Household and similar electrical appliances - Test code for the determination of airborne acoustical noise - Part 2-14: Particular requirements for refrigerators, frozen-food storage cabinets and food frozeers
This part of IEC 60704 specifies methods for measuring airborne acoustical noise emitted by
electric refrigerators, frozen-food storage cabinets, food freezers and their combinations for
household and similar uses, supplied from the mains or from batteries.
The term "similar use" means "use under conditions similar to those in a household", for
example, in cafés, restaurants, hotels, and similar establishments.
This standard does not apply to appliances, equipment or machines designed exclusively for
industrial or commercial purposes.
This standard is concerned with objective methods of engineering accuracy (engineering
method, grade 2, according to IS0 2204) for determining sound power levels, (LW expressed
in decibels with reference to a sound power of 1 pW, of airborne acoustical noise within the
specified frequency range of interest, and for specified operating conditions of the appliance
to be measured.
The frequency range of interest includes the octave bands with centre frequencies between
125 Hz and 8 000 Hz (this interval being, for practical reasons, narrower than the frequency
range of audible sound).
The following sound power levels are used:
– A-weighted sound power level, LWA;
– octave band sound power levels, LWOct.
In general, the methods described are specified for appliances operated with no operator
present.
The noise measurements are made while the compressors are running.
Requirements as to an indication of the noise emission values are not the subject of this
standard.
This standard does not include methods for determining sound power levels with precision
accuracy (precision method, grade 1, according to IS0 2204) specified, for example, in IS0
3741, IS0 3742 and IS0 3745; they may, however, be applied if the appropriate
instrumentation and test environments are available.