The fridge is a part of everyday life. It was invented with the sole purpose of keeping food items cool, making them last longer. Most refrigerators are rectangular in shape and white or stainless steel, but they can come in almost any color. There are a range of different styles with most refrigerators having an in-built freezer section. Refrigerators are an amazing piece of machinery. Have you ever wondered how your fridge works? Read on to find out.
The basic principle behind how your fridge works is the laws of thermodynamics. This essentially means that if you place a cool object and a warm object next to one another the warm object will start to cool and the cool object with start to warm. In a refrigerator the evaporation of a liquid is used to absorb the heat. This is like when you place water on your skin to cool you down. The water becomes warmer and evaporates absorbing the heat of your skin. The refrigerant or liquid used in your fridge evaporates at an extremely low temperature and therefore creates low temperatures within the fridge.
There are five main parts that contribute to the operation of your fridge. These are:
- The compressor- which is powered by the motor
- The condenser- heat exchange pipes on the outside of the fridge
- Expansion valve
- Heat exchange pipes inside the fridge
- Refrigerant- R134A or R410A which evaporate at -27o F or -32o C
All five parts work together to cool the inside of your fridge.
How Does A Fridge Work?
When you hear the motor start your fridge is beginning its refrigeration cycle. It is a cycle that repeats itself over and over again. Your fridge is a closed system meaning that nothing is added or taken away at any stage of its cycle. The compressor is the first stage of refrigeration. It compressors or squeezes the refrigerant (which is in a liquid state) to form a gas. The gas becomes highly pressurized and very hot. This gas then passes through the condenser or the heat exchange pipes on the back of your fridge. This helps the gas to lose the heat gain through the compression stage. As the refrigerant cools it becomes a liquid and flows through the expansion valve. This passes the liquid from a high-pressure area to a low pressure area turning it into a fast-moving, cold mist (which is more liquid in nature). As the mist passes through the heat-exchange pipes on the inside of the fridge it start evaporating which absorbs the heat for the inside of the fridge. This makes the inside of your fridge nice and cold and good for storing foods. As the mist continues its journey it absorbs more heat through evaporation and its temperature rises. It is then drawn back into the compressor and the cycle starts again.