10
S4179544
1-8. Additional Refrigerant Charge
Additional refrigerant charge amount is calculated from
the narrow tube total length as follows.
Table 1-14 Amount of refrigerant additional
charge per meter, according to narrow
tube size
Narrow tube size
Amount of refrigerant
additional charge/m (g/m)
ø9.52
75
ø12.7
125
■
Check of density limit
When installing an air conditioner in a room, it is
necessary to ensure that even if the refrigerant gas
accidentally leaks outside, its density does not exceed
the limit.
If it is possible for the density to exceed the limit, it is
necessary to set up an opening between it and the
adjacent room, or to install mechanical ventilation
which is interlocked with a leak detector.
(Total refrigerant charged amount : kg)
Min. indoor volume where the
indoor unit is installed : m
3
Density limit 0.15 (kg/m
3
)
The density limit of R-22 which is used in this unit is
0.15 kg/m
3
(ASHRAE Standard).
The shipped outdoor unit comes charged with the
amount of refrigerant fixed for each type; so add it to
the amount that is charged at the field.
(For the refrigerant charge amount at shipment, refer
to the nameplate of the unit.)
1-9. Installing the Distribution Joint
(1)
●
The installation direction of the T-joint (not
supplied) should be either horizontal or vertical.
The direction of the connection port to each
indoor unit must be upward (15
°
to 30
°
) when
the main tube is horizontal and can be in any
direction, but the branch tube must be upward
when the main tube is vertical. (L3 indicates
tubing which is 2 m or less and connected by a
T-joint.)
●
Make sure that the end point is solidly welded
shut. Also pay attention to the insertion distance
of each connection tube so refrigerant flow
inside the T-joint is not blocked.
●
Never diverge a branch tube again after the T-
joint (that is, there can only be 1 branch in a
line).
(
)
Always check the gas den-
sity for the room in which
the unit is installed.
Required amount of additional charge
= (Amount of additional refrigerant charge per
meter of each size of narrow tube x its tube length)
+ (...) + (...)
* Always recharge accurately using a scale.
Minimum indoor volume & floor area compared
with the amount of refrigerant is roughly as given
in the following table.
>
5
13.5
27.0
40.5
54.0
67.5
81.0
94.5
108
121.5
135
5
10
15
20
25
30
35
40
45
50
m
3
m
2
Total amount of refrigerant
0766_M_I
Min. indoor floor area
(when the ceiling is 2.7 m high)
Min. indoor volume
10
15
20 kg
Range below the
density limit of
0.15 kg/m
3
(Countermeasures
not needed)
Range above the
density limit of
0.15 kg/m
3
(Countermeasures
needed)
When in horizontal use
Can be at
any angle
Solidly welded shut
Indoor unit
Indoor unit
L3 2 m
Outdoor unit
0768_M_I
<
–
Main tube
Indoor unit
Horizontal
line
Slant
15
°
to 30
°
Horizontal line
Solidly
welded
shut
Indoor unit
Indoor L3 2 m
<
–
Outdoor
unit
0767_M_I
When in vertical use
