2
2
- 16
Design of Mini Multiset
2. System Design
Minimum indoor volume & 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 leak-
ing refrigerant can accu-
mulate, since refrigerant
gas is heavier than air.
Table 2-10 Ranges that Apply to Refrigerant Tubing Lengths and to Differences in Installation Heights
Items
Marks
Contents
Length (m)
L1
Max. tubing length
Actual length
150
Equivalent length
175
L (L2 – L3)
Difference between max. length and min .
40
length from the No.1 distribution joint
1
,
2
~
n
Max. length of each distribution tube
30
1
+
2
+~
n–1
Total max. tubing length including length of
200
each distribution tube (only liquid tubing)
H1
When outdoor unit is installed higher than indoor unit
50
When outdoor unit is installed lower than indoor unit
40
H2
Max. difference between indoor units
15
L = Length, H = Height
Allowable tubing
length
>
>
Allowable elevation
difference
>
>
>
>
>
>
+L1
WARNING
Always check the gas den-
sity limit for the room in
which the unit is installed.
2-10. Check of Limit Density
When installing an air conditioner in a room, it is nec-
essary to ensure that even if the refrigerant gas acci-
dentally 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 refrig-
erant charge amount at shipment, refer to the unit’s
nameplate.)
