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Elevators Are Part of the Energy Efficiency Puzzle, Too

Every little bit counts in the race to make buildings more energy-efficient. Property owners will soon have to meet strict energy and emissions standards globally, leaving some scrambling to cut energy wherever they can. Building systems like HVAC are an obvious target because they consume so much power. But after addressing all the most significant areas, buildings will have to look in other places. If a building must eventually become net-zero emissions, energy efficiency will have to encompass almost every part of the property. One part that might get overlooked is elevators. Elevators don’t consume a ton of energy compared to other systems, but the upgrades can move the needle on reductions more than many property managers may assume.

The average elevator today accounts for about 2 to 3 percent of a commercial building’s energy consumption, according to Monica Miller Brown, Senior Sustainability Manager at TK Elevator. Miller Brown pointed out, though, that motor-generated elevators consume more, as much as 8 to 10 percent of an average building’s energy. Many older model elevators use motor generators for their drive systems, and the drives are constantly running. These drives generate a lot of heat, and it requires more energy to cool them down. Upgrading to a modern, gearless elevators system can help tremendously. Gearless modernization eliminates the motor-generator, decreasing noise levels, and energy consumption.

A complete modernization of an elevator system improves energy efficiency vastly and helps other areas, such as safety and tenant satisfaction. But complete modernization isn’t cheap by any means, costing as much as $120,000 to $130,000 per elevator, and perhaps even more. If that type of complete upgrade isn’t in the budget, property owners can target specific elevator components one at a time. The easiest elevator energy upgrades involve lighting. Switching to LEDs for cab lighting and buttons is simple and provides a quick payback period. Some property owners assume elevators are like refrigerators where the lights turn off when they’re not in use, but that’s not the case. New tech enables elevators to go in standby mode, turning off cab interior lighting and ventilation for about 15 minutes after being unoccupied. The same standby mode upgrade can be used for escalators, also part of building transportation systems.

Machine Room-Less (MRL) elevator tech is another upgrade to consider. Advances in motor, control, and rope technology have made it possible to house the traction motor in the elevator hoistway instead of its dedicated machine room, hence the name Machine Room-Less. The National Elevator Industry, Inc., estimates MRL can save up to 50 percent more energy than traditional designs. The reduced size of the equipment and necessary horsepower means MRL uses less fuel than conventional systems. Machine Room-Less elevators offer attractive energy savings, but the biggest draw for property owners is usually saving space in a building. Eliminating the machine room frees up about 60-plus square feet of space for storage, offices, or something else. MRLs have proliferated in popularity in the past two decades, but they’re usually only used in low- to mid-rise buildings. “We look at using MRL in buildings on a case-by-case basis,” Miller Brown said. “We’ll run an energy calculation for every job considering them. Sometimes, conventional hydraulic elevators in low-rise buildings are more efficient than MRL technology.”

The tech advance with the most potential is regenerative drives, which recycle the energy and heat produced when elevators slow down or break and put the power back into the building. That energy is then reused for other elevators or to power other electrical loads. Costs have come down for elevator regeneration, but Miller Brown said it’s still a bigger upgrade that’s typically deployed in high-rises. TK Elevator installed 20 of these drives for elevators in one of their facilities in Atlanta and slashed elevator energy use by 40 percent. It enabled the company to gain a few LEED points and push the building closer to LEED Gold status. Regenerative drives are more common in buildings today but not quite the standard. From an ROI perspective, regenerative drives don’t provide the quickest payback despite the significant energy savings. Property owners often target this upgrade in longer-range capital planning. “Regenerative drives should definitely be a consideration,” Miller Brown said, “but not the first lever to pull for a quick return on investment.”

Some elevator upgrades also have dual benefits, according to Amy Blankenbiller, Executive Director of the National Elevator Industry, Inc. (NEII). Destination dispatch works when occupants enter their destination floor at the lobby console and then passengers with the same or neighboring floors ride the same trip. This tech is usually only used in very tall buildings, and it reduces the number of stops, thereby reducing energy consumption. Many destination dispatch systems also have a particular function for mobility-impaired or disabled occupants, as they send elevators to serve them. There’s a special button to press, and when the elevator arrives, door open time is extended, and the door close time is temporarily disabled.

For now, many elevator energy standards haven’t been officially codified in building codes or given much inclusion in energy rating systems like LEED. The elevator industry is looking to change that soon, though. Green Business Certification, Inc. and the U.S. Green Building Council will likely never provide a specific building product a point for LEED certification. Still, savings from elevators and other aspects of elevators get factored in. For example, more efficient elevators improve baseline energy performance and earn points under LEED’s Energy and Atmosphere category. More eco-friendly materials used in elevator products, such as recycled steel and aluminum, also impact LEED categories like Material and Resources and Indoor Environmental Quality. Choosing elevator products with a low emittance of Volatile Organic Compounds is good for indoor air quality and  affects the environmental quality category. Overall, it’s estimated that more efficient and environmentally friendly elevators and escalators can gain more than 25 LEED rating points through recycling, energy efficiency, and building materials.

As for building codes, Blankenbiller of NEII told me that, for the most part, the priority with the codes regarding energy efficiency is to pave the way for tech innovation while also ensuring safety. She said there are standards for elevator energy published that aren’t officially code, but they’re third-party certified, and the certification process is arduous. “Code development takes a very long time, so this enables certified elevator technologies to be introduced in a much shorter amount of time,” Blankenbiller said.

Elevator energy efficiency isn’t a prominent area that property managers look at, but it helps in the push to make buildings more efficient. New energy regulations will mean that every percentage of reduction counts, so squeezing out some savings from building transportation systems matters. Complete modernization of an elevator system may not be realistic for some property owners, but taking a piecemeal approach can chip away and aggregate energy savings over time. Some tech, like regenerative drives, have higher upfront costs and could take about four to seven years for payback periods. But other simple upgrades like LED cab lighting are quick and easy wins. If buildings must become net-zero emissions and reduce energy by that much eventually, property owners must leave no building system behind. If buildings are going green entirely, elevators need to, too.

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