How A Refrigerator Works?
The simple explanation for how a refrigerator works uses a comparison to water evaporating from a person’s skin after he or she gets out of a swimming pool. According to this explanation, the water vapor leaves the skin and takes a portion of the body heat with it. That’s what makes the person feel cooler or even cold. In refrigeration, chemicals are the main factor in cooling, rather than water. This was true for many years with older refrigerators.
One way to get a better idea about putting a gas or liquid under pressure is to think of a tire on a car, motorcycle or other vehicle. The air is pushed into the tire and the process can make the pump and the tire get warm. Releasing the air will cause it to become cool as it expands into the surrounding air. Compressing and expanding certain chemicals or gases causes them to heat up or cool down. This can be used in the refrigeration.
According to more scientific definitions of refrigeraton, one of the laws of thermodynamics is responsible for the change in temperature. A gas called Freon passed through a winding metal tube in earlier models of refrigerators. It is first pumped through the tubing as a liquid but becomes a vapor/gas in the “coils” near the freezer area of the unit. This takes heat from the freezer area, causing that closed space to become colder. Because there is more open area in the refrigerator section and the coils of tubing are fewer, less heat is taken away by the Freon.
The gas is turned back to a liquid in tubing outside the refrigerator, as it is being compressed. Heat is transferred to the air around the refrigerator and the process starts again.
Newer refrigeration units don’t use Freon (known by the chemical name chloro-fluorocarbons. A different type of chemical gas is used in a similar process with similar results. Motors and compressors help compress the gas and it heats up under this pressure. As it passes through the coils and cools (giving up heat to the surrounding air) it becomes liquid. When it goes through an expansion valve, the process causes the liquid to become vapor. The process is generally the same as with older refrigerators and is repeated over and over.
The refrigerator “knows” when to operate based on a heat-sensing device. The process is similar to that which regulates the temperature of the home, stopping and starting the furnace. But with a refrigerator the process involves taking the heat or any warmth inside the refrigerator and transferring it to the outside air. This is where the cooling and pressurizing of the chemicals comes in.
Of course, the objects we place into the refrigerator may be at room temperature but they will eventually become as cool as the air in the enclosed refrigerator space. But first, the rather simple process of cooling and heating, condensing and expanding has to take place. With the new designs and chemicals, the refrigeration process has become very efficient.
Category: Home & Garden, Home Appliances, Technology