When air conditioning first appeared -- a technology initially developed for use in textile factories -- it was feared by many as unhealthy. So how did it make it into so many homes?
In fact, resistance to the technology came from the Open Air Movement -- a major trend in thinking in the early 20th century. Supporters believed indoor air to be unhealthy, filled with CO2 that could damage our bodies, and so strongly opposed air conditioning too.
But there was a forward-thinking group that realised that air conditioning could be useful for people: cinema owners. As movie theatres slowly adopted the technology during the 1930s and 40s, it became popular with patrons and, realising they weren't dying, they decided to use it at home too. Now, 80 years later, we couldn't imagine life without AC. Watch the video to find out more about the story. [Engineering Guy]