42
Refrigerant pipe installation
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Example of refrigerant calculation for HP models
Classification
Size of liquid pipe
[mm (inch)]
Length [m (ft)]
Unit amount of
refrigerant [kg/m
(lb/ft)]
Amount of
additional
refrigerant [kg (lb)]
Total amount
of additional
refrigerant [kg (lb)]
①
②
①
×
②
∑(
①
×
②
)
Liquid pipe (
ⓐ
)
Ø6.35 (Ø1/4)
35 (114.8)
0.02 (0.013)
0.7 (1.49)
5.575 (12.19)
Ø9.52 (Ø3/8)
50 (164.0)
0.06 (0.040)
3.0 (6.56)
Ø12.70 (Ø1/2)
15 (49.2)
0.125 (0.084)
1.875 (4.13)
Classification
Model name of
indoor unit
Number of units
Unit amount of
refrigerant [kg/EA
(lb/EA)]
Amount of
additional
refrigerant [kg (lb)]
Total amount
of additional
refrigerant [kg (lb)]
①
②
①
×
②
∑(
①
×
②
)
Indoor unit (
ⓑ
)
4way cassette
(AM018FN4DCH)
4
0.45 (0.99)
1.8 (3.96)
ⓑ
3.30 (7.26)
Slim duct
(AM024FNLDCH)
2
0.45 (0.99)
0.90 (1.98)
Slim duct
(AM012FNLDCH)
1
0.35 (0.77)
0.35 (0.77)
1way cassette
(AM012FN1DCH)
1
0.25 (0.55)
0.25 (0.55)
- Total amount of refrigerant (
ⓐ
+
ⓑ
) = 5.575 + 3.30 = 8.875 (kg)
= 12.19 + 7.26 = 19.45 (lb)
Temper grade and minimum thickness of the refrigerant pipe
Outer diameter
Minimum thickness
Temper grade
mm
inch
mm
inch
6.35
1/4
0.70 0.028
Annealed
9.52
3/8
0.70 0.028
12.70
1/2
0.80 0.031
15.88
5/8
1.00 0.039
19.05
3/4
0.90 0.035
Drawn
22.22
7/8
0.90 0.035
25.40
1
1.00
0.039
28.58 1
1/8
1.10 0.043
31.75 1
1/4
1.10 0.043
34.92 1
3/8
1.21 0.048
38.10 1
1/2
1.35 0.053
41.28 1
5/8
1.43 0.056
44.45 1
3/4
1.60 0.063
50.80 2 2.00 0.079
53.98 2
1/8
2.10 0.083
t
For pipes larger than Ø 3/4" (Ø 19.05mm), drawn type (C1220T-1/2H or C1220T-H) type copper pipe must be
used. If a annealed type (C1220T-O) copper pipe is used, pipe may break due to its low pressure resistance and
cause personal injury.
CAUTION