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505095M 1/3/06
Refrigerant Piping
If the XC15 unit is being installed with an indoor coil and line
set, make the refrigerant connections as outlined in this
section. f an existing line set and/or indoor coil is going to
be used to complete the XC15 system, refer to this section,
as well as the flushing section which follows.
Field refrigerant piping consists of liquid and vapor lines
from the outdoor unit (sweat connections) to the indoor coil
(flare or sweat connections). Use Lennox L15 (sweat, non−
flare) series line sets as shown in table 2 or use field−fabri-
cated refrigerant lines. Valve sizes are also listed in table 2.
Table 2
Refrigerant Line Sets
Valve Sizes
Recommended Line Set
Model
Liquid
Line
Vapor
Line
Liquid
Line
Vapor
Line
L15
Line Sets
−024
−030
−036
3/8 in.
(10 mm)
3/4 in.
(19 mm)
3/8 in
(10 mm)
3/4 in.
(19 mm)
L15−41
15 − 50 ft.
(5 − 15 m)
−042
−048
3/8 in.
(10 mm)
7/8 in
(22 mm)
3/8 in.
(10 mm)
7/8in
(22 mm)
L15−65
15 − 50 ft.
(5 − 15m)
−060
3/8 in.
(10 mm)
1−1/8 in.
(29 mm)
3/8 in.
(10 mm)
1−1/8 in.
(29 mm)
Field
Fabricated
NOTE − When installing refrigerant lines longer than 50
feet, contact Lennox Technical Support Product
Applications for assistance. To obtain the correct
information from Lennox, be sure to communicate the
following points:
S
Line set diameters for the unit being installed (from
table 2)
S
Model (XC15) and size of unit (e.g. −060).
IMPORTANT
Matching XC15 with new Indoor Coil and Line
SetIf an existing indoor coil equipped with an
RFCI metering device is being replaced, also install
a new liquid line prior to installing the XC15 unit.
Installing Refrigerant Line
If refrigerant lines are routed through a wall, seal and iso-
late the opening so vibration is not transmitted to the build-
ing. Pay close attention to line set isolation during installa-
tion of any HVAC system. When properly isolated from
building structures (walls, ceilings. floors), the refrigerant
lines will not create unnecessary vibration and subsequent
noises. Also, consider the following when placing and
installing a high−efficiency outdoor unit:
1.
Placement
Some localities are adopting sound ordi-
nances based on the unit’s noise level registered from
the adjacent property, not from the installation proper-
ty. Install the unit as far as possible from the property
line. When possible, do not install the unit directly out-
side a window. Glass has a very high level of sound
transmission (see figure 8).
Install unit
away from
windows
Two 90° elbows installed in line
set will reduce line set vibration.
Figure 8
Outside Unit Placement and Installation
2.
Line Set Isolation
The following illustrations dem-
onstrate procedures which ensure proper refrigerant
line set isolation. Figure 10 shows how to install line
sets on horizontal runs. Figure 11 shows how to make
a transition from horizontal to vertical. Figure 12 shows
how to install line sets on vertical runs.
Installing Isolation Grommets
Locate the isolation grommets (provided). Slide grommets
onto vapor and liquid lines. Insert grommets into mullion to
isolate refrigerant lines from sheet metal edges.
WARNING
Polyol ester (POE) oils used with R−410A refriger-
ant absorb moisture very quickly. It is very impor-
tant that the refrigerant system be kept closed as
much as possible. DO NOT remove line set caps or
service valve stub caps until you are ready to make
connections.
