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■ Table 6 Indoor Unit Tubing Connection Size
Indoor unit type 22 28 36 45 56 60 73 90 106 112 140 160 180
*1
224
*1
280
*1
Distribution joint –  
solenoid valve kit tubing
Suction tube  ø15.88
ø19.05 ø22.22
Discharge tube  ø12.70
ø15.88 ø19.05
Liquid tube ø9.52
Solenoid valve kit –  
Indoor unit tubing 
connection
Gas tube  ø12.70 ø15.88
ø19.05 ø22.22
Liquid tube  ø6.35 ø9.52
*1: For the solenoid valve kits, use CZ-P160HR3 with parallel specications. Branch the tubing before and after the solenoid valve kits.
1-7. Straight Equivalent Length of Joints
Design the tubing system by referring to the following table for the straight equivalent length of joints.
Table 7 Straight Equivalent Length of Joints
Gas tubing size (mm) 12.7  15.88  19.05  22.22  25.4  28.58  31.75  38.1 41.28
90° elbow 0.30 0.35  0.42  0.48  0.52  0.57  0.70  0.79 0.85
45° elbow 0.23 0.26  0.32  0.36  0.39  0.43  0.53  0.59 0.64
U-shape tube bent (R60-100 mm) 0.90 1.05  1.26  1.44  1.56  1.71  2.10  2.37 2.55
Trap bend 2.30  2.80  3.20  3.80  4.30  4.70  5.00  5.80 6.80
Y-branch distribution joint Equivalent length conversion not needed.
Ball valve for service Equivalent length conversion not needed.
Table 8 Refrigerant Tubing
Tubing size (mm)
Material Temper - O Material Temper - 1/2 H • H
ø6.35 t0.8 ø22.22 t1.0
ø9.52 t0.8 ø25.4 t1.0
ø12.7 t0.8 ø28.58 t1.0
ø15.88 t1.0 ø31.75 t1.1
ø19.05 t1.2 ø38.1 over t1.35
ø41.28 over t1.45
1-8. Additional Refrigerant Charge
Additional refrigerant charge amount is calculated below.
Required amount of additional refrigerant charge 
=  [ (Amount of additional refrigerant charge per meter of each size of liquid tube × its tube length) + (...) + (...)]  
+ [(Necessary amount of additional refrigerant charge per outdoor unit) + (...) + (...)] 
+ [(Necessary amount of additional refrigerant charge per meter of each size of discharge tube × its tube length) + (...) + (...)]
*Always charge accurately using a scale for weighing.
* If the existing tubing is used and the amount of on-site refrigerant charge exceeds the value listed below, change the size of the tubing 
to reduce the amount of refrigerant. 
Total amount of refrigerant for the system with 1 outdoor unit: 50 kg 
Total amount of refrigerant for the system with 2 outdoor units: 80 kg 
Total amount of refrigerant for the system with 3 outdoor units: 105 kg
Table 9 Necessary Amount of Additional Refrigerant Charge Per Meter, According to Liquid Tubing Size
Liquid tubing size (mm) 6.35  9.52  12.7   15.88  19.05  22.22 
Amount of additional 
refrigerant charge/m (g/m)
26  56   128 185  259   366 
Table 10 Necessary Amount of Additional Refrigerant Charge Per Outdoor Unit
U-8MF3R7 U-10MF3R7 U-12MF3R7 U-14MF3R7 U-16MF3R7
1.0 kg 1.0 kg 3.9 kg 3.9 kg 3.9 kg
Table 11 Refrigerant Charge Amount at Shipment (for Outdoor Unit)
U-8MF3R7 U-10MF3R7 U-12MF3R7 U-14MF3R7 U-16MF3R7
9.8 kg 9.8 kg 11.8 kg 11.8 kg 11.8 kg
*  When bending the tubes, use a bending 
radius that is at least 4 times the outer 
diameter of the tubes. 
In addition, take sufficient care to avoid 
crushing or damaging the tubes when 
bending them.
Unit: mm
00_341136_2WAY_Eng.indb   12 2022/9/19   9:27:13