LG Multi V water mini Series Installation Operation & Maintenance page 33

The following is an example of manual pipe size calculations. Designers are highly encouraged to use LATS instead of manual calculations.
Selecting the Refrigerant Piping
Example: Five (5) indoor units connected
Water-Source Units (WSU).
IDU: Indoor Units.
A: Main Pipe from Water-Source Unit to Y-branches.
B: Branch Piping.
C: Branch Piping to Indoor Unit (IDU).
Table 17: Size of Main Pipe (A) (From Water-Source Unit to Y-branches).
Water-Source Unit Capacity (Btu/h)
37,500
49,500
54,600
Table 18: Size of Branch Piping (B) to Branch Piping (B).
Indoor Unit Capacity (Btu/h)
19,100
54,600
76,400
Table 19: Size of Branch Piping to Indoor Unit (C).
Indoor Unit Capacity (Btu/h)
19,100
54,600
REFRIGERANT PIPING DESIGN
Figure 28: Selecting Refrigerant Piping.
Gas Pipe
Main Pipe
A
Liquid Pipe (Inches O.D.)
Liquid Pipe (Inches O.D.)
Liquid Pipe (Inches O.D.)
Due to our policy of continuous product innovation, some specifications may change without notification.
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Water Source Unit
Liquid Pipe
Branch Piping
B
Header
C
Branch Piping
B
C
Ø3/8
Ø3/8
Ø3/8
Ø1/4
Ø3/8
Ø3/8
Ø1/4
Ø3/8
Pipe Sizing
Header
C C C
IDU IDU IDU
Branch Piping
B
C C
IDU
IDU
Gas Pipe (Inches O.D.)
Ø5/8
Ø5/8
Ø3/4
Gas Pipe (Inches O.D.)
Ø1/2
Ø5/8
Ø3/4
Gas Pipe (Inches O.D.)
Ø1/2
Ø5/8
IDU
IDU
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