Advancing the effective use of light for society and the environment.

Wednesday, January 12, 2005

New Case Studies Highlight Commercial Daylighting Concepts
Harmony Library in Fort Collins, Colo.
Harmony Library in Fort Collins, Colo.

On the heels of its first case study release for Smith Middle School, the Daylight Dividends program has published two additional case studies of commercial daylighting strategies: Harmony Library in Fort Collins, Colo., and TomoTherapy, Inc., in Madison, Wis.

Creating a "comfortable, inviting place" at Harmony Library

Serving the local area and students at Front Range Community College, Harmony Library takes advantage of a predominantly sunny climate in Fort Collins. To achieve low operational and maintenance costs while providing a high-quality library atmosphere, architects incorporated daylighting into initial concepts, starting with the building's orientation and shape. Most windows face north and south, limiting direct sun exposure while capturing full lighting benefits. Clerestory windows along the main room's long spine allow light penetration to the book stacks, oriented perpendicular to the windows to reduce shadows. Perforated overhangs over windows, manually operated perforated shades, and neutrally tinted glass limit glare. Light-colored walls and ceilings help reflect daylight throughout the open, cheerful space.

TomoTherapy HQ in Madison, Wis.
TomoTherapy HQ in Madison, Wis.

Custom-built direct/indirect luminaires provide a low level of general lighting within the library and are switched off in response to daylight, while task lighting using 13-watt compact fluorescent lamps aids readers at study tables. A timer conserves energy by automatically turning off each task light after two hours of use.

In general, the daylighting scheme has been well-received by library users, prompting one patron to comment, "The amount and type of light in here makes the library a very comfortable, inviting place. There is always plenty of natural light and never any harsh blue/white light."

Bringing the outdoors in at TomoTherapy

Madison, Wis., is home to TomoTherapy, Inc., a technologically advanced company that has developed a unique medical system to deliver conformal radiation therapy to cancer patients. TomoTherapy's headquarters are leased from The Gialamas Company, a building owner that incorporates some type of daylighting into about 75 percent of its facilities.

TomoTherapy uses its three-story building for administrative offices, programming, engineering, research and development, and assembly work. The facility incorporates large, tinted, low-e windows to provide daylight and a connection to the outside environment, which according to at least one employee, increases positive thinking.

The open office spaces near the east- and west-facing windows use direct/indirect fluorescent fixtures equipped with dimming ballasts that adjust the electric lighting intensity in response to daylight levels. Most of the private and semi-private offices employ motion sensors to control electric lighting. In these offices, occupants control light levels manually.

The complete case studies for each of these projects can be downloaded from the Daylight Dividends Web site.

The Daylight Dividends program, administered by the Lighting Research Center, is a national effort to educate and provide evidence, guidance, and perspectives supporting the use of daylighting in commercial and educational facilities. Program sponsors include: California Energy Commission, Connecticut Light and Power Company, Iowa Energy Center, New York State Energy Research and Development Authority, North Carolina Daylighting Consortium, Northwest Energy Efficiency Alliance, and the U.S. Department of Energy.

About the LRC

The Lighting Research Center (LRC) is part of Rensselaer Polytechnic Institute and is the leading university-based research center devoted to lighting. Founded in 1988, the Lighting Research Center has built an international reputation as a trusted and reliable source for objective information about lighting technologies, applications, and products. Its mission is to advance the effective use of light and create a positive legacy of change for society and the environment.



2005 Rensselaer Polytechnic Institute, Troy, NY 12180 USA.

Rennselear Polytechnic Institute