I hate revolving doors. They come third in my list of top ten hated things, behind birds (shudder) and peaches (don’t ever bring one near me. I am not joking).
I hate revolving doors because they never move at the right speed. Too slow and you have to shuffle round inside them looking like a shackled prisoner on a chain gang. Too fast and they are lethal for slow-moving grannies and small children*. If they are automatic they make a horrible swooshing noise that belongs in a horror movie. Stephen King would be proud.
So it came as a great surprise to me to find out that revolving doors actually serve a purpose other than to irritate me. The warm air in tall buildings can cause dangerous air drafts called the ‘chimney effect’, when cold air from the outside blows in through an open door at the base of a building and is sucked up through vents in the roof at high speed. The force of this can actually blow out windows. The design of the revolving door makes sure a draft never enters the building. At the same time, this also means that energy is conserved within the building as heat can’t escape through open doors.
Before such things as fire regulations came into force, revolving doors were blamed for thousands of deaths in burning buildings because they became jammed when panicking people surged towards them. These days, all buildings must have at least one hinged door next to the revolving door and/or have folding panels within the revolving doors. It’s a win-win situation with revolving doors these days but it still does not alleviate my intense dislike of the things.
* In 2005, a 6 year old Japanese boy became trapped in a revolving door and died.
You spin me right round baby
H. Bockhacker of Berlin was granted a German patent in 1881 for “Tür ohne Luftzug” or “Door without draft of air”. Theophilus Van Kannel, a Swiss-American was granted a US patent in 1888 for a “Storm-Door Structure”.