He was a young electrical engineer trying to solve a humidity problem at the Sackett-Wilhelms Lithographing and Publishing Company in Brooklyn, N.Y. In the warm summers, paper stock at the plant would sometimes absorb moisture which made it difficult to apply the layered inking techniques.
Carrier caused the air inside the building to blow across chilled pipes. The cooled air didn’t carry as much moisture as the warm air. The process reduced the humidity in the plant, which stabilized the moisture content of the paper. This experiment to reduce the humidity had the side benefit of lowering the air temperature, but turned out to be an important step in creating modern air conditioning system.
Carrier had become the father of cool!