Multiple Outdoor Units: Possible Layouts - Daikin VRV IV+ RYYQ14U7Y1B Series Installer And User Manual

18 | Piping installation

18.1.9 Multiple outdoor units: Possible layouts

Installer and user reference guide
82
Maximum allowable height difference
H1 ≤50 m (40 m) (if outdoor is located below indoor units)
H2 ≤15 m
H4 ≤40 m
H5 ≤15 m
H6 ≤5 m
Maximum allowable length after branch
The pipe length from the first refrigerant branch kit to the indoor unit ≤50 m.
Example: b+g+l≤50 m
If the piping length between the first branch and BP unit or VRV DX indoor unit is
over 20 m, it is necessary to increase the gas and liquid piping size between the
first branch and BP unit or VRV DX indoor unit. If the piping diameter of the sized
up piping exceeds the diameter of the piping before the first branch kit, than the
latter also requires a liquid piping and gas piping size up.
▪ The piping between the outdoor units must be routed level or slightly upward to
avoid the risk of oil retention into the piping.
Pattern 1
a
b
a
b
a
b
a To indoor unit
b Piping between outdoor units
NOT allowed (oil remains in piping)
Allowed
▪ To avoid the risk of oil retention to the outmost outdoor unit, always connect the
stop valve and the piping between outdoor units as shown in the 4 correct
possibilities of the figure below.
a
b b
a
b b
b
b
Pattern 2
a
b
a
b
a a
b
RYYQ+RYMQ+RXYQ8~20U7Y1B
VRV IV+ heat pump
4P546228-1B – 2020.10