Sound and vibration management
Compressor sound radiation
For sound radiating from the compressor, the
emission path is airborne and the sound waves
are travelling directly from the machine in all
directions.
The Danfoss SM / SY / SZ scroll compressor is
designed to be quiet and the frequency of the
sound generated is pushed into the higher
ranges, which not only are easier to reduce but
also do not generate the penetrating power of
lower-frequency sound.
Use of sound-insulation materials on the inside of
unit panels is an effective means of substantially
reducing the sound being transmitted to the
outside. Ensure that no components capable of
transmitting sound / vibration within the unit
come into direct contact with any non-insulated
parts on the walls of the unit.
Because of the Danfoss’s unique design of a
full-suction gas-cooled motor, compressor body
insulation across its entire operating range is
possible. Acoustic hoods are available from
Danfoss Commercial Compressors as accessories.
They have been developed to meet specific extra
low noise requirement. They incorporate sound
proofing materials and offer excellent high and
low frequency attenuation. These hoods are
quick and easy to install and do not increase the
overall size of the compressors to a great extend.
Refer to section "Running sound level" for sound
attenuation and code numbers.
Mechanical vibrations
Vibration isolation constitutes the primary
method for controlling structural vibration.
Danfoss SM / SY / SZ scroll compressors are
designed to produce minimal vibration during
operations. The use of rubber isolators on
the compressor base plate or on the frame
of a manifolded unit is very effective in
reducing vibration being transmitted from the
compressor(s) to the unit. Rubber grommets
are supplied with all Danfoss compressors.
Once the supplied rubber grommets have been
properly mounted, vibration transmitted from
the compressor base plate to the unit are held
to a strict minimum. In addition, it is extremely
important that the frame supporting the
mounted compressor be of sufficient mass and
stiffness to help dampen any residual vibration
potentially transmitted to the frame. For further
information on mounting requirements, please
refer to the section on mounting assembly.
The tubing should be designed so as to both
reduce the transmission of vibrations to other
structures and withstand vibration without
incurring any damage. Tubing should also be
designed for three-dimensional flexibility. For
more information on piping design, please see
the section entitled "Essential piping design
considerations".
Gas pulsation
The Danfoss SM / SY / SZ scroll compressor
has been designed and tested to ensure that
gas pulsation has been optimized for the
most commonly encountered air conditioning
pressure ratio. On heat pump installations and
other installations where the pressure ratio
lies beyond the typical range, testing should
be conducted under all expected conditions
and operating configurations to ensure
that minimum gas pulsation is present. If an
unacceptable level is identified, a discharge
muffler with the appropriate resonant volume
and mass should be installed. This information
can be obtained from the component
manufacturer.
41
FRCC.PC.003.A5.22
Application guidelines
