Waste Water Treatment Plant – All Noise control

Waste Water Treatment Plant contacted All Noise control to reduce noise generated by operation of three large (600 H.P…) Centrifugal Turbo-Air blowers at a Waste Water Treatment Plant.
Criteria:
Reduce noise levels emanating from existing sound level readings of up to 100 dB (A) to meet specification which reads: “the measured noise level at a distance of one meter shall not exceed 90 dB (A).” beyond the spec., reduce noise levels in the room to below 85 dB (A), if possible, for employees in the building, and reduce noise levels “as low as possible” outside the building for neighbors. In addition, allow for adequate intake airflow for blower operation. Also, allow for easy and immediate access to blowers for daily inspections and servicing.
Solution…..
“All Noise Control” Acoustical Curtain Panels installed on a floor and wall mounted double track system. The perimeter panels were ANC-AB13-2” with a durable, heavy duty reinforced loaded vinyl noise barrier outer surface and a 2″ thick aluminized vinyl faced quilted fiberglass sound absorber as the inner surface. Divider panels of an ANC-AB12 composite material with a noise barrier septum in the middle and the aluminized vinyl faced quilted fiberglass absorber on both sides, allowed for accessing or maintenance on one unit while still providing noise control for the other two units. The Double Track Curtain Hardware System offers this immediate access with each and every panel capable of acting as a sliding door. Two-inch spacing off the floor and an open top provided for adequate airflow to the Turbo-Blowers.
Results….
Sound Level Reading taken at a point three feet in front of Unit #1 illustrates a 14 dB (A) reduction from 97 dB (A) to 83 dB (A). An octave Band analysis shows a 15 dB reduction at 250 Hz and 23 dB reductions at 8000 Hz.