Sound insulation for DC

[Juss1]

Just picked up a new (to me) 3hp DC. Sounds like a jet in my small shop.  I want to make a small enclosure attached to my shop and put some noise dampening material. 

1. What have you guys to work well to combat noise but won’t break the bank

2. What type of opening do I need to have as to not create back pressure.  Since I’m more worried about disturbing my neighbors my initial thought was to have the opening in my shop.

Thoughts?

   

   

   

[MichaelMouse]

Just picked up a new (to me) 3hp DC. Sounds like a jet in my small shop.  I want to make a small enclosure attached to my shop and put some noise dampening material. 

1. What have you guys to work well to combat noise but won’t break the bank

2. What type of opening do I need to have as to not create back pressure.  Since I’m more worried about disturbing my neighbors my initial thought was to have the opening in my shop.

Thoughts?

Anything that controls waves of air (sound) will also try to control spread of heat from the motor.  Make your closet with  half-foot of clearance, and vent it through a couple of (stacked) furnace filters, as required.

[Hank Knight]

I had the same problem. My ClearVue 1800 cyclone was a screamer in my basement shop. I built an enclosure around it insulated with regular fiberglass house insulation and sheeted it with Homasote - both very inexpensive. Homosote is a sound dampener and a much better choice than sheetrock or other hard wall board material. I did some online reasearch into sound baffling/dampening and figured out how to build baffled vents around the top of my enclosure to vent the filered air back into the shop. I was able to get about 200 sq.in. of vent opening and that has been sufficeint to avoid choking off the air flow from the cyclone. I haven't had a problem with the air flow or overheating. All in all, it has been a grerat success. It doesn't kill the noise entirely, but it dampens it enough to make it relatively pleasent to work around. You can carry on a conversation in normal tones in the shop wirth the cylcone running. My kitchen and family room are directly above my basement workshop and my wife doesn't complain about the noise. That's all the verification I need.

[Juss1]

I had the same problem. My ClearVue 1800 cyclone was a screamer in my basement shop. I built an enclosure around it insulated with regular fiberglass house insulation and sheeted it with Homasote - both very inexpensive. Homosote is a sound dampener and a much better choice than sheetrock or other hard wall board material. I did some online reasearch into sound baffling/dampening and figured out how to build baffled vents around the top of my enclosure to vent the filered air back into the shop. I was able to get about 200 sq.in. of vent opening and that has been sufficeint to avoid choking off the air flow from the cyclone. I haven't had a problem with the air flow or overheating. All in all, it has been a grerat success. It doesn't kill the noise entirely, but it dampens it enough to make it relatively pleasent to work around. You can carry on a conversation in normal tones in the shop wirth the cylcone running. My kitchen and family room are directly above my basement workshop and my wife doesn't complain about the noise. That's  all the verification I need.

Thanks.  My initial thought was fiberglass insulation.  Care to share any pics of your set up


And as side question.  I currently just have 4" SD piping but will upgrade to a larger diameter.  Leaning towards spiral but will depend on how much it will cost.  Is 6" sufficient will I get significantly better performance going bigger.  I want to emphasize significant because the cost of going bigger is alot.   I remember someone posting an online calculator to determine the correct size pipe given your longest run, dc, machine, etc.  Anyone remember the link?

[jteneyck]

IIRC there was an article in FWW not long ago about how someone noise proofed his DC while still allowing air to flow back into his shop so as to prevent conditioned air loss.  

I'm pretty sure 6" piping will be your best choice for the main run.  Look at Pentz's calculations and recommendations.  

That thing looks like it was built for the military.  

John

[Hank Knight]

Juss1, here are some photos of my D/C closet with a little explanation:

1. my workshop is tiny (17' X 27'), so didn't have room to build a large closet around my cyclone. Mine is just large enough to house the cyclone. I put peg board on the outside after sheeting the outside walls with Homasote to give me a place to hang router bits and other stuff. Here is the outside view:

0D352344-A9B9-412C-B35C-DDD5893CA492 by Hank Knight, on Flickr

The door is divided in half like a French door to give me access to the dust bin without having to open the whole thing. The doors are made of a 2X4 frame with Homasote sheeting, insulated with closed cell foam insulation between the sheets and hung with heavy piano hinges. At the top above the door in the photo is one of the baffled exhaust vents. The outside opening opening is 4" X the width of the door. It has Homasote sheeting on both sides of the 2X4 frame. The space between the sheets has a Homasote sound baffle that runs down the middle of the space. The baffle runs all the way from the top of the opening and stops 5" short of the bottom. Exhaust air must make a U turn, starting at the top of the inside duct, running down to the bottom of the baffle where it makes a 180º turn up the other side and out the top vent on the outside of the wall into the shop. The baffle reflects and absorbs sound waves before they get to the outside. How this works is a subject too long for this post, but some online research into sound baffles will provide several good articles on the subject with diagrams that helped me design my baffles. My closet has baffled vents around the top three sides. They provide enough air flow capacity for my cyclone without restricting its suck.

Here is a photo of the exhaust vent above the door:

87B3B8BD-38A5-4D35-8063-1059950EC9B7 by Hank Knight, on Flickr

Here is the interior with the door completely open. As you can see, it's a pretty small closet:

8B4E4AC8-F105-4F6E-84B9-CFF20B8175DB by Hank Knight, on Flickr

I stapled 1/2" hardware cloth to the inside of he 2X4 frame to give the fiberglass insulation some backing. The insulation went against the hardware cloth and the exerior Homasote sheeting went on. I bradded on some 1/2" firring strips to the outside and bradded the peg board to that to finish it off. Here is the inside view of he hardware cloth and the pink fiberglass insulation. The clear palstic box-looking structure at the top of the photo is the cyclone's intake duct.

4A531C5E-5A15-433F-8876-FB844884AE89 by Hank Knight, on Flickr

This photo shows the top inside walls of the closet with the interior exhaust ducts at the very top. By the way, don't forget to insulate the ceiling of the closet, and you need to seal any and all cracks in your structure that would allow pesky sound waves to escape. I sealed my door with foam tape and stuffed fiberglass in any other open cracks and crevices I found.

D1D6B7D2-3042-4829-93A3-F326EA99FC23 by Hank Knight, on Flickr

You asked about the best size for the main ductwork. It depends on your D/C unit. The rule is bigger= better, but your D/C must move enough air to keep the pressure high enough to be effective. My main ducts are 6" in diameter with 4" drops to most of my machines. I have a 6" drop to my radial arm saw and to my lathe, but all the rest are 4" drops. Here is a photo of the outside of my closet with the main intake duct:

75FDE2CF-970A-4E93-9B31-8D1224C8FCC6 by Hank Knight, on Flickr

My 6" duct branches about 4' after it exits the closet and runs down both sides of my shop with 4" drops as needed aloing the way. Run the large duct as close to your machines as is practical before reducing it. You want the air flow as open as possible as long as possible to move as much air as possible. The smaller the duct, the more it restricts the air flow. You probably should check the owner's manual for your D/C for the recommended duct size. I notice that your machine has multiple 4" outlets. That probably means it moves enough CFM to handle a 6"main duct. You'll need some kind of adaper in place of the 3 X 4" turret you currently have on the machine.

I'm sure this is more than you wanted to hear and know about my D/C closet, but I hope it helps and gives you some ideas.

[mdhills]

Hank,
  Thanks for sharing the photos and details.

What is the floor area of your DC closet? 

thanks,
Matt

[Juss1]

Thanks for all the info hank. Definitely not too much and will help a lot as I go forward. The specs of my machine are


3 HP
220V / 60Hz / 1PH / 3450 RPM
Running AMP: (with 8” inlet) 17A at 220V
Air Volume: 1624CFM (cubic feet per minute)
Max static pressure: 11.2 Inches of water
Fan Size: 15.5”
Inlet: Ø8”

High frequency remote control switch 46 gallon Octagon drum
351 lbs (159 kgs) 419 lbs (190 kgs)
filtering area: 9.5 m2 (102 ft2)
Black HEPA Ø15.74” x 35.43” (Ø40 x 90cm) x 1pc