where occupied at a volume required to not exceed the higher of a temperature rise of 18°F (10°C) above inlet air temperature or a maximum temperature of 122°F (50°C).

  1106.4 Natural Ventilation. When a refrigerating system is located outdoors more than 20 feet (6096 mm) from building openings and is enclosed by a penthouse, lean-to, or other open structure, natural or mechanical ventilation shall be provided. The requirements for such natural ventilation shall be in accordance with the following:

  (1) The free-aperture cross section for the ventilation of a machinery room shall be not less than as determined in accordance with Equation 1106.4.

  F = √ G (Equation 1106.4)

  Where:

  F = The free opening area, ft [2] (m [2] ).

  G = The mass of refrigerant in the largest system, any part of which is located in the machinery room, pounds.

  For SI units: 1 square foot = 0.0929 m [2], 1 pound = 0.453 kg

  (2) Locations of the gravity ventilation openings shall be based on the relative density of the refrigerant to air.

  [ASHRAE 15:8.14]

  1106.5 Combustion Air. No open flames that use combustion air from the machinery room shall be installed where refrigerant is used. Combustion equipment shall not be installed in the same machinery room with refrigerant-containing equipment except under one of the following conditions:

  (1) Combustion air shall be ducted from outside the machinery room and sealed in such a manner as to prevent refrigerant leakage from entering the combustion chamber.

  (2) A refrigerant detector, that is in accordance with Section 1106.2.5, shall be installed to automatically shut down the combustion process in the event of refrigerant leak age.

  Exception: Machinery rooms where carbon dioxide (R-744) or water (R-718) is the refrigerant.

  1106.6 Ventilation Intake. Makeup air intakes to replace the exhaust air shall be provided to the refrigeration machinery room directly from outside the building. Intakes shall be located as required by other sections of the code and fitted with backdraft dampers or other approved flow-control means to prevent reverse flow. Distribution of makeup air shall be arranged to provide thorough mixing within the refrigeration machinery room to prevent short circuiting of the makeup air directly to the exhaust.

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  REFRIGERATION

  1106.11.6.1 Mechanical Ventilation. The machinery room shall have a mechanical ventilation system in accordance with Section 1106.11.11. The mechanical ventilation system shall:

  (1) Run continuously, and failure of the mechanical ventilation system actuates an alarm, or

• CMC § 35.68 Medium relevance — show source text

  52|China Lake Naf|35.68|–117.68|California| |747020|0.50|Lemoore Reeves NAS|36.33|–119.95|California| |747185|0.46|Imperial|32.83|–115.58|California| |747187|0.46|Palm Springs Thermal AP|33.63|–116.17|California| |747188|0.48|Blythe Riverside Co Arpt|33.62|–114.72|California|

  iii. Required Mechanical Ventilation Rate [ASHRAE 62.2:4.1.2] The Required Mechanical Ventilation Rate ( Q fan ) shall be calculated using Equation 150.0-F. (Equation 150.0-F) Q fan = Q tot – Φ ( Q inf × A ext )

  where:

  Q fan = required mechanical ventilation rate, cfm (L/s). Q tot = total required ventilation rate, cfm (L/s) from Equation 150.0-B. Q inf = effective annual average infiltration rate, cfm (L/s) from Equation 150.0-E. A ext = 1 for single-family detached homes, or the ratio of exterior envelope surface area that is not attached to garages or other dwelling units to total envelope surface area for attached dwelling units not sharing ceilings or floors with other dwelling units, occupiable spaces, public garages, or commercial spaces. Φ = 1 for balanced ventilation systems and Q inf /Q tot otherwise. iv. Requirements for balanced and supply-only ventilation systems. a. IAQ filter and HRV/ERV accessibility: System air filters and HRV/ERV heat/energy recovery cores shall be located such that they are accessible for service from within occupiable spaces, basements, garages, balconies, and mechanical closets. Filters and heat/energy cores behind access panels, access doors, or grilles located not more than 10 feet above a walking surface inside a space specified above comply with this requirement. Exception to Section 150.0(o)1Civa: Systems that require servicing from inside the attic shall have the following:

  1. A fault indicator display (FID) meeting the requirements of Reference Appendix JA17.
  2. An attic access door located in a wall or, where attic access is provided through a ceiling, an attic access hatch that includes an integrated ladder.
  3. A walkway from the attic access door to the HRV/ERV. b. IAQ system component accessibility: Fans, motors, heat exchangers, filters and recovery cores shall meet all applicable requirements of California Mechanical Code Section 304.0 accessibility for service. c. Outdoor air intake design: Outdoor air intakes shall comply with California Mechanical Code Section 402.4.1.

  d. Outdoor air intake location and accessibility: To provide access for cleaning, outdoor air intakes shall be accessible. Air intakes located not more than 10 feet above a walking surface comply with this requirement. If located on roofs, they shall meet the requirements of California Mechanical Code Section 304.3.1.

  Exception to Section 150.0(o)1Civd: Outdoor air intake serving equipment with an FID meeting the requirements of Reference Appendix JA17.

  2025 CALIFORNIA ENERGY CODE 171

  on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

• CMC § 304.8 Medium relevance — show source text

  dumpsters|15| |
  
  Plumbing vents terminating at least 3 feet above the
  level of the outdoor air intake|3| |
  
  Plumbing vents terminating less than 3 feet above
  the level of the outdoor air intake|10| |
  
  Roof, landscaped grade, or other surface directly
  below intake|1| |
  
  Thoroughfare with high traffic volume|25| |
  
  Truck loading area or dock, bus parking/idling area|25| |
  
  Vents, chimneys, and flues from combustion appli-
  ances and equipment|15|

  For SI units: 1 foot = 304.8 mm

  402.4.1.1 Exhaust/Relief Outlets. Separation criteria for Class 2 and Class 3 exhaust/relief outlets apply to the distance from the outdoor air intakes for one ventilation system to the exhaust and relief outlets for any other ventilation system. [ASHRAE 62.1:5.5.1.1]

  402.4.1.2 Fuel-Burning Equipment. The minimum distances relative to fuel-fired appliances shall be as required by NFPA 54/ANSI Z223.1 for fuelgas-burning appliances and equipment, NFPA 31 for oil burning appliances and equipment, and NFPA 211 for other combustion appliances and equipment.

  [ASHRAE 62.1:5.5.1.2]

  402.4.1.3 Roof, Landscaped Grade, or Another Surface Directly Below Intake. Where snow accumulation is expected, the surface of the snow at the expected average snow depth shall be considered to be a surface directly below an intake.

  Exception: The minimum separation distance in Table 402.4.1 shall not apply where outdoor surfaces below the air intake are sloped more than 45 degrees (0.79 rad) from horizontal or where such surfaces are less than 1 inch (25.4 mm) in width.

  [ASHRAE 62.1:5.5.1.3]

  402.4.1.4 Laboratory Exhaust. Separation criteria for fume hood exhaust shall be in compliance with ANSI/ASSP Z9.5. [ASHRAE 62.1:5.5.1.4]

  402.4.2 Rain Entrainment. Outdoor air intakes that are part of the mechanical ventilation system shall be designed to manage rain entrainment in accordance with one or more of the following:

  (1) Limit water penetration through the intake to 0.07 oz/(ft [2] - h) [21.5 g/(m [2] - h)] of inlet area when tested using the rain test apparatus described in UL 1995.

  (2) Select louvers that limit water penetration to a maximum of 0.01 oz/ft [2] (3.05 g/m [2] ) of louver free area at the maximum free area intake velocity through the louver. This water penetration rate shall be determined when subjected to the water penetration test in AMCA 500-L or equivalent. Manage the water that penetrates the louver by providing a drainage area or moisture removal devices.