Third-party sound testing is essential to verifying noise levels because published sound data are often confusing and can mislead product specifiers and end users. Urban and industrial development continues to increase around the globe, leading to a growing number of noise control regulations. In response, building designers and owners strive to be “good corporate citizens” by identifying quieter HVAC equipment, including cooling towers.
There is no single, universal method of specifying cooling tower sound. Either sound pressure level or sound power level measurements – or a combination of both – may be employed. Inaccurate cooling tower sound data are not uncommon; examples include calculating the sound power level of only one cell of a multi-cell tower or discounting the sound produced by falling water. Additionally, ambient noise at the site can hamper field measurements.
How can cooling tower users verify that stated sound levels are legitimate? The ATC-128 test code developed by the Cooling Technology Institute (CTI) provides a methodology for instrumentation, measurement and evaluation of sound pressure and sound power levels. By specifying that cooling towers must be independently tested by a CTI-licensed sound consultant and acoustical engineer, misleading sound level data become the exception.