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7
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Piping installation
Installer reference guide
32
RXTJ-A_RXTA-C_RXTM-A_RXTP-A
R32 split series
4P728168-1 – 2023.03
Outer diameter (Ø)
Temper grade
Thickness (t)
(a)
6.4 mm (1/4")
Annealed (O)
≥0.8 mm
t
Ø
9.5 mm (3/8")
Annealed (O)
(a)
Depending on the applicable legislation and the maximum working pressure of the unit
(see "PS High" on the unit name plate), larger piping thickness might be required.
7.1.2 Refrigerant piping insulation
▪
Use polyethylene foam as insulation material:
-
with a heat transfer rate between 0.041 and 0.052 W/mK (0.035 and
0.045 kcal/mh°C)
-
with a heat resistance of at least 120°C
▪
Insulation thickness
Pipe outer diameter (Ø
p
) Insulation inner diameter
(Ø
i
)
Insulation thickness (t)
6.4 mm (1/4")
8~10 mm
≥10 mm
9.5 mm (3/8")
10~14 mm
≥13 mm
Ø
i
Ø
i
t
Ø
p
Ø
p
If the temperature is higher than 30°C and the humidity is higher than RH 80%, the
thickness of the insulation materials should be at least 20 mm to prevent
condensation on the surface of the insulation.
7.1.3 Refrigerant piping length and height difference
What?
Distance
Maximum allowable pipe length
20 m
Minimum allowable pipe length
1.5 m
Maximum allowable height difference
15 m
7.2 Connecting the refrigerant piping
CAUTION
▪
No brazing or welding on site for units with R32 refrigerant charge during
shipment.
▪
During installation of the refrigeration system, joining of parts with at least one
part charged shall be performed taking into account the following requirements:
inside occupied spaces non-permanent joints are NOT allowed for R32 refrigerant
except for site made joints directly connecting the indoor unit to piping. Site
made joints directly connecting piping to indoor units shall be of non-permanent
type.