Charging additional refrigerant
Outdoor Unit
Figure of Simultaneous twin
Indoor Unit
Indoor Unit
Outdoor Unit
2
3
1
Figure of Simultaneous double twin
Indoor Unit
Outdoor Unit
4
129-EN
Figure of Single
Indoor Unit
Figure of Simultaneous triple
Indoor Unit
Indoor Unit
Outdoor Unit
4
2
1
Indoor Unit
Indoor Unit
Indoor Unit
5
6
7
2
3
1
– 65 –
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
Diameter of connecting pipe
(liquid side)
ℓ
Ø12.7
Simultaneous twin
Diameter of connecting pipe
(liquid side)
ℓ1
ℓ2
Ø12.7
Ø9.5
Indoor Unit
Simultaneous triple
Diameter of connecting pipe
(liquid side)
ℓ1
ℓ2
Ø12.7
Ø9.5
3
Simultaneous double twin
Diameter of connecting pipe
(liquid side)
Outdoor
unit
ℓ1
GM224
Ø12.7
GM280
Ø12.7
Gas leak inspection
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.
Amount of additional
refrigerant per meter (g/m)
Amount of refrigerant charged for main pipe
α
80
Amount of additional
refrigerant per meter (g/m)
Amount of refrigerant charged for main pipe +
amount of refrigerant charged for branch
ℓ3
α
β
Ø9.5
80
40
Amount of additional
refrigerant per meter
Amount of refrigerant charged for main pipe +
(g/m)
amount of refrigerant charged for branch
α
β
ℓ3
ℓ4
Ø9.5
Ø9.5
80
40
Amount of additional
refrigerant per meter (g/m)
Amount of refrigerant charged for main pipe +
amount of refrigerant charged for first branch
piping + amount of refrigerant charged for
α
β
ℓ2, ℓ3
ℓ4 to ℓ7
γ
Ø9.5
Ø6.4
80
40
20
Ø9.5
Ø9.5
80
40
40
Amount of additional refrigerant (g) =
α
× ( ℓ – 30)
Amount of additional refrigerant (g) =
piping
α
β
× ( ℓ1 – 28) +
× ( ℓ2 + ℓ3 – 4)
Amount of additional refrigerant (g) =
piping
α
× ( ℓ1 – 28) +
β
× ( ℓ2 + ℓ3 + ℓ4 – 6)
Amount of additional refrigerant (g) =
second branch piping
α
× ( ℓ1 – 28) +
β
× ( ℓ2 + ℓ3 – 4) +
γ × ( ℓ4 + ℓ5 + ℓ6 + ℓ7)
Indoor unit inspection locations
(piping connections)
Refrigerant
piping
Indoor unit side piping
Outdoor unit inspection locations
130-EN