Technical data

Precision Air Conditioning
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Precision Air Conditioning
Technical Manual : 6258867 F 07/2012
21
Sound Measurement Method
All sound data quoted has been measured in the third-octave band limited values, using a
Real Time Analyser calibrated sound intensity meter in accordance with BS EN ISO9614
Part 1 : 1995.
MEASUREMENT OF
SOUND DATA
All Sound Power Levels quoted are calculated from measured sound intensity according
to BS EN ISO9614 Part 1 : 1995.
SEMI HEMISPHERICAL
Sound Pressure Levels are calculated from sound power using the semi-hemispherical
method where the noise source is in junction with 2 boundaries i.e. the floor and 1 wall.
FREE FIELD
For comparison, the semi hemispherical figures can typically be reduced by 3dB to
provide free field conditions.
The sound data quoted is based on the unit having return air application with
ducted discharge air.
IMPORTANT
Case breakout sound data is therefore independent of the discharge air
sound data.
For non-ducted discharge air applications, the overall case breakout sound levels
may increase, due to the discharge sound being predominant.
Within the conditioned space, sound from in-room ducted discharge air grilles and
other equipment will contribute to the overall sound level and should therefore be
considered as part of sound calculations.
Specialist acoustic advice is recommended for noise critical applications.
Front Return Air Configuration Rear / Base Return Air Configuration
(Optional)
(1)
(2)
(3)
(1)
(3)
(4)
(2)
(1) Return Air
(2) Case Breakout & Front Return Air
(3) Discharge Air
(1) Return Air Option or
(2) Base Return Air Option
(2) Case Breakout
(4) Discharge Air
GENERAL