Frank J Warner wrote:
Couple months ago I bought one of these:

http://tinyurl.com/yyqd

to replace my aging and no longer fully functional home-made air
compressor. (Link is to Sears, Craftsman 15 Gal 3HP air compressor.)

When I got it home and plugged it in, I couldn't believe my ears. The
thing sounds like a machine gun going off, continuously, until the
tank
fills and the automatic shutoff cuts in, which seems like a half hour
but is probably closer to five minutes. (Try it in a newly
sheetrocked
bedroom, with a texture hopper on the end of the hose, and nothing to
muffle the noise!)

My old compressor was almost whisper-quiet. I could use it any time
of
day or night without waking the whole neighborhood, let alone members
of my household, since my shop is attached to my house, and I didn't
have to scream to make myself heard 10 feet away.

I'm ready to chuck this new one. Really. Just put a free sign on it
and
wheel it out to the sidewalk. I'll eat the $200.

But I need ideas for a replacement that doesn't sound like a friggin'
50-Cal going off in my workshop.

Any help and recommendations would be appreciated. Do mfrs put dBs on
their specs anymore?

-Frank

Homework, as others have said. Direct drive and oiless means that the
motor runs at twice the speed of a belt drive with more than twice the
noise. It usually means that the pump is also alloy and the piston
head is synthetic of some type. They can be handy for portable use
where you don't want oil spilling if the thing tips over in the back of
the van, just run the thing a LONG ways away from where you want to
work. Short drop cord, looong hose. There's also no problems with oil
contamination if you want to run a small paint gun. I have one of
these for that reason, you can cut the noise down a lot with some
judicious baffling around it, big cardboard boxes work OK as long as
you can keep it cool.

Mid-range is a belt drive with an oil-filled compressor, these have
alloy pumps with iron sleeves. I've also seen a direct drive with the
same features, I wasn't able to find a motor plate with the speed,
though.

High-end is the all-iron pump with belt drive, these tend to be on the
heavy end for portable operation, you aren't likely to sling one into
the back of a pickup single-handled.

The guy at the local Tool King says that the oilless Porter Cables are
pretty quiet, I didn't hear one run, though. Also, no feedback on
returns.

Sears is also probably NOT the place to go compressor shopping. I do
realize they are sometimes the only place in many miles for tool
shopping in some areas of the country.

Stan