SiEN34-705 Appendix
General Information 135
7.3.3 Branch with Refnet Header
Heat Pump 50Hz/60Hz, Cooling Only 50Hz (RX(Y)Q5~54P, 50PH)
(Connection of 8 indoor units Heat pump system)
Single outdoor
system
(RX(Y)Q5 ~ 18P)
Example refrigerant branch using REFNET header
Multi outdoor
system
RX(Y)Q20P ~
RX(Y)Q16PH ~
a
H1
H2
cde
f
g
hi
b
123 456 7
8
Outdoor unit
Indoor units (1 - 8)
REFNET header
(
)
H2
8
H1
H3
a
cde
f
g
h
i
b
1234567
Outdoor unit
Indoor units ( 1 - 8)
REFNET header
Maximum
allowable
length
Between outdoor (*2) and indoor units
• Actual pipe length
Pipe length between outdoor (*2) and indoor units ≤ 165m
Example unit 8: a + i ≤ 165m
• Equivalent length
Equivalent pipe length between outdoor (*2) and indoor units ≤ 190m *(See Note 1)
(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 (*2) to all indoor units ≤
1000m
Between outdoor unit and Outdoor unit multi connection piping kit
(Only for multi system)
• Actual pipe length
Pipe length between outdoor unit and Outdoor unit multi
connection piping kit ≤10m
• Equivalent length
Equivalent length between outdoor unit and Outdoor unit multi connection piping kit ≤ 13m
Allowable
height
length
Between outdoor and indoor units
• Difference in height
Difference in height between outdoor and indoor units (H1) ≤ 50m
( ≤ 90m 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 (H3) ≤ 5m
Allowable
length after
the branch
• Actual pipe length
Pipe length from first refrigerant branch kit (either refnet joint or refnet header) to indoor unit ≤ 40m
*(See Note 2)
Example unit 8: i ≤ 40m
Refer Note 1 and Note 2 on page
143, 144.
*2 In case of multi outdoor system, re-read to the first Outdoor unit multi
connection piping kit as seen from the indoor unit.
r
t
s
r ≤ 10m (Equivalent length: ≤ 13m)
s ≤ 10m (Equivalent length: ≤ 13m)
t ≤ 10m (Equivalent length: ≤ 13m)
Outdoor unit