In 1888, Theophilus Van Kannel invented the revolving door not because he cared about efficiency or convenience, but because he couldn't stand holding open a regular door. More specifically: he loathed chivalry, and he thought a new door was the perfect way around it.Continue Reading
Little did he know, revolving doors would be cleaner and more energy efficient than standard doors - but hardly anyone would use them. Van Kannel's patent, #387571, was based off of an existing door invented by German H. Bockhacker: Tür ohne Luftzug, or "door without draft of air." It was initially called a "storm door structure," and true to its original name, its aim was to keep the outside elements outside.
The design was about eight times more efficient than regular doors, in fact. But for a variety of reasons - design, difficulty of use - most people have preferred to use regular doors over the revolving option. For example, in 2006, students from MIT found that only about 20-30 percent of students used revolving doors. Over several years, the students argued, this could waste a tremendous amount of money in energy costs. They resolved to put up signs around campus urging other students to use the revolving doors.
Andrew Shea, a New York designer, decided to do the same at Columbia University. By using signs, Shea managed to get about 70 percent of the people to use revolving doors - much higher than the 30 percent he'd seen earlier.Learn more about Inventions