Decibel Decrease!

SPF Brings the Noise Down for Turbine Facility


By Jessica A. Baris

Engineers at an energy company in York, Pennsylvania, were having a problem, a noise problem. The old duct system in their natural gas turbine facility was generating too much noise from the vibration of the turbines. The engineers were trying to figure out a solution, and they soon turned to spray polyurethane foam (SPF) for an answer. An Internet search led them to in-state Barrier Spray Foam.

“The client found us through our website,” says Randy Hess, a partner with Barrier Spray Foam. “The engineers had done their homework before they contacted us. They were fairly   knowledgeable before we got to them.”

The engineers were up for trying anything out of the ordinary. Spray foam is typically used for insulation, but Barrier knew that it could work for soundproofing, too.

“Open-cell foam is generally known to deaden straight sound because it has more air pockets in it,” says Hess. Soon, Barrier was hired to do a test application.

Putting Foam to the Test

The two-man crew arrived on site with a Graco Reactor E-30 and a Fusion Air Purge spray gun. The engineers wanted one turbine to be sprayed to see how much spray foam could reduce the decibels—if it could do it at all.

The Barrier crew sprayed the duct work with 2 inches of Lapolla’s 2-pound closed-cell foam and 2 inches of ½-pound open-cell foam on top of that. The engineers—and even Barrier—were up for a nice surprise.
 
“The engineers did decibel testing and found that the spray foam reduced the sound by 13.5 decibels,” says Hess. “The engineers were delighted with it. They didn’t think it would be by that much.”

Chris Harnish, the applicator on the job, was impressed with the difference as well.

“I was surprised with the results,” he says. “We got it within the range they were looking for, so they decided to have us do all four turbines.”

The 2-pound, rigid foam eliminated the vibration in the loose metal duct work. The ½-pound, open-cell foam was applied on top of it for soundproofing. Barrier had the system down pat.

Suppressing the Sound

The Barrier crew went on to spray the facility’s 19,200 board feet. The first section was completed after one full day of spray foam application, and the rest of the job was completed in three more days. “It’s an enormous facility,” says Hess. “The ductwork was in okay condition; it was just loose and not fitting well, so a lot of noise was the result of it vibrating. Applying the foam was a much better option than replacing all of the duct work.”

York Holdings provided the lifts for the spray crew and maneuvered them while the applicators sprayed the duct work. “They chauffeured us around,” says Harnish. “We were strapped in to the lift with safety lines. It took one person on the floor to keep the lines out of the way so the lift wouldn’t drive over them, to keep the plastic spread for overspray, and to check on pressures in the rig.”

Another way the spray crew managed the lines was to wrap Velcro straps around the hose. “We latched the Velcro section of the hose to the lift so that we were only handling the weight of 10 feet of hose.”

After the foam was applied to an entire turbine, the crew applied International Fireproof Technology Inc.’s DC-333 thermal barrier. Hess said of the job, “Besides the usual temperamental equipment, it was just a usual spray.” But he and Harnish both agree that the purpose of the spray foam couldn’t be called “usual” or “ordinary” in any way. In fact, it’s a project that demonstrates spray foam’s wide range of potential uses. 

“Spray foam is not at the top of the list for soundproofing,” says Harnish, “but in this application, it did a number of things. It cut down vibration and absorbed sound—it was the application that they were looking for.”
Harnish said that at first, the engineers had a heavy gauge rubber that they tried to mount to the substrate for soundproofing. That system didn’t work out. “It was very cumbersome and did not adhere well; it was a mess for the guys,” says Harnish.

It is said that life is about taking chances and trying things out, even when the outcome is unknown, and that’s the spirit with which Barrier approached the turbine problem.

“We had no way of knowing our success because there aren’t any studies out there,” says Harnish. “But the engineers at the facility have the test results to back it all up.”

Everyone involved in this spray foam project agrees on one thing, and that is, in Harnish’s words, “It really works.”

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