Ex. E <br />(e) Composite Correction <br />By making the above noted corrections to the SSA model, the SSA impact noise levels are <br />shown to be consistently 4.5 dB too low. <br />Air Conditioning Levels <br /> <br /> (dBA) SSA level Both Distance Hush kit SSA <br /> unmitigated units adjusted adjusted corrected over estimated <br /> 27 +4 +5.5 -5 31.5 +4.5 <br /> 40 +4 +5.5 -5 44.5 +4.5 <br />30 (35 +4 +5.5 -5 34.5 +4.5 <br />Although the corrected levels do not change the general conclusion reached by the original SSA <br />approach, the margin of safety is greatly minimized. To the South, the noise level 44.5 dBA is <br />less than code 45 dBA but more than the recommended limit of 35 dBA. <br />B) Emergency Equipment Power Generator <br />There are two aspects to the generator noise, one being the noise created inside the generator <br />room and released out of the fresh air vents in the wall of the room. The other is the noise <br />SSA specified that generator is a <br />Kohler 50 Kw diesel Motor/Generator set, 50REOZJD open side unit and that the diesel <br />generator and the exhaust is rated 102 dBA . <br />However, SSA made a mistake. Manufacturer spec for the exhaust is actually 102 dBA @ 1 <br />meter, which is 3.3 feet, not 3 feet which means SSA underestimated the impact on community <br />noise. Octave band data was also available from manufacturer but not used by SSA. <br />a) Generator Room Noise <br />The generator room will have two large openings in the south wall. The ambient air is drawn <br />into the room through the inlet opening by the suction effect of the radiator fan. The inlet air that <br />is pulled past the radiator warms up and is expelled from the room through the second opening. <br />The two openings need to be as far apart as possible so the exhausting warm air is not pulled <br />back into the radiator inlet. There are no plan details included in the application, in the noise <br />report by SSA or in the paperwork from Technology Associates that present this venting system. <br />i) SSA Generator Room Calculation <br />SSA states the air inlet is <br />absorbing material. It must be the radiator inlet baffle. SSA states the warm air exhaust opening <br />will be fit with a sound absorbing louver system, ALV-MV-8. SSA claims but does not prove <br />how both economical hood and expensive louver are both rated for 17 dBA attenuation.The <br />size of the 2 openings in the south wall of the Generator Room and location of muffler exhaust <br />are also not specified. <br />7 <br />