36
9.5.3 - Return air plenum attenuation
The sound power level measurements were carried out on a
non-ducted unit without return air plenum. If the unit includes
a return air plenum, correct the sound power levels (RET)
using the correction factors in the table below:
Unit size Octave band frequency (Hz)
125 250 500 1K 2K 4K 8K dBA
42EM 1.0 -0.8 -1.7 -3.7 -10.6 -13.4 -9.6 -7.6 -3.4
42EM 2.1, 3.1 -1 -3 -6 -9 -13 -9.4 -6 -4.8
42EM 2.2, 3.2 -1.1 -2.7 -5.4 -9 -13.2 -8.8 -6.1 -4
42EM 2.3, 3.3 -0.4 -1.1 -2.6 -7.4 -10.7 -6.8 -4.1 -2.5
9.5.4 - Sound damper attenuation
As a standard option a sound damper can be added in the
return air of a non-ducted return air version.
This will dampen the sound on the return air side and main-
tain accessibility to the filter from the rear of the unit.
This sound damper is designed to minimise air pressure loss.
Octave band frequency (Hz)
125 250 500 1K 2K 4K 8K dBA
Attenuation -0.3 -1.7 -3.8 -5.8 -10.6 -16.9 -8.5 -3
To Next Page
Loading...
