18
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Piping installation
Installer and user reference guide
87
REMA5+REYA8~20A7Y1B
VRV 5 heat recovery
4P687640-1 – 2022.07
Term
Definition
Height difference [m]
H3
Height difference
between outdoor units
5
(a)
The allowable height difference is 50 m in case the outdoor unit is positioned higher than
the indoor unit, and 40 m in case the outdoor unit is positioned lower than the indoor unit.
If only VRV DX indoor units are used, the allowable height difference between outdoor and
indoor units may be extended to 90 m, without the need of an additional option kit. In this
case, make sure all conditions below are met:
The outdoor unit is positioned higher than the indoor units:
•
Minimum connection ratio: 80%
•
Size up the liquid piping (refer to
"18.1.4 To select the piping size"
•
Activate the outdoor unit setting. Refer to the service manual for more information.
The outdoor unit is positioned lower than the indoor units:
•
Size up the liquid piping (refer to
"18.1.4 To select the piping size"
•
Activate the outdoor unit setting. Refer to the service manual for more information.
•
No technical cooling
(b)
If single outdoor units or standard multi-outdoor combinations >20 HP are connected to
only VRV DX indoor units, then the height difference between indoor units (= H2) can be
increased from 15 to 30 m. However, this limits the allowable maximum length of the
longest pipe (see
"Connection with only VRV DX indoor units"
18.1.8 Single outdoor units and standard multi-outdoor-unit combinations >20 HP
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)
Pipe
Maximum length (actual/equivalent)
Longest pipe from the outdoor unit or
the last multi-outdoor piping branch (A
+B1+C1, A+B2+C2, A+B1+C3, A+B1+D
+C4)
165 m/190 m
(a)
120 m/165 m
(a)(b)
