Before Carrier’s invention, ice was often harvested and stored during cold months to cool the air in the summer. Over time, air conditioning became more common in houses and cars to improve the comfort of the people inside. The cooling effect of the machine also happened to increase worker productivity in the hot summer, so demand for this new invention quickly increased.
You might not have known, but modern air conditioning was actually invented by Willis Carrier in 1902 to control the humidity of the air in a printing factory. Air conditioning (also called “AC” or “A/C”) is the process of controlling the temperature and humidity of air.