Note On Adding Refrigerant - Midea MTI-24FNXD0 MOU-24FN1-QD0 Instruction Manual

Note On Adding Refrigerant

CAUTION
• Refrigerant charging must be performed after wiring, vacuuming, and the leak testing.
DO NOT exceed the maximum allowable quantity of refrigerant or overcharge the system.
•
Doing so can damage the unit or impact it's functioning.
• Charging with unsuitable substances may cause explosions or accidents. Ensure that the
appropriate refrigerant is used.
• Refrigerant containers must be opened slowly. Always use protective gear when charging the
system.
DO NOT mix refrigerants types.
•
• For the R290 or R32 refrigerant model, make sure the condtions within the area have been
made safe by control of ammable material when the refrigerant added into air conditioner.
• The maximum refrigerant charge amount of R32 is 305 grams.
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 additional refrigerant to be
charged can be calculated using the following formula:
R22
(orifice tube in the indoor unit):
R22
(orifice tube in the outdoor unit):
R410A:
(orifice tube in the indoor unit):
R410A:
(orifice tube in the outdoor unit):
R32 :
 Page 28 
Liquid Side Diameter
φ6.35(1/4") φ9.52(3/8")
(Total pipe length - (Total pipe length -
standard pipe length)x standard pipe length)x
30g (0.32oZ)/m(ft) 65g(0.69oZ)/m(ft)
(Total pipe length - (Total pipe length -
standard pipe length) standard pipe length)
x15g(0.16oZ)/m(ft) x30(0.32oZ)/m(ft)
(Total pipe length - (Total pipe length -
standard pipe length) standard pipe length)
x30g(0.32oZ)/m(ft) x65g(0.69oZ)/m(ft)
(Total pipe length - (Total pipe length -
standard pipe length) standard pipe length)
x15g(0.16oZ)/m(ft) x30g(0.32oZ)/m(ft)
(Total pipe length - (Total pipe length -
standard pipe length)x standard pipe length)x
12g(0.13oZ)/m(ft) 24g(0.26oZ)/m(ft)
φ12.7(1/2")
(Total pipe length -
standard pipe length)x
115g(1.23oZ)/m(ft)
(Total pipe length -
standard pipe length)
x60g(0.64oZ)/m(ft)
(Total pipe length -
standard pipe length)
x115g(1.23oZ)/m(ft)
(Total pipe length -
standard pipe length)
x65g(0.69oZ)/m(ft)
(Total pipe length -
standard pipe length)x
40g(0.42oZ)/m(ft)