Daikin VRV II Series Design, Installation & Testing Instructions page 117

Si39-303
7.3.2 Branch with refnet joint and refnet header
(Connection of 8 indoor units Heat pump system)
(RXYQ5 ~16)
When multiple
Between outdoor
Maximum
and indoor units
allowable
length
• Actual pipe length
Pipe length between outdoor and indoor units ≤ 150m
Example unit 6: a + b + h ≤ 150m, unit 8: a + i + k ≤ 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 6: b + h ≤ 40m, unit 8: i + k ≤ 40m
the branch
General Information
Branch with refnet joint and refnet header
One outdoor
unit installed
outdoor units
installed
(RXYQ18 ~ )
Outdoor unit
a
H1
b
Refnet header
c d e
1 2 3
Indoor units (1-8)
Outdoor unit
a
A
H1 b
Refnet header
c d e
1 2 3
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 joint (B)
i
A
B
k
j
7 8
H2
g
f h
4 5 6
REFNET joint (A • B)
H3
i
B
k
j
7 8
H2
g
f h
4 5 6
Outdoor unit
s
r
t
Appendix
r ≤ 10m
s ≤ 10m
t ≤ 10m
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