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24
Piping Handling
Pipes used for the refrigerant piping system must
include the specified thickness, and the interior must be
clean. While handling and storing, do not bend or
damage the pipes, and take care not to contaminate the
interior with dust, moisture, etc.
Refrigerant System Engineering
Proper system operation depends on the installer using
utmost care while assembling the piping system.
WARNING
LG Electronics U.S.A.,Inc., is not responsible for any piping
calculations, refrigerant leaks, degradation of performance,
any other potential problems or damages caused by the
interconnecting piping, their joint connections, isolation valves,
or introduced debris inside the piping system.
Selection of Piping Size
WARNING
For piping work, follow the maximum tolerated length,
difference in height, and length after a branch
•
Use only the pipe size selected by the LATS HVAC pipe
system design software. Using a different size is prohibited
and will result in a system malfunction or failure to work at
all.
•
Larger-capacity outdoor units must be the master in a multi-
frame system
•
Master outdoor unit capacity must be greater than or equal
to the slave1 outdoor unit capacity, and, where applicable,
slave1 outdoor unit capacity must be greater than or equal
to the slave2 outdoor unit capacity.
•
Connection piping from branch to branch cannot exceed
the main pipe diameter (A) used by the outdoor unit.
•
Install the header branches or heat recovery units so that
the pipe distances between the between the connected
indoor units are minimized. Large differences in pipe
distances can cause indoor unit performances to fluctuate.
•
Y-branches and other header branches cannot be installed
downstream of the initial header branch
Determine the proper size referring to following tables
and reference figure (only for indication)
Table 3: Piping Outer Diameter size
Outdoor unit
Capacity Ton
(kBtu/h)
Liquid pipe
OD
Low Pressure
Pipe OD
High Pressure
Pipe OD
10 (119.7)
1/2 in
(12.7mm)
1-1/8 in
(28.58 mm)
3/4 in
(19.05 mm)
12 (144)
7/8 in
(22.22 mm)
14 (168)
5/8 in
(15.88 mm)
16-18
(192-206))
1-1/8 in
(28.58 mm)
20 (233.1)
1-3/8 in
(34.9 mm)
22-28
(264-336)
3/8 in
(9.52 mm)
30-42
(360-504)
1-5/8 in
(41.3mm)
Table 4: Main Pipe (A)
Pipe Diameter when pipe length is ≥ 295feet (90m)
Outdoor unit
Capacity Ton
(kBtu/h)
Liquid pipe
OD
Low Pressure
Pipe OD
High Pressure
Pipe OD
10 (119.7)
1/2 in.
(12.7 mm)
No Increase
No Increase
12 (144)
14 (168)
5/8 in
(15.88 mm)
16-18
(192-206))
20 (233.1)
22-28
(264-336)
7/8 in
(22.22 mm)
30-42
(360-504)
Table 5: Pipe B/C/D/E between Y-branch and Y-branch /
DOAS
Downstream
DOAS
Capacity(kBtu/h)
Liquid pipe
OD
Low
Pressure
Pipe OD
High
Pressure
Pipe OD
＜
114,700
3/8 in
(9.52 mm)
7/8 in
(22.22 mm)
3/4 in
(19.05 mm)
＜
172,000
1/2 in.
(12.7 mm)
1-1/8 in
(28.58 mm)
7/8 in
(22.22 mm)
＜
229,400
5/8 in
(15.88 mm)
＜
248,500
1-3/8 in
(34.9 mm)
1-1/8 in
(28.58 mm)
＜
344,000
3/4 in
(19.05 mm)
＜
592,000
1-5/8 in
(41.3mm)
1-3/8 in
(34.9 mm)
Figure 9: Piping Sizing
