My new (to me) compressor is a 2 stage, 175 psi rated. But it seems to
me that one would only set it for 175 psi if you had a tool that needed
that much, or if you needed a burst of air at greater than the pump's
cfm rating (the extra pressure would be a reserve that you could draw
down). In ordinary use of normal pressure tools that don't use more
than the pump's cfm, I'd think that you'd set the pressure switch to
cut-in at the highest pressure that your tools use and cut-out at some
reasonable differential above that. Then your pressure would never be
lower than your tools need and energy would not wasted pumping to
greater than the needed pressure (pumping from 125 to 150 requires more
energy than pumping from 100 to 125). For example, cut in at 100 psi
and out at 125.
But, the extra energy in the higher pressure air is recovered when the
air is regulated down to lower pressure/higher volume. Not fully
recovered, of course, due to inefficiencies. I guess the question then
becomes: "Is the efficiency of pumping to a higher pressure that much
less than pumping to a lower one?"
What do you other guys with 2 stage compressors do?
Thanks,
Bob
- posted
15 years ago