Daikin VRV II Series Design, Installation & Testing Instructions page 118

Appendix
7.3.3 Branch with refnet header
(Connection of 8 indoor units Heat pump system)
Between outdoor
Maximum
and indoor units
allowable
length
• Actual pipe length
Pipe length between outdoor and indoor units ≤ 150m
Example unit 6: a + i ≤ 150m
• Equivalent length
Equivalent pipe length between outdoor and indoor units ≤ 175m
(assume equivalent pipe length of refnet joint to be 0.5m, that of refnet header to be 1m,
calculation purposes)
• Total extension length
Total piping length from outdoor unit* to all indoor units ≤ 300m
Between outdoor branch and indoor unit
(Only for RXYQ18 or more)
• Actual pipe length
Piping length from outdoor branch to outdoor unit ≤ 10m
(Approximately length: max 13m)
Between outdoor and indoor units
Allowable
• Difference in height
height
Difference in height between outdoor and indoor units (H1) ≤ 50m
length
(Max 40m if the outdoor unit is below)
Between indoor and indoor units
• Difference in height
Difference in height between adjacent indoor units (H2) ≤ 15m
Between outdoor and outdoor units
• Difference in height
Difference in height between outdoor unit (main) and outdoor unit (sub) (H3) ≤ 5m
• Actual pipe length
Allowable
Pipe length from first refrigerant branch kit (either refnet joint or refnet header) to indoor unit ≤ 40m
length after
Example unit 8: i ≤ 40m
the branch
112
One outdoor
unit installed
(RXYQ5 ~16)
When multiple
outdoor units
installed
(RXYQ18 ~ )
Branch with refnet header
Outdoor unit
a
b c d e
1 2 3 4
Indoor units (1-8)
Outdoor unit
a
b c d e
1 2 3 4
Indoor units (1-8)
*If the system capacity is RXYQ18 or more, re-read to
the first outdoor branch as seen from the indoor unit.
Refnet header
H1
g
f h
5 6 7
H2
8
Refnet header
H3
H1
g
f
h
5 6 7
H2
8
Outdoor unit
s
r
t
General Information
Si39-303
r ≤ 10m
s ≤ 10m
t ≤ 10m