1. Frosting will happen when there is a relatively lower pressure of refrigerant in the evaporator coil.

2. This low pressure could be due to either :

     (a) malfunction of compressor – unable to develop the optimum high pressure needed.

     (b) refrigerant leakages in the system.

     (c) dirty filter/drier.

     (d) dirty strainer of the TEV.

3. This cause the operating temperature of the refrigerant to reach very close to or at or below the

     freezing point of water

4. In an environment with high relative humidity, ice will be formed on the evaporator coils.