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Piping installation
Installer and user reference guide
84
RXYTQ
VRV IV+ heat pump for high ambient temperatures
4P561157-1B – 2021.11
NOTICE
The refrigerant charge of the system must be less than 100 kg. This means that in
case the calculated total refrigerant charge is equal to or more than 95 kg you must
divide your multiple outdoor system into smaller independent systems, each
containing less than 95 kg refrigerant charge. For factory charge, refer to the unit
name plate.
Formula:
R=[(X
1
×
Ø22.2
)×0.37+(X
2
×
Ø19.1
)×0.26+(X
3
×
Ø15.9
)×0.18+
(X
4
×
Ø12.7
)×0.12+(X
5
×
Ø9.5
)×0.059+(X
6
×
Ø6.4
)×0.022]+A
R
Additional refrigerant to be charged [in kg and rounded off to 1 decimal place]
X
1...6
Total length [m] of liquid piping size at
Øa
A
Parameter A (see below)
Parameter A:
Piping length
(a)
CR
(b)
A
(c)
8 HP
10+12 HP
14+16 HP
≤30 m
50%≤CR≤105%
0 kg
1 kg
105%<CR≤130%
0.5 kg
1.5 kg
>30 m
50%≤CR≤70%
0 kg
1 kg
70%<CR≤85%
0.3 kg
0.5 kg
1.5 kg
85%<CR≤105%
0.7 kg
1 kg
2 kg
105%<CR≤130%
1.2 kg
1.5 kg
(a)
Piping length is considered the distance from the outdoor unit to the farthest indoor unit.
(b)
Total CR = Total indoor unit capacity connection ratio
(c)
In case of a multi-outdoor-unit system, add the sum of the individual outdoor unit charge
factors.
Metric piping.
When using metric piping, replace the weight factors in the formula
by the ones from the following table:
Inch piping
Metric piping
Piping
Weight factor
Piping
Weight factor
Ø6.4 mm
0.022
Ø6 mm
0.018
Ø9.5 mm
0.059
Ø10 mm
0.065
Ø12.7 mm
0.12
Ø12 mm
0.097
Ø15.9 mm
0.18
Ø15 mm
0.16
Ø16 mm
0.18
Ø19.1 mm
0.26
Ø18 mm
0.24
Ø22.2 mm
0.37
Ø22 mm
0.35
Connection ratio requirements.
When selecting indoor units, the connection ratio
must comply with the following requirements. For more information, see the
technical engineering data.
Indoor units
Total CR
(a)
VRV DX
50~130%
(a)
Total CR = Total indoor unit capacity connection ratio
