14 Piping installation
Installation and operation manual
17
RWEYQ8~14T9Y1B
VRV IV water-cooled system air conditioner
4P452190-1D – 2020.10
Pipe Ø
Temper grade of piping material
≥19.1 mm
1/2H (half hard)
▪ All piping lengths and distances have been taken into
consideration (see About the piping length in the installer
reference guide).
▪ The pipe thickness of the refrigerant piping shall comply with the
applicable legislation. The minimal pipe thickness for R410A
piping must be in accordance with the table below.
Pipe Ø
Minimal thickness t
6.4 mm/9.5 mm/12.7 mm
0.80 mm
15.9 mm
0.99 mm
19.1 mm/22.2 mm
0.80 mm
28.6 mm
0.99 mm
34.9 mm
1.21 mm
41.3 mm
1.43 mm
▪ In case the required pipe sizes (inch sizes) are not available, it is
also allowed to use other diameters (mm sizes), taken the
following into account:
▪ Select the pipe size nearest to the required size.
▪ Use the suitable adapters for the change-over from inch to mm
pipes (field supply).
▪ The additional refrigerant calculation has to be adjusted as
mentioned in
"14.5.3 To determine the additional refrigerant
14.1.2
To select the piping size
INFORMATION
Please select the proper pipe sizes depending on the
mode of your system. There are 2 possible modes:
▪ heat pump,
▪ heat recovery.
Determine the proper size using the following tables and reference
figure (only for indication).
In case of heat pump system
A
B
B
B
C
D
F
G
E
x
y
b
a
3
1
2
4
5
1,2
VRV DX indoor unit
3
Branch selector box (BP*)
4,5
RA DX indoor unit
a,b
Indoor branch kit
x,y
Outdoor multi connection kit
In case of heat recovery system
A
B
B
B
C
D
E
E
x
y
b
a
4
3
1
2
1,2
VRV DX indoor unit
3
Branch selector unit (BS*)
4
Cooling only VRV indoor unit
A~E
Piping
a,b
Indoor branch kit
x,y
Outdoor multi connection kit
A, B, C: Piping between outdoor unit and (first)
refrigerant branch kit
Choose from the following table in accordance with the outdoor unit
total capacity type, connected downstream.
In case of heat pump system
Outdoor unit
capacity type (HP)
Piping outer diameter size (mm)
Gas pipe
Liquid pipe
8
19.1
9.5
10
22.2
12~16
28.6
12.7
18~22
15.9
24
34.9
26~34
19.1
36~42
41.3
In case of heat recovery system
Outdoor unit
capacity type (HP)
Piping outer diameter size (mm)
Liquid pipe
Suction gas
pipe
High
pressure/low
pressure gas
pipe
8
9.5
19.1
15.9
10
22.2
19.1
12
12.7
28.6
14~16
22.2
18
15.9
20~22
28.6
24
34.9
26~34
19.1
36
41.3
38~42
34.9
D: Piping between refrigerant branch kits or
refrigerant branch kit and BS unit
Choose from the following table in accordance with the indoor unit
total capacity type, connected downstream. Do not let the
connection piping exceed the refrigerant piping size chosen by the
general system model name.
