On Nov 30, 3:16 pm, BobH
wrote:
I am looking at replacing my old shop air compressor and have been
looking at the rotary screw type compressors --

I agree with some of the previous posters. Rotary units are typically
made for continuous operation, with a loading/unloading control loop
based on the pressure settings. I don't know if your situation
involves a separate enclosed room where the compressor is located, but
if you have that situation, the air dryer should not be in an
environment where the temperature is really elevated. They don't work
very well when the ambient temp is up in the 100+ F range. As a note
to Snag -- If you are getting oil and water in the distribution lines,
there MAY be an issue with one of the control/valve components on the
compressor. I had that experience a couple of times with a 25HP
Quincy, where the valve assembly got stuck, and proceeded to allow
significant oil into the air lines. Not pretty, especially in a
cleanroom environment.... Otherwise, they work very well, and the air
is pretty clean. There is no substitute for point-of-use coalescing
filtration, though, and in-line adsorbers that change color when they
start getting contaminated.