Design Lab Sheds Light on Energy Conservation
A mockup is a full-scale installation of a proposed lighting system. Actual light fixtures, fixture placement, ceiling height, room dimensions, surface finishes, and furniture layout can all be evaluated in a mockup. This allows the design team to literally walk around in a design and make necessary changes before actual construction begins.
The mockup room is a 30 by 40-foot (9 by 12-meter) space with two movable 20 by 18-foot (6 by 5.5-meter) ceilings that can be set any height from 5 up to 15 feet (1.5 up to 4.5 meters). One of the 40-foot (12-meter) walls has southern exposure glazing over most of its area that can be used to simulate windows for a side-lit space. Or it can be blacked out with shades for non daylit (or nighttime) spaces. Standard wall heights are 9 or 12 feet (2.5 or 3.5 meters), and these can be arranged to create rooms, hallways, or parts of larger spaces. Light fixtures can be ceiling-mounted, pendant, wall-mounted, or architectural (coffers, soffit, niches, etc.).
Anatomy of a Mockup
A recent example of a full-scale mockup was a prototypical classroom for the North Clackamas High School, designed by BOORA Architects, of Portland, Oregon. The mockup was constructed to evaluate the proposed architectural design and lighting strategies. Both daylight and electric lighting were evaluated, individually and as an integrated approach.
The classroom ceiling incorporates a suspended "cloud" that covers most of the room but is pulled back from the walls by 2 to 4 feet ( 0.6 to 1.2 meters) on all sides. This cloud is sloped and drops to a low point about two-thirds of the way back from the window wall. It was mocked-up with white "blackout" fabric stretched over a wood frame.
Interior lightshelves were constructed of perforated metal. Their inside edges were wooden coves to hold the electric lighting. An exterior lightshelf was simulated with foam core board. The classroom's complex ceiling and its interior and exterior lightshelves made this a much more elaborate mockup than is standard for the lab.
The mockup was evaluated for spatial qualities, daylight levels, electric lighting design, lighting quality, and implications for lighting controls. Although some of these can be measured quantitatively, others, such as spatial qualities, are best evaluated subjectively, by walking around in the space. No other evaluation method can match the mockup studio's ability to provide this.
The architects and the school representatives were very pleased with the spatial qualities of the classroom. The sloped ceiling creates an interesting effect that reduces the scale of the room to "human height" in the center while maximum height at the perimeter for clerestory glazing.
The suspended ceiling stopped short of the lightshelf and it became evident from viewing the mockup that this compromises the function of the lightshelf and the indirect electric lighting mounted in it. Too much of the daylight is "thrown away" into the recess above the cloud. The evaluators recommended extending the "cloud" over part of the interior lightshelf.
The evaluators looked at both direct and indirect electric lighting schemes and quickly agreed that they preferred the latter. Quantitative measurements showed that this lighting could provide about 30 footcandles of light fairly evenly across the space, sufficient for classroom work.
Thus, the mockup succeeded in informing the redesign process and confirming the sufficiency of the lighting schemes. The architects could then proceed with confidence that the hybrid electric/daylighting approach would work well for both energy conservation and high-quality spatial design.
New research has shown that daylight makes people more productive, increases sales, and increases worker satisfaction. Effective use of daylight is at the cutting edge of architecture in the new millennium. The cost of designing, creating, and operating buildings is just a fraction of the cost of the people inside those buildings. Therefore, design decisions for the sake of initial cost or so-called efficiency that make workers and businesses less productive are the most expensive mistakes to make.
Access to the Lighting Design Lab
Three years ago the lab expanded into cyberspace with a Web site that offers a wealth of information on lighting products and design techniques, guides to Lab services, and downloads of nearly every handout available at the Lab itself. There is a virtual tour of the Lab, postings of notable lighting locations, and extensive links to other lighting and energy sites. It also has a free e-mail newsletter to keep you up-to-date on lighting events in the Pacific Northwest.
The bricks-and-mortar technical reference library is open to the public at 400 E. Pine Street in Seattle. It has a collection of lighting catalogs, technical references and standards, periodicals, videotapes, lighting software, and energy code information. Consultations are available in person, by telephone (800) 354-3864 or (206) 325-9711, by fax (206) 329-9532, and by e-mail.
Now in its tenth year, the Lighting Design Lab is sponsored by Seattle City Light, the Northwest Energy Efficiency Alliance, Puget Sound Energy, other electric utilities, and environmental organizations.
Randy Smith is the librarian and webmaster for the Lighting Design Lab.
A version of this article first appeared in the Seattle Daily Journal of Commerce.