CEILING-CONCEALED
B-56
NOISE CRITERIA
CUR
VES
S series
CEILING-
CONCEALED
2m
Aux.duct
1m
1.5m
Measurement location
NOTE: The sound level is measured in an anechoic room where echoes
are few, when compressor stops. The sound may be bigger than
the indicated level in actual use due to surrounding echoes. The
sound level can be higher by about 2 dB than the indicated level
during cooling and heating operation.
90
80
70
60
50
40
30
20
10
63
125
250
500
1000
2000
4000
8000
APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
NC-60
NC-50
NC-40
NC-30
NC-20
NC-70
BAND CENTER FREQUENCIES, Hz
OCT
A
VE BAND SOUND PRESSURE LEVEL, dB (0 dB = 0.0002 bar)
SEZ-KD25VA(L)
External static pressure: 15Pa
High
Middle
30
SPL(dB)
26
Low
23
LINE
NOTCH
90
80
70
60
50
40
30
20
10
63
125
250
500
1000
2000
4000
8000
APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
NC-60
NC-50
NC-40
NC-30
NC-20
NC-70
BAND CENTER FREQUENCIES, Hz
OCT
A
VE BAND SOUND PRESSURE LEVEL, dB (0 dB = 0.0002 bar)
SEZ-KD25VA(L)
External static pressure: 5Pa
High
Middle
29
SPL(dB)
25
Low
22
LINE
NOTCH
90
80
70
60
50
40
30
20
10
63
125
250
500
1000
2000
4000
8000
APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
NC-60
NC-50
NC-40
NC-30
NC-20
NC-70
BAND CENTER FREQUENCIES, Hz
OCT
A
VE BAND SOUND PRESSURE LEVEL, dB (0 dB = 0.0002 bar)
SEZ-KD25VA(L)
External static pressure: 50Pa
High
Middle
33
SPL(dB)
29
Low
25
LINE
NOTCH
90
80
70
60
50
40
30
20
10
63
125
250
500
1000
2000
4000
8000
APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
NC-60
NC-50
NC-40
NC-30
NC-20
NC-70
BAND CENTER FREQUENCIES, Hz
OCT
A
VE BAND SOUND PRESSURE LEVEL, dB (0 dB = 0.0002 bar)
SEZ-KD25VA(L)
External static pressure: 35Pa
High
Middle
31
SPL(dB)
28
Low
24
LINE
NOTCH
B.2.6 NOISE CRITERIA CURVES