Five Myths of Tubular Daylighting Devices

Are these myths preventing you from specifying/purchasing tubular daylighting devices for your commercial facility?

Michael Sather, commercial marketing manager at Solatube International Inc., Vista, CA

Michael Sather, commercial marketing manager at Solatube International Inc., Vista, CA

Many people are familiar with the concept of tubular daylighting devices (TDDs), often generically referred to by more informal names such as solar tubes, sun tunnels, light pipes, or tube lights. The general concept is simple: A dome, attached to a roof with a self-mounted flashing or mounted on a curb, captures sunlight, transfers it into the building through a highly reflective tube, and delivers it into the interior space through a diffuser lens mounted at the ceiling level or at the end of the tube in an open ceiling.
   In the past 13 years, TDDs have revolutionized the way buildings are illuminated. When applied correctly, a building can be fully daylit using only the natural light supplied by the TDDs for 90% or more of the occupied hours of the year, relying on electric lights only as a backup during extremely overcast days or at night.
   That said, how do you know if TDDs are the right choice for daylighting your project? What key aspects should you consider when selecting the best TDD for a specific application? To help answer these questions and give you a better understanding of this product category, let’s explore five myths of TDDs.

When applied correctly, a building can be fully daylit using only the natural light supplied by the TDDs for 90% or more of the occupied hours of the year, relying on the electric lights only as a backup during extremely overcast days or at night.

When applied correctly, a building can be fully daylit using only the natural light supplied by the TDDs for 90% or more of the occupied hours of the year, relying on the electric lights only as a backup during extremely overcast days or at night.

Myth 1: Tubular daylighting devices are only for residential applications or small spaces.
The original TDDs that appeared in the U.S. market in the early 1990s were strictly designed for residential spaces. In the past two decades, the TDD category grew to rival and eventually surpass traditional skylights for residential applications.
   Building on that residential-market success, the world’s first commercial-grade TDD appeared on the scene in the year 2000. This new technology boasted a 21-in.-dia. tube and a transition box for a grid ceiling system, which allowed a round tube to accommodate a square diffuser, simply by replacing a 2 x 2-ft. ceiling tile. Open-ceiling models also debuted at this time and featured a diffuser lens attached directly to the tube bottom. As a result, the approach to daylighting commercial buildings was greatly simplified and the daylight fixture concept was born.

Specular reflectance, which refers to a concentrated bundle of light transferred down the tube through the diffuser, is the key factor in determining how effective a TDD is at delivering light to an interior.

Specular reflectance, which refers to a concentrated bundle of light transferred down the tube through the diffuser, is the key factor in determining how effective a TDD is at delivering light to an interior.

Myth 2: Tubular daylighting devices are only for the top floor.
Specular reflectance, which refers to a concentrated bundle of light transferred down the tube through the diffuser, is the key factor in determining how effective a TDD is at delivering light to an interior. It is often confused with total reflectance, which refers to scattered light that is reflected in every direction. Total reflection is not an indicator of throughput since this would include light reflecting back up the tube.
   When daylight moves through a TDD, it reflects (or bounces) off the tubing surface. With each bounce, a small amount of that light is lost. For each 90-deg. turn, only about 5% of the light is lost. This makes possible tube runs of great distances, spanning multiple floors, running down chases in the walls, and using multiple 90-deg. turns to be able to deliver daylight deep into the interior of multistory buildings.

When daylight moves through a TDD, it reflects (or bounces) off the tubing surface. With each bounce, a small amount of that light is lost. For each 90-deg. turn, approximately only 5% of the light is lost.

When daylight moves through a TDD, it reflects (or bounces) off the tubing surface. With each bounce, a small amount of that light is lost. For each 90-deg. turn, approximately only 5% of the light is lost.

Myth 3: Tubular daylighting devices are only effective at certain times of the day or year.
Factors affecting seasonal consistency are a combination of specular reflectance, dome optics, spectral selectivity, color temperature maintenance (CTM), and solar heat gain. Lower end TDDs will have a greater difference in daily and seasonal variation due to a lack of the above mentioned properties.
   Advanced TDDs offer daily and seasonal consistency by incorporating dome technologies with passive internal reflectors or Fresnel-lens optics to help efficiently collect low-angle sunlight. This can greatly increase performance in the early morning or late day. During the winter months, when the sun is low in the sky, this is an especially important consideration in Northern latitudes.

Myth 4: Tubular daylighting devices are unpredictable.
While dome optics and tubing material will play a major role in the predictability and consistency of a TDD, you must also take into account the overall design. Even the most advanced TDDs can be designed incorrectly into a space. If you use too many units, the results can be overwhelming; if you use too few, the results can be disappointing. Most TDD manufacturers offer daylight dimming devices that provide total control over the amount of daylight entering the space.

Myth 5: All tubular daylighting devices are the same.
This statement is equivalent to saying all cars are the same. To ensure you select the right TDD for your particular project needs, there are three main considerations: the manufacturer, the product, and the partner:

  • The manufacturer. Significant differences exist in the product offerings and core focus of companies manufacturing TDDs. Some manufacturers specialize in TDDs as their sole business, whereas other companies may only offer TDDs as a small part of their overall product line.
  • The product. Be sure to specify a product that meets the needs of the space. Most TDD manufacturers will offer a wide range of models and component options to create the right configuration for the specific application and climate.
  • The partner. Once a manufacturer is selected, it is probably best to make sure there is a factory-trained distributor or representative to assist with the project. Most TDD manufacturers will have a partner who works with you at a local level from project conception through completion to help you meet your daylighting goals and stay within your budget. These companies typically offer installation services as well as installation training for subcontractors to ensure your project is a success.

Michael Sather is the commercial marketing manager at Solatube International Inc., Vista, CA.

Ask Questions, Then Design Lighting

Lighting design should be part of the initial facility design phase to ensure effective illumination and energy savings.

Cheryl Ford, marketing manager for OSRAM Sylvania, Danvers, MA.

Cheryl Ford, marketing manager for OSRAM Sylvania, Danvers, MA.

The intended use for a building and the owner’s design goals not only affect the layout, finishes, and furnishings, but have a significant impact on lighting needs and energy costs. Unfortunately, lighting often is not discussed in the early design stages for new and major renovation projects. If lighting is a part of the early discussions, it is much more likely that the best possible luminaires will be chosen to fit the style of the building and its intended use.
   Discussing lighting early will also help ensure the building’s design can accommodate the desired luminaires and controls to achieve the lowest energy and maintenance cost without sacrificing lighting quality. Before specifying lighting, answer the following questions.
   Who is the end user?
   Is the building owned by a company for its own use or is the space being leased to multiple tenants? For businesses, branding by way of unique building design and layout plays a part in establishing that brand. In addition, exterior and interior lighting are equally important for the safety and well being of workers, customers, and clients. If a building is to be occupied by a single company, it is easier to minimize the number of luminaire types. For leased spaces, tenants often want the space constructed to meet their requirements, and this includes lighting. Lease agreements vary, but tenants often are required to pay utilities on the leased space, so work with them to install the most energy-efficient lighting possible.
   What is the desired style or look?
   Aesthetically pleasing lighting can be modern, contemporary or traditional, and there is a variety of luminaires from which to choose. For an unobtrusive modern look, recessed flat-panel, recessed indirect, or architectural recessed 1×4, 2×2, or 2×4 luminaires can provide a very clean look and uniformly lit spaces. For a more contemporary look, single pendant-mount luminaires can be geometrical, adding an artistic look to the space. There are also more traditional long linear runs of indirect/direct pendant-mount luminaires with an up-light and down-light component providing extremely low-glare lighting. In addition, these luminaires light the ceiling, brightening the look of the space.
   You do not need to sacrifice on the aesthetics of a luminaire just to save energy. State-of-the-art high-efficiency, long-life fluorescent lamp and ballast systems are available in many styles, providing energy savings as high as 40%, compared with standard T8 fluorescent units. Luminaires using LED systems that offer energy savings as high as 50% when compared to conventional fluorescent systems are available.
   How will spaces be used?
   How a space is to be used determines required lighting levels. In the past, however, many interiors have been over lit. Fortunately, the Illuminating Engineering Society of North America (IESNA), New York, has established recommended lighting levels for specific tasks, and following these guidelines will reduce over-illumination and wasted energy.
   The type of space will also dictate the need for additional lighting controls, and this may influence your luminaire choice. Many LED luminaires come with integrated controls for installation ease. Also, layers of light, especially for hospitality and classroom lighting, provide the flexible lighting typically desired. For office environments, the use of task lighting allows overhead lighting levels to be scaled back, reducing energy usage.
   What are the latest energy code requirements?
   ASHRAE 90.1 and California Title 24 have maximum power-density requirements (W/sq. ft.) and mandatory control provisions for interior and exterior applications. The latest versions of each have additional mandatory control requirements. Alterations affecting more than 50% of the lighting load must conform to the codes.
   ASHRAE 90.1-2010 requires space control for enclosed areas with at least one control step between 30% and 70% of full power. Exceptions include corridors, public lobbies, restrooms, stairwells, storage rooms, and electrical/mechanical areas. Various auto-off requirements also are established, particularly for parking garages.
   California Title 24 2013 has added more multi-level control requirements, specified by space type for areas greater than 100 sq. ft. Auto-off requirements are also established for interior and exterior spaces and parking garages. There also are specific requirements for daylighted zones and use of occupancy sensing or auto scheduling. Demand response is now required for all non-residential buildings of more than 10,000 sq. ft.
   When does daylighting make sense?
   There is trend in commercial buildings to use more natural light and provide occupants with outdoor views for health and well-being benefits, as well as to save energy. However, to make daylighting effective, the building design and window selection are extremely important. North/south-facing windows and windows with the proper glazing to minimize glare need to be incorporated into the design. In new-building construction, light shelves and skylights improve daylight use. A window-shading system can effectively control the amount of sun that enters a space. Light sensors and 0- to-10-V dimming is the best way to reduce the luminaire light level in response to available daylight.
   Which lighting technology?
   The cost to install LED lighting instead of conventional fluorescent and high-intensity-discharge technology has decreased immensely in the past several years. LED luminaire performance, controllability, and color quality is equivalent to many fluorescent systems, so for new construction LEDs may be the best choice. For retrofit projects, high-efficiency, long-life fluorescents may be the least expensive option, but do not rule out LED retrofit solutions that use the existing luminaire housing. Utility rebates are available for DLC-qualified (DesignLights Consortium, Lexington, MA) LED luminaires and for high-efficiency and supersaver fluorescent systems, reducing the cost to install the most efficient lighting.
   Lighting can help shape a business and its outcomes in very subtle ways. When done correctly, it can dazzle people, provide comfort, and improve productivity. Quality lighting does not need to break the budget, and it can be very energy efficient. In evaluating lighting options, look at the total cost of ownership. Hire a lighting designer to make sure the best lighting system is designed for the facility.

Cheryl Ford is a marketing manager for OSRAM Sylvania, Danvers, MA. She has
more than 30 years of lighting experience; has held various positions in engineering, marketing, and sales; and is a NCQLP lighting certified professional. Watch for regular lighting columns from Cheryl at cbpmagazine.com/blog.

Stratford, ON to investigate upgrade to LEDs

Stratford ON

Stratford, ON, is famous for the Stratford Shakespeare Festival. Perhaps they'll also become famous for their LED lighting.

The City of Stratford, Ontario, has started a pilot project that will evaluate replacing existing streetlights (potentially as many as 4,000 units) with energy-efficient LED fixtures. This project has helped earn Stratford become one of the “Top Seven Intelligent Communities for 2012″ by the Intelligent Community Forum (ICF) a New York-based think tank dedicated to studying the use of information and communications technology to create the community of the 21st Century.

Stratford shares the kudos with communities having populations and economies many times its size: Austin, Texas; Oulu, Finland; Quebec City, Quebec; Riverside, California; Saint John, New Brunswick and Taichung City, Taiwan. All seven communities were feted last week at ICF’s annual “Building The Broadband Economy” summit conference in New York City. The goal of the awards program is to increase awareness of the role that broadband communications and information access technologies play in shaping the economic and social development of communities worldwide.

The pilot project will include Toshiba’s LED roadway and area lighting fixtures. These fixtures are a direct replacement for conventional high intensity discharge (HID) lighting, such as high-pressure sodium or metal halide lamps. With the new LED lighting fixtures, Stratford could save up to 30% in energy costs.

Stratford, Ontario is a city of 32,000 in southwestern Ontario, famous for the Stratford Shakespeare Festival. The city was twice designated one of the world’s Top Seven Intelligent Communities, in 2011 and 2012, by the New York-based broadband think tank, the Intelligent Community Forum.

SOURCE Awards Winners Announced

Cooper LIghtingCooper Lighting has announced the winners of the 35th Annual SOURCE Awards national lighting design competition. The winners were recognized at LIGHTFAIR International 2012 in Las Vegas, NV. Five professional awards and six student awards were presented.

Top honors in the Professional Commercial Category went to Focus Lighting, Inc., New York, N.Y., and the design team of Paul Gregory, principal designer; Michael Cummings, principal lighting designer; Christine Hope, senior lighting designer; Scott Hay, lighting designer; and Dan Nichols, project manager for the lighting of The Chandelier lounge and bar located at The Cosmopolitan of Las Vegas. In addition, Focus Lighting, Inc. was also honored with an Award of Recognition for the lighting of the Dinosaur Hall at the Natural History Museum of Los Angeles County, located in Los Angeles, Calif. The design team for that project included Paul Gregory, principal lighting designer; Juan Pablo Lira, senior lighting designer; Hilary Manners, lighting designer; and Kenneth Schutz, project manager.

In the Professional Residential Category, top honors went to Robert Singer, president, and Jason Diaz, lighting designer of Robert Singer and Associates, Inc., Basalt, Colo. for the lighting design of a townhome located in Vail, Colo.

Two Honorable Mention awards were presented, one in the Commercial Category and one in the Residential Category. Denver-based RLN and the design team of Rachel Petro Fitzgerald, lighting designer; AnneMarie Dienstbach, project manager; Marc Herndon, lead interior designer; Sarah McGarry, interior designer; and Kristian Barowsky, technical support assistant were honored for the lighting design of the law firm of Dorsey & Whitney, LLP located in Denver, Colo. In the Residential Category, Christopher M. Thompson, principal; James L. Sultan, senior lighting designer; and Kimberly D. Taylor, lighting designer of Seattle, Wash. based Studio Lux, LLC received an Honorable Mention award for their work on the Indian Wells Residence, an 11,030 square foot home located in Indian Wells, Calif.

In the Student Category, students in the design, architectural, lighting and engineering disciplines enter conceptual lighting design installations. Six awards were given: one Winner, two Honorable Mentions and three Awards of Recognition. The team of Francis D’Andrea, Derek Sommers and Austin Weller from the University of Cincinnati picked up the winning honor for their conceptual lighting design project of an upscale health spa titled Full Disclosure. Also from University of Cincinnati, Jennifer Sullivan was awarded an Honorable Mention award for her project of a retail cosmetics store called Orchard Beauty, Orchard Road. In addition, Ali Patterson from Ball State University was honored with an Honorable Mention Sustainable Design Award for her project of a Mountain Spirit Healthcare Facility.

An Award of Recognition honor was presented to the team of Nicolas Payan, Anna Pogorelova and Lawrence Rocha-Benavides from the University of Cincinnati for their COSMOS restaurant while Melina C. B. Pereira, from the University of Cincinnati also won for her Chicago Convention Center – Fulton Square Building Renovation lighting design. Kristin Millican from Mississippi College also received an Award of Recognition for her art gallery project titled A Site Gallery.

The University of Cincinnati students were under the direction of Brian Davies, associate professor at University of Cincinnati’s College of Design, Architecture, Art, and Planning. Millican was under the direction of Mandy Berdami, assistant professor and program coordinator of interior design at Mississippi College and Patterson was under the direction of Thelma Lazo-Flores, PhD, assistant professor in interior design at Ball State University.

Professional winners Focus Lighting, Inc. and Robert Singer and Associates, Inc. received a $2,000 monetary award. Student winners D’Andrea, Sommers and Weller split a $1,500 award and Sullivan and Patterson were given $500 for their Honorable Mention awards. All winners were presented with a crystal trophy and offered an invitation to attend a complimentary class at the SOURCE, Cooper Lighting’s state-of-the-art education center located at the company’s headquarters in Peachtree City, Ga. The students’ instructors are also invited to attend a class. All winners received national and local publicity.

The annual competition, which focuses on furthering the understanding, knowledge and function of lighting as a primary element in design, requires the primary and predominant use of Cooper Lighting products. Cooper Lighting has held this competition since 1977.

Entries are judged on the blending of aesthetics, creative achievement, technical performance and the degree in which the lighting met the project constraints and design concept goals.

DOE Updates High-Efficiency Parking Structure Lighting Specification

Dept. of EnergyA CBEA Project Team has updated the High-Efficiency Parking Structure Lighting Specification. First released in 2009, version 1.1, released on February 15, 2012, has updates related to IES TM-21 and anticipated RP-20 requirements. In addition to focusing on the efficiency of each of these technologies, the Project Team investigated how the role of controls and the specific use of each technology can lead to even greater energy savings. The maximum allowed installed power density within the specification is 40% below ASHRAE/IES Standard 90.1-2007. Additional energy savings are possible from the use of lighting controls and daylighting.

Questions on this specification should be sent to the Pacific Northwest National Laboratory (PNNL) at CBEA@pnnl.gov.

North American Manufacturers Form Consortium for Solar Lighting

Consortium for Solar LightingFour manufacturers recently founded the Consortium for Solar Lighting (CSL). The CSL’s founding members are Sharp Electronics Corporation, Carmanah Technologies Corporation, Inovus Solar, Inc., and SolarOne Solutions, Inc.

The mission of this group is to accelerate the adoption of reliable solar lighting technology through the development of universal specifications intended to support customers’ fair and comprehensive evaluation of commercial-scale lighting systems. In the process, the group expects that these specifications will foster awareness of solar powered lighting and the applications where it is a viable alternative to conventional grid-connected lighting technology.

The group is focused on assessment of the energy balance of a system design to ensure operation that is aligned with customer’s expectations. Other aspects of the system design, including standards that apply to individual components of the system, lighting characteristics or aspects that relate to safety are already being addressed through national and international bodies such as Commission International D’eclairage (CIE), Illuminating Engineering Society of North America (IESNA), International Electrotechniques Commission (IEC) and Underwriters Laboratories (UL).

The first milestone of the of group is to develop common terminology and key metrics presented in a consistent, user-friendly form that can be readily adopted by municipal, government and commercial customers and specifiers. A white paper on this topic, “Solar Lighting Recommended Practices: System Sizing – Preliminary Version” is scheduled for release on June 15, 2011. An introductory flyer about the Consortium and its mission will be available during the 2011 LightFair in Philadelphia, PA on May 17-19, 2011 at the booths of the respective members as well as through their corporate websites. The founding members invite other North American solar powered lighting manufacturers who are able to commit time and resources to join them in establishing a formal organization to pursue the CSL’s mission.

To inquire about participation in the CSL please contact info@consortiumforsolarlighting.com

LumenOptix Acquires Westinghouse Lighting Solutions

LumenOptix, LLC has acquired the assets of Global Industrial Lighting Solutions, which was also known as Westinghouse Lighting Solutions. LumenOptix will continue to leverage precision optics and superior designs to manufacture the most energy-efficient-lighting fixtures in the industry. The transition of assets which includes inventory, equipment and personnel, will be coordinated to ensure consistent service to customers. The LumenOptix team will continue to operate in the Westinghouse Lighting Solutions facility until the transition is complete in June, 2011.

OSRAM Opto Semiconductors Expands

Opto Semiconductors will step up its production output by converting its two chip manufacturing facilities to 6-inch wafers while expanding production at both plants. A new production building is currently under construction in Penang, Malaysia, while in Regensburg, Germany, the existing space is being reallocated. The two facilities will each be converting to the new manufacturing technology, introducing 6-inch wafers to replace the current 4-inch wafers. These measures are expected to almost double the chip production capacity for white LEDs by the end of 2012.

The capacity expansion will primarily affect InGaN chips employing thin-film and UX:3 technology, which are required in the production of white LEDs. In the new production facilities, these chips will be manufactured on 6-inch wafers from the start and no longer on wafers with a 4-inch diameter.

With this move, OSRAM Opto Semiconductors is positioning itself to capitalize on the growth  of international LED markets. When this expansion is complete, the Penang chip manufacturing plant will have approximately 25,000 sqm (269,000 sq. ft.) and employ 400 more workers. No additional space is being created at the Regensburg plant. Instead, the production facilities are being switched over to LED production and may be operational as early as the summer of 2011.

Lutron Electronics Opens New York Global Specification Office

LUTRONLight control manufacturer Lutron Electronics has opened a New York global specification office. The new 2,300 square-foot specification office is at 1 Penn Plaza, Suite 1714, New York, NY 10119.

The New York facility features a diverse line of Lutron light control products presented in an innovative and versatile commercial office. The space includes an open office mock-up, a private office and a conference room. The specification office provides visitors with the opportunity explore a wide variety of product applications, including control of high-efficacy lighting sources, sustainable light control options and daylight harvesting strategies.

Lutron specification offices throughout the world offer commercial support for architects, specifiers, engineers, energy managers, system designers and their clients. The New York, NY location joins the company’s many global specification offices including Toronto, Tokyo, Hong Kong, Singapore, Dubai, London, Sao Paolo, Shanghai and Chihuahua.

East Cleveland On the Road to Savings With NE Ohio’s First Major LED Street Lighting Installation

LED LIghting in East Cleveland, OHThe City of East Cleveland is decreasing energy costs by replacing 45 standard-technology municipal street lights with LED roadway street lights. The project grows out of a long partnership between GE Lighting and East Cleveland, which has been the home of the unit’s headquarters for close to 100 years. A one-mile block along Noble Road serves as a demonstration to other municipalities of the benefits of a higher-efficiency lighting system.

The U.S. Department of Energy’s national laboratories predicts that LED lights reduce energy needs by more than 50 percent and maintenance costs by more than 80 percent compared to traditional lights. It’s estimated that the new LED street lights will reduce the city’s energy use by 28 million watts a year.

Mayor Norton said that the LED street lights give city residents the enhanced security associated with this high-performance lighting system. The system shines a bright, more uniform light across the entire area it illuminates, versus spotty, hot spots of light typical of certain other lighting technologies used in roadway lighting. Even with less lumens, or light level, compared to a high-intensity discharge street lighting system, the LED system better directs the light to where it is needed due to its advanced optics. The LED street lighting system is more precisely focused, which reduces light pollution and limits glare.

Earlier this year, GE Lighting and its LED unit, GE Lighting Solutions, earned more awards than any other company in the 2010 Next Generation Luminaires™ (NGL) Competition, including a Best-in-Class award for the GE Evolve™ LED street lighting system. GE LED lighting products for refrigerated display, architectural and outdoor applications were also recognized in the competition. The event is sponsored by the U.S. Department of Energy, the Illuminating Engineering Society of North America and the International Association of Lighting Designers for “excellence in the design of energy-efficient LED luminaries for general illumination lighting.” A global industry leader, GE Lighting has provided more than 20 million feet of LED signage and architectural lighting around the world and installed over six million LED traffic and rail signals globally. GE has the world’s largest installed base of LED refrigerated display lighting in the world – a category the company invented.