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Refrigerators

Refrigerators. Lizmayling Roa. Why are they so important?. Keep your food cold and fresh. Without food you can’t live. Melted ice cream doesn’t taste as good. You want to eat spoiled milk with your fruity pebbles? I didn’t think so. Historic Info.

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Refrigerators

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  1. Refrigerators Lizmayling Roa

  2. Why are they so important? • Keep your food cold and fresh. • Without food you can’t live. • Melted ice cream doesn’t taste as good. • You want to eat spoiled milk with your fruity pebbles? • I didn’t think so.

  3. Historic Info • Since the mid- 1800's, refrigerators have been widely used to keep food from spoiling. • In 1805, Oliver Evans, designed the first refrigeration machine. • Refrigeration is not a natural process. • According to the second law of thermodynamics, all processes involving the transfer of heat move it from the hotter body to the colder body,

  4. How does it work? • A gas cools on expansion. • When you have two things that are different temperatures that touch or are near each other, the hotter surface cools and the colder surface warms up. This is a law of physics called the Second Law of Thermodynamics

  5. Why is your fridge running? • Chloro-Flouro-Carbon or CFC • This gas was found to hurt the environment if it leaks from refrigerators. So now, other chemicals are used in a slightly different process. • Modern refrigerators don't use CFC. • HFC-134a, also called tetrafluoroethane. • HFC turns into a liquid when it is cooled to -15.9 degrees Fahrenheit (-26.6 degrees Celsius).

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