Gree GMV-60WL/C-T Owner's Manual page 19

(2) Calculation of the amount of additional refrigerant.
Adding refrigerant method includes 2 steps as follow:
1) Amount of additional refrigerant depending on the pipe size(X).
2) Amount of additional refrigerant depending on Quantity of IDU(Y).
Total charging amount =X+Y
Detail calculation is as follow:
1) X= ∑(Liquid pipe length×amount of additional refrigerant of each 1m)
Diameter of liquid pipe
(mm/inch)
kg/m
oz/inch
2) Y=(Quantity of IDU－2) ×0.3 kg(10.58oz)
First confirm that there is no leakage from the system. When compressor is not working, charge
additional R410A with specific amount to the unit through the filling opening of the liquid pipe valve of
the outdoor unit. If required amount cannot be quickly filled due to pressure increase of the pipe, then
set the unit in cooling startup and fill refrigerant from the low pressure check valve of the outdoor unit.
Example：
IDU:
IDU ①
No.
Duct type
Model
GMV-N18G/A3A-D(U)
Liquid pipe:
No.
Pipe size
Length
Φ19.05(Φ3/4) Φ15.9(Φ5/8)
0.25
0.224
IDU ②
Duct type
GMV-N12G/A3A- D(U)
A
Φ9.52mm
(Φ3/8inch)
10m
(32-3/4feet) (16-3/8feet)
Φ12.7(Φ1/2)
0.17 0.11
0.152 0.099
IDU ③
Duct type
GMV-ND09PLS/A-T(U)
B
Φ9.52mm
(Φ3/8inch)
5m
(13-1/8feet)
16
DC Inverter Multi VRF System
Φ9.52(Φ3/8) Φ6.35(Φ1/4)
0.054
0.048
IDU ④
Duct type
GMV-ND09PLS/A-T(U)
C
Φ9.52mm
(Φ3/8inch) (Φ1/4inch)
4m
(16-3/8feet)
0.022
0.020
D
Φ6.35
5m