How Quiet Can I Get From Boxing a Noisy Shop Vac?

[jaykchan]

I want to box in a noisy shop vac (from Ridgid) to minimize its noise to _very_ low. I have come across many designs like that in books and in this newsgroup, and I believe boxing in a shop vac should cut down the noise significantly. I have a couple questions though:

- How quiet should I expect to get from boxing it in? Will it be quiet enough that I can use it at 6:00 o'clock in the morning on my boat (parked on my driveway) inside the boat cover? Please note that I live in a 1/4 acre property and my neighbor's house is practically next to my driveway. What's the dB level that I can cut down to anyway?

- Will the motor run hotter than it should if it is enclosed inside a box with air vent on the side of the box? How much room I should leave on top of the motor to allow enough cooling? I am asking this because I need to run it with my sander to sand the boat deck flat, and this may take longer than 10 minutes; therefore, I am afraid of overheating the motor.

Yes, this is not a strictly woodworking question. But I figure people into woodworking should be the expert in this area.

Thanks in advance for any info.

Jay Chan

[Greg D.]

Hi,

You just have a big, big, big problem...

A vacuum cleaner by definition sucks up air, a lot of air... all that air has to go somewhere... Did you ever notice a shop vac pushes air on the other side?

Now ask yourself the same question again... Can you box in a shop vac?

The answer is no. You'll have to provide some sort of air exaust thus killing the whole concept of making a box.

You want a solution? Buy a Fein vacuum cleaner... There's a lot quieter than those stupid Shop Vacs or Ridgid...

Hope this helps,

Greg D.

[joeljcarver]

I've seen muffler-like attachments that connect to the exhaust. I'm not sure that a box surrounding the vac would be effective. The first thought would be that it would limit it's mobility.

Recently, I've started wearing ear muff protection when I use my whining Milwaukee vac. As I get older, I have to save as much of my hearing as I can.

[Andy]

I have one for my noisy Ridgid - makes a little difference; not much. It seems to me that if you built a box out of 1/4" pegboard, and lined it with carpet, the air could still escape but much of the noise would be muffled. You could even line the top of the box with egg-crate foam or acoustical tiles or something, and since this relatively high-frequency noise is fairly directional, extra insulation in the top should help, especially if the vac is down in a boat. No clue about dB levels. Another thing to consider is a longer hose, so you can "hide" the vac where it might be more isolated/insulated. Woodcraft, Lee Valley, and others have longer, better hoses, i.e.

overheating, I wouldn't worry too much. I've run my Ridgid for probably an hour straight, hooked to my plunge router that has a restricted (

[Edwin Pawlowski]

Not really. Sure, it will be vented, but still a box. It can be lined with sound dampening materials and have a vent on the top, side, or bottom. Your computer is in a box isn't it?

[mac davis]

The best thing a box or wall will do is deflect the noise in a different direction, usually up, which can help quite a bit....

You might also try a long hose and using your garage for the "box"...

I bought a "noise reducer" from Craftsman that goes in the "blower" port and it seems to make a bit of difference without any noticeable loss of suction...

Bottom line is that if there is much cost involved in building the box, including vents, cooling fan, etc., it might be more cost effective to buy a quieter vac...

Mac

[jaykchan]

Yes, I have already had that muffler-like attachment on my Ridgid shop vac. Unfortunately, it doesn't do a thing. I really cannot tell if it makes any difference at all in term of cutting down noise. I believe the main problem is that the noise seems to be coming from the motor that is on top of the shop vac, and not from the blower port. Therefore, attaching the muffler-like attachment to the blower port doesn't really cut down on the noise in my shop vac.

Thanks for the info anyway. Your info may help other people whose shop vacs have a different design than mine.

Jay Chan

[jaykchan]

small that I need to put the shop vac in one end of the boat while I work on the other end of the boat. But the hose will not be long enough for me to hide the shop vac inside the garage because that will be too far away and too much work.

[jaykchan]

I figure that I would need a 20-ft hose in order to link a shop vac in garage to the boat deck. And then I need to cut a hole in my garage wall to pass the hose. That doesn't sound like something that I want to do.

The muffler-like attachment that I bought for my Ridgid shop vac doesn't do a thing in term of cutting down noise. I still have it attached to my shop vac -- not to reduce noise, but to redirect the exhaust air down toward the floor.

Yes, I may end up buying a quiet (and expensive) Fein shop vac. But I would like to try the low cost solution first (boxing the vac in) before committing to the costly solution. Moreover, I can put the same box over the Fein shop vac to further cut down the noise; therefore, the investment on building the box will not be wasted.

Seem like no one can tell me if boxing-in the shop vac will cut down the noise significantly. I guess I will have to try building one and see what will happen.

Jay Chan

mac davis wrote:

[brianlanning]

Someone, I think hoover, makes this thing called teh GUV. It's a wall-mounted shop vac. It seemed reasonably priced iirc. You could go with that, enclose it, and get long hoses like the others mentioned.

brian

[Andy]

Please let us know what materials you use and if/how much your box helps. I'd be very curious - I'll probably build some kind of box eventually. Another thing I've done is to secure a piece of open-cell foam over the blower/motor housing on top of my Ridgid vac. This helps a little with noise, but mostly it keeps the cooling fan from blowing air/debris up into my face. Again, this hasn't caused overheating, even combined with the other factors I mentioned in my earlier post. Thanks, Andy

[Andy]

Also, have you tried searching the google groups rec.woodworking archives? I searched for shop vac box and got some good info - especially this thread:

snippet, in case the link doesn't work, from Joe Nation, May 15,

2003: "The best way to quite a shop vac it to put it into a box. I built a 30" cubical box with a door and latch on one side, put the cube on casters, lined the inside of the cube with carpet scraps, drilled a hole for the vaccum hose to exit the box and drilled 4 smaller holes (about 1.5" in diameter) along the back bottom edge of the box for ventilation and to allow the vaccums exhaust streem to exit the box. The reduction in noise from the vaccum is remarkable. I do not have any sound level measurements but, I can talk or listen to the radio at normal sound levels with the vaccum running. This solution works!!! I often forget to turn the vaccum off after I have been using it for a long period of time at my workbench because it runs so quitely. It does not degrade the peformance of the shop vaccum or shorten its expected operating life. " Andy

[Gordon Airporte]

If drilling a few holes for exhaust works, that's fairly easy to do and it's great. Personally, I think baffling an entire wall of the box is probably the way to go to maximize exhaust flow and minimize noise. Like so:

-------- | | | | | | | | | | | |

--------

[else24]

I have my cheapo shop vac inside a plywood box. It's carpeted all over, it has a series of holes drilled at the top back, AND I made a little air chute that channels the air down to about the bottom of the box.

It cuts the noise about in half. Maybe a little more. When I show it to friends, they listen to it with the door shut and say "Yeah. That's nice. I guess it's quiet." Then I open the door and they go "WOW. Okay, I see what you mean. Shut the door."

So, it helps but it doesn't make it whisper quiet. When I had the shop in the basement though, SWMBO said said there were times she didn't know it was on, as opposed to not being able to hear the tv.

It's been in that box for a couple years now. No problems. I keep the planer on top of the box and it's got a power strip on it. Instead of the shop vac underfoot, I've got a workstation with a shop vac inside it. One of the better shop improvements I've made.

The carpet makes the difference. I used cardboard for a while till I found some clean scraps, and the carpet really damped out the sound.

[jimmy]

I found that heavy foam carpet underlay is a better box liner, easy to find (you can find huge unused chunks (rollends) in dumpsters behind carpet stores) and it's easy to glue into place in layers. I have 4 layers in the 'box' under my work bench and my huge noisy Shopvac is very quiet, as is my air compressor. My AC sits on top of 3 layers of carpet underlay as well.

[jaykchan]

Thanks for the line-art that shows the way to channel the air flow into the box while dampening the sound. This seems to be an easier and better design than what I have in mind. I will definitely keep this in mind when I build the box.

Jay Chan

Gord> If drilling a few holes for exhaust works, that's fairly easy to do and

[jaykchan]

A snippet, in case the link doesn't work, from Joe Nation, May 15,

Yes, I have already read that post. But I have a difficulty translating what he said to the kind of low noise level that I want. Seem like this is very subjective, and I need to build it to find out.

Jay Chan

[jaykchan]

Thanks for the suggestion of using 4 layers of carpet underlayment. It should be easier-to-get and cheaper than special sound-dampening foam. I will keep this in mind.

Jay Chan

[jaykchan]

Thanks for the encouraging info. Sound like boxing-in the shop vac is a good way to reduce the noise, and I should not get into the problem of overheating the motor.

May I ask you two questions:

- How much room do you leave above the motor inside the box? Here, I am assuming that the motor in your shop vac is mounted on top of the shop vac just like many shop vacs. I am asking this trying to figure out how much room to leave in order to prevent overheating the motor.

- Is your setup quiet enough to be used at 5:30am in the morning in your driveway if your neighbor's house is just 20-ft away from the shop vac?

Thanks in advance for any more info.

Jay Chan

[jimmy]

Pick the really heavy stuff, in weight. It makes great weather stripping as well.