Optimizing Elevator Systems: The Crucial Role of Traffic Analysis in Building Design
Why do you need an elevator traffic analysis?
It is extremely important to design for good elevator performance for the life of any building. An elevator traffic analysis should be performed to provide the solution that balances cost and performance, including the correct number of elevators, capacity, speed, and equipment type.
The locations of the elevators throughout a new building should be determined in the initial stages of building design. Once the designers and building owners have determined the population and usage requirements, and conceptual drawings are progressing, that’s the time for a traffic analysis. This will allow us to provide the hoistway sizes in the early stage so that the structural engineer, and other consultants, can move forward with the design of the building.
Less elevators than required can have a detrimental effect for the life of the building with longer than expected wait times and queuing in the elevator lobby. Correcting poor elevator performance once the building is constructed usually entails adding elevators or reducing the occupancy, which can be difficult to achieve. Conversely, too many elevators add unnecessary additional costs to building construction, and for the maintenance and modernization over many years.
Design and Planning:
In the schematic design phase of a building, a traffic analysis provides the ability to locate and group the banks of elevators, along with the service or freight elevators for special uses. The distance between elevator banks and location of the groups relative to the building entrances coupled with the passengers’ destination needs to be considered to optimize the occupant flow through the space.
Special uses for material distribution, especially for hospitals and laboratories, are calculated in the early phases. Decisions can be made to group these services with other uses or isolate this distribution with dedicated elevator systems. Each building has its own distinct needs and requires planning of elevator systems based on projected usage patterns, building occupancy, and usage types such as residential, office, health care, laboratory, and education. Each type of building will have its own published parameters for acceptable design.
Where additions are added to existing buildings, data needs to be gathered on how many people use the elevators, their destinations, and the times they travel, to determine the elevator system required for the facility in its entirety.
Elevator Traffic Analysis Parameters and Terminology:
Handling Capacity: The handling capacity is the percentage of the building population that the elevator system can move in a 5-minute period. Each type of building has a desired handling capacity to be moved in a peak five-minute period based on empirical, or observed, values. For example, an office building will be in the 11% to 13% range, and a residential building will be in the 5% to 7% range.
Interval: The interval is the average time between elevator departures from the main floor. Each type of building has expected values, again, based on empirical results. For office buildings the expected interval will be between 20 and 30 seconds, whereas an apartment building will be in the 40 to 60 second range. In an office building, people tend to be more impatient, and expect fast service, than in a residential building.
Average Wait Time: The average wait time is calculated as 60% of the interval with static elevator calculations. Simulation based traffic analysis programs will determine the average wait time based on multiple iterations utilizing a random traffic generator, and multiple iterations. In our studies we will provide the average wait times, as this terminology is a clearer way of conveying this information.
Building use Changes
A change in building use, such as office to residential, or an office building to a classroom necessitates an elevator system evaluation and a traffic analysis. One of these changes will reduce the load on the elevators and the other will substantially increase the passenger load on the system. We can make the evaluation and recommend a course of action.
How ATIS can Help
ATIS utilizes a traffic analysis program that runs simulations based on all the necessary inputs. Our knowledge of the building parameters, elevators systems, and our experience with coordinating with design professionals to understand the occupancy and traffic flow through the building results in systems which provide strong elevator service. We will work within your plan for the best outcome.
In existing buildings where the elevators are not performing as well as expected, we can make an evaluation of the system to determine if the equipment is performing as designed. Often the parameters in the controllers are not set to initiate up-peak operation properly. Door performance times can be adjusted to improve the performance. Additional adjustments can be made which will collectively have a positive effect on the system’s performance.
Summary:
Elevator traffic analysis is a fundamental aspect of building design that ensures the elevator system is efficient, effective, and able to accommodate the needs of its users. By understanding traffic patterns, estimating demand, and using simulation models, building planners can optimize elevator performance and enhance occupant satisfaction.
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