1
1-302
1-8. Noise Criterion Curves
Concealed-Duct Type
400063 125 250 800020001000500
60
50
40
30
20
10
400063 125 250 800020001000500
60
50
40
30
20
10
400063 125 250 800020001000500
60
50
40
30
20
10
NC-20
NC-30
NC-40
NC-50
NC-20
NC-30
NC-40
NC-50
NC-20
NC-30
NC-40
NC-50
1-8. Noise Criterion Curves
Concealed-Duct Type
1. Value obtained in the actual place where the unit is
installed may be slightly higher than the values shown
in this graph because of the conditions of operation,
the structure of the building, the background noise and
other factors.
2. The test results were obtained from an anechoic room.
3. The layout of the testing condition is shown at right.
To evaluate the noise level, the maximum value of the measured sound pressure level is used. Read the value at
each frequency level (on horizontal axis, center of the sound pressure band) from 63 Hz to 8000 Hz, and select the
corresponding maximum value indicated on the vertical axis.
REMARKS:
NOTE
Both 50Hz / 60Hz
Strong
Weak
MODEL
SOUND LEVEL
CONDITION
: SPW-US165H
: STRONG 34 dB(A)
WEAK 30 dB(A)
: 1.5 m directly below unit
Sound pressure level (dB)
(0dB = 0.0002μbar)
Approximate
minimum
audible limit for
continuous noise
Overall
Frequency at center of sound pressure band (Hz)
MODEL
SOUND LEVEL
CONDITION
: SPW-US125H
: STRONG 32 dB(A)
WEAK 28 dB(A)
: 1.5 m directly below unit
Sound pressure level (dB)
(0dB = 0.0002μbar)
Approximate
minimum
audible limit for
continuous noise
Overall
Frequency at center of sound pressure band (Hz)
MODEL
SOUND LEVEL
CONDITION
: SPW-US185H
: STRONG 35 dB(A)
WEAK 31 dB(A)
: 1.5 m directly below unit
Sound pressure level (dB)
(0dB = 0.0002μbar)
Approximate
minimum
audible limit for
continuous noise
Overall
Frequency at center of sound pressure band (Hz)
Auxiliary Duct
of 2 m length
Air discharge
Air intake
1.5 m
1.5 m directly below unit
(Concealed-Duct Type)
Auxiliary Duct
of 1 m length
Unit
NC-70
NC-60
NC-50
NC-40
NC-30
NC-20
NC-70
NC-60
NC-50
NC-40
NC-30
NC-20
NC-20
NC-30
NC-40
NC-50
NC-60
NC-70
NC-20
NC-30
NC-40
NC-50
NC-60
NC-70
SM830160-03ClassicPAC-iA4.ind302302SM830160-03ClassicPAC-iA4.ind302302 2010/02/1610:26:442010/02/1610:26:44