Refrigerant Piping - Lennox 14HPX?018 Installation Instructions Manual

Refrigerant Piping

If the 14HPX unit is being installed with a new indoor coil
and line set, plumbing connections should be made as out-
lined in this section. If an existing line set and/or indoor coil
is going to be used to complete the 14HPX system, refer to
the following section that includes flushing procedures.
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-fabricated refrigerant lines.
Refer to Refrigerant Piping Guide (Corp. 9351−L9) for
proper size, type, and application of field−fabricated lines.
Valve sizes are also listed in table 2.
PLUMBING CONNECTIONS 14HPX MATCHED
WITH NEW INDOOR COIL AND LINE SET
If replacing an existing coil that is equipped with a liquid line
functioning as a metering orifice, replace the liquid line
prior to installing the 14HPX unit. See table 2.
Figure 6. Typical Field Wiring Diagram
Page 5
Table 2. Refrigerant Line Sets
Field
Connections
Mod-
el
Liquid Vapor
Line Line
−018 3/8 in. 3/4 in
(10 mm) (19 mm)
−024
−030
−036 3/8 in. 7/8 in
(10 mm) (22 mm)
−042
−048
−060 3/8 in. 1−1/8 in.
(10 mm) (29 mm)
NOTE − Units are designed for line sets of up to fifty feet (15
m); for longer lengths, consult the Lennox Refrigerant Pip-
ing Guide (Corp. 9351−L9). Select line set diameters from
table 2 to ensure that oil returns to the compressor.
Recommended Line Set
Liquid Vapor L15
Line Line Line Sets
3/8 in. 3/4 in L15−41
(10 mm) (19 mm) 15 ft. − 50 ft.
(4.6 m − 15 m)
3/8 in. 7/8 in L15−65
(10 mm) (22 mm) 15 ft. − 50 ft.
(4.6 m − 15 m)
3/8 in. 1−1/8 in. Field
(10 mm) (29 mm) Fabricated
14HPX SERIES