Session F2C
Work in Progress - Multidisciplinary Laboratory for Development, Design and Consumer Testing of Marketable Residential LED Luminaires Janice K. Means1, Lisa Anneberg 2, Christina Snyder3, and Jin Feng4 Departments of Architecture and Design, Electrical and Computer Engineering, Lawrence Technological University, Southfield, MI 48075
[email protected],
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Abstract - Electrical engineers and architects collaborate in ‘real life’. In the university, this rarely happens. This paper presents novel approaches to a laboratory that brings electrical engineering and architecture students together. Lawrence Technological University is participating in the ‘Solar Decathlon 2007’ international competition. Lighting is a critical part of this competition and ‘lighting energy use’ is one of the ten competitions. The designed house will have varying lighting requirements, and innovative energy conserving lighting approaches are required. The LTU laboratory facility will eventually have several stations known collectively as ‘The Lighting Lab’. Electrical engineering students work on the technical aspects of light measurement and the design and manufacturing of luminaires, whereas architecture students work on designing esthetically pleasing lighting luminaires that meet the illumination requirements. Equipment in the lab includes various luminaries, lamps, an artificial sky fixture, a direct beam sunlight simulator, light meters and demonstration displays. Students become familiar with direct/indirect light sources and conventional and low-voltage lighting, and then develop how it can be used for task, decorative and general lighting. A focus for research is the study of LEDs [light emitting diodes]. LED luminaries require further development to provide required illumination at work surfaces in an esthetically pleasing way. Index Terms illumination, efficacy, luminaire, media, air, global climate, embodied energy, engineering, architecture, monitoring, lighting, LED, Zero Energy Homes, Solar Decathlon, 12VDC INTRODUCTION Lighting systems employing light emitting diodes, LEDs, are potentially a viable, energy-efficient, ecologically-beneficial alternative to currently used incandescent residential lighting. The development of marketable LED luminaires poses a
challenge in both the social and technical realms. Success in designing these luminaires will benefit humanity and the environment, and should revive the residential lighting market. Lawrence Tech students from the College of Engineering (Electrical Engineering Majors) and the College of Architecture (both Architecture and Interior Design majors) will work in this cooperative, multidisciplinary educational laboratory to design what is envisioned as a paradigm shift in LED luminaire design. There is additional opportunity to involve a graduate student from the College of Management to assist with marketing research for the LED luminaire(s). Deliverables: The projected outcome is the design of a minimum of two consumer-pleasing LED luminaires displaying acceptable color rendition and required lumen light levels for residential mood and task lighting. Tour participants of the Lawrence Tech 2007 Solar Decathlon house in Washington DC in October 2007 will be surveyed on their opinion of the prototype luminaires. This survey will provide feedback for improving the designs and give an indication of potential marketing viability. It will also help to set the course direction for a second phase of research. A graduate management student will perform an in depth market analysis as follow-up to the initial opinion survey to additionally improve the potential of successfully going to market. Engineering students will further investigate optimization of material choices for embodied energy, first cost and workability in the manufacturing process while the architectural and design students insure that aesthetics of the designs are maintained. SOCIAL CHALLENGE Luminaires using LED technology have not yet been embraced by the American consumer for residential lighting. However, LEDs are rapidly appearing, albeit not extensively, in American commercial applications, e.g., in emergency exit signs, various store displays, applications for holiday decorating, and flashlights. Outside the United States, architectural exterior and interior applications of LED lighting
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Janice K. Means, PE, Assistant Professor, College of Architecture and Design,
[email protected] Lisa Anneberg, PhD, Associate Professor, College of Engineering,
[email protected] 3 Christina Snyder, RA, Lecturer in Architecture, College of Architecture and Design,
[email protected] 4 Jin Feng, PhD, College Professor, College of Architecture and Design, 2
1-4244-1084-3/07/$25.00 ©2007 IEEE October 10 – 13, 2007, Milwaukee, WI 37th ASEE/IEEE Frontiers in Education Conference F2C-13
Session F2C are found in a wide variety of applications, although not for the residential market. American acceptance of LED technology is most likely due to a lack of commercially available luminaires exhibiting good color rendering properties, competitive pricing, attractive appearance and desired lumen levels at conventional distances from a working surface. TECHNICAL AND MARKETING CHALLENGE The use of energy conserving lamps, i.e., high efficacy LEDs, is the most affordable way to reduce lighting electrical demand. Ancillary benefits to using LED lighting are: reduced heat production and thus lower cooling loads and operating costs; lower emissions of greenhouse gases, mercury and particulates; and greater ease in using alternative energies since LEDs can be powered by direct current. However, there are perceived and real technical and marketing challenges related to acceptance and use of LEDs. First of all, it is generally thought that the color rendition of LEDs is poor, e.g., white LEDs have a bluish cast. Color rendering index, CRI, is a 1 to 100 scale to compare a light source’s capability of rendering color relative to a reference source. (Compared sources ideally have similar color temperatures.) Some CRI values are: Daylight 100; LEDs 70’s to low 90’s; tubular fluorescent lamps 75 to 85; and incandescent lamps at 99 or higher. Interestingly, recent research has shown that subjects comparing reading comfort from LEDs, halogen and incandescent lamps, actually preferred the LEDs according to researchers at the Lighting research Center at Rensselaer Polytechnic Institute in Troy, New York. The researchers also concluded that CRI was not a good metric for evaluating LEDs. Additionally, LEDs come in several colors. The temperature of white LEDs is about 5000oK, as compared with a 4200oK temperature for cool white fluorescent lamps and about 3000oK for an incandescent flood lamp. Separate LED lights must be grouped to provide amble lumen output. Although LEDs have high efficacy (lumen to watt ratios), individual lamps give off only small amounts of illuminance. Therefore, LED luminaires use multiples of LED lamps. Most also have a utilitarian look Due to the small numbers being produced with lack of current demand, first costs are also higher when compared with conventional lamps, DESIGN APPROACH
attractive luminaires which provide required lumen levels at reasonable distances, while being constructed of materials and in a manner to encourage mass production and reasonable costs for the residential consumer. Additional goals include using materials with low embodied energy and selecting and designing controls to further lower operating costs. Students will initially design 12-volt DC LED lighting systems since they typically contain fewer components, are cheaper to produce, and are more applicable for off-grid homes relying on alternative energy. Lawrence Tech students have a unique opportunity to test their designs on an off-grid residential structure as part of the 2007 Solar Decathlon (SD) competition. The SD home will be building-integrated photovoltaic (BIPV) powered and will be extensively data-monitored for the SD competition. It will be constructed on the Mall in Washington, DC in October of 2007 where thousands of people will be able to tour it and view the lighting prototype luminaires first hand. As part of the marketing research, tour attendees will be surveyed for their impressions of the prototype luminaires. Students then will modify and further perfect their designs using the measured data and survey information gleaned from the SD home installation. In a later phase, refined luminaire designs will be used to accommodate 120 VAC LED units. Data taking will continue with these grid-connected LED luminaires, market research will be done in greater depth with a wider test group, and manufacturer(s) will be contacted to consider producing the best LED luminaire design(s). There will also be an outreach initiative educate the public on LED lighting luminaire use in their homes. IMPACT The proposed educational research directly impacts the three pillars of sustainability: people, prosperity and the planet. Every decision toward the development of feasible LED luminaires will be guided by these principles, as evidenced by its linked association with Solar Decathlon requirements of energy efficiency, fossil fuel abstinence, and demonstration of economically feasible designs. In summary, this educational research lighting lab will encourage collaboration between engineering and architectural students as they study lighting and become skilled at designing innovative, energy-conserving, long-lasting, nonpolluting, and marketable LED luminaires for a sustainable future world.
Students will test several LED lamps, verify specifications and then design prototype LED lighting luminaires. The electrical REFERENCES engineering students will concentrate on the technical aspects related to electrical components, architecture students will [1] Stein, Benjamin, Reynolds, John S., Drondzik, Walter T., address the quality and quantity of light requirements, and the Kwok, Alison G., Mechanical and Electrical Equipment interior design students will address the aesthetics, although it for Buildings, Wiley, Inc., 2006. is anticipated that there will many crossovers in responsibility. [2] Whitehead, Randall, Residential Lighting: A Practical The management graduate student will analyze and estimate Guide, Wiley, Inc., 2003. potential costs for production. [3] Descottes, Herve, Ultimate Lighting Design, Te Neues At least two types of luminaires will be developed, Publishing Co., 2006. although multiple versions will be created for varying residential applications. Goals are to create architecturally 1-4244-1084-3/07/$25.00 ©2007 IEEE October 10 – 13, 2007, Milwaukee, WI 37th ASEE/IEEE Frontiers in Education Conference F2C-14
