Theres a humming noise permeating throughout City Hall these days.
City Hall employees have been hearing and complaining about an irritating, high-pitched noise caused by new high-efficiency heating, ventilation and air conditioning equipment installed last summer and turned on several weeks ago when the warm weather began to set in.
At first, information technology manager Peter J. Keenan thought it was his tinnitus a ringing noise that seems to originate from the ears or head acting up when he started hearing it.
But it was actually a vibrating pipe that runs from the basement, where the HVACs new high-efficiency chiller is located, and goes to the roof, City Engineer Kurt W. Hauk said.
The annoying noise comes and goes during the day, he said.
It seems to be worse in Mr. Keenans second-floor office, in a nearby womens restroom and in the city clerks office. It was so loud in the City Hall lobby that Mr. Hauk recorded it Friday at 70 decimeters, the same level as a vacuum cleaner.
Mr. Keenan compared the humming sound to the noise an electrical transformer makes.
People find it annoying because its a pure tone noise, which is about six to eight degrees above background noises, Mr. Hauk said.
It gets louder and softer, Mr. Keenan said. Its something people certainly notice.
He hopes the problem can be fixed soon. The city plans to hire an acoustic engineer, who will look at a handful of options to see what can be done, Mr. Hauk said. That cost has not been determined.
Mr. Hauk had no inkling this was going to happen until the chiller, a refrigerating system used to cool off commercial buildings, was tested in late April and the noise began soon afterward.
The city purchased the chiller and other equipment from Maryland-based HVAC company Trane for $85,824. The city also paid Hyde-Stone Mechanical Engineers, Watertown, $187,000 to install it.
But the noise problems are not covered by the warranty because the equipment actually works correctly, Mr. Hauk said.
Apparently, that has irritated the Watertown City Council so much that council members delayed taking action earlier this month on giving a $473,000 contract to Hyde-Stone for an HVAC project at the citys wastewater treatment plant.
Council members will discuss that contract at Monday nights meeting, which starts at 7 p.m. in City Halls third-floor council chambers.