Daikin VRV IV+ Installer And User Reference Manual page 32

5 | Preparation
E: Piping between refrigerant branch kit and indoor unit
Installer and user reference guide
32
Example:
▪ Downstream capacity for E=capacity index of unit 1
▪ Downstream capacity for D=capacity index of unit 1+capacity index of unit 2
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 or Hydrobox).
Indoor unit capacity index
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
a Outdoor unit
b Main pipes
c Increase if the equivalent piping length is ≥90 m
d First refrigerant branch kit
e Indoor unit
HP class
8
10
12+14
16
18~22
24
26~34
36~54
(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.
Piping outer diameter size (mm)
Gas pipe
12.7
15.9
19.1
22.2
d
c
Size up
Piping outer diameter size (mm)
Gas pipe
19.1 → 22.2
(a)
22.2 → 25.4
(b)
28.6
(a)
28.6 → 31.8
(b)
34.9
(a)
34.9 → 38.1
(b)
41.3
Liquid pipe
6.4
9.5
Liquid pipe
9.5 → 12.7
12.7 → 15.9
15.9 → 19.1
19.1 → 22.2
RYYQ+RYMQ+RXYQ8~20U7Y1B
VRV IV+ heat pump
4P546228-1A – 2019.10