Manage Sound And Vibration; Compressor Sound Radiation - Danfoss VLZ065 Application Manuallines

Manage sound and vibration

Compressor sound
radiation
24
AB444226142054en-000101
Typical sounds and vibrations in systems can be
broken down into the following three categories:
• Sound radiation (through air)
• Mechanical vibrations (through parts and
structure)
For sound radiating from the compressors,
the emission path is air and the sound waves
are travelling directly from the machine in all
directions.
Compressor model Frequency RPS
VLZ065
Sound power and attenuation are given at ARI conditions, measured in free space
 Attenuation given with acoustic hood
Materials are UL approved
Mitigations methods:
We can consider two means to reduce
compressors sound radiations:
1. Acoustic hoods are quick and easy to install
and do not increase the overall size of the
compressors. Acoustic hoods are available from
Danfoss as accessories. Refer to the table above
for sound levels, attenuation and code numbers.
2. Use of sound-insulation materials on the inside
of unit panels is also an effective means to reduce
• Gas pulsation (through refrigerant)
The following sections focus on the causes and
methods of mitigation for each of the above
sources.
Sound levels are as follows:
• For compressors running alone:
Sound power
dB(A)
60 79
110 88
radiation.
Note: During compressor shut down, a short
reverse rotation sound is generated. The duration
of this sound depends on the pressure difference
at shut down and should be less than 3 seconds.
This phenomenon has no impact on compressor
reliability.
380V
Acoustic hood
Attenuation
code number
dBA 
7
120Z5084
8