On 17 July 1902, the first air (temperature and humidity) conditioning went into operation in a Brooklyn printing plant. Fluctuations in heat and humidity in the plant had been causing the dimensions of the printing paper to keep altering slightly, enough to ensure a misalignment of the colored inks. The new air conditioning machine created a stable environment and aligned four-color printing became possible.
This was done by Willis Haviland Carrier, within one year after he graduated from Cornell University with a Masters in Engineering, who started on a salary of $10.00 per week.
The 'Apparatus for Treating Air' (U.S. Pat# 808897) granted in 1906, was the first patent awarded to Willis Haviland Carrier. Even though, the recognized 'father of air conditioning' is Carrier, the term 'air conditioning' was actually originated by Stuart H. Cramer, who used the phrase 'air conditioning' in a 1906 patent claim filed for a device that added water vapor to the air in textile plants - to condition the yarn.
In 1911, Willis Haviland Carrier disclosed his basic Rational Psychrometric Formulae to theAmerican Society of Mechanical Engineers. The formula still stands today as the basis in all fundamental calculations for the air conditioning industry. The story is that Carrier he received his 'flash of genius' for the theory while waiting for a train. It was a foggy night and his mind drifted into the problem of temperature and humidity control. By the time the train arrived, Carrier had got the explanation or understanding of the relationship between temperature, humidity and dew point.
Industries flourished with the new ability to control the temperature and humidity levels during and after production. Willis along with six other engineers formed the Carrier Engineering Corporation in 1915 with a starting capital of $35,000 (1995 sales topped $5 billion) to focus on developing air conditioning technology.
In 1921, Willis Haviland Carrier patented the centrifugal refrigeration machine. The 'centrifugal chiller' was the first practical method of air conditioning large spaces.