The COOLEST Thing Ever!

    Between the delicious food, beautiful landscapes, and friendly people, Italy really seems like utopia. I especially love it here; it’s actually difficult for me to think of things I dislike! Okay, so, sure, if you were to ask some of my friends, you’d know that the “merchants” selling flowers bother me, but I’ve learned how to not let them get to me as much as they did for our first few days here. One thing that I think I will never be able to get over, however, is this brutal heat we’ve been experiencing lately, especially considering my natural hotness - ;) - and the fact that I grew up in a home that was constantly air conditioned. To be honest, one of the things I miss most about home is our air conditioner, so I decided to learn about how they work.
    Air conditioning is based upon the idea that the process of a liquid changing phases into a gas requires heat (To be honest, this is probably the COOLEST use of PV=nRT that I’ve ever seen). Air conditioners harness this phenomena by using heat found in hot air to evaporate compounds with low boiling points, thus cooling the air. These compounds, such as Dichlorodifluoromethane, more commonly known as freon, are called “refrigerants,” and they are found in the “evaporator coils” of the air conditioner. Refrigerants enter the evaporator coils in their liquid phase. A fan blows hot air from the surrounding area over the evaporator coils, and, as they absorb the air’s heat (thus cooling it), the refrigerants enter their gas phase.
    Next comes what I think is the most ingenious facet of the air conditioner: The condensation of the refrigerant back into its liquid phase for re-use. After entering the gas phase, the refrigerant is moved to the compressor, which, as its name implies, compresses the gas by applying lots of pressure to it in order to facilitate its return back to its liquid phase. This, however, raises the temperature of the liquid. In order to cool it back down below its boiling point for the pressure at which it needs to be evaporated, the excess heat produced is released into the area surrounding the air conditioner via transport through condenser coils and the help of another fan. Finally, the refrigerant will pass through the expansion valve, the valve that determines the flow of liquid refrigerant, to re-enter the evaporator coils, and the whole process will repeat itself.

Freon

    Air conditioners do more than just cool the air, though. They also act as dehumidifiers (De-humidifying a paper factor was the impetus for the creation of the first air conditioner, actually). Temperature dictates relative humidity (the amount of water the air can hold), thus, since refrigerants cool the air around them, they condense water out of the air. This is why most air conditioners have a condensation pan inside of them.
    I love air conditioning almost as much as I love Italy, but air conditioning, just like all seemingly perfect things (see Italy above), has its one fatal flaw: negative environmental impact. Refrigerants like freon eat away at the ozone layer in our atmosphere, the layer that protects us from the sun’s UV rays. Fortunately, new refrigerants that should have much less of  an environmental impact (freon is actually illegal to use now) are being developed and used. If only I could have such hopeful news for Italy’s heat problem. Oh well. Just like how air conditioning’s flaw will not stop me from using it, Italy’s flaw will not stop me from loving it.

I forgot to put my sources before...so here they are! 

http://www.howstuffworks.com/ac.htm
http://home.howstuffworks.com/freon-utilized-in-air-conditioning.htm