They all need a little oil, but most people tend to over-do it and
it gets a bit messy. Only needs a drop or two a day, for light duty.
(Or they forget to oil them, and the tool dies a quick death.)
You can install an inline mist oiler on your workbench outlet that
you use the air tools at. But then you have to be REALLY careful not
to mix your hoses used with oiled air with your 'clean' hoses, or
you'll go to paint something and wreck a paint job getting oil
(residue from inside the hoses) into the paint.
For a proper compressor: Big, yes. Noisy, not really, if you buy a
proper belt-drive unit where the compressor is turning under 800 RPM
or so. The little 3450 RPM direct drive pancake compressors are not
enough to run a die grinder for any usable duty time, they make more
noise than they do air.
I have the "5 HP" (really a 4, but it's enough) Husky (Campbell
Hausfeld) 2-stage 80 gallon, and it's not noisy at all when running.
The fancier compressors from Ingersoll-Rand and Quincy are even
quieter and will run practically forever (even if used a lot), but you
pay a heck of a premium for a few Db's.
And I have the lumber and a solid-core door to build a little closet
around the unit, that will make it virtually silent - just need a
small vent fan before I start enclosing it, so it doesn't cook itself
if run for long periods...
Tethered? I plumbed my house[*] for air. ;-)
[*] Places I'd likely use air tools.
Don't forget to put an outlet under the eaves or on the backside of
a framed "chimney", so the roofers have a convenient place to plug in.
Did you ever notice that you can get nice recessed "wall hydrants" for
water faucets outdoors, but nobody makes them for air?
Or a flush plate-mountable air QD fitting that would look good
inside a house? I'm just going to put the air-line drop in the
front closet, and paint the pipe when I'm done.
--<< Bruce >>--