Office Worker Preferences of Exterior Shading Devices: A Pilot Study

Solar shading devices are commonly used in offices to reduce cooling loads and glare from windows, but they also affect daylighting and the view to the outside. In this study, the function and operation of an awning and an exterior venetian blind as well as their influence on the view out was assessed by fifty office workers. The preferred position of the shading devices, the interior illumination and the weather conditions were recorded. An interior dimmable lighting fixture was introduced in order to see if there was a difference between the shading devices regarding the need of complementary electric lighting. The awning was found easier to adjust than the venetian blind. Both shading devices somewhat affected the view to the outside. The shading devices were used frequently to avoid glare from the window. However, preliminary results show no or weak correlation between common lighting concepts such as interior illuminance or sky luminance and how much the shading device was pulled down. On the other hand, there was a weak relationship between the existence of sunlight patches in the room and the position of the shading device. Further, the awning showed to be sensitive to wind, creating a disturbing “flickering” sunlight patch on sunny, windy days. There was no difference between the shading systems in the use of complementary electric lighting.