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A user study on lighting quality perceived in offices
conducted jointly with Fraunhofer IAO shows that
users’ preferences with respect to colour temperature
differ strongly. Usually, colour temperatures between
2700 K and 6500 K are perceived as ideal, with a clear
preference for 4000 K and 5000 K. Another
result of the study is that office users rate their situa-
tion at work significantly higher where it is possible
for them to adjust the lighting to their individual
needs. Since synchronisation of people’s inner clock
through daylight is not ensured indoors during the
dark months of winter, DIN SPEC 67600:201304
also includes specific design recommendations for
biologically effective lighting. In this case, artificial
lighting solutions incorpo rating wide-area panels
emitting diffuse light such as ONDARIA tunableWhite
combined with lighting management are vital for
supporting daytime activities and ensuring a good
night’s sleep.
Thanks to the LITECOM lighting management
system and therefore continuously adjustable
colour temperatures ranging from 2700 K to 6500 K,
ONDARIA tunableWhite is perfectly tailored to the
users’ individual needs and biological requirements –
with technical perfection, as the illuminance level
remains constant even with changing colour tempera-
tures.
Biological lighting effects
ONDARIA tunableWhite
zumtobel.com/study-office
zumtobel.com/litecom
Stimulation in the morning
Colour temperature: 5000 K
Eh* (daylight and artificial lighting): higher than 500 lx
Aim: synchronising people‘s circadian rhythm,
complete suppression of melatonin release
During the day at sunshine
Colour temperature: 4000 K
Eh* (daylight and artificial lighting): higher than 1000 lx
Aim: enhancing people’s well-being through
well-matched colour temperature, accordingly warmer
light colours during sunshine
During the day with cloudy sky
Colour temperature: 6500 K
Eh* (daylight and artificial lighting): higher than 800 lx
Aim: enhancing people’s well-being through
well-matched colour temperature, accordingly cooler
light colours with overcast sky
Getting ready for sleep
Colour temperature: 2700 K
Eh* (daylight and artificial lighting): higher than 500 lx
Aim: synchronising people’s circadian rhythm,
no interference with melatonin release, restful sleep
* Eh = horizontal illuminance
