Daikin VRV IV+ Series Installation And Operation Manual page 16

14 Piping installation
Outdoor unit Piping outer diameter size (mm)
capacity type (HP)
Gas pipe
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
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
d
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
Installation and operation manual
16
Liquid pipe
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
Liquid pipe
12.7 6.4
15.9 9.5
19.1
22.2
e
Liquid pipe
9.5 → 12.7
(a)
Size up
HP class Piping outer diameter size (mm)
Gas pipe
(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
▪ 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 22].
14.1.3 To select refrigerant branch kits
Refrigerant refnets
For piping example, refer to "To select the piping
▪ When using refnet joints at the first branch counted from the
outdoor unit side, choose from the following table in accordance
with the capacity of the outdoor unit (example: refnet joint a).
Outdoor unit capacity type
(HP)
8+10
12~22
24~48
▪ For refnet joints other than the first branch (example refnet joint b),
select the proper branch kit model based on the total capacity
index of all indoor units connected after the refrigerant branch.
Indoor unit capacity index
<200
200≤x<290
290≤x<640
≥640
▪ Concerning refnet headers, choose from the following table in
accordance with the total capacity of all the indoor units connected
below the refnet header.
VRV IV+ heat pump for high ambient temperatures
Liquid pipe
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
the additional refrigerant
size" [ 4 15].
2 pipes
KHRQ22M29T9
KHRQ22M64T
KHRQ22M75T
2 pipes
KHRQ22M20T
KHRQ22M29T9
KHRQ22M64T
KHRQ22M75T
RXYTQ8~16U7YF
4P546223-1B – 2020.10