Refrigerators have taken a bumpy road over the past 262 years. William Cullen created the first refrigerator, although it was not suitable for any use on a daily basis. Not until 1834 was a practical refrigerator invented by Jacob Perkins. Since the 1830s, refrigerators have taken a huge step forward. Refrigeration units have changed drastically throughout the last 200 years.
The basic refrigeration parts are extremely similar to those in any air conditioning unit. Refrigeration parts are essentially broken down into four main spots with one area used twice. One of the most important refrigeration parts is the compressor. The compressor starts and ends the entire refrigeration process. If this goes down, the entire system will fail. The refrigerant gas is the main key regarding the compressor. Refrigerant is the liquid inside the refrigerator used to cool it to a low temperature, thus creating the cooler temperatures inside. In today's major industrial installations, companies are beginning to use ammonia instead of refrigerant. Ammonia cools at a temperature of 27 degrees below zero Fahrenheit, or 32 degrees below zero Celsius. The compressor will begin to compress the gas creating a higher pressure and temperature of the refrigerant.
From the compressor to the heat exchanging coils on the outside of the refrigerator, the coils help keep the pressure of the refrigerant down through the dissipation of its heat. This process is done through pressurization. While cooling, the refrigerant begins to condense back into a liquid as it flows through the expansion valve. The expansion valve is the final item of the refrigeration parts on the outside of the refrigerator. When traveling through the expansion valve, the refrigerant goes from high pressure to low pressure.
When flowing through the expansion valve, the refrigerant rapidly goes from a high pressure situation with warmer temperatures to a lower pressure situation with cooler temperatures. The refrigerant passes through another set of heat exchanging coils. These heat exchanging coils remain on the inside of the refrigerator. While passing through the expansion valve, the refrigerant will expand and evaporate. Through the process of evaporating, the heat is absorbed and temperatures will drop. By the temperatures dropping in the heat exchanging coils inside the refrigerator, temperatures in the refrigerator will begin to drop as well. The heat exchanging coils will lead back to the compressor which is on the outside of the refrigerator and the refrigeration parts will start the cycle all over again.