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HOWIT’SDONE
ILLUSTRATION BY MARIO WAGNER
HEMISPHERESMAGAZINE.COM
•
MAY 2012
39
1
Daylight includes a
balanced spectrumof all
colors of light—among
thembluewavelengths,
which are scarce in both
incandescent bulbs and
energy-efficient fluores-
cents. In order to imitate
the balance of natural
light, Fraunhofer outfitted
ceiling tiles with red, green,
blue andwhite LEDs that
together can produce 16
million different hues.
3
Finally, Fraunhofer
added the pièce de résist-
ance: light that changes.
“We did a study where
we had the light change
slowly over the course of
the day; every half hour; or
every couple of minutes,
like a sunny day withmov-
ing clouds,” says Oliver
Stefani, Fraunhofer visual
technologies manager.
“Eighty percent of people
preferred the sunny day.”
2
To have the panels
look less like a billboard
andmore like a real sky,
the scientists reduced
the ceiling’s resolution
(making it, basically, the
opposite of anHDTV) by
covering the LEDs with a
layer of foil diffusers. Then
theymeasured ambient
outdoor light during differ-
ent weather conditions and
times, and programmed
the virtual sky tomatch.
Best and
Brightest
Researchers have long
known that natural day-
light is be er for humans
than the fluorescent bulbs
most of us languish under
for eight to 10 hours a day.
Adding windows or simply
improving artificial light
in offices has been shown
to increase productivity,
boost morale and reduce
the number of sick days,
headaches and cases of
eyestrain among workers.
The effect is so strong
that some companies, like
aerospace engineering firm
Lockheed Martin, believe
they’ve won billions of dol-
lars in additional contracts
just by incorporating more
natural light into their
workspaces.
This got scientists at
German applied-research
group Fraunhofer wonder-
ing: If an office had a ceiling
that mimicked a daytime
sky, complete with gently
dri ing clouds, would
workers be even happier?
It seems they would. Here’s
how Fraunhofer did it.
BY JACQUELINE DETWILER