Shop Air

[PCW]

I'm working on the new shop now and one thing I learned about the old shop is that I don't want the air compressor inside the shop. However, when you live in a relatively nice neighborhood, outside is probably going to piss folks off.

So, I did a search for quiet air compressors and came up with several models that are rated under 80 decibels. I'm thinking that at that level, maybe I could put it outside, maybe in a shed even and not piss folks off.

I'm mostly asking an open question about what smaller builders or hobby builders or even big guys are using for shop air, recommendations, or just flat ingenious ideas that you guys have come up with to have air and not the noise associated with the air compressor.

Here are a few I found from cheap to more expensive:
Dewalt D55168 Heavy-Duty 200 PSI 15 Gallon 120 Volt Electric Wheeled Portable Workshop Compressor - Rockler Woodworking Tools

Buy Porter-Cable Shop Boss Oil-Free Vertical Portable Compressor, 175 PSI, 2-Stage 25 Gallon, Model CPFC at Woodcraft.com

Ingersoll Rand Garage Mate Single-Stage Air Compressor - P1.5IU-A9 | CSN Tools

I'd think that Porter Cable would keep me happy as it's bigger than what I have now and should be way more quiet but I don't know.... I'd still like to put it outside and pipe in the air to the new shop.

One thing I did right that I will certainly do again and should share is that I put a H shaped line on the ceiling of the old place with 90 degree fittings to have 4 drops in all four corners of the garage. That give me air no matter where I am and since it's in the corners, no need to ever roll up a hose. I just purchased 25' lines, cut them in half, then put barb fittings on the other end. works great.

[echelon_john]

IMO the biggest drive of air system decisions is whether you'll be sandblasting with it or not. If you are, you need larger storage capacity and volume than many of the smaller compressors can provide. 60gal min, 80 gal+ better.

If you aren't blasting, and just want air to run die grinders/small tools, inflate stuff and blow stuff, then you could probably get by with a smaller compressor. The quietest I've heard by far was one that some guys doing work on my house used; it was a small Makita compressor. It was significantly quieter than my Porter Cable pancake compressor, and seemed to make noise at a much lower frequency that wasn't as annoying. I was thinking that a trick setup would be to use a small compressor like this, but add a large reserve tank to the system.

Another option is to run a large compressor inside, but build a sound insulating cabinet around it. The important thing here is to make sure you run a fresh air feed into the compressor's intake from outside the cabinet. Heat buildup can be an issue in this scenario, but again, it depends on how you're using it. I have a Porter Cable 80gal compressor that's fairly loud, but for tasks like grinding/drilling it doesn't cycle on too frequently, so I'm not worried about heat. If I'm sandblasting constantly for more than a few minutes, I'll open the cabinet and just wear ear protection so I can be confident it's not getting too hot. Even when I blast for long periods, it gets WARM for sure, but never so hot that I'd really be nervous with it in the cabinet.

Alternatively, have you considered building a sound-insulated cabinet for it just outside your shop? In TX I would think that would work well, assuming you're not dealing with the kind of winters we 'enjoy' up here. Maybe not enough soundproofing to blast at 2AM, but depending on the ambient noise in the neighborhood that could be an option. Probably not as loud as the omnipresent leaf blowers we all listen to!

Guess my advice would be to actually listen to whichever model you plan to buy so you can hear how loud it is; some seem louder than others even though they're rated at the same dB...

[Craig Ryan]

A small motor on a big tank won't really help much. You'll end up waiting just as long as a small tank. A guy who rebuilds compressors that retired from IR told me a few things. You get what you pay for was one. The oil free systems are usually louder. A pump that's large enough to do the job and not have to be turned up and run full out will be quieter and last longer. A small unit you run hard will develop more heat and water in your air. If you put your compressor in a bad environment it won't last as long. You need to decide how much air you need to push through and then work back from there. The best units which are larger, quieter, more expensive are rotary screw. When i was shopping it didn't take long to see the cut off in price features, and what is pushed at the big box stores. Most of those are meant to look big sitting in the garage when you check the air in your car's tires. If you're not blasting or painting, maybe you should consider electric tools? I think you need to spend up over 1K to start approaching anything good, and more than that if you want have 15cfm or better. Just some thoughts.
Craig

[PCW]

All settled....

The quick of this is that, just like most industrial machines, they don't build 'em like they used to I suppose. My old 110V compressor is a 3.5HP 110V (and can be wired for 22) that does 6.8CFM@90PSI and 8.5CFM@40PSI. It's got a 25 gallon tank. I dare you to find anything remotely close to 3.5HP that runs on 110V or does anything more than 5ish CFM and runs on 110V. SO, 220V was the only real solution and I went belt drive. Unlike bikes, belt drive on air compressors is certainly proven and the more desired way to go than direct drive... On second thought, that applies to bikes too I suppose.

The "new" compressor is used, got it off of Craigslist, and specs are 5HP 220V (15A) that does 10CFM@90 PSI and 12CFM@40PSI and is a LOT more quiet than the other one. It comes from the same generation as my 110 did and is also a Craftsmen, this was just the upgraded model it looks like and all the parts are still available from Sears should anything go wrong--and for not much money. I'm still going to put an insulated doghouse around it and probably will put that all inside of an insulated shed outside so I don't have to hear it and that means the neighbors will have no chance of hearing it either. I'm planning on installing vents (and possibly fans) in doghouse and sound insulating the shed and installing a ridge vent and probably floor vents to start. I think that will keep it plenty quiet and cool even in the Texas weather. Furthermore, it will be pretty much out of the sun in the location I've chosen for the shed.

I'm planning on about 60' of 1" galvanized along the ceiling so that I can have lots of drops the different work stations so that adds about 10 more gallons to the capacity. So I'll have doubled my capacity, increase my flow from ~7CFM to ~10CFM, quieted the whole thing from ARE YOU FREAKIN' SERIOUS loud to a whisper and in the end, shouldn't really be out much bread 'cause I have a buyer for the old compressor that is willing to pay about what I paid for the new one.

One of these days, the new shop will be done and I'm going to build frames again. 2011 is looking like a great year.

Thanks for the PMs from those that can't post on this forum and thanks for the feedback from you guys that could.