Insulating a mechanical room for sound suppression

[ScaldedDog]

I've walled off a 7x11' room to house my compressor, lift pump and boiler, as well as for bike storage. The walls are 2x6, and I'm putting 7/16" OSB and 5/8" drywall on both sides.

Being a bit of a freak about noise, I was thinking of using 8 or 10" of fiberglass insulation stuffed into the 2x6 wall core. I know this is a bad idea for thermal insulation, but I don't care about that. Is this a better, or worse, idea than simply using standard 6" R-19 fiberglass?

BTW, the actual exterior walls will have R-19 no matter what, as there I do care about thermal insulation.

Mark

 

[rinny_tin_tin]

I've walled off a 7x11' room to house my compressor, lift pump and boiler, as well as for bike storage. The walls are 2x6, and I'm putting 7/16" OSB and 5/8" drywall on both sides.

Being a bit of a freak about noise, I was thinking of using 8 or 10" of fiberglass insulation stuffed into the 2x6 wall core. I know this is a bad idea for thermal insulation, but I don't care about that. Is this a better, or worse, idea than simply using standard 6" R-19 fiberglass?

BTW, the actual exterior walls will have R-19 no matter what, as there I do care about thermal insulation.

Mark

Better check code requirements as you identify a boiler (combustion equipment) and spaces containing combustion equipment not only have to meet certain size requirements, but also require louvers or other air openings that may not optimize your noise concerns

 

[Ironcrow]

Double offset studs and something like this:
http://www.acoustiblok.com/products.html

Lacking that, yes, overstuffing the walls with fiberglass is better than nothing.

 

[Kevin54]

Double offset studs and something like this:
http://www.acoustiblok.com/products.html

Lacking that, yes, overstuffing the walls with fiberglass is better than nothing.

Nice site for ideas

 

[senlow]

Low density fiberglass insulation doesn't help much. Compressed fiberglass will be better, but still is not very effective.

The best solution is a double wall. This will isolate the sound. A compact method of getting most of the benefits of a double wall is to build a staggered wall. This is done by using 2x6 sole plates and 2x6 top plates. Then stagger 2x4 studs from one side of the 2x6's to the other side. Since you have already built your walls, I'll assume that this is not an option.

You can also achieve good isolation by using resilient channel or a viscoelastic adhesive (flexible) between the osb and the drywall. Green Glue is a popular adhesive for this application.

Mass blocks sound. The mass of the OSB combined with 5/8" drywall is a good idea.

You must block all sound paths. Use a fully sealed exterior door.

Also be sure that the compressor itself is isolated. Use isolation mounts for the base. Do not run rigid conduit to the compressor - use flexible conduit or a cord. Also isolate the compressor from the pipe with a flexible hose.

 

[D KRAGER]

I've read that cellulose insulation is better at sound deadening than fiberglass.....

 

[Rigmaster]

I've heard that egg cartons stapled to the wall around the compressor really cuts down on the noise. Certainly not a primary noise reduction plan, but once you get the wall insulation done, this might be a good idea to further cut down on noise. I would think you could use that egg crate foam padding too, if you could find enough big sheets to do the job.

 

[senlow]

Using egg cartons for sound absorbsion is an urban myth. Egg cartons are nothing but a fire hazard.

Egg crate foam will reduce the noise reflected off of the walls inside the room. Rigid fiberglass panels (Owens Corning 700 series) will be more effective. However, it is more costly.

 

[bluesman2a]

They also make a particular type of drywall for sound deadening. Don't remember much about it, but saw them use it on an episode of Holmes on Homes. Seemed pretty effective.

 

[d110pickup]

I think Bluesman is refering to Homasote. Google it and you'll find a ton of info.
Mike

 

[hansen1]

I would look at Quiet Rock. They have several styles of sheet rock and it looks impressive at sound deading.

http://www.quietsolution.com/html/quietrock.html

 

[gbcamp72]

look into a product from Armstrong called sound soak.

http://www.armstrong.com/commceilingsna/article36299.html

 

[e-tek]

The BEST DIY soundproofing information is here: http://www.soundproofing101.com/soundproofing_3.htm

I'm going to use these practices for my compressor room as well as doing bedroom and rec-room additions in my home. Good luck!

 

[ScaldedDog]

Wow! You guys are hugely helpful! For the sake of expense, time, and in the interest of not being a nut about this, I think I'll add a layer of silicon caulk when putting up the OSB and drywall on each side, and call that good. I might blow in cellulose, too, as I'd kicked around doing that, anyway.

My primary interest is in keeping garage noise in the garage, and out of the neighborhood. To that end, I've done the following:

1) Bought a 2-stage Eaton compressor which, though more than I need, runs at a low RPM.

2) Built the mechanical room to house the compressor, etc, as described above. (BTW, I think I'm OK on code issues with the boiler, as it'll be direct vented out the roof for both combustion and exhaust air. I'll check, though.)

3) The garage outside walls are also 2x6 construction, and will also have 7/16" OSB and 5/8" drywall on the inside. The outside is brick - with a 1" airspace between the wooden wall and brick - on the bottom 5', and stucco over 1" of polystyrene. I'm planning on just R19 fiberglass, but may investigate cellulose there, too. Is there any way to apply/install it prior to putting up the drywall?

Thanks again!!

Mark

 

[Rigmaster]

Using egg cartons for sound absorbsion is an urban myth. Egg cartons are nothing but a fire hazard.

Egg crate foam will reduce the noise reflected off of the walls inside the room. Rigid fiberglass panels (Owens Corning 700 series) will be more effective. However, it is more costly.

Fire hazard- perhaps

Urban Myth- nope.........

 

[Tech Guy]

Did a drum room in a basement several years ago with a friend. Tested acoustics using egg crates on the insulated walls and the results were in black and white on the computer. Huge sound deflection. We added thick rubber mat to the floor so it would not transmit through the concrete. Also did a double door (1/2" air gap in between. Now you can watch tv upstairs and not hear the two drum kits.

 

[Striker]

Evening:

Being a frequent lurker of AVSForum, why not take a page out of the home theater construction book? Use double drywall around the area of interest with Green Glue sandwiched between the two pieces. It does indeed work.

http://www.greengluecompany.com/

 

[senlow]

Did a drum room in a basement several years ago with a friend. Tested acoustics using egg crates on the insulated walls and the results were in black and white on the computer. Huge sound deflection. We added thick rubber mat to the floor so it would not transmit through the concrete. Also did a double door (1/2" air gap in between. Now you can watch tv upstairs and not hear the two drum kits.

Sound deflection? Egg crates do not bend sound. Their absorptive properties are minimal. They are not a sound barrier. They will provide some high frequency diffusion, but that affects sound inside the room.

A sealed double door works well. The rubber mat on the floor will isolate the drum from the floor. Both of these treatments are very effective.

 

[redsky49]

Typical commercial applications include the double stud wall mentioned above, plus a double layer of gyp board, installed on the equipment room side, with offset joints. Wall density is important for sound attenuation. Important to seal all gaps, top and bottom, and to use separate floor and top plates.

Big caution! If there are any fuel burning devices you must have adequate combustion air. Typically this is a duct to the outside, or if you are using interior air, there must be two intake grilles, one high and the other low communicating with the mechanical room. These must be sized to code based on the total input btuh of all equipment. Additionally you will need make-up air for the compressor.

Access door should be an exterior type door, well insulated, with weather strips at all sides.

Don't use egg cartons or any other material that will easily crumble or be damaged.

Attention to detail is required for superior results.

 

[ScaldedDog]

Big caution! If there are any fuel burning devices you must have adequate combustion air. Typically this is a duct to the outside, or if you are using interior air, there must be two intake grilles, one high and the other low communicating with the mechanical room. These must be sized to code based on the total input btuh of all equipment. Additionally you will need make-up air for the compressor.

So, if I'm direct venting the boiler to the outside for both combustion and exhaust, I don't need to provide the high/low intake grilles, correct?

I think I've got the make-up air for the compressor covered, but want to make sure I've got any heat-related code issues covered, as well.

Thanks,

Mark

 

[redsky49]

"So, if I'm direct venting the boiler to the outside for both combustion and exhaust, I don't need to provide the high/low intake grilles, correct?"

Yes, that is correct, if there are no other combustion devices in the space.

Also be sure to maintain required service clearances for all devices.

Are you doing this without pulling a permit?

 

[ScaldedDog]

No, I've got a permit, but those guys seem to be better at telling you what *did* wrong, than what *to do* right.

Mark

 

[redsky49]

You certainly can find a lot of opinions.

You will need an emergency disconnect near the door to shut down the boiler. The gas train will be checked by the inspector, as will the venting. Is there a pressure regulator located inside the space? If so, many jurisdictions require these to be vented to the outside. Once the inspector gets on site, he can flag any violation he sees. Keep the space free of debris and don't use it as a storage area. The thimble, the device where the flue/combustion air duct penetrates the ceiling, will also be looked at. Make certain that the top of the flue is 4' higher than the highest roof point within 10', etc., etc. There are a ton of code requirements, but I guess all that you asked about was sound attenuation.

I have to admit that I worry about all the self-installed gas equipment that is discussed on this forum. There are a lot of opportunities for a serious screw-up. Not just a gas leak, but also the chance of CO buildup. Maybe have a master plumber do a look-see before you call for the final inspection. Then again, I have seen some very inventive piping done, even by experienced mechanics.

Take your time and best of luck.

 

[stingry]

The BEST DIY soundproofing information is here: http://www.soundproofing101.com/soundproofing_3.htm

I'm going to use these practices for my compressor room as well as doing bedroom and rec-room additions in my home. Good luck!

e-tek
Sorry to drag up this old post but was curious how that worked out for you? Found this old post while searching on sound deadening ideas for a new compressor room that I will be building.

Cheers
Steve

 

[Weedwaka]

Roxul safe and sound if you have it in your area.

 

[wyattboche]

Has anyone used spray foam insulation for sound dentanor instead of standard fiber glass insulation?

 

[stingry]

Has anyone used spray foam insulation for sound dentanor instead of standard fiber glass insulation?

Have did a lot of internet based research on sound deadening and have not run across any articles that mentioned spray foam as a sound deadener. One article did say that foam board may actually transmit sound. There is a lot of information out there and the common themes for effective sound deadening are isolating the noise source from sound transmitting materials, i.e. wall studs, flooring, etc. and using dense materials such as drywall and cement blocks. A double stud wall or offset stud wall seems to be the most effective method of blocking sound. This is why I was curious if e-tek had used this method and if it was effective.

I have an Ingersoll-Rand T20 two-stage compressor and it is really loud. It has a built in inlet filter so adding a muffler is not possible without a lot of modification. I will be moving it to a new shop and I would like to build a sound-insulated rooom to put it in.

I would appreciate any input from anyone who has actually built something like this. Thank You


Cheers
Steve

 

[ScaldedDog]

Since I started this thread and followed the process I outlined in post #14, I thought I'd post up the results: Great! The compressor can't be heard outside the house, at all, and that was my primary goal. I set the compressor on a couple thicknesses of cow mat, and cut a couple of cow mat strips for the bottom of the french doors leading into the room. With the doors shut, I can hear the compressor in the garage enough to know it's on, but not much more. Most pleased.

Mark

 

[7echo]

For more information on sound deadening check out the article in the current issue of Journal of Light Construction.

 

[Vinko]

Rigid fiberglass panels (Owens Corning 700 series) will be more effective. However, it is more costly.

For one room, where I had to try to lessen noise as an afterthought, I believe I used the above at over 1" thick. Closer to 2". I put them on the wall with glue and then put sheets of 3/4" ply. It helped considerably. I'll find out the exact stuff I used, but I believe it's similar to the Corning stuff.

 

[fireguy]

Have did a lot of internet based research on sound deadening and have not run across any articles that mentioned spray foam as a sound deadener.
Steve

the only time I have used spray foam was for the insualtion values. I would read the instructions, noting what the flammability rating is w/o a covering on the foam.

 

[e-tek]

e-tek
Sorry to drag up this old post but was curious how that worked out for you? Found this old post while searching on sound deadening ideas for a new compressor room that I will be building.

Cheers
Steve

Haven't done the compressor yet, but am starting on our master bedroom/walk-in/ensuite bath soon. After speaking to a few businesses and experts, I've decided to use the double-drywall method, sandwiching foam between them, which maintains a dead air-space. You only need to put a few strips of foam between each board to maintain the air space. If using spray foam, you're supposed to wait for the foam to dry before placing the next board over so it maintains it's loft and air-spaces within. You only need 3/8-1/2inch air space It seems to be the most cost and space-effective method I've come across. In the links below, you'll find that another method is to put various-vinyl sheeting between, or just against wall-board, because differing densities also decrease sound waves.

I've been using ear plugs in the shop whenever I'm in there so the compressor is less of a problem lately - although I do have to crank the tunes to hear them!


Things to put between wall-board:



GreenGlue:
http://www.globalspec.com/FeaturedProducts/Detail/AcousticalSolutions/Green_Glue/137440/1

Foams:

http://www.globalspec.com/FeaturedProducts/Detail/MerryweatherFoam/FOAM_FOR_SOUND_ABSORPTION/38536/1

Vinyls:

http://www.globalspec.com/FeaturedProducts/Detail/ArtUSANoiseControlProducts/Noise_Control_Materials/36012/1