The interest in and, in some cases, the mandated requirement of implementing sustainable building practices is becoming a worldwide phenomenon. One driver of the demand for increased sustainability comes from estimates that buildings, by themselves, consume more than 40 percent of the world’s energy and contain unrecycled materials, while producing more than 40 percent of all global waste and greenhouse gases.
Today’s sustainable building trends bring together an array of practices and techniques designed to reduce and even eliminate the effects of buildings on both the environment and human health. Green building often emphasizes taking advantage of renewable resources, as well as techniques, such as using packed gravel or permeable concrete to enhance the replenishment of ground water. And the development of both sustainable building certifications and green building standards and codes is driving many of these green building concepts.
While the practices or technologies employed in sustainable building are continually evolving and may differ in each region of the country, the concept’s essence is the optimization of one or more of the principles of site and structure design efficiency, water and materials efficiency, indoor environmental quality enhancement, operations and maintenance optimization, and waste reduction. What concerns electrical contractors within the framework of green building certification and/or green building standards and codes, however, is energy efficiency, which inevitably involves lighting in terms of both performance and quality.
The role of lighting
The voluntary effort aimed at improving the energy efficiency of nonresidential buildings throughout Europe began in 1995 when the European Commission launched the Green Building Program. In the United States, the U.S. Green Building Council (USGBC), Washington, D.C., and its standard for sustainable building design, known as Leadership in Energy and Environmental Design (LEED), is the driving force behind the green building movement. LEED offers a set of well--documented, scientifically proven performance criteria and a point system for attaining any one of several certification levels.
According to the USGBC, lighting contributes to a LEED project by delivering minimum energy-performance levels that meet third-party standards, such as ASHRAE 90.1 or the Environmental Protection Agency’s (EPA) benchmarking tool. It enables additional credits to be earned by outperforming such standards by a specific percentage. All versions of LEED offer credits for providing varying levels of individual lighting control and ensuring that common areas contain separate controls. In addition, there are varying credits for reducing light pollution by limiting light trespass, thereby improving nighttime visibility. Lighting energy loads are factored into a LEED design through the energy model (EAp2/c1) and into a LEED existing building project through EPA’s Energy Star portfolio manager tool, which enables better understanding of a building’s energy performance and the program’s certification requirements.
“Identifying appropriate lighting adjustments during building operations is best done through a building management system that tracks submetered readings of lighting energy use,” said Marie Coleman, USGBC spokesperson.
If a third of the energy consumption of a typical commercial building is attributed to lighting, the project team can apply lighting technologies that reduce the lighting energy consumption by half, thereby reducing the overall building consumption by 15 percent, or roughly 15 points on the Energy Star rating scale, according to Robert Sauchelli, Energy Star program manager.
“Lighting is probably the biggest single opportunity the electrical contractor can take advantage of in achieving Energy Star certification, that is, a rating of 75 or higher on our free, online portfolio manager rating tool,” he said.
The Energy Star program promotes efficient lighting as one of the first activities to undertake to make a building more energy efficient.
“Energy-efficient lighting has positive downstream impacts on all the other building systems and on obtaining Energy Star certification,” Sauchelli said.
Other standards, energy codes and programs exist beyond just Energy Star and LEED. In an effort to guide green building design and construction, many municipalities have tried to incorporate green building certification programs. This, however, has created problems with code officials and enforcement, which has led to the development of the ANSI/ASHRAE/USGBC/IES Standard 189.1 according to Nick Ferzacca, PE, LEED, associate principal of Architectural Engineers Inc., Boston, and vice chair of the standard’s committee.
“Standard 189.1 is not designed to replace existing credit-based approaches to sustainable buildings but to provide code-enforceable language for municipalities or building owners to use,” he said.
Lighting plays a substantial and important role in Standard 189.1, including requirements for reduced light pollution and light trespass, reduced lighting power densities, additional lighting control requirements, and daylight harvesting.
“Energy-efficient lighting helps lower overall energy consumption, improves indoor environmental quality and reduces light pollution,” Ferzacca said.
The overall goal for Standard 189.1 is to have buildings consume 30 percent less energy than those buildings constructed in compliance with ASHRAE 90.1 2007.
Although the role of building codes, in general, is to be a minimum standard of construction practice for preserving the life safety, health and welfare of the public in the built environment, the increased focus on issues of energy independence and security has driven the incorporation of energy performance levels into those codes. In addition to Standard 189.1, the International Code Council (ICC), through its International Energy Conservation Code (IECC), establishes maximum lighting power densities for both building interiors and exteriors and lighting system control requirements that directly reduce the duration of lighting and decrease illumination levels through automatic control devices.
“The IECC’s methodology makes use of currently available lighting product characteristics, light loss factors, and illuminance values from current IESNA illuminance recommendations, building construction data, and professional design experience,” said Darren Myers, ICC technical director of energy programs.
Different from a minimum code designed to protect the built environment, and the occupants therein, from the natural environment, ICC’s International Green Construction Code (IGCC) acts as an overlay to other existing international codes and establishes a baseline level of performance for the forthcoming 2012 IGCC to be at a 30 percent improvement over the provisions of the 2006 IECC and at least a 15 percent improvement over the provisions of the 2009 version.
“Additional light and power-efficiency measures found in IGCC PV1.0 include, among others, sleeping unit controls, such as those found in hotels, automatic daylight controls and a minimum fenestration area for specific occupancy-types, and a certain number of receptacles and electrical outlets to be controlled by an occupancy sensor or time switch,” Myers said.
Technologies of light
Green building certification programs don’t list specific lighting technologies, but there are a few concepts that lead the market in helping building owners and electrical contractors choose well.
“The first key is to use luminaries that are not just highly efficient at getting the light out of the fixture but that also have well designed optics so the light gets on the intended surfaces,” Coleman said.
The second piece of advice from the LEED Technical Advisory Group (TAG) is to implement lighting control technologies.
“Energy use can be optimized when lighting controls are used to put the right amount of light on the right place at the right time,” Coleman said.
According to Sauchelli, Energy Star recommends the use of generally accepted lighting efficiency strategies in obtaining certification.
“There are so many opportunities to improve lighting efficiency in buildings with the use of proven technologies that have produced results over time and that are low risk, such as lamp, fixture and ballast replacement; the use of appropriate controls; bilevel switching; occupancy sensors; dimming ballasts; and daylight harvesting,” Sauchelli said.
According to Ferzacca, linear lamp and ballast manufacturers continue to improve efficiency in T8 and super T8 lamps.
“However,” he said, “controls are, at this point, the largest contribution to improving efficiency through sophisticated addressable ballasts and the use of daylight and motion sensors.”
Ellen Bossert, the head of green and sustainability initiatives for Philips Lighting Co., Somerset, N.J., advises contractors to remember that choosing lighting technology is dependent on the application.
“In discussing a commercial office building, lighting can be broken down into general lighting, task lighting and specialty lighting,” Bossert said.
Leading technologies used in a project endeavoring to achieve green building certification include T5 fixtures with integrated controls for general lighting applications, which reduce the number of fixtures required for a project by at least 10 percent while improving lighting quality and levels; compact fluorescent lamps and light-emitting diode (LED) down lighting; dimming fixtures for task-lighting applications; and LED and ceramic metal halide (CDM) technology for specialty applications, such as in an atrium and in parking lots and garages.
“Each of these technologies will fulfill all the requirements and points under the LEED rating system for lighting as well as comply with ASHRAE code requirements,” she said.
However, when dealing with any mercury-containing lighting products, contractors need to realize that choice could actually reduce program points, according to Jason Barbour, vice president of solid state lighting for Diogen Lighting, Centennial, Colo.
“In addition, long-life fluorescent lighting requires specific instant-start ballasts, which are not inexpensive,” he said.
Induction technology may be making a comeback. The first lighting product to use induction technology was the Philips QL lamp, originally introduced in Europe in 1990 and in the United States in 1992. Essentially a hybrid between incandescent and fluorescent, according to Barbour, induction lighting consumes less power than either. Induction technology is long-lived, up to 100,000 hours; provides high-quality white light; has instant start and restrike capabilities; and operates at a low temperature.
“Induction technology, however, cannot be dimmed, still uses gas, and still emits ultraviolet light,” Barbour said.
When used in the proper applications and formats, LED lighting is proving itself to be very valuable. LED’s primary advantages are its reduced energy consumption, improved thermal management properties, and instant start and restrike properties.
“Lower end LED sources are not always dimmable and without a standard for operations, contractors need to be careful that the LED product they are choosing comes from a reputable source and is UL tested and listed,” Barbour said.
LEED, Energy Star, ASHRAE, ICC and lighting product manufacturers all have the tools contractors need to actively collaborate with a project’s design team in the right choice of lighting systems to ensure both green-building code and green- building certification compliance.
BREMER, a freelance writer based in Solomons, Md., contributes frequently to ELECTRICAL CONTRACTOR. She can be reached at 410.394.6966 and firstname.lastname@example.org.