Maybe this should be in Factual Questions. Feel free to move it.
I was in one of the old, beautiful office buildings in our downtown. It was built in 1895. The lobby walls are gray and pink granite and there are brass fittings everywhere. It also has one of the few remaining revolving doors. When I enter or exit this building, I always use the revolving door. I love it and it reminds me of being a kid. Kids love a revolving door.
Anyway, I was pondering that door the other day. What was the purpose of those doors? Wouldn’t it be a hindrance when everyone went home for the day? You would have to wait your turn to get out. It would be a cluster in an emergency. There are regular doors flanking the revolving door but I’m not sure if those have always been there or if there was more than one revolving door.
Revolving doors allow for a lot of people to go in and out while avoiding outrush of air. In a very tall building air pressure starts to build up at the bottom, which can result in a rush of wind blowing out a door when opened. Revolving doors prevent that. They also better prevent heat loss (or cooling loss in summer) than do regular doors.
We have a revolving door at my office building and it is flanked by two conventional doors. I’ll use the revolving one if there’s nobody else in front of me but some of the dudes that work here (and it’s always men; maybe due to their strength?) want to spin it like they’re on Wheel of Fortune. I don’t feel like timing my entry like a jump roper running into a double dutch game.
I recall a lot of revolving doors in Chicago which wouldn’t have really given me pause but I had never seen those rubber flaps they put on the bottom. It was indeed explained it’s to keep out the cold.
I’ve never heard nor experienced that. It’s much more common for the lobby to be negatively pressurized because of warm air rising up the elevator shafts (stack effect). That makes swinging doors to the exterior harder to open (they swing out so you have to push hard on them to get out, or pull hard to go in), then there’s a rush of air blasting into the poor security guard at the front desk. It can be even worse if there’s an atrium. It is worse in cold weather, but it doesn’t seem to reverse even in hot climates like Phoenix or Kuala Lumpur. I could see a large building that’s not too tall, like 10 stories, with a big atrium spilling out cold air in a hot climate (like Vegas hotels or big conference centers), but that’s a different beast than your typical office high rise.
The roof of the Tokyo Dome is supported by internal air pressure, so revolving doors are a necessity to keep the roof from collapsing while everybody is arriving or leaving at the same time. When I left a game there, ushers were posted at the doors to help them from spinning too fast but even then you had to move at a brisk pace to avoid getting smacked from behind.
I experienced the same thing when I attended a Twins game at the old Metrodome in Minneapolis. That stadium had regular doors, as well (for faster evacuation in the case of an emergency), but they had security guards there to keep people from using the non-revolving doors during normal use, for that very reason.
Several states banned the revolving doors after people died trying to escape from fires in the buildings. Many were replaced with legal ones whose panels were hinged to fold outwards in panic situations.
The first and last time I visited MIT in Cambridge, Mass., decades ago, the main building had at least one, flanked by swinging doors, and over it was a large sign “NOT AN ACCREDITED EGRESS”.
As per some above air flow stats, I found this (perhaps inspired by the MIT egress message(s):
In 2006, a team of graduate students at MIT conducted an analysis of door use in one building on campus, E25, where they found just 23% of visitors used the revolving doors.
According to their calculations, the swinging door allowed as much as 8 times more air to pass through the building than the revolving door.
Based on their energy costs in 2006, the study concluded that if everyone were to use the revolving doors in Building E25, MIT would save almost $7,500 in natural gas a year . That’s enough to heat five houses over the same time frame.
MIT published the study and encouraged students to used the revolving doors in all buildings to save energy.
I guess this shows how out of touch I am, and my need to get out more. Are revolving doors a thing of the past? I haven’t worked in downtown Chicago for about 12 years, but when I did, they were the standard on just about every office building, store, museum, etc.
Come to think of it, out here in the burbs it is more common to have push or auto open doors.
I just went back to my office in downtown Chicago this week, for the first time in two years. There are still revolving doors at Union Station, and there are still revolving doors at my office building.
I decided to see how common they really were and do some street view “walking” of downtown Chicago. The random place I started included two revolving doors on the very first building I zoomed in on (Chicago Bar Association - 321 S Plymouth Ct). Based on this anecdote, I believe every building has at least one. If anyone wants to continue my vigorous research, please feel free to reference my initial, ground-breaking study.
They’re still de rigueur in highrises, which is why you don’t encounter them in the suburbs. All that said, creative balancing of the HVAC system and pressurization of upper levels, as well as better sealed curtain walls and other air infiltration mitigations has made revolving doors less of a need than they were in the past, at least in new construction. Mechanically they’re very complicated, they’re expensive to install and maintain, and you still need regular doors for the mobility impaired, deliveries, and emergencies (even the collapsible revolving doors don’t usually provide enough opening area to meet egress requirements by themselves).
I went to a concert* at B.C. Place stadium years ago. I didn’t give the revolving door much thought on the way in. After the concert, the staff had opened the regular doors to let people out more quickly. There was a strong tailwind just I passed through the door. It was very localized, though; a few feet either side of the door and I didn’t notice a thing.
Straight out of university, nervous and a little awkward in a new business suit, the morning had been full of introductions and talks about how the company worked. It was time to take the new recruit for lunch. He was a bright, well educated fellow if a little nervous. Very young and very green. A short walk with colleagues in a nearby building that housed the cafeteria and to file one by one through the entrance with a revolving door.
What did he do? You guessed it! He crammed himself into the same section of the revolving door as his rather startled new boss. Getting stuck as someone else was trying to exit on the other side carrying luggage. We all looked at each other, all veterans of many an office layout, trying to suppress the laughter. We had just recruited a Mr Bean. Later we stood well back to watch him tackle the paternoster lift.
Pardon the partial hijack: Just watched the 50-second video of the cool paternoster lift at Sheffield U in UK (one of only two in UK). What happens to an occupant who doesn’t vacate the cubicle at the top floor or bottom floor? Why only 2 in the whole UK? Disabilty non-accessible?
I suspect Chicago would have a higher percentage of revolving doors due to that whole wind thing. Swing doors have a nasty habit of being impossible to close in really high wind conditions, along with having a nasty habit of the wind catching them, ripping the door out of people’s hands and slamming them against the wall. Breakage has been known to happen. So the revolving door not only helps with temperature control but also avoids injuries from wind caught swing doors slamming back and forth.
