17 | Piping installation
Installer and user reference guide
65
RXYTQ
VRV IV+ heat pump for high ambient temperatures
4P561157-1B – 2021.11
Definitions
Term Definition
Actual piping length Pipe length between outdoor
(a)
and indoor units.
Equivalent piping length
(b)
Pipe length between outdoor
(a)
and indoor units.
Total piping length Total piping length from the outdoor
(a)
to all indoor
units.
H1 Difference in height between outdoor and indoor
units.
H2 Difference in height between indoor and indoor
units.
H3 Difference in height between outdoor and outdoor
units.
(a)
If the system capacity is >16HP, re-read "the first outdoor branch as seen from the indoor
unit".
(b)
Assume equivalent piping length of refnet joint=0.5m and refnet header=1m (for
calculation purposes of equivalent piping length, not for refrigerant charge calculations).
17.1.6 Piping length: VRV DX only
For system only containing VRVDX indoor units:
System setup
Example Description
Example 1.1
a
A
h i j k l m n
B C D E F G
pb c d e f
1 2 3 4 5 6 7
8
g
H1
H2
Single outdoor
Branch with refnet joint
Example 1.2
a
b
c d e f
i
k
j
g h
A B
1 2 3 4 5 6
7 8
H1
H2
Single outdoor
Branch with refnet joint
and refnet header
Example 1.3
a
c
b d e f
i
g h
1 2 3 4 5 6 7
8
H1
H2
Single outdoor
Branch with refnet header