Never before in my life have I encountered revolving doors so often as in Germany, and every time I have to use one, I wonder what’s exactly the point.
Any ideas? The only think I can think of is that they slow down people on purpose, for crowd control.
Likely also for energy efficiency, but then the double doors system that I’m use to seems more efficient and probably cheaper than revolving doors.
Installer here. They are precisely for what the other commenter said, and for traffic control. Think of the large hoards of cattle, I mean people, that enter and exit large office buildings at the same times everyday. If they were normal swing doors, or automatic sliders, climate-control wouldn’t be able to keep up, as the doors would be open the whole time.
Are they objectively more efficient than an airlock system like this, or is their popularity accidental?
I can imagine they are more expensive than a double door system.
If you have a large stream of people constantly entering or leaving the building, both doors will be open all the time. In a rotating door, people can enter and exit simultaneously and constantly but you still have a working air lock that exchanges less air with the outside than a door that is open all the time.
They also keep the heat in
Yeah, that makes sense. It’s the same for where I come from (but keep the cold in, instead), and the airlock system is by far the preferred solution. I think only IKEA insists on revolving doors where I came from.
Cheaper is relative. Those double door systems need a lot more space if designed for many people (where you need two or three of those sets side by side), which is expensive.
And as simply someone who wants to enter a public building I prefer revolving doors. More user friendly.
Describe your double door system?
It’s not a great photo, but basically you have two doors (manual, automatic, or slide) in a series, with an “airlock” space between. You open the outside door, step in the space, the outside door closes behind you, then you open the inside door and step into the building.
Perhaps because I’m far more used to them, they seem more efficient to me.
PS. This system is used in Germany too, but in very few spaces. I’ve seen it mostly in restaurants.
