To Select The Piping Size - Daikin VRV IV+ RXYTQ8U5/U7YF Installation And Operation Manual

Pipe Ø Temper grade of piping material
≤15.9 mm
≥19.1 mm
▪ All piping lengths and distances have been taken into
consideration (see About the piping length in the installer
reference guide).
14.1.2

To select the piping size

Determine the proper size using the following tables and reference
figure (only for indication).
a A x
D
b b
E
1 2 3 4
1,2,3,4 VRV DX indoor unit
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.
Outdoor unit Piping outer diameter size (mm)
capacity type (HP)
Gas pipe
8
10
12~16
18~22
24
26~34
36~48
D: Piping between refrigerant branch kits
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.
Indoor unit capacity Piping outer diameter size (mm)
index
Gas pipe
<150
150≤x<200
200≤x<290
290≤x<420
420≤x<640
640≤x<920
≥920
Example:
▪ Downstream capacity for E=capacity index of unit 1
▪ Downstream capacity for D=capacity index of unit 1+capacity
index of unit 2
RXYTQ
VRV IV+ heat pump for high ambient temperatures
4P546223-1C – 2021.11
O (annealed)
1/2H (half hard)
B B B
C
y
Liquid pipe
19.1 9.5
22.2 9.5
28.6 12.7
28.6 15.9
34.9 15.9
34.9 19.1
41.3 19.1
Liquid pipe
15.9 9.5
19.1
22.2
28.6 12.7
15.9
34.9 19.1
41.3
E: Piping between refrigerant branch kit and
indoor unit
Pipe size for direct connection to indoor unit must be the same as
the connection size of the indoor unit (in case indoor unit is VRV DX
indoor).
Indoor unit capacity Piping outer diameter size (mm)
index
Gas pipe
15~50
63~140
200
250
▪ 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 the size of
the main pipes has to be increased. More specifications can be
found in the technical engineering data book.
a
b
c
a Outdoor unit
b Main pipes (increase if the equivalent piping length is
≥90 m)
c First refrigerant branch kit
d Piping between refrigerant branch kit and indoor unit
e Indoor unit
Size up
HP class Piping outer diameter size (mm)
Gas pipe
8 19.1 → 22.2
10 22.2 → 25.4
(b)
12+14 28.6
16 28.6 → 31.8
18~22
(b)
24 34.9
26~34 34.9 → 38.1
(b)
36~48 41.3
(a)
If the size-up size is NOT available, you must use the standard
size. Sizes bigger than the size-up size are NOT allowed. But
even if you use the standard size, the equivalent piping length is
allowed to be more than 90 m.
(b)
Pipe size-up is NOT allowed.
▪ 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 (mm)
6.4/9.5/12.7
15.9
19.1/22.2
28.6
34.9
41.3
14 Piping installation
Liquid pipe
12.7 6.4
15.9 9.5
19.1
22.2
e
d
Liquid pipe
9.5 → 12.7
(a)
12.7 → 15.9
(a)
15.9 → 19.1
(a)
19.1 → 22.2
Minimal thickness t (mm)
0.80
0.99
0.80
0.99
1.21
1.43
Installation and operation manual
15