"Stormin Mormon" fired this volley
in :


I had thought filter driers were chemical system. And that
you couldn't restore them. Maybe on cars, you can?

Yes, I easily imagine it drawing the system full of
humidity. And of course, the compressor oil is hydoscopic.

Some are calcium chloride-based, and only baking will dry them. Many
contain "molecular seives". They're ceramic pellets about the size of #6
shot that have precisely-sized pores that will only admit and hold water
molecules, while rejecting or releasing other substances. They can be
"recharged" either by baking or by holding a hard vacuum on them for a
time.

And yes, the oil is quite able to absorb a quantity of water -- in fact,
that's part of its duty in a system. Water not in vapor form, and
entrained like that isn't nearly as harmful to the system as hot vapor in
contact with chloro/fluoro-carbons, or free liquid.

LLoyd