AT&T EG46 Fox Hollow Road & Amazon Road <br />Predicted Equipment Sound Levels <br />Page 2 <br />24-Hour Operation Equipment <br />The equipment will be located in a shelter served by two Marviar air conditioning units. According <br />to manufacturer data, the Marvair AVP48 air-conditioning which each produce 72 dB(A) at 5 feet. <br />The equipment will operate on a lead/lag cycle such that one unit will be in operation at a time. <br />To predict equipment noise levels at the receiving properties, this survey uses the methods <br />established by ASHRAE and AHRI Standard 275-2010. Application factors such as location, <br />height, and reflective surfaces, and noise reduction from intervening elements are accounted for <br />in predicting the sound level at the receiving properties. <br />The nearest receiving properties are approximately 90 feet to the west, 180 feet east across W. <br />Amazon Road, and 200 feet south across Fox Hollow road. The building blocks the equipment <br />noise to the property to the west, and the cedar fence surrounding the tower blocks the equipment <br />to the east. The predicted sound levels are shown in the table below. <br />Table 1 <br />Application Factors and Predicted Noise Levels <br />Proposed New Equipment <br />Application Line 1 Equipment Sound Pressure Level at 5 ft., LPs <br />72 <br />72 <br />72 <br />2 Building / Wood Fence Reduction <br />-20 <br />-6 <br />3 Distance Factor (DF) <br />DF = 20 to io Dl/D2 <br />-25 <br />90 ft <br />-31 <br />180 ft <br />-32 <br />200 ft <br />4 New Equipment Sound Pressure Level at Receiver, LPR <br />27 <br />35 <br />40 <br />According to the predicted noise levels, the equipment would be below the 45 dBA code limit, but <br />would not meet the City's recommended 35 dBA level at the south property line. Mitigation <br />measures to meet this recommended noise level are provided below. <br />Noise Mitigation: <br />The following noise mitigation must be implemented for the AC units: <br />• Install a Marvair External Low Noise Blower (ELNB) kit on each unit. The kit replaces the <br />condenser prop fan and motor with a sound absorbing hood, blower and motor and <br />controls to reduce external sound levels. The kit will reduce noise levels by 6 dBA. <br />With the noise mitigation installed, noise levels from the AC units will be 34 dBA at the south <br />property line and will meet the City's recommended 35 dBA level. <br />