1.1 General
This document is one of a series dedicated to air-cooled heat exchangers.
- forced convection air cooled refrigerant condensers as specified in EN 327;
- forced convection unit air coolers for refrigeration as specified in EN 328;
- air cooled liquid coolers "dry coolers" as specified in EN 1048.
This document provides information for assessing and presenting the acoustic emission characteristics of heat exchangers under stationary operating conditions.
This document is applicable to selfstanding forced convection air cooled refrigerant condensers and air cooled liquid coolers "dry coolers" and air coolers.
1.2 Size of source
The method specified in EN ISO 3744, EN ISO 3745, EN ISO 3746, EN ISO 9614 1, EN ISO 9614 2 and EN ISO 9614-3 is applicable to noise sources of any size. Limitations for the size of the source are given in 1.3 of EN ISO 3741:2010, EN ISO 3743 1:2010 and EN ISO 3743 2:2009.
1.3 Object
This document offers ways to determine the sound power level of units. Some of them are specifically adapted to provide results with low uncertainties, by using laboratory class or engineering class acoustic methods under highly controlled working conditions. Those results are suitable for certification, labeling and marking purposes.
This document is concerned with objective methods for determining sound power levels LW, expressed in decibels (dB) with reference to a sound power of one picowatt (1 pW), of airborne acoustical noise within the specified frequency range of interest and for prescribed operating conditions of the appliance to be measured:
- A-weighted sound power level, LWA;
- spectral sound power levels;
- emission sound pressure level at workplace, LpA.