Stepping into your building’s elevator or onto the escalator, you’re probably not thinking about how sustainable or “green” your mode of transportation is.
But, with all the talk surrounding sustainability in building products, did you know that even today’s vertical-transportation systems are being developed with green features? The buttons you push in a new elevator are probably lit by LEDs, recycled materials were likely used in its construction, and the elevator may even be generating energy to use in other parts of your building.
Experts at four of the largest vertical-transportation organizations recently revealed major sustainable features in elevators and escalators, many of which will save you energy and money.
Machine Room-Less Elevators. Introduced to the United States less than a decade ago, the machine room-less elevator (MRL) is suitable for low-rise buildings and offers a number of sustainable benefits over its predecessor, the hydraulic elevator. All of the mechanical equipment for an MRL fits in the elevator hoistway, eliminating the need for standalone machine and equipment rooms.
Not only does an MRL save space, the motor uses substantially less horsepower than a traditional hydraulic elevator. “[When] using the smaller motor [of an MRL], you’re not only using less energy, you’re generating much less heat; hence, you’re using less power to cool the building or to cool the machinery area. All those kinds of things snowball into significant reductions in energy,” says Ken Segel, vice president of marketing for Morristown, NJ-based Schindler Elevator Corp.
Oils/Lubricants. The MRL does not use any oil, which adds to its list of green attributes (the oils and lubricants used in hydraulic systems can be poisonous to the environment, especially if they saturate groundwater). But, there is an environmentally friendly solution for existing hydraulic systems: Vegetable oil can be used as a replacement in certain elevator applications.
Regeneration. In elevator systems, regeneration is achieved by using an alternating current VVVF (variable voltage, variable frequency) drive; they reduce peak power demand by harnessing the energy created from the system. Rick Pulling, director of Farmington, CT-based Otis Elevator’s high-rise program, explains: “When the heaviest load is moving in the downward direction in an elevator hoistway, [it] generates electricity. A regenerative drive gives us the ability to put it back into the building grid, where it can be used by other sources seeking power on the building's grid.”
Software. Much of what makes an elevator system work efficiently is more than just the inner mechanics. New control systems have improved dispatching capabilities. These programs move riders to their destinations more quickly by grouping them based on their destinations (which also makes efficient use of energy). Another software innovation revolves around times of peak demand: “During the middle of the day, when people aren’t using the elevators and they’re in their offices, we can run elevators slower or we can actually turn off elevators that aren’t needed. Conversely, during peak times, we can run them faster,” claims Stuart Prior, COO in Latin and South America at Frisco, TX-based ThyssenKrupp.
Power Intelligence. Some of today’s escalators have more intelligent capabilities than in the past. “[This new type of escalator] has a way of sensing how much power it needs and can adjust the energy consumption. It only goes up to full power when it senses that the elevator is loaded up with people,” explains Aaron Ites, director of product management at Moline, IL-based KONE.
Systems in Europe have taken this technology even further. There, some escalators and moving walks will idle very slowly or even stop until they “sense” a person approaching. Building code in the United States has yet to allow this equipment, but experts seem confident that it’s not too far away. “Besides the elevator companies pushing for this, you have organizations like the [Washington, D.C.-based U.S. Green Building Council] leaning on this also,” says Segel.
Reuse of Materials. In some modernizations, existing materials can be reused by building a new escalator inside of the existing one, reducing waste and resources. Retrofits are also available to increase the energy efficiency of older escalators.
Historically, vertical transportation systems have provided energy efficiencies and long, sustainable life-cycles. Today, the emphasis on green has made the benefits more visible and strengthened the argument for developing cleaner, more efficient processes. “The definition of green should apply to the entire process, beginning in the design and manufacturing phases,” Pulling says. “It’s really a cradle-to-grave look at how the elevator is both produced and ultimately used.”
Anne K. Goedken ([email protected]) is new products editor at Buildings magazine.