Daikin VRV II REYQ8M8W1B Instruction Manual page 11

Precautions when selecting branch piping.
If the overall equivalent piping length is ≥90 m, be sure to enlarge the
main pipe in the liquid-side piping. Do not enlarge the main pipe in
the discharge-side and suction-side piping.
[Liquid side]
REYQ8+10 Ø9.5
REYQ12~16 Ø12.7
REYQ18~24 Ø15.9
REYQ26~48 Ø19.1
Cautions for installation of multiple outdoor units
1. The piping between the outdoor units must be routed level or slightly
upward to avoid the risk of oil detention into the piping side.
Pattern 1
1
2
1 To indoor unit
2 Piping between outdoor units
Pattern 2
1
1 To indoor unit
Prohibited pattern: Change to Pattern 1 or 2
1
1 To indoor unit
2. To avoid the risk of oil retention to the stopping unit side, always
connect the stop valve and the piping between outdoor units as
shown in the figure A or figure B.
A
B
REYQ8~16M8W1B
VRVII System air conditioner
4PW23712-1
Ø12.7
Ø15.9
Ø19.1
Ø22.2
1
2
1
1
A
B
Prohibited pattern
1
2 2
1
2 2
Change to pattern 1 or 2
A B
C
1
3
Change as shown in the figure below
1
A Unit A
B Unit B
C Unit C
X Not allowed
O Allowed
1 To indoor unit
2 Oil collects to the stopping outdoor unit.
3 Oil collects to the outdoor unit C when the system stops.
3. If the piping length between the outdoor unit-connecting pipe kits or
between the outdoor units exceeds 2 m, create a rise of 200 mm or
more in the gas line within a length of 2 m from the kit.
If ≤2 m
1
≤2 m
2
1 To indoor unit
2 Piping between outdoor units
If ≥2 m
1
≤2 m
2
1
≤2 m
1 To indoor unit
2 Piping between outdoor units
2
2
A B
1
3
1
≥2 m
≤2 m
2 2
Installation manual
C
6