Of all the conveniences of today’s world, refrigeration is one that has certainly changed the modern lifestyle the most. Most people take for granted the fact that we can freeze chicken for months on end, or purchase a head of lettuce and keep it fresh for a week. However, these simple luxuries were not necessarily well known to households of yesterday!
The Concepts Behind Refrigeration Units
A refrigerator’s main purpose is to remove inner heat from its storage area. Liquid refrigerant is slowly vaporized, and as it does it cools the air inside the refrigerator, bringing everything to an effectively low temperature. It does so by using expanding gasses that pull the heat directly out of the air itself, cooling everything in the process.
The first refrigerators relied on the freezing properties of ice and snow. Pits were dug into the ground, lined with leaves or hay, then filled with snow and ice found in the area or on a nearby mountain. Whatever meat and vegetables kept in these pits could only be kept cool as long as the ice stayed well insulated.
Unfortunately for hot climates, refrigeration from ice and snow was not an option. Livestock had to be kept alive, and when meat was needed to be transported, it had to be salted and dried. Vegetables and fruit had to be picked and eaten right off the vine or it would have become rotten in the sun!
The Invention of Modern Refrigeration
The very machine made for the purpose of refrigeration was invented in 1748 by William Cullen of the University of Glasgow. However, it wasn’t until the early 1800s that practical refrigerators were introduced into the world. Several different gasses and vapor compression cycles were experimented with until 1928, when Thomas Midgely Jr. began using the chemical compound Freon in his refrigerators.
Today, refrigerators come in all shapes, sizes and purposes. They are built to keep food fresh in homes, in marketplaces and in restaurants. In addition to the most obvious means of refrigeration, freezers and cooling displays can also be made for specialty products such as wines, pastries, and floral arrangements.
Deciding on the Best Refrigerator
Choosing a method of refrigeration depends on many different factors. Of course, the main element that must be taken into account is what type of produce, and how much of it, is going to be kept cold at a time. Also, refrigerators meant for business use can be much bigger and require higher energy expectations than those built for home use.
Specialty items like wine and flowers demand particular care regarding proper temperature. Of course, another consideration is how these businesses display their products to the public. Some businesses choose to use walk-in refrigeration units that combine proper care with a more colorful and decorative way to show their wares to customers.