By the early Medieval period in China, around the 8th century, large rotary fans began to be developed that were powered by water (Figure 2). Some fans would even blow over water or have water combined with the rotary motion of the fan to create something akin to air conditioning by cooling water and then having the cool air circulate. In the 17th and 18th centuries, early experiments with fan-like systems, which were manually powered, were used to help ventilate large halls or even mine shafts. By the 18th and early 19th century, several innovations began to develop. One was streets began to have more awnings installed so that more shade would be available. In 1837 William Fourness began to use steam to power fans. These were large devices that were not very portable, but nevertheless steam-driven fans enabled some cooling of larger spaces possible. By the mid-19th century, heavy curtains began to become fashionable in homes as well as high ceilings, although these were already evident in some early Medieval homes and palaces. The curtains would block out sun light from coming into the house during the day, while high ceilings would allow the heat to move higher up and away from the occupants in a room. In the Victorian period, house plants also became popular, which helped to reduce air temperature in homes when plants released moisture. It was during this time also that public parks became popular, which were green spaces that also were relatively cooler than other built-up areas of urban areas. These became places people would flock to during the summer to relax.
Major technical innovation began in the 1880s, with the invention of the electric fan by Schuyler Wheeler
in 1882. The fan was marketed by the American company Crocker & Curtis. Ceiling fans were developed at about the same time in 1882 by Philip Diehl. Many early fans used oil or kerosene to power them. Nevertheless, ceiling fans did not become common in homes until the 1920s, when prices for creating them dropped and became a more common feature to install in homes by builders.
[[File:Web IMG 1421.jpg|thumb|Figure 2. Large rotary fans were already used in early Medieval China for cooling. ]]