In which scenario is a refrigeration cycle considered efficient?

A refrigeration cycle is considered efficient when the heat absorption is high compared to the work input. This means that for a given amount of energy (work) expended to move heat, the system is able to absorb a significant amount of heat from the refrigerated space. Efficiency in a refrigeration process is fundamentally about maximizing the heat extracted while minimizing the energy consumed in doing so.

In practical terms, this relates to the Coefficient of Performance (COP) of the refrigeration cycle, which is defined as the ratio of heat removed from the refrigerated space to the work input. A higher COP indicates a more efficient system because it shows that the refrigeration system is capable of transferring a larger quantity of heat for each unit of work put into the process.

In contrast, low refrigerant pressure, high compression ratios, or high evaporator temperatures can all lead to increased energy costs or reduced overall system effectiveness. Therefore, choosing scenarios where the cycle optimally utilizes energy to absorb heat directly leads to greater efficiency and effectiveness in the refrigeration application.