Introduction
A freezer is an appliance which provides a temperature below the point of water freezing (operate at around -17°C). Therefore it differs from a refrigerator, or 'fridge' for short, which maintains a heat slightly above when water freezes.
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Introduction cont..
The history of the freezer is more extensive, notably the 'Icebox', which was a wooden or metal box with a block of ice and a circulation of air.
There has been numerous systems designed in an attempt to freeze food. By the turn of the 20th century the 'Icebox' and 'Icehouses' were by far the most common. 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 freezers used either methyl formate or sulfur dioxide as a refrigerant. The first non-toxic refrigerant used was 'Freon', which was non-flammable and designed by DuPont.
In later years however, it was 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 great strides have been made to make fridges more environmentally friendly. They have always been the domestic appliance which consumed the most electrical resource.
No doubt, in part, due to having to be 'on' non-stop. Modern freezers now consume much less power, 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. Whilst 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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