GCAP Industrial Ammonia Refrigeration Training Practice Test - Exam Prep & Study Guide

The overfeed system is accurately identified as the type that employs a liquid pump to transfer liquid to evaporators. In this configuration, the liquid refrigerant is delivered in excess or "overfed" into the evaporators. This ensures that the evaporator coils receive a consistent supply of liquid refrigerant, which is crucial for maintaining efficient heat absorption and enhancing the refrigeration process.

One key feature of the overfeed system is that it allows for better control over the refrigerant flow, which can lead to more efficient operation and better cooling performance. The pump's role is to ensure that liquid refrigerant circulates optimally, allowing for efficient evaporator function and preventing issues such as coil starvation that could occur if the refrigerant supply were insufficient.

In contrast, while flooded systems do involve liquid refrigerant, they primarily depend on the natural circulation and pressure differential rather than utilizing a pump to actively feed the evaporators. Direct expansion systems, on the other hand, operate by allowing the refrigerant to expand and vaporize directly in the evaporator without additional pumping, and shell and tube systems mainly refer to a type of heat exchanger design rather than a specific refrigeration system type.