Security against human and natural hazards is a growing concern, and entry doors are a key focus. Most revolving door manufacturers offer various locking options that can ensure the building is securely closed at night or during non-opening hours. Options include different types of locking mechanisms that secure the door wings in their standard resting position, and night sliding doors that close over the throat opening of the revolving door.
Doors can be locked from a remote location, and access control systems can be integrated with the door to allow authorized users to enter or exit the building. Many employee-only entrances use security revolving doors to prevent ‘tailgating’ and ‘piggybacking.’ Vandal- and bullet-resistant glass is also available.
Recommended surrounding features
A popular strategy in colder sections of the country, building overhangs provide shelter from weather and keep snow and rain from getting inside the door. However, as described earlier, interior throat opening or keyhole connections can create the same benefit within the entry itself—this makes for a simpler, cost-effective solution by requiring less of an exterior overhang to be built. Additionally, if access control is used, an overhang provides protection during the brief pause when a user must gain authorization before entering a security revolving door.
Adequate attention should also be paid to flooring. Although there is no industry standard, most door manufacturers require the floor surface beneath the door’s footprint to be perfectly dead level (or within a few millimetres) to ensure proper operation and correct weather seal along the bottom of the door wings.
Using different flooring materials for the circular footprint of the revolving door itself visually signifies to users the actual path of the moving door wings and makes for less confusion and hesitation upon entering. The installation of the matting materials at the exterior and interior helps avoid slips and falls.
Many buildings also employ stainless steel floor grates on the exterior or interior side of the door or even underneath it to collect dirt and debris before entry and decrease maintenance costs. Grating or matting that continues 3 m (10 ft) or more into the interior space can also help qualify for points under the Leadership in Energy and Environmental Design (LEED) program, working toward Indoor Environmental Quality (EQ) Credit 5, Indoor Chemical and Pollutant Source Control.
Capacity and type of use
While these concerns are certainly important, the biggest issues in specifying a revolving door are capacity and character of expected traffic. Architects will have to consider how many and what type of people are expected to enter and exit a facility. Will rush hours be a challenge or is traffic spread throughout the day? Do doors have to accommodate individuals with luggage or shopping carts? Capacity is based on type of facility and user demographic.
Automatic revolving doors of any wing configurations, with large compartments, safety sensors, and ‘push to slow’ buttons, are generally applicable for facilities accommodating families, children, the elderly, or rolling baggage and carts, including museums, hospitals, airports, large retail establishments, hotels, and casinos. Small office buildings, restaurants, and specialty, high-end retail buildings are ideal for three- or four-wing manual revolving doors. Optimal capacity is reserved for ‘trained traffic’—users familiar with the doors and the building who are either residents or employees and come and go on a regular basis. (Ultimately, there are laws [such as AODA] requiring accessibility be taken into account for all projects. However, facilities want all visitors to maximize the energy efficiency by using the revolving doors; they can complete both objectives by installing automatic revolving doors with large compartments that offer accessibility.)
Factors affecting capacity and user comfort include:
- diameter of the drum;
- throat opening;
- manual or automatic operation;
- compartment size and number of door wings; and
- positioning drive on manual revolving doors.
This is expressed in terms of x number of people per direction per minute. For example, ‘1×15’ refers to a one-way door that allows 15 people through in one minute, for a total of 15 people/minute. One-way doors, however, have limited application. The more typical capacity equation is ‘2×24,’ signifying a two-way door that allows 24 people per direction in one minute for a total of 48 people/minute.
When calculating throughput, an individual’s comfort zone should be considered. Most people would prefer a comfort zone around them totalling about 1 m2 (12 sf). To roughly gauge the capacity of a revolving door, one can divide a compartment area by this dimension and then multiply the number of compartments by the recommended number of revolutions per minute (RPMs).