School District 65 OKs Recommendations to Reduce Chiller Noise

will move quickly to land a spot on the agenda of the Lake Bluff Zoning Board after voting unanimously during Tuesday night’s Board of Education meeting to approve five recommendations to reduce the noise of the heating, ventilation and air-conditioning compressors at .

One of those recommendations will need the approval of the Zoning Board because it asks to increase the height of the walls around the chiller by 3.5 feet with an acoustic metal material. The Zoning Board meets the third Wednesday of every month, and the next meeting is Jan. 18, 2012.

The other four approved recommendations were:

• Install acoustical panels on the interior of all four walls and some of those panels will extend beyond the height of the current wall.

• Install baffles over the top of the enclosure.

• Add wrapping to pipes and other parts of the chiller itself.

• Install discharge fan silencers to the top of the chiller.

The recommendations came as a result of nearly five months of inquiry by District 65, including the input from , a noted environmental noise expert from the University of Illinois who conducted noise level tests on the chillers. The action came after a three-year struggle by homeowners whose backyards face the chiller and who have spent summers inside or with their windows closed because of the noise level coming from the unit.

helped to form the impacted neighbors into a group, numbering more than 70, called the Middle School Noise Abatement committee. He and his wife, Kristan, first spoke in front of the board in late July, and since then the two sides have worked toward Tuesday night’s vote.

Defining Decibel Reduction

The five recommendations will help reduce the noise level from 14 to 18 decibels, according to Schomer. Clifford said Tuesday night before the vote that he wasn’t sure what that meant.

“We have all struggled with what does 18 decibel reduction really means,” he said. “I can’t gauge decibel with my ears. I can only gauge what is pleasant and what is not.”

Mark Rubino tried to give Clifford an example. Rubino, president of Industrial Noise Control (INC), a noise abatement company in Aurora, also has been part of the inquiry since the summer. is expected to perform the recommended work over the next four months after an agreement is inked with District 65. BRD Noise and Vibration Control Inc., of western Pennsylvania, which was brought on site to review the sound issue by the chiller’s manufacturer, Trane, also bid on the project.

“A 20 decibel reduction is a quarter as loud as it was,” Rubino explained. “A 10 to 14 decibel level reduction is very substantial.”

Rubino then tried to demonstrate decibel levels by having people in the Village Hall room clap, followed by silence.

“That was 85 decibels. Now we’re at 45,” Rubino said, noting the before and after readings. “You’re going from 54 decibels (the sound reading of the chillers) down to the low 40s. You will perceive the difference as one-quarter as loud as what you are hearing now.”

After the meeting, Clifford said he was pleased the board voted to approve all five measures rather than just one or two. Now he will have to wait until May to find out what those measures sound like.

“We’ll reserve judgment on how much of a difference it will make when they turn it on,” he said.

Project Completion by April

Jane Lair, District 65’s director of business services, does not expect the chiller to be turned on until May. Rubino’s timeframe for completion of the work is April 1. Once the agreement with the school district is signed, INC’s engineers will prepare drawings that would prove valuable to use at the Zoning Board meeting to illustrate the change in height of the walls around the chiller.

The winter months will be used to complete the fabrication work, and then Rubino estimated eight to 12 business days to complete the installation.

“It’s all weather-dependent,” Rubino said. “We don’t want to attempt to do the installation during the winter. We should be able to do the field work in March, possibly a little sooner.”

INC’s bid to complete the job was $100,415 and will be paid primarily out of the District 65 capital projects fund, Lair said, indicating there is “just over $100,000” available. Though the bid has not been finalized, Lair said the scope of the project will not change and if additional funds are needed, they can be taken from the district’s operating budget. But she noted, “it will be very, very little.”

One other option to enclose the chiller had been discussed, but in his opening remarks interim Superintendent Ben Martindale said in talking to Dr. Shomer and others, it was deemed unfeasible.

“It would be very expensive, and you would have to completely dismantle the current structure and start over,” Martindale said. “It would entail some significant modifications and probably compromise the efficiency operation of the current unit.”

In addition to the sound reduction measures to the chiller unit, the school district will take two additional steps.

Additional Measures Taken at Middle School

Previously, the middle school’s chiller was run during the summer months to assist in keeping the school’s computer servers cool. The district will spend between $4,000 and $5,000 on a separate cooler and walls will be installed around the servers.

Secondly, the district’s vendor for custodial services has been contacted and they will move their summer crew to daytime hours rather than the previous 3 to 11 p.m. shift.

The two moves will help the district move toward not running the chiller during the evening hours from 5 to 11 p.m.