What is a "ton" of refrigeration defined as?

A "ton" of refrigeration is defined specifically as the amount of heat required to melt 1 ton of ice at 32°F over the course of 24 hours. This definition is rooted in the historical context of refrigeration, where ice was used for cooling and the capacity of refrigeration systems was measured based on how much ice they could produce or melt.

The 12,000 BTUs (British Thermal Units) per day required to melt this quantity of ice directly correlates to the cooling effect that refrigeration systems must provide. Thus, this measurement serves as a standard unit in the industry to quantify the capacity of refrigeration systems, giving engineers and technicians a clear understanding of their operational capabilities in terms of cooling.

The other options reference operational settings or conditions involving chillers, but they do not accurately describe the standard definition of a "ton" of refrigeration, which is tied directly to the melting of ice at a specific temperature.