Quieting the DC

[Jason Solodow]

Come Saturday my family and I are moving to a new house with a full basement that will be mostly devoted to woodworking. SWMBO doesn't really want to hear my DC while it's running (I'm not a big fan of listening to it either) so I'm going to build out a small room with sound proofed walls to hopefully muffle it. Obviously it's going to have to have doors on it so I can empty it, but I'm concerned that that will allow a lot of noise to escape through the doors. I considered buying some hollow bifold doors and injecting expanding foam into them but not sure how well that will work. Any suggestions?

[Allan Speers]

Come Saturday my family and I are moving to a new house with a full basement that will be mostly devoted to woodworking. SWMBO doesn't really want to hear my DC while it's running (I'm not a big fan of listening to it either) so I'm going to build out a small room with sound proofed walls to hopefully muffle it. Obviously it's going to have to have doors on it so I can empty it, but I'm concerned that that will allow a lot of noise to escape through the doors. I considered buying some hollow bifold doors and injecting expanding foam into them but not sure how well that will work. Any suggestions?

A few quick thoughts, from a guy who used to design recording studios for a living & knows a few things about acoustics:

1: A dc has to breathe, even more than we do! Sadly, sound is very good at escaping through even the tiniest crack. And there's the dilemma.

So, unless you plan on building a complete enclosure, with a "muffler" type baffled exhaust port, you should be thinking about ABSORPING a little sound, instead of containing it. Both are possible, but the latter is infinitely more difficult.

2: As far as what material to use, you first have to know what frequencies you are dealing with. For anything above 125 hz or so, you'll do well with standard 3 lbs / cubic ft (or denser) mineral wool. I dobt youreheavy noise is below that. If you have no high pitched whine as well, then you should use a denser wool, maybe 5 lbs . cubic ft, as that will be less effective at really high frequencies but more effective down in the 125 - 500 hz range.

3: If you really want silence, then encase the whole thing in MDF. (lined on the inside with mineral wool.) - but make sure there are ZERO air gaps anywhere, or you will be wasting your time & money. - and don't forget to build that muffler-type (overlapping baffles) exhaust port !


4: Oh, and if you build a window, so you can see when your can is getting full, use real glass, not plexiglass, because it's much denser. - And use 2 panes of glass with an air gap in-between. I'm being picky, but you might as well do it right.

[Jim Andrew]

If you are going to install a door, why not use an exterior door, like a prehung door with built in weatherstrip. The steel exterior doors are filled with insulation. And they have a rubber strip on the bottom of the door and a sill to seal the bottom. Use caulk under the sill and put screws through the sill into the floor.

[Jason Roehl]

Also make sure you isolate the DC from the structure when you mount it--use rubber washers and the like for mounting it. It doesn't do much good to absorb all the sound from it if it's vibrating the snot out of the china cabinet upstairs.

[Allan Speers]

Also make sure you isolate the DC from the structure when you mount it--use rubber washers and the like for mounting it. It doesn't do much good to absorb all the sound from it if it's vibrating the snot out of the china cabinet upstairs.

Excellent point. I was thinking about a floor-mount DC, on cement, but yes, anything else and vibration is your enemy.

[Frank Pratt]

I used 2 exterior pre-hung doors mounted back to back. They are inexpensive steel doors filled with foam insulation. But because foam is pretty crappy at sound isolation, so I attached a layer of 3/4" MDF to each door with a layer of Green Glue in between. A second set of weatherstripping meets the edges of the MDF when the doors are closed for additional blockage.

I can shout at the top of my lungs & someone on the other side can barely hear me. The dust collector isn't connected yet so I don't know how well it will work with that yet.

[John K Jordan]

Jason,

Insulate the walls but don't forget the ceiling since it's in the basement.

For my shop I built a 4x8 insulated room for the 5 hp cyclone and the 5 hp air compressor. I hung the cyclone on an exterior wall and the air compressor is on the concrete floor. I brought all the controls (remote, bin sensor), cutoff switches, and compressed air filters and valving outside the closet into the main shop area. My shop is a few hundred feet from the house so I don't have to worry about that, but I didn't want to hear the thing myself!

I used 6" staggered stud walls - the studs are staggered with half on one 1/2" plywood wall and half on the other with insulation winding between. Since no stud contacts both walls, sound cannot easily get transmitted from the inner to the outer wall. I built a stand-alone building for my shop so I didn't have to worry about sound coming through the floor - the ceiling insulation was sufficient. I put heat and air in the shop so I return the filtered air to the shop through a baffled plywood duct with multiple 90 deg turns and coated inside with sprayed on rubber. I did not muffle the exhaust (which is supposed to make a big difference.)

i used standard insulated steel doors (double to make access easier) but I didn't worry too much about sound through them since they don't open into the wood shop area but into my equipment bays.

The sound in the shop is quite reasonable, 60-some db, down from the mid 90s. There is more noise from the air being pulled through the tools than coming through the walls or through the air return duct.

My cyclone is a CV1800. There is quite a bit of discussion about sound reduction on the ClearVue cyclone forum if you want to read more about what others have done.

JKJ

[Ole Anderson]

I built my door with a piece of drywall sandwiched between layers of OSB. Most of room is lined with 3.5" of Roxul safe and sound, the air exits back to the shop between the joists which were lined with the mineral wool to absorb reflections. Most of your sound is in the low frequencies, which I believe are less prone to escape gaps, so now you have two opinions to choose from. You may have seen my video: https://www.youtube.com/watch?v=8X8qwMqm3Ek

[Mike Henderson]

I wasn't going for complete sound suppression so I just built a closet with drywall. I have a vent at the floor to let the air out and an interior door. I can hear the dust collector running but it's a lot quieter than if it was out in the open. I barely notice it running. I have a remote control so I like that I can hear it enough to know that it's running (or off, when I turn it off).

Mike