20
Checking of limit density
Density limit is determined on the basis of the size of a
room using an indoor unit of minimum capacity. For
instance, when an indoor unit is used in a room (floor
area 7.43 m
2
×
ceiling height 2.7 m = room volume
20.06 m
3
), the graph at right shows that the minimum
room volume should be 14.1 m
3
(floor area 5.2 m
2
) for
refrigerant of 4.238 kg. Accordingly, openings such as
louvers are required for this room.
<Determination by calculation>
Overall refrigerant charge amount for the air conditioner: kg
(Minimum room volume for indoor unit: m
3
)
=
4.238 (kg) + 3.5 (kg)
= 0.39 (kg/m
3
)
≥
0.3 (kg/m
3
)
20.06 (m
3
)
Therefore, openings such as louvers are required for
this room.
Obtain charge amount for each tubing size
Note that the charge amounts per 1 meter are different for each liquid tubing size.
ø9.52
→
LA + LB + LC + LD
: 65 m
×
0.056 kg/m = 3.64 kg
ø6.35
→
1 + 2 + 3 + 4 + 5 : 23 m
×
0.026 kg/m = 0.598 kg
Total
4.238 kg
Additional refrigerant charge amount is 4.238 kg.
Be sure to check the limit density
for the room in which the indoor
unit is installed.
CAUTION
Example of each tubing length
Main tubing
Distribution joint tubing
LA = 40 m
Indoor side
LB = 5 m
1 = 5 m
4 = 6 m
LC = 5 m
2 = 5 m
5 = 5 m
LD = 15 m
3 = 2 m
LD
L1
L2
LC
LB
LA
Mai
n
t
u
be of
un
it
1
s
t bra
n
ch
model 22
model 2
8
model
3
6
model 56
model 7
3
U
n
it di
s
trib
u
tio
n
t
u
be
1
2
3
4
5
Example:
40
35
30
25
20
15
10
5
0
108.0
94.5
81.0
67.5
54.0
40.5
27.0
13.5
0
10
20
30
Total amount of refrigerant
Min. indoor floor area
(when the ceiling is 2.7 m high)
m
2
kg
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)
m
3
06-065 Mini ECO-i II for ARGO 2/8/06 4:37 PM Page 20
