Data Center Air-cooled Chiller Broadband and Tonal Noise Control

Abstract

Data centers require vast amounts of cooling using large farms of air-cooled chillers as the primary equipment of choice. The amount and nature of noise generated by these chiller farms to the surrounding area can create complaints and the noise control solutions require an understanding and knowledge of both broadband and tonal noise. The dominant noise sources on air-cooled chillers are compressors and condenser fans, each of which produce both broadband and tonal noise spectrums. Therefore, noise control solutions should address both the broadband and tonal aspects of the source. A common noise control solution for chillers serving data centers is a sound barrier wall and while effective at providing overall broadband noise control, does little in targeting tonal issues. However, a sound barrier wall can be supplemented to address these tonal issues by applying source treatments to the chiller, such as a sound cover treatment for the compressors and associated refrigerant piping and sound stacks and intakes for the condenser fans. In addition, barrier walls an create a "pit" application impeding chiller condenser fan discharge air resulting in recirulation and nuisance trips. Using a sound stack source treatment with a barrier wall can help mitigate this issue while providing attenuation.