Note on Adding Refrigerant
Some systems require additional charging depending on pipe lengths. The standard
pipe length varies according to local regulations. For example, in North America, the
standard pipe length is 7.5m (25'). In other areas, the standard pipe length is 5m (16'). The
refrigerant should be charged from the service port on the outdoor unit's low pressure valve.
The additional refrigerant to be charged can be calculated using the following formula:
ADDITIONAL REFRIGERANT PER PIPE LENGTH
Connective Pipe
Air Purging
Length (m)
Method
≤ Standard pipe
Vacuum Pump
length
> Standard pipe
Vacuum Pump
length
For R290 refrigerant unit, the total amount of refrigerant to be charged is no more than:
387g (<=9000Btu/h), 447g (>9000Btu/h and <=12000Btu/h), 547g (>12000Btu/h and
<=18000Btu/h), 632g (>18000Btu/h and <=24000Btu/h).
CAUTION DO NOT mix refrigerant types.
Page 20-GB
Liquid Side: ø6.35 (ø0.25")
R32:
(Pipe length – standard length) × 12g/m
(Pipe length – standard length) × 0.13oZ/ft
R290:
(Pipe length – standard length) × 10g/m
(Pipe length – standard length) × 0.10oZ/ft
R410A:
(Pipe length – standard length) × 15g/m
(Pipe length – standard length) × 0.16oZ/ft
R22:
(Pipe length – standard length) × 20g/m
(Pipe length – standard length) × 0.21oZ/ft
Additional Refrigerant
N/A
Liquid Side: ø9.52 (ø0.375")
(Pipe length – standard length) × 24g/m
(Pipe length – standard length) × 0.26oZ/ft
(Pipe length – standard length) × 18g/m
(Pipe length – standard length) × 0.19oZ/ft
(Pipe length – standard length) × 30g/m
(Pipe length – standard length) × 0.32oZ/ft
(Pipe length – standard length) × 40g/m
(Pipe length – standard length) × 0.42oZ/ft
R32:
R290:
R410A:
R22: