Forum Groningen

Forum Groningen is a new, multifunctional meeting place in the center of the Dutch city of Groningen. It concerns the complete renewal of the east side of the city’s central square. The Forum accommodates a library, cinema, comic book museum, restaurant, and spaces for debate and study.


In 2015 it came to light that the design of the building did not fully address potential earthquakes. A temporary shutdown of the construction was required to create a new design for an earthquake-resistant building. This presented an opportunity to review the lighting plan and Lichtpunt Theatertechniek and Huisman & van Muijen were selected to come up with a new lighting design. The original lighting design by NL-architects was based on linear fluorescent tubes. In the new plan, these would be converted to LED wherever possible. Using LED luminaires would reduce power consumption and open new illumination possibilities.

NL Architects was responsible for the design of the building and its striking, impressive lighting, with almost 1200 luminaires incorporated into the Forum Atrium’s slatted ceiling and the public spaces around the building. "We wanted to provide each floor with its unique atmosphere," says Pieter Bannenberg of NL Architects. “This also had to be reflected in the pattern and usage of light. Preferably using just one type of fixture, which would be fully integrated with the light source. We also wanted the ability to dynamically adjust the light display (tunable white), in response to the time of day, seasons, or activities in the building.” Tunable white (dynamic white) LED fixture could provide a range of color temperatures and deep dimming across at any color temperature.

Completely new luminaire

TDE-lighttech was selected to design and build a new luminaire that would stay true to the original design, achieve the desired light value, and guarantee completely uniform light intensity and color temperature on a large scale. "Fortunately, working with LEDs offered greater freedom than working with fluorescent lighting," says Carl Holman, TDE-lighttech electronics engineer. “For example, I was able to place the suspension feet in the middle of the tube, which yielded both practical and aesthetic benefits. The solution had to last for at least ten years; both the LEDs and optical plastics needed to provide superior color consistency over time – no yellowing. Installation of the luminaires also had to be quick and easy and provide the smoothest possible illumination, without blinding glare. Everything up to the printed circuit board was specially developed for this project. We worked on the design until it was efficiently scalable and producible.”

"Our final design was a tube with semi-transparent caps at the ends," adds Donald van Rijswijk, R&D engineer at TDE-lighttech. “Completely enveloping the LED in a plastic housing was not an option, because we would not be able to dissipate the heat generated by the system. We eliminated as much aluminum as we could to ensure that the illuminating tube would be as visible as possible. The LED modules in the luminaires consist of one single printed circuit board so that no soldering was required. This result was a perfectly uniform light image."

  • Color temperature adjustable from 2500K to 4000K
  • Three sizes: 600mm, 1200mm and 1500mm
  • Lumen output: 2500K: 1140 lm/m and 4000K: 1620 lm/m
  • Efficiency: > 100 lumen per Watt

Unique driver for DALI DT 8

"The original design for the Forum’s lighting system, required just one color, which could be controlled from one DALI address, but tunable white uses two colors," said Bob van der Klaauw, who was working at Lichtpunt Theatertechniek at the time. Controlling the new tunable white LED fixtures required double the number of DALI addresses and 20 extra DALI lines. Because this was not feasible, the forum asked TDE to realize a solution in which the dynamic-white LED fixture could be controlled using just one DALI bus address. With its DALI DT8 drivers, eldoLED helped to make it possible to achieve the specified light output, color temperature and control without adding any additional DALI lines or infrastructure. This is one of the first projects in the Netherlands in which DALI DT8 fully comes into its own.

Increase lifetime and reduce power.

Thanks to smart energy management, eldoLED and TDE-lighttech surpassed the requirements for light output and energy consumption. With a smart combination of warm and cool LEDs, the total used wattage was kept to a minimum. By optimizing power consumption, the LEDs produce less heat benefiting both lifespan and color consistency.


NL Architects, Lichtpunt Theatertechniek, Huisman & van Muijen, eldoLED and TDE-lighttech worked closely together through the process of design review, creation of a new luminaire, experimental test set-ups and ultimately installation and commissioning.

“Through consultation, joint sketching, 3D drawings and prototypes, we reached a great result together,” Pieter said. “There were a clear concept and starting point, but we needed input from everyone involved to achieve this - from technical implementation to finding the best way to mount the luminaires." Carl adds: " Thanks to close contact, short lines of communication and excellent cooperation, a solution was found every time. As far as I know, this solution is unique.”


Cooperation: Lichtpunt Theatertechniek, eldoLED, NL Architects en Huisman & van Muijen installatieadviseurs

Video: Installatie360

Pictures: Peter Baas

TDE-lighttech provided a completely new LED luminaire that resembles a fluorescent tube, guarantees a uniform brightness and color temperature on a large scale, achieves the desired light value, generates an even light image and is easy to install.

Realized projects

The unique modular design of LED products gives lighting designers and architects unprecedented flexibility in the implementation of each project. Together with our clients we realized these challenging projects.



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The Netherlands

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