s.ky blue information

The Solar Decathlon is a project of the U.S. Department of Energy (DOE) in partnership with DOE's National Renewable Energy Laboratory.

Lighting Design

Lighting Design: 57.000 out of 75 possible points

 

Teams earn points in this contest by designing functional, energy-efficient, and aesthetically pleasing lighting systems. The jury evaluates the teams' lighting designs, which are required to integrate both electric and natural light, from functional and aesthetic standpoints. Points are also awarded for energy efficiency. The jury assesses:

  • Electric Lighting Quality—Are the lighted spaces rich and varied? Do they have adequate light for tasks? Do they have good color rendition? Are the luminaires attractive? Do they properly distribute light?
  • Daylighting Quality—Have human factors, such as physiology, perception, preferences, and behavior, been addressed? What are the effects of daylight on all materials, including furniture, artwork, and plants? Is the admission of direct and diffuse sunlight effectively controlled?
  • Ease of Operation—Is the operation of the manual and automatic lighting controls intuitive?
  • Flexibility—Can the lighting system accommodate all activities and aesthetic requirements in all seasons?
  • Energy Efficiency—Do the lighting controls help reduce lighting energy consumption throughout the year?
  • Building Integration—Have the lighting design and controls been effectively integrated into the building?

 

s.ky blue approach

 

The live.light tagline drives the major integrated lighting strategies for our s.ky blue house. The focus of this approach centers on balancing natural and artificial light sources through an adaptive and controllable system. Whereas incoming natural daylight is harvested to take advantage of its light without adverse heat gain, the various artificial sources maintain a continuous and controllable light rendition over the course of the day.

Our approach was based upon a total integration between the solar and thermal envelope and the corresponding interior lighting effects. To accentuate the architectural planes of space, windows were placed in strategic locations and serve a variety of functions:

  • Make small spaces seem larger to bridge between inside and outside spaces
  • Separate the walls from the roof
  • Give the appearance of a floating volume above the thermal envelope
  • Illuminate the floor
  • Emphasize the continuous quality of the space as well as its vertical expression
  • Allow for distant and framed views of the natural landscape beyond the house.

 

In summary, our painting with light approach has both psychological and physiological experiential effects upon those occupying the space, thus meeting our desired goal, most notably, to result in a visually interesting, inviting, warm, and comfortable experience.

process

 

The “light” team used AGI32, version 2.0 and Revit 2009 to develop a series of virtual simulations to optimize the interior and exterior lighting values for the house. Working alongside Joe Reybarreau and CMTA Engineers David Higgins and Isaac Fedyniak, the team formulated a range of 3D Radiosity based point-by-point imaging solutions to give a continuous light rendition throughout the day and into the night.

Through these models and simulations, the design team derived a lighting solution for the s.ky blue house that balances between the poetic and the dramatic. This solution works well with the design of the house as it oscillates between opacity, translucency, and transparency.

As depicted in the AGI32 renders, rather than being designed as a dark cloud over the otherwise light thermal volume, the solar array serves a reflective capacity for the project. Light reflected from the white cool roof and the underside of the solar tracking roof permeates through the north facing skylights. Striations of light penetrate to the thermal roof between panels of BIPV to create a direct doubling effect of indirect and direct sunlight inside of the house.

The direct correspondence between the adaptable roof form and the interior lighting volume forms a floating thermal roof and perforated light tube that appears to be supported only by a continuous ribbon of glass. These virtual simulations also guarantee the appropriate lighting levels at the competition work surfaces.

Innovations

 

The architectural, engineering, interior design, and lighting design teams collaborated to develop a series of California Title 24 compliant, innovative strategies to achieve our project goals. These innovations include:

  • Daylight harvesting with self-dimming, digital photocells
  • Electronically tintable glass
  • High-efficacy luminaries
  • Indirect T-5 lighting sources
  • Selective use of solid state LED lighting fixtures
  • Zoned lighting through programmed control
  • Exterior illuminated façade
  • Occupancy sensors

 

Daylight Harvesting with self-dimming, digital photocells

While daylight harvesting has been around for years, it is a growing technology. This advanced light control reduces the energy consumption by the fixtures by locating digital photo-sensors to detect daylight levels and automatically adjust the output level of the luminaries.

Electronically Tintable Glass

The use of electronically tintable glass is in direct response to our desire to produce power and reduce energy consumption and carbon footprint, while at the same time helping to control solar heat gain. These products are linked to an atmospheric clock and control system to optimize the house in terms of shading to prevent heat gain during the Kentucky cooling months and supplement heat gain during the winter months.

In addition, the choice of this product and the method of its integration blocks glare, increases interior daylight illumination, and reduces fading due to ultraviolet and visible light. Programmable settings are another benefit of the system, but in case of program failure a master override switch will be located in an isolated location which has the function to turn the system on or off when needed. Since the amount of light we receive varies throughout the year, the system can be reprogrammed to factor in these changing conditions.

High-efficacy Luminaries

The team opted for a combination of T-5 fluorescent with 100lpw and LED fixtures with 60lpw to maintain a continuous and balanced color rendition throughout the house so as not to create hot spots, glare, or other types of visual discrepancies and to reduce the overall Light Power Density of the house.

Indirect T-5 Lighting Sources

One core principle of our lighting strategy was to reduce visual clutter and maintain clean lines and surfaces. For this reason slender profiled, dimmable, T-5, 3000K Color temperature lamps with an average lamp life of 20,000 hours, and a high Color Rendition Index (CRI) were integrated into the house’s plan. Compared to conventional T-5 systems the particular fixtures that we selected have a 3-year payback period with increased savings over the next 15-20 years.

Selective Use of LED Task Lighting

To supplement the indirect fixtures, the team selected state-of-the-art, low profile LED light sources to provide long life, good color rendition, and low power consumption at the competition task areas. The kitchen and office work surfaces benefited especially. These high-efficacy, high-brightness, light fixtures are dimmable and have an integrated thermal management technology. The lights chosen for these purposes have a 2700K Color temperatures lamps and an average lamp life of 50,000 hours.

Zonned Lighting Through Programmed Controls

The house has optimized the overall control of the interior light rendition by integrating a total light management system to dim and/or switch all electric lighting and balance daylight harvesting. Fixtures for general lighting consist of high efficient T-5 indirect fixtures with smart ballast technology. This ballast technology allows for individual fixture control enabling zoning of fixtures in the house to particular sensors.

All light fixtures have both individual and collective controls, which increase energy savings between 40%-70%, increase spatial flexibility, and increase homeowner comfort. By controlling each light fixture both individually and collectively, the homeowner has greater personal light control for each desired task or for preprogrammed light scenes.

Once programmed the zones can be controlled by an override switch if full light or no light is desired. The zones can be reprogrammed for special events or the changing seasons so the desired lighting is achieved. Like the electronically tintable glass controls linked to an atmospheric clock, the controls are linked to time of day schedules, but also have AV integration to dim lights for entertainment purposes.

An Exterior Illuminated Façade

The concept of live.light is site malleable, thus allowing the homeowners to select a particular “scene.” The exterior accent lights consist of under handrail LED lighting strips to illuminate the walking path. In addition to the rail lighting, the team designed a customizable process for adding visual interest to the façade. The process includes selecting an appropriate photographic image which can then be pixelated, transformed into G-code, and applied to the building’s exterior as a perforated rainscreen. This screen serves two purposes: to add texture and interesting lighting variations to the exterior wall of the architecture.

Occupancy and Motion Sensors

As part of the controls of the lighting systems, occupancy sensors automatically turn lights on, or in the case of the bathroom, turns the ventilation fan on when a room is occupied and off when the room is vacant. In addition, the products selected work seamlessly with the whole house integrated system to automate switching and dimming of the lights, whereby reducing the potential for wasted energy in unoccupied spaces. The sensors that are in this project were a hybrid design that incorporates digital photo cells and dual technology occupancy sensors.