Due to our policy of continuous product innovation, some specifications may change without notification.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
Sample Layouts
Note:
Images are for illustrative purposes only and are not accurate
representations. For specific detail on piping limitations and
other refrigerant system rules, review the information in this
entire piping section, see the Multi V 5 LGRED Engineering
Manual, and follow the LATS diagram
Example: Triple-frame system, three (3) Compact
DOAS units connected
ODU: Outdoor Units.
DOAS: DOAS Units
A: Main Pipe from Outdoor Unit to First Y-Branch
B: Y-Branch to DOAS Units or Y-branch to Y-branch.
Table : DOAS unit connecting pipe from Y-Branch
Model(ton)
Liquid pipe
OD
Low
Pressure
Pipe OD
High
Pressure
Pipe OD
ARND203DCR4
1/2
1-1/8
7/8
ARND153DCR4
1/2
1-1/8
3/4
Figure 13: Piping Sizing
Table : Main Pipe (A) Diameters from Outdoor Unit to First Y-Branch
ODU
Capacity
(ton)
Standard Pipe Diameter
Pipe diameter when pipe length is 296feet or when height
differential
Liquid Pipe
(inches OD)
Low Pressure Vapor
Pipe (inches OD)
High Pressure Vapor
Pipe (inches OD)
Liquid Pipe
(inches OD)
Low Pressure Vapor
Pipe (inches OD)
High Pressure Vapor
Pipe (inches OD)
10
1/2 Ø
1-1/8 Ø
3/4 Ø
5/8 Ø
No Increase
No Increase
12
1/2 Ø
1-1/8 Ø
7/8 Ø
5/8 Ø
No Increase
No Increase
14
5/8 Ø
1-1/8 Ø
7/8 Ø
3/4 Ø
No Increase
No Increase
16-18
5/8 Ø
1-1/8 Ø
1-1/8 Ø
3/4 Ø
No Increase
No Increase
20
5/8 Ø
1-3/8 Ø
1-1/8 Ø
3/4 Ø
No Increase
No Increase
22-28
3/4 Ø
1-3/8 Ø
1-1/8 Ø
7/8 Ø
No Increase
No Increase
30-42
3/4 Ø
1-5/8 Ø
1-1/8 Ø
7/8 Ø
No Increase
No Increase
Table 4: Refrigerant Pipe (B) Diameters between Y-branches and Y-branches / DOAS unit
Downstream DOAS Capacity(Btu/h)
Liquid Pipe
(inches OD)
Low Pressure Vapor Pipe
(inches OD)
High Pressure Vapor Pipe
(inches OD)
< 172,000
1/2 Ø
1-1/8 Ø
7/8 Ø
< 229,400
5/8 Ø
1-1/8 Ø
7/8 Ø
< 248,500
5/8 Ø
1-3/8 Ø
1-1/8 Ø
< 344,000
3/4 Ø
1-3/8 Ø
1-1/8 Ø
< 592,000
3/4 Ø
1-5/8 Ø
1-3/8 Ø
Conditional Applications
Conditional applications are computed in LATS. See below for an explanation of when pipes are upsized.
If the equivalent length between the first Y-branch to the farthest DOAS
unit is >131 feet (maximum 295 feet):
•
Pipe segment diameters between the first branch and the last branch must be sized up by one. This applies to both
liquid and low / high vapor pipes. If the next size up is not available, or if the pipe segment diameters are the same
as main pipe (A) diameters, sizing up is not possible.
•
While calculating total refrigerant piping length, pipe (B) segment lengths between the first Y-branch and second Y-
branch, and between the second Y-branch and the DOAS unit must be calculated by two.
•
[Length of pipe from outdoor unit to farthest DOAS unit (A+B)]
– [Length of pipe from outdoor unit to closest DOAS
unit (A+B)] ≤ 131 feet
27
