The air conditioning unit, one of modern man’s symbols of comfort, is on the list of those inventions that seem to have appeared by chance. The story goes that its creator, engineer Willis Haviland Carrier (1876-1950), then at the age of 25, discovered the basis for the principle of refrigeration (the condensation point) when observing a dense mist that covered the railway station in Pittsburgh, United States, while he was waiting for his train. Recently graduated, Carrier took little time to test and to apply his idea.
A print shop from Brooklyn, in New York, called Sacket-Wilhems Lithographing, had a problem that was apparently insoluble. The quality of printing was very bad, because of the excessive humidity in the air, which would dilate the paper and leave the colors blurred. In 1902, Carrier was called in to try to solve the matter and apply his theory for an air conditioner, which included four items: temperature control, humidity control, control of the circulation of the air and ventilation, and purification of the air. He designed a machine to reduce the humidity in the air and to make the air circulate through artificially cooled ducts. The system worked – it was the first process of air conditioning done mechanically.
Success and the expansion of the invention obliged Carrier to draw up bibliographical documents that could be consulted by technicians. His Psychrometric Chart (the measurement of humidity by means of an apparatus, the psychrometer) became a point of reference for studies in refrigeration and climatizing all over the world. Besides its scientific interest, the chart was used by sales team of the company set up by the engineer with six partners in 1915, the Carrier Engineering Corporation.
Factories, offices, cinemas, theaters, schools and residences did not delay in adhering to the comfort brought about by the control of the temperature. In the 20s, another innovation: besides cooling down the air during the summer, new apparatuses started also to heat, humidify and purify the air during the winter. The Carrier system arrived in Brazil at the end of the same decade, to alleviate the extreme heat in the gold mines of Morro Velho, in Minas, where work was carried out at great depths. Nowadays, the Carrier Corporation is in Brazil associated to Springer, a company founded in Porto Alegre.Republish