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A freezer is an appliance which provides a temperature below the point at which water freezes (-17°C). Therefore, a freezer differs from a refrigerator, or 'fridge' for short, which maintains a heat slightly above the point where water freezes. The history of the freezer is more extensive, notably the 'Icebox', which was a wooden or metal box with a block of ice and mechanism providing a circulation of air. There has been numerous mechanisms designed to freeze food. By the turn of the 20th century, the 'Icebox', or 'Icehouse', was by far the most widespread. Before this date, artificial attempts to freeze food, such as using toxic materials like ammonia, proved too hazardous to health. The first commercially successful mechanical freezer used methyl formate or sulfur dioxide as a refrigerant. The first non-toxic refrigerant was 'Freon', which was non-flammable and designed by DuPont. Only recently was it found that 'Freon' had a negative effect to the Earth's ozone layer, so was fazed out or banned by some countries by the 1980's. In recent decades alot of effort have been made to make fridges more environmentally friendly. Freezers have always been a domestic appliance which consumed alot of electrical resource. No doubt, in part, due to operating non-stop. Modern freezers now consume alot less energy, and use a refrigerant called 'HFC-134a', which has no negative effect to the ozone layer. It has taken time for freezers to penetrate the consumer market worldwide. While freezer's were sold in large numbers in the US by the 1940's, they were still too expensive for most other nations, costing nearly the same as a brand new car. Only by the 1970's did Europe and the UK reach the same domestic sales
figures as the US.
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Freezer
