The ozone layer prevents ultraviolet sunlight from reaching Earth. (The Ozone hole, 2012). Without the ozone layer, it would be more likely to get skin cancer, eye damage, harm wildlife, reduce crop yields, and change the ocean food chain. The ozone is a molecule made up of three oxygen atoms. Ground-level ozone is the main component of smog and is harmful to humans. Atmospheric ozone collects in the stratosphere, which is about nine to twenty-two miles above the surface of the Earth. It was discovered in 1985 that there was a hole in the ozone above Antarctica. CFC’s, were constantly eroding our ozone layer. (Roach, 2010).
In old refrigerators, ammonia gas is used to keep the refrigerator cool. Pure ammonia gas is highly toxic to people and if a refrigerator containing it leaked, it would pose a threat. Switching to CFC’s was a “nontoxic” replacement that depleted the ozone layer. Then they switched to a more environmental friendly coolant. Although many refrigerators still use ammonia. (Brian; Elliot, 2006).
Refrigerators need five major components to keep cool. The compressor compresses the ammonia gas and the compressed gas heats up as it’s pressurized. The coils on the back of the refrigerator let the hot ammonia gas disperse its heat and the gas condenses into liquid at high pressure. The high pressure ammonia liquid flows through the expansion valve. One side of the valve has high pressure ammonia liquid and the opposite side is a low pressure area because the compressor sucks gas out of that side.
The liquid ammonia immediately boils and vaporizes with the temperature dropping to -27 degrees Fahrenheit which makes the inside of the fridge cold. The compressor sucks up the ammonia gas and the cycle repeats. (Brian; Elliot, 2006)The coolant is trapped inside coils and makes a circuit through them and changes back and forth from a liquid to a gas.
Ammonia gas does not affect the Ozone layer but it is highly toxic to humans. When they switched to CFC’s, that’s when the refrigerators added to the list of things depleting the Ozone Layer. Du Pont discovered this replacement in the 1930’s. They are used in a variety of industrial, commercial, and household applications. The CFC’s were released into the atmosphere and went up into the stratosphere. In the 1970’s, it was discovered that the CFC’s in use are harmful to the Ozone Layer. The ultraviolet radiation at the atmospheric altitude breaks down CFCs, freeing the chlorine. Under the proper conditions, this chlorine has the potential to destroy large amounts of ozone. As of the 1990’s, they put a more environmental friendly coolant in refrigerators.