Which statement best describes the operation of a single acting compressor?

The operation of a single acting compressor is characterized by its design, which allows the compression to occur on only one side of the piston during each cycle. When the piston moves in one direction, it compresses the gas in the compression chamber on that side. As the piston reaches the end of its stroke, the gas is discharged, and the return stroke allows the piston to draw in more gas, but this occurs without any compression on the return side. This distinct mechanism is what differentiates a single acting compressor from other types, such as double acting compressors, which compress gas on both sides of the piston, thereby increasing efficiency and capacity.

In the context of the question, the other options do not accurately describe the function of a single acting compressor. For instance, the idea that the compressor operates continuously reflects more on the operational aspect of specific models or types rather than the fundamental design of single acting compressors. Similarly, the mention of an inverter drive pertains to speed control technology and is not inherently related to the classification of the compressor as "single acting." Thus, the selection stating that the refrigerant gas is compressed on only one side of the piston is the most accurate description of how a single acting compressor operates.