Let There
Be (Sun)Light
by David Pescovitz
Daniel
Glaser holds an architectural model of a building. Historically,
designers would place these models in the sun to simulate
daylight distribution within the structure; but Glaser's
new software offers designers a much improved way to visualize
the sun's effects on a building. (Click for larger
image.)
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Berkeley graduate student Daniel Glaser has come up with the most
pleasant, energy-efficient, and inexpensive light-source for buildings.
It's called the sun. Now all he has to do is convince building designers
to use it.
A Ph.D. candidate in the Interdisciplinary Graduate Program,
Glaser created a software tool that enables designers to study
the distribution of daylight in a building. After digitally drawing
a model of an architectural space complete with windows, the user
can watch how sunshine illuminates the rooms over the course of
a day or even the seasons. This visualization can quickly reveal,
for example, that a constantly shaded corner might do well with
a wall sconce, while a desk near a window would better be served
by a fixture on its own circuit that can be switched on only at
night.
"We're trying to make tools so designers can more easily think about daylight and use it in their lighting designs," says Glaser, who is assisted in his research by undergraduate computer science students. "Lighting systems can consume almost half the energy in a building."
In California alone, he adds, that energy sink corresponds to
$9 billion annually or 10 billion tons of carbon emissions. And
while engineers are developing more efficient bulbs and sensors
to reduce energy waste, Glaser believes that the lighting problem
is as much about people as it is about technology.
"In a big commercial building, you can have architects, lighting designers, electrical engineers, and other consultants all thinking about lighting and following institutional guidelines and state laws," Glaser says. "Meanwhile, their decisions ultimately have a great psychological impact on the people who inhabit the building."
In
this view of Glaser's software, each square in the grid
depicts how the sunlight fills a structure at a particular
time of day throughout the seasons. (Click for larger
image.)
Courtesy
Daniel Glaser
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To tackle this multifaceted socio-technological problem, Glaser has taken the cross-disciplinary approach embodied by the Center for Information Technology Research in the Interest of Society (CITRIS). Along with Electrical Engineering and Computer Sciences professor John Canny, Glaser seeks guidance from associate professor of architecture M. M. Susan Ubbelohde and professor Rogers Hall in the Graduate School of Education. While Ubbelohde grounds Glaser's work in architectural practice, Hall offers insight into the use of systematic user studies to determine how the new technology might fit into or change a designer's process.
For example, in one of Glaser's videotaped "field tests," a professional lighting designer clearly understood what the sunlight simulation revealed about how the sun would illuminate different parts of the structure throughout the day. But when Glaser asked the professional about how she might design a lighting system for the building, she surprisingly replied that she would begin the process under the assumption that the rooms get no natural light at all.
"It's amazing but due to professionally-developed conventions, most designers have been trained to simply ignore sunlight," Glaser explains. "They say they can't depend on it because it changes."
With the software tool though, designers can visualize those variations and
act accordingly. Indeed, the same user test ended with the designer
creating a higher-quality and more energy efficient design thanks
to the software. According to Glaser, the next-generation software
could enable the simulation of electric lighting along with sunlight
or take into account sophisticated sky models so designers can
make better choices with respect to daylight variation —
for instance in a city that's consistently cloudy.
"Lighting professionals know best how to answer lighting design questions," Glaser says. "If the software provides enough information, they'll give us the performance improvements we're looking for."
