– 65 –
Charging additional refrigerant
3
2
4
1
2
3
1
5
4
2
1
3
7
6
Outdoor Unit
Indoor Unit
Figure of Single
Outdoor Unit
Figure of Simultaneous twin
Indoor Unit
Figure of Simultaneous triple
Figure of Simultaneous double twin
Indoor Unit
Outdoor Unit
Indoor Unit
Indoor Unit
Indoor Unit
Outdoor Unit
Indoor Unit
Indoor Unit
Indoor Unit
Indoor Unit
Formula for calculating the amount of additional refrigerant
(Formula will differ depending on the diameter of the liquid connecting side pipe.)
* ℓ1 to ℓ7 are the lengths of the pipes shown in the figures above (unit: m).
Single
Simultaneous twin
Simultaneous triple
Simultaneous double twin
Gas leak inspection
Diameter of connecting pipe
(liquid side)
Amount of additional
refrigerant per meter (g/m)
Amount of additional refrigerant (g) =
Amount of refrigerant charged for main pipe
ℓ
α
Ø12.7
80
α
× ( ℓ – 30)
Diameter of connecting pipe
(liquid side)
Amount of additional
refrigerant per meter (g/m)
Amount of additional refrigerant (g) =
Amount of refrigerant charged for main pipe +
amount of refrigerant charged for branch
piping
ℓ1
ℓ2
ℓ3
α
β
Ø12.7
Ø9.5
Ø9.5
80
40
α
× ( ℓ1 – 28) +
β
× ( ℓ2 + ℓ3 – 4)
Diameter of connecting pipe
(liquid side)
Amount of additional
refrigerant per meter
(g/m)
Amount of additional refrigerant (g) =
Amount of refrigerant charged for main pipe +
amount of refrigerant charged for branch
piping
ℓ1
ℓ2
ℓ3
ℓ4
α
β
Ø12.7
Ø9.5
Ø9.5
Ø9.5
80
40
α
× ( ℓ1 – 28) +
β
× ( ℓ2 + ℓ3 + ℓ4 – 6)
Outdoor
unit
Diameter of connecting pipe
(liquid side)
Amount of additional
refrigerant per meter (g/m)
Amount of additional refrigerant (g) =
Amount of refrigerant charged for main pipe +
amount of refrigerant charged for first branch
amount of refrigerant charged for
second branch piping
ℓ1
ℓ2, ℓ3
ℓ4 to ℓ7
α
β
γ
GM224
Ø12.7
Ø9.5
Ø6.4
80
40
20
α
× ( ℓ1 – 28) +
β
× ( ℓ2 + ℓ3 – 4) +
γ
× ( ℓ4 + ℓ5 + ℓ6 + ℓ7)
GM280
Ø12.7
Ø9.5
Ø9.5
80
40
40
Use a leak detector manufactured specially for HFC refrigerant
(R32, R410A, R134a, etc.) to perform the R32 gas leak inspection.
* Leak detectors for conventional HCFC refrigerant (R22, etc.)
cannot be used, as the sensitivity drops to approximately 1/40
when used for HFC refrigerant.
• R32 has a high working pressure, so failure to perform the installation
work properly may result in gas leaks such as when the pressure rises
during operation. Be sure to perform leak tests on the piping
connections.
Indoor unit inspection locations
(piping connections)
Indoor unit side piping
Outdoor unit inspection locations
129-EN
130-EN
Refrigerant
piping
