Transcript
Spli
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6 m
FOR THE FIRST TIME, LEDS MEET THE CHALLENGE OF URBAN LIGHTING, COMBINING PHOTOMETRIC PERFORMANCE AND VISUAL COMFORT!
As part of the renovation of its seafront - the Riva - the city of Split chose Schréder for this world
first, using “Cree” LEDs which have only just been launched on this constantly evolving market.
The Riva is a must-see attraction for the millions of tourists who come to Dalmatia each year to
visit the hundreds of islands scattered along the length of its coast.
Fifteen luminaires have been installed, each one incorporating 180 high-power LEDs which
diffuse a remarkable warm, white light (3000 K). The luminaires comprise 45 modules (IP 67),
each equipped with 4 LEDs. Each module is orientated in a precise way to achieve a specific goal,
which is to master light. Indeed, LEDs provide a very directional lighting, which requires extreme
precision in their orientation when they are used in urban lighting applications. This was the
challenge which was taken up by the Schréder designers and engineers.
The first measurements highlight what is also clear to the
objective observer: an average illuminance of 32 lux, with an
overall uniformity of 40%.
Officially inaugurated on 7th May 2007, this focal point of Croatian
social life has already welcomed thousands of visitors, who are
sure to have appreciated the visual comfort provided by this new
type of urban lighting while enjoying a relaxing stroll.
LEDs: a world first
Schréder developed and manufactured this tailor-made solution
in collaboration with the architectural studio 3LHD, the urban
furniture designer Numen/For Use, the lighting designers
Nova-lux and ZTT Zagreb, its exclusive distributor in Croatia.8m
Eave
= 32 lux
Overall uniformity = 40%
19,5 m
BRIGHT LIGHT OR LOW LIGHTLEDs emit a directional flux, making it possible to meet
the architect’s requirement of lighting the main thoroughfare
very precisely, with the seafront promenade remaining in
semi-darkness.
Those enjoying a walk in the area therefore have the choice
of heading towards the light or towards a space with a more
intimate ambiance.
VISUAL COMFORTEach luminaire incorporates 180 high-power LEDs
which diffuse an exceptional warm, white light
(3000 K), a source of visual comfort. The luminaires
consist of 45 modules (IP 67), each fitted with 4 LEDs.
μR® (micro-reflector)Opposite the lighting columns fitted with
LEDs, there are support frames for awnings
incorporating floodlights specially developed
for this application. Each floodlight consists of
a sealed IP 66 optical compartment with a μR®
micro-reflector with a 35 W metal halide lamp
with ceramic arc tube.
These floodlights will illuminate the terraces
which are soon to be renovated. Other floodlights
(70 W), also integrated into the lighting columns,
illuminate the sidewalk running along the
building façades.
DYNAMIC VARIATIONA dynamic variation system controlled using the DALI
protocol makes it possible – via lines of 3 modules - to create
various fun effects according to the ambiance required.
As the modules are managed separately, this system also
allows the initial photometric distribution to be modified,
a factor which therefore helps to save energy and extend
component life.
DIANA and ZLATKO GALÍC of Nova-lux are the lighting designers
behind this project.
Why did you choose to use LEDs for public lighting? We chose LEDs because we wanted a very directional lighting. Our design was based on illuminating
the esplanade clearly, while leaving the seafront promenade in semi-darkness. Using LEDs meant we
could prevent light from invading that space.
Our aim was to achieve a comfortable colour temperature, neither too cold nor too warm. We initially
opted for a combination of white LEDs with some amber coloured LEDs to create a warm atmosphere.
Then Schréder offered us LEDs which matched exactly what we were looking for, so that we did not
need to use combinations, which are not always visually attractive.
How did your cooperation with the architect in charge of the project, Sasa Begovíc, proceed?The architect had a view of the ensemble which was consistent in all details, and the lighting had
to fit in with that view. We chose to use public lighting with LEDs, allowing the promenade area to
remain darker, because the architect did not want the renovation of the esplanade to disturb people’s
habits. This seafront promenade is where young lovers go for a stroll and we wanted to respect that
tradition! It was necessary to offer local people the choice of walking in the light or strolling in a more
intimate space.
What were the basic criteria which this lighting project had to meet? When this project was presented to us, the first and main parameter was to achieve an excellent
uniformity of illuminance at ground level. We initially went for a traditional solution based on light
conduction. Then we realised that LEDs could also meet this challenge. And what’s more, meet it better!
A world first with LEDs, it must have been quite an adventure? When we see the results, it certainly has been quite an adventure, but it has also been a race against
time. To satisfy the lighting designer, we had to develop this project in 3 months.
In this short period, we produced a real public lighting luminaire which offers the same photometric
performance and the same standard colour temperature for this type of application as well as an
excellent uniformity of illuminance.
All of this has been achieved! Moreover, when you look at this installation, you are also struck by the
very low glare generated by the LEDs.
Which LEDs did you recommend?We suggested a completely new type of LED. These LEDs produce a warm white light, which is visually
very comfortable and pleasant. Furthermore their output is 52 lumens/watt, which is nothing less
than remarkable.
We would also like to point out that these LEDs have no problems with uniformity of colour.
How did you deal with the photometric aspect of this LED application for public lighting? As LED lighting is very directional, we had to perfect an accurate system for positioning the LEDs in order
to achieve excellent uniformity and to illuminate precisely the spaces which had to be illuminated.
We were able to manage this aspect thanks to the Schréder R&D Centre, which used calculation software
to specify the optimum photometric design and then validated the design on the goniophotometer in its
test laboratory.
The illuminance obtained is perfect because the specification required us to provide a minimum
illuminance of 15 lux and we achieve an average of 32 lux.
To ensure that this world first was a success, Schréder involved its LED
development department at Bornem in Belgium,
as well as its Research and Development Centre.
Sebastian Esposito is one of the
technical developers for this project.
Why was a dynamic variation system incorporated? There was a requirement to create dynamic effects
for reasons of ambiance. This dynamic variation
system designed by Schréder really can generate a
great many styles of lighting and festive effects.
Furthermore - and this is not a negligible factor
- the dynamic variation system also makes it
possible to reduce energy consumption by varying
the intensity of all the modules or by keeping
some modules at maximum intensity and others
at 30% or 50% intensity.
As for the photometry, the light distribution can be
modified by switching certain modules off or on,
or by varying the intensity of some of them.
If necessary, just a limited area of the promenade
can be illuminated and the rest left in darkness.
There are tremendous possibilities for photometric
and festive lighting, and for saving energy, not to
mention the extension of component life when
the lighting is used less intensively.
www.schreder.com
the urban light
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