Refrigerant Piping
The Amount of Refrigerant
1. Normal condition
The calculation of the additional charge should take into account the length of pipe.
Product Charge(kg(lbs))
A
B
Additional charge(kg(lbs))
=
Total liquid pipe (m(ft))
Additional refrigerant charge
x
amount per liquid pipe 1m(3.3ft)
(Table 1)
+
Correction Factor (kg(lbs))
(Table 2)
Total amount(kg(lbs))
Table 1
Pipe diameter at
Ø6.35(1/4)
liquid side(mm(inch))
Additional
Refrigerant
amount (lbs/ft)
2. Special condition
In case of the No. of CST TE/RAC SE 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.
I Additional refrigerant charging amount (kg(lbs))
= (A x
+ B x ß) - (AVG x ß)
• A = Total No. of TE and SE Indoor units,
• B = Total No. of except TE and SE Indoor units, ß = 0.3
• AVG = 50% of Max. No. of connectable Indoor units.
Example)
1) Installation Information
- Outdoor unit : 5HP
- Total indoor units : 6 units (TE 3 units, SE 2 units, BH 1 unit)
2) Information from PDB
- Max. No. of connectable indoor units : 8 units
- Calculated additional refrigerant amount = 2kg(4.4lbs)
3) Additional refrigerant charging amount
= (5 units x 0.5+1 unit x 0.3) - (5 units x 0.3) = 1.3kg(2.9lbs)
Revised the total refrigerant charging amount = 2kg(4.4lbs) +1.3kg(2.9lbs)
30
Outdoor Unit
=
+
A
B
Ø9.52(3/8)
Ø12.7(1/2)
Ø15.88(5/8)
0.015
0.041
0.079
Example : 5 HP
L1
L1
Ø9.52:10m(32.8ft)
L2
Ø9.52:10m(32.8ft)
a
Ø9.52:3m(9.8ft)
b
Ø6.35:3m(9.8ft)
Additional charge amount R (kg)
= (Lx x 0.022kg/m) + (Ly x 0.061kg/m) + Correction factor
= (12 x 0.022kg/m) + (28 x 0.061kg/m) + 0
= 1.972
Additional charge amount R (Ibs)
= (Lx x 0.015kg/m) + (Ly x 0.041kg/m) + Correction factor
= (39 x 0.015kg/m) + (92 x 0.041kg/m) + 0
= 4.357
Ø19.05(3/4)
Ø22.2(7/8)
0.116
0.178
0.237
= 0.5
=3.3kg(7.3lbs)
L2
L3
a
b
c
L3
Ø9.52:5m(16.4ft)
c
Ø6.35:4m(13.1ft)
Lx : Real total length of liquid pipe
Ø6.35mm(1/4inch)
Ly : Real total length of liquid pipe
Ø9.52(mm)(3/8inch)
Table 2
HP
PRODUCT CHARGE(kg(Ibs))
3.7(8.2)
CF(kg(Ibs))
-0.5(-1.1)
d
d
Ø6.35:5m(16.4ft)
4
5
3.7(8.2)
0(0)