Fujitsu AJ**A72LBTF - Page 30

En-30
A = + +
B =+++
+
Total length of
ø19.05 mm
liquid pipe
m
kg
× 0.268
kg/m
Total length of
ø15.88 mm
liquid pipe
m
kg
× 0.178
kg/m
Total length of
ø12.70 mm
liquid pipe
m
kg
× 0.114
kg/m
Total length of
ø9.52 mm
liquid pipe
m
kg
× 0.058
kg/m
Total length of
ø6.35 mm
liquid pipe
m
kg
× 0.021
kg/m
Additional charge calculation formula
• Additional refrigerant charge amount is calculated according to calculated value from its pipe length of liquid pipe and additional
amount for outdoor unit.
• Round up the calculated result to two decimal places.
Calculation of additional charge refrigerant
1. Calculation of additional amount for outdoor unit
Outdoor unit 1
additional amount for
outdoor unit
kg
Outdoor unit 2
additional amount for
outdoor unit
kg
Outdoor unit 3
additional amount for
outdoor unit
kg
2. Calculation of additional amount for pipe length
3. Calculation of additional charge refrigerant
C = A + B
Calculation example) Where 3 outdoor units (AJ
126LBTF, AJ A90UBTF and AJ A72UBTF) are connected in a system.
1. Calculation of additional amount for outdoor unit:
A = 3.70 (kg) + 2.20 (kg) + 2.20 (kg)
= 8.10 (kg)
2. Calculation of additional amount for pipe length:
In case refrigerant piping lengths are as below
ø19.05: 50 m, ø15.88: 25 m, ø12.70: 0 m, ø9.53: 20 m, ø6.35: 15 m
Additional amount for pipe length:
B = 50 (m) × 0.268 (kg/m) + 25 (m) × 0.178 (kg/m) + 0 (m) × 0.114 (kg/m) + 20 (m) × 0.058 (kg/m) + 15 (m) × 0.021 (kg/m)
= 19.325 (kg)
3. Calculation of additional charge refrigerant:
C = A + B = 8.10 (kg) + 19.33 (kg)
= 27.43 (kg)
AJ A72LBTF 11.8 2.2
AJ
A90LBTF 11.8 2.2
AJ
126LBTF 11.8 3.7
AJ
A72UBTF 11.8 2.2
AJ
A90UBTF 11.8 2.2
AJ
126UBTF 11.8 3.7
Model
Factory charged
amount (kg)
A
Additional
amount for
outdoor unit (kg)
6.35 0.021
9.52 0.058
12.70 0.114
15.88 0.178
19.05 0.268
Diameter of
liquid pipe (mm)
B
Additional
amount for pipe
length (kg/m)
9374241033_IM_en_p18-36.p65 26/8/2008, 18:2330