Page 12
New or Replacement Line Set11
This section provides information on new installation or
replacement of existing line set. If a new or replacement
line set is not required, then proceed to
Brazing
Connections
on Page 14.
If refrigerant lines are routed through a wall, 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.
Also, consider the following when placing and installing a
high−efficiency air conditioner:
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 braze connections). Use Lennox L15 (braze,
non−flare) series line set, or use field−fabricated refrigerant
lines as listed in Table 2.
Table 2. Refrigerant Connections and Line Set
Requirements
Model
Valve Field Connections and Recommended Line
Set
Liquid
Line
Suction
Line
L15 Line Set
−024
3/8 in.
(10 mm)
3/4 in.
(19 mm)
L15 line set sizes are dependent on
unit matchup. See Engineering
Handbook to determine correct line
set sizes.
−036
−048
3/8 in.
(10 mm)
7/8 in.
(22 mm)
−060
3/8 in.
(10 mm)
1−1/8 in.
(29 mm)
Field Fabricated
NOTE Some applications may required a field provided 7/8" to
1−1/8" adapter
NOTE − When installing refrigerant lines longer than 50
feet, contact Lennox Technical Support Product
Applications for assistance or Lennox piping manual. To
obtain the correct information from Lennox, be sure to
communicate the following points:
S
Model (TPA*S4) and size of unit (e.g. −060).
S
Line set diameters for the unit being installed as listed
in Table 2 and total length of installation.
S
Number of elbows and if there is a rise or drop of the
piping.
LIQUID LINE FILTER DRIER12 INSTALLATION OR
REPLACEMENT
The filter drier (one is shipped with each unit) must be field
installed in the liquid line between the outdoor unit’s liquid
line service valve and the indoor coil’s metering device
(TXV) as illustrated in Figure 10. This filter drier must be
installed to ensure a clean, moisture−free system. Failure
to install the bi−flow filter drier will void the warranty. A
replacement filter drier is available from Lennox. See
Brazing Connections
on Page 12 for special procedures
on brazing filter drier connections to the liquid line.
OUTDOOR
UNIT
LIQUID LINE
SERVICE VALVE
LIQUID LINE
FILTER DRIER
LINE
LIQUID
LINE
BRAZE CONNECTION POINTS
Figure 10. Typical Bi−Flow Liquid Line Filter
Drier Installation
LINE SET ISOLATION
CAUTION
Brazing alloys and flux contain materials which are
hazardous to your health.
Avoid breathing vapors or fumes from brazing
operations. Perform operations only in well ventilated
areas.
Wear gloves and protective goggles or face shield to
protect against burns.
Wash hands with soap and water after handling brazing
alloys and flux.
IMPORTANT
The Environmental Protection Agency (EPA) prohibits
the intentional venting of HFC refrigerants during
maintenance, service, repair and disposal of appliance.
Approved methods of recovery, recycling or reclaiming
must be followed.
IMPORTANT
If this unit is being matched with an approved line set
or indoor unit coil which was previously charged with
mineral oil, or if it is being matched with a coil which
was manufactured before January of 1999, the coil
and line set must be flushed prior to installation. Take
care to empty all existing traps. Polyol ester (POE) oils
are used in Lennox units charged with HFC−410A
refrigerant. Residual mineral oil can act as an
insulator, preventing proper heat transfer. It can also
clog the expansion device, and reduce the system
performance and capacity.
Failure to properly flush the system per the
instructions below will void the warranty.
