On Fri, 10 Aug 2007 15:44:51 -0500, Ignoramus22443
wrote:

On Fri, 10 Aug 2007 15:43:00 -0500, Don Foreman wrote:
On Fri, 10 Aug 2007 06:20:21 -0500, Ignoramus22443
wrote:

Forgot to add Mike, but I would also suggest looking for a "real 5 HP"
compressor. It would improve your productivity working on certain
tasks such as sanders or air hammers, on real projects.

i

The 3HP IR he's looking at produces more air (11.3 acfm @ 90PSIG) than
some "real 5HP" units do. Exceptions would be 2-stage units. Buying
a used compressor (except perhaps a Quincy) is a bit of a crapshoot
unless there is some way to know its history.

My 5 HP compressor makes about 14 CFM. It is single stage.

That's nice. Where can Mr. Henry buy one like it next week, pray
tell?

5 HP (with 15% friction) can theoretically deliver 25.6 ACFM at 90
PSIG in adiabatic single-stage compression. Pumps vary a lot in
efficiency. More efficient pumps tend to be larger and more
expensive. Example: IR pump model S-20 (single stage) delivers 19.5
ACFM @ 120 PSI with 5 HP. Figure about $1300 just for the 155-lb
pump.

There are also "consumer models" that deliver less than 10 ACFM from 6
HP.

My point was to look at ACFM, not horsepower.