The very first attempt to build an air conditioner was made by Dr. John Gorrie in the 1830s. Gorrie was a physician in Apalachicola, Florida, and he wanted to be able to help patients who were suffering from malaria and yellow fever. He created an ice-making machine with a fan attached. The fan blew air over a bucket of ice, cooling rooms. The machine's compressor used ammonia, which was rather unsafe, and as a result of this, Gorrie could not get financial backing for his machines.

It was not until 1902 that American engineer Willis Carrier came up with an air conditioner that was very similar to modern day ones. Carrier's machine used chilled coils in order to cool air, and the machine could also lower humidity levels.

Carrier's air conditioners was very successful, at first being used in industrial buildings such textile mills. However, Carrier's air conditioning units were large and expensive. They were also still dangerous because like Gorries, they used ammonia as coolant. Carrier made two major improvements to his machine in 1922. The first was to replace ammonia with a safer coolant called dielene. The second was to add a central compressor which dramatically reduced the size of the machine. Soon after these improvements, places such as movie theaters, department stores, offices and railroad cars all began buying air conditioners. After World War II, air conditioners that fit in windows were invented, and sales increased from 74,000 units sold in 1948 to 1,045,000 sold in 1953.

The invention of air conditioning had many incredible affects on the American way of life. People's daily chores changed, and even where they lived changed. Before air conditioning was invented, summers in southern cities, as well as in many northern ones, was absolutely intolerable. Homes used to have to be built with high ceilings and strategically placed windows in order to take advantage of natural ventilation. After the invention of air conditioning, houses could have lower rooftops, and were thus cheaper to build. Also, ever since the 1940s the states with the fastest-growing population have been those in the South, where air conditioning made the hot summers tolerable.

It has been proven that people are more alert and productive when they are comfortable and the air around them is between 72°F and 74°F. Nowadays, almost every American family and office can afford to have their own air conditioner. And modern air conditioning systems have only improved over the decades.

In the 1960s, centralized air conditioning became available and more affordable. Centralized air conditioners use ducts and vents to distribute cooled air to every room in a house. They are much more efficient than window units, and are much less noisy. Additionally, centralized air conditioners do not block your view out of your window or take up space in your home. Most of the time the compressor is located somewhere out of the way. Additionally, centralized air conditioners also filter out particles such as dust and lint as they cool the building, keeping the air clean as well.