Case study: Louvre

In 2005, the Mona Lisa, still the central exhibit of the Louvre Museum, was moved to the renovated room ‘Salle des Etats’,  where it is surrounded by other paintings of the Venetian School, including Paolo Veronese’s monumental fresco ‘Wedding at Cana’.

During the four-year renovation, the lighting system was also upgraded. To allow the exhibited works to shine in all their glory, museum architect Lorenzo PIQUERAS was commissioned in 2001 to redesign the immense 800 m² room. One requirement was that the daylight and the artificial light, which enters the rooms via a gigantic glass ceiling, be optimally geared to each other and made to look as natural as possible. Professor Marc Fontoynont, responsible for lighting research at the French ENTPE, the State National School of Public Works, also assisted in the project. He asked ETAP to design the lighting system for the room in accordance with his specifications.

The light dome, some 300 m², was to take the form of one gigantic luminaire. This task was by no means simple because the structure of the glass ceiling was also to be arched by a double, bent diffuser in polycarbonate. Obviously, the lamps were not to be reflected in the dome. In addition, the luminaires must be able to withstand the most extreme temperatures: very low minimum temperatures in the winter, but above all very high summer temperatures below the light dome without air conditioning.

ETAP advised the use of 360 E52 and E53 luminaires with very high efficiency HRA aluminium reflectors. The 2 x 80W luminaires are of superior quality and perfectly adapted to the demanding environment. The wide- and narrow-angle reflectors  provide an even illumination of the dome, resulting in uniformly illuminated walls and floor.

The luminaires were fixed to obliquely arranged frames suspended from the glass ceiling. The frames can be rotated to facilitate replacement of the lamps or ballasts. The ventilation openings in the reflectors and the resulting convection streams minimise dust accumulation on the lamps, allowing the nominal lighting intensity to be maintained, without any additional cleaning being required.

To reduce fluctuations in the lighting level, a sensor was installed which switches off the luminaires when there is too much daylight. Only in this way can the invaluable and exceptional works of the Louvre be optimally illuminated.