Page 10
506636−01
New or Replacement Line Set
REFRIGERANT LINE SET
This section provides information on installation or
replacement of existing line set. If new or replacement line
set is not being installed then proceed to
Brazing
Connections
on page 12.
IMPORTANT
Lennox highly recommends changing line set when
converting the existing system from HCFC−22 to
HFC−410A
.
If that is not possible and the line set is the
proper size as reference in table 2, use the procedure
outlined under Flushing the System on page 13.
If refrigerant lines are routed through a wall, then seal and
isolate the opening so vibration is not transmitted to the
building. Pay close attention to line set isolation during
installation of any HVAC system. When properly isolated
from building structures (walls, ceilings. floors), the
refrigerant lines will not create unnecessary vibration and
subsequent sounds. See figure 7 for recommended
installation practices. Also, consider the following when
placing and installing a high−efficiency outdoor unit.
Liquid lines that meter the refrigerant, such as RFC1 liquid
lines, must not be used in this application. Existing line set
of proper size as listed in table 2 may be reused. If system
was previously charged with HCFC−22 refrigerant, then
existing line set must be flushed (see
Flushing Line Set
and Indoor Coil
on page 15).
Field refrigerant piping consists of liquid and vapor lines
from the outdoor unit to the indoor unit coil (braze
connections). Use Lennox L15 (sweat, non−flare) series
line set, or field−fabricated refrigerant line sizes as listed in
table 2.
NOTE When installing refrigerant lines longer than 50
feet, see the Lennox Refrigerant Piping Design and
Fabrication Guidelines, CORP. 9351−L9, or contact
Lennox Technical Support Product Applications for
assistance.
To obtain the correct information from Lennox, be sure to
communicate the following information:
Model (XC14) and size of unit (e.g. −036).
Line set diameters for the unit being installed as listed
in table 2 and total length of installation.
Number of elbows vertical rise or drop in the piping.
The compressor is charged with sufficient Polyol ester oil
for line set lengths up to 50 feet. Recommend adding oil to
system based on the amount of refrigerant charge in the
system. No need to add oil in system with 20 pounds of
refrigerant or less. For systems over 20 pounds − add one
ounce of every five pounds of refrigerant.
Recommended topping−off POE oils are Mobil EAL
ARCTIC 22 CC or ICI EMKARATE
RL32CF.
IMPORTANT
Mineral oils are not compatible with HFC−410A
.
If oil
must be added, it must be a Polyol Ester oil.
Table 2. Refrigerant Line Set Inches (mm)
Model Number
Field Connections
Recommended Line Set
Liquid Line
Suction Line
Liquid Line
Suction Line
L15 Line Set
XC14−018−230
3/8" (10 mm)
3/4" (19 mm)
3/8" (10 mm)
3/4" (19 mm)
L15−41 15 ft. − 50 ft. (4.6 m − 15 m)
XC14−024−230
XC14−030−230
XC14−036−230
3/8" (10 mm)
7/8" (22 mm)
3/8" (10 mm)
7/8" (22 mm)
L15−65 15 ft. − 50 ft. (4.6 m − 15 m)
XC14−041−230
XC14−042−230
XC14−047−230
XC14−048−230
XC14−060−230
3/8" (10 mm)
1−1/8" (29 mm)
3/8" (10 mm)
1−1/8" (29 mm)
Field Fabricated
NOTE Some applications may required a field provided 7/8" to 1−1/8" adapter
