II - 18
Design of W-ECO MULTI SYSTEM
2
TD831077
2. Example of System Design
Total cooling capacity after distribution joint
Wide tube
Narrow tube
1
Tubing
2
Additional
1
×××××
2
/ Outdoor unit type / Indoor unit type
length (m)
refrigerant (g/m)
(g)
Main tube
LE2
10.6 + 7.3 + 7.3 = 25.2 kW
28.58 (1 1/8)
12.70 (1/2)
4
125
500
LF
7.3 + 7.3 = 14.6 kW
19.05 (3/4)
9.52 (3/8)
5
75
375
Distribtuon
I4
36 type
19.05 (3/4)
9.52 (3/8)
4
75
300
branch
I5
25 type
15.88 (5/8)
9.52 (3/8)
6
75
450
I6
25 type
15.88 (5/8)
9.52 (3/8)
7
75
525
After extending indoor and outdoor unit
7
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 (3) is used in a room
(Floor area 15 m
3
×
Ceiling height 2.7 m = Room volume
40.5 m
3
), the graph on the right shows that the minimum
room volume should be 159 m
3
(Floor area 59 m
2
) for
refrigerant of 47.64 kg, and accordingly openings like louvers
are required for the room.
<Determination by calculation>
(Minimum room volume for an indoor unit : m
3
)
Overall refrigerant charge amount for
the air-conditioner : kg
(
)
=
47.64 (kg)
40.5 (m
3
)
= 1.18 (kg/m
3
) 0.3 (kg/m
3
)
Therefore, openings like louvers are required for the room.
Additional refrigerant charge amount for extension = 2,150 g
Total refrigerant charge amount including initial charge amount
= 20,000 g (190 type) + 8,000 g (70 type) + 17,690g + 2,150 g = 47,640 g
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
1669_M_I
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
>