Compressor Noise
Thoughts on choosing a quieter air compressor, or muffling a noisy one. April 18, 2006
Question
In the process of updating equipment, I am looking at air compressors and realizing that, apples for apples, they are fairly close in quality and capability. The one thing I have tried to enter into the equation is noise levels, and I'm finding it difficult (online anyway) to find decibel levels for all the different models. The only one I have found is the Porter Cable, but I am not interested in the PC. What's the quietest air compressor? Having to listen to this thing run all day, every little bit helps. I'm looking at either 60 or 80 gallon units, 230v, anywhere between 5-7hp.
Forum Responses
(Cabinetmaking Forum)
From contributor P:
Quietest? Certainly not mine! I think compressors are much like helicopters - there has been zero attention paid to noise levels, and there won't be until there is enough feedback from the people who use them demanding quiet. For now, the only thing you can do is put the compressor in another location (or insulate it acoustically). Noise pollution is a serious problem in a woodshop. I have an old Makita chopsaw (nicknamed "Japan's Revenge"). I yell out a warning to other shop members to grab ear protection before I cut with it. If OSHA ever put a decibel meter on it, I'd be closed down. I think there are probably a lot of other semi-deaf woodworkers out there who will agree.
From contributor R:
I am sympathetic - it is a most annoying noise. But I suspect any improvements by one unit over the next will be incremental, and not worth making it a key buying decision criteria. I'd suggest just cobbling together a quick sound enclosure. I have a much smaller unit - 6 HP 20 gal SpeedAire - and used the box it came in to make the enclosure. Have to be a little careful about cooling air flow, but cuts the sound more than you would imagine.
From contributor B:
I have a fairly new 32 gallon Craftsman and it is too loud. I have been thinking about an enclosure to keep the noise down. Contributor R, how did yours work? What did you make it with?
From contributor J:
You need to look at a screw type compressor. Note the low sound level. Screw compressors are very nice, but not inexpensive.
From contributor C:
In my experience, a 2 stage oil lubricated air compressor is the quietest kind. Still not really quiet, by any means, but a little lower on the decibel level.
From contributor R:
As I said, I just used the box it came in - left the handle off the compressor, cut the bottom out of the box, and punched a couple holes through the side for the airline and power cord. Keep in mind, I don't have air tools (grinders, sanders, etc) and don't spray (much), so the compressor doesn't run all that much and therefore heat buildup is not a problem. If it did run a lot, I'd have to do something different - like baffled air venting and so on. As far as effectiveness, better than you would imagine for cardboard, but less than perfect. As far as I'm concerned, silent would be just about right. But it's a cheap fix and easy to try.
From contributor L:
I use a 60 gallon Ingersol (model ss-3) in the shop. Although nothing is silent, it was a revelation compared to the Emglo that I use in the field. Beyond being definitely much less offensive while running, its main silence comes from the fact that it cycles maybe two or three times a day, and not every ten minutes like the small compressor.
From contributor E:
My Ingersoll is quiet enough. You can talk to somebody only 10 feet from it.
From the original questioner:
Thanks. The Ingersoll Rand is the one I've been looking at the most, but can't seem to get the specs online. Anyway, I do a lot of spraying already and was looking into the Kreg foreman and a Blum machine, plus sanders, so I would say it's definitely going to get continuous use. Any other thoughts on Campbell Hausfeld or any other model?
From contributor G:
I bought a couple of tires for my trailer one day and was struck by how quiet the compressor was that the tire store was using. They run their compressors quite a bit all day with the air tools, and the tank on that one was at least 80 gals. My advice - check out a few tire stores and see if what they use would work for you. I use an 80 gallon 2-stage Devilbiss that I want to enclose because of the sound, because it always seems to kick in when I'm on the phone.
From contributor L:
If your compressor is going to support that much usage, that is all the reason you need to get a two stage compressor. I don't know the decibel difference between single and double stage units, but I bet the manufacturers do.
From contributor P:
My 32 gallon Craftsman compressor is about 6 years old and has run everything in the shop without a hitch all that time (including all day spraying and surface sanding), but it approaches painfully loud. The reason I chose that particular brand is that extensive research at the time showed me that Campbell Hausfeld was one of the most reliable brands around... and they happen to also manufacture Craftsman compressors (or at least did 6 years ago).
From contributor Y:
A screw type compressor will be quieter than any piston job. We bought a Kaeser SM8 with a refrigerated air dryer. It's damn near silent, but cost $7,000. They make smaller ones, though.
From contributor U:
We have a Kaeser screw compressor, which also runs all day - I wouldn't call it silent, but the noise is quite different from a piston compressor. Best to build some kind of enclosure if you want it quieter.
From contributor D:
The Craftsman oil-less compressors are terribly noisy. I finally retired mine a few years ago to my garage and I can't be in there when it is running. I bought a 7 hp 80g Coleman and it is a lot quieter but still somewhat loud. This week we moved it to the basement of my shop and ran copper airlines throughout the shop and I like it much better.
From contributor S:
Ditto on the Ingersoll Rand. Mine is old. Parts are still readily available. Mine is a two stage oil lubricated with a 5 hp motor and an 80 gallon horiz tank. When it comes on, its noise level is probably on par (annoyance wise) with the table saw. You probably want a bigger one. I think they build on the same basic frame that would be big enough for you. I think they fall in between the Lowes/Home Depot price range and the screw types. That said, I've never used a screw type, so there may be advantages that outweigh the cost. I found that in Philadelphia, there was a local IR service shop where I could deal on parts, tanks, used/rebuilt units with a real person. That's worth a whole bunch when the compressor's down and you have a job to spray today! I bought the parts I needed, rebuilt the top end and put mine together (I got it as a basket case). It's been running perfectly for 10 years with only oil and filter changes.
From contributor M:
Look at the speed the pump runs. The slower the pump, the quieter - generally speaking. Look for those running around 800 rpm. These will generally last longer. Some of the cheap compressors take big motors spinning fast to increase the output. This takes a toll on the pump, motor, and your ears.
From contributor O:
Those big tire store pumps are definitely two stage and that's the key. Some single stage compressors have twin cylinders, but are still just single stage and are real ear busters.
From contributor N:
Check with eatoncompressor.com. They have been great to deal with as far as I'm concerned. They know everything about air compressors. Their prices cannot be beat, nor their quality. I am not an agent of theirs. I have only done business with them.
The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment).
Comment from contributor I:
Regarding noise: as a general rule, the slower the pump runs, the lower the frequency of the noise. Most people I know tend to prefer the lower frequency yet it tends to travel more through walls, etc. I bought an IR SS5 upright which is single stage but a fairly slow running pump. I mounted it on rubber and though it still makes a good deal of noise, it is definitely quieter than many others in its size class.
The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment).
Comment from contributor A:
Regarding air compressor noise, I have a big 2-stage compressor. It was quite noisy when I got it, but I replaced the plastic and foam air filter with a Solberg automotive style filter that I bought from Grainger and the noise level dropped dramatically. I had to make an adapter for the new filter, but it was well worth the trouble.
