Northern Lights: Interior lighting design in Alaska architecture.

• Author: Navarro, Bruno J.
• Position: ARCHITECTURE & ENGINEERING SPECIAL SECTION

With just three hours and forty-two minutes of sunlight on the shortest day of the year, Fairbanks--like much of Alaska-presents multiple challenges for lighting designers looking to create a pleasant, comfortable environment.

While the angle of the sun remains low throughout winter, hewing close to the horizon around the winter solstice, the other half of the year brings a wealth of daylight, creating two situations that can wreak havoc on circadian rhythms.

"The dynamics of our light cycle up here are so unique," says Dana Nunn, interior design director at Bettisworth North, an Anchorage architecture firm. She notes that the sun's changing angles throughout the year can change the color and the quality of the light dramatically.

"Figuring out how to balance that and give people a comfortable space to work in or to learn in, it's important to layer light and controls, just so people can create a lighting environment that's best for what they're doing in the moment."

Yet energy consumption also plays a factor, with Alaska residents often paying higher energy costs than anywhere in the United States.

That's where LED technology, combined with integrated controls, can help manage energy use, Nunn says.

Ideally, good lighting design incorporates a "variable and flexible lighting system so that things are just as well-lit in the winter as they are in the summer," she says. "It would be great to start with a cooler color temperature at the beginning of the day, coming down to warmer temperature during the day."

Lighting and Mood

Nunn says that decades of research, industry standard, and best practices help determine the ideal brightness levels for various spaces, depending on their intended use, measured in foot-candles: full, unobstructed sunlight produces approximately 10,000 foot-candles of light, while an overcast day generates about 100 foot-candles.

Lighting levels in people's work and living spaces can affect their anxiety, wellness levels, and mental acuity levels, Nunn says. That makes it important to take into account what outcomes designers are aiming for in a given architectural space.

"We talk a lot about circadian rhythm," Nunn says, noting that a lighting design's effect in healthcare organizations and hospitals is critical--especially when natural window light is limited. For instance, one challenge may be designing lighting to shift circadian rhythm while still allowing patients to get quality, restful sleep.

On the other hand, some clients might find that an aggressive lighting strategy best serves their interests, Nunn says, using the example of a tech company with employees working in three shifts.

"We're designing to meet building code at the very least, while also layering lighting with health and wellness concerns in mind," Nunn says. "Oftentimes, the code has a target range."

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