What is the main substance used to produce refrigeration through expansion or vaporization?

The main substance used to produce refrigeration through expansion or vaporization is the refrigerant. Refrigerants are specially formulated fluids that absorb heat from their surroundings during the vaporization process, thereby cooling the area around them. In a refrigeration cycle, the refrigerant transitions between liquid and gas states. When the refrigerant expands, it evaporates and absorbs heat, resulting in a cooling effect. This process is fundamental to the operation of refrigeration systems, as refrigerants carry heat away from the environment being cooled.

In contrast, while a coolant may refer to substances that can transfer heat away from a system, it does not specify the phase change utilized primarily in refrigerating systems. Condensate refers to the liquid that forms when vapor cools, typically in a different context unrelated to refrigeration cycles directly. Lastly, compressor fluid might suggest the lubricant or liquid used in the operation of compressors but does not refer specifically to the fluid responsible for absorbing heat in the refrigeration process.