Which component is critical in preventing ice build-up in a refrigeration system?

The thermostatic expansion valve (TXV) plays a crucial role in preventing ice build-up in a refrigeration system by regulating the flow of refrigerant into the evaporator. Its primary function is to maintain the correct superheat, which is the temperature of the refrigerant vapor above its boiling point at a given pressure. By ensuring that the right amount of refrigerant enters the evaporator based on the cooling load, the TXV prevents the evaporator from becoming too cold, which can lead to excessive moisture freezing on the evaporator coil.

When the evaporator temperature is well-controlled and the superheat is appropriately maintained, it reduces the risk of moisture in the air condensing and freezing on the evaporator. This is predominantly why ice build-up is mitigated, as the TXV responds to the changing conditions in the evaporator, allowing just enough refrigerant to promote efficient heat exchange without dropping the temperature excessively.

Other components, while important for overall operation, do not have the same direct impact on preventing ice formation within the system.