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14 Piping installation
Installation and operation manual
18
RWEYQ8~14T9Y1B
VRV IV water-cooled system air conditioner
4P452190-1D – 2020.10
In case of heat pump system
Indoor unit capacity
index
Piping outer diameter size (mm)
Gas pipe
Liquid pipe
<150
15.9
9.5
150≤x<200
19.1
200≤x<290
22.2
290≤x<420
28.6
12.7
420≤x<640
15.9
640≤x<920
34.9
19.1
≥920
41.3
In case of heat recovery system
Indoor unit capacity
index
Piping outer diameter size (mm)
Liquid pipe
Suction gas
pipe
High
pressure/low
pressure gas
pipe
<150
9.5
15.9
12.7
150≤x<200
19.1
15.9
200≤x<290
22.2
19.1
290≤x<420
12.7
28.6
420≤x<640
15.9
28.6
640≤x<920
19.1
34.9
≥920
41.3
Example:
▪ Downstream capacity for E=[capacity index of unit 1]
▪ Downstream capacity for D=[capacity index of unit 1]+[capacity
index of unit 2]
E: Piping between refrigerant branch kit or BS unit
and indoor unit
For heat pump and heat recovery system
Pipe size for direct connection to indoor unit must be the same as
the connection size of the indoor unit.
15~50
12.7
6.4
63~140
15.9
9.5
200
19.1
250
22.2
▪ If a size-up of the piping is required, refer to the table below.
e
d
b
c
a
a
Outdoor unit
b
Main pipes
c
Increase
d
First refrigerant branch kit
e
Indoor unit
Size up
HP class
Liquid piping outer diameter size (mm)
8
9.5 → 12.7
10
12+14
12.7 → 15.9
16
18~22
15.9 → 19.1
24
26~34
19.1 → 22.2
36~42
F: Piping between refrigerant branch kit and
branch selector box (BP box)
Heat pump system in case of single outdoor unit
Pipe size for direct connection on branch selector box (BP*) must be
based on the total capacity of the connected indoor units (only in
case RA DX indoor units are connected).
Total capacity index
of connected indoor
units
Piping outer diameter size (mm)
Gas pipe
Liquid pipe
20~62
12.7
6.4
63~149
15.9
9.5
150~208
19.1
Example:
Downstream capacity for F=[capacity index of unit 4]+[capacity index
of unit 5]
G: Piping between branch selector box (BP box)
and RA DX indoor unit
Heat pump system in case of single outdoor unit
Only in case RA DX indoor units are connected.
Indoor unit capacity
index
Piping outer diameter size (mm)
Gas pipe
Liquid pipe
20, 25, 30
9.5
6.4
50
12.7
60
9.5
71
15.9
14.1.3
To select refrigerant branch kits
Refrigerant refnets
For piping example, refer to
"14.1.2 To select the piping size"
▪ When using refnet joints at the first branch counted from the
outdoor unit side, choose from the following table in accordance
with the capacity of the outdoor unit (example: refnet joint a).
Outdoor unit
capacity type (HP)
2 pipes
3 pipes
8+10
KHRQ22M29T9
KHRQ23M29T9
12~22
KHRQ22M64T
KHRQ23M64T
24~42
KHRQ22M75T
KHRQ23M75T
▪ For refnet joints other than the first branch (example refnet joint b),
select the proper branch kit model based on the total capacity
index of all indoor units connected after the refrigerant branch.
Indoor unit capacity
index
2 pipes
3 pipes
<200
KHRQ22M20T
KHRQ23M20T
200≤x<290
KHRQ22M29T9
KHRQ23M29T9
290≤x<640
KHRQ22M64T
KHRQ23M64T
≥640
KHRQ22M75T
KHRQ23M75T
▪ Concerning refnet headers, choose from the following table in
accordance with the total capacity of all the indoor units connected
below the refnet header.
Indoor unit capacity
index
2 pipes
3 pipes
<200
KHRQ22M29H
KHRQ23M29H
200≤x<290
290≤x<640
KHRQ22M64H
(a)
KHRQ23M64H
(a)
≥640
KHRQ22M75H
KHRQ23M75H