Daylighting and solar shading performances of an innovative automated reflective louvre system

• Reflective louvres potentially reduce the need for artificial lighting by improving daylight distribution in the building.
• The tested system reduced the need for artificial lighting by 60%.
• The tested device works optimally under sunny conditions and considerably improve daylight distribution under overcast sky conditions.
• Occupants’ behaviours can greatly affect the available daylight and use of artificial lighting in the building.
• Reflective louvres can delay the air temperature rise by blocking/reflecting the sunlight reducing the cooling loads.

Traditional windows, as the major source of daylight, have a common problem which is uneven distribution of daylight in the room. Several innovative daylighting systems such as light shelves, fixed and movable reflective louvres, reflective sills, prismatic glazing, light pipes, etc., have been developed to address this problem. This paper reports on a research programme that investigates retrofitted solutions to uneven distribution of daylight in deep-plan office buildings. The work presented here follows initial investigations into the design and applicability of an automated retrofitted panel thermal shutters which can also act as a sunshade and daylighting system. The system has a patented function which allows each shutter/louvre to be controlled and placed separately from other louvres. This study evaluates the effectiveness of the system when acting as a sunshade, light shelf, reflective louvre, and reflective sill under clear, overcast, and sunny sky conditions. According to the results, the system significantly improved daylight distribution and reduced the need for artificial lighting by 60%.