by Glen Tracy
Revolving doors are enjoying resurgence across many project types due to their ability to prevent unwanted air infiltration and enhance the aesthetic appeal of an entrance. However, specifiers will find detailing for revolving doors challenging because of the availability of a wide range of door types with different capabilities.
Rarely does one type of door fit a specific kind of building. There are also online specification services providing “master” revolving door specs bundling numerous types of doors into a single, lengthy document. All possible options are included, and the architect or specifier has to know what to keep and what to delete. This process creates the potential for errors. Additionally, there can be multiple people involved in creating specifications versus drawings, making it easier for a specification and a drawing to get out of sync. For example, a specification may indicate a three-wing door or metal-framed door, while the drawing shows four wings and all-glass construction.
Inconsistent, erroneous revolving door specs and misaligned drawings can waste time and, potentially, money. When estimators have questions, they submit requests for information (RFIs) to architects that are sometimes answered in several days or more, potentially delaying the bid process. On the receiving end of an erroneous spec, estimators are forced to provide alternates for different door options because they are not sure what the architect is specifically looking for. These factors can delay projects and, in the worst case, lead to installation of the wrong type of revolving door, causing a host of issues for the end user and pedestrians.
At the end of the day, there should be a clear understanding among all parties as to the type of revolving door to be installed to achieve an “apples to apples” bidding process. Therefore, the author has put together eight steps to walk readers through the selection of the revolving door and create a clear specification and drawing package estimators will appreciate and respond to quickly.
Step 1: Determine how many and who will use the door
One of the biggest issues seen in the specification of revolving doors is a failure to understand the capacity and character of expected traffic, leading to the selection of a revolving door model not suitable to the needs of the business.
Obviously, the traffic expected in a small office building will be different from an airport terminal. Designers must consider who and how many are expected to enter and exit the facility. Will rush hours be a concern, or will traffic be dispersed throughout the day? Will the doors have to accommodate individuals with luggage or shopping carts? Will hospital gurneys be used?
Manufacturers publish capacity, or throughput, numbers for each revolving door model. However, these numbers should only be a starting point. If a door will accommodate families, children, the elderly, or the disabled—any user who is not accustomed to entering through a revolving door and/or may need extra time—it will perform at the lower end of the published capacity range. Applications where residents or employees come and go through the revolving door on a regular basis receive optimum or maximum capacity.
The Cliff Lodge and Spa at Snowbird Ski and Summer Resort in Salt Lake City, Utah, is an example of appropriate consideration of traffic type and volume when selecting a revolving door for the building’s entrance. First, architects determined the maximum level of traffic the door would need to handle. They did this by identifying the number of people who would be at the resort if all of the rooms were booked. Second, the architects took into consideration the type of traffic entering the door. Guests usually come to the resort to stay for a week or more. The door had to be capable of handling carts with household goods, luggage, skis, and snowboards.
By taking the time to understand the capacity and expected traffic at a building’s entrance, specifiers and architects will be better equipped to select the appropriate door for their clients.
Step 2: Select the appropriate door operation
Revolving doors are available in either manual or automatic operation. A manual revolving door is offered with smaller diameters and is ideal for applications where the user’s hands are relatively empty—retail shops, office buildings, restaurants, condominiums, and public buildings. Automatic doors are available in diameters up to 6 m (20 ft) and can accommodate luggage, wheelchairs, and gurneys. They are suitable for applications such as hotels, casinos, hospitals, and grocery stores.
Once the specifier or architect has selected the appropriate operation for the application, there are a few additional considerations for writing the spec.
For manual revolving doors, one can choose between metal-framed construction and all-glass construction (a popular choice). In either case, it is critical to specify either a mechanical or electro-mechanical speed control system. A mechanical speed control is sturdy and prevents hazardous rotation speeds, but limits the size of the door because people have to push the full weight of the doors. For every 152 mm (6 in.) of added diameter, a revolving door wing becomes about 45 kg (100 lb) heavier.
A modern, electro-mechanical speed control stops excessive rotation speed, but also makes it possible to have several other features for adding value to the entry. For example, one can include power assist—for providing an added boost to door rotation once a user pushes on the door wing—and automatic door wing positioning where the wings come to rest at the end posts when rotation is completed. Doors with the power assist feature can also be taller and wider than purely mechanical doors because the technology reduces user exertion.
For automatic doors, specifiers should consistently select safety and motion sensors as well as other features required by the American National Standards Institute (ANSI) 156.27, Power and Manual Operated Revolving Pedestrian Doors. A failure to include these safety features in the specification can leave an estimator confused: did they really want a manual door instead?