Additional charging amount for Twin type
Pre-charge length < L1 + L2 + L3
The additional charging amount will be calculated as follows.
• A: Piping length (m) of liquid pipe with outside diameter of 9.52 mm (1/2 in)
• B: Piping length (m) of liquid pipe with outside diameter of 6.35 mm (3/8 in)
• Additional charging amount (g) = (A × 40) + (B × 20) - 1,200
NOTE:
Do not remove refrigerant, even if the additional amount calculated is negative.
Example:
Indoor unit
24,000 Btu/h
Indoor unit
24,000 Btu/h
Outdoor unit
54,000 Btu/h
Liquid pipe (mm)
Gas pipe (mm)
6.35
12.70
L2: 15 m
Liquid pipe (mm)
Gas pipe (mm)
6.35
12.70
L3: 7 m
Liquid pipe (mm)
Gas pipe (mm)
9.52
15.88
L1: 20 m
Liquid pipe diameter (mm) Piping length (m) Coefficient
9.52 20 A = 20
6.35 22 B = 22
Applying the formula,
(20 × 40) + (22 × 20) - 1,200 = 40
The additional charging amount is 40 g.
- 99 -
2-5. Additional charge calculation 2. Pipe design
SYSTEM
DESIGN
SYSTEM
DESIGN