Chronically neglected in favor of lower-hanging fruit, elevators are nowhere near the top of most FMs’ energy upgrade priorities.
These machines represent 3-7% of your building’s energy consumption, however – so while elevators may not be your biggest energy consumer, they offer potential for considerable cost and energy savings.
Target the major sources of elevator energy waste with a solution tailored to your budget.
Smart Tracking Strategies
Start your elevator efficiency upgrades by first getting a handle on how much energy each machine uses. Submetering involves installing data logging equipment in the entire bank of elevators to measure current and voltage in incoming electrical lines. This practice results in the most accurate measurements, and some utilities will subsidize energy efficiency upgrades depending on the results, notes Jack Tornquist, vice president of the elevator consulting group for the consultancy Lerch Bates.
The initial investment can be significant, which discourages many building owners from tracking energy consumption closely despite the possible savings, says Andy Kohl, president of The Elevator Consultants.
“The meters themselves are anywhere from $2,500 to $6,000,” adds Brad Nemeth, vice president of sustainability for ThyssenKrupp Elevator Corp. “The minimal investment is about $4,000, and then you’re replicating that across however many elevators you have.”
Not comfortable monitoring consumption in-house? Consider bringing in a third party to conduct an audit, recommends Bill Lippman, vice president of modernization sales for Schindler Elevator Corporation.
“An elevator audit will evaluate the age of the equipment, when it was installed, and if or when it was modernized,” Lippman explains. “If the system is over 15 to 20 years old, there are huge potential gains to be had in energy efficiency and reliability simply because of the technological advancements that have taken place in that time.”
Where to Find Waste
To determine where the most cost-effective improvements can be made, your next step is examining components responsible for the most energy use.
“One of the largest sources of energy waste in elevators is the drive system,” says Lippman. “Older drives, such as motor generator sets, are continuously running, which can be very inefficient and contribute to a large waste of energy. They can also contribute to hidden energy costs in a building because they generate a lot of heat, which can require additional energy from HVAC to cool the equipment.”
Still have a hydraulic elevator? Its motor likely uses 40-60 HP, compared to the 6-8 HP motor typical of a modern machine room-less (MRL) elevator, says Kellie Lindquist, marketing manager for KONE Elevators and Escalators. That means whenever the elevator is actively working, it’s expending energy, Kohl adds, whether it’s hoisting the car or just leveling as it approaches the right floor.
“For hydraulics, there are some new products out that can do a really good job because they cut down on the floor-to-floor time,” Kohl explains. “If it takes 12 seconds to get to your floor in a hydraulic elevator and you can take that to 9 to 10 seconds, that three seconds every time the elevator runs can add up pretty quickly. If the motor’s not running, you’re saving energy.”