Although many were at least partially in the ground, some were designed as thatched roof pits that could keep food cold or provide chipped ice for drinks and desserts -- with the help of snow and ice brought in from lakes -- for about a year. The process was similar to the ice cave, with an insulator such as sawdust or small branches that was topped with snow and sawdust.
These eventually gave way to the creation of the icebox, a small cabinet that had a compartment for holding a large block of ice and another compartment for storing food.
These were common until about the s, when electric refrigerators and freezers began to make their debut. By then, science and industry had established the idea of mechanical refrigeration, in which a circulating chemical gas kept things in a compartment cold. That's why today's mechanically circulated vapor-driven freezers are a little more complicated and efficient than hollowed-out ice caves filled up with mountain snow.
Up next, we'll find out how several scientific discoveries led up to the creation of the modern freezer we use today. As electricity was now more widely available, crude but very expensive freezers became available commercially in Europe and the US. However, they were still inefficient. Outside air could get inside the freezer, so they still had to be sorted inside icehouses to ensure the temperature was controlled properly.
Since then though, freezers have improved greatly, thanks to more efficient ways to keep the cold air on the inside, much better chemicals, and complex machinery. In order to understand how a freezer works, it is a good idea to think about a river winding through countryside and mountains on the way towards the ocean. It then empties, then is lifted into the sky with the clouds, is converted into rain and that then re-enters back into the same river again and flows down into the same ocean.
The refrigerant flows and then transforms back from a liquid into gas and then back again. Nowadays, the refrigerants that are commonly used are HFCs. Others such as HCFCs and CFCs are strictly regulated and actually banned from being used in various products because they play a part in the depletion of the ozone layer.
Recommended Reading: Check out our guide to refrigerant detectors. You can read it here. The cooling process begins with the refrigerant in the form of a vapor underneath low-pressure. It flows into the compressor, which is normally found at the lower back.
This squeezes the particles of the vapor, heating it up, converting It into a higher-pressure form. This pressurized, hot refrigerant is then pumped from the compressor into a tube and the condenser.
It was during his time at PLU that he began his journey with sustainability and it's what has led him to writing for Green Living Ideas. He currently resides in Honolulu and works for Pono Home, an energy efficiency company focused on reducing carbon emissions and promoting a healthier, greener lifestyle.
CFL vs. Contact Us Newsletter Advertise. Conservation Published on September 12th, by Peter Young 1. When the sensor senses that it's cold enough inside a refrigerator, it turns off the compressor.
If it senses too much heat, it switches the compressor on and begins the cooling process again. Refrigerators work by causing the refrigerant circulating inside them to change from a liquid into a gas. This process, called evaporation, cools the surrounding area and produces the desired effect. You can test this process for yourself by taking some alcohol and putting a drop or two on your skin.
As it evaporates, you should feel a chilling sensation - the same basic principle gives us safe food storage. To start the evaporation process and change the refrigerant from liquid to gas, the pressure on the refrigerant needs to be reduced through an outlet called the capillary tube.
The effect is similar to what happens when you use an aerosol product such as hair spray. When you release the contents into the lower pressure open space, it turns from a liquid to a gas.
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