2
2
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Design of 3-WAY FLOW LOGIC
1. Model Selecting and Capacity Calculator
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Additional refrigerant charge amount
Additional refrigerant charge amount is calculated from the liquid tubing total length as follows.
Amount of Refrigerant Charge Per Meter, According to Liquid Tubing Size
Liquid tubing size
Amount of refrigerant
charge/m (g/m)
φ
6.35
26
φ
9.52
56
φ
12.7
128
φ
15.88
185
φ
19.05
259
φ
22.22
366
Required amount of charge = (Amount of refrigerant
charge per meter of each size of liquid tube
×
its tube
length) + (...) + (...)
*Always charge accurately using a scale for weighing.
WARNING
Always check the gas den-
sity limit for the room in
which the unit is installed.
1-4. Check of Limit Density
When installing an air conditioner in a room, it is neces-
sary to ensure that if the refrigerant gas accidentally
leaks out, its density does not exceed the limit level for
that room.
If the density could exceed the limit level, it is neces-
sary to provide an opening between the unit and the
adjacent room, or to install mechanical ventilation
which is interlocked with the leak detector.
(Total refrigerant charged amount: kg)
(Min. indoor volume where the indoor unit is installed: m
3
)
Limit density 0.3 (kg/m
3
)
The limit density of refrigerant which is used in this unit
is 0.3 kg/m
3
(ISO 5149).
The shipped outdoor unit comes charged with the
amount of refrigerant fixed for each type, so add it to
the amount that is charged in the field. (For the refriger-
ant charge amount at shipment, refer to the unit’s
nameplate.)
Minimum indoor volume and floor area as against the
amount of refrigerant is roughly as given in the follow-
ing table.
40.5
54.0
20
30
40
50
60
70
80 kg
67.5
81.0
94.5
108.0
121.5
135.0
148.5
162.0
175.5
189.0
202.5
216.0
229.5
243.0
256.5
270.0
m
2
m
3
Total amount of refrigerant
Min. indoor floor area
(when the ceiling is 2.7 m high)
Min. indoor volume
Range below the
density limit of
0.3 kg/m
3
(Countermeasures
not needed)
Range above the
density limit of
0.3 kg/m
3
(Countermeasures
needed)
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
CAUTION
Pay special attention to any
location, such as a basement,
etc., where leaking refrigerant
can accumulate, since refrig-
erant gas is heavier than air.
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Check of limit density
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