Came across your excellent website using a Google search. I happen to be a contractor, and this is for a situation at my own offices. We have a boiler that is located in a separate room, but more or less in the center of our offices. The room is masonry and it has a fire rated door. I would like to install sound absorbent materials on the interior side of the block in the boiler room, as well as on the interior of the metal door to lessen the boiler sound that currently escapes from the room. Therefore, I need a product that can be somehow adhered. And while there is no open flame, due to the nature of the room I would prefer to use something that is not an outright fire hazard.
Your suggestions and assistance will be greatly appreciated.
H.S.
Wantagh, NY
H.S.,
I only have a few products that will both absorb echo as well as block sound transmission. I will do my best to go through the basic idea of blocking sound and explain how each panel works, but if you have questions, please feel free to call. All of the products that I am going to suggest are Class A/1 Fire rated, and would adhere directly to the wall with adhesive. I would be happy to quote any or all of these options for you if you could let me know the square footage needed as well as your address.
Boiler or mechanical rooms are generally pretty noisy places. Not only are you going to have multiple noise sources but one will almost always find that these are rooms made up of all hard surfaces. The sound from the machines has no where to go, and the sound waves will just bounce from surface to surface. Believe it or not, the sound pressure in the room can actually be greater than the sum of all of the sound being made by the machines because of these reflections. So, I would suggest a product that will not only help the existing wall block the sound from leaving the room, but also absorbing the reverberation inside of the room itself.
The first and most effective is the Melamine Composite acoustical panels. These panels are made from the standard acoustical foam that pretty much everyone is familiar with. In the center of these panels is a layer of Mass Loaded Vinyl noise barrier which is basically a technology that has been designed to replace lead. As the sound wave hits the dense vinyl, it will move or vibrate the vinyl slightly turning the sound energy into heat energy which is how the sound is blocked. These panels have an STC (sound transmission coefficient) rating of 27, which basically means that they stop 27 dBa from passing through them. This rating is an average of high, mid and low frequencies but please keep in mind, the lower the frequency, the easier it is for the sound to make it's way through pretty much anything you put in front of it. The melamine composite panels also have a soft foam surface which will help reduce the echo and reverberation in the room. The NRC (noise reduction coefficient) of these panels is .85 which means that essentially eighty-five percent of the sound that hits the surface will be absorbed. A ballpark price for the melamine composite panels is $11.00 per square foot.
Melamine Composite Panels
Thickness
STC
NRC
Cost Per Sq. Ft.
1-3/8"
27
.85
$11.00
Another panel that you might want to consider is the Sound Silencer panels. These are a panel made from a polypropylene bead board, and although they are more cost effective than the previous option, they are also slightly less effective. Here is the data for the product:
Sound Silencer Acoustical Panels
Thickness
STC
NRC
Cost Per Sq. Ft.
1"
9
.45
$4.50
2"
13
.70
$6.50
One other option is the Echo Eliminator Composite panels. This is a cotton based panel with an aluminized mylar facing on one side. The NRC is .90 and the STC is 17. Ballpark cost is $7.00 per square foot.
Echo Eliminator Composite Panels
Thickness
STC
NRC
Cost Per Sq. Ft.
1"
17
.90
$7.00
The panel that will be the best option for you basically depends on what you need acoustically as well as the budget that you have for the project. I would be happy to talk to you about the products and even get some product samples and literature out to you. All of the links above will take you to the respective web pages on my site, and at the bottom of each page you will find a PDF icon that will bring up a printer-friendly format of all of the product information.