Specifications
Installation and operation manual
12
RXYQQ8~20T7Y1B
VRV IV System Air Conditioner
4P345099-1 – 2013.04
9.3. Selection of piping size
Determine the proper size referring to following tables and reference
figure (only for indication).
1~4
VRV DX indoor unit
a,b,c Indoor branch kit
x,y Outdoor multi connection kit
9.3.1. Piping between outdoor unit and (first) refrigerant
branch kit: A, B, C
Choose from the following table in accordance with the outdoor unit
total capacity type, connected downstream.
9.3.2. Piping between refrigerant branch kits: D
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.
Example:
Downstream capacity for E=capacity index of unit 1
Downstream capacity for D=capacity index of unit 1+capacity index
of unit 2
9.3.3. Piping between refrigerant branch kit and indoor unit: E
Pipe size for direct connection to indoor unit must be the same as the
connection size of the indoor unit.
When the equivalent pipe length between outdoor and indoor
units is 90 m or more, the size of the main pipes (both gas side
and liquid side) must be increased. Depending on the length of
the piping, the capacity may drop, but even in such a case it is
possible to increase the size of the main pipes.
1 Outdoor unit
2 Main pipes
3 Increase
4 First refrigerant branch kit
5 Indoor unit
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.
The refrigerant pipes and branches must meet the condition of
design pressure 33 bar (3.3 MPa). If it is NOT possible to
confirm this, use the refrigerant branch as mentioned in this
chapter.
Confirm that the (pipe) thickness may NOT be less than the
required minimum thickness.
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
Indoor unit capacity
index
Piping outer diameter size (mm)
Gas pipe Liquid pipe
<150 15.9
9.5150≤
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 19.1
A
BBB
C
D
E
x
y
b
a
12 34
c
Indoor unit capacity index
Piping outer diameter size
(mm)
Gas pipe Liquid pipe
15, 20, 25, 32, 40, 50 12.7 6.4
63, 80, 100, 125 15.9
9.5200 19.1
250 22.2
Size up
HP Class Gas side (mm) Liquid size (mm)
8 19.1
→ 22.2
9.5
→ 12.7
10 22.2
→ 25.4
(a)
(a) If size is NOT available, increase is NOT allowed.
12+14 28.6
(b)
(b) Increase is NOT allowed.
12.7 → 15.9
16 28.6
→ 31.8
(a)
18~22 28.6 → 31.8
(a)
15.9 → 19.1
24 34.9
(b)
15.9 → 19.1
26~34 34.9
→ 38.1
(a)
19.1 → 22.2
36~42 41.3
(b)
Pipe Ø (mm) Minimal thickness t (mm)
6.4 0.4
9.5 0.5
12.7 0.7
15.9 0.9
19.1 0.6
(a)
(a) If annealed temper grade is 1.
22.2 0.6
28.6 0.8
31.8 0.9
34.9 1.0
38.1
1.1
41.3
1
5
2 3
4