CALIFORNIA MECHANICAL CODE - MATRIX ADOPTION TABLE
CHAPTER 4 - VENTILATION AIR
(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
DSA
OSHPD
BSCC
DPH
AGR
DWR
CEC
CA
SL
SLC
1
2
1-AC
AC
SS
SS/CC
1
2
3
4
Adopt Entire Chapter
x
x
Adopt Entire Chapter as amended (amended sections listed below)
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.
This chapter contains requirements for
ventilation air supply, exhaust, and makeup air requirements
for occupiable spaces within a building. [OSHPD 1, 2, 3 & 4]
See Sections 404.0 through 418.0. [SFM] Air filters shall
comply with all requirements of Part 12, Title 24, Chapter 12-
71, SFM Standard 12-71-1.
Occupiable spaceslisted in Table 402.1 shall be
designed to have ventilation (outdoor) air for occupants in
accordance with this chapter. Ventilation air supply requirements
for occupancies regulated by the California Energy
Commission are found in the California Energy Code.
TABLE 402.1
MINIMUM VENTILATION RATES IN BREATHING ZONE1, 2, 4
[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.
For SI units: 1 cubic foot per minute = 0.0283 m3/min, 1 square foot = 0.0929 m2
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 listedoccupancy 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 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
provided.
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.
Mechanical
ventilation for health care facilities shall be designed
and installed in accordance with this code and ASHRAE
170-2013, through Addendum ae, as published with
"Guidelines for Design and Construction of Hospitals and
Outpatient Facilities," 2014 edition (published by The
Facility Guidelines Institute). All supply-air, return air,
and exhaust-air systems shall comply with ASHRAE 170.
The text of ASHRAE 170 shall be modified as follows:
ASHRAE 170. Section 6.1.2.1 -- Not adopted.
ASHRAE 170. Section 6.3.2 -- Not adopted.
ASHRAE 170. Table 6.4 - Not adopted.
ASHRAE 170. Section 6.4-6.4.4 -- Not adopted.
ASHRAE 170. Section 6.9 -- Not adopted.
ASHRAE 170. Section 7.1a -- Modify as follows:
Replace reference to Table 7.1 with reference to
Table 4-A.
ASHRAE 170. Section 7.2.1a through e -- Not
adopted.
ASHRAE 170. Section 7.2.2 a through c, and e --
Not adopted
ASHRAE 170. Section 7.2.3 -- Not adopted.
ASHRAE 170. Section 7.3.1 -- Modify as follows:
Replace reference to Table 7.1 with reference to
Table 4-A.
ASHRAE 170. Section 7.4.1 -- Modify as follows:
Delete the Exception that allows for high return
grilles.
A mechanical ventilation system is not required where
natural ventilation openings comply with the requirements
of Section 402.2 and are permanently open or have
controls that prevent the openings from being closed
during occupancy.
Spaces, or portions
of spaces, to be naturally ventilated shall be located
within a distance based on the ceiling height, in accordance
with Section 402.2.1.1, Section 402.2.1.2, or
Section 402.2.1.3, from operable wall openings in accordance
with Section 402.2.2. For spaces with ceilings
which are not parallel to the floor, the ceiling height shall
be determined in accordance with Section 402.2.1.4.
[ASHRAE 62.1:6.4.1]
For spaces with
operable openings on one side of the space, the
distance from the operable openings shall be not
more than 2H, where H is the ceiling height.
[ASHRAE 62.1:6.4.1.1]
For spaces with
operable openings on two opposite sides of the
space, the distance from the operable openings shall
be not more than 5H, where H is the ceiling height.
[ASHRAE 62.1:6.4.1.2]
For spaces with operable
openings on two adjacent sides of a space, such
as two sides of a corner, the distance from the operable
openings shall be not more than 5H along a line
drawn between the two openings that are farthest
apart. Floor area outside that line shall comply with
Section 402.2.1.1. [ASHRAE 62.1:6.4.1.3]
The ceiling height, H, to
be used in Section 402.2.1.1 through Section
402.2.1.3 shall be the minimum ceiling height in the
space.
Exception: For ceilings that are increasing in height
as distance from the openings is increased, the
ceiling height shall be determined as the average
height of the ceiling within 20 feet (6096 mm) from
the operable openings. [ASHRAE 62.1:6.4.1.4]
Spaces, or portions of spaces, to be naturally ventilated shall be
permanently open to operable wall openings directly to
the outdoors, the openable area of which is a minimum of
4 percent of the net occupiable floor area. Where openings are covered with louvers or otherwise obstructed, openable
area shall be based on the net free unobstructed area through the opening. Where interior rooms, or portions of
rooms, without direct openings to the outdoors are ventilated
through adjoining rooms, the opening between rooms
shall be permanently unobstructed and shall have a free area of not less than 8 percent of the area of the interior
room nor less than 25 square feet (2.3 m2). [ASHRAE
62.1:6.4.2]
The means to open required operable openings shall be readily accessible to
building occupants where the space is occupied. Controls
shall be designed to coordinate operation of the natural
and mechanical ventilation systems. [ASHRAE
62.1:6.4.3]
Where natural ventilation is
not permitted by this section or the building code, mechanical
ventilation systems shall be designed, constructed, and
installed to provide a method of supply air and exhaust air.
Mechanical 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.
Required outdoor-air
intakes shall be covered with a screen having not less than 1/4 of an inch (6.4 mm) openings, and shall have not more than 1/2
of an inch (12.7 mm) openings.
Outdoor air intakes that
are part of the mechanical ventilation system shall be
designed to manage rain entrainment, to prevent rain
intrusion, and manage water from snow in accordance
with ASHRAE 62.1.
[HCD 1 & HCD 2] Each
bathroom shall be mechanically ventilated in accordance with
Division 4.5 of the California Green Building Standards Code
(CALGreen).
Ventilation zone parameters shall
be determined in accordance with Section 403.2.1 through Section 403.2.3 for each ventilation zone served by the ventilation
system. [ASHRAE 62.1:6.2.2]
The outdoor
airflow required in the breathing zone of the occupiable
space or spaces in a ventilation zone, i.e., the breathing
zone outdoor airflow (Vbz), shall be not less than the
value determined in accordance with Equation 403.2.1.
Vbz = Rp•Pz+ Ra•Az(Equation 403.2.1)
Where:
Az
=
zone floor area: the net occupiable floor area of the ventilation zone, square feet (m2).
Pz
=
zone population: The number of people in the ventilation zone during typical usage.
Rp
=
outdoor airflow rate required per person as determined from Table 402.1.
Ra
=
outdoor airflow rate required per unit area as determined from Table 402.1. [ASHRAE 62.1:6.2.2.1]
The zone
air distribution effectiveness (Ez) shall be not greater
than the default value determined in accordance with
Table 403.2.2. [ASHRAE 62.1:6.2.2.2]
TABLE 403.2.2
ZONE AIR DISTRIBUTION EFFECTIVENESS1, 2, 3, 4, 5
[ASHRAE 62.1: TABLE 6.2.2.2]
AIR DISTRIBUTION CONFIGURATION
Ez
Ceiling supply of cool air.
1.0
Ceiling supply of warm air and floor return.
1.0
Ceiling supply of warm air 15°F or more above space temperature and ceiling return.
0.8
Ceiling supply of warm air less than 15°F above space temperature and ceiling return provided that the 150 feet per minute (fpm) supply air jet reaches to within 4.5 feet of floor level.
1.06
Floor supply of cool air and ceiling return, provided that the vertical throw is more than 50 fpm at a height of 4.5 feet or more above the floor.
1.0
Floor supply of cool air and ceiling return, provided low velocity displacement ventilation achieves unidirectional flow 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.
1.2
Floor supply of warm air and floor return.
1.0
Floor supply of warm air and ceiling return.
0.7
Makeup supply drawn in on the opposite side of the room from the exhaust, return, or both
0.8
Makeup supply drawn in near to the exhaust, return, or both locations
0.5
For SI units: °C = (°F-32)/1.8, 1 foot per minute = 0.005 m/s, 1 foot = 304.8 mm
Notes: 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.
The zone outdoor airflow (Voz), i.e., the outdoor airflow rate that shall be provided to the ventilation zone by the supply air distribution system, shall be determined in accordance with Equation 403.2.3. [ASHRAE 62.1:6.2.2.3]
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 62.1:6.2.3]
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 62.1:6.2.4]
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
403.5.4. [ASHRAE 62.1:6.2.5]
The primary
outdoor air fraction (Zpz) shall be determined for ventilation
zones in accordance with Equation 403.5.1.
[ASHRAE 62.1:6.2.5.1]
Zpz = Voz/Vpz(Equation 403.5.1)
Where: Vpz is the zone primary airflow, i.e., the primary airflow
rate to the ventilation zone from the air handler, including
outdoor air and recirculated air. [ASHRAE 62.1:6.2.5.1]
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.
The uncorrected outdoor air intake (Vou) flow shall be determined in
accordance with Equation 403.5.3(1). [ASHRAE
62.1:6.2.5.3]
Vou = D Σ all zones (Rp•Pz) + Σ all zones(Ra•Az)[Equation 403.5.3(1)]
The occupant diversity ratio (D) shall be determined
in accordance with Equation 403.5.3(2) to account for
variations in population within the ventilation zones served
by the system.
D = Ps/Σ all zonesPz[Equation 403.5.3(2)]
Where the system population (Ps) is the total population
in the area served by the system.
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 403.5.3(1). [ASHRAE 62.1:6.2.5.3.1]
Ventilation systems shall be designed to be capable of providing not
less than the minimum ventilation rates required in the
breathing zone where the zones served by the system are occupied, including all full and part-load conditions. The minimum
outdoor air intake flow shall be permitted to be less than the
design value at part-load conditions. [ASHRAE 62.1:6.2.6.1]
Where it is known that
peak occupancy will be of short duration or the ventilation
will be varied or interrupted for a short period of
time, the design shall be permitted to be based on the
average conditions over a time period (T) determined in
accordance with Equation 403.6.1.
T = 3v/Vbz(Equation 403.6.1)
Where:
T
=
averaging time period, minutes.
v
=
the volume of the ventilation zone for which averaging is being applied, cubic foot (m3).
Vbz
=
the breathing zone outdoor airflow determined in accordance with Equation 403.2.1 and design value of the zone population (Pz), cubic foot per minute (cfm) (m3/min).
Acceptable design adjustments based on this optional
provision shall be in accordance with the following:
Zones with fluctuating occupancy: The zone population
(Pz) shall be permitted to be averaged over
time (T).
Zones with intermittent interruption of supply air: The
average outdoor airflow supplied to the breathing
zone over time (T) shall be not less than the breathing
zone outdoor airflow (Vbz) calculated using Equation
403.2.1.
Systems with intermittent closure of the outdoor air
intake: The average outdoor air intake over time (T)
shall be not less than the minimum outdoor air intake
(Vot) calculated using Equation 403.3, Equation 403.4,
or Equation 403.5.4. [ASHRAE 62.1:6.2.6.2]
Exhaust airflow shall be
provided in accordance with the requirements in Table 403.7.
Exhaust makeup air shall be permitted to be a combination
of outdoor air, recirculated air, and transfer air.
For SI units: 1 cubic foot per minute = 0.0283 m3/min, 1 square foot = 0.0929 m2
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 Rate is per water closet, urinal, or both. Provide the higher rate where periods of heavy use are expected to occur, e.g., toilets in theatres, schools, and sports
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.
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 listedoccupancy that is most similar in terms of occupant density
and occupancy type shall be used.
9Exhaust air that has been cleaned in accordance with the criteria of Class 1 shall be permitted to be recirculated.
10 [HCD 1 & HCD 2] A bathroom is any room containing a bathtub, a shower, a spa, or a similar source of moisture.
Exhaust rate for parking
garages shall be in accordance with Table 403.7. Exhaust
rate shall not be required for enclosed parking garages
having a floor area of 1000 square feet (92.9 m2) or less
and used for the storage of 5 or less vehicles.
Mechanical ventilation systems shall be permitted
to operate intermittently where the system is
designed to operate automatically upon detection of
vehicle operation or the presence of occupants by
approvedautomaticdetection devices.
Approvedautomatic carbon monoxide sensing
devices shall be permitted to be employed to modulate
the ventilation system to not exceed a maximum
average concentration of carbon monoxide of 50
parts per million during an eight-hour period, with a
concentration of not more than 200 parts per million
for a period not exceeding one hour. Automatic
carbon monoxide sensing devices installed to modulated
parking garage ventilation systems shall be
approved in accordance with Section 301.2.
[HCD 1 & 2] In
lieu of the exhaust rates in Table 403.7, ventilation
systems shall be capable of providing 14,000 cfm
(6608 L/s) of exhaust air for each operating vehicle.
Number of operating vehicles shall be determined
based on 2.5 percent of all parking spaces (and not
less than one vehicle).
[HCD 1 & 2] To ensure proper exhaust of contaminated air and
fumes from parking garages, exhaust systems
utilizing multiple exhaust inlets shall be designed so
that exhaust inlets are distributed in such a manner
that no portion of the parking garage is more than
50 feet (15240 mm) from an exhaust inlet. Such
exhaust inlets shall be installed so that the highest
elevation of the exhaust inlet is no greater than 12
inches (305 mm) below the lowest ceiling level.
Exception: Garage exhaust systems designed without
distributed exhaust inlets may have their exhaust
inlets designed based on the principles of engineering
and mechanics and shall provide the minimum
required exhaust rate in Table 403.7.
The system shall be permitted to be designed to reset the outdoor air intake flow (Vot), the space or ventilation zone airflow (Voz) as operating conditions
change. [ASHRAE 62.1:6.2.7]
Air shall be
classified, and the recirculation or transfer shall be limited in
accordance with Section 403.9.1 through Section 403.9.4.
[ASHRAE 62.1:5.16] Recirculated air shall not be taken from
prohibited locations in accordance with Section 311.3.
Recirculation of Class 2 air within
the space of origin shall be permitted. Recirculation or
transfer of Class 2 air to other Class 2 or Class 3 spaces
shall be permitted, provided the other spaces are used for
the same or similar purpose or task and involve the same
or similar pollutant sources as the Class 2 space. Transfer
of Class 2 air to toilet rooms shall be permitted. Recirculation
or transfer of Class 2 air to Class 4 spaces shall
be permitted. Class 2 air shall not be recirculated or transferred
to Class 1 spaces. Where using an energy recover
device, recirculation from leakage, carryover, or transfer
from the exhaust side of the energy recovery device shall
be permitted and the recirculated Class 2 air shall not
exceed 10 percent of the outdoor air intake flow.
[ASHRAE 62.1:5.16.3.2]
Recirculation of Class 3 air within
the space of origin shall be permitted. Class 3 air shall
not be recirculated or transferred to other spaces. Where
using an energy recover device, recirculation from
leakage, carryover, or transfer from the exhaust side of
the energy recovery device shall be permitted and the
recirculated Class 3 air shall not exceed 5 percent of the
outdoor air intake flow. [ASHRAE 62.1:5.16.3.3]
This section presents an alternative procedure
for calculating the system ventilation efficiency (Ev) where
values in Table 403.5.2 are not used. The system ventilation
efficiency shall equal the lowest zone ventilation efficiency
among the ventilation zones served by the air handler in
accordance with Equation 404.1. [ASHRAE 62.1:A1.3]
The average outdoor
air fraction (Xs) for the ventilation system shall be determined
in accordance with Equation 404.2.
Xs = Vou/Vps(Equation 404.2)
The uncorrected outdoor air intake (Vou) shall be determined in accordance with Section 403.5.3, and the system
primary airflow (Vps) shall be determined at the condition
analyzed. [ASHRAE 62.1:A1.1]
The zone ventilation efficiency (Evz) shall be the efficiency with which a system distributes outdoor air from the intake to an individual
breathing zone, and shall be determined in accordance with Section 404.3.1 or Section 404.3.2. [ASHRAE 62.1:A1.2]
For single supply systems, where the air supplied to a ventilation zone is a
mixture of outdoor air and system-level recirculated air,
zone ventilation efficiency (Evz) shall be determined in
accordance with Equation 404.3.1. Examples of single
supply systems include constant-volume reheat, single-duct
VAV, single-fan dual-duct, and multizone systems.
Evz = 1+ Xs-Zpz(Equation 404.3.1)
The average outdoor air fraction for the system (Xs)
shall be determined in accordance with Equation 404.2
and the primary outdoor air fraction for the zone (Zpz)
shall be determined in accordance with Section 403.5.1.
[ASHRAE 62.1:A1.2.1]
For secondary-recirculation systems where the supply air or a
portion thereof to a ventilation zone is recirculated air
from other zones, without being directly mixed with
outdoor air, the zone ventilation efficiency (Evz) shall be
determined in accordance with Equation 404.3.2(1).
Examples of secondary-recirculation systems include
dual-fan dual-duct and fan-powered mixing box systems,
and systems that include transfer fans for conference
rooms.
The system air fractions Fa, Fb, and Fc shall be
determined in accordance with Equation 404.3.2(2),
Equation 404.3.2(3), and Equation 404.3.2(4). The zone
primary air fraction (Ep) shall be determined in accordance
with Equation 404.3.2(5). For single-zone and
single-supply systems Epshall equal to 1.0. The zone
secondary recirculation fraction (Er) shall be determined
by the designer based on system configuration. The zone
air distribution effectiveness (Ez) shall be determined in
accordance with Section 403.2.2. [ASHRAE 62.1:A1.2.2]
Fa = Ep+(1-Ep)•Er [Equation 404.3.2(2)]
Fb = Ep [Equation 404.3.2(3)]
Fc = 1-(1-Ez)•(1-Er)•(1-Ep)[Equation 404.3.2(4)]
Ep = Vpz/Vdz [Equation 404.3.2(5)]
Where:
Ep - Primary air fraction: The fraction of primary air in
the discharge air to the ventilation zone.
Er - Secondary recirculation fraction: In systems with
secondary recirculation of return air, the fraction of
secondary recirculated air to the zone that is representative
of average system return air rather than air directly
recirculated from the zone.
Fa - Supply air fraction: The fraction of supply air to the
ventilation zone from sources or air outside the zone.
Fb - Mixed air fraction: The fraction of supply air to the
ventilation zone from fully mixed primary air.
Fc - Outdoor air fraction: The fraction of outdoor air to
the ventilation zone from sources of air outside the zone.
Vdz - Zone discharge airflow: The expected discharge
(supply) airflow to the zone that includes primary airflow
and secondary recirculated airflow, cfm (m3/min).
Vpz - Zone primary airflow: Determine in accordance
with Section 403.5.1.
Xs - Average outdoor air fraction: At the primary air
handler, the fraction of outdoor air intake flow in the
system primary airflow.
Zpz - Primary outdoor air fraction: The outdoor air fraction
required in the primary air supplied to the ventilation
zone prior to the introduction of secondary recirculation
air. [ASHRAE 62.1: A4]
[For OSHPD 1, 2, 3 & 4] Direct evaporative cooling systems
where the air directly contacts the wetted surface or spray shall
be limited in health facilities to nonpatient areas such as
laundry rooms, food preparation areas, and boiler or
machinery rooms. Similar rooms with high heating-producing
equipment will be considered 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.
TABLE 4-B
FILTER EFFICIENCIES FOR CENTRAL VENTILATION AND AIR-CONDITIONING SYSTEMS IN GENERAL ACUTE
CARE HOSPITALS, ACUTE PSYCHIATRIC HOSPITALS, OUTPATIENT FACILITIES, AND LICENSED CLINICS1
AREA DESIGNATION
MINIMUM NUMBER OF FILTER BANKS
FILTER EFFICIENCY % FILTER BANK
(MINIMUM EFFICIENCY REPORTING VALUE MERV)5
NO.11
NO.21
NO.31
Orthopedic operating room, bone marrow transplant operating room, organ transplant operating room
3
30%
90%
99.97%3
(8)
(14)
(17)
Protective environment rooms
3
30%
90%
99.97%4
(8)
(14)
(17)
Angiography; cardiac catheterization labs; operating rooms; interventional imaging procedure rooms; delivery rooms nurseries; patient care, treatment, cystoscopy, cesarean operating room, diagnostic, and related areas; airborne infection isolation rooms; areas providing direct patient service or clean supplies such as sterile and clean processes, and patient area corridors
2
30%
90%
-
(8)
(14)
-
Laboratories
2
30%
80%
-
(8)
(13)
-
Administrative, med staff support areas, bulk storage, soiled holding areas, food preparation areas, public cafeterias, and laundries
1
30%
-
-
(8)
-
-
Psychiatric hospitals intended for the care
and treatment of inpatients who do not require
acute medical services
1
30%
-
-
(8)
-
-
1 Based on ASHRAE 52.2. 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 CENTERS1
AREA DESIGNATION
MINIMUM NUMBER OF FILTER BANKS
FILTER EFFICIENCY % FILTER BANK
(MINIMUM EFFICIENCY REPORTING VALUE MERV)3
NO.11
NO.21
All areas for inpatient care, treatment and/or diagnosis, and those areas providing direct service or cleaning supplies
2
30%
80%
(8)
(13)
Administrative, bulk storage, soiled holding, laundries and food prep areas
1
30%2
-
(8)
-
1 Based on ASHRAE 52.2. 2 Filters are not required for evaporative coolers serving laundries and food preparation areas. 3 The numbers in parentheses represent MERV rating based on ASHRAE 52.2.
All supply-air, return air, and exhaust-air systems
shall be mechanically operated and such systems for
areas listed in Table 4-A shall be operated continuously.
Natural ventilation through windows or other openings
such as louvers will be considered as supplemental to the
required mechanical ventilation systems.
Exceptions:
Natural ventilation shall not be used in airborne
infection isolation rooms and protective environment
rooms.
The number of air changes may be reduced to 25
percent of the indicated value in Table 4-A, when the
room is unoccupied, if provisions are made to ensure
the following:
The number of air changes per hour indicated
is reestablished whenever the space is occupied.
The pressure relationship with the surrounding
rooms is maintained when the air changes per
hour are reduced. In areas requiring no continuous
directional control as identified in accordance
with Table 4-A, ventilation systems may
be shut down when the space is unoccupied and
ventilation is not otherwise required. Ventilation
shall not be reduced in rooms specifically
used for airborne infection control, such as
waiting rooms, triage rooms, corridors, reception
areas, areas adjacent to waiting areas,
airborne infection isolation rooms, negative
pressure exam room, negative pressure x-ray
treatment rooms, and protective environment
rooms. All operating and delivery rooms shall
maintain a minimum of six air changes per hour
of total air when not in use.
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 RELATIONSHIP 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
Administrative
NR
2
4
2
NR
NR
NR
NR
Airborne infection isolation anteroom (u)
(e)
NR
10
10
Yes
No
NR
NR
Airborne infection isolation
room (u)
Negative
2
12
12
Yes
No
max 60
70-75/21-24
Airborne infection isolation
treatment/exam room
Negative
2
12
12
Yes
No
NR
NR
Angiography room
Positive
5
15
12
NR
NR
NR
NR
Bathing room
Negative
NR
10
NR
Yes
No
NR
70-75/21-24
Bathroom
Negative
NR
10
10
Yes
No
NR
72-78/22-26
Bedpan room
Negative
NR
10
10
Yes
No
NR
NR
Blood bank/tissue storage
NR
2
6
6
NR
NR
NR
NR
Blood draw/phlebotomy
NR
2
6
6
NR
NR
NR
NR
Bronchoscopy, sputum collection, and pentamidine administration (n)
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
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
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
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.
Pharmacy compounding areas may have additional air change, differential pressure, and filtering requirements beyond the minimum of this table depending
on the type of pharmacy, the regulatory requirements which may include adoption of USP 797), the associated level of risk of the work (see USP [2013] in
Informative Appendix B), and the equipment utilized in the spaces.
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.
Pressure relationships need not be maintained when the room is unoccupied.
See Section 7.2 and its subsections for pressure-relationship requirements.
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 airflow
required. Where continuous directional control is not required, variations between supply cfm and return or exhaust cfm shall be minimized.
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
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.
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 Informative Appendix B.)
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. To satisfy exhaust needs, constant replacement air from
the outdoors is necessary when the system is in operation.
The RH ranges listed are the minimum and/or maximum allowable at any point within the design temperature range required for that space.
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.
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 relationships
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.
Surgeons or surgical procedures may require room temperatures, ventilation rates, humidity ranges, and/or air distribution methods that exceed the minimum
indicated ranges.
Treatment rooms used for bronchoscopy shall be treated as bronchoscopy rooms. Treatment rooms used for procedures with nitrous oxide shall contain provisions
for exhausting anesthetic waste gases.
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.)
See NFPA 99 for further requirements. 8
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.) are used.
The protective environment air flow 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 shall
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. Positive pressure in each anteroom shall be achieved by balancing the
supply cfm to not less than 75 cfm (35.4 L/s) greater than the exhaust and return cfm. Positive-pressure for each protective environment room the anteroom
serves shall be achieved by balancing the supply cfm to not less than 75 cfm (35.4 L/s) greater than the exhaust and return cfm.
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 relation 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 Table 4-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 the AII 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. Negative
pressure shall be achieved by balancing the exhaust cfm to not less than 75 cfm (35.4 L/s) greater than the supply cfm for each airborne infection isolation
room the anteroom serves. The anteroom shall have positive air pressure in relation to the airborne infection isolation room. A door louver, transfer
grille, or other acceptable means shall be provided to allow for airflow from the anteroom to the airborne infection isolation room.
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
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.
If the planned space is designated in the organization's operational plan to be utilized for both bronchoscopy and gastrointestinal endoscopy, the design parameters
for "bronchoscopy, sputum collection, and pentamidine administration" shall be used.
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.
This table is based on Table 7.1 in ASHRAE 170, "Ventilation of Healthcare Facilities", and is used with expressed written permission from ASHRAE.
Fans serving exhaust systems shall be located at
the discharge end of the system. 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.
Outdoor air intakes shall be
located at least 25 feet (7.62 m) from exhaust outlets of
ventilating systems, combustion equipment stacks,
medical-surgical vacuum systems, cooling towers, and
areas that may collect vehicular exhaust or other noxious
fumes. Plumbing vents shall be located in relation to
outdoor air intakes per California Plumbing Code. The
bottom 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.
Exceptions:
These dimensions may be reduced if it is demonstrated
by the submission of details and calculations
that location of intakes with respect to exhausts and
their orientation, or the use of special filters,
provides equal performance.
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 treatment
centers.
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.
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
Balance Council (AABC), the National Environmental
Balancing Bureau (NEBB), or the Testing, Adjusting and
Balancing Bureau (TABB).
Air supplied to operating rooms, cesarean
operating rooms, cardiac catheterization labs,
cystoscopy rooms, delivery rooms, and nurseries
shall be delivered at or near the ceiling of the area
served. In these areas and in morgues and autopsy
rooms all air removed from the area shall be
removed near floor level. Exhaust or recirculation inlets shall be located not less than 3 inches (76 mm)
nor more than 8 inches (203 mm) above the finished
floor, except in morgues and autopsy rooms where all of the exhaust air is removed through an autopsy
table designed for this purpose. At least two exhaust
or recirculation air inlets of equal capacity shall be
used in all cardiac catheterization labs, cystoscopy
rooms, operating rooms, and delivery rooms and
shall be located not less than 3 inches (76 mm) nor
more than 8 inches (203 mm) above the finished
floor.
Exception: For airborne infection isolation rooms
and protective environment rooms, see Sections
414.0 and 415.0.
Room supply air outlets and room recirculation
and exhaust air inlets installed in nonsensitive
areas shall be located not less than 3 inches
(76 mm) above the floor.
Exception: For airborne infection isolation rooms
and protective environment rooms, see Sections
414.0 and 415.0.
Corridors shall not be used to convey
supply, return, or exhaust air to or from any room if the corridor is required to be of fire resistive
construction per the California Building Code.
Exceptions:
Mechanically exhausted toilet rooms of 50
square feet (4.7 m2) or less and small rooms of
30 square feet (2.79 m2) or less such as janitor
closets, housekeeping rooms, and electrical or
telephone closets opening directly onto
corridor.
Air transfer caused by pressure differentials in
rooms required to have a positive or negative
air balance by Table 4-A.
Air from a patient room, exam room, treatment
room shall not be transferred to another
similar room without first having passed through air
filters as required by Table 4-B or Table 4-C.
Variable
air volume systems subjecting the patient to a fluctuating
air movement are not acceptable for airborne infection
isolation rooms, protective environment rooms or those
critically sensitive areas listed in Table 320.0. For
nonsensitive areas, variable air volume systems meeting
the following criteria can be considered:
The VAV system shall comply with code
requirements for outside air, total air, and pressure
relationship through the full range of operation from
minimum to maximum.
The central return or exhaust fan shall be
controlled to accomplish the variable air volume
requirements of the individual rooms served by the
fan as described in Section 407.5.1.3.
Variable air volume for return or exhaust
air shall be accomplished by utilizing an automatic
modulating damper in the return or exhaust air for
each zone. The damper will modulate from full open
to minimum position in conjunction with the supply
air VAV terminal box.
Filter efficiencies shall be certified by the manufacturer and shall be based on ASHRAE 52.2 Method
of Testing General Ventilation Air-Cleaning Devices for
Removal Efficiency by Particle Size when specifically set
forth in these standards.
A filter gauge shall be installed across each filter bank serving central air systems. The gauge shall be red
lined or a filter alarm light installed to signal when the
recommended maximum static pressure drop has been
reached.
Filter banks shall be visually inspected for torn
media and bypass in filter frames by means of a flashlight
or equivalent, both with fans in operation and
stopped. Tears in media and bypass in filter frames shall
be eliminated in accordance with the manufacturer's
directions and the requirements of the enforcing agency
prior to commencing operation of the system.
Central air-handling systems shall be maintained
in a reasonably clean condition during construction and
shall be cleaned as necessary prior to replacement of
temporary filter used during construction to ensure that
clean air will be delivered to the occupied spaces.
Filter bank No.1 shall be located upstream of
the air-conditioning equipment. Filter bank No. 2 and
filter bank No. 3 shall be located downstream of the
supply fan and all cooling and humidification equipment
with efficiencies as indicated in Table 4-B or Table 4-C.
Exception: Dry steam-type humidifiers for local room humidity control may be installed in the supply airduct
downstream of the final filter bank where designs are
specifically approved by the enforcing agency. Dry steam
is that which is defined in the ASHRAE HVAC Systems
and Equipment Handbook.
Filter bank No. 2 and filter bank No. 3 media
shall be rigid or supported (noncollapsing type) and
shall operate on the principles of impingement, straining,
and diffusion.
Noncentral recirculating air systems providing
cooling to high heat producing equipment located in
nonsensitive areas shall have a filter with 30 percent
average efficiency based on ASHRAE 52.2 or a minimum
efficiency reporting value (MERV) of 8 based on
ASHRAE 52.2.
Noncentral air systems serving any areas not
listed in Table 4-B shall be provided with filter arrangement
and efficiency specifically approved by the
enforcing agency.
Noncentral recirculating air handling systems,
for example, through-the-wall units, fan coil units, and
heat pumps may be utilized for single patient rooms of
one or more beds. Filtration for these units shall have a
minimum weight arrestance value of 50 percent, based
on ASHRAE 52.2 or a minimum efficiency reporting value (MERV) of 1, based on ASHRAE 52.2. The air
ventilation system providing the minimum air changes of
outdoor air shall comply with Table 4-B. These units may
be used as recirculating units only. All outdoor air
requirements shall be met by a separate central air
handling systems.
The air ventilation systems shall comply with
code requirements of this section for skilled nursing facilities,
intermediate care facilities and correctional treatment
centers and shall have filter bank efficiencies as
listed in Table 4-C.
Noncentral recirculating air-handling systems,
i.e. through the wall units, may be utilized for each
patient room with one or more beds. Filtration for these
units shall have a minimum weight arrestance value of 50
percent, based on ASHRAE 52.2 or a minimum efficiency
reporting value (MERV) of 1, based on ASHRAE 52.2.
The air ventilation system providing the minimum air
changes of outdoor air shall comply with Table 4-C.
These units may be used as recirculating units only. All
outdoor air requirements shall be met by a separate
central air handling system.
Airborne infection isolation rooms, protective
environment rooms, and sensitive areas in correctional
treatment centers shall comply with Section 408.2.
The air ventilation systems shall comply with
code requirements of this section for outpatient facilities
and shall have filter bank efficiencies as listed in Table
4-B.
The anchorage and supporting structural elements for
airducts shall be designed to withstand the lateral forces as
required by the California Building Code, Title 24, Part 2.
Hoods and safety cabinets may be used for normal exhaust of a space provided minimum air change rates are maintained. If air change standards
in Table 4-A do not provide sufficient air for proper
operation of exhaust hoods and safety cabinets (when in use),
supplementary makeup air (filtered and preheated) shall be
provided around these units to maintain the required airflow
direction and exhaust velocity. Makeup systems for hoods
shall be arranged to minimize "short circuiting" of air and to
avoid reduction in air velocity at the point of contaminant
capture.
Average face velocity shall
be at least 75 feet per minute (0.38 meters per second). Exhaust system shall be separate from the building
exhaust system. Exhaust fan shall be located at the
discharge end of the system. Exhaust duct system shall be
of noncombustible corrosion-resistant material as
required to meet the planned usage of the hood.
Fume hoods and their associated equipment
in the air stream intended for use with perchloric acid
and other strong oxidants shall be constructed of stainless
steel or other material consistent with special exposures.
Hoods and equipment shall be provided with a
water wash and drain system to permit periodic flushing
of duct and hood. When perchloric acid or other strong
oxidants are only transferred from one container to
another, standard laboratory fume hoods and the associated
equipment may be used in lieu of stainless steel
construction.
Each hood shall have a minimum
face velocity of 90 to 110 feet per minute (0.45 to 0.56
meters per second) with suitable pressure-independent
air-modulating devices and alarms to alert staff of fan
shutdown or loss of airflow. Each hood shall have filters
with a 99.97 percent efficiency (based on the DOP test
method) in the exhaust stream and be designed and
equipped to permit the safe removal, disposal, and
replacement of contaminated filters. Filters shall be as
close to the hood as practical to minimize duct contamination.
Fume hoods intended for use with radioactive
isotopes shall be constructed of stainless steel or other
material suitable for the particular exposure.
The air from dining areas may be used to ventilate the
food preparation areas only after it has passed through a filter with at least an 80 percent average efficiency based on
ASHRAE 52.2 or a minimum efficiency reporting value (MERV) of 13, based on ASHRAE 52.2.
Exception: For skilled nursing facilities, intermediate care
facilities and correctional treatment centers, the air from dining
area may be used to ventilate food preparation areas only after
it has passed through a filter with a 50 percent average efficiency
based on ASHRAE 52.2 or a minimum efficiency reporting value (MERV) of 10, based on ASHRAE 52.2.
Boiler, heater and electrical equipment rooms shall be
provided with outdoor air so as to maintain combustion rates
of equipment and temperatures in the rooms and in adjoining
areas as rated in this chapter.
Rooms in areas where excessive heat or moisture is
generated, where objectional odors or dust are present, or
where flammable or toxic gases may accumulate, which are
used by health facility personnel or patients, shall be provided
with exhaust ventilation to change the air a minimum of ten
times per hour.
Kitchen, morgues and laundries located inside a
hospital building or skilled nursing facility in which patients
are accommodated, or treated, shall be ventilated with
exhaust systems which will provide a minimum of ten air
changes per hour and prevent odors from entering patient
areas.
A separate, dedicated exhaust
system shall be provided for airborne infection isolation
rooms. The dedicated system may serve more than one
airborne infection isolation room, adjoining toilet room and
anteroom. The exhaust ducts shall be identified by appropriate
labeling with the words "Caution Airborne Infection
Isolation Rooms Exhaust" or similar terminology. Such
labeling shall be in a manner which is not readily removable
and shall appear on the exhaust duct at intervals of not more
than 20 feet (6096 mm) and at least once near each room
and each story traversed by the exhaust system. Exhaust fans
shall comply with Section 407.1.2. The discharge from
exhaust fans shall be located above the roof and shall be
located a minimum of 25 feet (7620 mm) from areas that may
be occupied, doors, operable windows, outdoor air intakes,
or other openings into the building. The exhaust fan
discharge shall be labeled in a manner which readily identifies
the precautions which should be observed. To ensure that the airborne contaminates do not reenter the building, one of the following shall be provided:
Exhaust discharge from fan shall extend at least
7 feet (2134 mm) above the roof and discharge vertically
upward. Self-draining stacks or equivalent shall be used
for rain protection. Rain caps which divert the exhaust
toward the roof shall be prohibited.
Exhaust shall discharge above roof level and
through an accessible HEPA filter. The HEPA filter shall
be located upstream of the exhaust fan and have a
minimum efficiency of 99.97 percent based on the DOP
method in accordance with Mil-Std. 282 or a minimum
efficiency reporting value (MERV) of 17, based on ASHRAE 52.2. Filter gage shall be installed across the
filter. For maintenance of air balance relationship, see
Section 407.3.2. The 25-foot (7620 mm) dimension
required by Section 414.1 may be reduced when a 99.97
percent HEPA filter or a minimum efficiency reporting value (MERV) of 17, based on ASHRAE 52.2 is used and
the reduced dimension is specifically approved by the
enforcing agency.
The supply outlets and exhaust inlets
shall be located to provide airflow patterns that prevent stagnation
of the air and eliminate short circuiting of the supply
to the exhaust, and minimize exposure of health care workers
to airborne infectious particles. Supply-air outlets shall be
located at or near the ceiling and at the end of the airborne
infection isolation room which is opposite the head of the bed.
Exhaust registers shall be located on the wall behind the
patient's head, or as close to that wall as practical and shall
be located not less than 3 inches (76 mm) nor more than 24
inches (610 mm) above the finished floor.
Exception: For correctional treatment centers, the location
and design of the supply outlets an exhaust or return inlets
shall not compromise the safety, security and protection of
staff, inmates and property.
The supply outlets and exhaust and
return inlets shall be located to provide airflow patterns that
prevent stagnation of the air and eliminate short circuiting of
the supply to the exhaust or return. Supply air shall be delivered
at or near the ceiling and near the patient's bed. All
exhaust or return registers shall be located near the entrance
to the protective environment room and not less than 3 inches
(76 mm) nor more than 8 inches (203 mm) above the finished
floor.
Exception: For correctional treatment centers, the location
and design of the supply outlets and exhaust or return inlets
shall not compromise the safety, security, and protection of
staff, inmates and property.
An alarm system which is based on static pressure
control, volumetric control, or directional flow measurement shall be provided for each isolation room. The alarm system
shall consist of a display monitor located on the corridor wall
near the door to the room and a visual and audible alarm
which annunciates at the room and at a nurses' station or
other suitable location that will provide responsible surveillance.
A time delay shall be provided to allow for routine
openings of doors. The alarm shall annunciate when the
supply, return, or exhaust fans are interrupted and when one
of the following conditions is not being met during closed
door conditions:
When the minimum air quantity difference of 75 cfm
(35.4 L/s) required by Table 4-A is not being maintained;
or
When a minimum pressure differential of 0.01 inch (0.003 kPa) of water and a minimum inward (outward
for protective environment rooms) air velocity of 100 feet
per minute (0.508 m/s) is not being maintained at the air
transfer opening required by Table 4-A.
Prior to acceptance of the rooms, the alarm system
shall be tested and operated to demonstrate to the owner or
designated representative that the installation and performance
of the system conforms to design intent.
[OSHPD 1, 2, 3 & 4] Prior to acceptance of the rooms, all mechanical
systems shall be tested, balanced, and operated to demonstrate
to the owner or designated representative that the
installation and performance of the systems conform to
design intent. All testing and balancing shall be performed
by a qualified independent agency certified by the Associated
Air Balance Council (AABC): the National Environmental
Balancing Bureau (NEBB); or the Testing, Adjusting and
Balancing Bureau (TABB).
When not located in the ETO sterilizer equipment room, exhaust during cylinder
change is required by installing a hood that is part of a dedicated ventilation exhaust system, positioned no more than 1 foot (305 mm) above or behind the point where the change of cylinders takes place.
The ventilation of sterilizer relief valve is required through a pipe connected to
the outlet of the relief valve exhausted directly to the
outdoors at a point high enough to be away from passersby, and not near any windows that open, nor near any
air-conditioning or ventilation air intakes.
The system
shall be designed to capture the ETO when the door is
opened following the completion of the sterilization
process. A hood or canopy closed on each end should be
installed over the sterilization door. A hood or canopy
shall be connected to a dedicated exhaust ventilation
system.
An Audible and visual alarm system
shall be installed to alert sterilizer operating personnel if the
air flow falls below design cubic feet per minute (L/s).
