14 Piping Installation; Preparing Refrigerant Piping; Refrigerant Piping Requirements; Refrigerant Piping Material - Daikin VRV IV-S RXYSQ4T8VB Series Installation And Operation Manual

14 Piping installation

14 Piping installation
14.1

Preparing refrigerant piping

14.1.1

Refrigerant piping requirements

NOTICE
Refrigerant R410A requires strict cautions for keeping the
system clean and dry. Foreign materials (including mineral
oils or moisture) should be prevented from getting mixed
into the system.
NOTICE
The piping and other pressure-containing parts shall be
suitable for refrigerant. Use phosphoric acid deoxidised
seamless copper for refrigerant.
▪ Foreign materials inside pipes (including oils for fabrication) must
be ≤30 mg/10 m.
14.1.2

Refrigerant piping material

▪ Piping material: Phosphoric acid deoxidised seamless copper.
▪ Flare connections: Only use annealed material.
▪ 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)
(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.
14.1.3

To select the piping size

Determine the proper size using the following tables and reference
figure (only for indication).
INFORMATION
▪ Combination of VRV DX and RA DX indoor units is not
allowed.
▪ Combination of RA DX and AHU indoor units is not
allowed.
▪ Combination of RA DX and aircurtain indoor units is not
allowed.
Installation and operation manual
18
(a)
Thickness (t)
Ø
≥0.80 mm
t
≥0.99 mm
≥0.80 mm
INFORMATION
If you install RA DX indoor units, you have to configure
field setting [2‑38] (= type of installed indoor units). See
settings" [ 4 30].
"Mode 2: Field
VRV DX
1
A
2
B-1 B-2
2 2
C-1 C-2 C-3 C-4
3-1 3-2 3-3 3-4
1 Outdoor unit
2 Refrigerant branch kits
3-1~3-4 VRV DX indoor units
4 BP units
5 RA 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
D Piping between refrigerant branch kit and BP unit
E Piping between BP unit and RA DX 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 "To determine
amount" [ 4 24].
A: Piping between outdoor unit and (first)
refrigerant branch kit
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
d
b
c
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 Piping outer diameter size (mm)
capacity type (HP)
Gas pipe
Standard
4+5 15.9
6 19.1
RA DX
1
A
2
D D
4 4
E E E E
5 5 5 5
the additional refrigerant
e
Liquid pipe
Size-up
19.1 9.5
22.2
RXYSQ4~6T8V/YB(*)
VRV IV-S system air conditioner
4P482275-1B – 2020.10