ORIGINAL CHANDELIERS TO HEAT
A PRESERVATED CHURCH

Batiactu – 2020/09/11

Vaucluse: original chandeliers to heat a preservated church

Designing chandeliers with aesthetic, functional, heritage and energy functions: such was the challenge of the French municipality of Pertuis to ensure the heating of its preserved church built at the end of the fourteenth century.

St Nicolas Church of Pertuis, located in the Vauclusian commune of Pertuis, has been equipped with chandeliers that are original and innovative to say the least. This religious edifice, built at the end of the 14th century and classified as a historical monument since 1911, was indeed looking for a specific heating system meeting several functionalities: first of all aesthetic, by designing lighting to enhance the interior decor; then functional, to provide thermal comfort to the parishioners and visitors; but also patrimonial, since it was a question of preserving the hygrometry and the air of the place in order to keep the protected furniture intact; and finally energetic, with a view to keeping energy consumption as low as possible.

It is thus starting from this concept that the glass craftsmen Natacha Mondon and Eric Pierre created five monumental heated glass chandeliers to light and heat the interior of the church, without distorting its historical and, of course, spiritual character.

An unusual heating system

For this project, all types of heating were in fact considered by the teams in charge, but the St Nicolas Church of Pertuis had a major floor problem. The latter dating from the 16th century and proving to be almost perfectly intact, and the vaults having been discovered during the digging, precautions and a certain adaptation were required. Thus, the cement slab and the original stones were removed, and part of the walls that held the slab were resurfaced. A new lime-concrete slab was laid before the stones were put back in, only 20% of them having been changed in the end.

Considered for a while for their ability to maintain a certain temperature, the distributed blowers were finally abandoned, because of the risks they would have posed to the paintings and the classified organ. The idea of heated chandeliers won the day, defended by the glass craftsmen Natacha Mondon and Eric Pierre, and supported by the city council of Pertuis which was already working on its side on a project of chandelier in the shape of a "cart wheel". But it was without counting with the DRAC - Regional Direction of Cultural Affairs - which posed as a constraint the need to be able to lower or even stop the heating. A two-year battle ensued between the administration, the municipality and the project manager, so that the concept was finally approved.

Taking over the existing system to finalize the installation

"The constraint we faced was that heating system manufacturers were not adapted to our configuration. So we had to take over existing elements to get to our end", explains the architect Martin Lefèvre to Batiactu. "The chandeliers are therefore supplied through the roof and the heating is well distributed throughout the building. The building is therefore not affected by these new installations." The electric current, and thus by extension the functioning of the chandeliers, is however only activated during religious ceremonies or other events.

Different lighting ambiences

The chandeliers of the church also offer different lighting moods, ranging from a rather "classical" luminosity - not too strong in order to preserve the character of the works and paintings - to a rather "event-like" lighting, intended for masses and concerts. These unique chandeliers are also part of the era of time and are real connected objects, controlled remotely by a tablet. Of course, a manual control station remains available if needed. Please note: each chandelier can be lit separately and provide immediate thermal comfort to people directly under its radiation.

First documented thermal study on the subject

This project also made it possible to carry out the first truly documented thermal study on the heating of an historical monument, confirmed by in situ measurements. In concrete terms, infrared radiation immediately ensures a comfort temperature of 62 to 66°F (17 to 19°C) inside the building in winter, and does not generate water vapor or condensation. Silent when in operation, the chandeliers also avoid the "hot head/cold feet" effect, thanks to the great height of their suspension (equal to or greater than 16 feet). And with a classic aesthetic, the luminaires integrate in their design the heating elements, to avoid their usual unattractive appearance.

© Corentin Patrigeon for Batiactu 2020/09/11