To Select The Piping Size - Daikin VRV 5 S Series Installer And User Manual

18 | Piping installation

18.1.3 To select the piping size

A: Piping between outdoor unit and (first) refrigerant branch kit
Installer and user reference guide
82
(a)
Depending on the applicable legislation and the maximum working pressure of the unit
(see "PS High" on the unit name plate), larger piping thickness might be required.
Determine the proper size using the following tables and reference figure (only for
indication).
VRV DX
2
B-1 B-2
2 2
C-1 C-2 C-3
3-1 3-2 3-3
1 Outdoor unit
2 Refrigerant branch kits
3-1~3-4 VRV DX indoor units
A Piping between outdoor unit and (first) refrigerant branch kit
B-1 B-2 Piping between refrigerant branch kits
C-1~C-4 Piping between refrigerant branch kit and indoor unit
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
"19.4 To determine the additional refrigerant
When the equivalent pipe length between outdoor unit and the furthest indoor
unit is 90 m or more (b+d), the size of the main gas pipe (b) must be increased
(size-up). If the recommended gas pipe (size-up) is not available, you must use the
standard size (which might result in a small capacity decrease).
a
b
a Outdoor unit
b Main gas pipe (increase piping size if length b+d ≥ 90 m)
c First refrigerant branch kit
d Piping between indoor unit and first refrigerant branch kit
e Furthest indoor unit
Outdoor unit
capacity type (HP)
4+5+6
1
A
C-4
3-4
e
d
c
Piping outer diameter size (mm)
Gas pipe
Standard Size-up (only 'b')
15.9
4
amount" [ 99].
Liquid pipe
19.1
VRV 5-S system air conditioner
4P600330-1D – 2023.02
9.5
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