About freezers:

In technical terms a freezer is referred to those appliances that keeps or maintains in the temperature inside the device below the freezing the point. The freezers generally keep their contents in a frozen state. Generally most of the freezers that are used operate at around minus 18 degrees Celsius. Generally the freezers that are used for domestic purposes are upright units, resembling refrigerators, or chests, resembling upright units laid on their backs. Many modern freezers that have evolved newly are equipped with ice making facilities. Before the evolution of the home freezers the commercial freezers were used widely during the first half of the 19th century. Most of these systems used toxic ammonia gas systems that made them unfit for their usage at homes.

Working principle of the freezers:

The domestic freezers were introduced in the year 1930 for the first time in the United States. It is worthy to note that in that time almost 60 % of the house holds used the freezers.

The main working principle of a refrigerator is based on heat exchange. The freezing effect of the refrigerator comes from the use of the heat pumps that operates in a refrigeration cycle. Generally the freezers consist of either a freezing compartment. Most of the house holds freezers uses the vapor compression cycle. This cycle uses a circulating refrigerant such as Freon that enters into the compressor as a vapor at its boiling point. The vapor is then compressed and exits the compressor as a superheated vapor. This superheated vapor then travels into different parts of the condenser which removes the superheat of the vapor by cooling it. The cooled vapor then travels through the remaining part of the condenser and is condensed into a liquid. The saturated liquid refrigerant almost turns into a partially vaporized refrigerant and is then circulated throughout the freezer with a fan. This partially vaporized refrigerant extracts the heat from the air inside the food compartment of the freezer and turns the temperature of the freezer's interior into chilling. Thus, the compressor freezers maintain such low temperatures within themselves.