2010-03-02-NAC-min - Laserfiche WebLink

Browse Search

Mr. Kropper asked if Equipment noise levels varied by time of day. A Shire representative suggested that HVAC operations did not vary with time of day or occupancy, but varied with environmental conditions, i.e., depending on the need for cooling versus heating. Citizen Comments Jeannie Canale, 29 Shade Street, commented that noise levels have gone up and their tones shifted since the installation of certain roof top equipment. A Shire representative responded that the installation of noise mitigation equipment is only partially completed. Michelle Ciccolo, 50 Shade Street, indicated that noise measured on Shire’s property line is less important than noise measured at residences, where it disturbs people. She suggested that some of the noise monitors proposed for Shire property line locations be placed at locations within nearby residential properties. Perhaps monitoring eight homes would be representative. Perhaps four houses would be sufficient. Mr. Galaitsis suggested that Shire representatives meet with Shade St. neighbors to select some mutually agreeable residential locations for some of the noise monitors. Both Shire representatives and residents agreed to do so. Mrs. Vicki Blier, 41 Shade St., inquired about the definition of a property line. A Shire representative opined that property line was a vertical plane from the line skyward. Shire Acoustics Consultant Comments Mike Bahtiarian, of Noise Control Engineering and consultant to Shire, briefed the NAC on a new 10-days old plan to address the noise problem. Copies of plan were distributed to members. The NAC was asked to review this plan in conjunction with the March 2, 2010 Shire HGT Ambient Sound Level Assessment Measurement Protocols (DRAFT). All proposed measurements would be conducted at ground level even though noise level may vary with height. Discussion ensued about proper design of a test to ascertain ambient noise levels including placement and count of microphones. Mr. Bahtiarian stated that the Shire team would measure octave-band and 1/3-octave-band levels at various locations with most of the Shire equipment off and some of the equipment on. He stated that another acoustics firm (Acentech from Cambridge) would model the buildings and the noise sources to calculate and subtract the active equipment noise out of the measured noise. Detailed discussion on pros and cons of plan ensued. Mr. Galaitsis and Mr. Earsy did not accept Mr. Bahtiarian’s suggestion to use L as an alternate approach to measuring EQ ambient noise. They both stated that L-90 is the appropriate metric. Mr. Galaitsis expressed concern about the Draft protocol’s modeling accuracy for ambient noise level, and suggested that the ambient noise level be actually measured with all Shire equipment shut down.