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How Did The First Electric Refrigerators Work?


How Did The First Electric Refrigerators Work?
Back in the Twenties, one electric refrigeration company dominated the market: Kelvinator. Its wooden cold box/ compressor combo cost $714 (nearly $9,800/£6,100 today) – way beyond the pocket of the average household. So, with the goal of bringing more affordable refrigerators to the masses, General Electric ploughed $18 million into making the GE ‘Monitor-top’ fridge.

They were called Monitor-tops because the cabinet was all steel and the condenser was sealed in a cylindrical enclosure on top, which made it look like the turret from a 19th-century ironclad warship – the USS Monitor.
These refrigeration units worked under the same principles as modern fridges. By using a compressor, a circulating refrigerant was transformed from vapour into a liquid and cooled to near-room temperature under pressure, before being released back into circulation. The sudden change in pressure caused the refrigerant to turn into a vapour again, which had to draw heat from the air inside the cabinet, ultimately cooling it.
Several models of the Monitor-top were made, including two and three-door units, but the most popular was the single-door variant, which originally sold for $300 in 1927.

How Did The First Electric Refrigerators Work?

Toxic Origins
Today, the inert tetrafluoroethane gas R134a is commonly used in fridges and freezers, but in the Twenties refrigerants like sulphur dioxide, methyl formate and methyl chloride were used.
These are quite toxic: sulphur dioxide causes burns on contact and can damage vision, methyl formate is highly flammable, while methyl chloride, or chloromethane, can cause dizziness, nausea and even seizures at high concentrations.
These nastier chemical refrigerants were replaced by Freon, a relatively harmless gas that, nevertheless, was banned in the production of new fridges in 1990 over concerns about CFCs’ effect on the ozone layer. Monitor-top fridges have become quite collectable now, the steel build ensuring many have survived for nearly a century. They are usually converted, with the dangerous gases removed and a modern compressor system installed to be eco-friendly.