Doas Layout Example / Selecting The Piping Size - LG ARND DCR4 Series Installation Manual

REFRIGERANT PIPING SYSTEM INSTALLATION

DOAS Layout Example / Selecting the Piping Size

erant system rules, review the information in this entire piping section, see the LG Split Compact DOAS Engineering Manual, and follow the LATS
diagram.
Example: Triple-Frame Multi V 5 Heat Recovery System with
Three (3) DOAS Units Connected
A: Main Pipe from Outdoor Unit to First Y-branch.
B / C / D / E: Pipes from First Y-Branch to Second Y-Branches and /
or Y-Branch to DOAS Units.
•
•
Main in a multi-frame system.
• Main heat recovery outdoor unit capacity must be greater than
or equal to the Sub1 heat recovery outdoor unit capacity, and,
where applicable, Sub1 heat recovery outdoor unit capacity must
be greater than or equal to the Sub2 heat recovery outdoor unit
capacity.
• Connection piping from branch to branch cannot exceed the main
• Install the Y-branches or DOAS units so that the pipe distances
between the between the connected DOAS units are minimized.
Large differences in pipe distances can cause DOAS unit perfor-
mances to fluctuate.
• Indoor units cannot be connected in a system with DOAS units.
Table 9: Main Pipe A Outside Diameter (O.D.) Sizes (from Outdoor Unit to DOAS Units).
ODU
Capacity
Liquid Pipe
(ton)
(inches OD)
10 1/2Ø
12 1/2Ø
14 5/8Ø
16-18 5/8Ø
20 5/8Ø
22-28 3/4Ø
30-42 3/4Ø
Table 10: Pipes B / C / D / E Outside Diameters (O.D.) from First Y-Branch to Second Y-Branch and / or Y-Branch to DOAS Unit.
Downstream DOAS Capacity (Btu/h)
22
Standard Pipe Diameter
Low Pressure Vapor High Pressure Vapor
Pipe (inches OD) Pipe (inches OD)
1-1/8Ø
1-1/8Ø
1-1/8Ø
1-1/8Ø
1-3/8Ø
1-3/8Ø
1-5/8Ø
Liquid Pipe O.D.
3/8 in.
1/2 in.
5/8 in.
3/4 in.
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.
Figure 11: DOAS Layout Example / Pipe Sizing.
Liquid Pipe
(inches OD)
3/4Ø 5/8Ø
7/8Ø 5/8Ø
7/8Ø 3/4Ø
1-1/8Ø 3/4Ø
1-1/8Ø 3/4Ø
1-1/8Ø 7/8Ø
1-1/8Ø 7/8Ø
Low Pressure Pipe O.D.
7/8 in.
1-1/8 in.
1-3/8 in.
1-5/8 in.
Pipe Diameter when Pipe Length is
Low Pressure Vapor High Pressure Vapor
Pipe (inches OD)
No Increase
No Increase
No Increase
No Increase
No Increase
No Increase
No Increase
High Pressure Pipe O.D.
-
Pipe (inches OD)
No Increase
No Increase
No Increase
No Increase
No Increase
No Increase
No Increase
3/4 in.
7/8 in.
1-1/8 in.
1-3/8 in.