Posts Tagged ‘ice box’

Refrigeration is Wonderful Technology

March 15, 2022

I bought a Kenmore refrigerator 18 years ago, and it is still working, but I decided to take pre-emptive action and replace it before it breaks down. It often shakes when it quits cycling, and I’m afraid it will cease functioning when the weather warms. Online sources suggest replacing refrigerators after 15 years, and I’ve been putting this off for a while. I’ve noticed house temperature makes a difference in how much the refrigerator labors. During the cooler months when our house is 67 degrees F, the refrigerator doesn’t cycle much, but during summer when the house is 77 degrees F, it seems to constantly cycle. I chose an energy efficient LG refrigerator to replace the Kenmore. It costs $830 to have it delivered from Lowes including hauling off the old one. 18 years ago, my Kenmore was priced at $800, showing inflation is minimal for refrigerators.

Refrigeration is an amazing invention, but I can track down no single person who invented electrical refrigeration. Instead, it seems to have been a collective advance in technology, and the concept was understood well before the widespread availability of electricity. As early as 1740 William Cullen, a Scottish scientist, demonstrated the principle of mechanical refrigeration, but he never made a usable refrigerator. Jacob Perkins invented a working refrigerator in 1838, but it failed commercially because nobody had electricity. John Gorrie invented an ice machine in 1842 to cool patients with yellow fever, but it was never used commercially to cool food. Breweries and meat-packing plants started using refrigeration in 1870 just when electrical power became more widely available. Albert Marshall patented the first mechanical refrigerator for home use in 1899, and this was followed by many other patented refrigerators at the turn of the century. At first refrigerators had to compete with iceboxes. Workers would cut big slabs of lake ice during winter and store the slabs in warehouses where they were insulated with sawdust. The ice was distributed to homes in urban areas. The ice slab was placed in the top of the icebox. The cool air sank and melting water would also cool the inside of the box. The ice had to be replaced every few days, and the melt water was a mess to clean up. Mechanical refrigerators began to replace iceboxes during the 1920s after William Durant introduced the Frigidaire model in 1918, and General Electric introduced their model in 1927. Nevertheless, many still referred to their refrigerators as iceboxes until well into the 1960s.

Before mechanical refrigerators people used iceboxes. Big slabs of ice were stored in massive warehouses where they were insulated with sawdust.
Old-fashioned icebox. Cool air sinks and melted water from the ice also cooled the inside of the box.
Early patented mechanical refrigerator.

The process of mechanical refrigeration is based on the principle of evaporation. When a gas cools it condenses to form a liquid. The evaporation of this liquid removes heat. Refrigerators have coils that hold refrigerant gases. Gas is forced into the coils inside the refrigerator where it cools to a liquid which removes heat from inside the refrigerator. The removed heat from this cooled liquid is turned into a gas that takes the heat into the coils outside the refrigerator. It is a self-contained system that cycles over and over.

Diagram from Science ABC showing the principle of mechanical refrigeration.
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