I've been reading this thread with some
interest. Back in 1978 I installed
a Carrier 3.5 ton unit, which, at that
time, was the high efficiency model. It
was 8.5. At that time it was called
EER. Anyway, I was told in order to
get that efficiency (in '78) it needed 1
1/8" suction line. Actually, at the
evaporator and at the
compressor/condenser, it is adapted down
to a
smaller diameter .... I think, 5/8" or
3/4". The condenser was also huge
for a 3.5 ton unit ... it's about 42"
high. It's interesting how things have
changed. I guess if I ever have to
change to the new refrigerant, it might
be difficult. But, considering we are
selling the house this year, it probably
won't happen. Anyway, it's probably
time for a replacement anyway.
The new owners can worry about that.
Moe Jones wrote:
I fully agree what you are saying but what feed back I am getting from
the manufactures is really some what surprising me when it comes to
warranty but then again I can understand what they are going through.
They tell me that they have lost so many compressors because of
contractors not using the right size copper and evaporator coils. They
want the evaporator coil to be around two years old before you replace a
condensing unit using the existing coil.
I have learned to go to http://www.ari.org/ to verify any evaporator
coil before replacing an existing condensing unit.
As you can see their 13 SEER condensing units are not that bad when
using the existing copper
and their 13 SEER chart goes somewhat you say below.
*Air Conditioning Condensing Units — 13 SEER Units*
*1-1/2 to 5 Ton, Single-Phase, R-22*
*Mfg. #*
*Nom. Tons*
*BtuH Cooling*
*Max. Fuse Size*
*Min. Circuit Amps*
*Liquid Conn.*
*Suction Fitting*
ERCS0181BB
1-1/2
18,000
15
10.1
3/8"
3/4"
ERCS0241BB
2
24,000
20
11.8
3/8"
3/4"
ERCS0301BB
2-1/2
30,000
25
16.7
3/8"
7/8"
ERCS0361BB
3
36,000
30
18.9
3/8"
7/8"
ERCS0421BB
3-1/2
42,000
35
21.9
3/8"
7/8"
ERCS0481BB
4
48,000
35
20.6
3/8"
7/8"
ERCS0601BB
5
60,000
50
31.8
3/8"
1-1/8"
.
--
Moe Jones
HVAC Service Technician
Energy Equalizers Inc.
Houston, Texas
www.EnergyEqualizers.com http://www.EnergyEqualizers.com
"Zephyr" wrote in
message news:BeSdnU4BFvEXjQ3bnZ2dnUVZ_sKunZ2d@championbroa dband.com...
FWIW: There's nothing wrong with Colemen. And, the line sizing is
fairly correct. Although on the 2-ton size 7/8" o.d. is a bit
much. I think it likely goes with stocking less sizes in the
warehouse. 7/8" is good to 3 or 4 Ton capacity depending on line
length. [You can turn to Proper Piping Practices manuals for the
refrigerant of choice.] You'll find that 5/8" is good for 2-Tons.
3/4" for 3-Tons. 7/8" 4-Tons, and 1-1/8" is good for 5 Tons for air
conditioning applications using R-22 or R-410a.
If the suction return line is too large, you may have oil return
problems depending if the evaporator coil is installed below the
condensing unit.
This is why a professional HVAC/R contractor is needed. He can
generally make the best choices for the particular installation.
One that will provide years of trouble free operation.