ANSI /ASHRAE /ASHE Standard 170-2008
Table 6-1 Minimum Filter Efficiencies
Space Designation
(According to Function)
Filter Bank Number 1
(MERV)a
Filter Bank Number 2
(MERV)a
Classes B and C Surgery, inpatient and
ambulatory diagnostic and
therapeutic radiology, inpatient
delivery and recovery services
7
14
In patient care, treatment, and
diagnosis, and those spaces providing
direct service or clean supplies and
clean processing (except as noted
below); AII rooms
7
14
Protective environment (PE) rooms
7
(HEPA)c,d
13b
N/R*
Laboratories; class A surgery and
associated semi-restricted spaces
* NR= not required
Note a: The minimum efficiency reporting value (MERV) is based on the method of testing described in ANSI/ASHRAE Standard 52.2-2007,
Method of Testing General Ventilation Air-Cleaning Devices for Removal Efficiency by Particle Size (see Informative Annex B: Bibliography).
Note b: Additional prefilters may be used to reduce maintenance for filters with efficiencies higher than MERV 7.
Note c: As an alternative, MERV-14 rated filters may be used in Filter Bank No. 2 if a tertiary terminal HEPA filter is provided for these
spaces.
Note d: High-Efficiency Particulate Air (HEPA) filters are those filters that remove at least 99.97% of 0.3 micron-sized particles at the
rated flow in accordance with the testing methods of IEST RP-CC001.3 (see Informative Annex B, Bibliography).
Design
Temperature (I),
F/C
RH (k), %
Air
recirculated by
means of room
units (a)
AII Room Air
Exhausted
Directly to
Outdoors (j)
Minimum
Total ACH
Minimum
Outdoor ACH
Pressure
relationship to
Adjacent Areas
(n)
ANSI /ASHRAE /ASHE Standard 170-2008
Table 7-1 Design Parameters— From ANSI/ASHRAE/ASHE Standard 170-2008
Surgery and Critical Care
Positive
4
20
N/R
No
20-60
Operating/Surgical cystoscopic
rooms (m), (n), (o)
Delivery room (Caesarean) (m), (n), (o)
Positive
4
20
N/R
No
20-60
Positive
4
20
N/R
No
20-60
Substerile service area
N/R
2
6
N/R
No
N/R
Recovery Room
N/R
2
6
N/R
No
20-60
Critical and intensive Care
N/R
2
6
N/R
No
30-60
Intermediate care (s)
N/R
2
6
N/R
N/R
Max 60
Wound Intensive care (burn unit)
N/R
2
6
N/R
No
40-60
Newborn Intensive care
Positive
2
6
N/R
No
30-60
Treatment room (p)
N/R
2
6
N/R
N/R
20-60
Classes B and C operating rooms (m),
(n), (o)
-1-
68-75 /
20-24
68-75 /
20-24
68-75 /
20-24
N/R
70-75 /
21-24
70-75 /
21-24
70-75 /
21-24
70-75 /
21-24
72-78 /
22-26
70-75 /
21-24
Design
Temperature (I),
F/C
RH (k), %
Air recirculated
by means of
room units (a)
AII Room Air
Exhausted
Directly to
Outdoors (j)
Minimum Total
ACH
Minimum
Outdoor ACH
Pressure
relationship to
Adjacent Areas
(n)
Table 7-1 Design Parameters—
From ANSI/ASHRAE/ASHE
Standard 170-2008 (continued)
Surgery and Critical Care (cont.)
Trauma room (crisis or shock) ( c)
Positive
3
15
N/R
No
20-60
70-75 /
21-24
N/R
Medical/anesthesia gas storage ( r)
Negative
N/R
8
Yes
N/R
N/R
Laser Eye room
Positive
3
15
N/R
No
20-60
ER waiting rooms (q)
Negative
2
12
Yes
N/R
Max 65
Triage (q)
Negative
2
12
Yes
N/R
Max 60
ER decontamination
Negative
2
12
Yes
No
N/R
Radiology Waiting Rooms(q), (w)
Negative
2
12
Yes
N/R
Max 60
Class A Operating/Procedure
room(o), (d)
Positive
3
15
N/R
No
20-60
Patient Room
N/R
2
6
N/R
N/R
Max 60
Toilet Room
Negative
N/R
10
Yes
No
N/R
Newborn Nursery Suite
N/R
2
6
N/R
No
30-60
Protective Environment Room (t)
Positive
2
12
N/R
No
max 60
Protective Environment Anteroom (t)
( e)
N/R
10
N/R
No
N/R
AII room (u)
Negative
2
12
Yes
No
max 60
AII anteroom (u)
N/R
N/R ( e)
10
Yes
No
N/R
Combination AII/PE Room
Positive
2
12
Yes
No
max 60
Combination AII/PE Anteroom
( e)
N/R
10
Yes
No
N/R
Labor/Delivery/Recovery/Postpartu
m (LDRP) (s)
Labor/Delivery/Recovery (LDR) (s)
N/R
2
6
N/R
N/R
max 60
N/R
2
6
N/R
N/R
max 60
Nourishment Area or Room
N/R
N/R
2
N/R
N/R
N/R
70-75 /
21-24
70-75 /
21-24
N/R
Patient Corridor
N/R
N/R
2
N/R
N/R
N/R
N/R
Resident Room
N/R
2
2
N/R
N/R
N/R
Resident gathering/activity/dining
N/R
4
4
N/R
N/R
N/R
Physical Therapy
Negative
2
6
N/R
N/R
N/R
Occupational Therapy
N/R
2
6
N/R
N/R
N/R
Bathing Room
Negative
N/R
10
Yes
N/R
N/R
70-75 /
21-24
70-75 /
21-24
70-75 /
21-24
70-75 /
21-24
70-75 /
21-24
X-Ray (diagnostic and treatment)
N/R
2
6
N/R
N/R
Max 60
X-Ray (surgery/critical care and
catheterization)
Darkroom (g)
Positive
3
15
N/R
No
Max 60
Negative
2
10
Yes
No
N/R
70-75 /
21-24
70-75 /
21-24
70-75 /
21-24
N/R
70-75 /
21-24
70-75 /
21-24
Inpatient Nursing
70-75 /
21-24
N/R
72-78 /
22-26
70-75 /
21-24
N/R
70-75 /
21-24
N/R
70-75 /
21-24
N/R
Nursing Facility
Radiology (v)
–2–
72-78 /
22-26
70-75 /
21-24
N/R
Design
Temperature (I),
F/C
RH (k), %
Air recirculated
by means of
room units (a)
AII Room Air
Exhausted
Directly to
Outdoors (j)
Minimum Total
ACH
Minimum
Outdoor ACH
Pressure
relationship to
Adjacent Areas
(n)
Table 7-1 Design Parameters—
From ANSI/ASHRAE/ASHE
Standard 170-2008 (continued)
Diagnostic and Treatment
Bronchoscopy, sputum collection,
and pentamidine administration (n)
Laboratory, general (v)
Negative
2
12
Yes
No
N/R
Negative
2
6
N/R
N/R
N/R
Laboratory, bacteriology (v)
Negative
2
6
Yes
N/R
N/R
Laboratory, biochemistry (v)
Negative
2
6
Yes
N/R
N/R
Laboratory, cytology (v)
Negative
2
6
Yes
N/R
N/R
Laboratory, glasswashing
Negative
2
10
Yes
N/R
N/R
Laboratory, histology (v)
Negative
2
6
Yes
N/R
N/R
Laboratory, microbiology (v)
Negative
2
6
Yes
N/R
N/R
Laboratory, nuclear medicine (v)
Negative
2
6
Yes
N/R
N/R
Laboratory, pathology (v)
Negative
2
6
Yes
N/R
N/R
Laboratory, serology (v)
Negative
2
6
Yes
N/R
N/R
Laboratory, sterilizing
Negative
2
10
Yes
N/R
N/R
Laboratory, media transfer (v)
Positive
2
4
N/R
N/R
N/R
Autopsy room (n)
Negative
2
12
Yes
No
N/R
Nonrefrigerated body-holding room
Negative
N/R
10
Yes
No
N/R
Pharmacy (b)
Positive
2
4
N/R
N/R
N/R
Examination Room
N/R
2
6
N/R
N/R
Max 60
Medication Room
Positive
2
4
N/R
N/R
Max 60
Gastrointestinal endoscopy
procedure room
Endoscope cleaning
Positive
2
6
N/R
No
30-60
Negative
2
10
Yes
No
N/R
Treatment room
N/R
2
6
N/R
N/R
Max 60
Hydrotherapy
Negative
2
6
N/R
N/R
N/R
Physical Therapy
Negative
2
6
N/R
N/R
Max 65
Negative
N/R
10
Yes
No
N/R
N/R
Soiled or decontamination room
Negative
2
6
Yes
No
N/R
Clean workroom
Positive
2
4
N/R
No
Max 60
Sterile Storage
Positive
2
4
N/R
N/R
Max 60
72-78 /
22-26
72-78 /
22-26
72-78 /
22-26
(h)
68-73 /
20-23
70-75 /
21-24
70-75 /
21-24
70-75 /
21-24
70-75 /
21-24
N/R
70-75 /
21-24
70-75 /
21-24
70-75 /
21-24
70-75 /
21-24
70-75 /
21-24
70-75 /
21-24
70-75 /
21-24
68-75 /
20-24
70-75 /
21-24
N/R
70-75 /
21-24
70-75 /
21-24
68-73 /
20-23
N/R
70-75 /
21-24
72-80 /
22-27
72-80 /
22-27
Sterilizing
Sterilizer Equipment Room
Central Medical and Surgical Supply
-3-
Design
Temperature (I),
F/C
RH (k), %
Air recirculated
by means of
room units (a)
AII Room Air
Exhausted
Directly to
Outdoors (j)
Minimum Total
ACH
Minimum
Outdoor ACH
Pressure
relationship to
Adjacent Areas
(n)
Table 7-1 Design Parameters— From
ANSI/ASHRAE/ASHE
Standard 170-2008 (continued)
Service
Food Preparation Center (i)
N/R
2
10
N/R
No
N/R
72-78 /
22-26
N/R
Ware Washing
Negative
N/R
10
Yes
No
N/R
Dietary Storage
N/R
N/R
2
N/R
No
N/R
Laundry, general
Negative
2
10
Yes
No
N/R
72-78 /
22-26
N/R
Soiled Linen (Sorting and Storage)
Negative
N/R
10
Yes
No
N/R
N/R
Clean Linen Storage
Positive
N/R
2
N/R
N/R
N/R
Linen and Trash Chute Room
Negative
N/R
10
Yes
No
N/R
72-78 /
22-26
N/R
Bedpan Room
Negative
N/R
10
Yes
No
N/R
N/R
Bathroom
Negative
N/R
10
Yes
No
N/R
Janitor's Closet
Negative
N/R
10
Yes
No
N/R
72-78 /
22-26
N/R
Soiled Workroom or soiled holding
Negative
2
10
Yes
No
N/R
N/R
Clean workroom or clean holding
Positive
2
4
N/R
N/R
N/R
N/R
Hazardous material storage
Negative
2
10
Yes
No
N/R
N/R
Support Space