REFRIGERATOR

The body uses a lot of energy daily, therefore, we eat food to keep it healthy and recreate the lost energy to keep fit. Food preservtions is very important. To reduce germs and prevent the food from going sour, we rely on refrigerators as a preservative measure.

According to Mary Bellis, refrigeration is the procedure of getting rid of heat from an enclosed space, or from a substance, to bring down its temperature. A refrigerator uses the evaporation of a liquid to absorb heat. The liquid, or refrigerant, used in a refrigerator evaporates at an extremely low temperature, creating freezing temperatures inside the refrigerator. It's all based on the following physics: - a liquid is rapidly vaporized (through compression) - the quickly expanding vapor requires kinetic energy and draws the energy needed from the immediate area - which loses energy and becomes cooler. Cooling caused by the rapid expansion of gases is the primary means of refrigeration today.

It was recently discovered that a part of the oxone layer around the earth which contains Chlorofluoro Carbon (CFC) is used in refrigerators to keep food cold. The refrigerator takes in heat at low temperature and rejects it at a higher temperature( second law of thermodynamics) energy is conserved during the process, using external energy to drive the process, the refrigerator is a heat pump.