Anidolic Systems – Façade

The LESO solar experimental building is a research facility that offers the possibility of monitoring and analysing the energy performance of passive and active solar facades in real “in-situ” conditions. Several novel solar technologies (advanced glazings, Trombe walls, building integrated photovoltaics, etc.) have been investigated in collaboration with the building industry.

The southern façade of the building, which hosted the different solar experminental solar facades (see Figure), was refurbished in 1999. The new façade beneifitted from the experience gained by the Solar Energy and Building Physics Laboratory in the different fields of building technology, in order to design and set-up a Sustainable Anidolic Façade.

The following features characterise the 200 m2 refurbished façade :

  • more than 80 % of the construction materials are wood based, which reduces the environmental impact of the façade (greenhouse gas emissions, photo-smog gas emissions, etc.);
  • the lower part of the façade, protected against rain by a horizontal shelf, is equipped with a low-emissivity insulated double glazing unit held by wooden frames (U= 1.4 W/m2K);
  • the upper part, fitted on the rain protecting shelf, is a dayligting anidolic system set-up with a non-protuberant zenithal collector.

External solar blinds are avalaible for both parts of the building façade; they are motorised and can be moved independently by the building users.

anidolic facade wood, normal windows below and tilted glazing above for reflection from shelf to ceiling   anidolic facade diagram
External view of the Sustainable Anidolic Façade of the LESO solar experimental building refurbished in 1999   Vertical cross-section of the Sustainable Anidolic Façade of the LESO solar experimental building

The assessment of the luminous performance of the sustainable anidolic façade, together with the every day life experience of the building users, confirmed the superior visual amenity and comfort offered by the refurbished façade. Compared to the original façade design (wooden façade with horizontal rain protecting shelves), a significantly higher luminance and illuminance homogeneity is achieved by the sustainable anidolic façade, together with an increase of the daylight factor deep in the room (4–5 meters from façade).