To improve refrigeration efficiency, what should be reduced at the compressor inlet?

The correct choice focuses on the concept of specific volume, which is the volume occupied by a unit mass of a substance. In a refrigeration system, reducing the specific volume at the compressor inlet means that the refrigerant entering the compressor is more concentrated, or in other words, there is less volume of vapor for the same mass of refrigerant. This improves the thermal efficiency of the compression process.

When specific volume is reduced, the compressor can work more efficiently because it compresses a denser gas. This leads to a higher discharge pressure and better overall system performance. Improving the suction conditions, such as by ensuring a lower specific volume, allows the compressor to operate closer to its optimal efficiency, thus enhancing the overall refrigeration cycle.

While reducing liquid volume, suction pressure, or ambient temperature could have effects on refrigeration performance, they do not directly relate to the efficiency gained through adjusting specific volume at the compressor inlet, which is the key factor in achieving enhanced compression and efficiency within the system.