Science and technology of the Tang dynasty
The inventor Ding Huan (fl. 180 AD) of the Han dynasty invented a rotary fan for air conditioning, with seven wheels 3 m (10 ft) in diameter and manually powered. In 747, Emperor Xuanzong had a "Cool Hall" built in the imperial palace, which the "Tang Yulin" (唐語林) describes as having water-powered fan wheels for air conditioning as well as rising jet streams of water from fountains. During the subsequent Song dynasty, written sources mentioned the air conditioning rotary fan as even more widely used.
Alice H. Parker
Alice H. Parker (b. 1895) was an African American inventor known for her contribution to the heating furnace. She invented a furnace that supplied central heating for entire homes and buildings, which was patented on December 23, 1919. This was much safer than burning firewood. Her heating furnace was different from the other furnaces around at that time. Her design had air ducts that allowed heat to spread throughout the structure. Parker's invention included a multiple burner system and used natural gas. What made it especially unique is that it was like later zone heating, where the temperature could be moderated in different areas of a building. Parker was born in Morristown, New Jersey. She attended Howard University Academy, a high school located in Washington D.C., and was granted a certificate with honors in 1910.