Daylighting Dimming And Energy Savings: The Effects Of Window Orientation And Blinds

Secondary Author(s)

Parker, Danny

Report Number





Energy Consumption; Buildings; Windows


The Daylighting Test Facility (DTF) located at Florida Solar Energy Center, was used to study daylight dimming systems and how orientation and blinds effect energy savings. To evaluate the impact of blinds on dimming savings, the energy consumption was compared in two pairs of offices for all four window orientations: north, south, east and west. One office in each pair had blinds in a fixed position (down and open) and the other office had no blinds. From September through December of 1994, data were collected on the north- and south-facing offices. The DTF was rotated 90 degrees and data were collected from January through April for east- and west-facing offices. The DTF was also modeled on DOE2.1 and the predicted energy usage was compared to the actual data. The study showed that daylight dimming systems can provide significant energy savings. Energy savings ranged from 24% to 51% depending on the orientation and whether the office had blinds. The research suggest adjustments to parameters used with the DOE2.1 daylighting model to improve the accuracy of its predictions.

Date Published



Buildings - Energy Consumption; Buildings - Windows

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