Page 10
506238−01 06/09
REFRIGERANT LINE SET
Field refrigerant piping consists of liquid and suction lines
from the outdoor unit (braze connections) to the indoor unit
coil (flare or sweat connections). Use Lennox L15 (sweat,
non−flare) series line set, or use field−fabricated refrigerant
lines as listed in Table 2.
Table 2. Refrigerant Line Set
Model
Field Connections
Recommended Line Set
Liquid
Line
Suction
Line
Liquid
Line
Suction
Line
L15 Line Set
−036
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)
NOTE When installing refrigerant lines longer than 50
feet, see the Lennox Refrigerant Piping Design and
Fabrication Guidelines, or contact Lennox Technical
Support Product Applications for assistance. To obtain the
correct information from Lennox, be sure to communicate
the following points:
S
Model (XPG20) and size of unit (e.g. −036).
S
Line set diameters for the unit being installed as listed
in Table 2 and total length of installation.
S
Number of elbows and vertical rise or drop in the
piping.
MATCHING WITH NEW OR EXISTING INDOOR COIL
AND LINE SET
The RFC1 metering line consisted of a small bore
copper line that runs from condenser to evaporator coil.
Refrigerant is metered into the evaporator by utilizing
temperature/pressure evaporation effects on refrigerant in
the small RFC line. The length and bore of the RFC line
corresponded to the size of cooling unit.
Existing line set of proper size may be reused. If system
was previously HCFC−22 then lines must be flushed (see
Flushing the System
on page ). If a Lennox RFC1 liquid line
is existing, it must be replaced.
If the XPG20 must be matched with a proper coil. The only
existing installed coils that could be re−used would be
current coils listed in the XPG20 matchup charts.
INSTALLING LINE SET
Line Set Isolation
This reference illustrates
procedures, which ensure proper refrigerant line set
isolation:
S
Installation of a
transition from vertica
l
to
horizontal
is illustrated in Figure 11.
S
Installation of
line set on vertical runs
is illustrated in
Figure 12.
S
Installation of
line set on horizontal runs
is
illustrated in Figure 13.
NOTE − Similar installation
practices should be used if
line set is to be installed on
exterior of outside wall.
PVC
PIPE
FIBERGLASS
INSULATION
CAULK
OUTSIDE
WALL
SUCTION LINE
WRAPPED WITH
ARMAFLEX
LIQUID LINE
IMPORTANT
! Refrigerant lines
must not contact structure.
OUTSIDE WALL
LIQUID LINE
SUCTION LINE
IMPORTANT
- Refriger-
ant lines must not contact
wall.
WOOD BLOCK
BETWEEN STUDS
STRAP
SLEEVE
WOOD BLOCK
STRAP
SLEEVE
WIRE TIE
WIRE TIE
WIRE TIE
INSIDE WALL
Figure 11. Refrigerant Line Set: Transition from
Vertical to Horizontal
ANCHORED HEAVY NYLON
WIRE TIE OR AUTOMOTIVE
MUFFLER-TYPE HANGER
STRAP LIQUID
LINE TO SUCTION
LINE
WALL
STUD
LIQUID LINE
METAL SLEEVE
SUCTION LINE − WRAPPED
IN ARMAFLEX
AUTOMOTIVE
MUFFLER-TYPE HANGER
Figure 12. Refrigerant Line Set: Installing Vertical
Runs (New Construction Shown)
