Noise Curtains

by dB Engineering

Quieting a roomful of buzz saws

If you've ever used a power saw in the basement, your family was probably more irritated with the noise than excited about your creation. Imagine what a saw mill sounds like!

The owner of this sawmill didn't have to imagine anything; his compact, efficient sawmill cuts and planes hardwood from raw logs for the furniture industry.

After renovating the building, he found that the new walls and ceilings contributed to a significant increase in noise levels. It was a problem that the owner and his insurance company wanted resolved for the comfort and safety of his employees.

After assessing the problem, it was determined that the noisiest part of the operation, the actual sawing, could not be isolated because every piece of equipment had to remain accessible to perform that function. Acoustic enclosures were considered impractical. Instead of isolating the noise at the source, they decided to treat the environment.

It was recommended that a large quantity of Polywrap Acoustic Baffles be suspended from the ceiling throughout the entire mill. Since the ceiling height was less than ten feet, the suspended baffles placed a great deal of absorption close to the noise sources.

The customer's goal of a 5 dB(A) noise reduction was exceeded. By virtually eliminating reverberation as a factor, noise levels were reduced by approximately 8 dB(A) throughout the entire mill. Even better, the cost of the project was so low that the owner was well satisfied.

The owner and his employees now work in a much more comfortable atmosphere. Besides the obvious benefits of increased productivity and a quieter place to work, Les knows that his operation will always be in compliance with OSHA noise standards - and there's a lot of comfort in that!

Polywrap Baffles are an effective tool to improve room acoustics. The cost, even in large quantities, is affordable to virtually any business. Polywrap Baffles are best utilized in applications where they will not be subjected to abrasion or traffic.

The standard Polywrap Baffle comes in white, 2' w. x4' l. x1 1/2" th. with grommets installed for easy hanging.

Polywrapped Style
Absorption coefficients-sabins/unit
One-third octave band center frequency Hz

Style 125 250 500 1000 2000 4000 NRC
Polywrap 2.6 5.6 9.1 11.9 9.5 6.3 9.05


Table showing how the human ear perceives noise reduction.

Decibel Reduction Reduction Experienced by Ear
2 15%
4 23%
6 38%
8 48%
10 56%
12 63%
14 68%
16 75%
18 77%
20 81%