A ton of refrigeration (TR or TOR), also called a refrigeration ton (RT), is a
unit of
power used in some countries (especially in North America) to describe the heat-extraction capacity of
refrigeration and
air conditioning equipment.
It was originally defined as the rate of
heat transfer that results in the freezing or melting of of pure
ice at in 24 hours.
The modern definition is exactly .
Air-conditioning and refrigeration equipment capacity in the U.S. is often specified in "tons" (of refrigeration). Many manufacturers also specify capacity in BTU/h, especially when specifying the performance of smaller equipment.
History
The ton of refrigeration is equivalent to the consumption of one ton of ice per day and originated during the transition from
stored natural ice to
mechanical refrigeration. Just as
horsepower and
candlepower were intuitive units of measure for people living through the transition from
horse to steam power
"Horsepower"
''Encyclopædia Britannica Online''. Retrieved 4 July 2022. and from flame-based to electric lighting, so was the ton of refrigeration an intuitive unit of measure during a technological change, as the ice trade gradually included growing percentages of artificial ice (ice from ice-making plant) in addition to its natural ice supplies. The TR unit was developed during the 1880s. Its definition was set at the level of an industry standard in 1903, when Thomas Shipley of the York Manufacturing Company led the formation of an industry association (the Ice Machine Builders Association of the United States) along with standardization
Standardization or standardisation is the process of implementing and developing technical standards based on the consensus of different parties that include firms, users, interest groups, standards organizations and governments. Standardization ...
of several equipment specifications.
See also
* Heating, ventilation, and air conditioning
Heating, ventilation, and air conditioning (HVAC) is the use of various technologies to control the temperature, humidity, and purity of the air in an enclosed space. Its goal is to provide thermal comfort and acceptable indoor air quality. HV ...
* Joule
* Ton
References
Bibliography
*
{{United States Customary Units
Units of power
Customary units of measurement in the United States
pt:TR