Ice cream and popsicles on a hot day have become a refreshing summer tradition – so much so that we often take for granted the convenience of an icy cold freezer – but all it takes is one conversation with a member of the Greatest Generation to remember that those conveniences used to be rare luxuries.
The technology of cooling has changed dramatically in the last hundred and fifty years, but refrigeration, in some form or other, has existed for thousands of years. Ancient Chinese lyrics from 1000 B.C. refer to the traditional filling and emptying of ice cellars, though little is known about how those ice cellars would have been constructed. Greeks and Romans dug snow pits and insulated them to preserve the cold, while those in ancient Egypt and India would use evaporation to cool their water in shallow jugs.
By the sixteenth century, those in Europe had discovered that adding chemicals like saltpeter to water could make its temperature fall. Rotating bottles in a saltpeter & water solution became a popular method of cooling wine and other beverages – which led to the rise in popularity of ice drinks in France by the end of the seventeenth century.
The demand for ice soon sparked a commercial ice trade and in the Americas in the first half of the nineteenth century the ice industry grew rapidly. Blocks of ice were cut and transported quickly to more temperate areas, using various forms of insulation. But as this practice went on, it became more and more clear that not all ice was created equal. Pollution and sewage dumping meant the ice wasn’t always sanitary – even if it was keeping things cold.
Refrigeration machines using the compression and expansion of gases were first invented in the 1800s – and were quickly adopted by the brewing industry until almost every brewery used them by the end of the century – but they weren’t commonly used in households until much later. Through most of the nineteenth and early twentieth centuries, ice boxes were commonly used – heavily insulated boxes made of metal or wood which had a space for both food and a block of ice which would be delivered by an ice wagon. That ice would melt and the water pans would need to be emptied daily – which could get messy.
By 1920, mechanical iceboxes became available and instead of a block of ice, they used a method that involved vaporizing a liquid refrigerant – there were two methods of vaporizing, either a gas flame heating the refrigerant until it vaporized or a tiny electric motor compressing the liquid to turn it into gas. With the influence of companies like GE and the growing electric utility industry, the electric motor would become the standard.
Some coolants were dangerous and could be fatal when they leaked, but using Freon and hermetically sealed cooling units, the new refrigerator began being sold as a complete unit in 1925.
In 1921, 5,000 mechanical refrigerators were manufactured in the US. Ten years later that number was over a million and only six years later, it was close to six million. Then the modern refrigerator really took off after WWII. By 1950, more than 80 percent of American farms and more than 90 percent of urban homes had one.
No more ice wagons and water pans to empty. No more sewage in our blocks of ice. Just the luxury of cold whenever we want it.
And as the technology of refrigeration continues to evolve, we’ll be ready to help you with your heating and cooling needs.