How a revolving door interrupts the rush of air
A conventional swinging door briefly creates a wide, direct opening between the lobby and the street. If wind pushes on the building—or indoor and outdoor air are at different pressures—air can rush through that opening. The result may be a draft, but it can also make the building’s heating or cooling system work harder to replace conditioned air that escapes.
A revolving door changes the geometry of the exchange. Its panels divide the circular enclosure into compartments. As the door turns, one compartment carries a person through the entrance while the panels continue to separate most of the lobby from the outside. The curved walls and close-fitting edges limit how much air can pass around the panels at once.
A moving buffer, not a sealed lock
The door does not make the entrance airtight. Small gaps remain, and air still moves with people and with the rotating compartments. But unlike a swing door, it generally avoids opening a broad passage straight through the building. That reduces the size and duration of the air pathway, so pressure differences have less opportunity to drive a strong gust into the lobby.
The benefit is especially noticeable at busy entrances. A swing door left open as people pass can let the street’s air flow inward for several seconds; a revolving door keeps its moving panels in place throughout the passage. The same design that lets people enter continuously therefore acts as a practical buffer between two different air environments.
