The Situation

With the noise levels associated with an airport industrial area, identifying noise from a specific source - say, a testing facility for aero-derivative gas turbines - could be considered a formidable task. But if you wanted a guarantee that your facility was helping to create calm in a very noisy environment, you would call on ATCO Noise Management to deliver a complete noise solution, which is exactly what TransCanada Turbines (TCT) did for their Calgary, Alberta facility.

Arriving at a suitable noise level target would prove to be a challenging first step in this project. ATCO performed an extensive series of ambient noise measurements on the TCT property and met with the Calgary Airport Authority to establish a target level of 65 dBA measurable at the nearest office building, located 492 feet to the east of the facility. Noise levels within the preparation shop, attached to the test cell, were targeted at 85 dBA.

The TCT facility would be used for testing a wide variety of turbines including Rolls-Royce Avon and General Electric models up to their LM2500, capable of producing sound levels ranging from 113.7 dBA to 115.3 dBA. After initial analysis, ATCO identified the primary external noise contributors as the walls of the test cell, the exhaust/ventilation openings, the air intake system and the combustion exhaust. Because the noise levels would vary with the size of the turbines being tested, the acoustical solution would need to be effective at containing the noise levels produced by the largest turbines.

The Solution

The walls and roof of the test cell were constructed of 400-mm thick reinforced concrete. The thickness of the concrete, combined with ATCO's four inch acoustical lining, helped to ensure that the targeted dBA levels were achieved. The choice of structure also satisfied containment requirements in the unlikely event of a turbine disintegrating during testing.

The considerable exhaust noise generated by the test cell represented a significant potential source of noise leakage, which ATCO addressed through the installation of an augmentor tube and a custom-designed exhaust silencer. For the control room and preparation room, ATCO acoustically treated the walls, ceiling and doors using a specific combination of acoustical assemblies from a comprehensive suite of 25 tested and approved acoustical solutions.

The TransCanada Turbines project was a first of its kind for ATCO Noise Management, but after its successful completion, will undoubtedly not be the last…

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 labour costs which are incorporated into the acoustical design model, resulting in cost effective solutions to noise problems. We also offer ambient noise surveys, regulatory review, preparation of acoustical specifications, budget pricing and post-construction testing.