Application: Elevator Sizing and Fleet Calculation
Example
A mid-rise office building requires an elevator system. The estimated peak 5-minute passenger arrival rate is 120 people. An elevator manufacturer proposes a system with cars that hold 15 passengers (P) and have a calculated Round Trip Time (RTT) of 150 seconds. How many elevators (N) are needed to meet the demand, and what will the resulting Interval (I) be?
Step-by-Step Solution
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Application: Calculating Escalator Handling Capacity
Example
An escalator operates at a standard speed of 0.5 meters per second (m/s). The escalator has a clear step width of 1000 mm (wide enough to accommodate two average persons per step side-by-side) and a step depth of 400 mm. Assuming a practical loading density of 1.5 persons per step, calculate the theoretical continuous handling capacity of the escalator in persons per hour (pph).
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Application: Elevator Round Trip Time Components
Example
Break down the theoretical Round Trip Time (RTT) of a passenger elevator. A single car with a capacity of 10 passengers serves 10 floors (traveling 30 meters total one way at 1.5 m/s). It makes an estimated 5 probable stops during a typical up-peak morning rush. Calculate the approximate RTT considering travel time, door operation times, and passenger transfer times.
Step-by-Step Solution
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Key Takeaways
- Trade-offs: Increasing the number of elevators improves interval times but permanently consumes valuable, revenue-generating rentable floor space (Core Area).
- Traffic Profile: Office buildings prioritize the massive Morning Up-Peak, while residential buildings must also balance heavy Two-Way traffic in the evenings.
- Integration and Safety: Elevators are highly complex, potentially lethal machines that require robust, mechanical fail-safes (Governors) and must flawlessly integrate with the building's fire alarm system (Phase I/II Recall) and emergency Gensets during blackouts.