A new ceiling light spanning the counter hall at Valiant Bank, Bahnhofplatz in Bern has been backlit by Tridonic’s Tunable White LED technology to create a dramatic centrepiece. After eight months of refurbishment, the 1913 listed building has been totally refurbished by Rykart Architeken AG to bring the building up to present day standards.

One of the major decisions of the project was to reinstate the light ceiling in the counter hall but instead of using daylight, the large format ceiling panels are backlit by Tridonic’s Tunable white which picks up on the dynamic properties of natural light but enables variable light colours to be created.

To gain more office space on the upper floors, the light ceiling was closed in the 1970’s but the refurbishment of the existing ceiling has included 36 light emitting coffers measuring 90 x 90cm each. While a return to a completely daylight ceiling was not possible, efficient LED technology, which now backlights the ceiling panels, pick up on the stunning centrepiece which takes its inspiration from nature and simulates the changes in natural daylight over the course of a day.

“The idea of the architects was to bring back to life the original situation with the atrium and daylight. So it was obvious to backlight the ceiling with LED technology that offers Tunable White functionality. We have put this into practice with a system solution from Tridonic, which allows us to seamlessly vary the light colour between 3,000 and 6,000 kelvin and to simulate daylight changes,” explains David Breil, Director at Licht+Raum. His company planned and implemented the light ceiling in the counter hall.

Easy integration of LED technology and control
In the ceiling coffers, Licht+Raum used its square low-profile ZETA luminaires. The ZETA luminaire housing made of aluminium is closed off in the room by a cover of satinised acrylic. If the luminaires are fitted with LED modules, the material reliably disperses individual LED light points, producing homogeneous illumination.

The luminaires are equipped with LED light engines from the Tridonic QLE PREMIUM Tunable White module family. They have been chosen especially because of their high quality of light. The modules offer infinitely adjustable colour temperatures at constant luminous flux, but can also be dimmed between 100 and 10% without colour shifts. The PREMIUM Tunable White series comes in various designs, with each luminaire containing four LED light engines in square versions (QLE) with a luminous flux of 1,250 lumen each.

Tridonic offers lighting designers a complete lighting solution which consists of an LED engine, LED driver and matching lighting control components. These systems comprise perfectly matched technology and make project-specific implementation of Tunable White particularly easy. The customer can choose the necessary LED light engines, the lighting control protocol and the desired control interfaces (touch panel or switch) and will receive a complete package tailored to their project. To ensure the quality of light and colour consistency, the system is precisely calibrated ex works.

Automatic and individual

The LED drivers provide digital interfaces for various lighting control protocols – DALI DT8, DSI, switchDIM and colourSWITCH. In the counter hall at Valiant Bank the light is controlled via DALI x/e-touchPANEL 02. Thanks to its 7” colour touch screen, it serves as a start-up, control and operating unit. User-friendly software enables scenes to be programmed and recalled manually or on a time-controlled basis. A Tunable White program has already been installed at the factory and only needs to be linked to the desired schedule. In the counter hall, the lights will go through a gradual change of colour temperature, starting at warm white in the morning, moving on to neutral white and cold white at midday and finishing with warm white in the evening. Various lighting scenes for non-everyday use are also stored. The lighting can be controlled and dimmed manually at any time via the touch panel.

Synergy of tradition and high tech
“We are proud that our historic property from 1913 is now offering such friendly and open premises,” said Marc Andrey, Press Officer at Valiant Bank AG, summing up the project. “Old and trusted yet modern – the new branch perfectly combines these two attributes and the revitalisation of the light ceiling is an impressive example of that.” Starting as a traditional architectural element, the light ceiling has now returned to the counter hall with modern technology, giving it a very special quality thanks to the dynamic light.