INGENIEUR
INGENIEUR
Skyscrapers are built to last longer than regular buildings
should also encourage projects to pursue an efficiency-rating system such as LEED , BREAM , and ENERGY STAR [ 10 , 11 ].
RECENT TECHNOLOGICAL DEVELOPMENTS
Much of the “ green ” agenda focuses on reducing energy consumption . Buildings consume about 40 % of the world ’ s energy , and elevators account for 2 %– 10 % of a building ’ s energy consumption . During peak usage hours , elevators may utilise up to 40 % of the building ’ s energy [ 19 ]. Quantitative studies on the energy consumption of newer and older elevator technologies are now being conducted to assess the value of the new technologies . In this regard , ISO 25745-2:2015 standards are used to help estimate energy consumption . These standards provide measured values and calculations on an annual basis for different types of elevators and present the data according to different energy classification systems for new , existing , and modernised elevators .
For simplicity , new elevator technologies are discussed within two categories : energy-efficient hardware and energy-efficient software . Other technologies related to elevators are discussed in the subsequent section . To provide development continuity , the discussion starts by briefly mentioning earlier energy-efficient innovations and then moves to the most recent ones [ 8 , 12 , 23 ].
ENERGY-EFFICIENT HARDWARE
AC and DC Motors One of the significant advances in elevator technology has been the replacement of conventional brushed DC ( direct current ) motors with more efficient AC ( alternating current ) motors . Before the 1990s , elevator systems relied on DC motors because it was easier to control elevator acceleration , deceleration , and stopping . As a result , AC power typically was restricted to freight elevators , where comfort and speed were not as critical as in passenger elevators . By the late 1990s , however , more elevators had moved to AC
16 VOL 94 APRIL-JUNE 2023