With a growing emphasis on sustainable building management systems, elevator manufacturers are concentrating more on the product lifecycle from its manufacture to installation, maintenance and modernisation. At the same time architects, builders, building owners and facility managers are exploring ways to increase elevator efficiency and reduce energy consumption through upgrading and installing latest elevator technology.
It is estimated that horizontal/vertical transportation account for 2-10% of the building’s energy consumption, which amounts to 40% of the world’s energy intake. Building energy consumption is largely influenced by the elevator type and technology. Besides, a sustainable elevator system would also require investment in a range minor upgradation like lighting improvements to a complete energy-efficient system design and installation. LED lighting, closed-loop door operators or automatic fan and light shut-off, help cut down on building’s energy consumption.
According to an article written by Henry Gifford for Home Energy Magazine, a hydraulic model uses 30 times more electricity than a traction elevator. Traction elevators ride on cables, using weights to counterbalance the weight of the cab. Since it uses a single motor to overcome friction, it uses less energy than hydraulic elevators. However, two to three decades back, traction elevators ran on DC hoist motor, which required a motor generator in order to convert AC (alternating current) power into DC power. Most of the energy used by these elevators happens when it is idle from the heating, cooling and lighting systems. In fact, relatively the energy used in light sensor stairways exceeds that of the energy used for a traction elevator ride.
Technological advancements with the introduction of SCR (silicon-control rectifiers) drives have eliminated the requirement of dual motors, significantly reducing energy consumption and operating costs in traction elevators.
Hydraulic elevators on the other hand use a pump system to push a cylinder of fluid on a piston for lifting the cab. Since the energy used to lift the elevator does not get recovered on the trip going down, it leads to complete loss of energy. Hydraulic elevators do not use a counterweight system. Unlike older systems which used water, modern elevators use oil in the pump system. While oil does away the rusting issues, it raises major safety concerns in case of any leaks in the system.
A major advantage with hydraulic elevators is that it allows for a simple building structure. The cylinder used to move the elevators up and down is supported by the soil beneath the building versus the building itself. Modernizations in elevator have upgraded elevator performance, reduced energy consumption and decreased the impact on IAQ. Significant energy savings can be achieved with the installation of destination control software, which is known to create up to 35% more efficient passenger transportation. Grouping elevators by destination improves routing and enables fewer trips. Shortest travel time can be achieved through a dispatching system which directs passengers to the elevator that will get them directly to their destination.
Instead of buttons in the car, passengers can use the keypad or touch screen in the lobby to register the floor to which they want to travel to. The keypad or touch screen will graphically direct passengers to the appropriate car that will take them to their destination. Guided by a formula based on estimated time to destination, the system takes into account each person’s desired stop and dispatches the car that will provide the fastest trip time.
As the elevator car arrives, the lobby position indicators enables passengers to see designated stops and direct them to their appropriate ride. In most modern commercial buildings accommodating multiple office spaces are faced with high traffic handling pressure especially in the mornings and evenings. Elevators running on the destination control software increases efficient passenger-handling capacity to meet high-traffic needs. Considerable time and energy is saved by avoiding elevator stopping at multiple floors for different individuals. The dispatch system groups passengers traveling to a specific floor in one trip.
Moreover, the passenger waiting time can be reduced up to 30% and the handling capacity can be increased considerably. A number of people can be transported efficiently in a set time. Destination control systems improve building efficiency and can even increase overall property value. Elevators running at peak performance use less energy. To maximize the performance and safety of elevator products, a code-compliant preventive maintenance program is important.