A revolving door is something that has three or four doors which droop on a center ray and turn around an upright axis within a round area. Revolving doors are power resourceful as much as they stop drafts, therefore stopping in increases of the heating or cooling necessary for the building. And in the same time many people can pass in and out for the door. Revolving doors are also known for the glamour and prestige of the building and its structural design. To the center ray of the revolving door you can see three or four doors called leaver or the wings.