64 | LIMITS / PLACEMENT
LIMITS / PLACEMENT | 65
Piping Limitations and Placement Considerations
MUL
TI V W
ater IV Source Unit Engineering Manual
© LG Electronics Canada, Inc., North York, ON Canada. All rights reserved. “LG” is a registered trademark of LG Corp.
.
© LG Electronics Canada, Inc., North York, ON Canada. All rights reserved. “LG” is a registered trademark of LG Corp.
Table 35: Piping Limitations for Heat Recovery Operation.
Length
Total pipe length
Longest actual pipe length
Equivalent pipe length
1
A + ΣB + ΣC ≤ 1,640 feet
≤656 feet
≤738 feet
ℓ
Longest pipe length after first branch
≤131 feet (295 feet conditional application)
Elevation 1
Elevation differential (Water Source Unit ↔ Indoor Unit)
Height ≤164 feet
Elevation 2
Elevation differential (Indoor Unit ↔ Indoor Unit) [IDUs connected to separate HRUs which are parallel (Y-branch) connected.]
Height ≤131 feet
Elevation 3
Elevation differential (Indoor Unit ↔ Connected HRU or Series Connected HRU]
Height ≤49 feet
Elevation 4
Elevation differential (Indoor Unit ↔ Indoor Unit [connected to same Heat Recovery Unit])
Height ≤49 feet
Elevation 5
Elevation differential (Highest WSU ↔ Lowest WSU unit)
Height ≤16 feet
Distance between WSU to WSU
≤33 feet
Distance between fittings and Indoor Unit
≥20 inches
Distance between fittings and Y-branches / Headers
≥20 inches
Distance between two Y-branches / Headers
≥20 inches
Height differential between two Heat Recovery Units if installed with a Y-branch
≤98 feet
Height differential between two series-piped Heat Recovery Units
≤16 feet
Maximum number of Heat Recovery Units per system
16
1
Assume equivalent pipe length of Y-branch is 1.6 feet, and equivalent pipe length of header is 3.3 feet.
PIPING LIMITATIONS
For Systems Designed for Heat Recovery Configuration
Following pages present Multi V Water V piping limitations and are for illustrative purposes only. Designers MUST use LATS when designing LG VRF
systems.
For Heat Recovery Unit information, refer to the applicable Engineering Manual on
www.lghvac.com
.
WSU: Water Source Unit
HRU: Heat Recovery Unit
IDU: Indoor Unit
A: Main Pipe from Water Source Unit
to First Y-branch.
B: HRU to HRU, Y-branch to HRU, HRU
to Header, or Y-branch to Y-branch.
C: Heat Recovery Unit / Header to
Indoor Unit.
Example of Pipe Sizing When Installing a Heat Recovery System
Example: Triple-frame system,
four (4) heat recovery units, one
(1) header, and twelve (12) indoor
units connected
• Always reference the LATS Multi V
software report.
• Largest capacity WSU must be the
master in a multi-frame system.
• Master WSU capacity must be greater
than or equal to the slave1 WSU
capacity, and, where applicable, slave1
WSU capacity must be greater than or
equal to the slave2 WSU capacity.
• Connection piping from branch to branch cannot exceed the main pipe diameter (A) used by the water source unit.
• Install the header branches or heat recovery units so that the pipe distances between the between the connected indoor units are mini-
mized. 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.
• Total capacity of indoor units in series connection of heat recovery units ≤192,400 Btu/h.
• If large capacity indoor units (>12,000 Btu/h with piping sizes >5/8Ø / 3/8Ø) are installed, the valve group setting must be used. (Refer to
the PCB of the heat recovery unit for the valve group control setting.)
PIPING LIMITATIONS
For Systems Designed for Heat Recovery Configuration
Following pages present Multi V Water V piping limitations and are for illustrative purposes only. Designers MUST use LATS when designing LG VRF
systems.
Figure 28: Heat Recovery Triple-Frame Connections.
Elev
ation 1
≤164 ft.
Elev
ation 2
≤131 ft.
S lav e 1 WS U
S lav e 2 WS U
A
Y -branch ( first)
B
C
Closest
IDU
C
H RU
C
C
B
B
C
C
C
C
B
B
C
C
x
H eader
C
C
E lev ation 5
≤16 ft
B
Y -branch ( second)
H RU
H RU
H RU
IDU
IDU
IDU
IDU
IDU
IDU
IDU
IDU
IDU
IDU
Farthest
IDU
Brazed
cap
98 ft.
16 feet
M aster WS U
Elev
ation 3
≤49 ft.
M ulti-Frame
Connector
To indoor units
To WS U
Y -branch
E
lev
ation 4 49 ft.