Willis Carrier invented the first modern air conditioning system in 1902. He designed the system initially to solve a humidity problem at the Sackett-Wilhelms Lithographing and Publishing Company in Brooklyn New York. The paper stock that they used in their business would absorb too much moisture in the summer months making it difficult to apply ink to the stock for various jobs. On thinking about the predicament Willis came up with an ingenious insight on how to correct this problem for the printer. He reasoned that if he drew the hot air in the plant across a set of chilled pipes that doing this might solve the problem. Much to his surprise, when he tried it not only lowered the temperature of the air, but also caused the air to reduce its humidity load, which stabilized the paper used in the printing process. After this success Carrier realized he had developed a new technology with far reaching implications and it wasn't long before commercial air conditioning systems were being installed in theatres and department stores all across America making the hot summer months more bearable for everyone. He also came to understand that all this technology would require AC repair procedures. These regular AC repair and maintenance service protocols were yet another boon to Carrier's new business. Because they allowed all their new customers the surety that if they followed them their new systems would always be running in tip top shape.
Modern air conditioners use a refrigerant to cool the air instead of chilled pipes. By using a refrigerant air conditioners take advantage of a very simple scientific principal. When a liquid converts to a gas it absorbs heat when it convert to back to a liquid the heat is released. This principal is called phase conversion. Modern systems capitalize on phase conversion by forcing a mix of chemical compounds to evaporate and condense over and over in a closed system that is surrounded by coils. The coils are used to dissipate the heat and chill the surrounding air. The compounds used in these refrigerants have special properties, which enable them to change at relatively low temperatures. These systems also contain fans the move warm interior air over cold refrigerant filled coils and another set of coils that are specifically used to exhaust the waste heat to the outside.
Even though the biggest job an air conditioner does is to cool the air that is by no means all it does. The other job it does it to monitor and regulate the temperature by using a thermostat. They also have filtering mechanisms and have a secondary function as a dehumidifier. Because dehumidifying is a function of the cooling process all air conditioning systems have drains and moisture collection pans attached to or near the unit.
Along with units manufactured for building other smaller systems were develop that could be installed in automobiles, buses, trucks and every kind of transportation vehicle imagined. Along with all these other systems regularly scheduled maintenance programs were established to minimize their AC repair down time.