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More Than 80 Percent Of Electrical Contractors Work With Lighting Controls

By Craig DiLouie, on July 15, 2011

ELECTRICAL CONTRACTOR recently published a very informative article detailing the results of a survey of more than 700 readers about lighting and lighting controls, conducted by Renaissance Research & Consulting.

“More than 80 percent of ECs perform some controls work. Fifty percent of them work on “all aspects” of controls (specify or influence and install). The most-mentioned types of controls included wall dimmers, wall timers, touch panels, and sensors and occupancy/motion sensors (photocells), followed closely by relay or circuit breaker panels and outdoor controls. Least-mentioned types among respondents included distributed lighting controls and daylight harvesting controls.”

Click here to read the article.

AIA Announces Results of First Year of Projected Energy Use Data from Firms Participating in 2030 Commitment Program

By Lighting Controls Association, on June 2, 2011

In 2009, the American Institute of Architects (AIA) introduced the 2030 Commitment Program, a voluntary initiative for AIA member firms and other entities in the built environment that asks these organizations to make a pledge, develop multi-year action plans, and implement steps that can advance AIA’s goal of carbon neutral buildings by the year 2030. At the end of the 2010 calendar year, firms were asked to submit an assessment of their 2010 design work using a tool released by the AIA last year.

A new report, Measuring Industry Progress towards AIA 2030 Carbon Reduction Goal, includes data from 56 firms accounting for nearly 385 million gross square feet (GSF) nationwide. The key findings include:

* Firms reported a combined average 35.1% predicted energy use intensity (PEUI) reduction from the national average EUI.
* The largest PEUI reduction reported by a firm is 70.6%
* The smallest PEUI reduction reported by a firm is 11.6%
* The combined firms design portfolio that is meeting the current goal of a 60% reduction in carbon emissions reduction from the national average is 12.1%
* The largest percentage of GSF of active projects meeting goal reported by one firm is 69.8%
* The smallest percentage of GSF of active projects meeting goal reported by one firm is 0% (reported by multiple firms)
* GSF of projects currently being energy modeled is 58%
* The percentage of projects that will collect actual data is 38%

The full report also contains participating firm demographics, energy reduction initiatives undertaken by firms and anecdotal accounts of the challenges and lessons learned through participating in the 2030 Commitment Program. Occupancy sensors were considered a key energy reduction strategy in the survey.

Study Points to Productivity Benefits of Adjustable Lighting Control

By Lighting Controls Association, on May 18, 2011

The Philips blog recently published a summary and link to a study pointing to the productivity benefits of offering adjustable lighting to office workers.

“If you boost the lighting at certain times of day, you’ll get a better performance from workers,” remarks Dr Martine Knoop, a senior lighting specialist at Philips Lighting, commenting on the study that took place at Bartenbach Lichtlabor in Austria. The scientists found in 2007 that if offices used more adjustable lighting, the employees working within them would work more productively.

1. They drastically brightened the lights for half an hour at 9.30am and an hour at 1pm from a normal level of 500 lux to 1800 lux.
2. At the same time, they measured levels of melatonin, the hormone that tells us it is time to sleep, and found the lighting reversed the sleepy feelings sometimes felt at these times of day.

A key finding:

The conclusion is simple: if you are tired, turn up the lights. The connection between the effect of lighting on alertness was demonstrated in 2002, when David Berson, a US neuroscientist, identified a receptor in the human eye that connects to the main inner body clock. Since then, a whole branch of lighting and ergonomics, the study of efficiency at work, has blossomed. “We know we can do something about this problem; there’s an awareness about it, and we think we can support people out there,” states Dr Knoop. The more widespread use of adjustable lighting, it seems, is the answer to our discomfort; perhaps not a remarkable finding.

Check it out here.

Research Demonstrates Controls Can Help Reduce School Average Power Density to About Half of ASHRAE 2004/2007

By Craig DiLouie, on April 12, 2008

Education has become a major construction market in recent years. In 2005, about $80 billion in spending made the K-12 and higher education markets the largest nonresidential segment, which held in 2006 ($85 billion) and 2007 ($100 billion) and will likely hold in 2008-09.

And it’s a good thing, too. Each year, more and more students are using facilities that are getting older and older, and using them differently than previous generations.

Figure 1. Lighting typically represents 30-40% of school utility costs.

Consider that in the fall of 2006, nearly 50 million students began using more than 385,000 school buildings; the number attending public elementary and secondary schools had risen 24 percent since 1985. According to the U.S. Department of Energy, just a few years before—in 2003—more than 60% of all school floorspace had been built before 1980, and 40% of that space had never been renovated. And students are increasingly using whiteboards, computers, Internet and multimedia, making classroom design as sophisticated as hi-tech corporate board rooms and conference spaces. To top it off, energy codes are becoming more and more restrictive on schools: A maximum power density of 1.6W/sq.ft. for classroom is prescribed by ASHRAE Standard 90.1-1999/2001, 1.4W/sq.ft. by ASHRAE 90.1-2004/2007, and 1.2W/sq.ft. by California’s Title 24-2005.

So the public and private sectors are spending record funds on school construction, renovation and modernization. Demand for lighting quality and flexibility is increasing to keep up with new visual needs, and the amount of power available for lighting is decreasing. This implies that tough design choices must be made; as the average school building built today will last the next 40-50 years, these choices are critical.

The high-performance schools movement, promoted by organizations such as the Collaborative for High Performance Schools, provides guidance on how to achieve schools that have good lighting, indoor air quality, temperature and humidity and acoustics, and minimized energy consumption, resource allocation and costs. Reducing energy costs is welcome to most schools; lighting alone typically devours 30-40% of school utility expenditures. But is lighting up to the task? Can today’s lighting technology provide a quality visual environment with the kind of flexibility required in high-end conference rooms, while minimizing energy costs and meeting tough energy codes?

The New York State Energy Research and Development Authority (NYSERDA) took this one step further by basically asking what’s the best value in school lighting, with value being defined as the most appropriate lighting for the lowest energy cost?

NYSERDA sponsored a demonstration project featuring a new Integrated Classroom Lighting System (ICLS) created by Finelite, Inc., a fixture manufacturer, installed as a retrofit into 28 existing classrooms at seven schools and universities. The Lighting Research Center (LRC) assessed teacher and student satisfaction.

The result is a design template demonstrated to satisfy audio-visual needs and improve teacher and student satisfaction while reducing lighting power density to an average 0.73W/sq.ft., nearly 50% less than ASHRAE 90.1-2004/2007. Although Finelite optimized the design into an engineered system integrating the company’s light fixtures with state-of-the-art lighting control strategies, the template, if properly designed, can be treated as open source with suitable products from a wide range of manufacturers.

The design typically is composed of two rows of direct/indirect pendants with a wallwasher whiteboard fixture mounted on the main teacher board. The fixtures are placed parallel to the window, with the rows spaced 14-15 ft. apart.

Figure 2. The ICLS template.

Legend:

1) Two rows of two-scene indirect/direct luminaires mounted perpendicular to the main teaching wall (parallel to window wall) and spaced 14-15’ apart.

2) A dedicated luminaire is used to illuminate the whiteboard on the main teaching wall.

3) Teacher control is placed at the front of the classroom. For easy teacher access place controls within 6 inches of the whiteboard.

4) Sensors are placed in the center of the classroom. Sensors always include occupancy and daylight harvesting is added where appropriate.

5) A master ON/OFF switch is by every door to the classroom.

Each fixture uses three high-performance (3100-lumen) T8 lamps—with one inboard lamp providing the downlight component and two outboard lamps providing both uplight and downlight. The inboard lamp and outboard lamps are electrically separate so that they can be separately controlled.

The fixtures are integrated into a lighting and control system featuring a ceiling-mounted dual-technology occupancy sensor placed between the rows of pendants, a master switch at the door and a “teacher control center” located near the main teaching board, which features:

A “Whiteboard” switch that turns the wallwashing fixture mounted on the main teaching board ON and OFF;
A “General/AV Mode” enabling the teacher to switch between General mode (downlight OFF, uplight/downlight ON) and A/V (and reading) Mode (downlight ON, uplight/downlight OFF; and
A “Quiet Time” switch that overrides the occupancy sensor for one hour, keeping the light on during long periods of occupied non-movement such as standardized testing.

Figure 3. The “Teacher Control Center,” which was mounted 6 inches from the main teaching board.

Teachers were also able to access another option, A/V Dimming Mode, which allowed them to turn on and then dim the inboard lamp providing the downlight component. This required a dimmable ballast. All controls were connected via a CAT-5 plenum-rated low-voltage line with plug-and-play connections.

Optionally, a photosensor can be added, adjusting light output based on daylight availability.

Figure 4. Hunter High classroom with the lights on General Mode.

Figure 5. Hunter High classroom with the lights on A/V Mode.

Watt Stopper/Legrand provided off-the-shelf power and auxiliary relay packs to accomplish the fixture switching, the occupancy sensors with the customized Quiet Time feature, and switches for the teacher control station (through its sister company Pass & Seymour Legrand). Click here to see an interview with Jon Null, Director of Marketing for Watt Stopper/Legrand, about this project, or scroll down.

Results:

Because all three lamps cannot be ON at the same time, the maximum lighting power density is capped at about 0.8W/sq.ft.
The switching controls reduced average lighting power density to 0.73W/sq.ft., about half of ASHRAE 2004/2007 and about 40% less than Title 24.
The LRC found that teachers generally preferred ICLS to the previous lighting system and that students also rated it favorably.
The system was installed for $1.83-$2.29/sq.ft.; options such as daylight switching and a third fixture row to increase uniformity, add to the cost).
The LRC found that installers generally characterized the system as “easy to install.”
The design is suitable for both new construction and retrofit.

Figure 6. The combination of energy-efficient lighting and integrated controls reduce average lighting power density to an average 0.73W/sq.ft. Click on the image to see it enlargened in a new window.

Direct/indirect lighting and separately controlled fixtures for general and main teaching board lighting are considered best practices by the Collaborative for High Performance Schools. Optimizing this approach as a system with integrated controls maximizes its utility for A/V functions while minimizing energy consumption. Many of the research findings of this study are being incorporated into best practice developed by the Collaborative as well as the U.S. Green Building Council’s LEED for Schools green building rating system, according to LRC.

For more information about ICLS, including the complete reports on the California Energy Commission and NYSERDA demonstration projects, click here.

Study: Controls Combine to Deliver Large, Persistent Energy Savings and Improved Occupant Satisfaction in Open Office

By Craig DiLouie, on December 13, 2007

What are the benefits of combining advanced lighting control strategies in the same space? Are the energy-saving benefits of lighting controls persistent over time? Can advanced lighting controls be successfully applied to open offices given concerns about jurisdiction conflicts, lighting uniformity, etc.? Can they enhance worker satisfaction?

A new office lighting field study addresses these questions. Involving about 90 workers in a real-world open-office environment, the one-year study determined that occupancy sensing, daylight harvesting and individual occupant dimming control worked together in the building to produce average energy savings of 47% while correlating with higher occupant environmental and job satisfaction.

The study demonstrates that sophisticated lighting control strategies can be combined successfully to generate persistent, large energy savings in open-plan offices while improving occupant satisfaction with their jobs and workspace.

“The industry has long sought objective evidence that lighting controls not only save energy, but also benefit organizations in other ways such as occupant satisfaction,” says Dr. Guy Newsham, senior research officer for National Research Council Canada – Institute for Research in Construction. “This research provides such evidence.”

The study

The one-year study occurred within four floors of an open-plan office building in Canada. The building selected for the project was attractive to the research team for several reasons. First, it contained a sophisticated control system operating in an open-plan office setting, an environment often perceived as unfriendly to sophisticated control strategies. Second, this control system combined three control strategies—occupancy sensing, daylight harvesting and individual dimming control. Third, the control system was already installed and in operation. Finally, the site manager was agreeable to the research team not only monitoring energy savings, but also surveying occupants on matters related to environmental and job satisfaction.

Four years earlier, the building had installed 195 direct/indirect lighting fixtures to replace 530 recessed 2×4 T8 deep-cell parabolic fixtures. The new fixtures, centered over the cubicle workstations and containing 3x32W T8 lamps powered by two electronic ballasts, reduced installed lighting wattage by about 40%.

The direct/indirect lighting system features advanced controls, while the parabolic system does not. Workers occupying 86 workstations on three and a half floors participated in the study by using the advanced controls, while workers on half of one floor were still using the old parabolic system, a setup that allowed a comparison between the two groups. Monitoring software was installed to collect detailed data for a period of one year.

“Our research group has had a strong interest in lighting controls over many years, and the opportunity to conduct a field study offered a great complement to the laboratory studies we’ve conducted,” Newsham points out. “There was almost no information available on the long-lasting success of energy-saving lighting control technologies when used in combination in real buildings. In addition, a field study allowed us to explore effects that simply can’t be addressed in anything but a real workplace, but such as those related to organizational productivity. I think everyone agrees that new technologies should demonstrate benefits for occupants and their organizations, as well as energy savings, and such outcomes will promote their adoption.”

The control system

The direct/indirect fixtures contained an integral occupancy sensor and photosensor. The center lamp, connected to a fixed-output electronic ballast, produced the indirect (uplight) component of the fixture; this ensured uniformity of light on the ceiling. The two outboard lamps, connected to a dimmable electronic ballast, produced the direct (downlight) component of the fixture; light output varied based on signals from four control inputs.

If the occupancy sensor detected vacancy in the workstation below, it signaled the dimming ballast to gradually dim the downlight (outboard) lamps until reaching 0% light output, at which point they were switched off. If the sensor detected occupancy, it signaled the ballast to start the lamps and restore light output to the last set level.

The photosensor monitored light levels on the below task plane, which received variable contributions from daylight available through windows. When light levels exceeded the occupant-set level, the photosensor signaled the dimming ballast to dim the downlight lamps.

Occupants could also dim the lamps forming the direct, or downlight, component of their lighting fixtures via an on-screen slider on their desktop PCs, thereby enabling them to choose their own preferred task light levels.

With this setup, researchers were able to study the overall effect of the combined control system, and estimate the relative contributions of each control type to the overall savings, for a period of one year. The study was conducted in three phases—phase 1 (39 workdays) with just the occupancy sensors and individual dimming controls active, and with a sensor time delay of 8 minutes with 7 minutes of dimming before shutoff; phase 2 (140 workdays) with all controls enabled, and with an occupancy sensor time delay of 12 minutes with 3 minutes of dimming before shutoff; and phase 3 (61 workdays), the same as phase 2 but with email reminders encouraging occupants to use the individual control feature in their workstations.

Just before the study was initiated, the control system was recalibrated. As new employees were hired and entered the study area, or existing employees were re-assigned, the IT department, responding to a request from the energy manager, quickly re-enabled the individual control feature, which would prove critical in sustaining this control strategy.

A fourth control strategy—global automatic on/off switching from a central point of control based on a daily schedule (7:30 AM to 5:00 PM workdays)—was in effect but not included in the study.

The results

By replacing the recessed parabolic fixtures with the direct/indirect fixtures, energy savings of about 40% were realized and lighting power density was reduced from about 0.92W/sq.ft. to about 0.54W/sq.ft.

The combined control system increased lighting energy savings to 67-69% compared to the old parabolic system. Further, the direct/indirect fixtures operating with the control system produced 42-47% energy savings compared to if the fixtures operated at full light output without the controls. All energy savings resulting from the use of the controls were accompanied by concomitant demand reductions. Because the controls ensured that not all lighting power was used at any one time, the average lighting power density in use was about 0.28W/sq.ft. The site manager estimated a simple payback for the advanced system, based on energy cost savings alone, to be 2-4 years in a new installation and 4-12 years in a retrofit installation.

If installed alone, the occupancy sensors would have produced an estimated average 35% savings, daylight harvesting 20% and individual dimming control 11%. Daylight harvesting savings were higher in perimeter workstations, as would be expected (due to closer proximity to windows), and the researchers estimate that savings would have matched the occupancy sensor savings if perimeter fixtures had been allowed to dim below 50% output based on the photosensor signal (deeper dimming based on occupancy sensors or personal control was allowed).

Occupant surveys demonstrated a correlation between the presence of the controls and higher job and environmental satisfaction. While individual dimming’s contribution to overall energy savings was relatively small, researchers credited the improvements in occupant satisfaction to the individual control feature. The researchers are currently looking deeper into the relationship between the controls and worker satisfaction, and hope to publish their results by 2009.

“This study demonstrates that the right package of controls, properly maintained, can produce large, persistent energy and demand savings coupled with benefits to occupants and their organizations, and refutes suggestions that these kinds of control systems cannot work well in open-plan offices,” concludes Newsham. “Although such systems do have a higher initial cost than standard office lighting systems, the overall benefits may justify the investment, especially in the context of other investments organizations make in their employees and their work environments.”

The field study was supported by the Government of Canada, BC Hydro Power Smart and Ledalite Architectural Products. To see the complete study, click here.

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