Note On Adding Refrigerant - Midea MS-09CRFB Installation Manual

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:
Connective Pipe Air Purging
Length (m) Method
< Standard pipe length Vacuum Pump
> 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
ADDITIONAL REFRIGERANT PER PIPE LENGTH
Liquid Side: Ø 6.35 (ø 0.25")
R32:
(Pipe length – standard length) x 12g/m
(Pipe length – standard length) x 0.13oZ/ft
R290:
(Pipe length – standard length) x 10g/m
(Pipe length – standard length) x 0.10oZ/ft
R410A:
(Pipe length – standard length) x 15g/m
(Pipe length – standard length) x 0.16oZ/ft
R22:
(Pipe length – standard length) x 20g/m
(Pipe length – standard length) x 0.21oZ/ft
mix refrigerant types.
Additional Refrigerant
N/A
Liquid Side: Ø 9.52 (ø 0.375")
(Pipe length – standard length) x 24g/m
(Pipe length – standard length) x 0.26oZ/ft
(Pipe length – standard length) x 18g/m
(Pipe length – standard length) x 0.19oZ/ft
(Pipe length – standard length) x 30g/m
(Pipe length – standard length) x 0.32oZ/ft
(Pipe length – standard length) x 40g/m
(Pipe length – standard length) x 0.42oZ/ft
R32:
R290:
R410A:
R22:
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