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<Formula for Calculating Additional Refrigerant Amount>
Do not remove the refrigerant even if the additional refrigerant amount becomes
minus result as a result of calculations by the following formula and operate the
air conditioner as it is.
A:
Additional refrigerant amount per meter of actual main piping length (kg)
B:
Additional refrigerant amount per meter of actual branch piping length (kg)
L:
Actual length of main piping (m)
a, b: Actual length of branch piping (m)
1. Be certain to write the additional refrigerant amount, pipe length (actual
length), head and other specification on the nameplate put on the outdoor unit for recording.
2. Seal the correct amount of additional refrigerant in the system.
• Use a leak detector manufactured specially for the HFC refrigerant (R32, R410A, R134a, etc.) when testing R32, R410A.
The sensitivity of leak detectors for previous HCFC refrigerants (such as R22) lowers to about 1/40 when used with
HFC refrigerants and these detectors cannot be used.
Additional Refrigerant Amount
Additional refrigerant amount (kg) = Main piping additional refrigerant
amount (kg) + Branch piping additional
refrigerant amount (kg)
= A × (L – 28) + B × (a + b – 4)
Standard piping length
R410A
Model
Additional refrigerant
amount per Meter (kg/m)
Main piping
Branch
piping
A
B
140 AT
160 AT
28m
2m
0.040
0.040
CAUTION
Gas Leak Test
a
b
L
H
Δ
h
Indoor unit B
Indoor unit A
Branch pipe
Outdoor unit
Main
piping
Branch
piping
Branch
piping
80 AT
110 AT
28m
2m
0.040
0.020
Standard piping length
R32
Model
Additional refrigerant
amount per Meter (kg/m)
Main piping
Branch
piping
A
B
140 AT
28m
80 AT
110 AT
28m
2m
2m
0.035
0.035
0.035
0.020
