10 . Sound Levels
1.0m
Duct
CONCEALED DUCT TYPE
Microphone
18,000 BTU/H
24,000 BTU/H
36,000 BTU/H
48,000 BTU/H
Octave band center frequency
0
Hz
1
So
un
d
pr
es
su
re
le
ve
ld
B
0
0d
B
=
0.
00
02
2
ba
r
1
Audibility limits of
continuous white
sound
Octave band center frequency
0
Hz
1
S
ound
pr
es
su
re
le
ve
ldB
0
0d
B=0
.0002
2
ba
r
1
Audibility limits of
continuous white
sound
Octave band center frequency
0
Hz
1
So
un
d
pr
es
su
re
le
ve
ld
B
0
0d
B
=0
.0
00
2
2
ba
r
1
Audibility limits of
continuous white
sound
Octave band center frequency
0
Hz
1
S
ound
pr
es
sur
e
le
ve
ld
B
0
0dB
=0
.0
002
2
ba
r
1
Audibility limits of
continuous white
sound
