The sun shading PV modules have been added to this old laboratory building (1963) as part of the renovation process. The south facade had a problem with overheating in the summer. The problem was a reason for the way the PV modules have been used. Shaped as the external louvres system that forms a separate facade (about 80 cm from the building), the PV modules protect the interior against excessive solar heat gain in the summer. Their external location efficiently prevents the „greenhouse effect” that occurs when sun rays enter the inner space via glazing. In summer, sun rays fall onto opaque PV modules. In this way desirable shading of the building is provided. During
winter, when the inner space heating is needed, solar radiation contributes to passive solar heating. Owing to sun shading modules, arrangement and their angle of inclination, the sun rays are able to enter the building, warming up the southern zone of the inner space. Likewise in summer, PV modules’ usage affects thermal environment in winter and is in charge of thermal comfort of the user.

The same applies to the lighting environment. The PV modules’ usage contributes to providing diffused daylight both in the winter and in the summer when the direct solar radiation is most frequent. In the sunny days, the sunlight diffusion is obtained due to sun rays’ deflection against PV modules’ surface, which is the result of the optimal PV modules’ position. This prevents strong contrast, shadow patterns and glare effects from appearing in the inner space.

To facilitate visual contact with the outer surroundings, a movable row of the sun shading PV modules has been designed. This allows the user to set their position according to his will and sustain visual contact with the outside. The rest fixed rows (of which two are visible from the interior) partially interfere with the contact. However they very slightly affect the visual comfort of the user (fig.4).