Volume: 22S1 • April 1996
Guidelines for Preventing the
Transmission of Tuberculosis in Canadian Health Care
Facilities and Other Institutional Settings
Appendix F
Air Changes Per Hour and Time in Minutes Required
for Removal Efficiencies of 90%, 99% or 99.9% of
Airborne Contaminants*
Minutes required for a removal efficiency
of:
|
Air Changes Per Hour
|
90%
|
99%
|
99.9%
|
1
|
138
|
276
|
414
|
2
|
69
|
138
|
207
|
3
|
46
|
92
|
138
|
4
|
35
|
69
|
104
|
5
|
28
|
55
|
83
|
6
|
23
|
46
|
69
|
7
|
20
|
39
|
59
|
8
|
17
|
35
|
52
|
9
|
15
|
31
|
46
|
10
|
14
|
28
|
41
|
11
|
13
|
25
|
38
|
12
|
12
|
23
|
35
|
13
|
11
|
21
|
3
|
14
|
10
|
20
|
30
|
15
|
9
|
18
|
28
|
16
|
9
|
17
|
26
|
17
|
8
|
16
|
24
|
18
|
8
|
15
|
23
|
19
|
7
|
15
|
22
|
20
|
7
|
14
|
21
|
* This table is prepared according to the formula
t=(in C2/C1)/(Q/V)=60, which is an adaptation of
the formula for the rate of purging airborne
contaminants (100-Mutchler 1973) with t1=0 and
C2/C1=1— (removal efficiency/100).
|
-
Source:
-
Adapted from CDC. Guidelines for preventing the
transmission of Mycobacterium tuberculosis
in health-care facilites, 1994. MMWR
1994;43(No. RR-13):1-32.
[Previous] [Table of Contents]
|