So what materials are "best" for a DC/compressor closet?

[Joshua Dinerstein]

I have been a member over in the Turning forum for a year or so now. But it appears it is finally time for me to move my wood shop from the garage down to the basement to give the LOML, we got married 6 months ago, room to park in the garage this winter. So I did what comes naturally and I came here to see what you guys had to say.

After a week of searching searching this WorkShops forum I have garnered a great deal of information. Many thanks to those who take the time to post and answer questions.

So the short question for those tired of reading this already is: Are there any preferred materials for making a DC/Compressor closet out of to help reduce sound the most?

The longer explanation and question is: So my story... Almost a year ago I purchased a HF 2hp double-cloth-bag DC unit on sale. I was tired of the massive amounts of sawdust all over the garage. :mad: In the end with stacked coupons and sales I paid $149 for it. Not a bad price I thought. I took it home, set it up, turned it on and popped the breaker. Turns out I should have read things more carefully. A 19amp draw on a 15amp breaker was just never going to work. I never got around to stringing a new wire and so it has sat entirely unused ever since. So I still have the dust, I don't have the new line to the garage and I have still enjoyed turning. It is amazing what you can learn to live with isn't it?!!? ;) But as mentioned times have changed.

So from my reading here what it appears will work best is either a box/closet for the dc down in the basement or one outside the house. I have a conveniently placed window and could run it the lines to and from through said window to an outside location. However my bride of six months made it clear that she would kill me if I tried. :) So I am going to be building a closet area in my as yet entirely unfinished basement. Which honestly is something that works for me anyway.

I have followed Jim's and Chuck's comments as well as those of others on here about how they had constructed theirs and how well they felt it had worked. I believe I have a nicely laid out spot and arrangement for such a closest. I plan to copy Charles Seehuetter 4x8 closet and use Jim Becker's baffle for the return air to try and cut the noise as much as possible. So the design isn't really my problem.

I also started up a few PM conversations with Jim and others asking about their own successes and what they had done and found to work and not work.

The thing that struck me is that each has chosen different materials to construct theirs out of. Some used OSB or plywood on the outside walls of their closet in place of sheetrock. Some insulated the inner walls, and ceiling, others did not. Some used pegboard as the inner wall material and other recommended things like acoustic foam or whipermat or something similar.

So I am just wondering is there any kind of a consensus on what materials to use to try and get the best noise suppression possible? Is there really much of a difference between them? Is Plywood/osb really better than sheetrock? etc...

Anyone care to chime in with their thoughts? oh come on... You know you do! :D

Thanks!
Joshua

[Ken Fitzgerald]

Joshua,

This will sound crazy but......the best sound insulator I've seen used is as follows:

2 sheets of 1/2" or 5/8" sheetrock over the studs with fiberglass insulation in the walls. The sount that a 3T MR scanner makes is incredible even to my nearly deaf ear....the other ear is totally deaf. A local hospital installed doubled sheet rock over the walls of the scan room with insulation between the studs....NADA....I have to turn up the sound on the console patient intercom to tell if the machine is even scanning. And.....sheetrock is realitively inexpensive.

That's my intentions when I get around to enclosing my DC.

[Prashun Patel]

Drywall is so dense, it does a great job absorbing sound. The more layers, the better the dampening. People put up pegboard with insulation because soundwaves go into the holes and lose their energy in the insulation bats which have a lot of surface area.

You'll also get a lot of sound transmission through conduction. So, if you wanted to go crazy, you might make a 'thermos' of sorts combining the 2 techniques:

Make an inner wall with pegboard and insulation and drywall on the outer wall. Then have a deadspace of air and build a second framed wall outside of the original. Sheathe the outer wall of that 2nd frame with drywall, taking reasonable care to eliminate contact between the inner and outer frames. The dead air space will also mitigate sound transmission.

[Anthony Whitesell]

When I purchased my air compressor, there was a section about enclosures and walls in the manual. I have a Craftsman upright compressor (40 or 60 gal). Per the manual, it should not be placed within 12" of a wall on one or two sides and not within 18" on three or four sides. The picture was much more descriptive than the sentance. What it's trying to say is to keep it 12" away from against a single wall or in a corner. If surrounded by three or enclosed by fours walls, then there should be atleast 18" clearance all around the tank for intake and cooling airflow. If I enclose this air compressor, the cabinet would be about 5' in diameter, per the manual.

[Burt Alcantara]

I'm in the process of building a room-within-a-room for my ClearVue CV1400. When this machine is turned on it sounds like you are on the tarmac at a major airport.

I've researched soundproofing by reading numerous posts on forums that dealt with the construction of home theaters, recording studio construction both amateur and professional and sound problems involving condos and townhomes.

The consensus was using a double drywall sandwich with Green Glue (http://www.greengluecompany.com/) between studs stuffed with R13 followed by another sandwich on the source side. Every incident where this method was used was followed by statements of resounding success.

Now, your DC may not sound like a 747 so this solution might be somewhat overkill. In any case, the best soundproofing would be a closet. If you choose to go with a sheet such as drywall, OSB, MDF, particle board, plywood, etc, you would be better with at least 1/2" drywall as it is the most efficient of the above and most economical. You can stuff the wall with any type of insulation including some of the newer non-fiberglass materials like bonded logic cotton.

The important thing to remember is MASS! Mass is the big sound stopper. Many studios use lead because of its superior mass.

Here are some other sites to checkout:
Super Soundproofing Co (http://soundproofing.org/)- also check their forum
Acoustical Surfaces (http://www.acousticalsurfaces.com/)
Foam Factory (http://www.usafoam.com/)
QuietRock (http://www.quietsolution.com/html/quietrock.html) - good examples of STC comparisons
Acoustiblok (http://acoustiblok.com/)
Studio Forums (http://studioforums.com/eve)
SoundStop (http://www.soundstop.net/)
Sound Isolation Store (http://www.soundisolationstore.com/Green_Glue_for_Sound_Dampening_and_Isolation_s/20.htm)
Bill Pentz on Noise Control (http://billpentz.com/woodworking/Cyclone/ducting.cfm#NoiseControl)
Owens Corning (http://owenscorning.com/comminsul/products.asp?product=271&system=81) - Duct board and other products

Good luck,
Burt

[Jamie Delker]

Joshua,

This will sound crazy but......the best sound insulator I've seen used is as follows:

2 sheets of 1/2" or 5/8" sheetrock over the studs with fiberglass insulation in the walls. The sount that a 3T MR scanner makes is incredible even to my nearly deaf ear....the other ear is totally deaf. A local hospital installed doubled sheet rock over the walls of the scan room with insulation between the studs....NADA....I have to turn up the sound on the console patient intercom to tell if the machine is even scanning. And.....sheetrock is realitively inexpensive.

That's my intentions when I get around to enclosing my DC.


I'll second that. I did some work on/in a recording studio a while back, and all the walls (interior and exterior) and ceilings had 2 sheets of sheetrock installed and insulation in any open space in between. Of course there were other sound dampening measures (carpeted walls, baffles, etc.), but a 5 piece rock band playing full bore was merely a whisper on the outside.

[Joshua Dinerstein]

If I enclose this air compressor, the cabinet would be about 5' in diameter, per the manual.
Hummm.... Well I was planning a 4'x8' closet. So I am wide enough on one dimension but perhaps just a tad under it on the other. I can either build a bigger room or check my compressors manual to see what it has to say. I have a 40gallon upright. Thanks for the feedback. That is definitely worth checking out.

Joshua

[Greg Cole]

Hi Josh.
My DC closet is @ 3'6" x 3'6" (or so) from floor to ceiling. I went with 2x6 walls and standard fiberglass insulation, with OSB on the inside and peg board on the outside. Yup 180* from the "usual" way of using the pegboard on the inside... but I need the pegboard on the outside to hang stuff on, small shop syndrome.
In all honesty, when you're running your DC, you will have another machine running creating ambient noise 99% of the time. I wouldn't worry about making the DC closet lined with any pricey noise abatement specialty products, IMO.
DC is a canister style 2HP. When I have the radio on "normal" volume levels, I can still hear every word when I light up the DC. Much Much better than without the closet and it makes the shop vac seem unbearable now.

[Chris Padilla]

You could also stagger stud the walls. Build up a wall with 2x6 sill plates and 2x4 studs. The idea is that the stud on one side of the wall does not touch the other side of the wall and therefore won't act as a sound transmitter. You can then pile on two layers of drywall on both sides if you like but likely, 1 layer will be enough with the staggered-stud approach. You can always test it to see. Use a solid core, exterior door as well (better insulated).

[Joshua Dinerstein]

The consensus was using a double drywall sandwich with Green Glue (http://www.greengluecompany.com/) between studs stuffed with R13 followed by another sandwich on the source side. Every incident where this method was used was followed by statements of resounding success.

Interesting. I wonder what the green glue really is. For the size of what I am building I need way less than 1 case of it. And at $177 a case for just the glue I think I will wait and try doubling the sheetrock up with other mechanism. perhaps liquid nails or something.

I wonder what else would work well enough.

Joshua

[Joshua Dinerstein]

You could also stagger stud the walls. Build up a wall with 2x6 sill plates and 2x4 studs. The idea is that the stud on one side of the wall does not touch the other side of the wall and therefore won't act as a sound transmitter. You can then pile on two layers of drywall on both sides if you like but likely, 1 layer will be enough with the staggered-stud approach. You can always test it to see. Use a solid core, exterior door as well (better insulated).

That is another good idea! Thank guys! I was planning to stagger the studs but hadn't thought about just using a 2x6 as the floor and ceiling plate to get it take care of.

I was actually going to try and construct the door as I have seen a few others do. Just build a swinging wall section if you will. I just think that a door segment full of the same noise abatement stuff would be better than a solid door that would seemingly transmit the sound through it quite effectively.

Anyone had any experience with the door part of this equation?

Thanks!
Joshua

[Ross Ellis]

Interesting. I wonder what the green glue really is. For the size of what I am building I need way less than 1 case of it. And at $177 a case for just the glue I think I will wait and try doubling the sheetrock up with other mechanism. perhaps liquid nails or something.

I wonder what else would work well enough.

Joshua

Green glue is basically an adhesive that stays "spongy". I used it for my theater and for a closet, a case is way too much. You would need more like 3-4 tubes. Based on my use I can't really think of anything that would yield similar results. Like others have said, other machines will be running so total isolation isn't really necessary. I think doubling up firecode would be plenty. You can also seal around any electrical sockets and other joints to help out. With a closet, I would think the door would be your weak point and let some sound out even if you went with the green glue.

[Joshua Dinerstein]

Green glue is basically an adhesive that stays "spongy". I used it for my theater and for a closet, a case is way too much.
Interesting... No... I really don't know of anything that stays spongy like that. Anyone know where you can buy it by the tube or just a smaller amount? I suppose I could use rubber cement. That was the only thing that came to mind. :rolleyes:

Thanks,
Joshua

[Ken Fitzgerald]

Joshua,

I think you are really over engineering this thing....way overengineering it. If you just screw double-thickness drywall over the interior wall of the closet, insulate the walls, cover the outside of the wall and use a "Z" shaped return duct like Jim Becker the biggest leakage will be through your door. Even then, I'd just use a common ordinary hollow core door. The tool that you are using (t/s, planer, jointer) will be the biggest noise maker by far IMHO. I'd be sure and seal around any electrical ducts but I think you will be fine.

[Ross Ellis]

Interesting... No... I really don't know of anything that stays spongy like that. Anyone know where you can buy it by the tube or just a smaller amount? I suppose I could use rubber cement. That was the only thing that came to mind. :rolleyes:

Thanks,
Joshua

When you put green glue on, you lay a sheet of drywall flat..and squirt the green glue onto it. Picture writing letters with cake icing. You leave it like that. You don't spread it.

I also think you are over thinking it. I used Green Glue and double drywall in my theater as it is located directly under the Master Bedroom, and I like to watch movies late night while the wife is sleeping.

[John Eaton]

The stagger-studding technique as related by Chris is often used to insulate heavy noise houses - like those built near interstates and airports so I'd also recommend it.

-- John

[Ron Dorsch]

Add resilient 1/2" "z" furring chanels between any sheets of gyp board at 24" o/c. Make sure the sheets are of a different thickness, 1/2" & 5/8". Put the resilient channel to the sound side. Ad 1/2" fiber board to the other side of the stud plus 1/2" gyp In other words, 5/8" gyp, 1/2" resilent channel, 1/2" gyp, 3" wood stud, fiber board, 1/2" gyp. If you care to use double stud wall construction separate the top & bottom plate by 1". Different gyp thickness will resonate at different frequencies and provide greater sound deadening. Similar thicknesses will create s similar ressonance and could amplify the sound. This should stop any sound from leaving the area. Ant doorsh should have a double door too similar to a hotel party wall. :cool:

[Dave Bender]

The best isolation is obtained using a dense material. First you'll want to isolate the machine from the floor or walls. Vibration mounts are good for this. You might also want to try accoustically decoupling the DC from the ductwork by cutting your main inlet (8" or whatever) and then joining back with a rubber coupling. Now for the walls. Using double drywall with an air space between is good but using some accoustic lead (lead paneling) is fantastic for stopping sound transmission. You'll also need to seal all openings as well as installing a proper door (as is used in a recording studio). I like to use Illbruck PROSPEC Decibel Drop Viscoelastic Dampening Compound inbetween two layers of drywall or use the aforementioned accoustic lead (about $300 for a 4'x20' roll) if you really want to cut out sound transmission.

[Matt Ocel]

I've built over 400 muti-unit homes with "Common walls" I had to comply to certian STC ratings. I've had sound transmission testing done on different configurations of constructed walls by sound engineers.

Ken nailed it.
Use a couple layers of drywall. The more you use the better STC rating.
Don't waste your money on anything else.

FYI. Seal any penetrations with caulk, and caulk your plates to the floor, thats cheap and will help a little also.

[Dave Bender]

I've built a few recording studio's, some in appartments and to really cut down sound transmission accoustic lead is the way to go (as well as building rooms within a room but that gets expensive). Double drywall (with an air gap) is a good place to start but there are othing things that can be done if that isn't enough.

[Matt Ocel]

I've built a few recording studio's, some in appartments and to really cut down sound transmission accoustic lead is the way to go (as well as building rooms within a room but that gets expensive). Double drywall (with an air gap) is a good place to start but there are othing things that can be done if that isn't enough.

Absolutley there is. No question about it. You can spend alot of money on sound proofing.

But we're talking about a DC closet in a workshop.

Two layers of drywall and forget about it.
Dry wall for the whole project would be under $100.

[Joshua Dinerstein]

Ken nailed it.
Use a couple layers of drywall. The more you use the better STC rating.
Don't waste your money on anything else.

FYI. Seal any penetrations with caulk, and caulk your plates to the floor, thats cheap and will help a little also.

Cool. Thanks everyone. I will do it. Caulk things top and bottom and double up the sheetrock. Excellent.

Joshua

[Joshua Dinerstein]

I think you are really over engineering this thing....way overengineering it. If you just screw double-thickness drywall over the interior wall of the closet, insulate the walls, cover the outside of the wall and use a "Z" shaped return duct like Jim Becker the biggest leakage will be through your door. Even then, I'd just use a common ordinary hollow core door. The tool that you are using (t/s, planer, jointer) will be the biggest noise maker by far IMHO. I'd be sure and seal around any electrical ducts but I think you will be fine.
Thanks Ken.

I do believe you are right and I am way over-engineering it. I guess I kind of got caught up in it all. Also with the noise of the DC unit I guess I just figured I was going to have to get pretty creative to actually cut the noise down enough.

But I can surely start with a double wall and some insulation and pegboard and then revisit it if I need to.

Oh and the only 2 shop power tools I actually have are a lathe and the bandsaw I use to rough shapes blanks for it on. So no planers but hey one never knows about the future! :D

I appreciate the help!
Joshua

[Jim Becker]

Joshua, don't forget we NEED pictures of your new DC closet... ;)

[Joshua Dinerstein]

Joshua, don't forget we NEED pictures of your new DC closet... ;)

Deal! :) And hopefully lots and lots of photos of it during construction. I mean hey why not! :D

Joshua

[Wayne Cannon]

Really good suggestions here. A couple of key points:

There are two ways to minimize sound transmission:


Sound energy moves dense, heavy materials much less than lighter materials -- hence the benefit of doubled 5/8" sheet rock or cement board (or steel, or granite :) ) and thick glass in windows. Whatever is behind the dense, heavy layer will receive a much smaller vibration.
Absorbing sound waves turns them into heat. Green glue, thick sound-absorbant rubber, etc., absorb sound.

Prevent sound vibrations from sneaking around or through -- e.g., through cracks, openings for outlets, under doors, through windows, through un-broken studs, etc.

In radio broadcast studios, we used to mount doubled 1'x2' sheet rock panels to sound absorbant clips so they couldn't conduct sound directly to the inside studs of double-stud & -plate walls. Today, clips are still used, but dense rubber foam made especially for sound absorption is also popular.