129 112TH ST SE CLEARWIRE ANTENNAS 2018-01-02 MF Import

, Clearvvire P89@ 2 WA-SN0195•F Adams Predicted Equipment Noise Levels The new equipment consists of one ClaarWire IQ-4000VS Sile Support Cabinet, which according to manufacturer data has a 55 dBA noise level at 5 feet. To predict the equipment noise levels at the roceiving property lines, this survey used the methods established by Air-Conditioning and Refrigeration Institute (ARI) Standard 275 dated 1997. "Application factors"such as localion, height, and reflective surfaces are taken into I consideration to predict the sound level at a specific location. The nearest receiving property is 5 (eet east of the wireless tacility. The predicted sound level at the nearest receiving property is shown below. Table 1 Application Factors and Predicted Noise Levels Pro osed New E ui ment Line A Iication Factor West 1 Existin E ui ment Sound Pressure Level at 3 ft. dBA , L 1 55 2 Dislance Feclor(DF): •� DF = 2010 d1/d2 5 h 3 Predicted Noise Level al Receiver PropeRy Line 55 Add lines 1 and 2 As shown in Table 1, the predicted sound pressure level produced by the new equipment is 55 dBA at the nearest receiving property, which does not meet the 45 dBA nighttime code limit. In order to meet code, a barrier of the following minimum specifications should be ccnstructed. Noise Barrier The noise barrier should be 6-feet tall and be constructed from continuously solid '/." plywood or material with a suriace weight of at least 2.5 pounds per square foot and framed on wood or metal posts. There should be no gaps or joints in the barrier. The inside ot the barrier should be lined with sound absorbing Quash rigid foarn board QFR 2" lhick (available from Forrest Sound Products, (425) 646-9703). This assembly will drop the noise level from the equipment at the nearest receiving property to 45 dBA. If you have any questions or require further information, please feel free to call. Sincerely, SSA Acoustics, LLP Alan Burt ACOUSTICAL CONSULTANT ��/