In late 1902, the first modern, electric-powered air conditioning system was invented by Willis Carrier (1876-1950). The difference between its design and Wolff's design is not only to control the temperature, but also to control the humidity of the air to improve the quality of the production process at a printing plant in Bucklin, New York. This technology provides a low heat and humidity environment to make the paper area and ink arrangement more accurate. Afterwards, Carrier's technology began to be used in the workplace to improve production efficiency. Carrier Engineering Company was also established in 1915 to cope with the surge in demand.
Under the gradual development, air conditioning began to be used to improve the comfort in homes and cars. The sales of residential wall-mounted split air-conditioning systems did not really take off until the 1950s. Built in 1906, the Royal Victoria Hospital in Belfast, Northern Ireland is of special significance in architectural engineering and is known as the world's first air-conditioned building.
