LG MULTI V IV ARUN072BTE4 - Page 117

119
Installation
Due to our policy of continuous product innovation, some specications may change without notication.
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Heat Recovery Units
REFRIGERANT PIPING DESIGN
1. Series connection of heat recovery units: Total
capacity of indoor units ≤192,000 Btu/h.
2. Refer to the heat recovery unit PCB for valve
group control setting.
3. Maximum capacity of each port is 54,000 Btu/h
and eight (8) indoor units.
4. Do not skip ports when connecting indoor units.
Start at port 1, then 2, then 3, then 4
Pipe Sizing for Heat Recovery Systems
Note:
Heat Recovery Unit PRHR021A (Two Ports) PRHR031A (Three Ports) PRHR041A (Four Ports)
Low-pressure vapor pipe (inches) 7/8Ø 1-1/8Ø 1-1/8Ø
High-pressure vapor pipe (inches) 3/4Ø 7/8Ø 7/8Ø
Liquid pipe (inches) 3/8Ø 1/2Ø 1/2Ø
Combining Heat Recovery Ports for Large Indoor Units (currently includes High Static Ducted models ARNU76GB8-,
ARNU96GB8-)
It is necessary to combine two ports on a heat recovery unit when installing a single indoor unit with a capacity exceeding 54,000 Btu/h. Two
neighboring heat recovery ports are combined using a reverse Y-branch that is then connected to the one large indoor unit.
Vapor pipe Ø5/8, Liquid pipe Ø3/8
Brazed connections
1
2
3
4
Remove caps before
brazing
Liquid pipe
Low-pressure vapor pipe
High-pressure vapor pipe
Figure 28: Close Up of the Heat Recovery Unit Connections.
Table 44: Heat Recovery Unit Piping Connection Sizes.
First Heat Recovery Unit Second Heat Recovery Unit
1 2 3 4
96
Mbh
1 2 3 4
28
Mbh
28
Mbh
Top Top
21
Mbh
18
Mbh
15
Mbh
7
Mbh
Figure 29: Heat Recovery Unit Ports Connections for Large Indoor Units.
If large capacity indoor units (larger than 54,000 Btu/h) are installed, the Y-branch pipe shown in the table below should be used to twin
the ports.
Models Vapor pipe Liquid pipe
Unit: Inch
ARBLN03321
16-1/4
15-3/8
I.D. 3/4
I.D. 3/4
I.D. 3/4
I.D. 1/2
I.D. 1/2
2-3/4
I.D. 5/8
I.D. 5/8
I.D. 1
I.D. 1
O.D. 1
3-3/16
4-3/8
3-5/16
2
3
3
O.D. 3/4
O.D. 3/4
12
I.D. 7/8
I.D. 7/8
I.D. 7/8
I.D. 1-1/8
1
I.D. 1/2
I.D. 1/2
I.D. 1/2
13-1/16
12-5/8
I.D. 1/4
I.D. 1/4
I.D. 3/8
I.D. 3/8
I.D. 3/8
2-15/16
Note: