Installation
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7.6 Calculation of amount of refrigerant
The calculation of the additional charge should take account of the diameter and length of the pipe.
◆
Special condition
In case of the No. of CST TE, TQ/RAC SE/ARTCOOL SF models are over than 50% of the connected
indoor units when the total No. of connected indoor units are over than 50% of the max. connectable
indoor units.
■
Additional refrigerant charging amount (kg) :
= (A x + B x ß) - (AVG x ß)
• A = Total No. of TE, TQ, SE and SF Indoor units,
= 0.5
• B = Total No. of except TE, TQ, SE and SF Indoor units, ß = 0.3
• AVG = 50% of Max. No. of connectable Indoor units.
Example)
1) Installation Information
- Outside unit : 10HP
- Total indoor units : 6 units (TQ 3 units, SE 2 units, BH 1 unit)
2) Information from PDB
- Max. No. of connectable indoor units : 16 units
- Calculated additional refrigerant amount = 2 kg :
3) Indoor refrigerant charging amount
= (5 units x 0.5+1 unit x 0.3) - (8 units x 0.3) = 0.4 kg :
Revised the total additional charging amount =
= 2 kg + 0.4 kg
= 2.4 kg
+
=
Total amount(kg)
A
B
+
C
Additional charge (kg)
Product Charge(kg)
=
+
+
+
+
+
+
=
+
Total liquid pipe (m): Ø22.2mm
x 0.354(kg/m)
x 0.266(kg/m)
x 0.173(kg/m)
x 0.118(kg/m)
x 0.061(kg/m)
x 0.022(kg/m)
Total liquid pipe (m): Ø19.05mm
Total liquid pipe (m): Ø15.88mm
Total liquid pipe (m): Ø12.7mm
Total liquid pipe (m): Ø9.52mm
Total liquid pipe (m): Ø6.35mm
CF(kg)
(Correction Factor)
Total amount(kg)
If a negative result is obtained from
the calculation, no refrigerant needs
to be added.
A
A
B
B
CAUTION
Outside unit
Header branch
Indoor unit
Ex) 10HP
Additional Charge = A x 0.061 + B x 0.061 + C x 0.061
+ D x 0.061 + E x 0.022 + CF
= 50 x 0.061 + 10 x 0.061 + 10 x 0.061
+ 10 x 0.061 + 10 x 0.022 + 0(CF)
= 5.1kg
A : Ø9.52, 50m
B : Ø9.52, 10m
C : Ø9.52, 10m
D : Ø9.52, 10m
E : Ø6.35, 10m
