A freezer is a common machine that consists of a thermally insulated compartment and a heat pump (mechanical, electronic, or chemical) that transfers heat from the inside of the freezer to its external environment so that the inside of the freezer is cooled to a temperature below the ambient temperature of the room.
Now, refrigeration is an essential food storage technique. The lower temperature lowers the reproduction rate of bacteria, so the freezer reduces the rate of spoilage. A freezer maintains a temperature a few degrees above the freezing point of water. Optimum temperature range for perishable food storage is 3 to 5 °C (37 to 41 °F). A similar device that maintains a temperature below the freezing point of water is called a freezer.
The first cooling systems for food involved using ice. Artificial refrigeration began in the m-i-d 1750s, a-nd developed in the early 1800s. In 1834, the first working vapor-compression refrigeration system was built. The first commercial ice-making machine was invented in 1854. In 1913, freezers were invented. In 1923 Frigidaire introduced the first self-contained unit. The introduction of Freon in the 1920s expa-nded the freezer market during the 1930s.
Freezer units are used in households and in industry and commerce. Commercial freezer units were in use for almost forty years prior to the common home models.