18
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Piping installation
Installer and user reference guide
88
REMA5+REYA8~20A7Y1B
VRV 5 heat recovery
4P687640-1 – 2022.07
Pipe
Maximum length (actual/equivalent)
Longest pipe after the first branch or
multi BS unit (B1+C1, B2+C2, B1+C3,
B1+D+C4)
40 m/—
(c)
In case of a multi-outdoor setup:
longest pipe from the outdoor unit to
the last multi-outdoor piping branch (E)
10 m/13 m
Total pipe length
1000 m/—
(a)
If the equivalent piping length is more than 90 m, size up the main liquid piping according
to
"18.1.4 To select the piping size"
81].
(b)
If the height difference between indoor units (=H2) is between 15 and 30 m, then the
allowable maximum length of the longest pipe is limited to 120/165 m (actual/equivalent).
(c)
The limitation can be extended to 90 m if the following conditions are met:
•
The piping length between all indoor units and the BS unit is ≤40 m.
•
Size-up:
→ It is required to size-up the liquid piping between the first branch kit or BS unit and the last
branch kit or last BS unit.
→ It is also required to size-up the liquid piping downstream of the BS unit if the last refrigerant
branch kit is located downstream of the BS unit.
→ It is not required to size-up the liquid piping between the BS unit and indoor units.
→ If the increased pipe size is larger than the pipe size of the main pipe, also increase the size of the
main pipe.
•
In case of size-up of the liquid piping, double its length in the calculation of the total piping length.
Make sure the total piping length is within limitations.
•
The piping length difference between the nearest indoor unit to the outdoor unit and the farthest
indoor unit to the outdoor unit is ≤40 m.
18.1.9 Standard multi-outdoor-unit combinations ≤20 HP and free multi-outdoor-unit
combinations
Connection with only VRV DX indoor units
H3
H1
E
A
B2
B1
a
b
b
c
c
d
c
d
d
e
D
H2
C2
C4
C3
C1
a
Outdoor unit
b
VRV DX indoor unit
c
Branch selector (BS)
d
VRV DX indoor unit (duct)
e
VRV DX indoor unit (large duct)
