Effects of Interior Design on the Daylight Availability in Open Plan Offices

Christoph F. Reinhart, National Research Council Canada

Keywords

Abstract

The COPE (cost-effective open plan environments) project investigates the effect of open-plan office design on the indoor environment and on the occupant satisfaction with that environment. COPE is sponsored by a consortium of North American public and privatesector organizations and relies on field, laboratory and simulation studies to address design aspects like acoustics, lighting quality, indoor air quality, operating costs and energy efficiency.

This paper describes the influence of various design variables on the daylight availability and electric lighting requirements in open plan office spaces using the RADIANCE-based annual daylight simulation method DAYSIM. To make simulation results more reliable a manual and an automated blind control strategy have been considered. Five climatic centers which represent the ambient daylight conditions of 186 North American Metropolitan Areas have been identified. For these five climatic centers over 1000 office settings have been investigated which feature varying external shading situations, glazing types, facade orientations ceiling designs and partition arrangements. The daylight performance of the offices was expressed in terms of their daylight autonomy distributions and energy savings for an ideally dimmed lighting system.

The simulation results reveal, that the daylight availability in peripheral offices allows for electric lighting energy savings between 25% and 60% for an ideally commissioned, dimmed lighting system depending on the underlying blind control strategy. 2nd row offices receive considerably less daylight even though a reduced partition height and increased ceiling reflectances can double electric lighting energy savings up to 40%.