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Are there scratches or dents on the existing pipes?
NO
Is it possible to operate the existing air conditioner?
YES
• After the existing air conditioner is operated in cooling
mode for approx. 30 minutes or longer,* recover the
refrigerant.
• For cleaning the pipes and recovering oil
•
Refrigerant recovery: Pump down method
• Remove the existing air conditioner from the piping
and carry out flushing (nitrogen pressure 0.5 MPa) to
remove any remains inside of the pipe.
Note: In case of twin pipes, also be sure to flush the
branching pipe.
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.)
NO
Connect the indoor / outdoor units to the existing pipe.
• Use a flare nut attached to the main unit for the indoor /
outdoor units. (Do not use the flare nut of the existing
pipe.)
• Re-machine the flare machining size to size for R32,
R410A.
• (Airtight test), Vacuum dry, Refrigerant charge, Gas leak
check
Test run
63-EN
YES
Existing pipes: Cannot be used.
• Use new pipes.
NO
Nitrogen gas pressure 0.5 MPa
(If there is discharge of remains, it is judged that a
large quantity of remains are present.)
YES
Clean the pipes or use new pipes.
Piping necessary to change the flare nut / machining
size due to pipe compression
1) Flare nut width: H
Copper pipe
Ø6.4
Ø9.5
Ø12.7 Ø15.9
outer diameter
For R32, R410A
17
22
26
H
For R22
Same as above
24
2) Flare machining size: A
Copper pipe
Ø6.4
Ø9.5
Ø12.7 Ø15.9
A
outer diameter
For R32, R410A
9.1
13.2
16.6
For R22
9.0
13.0
16.2
Becomes a little larger for R32, R410A
Do not apply refrigerator oil to the flare surface.
Warnings on Refrigerant Leakage
Check of concentration limit
The room in which the air conditioner is to be installed requires a design that in the event of refrigerant
gas leaking out, its concentration will not exceed a set limit.
The refrigerant R32 or R410A which is used in the air conditioner is safe, without the toxicity or combustibility of
ammonia, and is not restricted by laws to be imposed which protect the ozone layer. However, since it contains more
than air, it poses the risk of suffocation if its concentration should rise excessively. Suffocation from leakage of R32
or R410A is almost non-existent. With the recent increase in the number of high concentration buildings, however, the
installation of multi air conditioner systems is on the increase because of the need for effective use of floor space,
individual control, energy conservation by curtailing heat and carrying power etc.
Most importantly, the multi air conditioner system is able to replenish a large amount of refrigerant compared with
conventional individual air conditioners. If a single unit of the multi conditioner system is to be installed in a
small room, select a suitable model and installation procedure so that if the refrigerant accidentally leaks out, its
concentration does not reach the limit (and in the event of an emergency, measures can be made before injury
can occur).
In a room where the concentration may exceed the limit, create an opening with adjacent rooms, or install
mechanical ventilation combined with a gas leak detection device.The concentration is as given below.
The concentration limit of R32 or R410A which is used in multi air conditioners is 0.3 kg/m³.
NOTE 1
If there are 2 or more refrigerating systems in a single refrigerating device, the amounts of refrigerant should be as
charged in each independent device.
e.g., charged amount (10 kg)
(mm)
Room A
29
27
For the amount of charge in this example:
The possible amount of leaked refrigerant gas in rooms A, B and C is 10 kg.
The possible amount of leaked refrigerant gas in rooms D, E and F is 15 kg.
(mm)
NOTE 2
The standards for minimum room volume are as follows.
19.7
1) No partition (shaded portion)
19.4
– 32 –
Total amount of refrigerant (kg)
Min. volume of the indoor unit installed room (m
3
)
Concentration limit (kg/m
3
)
Outdoor unit
e.g., charged amount (15 kg)
Room B
Room C
Room D
Room E
Room F
Indoor unit
EN
ID
ID
64-EN
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