All professionals in the field of low-temperature technologies are strongly encouraged to strictly adhere to the internationally established and approved definitions, by the International Institute of Refrigeration and the ASHRAE, of the following words: cooling, refrigeration, chilling, freezing and cold chain.

Last year, a group of experts from the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) and the International Institute of Refrigeration (IIR) came together to establish universal definitions of five essential terms characterizing the refrigeration sector.

The IIR calls on all national refrigeration organizations and associations, as well as all HVACR professionals to adopt and disseminate these five key definitions across their publications and activities!

The five fundamental terms of refrigeration:

  • Cooling: Removal of heat, usually resulting in a lower temperature and/or phase change, and lowering temperature.
  • Refrigeration: Cooling of a space, substance or system to lower and/or maintain its temperature below the ambient one (removed heat is rejected at a higher temperature). Artificial cooling.
  • Chilling: Cooling of a substance without freezing it.
  • Freezing: Solidification phase change of a liquid or the liquid content of a substance, usually due to cooling.
  • Cold Chain: Series of actions and equipment applied to maintain a product within a specified low-temperature range from harvest/production to consumption.

The IIR International Dictionary of Refrigeration

These five terms can be found in the IIR International Dictionary of Refrigeration.

The Dictionary contains more than 4,300 words in all fields of refrigeration - including air conditioning – as well as their translations in 11 languages.

Consult the Dictionary at

About IIR

The International Institute of Refrigeration (IIR) is an independent intergovernmental science and technology-based organisation promoting refrigeration knowledge and associated technologies that improve quality of life in a cost-effective and environmentally sustainable manner including:

  • Food quality and safety from farm to consumer
  • Comfort in homes and commercial buildings
  • Health products and services
  • Low temperature technology and liquefied gas technology
  • Energy efficiency
  • Use of non-ozone depleting and low global warming refrigerants in a safe manner.