Changes

Air conditioning became the main innovation for modern cooling. In 1902, Willis Carrier invented the air conditioner, with the first machine he invented also able to control humidity. Carrier used his knowledge of heating objects with steam and reversed the process so that objects became cool. Stuart W. Cramer coined the term air conditioning, where his device used water and "conditioned" it so that the moisture would then be used to create cold air. The first house to have air conditioning was built in 1914, which was built in Minneapolis. David St. Pierre DuBose soon after created the first home with central air conditioning, by creating ducts throughout the house that would take the cold air from the air conditioning unit and blow it around the house. In 1945, the portable air conditioning unit was created by Robert Sherman.