The effect of window shading design on occupant use of blinds and electric lighting

Occupant use of interior shading devices is one of the most influential factors in the admission of daylight into the buildings. Based on a number of observations, occupants don't adjust shading devices frequently, and once lowered, the blinds are left in place for days or even weeks leading to reduced energy savings from daylight. Previous shade control behavior studies focus on environmental conditions such as transmitted vertical irradiance to predict the deployment of the shades; while there have been very few studies focusing on the factors that affect the raising of the interior shading devices by the occupants. This paper examines the effect of an interior lightshelf system on occupants' use of blinds and electric lighting. The results suggest that in identical environmental conditions, occupants whose workstations were located within the lightshelf zone demonstrated a lower window occlusion than those who were located in the area with conventional windows. Additionally, occupants in the lightshelf zone used less electric lighting than those in regular window design area.

► Shade raising events are very difficult to predict.
► Window shading design may have an effect on occupants' use of venetian blinds.
► Subdivided windows with lightshelves can reduce lighting energy use in buildings.