3-3.Refrigerant Charging Calculation - Mitsubishi Electric CITY MULTI H Series Manual

3. Piping Design
3-3. Refrigerant charging calculation
At the time of shipping, the outdoor unit is charged with the refrigerant. As this charge does not include the amount needed
for extended piping, additional charging for each refrigerant line will be required on site. In order that future servicing may be
properly provided, always keep a record of the size and length of each refrigerant line and the amount of additional charge
by writing it in the space provided on the outdoor unit.
(1) Calculation of additional refrigerant charge
Calculate the amount of additional charge based on the length of the piping extension and the size of the refrigerant
line.
Use the table to the below as a guide to calculating the amount of additional charging and charge the system
accordingly.
If the calculation results in a fraction of less than 0.1kg, round up to the next 0.1kg. For example, if the result of the
calculation was 12.38kg, round the result up to 12.4kg.
If the calculation results in a fraction of less than 1oz, round up to the next 1oz. For example, if the result of the
calculation was 435.1oz, round the result up to 436oz.
<Additional Charge>
Total length of liquid
Additional
refrigerant charge
=
(kg)
(oz)
Table3-2-3-1. Value of
Total capacity of connecting indoor units
Models
Models
Models
Models 127
Models 145
Models 181
Models 235
Example: PUHY-HP96THMU
m [kg]
Indoor 1: P48
2: P36
3: P15
4: P12
5: P24
The total length of liquid pipe of each size is as follows:
12.7 : A = 40 = 40 m
9.52 : B + C + D + a + b + e = 10 + 15 + 10 + 10 + 5 + 10 = 60 m
6.35 : c + d = 10 + 10 = 20 m
A
Total capacity of connecting Indoor units Pt :
Pt = P48 + P36 + P15 + P12 + P24 = P135, therefore
a
P48
m [kg]
Total length of liquid
Additional
refrigerant charge
=
0 (m) x 0.29 (kg/m)
(kg)
=
= 12.4 kg
or
ft. [oz]
Total length of liquid
Additional
refrigerant charge
=
(oz) 0 (ft.) x 3.1 (oz/ft.)
=
= 436 [oz]
Total length of liquid
+
(m) x 0.29 (kg/m) (m) x 0.20 (kg/m)
(ft.) x 3.1 [oz/ft.] (ft.) x 2.15 [oz/ft.]
27 2.0 kg [71 oz]
28 54
2.5 kg [89 oz]
55 126 3.0 kg [106 oz]
144 3.5 kg [124 oz]
180 4.5 kg [159 oz]
234 5.0 kg [177 oz]
6.0 kg [212 oz]
A: 40 m a:
B: 10 m b:
15 m c:
10 m d:
e:
B C
b
P36
Total length of liquid
+
x 0.29 (kg/m) x 0.20 (kg/m)
0 (m) x 0.20 (kg/m)
0 0
+
Total length of liquid
+
x 3.1 (oz/ft.) x 2.15 (oz/ft.)
0 (ft.) x 2.15 (oz/ft.)
0 0
+
SYSTEM DESIGN
Total length of liquid Total length of liquid
+ +
(m) x 0.12 (kg/m) (m) x 0.06 (kg/m)
(ft.) x 1.29 [oz/ft.] (ft.) x 0.65 [oz/ft.]
ft. [oz]
10 m Indoor 1: P48 A:
5 m 2: P36 B:
10 m 3: P15 C:
10 m 4: P12 D:
10 m 5: P24
The total length of liquid pipe of each line is as follows:
A = 131 = 131ft.
+ a + b + e = 32 + 49 + 32 + 32 + 16 + 32 = 193ft.
Total capacity of connecting Indoor units Pt :
= 3.5kg Pt = P48 + P36 + P15 + P12 + P24 = P135, therefore
D
c d
P15 P12
Total length of liquid Total length of liquid
+ +
x 0.12 (kg/m) x 0.06 (kg/m)
40 (m) x 0.12 (kg/m) 60 (m) x 0.06 (kg/m)
40 x 0.12
+ +
Total length of liquid Total length of liquid
+ +
x 1.29 (oz/ft.) x 0.65 (oz/ft.)
131 (ft.) x 1.29 (oz/ft.) 193 (ft.) x 0.65 (oz/ft.)
131 x 1.29
+ +
Total length of liquid
+
(m) x 0.024 (kg/m)
(ft.) x 0.26 [oz/ft.]
131ft. 32ft.
32ft. b: 16ft.
49ft. c: 32ft.
32ft. d: 32ft.
e: 32ft.
= 124oz
e
P24
Total length of liquid
+
x 0.024 (kg/m)
20 (m) x 0.024 (kg/m)
60 x 0.06 20 x 0.024
+
Total length of liquid
+
x 0.26 (oz/ft.)
64 (ft.) x 0.26 (oz/ft.)
193 x 0.65 64 x 0.26
+
DATA U5
+
+ 3.5
+ 3.5
+ 124
+ 124
4 - 93