ABSTRACT
The sound power of fans is dependent on the fan type and can vary considerably, depending on the operating point compared to the point of maximum efficiency. Manufacturer’s data should always be used for fan sound power levels, these data are typically sound power levels of inlet, discharge and casing. The compressor is usually the dominant noise source in a refrigeration unit, so that it is generally sufficient to consider noise generation from this source alone when considering a packaged chiller. Noise produced by gas and steam vents can be estimated by assuming they are free jets. The estimation procedure for free jets is then used to calculate sound power and sound pressure levels. Steam valves are a common source of noise in industrial plants. Sound pressure levels generated by them can be estimated using the procedures outlined previously for gas valves.
