When the amount of refrigerant is low, the performance of the air conditioning is reduced. Overfilling also has a bad influence on the air conditioning system.
Therefore, if abnormal operation is found, we recommend that the system be inspected by an authorized Kia dealer.
WARNING - Vehicles equipped with R-134a

Because the refrigerant is at very high pressure, the air conditioning system should only be serviced by trained and certified technicians. It is important that the correct type and amount of oil and refrigerant is used.
Otherwise, it may cause damage to the vehicle and personal injury.
WARNING - Vehicles equipped with R-1234yf

Because the refrigerant is mildly inflammable and at very high pressure, the air conditioning system should only be serviced by trained and certified technicians. It is important that the correct type and amount of oil and refrigerant is used.
Otherwise, it may cause damage to the vehicle and personal injury.
Air Conditioning refrigerant label
Automatic climate control systemKia Niro 2017 (DE HEV) Service Manual: Clutch Actuator Assembly Specifications
Specifications
Item
Condition
Specification
Resistance (line to line)
Motor 1
57 mΩ ± 10 %
Motor 2
57 mΩ ± 10 %
Rated voltage
12 V
...
Kia Niro 2017 (DE HEV) Service Manual: AC Inverter Unit Repair procedures
Removal
1.
Disconnect the negative (-) battery terminal.
2.
Remove the luggage side trim [RH].
(Refer to Body - "Luggage Side Trim")
3.
Disconnect the AC inverter unit connector (A).
...