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English
14.2. Calculating the additional refrigerant charge
NOTE
The refrigerant charge of the system must be less than 210 lbs.
(95.2 kg). This means that in case the calculated total refrigerant
charge is equal to or more than 209 lbs. (94.8 kg) you must divide
your multiple outdoor system into smaller independent systems, each
containing less than 209 lbs. (94.8 kg) refrigerant charge. For factory
charge, refer to the unit nameplate.
14.2.1. How to calculate the additional refrigerant to be charged
Additional refrigerant to be charged=R (lbs.). R should be rounded off
in units of 0.1 lbs.
R=[(X
1
×
φ
7/8)
×
0.249+(X
2
×
φ
3/4)
×
0.175+(X
3
×
φ
5/8)
×
0.121+(X
4
×
φ
1/2)
×
0.081+(X
5
×
φ
3/8)
×
0.040+(X
6
×
φ
1/4)
×
0.015]+[A]
X
1...6
=Total length (ft. (m)) of liquid piping size at Øa
* In units of 0.1 kg, additional refrigerant to be charged=R (kg).
R=[(X
1
×
φ
22.2)
×
0.37+(X
2
×
φ
19.1)
×
0.26+(X
3
×
φ
15.9)
×
0.18+(X
4
×
φ
12.7)
×
0.12+(X
5
×
φ
9.5)
×
0.059+(X
6
×
φ
6.4)
×
0.022]+[A]
Parameter [A]
Outdoor unit capacity type
The amount of refrigerant
RXYQ 72A type
0.0 lbs./unit (0.0 kg/unit)
RXYQ 96A type
0.0 lbs./unit (0.0 kg/unit)
RXYQ 120A type
0.0 lbs./unit (0.0 kg/unit)
RXYQ 144A type
3.4 lbs./unit (1.5 kg/unit)
RXYQ 168A type
3.9 lbs./unit (1.8 kg/unit)
RXYQ 192A type
18.5 lbs./unit (8.4 kg/unit)
RXYQ 216A type
18.7 lbs./unit (8.5 kg/unit)
RXYQ 240A type
19.0 lbs./unit (8.6 kg/unit)
Example for refrigerant branch using REFNET joint and REFNET
header for systems and each pipe length as shown below. (Example
2.2.1, 7.5.2. System only containing VRV indoor units on page 13)
Outdoor system: RXYQ264AATJ
*
(RXYQ144AATJ
*
+ RXYQ120AATJ
*
)
a:
φ
3/4 × 60 ft.
e:
φ
3/8 × 15 ft.
i:
φ
1/2 × 20 ft.
t:
φ
1/2 × 15 ft.
b:
φ
5/8 × 15 ft.
f:
φ
3/8 × 15 ft.
j:
φ
3/8 × 20 ft.
c:
φ
3/8 × 15 ft.
g:
φ
1/4 × 15 ft.
k:
φ
3/8 × 20 ft.
d:
φ
3/8 × 15 ft.
h:
φ
1/4 × 30 ft.
s:
φ
1/2 × 10 ft.
R = ( 60×0.175 + 15×0.121 + 45×0.081 + 100×0.040 + 45×0.015 ) + 3.4
↑
a
↑
b
↑
i, s, t
↑
c, d, e, f, j, k
↑
g, h
↑
RXYQ144AATJ
*
= 24.035
⇒
24.0 lbs.
Round off in units of 0.1 lbs.
INFORMATION
• When using multi models, add the sum of individual capacity types.
• Piping length is considered the distance from the outdoor unit to the
farthest indoor unit.
When selecting indoor unit, certain connection ratio limitations must
be followed. Refer to Engineering Data Book for detailed information.
01_EN_Main_VRV6_HP_IM.indd 30
01_EN_Main_VRV6_HP_IM.indd 30
2022/12/08 17:56:15
2022/12/08 17:56:15
