I was very surprised when I saw what Coleman recommended for their:

Air Conditioning Condensing Units - 14 SEER Units
2 to 5 Ton, Single-Phase, R-22



Mfg. #
Nom. Tons
BtuH Cooling
Max. Fuse Size
Min. Circuit Amps
Liquid Conn.
Suction Fitting

FRCS0241BF
2
24,000
20
12.1
3/8"
7/8"

FRCS0301BF
2-1/2
30,000
20
14.9
3/8"
7/8"

FRCS0361CD
3
36,000
25
18.1
3/8"
7/8"

FRCS0421CE
3-1/2
42,000
30
17.8
3/8"
1-1/8"

FRCS0481CE
4
48,000
35
20.6
3/8"
1-1/8"

FRCS0601BG
5
60,000
50
31.8
3/8"
1-1/8"




--
Moe Jones
HVAC Service Technician
Energy Equalizers Inc.
Houston, Texas
www.EnergyEqualizers.com
"Zephyr" wrote in message m...
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