Sixteenth International Conference on Solid State Lighting and LED-based Illumination Systems
We have developed an innovative lighting system prototype for a patient room application that int... more We have developed an innovative lighting system prototype for a patient room application that integrates a multi-channel luminaire platform into indoor general area luminaires. This system is energy efficient, spectrally tunable, and supports the visual and nonvisual needs of occupants. We evaluated the performance of two separate multichannel platforms in different luminaire types, using a unique color-processing algorithm. The LED modeling and simulations enabled optimization of spectral power distributions, color, light output, and efficacy. This paper discusses the complicated results of SPDs developed for the patient room application, especially how they are effective for positively supporting the human visual and non-visual (circadian) systems. Additionally, application measurements demonstrate the large impact of the application space on the resulting SPD of a luminaire, calling into question the feasibility of using traditional field measurements to validate luminaire performance.
A field study was conducted at three clothing stores to validate previous laboratory findings ind... more A field study was conducted at three clothing stores to validate previous laboratory findings indicating that colored LEDs used as background display lighting could: 1) lower the power demand of accent lighting by up to 50 percent; and 2) provide greater attention capture and visual appeal than current lighting practice. Blue LEDs provided a colored background for window mannequins by illuminating white backdrops. Eliminating fluorescent general lighting and reducing the number and wattage of halogen accent lamps in the display windows reduced the lighting power demand by up to 50 percent. During an eight-week period, more than 700 shoppers rated the attractiveness, eye-catching ability, comfort, and visibility of four different lighting conditions. The results of this field study showed that by introducing color contrast between the displayed objects and the background, the power demand of the accent lighting could be reduced by up to 50 percent without sacrificing visual appeal, visibility, ability to capture the attention of shoppers, and the ability to see the colors of the objects on display. Furthermore, the sales of the products on display were not affected by the 50 percent reduction in lighting.
LEDs systems are now favorably competing with traditional systems in many architectural lighting ... more LEDs systems are now favorably competing with traditional systems in many architectural lighting applications. LEDs offer many unique attributes not available before in other light sources. However, matching the needs of each application to the specific attributes of LEDs is critical to achieving successful applications.
Lighting plays a pivotal role in neonatal intensive care units (NICUs). Lighting must accommodate... more Lighting plays a pivotal role in neonatal intensive care units (NICUs). Lighting must accommodate 3 distinctly different groups: newborns, health care professionals, and families. Although wards housing several infants still exist, many NICUs are being designed as a series of single-family rooms. All individuals interacting in these environments have a right to expect a supportive lighting system. Lighting should be quiet, reliable, efficient, and maintenance-free. Lighting should be as simple to change as the moment-to-moment needs of the different populations change. The intent of this article is to provide relevant direction as it pertains to lighting design in today's NICUs. After reviewing the lighting accommodations required for 3 distinctly different groups of people-infants, families, and staff-basic concepts deemed important for design considerations in the NICU are outlined. This article puts forth a goal-oriented approach to ensuring a successful lighting result, and refers to useful lighting resources.
Injuries resulting from falls in seniors are a significant health concern. Visual information is ... more Injuries resulting from falls in seniors are a significant health concern. Visual information is important for postural control in seniors and postural control is affected by the light level. Moderate ambient illumination might be effective for postural control, but might compromise subsequent sleep efficiency and quality for seniors. In addition to safety concerns, a night lighting system must also be accepted by seniors. Researchers investigated if a self-luminous, night lighting system that provided horizontal and vertical cues could positively affect postural control in older subjects and evaluated its acceptance among seniors. The results showed that the night lighting system was effective for maintaining postural control in the critical, early phase of the sit-to-stand task and that it was preferred over conventional night lights.
ABSTRACT ,!This field study uses a new model home demonstrating good lighting-design principles w... more ABSTRACT ,!This field study uses a new model home demonstrating good lighting-design principles with energy-efficient solutions. Surveys showed that builders and the general public accepted and even preferred the appearance and the lighting effects of energy-efficient lighting technologies. Key to the success was integration with architectural features, colour schemes, and user lifestyle. Detailed survey results, energy savings, and illuminance comparisons are presented, as well as a discussion of ongoing barriers to the use of energy-efficient technology. Designers share ‘lessons learned’ from this design case study.
Roundabout lighting consisting of pole-mounted high pressure sodium luminaires can be energy inte... more Roundabout lighting consisting of pole-mounted high pressure sodium luminaires can be energy intensive and does not necessary provide clear delineation for drivers and pedestrians navigating a roundabout. Using the ecoluminance concept developed in a previous study, lighting integrated with vegetation using lower mounting heights and reflected light from plants and retroreflective elements, it could be possible to provide illumination at a roundabout using substantially less energy. Two short term lighting demonstrations, using the ecoluminance approach and using lower-wattage luminaires producing "white" illumination, were conducted at a real-world roundabout location in New York State. Feedback from transportation engineers and members of the public was used to refine the ecoluminance concept for a final lighting demonstration, consisting of shrubs and trees in the central roundabout island, landscape lighting for these items, pedestrian bollard lighting at crosswalks, overhead light-emitting diode (LED) luminaires in sidewalk and roadway areas, and retroreflective markers to delineate the perimeter of the central island. Photometric measurements confirmed the simulations performed during the design phase, and supported that pedestrians and roadway elements were visible to drivers and pedestrians. Observations of approaching vehicle speeds with the ecoluminance system installed and with the conventional lighting installed revealed little difference in approach speeds. The ecoluminance system had similar initial costs, mainly because of high LED equipment costs (which are decreasing over time) and used only one-fourth the energy of the conventional roundabout lighting system.
Great strides have recently been made in the development of white light emitting diodes (LEDs), a... more Great strides have recently been made in the development of white light emitting diodes (LEDs), although perceptible variations remain in the color and brightness of nominally identical products. The objective of this study was to examine color and brightness discriminability between different white LEDs when used as illuminants of colored and achromatic objects. A method of successive comparisons was used to assess discriminability rather than the more typical simultaneous (side-by-side) comparisons using a "same-different" response protocol. Three-dimensional "tolerance zones" were developed based upon discriminability in a chromaticity (u', v') and luminance when illuminating the colored and achromatic objects. These "tolerance zones" could be used to establish specification tolerances for different lighting applications.
Sixteenth International Conference on Solid State Lighting and LED-based Illumination Systems
We have developed an innovative lighting system prototype for a patient room application that int... more We have developed an innovative lighting system prototype for a patient room application that integrates a multi-channel luminaire platform into indoor general area luminaires. This system is energy efficient, spectrally tunable, and supports the visual and nonvisual needs of occupants. We evaluated the performance of two separate multichannel platforms in different luminaire types, using a unique color-processing algorithm. The LED modeling and simulations enabled optimization of spectral power distributions, color, light output, and efficacy. This paper discusses the complicated results of SPDs developed for the patient room application, especially how they are effective for positively supporting the human visual and non-visual (circadian) systems. Additionally, application measurements demonstrate the large impact of the application space on the resulting SPD of a luminaire, calling into question the feasibility of using traditional field measurements to validate luminaire performance.
A field study was conducted at three clothing stores to validate previous laboratory findings ind... more A field study was conducted at three clothing stores to validate previous laboratory findings indicating that colored LEDs used as background display lighting could: 1) lower the power demand of accent lighting by up to 50 percent; and 2) provide greater attention capture and visual appeal than current lighting practice. Blue LEDs provided a colored background for window mannequins by illuminating white backdrops. Eliminating fluorescent general lighting and reducing the number and wattage of halogen accent lamps in the display windows reduced the lighting power demand by up to 50 percent. During an eight-week period, more than 700 shoppers rated the attractiveness, eye-catching ability, comfort, and visibility of four different lighting conditions. The results of this field study showed that by introducing color contrast between the displayed objects and the background, the power demand of the accent lighting could be reduced by up to 50 percent without sacrificing visual appeal, visibility, ability to capture the attention of shoppers, and the ability to see the colors of the objects on display. Furthermore, the sales of the products on display were not affected by the 50 percent reduction in lighting.
LEDs systems are now favorably competing with traditional systems in many architectural lighting ... more LEDs systems are now favorably competing with traditional systems in many architectural lighting applications. LEDs offer many unique attributes not available before in other light sources. However, matching the needs of each application to the specific attributes of LEDs is critical to achieving successful applications.
Lighting plays a pivotal role in neonatal intensive care units (NICUs). Lighting must accommodate... more Lighting plays a pivotal role in neonatal intensive care units (NICUs). Lighting must accommodate 3 distinctly different groups: newborns, health care professionals, and families. Although wards housing several infants still exist, many NICUs are being designed as a series of single-family rooms. All individuals interacting in these environments have a right to expect a supportive lighting system. Lighting should be quiet, reliable, efficient, and maintenance-free. Lighting should be as simple to change as the moment-to-moment needs of the different populations change. The intent of this article is to provide relevant direction as it pertains to lighting design in today's NICUs. After reviewing the lighting accommodations required for 3 distinctly different groups of people-infants, families, and staff-basic concepts deemed important for design considerations in the NICU are outlined. This article puts forth a goal-oriented approach to ensuring a successful lighting result, and refers to useful lighting resources.
Injuries resulting from falls in seniors are a significant health concern. Visual information is ... more Injuries resulting from falls in seniors are a significant health concern. Visual information is important for postural control in seniors and postural control is affected by the light level. Moderate ambient illumination might be effective for postural control, but might compromise subsequent sleep efficiency and quality for seniors. In addition to safety concerns, a night lighting system must also be accepted by seniors. Researchers investigated if a self-luminous, night lighting system that provided horizontal and vertical cues could positively affect postural control in older subjects and evaluated its acceptance among seniors. The results showed that the night lighting system was effective for maintaining postural control in the critical, early phase of the sit-to-stand task and that it was preferred over conventional night lights.
ABSTRACT ,!This field study uses a new model home demonstrating good lighting-design principles w... more ABSTRACT ,!This field study uses a new model home demonstrating good lighting-design principles with energy-efficient solutions. Surveys showed that builders and the general public accepted and even preferred the appearance and the lighting effects of energy-efficient lighting technologies. Key to the success was integration with architectural features, colour schemes, and user lifestyle. Detailed survey results, energy savings, and illuminance comparisons are presented, as well as a discussion of ongoing barriers to the use of energy-efficient technology. Designers share ‘lessons learned’ from this design case study.
Roundabout lighting consisting of pole-mounted high pressure sodium luminaires can be energy inte... more Roundabout lighting consisting of pole-mounted high pressure sodium luminaires can be energy intensive and does not necessary provide clear delineation for drivers and pedestrians navigating a roundabout. Using the ecoluminance concept developed in a previous study, lighting integrated with vegetation using lower mounting heights and reflected light from plants and retroreflective elements, it could be possible to provide illumination at a roundabout using substantially less energy. Two short term lighting demonstrations, using the ecoluminance approach and using lower-wattage luminaires producing "white" illumination, were conducted at a real-world roundabout location in New York State. Feedback from transportation engineers and members of the public was used to refine the ecoluminance concept for a final lighting demonstration, consisting of shrubs and trees in the central roundabout island, landscape lighting for these items, pedestrian bollard lighting at crosswalks, overhead light-emitting diode (LED) luminaires in sidewalk and roadway areas, and retroreflective markers to delineate the perimeter of the central island. Photometric measurements confirmed the simulations performed during the design phase, and supported that pedestrians and roadway elements were visible to drivers and pedestrians. Observations of approaching vehicle speeds with the ecoluminance system installed and with the conventional lighting installed revealed little difference in approach speeds. The ecoluminance system had similar initial costs, mainly because of high LED equipment costs (which are decreasing over time) and used only one-fourth the energy of the conventional roundabout lighting system.
Great strides have recently been made in the development of white light emitting diodes (LEDs), a... more Great strides have recently been made in the development of white light emitting diodes (LEDs), although perceptible variations remain in the color and brightness of nominally identical products. The objective of this study was to examine color and brightness discriminability between different white LEDs when used as illuminants of colored and achromatic objects. A method of successive comparisons was used to assess discriminability rather than the more typical simultaneous (side-by-side) comparisons using a "same-different" response protocol. Three-dimensional "tolerance zones" were developed based upon discriminability in a chromaticity (u', v') and luminance when illuminating the colored and achromatic objects. These "tolerance zones" could be used to establish specification tolerances for different lighting applications.
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Papers by Patricia Rizzo