Case Study: Industrial Acoustic & Sound Absorbing Curtains and Baffles

Company: RMS Roller Grinder

Set-Up:
The customer has a separate room (Size: 14’H x 24′ W x 24′ L) for fabrication of metal units
The customer already put “egg crate foam” onto some of the wall surfaces, hoping it would reduce the over all noise. But even with the foam on the walls there was still a constant decibel measurement of
90-100 Db
Customer described as 150 psi of gushing air- frequency was high to mid-range
Budget of 10K to get to 85 Db or less

In- and outside of the room before the customer installed the acoustic curtains and baffles from AmCraft.

As the noise originates within the room, our objective is to both mitigate the internal noise and block as much noise transmission through the door areas.

Options we presented:
Retractable acoustic panels surrounding the hoist inside of the room.
Retractable acoustic curtains in front of the 12′ H x 13′ W big barn door and a 7′ H x 3′ W man door.
Industrial ceiling baffles to cover up some of the hard ceiling surfaces.
Industrial free hanging baffles to suspend from the ceiling as close to the noise source as possible.
4″+ thick 11′ high x 60″ wide Industrial Corner Baffles

Limitations in the room:

Because an overhead hoist and a robotic arm had to operate in the room, the free-hanging baffles and the ceiling baffles were not an option. Additionally, the customer had a budget to stick to, which eliminated the option of panels around the hoist.

Customers perspective:

The customer felt most of the noise would come through the closed doors and they opted to first choose 2 or 3 options and measure the results. If more acoustic insulation was needed to reach the 85 dB goal, then we can always add more Industrial acoustic curtains or panels and noise absorbing baffles.

Customers Decision:
Two retractable acoustic curtains in front of both doors
Large corner baffles with industrial thickness each at 11′ H x 60″ wide.

Choice of the material that faces the noise on both the curtains and baffles:

Because of the industrial setting, the customer chose the PVC-coated mesh material to be on the front side of the curtains and the baffles to make sure the noise will find its way into the sound-dampening materials.

Customers review:
After the first shipment: Thanks for the update. We received the first shipment and have installed the big curtain and
corner baffles. There is a noticeable reduction in noise already! We are hoping it will improve
even more when we get the remainder of the items installed!
After the final shipment: We have all of the components we ordered from you installed now. I just wanted to let you know
what we have found before and after installing these. Before we were at 97db and after
installing your curtains and wall baffles we were able to get the noise level down to right around
85db. They have also helped to change the pitch of the noise making it much more comfortable
to work around. Thanks for taking the time to work with us to find a great solution that fit

A reduction of 12 dB has been achieved.

12 decibels might not seam like a large reduction, but it is!
Because, the perception of loudness is not a linear relationship with decibel levels, but rather follows a logarithmic scale. As a result, small changes in decibels can have significant effects on our perception of loudness.

A reduction of 10 decibels makes the sound appear to be about half as loud to the human ear.

Another intriguing aspect of this case study is the alteration not only in the noise’s loudness, but also in the pitch of the sound, resulting in a more pleasant acoustic environment.