38
Outside Unit
Calculation of amount of refrigerant
Refrigerant piping system
The calculation of the additional charge should take into account the length of pipe.
Product Charge(kg(lbs))
Additional charge (kg(lbs))
=
+
+
+
+
+
+
=
+
x 0.237 lbs/ft
x 0.178 lbs/ft
x 0.116 lbs/ft
x 0.079 lbs/ft
x 0.041 lbs/ft
x 0.015 lbs/ft
CF(kg(lbs))
(Correction Factor)
If a negative result is obtained from
the calculation, no refrigerant needs
to be added.
A
A
B
B
CAUTION
Total liquid pipe (m(ft)): Ø22.2mm(7/8inch)
Total liquid pipe (m(ft)): Ø19.05mm(3/4inch)
Total liquid pipe (m(ft)): Ø15.88mm(5/8inch)
Total liquid pipe (m(ft)): Ø12.7mm(1/2inch)
Total liquid pipe (m(ft)): Ø9.52mm(3/8inch)
Total liquid pipe (m(ft)): Ø6.35mm(1/4inch)
Total amount(kg(lbs))
Outside unit
Header branch
Indoor
unit
Ex) 10HP
Additional Charge = A x 0.041 + B x 0.041 + C x 0.041
+ D x 0.041 + E x 0.015 + HR + CF
= 164 x 0.041 + 33 x 0.041 + 33 x 0.041
+ 33 x 0.041 + 33 x 0.015 + 0(CF)
=
11.3lbs(5.1kg)
A : Ø9.52(3/8), 50m(164ft)
B : Ø9.52(3/8), 10m(33ft)
C : Ø9.52(3/8), 10m(33ft)
D : Ø9.52(3/8), 10m(33ft)
E : Ø 6.35(1/4), 10m(33ft)
u
Special condition
In case of the No. of CST 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.
n
Additional refrigerant charging amount (kg(lbs)) :
Ⓒ
= (A x
α
+ B x ß) - (AVG x ß)
• A = Total No. of TQ, SE and SF Indoor units,
α
= 0.5
• B = Total No. of except 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 = 2kg (4.41lbs) :
Ⓑ
3) Indoor refrigerant charging amount
= (5 units x 0.5+1 unit x 0.3) - (8 units x 0.3) = 0.4 kg(0.88lbs) :
Ⓒ
▶
Revised the total additional charging amount =
Ⓑ + Ⓒ
= 2kg (4.41lbs) + 0.4 kg(0.88lbs)
= 2.4 kg(5.29lbs)
+
=
Total amount(kg)
A
B
+
C