ON THE UP AND UP: WHAT MAKES AN ELEVATOR GREEN?

publication date: Apr 14, 2008

by Stephanie Aurora Lewis, RA, LEED

Elevator manufacturers KONE, Otis and ThyssenKrupp have recently flooded the market with patents for eco-friendly inventions that allow elevators to run on much less energy and within much less space that current designs. For the seasoned elevator, several strategies are available for green modernizations as well. Yet beyond the new green technologies currently on the market, an elevator itself is an important green tool in the functionality of a tall, dense building. Bruce S. Fowle, senior partner at FxFowle Architects, said, “Vertical transportation via elevators makes way for dense communities, which in turn conserve precious green fields from the depleting nature of a sprawling city.”

Improvements Add Up to Falling Energy Costs
“Elevators use very little energy according to the overall amount within the building,” said Stuart Prior, executive vice president over product sales and marketing at ThyssenKrupp. Although elevators are modest energy users, they can still incorporate greater energy efficiency. One way to do so is to install what ThyssenKrupp calls a regenerative drive system. As the elevator cab ascends and descends, the counterweight, which weighs 40 percent more than the empty cab, moves in an opposite direction. In this energy-saving elevator drive, the electricity used to move both the cab and its counterweight is recycled into other parts of the elevator’s power and can even be redirected into other functions from within the building itself. As an added bonus, the regenerative drive system also increases the efficiency of passengers’ travel times.

Up and Coming Inventions
For new installations in small to medium-sized buildings, a compact machine tucked into the elevator core replaces the need for a large elevator room. The improved gearless motor no longer has slip rings, does not need lubricants and consumes only 60 percent of the energy required by other geared traction machines. Furthermore, the gearless design vibrates less and provides a quieter ride for its passengers. For the machine room-less elevators, KONE created the MonoSpace and the MiniSpace; Otis created the Gen2; and ThyssenKrupp created synergy.

Up-to-Date Green Technologies
When modernizing, Prior describes a few green strategies such as replacing existing incandescent lighting fixtures with LEDs, installing a light sensor that turns off the lights when not in use, updating to a microprocessor-based controller, switching out DC controllers with AC controllers, and using vegetable-based and highly refined petroleum-based fluids for hydraulic machines.
“There are approximately 900,000 elevators in use in North America and many of them are 40 to 50 years old. Today, the modernization business is as large a market as new construction,” Prior said.
Modernizing an elevator with a new type of technology may also garner extra Innovative Points in the LEED Existing Building (EB) registration system.

The Advantages of Building Up
New York City, where Otis’ first passenger elevator was installed in 1857, is an example of a vertical city that conserves natural resources simply by building with small geographical footprints. Fowle, who practices architecture in New York City, designed the first recognized green skyscraper in the United States. As an active member of the USGBC and in the development of various LEED programs, Fowle lauds the elevator as one of the most phenomenal building tools yet invented for green construction.
Prior agrees with Fowle. “To reduce the core space and to move people faster through the building are also two very important factors in making a building green,” he said.
Whether new or revitalized, elevators are green in their conceptual usage for vertical transportation yielding a dense building environment. And, the new green elevators, with their diminished energy usage and eco-friendly designs, add up to a win-win for the environment.

Works Cited
1. KONE. Green Elevator Product Assists in Energy-saving for New Generation Houses for 21st Century. 08 November 2006. http://www.kone.no/en_CN/main/0,,content=60596,00.html
2. KONE. KONE at the 5th China International Exhibition of Elevator Equipment and Technology in Beijing. 19 April 2002
http://www.kone.com/en_CN/main/0,,content=17031,00.html
3. The BOMA Magazine. Protecting the Environment and Your Money: How Elevators are Going Green. 09 April 2008.
http://www.fmlink.com/ProfResources/Magazines/article.cgi?BOMA:boma1015b.html
4. ThyssenKrupp Elevator. Machine Room-Less. 09 April 2008. http://www.thyssenkruppelevator.com/mrl.asp
5. Otis. Gen2 Elevator. 09 April 2008. http://www.otis.com/products/detail/0,1355,CLI1_PRD16916_PRT30_PST708_RES1,00.html
6. The Museum for the Preservation of Elevating History. Timeline. 09 April 2008. http://www.theelevatormuseum.org/timeline.htm

Editor's note: Photos provided by ThyssenKrupp.