Refrigeration is no simple subject. This is contrary to the common belief by many that refrigeration is mainly about cooling or coldness. The practice of refrigeration engineering is actually all about heat transfer. The term refrigeration could therefore be defined as heat energy removal so that a certain matter or space is colder than its surroundings. Heat energy is a form of energy that cannot be made, wiped out, or seen. On the other hand, heat energy can be moved. This concept encapsulates what is known as refrigeration.

To be able to understand the theory of refrigeration, one must consider the fact that cold is merely the nonexistence of heat. Heat must therefore be displaced in such equipment as the household refrigerator. First, the heat is taken by the evaporator which is then carefully displaced to the external parts of the refrigerator through the condenser. The condenser would be the one to make cooler air out of the transferred heat.

There are many uses for refrigeration-industrial refrigeration is more recognized when such words as refrigeration plants, ice plants, food processing companies, freeze drying, breweries, wineries, tube ice, crushed ice, or ice cubes are mentioned. Here are the qualifying features for industrial refrigeration:

• The size should be 100 tons or even larger
• The use of ammonia R-717
• A centralized system
• -60 to 55 degrees Fahrenheit of load temperature with usually at least a single load below 40 degrees Fahrenheit.

Ammonia refrigeration plays a huge part on the ever-growing refrigeration industry. All over the world, there is a growing interest on the use of ammonia as a refrigerant. Since chlorine and fluorine have had restrictions, ammonia has since become popular and has emerged as a widely-used refrigerant. Also, since chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) are now pending when it comes to the area of refrigeration, ammonia would, in the next few years, still continue to rise as one of the leading refrigerants in the world.

The refrigeration grade for ammonia is at 99.98 percent pure and is quite free of impurities such as water. This is also readily available and cheap-and its most qualifying feature to become an efficient refrigerant is its high absorption of heat.

Ammonia is an effective ingredient in refrigerating food and beverages. It may be considered as highly hazardous because of its irritating odors and corrosiveness but this compound is hardly combustible; hence, it is now widely used on air conditioning units and food processing plants.

Looking at all these aspects of refrigeration, one can deduce that it is far from simple; and it has many benefits to modern society. Minus these benefits, man would definitely not be able to cope with the onslaught of modernization.