La Mécanique Générale and Les Forges, Arles, France

La Mécanique Générale and Les Forges

“The opening of Mécanique Générale together with the Rencontres 2016 represents the second completed building by Selldorf Architects at LUMA Arles, following the summer 2014 opening of Les Forges. Originally built as the repair shop for SNCF railcars, Mécanique Générale required almost a total rebuild to transform it to an exhibition space. Given LUMA Arles’ fundamental commitment to experimentation, innovation and collaboration it was critical to design an exhibition space that would have great flexibility while still having a strong presence.“ [ Journal no 4 – summer 2016].

For both completed buildings, Transsolar has designed a sustainable climate and energy concept with a strong sense of the Mediterranean place. The passive and active design of the building has been optimized for daylight, natural ventilation and thermal comfort. Considering the local climate as well as the highly fluctuating visitor densities throughout the year a sustainable and resilient design was created satisfying the requirements of the curators and artists with reduced mechanical systems and a low energy demand.

A floor heating and cooling system, integrated into the polished concrete floor of the exhibition areas, creates radiant comfort. The high thermal passive and active mass is balancing out quick changing loads. The mechanical systems are designed to fresh air supply only. As heating/cooling and air conditioning are separated by design, the air handling systems became very small and as a result fully integrated into the slab. There are no visible mechanical systems in the exhibition spaces.
Natural ventilation is featured by openings in the façades and roof. The openings are fully integrated in the façades and supply the fresh outside air through displacement ventilation openings in the floor. By this design all walls are free to be used by the exhibition designers.

The building is designed to give the curators plenty of opportunities for the operation, natural ventilation, mechanical ventilation and mixed mode. In summer 2014 the exhibition spaces in Les Forges have been operated with natural ventilation and floor cooling. The readings show that even at high ambient temperatures of 35°C the temperatures in the exhibitions spaces always stayed below 25°C. For the Mécanique first readings at 29°C to 31°C ambient conditions indicated the excellent conditions in the exhibition spaces with about 25°C even with the floor cooling was covered by wood panels as part of the exhibition design.

With the completion of the new arts and research center designed by Frank O. Gehry in 2018 the building ensemble will be supplied with a sustainable energy supply concept based on the co-generation system fired by locally produced bio-oil and a large photovoltaic system integrated into the roof of the Grande Halle. With the implemented passive and active measures the objective is to reduce the primary energy demand by about 50% below a reference design based on RT 2005.

The design of the energy supply system of the LUMA Foundation will reflect the spirit of the Founder of LUMA Foundation, Maja Hoffmann by a sustainable building design and an energy supply based on renewables and low carbon operation challenging the paradigm of nuclear powered electrical energy production with unsolved environmental issues for future generations.

La Mécanique Générale and Les Forges

Measurements in Les Forges in summer 2014: With natural ventilation and the radiant floor cooling the temperatures in the exhibition can be well controlled. With ambient temperatures peaking to 35 °C, temperatures in the exhibition always remained cooler than 25 °C.

La Mécanique Générale and Les Forges

Energy concept of La Mécanique Générale