12
S4179544
1-11. Selecting Refrigerant Tubing Size and Calculating the Amount of Additional Charge
Table 1-17
Type
Rating capacity
Cooling
Heating
25 type: a
7.3
8.0
12 type: b
3.6
4.2
9 type: c
2.8
3.2
18 type: d
5.6
6.3
36 type: e
10.6
11.4
Unit: kw
0019_M_I
36
e
18
6 m
16 m
13 m
8 m
5 m
18 m
10 m
10 m
Main tube D
Main tube B
Main tube C
Main tube A
30 m
4 m
d
25
a
12
b
9
c
90 type
■
The tubing size is selected and the amount of additional charge can be found in the table of
refrigerant tubing sizes using the tubing system of each indoor unit.
Refrigerant amounts must be calculated for the amount of additional charge per 1m of narrow tube size.
Table 1-18
Additional Refrigerant Charge
Total cooling capacity of the
Wide tube
Narrow tube
1
Tubing
2
Additional
1
X
2
unit after the distribution joint
length
refrigerant
Main tube
A
7.3 + 3.6 + 2.8 +5.6 + 10.6
28.58 (1 1/8)
12.7 (1/2)
30 m
125 g/m
3,750 g
= 29.9 kw
B
7.3 + 3.6 + 2.8 = 13.7 kw
19.05(3/4)
9.52 (3/8)
5 m
75 g/m
375 g
C
3.6 + 2.8 = 6.4 kw
15.88(5/8)
9.52 (3/8)
10 m
75 g/m
750 g
D
5.6 + 10.6 = 16.2 kw
25.4 (1)
12.7 (1/2)
20 m
125 g/m
2,500 g
Distribution 25 type:a
7.3 kw (13 m)
15.88(3/8)
9.52 (3/8)
13 m
75 g/m
975 g
branch
12 type:b
3.6 kw ( 8 m)
12.7 (1/2)
9.52 (3/8)
8 m
75 g/m
600 g
9 type:c
2.8 kw (18 m)
12.7 (1/2)
9.52 (3/8)
18 m
75 g/m
1,350 g
18 type:d
5.6 kw ( 6 m)
15.88(5/8)
9.52 (3/8)
6 m
75 g/m
450 g
36 type:e
10.6 kw (10 m)
19.05(3/4)
9.52 (3/8)
10 m
75 g/m
750 g
Total amount
—
—
—
—
11,500 g
