As skyscrapers are getting higher , reducing the number of needed elevators becomes more important because they eat up valuable interior space on every floor [ 35 ]. This is more critical on upper floors where floor size gets smaller . In general , space-saving elevator design is important because in high-rises elevators occupy more space than any other services . Above 60 floors , arrangements of Double Deck elevators and sky lobbies could be useful . Also , Double Deck elevators are most useful for shuttle applications in very tall buildings . However , the Double Deck elevators also suffer from some operational challenges . For example , for local services , Double Deck elevators must load and unload two decks simultaneously . In addition , Double Deck elevators require stairs or escalators in the main lobby so that passengers can move between the lower and upper-level lobbies to get to their destination floor [ 36 ]. Consequently , Double Deck elevators became less popular because passengers were dissatisfied with having to transfer levels at the main lobby and due to non-coincident stops .
LED Lighting Energy-efficient light-emitting diode ( LED ) cab lights within an elevator car and their adjustment to movement detectors are one of the main contributors toward efficient power consumption in a building . LEDs save substantial energy as they require less power than incandescent , halogen , and fluorescent lamps . LED also emits less heat , resulting in less energy needed to cool the cab . LED lighting is currently utilised in many new buildings . Additionally , building owners are replacing traditional elevator lighting systems with LED lighting [ 38 ].
ENERGY-EFFICIENT SOFTWARE
New elevator control software allows for the conducting of elevator traffic studies , which inform how an elevator ’ s cycle affects its energy use . By observing and studying the irregular nature of elevator operation , the number of floors travelled , periods of peak load , low load , and empty trips , researchers can create energy consumption models to develop efficient control strategies and make recommendations for best management .
Destination Dispatching Systems In a conventional call system , the users push up and down buttons , and elevators answer the call . This system works fine in buildings that have low “ vertical ridership ” and do not experience “ rush hour ” traffic . In heavy traffic , a lot of buttons are pushed , resulting in a lot of elevator stops , increasing travel and wait time . Johannes de Jong explains that in a high-speed elevator , say with a speed of 6m / s , each stop may require as much as 10 – 13s [ 29 ].
To address this problem , elevator designers have invented the Destination Dispatching System ( DDS ). It was first introduced in the 1990s following the surge of increased microprocessor capacity during the 1980s . A DDS is an optimisation technique used for multi-elevator installations that groups passengers for the same destinations into the same elevators . In real-time , the system analyses input data from passengers and efficiently groups their destinations , resulting in fewer stops for every elevator trip . Upon entering a destination by using keypads or touch screens on the Destination Operation Panel ( DOP ), usually placed strategically in the lobby , the system quickly signals and directs each passenger to the assigned elevator ( Figure 5 ).
DDS provides important benefits , including decreasing energy consumption , reducing waiting time , and minimising crowding and congestion in the building lobbies and hallways . DDS manufacturers claim that the average travelling time can be reduced by about 30 %. The average wait time for the elevator in a typical 16-floor building with a dispatch system is 13s , while the average wait time for the elevator in the same building with a conventional system is 138s [ 37 ].
In addition to saving time , the system eases pedestrian traffic flow since each passenger heads directly to a specific elevator , eliminating the need to rush to every arriving elevator , a common behaviour exhibited by passengers . The system also improves accessibility , as a mobility-impaired passenger can move to his or her designated car in advance . The DDS is mostly appreciated during “ rush hours ”, usually experienced in the morning and lunchtime [ 18 ]. Due to increased efficiencies in handling large numbers of people , DDS reduces the required number of elevators . It also decreases wear and tear because the elevators make fewer stops [ 39 , 40 ].
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