– 26 –
Are there scratches or dents on the existing pipes?
Is it possible to operate the existing air conditioner?
y
After the existing air conditioner is operated in cooling
mode for approx. 30 minutes or longer,* recover the
refrigerant.
y
For cleaning the pipes and recovering oil
y
Refrigerant recovery: Pump down method
y
Remove the existing air conditioner from the piping
and carry out
fl
ushing (nitrogen pressure 0.5 MPa) to
remove any remains inside of the pipe.
Note:
In case of twin pipes, also be sure to
fl
ush the
branching pipe.
Connect the indoor / outdoor units to the existing pipe.
y
Use a
fl
are nut attached to the main unit for the indoor
/ outdoor units. (Do not use the
fl
are nut of the existing
pipe.)
y
Re-machine the
fl
are machining size to size for R32.
y
(Airtight test), Vacuum dry, Refrigerant charge, Gas
leak check
Test run
Was largely discolored oil or a large quantity
of remains discharged? (When the oil deteriorates,
the color of the oil changes to a muddy
or black color.)
Existing pipes: Cannot be used.
y
Use new pipes.
Clean the pipes or use new pipes.
Piping necessary to change the
fl
are nut / machining
size due to pipe compression
1) Flare nut width: H
H
(mm)
Copper pipe
outer diameter
Ø6.4
Ø9.5 Ø12.7 Ø15.9
For R32, R410A
17
22
26
29
For R22
Same as above
24
27
2) Flare machining size: A
A
(mm)
Copper pipe outer
diameter
Ø6.4 Ø9.5 Ø12.7 Ø15.9
For R32, R410A
9.1
13.2
16.6
19.7
For R22
9.0
13.0
16.2
19.4
Becomes a little larger for R32
Do not apply refrigerator oil to the
fl
are surface.
(If there is discharge of remains, it is judged that a
large quantity of remains are present.)
YES
YES
NO
NO
NO
YES
Nitrogen gas pressure 0.5 MPa
