Thank You Willis Carrier

AC01I love air conditioning. It is one of the best inventions ever. Especially at this point of the year where heat indexes can soar to triple digits.

Shout out to Willis Carrier.

Willis Carrier invented the modern day air conditioner in 1902 and for over 100 years we all have experienced the “aahhh” when we walk into an air conditioned room.

Carrier’s initial intent was to solve air quality issues. He invented something which not only controlled temperature but also controlled humidity, air circulation, ventilation and cleansed the air. More than simply cool the air, it is to condition the air.

I love having conditioned air.

Air conditioning wasn’t as available when I was growing up in Georgia.  Today I wonder how we ever survived with using fans and opening the windows.  That was our “air conditioning”.  Even my first car – Chevrolet Chevette – was without air conditioning.  It had imitation leather seats and fried me every day to/from work.  My air conditioner was all four windows rolled down.

I remember in high school that there are a few classrooms which had window units and it was an amazing relief to have class with those lucky teachers.  Not to make excuses but it’s really hard to be engaged in class when you are sweating and suffocating from the heat.

When my parents would take me with them to our church organization’s state convention in Macon, Georgia every summer, it was a treat to stay in a hotel because it was air conditioned.  Walking to the Macon City Auditorium was not fun in the heat, sweating in my church clothes but as soon as we entered the doors to the auditorium there was the wonderful “aaahhh” feeling of the air conditioning.

Yes, I’m in love with air conditioning.  It ranks right up there for this Southerner along with a cold glass of sweet tea.

Growing up I remember putting box fans in the window at night to keep my room cool as I slept.  That is – when I could finally go to sleep with worrying about someone breaking in.  We sacrificed security for comfort during those days but, then again, people were more trusting then anyway.

Willis_Carrier_1915Willis Carrier featured an igloo at the 1939 World’s Fair in New York to give visitors a look into the future of air conditioning.  I wonder what he would think about his invention today.

The basic concept behind air conditioning is said to have been applied in ancient Egypt, where reeds were hung in windows and were moistened with trickling water. The evaporation of water cooled the air blowing through the window. This process also made the air more humid, which can be beneficial in a dry desert climate. Other techniques in medieval Persia involved the use of cisterns and wind towers to cool buildings during the hot season.

So if we want to go way back, let’s also give credit to the Egyptians for the origin of today’s cooling devices.

Air conditioning units use chemicals that convert from gas to liquid and back again quickly. These chemicals transfer the heat from the air inside your property to the outside air. The AC unit has three key parts. These are the compressor, the condenser, and the evaporator. Your unit’s compressor and condenser are typically located in the outside part of the air conditioning system. Inside the house is where you will find the evaporator. The cooling fluid reaches the compressor as a low-pressure gas. The compressor squeezes this gas/fluid, and the molecules in the liquid are packed closer together. The closer the compressor forces these molecules together, the higher the temperature and energy rise. This working fluid exits the compressor as a high-pressure, hot gas, and it moves to the condenser. The outside unit of an air conditioning system has metal fins all around the housing. These fins work like the radiator on a vehicle, and they help dissipate heat more quickly.ac02When the fluid leaves the condenser, it is much cooler. It’s also changed from a gas to liquid because of the high pressure. The fluid makes its way into the evaporator through a minuscule, narrow hole and when the liquid reaches the other side of this passage, its pressure drops. When this happens, the fluid begins to evaporate to gas. As this occurs, the heat is extracted from the surrounding air. This heat is required to separate the molecules of the liquid into a gas. The metal fins on the evaporator also help exchange thermal energy with the surrounding air. When the refrigerant leaves the evaporator, it is once again a low-pressure, chilled gas. The process starts all over when it goes back to the compressor. There is a fan that’s connected to the evaporator, and it circulates air around the inside of the property and across the fins of the evaporator. The air conditioner sucks air into the ducts through a vent. This air is used to cool gas in the evaporator, and as the heat is removed from the air, it’s cooled. Ducts then blow air back into the house.

Yeah, I don’t understand all that either but I’m just glad it WORKS.

So when you enter an air conditioned building today to escape the scorching heat index outside, give thanks to Willis Carrier by saying “aaaahhhhh”.




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