DCPCUP-2014-02291 - Laserfiche WebLink

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Enbridge Energy, LP Hoover & Keith, Inc. Waterloo Pump Station RN 3083/JN 4796 Noise Impact Analysis (10/10/14) shall not be utilized. Each ventilation inlet and exhaust outlet shall assume that the following sound pressure levels exist inside the pump house building at and adjacent to the ventilation equipment: SPLs per Octave-Band Center Fre . &A-Wt. Level 31.5 63 125 250 500 1000 2000 4000 8000 dBA 75 80 85 85 85 80 80 75 65 87 ➢ As a minimum, air-supply fans used for ventilation should include a metal boot enclosing the fan; a minimum 36-inch length exterior silencer and a weather hood lined with acoustical insulation. Assuming separate roof exhaust vents will be utilized, each roof exhaust vent, as a minimum, should include a 36-inch length silencer(i.e., baffle-type design) mounted between the building surface and vent/hood (i.e., in the ventilator throat). 5.2 VFD System Cooling Exhaust Air and associated Components Air Exhaust System for VFD: It is anticipated that the air exhaust of each VFD cooling system will be exhausted via an opening located on the ESB building wall (via a louver). Based on this design, the A-wt. sound level generated from the air exhaust opening of the VFD air exhaust system (including any noise control) should not exceed 40 dBA at 50 feet. It is recommended that a 5-ft. length (min.) parallel-baffle silencer should be installed in-line with the VFD air exhaust ductwork, preferably in the VFD exhaust ducting located inside the ESB Building. If it is not feasible to insert the recommended silencer in-line with the interior air exhaust ductwork, the silencer may have to be mounted on the exterior wall of the air exhaust opening. For reference, the following table lists the recently-measured A-wt. sound level and unweighted O.B. SPLs at 5 feet and 50 feet from the air exhaust opening of a typical "modular-type" VFD Building at another Enbridge pumping station. Meas'd Sound Levels at 5 Ft. &50 Ft. for VFD Air Exhaust O ening Distance 31.5 63 125 250 500 1000 2000 4000 8000 A-Wt. 5 Ft. 76 dB 72 dB 78 dB 72 dB 70 dB 68 dB 68 dB 65 dB 58 dB 74 dBA 50 Ft. 64 dB 61 dB 65 dB 62 dB 60 dB 57 dB 56 dB 52 dB 46 dB 63 dBA Other Equipment/Components: The A-wt. sound level of each wall-mounted AC unit should not exceed 40 dBA at a distance of 50 feet from the equipment during operation. In addition, for the ESB Building, assuming wall openings will associated with the building air ventilation system, it may be necessary to employ acoustical-type louvers and/or other type of noise control measures to reduce the noise of internal equipment(e.g., VFDs, etc.)that radiates through any building ventilation openings. -4-