Ceiling Concealed Duct(High Static) _ 23
Indoor Units
9. Sound Levels
Sound Pressure Level (50Pa)
Octave Band Center Frequency (Hz)
Octave Band Sound Pressure Level (0 dB = 20 μPa)
10 
20 
30 
40 
50 
60 
70 
80 
63  125  250  500  1 000  2 000  4 000  8 000 
NC-15 
NC-20 
NC-25 
NC-30 
NC-35 
NC-40 
NC-45 
NC-50 
NC-55 
NC-60 
NC-65 
Approximate
Hearing
Threshold    
Octave Band Center Frequency (Hz)
Octave Band Sound Pressure Level (0 dB = 20 μPa)
10 
20 
30 
40 
50 
60 
70 
80 
63  125  250  500  1 000  2 000  4 000  8 000 
NC-15 
NC-20 
NC-25 
NC-30 
NC-35 
NC-40 
NC-45 
NC-50 
NC-55 
NC-60 
NC-65 
Approximate
Hearing
Threshold    
Octave Band Center Frequency (Hz)
Octave Band Sound Pressure Level (0 dB = 20 μPa)
10 
20 
30 
40 
50 
60 
70 
80 
63  125  250  500  1 000  2 000  4 000  8 000 
NC-15 
NC-20 
NC-25 
NC-30 
NC-35 
NC-40 
NC-45 
NC-50 
NC-55 
NC-60 
NC-65 
Approximate
Hearing
Threshold    
ARNU28GBGA4 ARNU36GBGA4 ARNU42GBGA4
n High
▲ Mid
l Low
n High
▲ Mid
l Low
n High
▲ Mid
l Low
Model
Sound Pressure Levels (dB(A),H-M-L)
External Static Pressure (Pa)
50 80 100 120 140
160
ARNU28GBGA4 29-25-23 33-29-26 34-33-30 35-34-31 36-35-32 37-36-33
ARNU36GBGA4 33-31-28 36-34-31 37-35-32 39-37-34 40-38-35 41-39-36
ARNU42GBGA4 36-33-30 39-36-33 40-38-35 42-39-36 43-40-37 44-41-38
Overall
1.5m
2m
2m
DUCT
DISCHARGE
SUCTION
DUCT
❈ Measuring place : Anechoic chamber
Notes:
1. Sound measured at 1.5m away from the center of the unit
2. Operating condition|
- Power source : 220-240V 50Hz / 220V 60Hz
- Cooling : Indoor temperature (27°C DB, 19°C WB),
Outdoor temperature (35°C DB, 24°C WB) 
- Heating : Indoor temperature (20°C DB, 15°C WB),
Outdoor temperature (7°C DB, 6°C WB)
3. Reference accoustic pressure 0dB = 20μPa
4. Sound level will vary depending on a range of factors such as the
construction(acoustic absorption coefficient) of particular room in
which the equipment in installed.