Teachers Centre
More Links
science home
HOME
howdoesyourfridgeworktexturenew.gif (5716 bytes)
Have you ever wondered ...
how your fridge cools the food you put inside it? This is a good practical example of the gas laws in action. Temperature, pressure and volume all have a part to play in the cooling process.
fridge still.jpg (12298 bytes)
CLICK HERE to see an animated diagram of how a fridge works. (Close the new window to return to this page).
Gas is drawn at low pressure and low temperature through a line. The gas is compressed using electricity to a higher pressure and its temperature rises (just like a bicycle pump which gets warmer when you are pumping up a tyre). It is then transferred to a condenser where the heat is removed and the gas begins to condense into a liquid. The heat is released via cooling fins on the back of the fridge unit. The liquid then goes through an expansion device where its pressure is suddenly lowered, it expands and some of the liquid turns very quickly into a vapour. This change of state has a cooling effect. Now the cold vapour and liquid are able to cool the air in the cabinet of the refrigerator through an evaporator. The liquid absorbs the warmth from the air inside the refrigerator and turns back into a low temperature gas, at low pressure. It now starts its journey again through the compressor.
For more information about refrigeration technology try:
www.howstuffworks.com/refrig.htm
Teachers Centre |Feedback| More Links | HOME