Revolving Doors: A New Spin on an Old Technology
Revolving doors have two to four wings, and are available in both manual and automatic models. Smaller four-wing models and large automatic two-wing models, which have two smaller wings on either end (like a “y”), provide better seals to the vestibule than do three-wing models. All of these wings collapse outward in case of fire, allowing an unrestricted exit.
Important considerations for selecting a revolving door include size of the building opening, number of people using the entrance per minute, handicapped accessibility, luggage usage, and security or control of access. Manual models are six to ten feet (1.8–3 m) in diameter and are usually the most cost-effective option. They are used for restaurants, banks, universities, libraries, and other buildings where wheelchair access and luggage are not prime concerns. Typically available in three- and four-wing models, these doors can handle 20 to 50 people per minute and use speed reducers that keep the rotations below 8 to 12 per minute (the maximum speed allowable by the National Fire Protection Association), depending on diameter.
Published May 1, 2010