Elevatoring is the analysis of the requirements of vertical transportation of people and materials in a building, under all operating conditions. Such transportation requirements may be studied from a compatibility aspect, as in an office building from a function aspect, as in a hospital or from a merchandising point of view, in a department store.
The first essential step in elevatoring is pedestrian planning, that is, determining how many people will require transportation, what the peak traffic will be, and how it will occur—all up, up with partially down traffic, or equally up and down simultaneously.
Some wellestablished guidelines may be available, as will be demonstrated in the various chapters on commercial, institutional, and residential buildings. For some projects, extensive study of the expected pedestrian movements must be made before the process of determining the requirements for elevators or escalators can start.
Once the critical pedestrian traffic is established or estimated, the next steps can be taken.
Elevatoring requires consideration of all the time factors and movements that take place during the operations providing transportation for people and/or materials. These time factors must be related to a total time required for the service, based on the actual or estimated demands. Efficient elevatoring requires minimizing the time factors to maximize service.
The time components of an elevator round trip that will be studied and evaluated are as follows:
- Loading Time. The time required for a number of people to board an elevator car, moving stairway, or moving walk, or the time required to load material or a vehicle on to an elevator or lift. Loading time must be considered under many conditions of operation, consisting of narrow or wide elevator cars, wide doors, narrow doors, arrangement of elevators, and partially filled or empty elevators.
- Transfer Time. The time to unload (or reload) an elevator at a local stop above the main landing. Transfer time is based on all the considerations of loading time plus, essentially, the density of the passenger or other load remaining on the elevator, and the direction of the transfer—either entering or leaving. These two elements, loading and transfer time, are the most difficult to quantify because, in general, these times are based on the interaction of people. Estimates have been made based on hundreds of field traffic studies of human behavior, and the con- clusions are reluctantly (because of the doubt that such a person exists) based on “the average person.” Transfer time is mitigated by both legislation and environmental considerations. Most elevators are held at a ﬂoor for a minimum period of time based on the time it takes to exit and a separate time allowed for entry. The Americans with Disabilities legislation has mandated a minimum of 3 seconds for a person to exit and an extended time to enter, based on the location of the landing call button in proximity to the entrance to an elevator. These factors must be considered in calculating total transfer time. Extended discussion is given in specific application examples. The other factors in an elevator or escalator trip are the mechanical times, which can be established accurately and ensured by a specification that can be developed before installing an elevator or escalator.
- Powered Door-Closing Time. This is a function of door weight (mass). Width of opening and type of opening for horizontally sliding doors—center opening, single-slide, two-speed, or the height of the opening for verti- cal biparting doors for freight application—involve different masses that affect closing speed. The kinetic energy of closing doors is limited by elevator safety codes and is usually established at no more than 7 ft poundal (0.29 joules). In practical terms, this means that the familiar 48-in. (1200-mm) center-opening sliding door will require about 3 sec to close. Closing and opening time is a vital consideration in elevatoring, because the door operation on a typical elevator occurs hundreds of times a day.