Applications of Refrigeration

What is Refrigeration?

Refrigeration deals with the cooling of bodies or fluids to temperatures lower than those of surroundings. This involves the absorption of heat at a lower temperature and rejection to a higher temperature of the surroundings.

In olden days, the main purpose of refrigeration was to produce ice, which was used for cooling beverages, food preservation, and refrigerated transport, etc. Nowadays refrigeration and air conditioning find so many applications that they have become very essential for mankind, and without refrigeration and air conditioning, the basic fabric of the society will be adversely affected. Refrigeration and air conditioning are generally treated in a
single subject due to the fact that one of the most important applications of refrigeration is in cooling and dehumidification as required for summer air conditioning. Of course, refrigeration is required for many applications other than air conditioning, and air conditioning also involves processes other than cooling and dehumidification.

Applications of Refrigeration
For the convenience of study, refrigeration applications may be grouped into four general categories:

1. Domestic refrigeration.

2. Commercial refrigeration.

3. Industrial refrigeration.

4. Marine and transport refrigeration.

1. Domestic Refrigeration

Domestic refrigeration is rather limited in scope, being concerned primarily with household refrigerators and home freezers, however, because the number of units in service is quite large, domestic refrigeration represents a significant portion of the refrigeration industry.

Domestic units are usually small in size, having power input ratings of between 35 W and 375 W and are of the hermetically sealed type. Since these applications are familiar to everyone, they will not be described further here. However, the problems encountered in the design and maintenance of these units can be studied from any standard book regarding Refrigeration and Air Conditioning.

2. Commercial Refrigeration

Commercial refrigeration is concerned with the designing, installation, and maintenance of refrigerated fixtures of the type used by retail stores, restaurants, hotels, and institutions for the storing, displaying, processing, and dispensing of perishable commodities of all types.

3. Industrial Refrigeration

Industrial refrigeration is often confused with commercial refrigeration because the division between these two areas is not clearly defined. As a general rule, industrial applications are larger in size than commercial applications and have the distinguishing feature of requiring an attendant on duty, usually a licensed operating engineer. Typical industrial applications are ice plants, large food- packing plants (meat, fish, poultry, frozen foods, etc.), breweries, creameries, and industrial plants, such as oil refineries, chemical plants, rubber plants, etc. Industrial refrigeration includes also those applications that are concerned with the construction industry.

4. Marine and Transportation Refrigeration

Applications falling into this category could be listed partly under commercial refrigeration and partly under industrial refrigeration. However, both these areas of specialization have grown to sufficient size to warrant special mention Marine refrigeration, of course, refers to refrigeration aboard marine vessels, and includes, for example, refrigeration for fishing boats and for vessels transporting perishable cargo as well as refrigeration for the ships stores on vessels of all kinds.

Transportation refrigeration is concerned with refrigeration equipment as it is applied to trucks, both long-distance kinds of transport and local delivery, and to refrigerated railway cars.