LightNOW

At LIGHTFAIR 2017 in Philadelphia, DOE once again hosted an informational booth that offered free educational sessions to attendees.

DOE has now made these presentations available for free download. They include:

Connected Lighting Systems Efforts
Michael Poplawski, PNNL

A Case of the Blues: Research Reveals Why Spectrum Alone is Not Enough
Bruce Kinzey, PNNL

Download them here.

ANSI Accredited Standards Committee C78, Electric Lamps, recently published ANSI C78.52-2017 American National Standard for Electric Lamps—LED (Light Emitting Diode) Direct Replacement Lamps—Method of Designation. The National Electrical Manufacturers Association (NEMA) serves as secretariat for the standard.

ANSI C78.52 is a new lighting standard on how to designate LED lamps that are direct replacements for existing, ANSI-standardized, non-LED lamps. Lamps covered in this standard contain LED-based light sources.

Andrew Jackson, Manager, Corporate Regulatory & Certification Laboratory, Chair of the ANSI C78 Committee: “This new standard also provides an LED Direct Replacement Lamp Code Designation Request Form.” This form allows a manufacturer to request a direct replacement designation using lamp characteristic data.

ANSI C78.52-2017 can be purchased for $350 in hard copy or as an electronic download on the NEMA website. Click here to learn more.

Below is an application story I wrote for the May issue of tED Magazine. Reprinted with permission.

As of November 2016, put-in-place construction spending in the United States reached $82 billion, a 6.3-percent increase over 2015. After power and highway and street construction, educational facilities are the largest construction market in the country.

Today, nearly 55 million students attend school in some 130,000 K-12 buildings in the United States. Arguably, the most important room in these buildings is the classroom, where the majority of instruction occurs.

General-purpose classrooms typically serve 20 to 75 students and are at least 350 sq.ft. In regards to education technology, many modern classrooms bear little resemblance to those used to teach previous generations. A large number of classrooms now use computers, mobile devices and interactive whiteboards as instructional tools.

This article discusses lighting and control for K-12 general-purpose classrooms based on three sources: ANSI/IES RP-3-13, American National Standard Practice on Lighting for Educational Facilities, 2014 national Collaborative for High-Performance Schools (CHPS) criteria (a points-based design rating system), and the 2010/2013 ASHRAE/IES 90.1 energy standards.

General lighting

The primary lighting layers in a classroom are general and supplemental lighting.

For general lighting, RP-3 recommends uniform lighting on horizontal task surfaces, which provides task layout flexibility while promoting alertness and visual acuity. Light levels should satisfy Illuminating Engineering Society (IES) recommendations. Design light levels depend on factors such as the luminaires’ placement, output and distribution as well as the room dimensions and surface reflectances. Recommended surface finish reflectances are 90 percent ceiling, 80 percent window, 70 percent whiteboard, 5-20 percent chalkboard, 60 percent wall, 25-40 percent task surface, and as light as practical for the floor.

The general lighting typically may be segmented into two zones, one for the educator and one for the students. The educator zone focuses on light on vertical surfaces (teaching wall), and the student zone focuses on light on horizontal surfaces (desktops). The designer must take care to avoid glare—reflections on computer screens and whiteboards and direct glare for the educator—which can be challenging with lower ceiling heights.

Daylight is a valuable source of light for general lighting in classrooms. Ideally, students will be seated with sightlines parallel to windows. The daylight entering the space should be controlled with accessories such as windows or blinds. CHPS imposes significant daylight requirements.

Luminaires may emit direct or indirect light distribution or a combination of both, such as direct/indirect. With a direct/indirect luminaire, the direct emission places light on the task and produces some shadowing for modeling. The indirect emission, meanwhile, provides soft, diffused ambient lighting that may be more visually comfortable and produce less reflection on computer screens, which may be tilted back.

The designer may add supplemental lighting to the educator zone. This lighting may be part of the general lighting or dedicated lighting such as a whiteboard luminaire. Its purpose is to raise vertical light levels on the education surface such as a whiteboard or across the entire educator zone. In the latter case, it also draws attention to and effectively models the educator.

Available equipment is constrained by energy codes, which limit interior lighting with a power allowance expressed in maximum W/sq.ft. ASHRAE/IES 90.1-2010 imposes a maximum allowable lighting power density of 0.99W/sq.ft. for school and university buildings if using the Building Area Method and 1.24W/sq.ft. for classrooms if using the Space by Space Method.

For commercial building applications where color rendering is important but not critical, a color rendering index (CRI) rating of 80+ is typically recommended. CHPS requires either a minimum of 80 or 85 CRI, depending on the selected points package.

CHPS options further require luminaires be RoHS compliant, have an L70 of 50,000 or 100,000 hours if LED, operate with an initial efficacy of at least 50 lumens/W, and/or produce a Percent Flicker that is 10 percent or less across the dimming range. For specific requirements that relate to different points packages, consult the CHPS criteria applicable to your project.

Flexibility

The large-scale introduction of projected images in general-purpose classrooms demands flexibility from the lighting system to produce optimal viewing conditions. RP-3 recommends controls that reduce or turn OFF during audiovisual (AV) presentations, with dimming being desirable for presentations using video and computer projection systems.

The lighting should be capable of at least two scenes, General (normal) and AV (multimedia) instruction. In the General mode, the lighting places 20-40 footcandles on desktops. In the AV mode, 5 footcandles, while limiting vertical light levels to 3 footcandles on the whiteboard or projection screen and 7-15 footcandles on the surrounding teaching wall.

CHPS encourages flexible controls by offering up to four points. For two points, the designer must provide indirect/direct lighting for all general-purpose classrooms. Control enables a choice of General or AV (10-30 footcandles in the student zone, maximum 7 on the screen) modes. Separate control must be provided for whiteboard vertical lighting. Where daylight-responsive controls are present, the light sensor takes precedence over manual dimming for the upper light level limit.

For two additional CHPS points, the designer can specify enhanced teacher controls, which provide teacher control at the front of the classroom for General/AV mode, whiteboard control and a manual override of the occupancy sensor time delay during written exams. The occupancy sensor signal in turn must be linked to a school-wide management system.

Tunable-white lighting allows deployment of another emerging dimension of control, which is correlated color temperature (CCT) tuning by activity or time of day. CCT tuning may be combined with intensity control to enable additional lighting modes throughout the day, such as “focus” (high intensity and cool shade of white light) for test taking, and “calm” (standard intensity and warm shade) to help calm an excited class.

Automatic controls

ASHRAE/IES 90.1-2010 and -2013 require manual control, occupancy sensing and daylight-responsive controls. Many commercial building energy codes are based on these standards or the International Energy Conservation Code (IECC).

At a minimum, the occupancy sensor must automatically turn the lights OFF within 30 minutes of the space being vacated. If the sensor automatically turns the lights ON, it must activate the lights to 50 percent or less of lighting power (bilevel switching).

For manual control, one or more manual switches must be installed at the entrance to control all lighting in the room. Additional manual controls may be installed as needed to support visual needs through flexibility.

Daylight-responsive controls must be installed where daylight is present through either sidelighting or toplighting. The output may be bilevel switching, step dimming or continuous dimming.

Learning with light

Lighting practice for educational facilities is changing alongside the teaching environment and its needs. Manufacturers have experience and offerings optimized for this market, and are therefore an excellent resource. To learn more about recommended practice, consult RP-3 published by the IES. To learn more about CHPS, download the applicable CHPS criteria at CHPS.net. To learn more about energy code requirements, consult the energy code in effect in the project’s jurisdiction.

As many as 77,000 new design and construction jobs would be created annually over 10 years–along with almost $7.4 billion more in annual GDP–if Congress and the Administration continue an important energy efficiency tax policy, according to an economic impact study by Regional Economic Models Inc. (REMI).

Section 179D of the tax code, also known as the Energy Efficient Commercial Buildings Deduction, allows qualifying building owners and businesses to receive up to a $1.80 per square foot tax deduction for certain energy efficient improvements placed into service during all open tax years. It was originally passed by Congress as part of the Energy Policy Act of 2005 in direct response to broader energy usage and independence concerns.

The REMI study documents job creation and GDP growth under three scenarios that continue energy efficiency tax policies:

· Modernizing Section 179D, including increasing the deduction to $3 per square foot and making certain other reforms to strengthen it, generates significant job creation – on average 76,529 per year during its first decade.

· A long-term extension of the deduction at its current $1.80 per square foot level creates an average of almost 41,000 jobs per year over 10 years.

· A long-term extension at $1.80 per square foot, extension of the deduction to hospitals, schools, and other non-profits and to tribal community facilities, and an increase in the energy efficiency requirements creates almost 40,000 jobs per year over the next decade.

The economic growth and job creation generated by a modernized Section 179D would result in a striking GDP return of ten to one when considering the cost of the tax policy, the study finds.

The study was co-funded by the American Institute of Architects (AIA), along with Alliant Group LP, Ameresco, Blue Energy Group, Concord Energy Strategies, Energy Tax Savers, Energy Systems Group, National Electrical Manufacturers Association (NEMA), the Natural Resources Defense Council (NRDC) and the United States Green Building Council (USGBC).

Click here to see the full study.

Soraa now offers directional luminaires under the Soraa Arc family. The offering includes track, pendant, downlight and surface-mounted designs as well as with luminaire SNAP accessories including trims, Snoot and wall washes in a variety of colors. Color temperatures include 2700K, 3000K and 4000K. All Arc luminaires feature Soraa VIVID COB light engines with full spectrum 95 CRI, R9 > 95 and Rw 100 typical. Black and white finishes are standard; custom colors are available on request. Arc luminaires with 9°, 10° and 15° beam spreads are also compatible with the existing Soraa SNAP SYSTEM to further customize beam and light color.

Arc products are available for order and begin shipping in early July 2017. Click here to learn more.

The National Electrical Manufacturers Association (NEMA) recently published NEMA 77-2017 Temporal Light Artifacts: Test Methods and Guidance for Acceptance Criteria.

Temporal Light Artifacts (TLA) are undesired changes in visual perception induced by a light stimulus whose luminance or spectral distribution fluctuates with time, such as flicker and stroboscopic effect.

This new lighting standard makes recommendations on methods of quantifying the visibility of TLA, and initial, broad application-dependent limits on TLA.

“Besides adjusting visible light output, many dimmer designs can react with LED light engines to produce additional light modulation in the form of TLA,” said Jim Gaines, PhD, of Philips Lighting and chair of the NEMA 77 working group. “NEMA 77 provides a method to quantify the likelihood that a given light modulation might produce observable TLA, and employs a measurement framework that allows for further refinement to develop application-specific guidelines.”

NEMA 77-2017 is available for $265 in hard copy and as an electronic download on the NEMA website. Click here to learn more.

A new study from the Lighting Research Center (LRC) at Rensselaer Polytechnic Institute found that office workers who receive a robust dose of circadian-effective light in the morning, from electric lighting or daylight, experience better sleep and lower levels of depression and stress, than those who spend their mornings in dim or low light levels.

The LRC research team, led by Dr. Mariana Figueiro, professor and director of the LRC’s Light and Health program, investigated the connection between circadian stimulus (CS), a measure of light’s impact on the circadian system, and sleep, depression, and stress in office workers.

The study included 109 participants at five office buildings managed by the U.S. General Services Administration (GSA). Sites included the GSA Central Office in Washington, D.C.; the Edith Green-Wendell Wyatt Federal Building in Portland, Oregon; the Federal Center South Building 1202 in Seattle, Washington; the Wayne N. Aspinall Federal Building and U.S. Courthouse in Grand Junction, Colorado; and the GSA Regional Office Building in Washington, D.C.

Each study participant wore a Daysimeter, a research tool developed by the LRC in 2004, and used in frequent studies to measure the amount of CS a person actually receives, along with their activity patterns. In the present study, each participant was asked to wear the Daysimeter as a pendant for seven consecutive days during data collection periods in winter, between December and February, and again in summer, between late May and August. Data collection was conducted between 2014 and 2016.

LRC researchers collected data on the participants’ sleep and mood using five questionnaires: the Center for Epidemiologic Studies Depression Scale (CES-D), the Perceived Stress Scale (PSS-10), the Pittsburgh Sleep Quality Index (PSQI), the Positive and Negative Affect Schedule (PANAS), and the Patient-Reported Outcomes Measurement Information System (PROMIS) Sleep Disturbance (SD). Participants were also asked to keep a sleep log of bedtimes and wake times, sleep latency, quality of sleep, and any naps taken.

Dr. Figueiro and her team found that office workers receiving a morning CS of at least 0.3, regardless of source (electric lighting and/or daylight), exhibited greater circadian entrainment, were able to fall asleep more quickly at bedtime, and experienced better quality sleep than those receiving a morning CS of 0.15 or less. CS, the calculated effectiveness of light’s impact on the circadian system, ranges from 0.1, the threshold for circadian system activation, to 0.7, response saturation.

Participants who received high CS (at least 0.3) in the morning were able to fall asleep faster at bedtime than those receiving low CS (0.15 or less), and this association was even stronger in the winter months. At bedtime, participants receiving low CS lay in bed for approximately 45 minutes before they could actually fall asleep, which can lead to reduced sleep duration for those with a fixed wake time.

Participants who received high CS in the morning reported lower levels of stress than those receiving low CS, and this finding was consistent during both summer and winter.

While receiving high CS in the morning is hypothetically the most beneficial for entrainment, participants receiving high CS during the entire workday (8:00 a.m. to 5:00 p.m.) experienced better sleep quality and felt less depressed compared to those receiving low CS.

The CS metric has been successfully applied to quantify lighting interventions in many other laboratory and field studies. In the laboratory, CS was used to predict melatonin suppression from self-luminous devices, and in the field, CS was used to predict entrainment in U.S. Navy submariners, and sleep quality and mood in persons with Alzheimer’s disease living in long-term care facilities.

“Our study shows that exposure to high CS during the day, particularly in the morning, is associated with better overall sleep quality and mood scores than exposure to low CS,” said Figueiro. “The present results are a first step toward promoting the adoption of new, more meaningful metrics for field research, providing new ways to measure and quantify circadian-effective light.”

“We are supporting this type of research so we can learn more about the connections between lighting and health,” said Bryan Steverson with GSA. “The data from this research will help support our efforts in developing new lighting practices that can optimize health benefits for federal employees working in our federal buildings.”

Along with Figueiro, co-authors of the study include Bryan Steverson, Judith Heerwagen, and Kevin Kampschroer of the GSA. LRC co-authors include Mark Rea, Kassandra Gonzales, Barbara Plitnick, and Claudia Hunter.

The present study is the first to measure personal circadian light exposure in office workers using a device calibrated to measure circadian-effective light. It is also the first to directly relate circadian-effective light measures to mood, stress, and sleep outcomes.

I wrote this news piece for the May issue of tED Magazine. Reprinted with permission.

The Lighting Research Center (LRC) at Rensselaer Polytechnic Institute recently released a circadian stimulus (CS) calculator. Based on the CS metric, this tool can aid lighting professionals to select light sources and light levels that will increase the potential for effective circadian light exposure in buildings.

Lighting and health is emerging as a significant lighting trend. While a lot of conversation is happening around tunable-white lighting, color spectrum is only part of the story. When specifying lighting for the circadian system, light level, spectrum, timing and duration of exposure must all be factored, in addition to previous light exposure, or photic history.

The CS metric is based on an LRC model of how the retina in the eye converts light stimulation into neural signals for the body’s circadian system. “Lighting for the circadian system employs lighting design objectives that differ from those typically used in traditional architectural lighting design, and therefore requires metrics that differ from those currently used by lighting designers,” says Professor Mariana Figueiro, Light and Health Program Director at the LRC.

The metric centers on determining weighted spectral irradiance distribution of the light incidence at the eye’s cornea, or circadian light (CLA). From this distribution it is then possible to calculate CS, which expresses CLA’s effectiveness from threshold (CS = 0.1) to saturation (CS = 0.7).

Exposure to a CS of 0.3 or greater at the eye, for at least one hour in the early part of the day, is effective for stimulating the circadian system and is associated with better sleep and improved behavior and mood.

In an October 2016 article in LD+A, the Illuminating Engineering Society’s magazine, Figueiro and other LRC researchers point to several ways in which designers can deliver prescribed amounts of CS:

• Request the spectral power distribution (SPD) of light sources as this information is more revealing than correlated color temperature (CCT). Light sources with a higher CCT (5000-6500K) generally provide higher CS, but this is not always true.
• Design for vertical (at the eye) not just horizontal (at the workplane) light levels and use luminaires that provide the best horizontal to vertical light level ratio. LRC evaluated a variety of luminaires and found that a direct-indirect optic provides the best ratio. Other solutions include luminous workstation panels and task lighting that offer vertical brightness.
• Light level and spectrum work together. Lower light levels generally produce lower CS values unless compensated by an SPD that delivers more power at shorter wavelengths (cooler light source). Figueiro points out that when designing for an average workplane light level of 30 footcandles (fc), the researchers found that a 6000K source was needed to achieve the target CS threshold of 0.3. A 4500K source for a workplane light level of 40 fc.

Figueiro advises that the design should also consider light exposure all day, who will be using the space, and layering the light to deliver lighting that is both functional and capable of circadian stimulation.

To use the CS calculator, designers should formulate a base condition by evaluating the space using the calculator and software such as AGi32. The design can later be fine-tuned by gain using the CS calculator, while also accommodating IES recommendations, energy codes and owner requirements.

The development of the CLA and CS metrics and calculator is potentially exciting for the lighting industry. With metrics and tools based on scientific research, the industry can begin developing and vetting practical design concepts aimed at stimulating a circadian response.

The CS calculator can be downloaded free at LRC.RPI.edu/programs/lightHealth/index.asp.

Following months of rumors, it is now confirmed that GE Lighting is up for sale, based on an internal memo by GE President and CEO Bill Lacey.

This does not include Current by GE, which focuses on IoT, networked lighting, and wireless lighting control in buildings.

tED Magazine has the story here.

This post updated 6/14/17

My contribution to the May issue of ELECTRICAL CONTRACTOR provides an update on the development of OLED technology, highlighting two Department of Energy (DOE) reports.

Check it out here.