Below 24 Volts

When you consider sustainability for residential or commercial projects, low-voltage power probably doesn’t even register. Top nods typically go to higher profile electrical and mechanical systems. If anything low voltage garners your consideration, it is likely to be high-efficiency lighting and daylighting concepts. But green advancements in technologies for construction and retrofits, as well as recycling efforts on the back-end are allowing low-voltage installations to support sustainability.

The DC debate

By and large, the industry recognizes the electrical contractor’s role in achieving cost sustainability. For many, however, the idea of leveraging low voltage into the picture currently sits somewhere outside the initial focus on renewable energy sources, power and energy savings and environmental protection.

“There’s really not much we can do on the limited energy side other than ensure that the products we’re using have long lifespans, longer than just a couple of years,” said Robert Hoertsch, vice president of Low Voltage Contractors Inc., Edina, Minn.

Strictly in theory, low-voltage 12V–24V -wiring is seen as less efficient than 100V line voltage supplied by utilities. That’s because higher voltage loses less during transmission, which is part of the reason why power companies transfer energy over high-voltage cables. However, today’s low-voltage technologies are evolving into the smart and agile players and are capable of running a leaner, more complex offense in new construction and retrofit playbooks.

“Contractors are experiencing a sea change. A lot of the practices and tools they’ve used are changing. We really have an opportunity as an industry to provide the educational tools to our installing customers to help them stay current with not only what the codes require, but also what the owners of these projects are asking for. Low voltage is a very straightforward and fairly cost-effective means to accomplish that,” said Tom Leonard, director of marketing for Leviton Lighting Controls Division.

Gary Christenson is a Boise, Idaho-based commercial developer of a bank building that is U.S. Green Building Council Platinum Leadership in Energy and Environmental Design--certified. He said the collaborative power of addressable networking technology in conjunction with low-voltage control hardware and software can provide measurable energy savings.

“The low-voltage side doesn’t have the stature or the mass cost that can be marked up. But it has the ability to use power over Ethernet to activate occupancy sensors and photocells. An entire system can be interconnected to the Internet in a daisy- chain fashion with the intelligence of addressable devices that can be tied back into computer controls,” he said.

Low voltage takes control

Hoertsch pointed out that, although LEED credits don’t apply directly to the installation of low-voltage products except in the area of lighting controls and building automation controls, the functionality of certain systems can contribute to credits and overall energy savings.

“If we sell an energy management system for a building, we can not only get rebates from a utility or local power company, but we can ensure that a customer’s ROI on the project is three to five years. The real energy story for low voltage is metering, load shedding, load sharing and balancing. It’s in building automation,” Hoertsch said.

Christenson agreed that load reduction is the key to future sustainability. His goal is to be constructing zero net-energy buildings in five years by building better envelopes, reducing loads and using controls to harness renewable energy sources such as solar power.

“What if we can create a network in our homes where we have a 110 circuit and a 12- or 24-volt circuit for DC and for powering our battery supply?” Christenson asked, suggesting that a hub-and-spoke configuration could eliminate line drops in DC circuits and replace long, standard cable runs to provide a single transformer, rather than a dozen transformers scattered around the house.

“We’ve got these kinds of transfer switches, these lighting devices, this kind of computing device. It would take minor changes to what it already is, and the rest of it is robust and dependable. We didn’t get Platinum LEED in our bank building with anything cutting-edge. We took existing products and adapted them, and that’s what I see low voltage doing,” Christenson said.

Low-voltage systems are actively automating a number of features in homes and commercial settings. Honeywell has partnered with In2 Networks to develop an Internet connection module (ICM) that converts several functions into Internet protocol, including lighting, security and HVAC.

According to Tim Trautman, Honeywell’s senior product manager of Cable and Custom Electronics, the green aspect is in the programming of the ICM and the connection between HVAC and security systems.

“If it’s the weekend and a homeowner goes out, the security system can send a message to the HVAC that the house is being vacated and to set the thermostat either up or down, so it does intermittent changes and provides additional energy savings,” Trautman said.

“There’s a whole world of 24 volts and below. There just needs to be a little paradigm shift to think about the skills that are employed on the datacom side and apply them on the lighting side,” Leonard said.

One of the simplest, most straightforward shifts a contractor can make is from traditional lighting clocks and contactors to integrated lighting control panels. Rather than fabricating a system of contactors and timeclocks, Leonard pointed out that the use of a low-voltage panel, such as the Leviton EZ-MAX, can replace all that hardware and couple it to a very flexible and powerful programming timeclock. Leviton’s Armada lighting control system also integrates with other automation systems and subsystems in residential or commercial settings such as security, HVAC, touchscreen, IP phones, distributed audio-video, motorized window treatments, pool equipment and various sensors.

Clyde Wixom, Leviton’s senior business development and Residential Systems marketing manager, said Armada will make an economic and environmental impact.

“Armada reduces costs by intelligently adjusting thermostat settings and automatically turning off unnecessary lights. It also provides for global settings to restrict bulbs burning at 93 percent,” he said.

According to Leviton, lighting currently is a relatively small component of the LEED system, yet it can be instrumental in achieving as few as eight or as many as 22 points within the program’s compliance.

Lighting management systems in the form of stand-alone devices, such as occupancy sensors, photocells timers and programmable timers, and integrated systems, such as relay panels, daylight managers, modular lighting control systems and dimmer cabinets, can directly impact LEED’s optimized energy performance.

For example, exceeding the energy requirements of ASHRAE/IESNA 90.1 by 15 to 60 percent can result in one to 10 additional energy points. Reductions in lighting energy and load shaping also can have a profound influence on building energy usage and may result in design considerations for the HVAC system. Also, reduced lighting loads may increase heating requirements in colder climates. The net benefit usually trends positive in most cases, since it typically costs less to heat than to cool a building.

The greening of information technology

Recent studies also show that energy efficiency and the environment take a hit from low-voltage communications cabling practices.

“A group of Gartner analysts revealed that IT activity accounts for 2 percent of global CO2 emissions, which is equivalent to the amount produced by the aviation industry. We typically think of emissions coming from transportation, heavy industry and power generation, but with recent work to address global issues, we see that, in fact, low-voltage IT and IT-related products can have an impact in several areas,” said Brian Duval, marketing communication manager at Siemon.

As a result, the network cabling company is taking a greener IT approach through the launch of a new online resource dedicated to sharing strategies on environmentally responsible practices for IT network professionals and electrical contractors.

Currently, there is no stipulation in LEED that specifically calls out the communication cabling side, but this cabling shouldn’t be excluded in the thought process of the electrical contractor considering the confluence of low voltage and green.

“It would be a long shot to say that if you put in Cat 7 cabling because it lasts longer, a LEED professional is going to give you a credit for that one activity. Nor should they. It takes a holistic approach. We’re helping people move towards those credits, especially when there are benchmarks for how much material needs to be recycled today,” Duval said.

Duval added that power alone can represent up to 50 percent of overall data center budgets. While a significant portion of power is consumed by IT equipment, a sizable power load is required to keep it cool. Many older data centers and even telecommunications areas have suffered from poorly managed moves, adds and changes over the years, leaving abandoned cabling channels behind. These unused channels often create air dams, which obstruct air flow, resulting in higher energy consumption and less-efficient cooling equipment.

That problem alone is enough to drive the removal of abandoned cabling, but there also may be issues with older cabling jackets not meeting current reduction of hazardous substances (RoHS) requirements.

“A lot of the equipment that we use either contains radioactive isotopes or lead or some other kind of material that is environmentally unfriendly,” Hoersch said. “Many customers have us document that we properly recycled used parts at a certified recycling facility.”

Dumping toxic loads

New construction and retrofits using low voltage are undergoing a green revolution through disposal mandates for waste materials. In many cases, older cables carry significant fuel load, which can pose fire threats and can release toxins, such as halogens, if ignited. Beyond the life and safety issues at risk, the proper removal and disposal/recycle of abandoned cable can remove a significant environmental risk.

Specifically, RoHS bans the use of lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyls and polybrominated diphenyl ethers.

Siemon products comply with RoHS Directive 2002/95/E, which impacts the entire global electronics industry and restricts the use of six hazardous materials found in their electrical and electronic products. Leviton Network Solutions also recently announced that its core connectivity products, such as Category 6 and Category 5e jacks, patch panels and patchcords, are lead-free and RoHS-compliant.

The EPA’s universal waste regulations streamline hazardous waste management standards for federally designated “universal wastes,” which include batteries, pesticides, mercury-containing equipment and lamps. The federal universal waste regulations are set forth in 40 CFR part 273. Since states can modify the universal waste rule and add additional universal waste(s) in individual state regulations, the EPA recommends checking with state officials for applicable regulations.

MCCLUNG, owner of Woodland Communications, is a construction writer from Iowa. She can be reached via e-mail at


About the Author

Debbie McClung

Freelance Writer
Debbie McClung, owner of Woodland Communications, is a construction writer from Iowa.

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