What style of system uses liquid pumps to transfer liquid to evaporators?

The correct choice refers to the overfeed system style, which is characterized by the use of liquid pumps to transfer refrigerant liquid to evaporators. In this system, the refrigerant is pumped in excess to ensure that the evaporators are adequately flooded with refrigerant, leading to efficient heat exchange and improved cooling capacity. By delivering liquid refrigerant directly and in abundance to the evaporators, the overfeed system enhances performance, particularly in applications that require a constant and controlled flow of refrigerant.

In contrast, the direct expansion (DX) system typically relies on the evaporation of refrigerant within the evaporator coils without the need for pumps, utilizing a metering device to regulate the flow. The flooded system also generally involves a different approach by maintaining a higher level of liquid refrigerant in the evaporator without active pump circulation. Each of these systems operates differently, and understanding their operational principles helps clarify why the overfeed system is identified specifically for its use of liquid pumps.