How does refrigeration work?
We all know what our refrigerator does, but how does it do it??
That low hum that your fridge exudes is clever science turning gas to liquid and vice versa to keep your food fresh and cool. To keep your food fresh, your refrigerator must be kept at a low temperature so that harmful bacteria can’t grow on your edibles.
So, let us delve into the refrigeration cycle and explain how it all works…
What is the basic concept of refrigeration?
The refrigerator uses pressure, condensation and evaporation in a closed circuit to remove heat from inside the fridge. The fluid that travels around this circuit is called the refrigerant.
Components that make up a refrigerator:
- Compressor - controls the flow of refrigerant
- Condenser coils (outside fridge)
- Expansion device
- Evaporator coils (inside fridge)
The Refrigeration Cycle - step by step
#1 The compressor squeezes the refrigerant vapour, increasing its pressure, and temperature, to create a hot gas. This gas is then pushed into the condenser coils on the outside of the refrigerator.
#2 When the hot gas is in the coils on the back of the fridge, it meets the cooler air temperature of the kitchen and condenses to form a high pressure liquid.
#3 This liquid refrigerant then goes through the expansion device where its pressure is quickly reduced, it expands and some of the liquid rapidly turns to vapour. The vapour refrigerant cools down as it flows into the evaporator coils inside the fridge.
#4 The cold liquid refrigerant absorbs the warmth inside the fridge, cooling down the air and food inside.
#5 Lastly, the refrigerant evaporates into low temperature, low pressure gas form and flows back to the compressor where the cycle begins again.
What temperature is optimal for my refrigerator?
The refrigerator temperatures for keeping food safe are:
- Fresh food - between 0°C and 4°C
- Chiller compartment - close to 0°C
The Australia Standard for fridges states the fresh food compartment should be at an average of 3°C. This is a good temperature to aim for as it is below the 4°C, but you're not going to freeze your food.
It sounds like common sense, but try to close the fridge door each time you go in to remove something. This can help the refrigerator stay at its optimal temperature. Also, try not to overload the fridge as this reduces the air flow inside and it has to work much harder to keep cool. If possible, invest in a fridge thermometer, which are reasonably priced, as it allows you to check that the temperature stays below 5°C to keep your food safe…and your beers cold!
For more information on using your refrigerator and its components, call Sea Air Mechanical Services, your local refrigeration specialists on 0401 787 183 or 1300 413 719. We specialise in refrigeration repairs, servicing and maintenance on the Sunshine Coast and across North Brisbane.
