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27AB218186428184en-US1501
GENERAL INFORMATIONPRODUCT INFORMATIONINTEGRATION INTO SYSTEMORDERING INFORMATION SYSTEM DESIGN
Manage sound and vibration
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)
• Gas pulsation (through refrigerant)
The following sections focus on the causes and
methods of mitigation for each of the above
sources.
Compressor sound
radiation
For sound radiating from the compressors,
the emission path is air and the sound waves
are travelling directly from the machine in all
directions.
Sound levels are as follows:
• For compressors running alone:
Compressor model
50 Hz 60 Hz
Acoustic hood
code number
Sound power
dB(A)
Attenuation
dBA
Sound power
dB(A)
Attenuation
dBA
HRM025-038 66 5 69 5 120Z5083
HRM040-047 67 5 70 5 120Z5083
HRM048-054 68 5 71 5 120Z5084
HRM058-060 69 5 72 5 120Z5084
HLM068-081 70 5 73 5 120Z5084
HCM094 71 5 74 5 120Z5085
HCM109-120 74 5 78 5 120Z5085
HRH029-032 65 5 68 5 120Z5083
HRH034-040 66 5 69 5 120Z5083
HRH041-054 67 5 70 5 120Z5084
HLH061 70 5 73 5 120Z5084
HLH068-HLJ083 71 5 74 5 120Z5084
HCJ091-106-121 73 5 76 5 120Z5085
Attenuation given with acoustic hood only
Acoustic hood could be applied for both single and tandem version compressors.
Materials are UL approved and RoHS compliant
Sound power and attenuation are given at ARI conditions, measured in free space
H*P series same as H*M series. Compressor’s noise test is after compressor run-in 72hrs. Maximum sound is +5dBA
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.
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 to a great extent. 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
radiation.