Probably a direct drive one ?

These are very noisy, I had one, still have it actually but it's not wired in, and it was terrible. I have it in the hay loft but can't run it without feeling really guilty .

Finished up getting a better compressor and plumbing both tanks together for volume. I bought a hydrovane but don't think they do real small ones, also have one of these Bambi compressors just for the odd bit of blowing off and these are that quite I keep forgetting to switch the thing off.

For airborne noise, ideally a closed box. Perhaps lined with an acoustic absorber …. depends on what you make box from (cement blocks for instance might do it alone but you may not want that). As soon as you make a hole in the box, though, an awful lot of the sound is going to come out. It can help to make a labyrinth passageway of the hole.

For structure borne noise you'll need some kind of shock-absorbing mounts.

How come it's so noisy? My compressor is in the garage with no noise/vibration precautions; my workshop in the basement diagonally adjacent and I can't hear it from there (no machines running). I can barely hear it from outside the garage with the garage door closed.

There are or at least there were small Hydrovane compressors. . I have one used a spray paint compressor and the same device was used by Dentists to run their drills. Relatively low volumes and pressures though.

Michael, can’t say I’ve ever heard of a ‘designed in’ pressure leak off on any compressor, especially over short periods of time, but then I’m no compressor expert!
Mine leaks off over a couple of days, but that’s because I’ve never bothered to check where it’s going even though I can hear a small air leak on the pressure reg’, I just know if I begin fiddling around with it, Sod’s law will dictate something will break and and put it out of action for weeks!
It ain’t really broke so I ain’t going to fix it ;>))
John

My compressor was a freezer compressor of some considerable age, when I first set it up, it was noisy, so I made a combined air filter and inlet silencer, it still makes a bit of noise, but not too bad.

You would need to take care if you box it in that you allow enough cooling air around the cylinder, and the electric motor. A revised air intake would be my first try at quietening it. The old machines with a cast iron cylinder and crankcase were quieter. Ian S C

I agree with Ian S C almost all of the noise from the compressor is induction noise. If you don't believe me take the air cleaner off , the noise will be deafening. Then try closing off the air inlet with a cork or something…. almost all the noise will have gone. Problem 2 is how to silence the inlet satisfactorily.

P.S. Ian… I enjoyed the Air Force museum at Wigram immensely.

In my dim and distant past as an apprentice, I can remember one of the mechanics digging a big hole under his garage, making a cover out of railway sleepers and shoving his compressor in that so it wouldn’t disturb his neighbours, think he also rigged up a long pipe for the air intake, which itself will cut noise!
Might be worth considering!

I built an 8ft x 6ft shop in my bedroom and can run my x2 mill with stock gear drive and my roommates can't hear a thing so I have some success in the area even if blind luck and overbuilding . I'd suggest googling for sound isolation boxes for more info and pictures (if you can avoid getting lost for hours, I can't).

There are 2 things that need to be controlled, vibration and airborne sound waves. Isolate the compressor from the floor of the box with some sort of resiliant material. Make the inside of the box big enough so that there was good airflow around the compressor.

Either line the inside of the box with sound isolating insulation (rockwool) and/or have an inner and outer wall for dead air. Using denser thicker material such as sheetrock, mdf or homosote for the walls will absorb more sound waves than light thin stuff. If using an inner wall try to isolate it as much as possible from the outer wall e.g. staggered studs, box in a box or resiliant fasteners. If doubling up on wall material using resiliant glue like Green Glue would help.

Make sure to seal gaps with caulk and use something like weatherstripping around the access door.

Next we have to deal with the pesky ventilation problem. For that I'd suggest muffler boxes (inlet and outlet)with baffles or corners lined with insulation. Every time sound waves have to change direction there's a drop in noise level so the more changes the better. Put a fan(s) inside the main box at the inlet and/or outlet for air circulation around the compressor. Wire up the fan as is most convenient for you.

Some of this stuff might be overkill but I bet you could build a box 2x2x1.5 fairly cheap, that's just about dead silent with the compressor running, assuming your measurements included room for insulation/airgap and airflow.

As this is my first technical post I'd appreciate questions, constructive criticism and clever snide remarks

steveTee, did you take the tour of the restoration hanger? The museum will expand into the new part once there are a few more large places built for functions that used to be held at the conference centre, but they are not in too big a hurry, it's making money which all museums need.

If you run into over heating of the compressor in the sound proof box, a large ex computer fan could be fitted, if you can, bring the air in from outside, and in the winter the exhaust air could go in the workshop, and outside in the summer, mind you, if your compressor is used as much as mine I'd just have one outlet, mine gets a run every month or three. Ian S C