Air conditioning
Modern air conditioning emerged from advances in chemistry during the 19th century, and the first large-scale electrical air conditioning was invented and used in 1902 by US inventor Willis Carrier. The introduction of residential air conditioning in the 1920s helped enable the great migration to the Sun Belt in the United States.
Automobile air conditioning
In 1939, Packard became the first automobile manufacturer to offer an air conditioning unit in its cars. These were manufactured by Bishop and Babcock Co, of Cleveland, Ohio. The "Bishop and Babcock Weather Conditioner" also incorporated a heater. Cars ordered with the new "Weather Conditioner" were shipped from Packard's East Grand Boulevard facility to the B&B factory where the conversion was performed. Once complete, the car was shipped to a local dealer where the customer would take delivery.