The Situation

The Hemphill Finished Water Pumping station in Atlanta, Georgia is located 150 feet (approximately the width of a football field) away from a commercial strip mall. Sunbelt Power Systems, based in Austell, Georgia, was contracted to design and construct a 10 MW standby power plant, capable of supplying the necessary electricity to keep the plant running in the event of an emergency.

With an eye, and an ear, to the proximity of the strip mall, a key project requirement was to reduce noise levels from 130 dBA inside the plant to 75 dBA at the mall, and accomplish this using acoustical architectural designs in a structure that matched the architectural look and feel of the surrounding neighborhood. When the acoustical architectural and engineering challenges were analyzed, Sunbelt looked to ATCO for the answers.

The Solution

The narrowness of the site meant that a conventional acoustical engineering approach was simply not possible. A normal approach would be to install an inlet silencer for each of the ten Caterpillar 3516 Spark-Ignited Generator sets. Instead, ATCO proposed a unique silencing solution that would convert an entire portion of the building into one huge silencer. Not only would this save money, it would also eliminate the heavy industrial look of the resulting structure by removing the necessity for constructing ten externally visible silencers.

ATCO designed the building’s air exchange system to channel 860,000 cfm (cubic feet per minute) of cooling air over the engines, then silenced the air flow by having it drawn up into a huge acoustical exhaust plenum specifically designed to absorb noise from interior sources.

From its comprehensive suite of 25 tested and approved acoustical assemblies, ATCO utilized Types B and E for the building’s acoustical walls and Type B for the roof. The Type E acoustical wall has high sound-absorbing and sound-blocking properties, and for this reason, was placed on the side and end walls facing the commercial strip. The less acoustical Type B wall formed the opposite walls and roof where noise containment was not as critical.The ATCO custom-engineered exhaust muffler and tailpipe assembly were hung from the roof, shifting structural weight off the power plant itself, reducing engine stress and allowing for ease of engine removal, for future maintenance and repair.

The good news – the mall across the street hasn’t lost any customers because of noise complaints…

About Us

As a company providing a full turnkey service to its clients, ATCO Noise Management is responsible for all acoustical design, material procurement and construction. This has enabled us to accumulate a comprehensive database of material and labor costs which are incorporated into the acoustical design model, resulting in cost effective solutions to noise problems. In addition to design, supply and installation, we also offer ambient noise surveys, regulatory review, preparation of acoustical specifications, budget pricing and post-construction testing.