Refrigerant Piping Material; To Select The Piping Size; To Select Refrigerant Branch Kits - Daikin VRV IV RKXYQ8T7Y1B Installation And Operation Manual

4 Preparation
▪ Foreign materials inside pipes (including oils for fabrication) must
be ≤30 mg/10 m.
4.2.2

Refrigerant piping material

▪ Piping material: Phosphoric acid deoxidised seamless copper.
▪ Piping temper grade and thickness:
Outer diameter Temper grade
(Ø)
6.4 mm (1/4") Annealed (O)
9.5 mm (3/8")
12.7 mm (1/2")
15.9 mm (5/8") Annealed (O)
19.1 mm (3/4") Half hard (1/2H)
22.2 mm (7/8")
(a) Depending on the applicable legislation and the unit's
maximum working pressure (see "PS High" on the unit
name plate), larger piping thickness might be required.
4.2.3

To select the piping size

Determine the proper size referring to following tables and reference
figure (only for indication).
c
a
EKEXV
A B
b
a Heat exchanger unit
b Compressor unit
c Refrigerant branch kit
VRV DX VRV DX indoor unit
EKEXV Expansion valve kit
AHU Air handling unit
A Piping between heat exchanger unit and compressor unit
B Piping between compressor unit and (first) refrigerant
branch kit (= main pipe)
C Piping between refrigerant branch kits
D 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 "5.6.2 To determine the additional refrigerant
amount" on page 15.
A: Piping between heat exchanger unit and
compressor unit
Use the following diameters:
Compressor unit Piping outer diameter size (mm)
capacity type
Gas pipe
5 HP
8 HP
Installation and operation manual
8
(a)
Thickness (t)
Ø
≥0.80 mm
≥0.99 mm
≥0.80 mm
D
C
c
D
D
VRV DX
D
AHU
VRV DX
Liquid pipe
19.1 12.7
22.2
B: Piping between compressor unit and first
refrigerant branch kit
Use the following diameters:
Compressor unit
capacity type
5 HP
8 HP
t
Standard ↔ Size-up:
If
The equivalent pipe 5 HP It is recommended to increase the
length between the
heat exchanger
unit and the
furthest indoor unit
is 90 m or more
8 HP ▪ You must increase the size (size-up)
C: Piping between refrigerant branch kits
Use the following diameters:
Indoor unit capacity
index
<150
150≤x<200
200≤x<260
D: Piping between refrigerant branch kit and
indoor unit
Use the same diameters as the connections (liquid, gas) on the
indoor units. The diameters of the indoor units are as follows:
Indoor unit capacity
index
15~50
63~140
200
250
4.2.4

To select refrigerant branch kits

For piping example, refer to
page 8.
Refnet joint at first branch (counting from the compressor unit)
When using refnet joints at the first branch counted from the
compressor unit side, choose from the following table in accordance
with the capacity of the compressor unit. Example: Refnet joint c
(B→C/D).
Piping outer diameter size (mm)
Gas pipe Liquid pipe
Standard Size-up Standard
15.9 19.1 9.5
19.1 22.2 9.5
Then
size (size-up) of the main gas pipe
(between compressor unit and first
refrigerant branch kit). If the
recommended gas pipe (size-up) is not
available, you must use the standard
size (which might result in a small
capacity decrease).
of the main liquid pipe (between
compressor unit and first refrigerant
branch kit).
▪ It is recommended to increase the
size (size-up) of the main gas pipe
(between compressor unit and first
refrigerant branch kit).
recommended gas pipe (size-up) is
not available, you must use the
standard size (which might result in a
small capacity decrease).
Piping outer diameter size (mm)
Gas pipe Liquid pipe
15.9
19.1
22.2
Piping outer diameter size (mm)
Gas pipe Liquid pipe
12.7
15.9
19.1
22.2
"4.2.3 To select the piping size" on
RKXYQ5+8T7Y1B
VRV IV compressor unit for indoor installation
4P408443-1B – 2016.04
Size-up
—
12.7
If the
9.5
6.4
9.5