419.2 Treatment Area/Room. Air shall be supplied over
California Mechanical Code (Title 24, Part 4) · 2019 edition · updated 2026-09-10 · California
Italicized text is a California amendment to the model code, as printed in the official publication.
the treatment surface by group E, nonaspirating supply dif- fusers. Air shall be returned or exhausted by registers located not less than 3 inches (76 mm) nor more than 8 inches (203 mm) above the finished floor, adjacent to the treatment sur- face.
72 2019 CALIFORNIA MECHANICAL CODE
VENTILATION AIR
TABLE 4-A PRESSURE RELATIONSHIP AND VENTILATION REQUIREMENTS FOR GENERAL ACUTE CARE HOSPITALS, SKILLED NURSING FACILITIES, INTERMEDIATE CARE FACILITIES, CORRECTIONAL
TREATMENT CENTERS, OUTPATIENT FACILITIES, AND LICENSED CLINICS
> >
| FUNCTION OR SPACE | PRESSURE RELATION- SHIP TO ADJACENT AREAS (f) (n) |
MINIMUM OUTDOOR ACH |
MINIMUM TOTAL ACH |
MINIMUM TOTAL ACH IF 100% O.A. |
ALL ROOM AIR EXHAUSTED DIRECTLY TO OUTDOORS (j) |
AIR RECIRCULATED BY MEANS OF ROOM UNITS (a) |
DESIGN RELATIVE HUMIDITY(k), % |
DESIGN TEMPERATURE (l),°F/°C |
|---|---|---|---|---|---|---|---|---|
anteroom (u) |
||||||||
room (u) |
||||||||
treatment/exam room |
||||||||
collection, and pentamidine administration (n) |
Negative |
2 |
12 |
12 |
Yes |
No |
NR |
68-73/20-23 |
medical and surgical supply space) |
Positive |
2 |
4 |
4 |
NR |
No |
max 60 |
72-78/22-26 |
holding (support) |
||||||||
(m), (n), (o) |
||||||||
procedure room |
||||||||
exam/treatment room (p) |
||||||||
procedure room (x) |
12 |
|||||||
2019 CALIFORNIA MECHANICAL CODE 73
VENTILATION AIR any other purpose or distributed to any other persons or parti es.
TABLE 4-A (continued) PRESSURE RELATIONSHIP AND VENTILATION REQUIREMENTS FOR GENERAL ACUTE CARE HOSPITALS, SKILLED NURSING FACILITIES, INTERMEDIATE CARE FACILITIES, CORRECTIONAL
TREATMENT CENTERS, OUTPATIENT FACILITIES, AND LICENSED CLINICS
>
| FUNCTION OR SPACE | PRESSURE RELATION- SHIP TO ADJACENT AREAS (f) (n) |
MINIMUM OUTDOOR ACH |
MINIMUM TOTAL ACH |
MINIMUM TOTAL ACH IF 100% O.A. |
ALL ROOM AIR EXHAUSTED DIRECTLY TO OUTDOORS (j) |
AIR RECIRCULATED BY MEANS OF ROOM UNITS (a) |
DESIGN RELATIVE HUMIDITY(k), % |
DESIGN TEMPERATURE (l),°F/°C |
|---|---|---|---|---|---|---|---|---|
procedure room |
||||||||
(LDR) (s) |
||||||||
postpartum (LDRP) (s) |
||||||||
and virus |
||||||||
(v) |
||||||||
storage (r) |
||||||||
formula room |
||||||||
suite |
||||||||
room (h) |
||||||||
PET, SPECT) |
||||||||
room |
||||||||
74 2019 CALIFORNIA MECHANICAL CODE
VENTILATION AIR
TABLE 4-A (continued) PRESSURE RELATIONSHIP AND VENTILATION REQUIREMENTS FOR GENERAL ACUTE CARE HOSPITALS, SKILLED NURSING FACILITIES, INTERMEDIATE CARE FACILITIES, CORRECTIONAL
TREATMENT CENTERS, OUTPATIENT FACILITIES, AND LICENSED CLINICS
>
| FUNCTION OR SPACE | PRESSURE RELATION- SHIP TO ADJACENT AREAS (f) (n) |
MINIMUM OUTDOOR ACH |
MINIMUM TOTAL ACH |
MINIMUM TOTAL ACH IF 100% O.A. |
ALL ROOM AIR EXHAUSTED DIRECTLY TO OUTDOORS (j) |
AIR RECIRCULATED BY MEANS OF ROOM UNITS (a) |
DESIGN RELATIVE HUMIDITY(k), % |
DESIGN TEMPERATURE (l),°F/°C |
|---|---|---|---|---|---|---|---|---|
operating room (m), (n), (o) |
||||||||
scopic room (m), (n), (o) |
||||||||
compounding area (b) |
||||||||
compounding area (b) |
||||||||
facility) |
||||||||
and treatment) |
||||||||
anteroom (t) |
||||||||
room (t) |
||||||||
gathering/activity/dining (nursing facility) |
NR |
4 |
4 |
4 |
NR |
NR |
NR |
70-75/21-24 |
(nursing facility) |
||||||||
(nursing facility) |
||||||||
room |
||||||||
holding,utility room |
2019 CALIFORNIA MECHANICAL CODE 75
VENTILATION AIR any other purpose or distributed to any other persons or parti es.
TABLE 4-A (continued) PRESSURE RELATIONSHIP AND VENTILATION REQUIREMENTS FOR GENERAL ACUTE CARE HOSPITALS, SKILLED NURSING FACILITIES, INTERMEDIATE CARE FACILITIES, CORRECTIONAL
TREATMENT CENTERS, OUTPATIENT FACILITIES, AND LICENSED CLINICS
>
| FUNCTION OR SPACE | PRESSURE RELATION- SHIP TO ADJACENT AREAS (f) (n) |
MINIMUM OUTDOOR ACH |
MINIMUM TOTAL ACH |
MINIMUM TOTAL ACH IF 100% O.A. |
ALL ROOM AIR EXHAUSTED DIRECTLY TO OUTDOORS (j) |
AIR RECIRCULATED BY MEANS OF ROOM UNITS (a) |
DESIGN RELATIVE HUMIDITY(k), % |
DESIGN TEMPERATURE (l),°F/°C |
|---|---|---|---|---|---|---|---|---|
(SNF & ICF only) |
||||||||
room |
||||||||
(crisis or shock) (c) |
||||||||
(surgery and critical care) (p) |
||||||||
and treatment) (x) |
||||||||
(nuclear medicine) |
||||||||
clinic |
||||||||
(burn unit) |
||||||||
treatment) |
||||||||
and catheterization) |
a. Notes for Table 4-A: Except where indicated by a “No” in this column, recirculating room HVAC units (with heating or cooling coils) are acceptable for providing that portion
of the minimum total air changes per hour that is permitted by Section 7.1 (subparagraph [a][5]). Because of the cleaning difficulty and potential for buildup
a. Except where indicated by a “No” in this column, recirculating room HVAC units (with heating or cooling coils) are acceptable for providing that portion
of the minimum total air changes per hour that is permitted by Section 7.1 (subparagraph [a][5]). Because of the cleaning difficulty and potential for buildup of contamination, recirculating room units shall not be used in areas marked “No.” Recirculating devices with HEPA filters shall be permitted in existing facilities as interim, supplemental environmental controls to meet requirements for the control of airborne infectious agents. The design of either portable or fixed systems should prevent stagnation and short circuiting of airflow. The design of such systems shall also allow for easy access for scheduled preventative maintenance and cleaning. b. Additional air change, ISO class, differential pressure, continuous pressure monitoring and filtering requirements for compounding areas shall comply with
California Board of Pharmacy regulations Title 16 §1735 & §1751, and USP <797> & <800>. Air supplied to the cleanroom suite must be introduced
b. Additional air change, ISO class, differential pressure, continuous pressure monitoring and filtering requirements for compounding areas shall comply with
California Board of Pharmacy regulations Title 16 §1735 & §1751, and USP <797> & <800>. Air supplied to the cleanroom suite must be introduced through 99.97% minimum HEPA filters located in the ceiling. At least 15 air changes per hour (ACPH) shall be provided to nonhazardous drug (non-HD) compounding buffer rooms through the ceiling. The HEPA filtered air from the PEC in the non-HD buffer room, when added to the HVAC-supplied HEPA- filtered air, shall increase the total HEPA-filtered ACPH to at least 30. If the PEC is used to meet the minimum total ACPH requirements, the PEC must not be turned off except for maintenance. All hazardous drug (HD) compounding areas and PECs shall be exhausted externally through 99.97% HEPA filtra- tion. Minimum air changes shall be met under operating conditions. Returns and exhaust grilles shall be mounted low on the wall unless a visual smoke study demonstrates dilution of particles and sweeping out of particles from the entire room. One return/exhaust should be placed near the refrigerator com- pressor. c. The term trauma room as used herein is a first-aid room and/or emergency room used for general initial treatment of accident victims. The operating room
within the trauma center that is routinely used for emergency surgery is considered to be an operating room by this standard.
c. The term trauma room as used herein is a first-aid room and/or emergency room used for general initial treatment of accident victims. The operating room
within the trauma center that is routinely used for emergency surgery is considered to be an operating room by this standard. d. Pressure relationships need not be maintained when the room is unoccupied. e. See Section 7.2 of ASHRAE 170 and its subsections for pressure-relationship requirements. f. For operating rooms, cardiac catheterization labs, angiography rooms, cystoscopy rooms, delivery rooms, cesarean operating rooms, newborn intensive
care, intensive care units, and nurseries provide approximately 15% excess supply air to the room or a sufficient quantity of excess supply air to maintain
For operating rooms, cardiac catheterization labs, angiography rooms, cystoscopy rooms, delivery rooms, cesarean operating rooms, newborn intensive
care, intensive care units, and nurseries provide approximately 15% excess supply air to the room or a sufficient quantity of excess supply air to maintain an appropriate positive air balance based on the room tightness and number of doors. For all rooms not listed in this footnote or not listed in Section 322.0 requiring either a positive or negative air balance, provide approximately 10% differential cfm between supply and return/exhaust airflow but not less than 25 cfm differential shall be provided regardless of room size. Room function, size, and tightness may be considered when determining the differential air- flow required. Where continuous directional control is not required, variations between supply cfm and return or exhaust cfm shall be minimized.
76 2019 CALIFORNIA MECHANICAL CODE
VENTILATION AIR
g. All air need not be exhausted if darkroom equipment has a scavenging exhaust duct attached and meets ventilation standards regarding NIOSH, OSHA, and
local employee exposure limits. 2, 3
h. A nonrefrigerated body-holding room is applicable only to facilities that do not perform autopsies on-site and use the space for short periods while waiting
for the body to be transferred.
local employee exposure limits. 2, 3
h. A nonrefrigerated body-holding room is applicable only to facilities that do not perform autopsies on-site and use the space for short periods while waiting
for the body to be transferred. i. Minimum total air changes per hour (ach) shall be that required to provide proper makeup air to kitchen exhaust systems as specified in ANSI/ASHRAE Standard 154. 4 In some cases, excess exfiltration or infiltration to or from exit corridors compromises the exit corridor restrictions of NFPA 90A, 5 the pressure requirements of NFPA 96, 6 or the maximum defined in the table. During operation, a reduction to the number of air changes to any extent required for odor control shall be permitted when the space is not in use. (See FGI [2010] in InformativeAppendix B.) j. In some areas with potential contamination and/or odor problems, exhaust air shall be discharged directly to the outdoors and not recirculated to other areas. Individual circumstances may require special consideration for air exhausted to the outdoors. Tosatisfy exhaust needs, constant replacement air from the outdoors is necessary when the system is in operation. k. The RH ranges listed are the minimum and/or maximum allowable at any point within the design temperature range required for that space. l. Systems shall be capable of maintaining the rooms within the range during normal operation. Lower or higher temperature shall be permitted when patients’ comfort and/or medical conditions require those conditions. m. National Institute for Occupational Safety and Health (NIOSH) criteria documents regarding occupational exposure to waste anesthetic gases and vapors, and
control of occupational exposure to nitrous oxide 7 indicate a need for both local exhaust (scavenging) systems and general ventilation of the areas in which the respective gases are utilized. Refer to NFPA 99 for other requirements. 8
n. If pressure-monitoring device alarms are installed, allowances shall be made to prevent nuisance alarms. Short-term excursions from required pressure rela tionships shall be allowed while doors are moving or temporarily open. Simple visual methods such as smoke trail, ball-in-tube, or flutterstrip shall be per
National Institute for Occupational Safety and Health (NIOSH) criteria documents regarding occupational exposure to waste anesthetic gases and vapors, and
control of occupational exposure to nitrous oxide 7 indicate a need for both local exhaust (scavenging) systems and general ventilation of the areas in which the respective gases are utilized. Refer to NFPA 99 for other requirements. 8
If pressure-monitoring device alarms are installed, allowances shall be made to prevent nuisance alarms. Short-term excursions from required pressure rela
n. If pressure-monitoring device alarms are installed, allowances shall be made to prevent nuisance alarms. Short-term excursions from required pressure rela tionships shall be allowed while doors are moving or temporarily open. Simple visual methods such as smoke trail, ball-in-tube, or flutterstrip shall be permitted for verification of airflow direction. o. Surgeons or surgical procedures may require room temperatures, ventilation rates, humidity ranges, and/or air distribution methods that exceed the minimum
m excursions from required pressure rela tionships shall be allowed while doors are moving or temporarily open. Simple visual methods such as smoke trail, ball-in-tube, or flutterstrip shall be permitted for verification of airflow direction. o. Surgeons or surgical procedures may require room temperatures, ventilation rates, humidity ranges, and/or air distribution methods that exceed the minimum
indicated ranges.
o. Surgeons or surgical procedures may require room temperatures, ventilation rates, humidity ranges, and/or air distribution methods that exceed the minimum
indicated ranges. p. Treatment rooms used for bronchoscopy shall be treated as bronchoscopy rooms. Treatment rooms used for procedures with nitrous oxide shall contain pro visions for exhausting anesthetic waste gases.
p. Treatment rooms used for bronchoscopy shall be treated as bronchoscopy rooms. Treatment rooms used for procedures with nitrous oxide shall contain pro visions for exhausting anesthetic waste gases. q. In a recirculating ventilation system, HEPA filters shall be permitted instead of exhausting the air from these spaces to the outdoors provided that the return
air passes through the HEPA filters before it is introduced into any other spaces. The entire minimum total air changes per hour of recirculating airflow shall
q. In a recirculating ventilation system, HEPA filters shall be permitted instead of exhausting the air from these spaces to the outdoors provided that the return
air passes through the HEPA filters before it is introduced into any other spaces. The entire minimum total air changes per hour of recirculating airflow shall pass through HEPA filters. When these areas are open to larger, nonwaiting spaces, the exhaust air volume shall be calculated based on the seating area of the waiting area. ( Note: The intent here is to not require the volume calculation to include a very large space [e.g., an atrium] just because a waiting area opens onto it.) r. See NFPA 99 for further requirements. 8
s. For intermediate care, labor/delivery/recovery rooms, and labor/delivery/recovery/postpartum rooms, four total ach shall be permitted when supplemental
r. See NFPA 99 for further requirements. 8
s. For intermediate care, labor/delivery/recovery rooms, and labor/delivery/recovery/postpartum rooms, four total ach shall be permitted when supplemental
heating and/or cooling systems (radiant heating and cooling, baseboard heating, etc.) areused.
s. For intermediate care, labor/delivery/recovery rooms, and labor/delivery/recovery/postpartum rooms, four total ach shall be permitted when supplemental
heating and/or cooling systems (radiant heating and cooling, baseboard heating, etc.) areused. t. The protective environment airflow design specifications protect the patient from common environmental airborne infectious microbes (i.e., Aspergillus spores). The anteroom shall have negative air pressure in relation to the protective environment room. A door louver, transfer grille, or other acceptable means may be provided to allow for airflow from the protective environment room to the anteroom. The protective environment room shall have positive- pressure in relation to the anteroom and adjoining toilet room. Recirculation HEPA filters shall be permitted to increase the equivalent room air exchanges; however, the outdoor air changes are still required. Constant-volume airflow is required for consistent ventilation for the protected environment. The pressure relationship to adjacent areas shall remain unchanged if the PE room is utilized as a normal patient room. Rooms with reversible airflow provisions for the purpose of switching between protective environment and AII functions shall not be permitted. u. The AII room described in this standard shall be used for isolating the airborne spread of infectious diseases, such as measles, varicella, or tuberculosis. The
airborne infection isolation room shall have negative pressure in relation to the anteroom, and the adjoining toilet room shall have negative pressure in rela-
u. The AII room described in this standard shall be used for isolating the airborne spread of infectious diseases, such as measles, varicella, or tuberculosis. The
airborne infection isolation room shall have negative pressure in relation to the anteroom, and the adjoining toilet room shall have negative pressure in rela- tion to the airborne infection isolation room. Supplemental recirculating devices using HEPA filters shall be permitted in the AII room to increase the equivalent room air exchanges; however, the minimum outdoor air changes of Table4-A are still required.AII rooms that are retrofitted from standard patient rooms from which it is impractical to exhaust directly outdoors may be recirculated with air from the AII room, provided that air first passes through a HEPA filter. When theAII room is not utilized for airborne infection isolation, the pressure relationship to adjacent areas, when measured with the door closed, shall remain unchanged and the minimum total air change rate shall be 6 ach. Switching controls for reversible airflow provisions shall not be permitted. The anteroom shall have positive air pressure in relation to the airborne infection isolation room. A door louver, transfer grille, or other acceptable means may be provided to allow for airflow from the anteroom to the airborne infection isolation room. v. When required, appropriate hoods and exhaust devices for the removal of noxious gases or chemical vapors shall be provided in accordance with NFPA 99. 8
w. The requirement that all room air is exhausted directly to outdoors applies only to radiology waiting rooms programmed to hold patients who are waiting for
v. When required, appropriate hoods and exhaust devices for the removal of noxious gases or chemical vapors shall be provided in accordance with NFPA 99. 8
w. The requirement that all room air is exhausted directly to outdoors applies only to radiology waiting rooms programmed to hold patients who are waiting for
chest x-rays for diagnosis of respiratory disease.
w. The requirement that all room air is exhausted directly to outdoors applies only to radiology waiting rooms programmed to hold patients who are waiting for
chest x-rays for diagnosis of respiratory disease. x. If the planned space is designated in the organization’s operational plan to be utilized for both bronchoscopy and gastrointestinal endoscopy, the design param eters for “bronchoscopy, sputum collection, and pentamidine administration” shall beused.
x. If the planned space is designated in the organization’s operational plan to be utilized for both bronchoscopy and gastrointestinal endoscopy, the design param eters for “bronchoscopy, sputum collection, and pentamidine administration” shall beused. y. For single-bed patient rooms using Group D diffusers, a minimum of six total ach shall be provided and calculated based on the volume from finished floor
to 6 ft (1.83 m) above the floor.
y. For single-bed patient rooms using Group D diffusers, a minimum of six total ach shall be provided and calculated based on the volume from finished floor
to 6 ft (1.83 m) above the floor. z. This table is based on Table 7.1 in ASHRAE 170, “Ventilation of Healthcare Facilities”, and is used with expressed written permission from ASHRAE. aa. Nurse station pressure relationship and ventilation requirements shall match the area in which it is located. ab. Air change per hour and ventilation rates for spaces not listed in Table 4-A may be per ASHRAE 62.1.
2019 CALIFORNIA MECHANICAL CODE 77
VENTILATION AIR any other purpose or distributed to any other persons or parti es.
TABLE 4-B FILTER EFFICIENCIES FOR CENTRAL VENTILATION AND AIR-CONDITIONING SYSTEMS IN GENERAL ACUTE
CARE HOSPITALS, ACUTE PSYCHIATRIC HOSPITALS, OUTPATIENT FACILITIES, AND LICENSED CLINICS 1
| AREA DESIGNATION | MINIMUM NUMBER OF FILTER BANKS |
FILTER EFFICIENCY % FILTER BANK | ||
|---|---|---|---|---|
| AREA DESIGNATION |
MINIMUM NUMBER OF FILTER BANKS |
(MINIMUM EFFICIENCY REPORTING VALUE MERV)5 | (MINIMUM EFFICIENCY REPORTING VALUE MERV)5 | (MINIMUM EFFICIENCY REPORTING VALUE MERV)5 |
| AREA DESIGNATION |
MINIMUM NUMBER OF FILTER BANKS |
NO. 11 |
NO. 21 |
NO. 31 |
plant operating room, organ transplant operating room, NICU formula preparation room, NICU treat- ment area/room |
3 |
|||
plant operating room, organ transplant operating room, NICU formula preparation room, NICU treat- ment area/room |
3 |
|||
ing rooms; interventional imaging procedure rooms;delivery rooms nurseries; patient care, treat- ment, cystoscopy, cesarean operating room, diag- nostic, and related areas; airborne infection isolation rooms; areas providing direct patient serv- ice or clean supplies such as sterile and clean processes, and patient area corridors |
2 |
30% | 90% | –– |
ing rooms; interventional imaging procedure rooms;delivery rooms nurseries; patient care, treat- ment, cystoscopy, cesarean operating room, diag- nostic, and related areas; airborne infection isolation rooms; areas providing direct patient serv- ice or clean supplies such as sterile and clean processes, and patient area corridors |
2 |
(8) |
(14) |
–– |
age, soiled holding areas, food preparation areas, public cafeterias, and laundries |
1 | |||
age, soiled holding areas, food preparation areas, public cafeterias, and laundries |
1 | |||
treatment of inpatients who do not require acute medical services |
1 | |||
treatment of inpatients who do not require acute medical services |
1 |
2 Based on DOP test in accordance with MIL-STD-282 or based on ASHRAE 52.2. 3 HEPA filters at air outlet or other locations when approved by the Authority Having Jurisdiction. 4 HEPA filter located in the supply duct which serves the positive-pressure isolation room or rooms may serve more than one supply outlet and more than one positive-pressure isolation room. HEPA filter or a filter with minimum efficiency reporting value (MERV) of 17 installation shall be designed and equipped to permit safe removal, disposal and replacement of filters. 5 The numbers in parentheses represent MERV rating based on ASHRAE 52.2.
TABLE 4-C FILTER EFFICIENCIES FOR CENTRAL VENTILATION AND AIR-CONDITIONING SYSTEMS IN SKILLED NURSING FACILITIES AND INTERMEDIATE CARE FACILITIES AND CORRECTIONAL TREATMENT CENTERS 1
| AREA DESIGNATION | MINIMUM NUMBER OF FILTER BANKS |
FILTER EFFICIENCY % FILTER BANK | |
|---|---|---|---|
| AREA DESIGNATION |
MINIMUM NUMBER OF FILTER BANKS |
(MINIMUM EFFICIENCY REPORTING VALUE MERV)3 | (MINIMUM EFFICIENCY REPORTING VALUE MERV)3 |
| AREA DESIGNATION |
MINIMUM NUMBER OF FILTER BANKS |
NO. 11 |
NO. 21 |
sis, and those areas providing direct service or clean- ing supplies) |
2 |
||
sis, and those areas providing direct service or clean- ing supplies) |
2 |
||
dries and food prep areas |
1 | ||
dries and food prep areas |
1 |
3 The numbers in parentheses represent MERV rating based on ASHRAE 52.2.
78 2019 CALIFORNIA MECHANICAL CODE
VENTILATION AIR
TABLE 402.1 MINIMUM VENTILATION RATES IN BREATHING ZONE 1, 2
[ASHRAE 62.1: TABLE 6.2.2.1] Note: Ventilation air supply requirements for occupancies regulated by the California Energy Commission are found in the California Energy Code.
| OCCUPANCY CATEGORY4 | PEOPLE OUTDOOR Air Rate Rp (cfm/person) |
AREA OUTDOOR Air Rate RA (cfm/ft2) |
DEFAULT OCCUPANT DENSITY3 (people/1000 ft2) |
AIR CLASS |
|---|---|---|---|---|
| CORRECTIONAL FACILITIES |
||||
EDUCATIONAL FACILITIES |
||||
FOOD AND BEVERAGE SERVICE |
||||
GENERAL |
||||
HOTELS, MOTELS, RESORTS, DORMITORIES |
||||
OFFICE BUILDINGS |
||||
MISCELLANEOUS SPACES |
||||
industrial and processes using chemicals) |
||||
2019 CALIFORNIA MECHANICAL CODE 79
VENTILATION AIR any other purpose or distributed to any other persons or parti es.
TABLE 402.1 (continued) MINIMUM VENTILATION RATES IN BREATHING ZONE 1, 2
[ASHRAE 62.1: TABLE 6.2.2.1]
| OCCUPANCY CATEGORY4 | PEOPLE OUTDOOR Air Rate Rp (cfm/person) |
AREA OUTDOOR Air Rate RA (cfm/ft2) |
DEFAULT OCCUPANT DENSITY3 (people/1000 ft2) |
AIR CLASS |
|---|---|---|---|---|
| PUBLIC ASSEMBLY SPACES |
||||
RESIDENTIAL |
||||
RETAIL |
||||
| SPORTS AND ENTERTAINMENT |
||||
Notes:
Notes: 1 This table applies to no-smoking areas. Rates for smoking-permitted spaces shall be determined using other methods. 2 Volumetric airflow rates are based on an air density of 0.075 pounds of dry air per cubic foot (lbda/ft3) (1.201 kgda/m3), which corresponds to dry air at a barometric pressure of 1 atm (101 kPa) and an air temperature of 70°F (21°C). Rates shall be permitted to be adjusted for actual density, but such adjustment is not required for compliance with this chapter. 3 The default occupant density shall be used where actual occupant density is not known. 4 Where the occupancy category for a proposed space or zone is not listed, the requirements for the listed occupancy category that is most similar in terms of occupant density, activities, and building construction shall be used.
ITEM-SPECIFIC NOTES FOR TABLE 402.1 a For high school and college libraries, use values shown for Public Assembly Spaces – Libraries. b Rate is capable of not being sufficient where stored materials include those having potentially harmful emissions. c Rate does not allow for humidity control. Additional ventilation or dehumidification shall be permitted to remove moisture. “Deck area” refers to the area
surrounding the pool that would be expected to be wetted during normal pool use, i.e., where the pool is occupied. Deck area that is not expected to be wet
surrounding the pool that would be expected to be wetted during normal pool use, i.e., where the pool is occupied. Deck area that is not expected to be wetted shall be designated as a space type (for example, “spectator area”). d Rate does not include special exhaust for stage effects, e.g., dry ice vapors, smoke. e Where combustion equipment is intended to be used on the playing surface or in the space, additional dilution ventilation, source control, or both shall be pro vided.
vided. f Default occupancy for dwelling units shall be two persons for studio and one-bedroom units, with one additional person for each additional bedroom. g Air from one residential dwelling shall not be recirculated or transferred to other spaces outside of that dwelling.
80 2019 CALIFORNIA MECHANICAL CODE
VENTILATION AIR
TABLE 403.2.2 ZONE AIR DISTRIBUTION EFFECTIVENESS1, 2, 3, 4, 5 [ASHRAE 62.1: TABLE 6.2.2.2]
| AIR DISTRIBUTION CONFIGURATION |
Ez |
|---|---|
minute (fpm) supply air jet reaches to within 4.5 feet of floor level. |
|
feet or more above the floor. |
|
and thermal stratification, or underfloor air distribution systems where the vertical throw is 50 fpm or less at a height of 4.5 feet above the floor. |
|
1 “Cool air” is air cooler than space temperature. 2 “Warm air” is air warmer than space temperature. 3 “Ceiling supply” includes any point above the breathing zone. 4 “Floor supply” includes any point below the breathing zone. 5 As an alternative to using the above values, Ez shall be permitted to be regarded as equal to air change effectiveness determined in accordance with ASHRAE 129 for air distribution configurations except unidirectional flow. 6 For lower velocity supply air, Ez = 0.8
TABLE 403.5.2 SYSTEM VENTILATION EFFICIENCY 1, 2, 3
[ASHRAE 62.1: TABLE 6.2.5.2]
MAX ( ≤ 0.15 ZPz) 1.0 Ev
≤ 0.25 0.9
≤ 0.35 0.8
≤ 0.45 0.7
≤ 0.55 0.6
> 0.55 Use Section 404.0
Notes:
1 “Max Zpz ” refers to the largest value of Zpz, calculated in accordance with Equation 403.5.1, among the ventilation zones served by the system.
2 For values of Max ( Zpz) between 0.15 and 0.55, the corresponding value of Ev shall be permitted to be
determined by interpolating the values in the table.
3 The values of Ev in this table are based on a 0.15 average outdoor air fraction for the system (i.e., the ratio
of the uncorrected outdoor air intake ( Vou) to the total zone primary airflow for the zones served by the air
handler). For systems with higher values of the average outdoor air fraction, this table is capable of resulting in unrealistically low values of Ev and the use of Section 404.0 is capable of yielding more practical
results.
2019 CALIFORNIA MECHANICAL CODE 81
VENTILATION AIR any other purpose or distributed to any other persons or parti es.
TABLE 403.7 MINIMUM EXHAUST RATES
[ASHRAE 62.1: TABLE 6.5]
| OCCUPANCY CATEGORY8 | EXHAUST RATE (cfm/unit) | EXHAUST RATE (cfm/ft2) | AIR CLASS |
|---|---|---|---|
cling |
|||
trial and health care facilities |
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Notes:
Notes: 1 Stands where engines are run shall have exhaust systems that directly connect to the engine exhaust and prevent escape of fumes. 2 Where combustion equipment is intended to be used on the playing surface, additional dilution ventilation, source control, or both shall be provided. 3 Exhaust rate is not required for open parking garages as defined in accordance with the building code. 4 Rateisperwatercloset,urinal,orboth.Providethehigherratewhereperiodsofheavyuseareexpectedtooccur,e.g.,toiletsintheatres,schools,andsports facilities. Otherwise the lower rate shall be permitted to be used. 5 Rate is for a toilet room intended to be occupied by one person at a time. For continuous system operation during normal hours of use, the lower rate shall be permitted to be used. Otherwise the higher rate shall be used. 6 For refrigeration machinery rooms, the exhaust rate shall comply with Chapter 11. 7 For continuous system operation, the lower rates shall be permitted. Otherwise the higher rate shall be used. 8 For unlisted occupancies for a proposed space not listed in the table, the requirements for the listed occupancy that is most similar in terms of occupant density and occupancy type shall be used. 9 Exhaust air that has been cleaned in accordance with the criteria of Class 1 shall be permitted to be recirculated. 10 Rate is per shower head. 11 [HCD 1 & HCD 2] A bathroom is any room containing a bathtub, a shower, a spa, or a similar source of moisture. 12 [HCD 1 & HCD 2] ANSI/ASHRAE 62.2: Tables 5.1 and 5.2.
82 2019 CALIFORNIA MECHANICAL CODE
CALIFORNIA MECHANICAL CODE – MATRIX ADOPTION TABLE
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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
▸Chapter 4 — VENTILATION AIR
Overview- 401.2 Filters. [BSC-CG], [DSA-SS & DSA-SS/CC] In
- 402.1 Occupiable Spaces.3 & 4] Occupiable spaces listed in
- 402.2 Natural Ventilation. Natural ventilation systems
- 402.3 Mechanical Ventilation. Where natural ventilation is
- 402.4 Outdoor Air Intake Protection. Required outdoorair intak…
- 402.5 Bathroom Exhaust Fans. [HCD 1 & HCD 2] Each
- 403.2 Zone Calculations. Ventilation zone parameters
- 403.3 Single-Zone Systems. For ventilation systems
- 403.4 One Hundred Percent Outdoor Air Systems. For
- 403.5 Multiple-Zone Recirculating Systems. For ventilation sys…
- 403.6 Design for Varying Operating Conditions. Ventilation sys…
- 403.7 Exhaust Ventilation. Exhaust airflow shall be provided i…
- 404.2 Average Outdoor Air Fraction. The average outdoor air fr…
- 404.3 Zone Ventilation Efficiency. The zone ventilation
- 403.8 Dynamic Reset. The system shall be permitted to
- 403.9 Air Classification and Recirculation. Air shall be
- 405.0 Evaporative Cooling System for Health CareFacilities. [F…
- 407.1 General.407.1.1 All supply-air, return air, and exhaust-…
- 407.3 Air Balance.407.3.1 The ventilation systems shall be des…
- 407.4 Air Circulation.407.4.1 Design of the ventilation system…
- 407.2 Outdoor Air Intakes and Exhaust Outlets.407.2.1 Outdoor …
- 407.5 Variable Air Volume.407.5.1 Variable Air Volume Systems …
- 408.0 Filters. [OSHPD 1, 1R, 2, 3, 4 & 5]408.1 General. Filter…
- 408.2 Filters for Hospitals.408.2.1 All air-ventilation system…
- 408.3 Filters for Skilled Nursing Facilities, Intermedi-
- 408.4 Filters for Outpatient Facilities.408.4.1 The air ventil…
- 409.2 Duct linings and their use shall meet the requirements
- 409.3 Insulation of Ducts. Cold air ducts shall be insu-
- 409.4 The anchorage and supporting structural elements for
- 410.1 Laboratory Ventilating Systems.[OSHPD 1, 1R, 2, 3, 4 & 5…
- 410.2 Exhaust Hoods and Safety Cabinets. Hoods and
- 410.3 Laboratory Fume Hoods. Laboratory fume hoods
- 411.0 Kitchen and Dining Areas. [OSHPD 1, 1R, 2, 3, 4
- 412.2 Floor surfaces in occupied spaces above such rooms
- 413.2 Kitchen, morgues and laundries located inside a hos-
- 414.0 Airborne Infection Isolation Rooms. [OSHPD
- 414.2 Air Distribution. The supply outlets and exhaust
- 415.0 Protective Environment Rooms. [OSHPD 1, 1R,
- 416.0 Alarms – Airborne Infection Isolation Rooms
- 416.2 Other acceptable alarm systems will be allowed when
- 416.3 [For OSHPD 4] For correctional treatment centers,
- 416.4 Prior to acceptance of the rooms, the alarm system
- 417.0 Testing and Balancing Airborne Infection Isola-
- 418.1 Air Changes. Sterilization Areas. [OSHPD 1, 1R, 2, 3, 4 …
- 418.2 Exhaust Requirements.418.2.1 All air from the ETO steril…
- 418.3 Ventilation Requirements.418.3.1 Aeration Units. The aer…
- 418.4 Gas Valves. Installation of gas line hand valves at the
- 418.5 Alarm Systems. An Audible and visual alarm system
- 419.2 Treatment Area/Room. Air shall be supplied over
- 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 — SIZING OF VENTING SYSTEMS AND OUTDOOR COMBUSTION …
- Appendix G — EXAMPLE CALCULATION OF OUTDOOR AIR RATE