For those who 'need to know.' The [rub] comes from the "different types of
oil." The older refrigerant R-22 [Freon] uses mineral oil The newer
refrigerant R-410a [Puron] uses a synthetic oil [PAG - poloyolyglycol]. The
mineral oil from years of old is not compatible because of miscibility. The
mineral oil tends to slug [thicken] under the newer refrigerant R-410a.

It is highly recommended that "if" you use the older copper lines with the
newer gas, you should be aware that the manufacturer recommends less than 5%
of mineral oil be allowed to mix with the newer gas. This concentration can
be tested with a refractometer. It is better to run new copper, but if you
have to use the older lines...... 5% is the highest concentration of mix
allowed.

The larger suction line is needed with the newer refrigerant because of
system capacity. If you choose to use a smaller refrigerant line, you
system capacity will suffer.

-
Zyp
"James" wrote in message
. ..
We just went from the old to the new freon, and they didn't change our
lines. They did a pressure test to make sure there were no leaks, and
said
the old lines were fine. We have not had any trouble at all.

James