CHICAGO — Energy-efficient elevators can significantly reduce the costs of operating a building, but the information needed to help building owners identify the appropriate elevator system — and the savings associated with it — aren’t readily available, according to a new study.
The study, conducted by the American Council for an Energy-Efficient Economy (ACEEE) based in Chicago, was published with the help of UTC Building & Industrial Systems, the parent company of Otis, a large manufacturer of elevators. Findings from the study were presented on Jan. 27 at the 2015 American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Winter Conference in Chicago.
Elevators and escalators make up 2 to 5 percent of the energy used in most buildings, but can reach as high as 50 percent during peak operational times, according to the study. At 5 percent, energy consumed annually by U.S. elevators is approximately five times than that used in all of Washington, D.C annually.
The technology exists today to reduce that consumption by 40 percent or more, especially by cutting energy use between trips when an elevator is idle. Some technologies have been found to reduce consumption by as much as 75 percent, but without a standard way to measure energy savings — and a rating system to distinguish more efficient elevators — building owners may be unaware of the benefits of upgrading to a more efficient system or choosing a more efficient system for new construction.
“Enhanced visibility when it comes to elevator efficiency can help customers grasp the full value package of better controls, improved performance, reduced sound, and increased comfort,” said Harvey Sachs, an ACEEE senior fellow and the study’s lead author.
The study lays out a framework for industry leaders to set common standards for measuring elevator efficiency. Those standards could lead to a rating system, such as the U.S. Environmental Protection Agency’s Energy Star ratings already in place for heating, ventilating and air-conditioning systems, and many home appliances. Clear standards also could lead energy utilities and government agencies to offer incentives, such as rebates, for very efficient models. Building label programs, such as the LEED program, could include elevator efficiency as a factor in certifying buildings. Currently, the LEED program considers elevators a part of unregulated "process loads," and there are no direct credits for installing more efficient systems.
“Owners see elevators as an extension of the building lobby — a way to include their personality and values in the building,” said John Mandyck, chief sustainability officer, UTC Building & Industrial Systems. “As consumers and tenants better understand and value the effects green buildings have on the health and productivity of inhabitants, clear standards for measuring elevator efficiency can provide a great opportunity to reduce operating costs and showcase the environmental attributes of a building.”
The report identified energy-efficient elevator technologies that can be included in building codes and factored in elevator rating and labeling systems. As almost all elevators are idle far more than they are moving, reducing standby power by turning off lights and cab ventilation systems can be relatively inexpensive and dramatically cut total energy use.
In addition, new technologies, such as coated steel belts that replace cable ropes in some elevators, allow for more efficient operation. Advanced dispatching software can improve the customer experience by reducing wait time while cutting energy use in half compared to traditional systems, according to the report.