Revolving doors are more than just unique eye candy in hotels and office buildings.  The main reason that businesses use these types of doors over conventional swing doors is that they offer tremendous energy savings.  Check out this MIT article, which gives detailed measurements on just how much energy these doors save.  If we used these doors (where they’re available) 100% of the time over their neighboring swing doors, it’d result in a 74% annual energy savings!  That’s huge!  So the next time you see a revolving door and a conventional door next to each other in an office building or hotel, please opt to use the revolving door.  It’s a small thing for each of us to do, but offers significant energy savings if we all do it.