Both air-conditioning and industrial refrigeration are based on the same mechanism: the cooling of a substance. The refrigerating system made up of a compressor, evaporator, fan, condenser and expansion device, is the heart of both systems. Despite this, there are substantial differences between the systems, the components used, the design methods and the structures they are used in, such as to merit separate treatment.

Air-conditioning is the process that allows specific temperature, relative humidity and air purity conditions to be created and maintained in a closed environment. Independently of the external climatic conditions, this process ensures, by controlling four variables (temperature, humidity, air movement and air quality), personal comfort, the correct storage of objects or mechanisms, and the maintenance of the correct conditions for certain phases in industrial processing.
In regards to air handling, industrial air-conditioning differs in a number of ways from air-conditioning for personal comfort.
In particular, industrial air-conditioning requires greater precision in regards to the control of temperature and humidity, the filtering standard and the removal of contaminants. Air-conditioning for personal comfort, as well as satisfying the temperature and humidity requirements of the people present, also falls into other disciplines, such as architectural design, meteorology, energy and acoustics, in order to re-create the ideal conditions for human psychological and physiological well-being.

The main process that air-conditioning is based on is the exchange of heat and water vapour between the inside environment, the outside environment and the people present.